A Dual-capacitor converter-type hybrid DC circuit breaker with adaptive reclosing capability

DC circuit breakers are critical equipment for fault clearance in DC power systems. Existing circuit breakers suffer from high costs, limited current-limiting capabilities, and insufficient reliability. This paper proposes a dual-capacitor converter-based hybrid DC circuit breaker topology with adaptive reclosing capability. This topology incorporates current-limiting branches to suppress the rise of fault currents. Its adaptive reclosing capability enhances circuit breaker reliability, preventing erroneous reclosing. The proposed topology primarily employs thyristors, diodes, and conventional mechanical switches for transitions during fault clearance at various stages, eliminating the need for separate capacitor charging equipment or fully controllable devices, thus offering significant economic benefits. A single-terminal equivalent DC system and a four-terminal flexible DC transmission system model are established based on the PSCAD/EMTDC simulation software. Simulations are carried out in both the single-terminal equivalent DC system and the four-terminal flexible DC transmission system. The results demonstrate that the proposed circuit breaker exhibits certain advantages in terms of reliability and economy.