A New Topology for Current-limiting Solid-state HVDC Circuit Breaker

Along with the further study of multi-terminal VSC-HVDC and HVDC Grid, as the key equipment, high voltage dc circuit breaker (DCCB) received great attention. Firstly, based on the comparison of the existing circuit breaker, a new topology for current-limiting HVDC circuit breaker was proposed in this paper. Secondly, the working principle of this breaker is analyzed. This topology allowing IGBT (insulation gate bipolar transistor) be used as main power switching devices. It has two operating modes: fault current limiting and circuit breaking, and has the advantages of lower power loss, large capability of turning off current, and high voltage level. The branches of this topology has the features of modularity, which can be flexibly configured to improve the breaking capacity and decrease the current density, and the directly parallel connection of the power switches could also be avoided. Finally, the topology is modeled in PSCAD/EMTDC, and the simulation result shows that the topology has good fault current limiting and circuit breaking performance. The reliability of the novel theory and the feasibility of the proposed topology is verified.