An improved pre-filtering moving average filter based synchronization algorithm for single-phase V2G application

Abstract

The performance and overall operation of grid- connected electric vehicle is directly affected by abnormal grid conditions. In this regard, Moving Average Filter (MAF) provide high noise cancellation capability and require less computational resources. However, the conventional in-loop MAF based synchronization suffers from slower dynamic response. In this paper, an improved pre-filtering MAF based PLL (IPMAFPLL) is proposed where MAF is removed from the control-loop and placed in the pre-filtering stage to improve the dynamic response of system. The phase drift provided by MAF under off-nominal frequency is further mitigated by introducing a compensation factor in the pre-filtering stage. The proposed technique is compared with conventional MAF-PLL and non-adaptive MAF- PLL. The simulation and experimental results show that our proposed approach have lower frequency overshoot and improved performance towards compensating grid harmonics under nominal and off-nominal grid frequencies.