Insulation Problems in Medium-Voltage Stator Coils Under Fast Repetitive Voltage Pulses

Author

Haq, Saeed Ul ; Jayaram, Shesha H. ; Cherney, Edward A.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Waterloo, Toronto, ON

Volume

44

Issue

4

fYear

2008

Firstpage

1004

Lastpage

1012

Abstract

In this paper, the degradation processes in stator-bar groundwall insulation that is subjected to steep-front voltage pulses, at different temperatures, are studied. The test conditions include pulse voltage amplitudes up to 6kV_p and pulse switching frequencies up to 3 kHz in ambient temperatures of 23degC , 120degC , and 155degC . During the aging process, the surface temperature is monitored with an infrared camera to determine the regions with highest temperatures and the partial discharge (PD) activity. The visual examination of failed bars confirmed that the groundwall insulation in these regions is degraded.

Keywords

ageing; induction motors; insulation testing; machine insulation; machine testing; monitoring; partial discharges; stators; aging process; degradation process; fast repetitive steep-front voltage pulse; groundwall insulation test; induction motor; infrared camera; medium-voltage stator coils; partial discharge; surface temperature monitoring; temperature 120 C; temperature 155 C; temperature 23 C; Aging; Coils; Degradation; Insulation; Medium voltage; Partial discharges; Stators; Switching frequency; Temperature; Testing; Adjustable-speed drives; converters; dielectric heating; groundwall insulation; induction motor; partial discharge (PD); pulse voltage; solid-state switches;

fLanguage

English

Journal_Title

Industry Applications, IEEE Transactions on

Publisher

ieee

ISSN

0093-9994

Type

jour

DOI

10.1109/TIA.2008.926305

Filename

4578787