Dynamic properties of double fed induction generator wind turbine gearbox under low voltage ride through conditions

Currently, double-fed induction generator (DFIG) wind turbines remain the predominant models in the wind power industry. As the integration of wind power into the grid continues to grow, the demands placed on wind power generators by the grid are also increasing. One typical requirement is low voltage ride-through (LVRT) capability. This study establishes a torsional dynamics model of DFIG wind turbines. The dynamic equations are solved by the Runge-Kutta method. The simulation results indicate that voltage sag can lead to low-frequency oscillation of the time-varying mesh force. Moreover, as the voltage amplitude of the power grid increases, the mesh state may transition from non-impact to unilateral impact or even bilateral impact.