Working method of grid-connected photovoltaic power generation system

The invention relates to a grid-connected photovoltaic power generation system which consists of a phase-locked loop, a current transformator, a repetitive controller and a PWM generator. The invention also relates to a working method of the grid-connected photovoltaic power generation system, comprising the steps of: (1) acquiring network voltage phase position and grid-connected current; (2) designing the repetitive controller; (3) setting the modulation ratio, switch frequency and sampling times within unit cycle of an inverter; and (4) sending the output of the repetitive controller into the PWM generator, completing the switch operation for the inverter, and finally finishing grid-connected control for solar photovoltaic power generation. The invention has the advantages that the output waveform is greatly improved, the grid-connected current harmonic content is low, the total harmonic distortion is less than 1%, dc component is not contained, the power factor of the inverter is high, all indexes such as electrical energy quality and the like is in accordance with the requirement of grid-connected engineering technology, and the invention has application prospect.