In order to further optimize the output current harmonic suppression effect of photovoltaic grid-connected inverters

this paper proposes a composite control strategy for the output current of LCL photovoltaic grid-connected inverters. This strategy combines proportional complex integral（PCI） control and repetitive control（RC）

draws a composite control block diagram

introduces a transfer function

and designs PCI and RC control parameters. It is concluded that the compound control can effectively suppress the current harmonics

save the control cost of the grid-connected system

and achieve the purpose of reducing the steady-state error of the fundamental frequency. By building the MATLAB/Simulink simulation platform and establishing the LCL type photovoltaic grid-connected inverter model

the comparison of the simulation results shows that compared with the PI+RC control strategy

the total harmonic distortion rate of the grid-connected current is reduced by 25.77%

significantly improving the quality of grid-connected current.