Contactless measurement of hysteretic transport AC losses in multifilamentary BiSrCaCuO-2223/Ag tapes

Gömöry, Fedor; Bettinelli, Daniela; Gherardi, Laura; Crotti, G.; Morin, D.

doi:10.1016/s0921-4534(98)00532-2

Cited by 8 publications

(7 citation statements)

References 9 publications

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“…This is obviously not the case for the measured total losses. By simply adding the magnetic loss and the resistive loss one expects to obtain the total loss, as it has been demonstrated for individual HTS tapes [6,7]. In the case of our stranded conductor, this is obviously not the case.…”

Section: Resultsmentioning

confidence: 82%

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Contactless electrical measurements of transport ac losses in a 3 m long superconducting cable

Træholt

Veje

Gömöry

et al. 2002

Supercond. Sci. Technol.

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The ac transport losses at 77 K of a 3 m long high-temperature superconducting (HTS) cable conductor were measured electrically using the conventional voltage signals recorded by two pairs of voltage taps (four probe measurements). Further, the signals from two contactless pick-up loops were employed. The contactless loops were placed on the same path as the wiring of the conventional voltage taps outside the cable, whereas the return path went through the centre of the former conductor, thereby encircling all of the superconducting layers. By this arrangement the magnetic part of the ac transport losses of the HTS cable could be singled out. The measurements confirmed that at currents, I, far below the critical current, I c , of the cable (I I c ) the losses are dominated by magnetic losses and above I c the magnetic losses level off and resistive losses become dominating.

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Section: Resultsmentioning

confidence: 82%

“…The oscillating magnetic (self) field that is generated by the current penetrates the superconductor in an irreversible way, so as to give rise to a hysteretic loss. The flux causing this loss can be measured by an appropriately placed contactless pick-up loop [6]. This has already been demonstrated on HTS tapes [7].…”

Section: Introductionmentioning

confidence: 95%

Contactless electrical measurements of transport ac losses in a 3 m long superconducting cable

Træholt

Veje

Gömöry

et al. 2002

Supercond. Sci. Technol.

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“…The losses have been measured at 59 Hz by a standard electrical characterization technique (see for example [10]), both with two voltage taps soldered onto the tape and by means of a contactless rectangular loop positioned beneath the tape. Figure 2 shows the measured losses as a function of the transport current, compared to the results of FEM simulations and to the prediction of Norris's analytical models [11].…”

Section: Simulationsmentioning

confidence: 99%

Analysis of Magnetic Field and Geometry Effects for the Design of HTS Devices for AC Power Applications

Grilli

Martini

Stavrev

et al. 2005

IEEE Trans. Appl. Supercond.

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Abstract-The performance of HTS devices is strongly influenced by local values of the current and field distributions. In this paper, we investigate the influence of the magnetic field and the geometrical configuration on the loss behaviour of a 200 kVA FCL prototype, composed by Bi-2223/Ag tapes wound around a cylindrical support. The investigation is performed by means of finite element computations, with the use of an axisymmetric 2D A-V formulation for taking into account the cylindrical geometry. The electrical behaviour of the superconductor is described by means of a B-dependent E-J power-law relation, derived from experimental measurements with a field of different orientation. Several geometrical configurations are analyzed and compared, in order to find the ones with the lowest AC loss.Index Terms-AC losses, finite element method, high temperature superconductors, magnetic field distribution

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“…Unfortunately, the expression (7) does not allow us to find the inverse function, E res (I) in a closed form and subsequently perform the integration in (11). In principle, it would be possible to work out an algorithm that performs the integration evaluating E res for each integration node as the root of the nonlinear equation (7).…”

Section: A Model For the Calculation Of Resistive Ac Lossmentioning

confidence: 99%

“…where we again used the fact that for the AC current (11) one finds that dI = −I a sin α dα = − I 2 a − I 2 dα. In this way, we have found that the resistive loss (16) can be expressed as…”

Section: A Model For the Calculation Of Resistive Ac Lossmentioning

confidence: 99%

Resistive losses in a high-T_cwire carrying AC current larger thanI_c

Gömöry

Janiková

Šouc

2002

Supercond. Sci. Technol.

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A procedure that allows the calculation of the resistive AC loss in a multifilamentary superconducting wire carrying AC transport current was developed. This loss mechanism, detected by the appearance of a finite drop of electrical potential along the wire, is significant when considering transport currents with amplitudes that exceed the critical current of the wire. The physical model behind our calculation for a common wire, that contains superconducting filaments in a metallic matrix, is the simple parallel combination of two elements: the superconductor standing for the properties of all the filaments, and the normal resistor representing the matrix. The total current carried by two parallel conducting paths is easily calculated for any imposed potential drop. But the inverse task-calculation of the potential drop that would force a defined current to be transported-requires us to resolve a nonlinear equation. We show how it is possible to evaluate the resistive loss by a procedure that needs to perform the root-finding operation in one point of the cycle only. The numerical integration is still necessary, but now it is easily performed because the integrand is explicitly defined. The procedure was successfully tested by comparison with experimental data.

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Contactless measurement of hysteretic transport AC losses in multifilamentary BiSrCaCuO-2223/Ag tapes

Cited by 8 publications

References 9 publications

Contactless electrical measurements of transport ac losses in a 3 m long superconducting cable

Contactless electrical measurements of transport ac losses in a 3 m long superconducting cable

Analysis of Magnetic Field and Geometry Effects for the Design of HTS Devices for AC Power Applications

Resistive losses in a high-T_cwire carrying AC current larger thanI_c

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Contactless measurement of hysteretic transport AC losses in multifilamentary BiSrCaCuO-2223/Ag tapes

Cited by 8 publications

References 9 publications

Contactless electrical measurements of transport ac losses in a 3 m long superconducting cable

Contactless electrical measurements of transport ac losses in a 3 m long superconducting cable

Analysis of Magnetic Field and Geometry Effects for the Design of HTS Devices for AC Power Applications

Resistive losses in a high-Tcwire carrying AC current larger thanIc

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Resistive losses in a high-T_cwire carrying AC current larger thanI_c