Integrated control on wind turbine drive-train torque

The wind turbine is a highly nonlinear system and its operating environment is extremely hostile. With the development of large-scale wind turbines and the introduction of flexible structures, vibration problems appear more and more serious. Random wind fluctuation, wind shear and tower shadow effect can all cause large ripples on drive-train torque. In this paper, two controllers are proposed for speed vibration suppression and torque ripple suppression. One is the observer-based state feedback generator torque controller, which can add damping to the first drive-train torsion mode. The other is the rotor collective pitch controller based on Active Disturbance Rejection Control (ADRC), which is designed to regulate generator speed. Both of the controllers are built on the basis of the model linearization method. The simulation results show that the control strategy can significantly reduce drive-train torque ripples, which demonstrates the excellent dynamic performance and robustness of the system, hence proves that the new method will have an important value in engineering application.