Influence of rotor eccentricity on magnetic density and core loss for induction motors

In order to investigate the influence of rotor eccentricity on magnetic density and core loss, a 55 kW induction motor was taken as an example in this paper, based on electromagnetic theory and Finite Element Method, a field-circuit coupling model was built to study magnetic density distribution and harmonic content with different eccentricity ratios under rated load conditions. The different eccentricity ratios of which values were 0%, 10%, 20%, 30% were selected to expressing the normal and different eccentricities. The magnetic density of the stator and rotor core was also researched. Furthermore, the regional core loss with various rotor eccentricity ratios was calculated accurately, through dividing the motor into seven parts. Then some experiments were carried to verify the solution model and show reasonable accuracy of calculate results. Finally, some useful conclusions could be obtained through the analyzing of eccentricity.