Practical on-line partial discharge tests for turbine generators and motors

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · IEEE Transactions on Energy Conversion (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/60.300147· OSTI ID:7250938

Campbell, S R; Stone, G C ^[1]; Sedding, H G; Klempner, G S ^[2]; McDermid, W ^[3]; Bussey, R G ^[4]

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1. Iris Power Engineering Inc., Mississauga, Ontario (Canada)
2. Ontario Hydro, Toronto, Ontario (Canada)
3. Manitoba Hydro, Winnipeg (Canada)
4. TransAlta Utilities, Calgary, Alberta (Canada)

Several utilities have found partial discharge testing to be very useful for identifying motors or generators with deteriorated stator winding insulation. Such partial discharge tests are sensitive to problems associated with overheated insulation, loose stator bars, and pollution, all of which can cause in-service failures with long associated outages and high repair/rewind costs. Unfortunately, the partial discharge test is not widely applied since present test methods require considerable skill to perform, and/or require machine outages. These problems are due to the stator winding partial discharges being masked by high levels of internal and external electrical noise. Partial discharge tests have now been developed which eliminate the effect of noise, thus allowing plant personnel to perform the test without any machine outage. Installations on several machines have shown that external noise can be eliminated by a pair of capacitive couplers (bus couplers) mounted on each phase of the output bus. Sensors which are mounted within the slots of the stator winding (SSCs) have been shown to eliminate both external and internal noise. An instrument called the TGA has been developed to measure the signals from either type of sensor, distinguish noise from stator winding partial discharge, and perform a pulse height, pulse phase analysis on the partial discharge signals. Using the TGA, deteriorated windings have been found to have as much as 20 times higher partial discharge activity than good windings. The SSC type of sensor is best for use on large turbine generators or other critical machines, due to its ability to effectively eliminate false indications of deteriorated windings.

• OSTI ID: 7250938
• Journal Information: IEEE Transactions on Energy Conversion (Institute of Electrical and Electronics Engineers); (United States), Journal Name: IEEE Transactions on Energy Conversion (Institute of Electrical and Electronics Engineers); (United States) Vol. 9:2; ISSN 0885-8969; ISSN ITCNE4
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
240200* -- Power System Networks
Transmission & Distribution-- (1990-)
DAMAGE
DETECTION
ELECTRIC GENERATORS
ELECTRIC MOTORS
ENGINES
MOTORS
PERFORMANCE TESTING
SIGNAL-TO-NOISE RATIO
TESTING
VOLTAGE DROP