Dynamic current sharing, voltage and SOC regulation for HESS based DC microgrid using CPISMC technique

To cope with uncertainties and intermittent nature of renewable energy resources (RER) such as wind energy and PV needed energy storage systems with higher reliable and robust control techniques. Because of the variable characters of RER to maintain the power demand and generation, voltage stability and also increase the energy storage system lifetime is a challenging task. Therefore, in this paper, a combined PI and sliding mode control technique (CPISMC) is proposed to improve the current sharing between battery and supercapacitor to suit the demand- generation disparity, maintain SOC within boundaries and thereby to regulate the dc bus voltage. The key benefits are that, in the proposed strategy, unwaged battery currents are redirected to the supercapacitor forward with high-frequency current elements resulting in improved battery life. The effectiveness of the proposed control strategy has been investigated through simulations including comparison with conventional control strategy. The advantage of the proposed control strategy over existing conventional control strategy are better dc bus voltage regulation, improved current-sharing among HESS and improved battery life. The results have been experimentally validated through hardware-in -loop (HIL) on FPGA-based real-time simulator.