Inverter-based distributed generation (IBDG) supply is widely used in microgrid for its ability to control and convert electrical energy well. In this paper, IBDG is equivalent to DC voltage source, and inverter control adopts double closed-loop control strategy for grid connection control. The outer ring is a voltage loop, which is mainly for the input voltage of the inverter, and is controlled to maintain stability; The inner ring is a current loop, whose main goal is to control the output current of the inverter to be in phase with the grid voltage. The inverter model is built in the PSCAD/EMTDC, and the effectiveness of the proposed inverter control strategy is verified by setting the load switching. The simulation operation shows that the output of the inverter with double closed-loop control strategy in the case of load change is still consistent with the set expectations.

Keywords： micro-grid ; inverter-based distributed generation (IBDG) ; double closed-loop control