Group-based Cooperative Control Strategy for AC Islanded MGs under Switching Communication Network

Abstract In this paper, a cooperative control strategy is presented to regulate frequency and voltage in AC islanded microgrids (MGs). The proposed method employs a two-level hierarchical communication network. The first network-level results in voltage and frequency regulation and precise active power-sharing in each group of distributed-generations (DGs) of an MG. The second network level is designed to achieve agreement among different MG groups to reach global stability. The controller considers switching topologies with time-varying links for both communication layers and the weakest connectivity for the MG network graph. The proposed strategy can intensely decrease high-bandwidth links, reduce total communication cost, improve system reliability, and enhance transient response. The proposed approach effectiveness is validated by the simulation of an AC test MG containing 9 DGs by MATLAB/Simulink under different scenarios.