Transient analysis for H-bridge type DC circuit breaker

The emerging use of dc power systems places a greater need for dc circuit breakers, an important part of system protection. Unlike with ac, for dc there is no inherent current-zero in the applied power to assist in the current interruption process. In this paper, a passive means to redirect the fault current to force a transient current reversal and a current zero in the switch element is analyzed. Passive inductance and capacitance elements are configured in an H-bridge structure that enables a solid-state thyristor SCR (or other switch element) within the bridge to open and achieve dc circuit breaker action. Time domain analysis with tests of this passive current-reversal H-bridge circuit breaker is presented along with a theoretical basis for breaker designs of this type. Results show this circuit can be designed to exhibit enhanced breaker performance with minimal component size and weight.