A New Energy Management Strategy Based on Fuzzy Logic and Law for Hybrid Energy Storage System in DC Microgrid

Energy management between renewable energy sources and energy storage systems is challenging especially in different operating modes in stand-alone DC microgrid. In this paper, a new energy management system strategy based on law and fuzzy logic is proposed for a stand-alone DC microgrid with hybrid energy storage system (HESS) consisting of battery and supercapacitor (SC). The design of the proposed system is simple and does not require the mathematical model of the system. The main advantages of the proposed strategy are: high DC link voltage reference tracking in the presence of source and load power disturbances, keeping the battery and supercapacitor charge level within the permissible range, preventing battery and supercapacitor from overcharge/discharge and controlling the battery charging/discharging rate. Moreover, the proposed strategy increases battery life span while decreasing its current stress by using high charge/discharge cycles in SC and providing the majority of the output current through it. The proposed technique has been simulated in MATLAB and results show the priority of this method from the abovementioned points of view.