Electrical machine insulation: Partial discharges, consequences and diagnostic technique

Partial discharges (PDs) are a symptom and at the same time a result caused by the deterioration and the aging of the insulation of a rotating machine. Comments, regarding the usefulness as a fault diagnosis method, the hysteresis method presented in previous publications are offered in this paper. This method points out that the size of a curve and the area that the curve creates as PDs occur may vary and it could be an indicator of the insulation's deterioration, the existing defects and the PDs that have taken place over the years.