PQ Theory-based Modelling and Simulation of a Shunt Active Power Filter for Improving Power Quality

Abstract

Over the past decades, there has been a significant rise in the use of nonlinear loads which draw harmonic, distorted current, and voltage at the point of connection with the utility grid. This distorted voltage and current affect the power system and also the end consumers. So, meeting the power quality criteria of the utility grid has become essential in the modern power system. In this paper, a comprehensive, organised methodology for designing a shunt active power filter (SAPF) is presented, highlighting its role as an efficient tool for power quality enhancement, providing reactive power compensation, and mitigation of distortion problems. The PQ theory is implemented to determine the reference currents, and hysteresis current control is utilised to generate the gate pulses that manage the switching of the voltage source inverter (VSI). The complete SAPF is validated through simulation in MATLAB/Simulink for non-linear balanced and unbalanced loads. The simulation response shows that the presented SAPF filter effectively mitigates harmonic distortion, which is below the standard thresholds of the Institute of Electrical and Electronics Engineers (IEEE). For non-linear balanced load conditions, the Total Harmonic Distortion (THD) is suppressed to 0.29%, while for non-linear unbalanced load conditions, the THD decreases to 1.81%.