New DTC scheme based-on SVM with sliding-mode observer for induction motors

Direct torque control based on space vector modulation (SVM-DTC) preserve DTC transient merits, furthermore, produce better quality steady-state performance in a wide speed range. The SVM-DTC system based on input-output linearization technique for induction machine drives is developed in this paper. A sliding-mode observer for estimating flux is introduced. The observer is inherently sensorless because they do not employ the rotor speed adaptation, and thus they are insensitive to speed estimation errors. Moreover, the observer is extremely robust. The simulations of conventional DTC and the proposed control topologies are given and discussed. It is concluded that the proposed control topology outperforms the conventional DTC in reducing torque ripple and parameter robust.