Research on Transient Damping Control of Virtual Synchronous Generator During Grid Faults

As development of the renewable generation, the dynamic characteristic of the system used to be dominated by synchronous generator has been gradually affected by the power electronic device. For maintaining the safety and stability of system frequency and voltage, the grid-forming control has been proposed and aroused extensive research, among which virtual synchronous generator (VSG) control is the most typical one. As imitating the dynamic of synchronous generator, the VSG control will produce transient power angle problem during grid faults. Therefore, the transient stability improvement strategy during faults needs to be further researched. In this paper, the reduced-order model of the VSG is established firstly. Then, the impact of VSG's virtual inertia and the damping control on transient power angle stability is researched. Further, to improve the transient power angle stability, a transient damping control of VSG utilizing the frequency variation as the integral feedback has been proposed. With the damping control, the increase of the frequency deviation during grid fault can be suppressed and the transient stability can be improved. Finally, simulations have been carried out and the effectiveness and availability are validated.