Inertia Control of Doubly Fed Induction Generator Based Wind Turbine Considering Torsional Vibration Suppression

The dynamic characteristics of grid frequency can be improved through short-term active power support from doubly-fed induction generator (DFIG)-based wind turbines with inertia control. However, the direct and rapid active power regulation under the existing inertia control strategy will have a negative impact on the small signal stability of the wind turbine, which is not conducive to the suppression of the torsional vibration in the drivetrain. The response characteristics of the inertia control strategy and the influence of the inertia control strategy on the damping characteristics of shafting are analyzed firstly in this work. On this basis, an inertia control method with slip as input signal is designed, which provides inertia and damping by adjusting active power. Then the parameter optimization method of the proposed inertia control strategy considering the shafting stability constraint is put forward. It is shown by the simulation results that the proposed inertia control strategy not only has a good inertia support effect, but also can effectively increase the equivalent electrical damping coefficient of shafting, improving the stability of the shafting.