Parasitic Capacitance Modeling for Toroidal Inductor Using Multi-Axial Sliced Finite Element Model

This paper presents an application of a multi-axial sliced finite-element (FE) model to predict parasitic capacitance of a ferrite core toroidal inductor. A time-harmonic 2-D FE problem is solved in several slices taken axially and radially from a 3-D toroidal inductor, and the precomputed capacitances between the conductor regions are considered to model the displacement currents. The frequency-dependent complex permeability and complex permittivity of the core are taken into consideration for characterizing the inductor over a frequency range of 10
$\mathbf{kHz}$
to 1 MHz. In particular, the self-resonance frequency of the inductor is studied. The validation of computed results is made against measurements.