Effect of Wear and Tear Bearing Fault in Induction Motor Drives Using FEM

Induction motors (IM) plays a critical role in many industrial applications. Though reliable IM are subjected to stator, rotor, bearing and miscellaneous faults. Among all the faults, bearing fault nearly accounts to 40% in IM. In inverter fed IM, bearings are subjected to severe stress due to switching of power converter devices which will cause more wearing away and degrade the performance of the bearing. Wear and tear is one of the common causes of faults in bearings and occurs due to lack of maintenance and poor handling which in turn will affect the friction co efficient of bearings. In this paper an analysis on bearing fault due to wear and tear in induction motor drive is realized using Finite Element Method (FEM). The effect of wear and tear of bearings in IM is incorporated in FEM by raising the friction coefficient of the rotor shaft. Several electromagnetic field quantities like flux line & flux density distribution over IM, air gap flux density radial component and its spatial FFT spectrum for various bearing friction coefficients are analysed in IM. The spatial FFT spectrum shows that the magnitude of fundamental element of air gap flux density radial component is decreased and magnitudes around 100 mm radial distance is increased depends on the intensity of wear and tear fault.