pd diagnostics on mv cables · pd diagnostics on mv cables rene hummel wets d’15 workshop...
TRANSCRIPT
![Page 1: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/1.jpg)
PD Diagnostics on MV cables Rene Hummel
WETS D’15 Workshop Organization: Jicable and Prospective 21OO
Palais des Congrès de Versailles, France Thursday, 25 June 2015
WETS D’15 3.2 Hummel
![Page 2: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/2.jpg)
aim of the presentation
PD detection PD measurement PD localization types of testing
![Page 3: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/3.jpg)
outline
Introduction – what are partial discharges? How to measure? localization: TDR – time domain reflectometry
sTDR – statistical TDR
overview of technologies in the market
![Page 4: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/4.jpg)
What is partial discharge ?
> Partial discharge (PD) is a localized dielectric breakdown of a small portion of a solid or liquid electrical insulation system under high voltage stress.
> Definition from IEC 60270 Specification: Localized electrical discharge that only partially bridges the insulation between conductors and which can or cannot occur adjacent to a conductor.
![Page 5: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/5.jpg)
What are partial discharges?
Partial discharge:
> Local electrical stress in the insulation or on the surface of the insulation
> Always generates electromagnetic signals
> Often accompanied by an emission of sound, light, heat and chemical reactions
![Page 6: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/6.jpg)
Evidence of partial discharges
![Page 7: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/7.jpg)
Breakdown of cable and termination
Seite 7
![Page 8: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/8.jpg)
Evidence of partial discharges
photo: IPH Berlin
![Page 9: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/9.jpg)
Electrical treeing in PE
Seite 9
![Page 10: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/10.jpg)
Evidence of partial discharges
photo: IPH Berlin
![Page 11: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/11.jpg)
Evidence of partial discharges
tracking structures
![Page 12: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/12.jpg)
Evidence of partial discharges
![Page 13: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/13.jpg)
Video ...
video: IPH Berlin
![Page 14: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/14.jpg)
How to measure?
![Page 15: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/15.jpg)
Charge – How to measure?
> Time Domain Integration
q = ∫ 𝑖 𝑡 𝑑𝑡 = 1𝑅
∫ 𝑢 𝑡 𝑑𝑡𝑡𝑡𝑡1
𝑡𝑡𝑡1
q
t1 t2
![Page 16: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/16.jpg)
Analog PD measurement systems
![Page 17: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/17.jpg)
”Digital” PD measurement systems
Filter is analogue!
![Page 18: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/18.jpg)
”Digital PD measurement system with digital filtering
![Page 19: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/19.jpg)
Types of PD
> Internal PD > Void discharges, „electrical treeing“
> External PD > Corona > Surface discharges
Solid insulation
Outer semicon
Solid insulation
Inner semicon
Image Source: Andreas Küchler – Hochspannungstechnik
![Page 20: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/20.jpg)
External PD
Corona discharge Surface discharge
![Page 21: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/21.jpg)
Internal PD
Cavity / void discharge Internal discharge in laminated material
Treeing
![Page 22: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/22.jpg)
PD classification
Semicon layer protrusion (stress concentration at the tip)
Void (field strength doubling)
Lines of electrical field
ɛn = 2
![Page 23: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/23.jpg)
Phase resolved partial discharge PRPD
PRPD correlation between PD pulses and voltage phase PD nature might be identified
![Page 24: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/24.jpg)
Phase resolved partial discharge – PRPD
Am
plitu
de
1 2 3 4 ...
5 50
Time (ms)
Am
plitu
de
Time
Trigger Trigger Trigger Trigger Trigger Trigger
> How is a PRPD created?
