Robust Adaptive Control

Abstract

In this thesis, a robust adaptive control scheme is proposed in order to drive an induction motor with high performance, even in the presence of unknown machine electrical parameters. Magnetic saturation within an induction motor results in nonlinear, changing flux dynamics. Also, rotor resistance changes with temperature as the machine is heated due to normal use, resulting in more parametric uncertainty. The proposed control scheme will cause the motor to track a desired reference model behavior, even in the presence of these unknown parameters. An adaptive control scheme known as L 1 adaptive control is used to ensure that this reference model behavior is realistic, so that robustness may be maintained even with very fast adaptation. This controller is limited by the flux observer used to provide information about flux magnitude and direction.ii