Analysis of Permanent-Magnet Machines Using an Anisotropic Magnetostatic Continuum Formulation

We present a magnetostatic continuum formulation for computing the magnetic fields and flux densities in permanent-magnet machine designs. This formulation offers certain advantages over traditional closed-form solutions and finite-element analysis. Our formulation is numerically robust. It models the tooth/winding region of the machine by using anisotropic permeability. Here, we derive spatial harmonics associated with the stator current density and rotor magnetization. We provide techniques to compute average flux density in the stator and rotor backirons and the stator teeth, and to calculate electromagnetic torque. The continuum formulation results compare well with those of finite-element analysis