Moving Average Filter-PLL-Based Voltage and Frequency Control of Standalone WECS

Precise and fast estimation of system frequency during distorted voltage has become the main challenge for phase locked loop (PLL) for wind energy conversion system (WECS). In this paper, moving average filter (MAF)-based PLL is proposed to solve this issue for permanent magnet synchronous generator (PMSG)-based WECS. MAF allows suitable measurement of frequency and eliminates dc offset, harmonics, and unbalance in voltage. Also scheme is able to perform harmonics reduction. Model of the proposed system for simulation is prepared in MATLAB/Simulink and its performance analysis is carried through a comparative simulation study with conventional synchronous-reference-frame (SRF) PLL, adaptive-frequency-loop PLL, type-1 PLL, and type-3 PLL. Simulation results verify that the proposed controller extracts the maximum-power from wind and stabilizes the system voltage and frequency during any variable/distorted working conditions. System performs considerably excellent during dynamic and steady-state condition.