Reduction of THD and Power Quality Improvement by using 48-pulse GTO-based UPFC in the Transmission Systems

This paper presents a 48 Pulse GTO-based Unified Power Flow Controller (UPFC) for power quality development in the Transmission system. It consists of a shunt converter which is operating as a Static Synchronous Compensator (STATCOM) to control the voltage at the source side and a Series converter which is operating as a Static Synchronous Series Capacitor (SSSC) to control the injected voltage and reactive power at the load side. This paper proposed Synchronous Reference Theory (SRF) based Phase locked loop for controlling the voltage at the source site. The Total Harmonic Distortion (THD) with UPFC resulted inside 43.93% and without UPFC resulted in 1.81% as per IEEE 519 standards. The results were simulated in MATLAB/SIMULINK.