FEM Models of Rotor Failures in Comparison to Real Measurement of IM by External Stray Field

The paper deals with the validation of the 2D FEM model of induction motor with rotor failures. Output results of FEM analysis are compared to the real laboratory measurement of asynchronous motor. External magnetic stray field is used like the basic diagnostic method of it. The main parameter to be analyzed is the induced voltage generated on the coil, which senses the external stray field in radial direction of motor axis. Fast Fourier Transformation is used to evaluate the individual components of the voltage spectrum according to common diagnostic procedures. 2D FEM model of asynchronous motor has the same parameters of real motor in laboratory including nominal output power, rpm, power factor, voltage and current. Irreversible machine failures are created with adjustment of rotor bar by drilling or in case of eccentricity by misaligned setting in bearings.