FEM Computation of Magnetic Field and Iron Loss in Laminated Iron Core Using Homogenization Method

This paper presents a novel method for analyzing transient magnetic fields in laminated iron cores. It is based on the finite-element method and a newly developed homogenization method is applied to model the lamination effectively. The homogenized constitutive relations, of which the approximation is only applicable to low-frequency problems, are derived analytically, neglecting eddy currents induced by time-varying magnetic fluxes parallel to the lamination. The loss due to the neglected eddy currents is estimated in the postprocessing state utilizing the obtained magnetic field variation. The calculated magnetic field is in good agreement with the measurement for a benchmark problem. It is demonstrated that the homogenized relations can be applied to the low-frequency problems