Characteristics of Streamer Discharge in SF₆ Gas Under Different Pressures

SF6 is widely used in GIS equipment due to its good insulation properties and high chemical reliability. As a common form of gas discharge, streamer discharge can cause severe damage to the insulation performance. Therefore, the study of the discharge characteristics of streamers in SF6 gas has practical solid engineering value. There are significant differences in the streamer propagation process in SF6 gas with different pressures. Aiming at the influence of pressure on the characteristics of streamer discharge, this article establishes a simulation model of streamer discharge for SF6 gas based on numerical computation. It systematically studies the characteristics of streamer discharge in SF6 gas with different pressures. The results show that high-pressure SF6 gas is less likely to propagate the streamer because of the weaker ionization of particles in high-pressure SF6, leading to a reduction in the number of charged particles at the streamer head as well as a reduction in the strength of the electric field at the streamer head. In addition, the equations for the streamer steady propagation electric field and the diameter of the streamer channel as a function of pressure were fitted, respectively.