A second order sliding mode state and parameter estimator for induction motors

In this paper it is proposed a state estimation scheme for three-phase induction motors of rotary and linear motion, by means of a second order sliding mode-based observer jointly with a nonlinear adaptive estimator. The proposed estimation structure allows the reconstruction of rotor fluxes, speed and rotor resistance based only on the measures of stator currents and voltages. It is shown, mathematically and through simulation, that the presented scheme estimates all the variables properly.