Numerical Modeling of Capacitive Effects in HF Multiwinding Transformers—Part II: Identification Using the Finite-Element Method

This paper is the second part of a work which aims at proposing a global approach for the numerical modeling of parasitic capacitances in high-frequency multiwinding transformers. In this part, we focus on the numerical identification using the finite-element method (FEM) of the capacitive circuits which have been introduced in a companion paper in the same issue. An original procedure based on the FEM in 2-D electrostatics is first presented. The validity of the 2-D approximation is thereafter discussed, and a new method which consists in solving two successive 3-D models (an electrokinetic problem in the windings and an electrostatic one in the dielectrics) is then exposed. The two methods are illustrated and experimentally validated on a three-winding transformer.