A Master-Slave Collaborative Control Strategy of High Voltage DC Circuit Breakers

High voltage DC circuit breaker is the key equipment in DC grid since its rapid and reliable breaking is a critical precondition for safe and reliable operation of system. In the paper, breaking of hybrid high voltage DC circuit breaker is analyzed first. Then to solve the problem about response time and system reliability, a master-slave collaborative control strategy of high voltage DC circuit breaker is proposed, it regards the grid-level protection as master control, and the inner protection is slave control. Making full use of the advantages of both two controls, the breaking is rapid and reliable. What's more, DC circuit breaker could still cut off the fault current in case of malfunction of one of these two protection. Finally, the simulation results in PSCAD/EMTDC show that the proposed control strategy is correct and effective, it shortens the fault response time and improves system reliability.