Maximum power tracking of a wind turbine using an adaptive barrier function global fast terminal sliding mode control approach

When a wind turbine operates in a region below the rated wind speed, it must track the desired rotor speed to maximize energy capture. However, uncertainties and unknown disturbances affect the speed and accuracy of the wind turbine in tracking this desired value. To address this issue, this paper proposes an adaptive barrier function global fast terminal sliding mode control method, recognized for its robustness and rapid convergence. The global fast terminal sliding mode combines the characteristics of traditional sliding mode and terminal sliding mode in the dynamic design of sliding mode, ensuring that the system state converges within a finite time and the tracking speed of the desired parameters of the wind turbine. The method introduces a barrier function whose intrinsic properties reduce the system's dependence on the uncertainty upper-bound setting, alleviate the chattering phenomenon, and guarantee the control accuracy. Furthermore, the control performance of the proposed method is compared with the two other methods in this paper under three wind speed conditions: step, random, and turbulent. In conclusion, the average settling time for the desired rotor speed of the proposed method is 6.94 % of other methods. The average maximum error and fluctuation range of the proposed method in tracking wind turbine parameters are 7.89 % and 10 % of other methods, respectively. The proposed method effectively improves the dynamic performance and accuracy of the wind turbine.