Journal ArticleDOI
Effects of eddy currents in transformer windings
P.L. Dowell
- Vol. 113, Iss: 8, pp 1387-1394
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
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Journal ArticleDOI
Calculation of leakage inductance in transformer windings
TL;DR: In this article, the authors presented a formula to calculate mutual impedance between transformer windings on ferromagnetic cores, which is based on the solution of Maxwell's equations for coils.
Proceedings ArticleDOI
Characterizing high-frequency effects in transformer windings-a guide to several significant articles
TL;DR: Several papers pertaining to the design and modeling of high-frequency transformer windings are reviewed in this paper, stressing their significant contributions and their relationship to the others, and the understandability and applicability are evaluated.
Journal ArticleDOI
Analytical Optimization of Solid–Round-Wire Windings
TL;DR: New closed-form analytical equations are derived for the normalized solid-round-wire diameter to achieve minimum ac winding losses for sinusoidal current that enable inductor and transformer designers to minimize winding loss without utilizing finite-element method analysis.
Journal ArticleDOI
High-frequency high-density converters for distributed power supply systems
J.G. Kassakian,M.F. Schlecht +1 more
TL;DR: The technical challenges of developing very high-power-density power supplies operating of switching frequencies in the vicinity of 10 MHz are considered in this article, where it is shown that successful development requires simultaneous considerations of topologies, materials, devices, control, electromagnetic interference, manufacturing, and packaging.
Proceedings ArticleDOI
Lumped parameter models for single- and multiple-layer inductors
TL;DR: In this paper, a method for modeling inductors under high-frequency operation is presented, which is based on analytical approaches which can predict turn inductances, turn-to-turn and turnto-core capacitances using physical structure of windings.
References
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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.