study committee b2 technical advisory group b2-ag-06 2011/andre - tutorial conductor...
Post on 06-Mar-2018
257 Views
Preview:
TRANSCRIPT
Study Committee B2Technical Advisory Group B2-AG-06
CIGREacute B2-AG-06 Seminar Bangkok
TutorialTutorial
Conductor FatigueConductor Fatigue
Louis Cloutier ConvenorLouis Cloutier ConvenorAndreacute Leblond Secretary
CIGREacute WG B230 Engineering Guidelines Relating to Fatigue Endurance Capability of ConductorClamp Systems
F b 28 2011February 28 2011copy CIGREacute 2011
Outline of PresentationOutline of Presentation
IntroductionExamples of Conductor Fatiguep gTypical Conductor ConfigurationsSome Characteristics of Suspension ClampsCIGRE Technical BrochuresCIGRE Technical BrochuresPrediction of Aeolian Vibration Amplitudes
Conductor Profile During Aeolian VibrationsField Measurements of Conductor VibrationsAnalytical Representation of the Fatigue Phenomenon
Laboratory Fatigue Tests ndash Resonant Type Test BenchesFatigue Endurance Data
Vibration Measurement AnalysisCase StudyConductor and Clamp Types Lacking Fatigue Data
Study Committee B2 - Technical Advisory Group B2-AG-06 32011-02-28
Conclusion
Introduction (I)Introduction (I)Aeolian vibrations
Small vibration amplitudes exceeding rarely the conductor diameter frequency range 3 to 150 Hz winds 1 to 7 ms
May lead to fatigue failure of conductor strands at suspension clamps
Such failures are caused by dynamic stresses resulting from reverse bendingfrom reverse bendingOther wind-induced conductor motions such as wake-induced oscillations and galloping may also be responsible
Study Committee B2 - Technical Advisory Group B2-AG-06 42011-02-28
for fatigue conductor strand failures
Introduction (II)Introduction (II)
Natural vibrations are not sinusoidal but show beatsbeatsExamples
Study Committee B2 - Technical Advisory Group B2-AG-06 52011-02-28
Examples of Conductor Fatigue (I)Examples of Conductor Fatigue (I)
Conductor fatigue occurs when wind-induced vibration is not controlledFretting fatigue has long been recognized as being the cause of strand failures in outer as well as inner layers of the conductorsSteel core can fail by overheating after aluminum layers areSteel core can fail by overheating after aluminum layers are separatedInterstrand microslip amplitude increases small cracks are
t d d t t l t t d f il
Study Committee B2 - Technical Advisory Group B2-AG-06 62011-02-28
generated and some propagate up to complete strand failures
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
CIGREacute B2-AG-06 Seminar Bangkok
TutorialTutorial
Conductor FatigueConductor Fatigue
Louis Cloutier ConvenorLouis Cloutier ConvenorAndreacute Leblond Secretary
CIGREacute WG B230 Engineering Guidelines Relating to Fatigue Endurance Capability of ConductorClamp Systems
F b 28 2011February 28 2011copy CIGREacute 2011
Outline of PresentationOutline of Presentation
IntroductionExamples of Conductor Fatiguep gTypical Conductor ConfigurationsSome Characteristics of Suspension ClampsCIGRE Technical BrochuresCIGRE Technical BrochuresPrediction of Aeolian Vibration Amplitudes
Conductor Profile During Aeolian VibrationsField Measurements of Conductor VibrationsAnalytical Representation of the Fatigue Phenomenon
Laboratory Fatigue Tests ndash Resonant Type Test BenchesFatigue Endurance Data
Vibration Measurement AnalysisCase StudyConductor and Clamp Types Lacking Fatigue Data
Study Committee B2 - Technical Advisory Group B2-AG-06 32011-02-28
Conclusion
Introduction (I)Introduction (I)Aeolian vibrations
Small vibration amplitudes exceeding rarely the conductor diameter frequency range 3 to 150 Hz winds 1 to 7 ms
May lead to fatigue failure of conductor strands at suspension clamps
Such failures are caused by dynamic stresses resulting from reverse bendingfrom reverse bendingOther wind-induced conductor motions such as wake-induced oscillations and galloping may also be responsible
Study Committee B2 - Technical Advisory Group B2-AG-06 42011-02-28
for fatigue conductor strand failures
Introduction (II)Introduction (II)
Natural vibrations are not sinusoidal but show beatsbeatsExamples
Study Committee B2 - Technical Advisory Group B2-AG-06 52011-02-28
Examples of Conductor Fatigue (I)Examples of Conductor Fatigue (I)
Conductor fatigue occurs when wind-induced vibration is not controlledFretting fatigue has long been recognized as being the cause of strand failures in outer as well as inner layers of the conductorsSteel core can fail by overheating after aluminum layers areSteel core can fail by overheating after aluminum layers are separatedInterstrand microslip amplitude increases small cracks are
