1. Insulation problems in medium-voltage stator coils under fast repetitive voltage pulses
- Author
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Haq, Saeed Ul, Jayaram, Shesha H., and Cherney, Edward A.
- Subjects
Variable speed drives -- Design and construction ,Electric driving, Variable speed -- Design and construction ,Electric current converters -- Design and construction ,Induction electric motors -- Equipment and supplies ,Electric current converter ,Business ,Computers ,Electronics ,Electronics and electrical industries - 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 6 kVp and pulse switching frequencies up to 3 kHz in ambient temperatures of 23 [degrees]C, 120 [degrees]C, and 155 [degrees]C. 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. Index Terms--Adjustable-speed drives, converters, dielectric heating, groundwall insulation, induction motor, partial discharge (PD), pulse voltage, solid-state switches.
- Published
- 2008