Semi-Analytical Modeling of Electromagnetic Performances in Magnet Segmented Spoke-Type Permanent Magnet Machine Considering Infinite and Finite Soft-Magnetic Material Permeability

In this paper, we present a semi-analytical model for determining the magnetic and electromagnetic characteristics of spoke-type permanent magnet (STPM) machine considering magnet segmentation and finite soft-material relative permeability. The proposed model is based on the resolution of the Laplace’s and Poisson’s equations in a Cartesian pseudo-coordinate system with respect to the relative permeability effect of iron core in a subdomain model. Two different magnet-segmented STPM machine was studied analytically and numerically. The effect of the iron core relative permeability on the STPM machine performances was investigated at no-load and on-load conditions with respect to certain values of iron core relative permeability by comparing cogging torque, electromagnetic torque ripple, and reluctance torque ripple waveforms. In order to validate the results of the proposed analytical model, the analytical and numerical results were compared. It can be seen that the analytical modeling results are consistent with the results of numerical analysis.