A Novel Hybrid DC Circuit Breaker Topology with Current Limiting Capability and Rapid Fault Isolation Time

When fault currents in Modular Multilevel Converter High Voltage Direct Current (MMC-HVDC) transmission systems rise too rapid, the DC circuit breakers (DCCBs) often have insufficient capacity. Therefore, this paper proposes a current-limited hybrid DC circuit breaker (CL-HCB) with fault current limiting and fast fault isolation of the dc grid to reduce the capacity requirement of the DCCB. The topology of the proposed CL-HCB discusses the operation process, metal-oxide arrester (MOA) properties, and parameter design. Besides, the energy dissipation circuit (EDC) is parallel to reduce the energy dissipation in MOA and decrease fault isolation time (FIT), which could reduce the thermal effects of the MOA and improve its reliability. Extensive simulation results verify the working principle and advantages of the proposed CL-HCB. Compared to conventional HCB under the same simulation parameters, the proposed CL-HCB has more advantages in limiting fault current and fault isolation.