Technology and application of operation control of DC distribution network

DC distribution network consists of distributed generation, energy storage, load and AC distribution network, With the rapid development of DC distribution network and the increasing proportion of DC load, the operation mode of DC distribution network is more flexible. Different from the traditional AC distribution network, the traditional AC distribution network has a single operation mode, while the DC distribution network can operate in both parallel mode and island mode. Therefore, a control method suitable for different operation modes of DC distribution network is urgently needed. In this paper, a control method about loop closing and loop opening of DC distribution network is proposed. When receiving the command of loop closing or loop opening from the master station or local monitoring system, the loop closing control is judged by the switch state, fault state and operation state of converter. It solves the problem that the traditional AC distribution network control strategy is not applicable in DC distribution network, it realizes the smooth switching of DC distribution network closed loop operation and opened loop operation. This method has been used in the DC coordinated control device and successfully applied in the national key research and development plan of Suzhou active distribution network.