A Novel Integrated Hybrid DC Circuit Breaker with Controlled Oscillation for Zero-Crossing

The zero-crossing scheme with low loss and high reliability has gradually become the key to the successful fault removal of DC circuit breakers. However, existing solutions either achieve reliable zero-crossing at the cost of higher losses or create a finite number of zero-crossing points at the cost of a continuous oscillating arc. In this letter, A Novel Integrated Hybrid DC Circuit Breaker (AC-HCB) is proposed. It continuously generates multiple zero-crossing points without oscillation arcs by detecting fault currents in real time and controlling the dynamic casting of full-bridge modules, improving commutation reliability. The auxiliary transfer switch is integrated in the main circuit breaker for cost savings. As a result, AC-HCB can achieve cost-effective and reliable performance. The feasibility of the proposed topology is fully verified by the simulation analysis of 500kV/14kA PSCAD/EMTDC.