t d d t t l t t d f il
Study Committee B2 - Technical Advisory Group B2-AG-06 62011-02-28
generated and some propagate up to complete strand failures
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Outline of PresentationOutline of Presentation
IntroductionExamples of Conductor Fatiguep gTypical Conductor ConfigurationsSome Characteristics of Suspension ClampsCIGRE Technical BrochuresCIGRE Technical BrochuresPrediction of Aeolian Vibration Amplitudes
Conductor Profile During Aeolian VibrationsField Measurements of Conductor VibrationsAnalytical Representation of the Fatigue Phenomenon
Laboratory Fatigue Tests ndash Resonant Type Test BenchesFatigue Endurance Data
Vibration Measurement AnalysisCase StudyConductor and Clamp Types Lacking Fatigue Data
Study Committee B2 - Technical Advisory Group B2-AG-06 32011-02-28
Conclusion
Introduction (I)Introduction (I)Aeolian vibrations
Small vibration amplitudes exceeding rarely the conductor diameter frequency range 3 to 150 Hz winds 1 to 7 ms
May lead to fatigue failure of conductor strands at suspension clamps
Such failures are caused by dynamic stresses resulting from reverse bendingfrom reverse bendingOther wind-induced conductor motions such as wake-induced oscillations and galloping may also be responsible
Study Committee B2 - Technical Advisory Group B2-AG-06 42011-02-28
for fatigue conductor strand failures
Introduction (II)Introduction (II)
Natural vibrations are not sinusoidal but show beatsbeatsExamples
Study Committee B2 - Technical Advisory Group B2-AG-06 52011-02-28
Examples of Conductor Fatigue (I)Examples of Conductor Fatigue (I)
Conductor fatigue occurs when wind-induced vibration is not controlledFretting fatigue has long been recognized as being the cause of strand failures in outer as well as inner layers of the conductorsSteel core can fail by overheating after aluminum layers areSteel core can fail by overheating after aluminum layers are separatedInterstrand microslip amplitude increases small cracks are
t d d t t l t t d f il
Study Committee B2 - Technical Advisory Group B2-AG-06 62011-02-28
generated and some propagate up to complete strand failures
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Introduction (I)Introduction (I)Aeolian vibrations
Small vibration amplitudes exceeding rarely the conductor diameter frequency range 3 to 150 Hz winds 1 to 7 ms
May lead to fatigue failure of conductor strands at suspension clamps
Such failures are caused by dynamic stresses resulting from reverse bendingfrom reverse bendingOther wind-induced conductor motions such as wake-induced oscillations and galloping may also be responsible
Study Committee B2 - Technical Advisory Group B2-AG-06 42011-02-28
for fatigue conductor strand failures
Introduction (II)Introduction (II)
Natural vibrations are not sinusoidal but show beatsbeatsExamples
Study Committee B2 - Technical Advisory Group B2-AG-06 52011-02-28
Examples of Conductor Fatigue (I)Examples of Conductor Fatigue (I)
Conductor fatigue occurs when wind-induced vibration is not controlledFretting fatigue has long been recognized as being the cause of strand failures in outer as well as inner layers of the conductorsSteel core can fail by overheating after aluminum layers areSteel core can fail by overheating after aluminum layers are separatedInterstrand microslip amplitude increases small cracks are
t d d t t l t t d f il
Study Committee B2 - Technical Advisory Group B2-AG-06 62011-02-28
generated and some propagate up to complete strand failures
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Introduction (II)Introduction (II)
Natural vibrations are not sinusoidal but show beatsbeatsExamples
Study Committee B2 - Technical Advisory Group B2-AG-06 52011-02-28
Examples of Conductor Fatigue (I)Examples of Conductor Fatigue (I)
Conductor fatigue occurs when wind-induced vibration is not controlledFretting fatigue has long been recognized as being the cause of strand failures in outer as well as inner layers of the conductorsSteel core can fail by overheating after aluminum layers areSteel core can fail by overheating after aluminum layers are separatedInterstrand microslip amplitude increases small cracks are
t d d t t l t t d f il
Study Committee B2 - Technical Advisory Group B2-AG-06 62011-02-28
generated and some propagate up to complete strand failures
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Examples of Conductor Fatigue (I)Examples of Conductor Fatigue (I)
