Bidirectional short circuit breaker for DC microgrid based on segmented current limiting solid state circuit breaker

Due to the fast development speed of the short-circuit fault in DC microgrid, which make traditional protection method cannot meet time requirement, a novel short-circuit current bidirectional blocking circuit topology based on segmented current limiting solid-state circuit breaker (SCLCB) is proposed. The main circuit uses two IGBTs connected in series module to realize double-conducting. A diode based full-bridge is used as blocking circuit to realize bidirectional blocking function, and a segmented resistor current limiting module is used to limit the rising rate of the fault current. The fault current is absorbed by blocking capacitor. The proposed DC blocking circuit can limit the fault current to a safe level in a very short time. The performance of the proposed blocking circuit is verified by saber simulation. The result shows that the blocking circuit can successfully limit the fault current within 6ms, and can suppress the turn-off overvoltage of main switch. The blocking circuit has good application prospects in DC microgrid protection.