In this paper

the characteristics of LCL filter are analyzed

LCL filter has resonant peaks in resonant frequencies

however the capacitor current feedback regulation can effectively restrain resonant peak. The properties of different controller are analyzed and compared

quasi PR controller realizes the control of AC variables in static coordinates without complicated coordinates transform

it holds the strong ability of resisting harmonic and has excellent robustness under unbalanced grid condition

so this paper puts forward a current double closed-loop controlling method based on quasi PR controller. Combining current double closed-loop controlling with maximum power point tracking controlling can maximize the use of solar energy and ensure the functions of grid-side converter. At last

a simulation model is built by the MATLAB/Simulink

simulation results validated the effectiveness and precise of the proposed control scheme.