Abstract：Considering the influence of grid voltage background harmonics in weak current networks，reverse

harmonic peaks appear in the grid-connected current under weighted average current control（WACC），making it

impossible for the system to achieve zero pole cancellation and thus affecting the stability of the grid-connected

system. An improved weighted average current（WAC）control strategy that effectively tracks the grid-connected

current through a quasi-proportional resonant controller was proposed. Introduced a frequency selection link into

the grid voltage feedforward channel to suppress high-order harmonics，and connected in series to eliminate phase

lag within the reverse resonance peak frequency range caused by the delay link，thereby improving system stability.

Theoretical analysis and Matlab/Simulink simulation results show that the improved WAC control strategy

proposed can improve the stability and adaptability of LCL inverters in weak current networks.

      Key words：weak grids；LCL inverter；weighted average current control（WACC）；grid-connected inverter；

frequency selection link；lead compensator