Title: Investigating The Impact Of Varying Pv Operating Power On Power Quality (Voltage And Current Harmonics)
Authors: Damfebo Franklin Ayebagbalinyo, Kemelayefa Kelvin Emiemokumor, Idongha Charles Godspower
Volume: 9
Issue: 12
Pages: 13-22
Publication Date: 2025/12/28
Abstract:
The increasing integration of photovoltaic (PV) systems into low-voltage distribution networks introduces harmonic distortions that affect overall power quality. This study investigates the impact of varying PV operating power on voltage and current harmonic distortions in a grid-connected PV system. The main objective is to analyze how changes in inverter loading influence total harmonic distortion (THD) levels under different operating conditions. A 3-kW grid-connected PV array was modeled and simulated using MATLAB/Simulink to evaluate system performance at half-rated (0.5P), rated (1P), and double-rated (2P) operating powers. The system includes a voltage-source inverter equipped with an LCL filter to ensure harmonic attenuation and smooth grid interfacing. Simulation results reveal that operating at reduced power (0.5P) increases current THD, while higher loading conditions (2P) significantly lower THD values. Specifically, increasing the inverter power from 0.5P to 2P resulted in approximately a 24% reduction in current THD, with voltage THD remaining within IEEE Std 519 permissible limits. The findings indicate that inverter loading and DC-link behavior substantially influence harmonic emissions. It is concluded that maintaining PV inverters near their optimal operating points and incorporating appropriate filtering or advanced control techniques can effectively enhance power quality and ensure compliance with grid standards.