Calculation of three dimensional permeance for structures containing nonlinear magnetic material

A method is presented for computing the upper and lower bounds to the permeance of three-dimensional electric machine regions containing nonlinear magnetic materials. Techniques for integrating the permeance integrals and for handling magnetic nonlinearity are described. Integrals that yield lower and upper bounds to the region permeance are derived from Ampere´s and Gauss´s laws. A parametric transformation is used to facilitate the calculation of the permeance. speed, accuracy, and the geometric insight into the field distribution make it useful for design analysis of electromechanical devices