Current Degradation in Superconducting AC Coils—Causes and Stabilization

Tsukamoto, O.; Amemiya, Naoyuki; Hlasnik, I.

doi:10.1007/978-1-4757-9053-5_75

Cited by 5 publications

(2 citation statements)

References 10 publications

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“…In this case, the currents in layers 1 and 2 flow in opposite directions. This is similar to the current distribution in a multifilament wire [14]. With the transport current I = 1000 A, almost all currents pass through et al [11]; ---, value calculated using the theory of Norris [11]; --, value calculated using the electric-circuit model.…”

Section: Resultssupporting

confidence: 72%

AC loss of a high- superconducting power-cable conductor

Noji

1997

Supercond. Sci. Technol.

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We investigate the AC loss of a high-T c superconducting power-cable conductor with four layers and interlayer insulation. The electric-circuit model is applied for the calculation of the AC loss of the conductor. The result of a calculation for the AC loss shows that the calculated value is nearly equal to the experimental value; therefore this model explains the electromagnetic property of the conductor well. Moreover the result of a calculation for the current distribution of the conductor indicates that almost all the current passes through the outer layer when the transport current is less than the I c of the conductor. Finally we calculate the relation between AC loss and the spiral pitch of the high-T c superconducting wires which make up the conductor. It is found that the AC loss is markedly decreased when the spiral pitch is less than 0.5 m.

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Section: Resultssupporting

confidence: 72%

AC loss of a high- superconducting power-cable conductor

Noji

1997

Supercond. Sci. Technol.

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“…[1][2][3][4] Under the assumption that each strand is straight, i.e., as shown in Figs. 1(a) and 2(a), has been investigated experimentally and theoretically, showing the phenomena of negative current in the central strand.…”

Section: Introductionmentioning

confidence: 99%

Calculations using the helical filamentary structure for current distributions of a six around one superconducting strand cable and a multifilamentary composite

Tominaka

2004

Journal of Applied Physics

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The current and magnetic-field distributions within a twisted six around one (6-1) superconducting strand cable and a twisted simple superconducting multifilamentary composite have been studied with the assumption that the current distribution within each strand or each filament is uniform. For this purpose, the vector potential and the magnetic field due to a helical conductor with a circular cross section is calculated from the numerical integration of the analytical expression for a helical thin conductor. The current distributions among each strand or each filament are obtained by minimizing the magnetic energy for the case of the insulated strands or filaments, and by requiring zero magnetic flux enclosed between any pair of strands or filaments for the case of the noninsulated strands or filaments. For the case of the untwisted insulated strands or filaments, it is confirmed that the calculated results coincide with those due to the inductance. The screening circulation currents among strands within a multistrand cable or filaments within a composite are obtained as the difference between the current distributions for the case with the noninsulated strand or filament and for the case with the imaginarily insulated strand or filament. As a result, it is revealed that the negative current in the inner strands or filaments is a universal feature of the current distributions for superconducting multistrand cables and multifilamentary composites during the current sweep. Finally, the magnetic field distributions of a twisted 6-1 superconducting strand cable and a twisted simple superconducting multifilamentary composite have been obtained.

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