Second-order sliding mode-direct torque control and load torque estimation for sensorless model reference adaptive system–based induction machine

Abstract

In this article, an improved sensorless direct flux and torque control is presented for high-performance induction motor drive. This algorithm integrates the super twisting control approach with direct torque control and model reference adaptive system. The super twisting algorithm is a second-order sliding mode approach that uses a continuous control law in order solves the problems of chattering and enhances control robustness against various uncertainties. Besides, a load torque observer design bed on super twisting–based design is presented to improve the speed regulation loop and to increase its rejection ability of load disturbances. Furthermore, the stator flux model reference adaptive system is used as a sensorless algorithm for rotor speed reconstruction. The association of dual estimators can increase the control system’s reliability and reduce its cost. The effectiveness of the proposed control algorithm has been verified through simulation and experimental work using MATLAB/Simulink software and dSpace 1104 implementation board, respectively.