Electric Field Simulation of 252 kV Arc Extinguishing Chamber Under Different Short-Circuit Breaking Modes

With the improvement of voltage level and system capacity, the power system puts forward higher requirements for the insulation performance of high-voltage switchgear. Uneven potential distribution or high field strength under different short-circuit breaking modes of circuit breakers may lead to partial discharge, resulting in breaking failure and serious consequences. Therefore, it is necessary to study the electric field distribution characteristics and its influencing factors under different short-circuit breaking modes of circuit breakers. In this paper, COMSOL Multiphysics simulation software is selected to establish the electric field simulation model, and the 252 kV circuit breaker is calculated and analyzed. The simulation results show that the maximum electric field intensity of the interrupter is always concentrated at the edge of the moving contact, and its value increases with the increase of transient recovery voltage. The uneven coefficient of electric field under all working conditions is 2.48, which is a slightly uneven electric field and meets the insulation requirements. By optimizing the structure of moving contact, the maximum field strength can be reduced by 4.30%. The research results provide a theoretical basis for insulation structure optimization and breaking reliability improvement under high TRV conditions, and verify the effectiveness of finite element simulation in insulation design of high voltage equipment.