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This paper proposes a ± 535 kV hybrid high voltage direct current (HVDC) circuit breaker. In this paper, the interruption processes of the main branch, transferring branch, and MOV (metal oxide varistors) branch are studied by PSCAD/EMTDC computer simulation. Simulation results indicate that an insulated gate bipolar transistor (IGBT) in the main branch will withstand the highest electrical stress (3305 V/2200 A) and the IGBT in the transferring branch will withstand the highest voltage stress (3327 V). Finally, the ± 535 kV hybrid HVDC circuit breaker prototype is manufactured; the test is carried out. Test results suggest that the ± 535 kV hybrid HVDC circuit breaker prototype developed for the Zhangbei four‐terminal voltage source converter (VSC)‐HVDC project can interrupt a ± 25 kA (high current) within 2.84 ms. The simulation results agreed very well with the actual test results of our novel ± 535 kV hybrid HVDC circuit breaker. The novel ± 535 kV hybrid HVDC circuit breaker functioned exceptionally well in achieving fast short‐circuit current isolation. [ABSTRACT FROM AUTHOR]

Series multi‐break mechanical switch is one of the critical components of high‐voltage hybrid DC circuit breakers. However, due to the existence of distributed capacitance, the voltage distribution between the breaks is not balanced. This paper proposed a voltage sharing configuration method of the mechanical switch of hybrid DC circuit breaker, and carried out the static DC voltage and the transient voltage distribution characteristics tests to verify its effectiveness. Considering the influence of whole structure of the circuit breaker, this paper established the electrostatic field model and circuit simulation model of a typical ±535‐kV hybrid DC circuit breaker. And it analyzed the influence of single break's opening fault, breaking open distance, and the shielding fitting on the voltage distribution characteristics of series six break mechanical switch. According to the simulation results based on the Zhangbei voltage source converter‐based high‐voltage direct current project type test parameters, the parameters design of the voltage sharing components of the mechanical switch are obtained, which can meet the voltage sharing coefficient requirement of 95%. [ABSTRACT FROM AUTHOR]