Subproblem Finite-Element Refinement of Homogenized Dielectric Layers in Wound Inductors for Accurate Local Stresses Computation

Recently, a homogenized model in 2-D electrostatics has been proposed in order to avoid the meshing of the thin dielectric layers surrounding the conductors of transformers. The model performs a smoothing of the physical fields, which leads to an incorrect estimation of the peak values of the electric field between the conductors. This issue is critical for a correct design of the transformer insulation. Therefore, in this paper, the subproblem finite-element method is employed, so as to refine the homogenized model on selected areas, and recover the small scale variations of the fields.