A Topology of a Self-Charging Current-Limiting Hybrid DC Circuit Breaker

Hybrid DC circuit breakers are a crucial component of DC grids, used to achieve fault isolation on the DC side. However, most existing circuit breakers lack current-limiting capabilities and are costly. In response, this paper proposes a self-charging current-limiting hybrid DC circuit breaker topology, which has three operating modes that can flexibly respond to different abnormal conditions in DC grids. The proposed topology primarily uses thyristors to achieve fault current commutation, significantly reducing the usage of IGBTs and thereby lowering the cost of the circuit breaker. By incorporating inductance and grounding bypass, the energy dissipation in the circuit breaker’s surge arrester is significantly reduced, and the fault clearing speed is improved. Moreover, the paper provides a detailed analysis and theoretical derivation of the proposed topology’s working process, with simulation verification conducted in a single-ended equivalent grid environment based on PSCAD/EMTDC. Comparative analysis with existing typical circuit breakers through simulation demonstrates the feasibility of the proposed DC circuit breaker, showing optimized performance in various aspects and promising application prospects.