Determination of Parasitic Capacitances in Inductive Components - A Comparison Between Analytic Calculation Methods and FEM-Simulation

Abstract

Flyback converters are commonly used in switching mode power supplies. An essential component of a flyback converter is the high-frequency transformer. In order to ensure a faultless operation of the converter, even at high operating frequencies, the parasitic capacitive effects in the transformer have to be considered during the engineering process. The negative effects of the parasitic capacitances on the currents in the converter windings increase with rising operation frequency [1]. The aim of this paper is to draw a comparison between analytic calculation methods and FEM-simulations by means of a simple sample transformer model. It is also verified that the dynamic component of the electric field can be neglected for the calculation of the parasitic capacitances for frequencies up to a few hundred kilohertz.