Intricate Lyapunov-based controllers targeted at the induction motor

This doctoral dissertation describes the design and implementation of various Lyapunov-based control strategies targeted at the induction motor. The body of the dissertation focuses on three areas of interest in induction motor control research: (i) the reduction of sensor measurements, (ii) the compensation for rotor resistance parametric uncertainty, and (iii) the inclusion of saturation effects in the electrical subsystem model. For each of the above proposed control strategies, experimental results were performed to illustrate the feasibility of implementation and also to illuminate the controller's performance.; In the first chapter, a sensorless control algorithm that achieves semi-global exponential rotor velocity tracking for the full-order, nonlinear dynamic model of an induction motor actuating a mechanical subsystem is presented. The proposed controller utilizes stator current measurements but is termed sensorless due to the fact that no mechanical sensors are required and that stator current measurements can be obtained in an inexpensive/simplistic manner (e.g., relatively inexpensive Hall Effect current sensors can be used to obtain current measurements). The control strategy utilizes a novel rotor velocity observer which facilitates the potential for improved rotor velocity tracking transient performance. In addition, the observed integrator backstepping technique is utilized to ensure that the observer-based controller remains bounded.; The second chapter details the design and implementation of an adaptive, singularity free, partial-state feedback position tracking controller for the full-order, nonlinear dynamic model of an induction motor driving a mechanical load. The controller ensures global asymptotic rotor position tracking despite parametric uncertainty associated with the rotor resistance and the mechanical subsystem. In contrast to previous work, the proposed controller requires only rotor position and stator current measurements (i.e., rotor velocity and rotor flux measurements are not required). In the third chapter, a singularity-free, rotor position tracking controller for the full order, nonlinear dynamic model of the induction motor that includes the effects of magnetic saturation in the electrical subsystem is presented. By utilizing a π-requivalent saturation model, an observer/controller strategy that achieves semi-global exponential rotor position tracking and only requires stator current, rotor velocity, and rotor position measurements is designed.