Adaptive direct torque control for induction motors with unknown resistances

In this paper, an adaptive state feedback control is designed for the direct torque and stator flux regulation with a fifth-order model of induction motor. The control design is based on exact input-output decoupling via state feedback. To achieve the decoupling control, it is shown that the tracking dynamics with respect to the outputs, the torque and the stator flux, is asymptotically stable at an admissible operating equilibrium. In the adaptive control, the uncertainty in the resistances of the stator and the rotor is considered, and the adaptation law is design to guarantee the boundedness of the parameter estimation and the output regulation performance. Finally, simulation results are presented to demonstrate the availability of the proposed controller.