Effects of High Magnetic Field on Partial Discharge and Dielectric Breakdown Behavior of Silicone Rubber

Abstract

In this article, space charge and partial discharge (PD) behavior and the breakdown strength of silicone rubber under ac and dc voltages are tested in high magnetic field. In the case of ac voltage, the effects of high magnetic field on promoting air gap breakdown result in the decrease in PD inception voltage. Polarization of specimens with higher speed and lower air gap breakdown voltage result in the increase in PD frequency and eventually causes the decrease in breakdown strength. In the case of dc voltage, energy level splitting due to Zeeman effects results in lower interface barrier, considering both the increase in electron affinity and the increase in density deference between donor-like and acceptor-like surface traps. The decrease in interface barrier causes more space charge injection. The electric field distortion caused by local space charge accumulation leads to the decrease in breakdown strength in high magnetic field.