Simulation study on arc motion process of DC miniature circuit breakers

Abstract

Based on the theory of magnetohydrodynamics, a mathematical model of air arc in the arc extinguishing chamber of a DC miniature circuit breaker was established. By coupling external circuit characteristics and contact movement process, the motion process of the arc was simulated and analyzed. On this basis, the effects of breaking speed, time constant, and magnetic field on the arc motion characteristics were studied. The study showed that increasing the breaking speed appropriately and adding appropriate magnetic field can improve the breaking performance of DC miniature circuit breakers. The research results can provide reference for the optimization design of DC miniature circuit breakers.