Journal ArticleDOI
Effects of eddy currents in transformer windings
P.L. Dowell
- Vol. 113, Iss: 8, pp 1387-1394
Reads0
Chats0
TLDR
In this article, the effect of eddy currents on transformer windings is considered and a method is derived for calculating the variation of winding resistance and leakage inductance with frequency for transformers with single-layer, multilayer and sectionalised windings.Abstract:
The effects of eddy currents in transformer windings are considered, and a method is derived for calculating the variation of winding resistance and leakage inductance with frequency for transformers with single-layer, multilayer and sectionalised windings. The method consists in dividing the winding into portions, calculating the d.c. resistances and d.c. leakage inductances of each of these portions, and then multiplying the d.c. values by appropriate factors to obtain the corresponding a.c. values. These a.c. values are then referred to, say, the primary winding and summed to give the total winding resistance and leakage inductance of the transformer. Formulas are derived and quoted for calculating the d.c. resistances and leakage inductances of the winding portions. Theoretical expressions are derived for the variation with frequency etc. of the factors by which the d.c. values must be multiplied to obtain the corresponding a.c. values. These expressions are presented in the form of graphs, permitting the factors to be read as required.read more
Citations
More filters
Journal ArticleDOI
Comparison of realization techniques for PFC inductor operating in discontinuous conduction mode
TL;DR: In this article, a planar inductor in which a lumped gap is replaced by a distributed air gap material is described and investigated, and a significant reduction in AC winding loss of the planar structure with the composite core is demonstrated.
Proceedings ArticleDOI
Using parallel windings in planar magnetic components
TL;DR: In this article, the authors present a review of the proper modeling strategy in order to take into account the current distribution through each paralleled winding, and apply better interleaving among the different windings.
Proceedings ArticleDOI
Optimal design and tradeoffs analysis for planar transformer in high power DC-DC converters
TL;DR: An improved interleaving structure with optimal behaviors is proposed in this paper, which constructs the top layer paralleling with the bottom layer and then in series with the other turns of the primary so that a lower magneto motive force (MMF) ratio m can be obtained as well as minimized AC resistance, leakage inductance and even stray capacitance.
Journal ArticleDOI
Two-dimensional analysis of the edge effect field and losses in high-frequency transformer foils
TL;DR: In this paper, the authors examined the case of a foil winding undergoing edge effect, a typical situation where classical one-dimensional theories underestimate the real losses, and systematically analyzed the dependence of the 2D field and the corresponding extra losses with the geometrical design variables describing the dimension and position of the winding.
Proceedings ArticleDOI
Transient thermal model of a medium frequency power transformer
TL;DR: In this article, a dynamic thermal model is introduced, with equivalent non-linear temperature dependent thermal resistances, and heat sources are determined taking into account non-sinusoidal excitations, and frequency dependent effects.
References
More filters
Journal ArticleDOI
Effective resistance to alternating currents of multilayer windings
Edward Bennett,Sidney C. Larson +1 more
TL;DR: In this article, a multilayer winding carrying an alternating current, such as the windings illustrated in figures 1, 2, and 3, each layer of copper lies in the alternating magnetic field set up by the current in all the other layers.
Journal ArticleDOI
Eddy Currents in Large Slot-Wound Conductors
TL;DR: In this article, the authors discuss the more important causes of eddy currents in heavy conductors carrying alternating currents and surrounded on three sides by iron, and propose a method to identify the most important causes.
Journal ArticleDOI
Effective Resistance to Alternating Currents of Multilayer Windings
Journal ArticleDOI
Eddy-Current Losses in Cylindrical Conductors, with Special Applications to the Alternating Current Resistances of Short Coils
TL;DR: In this article, it is shown that a considerable proportion of the effective resistance of inductive coils when used at radio frequencies is caused by the eddy-currents set up in the wires of the coils by the alternating magnetic field in which they are situated, and that in extreme cases the alternating current resistance may amount to more than one hundred times the direct current resistance.
Journal ArticleDOI
Heat Losses in the Conductors of Alternating-Current Machines
TL;DR: In this article, the authors show how hyperbolic functions of complex angles may be applied to the solution of the problem of heat losses in rectangular conductors that are embedded in open slots.