A novel synchronization method designed for single-phase distorted grid

Grid synchronization has always been a great challenge for single-phase gird-connected converters since only one signal is provided and it is beneficial for the control system if grid information is obtained rapidly and accurately. In this paper, a novel quadrature signal generation algorithm and a phase-locked loop based on it are proposed and analyzed. The proposed algorithm functions as two finite impulse response filters that can eliminate most harmonics in the input signal and the introduced phase-locked loop shows great harmonic cancellation ability with transient response less than half a cycle. Analysis, along with simulation and experimental results are presented to verify the feasibility and effectiveness of the proposed quadrature signal generation method and phase-locked loop structure.