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
Mass-Optimal Design Methodology for DC-DC Converters in Low-Power Portable Fuel Cell Applications
TL;DR: In this article, the tradeoff between efficiency and converter mass was investigated for low-power portable energy source market, and the effect of desired run-time or mission duration on the optimal dc-dc converter design was explored in detail.
Journal ArticleDOI
Winding Resistance and Power Loss of Inductors With Litz and Solid-Round Wires
TL;DR: An analytical model based on the one-dimensional Dowell's equation for computing the ac-to-dc winding resistance ratio of the litz-wire windings independent of the porosity factor is derived in this article.
Proceedings ArticleDOI
Reducing ac-winding losses in high-current high-power inductors
TL;DR: In this article, the authors proposed a two-winding technique to reduce the dc-current losses in high-current high-power inductors by using an inner auxiliary winding, which is connected in parallel with an outer main winding.
Journal ArticleDOI
High-efficiency on-board battery charger with transformer isolation, sinusoidal input current and maximum power factor
TL;DR: In this paper, a battery charger was developed for use in a battery powered electric road vehicle to charge the 144 V traction battery directly from the 220 V supply by drawing sinusoidal current at the input, to obtain, a high efficiency and to have transformer isolation from the supply.
Proceedings ArticleDOI
High-frequency models of ferrite core inductors
TL;DR: In this paper, a model of ferrite core inductors is presented, where the skin and proximity effects which increase the ac resistance of the inductor winding are considered, and the core losses are modeled by means of a frequency dependent series resistance.
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.