Input–output linearising tracking control of an induction motor including magnetic saturation effects

Abstract

The tracking control design of an induction motor, based on input–output linearisation with magnetic saturation included is addressed. The magnetic saturation is represented by a nonlinear magnetising curve for the iron core and is used in the control, the observer of the state variables, and in the load torque estimator. An input–output linearising control is used to achieve better tracking performances. It is based on the mixed ‘stator current – rotor flux linkage’ induction motor model with magnetic saturation considered in the stationary reference frame. Experimental results show that the proposed input–output linearising tracking control with saturation included behaves considerably better than the one without saturation, and that it introduces smaller position and speed errors, and better motor stiffness on account of the increased computational complexity.