Magnetic Flux Density Analysis of Cage Induction Motor used Permeance Model Considering Magnetic Saturation by Leakage Flux

This paper describes a method to analyze harmonic components of the air-gap flux density distribution on 3-phase cage induction motors, considering the influence of circumferential slot arrangement, stator winding pattern and distribution of air-gap permeance by leakage flux. The applied method is based on an analytical model of the permeance and the magneto-motive force distributions with non-linear model considering main and leakage flux saturation.

The proposed method is applied to the analysis of a cage induction motor at load and locked rotor conditions. As a result, the harmonic components of the air-gap flux density distributions at different driving conditions are shown quantitatively. The accuracy of the proposed method is confirmed by comparison with the finite element magnetic field analysis. From the comparison of these calculated results, the proposed method is shown to be appropriate and useful for quantitative estimation of harmonic flux for cage induction motors.