BEM Computation of the Internal Impedance of Air-Core Inductors Enforcing High-Order Surface Impedance Boundary Conditions

The internal impedance of an axisymmetric air-core inductor is computed by the boundary element method (BEM) coupled with high-order surface impedance boundary conditions (SIBCs), which considers the curvature of the cross sections of the conductors. The proposed method is based on the perturbation technique (PT) and provides accurate results in a wide frequency range by solving only once the BEM formulation. A flat spiral air-core inductor is considered as a test case and the finite element method (FEM) without SIBC is used to obtain the reference results.