ADAPTIVE FUZZY-ENHANCED HARMONIC MITIGATION IN HYBRID AC/DC MICROGRIDS: A NOVEL CONTROL FRAMEWORK FOR POWER QUALITY IMPROVEMENT

Abstract

Hybrid AC/DC microgrids have emerged as a promising solution for integrating renewable energy sources (RES) such as wind and solar power with distributed energy storage systems. However, the intermittent nature of RES and the nonlinear behavior of power electronic converters often lead to harmonic distortions, voltage fluctuations, and frequency instability, which degrade overall power quality. Traditional controllers, such as PI-based schemes, are limited in handling dynamic uncertainties and nonlinearities, resulting in poor harmonic suppression under varying operating conditions. This study investigates the application of optimized fuzzy logic controllers as a complementary control layer for distributed generation units in hybrid microgrids. The proposed fuzzy-based approach adaptively tunes control parameters to minimize total harmonic distortion (THD) in both voltage and current waveforms while simultaneously improving load frequency control. Simulation results conducted on a standard IEEE 9-bus test system demonstrate that the fuzzy controller significantly reduces harmonic content compared to conventional PI control, enhances voltage stability, and ensures faster frequency recovery during disturbances. The findings highlight the effectiveness of fuzzy logic in improving power quality and reliability in hybrid microgrids, making it a viable solution for future smart energy systems.