The transmission of alternating-current power with small eddy-current losses

1937 ◽  
Vol 80 (484) ◽  
pp. 395-400 ◽  
Author(s):  
A.H.M. Arnold
Keyword(s):  
Eddy Current ◽  
Alternating Current ◽  
Eddy Current Losses ◽  
Small Eddy

Magnetostrictive Properties of Epoxy-Bonded Tb0,3Dy0,7Fe1,9 Composites

2010 ◽  
Vol 89-91 ◽  
pp. 633-638 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Anna Wydrzyńska ◽  
Oleksii Iesenchuk ◽  
Ryszard Żuberek
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Matrix Composite ◽  
Polymer Matrix ◽  
Eddy Current ◽  
Manufacturing Technology ◽  
Polymer Matrix Composite ◽  
Eddy Current Losses ◽  
The Cost ◽  
Small Eddy

Tb0,3Dy0,7Fe1,9 composites attract much attention due to their large magnetostriction, and small eddy current losses. In this work intelligent polymer matrix composite materials consisting of Tb0,3Dy0,7Fe1,9 particles was obtained by mixing epoxy resin and Tb0,3Dy0,7Fe1,9 powder with grains from 38 to 106 μm. The relationships among the manufacturing technology of these materials, their microstructure, as well as their magnetostriction were evaluated. Resulting composites can extend the possibilities of application the magnetostrictive materials simultaneously reduce the cost of Tb0,3Dy0,7Fe1,9.

Note on Eddy Current Losses in the Sheaths of Rectifier Cables

1930 ◽  
Vol 26 (1) ◽  
pp. 115-116
Author(s):  
F. W. Carter
Keyword(s):  
Eddy Current ◽  
Current System ◽  
Alternating Current ◽  
Mercury Vapour ◽  
Present Communication ◽  
Eddy Current Losses

In previous communications to the Society the author has discussed the eddy current losses in the sheaths of cables supplying a polyphase alternating current system; and has given equations from which the loss could be computed in any case. The present communication deals with the particular case of the cables leading from the supply-transformers to the electrodes of a mercury vapour rectifier, and derives interest from the fact that the loss in the sheaths is found to be substantially independent of their nature.

scholarly journals III. Eddy-current losses in cylindrical conductors, with special applications to the alternating current resistances of short coils

1922 ◽  
Vol 222 (594-604) ◽  
pp. 57-100 ◽  
Keyword(s):  
Eddy Current ◽  
Eddy Currents ◽  
Alternating Current ◽  
Considerable Proportion ◽  
General Effect ◽  
Eddy Current Losses ◽  
Direct Current Resistance ◽  
Set Up ◽  
Cylindrical Conductors ◽  
Current Resistance

It is well-known 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. It is therefore important to have reliable formulæ for the eddy-current resistance of such coils in order to determine the conditions which will reduce the eddy-current losses to a minimum. The simplest case, that of a long straight cylindrical wire under the action of its own current, has been treated by Kelvin, Rayleigh, Heaviside, and others. The general effect is known as the “skin effect,” because the current tends to concentrate more and more upon the skin of the conductor as the frequency increases.

Determination of eddy current losses and hysteresis losses in magnetic circuits of electrical machines

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov
Keyword(s):  
Eddy Current ◽  
Magnetization Reversal ◽  
Eddy Currents ◽  
Technical Problem ◽  
Electrical Machines ◽  
Eddy Current Losses ◽  
Hysteresis Losses ◽  
Magnetic Circuits ◽  
Core Losses ◽  
Reversal Frequency

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.

Losses in ac of BSCCO-2223 superconducting monofilament and multifilament tapes at power frequencies

1997 ◽  
Vol 12 (11) ◽  
pp. 3085-3089
Author(s):  
S. Mench ◽  
M. Lelovic ◽  
T. Deis ◽  
N. G. Eror ◽  
U. Balachandran ◽  
...  
Keyword(s):  
Eddy Current ◽  
Anisotropy Field ◽  
Magnetic Losses ◽  
Field Orientation ◽  
Eddy Current Losses ◽  
Order Of Magnitude

The ac magnetic losses at power frequencies (60 Hz) were investigated for mono- and multifilament Ag-sheathed (Bi, Pb)2Sr2Ca2Cu3Oy (BSCCO-2223) tapes with similar Ic values at 77 K. The multifilament sample exhibited higher losses than the monofilament under the same conditions. Loss peaks are discussed in terms of intergranular, intragranular, and eddy current losses. Because of BSCCO's anisotropy, field orientation has a large effect on the magnitude of these peaks, even at relatively small angles. Losses for fields applied parallel to the c-axis of the textured BSCCO grains are larger by over an order of magnitude than those applied perpendicular.

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