Diagnosis of Actuator Parameter Faults in Wind Turbines Using a Takagi-Sugeno Sliding Mode Observer

A Takagi-Sugeno sliding mode observer (TS SMO) is used to detect and reconstruct parameter faults in the actuator dynamics of wind turbines. The actuator dynamics of the pitch system and of the generator are modeled as first or second order delay models. By choosing appropriate actuator fault matrices for the TS SMO design, parameter changes or faults in the actuator dynamics can be calculated from the reconstructed additive fault signal. Example simulations are performed using both a reduced-order model and the aero-elastic wind turbine simulation FAST by NREL. The presented fault reconstruction method appears promising to be used for fast fault detection schemes. The accuracy of the reconstruction, however, is still in need of improvement and the method lacks robustness with respect to model uncertainties, since no satisfactory reconstruction can be achieved in FAST simulations.