Multiple-Complex Coefficient-Filter-Based PLL for Improving the Performance of Shunt Active Power Filter under Adverse Grid Conditions

In recent years, shunt active power filters (SAPFs) are becoming a popular solution for power quality issues. A crucial part in synchronizing the SAPFs is the accurate estimation of the grid phase/frequency. The multiple-complex coefficient-filter-based PLL (MCCF-PLL) has interesting features under adverse grid conditions. The unique distinction of the MCCF-PLL from other PLLs is the ability of providing information about the sequence (polarity) of each individual frequency. However, the MCCF-PLL has not received much attention in APFs. In this paper, a study and an implementation of a selective harmonic cancelation technique based on MCCF-PLL to the SAPF is suggested. The proposed method proved its reliability and robust behavior in optimizing the performance of the SAPF under unbalanced and distorted grid conditions. The reliability of the proposed method is verified experimentally.