Comparison of Two Anisotropic Layer Models Applied to Induction Motors

A general description of the Anisotropic Layer Theory, which is derived in the polar coordinate system and applied to the analysis of squirrel-cage induction motors (IMs), is presented. The theory considers nonconductive layers, layers with predefined current density, and layers with induced current density. The electromagnetic field equations are solved by means of Fourier analysis. Furthermore, two different magnetic models for IMs are proposed, namely, the direct rotor current model and the indirect rotor current (IRC) model. The magnetic models are coupled to the single-phase equivalent circuit by means of an iterative algorithm, which also accounts for saturation of the main flux path. Finally, the calculation results are validated against results obtained from measurements on two benchmark motors. Comparison of the validation results shows that the IRC model is the more promising one.