Development and test research of 10kv DC circuit breaker based on the principle of coupled negative voltage

With the increase of multi-terminal flexible DC distribution network projects, medium-voltage DC circuit breaker, as the key equipment to remove DC short-circuit fault, plays a key role in the operation reliability of the whole DC distribution network. In order to meet the engineering needs of DC distribution network, a 10kV hybrid DC circuit breaker based on the coupling negative voltage principle is developed in this paper. Firstly, the topology and working principle of the DC circuit breaker are introduced. Furthermore, the design scheme of key components including fast mechanical switch, power electronic switch and coupling negative voltage device is given. Finally, a 10kV hybrid DC circuit breaker prototype is developed and tested. The results show that the 10kV hybrid DC circuit breaker can break 15kA short circuit current within 2ms, and has the characteristics of low loss and high reliability.