DC microgrid power coordination based on fuzzy logic control

Abstract

The power coordination in DC microgrids has a vital role in enhancing the performance and management of multi generation units. Renewable Energy Sources (RES) are limited to their available power with intermittent nature. Battery-based energy storage sources have limitations in the charging and discharging capabilities to avoid depleting the battery and preserve the State of Charge (SOC) within its satisfactory limits. The battery balances the power difference between RES and loads. However, in severe cases where the SOC is very low, load shedding is crucial. In this paper, a Fuzzy Logic Controller (FLC) has been proposed to coordinate the power flow of PV unit and battery to satisfy the load by full use of the available PV power. It controls the PV's output power and keeps the SOC and charging / discharging power of the battery within their required margins regardless of the variations in load. Furthermore, load shedding of low priority load has been implemented when the battery couldn't balance the microgrid power flow. Simplicity in managing multi input-multi output system by FLC is the main merit. Matlab/Simulink results are presented to validate the performance of the proposed controller.