Investigation of Surface Discharge on PE in Air and Nitrogen under Different Pressures Based on Pockel Effect

The influence of surface charge distribution on the development of surface discharge has gained great attention. In this paper, by applying two cycles of AC voltage on the needle plate electrode, the surface charge distribution under different gas pressures are obtained based on the surface charge measurement system. We found that with decreasing of the pressure, the length and radius of surface charge distribution have increased in air, and the discharge mode changes when the gas pressure is below a certain threshold in nitrogen. The polarity effect of surface discharge is observed and analyzed from the charge distribution. Electrons transport under different external environment is the main reason for the difference of surface charge distribution.