Analysis of the chosen speed and flux estimators for sensorless induction motor drive

In the paper chosen rotor flux and speed estimation methods for the speed sensorless induction motor drive are presented. Speed estimators based on: the sliding mode theory (SMO), model reference adaptive systems (MRAS) technique and two chosen concepts based directly on the rotor slip frequency calculation are discussed and compared. Stator flux and speed estimators sensitivity to the motor parameter uncertainties is investigated. Simulation and experimental results of the sensorless DTC-SVM without speed control loop are presented. The low speed region and the dynamic properties of the IM drive with electromagnetic torque and stator flux feedbacks are tested.