Conductor fatigue occurs when wind-induced vibration is not controlledFretting fatigue has long been recognized as being the cause of strand failures in outer as well as inner layers of the conductorsSteel core can fail by overheating after aluminum layers areSteel core can fail by overheating after aluminum layers are separatedInterstrand microslip amplitude increases small cracks are
t d d t t l t t d f il
Study Committee B2 - Technical Advisory Group B2-AG-06 62011-02-28
generated and some propagate up to complete strand failures
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Examples of Conductor Fatigue (II)Strand failures occur mainly at suspension clamps where such
Examples of Conductor Fatigue (II)
p psingular conditions are createdTo a lesser extent a similar phenomenon can occur at damper
phenomenon can occur at damper marker or spacer clampsEarly detection of conductor failure
i k f f il ( tt ti t
or risk of failure (attentiveness to early warnings)Wear and failure of conductor strands due to spacer clamp looseningFatigue usually takes many years
Study Committee B2 - Technical Advisory Group B2-AG-06 72011-02-28
Fatigue usually takes many years to become apparent
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Typical Conductor Configurations (I)An important component of an overhead power line
The conductor cost is up to about 40 of total capital investment
Typical Conductor Configurations (I)
The conductor cost is up to about 40 of total capital investment
The conductor size is chosen to suit electrical and mechanical requirementsThe most common conductor type is ACSR (Aluminum Conductor Steel Reinforced)The ratio of steel to aluminum areas vary widelyThe ratio of steel to aluminum areas vary widely
Study Committee B2 - Technical Advisory Group B2-AG-06 82011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Typical Conductor Configurations (II)Some Special Conductors
Typical Conductor Configurations (II)
Trapezoidal
Z-shaped compact
Self-damping
Expanded
Ri i d tRiver crossing conductor
Study Committee B2 - Technical Advisory Group B2-AG-06 92011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Some Characteristics of Suspension Clamps (I)Some Characteristics of Suspension Clamps (I)Most of the conductor fatigue test results refer to those
bt i d h th d tobtained when the conductor is supported in a short metallic clampThe ideal profile of the clampThe ideal profile of the clamp body follows the natural curvature of the conductorThe ends of the clamp bodyThe ends of the clamp body and the keeper must be rounded to avoid indenting the conductorThe clamp should be able to rotate in a longitudinal vertical plane to accommodate
t i l l d
Study Committee B2 - Technical Advisory Group B2-AG-06 102011-02-28
asymmetrical loads
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Some Characteristics of Suspension Clamps (II)
A i i
Some Other Suspension ClampsSome Characteristics of Suspension Clamps (II)
Armor grip suspension (AGS)
Elastomeric bushing with cage of preformed rodscage of preformed rods
Metal clamp with elastomeric insertSpecial river crossing clampSpecial river crossing clamp
Long saddle to reduce contact stress
Study Committee B2 - Technical Advisory Group B2-AG-06 112011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
CIGRE Technical Brochures (I)CIGRE Technical Brochures (I)
This TB covers a state of the art review on the following aspects of the problem the following aspects of the problem
Fretting behaviour in stranded conductorDetermination of fatigue enduranceDetermination of fatigue endurance capabilityInner conductor mechanics Assessment of vibration severity on actual linesEvaluation of conductor residual life
This TB covers the determination of possible damage and ways to predict remaining life of conductors as well as new methods to t t d t l t
Study Committee B2 - Technical Advisory Group B2-AG-06 122011-02-28
test conductorclamp systems
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
CIGRE Technical Brochures (II)This TB is a complement to TB 332 which was a state of the art review
CIGRE Technical Brochures (II)
Meant to be a reference for the practicing line engineer in the application of the latest technologyReviews the available design tools to achieve engineering solutionsIdentifies the inherent gaps in their
li tiapplicationGives the engineer a better comprehension of the two related phenomena
Fatigue of conductorsAeolian vibrations
This TB includes a review of those design tools and gives the
