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A dual-loop current control is discussed for <italic>LCL</italic>-type shunt active power filters (APFs), where inverter-side current feedback and point of common coupling (PCC) voltage feedforward both provide active damping (AD) effects for <italic>LCL</italic> resonance. However, two ADs are equivalently applied to different elements of <italic>LCL</italic> filter with narrow damping boundaries, which causes less robustness against grid impedance variation. Hence, this paper has presented a comprehensive approach to strengthen the system robustness against grid impedance variation. On the basis of phase compensated resonant unit, a delay-compensation scheme is firstly proposed to extend the damping boundary of inverter-side current feedback up to almost Nyquist frequency (<inline-formula> <tex-math notation="LaTeX">$f_{s}/2$ </tex-math></inline-formula>). Theory analysis considering PCC voltage feedforward indicates that the control system can keep robust to grid impedance when the initial <italic>LCL</italic> resonance frequency falls between <inline-formula> <tex-math notation="LaTeX">$f_{s}/3$ </tex-math></inline-formula> and the extended damping boundary. Moreover, a typical weighted proportional-resonant feedforward scheme is suggested to prevent high-frequency resonant units from inducing system instability under a large grid impedance. We finally validate the effectiveness of the proposed approach through experiments.