Modeling of Transformer Windings having Non-uniform Inductance Distribution

Abstract

A direct analytical procedure for analyzing power transformer windings with location-dependent series inductance is presented. This dependence is typically introduced in order to take the inter-turn mutual inductive coupling into consideration. The paper addresses the frequency domain analysis conducted in the complex s- or the jω-domains. Results for the frequency-dependent winding’s input impedance with different treatments of the transformer’s neutral point will be available. The frequency characteristics including the resonance frequencies are also presented. If required, the resulting expressions for the voltage and current distributions can be efficiently used for finding the winding’s response in the time-domain using the numerical inverse Laplace transform. The suggested approach is validated by its application to case studies for which solutions are available elsewhere.

Keywords: Power transformers, winding, modeling, equivalent circuit, distributed parameter circuits, non-uniform, frequency response, resonance