Influence mechanism and virtual power system stabiliser method of virtual synchronous generator for low-frequency oscillation of power system

The virtual synchronous generator (SG) (VSG) can not only enhance the inertia of the grid, but also introduce the oscillation characteristics of SG, which is easy to interact with the power angle of SG in the grid, and even produce low-frequency oscillation (LFO). The authors first construct a two-machine interconnected power system model containing VSG and traditional SG. The model is linearised to construct the state space equations to obtain the Phillips-Heffron model with VSG. The LFO path of action between VSG and SG is analysed. To reduce the negative damping torque provided by VSG to SG through this path, a virtual power system stabiliser (VPSS) is proposed and the controller parameters are adjusted according to the phase compensation method. Finally, the effectiveness of VPSS is verified by modal analysis and simulation comparison.