A Forced Resonant Low-Cost Multi-Port DC Circuit Breaker

Based on analyzing the disadvantages of the previous multi-port circuit breakers (MPDCCBs), this paper proposes a MPDCCB topology that utilizes a voltage source inverter to assist resonant current. The working principle of it has been analyzed. The injection current with gradually increasing amplitude is generated through the alternative conduction of IGBT, which is superimposed with the fault current to generate current zero crossing. The parameters of the proposed MPDCCB have been calculated. According to the design parameters, the circuit breaker has a current breaking capacity of 320kV/10kA. A simulation model has been established in PSCAD/EMTDC, and the proposed MPDCCB has been placed in a ± 320kV four-terminal DC grid for interruption simulation. The simulation results show that the proposed MPDCCB topology reliably isolates faults and keeps energy transmission during interruption. Compared to the existing multi-port circuit breakers, the proposed MPDCCB has high economic effectiveness, reducing costs by at least 45.3%.