Improved high-order integral fast terminal sliding mode-based disturbance-observer for the tracking problem of PMSG in WECS
Résumé
The present paper proposes a high-order sliding mode control approach for wind turbine (WT) with a permanent magnet synchronous generator (PMSG) under complex situations. The suggested control approach uses a disturbance observer (DO) with a modified super-twisting integral fast terminal sliding mode control (MSTIFTSMC) approach. The new developed method is specifically intended to ensure maximum power point tracking, track the state variables of the WT-PMSG, and enhance the quality of its output state variables. The strategy control is applied to the machine side converter (MSC) and grid side converter. In the MSC, DO combined with the MSTIFTSMC technique is designed for the rotor speed subsystem to attenuate the mechanical torque, which is considered an immeasurable disturbance. The proposed control technique based on DO: (i) ensures the convergence of the state variables of the WT-PMSG in finite-time; (ii) reduces the chattering issue in the sliding mode control (SMC); (iii) estimates mechanical torque then rejects them and compensates parametric uncertainties. To validate the tracking performance of the proposed control structure, three scenarios are presented with a comparison.