Comparative Analysis of STATCOM and DPFC for Power Quality Improvement under Unbalanced, Balanced and Dynamic Load Conditions

This research compares a Static Synchronous Compensator (STATCOM) and a Distributed Power Flow Controller (DPFC) in a grid-tied system to improve power quality. A voltage source inverter (VSI) serves as the primary interface in the grid-connected system. With the growing use of sensitive and floating loads, power quality issues such voltage sags and swells, harmonic distortion, and power oscillations have become crucial. Traditional compensation methods using reactive components like shunt/series reactors and capacitors often lead to drawbacks such as synchronous resonance. Flexible AC Transmission System (FACTS) that address these restrictions, enhancing condition of power and maintain quality standards. Among the many FACTS controllers, static synchronous compensator (STATCOM) and distributed power flow controller (DPFC) are extensively utilized for their capacity to manage voltage and enhance power flow. This study examines the effects of incorporating these devices into a grid-tied system under three distinct operating conditions: unbalanced load, balanced load, and dynamic load variation. The usefulness of both STATCOM and DPFC is assessed for voltage regulation, current waveform quality at the grid and load interfaces, response to voltage fluctuations, and Total Harmonic Distortion (THD). The MATLAB/SIMULINK environment, providing a distinct comparative context for evaluating the efficacy of each device.