Three-Dimensional Lumped-Parameter Magnetic Circuit Analysis of Single-Phase Flux-Switching Permanent-Magnet Motor

A 3-D lumped-parameter magnetic circuit model is developed for a single-phase flux-switching permanent-magnet motor. Particular attention is given to representing the complex air-gap flux paths by equivalent permeances so as to accurately model the asymmetry in the air-gap field distribution and to determine the back-EMF and inductance waveforms, as well as the average static torque. Leakage fluxes external to the stator outer surface and the end surfaces on the back-EMF waveform are also taken into account. The developed model is used to investigate the influence of the motor axial length and magnet dimensions on the end effect. Good agreement between predicted, finite element-calculated, and measured results is achieved.