Application of the impedance boundary condition in a finite element environment using the reduced potential formulation

The use of a boundary condition when dealing with HF magnetodynamic phenomena is presented. By removing the conducting parts drastic reduction of the domain to be modelled can be achieved. In the present approach very sparse linear algebraic systems are created and then solved. The asymptotic case, called the infinitely high frequency condition, which expresses field non-penetration in the conductor parts of the domain being studied, is discussed. Reliability of the infinitely high frequency condition is discussed. In a first application, the computation of the tangential component of the magnetic field is presented. The FLUX 3D finite element software package was used for the simulation of a semi-infinite conducting space excited by a very thin circular current loop. The proposed approach is also applied to a transformer which has already been modelled following traditional methods.>