scholarly journals Prediction of Eddy Current Losses in Cooling Tubes of Direct Cooled Windings in Electric Machines

Mathematics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 1096 ◽  
Author(s):  
Mohamed Nabil Fathy Ibrahim ◽  
Peter Sergeant
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Eddy Current ◽  
Electric Machines ◽  
Iron Core ◽  
Commercial Software ◽  
Eddy Current Losses ◽  
Switched Reluctance ◽  
Element Simulation ◽  
Core Losses

The direct coil cooling method is one of the existing cooling techniques for electric machines with concentrated windings, in which cooling tubes of conductive material are inserted between the windings. In such cases, eddy current losses are induced in those cooling tubes because of the time variant magnetic field. To compute the cooling tubes losses, either a transient finite element simulation (mostly based on commercial software), or a full analytical method, which is more complex to be constructed, is required. Instead, this paper proposes a simple and an accurate combined semi-analytical-finite element method to calculate the losses of electric machines having cooling tubes. The 2D magnetostatic solution of the magnetic field is obtained e.g., using the free package “FEMM”. Then, the eddy current losses in the tubes are computed using simple analytical equations. In addition, the iron core losses could be obtained. In order to validate the proposed method, two cases are investigated. In Case 1, a six-toothed stator of a switched reluctance machine (SRM), without rotor, is employed in which six cooling tubes are used while in Case 2 a complete rotating SRM is studied. The proposed method is validated by a 2D transient simulation in the commercial software “ANSYS Maxwell” and also by experimental measurements. Evidently, the proposed method is simple and fast to be constructed and it is almost free of cost.

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.

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.  

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