The factors influencing the impedance in the high-frequency range of grid-forming modular multilevel converters (MMC) are more complex than those of grid-following MMCs

making it difficult to analytically design an impedance shaping method suitable for high-frequency oscillation suppression in wide band. Therefore

this paper conducts a wide-frequency impedance modeling of the grid-forming MMC with virtual synchronous control strategy. It is analyzed that the MMC impedance in the high-frequency range is mainly influenced by the parameters of the virtual excitation link

voltage control link

and current control link. By studying the impact of eight active impedance shaping methods on the negative damping in the high-frequency range of MMC impedance

two active impedance shaping methods are proposed

namely

voltage notch filtering and virtual admittance band-pass filtering. These methods can weaken the negative damping effect near the center frequency band without introducing new negative damping. Further research reveals that the feasible domain of the filter center frequency for suppressing oscillation phenomena reaches several hundred hertz

with strong parameter robustness. Finally

time-domain simulations verify the effectiveness of the theoretical analysis in this paper

aiming to provide a reference for high-frequency oscillation suppression in MMC under active power grid support control strategies.