The DC circuit breaker with necessary bidirectional interruption capability

The HVDC technologies have become a promising solution for the future power grid, and DC circuit breaker (DCCB) is designed and tested to protect HVDC networks. Although there are several types of DCCB, they are basically designed for interrupting fault current in one direction. It has been noticed that capability of bidirectional interruption is necessary. Two possible bidirectional designs are demonstrated in this paper. In addition, installing DC capacitor at DC side of a VSC can lower the requirement of the DCCB due to the resonant current caused by this capacitor and the current limiting reactor in a DCCB. The simulation on PSCAD/EMTDC verifies the effectiveness of the proposed methods.