Transient magnetic field calculations in hysteretic media with FI/sup 2/TD formulations

The paper presents a computational approach for transient magneto-quasistatic field simulation including hysteretic ferromagnetic materials. The procedure is based on the finite integration implicit time domain formulation (FFTD) combining the inverse Preisach model with the successive approximation (SA) technique. Due to the hysteretic material behavior the definition of the permeability for the hysteretic ferromagnetic materials is modified for the SA technique. In order to improve convergence, a dynamic relaxation process is included. A combination of parabolic interpolation and golden section step based on Brent´s method is selected for determining the relaxation factor which minimizes the norm of the nonlinear system functional at each nonlinear iteration. This approach is compared to the M(H) iterative procedure, i.e., a polarization method that uses the Preisach model. The results of this comparison for a 3D test problem are presented and discussed.