Stabilization of DC Bus Voltage of an Isolated DC Microgrid

This paper deals with the robust control strategy used for the isolated DC microgrid. The DC microgrid considered here comprises a solar photo voltaic (PV) source, biomass, biogas, energy storage, and mixed loads. An observer based sliding mode controller is designed for biomass and biogas systems. The salient feature of a sliding mode controller is that it has a proportional integral sliding surface, due to which it can properly regulate the DC bus voltage irrespective of the disturbances caused by change in load. In order to integrate energy storage systems, a cascaded hybrid proportional integral Lypanov stability-based controller is designed, which ensures the global asymptotic stability of the closed loop system. This controller has better performance and faster response, irrespective of the presence of mixed loads. The effectiveness of controller is explored by simulation using MATLAB/Simulink.