In order to solve the problem of resonance in grid connected current and anti-resonance in open-loop gain under the control of weighted average current feedback（WACC）

an improved WACC method is proposed. Firstly

the capacitor current feedback control is introduced to improve the quality of grid connected current; then

the compensation link is introduced to ensure the reduced order characteristics of the control system

so as to effectively suppress the anti-resonance and grid current resonance in the control system considering the digital control delay. The results show that the proposed method can be adopted to effectively improve the amplitude margin of the control system from 2.2 dB to 8 dB

enhance the robustness of the system

reduce the harmonic distortion rate of grid connected current from 5.46% to 0.71%

and improve the quality of grid connected current. The proposed method can provide reference for the control of grid connected inverter in practical engineering.