Abstract: This work deals with conceptual study of unified power quality conditioner (UPQC) during voltage sag and swell on the power network. Power quality has become an important factor in power systems, for consumer and household appliances with production of various electric and electronic equipment and computer systems. The main causes of a poor power quality are harmonic currents, poor power factor, supply voltage variations etc. The Unified Power Quality Conditioner (UPQC) is a custom power device, which diminishes voltage and current related power quality issues. It uses a PWM control for firing the circuit and provides six clock pulses for operating the IGBTs circuit. It also prevents load current harmonics from entering the utility and corrects the input power factor of the load. In this, a frequency of 50 Hz is used for Indian systems.

Keywords: UPQC, DSTATCOM, DVR, PWM Pulses etc.