This paper proposes a novel nonlinear semi-analytical model (AM) for the magnetic field calculation of electric machines. The nonlinear properties and local saturation effect of the iron part are taken into consideration in Cartesian coordinates, which is the main contribution of the proposed model. Thus, high accuracy of electro-magnetic field results can be obtained with the low computation time cost. The model is developed based on the harmonic modeling (HM) technique by solving Maxwells equations. The detailed theoretical derivations, which use the complex Fourier series and the Cauchy product, are presented. To verify the proposed model, an axial flux permanent-magnet (PM) machine (AFPMM) is selected to be investigated. Both finite-element model (FEM) and experiments results agree well with that of the proposed model. Moreover, the nonlinear AM has potential application for other types of PM electrical motor in Cartesian coordinates, like flat PM linear machines.
- Harmonic model
- Cartesian coordinate
- Axial flux permanent-magnet machine
- Saturation effect