Cristin-resultat-ID: 1162552
Sist endret: 24. november 2014, 14:18
NVI-rapporteringsår: 2014
Resultat
Vitenskapelig artikkel
2014

Coupling currents and hysteresis losses in MgB2superconductors

Bidragsytere:
  • Niklas Magnusson
  • Sandra Madeleine Lindau
  • Henning Taxt og
  • Magne Runde

Tidsskrift

Superconductors Science and Technology
ISSN 0953-2048
e-ISSN 1361-6668
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2014
Trykket: 2014
Volum: 27
Hefte: 10
Artikkelnummer: 105003
Open Access

Importkilder

Scopus-ID: 2-s2.0-84907222770

Beskrivelse Beskrivelse

Tittel

Coupling currents and hysteresis losses in MgB2superconductors

Sammendrag

MgB2 multi-filamentary superconductors are widely considered for use in dc applications. To expand the possible application range to ac apparatuses, the development of a low ac loss wire is needed. This development involves several steps, and a solid understanding of the loss mechanisms is important to optimize that process as well as for evaluating dc wires exposed to current or magnetic field ripple. In this study we discuss the coupling currents and their influence on hysteresis loss as well as on coupling current loss. We give a phenomenological explanation of the origin and behaviour of the coupling currents and describe the loss patterns for hysteresis loss and coupling current loss separately. Finally, we interpret measured ac losses in an MgB2 wire cut into different lengths representing different equivalent twist pitches. Under certain circumstances short sample lengths are shown to give inaccurate measurement results. On the other hand, short sample lengths of non-twisted wires can be used to estimate the twist pitch necessary to electromagnetically decouple the superconducting filaments. For the studied MgB2 wire, with a pure titanium matrix, the losses were mainly hysteretic, although the level of these losses was lowered when reducing the equivalent twist pitch, and thereby the coupling currents. At 35 K the reduction in loss started at an equivalent twist pitch of approximately 36 mm, where the filaments were assumed practically fully coupled. The decoupling then continued all down to the shortest equivalent twist pitch of 9 mm.

Bidragsytere

Niklas Magnusson

  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS

Sandra Madeleine Lindau

  • Tilknyttet:
    Forfatter
    ved Institutt for elektrisk energi ved Norges teknisk-naturvitenskapelige universitet

Henning Taxt

  • Tilknyttet:
    Forfatter
    ved Energisystemer ved SINTEF Energi AS

Magne Eystein Runde

Bidragsyterens navn vises på dette resultatet som Magne Runde
  • Tilknyttet:
    Forfatter
    ved Elkraftteknologi ved SINTEF Energi AS
1 - 4 av 4