Study of Improved Decoupled Double Synchronous Reference Frame Phase-Locked Loop

Grid-connected inverters serve as the grid-connected interface for green energy generation, and phase-locked synchronization control is required for grid-connection. Aiming at the poor performance of decoupled double synchronous reference frame phase-locked loop under non-ideal power grids, and the existence of large distortion and oscillation in the detection frequency and phase errors, an improved structure is proposed to make up for the shortcomings in the performance of the traditional structure by combining with the advantages of the fourth order generalized integrator. The MATLAB/Simulink simulation results show that the harmonics can be effectively suppressed when the grid harmonic disturbances and voltage unbalance harmonic distortions are detected, and the detection effect of small response overshoot and high steady state accuracy can be realized.