A T-ψ formulation with the penalty function term for the 3D eddy current problem in laminated structures

In this paper we present a new eddy current model by means of the T-ψ formulation with the penalty function term for the three-dimensional(3D) nonlinear eddy current equations with laminated conductors. By omitting the insulating films between the neighboring laminations, the approximate model reduces the scale ratio by 2–3 orders of magnitude. Then it avoids very fine or very anisotropic mesh in coating films and can save computational work greatly in numerical approximations. We study the weak formulations of the original and the approximate problem to obtain their well-posedness. Further, we prove the convergence for the solution of the new model to the solution of the original problem as the thickness of coating films approaches zero.