To attenuate the LCL filter resonance peak, capacitor-current-feedback active damping is widely used in an LCL-type grid-connected inverter. Because of the adverse effect introduced by the digital control delay, the performance of capacitor-current-feedback active damping significantly deteriorates. The negative damping region appears from to . This weakens the stability and robustness of the grid-connected inverter against the grid impedance variation. A biquad filter is adopted to insert into the capacitor-current-feedback path to compensate for the phase-lag resulting from the digital control delay. The positive damping region can be expanded to, thus achieving high robustness against grid impedance variation. The proper discrete method is chosen and the system stability after compensation is analyzed. Also, a detailed close-loop parameter design procedure is presented to obtain better control performance. Finally, experimental results are provided to verify the effectiveness of the proposed method and the feasibility of the parameter design procedure.