Research on a New Type of Low Loss Low-Voltage DC Circuit Breaker

With the rapid development of low-voltage DC systems, higher requirements have been put forward for the breaking performance of traditional hybrid DC circuit breakers. To improve its breaking capacity and speed, this paper proposes a new type of low loss low-voltage DC circuit breaker (DCCB). The MOSFET converter switch (MCS) is an important component, which establishes a low loss conduction path for load current and can achieve bidirectional current flow. Due to the low conduction voltage drop of MOSFET, it can be naturally cooled without the need for water cooling, effectively reducing the size of circuit breakers and lowering costs. Through the cooperation of power electronic devices, the fault current can be quickly transferred. Thus, ensure the reliable shutdown of the circuit breaker. In addition, a new type of controllable MOV has been proposed, which can effectively reduce the peak voltage of IGBT in the transfer branch and improve the voltage utilization efficiency of IGBT. Ultimately, the simulation model of the DC system and the new designed DCCB have been established by PSCAD/EMTDC to validate the feasibility of the proposed scheme. This work provides a solid theoretical foundation for the development of more efficient and reliable DC power systems.