Hybrid electric-magnetic methods in eddy-current problems

We discuss a method of approximation of eddy-current equations in bounded space that relies on the use of the electric field as primary variable in the conductive parts and of the magnetic field in the air. Theoretical issues about this hybrid approach are addressed (is the problem well-posed?) and one shows that edge elements offer a straightforward way to discretize such formulations. The now-popular "A-V-phi" method is then shown to come as a variant of this formulation, in such a way that it allows the use of standard nodal elements. However, attention is called on the fact that the numerical convergence of the latter method may be in question. (C) 1999 Elsevier Science S.A. All rights reserved.