Theoretical expressions for AC losses of superconducting coils in external magnetic field and transport current with phase difference

2001 ◽  
Vol 357-360 ◽  
pp. 1205-1208 ◽  
Author(s):  
K. Kawasaki ◽  
K. Kajikawa ◽  
M. Iwakuma ◽  
K. Funaki
1995 ◽  
Vol 5 (2) ◽  
pp. 709-712 ◽  
Author(s):  
M. Ciszek ◽  
B.A. Glowacki ◽  
S.P. Ashworth ◽  
A.M. Campbell ◽  
J.E. Evetts

2006 ◽  
Vol 946 ◽  
Author(s):  
Francesco Grilli ◽  
Stephen P. Ashworth ◽  
Svetlomir Stavrev

ABSTRACTPractical applications of YBCO coated conductors (CC) involving superconducting coils will utilize tapes packed together in an arrangement resembling a vertical stack. In such configuration there is an important electromagnetic interaction between the tapes, which strongly influences the loss characteristic of the device.In the presence of an external magnetic field, the losses are reduced compared to an isolated tape because of the reduced aspect ratio of the conductor and, at least for low fields, because of an effective screening of the central part of the stack. On the contrary, in the case of AC transport current, the losses tend to increase due to the enhancement of the local field caused by the interaction of the self-field produced by neighboring tapes. In practical situations the conductor is usually subjected to both transport current and magnetic field, so that there is a trade-off between the two effects.In this paper we investigate, both experimentally and by means of finite-element method calculations, the ac loss behavior of a stack composed by a finite number of tapes in different working conditions, and we compare the AC losses to the ones of non-interacting tapes in order to determine if the use of stacked tapes is advantageous from the point of view of power dissipation.


2021 ◽  
Vol 11 (6) ◽  
pp. 2741
Author(s):  
Sergey Zanegin ◽  
Nikolay Ivanov ◽  
Vasily Zubko ◽  
Konstantin Kovalev ◽  
Ivan Shishov ◽  
...  

The article is devoted to the study of losses in devices based on high-temperature superconductors of the 2nd generation. The complexity of the devices under study increases from a single rack coil to a winding assembled from several coils, and finally to an electric machine operating in generator mode. This is the way to experimentally study the behavior of 2nd generation high temperature superconductor (2G HTS) carrying a transport current in various conditions: self-field, external DC, and AC magnetic field. Attention is also paid to the losses in the winding during its operation from the inverter, which simulates the operating conditions in the motor mode of a propulsion system.


2012 ◽  
Vol 22 (3) ◽  
pp. 4704604-4704604 ◽  
Author(s):  
T. Takao ◽  
K. Nakamura ◽  
T. Takagi ◽  
N. Tanoue ◽  
H. Murakami ◽  
...  

2006 ◽  
Vol 47 ◽  
pp. 113-117
Author(s):  
Petr Vašek

Longitudinal and transverse voltages have been measured on thin films of MgB2 with different width of superconducting transition range. The study has been performed in zero and nonzero external magnetic fields. The non-zero transverse voltage has been observed in close vicinity of the critical temperature in zero external magnetic field while far enough from Tc this voltage has been zero. In magnetic field it merges into transverse voltage which is an even function with respect to the direction of the field. Usual Hall voltage starts to appear with increasing magnetic field. At the highest field the even voltage disappears and only the Hall voltage is measurable i.e. the transverse even voltage is suppressed with increasing magnetic field and increasing transport current as well. New scaling between transverse and longitudinal resistivities has been observed in the form ρxy~dρxx/dT . This correlation is valid not only in the zero magnetic field but also in nonzero magnetic field where transverse even voltage can be detected. Several models trying to explain observed results are discussed. The most promising seems to be guided motion of the vortices.


AIP Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 117139 ◽  
Author(s):  
Xing-Xing Wan ◽  
Chen-Guang Huang ◽  
Hua-Dong Yong ◽  
You-He Zhou

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