The Frequency Characteristics of Transformer Windings Considering the Separation-Dependence of the Inter-Turn Mutual Parameters

Abstract

The paper presents a direct method for the determination of the frequency characteristics of transformer windings. The dependence of both the inter-turn mutual inductances and capacitances on the separation between these winding turns is taken into consideration. From measured data available in the literature, a formula for this dependence is derived. The voltage and current distributions along the winding will be governed by two integro-differential equations in terms of the location along the winding and the frequency. A direct solution of these equations will be presented. It doesn’t require any numerical iterative techniques or finite difference analyses. The frequency response, including the series and parallel resonance frequencies as well as the winding’s frequency-dependent input impedance for sample case studies are presented and discussed. Different transformer’s neutral treatments are addressed. These results are compared with the corresponding ones ignoring the non-uniformity of the mutual elements. In order to validate the proposed method, the paper is concluded by addressing special cases with known exact solutions.

Keywords: Power transformers, winding, modeling, distributed parameter circuits, non-uniform, frequency response, resonance, impedance characteristics, mutual parameters, integro-differential equations

Cite this Article

Mohamed M. Saied. The Frequency Characteristics of Transformer Windings Considering the Separation-Dependence of the Inter-Turn Mutual Parameters. Journal of Power Electronics and Power Systems. 2016; 6(3): 72–81p.