A digital PLL control method based on the FIR filter for a grid-connected single-phase power conversion system

A digital phase-locked loop (PLL) based on a fictitious two-phase transformation for a grid-connected single-phase power conversion system is described in detail. It is proposed that two voltage vectors v_alpha , v_beta are implemented by a finite impulse response (FIR) filter in this paper. The proposed method is verified by simulation and experiment. In the simulation, besides the steady state response, the influence of the changes of some parameters such as voltage magnitude, grid frequency, the filter order, the 3^rd harmonic injection, on the proposed method is simulated. The fast phase track is realized in the experiment.