The grid-forming converter can synchronize with the AC power grid and maintain DC-link voltage stability by using DC-link voltage control. However

the low frequency damping problem of grid-forming converters based on DC-Link voltage synchronization increases the risk of low frequency oscillation. In this paper

a small signal analysis model of grid-forming converters based on DC-link voltage synchronization is established

and the formation mechanism of low frequency damping is revealed by combining eigenvalue analysis and active power magnitude-phase analysis. It is found that the negative damping power component of the active feedback loop is the key source for the risk of low frequency oscillation in the system. This paper employs an equivalent implementation method with a positive damping branch and proposes a low frequency damping enhancement strategy based on reactive power feedforward. The reactive power feedforward branch is introduced into DC-link voltage control

which effectively reduces the risk of low frequency oscillation in traditional DC-link voltage synchronous control. Finally

experiments are carried out to verify the grid-forming converter under different working conditions

and the experimental results demonstrate the correctness of the theoretical analysis and the effectiveness of the low frequency damping strategy.