Harmonic detection of active power filter based on improved gray wolf algorithm with optimized VMD

Active power filters (APF) are essential in power systems for harmonic management, and their performance heavily relies on the harmonic detection capability. Recently, Variational Mode Decomposition (VMD) has emerged as a powerful time-frequency analysis method for processing nonlinear and non-stationary signals, which can effectively process harmonic signals in power systems. However, the conventional VMD method requires optimal selection of the number of modal decompositions and penalty factors to achieve the best signal decomposition accuracy. To overcome this challenge, an improved grey wolf optimizer has been proposed and applied to parameter optimization of VMD. The optimized VMD method has been used for harmonic detection, resulting in a significant reduction of the grid-side current THD from 31.04% to 3.88%. This has significantly improved the performance of the active power filter, and the experimental results support the effectiveness of the proposed approach.