基于PIC-MCC方法真空直流断路器弧后金属蒸气击穿过程分析

For the vacuum DC circuit breaker, the process of dielectric recovery after arc is an important physical process to determine whether the breaking is successful or not, thus it has been widely concerned by researchers. The main purpose of this paper is to study the development process and influencing factors of the breakdown stage of metal vapor in vacuum circuit breaker by particle simulation. Based on the Particle in Cell-Monte Carlo Collisions (PIC-MCC) method, a model of metal vapor breakdown after arc is established, and the development process of metal vapor breakdown is simulated in two-dimensional space and three-dimensional velocity. Then, the influences of some important factors, such as contact surface temperature, metal vapor density, contact distance, and voltage on breakdown are discussed. The simulation results show that, in a certain range, increasing the density of metal vapor, the breakdown occurs more rapidly; the higher the contact temperature is, the more prone to occur the breakdown is; the higher the peak value of transient recovery voltage is, the faster the breakdown occurs. In addition, when the field strength is constant, the breakdown is not easy to occur for a small opening distance, and when the opening distance is large, the breakdown time is hardly affected by the contact distance.