Improved ip-iq harmonic current detection algorithm and simulation based on instantaneous reactive power theory

Abstract

This paper analyzes the current status of harmonic suppression in power systems and explores the working principles and development trends of active power filters (APF). It reviews and summarizes existing harmonic current detection algorithms, highlighting the limitations of traditional algorithms under non-ideal grid voltage conditions. Based on the definition of positive-sequence active and reactive current vectors in the introduced p-q coordinate system and the theory of instantaneous reactive power in three-phase circuits, an ip-iq harmonic current detection model is first proposed. The detection performance of this algorithm under ideal and non-ideal voltage conditions is analyzed. Furthermore, an improved ip-iq harmonic current detection algorithm is proposed. Simulation results demonstrate that the improved ip-iq harmonic current detection algorithm exhibits the same performance under non-ideal grid voltage conditions as it does under ideal voltage conditions, accurately detecting the fundamental positive-sequence active current in load harmonic currents. This provides a reasonable current reference command for APF.