Sliding Mode Direct Torque Control for Induction Motor with Robust Stator Flux Observer

A sliding mode controller for induction motor (IM) is investigated in this paper. It features in very low flux and torque ripple. In order to guarantee electromagnetic torque and stator flux to track its reference signal strictly, the electromagnetic torque sliding mode variable and stator flux sliding mode variable were selected separately. Furthermore, a robust stator flux observer is designed for sliding mode direct torque controlled induction motor system. The design of state observer is based on regional pole assignment theory. The observer gain matrix is obtained by solving linear matrix inequality (LMI) using LMI Toolbox in MATLAB. Finally, the effectiveness and validity of the proposed control approach is verified by computer simulation results.