A Hierarchical Control Strategy for Isolated Microgrid with Energy Storage

Aiming at the problems of large frequency fluctuation, poor power supply reliability, and low energy efficiency in the operation of island microgrid, combining the advantages of master-slave control and peer-to-peer control, a hierarchical control based on coordinated control of grid-forming supply is proposed. The battery energy storage system (BESS) and fuel cell (FC) are controlled grid-forming supply, which adopts V/f control and virtual synchronous generator control respectively, and other distributed energy resources (DER) adopt PQ control as the grid-following supply. In the coordination algorithm, the state of charge (SOC) is used as the reference for the power regulation of the fuel cell, and the power differential term is introduced to improve the dynamic regulation performance to achieve the weak communication coordination between BESS and FC. MATLAB/Simulink simulation results show that the proposed method is correct and effective.