Investigation of the temperature rise due to eddy currents in large chopper disks operated at polarized neutron beamlines

Author(s):  
Hermann Stelzer ◽  
Christoph Weißbacher ◽  
Helmut Soltner ◽  
Franz Janssen ◽  
Michael Butzek ◽  
...  
2021 ◽  
Vol 16 (5) ◽  
pp. 797-805
Author(s):  
Bao-Ming Gao ◽  
Zheng-Yu Li ◽  
Jin-Wen Gao ◽  
Hao Liang ◽  
Zhi Yan ◽  
...  

Under working conditions, the conductive rods in the GIS flow through the power frequency alternating current. Due to the coupling effect of the magnetic field and electric field between the metal aluminum shell and the conductive rod, induced eddy currents are generated in the metal shell of the GIS. The heat generated by the current heating effect of the GIS conductive rod and the eddy current loss of the metal casing will cause the temperature rise of GIS equipment. Due to the limited volume, the heat dissipation capacity of GIS is poor. Excessive temperature rise will accelerate the insulation aging of GIS equipment, and even damage its insulation, which will affect safe operation. In order to obtain the temperature change law of GIS, related influencing factors such as eddy current loss, skin effect, proximity effect, convective heat transfer of SF6 gas, and gravity of SF6 gas are comprehensively considered. The finite element analysis is used to research and discuss GIS magnetic field distribution, eddy current, temperature distribution and SF6 gas velocity. The initial value of the temperature of each part is set to 293.15 K (20 °C), and the temperature in the GIS is calculated to gradually decrease from the inside to the outside under the rated AC current of 3150 A. The temperature at the conductive rod position is the highest at 335.32 K, and the temperature at the housing position is the lowest at 294.65 K.


1979 ◽  
Vol 40 (C5) ◽  
pp. C5-180-C5-182 ◽  
Author(s):  
J. X. Boucherle ◽  
D. Givord ◽  
J. Laforest ◽  
J. Schweizer ◽  
F. Tasset

1977 ◽  
Vol 38 (C1) ◽  
pp. C1-79-C1-84 ◽  
Author(s):  
N. S. SATYA MURTHY

1982 ◽  
Vol 43 (C9) ◽  
pp. C9-23-C9-29
Author(s):  
J. M. Dubois ◽  
P. Chieux ◽  
G. Le Caer ◽  
J. Schweitzer ◽  
J. Bletry

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov

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.


2014 ◽  
Vol 34 (1) ◽  
pp. 436-455 ◽  
Author(s):  
채수미 ◽  
YOONSEOKJUN ◽  
신호성 ◽  
김동진

1977 ◽  
Vol 5 (2) ◽  
pp. 102-118 ◽  
Author(s):  
H. Kaga ◽  
K. Okamoto ◽  
Y. Tozawa

Abstract An analysis by the finite element method and a related computer program is presented for an axisymmetric solid under asymmetric loads. Calculations are carried out on displacements and internal stresses and strains of a radial tire loaded on a road wheel of 600-mm diameter, a road wheel of 1707-mm diameter, and a flat plate. Agreement between calculated and experimental displacements and cord forces is quite satisfactory. The principal shear strain concentrates at the belt edge, and the strain energy increases with decreasing drum diameter. Tire temperature measurements show that the strain energy in the tire is closely related to the internal temperature rise.


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