Comparison of transport and magnetic AC losses in Bi-2223/Ag tapes — the role of superconducting core geometry

Gömöry, Fedor; Gherardi, Laura; Crotti, G.; Bettinelli, Daniela; Martini, L.; Bigoni, L.; Zannella, S.

doi:10.1016/s0921-4534(98)00455-9

Cited by 13 publications

(9 citation statements)

References 10 publications

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“…62 Furthermore, experimental evidence of a kink in actual superconducting tapes was shown for the case of a Ag/Bi-2223 tape with the superconducting core shaped as a circular shell 63 or two concentric elliptical shells. 40 Another interesting result for the Љ calculations is shown in Fig. 19, where we show the calculated results for x arrays of several strips with b/aϭ0.01 with a fixed separation distance of d/aϭ0.02.…”

Section: B Horizontal Arraysmentioning

confidence: 85%

“…This is the limiting case of filaments with a high number of intergrowths [35][36][37][38][39] or when coupling currents through the conducting matrix are of the same magnitude as the superconducting currents. 10,34,40,41 As explained in these references and below, the magnetic behavior for each of these two filament connection case is strongly different. Therefore, a detailed study of ac losses in superconducting cables should include these two cases.…”

Section: Introductionmentioning

confidence: 96%

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Magnetic properties of arrays of superconducting strips in a perpendicular field

2003

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Current profiles and field lines and magnetization and ac losses are calculated for arrays of infinitely long superconducting strips in the critical state in a perpendicularly applied magnetic field. The strips are arranged vertically, horizontally, and in a matrix configuration, which are the geometries found in many actual high-T c superconducting tapes. The finite thickness of the strips and the effects of demagnetizing fields are considered. Systematic results for the magnetization and ac losses of the arrays are obtained as function of the geometry and separation of the constituent strips. Results allow us to understand some unexplained features observed in experiments, as well as to propose some future directions.

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Section: B Horizontal Arraysmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 96%

Magnetic properties of arrays of superconducting strips in a perpendicular field

2003

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“…We apply the model to two different cases of filament connection: when the filaments are all interconnected or when they are isolated from each other. For AC loss reduction the latter is the preferred one [2], [11], although the former is often encountered in practice when there are filaments with a high number of intergrowths [12], [13] or when coupling currents through the conducting matrix are of the same magnitude as the superconducting currents [11], [14], [15].…”

Section: Modelmentioning

confidence: 99%

Theoretical AC susceptibility of superconducting multifilamentary tapes in a perpendicular field

Pardo

Sanchez

Navau

2003

IEEE Trans. Appl. Supercond.

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We study theoretically the AC susceptibility of hard type-II superconducting multifilamentary tape when placed in a perpendicular AC magnetic field. We focus on three different arrangements of identical filaments of rectangular cross-section: three filaments stacked in the applied field direction (vertical array), three filaments aligned in the field perpendicular direction (horizontal array), and the case of a 3 3 filament matrix. Real and imaginary AC susceptibility are calculated within the critical state framework. For the geometries of horizontal array and matrix are studied the cases whether the critical current returns inside each filament or it returns to the other filament placed symmetrically in the horizontal direction.

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“…It was reported by Eckelmann et al that, by twisting the filaments before rolling into a flat tape, one can reduce the coupling current loss [31]. It is also known that filament twisting can reduce AC losses in the transverse magnetic field [31][32][33][34][35][36][37][38][39][40][41][42]. AC losses in filamental BSCCO tapes, in general, can be effectively reduced when the filament size, the electrical resistivity of the matrix, and the twist-pitch of the filaments are properly modified [36].…”

Section: Introductionmentioning

confidence: 99%

Transport AC losses of Ag-sheathed Bi-2223 tapes with different twist-pitch using electrical methods

Jang¹,

Wong‐Ng²

2005

Supercond. Sci. Technol.

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A series of Bi-2223 ([Bi, Pb]:Sr:Ca:Cu:O = 2:2:2:3) tapes with 37 superconducting core filaments was investigated in an attempt to correlate critical current and alternating current (AC) losses with twist-pitch. The twist-pitch of these multi-filamentary tapes which were produced by the powder-in-(Ag)tube (PIT) method varies from 8, 10, 13, 30, 50, 70 mm to ∞ mm (non-twist). Critical current (I c) measurements which were conducted in zero field by a four-probe method under liquid-nitrogen temperature showed that I c is greater in the non-twist filament than that in twisted filaments. Among these tapes, three (twist-pitch of 10, 13, and 70 mm) were selected for AC loss experiments under a time-varying transport current. The results of AC loss measurements in general agree with that of the AC loss simulation using the ellipse model of the Norris equation. Simulation results show that the hysteretic AC loss is lowest in the non-twist tape and increases as the twist-pitch decreases. A much greater loss was found in tapes with small twist-pitch, i.e. 10 and 8 mm. Among different possible loss contributions to the total AC losses, the hysteretic loss was determined to be the main source. In addition, microstructural damage of tapes with small twist-pitch appears to contribute to the overall AC losses as well.

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Comparison of transport and magnetic AC losses in Bi-2223/Ag tapes — the role of superconducting core geometry

Cited by 13 publications

References 10 publications

Magnetic properties of arrays of superconducting strips in a perpendicular field

Magnetic properties of arrays of superconducting strips in a perpendicular field

Theoretical AC susceptibility of superconducting multifilamentary tapes in a perpendicular field

Transport AC losses of Ag-sheathed Bi-2223 tapes with different twist-pitch using electrical methods

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