Direct torque control of induction motor based on state feedback and variable structure fuzzy controllers

Direct torque control (DTC) is quite different from vector control and has several advantages over vector control. This paper presents intelligent control scheme together with conventional control scheme by fuzzy logic approach, to overcome the problems with uncertainties in the structure encountered with classical model based design. To adjust the speed of the direct torque control of induction motor drive, two control approaches are developed and applied. The first control approach combines the variable structure theory with fuzzy logic concept and in the second approach; a fuzzy state feedback controller is developed based on pole placement technique. Simulation studies have been carried out for different operating conditions of the drive system, the results have been presented and compared with those of the conventional method.