UPQC: A Custom Power Device for Power Quality Improvement

Abstract Power Quality (PQ) has increased concern amongst utilities at all levels of usage. The development of power electronic devices has made a notable impact on the quality of electric power supply. The operation of nonlinear loads generates harmonics and thus, deteriorates the quality of distribution system. In such cases both utilities and end users of electric power are gradually more concerned about the quality of power. This suggests that few course of action has to be taken so that the power quality can be improved. In this paper the main focus is on UPQC, which is a combination of series and shunt active power filters. The series APF alleviates voltage based distortions, while shunt APF mitigates current based distortions. UPQC alleviates the voltage and current based distortions concurrently as well as independently. UPQC improves power quality by compensating both harmonics and load current which thereby makes source current and load voltage sinusoidal at the required voltage level.The modelling of series APF, shunt APF and the UPQC has been carried out using MATLAB/Simulink.