Study Committee B2 - Technical Advisory Group B2-AG-06 132011-02-28
g gtransmission line engineer the limits to their application
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Prediction of Aeolian Vibration AmplitudesPrediction of Aeolian Vibration Amplitudes
Many utilities have their own design rules (for number of dampers) based on past experiencedampers) based on past experienceVibration severity can also be measured on existing linesA useful analytical approach is the Energy Balance Principle (EBP)Principle (EBP)The EBP leads to an estimate of conductor vibration amplitude based on equating the energy input from the wind with the energy absorption (damping) of thewind with the energy absorption (damping) of the conductor and dampersThe EBP can also be used for the direct design of the damping system for a new linedamping system for a new lineThe estimate of the expected vibratory motion from EBP is considered an upper bound and is therefore a safe value
Conditions can also be assessed through measurements on
Study Committee B2 - Technical Advisory Group B2-AG-06 142011-02-28
Conditions can also be assessed through measurements on existing lines
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Conductor Profile During Aeolian VibrationsConductor Profile During Aeolian Vibrations
Parameters describing conductor vibration include
Bending amplitude Yb Free loop amplitude ymaxb maxBending angle β Wave length λ and Loop length ℓ
This representation applies to metal clamps not to
Study Committee B2 - Technical Advisory Group B2-AG-06 152011-02-28
elastomer lined clamps
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Field Measurements of Conductor Vibrations (I)
Several methods to measure the vibration intensity of a conductor
Field Measurements of Conductor Vibrations (I)
vibration intensity of a conductor have been employedThe bending amplitude Yb method finally comes out as the most
It measures the differential displacement of the conductor at 89 mm from the last point of contact with the clamp
ypractical
p pThe reverse bending amplitude was presented as an alternative to permit the installation of the vibration recorder directly onto the conductorThe bending amplitude method must be properly interpreted when cushioned clamps are usedRecommended by IEEE in 1966 (also in the 2007 revision) and
Study Committee B2 - Technical Advisory Group B2-AG-06 162011-02-28
CIGRE SC22 WG04 1979 and SC22 WG11 TF02 1995
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Field Measurements of Conductor Vibrations (II)Field Measurements of Conductor Vibrations (II)
HILDAOntario Hydro RecorderTVM 90
Pavica Ribe LVRVibrec 400
Study Committee B2 - Technical Advisory Group B2-AG-06 172011-02-28
Scolar III
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Analytical Representation of the Fatigue Phenomenon (I)
a YpdE 2
H
a yt ca ep ese tat o o t e at gue e o e o ( )
( ) bpxa
a Ypxe
p+minus
= minus 14σ
EIHp =
An idealized bending stress in the top-most outer-layer strand (in the plane of the last point of contact) is calculated from the bending amplitude (Poffenberger-Swart formula)
Ea modulus of elasticity of outer wire material (Nmm2)
d diameter of outer layer wire (mm)
( )H conductor tension at average temperature during test period (N)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
x distance from the point of measurement to the last point of contact between the
Study Committee B2 - Technical Advisory Group B2-AG-06 182011-02-28
x distance from the point of measurement to the last point of contact between the clamp and the conductor
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Analytical Representation of the Fatigue Phenomenon (II)
fymEdπσ =
a yt ca ep ese tat o o t e at gue e o e o ( )
maxaa fyEI
Edπσ
The idealized bending stress can be derived from the free loop amplitude ymax which is the vibration parameter often measured in indoor test spans
Ea Youngrsquos modulus for the outer-layer strand material (Nmm2)
d diameter of outer layer wire (mm)
f frequency of the motion (Hz)f frequency of the motion (Hz)
m conductor mass per unit length (kgm)
EI sum of flexural rigidities of individual wires in the cable (Nmm2)
Study Committee B2 - Technical Advisory Group B2-AG-06 192011-02-28
g ( )
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Analytical Representation of the Fatigue Phenomenon (III)
Fatigue of conductors is due to microslip movements of wires inducing fretting fatigue
a yt ca ep ese tat o o t e at gue e o e o ( )
fretting fatigueThe phenomenon is complex and its exact modelling has yet to be completed
