Eur. Phys. J. Appl. Phys. 39, 109-112 (2007)
https://doi.org/10.1051/epjap:2007089

The effect of small variations in the magnetization curves of shielding material upon shielded fields

Lehrstuhl Allgemeine Elektrotechnik und Numerische Feldberechnung, Brandenburgische Technische Universität Cottbus, Postfach 101344, 03013 Cottbus, Germany

Corresponding authors: kost@aet.tu-cottbus.de jacobs@aet.tu-cottbus.de hahn@aet.tu-cottbus.de

Received: 18 January 2007
Accepted: 14 March 2007
Published online: 13 June 2007

Abstract

The shielding of strong electromagnetic fields at power frequency, performed by ferromagnetic plates, is often successfully modelled by the effective reluctivity. This method delivers good results for the RMS value of the shielded field. The following paper shows that a small variation of the magnetization curve (e.g. by taking another material charge) can strongly influence the shielded field. The field calculation is performed by the Finite Element Method (FEM), where for the interior plate region a) finite elements and b) non-linear Impedance Boundary Conditions (IBC) are used which circumvents the need to discretize the shielding plate.