绝缘材料对气固界面电荷积聚诱导沿面放电特性的影响

Gas-solid interface charge accumulation and the consequent decrease in surface flashover voltage have impeded the development of DC gas-insulated equipment. Investigation of the effect of insulating material on charge-induced surface discharges holds paramount importance in advancing high-performance insulation and enhancing the operational reliability of DC gas-insulated equipment. In this paper, an experimental platform for charge spot deposition and surface discharge is established. Then, the charge-induced surface discharge for three types of insulating materials, including polycarbonate (PC), polymethyl methacrylate (PMMA), and epoxy resin (EP) doped with Al₂O₃, are conducted. Additionally, the secondary electron emission yield (SEEY) and trap distribution of the insulating materials are measured, and the effect pattern and key factors of insulating materials on charge-induced surface discharges are obtained, along with the influence mechanism of microscopic parameters of insulating materials on surface discharge. The results indicate that the deposited positive charges inhibit the development of positive streamers, while deposited negative charges promote the development of positive streamers. Furthermore, the secondary electron emission yield of insulating materials mainly contributes to the residual charge density of streamer. As the trap energy level decreases, surface discharge in the insulating material becomes more likely. The sensitivity of streamer channels of insulation surface to the electric field is a crucial factor determining the effect of interface charges on surface discharge.