Sliding-mode direct torque control of an induction motor

Abstract

This paper proposes a 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. The authors 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. (1999). They also modify the flux observer of Benchaib and Edwards (2000) by using 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.