Impact of STATCOM on Voltage Regulation and Total Harmonic Voltage Distortion in Low Load Conditions

The operation of a STATCOM in regulating voltage levels and filtering harmonics under different load conditions is investigated. Utilizing a three-phase bridge for voltage regulation at the point of common coupling (PCC), the STATCOM is tested with six resistive and inductive load combinations across five load levels. Experimental results show that the STATCOM maintains a voltage deviation within 5% of the 380 V reference for most loads and achieves a harmonic filtering efficiency ranging from 1.39% to 72.67%. However, at higher loads, the STATCOM's performance diminishes as the loads exceed its power compensation capacity, resulting in a slight increase in system harmonics distortion compared to the significant drop in voltage, which has a greater impact on the electrical system. The STATCOM's control system, based on feedback loops, optimizes active and reactive power flow, ensuring effective voltage regulation and harmonic suppression. As a Flexible AC Transmission System (FACTS) device, STATCOM enhances voltage stability while mitigating harmonic distortion in the electrical system.