Sensorless Control of Induction Motors with Core Loss

In this work, a sensorless control scheme is presented for induction motors with core loss. The magnetization currents are calculated by first determining the stator fluxes, then, the rotor fluxes and the rotor velocity are estimated on the basis of stator current and voltage measurements by means of a super-twisting sliding mode observer. The estimated variables along with the measured ones are used to track a reference rotor velocity signal and an optimal rotor flux modulus that minimizes the power loss, all by means of a twisting controller. Simulations show that the proposed observer based controller scheme performs well when tracking a time varying rotor velocity signal.