Research on typical harmonic elimination algorithms in phase synchronization control

Phase synchronization results in distorted grid contain a certain amount of oscillations, failing to meet the requirement of high-performance grid-connected power converters. Moving Average Filter (MAF) and Delayed Signal Cancellation (DSC), as well as their derivations, i.e. Cascaded MAF (CMAF) and Cascaded DSC (CDSC), are main solutions to this problem. In this paper, the mathematical models of these methods are analyzed, and their improved versions, namely Periodical MAF (PMAF) and Periodical DSC (PDSC) are proposed, tackling the problems of conventional CMAF and CDSC in dealing with multiple harmonic components. Further comparisons are made between these methods, based on the dynamic performance, required data storage size, harmonics elimination and high-frequency noise suppression ability. A selection criterion for practical applications is established. Experiments results under different operating conditions are coherent with the analysis of these methods, and also confirmed the superiority of the proposed derivations.