An eddy current constraint formulation for 3D electromagnetic field calculations

The use of Coulomb´s gauge is sufficient for a unique solution in 3-D magnetostatic field calculations in terms of the magnetic vector potential. For the sinusoidal steady-state eddy current problem Coulomb´s gauge is not sufficient. The combination of Coulomb´s gauge and an eddy current constraint provides a simple way of guaranteeing uniqueness. A formulation for 3-D electromagnetic fields utilizing this constraint is proposed. Results comparing this formulation with other finite-element formulations and with experimental data are given.