Fundamental study on rotor eddy current losses in high frequency machines due to current harmonics

2015 ◽  
Author(s):  
Reza-Rajabi Moghaddam
Keyword(s):  
Eddy Current ◽  
High Frequency ◽  
Fundamental Study ◽  
Eddy Current Losses ◽  
Current Harmonics

Computation of high‐frequency TM eddy‐current losses in magnetic materials

1985 ◽  
Vol 57 (8) ◽  
pp. 3863-3865 ◽  
Author(s):  
T. H. Fawzi ◽  
M. T. Ahmed ◽  
P. E. Burke
Keyword(s):  
Magnetic Materials ◽  
Eddy Current ◽  
High Frequency ◽  
Eddy Current Losses

scholarly journals Spectral Element Method Modeling of Eddy Current Losses in High-Frequency Transformers

2019 ◽  
Vol 24 (1) ◽  
pp. 28 ◽  
Author(s):  
Koen Bastiaens ◽  
Mitrofan Curti ◽  
Dave Krop ◽  
Sultan Jumayev ◽  
Elena Lomonova
Keyword(s):  
Eddy Current ◽  
High Frequency ◽  
Spectral Element Method ◽  
Spectral Element ◽  
High Ratio ◽  
Two Dimensional ◽  
Eddy Current Losses ◽  
High Frequency Transformer ◽  
Benchmark System ◽  
Element Method

This paper concerns the modeling of eddy current losses in conductive materials in the vicinity of a high-frequency transformer; more specifically, in two-dimensional problems where a high ratio between the object dimensions and the skin-depth exists. The analysis is performed using the Spectral Element Method (SEM), where high order Legendre–Gauss–Lobatto polynomials are applied to increase the accuracy of the results with respect to the Finite Element Method (FEM). A convergence analysis is performed on a two-dimensional benchmark system, for both the SEM and FEM. The benchmark system consists of a high-frequency transformer confined by a conductive cylinder and is free of complex geometrical shapes. Two different objectives are investigated. First, the discretizations at which the relative error with respect to a reference solution is minimized are compared. Second, the discretizations at which the trade-off between computational effort and accuracy is optimized are compared. The results indicated that by applying the SEM to the two-dimensional benchmark system, a higher accuracy per degree of freedom and significantly lower computation time are obtained with respect to the FEM. Therefore, the SEM is proven to be particularly useful for this type of problem.

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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