Contact areas between round strandsContact areas between round strands are ellipticalFretting and microslip occur in these contact areasFatigue cracks develop out of these contact areasThe knowledge on fatigue performance of conductors mostly relies on results of laboratory tests made on conductors in fixed short metallic clampsshort metallic clamps
It is not possible at the moment to determine the fatigue endurance of a conductor alone
There is a wide diversity of design and geometry of conductors
Study Committee B2 - Technical Advisory Group B2-AG-06 202011-02-28
y g g yand supports
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Laboratory Fatigue Tests ndash Resonant Type Test BenchesLaboratory Fatigue Tests Resonant Type Test Benches
Constant amplitude excitationMeasurement of the bending Pneumatic tensioning system
Dynamometer Suspension clamp gamplitude Yb andor the free loop amplitude ymax
Most tests done with conductors supported in short metallic clampsSlider
DynamometerAmplitude measuring system
Rubber dampers
Wire break detectionVibrator
End clamp
Turnbuckle
55 degsupported in short metallic clampsClamps usually held in a fixed position on the test bench
Active length 7 m2 m 2 m
Study Committee B2 - Technical Advisory Group B2-AG-06 212011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Fatigue Endurance Data (I)
The results of fatigue tests ultimately lead to the presentation of a fatigue (S N) curve
Fatigue Endurance Data (I)
a fatigue (S-N) curveNote scatter in the dataThe endurance limit is determined at 500 megacyclesat 500 megacyclesIdealized bending stress relative to Yb vs megacycles to failureEndurance limitsEndurance limits
225 MPa for single-layer ACSR85 MPa for multi-layer ACSR
R f EPRI O B k
Study Committee B2 - Technical Advisory Group B2-AG-06 222011-02-28
Ref EPRI Orange Book
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Fatigue Endurance Data (II)Estimated bending amplitude endurance limits
Fatigue Endurance Data (II)
Study Committee B2 - Technical Advisory Group B2-AG-06 232011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Vibration Measurement Analysis (I)Vibration Measurement Analysis (I)
Rule of Thumb Approach to Interpreting Fatigue Data (IEEE)
Widely used set of empirical criteria (ldquoGuide for Aeolian Vibration Field Measurements of Overhead Conductorsrdquo
1368 200 )IEEE P1368 2007) The bending amplitude may exceed the endurance limit during no more than 5 of total cyclesduring no more than 5 of total cyclesNo more than 1 of total cycles may exceed 15 time the endurance limitNo cycle may exceed 2 times the fatigue endurance limit
Study Committee B2 - Technical Advisory Group B2-AG-06 242011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Vibration Measurement Analysis (II)Multi-Layer ACSR Fatigue Endurance Data
Vibration Measurement Analysis (II)
Statistical analysisS-N curves without wire f ilfailure
Average95 probability of survivalp y
Study Committee B2 - Technical Advisory Group B2-AG-06 252011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Vibration Measurement Analysis (III)
Based on Cumulative d th (Mi rsquo
Vibration Measurement Analysis (III)
damage theory (Minerrsquos rule)Total damage D at several stress levels σi cumulates linearly
D = Σ n ND = Σ niNi
Failure is predicted when
D Σ n N 1D = Σ niNi =1The accuracy of the resulting estimate of lifetime is between 50 d 200
Study Committee B2 - Technical Advisory Group B2-AG-06 262011-02-28
50 and 200
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Case Study (I)Report evaluated on 02052002
Transmission line Circuit 3002
Case Study (I)
Voltage (kV)Conductor typeLocation of measurementTerrainSpan length (m)
315ACSR PheasantTower 313 facing Tower 312Flat348 4Span length (m)
Recorder (Type and No)Remarks
3484PAVICA ndeg 5P02Installation date November 21 2001 0degC
First measurement atLast measurement atDuration of one measurement (s)Measurement cycle time (s)
21112001 180024022002 180010900
Total duration of measurement (s)Factor for extrapolation to one yearTotal number of measurements taken
912003457899120
Study Committee B2 - Technical Advisory Group B2-AG-06 272011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Case Study (II)Fatigue Endurance Limit Approach
12
PAVICA
Case Study (II)
10
Pa)
PAVICAFatigue endurance limit
6
8
lativ
e to
Yb
(MP
4
PS
stre
ss re
l
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 282011-02-28
0 10 20 30 40 50
Frequency (Hz)
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Case Study (III)Cumulative Damage Approach
