Subdomain perturbation finite-element method for skin and proximity effects

Skin and proximity effects are calculated in both active and passive conductors via a subproblem finite-element method based on a perturbation technique. A reference limit problem considering either perfectly electric or magnetic conductors is first solved. It gives the source for eddy-current perturbation subproblems in each conductor with its actual conductivity or permeability and its own mesh. These subproblems accurately determine the current density distributions and ensuing losses in conductors of any shape in both frequency and time domains, overcoming the limitations of the impedance boundary condition technique.