Calculating an electromechanical torque of a squirrel cage motor based on an axial flux obtained by the FEM

Abstract

This article presents a method of calculating an axial flux signal and how to use this signal to determine an electromagnetic torque for a squirrel cage induction motor in a steady state. Numerical analyses were performed using a two-dimensional field-circuit model for the squirrel cage induction motor. Most of analyses were performed for a symmetric motor and to estimate a magnitude of the electromagnetic torque, an algorithm was developed. The electromagnetic torque estimation method proposed in the article is easy to implement and does not require any interference into the drive system transmission. The analysis shows that it is possible for the induction motor to determine a load torque based on the axial flux measurement using a measuring coil applied to the motor, for example from the fan side.