After the virtual inertia control is adopted in a wind power grid-connected system

the dynamic stability of grid and wind turbine should be comprehensively analyzed. Friendly grid-connected function of additional control should be improved to enhance its promotion and application value. Firstly

the state equation of the wind power grid-connected system with virtual inertia is established. Secondly

the theory of small signal analysis is used to analyze the effect of virtual inertia control on the system damping characteristics. In order to improve the support function for system’s dynamic stability

the dynamic compensating signal is added to an inertia controller based on the extended state observation method. The shafting model of wind turbine is reduced according to integral manifold method

and the influence of virtual inertia control on wind turbine’s shafting oscillation is then analyzed. Moreover

a shafting transient energy function is established to provide the principle of parameter design for wind turbine’s shafting stabilizer. Finally

a power grid system with high-penetration wind power is established in RTLAB digital-analog hybrid simulation platform. The results show the proposed virtual inertia control significantly improves the swing stability of power angle

as well as decreases the wind turbine’s shafting oscillation.