Harmonic analysis and Power factor improvement with UPQC under two Novel control strategies

This paper presents unified power quality conditioner (UPQC)for power quality improvements in terms of\ud harmonics compensation and power factor correction in a three-phase four-wire distribution system.The UPQC\ud is implemented with PWM controlled voltage source converter (VSC) and switching patterns are generated\ud through Indirect PI and Synchronous Reference Frame controller. The selected topology for voltage source\ud converter is the three-leg and six-leg VSC for Indirect PI and Synchronous reference frame (SRF) control\ud strategies respectively. The behavior of UPQC has been analyzed by considering a case study with switching of\ud three phase half bridge diode rectifier and a parallel star connected unbalanced R-L loads. Harmonic spectrum\ud of the source current and load voltage are compared in between without UPQC and with UPQC by considering\ud both control strategies. The complete system has been modeled using MATLAB software with its stimulus’s\ud sim power system toolboxes