Research on Power Quality Improvement in Distribution System with Induction Motor Load Using Fuzzy Logic Controlled UPQC

This paper presents the operation of unified power quality conditioner (UPQC) as a universal active power conditioning device to mitigate both current as well as voltage distortions at a distribution end of power system network. The UPQC is designed by combining a series active power filter (DVR) and shunt active power filter (DSTATCOM) which shares a common DC link capacitor. Series compensator which is meant for voltage restoring is controlled by a fuzzy logic controller. Shunt compensator’s operation is controlled by extracting d axis and q axis current from load current and DC link voltage is maintained through a fuzzy logic controller. The performance of UPQC mainly depends upon how quickly and accurately compensation signals are derived. The steady state and dynamic operation of control circuit in different load current and/or utility voltages conditions is studied through simulation results. The presented method has acceptable dynamic response with a very simple configuration of control circuit. The designed UPQC is tested with an induction motor load. It is able to mitigate voltage sag/ swell, reactive power compensation, voltage fluctuations, harmonic elimination etc. under these load conditions. UPQC mitigates the voltage and current based distortion simultaneously as well as independently. The proposed system and controller is validated using MATLAB/simulink. The simulation results express a low THD and a perfect compensation.