LCL inverter has high frequency resonance risk when connected into weak power system. Therefore

the virtual damping strategy is used with filter capacitor current as a state variable. In view of the characteristic of inconvenience of filter current acquisition using the medium-voltage converter in wind turbine

an optimization virtual damping strategy with grid side converter current as state variable is proposed to realize high frequency suppression. Meanwhile

band-pass filter and differential phase compensation are used to optimize the virtual damping strategy

which can meet the low-frequency gain requirement of closed-loop system and compensate for delay in the digital control system. Finally

the suppression theory of high frequency is verified by experiments and simulations with two typical phenomena

the start and load in weak grid caught in weak grid transient in full power operation.