Fixed-Time Disturbance Observer-Based Adaptive Super Twisting Control for MPPT Tracking of Wind Energy Conversion System

In this paper, a control scheme based on adaptive super twisting controller (ASTC) combined with a fixed-time disturbance observer (FTDO) is proposed for a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG). The main objective of this controller is to track the maximum power point (MPPT) and ensure that the system operates with good performance despite the presence of known and unknown external disturbances. Firstly, the ASTC control is designed to perform optimal speed tracking of WECS based on PMSG without a priori information on the upper limit of system disturbances and uncertainties. Secondly, a fixed-time torque observer is designed to estimate aerodynamic torque without any additional sensors. Finally, simulation in the MATLAB/Simulink environment is carried out to validate the effectiveness and robustness of the proposed controller. Simulation results indicate that the ASTC-FTDO control offers a good tradeoff between extreme robustness, MPPT operation accuracy and low chattering effect.