Adaptive fixed-time sensorless maximum power point tracking control scheme for DFIG wind energy conversion system

This work investigates the adaptive fixed-time control scheme to the maximum power point tracking (MPPT) control of double-fed induction generator (DFIG) based wind energy conversion system (WECS). Firstly, a fixedtime observer is designed to estimate the aerodynamic torque without the wind speed sensors. Optimal torque control is employed to obtain the real-time value of the optimal rotation speed by the torque observer. Then, an adaptive fixed-time nonsingular terminal sliding mode controller is proposed to implement optimal rotation speed tracking for MPPT of DFIG based WECS without the upper bound information of disturbances and system uncertainties in advance. The complete proof process of the stability of system and fixed-time convergence characteristics of the observer and the controller based on the Lyapunov theorem is constructed. Finally, simulation studies verify the effectiveness and strong robustness of the proposed method by Matlab/Simulink.