An Improved Method of Solid State Circuit Breaker in Low Voltage DC Microgrid

With the rapid development of DC microgrid, the speed and reliability of circuit breaker protection in DC distribution networks have become more and more important. The power electronic switching devices used in solid-state circuit breakers(SSCB) has low overvoltage and overcurrent margins. Therefore, suppressing the overvoltage of the power electronic switching device in the case of a short-circuit fault, and quickly consuming the energy in the faulty circuit has become an important content of snubber circuit design. This article analyzes the operating mechanism of traditional circuit breakers. Then, an improved design scheme of solid-state circuit breaker snubber circuit is proposed, and the design method of related parameters is given. Finally, the correctness and effectiveness of the proposed snubber circuit are verified by simulation and experiment result.