High Voltage Electric Equipment Failure Diagnosis

7/29/2019 High Voltage Electric Equipment Failure Diagnosis

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High VoltageHigh VoltageElectrical EquipmentElectrical Equipment

Failure DiagnosisFailure Diagnosis

Presented by:

Spencer Tang & Terence Ng

T&T Inspection & Engineering Sdn Bhd



Ultrasound World VII 2011Ultrasound World VII 2011 22

High Voltage Electrical Equipment Failure Diagnosis

Definition of High Voltage (H.V. / H.T.)Definition of High Voltage (H.V. / H.T.)–– According to IEC standard,According to IEC standard,

High voltageHigh voltage is defined as those with more thanis defined as those with more than1000V (>1000V AC) for1000V (>1000V AC) for alternating currentalternating current

low voltagelow voltage (50~1000V AC) and(50~1000V AC) and extraextra--low voltagelow voltage

(<50V AC) circuits, in the context of building wiring(<50V AC) circuits, in the context of building wiringand the safety of electrical apparatus.and the safety of electrical apparatus.

–– In South East Asia, HV is ranging fromIn South East Asia, HV is ranging from

1kV (1000V), 3.3kV, 6.6kV, 11kV, 22kV,1kV (1000V), 3.3kV, 6.6kV, 11kV, 22kV,33kV, 132kV, 230kV, 275kV, 400kV & 500kV.33kV, 132kV, 230kV, 275kV, 400kV & 500kV.




Map of theMap of the AseanAsean





Characteristic of High VoltageCharacteristic of High Voltage–– Higher voltage required higher insulation levelHigher voltage required higher insulation level

–– Ability to penetrate insulation material (air,Ability to penetrate insulation material (air,vacuum, gas, oil, XLPE, PILC, porcelain, etc)vacuum, gas, oil, XLPE, PILC, porcelain, etc)

due to deterioration / aging / interruption /due to deterioration / aging / interruption /

human error, etc and create short circuit /human error, etc and create short circuit /discharge between phase to phase / phase todischarge between phase to phase / phase to

groundground

–– resulting severe facility damage / loss, injury /resulting severe facility damage / loss, injury /

deathdeath





NDT Technology of UltrasoundNDT Technology of Ultrasound–– a method to detect HV fault symptoma method to detect HV fault symptom

(electrical partial discharge(electrical partial discharge –– E.P.D.) from aE.P.D.) from asafesafe distancedistance

–– Provide safeProvide safe accessaccess via structure borne andvia structure borne andairborne method without direct expose to theairborne method without direct expose to thelive part / component.live part / component.

–– HighlyHighly sensitivesensitive ultrasound instrumentultrasound instrumentcoupled withcoupled with qualifiedqualified inspector will able toinspector will able todetect HV fault symptom (detect HV fault symptom (egeg: corona,: corona,tracking, arcing, mechanical looseness andtracking, arcing, mechanical looseness andetc)etc)




E.P.D. at 33kV VCBE.P.D. at 33kV VCB – – Cable VOIDCable VOID

Cable insulation void at cable compartmentCable insulation void at cable compartment




E.P.D. at 33kV VCBE.P.D. at 33kV VCB – – Cable VOIDCable VOID

Cable insulation void at cable compartmentCable insulation void at cable compartment

2007

J ul 2008

Oct 2008




E.P.D. at 33kV VCBE.P.D. at 33kV VCB – – Busbar Busbar

BusbarBusbar insulation deteriorationinsulation deterioration –– coronacoronapartial dischargepartial discharge




E.P.D. at 33kV VCBE.P.D. at 33kV VCB – – Breaker ContactBreaker Contact

Chemical reaction on conductorChemical reaction on conductor




E.P.D. at 132kV Lightning Arrester E.P.D. at 132kV Lightning Arrester

Internal partial discharge at porcelainInternal partial discharge at porcelain




E.P.D. at 33kV Overhead Disc Isolator E.P.D. at 33kV Overhead Disc Isolator

Airborne detected PD at disc isolatorAirborne detected PD at disc isolatorsuspension clampsuspension clamp –– sharp edges/sharp edges/

oxidization / deteriorationoxidization / deterioration





mechanical vibration / looseness in HVmechanical vibration / looseness in HVbreaker causes bybreaker causes by

–– the resonance of electrical frequency (50Hz /the resonance of electrical frequency (50Hz /60Hz) or electrical harmonics60Hz) or electrical harmonics

–– workmanship issue during on site installationworkmanship issue during on site installation

((egeg: tightening / torque, panel and floor: tightening / torque, panel and floorleveling, greasing, etc)leveling, greasing, etc)

–– Operator ignorant or mechanism error (Operator ignorant or mechanism error (egeg::

breaker misalignment, breaker arm bent,breaker misalignment, breaker arm bent,

shutter jammed, etcshutter jammed, etc




Mechanical vibration / looseness in HV breaker Mechanical vibration / looseness in HV breaker

Looseness detected at breaker &Looseness detected at breaker & busbarbusbar





Repair urgency on partial dischargeRepair urgency on partial dischargedetected:detected:

