Evaluation of electromagnetic performance of emerging failures in electrical machines using computational simulation

Common failures in industrial induction motors equipped with squirrel cage rotor are examined 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 40% reduction of winding coil in an inter-turn short circuit, for one of the phases. The waveform of the flux density was plotted directly, while the analysis of the harmonic distribution and its relation to the electrical failures was performed in the Fourier domain. The proposed methodology allows to clearly identify the fault conditions analyzed. 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.