Sliding Mode Control Scheme for Hybrid Energy Storage Technologies in a DC Microgrid

Intermittent nature of the renewable energy source i.e. photovoltaic leads to a demand of the battery energy storage system to sustain a continuous power supply for the load. However, the battery energy storage medium alone is not capable to meet the dynamic variation in the load demand. Therefore, there is a requirement for an additional energy storage medium i.e. supercapacitor (SC) that can handle the dynamic variation in the load demand. Further, the hybrid energy storage system (HESS) i.e. combination of battery and SC can provide the average and dynamic variation in the load demand, respectively. In this study, a sliding mode control (SMC) scheme is applied for controlling HESS in a photovoltaic-based microgrid. The SMC control strategy provides better power-sharing among the photovoltaic energy source, HESS and load. The simulation of microgrid is done using the MATLAB/Simulink tool. The simulation results with varying irradiance, and varying load demand verify this control strategy by maintaining the voltage of DC link constant at its nominal value.