Self-tuning Fuzzy PID Controller Design and Energy Management in DC Microgrid: Standalone and Grid Connected Mode

Abstract

This paper presents a control system and energy management strategy (EMS) with a standalone and grid- connected mode in the microgrid. The microgrid is energized by distributed energy resources (DER) such as photovoltaic panels, wind turbines and lithium-ion batteries. The controller structure for regulating the voltage regulation in this microgrid consisting of renewable energy sources and an energy storage system is covered. Overshoot, rise time, settling time performances of designed self-tuning fuzzy proportional- integral-derivative (SFPID) controller and conventional proportional-integral-derivative (PID) controller examined comparatively. In addition, an EMS has been proposed for loads that fed in the microgrid. Here, the aim is to make maximum use of RESs as much as possible, maintain voltage regulation, and ensure continuity in the feeding of the critical load. The system switches between the standalone and grid- connected modes if necessary. A model of the microgrid's dynamic behavior is constructed, and it is simulated in the MATLAB®/Simulink environment. The proposed SFPID controller stabilizes the bus voltage and frequency oscillations within the allowable tolerance limits in a short time despite the disturbance effects on the generation and load side.