Novel Bidirectional Hybrid DC Circuit Breaker Topology using Current Fed Converter

This paper proposes a Direct Current (DC) circuit breaker based on a coupled inductor capable of interrupting a short circuit current in a few hundreds of microseconds. It consists of five MOSFETs, a unipolar capacitor, a mechanical circuit breaker, an inductor, and a coupled inductor. The proposed topology is a hybrid circuit breaker that provides arcless disruption of current in the primary circuit. The breaking operation is based on the current reflected in the primary winding from the auxiliary resonant circuit. In the proposed converter, the time for circuit breaking is decreased using a current fed high gain converter, which acts as a boost converter to charge the capacitor. The same switches used in the current fed converters are used in commutation; hence, fewer components are required. The switches are operated in such a manner that the capacitor's voltage profile is unipolar. The proposed converter topology can interrupt the short circuit current in either direction. A comprehensive analysis, along with validation results with the developed 1kV, 50A rated mechanical circuit breaker are presented.