Coordinated Control of Battery Energy Storage System Based on Fuzzy Logic for Microgrid with Modified AC Coupling Configuration

Microgrid systems are an excellent solution to increasing demand for electricity and are a great way to incorporate renewable energy sources into the electrical energy distribution system. To overcome the fluctuation of renewable energy (PV) based generation, an energy storage system using a battery (BESS) can be used. This paper proposes power management with a modified AC coupling configuration, and a BESS coordinated control strategy based on fuzzy logic. The AC coupling configuration in the microgrid system generally uses batteries to store excesspower from the PV. In the proposed AC coupling configuration, two batteries are used, battery 1 (BESS 1) is used to store excess power of the PV array 1 (PVA1) via the inverter battery, while battery 2 (BESS 2) is used to store energy from the PV array 2 (PVA2) ). In this microgrid system, PVA1 is connected to the network, so that the power generated by PVA1 is sent to the AC bus grid using a solar inverter. For two-way power flow on the grid and BESS, inverter batteries are used. The main focus of this article is the analysis of the impact of fuzzy logic (FLC) control strategy and PI control on BESS. When the PV is connected to the grid, control fuzzy logic (FLC) produces an overshoot of 4.73% and a settling time of 14.04 seconds lower than the PI control, overshoot 55.14% and settling time 26.29 seconds. The THD of the voltage and current in this mode is 0.06% and 11.08%. When the microgrid is in island mode, FLC produces an overshoot of 0.54% and a settling time of 13.78, while control PI produces an overshoot of 68.78% and a settling time of 38.11 seconds. The THD of voltage and current in island mode are 0.8% and 11.35%. Therefore, modified AC coupling configuration with fuzzy logic control (FLC) strategy can be used to serve residential loads.