(1. School of Electrical Engineering, Southeast University, Nanjing 210096, China; 2. State Grid Jiangsu Electric Power Maintenance Branch Company, Nanjing 211102, China; 3. State Grid Nanjing Power Supply Company, Nanjing 210019, China)

Two control objectives in DC microgrids are to maintain the stability of voltage and proportional power sharing. While there is an internal trade-off between voltage regulation and power sharing in the conventional droop control, and centralized control is excessively dependent on the central controller. A finite-time consensus based distributed cooperative control is proposed for DC microgrids. On the basis of the droop control, a distributed secondary control is introduced, which includes a current correct control and a voltage regulate control. The strategy is based on the multi-agent system and its distributed interaction protocol. Each DG agent only interchanges output current information with its neighbors. Proportional power sharing is achieved through a finite-time consensus protocol. The voltage is regulated by using the average current. The proposed control scheme is implemented in the fully distributed manner, can meet the requirements of plug and play, and the finite-time consensus algorithm has a better convergence performance. To verify the effectiveness of the scheme, a detailed model of DC microgrid is built in PSCAD/EMTDC. Simulation results indicate that the proposed scheme can effectively achieve the control objectives of voltage regulation and proportional power sharing in DC microgrids. This work is supported by National Natural Science Foundation of China(No. 51477029)and National Key Research and Development Program of China(No. 2016YFB0900404).