PowerPD Case Studies Rev 2.6

CASE STUDYCASE STUDY

Latest Case History

PD Test ResultsPD Test Results

Partial Discharge Loose Parts ArcingPartial Discharge, Loose Parts, Arcing

Exact Spot Found

Exact Spot Found

Case Study 2DC transformer # 31@ China@

The mechanical (loose part) signal cannot always make a uniformed signal and does not produce a current. Thus the signal detected from #32 transformer is caused by a loose part that generates arcing (PD)

Loose part on lead connectionLoose part on lead connection

Case Study 3138KV, 100MVA Substation @ Texas, US

This is actual field data from the PD-TP500A. The top screen is Acoustic activity from sensor 2 (Red trace) This shows graphically a real PD repeating pattern. The bottom screen (green trace) is the electrical discharge to ground This is captured via the ‘High Frequency Current Transducer’the electrical discharge to ground. This is captured via the High Frequency Current Transducer

138 KV BUSHING ON PHASE B (PRIMARY) TERMINAL LEADWAS DEFECTED.

138 KV TERMINAL LEAD WAS DEFECTED.

Case Study 4500KV, 1500MVA Substation @ Idaho, US

Transformer; This data collected in June 4, 2007 from the transformer shows a very serious condition coming from outside of transformer, which

has a lot of decrease in the resistance (defective of insulator is high)has a lot of decrease in the resistance (defective of insulator is high).

PD transmits through the air and power line to all grounds of substation equipments.q p

Actual location of PD source

Actual location of PD source

Case Study 566 KV transformer # 2@ India

NDPL in the India, transformer #1 exploded (15 days till testing Tr#2)

66 KV transformer # 1@ India

Transformer; As PD increases, the resistance decreases (defective of insulator is high). Should prepare for the maintenance.

PowerPD was Locate Partial Discharge point using their “PD-TP500A” test device.The location of PD was found within 30 minutes!Th Middl f B h id # 3(Hi h V lt id )The Middle of B phase, side # 3(High Voltage side)

Case Study 6Rotating machine (condensing), US

The data was collected three months before the condensing rotating machine failed

Fault 1 (on “Back end”)

Fault 2 (on “back end”)

Fault 3 (on “front end”)

45 MVA Generator in Thailand

Internal Inspection Findings

??? MVA G t??? MVA Generator in Thailand

15 MVA Generator in Thailand

45 MVA Generator in Thailand

126.6 MVA Generator in ThailandThailand

148 MW Generator in US

Case Study 7PD source from inside of insulation

Internal Inspection Findings

Case Study 8Signal (PD and 6 pulse) was collected from HFCT installed on the tank ground of

Transformer. This signal(PD and 6 pulse) transmitted from the generator side.

6 pulse coming from Generator side

Inspection Findings

Case Study 9Warning level of PD was collected from HFCT installed on the tankWarning level of PD was collected from HFCT installed on the tank ground of Transformer. This PD transmitted from the generator and shot down the generator for maintenanceshot down the generator for maintenance

PD burst collected from HFCT

Inspection Findings

After serviceAfter service

Case Study 10230 KV 300 MVA @ Thailand@

PD burst collected from sensor3(yellow)

Internal Inspection Finding

Case Study 11500 KV 500MVA @ Philippines500 KV 500MVA @ Philippines

PD collected from AE and HFCT

Internal Inspection Finding: Burnt cable from 500kv winding to K pic2 3Burnt cable from 500kv winding to K_pic2.3

Case Study 12 Transformer Test Results:

• TTR Test OK• Doble Test OKDoble Test OK• Doble SFR Test inconclusive• ABB DFR Test:

– Indicates a problem between H&X Winding - Tertiary• Final DGA Test –

Acetylene 3 ppmMethane 1259 ppmEthane 163 ppmEthylene 7 ppmHydrogen 27123 ppm

• ABB Internal Inspection – B phase core shifted due to through f lt / i di t l ifaults/winding telescoping

Transformer test with TP500A @ US

Internal Inspection Findings

E id f h ti b BØ C C li D tEvidence of heating above BØ Core Cooling Ducts

Internal Inspection Findings

Shifted Core over BØ:

Shifted approx ¾” vertically & ½” Horizontally

Case Study 13PD source between winding (Data collected with TP500A)

Internal Inspection Findings

Case Study 14 Transformer Test Results:

• Final DGA TestFinal DGA Test Methane 532 ppmEthane 363 ppmEthane 363 ppmEthylene 13 ppmHydrogen 1,140 ppm (From last year 08 Hydrogen was at 964)y g , pp ( y y g )

PD source from inside of insulation (Data collected with TP500A)

Internal Inspection Findings

Case Study 15 220 KV GIS Test Results: Data collected with iGMS P8220 KV GIS Test Results: Data collected with iGMS_P8

Data from UHF1

Data from UHF2

Data from HFCT

Case Study 16 220 KV GIS Test Results: Data collected with iGMS_P8_

Data from UHF 1 Data from UHF 2 Data from UHF 3 Data from UHF 4