Power Quality Improvement by UPQC in Distribution System

Abstract — The quality of electrical power supply is adversely affected by the use of power electronic based equipment. Power quality problems raised are reduced by using Custom Power Devices (CPD).Unified Power Quality Conditioner (UPQC), is a device which allow the mitigation of voltage and current disturbances that could affect sensitive electrical loads. UPQC is a combination of Series Active Power Filter (APF) that compensates voltage harmonics of the power supply, and Shunt APF that compensates harmonic currents of a non-linear load. This paper presents realization of UPQC using PWM-VSI inverter in MATLAB/Simulink tool. A dqo transformation based PWM controller is used to derive gating pulses for the IGBT switch. Comparison of voltage and current level in different operating condition, along with the level of Total Harmonic Distortion (THD) with and without UPQC and faulted condition