Improved power management control strategy for renewable energy-based DC micro-grid with energy storage integration

This study presents an improved power management control strategy of a hybrid direct current (DC) micro-grid (MG) system consisting of photovoltaic cell, wind turbine generator, battery energy storage (BES), fuel cell (FC), and electrolyser. Based on the voltage and state of charge of BES, FC, and electrolyser, the proposed control scheme improved the dynamics of the DC-link voltage and contributes a better power management between each generation/source and load. A gain control technique is implemented in the grid-side inverter controller to regulate the modulation index and improving the voltage stability of the DC-link. Furthermore, the PI-controller gains of BES are tuned dynamically based on the deviation in voltage and its derivative using Takagi-Sugeno-fuzzy control to enhance the transient response of the voltage. For a reliable operation of the DC MG under standalone or prolonged islanding mode of operation, a priority-based load shedding algorithm is proposed for maintaining proper power coordination between different energy sources and storage devices. Owing to smoother and faster voltage response, the proposed control schemes can comply with the grid code requirements of the changing configuration of the modern renewable energy integrated DC MG. The effectiveness of the proposed control strategy is tested by comparing the existing scheme through MATLAB/SimulinkA (R).