A control strategy of hybrid active filter to compensate unbalanced load in three-phase three-wire power system

Abstract

This paper presents a control strategy of hybrid active filter for compensation of the three-phase three-wire industrial power system considering unbalanced loading. In addition to harmonic current compensation, the hybrid filter is designed to compensate both positive- and negative-sequence reactive power based on the so-called instantaneous power theory. Therefore, the compensated system behaves as a resistive network even in a reactive, nonlinear, or unbalanced circuit. Theoretical analysis and experimental results are given to verify effectiveness of the proposed method.