At present

the proposed broadband oscillation suppression method based on impedance remodeling is generally only applicable to a certain frequency band. When the grid impedance changes

the dominant frequency and amplitude of the oscillation mode change

and the oscillation can no longer be effectively suppressed. While suppressing the oscillation of the target frequency band

it will affect the impedance characteristics of other frequency bands

thereby increasing the risk of oscillation in those other frequency bands. To address the issues mentioned above

firstly

voltage feedback is introduced into the current inner loop of the three-phase grid-connected inverter

and the channel transfer function is designed to be applicable for realizing impedance remodeling of the inverter over a wider frequency band

thereby enabling multi-band oscillation. Then

a FIR band-pass digital filter without phase offset is designed

and the influence of the filter's discrete sampling frequency on system stability is eliminated based on phase correction. The oscillation suppression channel

composed of an FIR digital filter and a voltage feedback channel

can adjust the frequency band of the reshaping sequence impedance according to changes in grid impedance

without altering the impedance characteristics of other frequency bands. Finally

the effectiveness of the method are verified by simulation.