Influence of Air Pressure on Surface Flashover

The surface flashover is one of the most important factors that limit the performance of electric devices. In this article, the processes of surface flashover under different pressures are observed by a high-speed camera, and the differences between the plasma evolution processes are presented. Moreover, the simulation model of surface flashover under atmospheric conditions is established by a particle-in-cell code with direct simulation Monte Carlo (PIC-DSMC) code. Compared to the results of vacuum surface flashover, the reasons that caused the differences of the plasma evolution on surface flashover between vacuum condition and atmospheric condition are discussed. It is found that the competition between gas discharge and surface flashover would become more notable with the increase of air pressure. The results would be helpful to further understand the mechanism of the surface flashover.