ak best practices transformer maint
TRANSCRIPT
Best Practices in Transformer MaintenanceNWPPA, Anchorage, AK October 2009Wayne BishopWayne Bishop Business Development Manager
Today’s PresentationToday’s Presentation• Introduction to OMICRON• Meeting the Challenges in our Industry• Condition Assessment of Transformers• Condition Assessment of Transformers• New Technologies for Testing (Peter
F )Fong)– Current Transformer Testing– Dielectric Response Analysis
© OMICRON January 13, 2008 Page 2
OMICRONOMICRON• World Leader in the design and
f t f t t i t t fmanufacture of test instruments for power system apparatus
• Test Instruments in 130 countries• Team of 400 employees worldwidep y
© OMICRON January 13, 2008 Page 3
OMICRON worldwide– A truly international team with a worldwide
network
Houston / USA Shanghai / China
KoreaBoston/ USA
Stafford / Great Britain
Hong Kong
New Delhi / India
Madrid / Spain
Cergy / France
Berlin / GermanyMelbourne / Australia
Bahrain
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Klaus / Austria Erlangen / Germany
BUprim - Hardware– The Innovations in Primary
Testing!
MPD600 (PD) DIRANA (DFR)
CPC 100 Multifunctional CP CU1Primary Test Set CP CU1Coupling UnitCP GB1
Grounding Box
CPC 100 + CP TD1Power Factor Testing
Page: 511/9/2009
CT Analyzer FRAnalyzer (SFRA)
BUsec - Hardware
CMC 256plus CMC 356
CMC 156CMS 156
CMS 252CMS 252CMB IO-7
CMA 156
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Challenges Facing our Industry
With deregulation of the energy markets, the life span of electrical assets becomes critical. p
• All assets including all transformers have to be in service as long as possible.service as long as possible.
• For transformers this can mean continuous operation over the life span of the asset at full loadoperation over the life span of the asset at full load or even more since redundant transformer assets are not available.
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Situation for Most of IndustryS tuat o o ost o dust y
A large percentage of transformers are in service for more than 25 years – with the health of the transformers
t ft knot often known.
About 35% - 40% of all transformer faults are caused by ybreakdowns in the aged insulation.
• TemperatureTemperature• Moisture
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Situation Today
Many of the transformers in Germany have an age of 25-30 years
70
80
90
100
70
80
90
100
ers
30
40
50
60
70
30
40
50
60
70
f tra
nsfo
rme
0
10
20
30
0
10
20
30
1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55
No.
of
Problem: faults happen more often with increasing age
Betriebsalter der Transformatoren in JahrenAge of transformers / years
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increasing age
Healthy 90 year oldHealthy 90 year old
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Healthy?• Blood Tests
Urinal sis• Urinalysis• Temperature and Blood Pressure• Ultrasound • MRIMRI• Family Health History
Life Style Environment Stress• Life Style, Environment, Stress
© OMICRON January 13, 2008 Page 11
I thi H lth T f ?Is this a Healthy Transformer?
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Si il M th d lSimilar Methodology
Healthy Person ? Healthy Transformer ?Healthy Person ?• Blood Tests, Urinalysis,
Temperature
Healthy Transformer ?• DGA, Power Factor, %
Moisture Insulationp• Family History • Transformer Design
HistoryL d P fil L ti f• Stress, Environment,
Workplace, Lifestyle• Load Profile, Location of
Transformer
• Type of Care • Maintenance Program (TBM, CBM, RCM)
© OMICRON January 13, 2008 Page 13
Transformer DiagnosticsReview Patients History• Family History ofy y
– High Blood Pressure and Heart Disease– High Cholesterol, Cancer Risks, etc.
Review History of Transformer• Maintenance History• Operational History• Service Advisories• Factory TestsFactory Tests• Site Inspections• Routine Tests
© OMICRON January 13, 2008 Page 14
Generator Transformer 27/400kV
HV Bushing
Measuring Tap LV BushingMeasuring Tap LV Bushing
High Voltage Winding
Tapped Winding
L V l Wi di
Tap Selector
Diverter Switch
C
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Low Voltage WindingCore
Failure Mode Properties
Di l t i St• Dielectric Stress
• Thermal Degradation• Thermal Degradation
• Mechanical Stress• Mechanical Stress
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Maintenance Philosophies
• Time Based Maintenance (TBM)P f R ti P t ti M i tPerform Routine Preventative Maintenance
• Reliability Centered Maintenance (RCM)Focus Resources on Bad Actors
• Condition Based Maintenance (CBM)Condition Based Maintenance (CBM)Require Indication while In-service
• The Maintenance SpectrumRun to Failure Diagnostic Overkill
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Transformer Tests• DGA/Oil Screen/Furans• Power Factor and Capacitance• Power Factor and Capacitance• Excitation Current
Turns Ratio (TTR)• Turns Ratio (TTR)• SFRA• Leakage Reactance• DC Winding Resistance• Dielectric Frequency Response• IR
© OMICRON January 13, 2008 Page 18
Dielectric Thermal Mechanical
DGA DGA SFRA
Oil Screen Oil Screen Leakage Reactance
PF/Cap Thermal Imaging Capacitance
Excitation Current DC Winding Excitation CurrentExcitation Current DC Winding Resistance
Excitation Current
TTR DC Winding Resistance
Partial Discharge
Dielectric Frequency
© OMICRON January 13, 2008 Page 19
Response
Electrical Measurement Methods I
Measurement Method Application Indicated by Kind of
Test*on-/off-
line
Winding resistance (static)
Contact problems,broken or loose connections,broken conductors
High internal temperatures, e.g. indicated by DGA results or Buchholz Relay
FRT off
Wi di i t Contact problems at theWinding resistance (dynamic)
Contact problems at the diverter switch, broken transition resistors
DGA, Buchholz Relay FRT off
Leakage reactance (stray reactance)
Winding deformation High through-fault currents FRT offreactance)Frequency Response of the Stray Losses (FRSL)
Broken parallel strands High internal temperatures, e.g. indicated by DGA results
FT off
No-load impedance Core problems, shorted turns High internal temperatures, e g indicated by DGA results
FT offe.g. indicated by DGA results
Magnetising current Core problems, shorted turns High internal temperatures, e.g. indicated by DGA results
FT off
F=Fingerprint, R=Routine, T=Troubleshooting, S=Special
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Electrical Measurement Methods IIKindMeasurement
Method Application Indicated byKind
of Test*
on-/off-line
Turns ratio After Buchholz Relay Buchholz Relay has T off
Frequency Response Analysis (FRA)
Winding deformation, winding displacement, core faults, faulty screen or core
High through-fault currents, transportation
F(R)T off
screen or core
Insulation resistance Insulation problems Breakdowns, Buchholz Relay
FRT off
Capacitance and Main insulation: ageing, pDielectric Dissipation Factor
g g,moisture - Bushings: ageing, partial
DGA FRT on/off
Dielectric Response M t (FDS
Main insulation: ageing, i t B hi
high water content in il / hi h di l t i FRT ffMeasurement (FDS
and PDC)moisture - Bushings: ageing, partial
oil / high dielectric losses
FRT off
Partial Discharge Insulation problems DGA T on/off F=Fingerprint, R=Routine, T=Troubleshooting, S=Special
© OMICRON Page 21
g p g p