High-performance motion control of an induction motor with magnetic saturation

Abstract

Generalizes the authors' work on high-performance control of induction motors to machines that exhibit significant magnetic saturation. The controller design is based on the standard d-q model of the induction motor which has been modified to account for the saturation of the iron in the main (magnetic) path of the machine. An input-output linearization controller is used to provide independent (decoupled) control of the speed and flux. With this controller, the flux reference becomes an extra degree of freedom for the designer to help achieve performance objectives. Taking into account saturation along with the voltage and current constraints, the flux reference is chosen to achieve the optimal torque (maximum for acceleration and minimum for deceleration) at any given speed. Experimental results are given to demonstrate the input-output controller's effectiveness in providing the tracking of a given position and speed trajectory while simultaneously tracking the optimal flux reference. The set of experiments are fast point-to-point motion control moves with an inertial load comparing the input-output controller based on the saturated magnetics model with that based on the linear magnetics model.