Arc Simulation of High Voltage DC Molded Case Circuit Breaker

With the increase of photovoltaic installed capacity, 1500V DC photovoltaic power generation system is widely used, and the photovoltaic power generation system in DC short-circuit fault is serious, and serious DC short circuit faults in PV power generation systems require DC molded case circuit breakers with high voltage rating and good breaking capacity for fault removal. Arc caused by contact separation affects breaking capacity of molded case circuit breaker. Therefore, a two-dimensional DC molded case circuit breaker model is established, and the dynamic characteristics of the arc are simulated and analyzed by the MHD model. The temperature and pressure distribution of the arc during the breaking process and the waveform of the arc voltage and current were obtained. The simulation results show that the utilization ratio of the arc extinguishing deion plate is low, and the waveform results show that the arc voltage is hypo, which makes the current drop slowly, resulting in a long arcing time, the contact of the circuit breaker is seriously ablated, and the service life is shortened. Therefore, the arc extinguishing ability of circuit breaker can be improved by permanent magnet or gas materials.