Solution of inductances for bearingless switched reluctance motors with 3-D FEM based on different degree of freedom

Accurate calculation of inductance characteristics is the basis for the design and control of switched reluctance motor (BSRM). Based on different degree of freedom, inductances of main- and suspended windings for a BSRM are calculated using the enhanced incremental energy method by 3-D finite element methods of double scalar magnetic potential method, magnetic vector potential method and edge finite element method, respectively. The impacts of end effects on distributions of magnetic field and inductances are analyzed. The computational precisions of the three methods are investigated through comparing to the tested inductances. Moreover, the paper provides a theory reference to selections of methods for 3-D nonlinear electro-magnetic field computations.