Voltage Control of Islanded DC Microgrid Using Hierarchical Controllers Based on Kharitonov Theory

In this paper, a new hierarchical robust control approach based on decentralized and distributed schemes is proposed for voltage regulation and power sharing in islanded DC microgrids. In this method, using a decentralized robust PI control structure, the primary voltage control loop is designed based on Kharitonov’s theorem to be robust against uncertainties and disturbances. Then, using a distributed PI robust control, the voltage deviation caused by the droop control is compensated. The simulation results show the effectiveness of the proposed controller under different disturbances by using the MATLAB/SimPowerSystems toolbox. In addition, the proposed controller can increase microgrid reliability due to exchanging low data volume in communication channels.