Integration of Fuzzy-PI with STA–NTSMC: A Novel Hybrid Control Approach for Induction Motor Drives

This paper presents a novel fuzzy-PI integrated super-twisting nonsingular terminal sliding mode control (FPI–STANTSMC) strategy for high-performance induction motor drives. In the proposed scheme, a fuzzy-PI regulator adaptively tunes the proportional–integral gains in real time, enhancing steady-state accuracy and robustness against parameter uncertainties. The super-twisting algorithm (STA) generates a continuous control vector to mitigate chattering, while the nonsingular terminal sliding-mode control (NTSMC) surface guarantees finite-time convergence without singularities. Closed-loop stability is established through Lyapunov analysis. The controller is validated in MATLAB/Simulink under challenging scenarios, including wide-range bidirectional speed transitions, sudden load disturbances, and severe stator/rotor resistance variations. Comparative evaluations demonstrate that the proposed FPI–STANTSMC outperforms PI, fuzzy-PI, and PI-FOSMC controllers, with a reduction in rise time of about 41% relative to PI, 20% to PI-FOSMC, and 8% to fuzzy-PI. Overshoot is eliminated, whereas PI, fuzzy-PI, and PI-FOSMC exhibit overshoots of 1.8 rad/s, 0.8 rad/s, and 0.4 rad/s, respectively. Under rated load, the proposed scheme maintains near-zero steady-state error compared to 1 rad/s for PI and fuzzy-PI, 0.5 rad/s for PI-FOSMC, while preserving smooth electromagnetic torque with substantially reduced chattering. These results confirm the proposed strategy as a robust and practical solution for high-performance IM drives.