Analysis of rotor slotting saliency in induction motor sensorless control

This paper deals with induction machines analysis by Finite Element Analysis (FEA) for position sensorless control drives based on rotating voltage carrier injection. It focuses the analysis of the rotor slotting saliency, under the variations of: 1) supply of the machine (both the high frequency rotating voltage carrier and the fundamental frequency supply), 2) reference flux of the drive, 3) load torque, 4) rotor geometry design. The relative spatial harmonic of the stator inductance space-vector responsible for the rotor slotting effect has been chosen as an index for evaluating the response to the high frequency carrier. A methodology for retrieving the stator inductance space-vector from a FEA analysis is proposed as well. Results of the variation of the rotor slotting spatial harmonic of the stator inductance with the carrier frequency, the rotor flux linkage, the load torque and the rotor geometry are presented.