A novel bidirectional Z-source DC circuit breaker for DC microgrids

A novel bidirectional dc circuit breaker topology is investigated for operation in dc microgrids to help in protection schemes against short circuit faults. When a short-circuit fault occurs, the proposed topology utilizes a Z-source breaker circuit to naturally commutate off the SCR by diverting the current and reducing the current to zero through the SCR, thus avoiding circuit breaking under high current conditions. As compared to existing unidirectional dc circuit breakers, the proposed bidirectional z-source breaker works in applications that require bi-directional power flow between different nodes of microgrids. The analysis, operation and simulation of the new bi-directional breaker topology is presented. The results are obtained for comparative analysis through simulation and validated through hardware testing in the lab.