–– Rate of deteriorationRate of deterioration–– Location of the PD detectedLocation of the PD detected

–– Loading fluctuationLoading fluctuation -- on/off, surge start, peakon/off, surge start, peak

loadload

–– Surrounding environment conditionSurrounding environment condition –– seaside,seaside,

chemical industry, dusty areachemical industry, dusty area……–– External factorsExternal factors –– animal, human erroranimal, human error……




Repair urgency on PD detected

11kV CT flashover during breaker surge11kV CT flashover during breaker surgestart after maintenance due to ignorantstart after maintenance due to ignorant





Dusty and salty environment inducedDusty and salty environment inducedspeedy deterioration at 33kV VCBspeedy deterioration at 33kV VCB





High moisture environment inducedHigh moisture environment inducedoxidization & chemical reactionoxidization & chemical reaction





PD chemical effect on metal panelPD chemical effect on metal panel

Before After





Close PD location increase rate of Close PD location increase rate of deteriorationdeterioration





External factorExternal factor–– Minor corona partial discharge give way in 7 days dueMinor corona partial discharge give way in 7 days due

to road constructionto road construction





Client common question to inspector:Client common question to inspector:How long does the PD symptom can last before itHow long does the PD symptom can last before it

flashover??flashover??

Can we arrange shut down after our productionCan we arrange shut down after our production

peak time, may be about 6 months later??peak time, may be about 6 months later??

Should we shut down by tonight??Should we shut down by tonight??




Perfect match of Ultrasound and Thermography

Ultrasound (US)Ultrasound (US) –– hear what we cannothear what we cannothear;hear; Thermography Thermography (IR)(IR) –– see what wesee what we

cannot see.cannot see.–– Technology limitation but not weakness. Technology limitation but not weakness.

Integration of US & IR will supplement theIntegration of US & IR will supplement the

survey findings and produce a bettersurvey findings and produce a better

diagnosis resultdiagnosis result





11kV RMU required immediate attention11kV RMU required immediate attention

Sp1:temp 32.0

26.0

39.0 °C

30

35

Ar1:max 34.5

26.0

39.0 °C

30

35





Localizing the fault areaLocalizing the fault area

29.0

40.0 °C

30

32

34

36

38

ys ems

Ar1:max 67.6

Sp1:temp 44.6

25.0

70.0 °C

30

40

50

60

FLIR Systems





Localizing the fault areaLocalizing the fault area

27.0

31.9 °C

28

30

Ar1:max 36.1

24.0

39.0 °C

25

30

35

Hi h V l El i l E i F il Di i





NDT technology ease the inspector / owner toNDT technology ease the inspector / owner to

visualize & localize the faultsvisualize & localize the faults

How is the HV partial discharge look like in ourHow is the HV partial discharge look like in our

visual view???visual view???

–– Tx Tx HV corona ring;HV corona ring;

Ar3:max 30.5

Ar1 :max 40.1

Ar2:max 40.2

19.0

43.0 °C

20

30

40

TT HV C blHV C bl i ti l di hi ti l di h




Tx Tx HV CableHV Cable -- corona ring partial dischargecorona ring partial discharge

TT HV b hi ti l di hHV b hi ti l di h




Tx Tx HV bushing partial dischargeHV bushing partial discharge

TTx HV b hi ti l di hHV bushing partial discharge




Tx Tx HV bushing partial dischargeHV bushing partial discharge

Ar1:max 46.1

Ar3:max 44.3

Ar2:max 49.1

38.0

50.0 °C

40

45

Electrical partial discharge effect to plant/climberElectrical partial discharge effect to plant/climber




Electrical partial discharge effect to plant/climberElectrical partial discharge effect to plant/climber

HV flashover




HV flashover






To conduct a safe and effective inspection To conduct a safe and effective inspectionon high voltage electrical equipment, weon high voltage electrical equipment, we

should well understand and aware on:should well understand and aware on:

–– The safety measure of the HV equipment to The safety measure of the HV equipment to

be inspected;be inspected;

–– Our NDT instrumentsOur NDT instruments’’ strength and limitation;strength and limitation;–– Be observant and sensitive to the onBe observant and sensitive to the on--sitesite

condition of the HV equipment;condition of the HV equipment;

–– ““a careful inspector will live longer than a heroa careful inspector will live longer than a hero

(fool) in HV electrical system(fool) in HV electrical system””

230kV GIS230kV GIS




230kV GIS230kV GIS

:max 30.8

:max 32.8 :max 30.7

25.0

46.0 °C

30

35

40

45

FLIR Systems

25.0

46.0 °C

30

35

40

45

FLIR Systems

230KV GIS230KV GIS




230KV GIS230KV GIS

:max 30.9:max 32.8

25.5

46.0 °C

30

35

40

45

FLIR Systems

3MVA3MVA PauwelsPauwels TrafoTrafo




3MVA3MVA PauwelsPauwels Trafo Trafo









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Thank you Thank you

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High Voltage Electric Equipment Failure Diagnosis