Interaction of Partial Discharge in Air with Silicone Rubber

Partial discharge is one of the important factors to affect the long-term reliability of polymer insulators. This paper reports the surface degradation of five kinds of silicone rubber sheets caused by partial discharge. Samples were subjected to partial discharge for 8 hours and then voltage application was interrupted for 16 hours for recovery of hydrophobicity. The 24hour cycle was repeated 72 or 100 times. As indexes to characterize the partial discharge deterioration, the contact angle and surface erosion of samples were evaluated. It was confirmed that the sample without alumina trihydrate had the highest resistance to partial discharge degradation.