Breakdown of a Mixture of Silicone Oil and PE Powders in a Positive Point-to-Plane Electrode System

Abstract

The breakdown voltage, Vb, of silicone oil mixed with polyethylene (PE) powders was measured in a positive point-to-plane electrode system. In the dc case, Vb had a maximum value at a PE particle to silicone oil volume ratio of about 30%. The conduction current was larger in silicone oil than in the mixture; this could be explained by a smaller liquid flow in the latter. In the pulse test, using PE particles with a mean radius of 3 µm, Vb increased with increasing the ratio. A possible mechanism of the positive streamer is discussed with the help of a simplified model.