Enhancing Power Quality in PV-Integrated Systems: A Hybrid Adaptive Approach for Current Harmonics Extraction in Four-Wire SAPFs

This paper presents a simulation-based analysis of a four-wire, three-phase photovoltaic (PV) Shunt Active Power Filter (SAPF) designed to mitigate harmonic distortion and improve power quality. Implemented in MATLAB-Simulink, the system employs an adaptive harmonic cancellation algorithm based on the Widrow-Hoff ADALINE method for harmonic identification. Simulation results confirm its effectiveness in reducing Total Harmonic Distortion (THD) under fluctuating irradiance and unbalanced nonlinear loads, outperforming the conventional Adaptive LMS (Direct ADALINE) method. The proposed SAPF maintained sinusoidal, balanced source currents with minimal voltage overshoot and a near-unity power factor. Harmonic suppression was highly effective, keeping THD below 4% and reducing dominant 3rd, 5th, and 7th-order harmonics to under 1%, even under severe load imbalances and low irradiance. Additionally, stable DC link voltage ensured reliable compensation of reactive and neutral currents. These findings highlight the system’s potential to enhance grid stability, support renewable energy integration, and offer a scalable solution for modern power systems.