Phase delay solution based on instantaneous reactive power theory

Abstract

According to the theoretical detection method of instantaneous reactive power, the paper proposes a harmonic current detection method based on the combination of synchronous rotating coordinate system and PI control. This method adds PI adjustment after the filtering link to accurately track the current amplitude, realizes zero error control, and performs phase compensation on the rotating coordinate system to compensate the fixed phase delay time of the filter, so as to achieve the accuracy of the harmonic detection link. The analysis of the experimental results shows that the improved harmonic detection method is equally effective under the three-phase symmetrical load and three-phase asymmetrical load. Under three-phase symmetrical load conditions, the improved harmonic detection method reduces the THD of the grid current by 0.72% compared with the original method. Under three-phase asymmetrical load conditions, the improved method reduces the THD of the grid current by 0.11% compared to the original method.