Evaluation of Electromagnetic Performance of Emerging Failures in Electrical Machines

In the present paper, electromagnetic simulations of electric motors with early failures are presented. One of the most common failures in induction motors with squirrel cage rotor is considered in this paper. These failures are: broken rotor bars and short circuit in the inter-turn winding. The broken rotor bars failure was simulated with two consecutive broken bars in order to see how the magnetic flux density is affected. The inter-turn short circuit was simulated with the 40% reduction of winding coil in an inter-turn short circuit for one of the phases. In both cases the simulation was performed with the finite element software FEMM and the waveform of the flux density in both the motor air gap and the magnetic core was calculated. Comparative test of the real failure was performed in order to verify the results obtained from the simulation, good agreement between simulation and experimental measurements was obtained.