Abstract:A hierarchical coordinated control strategy is proposed for island AC/DC hybrid microgrids. First, the underlying control of a Dispatched Distributed Generation (DPDG) unit and an energy storage unit is designed to adjust the frequency of an AC subgrid and the voltage of a DC subgrid and ensure the independent and stable operation of both subgrids. At the same time, considering the influence of the Constant Power Load (CPL) on the DC subgrid, an improved droop control using P-V2 is designed to reduce the voltage deviation caused by traditional droop control. Considering the different charge or discharge capacity of each energy storage unit, the dynamic consistent equilibrium control strategy based on SOC is constructed to ensure the optimal operation of the storage subgrid. Based on the DC subgrid voltage and the AC subgrid frequency signals, it constructs a three-level control switching strategy of power autonomous level, power mutual aid level and energy storage balance level, so as to realize power mutual assistance among subgrids effectively and minimize the power loss of the system. Finally, a hybrid microgrid simulation model is built through Matlab/Simulink to verify the proposed control strategy. This work is supported by the National Natural Science Foundation of China (No. 61873159), Shanghai Science and Technology Commission (No. 18020500700), Shanghai Engineering Research Center of Green Energy Grid-Connected Technology (No. 13DZ2251900) and "Electrical Engineering" Shanghai Key Laboratory of Power Station Automation Technology of Class II Plateau Discipline.