Research on DC power flow controllable multi-port DC circuit breaker

Abstract

For the problem of fault isolation and power flow control in DC grid, this paper proposes a DC power flow controllable multi-port DC circuit breaker. Under the normal operation, this breaker has the function of DC power flow regulation, which is used to regulate the power flow on DC lines. After the DC system fails, this breaker is equivalent to the hybrid DC breaker, which is used to cut off the fault current and isolate the fault line. In the paper, the steady-state power flow regulation mechanism and transient current interrupting mechanism of the breaker are described in detail. Finally, a meshed DC grid is built in PSCAD/ EMTDC simulation platform. The simulation results show that the proposed topology has good performance in power flow control and current interrupting.