Comparison of three control algorithms for single-phase UPQC

Abstract

This paper employs a single-phase unified quality conditioner (UPQC), an integration of shunt and series active filters (APF), to perform voltage and supply current harmonics mitigation and power factor correction. Both the shunt and series APFs are realized using a single-phase, two leg voltage source inverter (VSI). Three control algorithms based on unit vector technique (UVT), Single-phase d-q theory and Fourier analysis are proposed and compared for single-phase UPQC. In each proposed control strategy the control is made over the fundamental supply current and fundamental supply voltage instead of the fast changing APFs current and voltage, thereby reducing the computational delay. A dynamic model of the UPQC is developed in the MATLAB/SIMULINK enviournment and the simulation results demonstrating the power quality improvement in the system are presented for distorted supply and a combination of linear and non-linear load.