Edge element computations of eddy currents in laminated materials

We studied different types of edge elements in three-dimensional computations of power dissipation in laminated conductors. The standard, lowest order (mixed first and zeroth order) basis on tetrahedral grids produces inaccurate results and grossly overestimates the losses. However, on hexahedral grids, aligned with the laminations, the standard edge elements give much more accurate results. If the grid cannot be aligned with the laminations, the dissipation can still be accurately computed with the lowest order hexahedral elements by using midpoint integration. Tetrahedral grids give accurate results if the complete first order basis is included, but this doubles the number of degrees of freedom.