ADVANCED HARMONIC MITIGATION IN GRID-INTEGRATED SOLAR PV SYSTEMS USING FRACTIONAL ORDER NOTCH FILTER AND FLC

Abstract

The increasing penetration of grid-connected solar photovoltaic (PV) systems has introduced several power quality challenges in modern electrical power systems, including harmonic distortion, voltage fluctuations, reactive power imbalance, and poor power factor. Conventional notch filters and classical control techniques often exhibit limitations in dynamic performance and disturbance rejection under varying operating conditions. This paper proposes a Fractional Order Notch Filter (FONF) integrated with a Fuzzy Logic Controller (FLC) for enhancing the power quality performance of grid-connected solar PV systems. The proposed controller employs fractional calculus-based filtering to achieve superior harmonic attenuation and frequency selectivity, while the fuzzy logic controller provides adaptive control under uncertain environmental and load conditions. The grid-connected PV system consists of a photovoltaic array, DC-DC boost converter with maximum power point tracking (MPPT), voltage source inverter (VSI), and the proposed FONF-FLC control scheme. The performance of the proposed system is evaluated under various operating scenarios including irradiance variations, nonlinear loads, and grid disturbances. Simulation results demonstrate significant improvements in total harmonic distortion (THD), power factor correction, reactive power compensation, and grid current quality compared to conventional integer-order notch filter approaches. The proposed methodology satisfies IEEE-519 harmonic standards and provides enhanced stability and robustness for renewable energy integration.