| This dissertation deals with the design of several nonlinear control algorithms for electric machines such as the switched reluctance motor (SR), permanent magnet stepper motor (PMS), brushless dc motor (BLDC), and the induction motor (IM). The proposed nonlinear control algorithms belong to the integrator backstepping family of controllers. The primary objective of each of the proposed controllers is to achieve position/velocity tracking of a desired, differentiable position/velocity trajectory. We also demonstrate how several secondary objectives such as compensating for parametric uncertainty, estimating an unavailable state, minimizing energy consumed by the machine, accounting for magnetic saturation in the core, etc., can be achieved within the framework of the integrator backstepping design. The proposed controllers are then verified via experimentation.; The integrator backstepping technique is a very intuitive, yet formal approach to solve control problems which involve cascaded subsystems. In this dissertation, we exploit the fact that electric machines can be expressed as a set of cascaded subsystems to design several nonlinear controllers which are based on the integrator backstepping technique. For the case when some of the parameters of the electromechanical model are not known exactly, we show how adaptive integrator backstepping tools can be used to design controllers which can achieve the desired position/velocity tracking objectives despite parametric uncertainty. Since for many electric machines, the developed torque is a function of the rotor position and the phase currents, we show how closed-form differentiable commutation strategies can be fused into the backstepping procedure.; This dissertation is divided into four self-contained chapters each of which represents a journal length paper. The first three chapters represent papers which have already been accepted to appear in major control journals. The fourth chapter represents an extended version of a published conference paper which has been submitted to a leading control journal. |
