Eddy currents in thin circular cylinders of uniform conductivity, due to periodically changing magnetic fields, in two dimensions

1927 ◽  
Vol 23 (8) ◽  
pp. 901-906 ◽  
Author(s):  
F. W. Carter
Keyword(s):  
Eddy Current ◽  
Eddy Currents ◽  
Two Dimensions ◽  
Circular Cylinders ◽  
Two Dimensional ◽  
Total Field ◽  
Current Field ◽  
Conducting Material ◽  
Eddy Current Losses ◽  
Three Phase

The paper deals with the eddy currents in thin circular cylinders of uniform conducting material, due to periodic currents in conductors lying parallel to the axis of the cylinder, or to the rotation of the cylinder in a two-dimensional field of force. The first of these problems was discussed by Mr M. B. Field in a paper entitled “Eddy current losses in three-phase cable sheaths,” read before the British Association at their Cambridge meeting in 1904. The solution proposed, however, although probably sufficient for the object, is mathematically defective, in that the field due to the current carried by the cable is assumed as the total field, the effect of the eddy-current field on the eddy currents themselves being left out of account.

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.

scholarly journals Increasing the required slip range of wound induction generator in wind power systems

2020 ◽  
Vol 9 (2) ◽  
pp. 436-442
Author(s):  
Ali Dalabeeh ◽  
Al-Mofleh Anwar ◽  
Tariq M. Younes ◽  
Ayman Al-Rawashdeh ◽  
Ayman Hindi
Keyword(s):  
Power Systems ◽  
Wind Turbine ◽  
Eddy Current ◽  
Power Flow ◽  
Eddy Currents ◽  
Reactive Power ◽  
Induction Generator ◽  
Material Loss ◽  
Eddy Current Losses ◽  
Wound Induction

Eddy currents losses in the rotor in high power generators do not allow operators, under high values of slip, to regulate voltage and control of reactive power flow. The paper presents a method that can accurately estimate the eddy current losses in electric machines with a less complicated procedure. The suggested method allows researchers to analyze and reduce the losses, and consequently, to improve the wind turbine induction generators efficiencies. The given approach, based on the conventional electric machine theory and the parameters supplied by the manufacturers, predicts the eddy current losses theoretically without the need of the measured material loss data or BH curve. Increasing the range of slip variation of induction motor can be achieved by using a rotor of two layers in the radial direction with different parameters. The first layer is a laminated layer of height (h), and the second is a solid (the rotor yoke). The computation of eddy current losses is useful to change the design of the machine to minimize the losses. This paper presents a detailed modeling of the effect parameters on the eddy current losses in wind turbine induction generator.

scholarly journals Analisa Stray Losses Pada Struktur Transformator Daya Satu Fasa 275 Kv 83.3 MVA

2020 ◽  
Vol 1 (1) ◽  
pp. 32-40
Author(s):  
Asep Saepudin Saepudin
Keyword(s):  
Finite Element ◽  
Eddy Current ◽  
Simulation Study ◽  
Single Phase ◽  
3D Finite Element ◽  
Eddy Current Losses ◽  
Versus Measurement ◽  
Three Phase

Background The jurnal discusse stray losses are generated by eddy current losses in the single phase transformer construction parts, such as Main tank, cover,core clamp and flitch plate. Stray losses can’t measurement direct and only calculated. Aim This study is to accurate calculated stray losses are generated in the single phase transformer construction parts in order to get more accurate calculated compared with measured and to know calculation versus measurement and versus simulation. Method This study using 3D Finite Element Metode with basis software ANSYS in the single phase transformer construction parts Result The stray losses in the single phase transformer construction parts, so that it hasn’t a simple stray losses divided by 3 compared to three phase transformers with same power and voltage. Conclusion Base on this study the total stray losses around 30%-37% from Load Losses and impove approxi-mately 9% compared between existing calculation and this simulation study versus measurement.  

AC losses of Roebel and CORC® cables at higher AC magnetic fields and Ramp Rates

2021 ◽  
Author(s):  
Mike D Sumption ◽  
John Murphy ◽  
Timothy J Haugan ◽  
Milan Majoros ◽  
Danko C van der Laan ◽  
...  
Keyword(s):  
Eddy Current ◽  
Eddy Currents ◽  
Flux Creep ◽  
Ac Losses ◽  
Radial Magnetic Field ◽  
Eddy Current Losses ◽  
Preparation Conditions ◽  
Sinusoidal Waveform ◽  
Helical Geometry ◽  
The Individual

Abstract We have measured ReBCO coated conductor-based CORC® and Roebel cables at 77 K in a Spinning Magnet Calorimeter which subjected the tapes in the samples to a radial magnetic field of 566 mT (peak) at frequencies up to 120 Hz (272 T/s, cyclic average) with an approximately sinusoidal waveform. The samples were oriented such that the field applied to the tapes within the cables was entirely radial, simplifying subsequent analysis. An expression for loss which included hysteretic, flux creep, and eddy current losses was fit to both the CORC® and the Roebel cables. This expression allowed easy comparison of the relative influence of eddy currents and flux creep (or power-law behavior) effects. The loss of both the CORC® and Roebel cables measured here were seen to be essentially the sum of the hysteretic loss, flux creep effects, and the normal metal eddy current losses of the individual tapes. The losses of these cables were measured at high B*dB/dt with no coupling current loss observed under the present preparation conditions. The influence of flux creep effects on loss were not negligible. The losses of the CORC® cable per meter of tape were seen to be reduced from the case of a flat tape because of the helical geometry of the tapes.

Calculation of eddy current losses using the electrodynamic similarity laws

2014 ◽  
Vol 63 (1) ◽  
pp. 107-114
Author(s):  
Dariusz Koteras
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Eddy Currents ◽  
Numerical Calculations ◽  
Eddy Current Losses ◽  
Similarity Laws ◽  
Good Agreement ◽  
Element Method

Abstract The results of the eddy currents losses calculations with using electrodynamics scaling were presented in this paper. Scaling rules were used for obtain the values of the eddy currents losses. For the calculations Finite Element Method was used. Numerical calculations were verified by measurements and a good agreement was obtained

Eddy‐current losses due to a surface crack in conducting material

1977 ◽  
Vol 48 (11) ◽  
pp. 4454-4459 ◽  
Author(s):  
A. H. Kahn ◽  
R. Spal ◽  
A. Feldman
Keyword(s):  
Eddy Current ◽  
Surface Crack ◽  
Conducting Material ◽  
Eddy Current Losses
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