Research on a Hybrid DC Circuit Breaker with Multi-stage Capacitor Commutation

With the widespread application of high-voltage direct current (HVDC) transmission systems in power grids, the need for fast and safe interruption of fault currents has become an urgent technical challenge. This paper proposes a hybrid DC circuit breaker based on multi-level capacitive commutation, which optimizes the interruption performance under various fault current conditions by paralleling different capacitor commutation branches. Through a graded capacitor design, the method enables rapid commutation and interruption under both high and low fault currents, effectively reducing interruption time. Simulation results validate the superior performance of this approach under different fault conditions, providing theoretical support for building a more efficient and reliable DC power system.