Power Factor Improvement Using Grid-Connected Solar Photovoltaic Systems: An Approximate Real-World Analytical Study of an 11-kV Industrial Feeder

Abstract

This study evaluates the potential of a grid-connected solar photovoltaic (PV) system equipped with a smart inverter to improve power factor in electrical distribution networks. An approximate real-world analytical case study was developed for a balanced 11-kV industrial feeder, 8 km in length, supplying a 1,000-kW and 800-kVAr inductive load with an initial lagging power factor of 0.781. Four operating conditions were examined: the uncompensated base case, conventional capacitor-bank compensation, smart-inverter reactive-only compensation, and daytime smart-PV operation at 800 kW active output. The calculations show that improving power factor to 0.95 using a capacitor bank requires approximately 471 kVAr and reduces feeder current from 67.2 A to 55.2 A. Achieving a power factor of 0.98 through reactive-only inverter support requires approximately 597 kVAr. During daytime operation, a 1.2-MVA inverter producing 800 kW retains an estimated reactive capability of 894 kVAr, exceeding the approximately 759 kVAr required to maintain a 0.98 power factor at the point of common coupling. Under the stated feeder assumptions, the reactive-only smart-inverter case reduces approximate copper losses by 36.5%, while combined local PV generation and reactive compensation produce a substantially larger reduction in grid current and feeder losses. The results indicate that smart PV inverters can provide flexible, continuous power-factor correction and voltage support, while avoiding some limitations of mechanically switched capacitor banks. However, the numerical results are engineering estimates based on disclosed assumptions rather than field measurements or validated simulation outputs. The study therefore provides a transparent preliminary design framework that can be refined using measured load profiles and MATLAB/Simulink validation.