Duality-Synthesized Circuit for Eddy Current Effects in Transformer Windings

Abstract

This paper presents a novel method to obtain an equivalent circuit for the modeling of eddy current effects in the windings of power transformers. The circuit is derived from the principle of duality and, therefore, matches the electromagnetic physical behavior of the transformer windings. It properly models the flux paths and current distribution from dc to MHz. The model is synthesized from a nonuniform concentric discretization of the windings. Concise guidelines are given to optimally calculate the width of the subdivisions for various transient simulations. To compute the circuit parameters only information about the geometry of the windings and their material properties is needed. The calculation of the circuit parameters does not require an iterative process. Therefore, the parameters are always real, positive, and free from convergence problems. The results are compared with conventional synthesis methods and finite elements for validation.