Algebraic multigrid preconditioner for harmonic eddy current problems in 3-D

The focus of this paper is on the efficient solution-both in CPU time and memory-for harmonic eddy current problems in three dimensions. The magnetic vector potential is used as the field variable and the discretization is performed by Ne´de´lec (edge) finite elements. The resulting system of equations is solved by applying a quasi-minimal residual solver with an appropriate algebraic multigrid preconditioner. The efficiency of the new solver will be demonstrated by a case study (coil with iron core) and by the computation of the magnetic field within an electric transformer.