抄録
The electrical insulating materials in motors are exposed to higher electric field in improving their performance such as high outputs and/or miniaturizations. Especially, the motor windings have the small gap at which partial discharge (PD) may occur under the high electric field and it can lead to dielectric degradation and breakdown. The actual power equipment is used under various environmental conditions. In actual case, PD may easily occur due to charge on the surface of the insulating parts. Therefore, it is important to clarify the partial discharge inception voltage (PDIV) characteristic at the small gap of the motor windings. In this study, we investigated the influence of surface charge on DC or AC partial discharge inception voltage in the insulation-air gap composite system.
