Multi-Port Hybrid DC Circuit Breaker for DC Distribution Network

The two-port hybrid DC circuit breaker (TP-HCB) combines the advantages of mechanical DC circuit breaker (DCCB) and solid-state DCCB, which has small loss during normal operation and fast action speed. However, the TP-HCB contains many IGBTs to withstand transient breaking voltage, therefore the total cost of TP-HCB is relatively high. In order to solve this problem, a new multi-port hybrid DC circuit breaker (MP-HCB) topology is proposed in this paper, the cost of which is much smaller than the total cost of separated TP-HCBs configured on each line connected to the DC bus. The control strategies of the MP-HCB in line fault, bus fault and fast-mechanical switch (FMS) failure are analyzed. The simulation results verify the feasibility of the proposed topology.