A novel variable domain adaptive fuzzy control of direct torque control for induction motor based on space vector control

Present work shows the merits of space vector modulation direct torque control(SVM-DTC) over the conventional direct torque control(conventional DTC). SVM-DTC technique is helpful in solving the basic issues of torque ripple and variable swithing frequency present in the conventional DTC. In order to get the reference voltage vector which is necessary for the SVM-DTC, this paper describes a method of controlling the torque of an induction motor using a hybrid fuzzy proportional integral(PI) controller. The speed control of induction motor is done by using the conventional proportional integral controller and the variable domain adaptive fuzzy controller. The adaptive fuzzy controller is designed by utilizing the adjustability of the contraction-expansion factor α on line and the adaptive law of factor β. The simulation results show, compared with the conventional SVM-DTC, the proposed algorithm can improve response speed and control precision, and reduce the torque ripple of the controlled system.