On a numerical method for 2D magnetic field computations in a lamination with enforced total flux

The paper deals with a numerical method for the evaluation of the electromagnetic loss in a lamination of an electric machine, based upon the Maxwell equations. The underlying problem consists in the computation of the unidirectional magnetic field in a cross-section of the laminate orthogonal to the enforced flux. thod starts from a suitable variational formulation of the governing parabolic problem with a nonlocal Neumann boundary condition accompanied by a Dirichlet side condition, involving nonlinear and hysteresis effects through the differential permeability coefficient. The variational problem is solved numerically by a finite element method, combined with a finite difference technique, which is deviced so as to take into account the nonlinear and hysteresis behaviour of the material. merical method is found to be effective and reliable.