In view of such problems as phase angle distortion and asymmetry of grid-connected currentof distributed power sourcedue to voltage imbalance

a kind of voltage positive and negative sequence separation and phase angle detection method based on a reduced-order resonant regulator is proposed. The existing positive and negative sequence separation method is introduced. The improvement to the shortcomings of its complicated operation is proposed and the improved separation method and its parameter design are analyzed.The improved positive and negative sequence separation method

compared to the traditional method

can quickly separate the unbalanced grid voltage and obtain the real-time phase angle

which ensure the realtime nature of the control system. Finally

the simulation is performed on the Matlab/Simulink software platformand the feasibility of the control strategy is verified through experiment.