12
Case Study (III)
10Pa
)
5 S-N curve50 S-N curve95 S-N curveAccumulated stress curve per year
6
8
ativ
e to
Yb
(MP
4
PS
stre
ss re
la
0
2
Study Committee B2 - Technical Advisory Group B2-AG-06 292011-02-28
001 01 1 10 100 1000 10000 100000 1000000
N = Accumulated megacycles per year
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Case Study (IV)
Evaluation of remaining lif ti D 1
1400
Case Study (IV)
lifetime D=1There is a 86 probability that the
1000
1200
e (y
ears
)
remaining lifetime exceeds 20 years 600
800
inin
g lif
etim
e
200
400R
ema
0 10 20 30 40 50 60 70 80 90 100
Probability of survival ()
0
Study Committee B2 - Technical Advisory Group B2-AG-06 302011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Case Study (V)
Assessment of the t d i
55
60
65Case Study (V)
most damaging frequenciesHelpful for 40
45
50
)Helpful for choosing the right damping system
25
30
35
Freq
uenc
y (H
z)
10
15
20
25
0 4 8 12 16 20 24 28
0
5
10
Study Committee B2 - Technical Advisory Group B2-AG-06 312011-02-28
0 4 8 12 16 20 24 28
Damage share ()
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Conductor and Clamp Types Lacking Fatigue Data
The extrapolation of fatigue data available to other types of conductors or to different types of support is not recommended
Conductor and Clamp Types Lacking Fatigue Data
conductors or to different types of support is not recommended
Bending amplitude method is valid only for armored or unarmored conductors fitted with solid metal-to-metal clamps
Not valid for cushioned clamps (armored or unarmored)
Little test data for conductors except ACSR and aluminum alloys
Some data for ACSR conductors with armor rods
There is a need for more published data on conductor fatigue
Study Committee B2 - Technical Advisory Group B2-AG-06 322011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Some Important Recent Contributions
Guide for Aeolian Vibration Field Measurements of Overhead Conductors IEEE P1368 2007 (a revision of
Some Important Recent Contributions
3 (IEEE 1966 Report)Transmission Line Reference Book Wind Induced Conductor Motion Second Ed EPRI 2007 (Chapter 3 ( p Fatigue of Overhead Conductors) a revision of the 1979 ldquoOrange BookrdquoFatigue Endurance Capability of ConductorClamp g p y pSystems ndash Update of Present Knowledge CIGRE TF B21107 TB No 332 October 2007Engineering Guidelines Relating to Fatigue Endurance g g g gCapability of ConductorClamp Systems CIGRE WG B230 TB No 429 October 2010
Study Committee B2 - Technical Advisory Group B2-AG-06 332011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Conclusion
Fatigue endurance capability of conductors is a very useful
Conclusion
parameter at the design stage as well as for a maintenance program
Aeolian vibrations and conductor fatigue are both highly complex phenomena
So far design tools proposed are a good example of the engineering approach to solve a complex problemg g pp p pAdequate determination of the fatigue characteristics of a conductorclamp system is very important in the design of a line
Acceptable level of conductor vibrationsAcceptable level of conductor vibrationsDetermination of safe design tensions
Future work is needed to better understand the importance of many other parameters
Study Committee B2 - Technical Advisory Group B2-AG-06 342011-02-28
many other parameters
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
CIGRE WG B2 30
Members L Cloutier (Convenor) A Leblond (Secretary) U
CIGRE WG B230
Members L Cloutier (Convenor) A Leblond (Secretary) U Cosmai P Dulhunty M Ervik DG Havard D Hearnshaw HJ Krispin M Landeira P Mouchard K Papailiou D Sunkle B WareingWareing
Corresponding Members JA Arauacutejo H Argasinska JM p g j g Asselin O Cournil G Diana K Halsan CB Rawlins R Stephen P Timbrell
Associated Experts T Alderton J Duxbury A Goel C Hardy A Laneville A Manenti Diana S Pichot T Seppauml P Van Dyke
Study Committee B2 - Technical Advisory Group B2-AG-06 352011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Speakers Contact InformationSpeaker s Contact Information
Andreacute Leblond PhD Eng
Tel 1-514-879-4100 ext 5734Tel 1 514 879 4100 ext 5734Fax 1-514-879-4855E-Mail leblondandre2hydroqcca
Address 85 rue Ste-Catherine Ouest 2nd floorMontreal QuebecMontreal QuebecH2X 3P4CANADA
Study Committee B2 - Technical Advisory Group B2-AG-06 362011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
Thank you Thank you
QUESTIONSQUESTIONS
Study Committee B2 - Technical Advisory Group B2-AG-06 372011-02-28
top related