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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Vector potential due to a circular loop in a toroidal cavity in a high-permeability core
TL;DR: In this article, a Green's function for a circular loop in a toroidal cavity in a high-permeability material was presented, and under certain conditions, the function may be expressed in terms of Jacobi's theta functions.
Proceedings ArticleDOI
Investigation of Optimal Excitation Waveforms for Medium Frequency Transformers
TL;DR: In this article, the authors investigated various excitation voltage waveforms for the medium frequency transformer (MFT) and identified the optimal multilevel waveforms in terms of total losses and system complexity.
Dissertation
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Electro-thermal Analysis of the Coupled Inductor for Quasi-Z Source Inverters
Peng Wenshu,Ping Liu,He Minjie +2 more
TL;DR: In this article, the sources of inductor power losses and temperature rise in a quasi-Z source impedance network are analyzed, and quantitative calculation formulas are derived, and a multi-physics joint simulation model is constructed based on ANSYS finite element software.
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Magnetic noise contribution of the ferromagnetic core of induction magnetometers
Christophe Coillot,M El Moussalim,E Brun,Amine Rhouni,R Lebourgeois,Gerard Sou,Malik Mansour +6 more
TL;DR: In this article, an induction sensor, made of a ferrite ferromagnetic core, is combined with a dedicated low voltage and current noise preamplifier, designed in CMOS 0.35 µm technology.
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.