A Bidirectional Efficient Circuit Breaker With Automatic and Controllable Shutoff Functions for DC Distribution Network

Compared with the solid-state circuit breakers based on insulated-gate bipolar transistor and MOSFET, circuit breakers based on thyristors have higher capacity and lower cost, which have been extensively studied. However, the existing circuit breakers based on thyristors cannot achieve fast and reliable shutoff of the fault current. Therefore, a novel efficient bidirectional circuit breaker is proposed in this article, which has the functions of automatic and controllable shutoff. In any current direction, only one thyristor is conductive, which eliminates unnecessary power losses. The automatic shutoff function can cut off the fault current independently without detection delay. The controllable shutoff function can isolate the fault reliably without being affected by the line inductance. The proposed topology integrates the advantages of high efficiency, fast reaction, and high reliability. Although the existing bidirectional circuit breakers based on thyristors may have one of these advantages, no circuit breaker integrates all of them. Finally, the proposed circuit breaker is verified through simulation and experiment at 1.2 kW.