The integration of grid-forming converters into low-impedance power grids may lead to subsynchronous oscillations. In response to this issue

this paper proposes a damping controller based on frequency compensation. First

we established a mathematical model and a dynamic model of the grid-connected system of the grid-forming converter

and analyzed the causes of subsynchronous oscillations in grid-forming converters under low impedance from a dynamic perspective. Then

we put forward a scheme of damping control based on frequency compensation

in which the angular frequency compensation signal is introduced to enhance the damping of the system so as to restrain the subsynchronous oscillation. Moreover

we analyzed the impact of the phase compensation time constant on the system and the optimization effects of different damping control gains. Finally

we carried out time domain simulation and hardware-in-the-loop simulation experiments on Matlab/Simulink platform and hardware-in-the-loop simulation test platform to verify the effectiveness of the proposed scheme.