A Single-Stage Grid-tied SPV System Using Fractional Order LMF Control for Power Quality Enhancement Under Nonlinear Load Conditions

Abstract

This work introduces a single-stage gridintegrated solar photovoltaic system (GISPV) governed by a fractional-order control approach developed using the LeastMean Fourth (FOPI-LMF) algorithm. The proposed configuration integrates a PV array with a voltage source converter (VSC) connected to a three-phase utility grid supplying nonlinear loads. The VSC operates as a multifunctional interface, delivering real power from the PV source while simultaneously compensating reactive power and suppressing current harmonics. As a result, grid current quality is enhanced, and harmonic levels are maintained within IEEE519 limits, even under distorted load conditions. To obtain the maximum power output from the photovoltaic system (PVS), the optimal operating voltage is identified using an Incremental Conductance (InC) based maximum power point tracking (MPPT) technique. The coordinated operation of the MPPT scheme and the fractional-order adaptive controller improves dynamic performance, DC-link voltage stability, and overall system robustness. Through comprehensive MATLAB/Simulink simulation studies conducted under varying irradiation levels and load conditions, the effectiveness of the proposed control strategy is validated, demonstrating consistent performance, improved power quality, and stable interaction with the utility grid.