Sliding-mode direct torque control of an induction motor

Abstract

This paper proposes new sliding-mode direct torque control (DTC) for an induction motor. This DTC is established by designing two sliding surfaces for the torque and the flux. We propose a novel sliding surface for the torque, which is based on the integral-sliding surface, whereas the sliding surface for the flux follows that of Benchaib et al. [16]. We also modify the flux observer of Benchaib and Edwards [17] by the adaptive sliding-mode method. This not only eliminates the estimation of the uncertainty bounds, but also improves the performance of sliding control. A practical application of the proposed DTC to the position control of a motor is also presented. Some experiments verify the control theory and demonstrate the usefulness of the proposed DTC.