VOLUME 14, ISSUE 7, JULY 2026

Abstract: Power quality degradation caused by reactive power demand and harmonic distortion has become a major concern in modern electrical distribution systems with increasing penetration of nonlinear and inductive loads. This paper proposes a Static Synchronous Compensator (STATCOM) integrated with an LCL filter and a cascaded dq-axis PI control strategy to achieve effective reactive power compensation and dynamic power factor correction. The proposed controller employs a Synchronous Reference Frame Phase-Locked Loop (SRF-PLL) for accurate grid synchronization and decoupled active–reactive power regulation, ensuring stable operation under varying load conditions. The complete system is developed and validated in MATLAB/Simulink, where the LCL filter significantly suppresses switching harmonics while the PI controller provides fast transient response and robust DC-link voltage regulation. Simulation results demonstrate a substantial improvement in grid power factor from 0.894 (lagging) to unity, with load current and voltage THD values of 0.01% and 0.02%, respectively.The proposed STATCOM configuration exhibits excellent dynamic performance, superior power quality enhancement, and reliable reactive power compensation, making it a practical solution for modern industrial and utility distribution networks.

Keywords: STATCOM, Power Factor Correction, LCL Filter, PI Controller, dq-Frame, SRF-PLL, Reactive Power Compensation, VSC, FACTS, MATLAB/Simulink.