Optimization of energy management in Malaysian microgrids using fuzzy logic-based EMS scheduling controller

Area of Science:

• Electrical Engineering
• Renewable Energy Systems
• Control Systems

Background:

• Microgrids (MGs) face security challenges due to bidirectional power and data flow.
• Integrating renewable energy sources and managing fluctuating demand requires sophisticated energy management.

Purpose of the Study:

• To design and assess a Fuzzy Logic Controller (FLC) for an Energy Management System (EMS) in Malaysian microgrids.
• To evaluate the FLC's effectiveness in balancing energy supply and demand considering renewable intermittency and load variations.
• To compare FLC performance against a Proportional-Integral Controller (PIC) regarding battery State of Charge (SoC) and grid current Total Harmonic Distortion (THD).

Main Methods:

• A microgrid model comprising Photovoltaic (PV) systems, battery storage, grid connection, and loads was developed in MATLAB/Simulink.
• A Fuzzy Logic Controller (FLC) was designed for the EMS, incorporating a Maximum Power Point Tracking (MPPT) controller for PV optimization.
• System performance was analyzed by monitoring battery SoC, source power output, and grid current THD, comparing FLC with PIC.

Main Results:

• FLC demonstrated superior control over battery SoC, effectively preventing overcharging (above 80% SoC) and over-discharging (below 20% SoC).
• While PIC reduced THD, FLC's primary strength was in managing battery charge states, ensuring system longevity.
• Both FLC and PIC-based EMS achieved grid current THD below 5%, adhering to IEEE 519 standards.

Conclusions:

• FLC is a viable and effective solution for managing energy scheduling in microgrids with intermittent renewables and variable loads.
• FLC's robust SoC control is critical for optimizing microgrid performance and ensuring the reliability of battery energy storage.
• The study confirms the potential of FLC in enhancing microgrid stability and efficiency while meeting harmonic standards.