Simulation of breakdown mechanism in high-power spark gaps filled with nitrogen gas at atmospheric pressure

A comparative computational analysis of electrical breakdown is done by introducing imperfection or void in a dielectric inside a high-voltage cavity design with nitrogen as the background gas. The simulations have been carried out using 3D particle-in-cell tools. The partial discharge (PD) causes electric field strength variations along the dielectric and ionization of the gas inside the void that lead to breakdown of the gas and plasma formation with varied particle (ions and electrons) momenta within the dielectric. The PD effects in the dielectric rupture condition with an irregular void and fissure are compared with a smaller void enclosed by the dielectric. The charged particle dynamics in dielectric and its effect on the streamer present in the outside cavity are observed.