High-Performance Induction Motor Speed Control Using a Robust Hybrid Controller With a Supertwisting Sliding Mode Load Disturbance Observer

Abstract

To enhance the speed control performance of a three-phase induction motor (IM) controlled by the vector control strategy, a new design of a hybrid controller (HC) is proposed based on the super-twisting algorithm (STA) and fuzzy approach. STA is chosen for its ability to decrease the ingrained chattering phenomenon in the classical sliding mode control (SMC) with maintaining tracking precision and robustness. Nevertheless, the control gains included in the control law have an evident impact on suppressing the chattering phenomenon and increasing the system's dynamic response speed. Therefore, firstly, a robust HC based on the fuzzy logic control (FLC) approach that operates as a fuzzy supervisor to on-line self-tune the value of the gains according to the system states is suggested to achieve high dynamic performance and limit the chattering effect. Secondly, to enhance the disturbance refusal capability, a super-twisting sliding mode load disturbance observer (STSMLDO) is developed to estimate the load torque disturbances. Then the estimated disturbance is introduced into the equivalent control law. Subsequently, the system stability is verified by the Lyapunov theorem. Finally, the superiority of the proposed scheme is validated through comparison with the advanced and traditional controllers in simulation and experimental studies.