Doble Monitoring Power Cables Gis

7/27/2019 Doble Monitoring Power Cables Gis

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On-line Partial Discharge

Monitoring and Diagnosis

on Power Cables

Dipl.-Ing. Gregor Pudlo


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Conventional electrical measurement

-Integration at frequency domain

Narrow-band

Wide-band

- Integration at time domain

Electrical measurements with high frequencies- HF / VHF method 40 MHz to 300 MHz

- UHF method 300 MHz to 3 GHz

Acoustic measurements 10 kHz to 300 kHz

Optical measurements ultraviolet visible infrared range

Chemical measurement

Background: PD Detection Methods


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PD testing circuit acc. non-conventional measuring method. UHF-PD-

Sensor connected at the HV- and EHV- Termination

(Crossing Area: GIS - Power Cable)

HV Termination with

Decoupling Loop

PD Testing Circuit for UHF Measurements

at Power Cable Accessories


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5

external sensor

window sensorinternal sensor

capacitive (window-) sensor

external sensor

acoustic coupler

standard coupling

capacitance

external sensor

ultra wide band

inductive coupler

Ck

Spacer

PDM System PD Guard/UHFSignal Decoupling Technique at GIS


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6

PDM System PD Guard/UHFPrincip le Application fo r the PD Guard/UHF


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PD Guard for Partial Discharge

Monitoring


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Inductive Line coupler PD sensor

(100 MHz 1 GHz)

- with integrated capacitor (2 nF)

100MHZ 1GHZ

Transfer Characteristic

PD Sensor for Cable Accessories

Monitoring


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X-ray photo for QA

purposesPD Sensor for ungrounded

Termination:

high impedance inductive

coupler

PD Sensor for Cable Accessories

Monitoring

Application into GIS section

Installation example


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Case Study A)

On-site UHF-PD Monitoring Set-Up, 400-kV-XLPE -Cable system


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HV Test Setup: Reactor,Loading Capacitor, Blocking

Impedance, Connection to the400kV Cable under Test

PD Instrumentation

PDM-System LDS-6/UHF(Zero-Span-Mode-Measurement)

PD SensingPD Current Sensor

Test Procedure

Case Study A)

Test Procedure & Instrumentation for AC and PD Commissioning

Tests of the 400 kV Power Cable System


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Procedure for the Test of the

400kV-Power Cable

Recording at 230 kV Test Vol tage

Near & Remote EndMeasured PD Signals at 230 KV test voltagelevel are not above the baseline

Recording at 320 kV Test Voltage (One-

Hour-Test),

Noise Identification: Clearly assigned noisesignal caused by electronics of theResonance Test System

Case Study A)

Measuring Results of the 400kV Power Cable Commissioning Tests


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Temporary measuring

instrumentation at the GIS-sealing ends for the AC- and

PD commissioning test at

Wufong

Application layout for permanent

PD monitoring, project Wufong, Taiwan

Case Study B)

Application Layout for PD Monitoring at 345 kV EHV Substation,

Wufong, Taiwan


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Sensor- and instrumentation- arrangement for PD monitoring of 345 KV EHV Substation

Case Study B)

PD Sensor- and Instrumentation-Arrangement


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Test condition for on-site AC test combined with a on-site PD test at Wufong,

AC Resonance Test Set connected to the power cable under test .

Case Study B)

Test Procedure & Instrumentation for the AC- and PD Test


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GIS A+ GIS B-

Phase resolved PD pattern recorded at 199 KV test vol tage.

Clearly assigned PD phenomena at GIS A+, cross-over coupl ing

at GIS B-

Case Study B)

Measuring Results PRPD Pattern


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Tracking path as reason for partial discharges caused by foreign matter

in the high voltage insulation system

Case Study B)

Defect due to improper termination assembling


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Recorded Phase resolved PD Pattern

at GIS-sealing end, phase S

Initial measurement as

start of the periodic

monitoring

Time domain signal of the decoupled PD signal at GIS-sealing

end,

phase S, and h is correlated frequency spectrum

Case Study C)

Periodic PD Monitoring as Inspection Test of 161 KV GIS-sealing ends


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PRPD-Pattern of 1st & 2nd review, recorded each at phase S

Synchronized PD Measurement; symmetrical appearances

Case Study C)

Periodic PD Monitoring as Inspection Test of 161 KV

GIS-sealing ends


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Circuit A de-energized anddisconnected, circuit B in service.

Circuit A in service, circuit B de-energized and disconnected

Schematic Overview of the

investigated GIS,(GIS-sealing ends both circuits A

and B)

AE Measuring Results

Tabulated measured averaged

peak values by using the

acoustic instrument, type

AIA100, at the different

measuring points

AE-Measurement conf irmed the or ig in of PD source in one termination each

investigated circuit

Case Study C)

AE-PD-Measuring Results


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Af ter further disassembling serious trace path as

result of partial discharge activities has been

found.

Disassembling of the GIS-sealing end. No abnormalcondi tion observed at the surface of cable

termination.

Case Study C)

Identified defect in the insulation system GIS-sealing end


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PD Measuring Setup for the Insulation Check the power cable accessories

PD Monitoring Instrumentation: LDS-6/UHF

(frequency selective and ultra wideband- measuring method)

Case Study D)

Periodic PD Monitoring as Quality Check


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Switching

No.

Measuring series as part

of the periodic

monitoring

StatusMeasuring

methodInstrumentation

1Initial measurement

(quality check)

Circuit A energized

Circuit B energizedElectrical

LDS-6/UHF

(zero-span-mode, UWB)

2 Nine-month later

Circuit A: deenergized

(circuit breaker and busbar

disconnector open, circuitdisconnector closed)

Circuit B: in service

ElectricalLDS-6/UHF


Acoustic AIA100

3 Nine-month later

Circuit A in service

Circuit B: deenergized

(circuit breaker and busbardisconnector open, circuit

disconnector closed)

ElectricalLDS-6/UHF


Acoustic AIA100

Case Study D)

Test configuration for the periodic inspection test


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Phase Resolved PD Pattern

Circuit A in service, Circuit B in service

(UWB-recording)

V-T-Recording

Circuit A in service, Circuit B in service

(UWB-recording)

PD signal vs. time, constant PD

level at phase L2, each circuit

Clearly assigned PD appearances

at phase L2, each circuit

UHF-Measuring Results identified defect in GIS sealing ends

Case Study D)

UHF-PD-Measuring Results of the inspection test


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Tabulated recorded phase resolved PD pattern - circuit A in service. (zero-

span-recording)

Case Study D)

Interpretation PRPD Pattern


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All XLPE-Cable are tested in the factory with high sensitivity.

after transport and laying are performed the oversheath test:

> oversheath undamaged = polymer insulation is intact

the jointing of terminations is handwork on the cable ends.

> Here errors can occur

Therefore a PD test is very important with a focus on the

> terminations and joints after jointing.

UHF-PDM method is a successful measurement system for

> PD-On-Site-Tests on HV- and EHV-XLPE cable systems.

Conclusions


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Contacts

Doble Lemke AG Doble Lemke GmbHKaiserstrasse 9 Zschoner Ring 94310 Rheinfelden 01723 Kesselsdorf Switzerland Germany

Tel.: +41-61-836-8000 Tel.: +49-35204-3900-0

Fax: +41-61-836-8001 Fax: +49-35204-3900-111E-Mail: [email protected] E-Mail: [email protected]://www.doble-lemke.eu http://www.doble-lemke.eu


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Many thanks

for your attention !

Documents

Doble Monitoring Power Cables Gis