PSO based power sharing scheme for an islanded DC microgrid system

This paper proposes a power sharing scheme for an Islanded DC microgrid with hybrid energy storage system (HESS). HESS comprises of battery and supercapacitor (SC), where the usage of supercapacitor reduces the current stresses on the battery. This scheme reduces the losses in the HESS interfacing converters along with State of Charge (SOC) balancing. To maintain a constant DC link voltage a DC link voltage controller is employed which is quick and has better regulation compared to droop controlled scheme. An objective function is formed by taking the power loss and SOC into consideration. A centralized controller is employed for sensing the battery's SOC and current demanded by DC link voltage controller. This centralized controller uses Particle Swarm Optimization (PSO) for solving the objective function and generate optimized coefficients which will share the power among the HESS interfacing converters. The proposed scheme is tested and validated using MATLAB based simulink environment.