Calculation of eddy current losses in nonlinear ferromagnetic materials

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.

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Numerical analysis of eddy current losses in infinitely long, thin non-magnetic conductive plates.

IEEJ Transactions on Power and Energy ◽

10.1541/ieejpes1972.109.339 ◽

1989 ◽

Vol 109 (8) ◽

pp. 339-346

Author(s):

Takao Takahashi

Keyword(s):

Numerical Analysis ◽

Eddy Current ◽

Eddy Current Losses

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

Journal of Materials Research ◽

10.1557/jmr.1997.0401 ◽

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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