Nonlinear Robust Voltage Regulation and Balanced Demand Response of an Islanded DC Microgrid

Robust voltage regulation and balanced demand response of the islanded DC microgrids (MGs) in the presence of variable loads and different solar irradiations have gained increasing interest in recent years. To achieve these objectives, a nonlinear robust cascaded voltage controller comprised of proportional integral (PI) and sliding mode control (SMC) methods is proposed for the battery energy storage system (BESS) in this paper. A backstepping sliding mode control (BSMC) is also investigated for maximum power point tracking (MPPT) of the solar array. The efficient performance of the proposed nonlinear control approach is analyzed by MATLAB/Simulink. The simulation results demonstrate robust voltage regulation of DC bus with minor tracking error and fast response against load demand and irradiance variations in addition to ensuring the balanced demand response of DC MG.