Application of the Sub-Region Model to Outer-Rotor and Inner-Rotor Flux-Switching Permanent Magnet Machines for Accurate Electromagnetic Performance Prediction

This paper presents a general analytical subdomain model for flux-switching permanent magnet machines (FSPMMs), applicable to any number of stator slots and rotor poles, for both outer and inner-rotor configurations. The model considers excitation from permanent magnets alone, as well as combined excitation from magnets and double-layer armature windings. The aim is to predict magnetic field distribution, cogging torque, electromagnetic torque, and self- and mutual inductances by solving Maxwell's equations analytically. To keep the model tractable, magnetic saturation is neglected by assuming infinite iron permeability. This simplification makes the method well-suited for preliminary design and parametric studies, where speed and flexibility are more important than absolute precision. The subdomain approach is conceptually similar to finite element method (FEM), in that the number of harmonic terms used in each region is analogous to the number of mesh elements. Validation is carried out by comparing analytical results with those obtained from FEM, covering both PM-only and combined excitation cases. The good agreement observed confirms the accuracy of the proposed model, highlighting its usefulness as a fast and reliable design tool for FSPMMs.

کلیدواژه ها:

Flux-switching ، Analytical model ، Finite element method ، Sub-region ، Boundary conditions ، Outer rotor ، Inner rotor