A speed-sensorless vector control of induction motor operating at high efficiency taking core loss into account

This paper proposes a speed-sensorless vector control method for an inducti on motor operating at high efficiency and high response, in which core loss is taken into account, and discusses the system's performance. The propose d vector control system consists of a speed-adaptive rotor-flux observer wh ich takes core loss into account and employs a direct-field-oriented contro l scheme which compensates for the influence of core loss, On the basis of simulation and experimental results, we show that the proposed system can e stimate motor speed even when the rotor flux is changed.