The control and protection technology of DC system with clearing short-circuit fault and improving power supply reliability as the objective is one of the key technology to develop new power system. The hybrid DC circuit breaker based on semiconductor components has been applied for the pilot project as the core component. In order to solve the problems of high cost and reliability in operation

a new combined DC circuit breaker system topology is proposed in this paper

the circuit breaker in the conventional DC branch system is replaced by the mechanical switch. It can greatly reduce the overall cost and failure rate. The opening speed of the fast DC circuit breaker based on the converter principle can meet the development of fault current and is expected to be used directly for the control and protection of DC system. The software platform with the supervisory control and data acquisition (SCADA) concept of AC distribution automation is tried to be rebuilt to innovate the topology of DC distribution system and give a better choice for distributed multi energy intelligent networking with higher reliability and economic advantages.