Fuzzy Logic for Energy Management in Hybrid Energy Storage Systems Integrated DC Microgrid

Abstract

The direct current (DC) systems have outstanding advantages compared to the alternating current (AC), especially when it comes to renewable energy resources (RER) and microgrids (MGs). Therefore, the DC microgrid (DCMG) has become popular and drawn the attention of researchers. Due to the integration of different power sources in the single DC bus, including solar photovoltaics (PV), wind farms, diesel generators, and energy storage systems, maintaining stable bus voltage requires a complicated control system to ensure a fast-decision-making procedure. This paper presents an energy management strategy for the DCMG using a fuzzy logic-based controller. The proposed DCMG uses a hybrid energy storage system (HESS) for energy balancing and a diesel generator as a backup. The proposed strategy uses generation and loads demand and battery state of charge (SoC) to control the power flow within the MG. The energy management system keeps the SoC in a suitable range to increase the battery life. By controlling the charging and discharging of the HESS, the proposed method has a fast response to the load variation and RER intermittency to prevent the fluctuation of the voltage level of the DC bus and keep it constant. The obtained results validate the efficacy of the proposed fuzzy logic controller.