Partial discharge screening test for internal voids and delaminations in stator coils and bars

Author

McDermid, W. ; Bromley, J.C.

Author_Institution

Manitoba Hydro, Winnipeg, Man., Canada

Volume

14

Issue

3

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

292

Lastpage

297

Abstract

Beginning in 1989 a partial discharge screening test was applied to stator coils and bars for which the measuring frequency bandwidth was approximately 8 MHz to 100 MHz. In this frequency range, the measurement is more sensitive to partial discharges in internal voids and delaminations than is the case for discharges associated with surface coatings. Recently changes have been made to the test circuit which have improved the repeatability of the measurement. Selection of the operating voltage for particular stator coils and bars based on their partial discharge screening test results may reduce the risk of future problems with the winding

Keywords

hydroelectric generators; insulation testing; machine insulation; machine testing; partial discharge measurement; stators; voids (solid); 8 to 100 MHz; delaminations; frequency range; hydrogenerator insulation breakdown testing; internal voids; measuring frequency bandwidth; operating voltage selection; partial discharge screening test; repeatability; stator bars; stator coils; test circuit; winding; Bandwidth; Bars; Circuit testing; Coils; Delamination; Frequency measurement; Partial discharge measurement; Partial discharges; Stators; Surface discharges;

fLanguage

English

Journal_Title

Energy Conversion, IEEE Transactions on

Publisher

ieee

ISSN

0885-8969

Type

jour

DOI

10.1109/60.790872

Filename

790872