Design of a robust H∞ dynamic sliding mode torque observer for the 100 KW wind turbine

This article presents a novel technique for the design of a robust dynamic nonlinear observer in the H∞ scheme for the Lipschitz nonlinear model of the wind turbine. It is a challenging problem due to the aerodynamic nonlinearity of blades. A drive train of the 100 KW wind turbine benchmark model, developed by Aalborg University and KK-electronic a/c, is conducted to exhibit the effectiveness of the proposed observer approach. The new Lipschitz constant definition for this system is expressed. Based on the new dynamic method, the Lipschitz constant is increased. Therefore, the operating region is increased. A new dynamic sliding mode observer is introduced for torque estimation in the drive train. The design methodology is the use of dynamic gain instead of static one in the sliding mode observer. The dynamic observer design offers an extra degree of freedom over the classical static gain observer. We established the conditions for the suggested dynamic observer stability. The proposed approach provides the observer robustness against nonlinear uncertainties due to the maximizing the Lipschitz constant. Moreover, the design procedure with the effect of system and sensor noises is considered. Results illustrate the advantage of this work in comparison with other observers. Finally, the results are evaluated with the wind turbine simulator software FAST. [Display omitted] •The paper studies a new robust sliding mode observer for the nonlinear wind turbine Drivetrain.•Based on the extra degree of freedom the operating region of the wind turbine has been enlarged.•The goal is to obtain a filter to stabilize the error dynamics without loss of performance.•Another contribution is improving the observer behavior by attenuating noise.•To validate the model, the drivetrain model was tested in FAST wind turbine software.