Enhanced stator flux and torque control in isolated wind-driven induction generators using a third-order super-twisting sliding mode controller

The self-excited induction generator (SEIG) is a promising solution for wind energy conversion in isolated and off-grid applications owing to its simplicity, robustness, and low maintenance requirements. However, its terminal voltage is highly sensitive to variations in rotor speed and load, which complicates regulation. This paper proposes a robust control approach based on third-order super-twisting sliding mode control (3-STSMC) to enhance voltage regulation and dynamic performance. The proposed controller regulates both the stator flux and electromagnetic torque to maintain a stable DC-link voltage at the rectifier output, even under significant disturbances. A comprehensive comparative simulation study against 2-STSMC, fuzzy logic control (FLC), and proportional–integral (PI) controllers validates the superior dynamic response, lower steady-state error, and substantial reduction in stator current total harmonic distortion (THD) achieved by the proposed 3-STSMC approach. Simulation results confirm the effectiveness of the proposed technique in improving flux stability, torque smoothness, and total harmonic distortion in isolated SEIG-based wind systems.