10 20
![Page 25: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/25.jpg)
Further ways of PD analysis – Trend
Charge vs. time
Applied voltage vs. time PD repetition rate vs. applied voltage
PD repetition rate vs. time
![Page 26: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/26.jpg)
Further ways of PD analysis – 3CFRD (3 Center Frequency Ratio Diagram)
> Pulse Shape Analysis: 3CFRD or Time/Frequency map
T/W map
![Page 27: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/27.jpg)
Influence of inverse gating on external disturbances
External disturbance PD Noise
![Page 28: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/28.jpg)
Localization
![Page 29: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/29.jpg)
TDR – Time domain reflectometry
> A single PD pulse on an expanded test objects (cable) causes traveling waves in both directions
> Pulses reaching the far cable end will be reflected
> The reflected pulse will also be measured at the near end
> The time delay of these 2 pulses depends on the PD fault position
PD fault location measuring
point
near
end
far e
nd
scope view u
t
t1 t2 ∆t
![Page 30: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/30.jpg)
TDR Curves for calibration and for PD
> Calibration > equal distances between
echos (partial reflections from joints possible)
> PD > typically 2 different time
distances
1st pulse
2nd pulse
3rd pulse
![Page 31: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/31.jpg)
Calculation of fault position
PD fault position from
> Far End
> Near End
2fault PDtl v ∆= ⋅
2fault PDtl L v ∆= − ⋅
![Page 32: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/32.jpg)
PD propagation speed
If v is unknown it can be found during calibration
> if cable length is known
> if only a single type of cable is tested
𝑣 = 1
𝜀𝑟,𝑟𝑟𝑟 ∙ 𝜀0 ∙ 𝜇𝑟 ∙ 𝜇0 =
1𝜀𝑟,𝑟𝑟𝑟
∙ 𝑐0
![Page 33: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/33.jpg)
Travelling speeds and capacities in specific cable types
Cable type Typical travelling speed in
m/µs
Typical capacity in nF/km For conductor cross sections in mm²:
120 240 500 630 1200 1600 2500
XLPE 10kV 154-160 350 450 610 630 - - -
XLPE 20kV 164-170 240 300 400 - - - -
XLPE 30kV 170-176 160 210 280 - - - -
XLPE 60kV 174-176 - - - 236 - - -
XLPE 110kV 174-176 - 121 163 177 271 301 378
XLPE 150kV ~181 - - - - 225 - -
XLPE 220kV - 106 143 155 236 260 294
XLPE 400kV - - - 119 171 188 226
EPR 10kV 130-134 ~300 500 - - - - -
![Page 34: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/34.jpg)
> A single PD pulse on an expanded test objects (cable) causes traveling waves in both directions
> Pulses will be reflected in the far cable end but partly also on every joint
> The reflected pulses will also be measured at the near end
600 m 200 m 400 m 3 µs 1 µs 2 µs
STDR – Statistical time domain reflectometry
measuring point
PD fault location
near
end
far e
nd
Joint Joint
scope view C
t
10 pC
0 µs 4 µs 10 µs 12 µs
Assumption – Joints: 80% signal transmission; 20% signal reflection
![Page 35: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/35.jpg)
> Specific impulses are correlated to all measured impulses
> The results of this correlation > time difference between impulses > relative amplitude of the correlated impulse
are drawn into the STDR histogram
STDR – Statistical time domain reflectometry
scope view C
t
10 pC
0 µs 4 µs 10 µs 12 µs
100 % STDR histogram
0 µs 5 µs 10 µs t
![Page 36: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/36.jpg)
overview of technologies
in the market
![Page 37: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/37.jpg)
technologies in the market
very low frequencies (VLF) 0.01 Hz – 0.1 Hz – some Hz
close to power frequencies 50Hz / 60Hz - 20Hz to 300Hz
offline offline or online
mostly on-site testing in factory or on-site testing
![Page 38: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/38.jpg)
technologies in the market
sinus wave cosin rectangular damped AC
sinus voltage
mostly with coupling capacitor coupling capacitor or high frequency current transformer (HFCT)
![Page 39: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/39.jpg)
voltage types
![Page 40: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/40.jpg)
Cosinus rectangle - CosRec
![Page 41: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/41.jpg)
CosRec – Zoom on falling slope
![Page 42: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/42.jpg)
CosRec – Zoom on falling slope
![Page 43: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/43.jpg)
CosRec – PD only in slopes
![Page 44: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/44.jpg)
damped AC
source: http://hvgrid-tech.com
![Page 45: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/45.jpg)
standards
IEC60885-3
IEC 60840
IEC 60502-2
IEEE 400 documents (.1 , .2 , .3, .4 , .5)
CENELEC HD620 S1
CIGRE guides
![Page 46: PD Diagnostics on MV cables · PD Diagnostics on MV cables Rene Hummel WETS D’15 Workshop Organization: Jicable and Prospective 21OO Palais des Congrès de Versailles, France](https://reader031.vdocuments.us/reader031/viewer/2022022110/5c0cf15a09d3f2e4358cf999/html5/thumbnails/46.jpg)