Title
Further Improvements in Topological Transformer Model Covering Core Saturation
Abstract
This paper is devoted to improvements of the low-frequency topological model of a three-legged stacked-core transformer. It is shown that B hysteresis loops employed in the transformer model and Psi - i curves measured at transformer terminals are quite different in shape. Adistinction is made between transformer modeling at moderate and deep saturations, separated conditionally by the level of technical saturation (near 2 Tesla) typical for grain-oriented steels. In the former case, in addition to the magnetic coupling of different phase windings through the core, an important part is played by air gaps at core joints. It is found that the effective gap length depends on the instantaneous magnetic flux and this dependence is proposed to implement by a variable inductance. It is shown that regardless of the core saturation depth, an important role in the transformer modeling belongs to the distribution of the zero-sequence path between all three phases. In addition to accurate replications of the special purpose saturation test, the modeled results are in a close agreement with positive- and zero sequence data measured on a 50 kVA transformer, as well as with the measured inrush currents.
Year
DOI
Venue
2022
10.1109/ACCESS.2022.3183279
IEEE ACCESS
Keywords
DocType
Volume
Saturation, three-legged transformer, topological model, transients, core gap
Journal
10
ISSN
Citations 
PageRank 
2169-3536
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
Sergey E. Zirka100.68
Dennis Albert200.34
Yuriy Moroz300.34
Herwig Renner403.72