| 1. |
- Schönborg, Niclas, et al.
(författare)
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Impact of DC components in transport current and external magnetic field on hysteresis losses in an HTS tape
- 2004
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Ingår i: IEEE transactions on applied superconductivity (Print). - 1051-8223 .- 1558-2515. ; 14:3, s. 1955-1958
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Tidskriftsartikel (refereegranskat)abstract
- The high-temperature superconductor (HTS) development is presently intensive, and one can expect that HTSs will be used in different electric devices in the future. In some of these devices, e.g., a magnetostrictive actuator, the conductor will be exposed to both ac and dc transport currents and external magnetic fields. One of the most important parameters in the design of electric devices is the power loss. It is, therefore, of importance to develop models that are able to predict the power loss in devices based on HTSs. In this paper, we present an experimental characterization of the hysteresis losses in an HTS tape exposed to ac or dc transport currents in combination with external magnetic fields. The experimental results are compared to some existing models based on the critical state model. The power loss was measured on a multifilamentary Bi-2223 tape at constant temperature (70 K) and frequency (50 Hz).
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| 2. |
- Wass, Torbjörn, et al.
(författare)
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AC losses in applied longitudinal magnetic fields at variable temperatures
- 2004
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Ingår i: IEEE transactions on applied superconductivity (Print). - 1051-8223 .- 1558-2515. ; 14:1, s. 22-27
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Tidskriftsartikel (refereegranskat)abstract
- In most power devices, the conductor is carrying anac transport current while it is exposed to an ac magnetic fieldtransverse to the current path. In certain applications, such aspower cables or a control winding in a controllable reactor, theconductors are exposed to a magnetic field component longitudinalto the tape axis that is parallel to the current path. To createan improved base for the design of such power devices it is ofinterest to study the losses in high-temperature superconductortapes due to longitudinal field in detail. We have investigated thelosses at several temperatures of a nontwisted multifilamentaryBi-2223 tape when it was exposed to a longitudinal magnetic field.The losses were measured with a calorimetric method and theresults were compared with the critical state hysteresis loss model.The hysteresis losses are dominating at power frequencies (50,60 Hz) in the investigated field range 2–200 mT and are accuratelydescribed by the critical state hysteresis model.
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| 3. |
- Wolfbrandt, Anna, et al.
(författare)
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AC losses in a BSCCO/Ag tape carrying AC transport currents in AC magnetic fields applied in different orientations
- 2001
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Ingår i: IEEE transactions on applied superconductivity (Print). - : Institute of Electrical and Electronics Engineers (IEEE). - 1051-8223 .- 1558-2515. ; 11:4, s. 4123-4127
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Tidskriftsartikel (refereegranskat)abstract
- In most prospective electric power applications of high-temperature superconductors (HTSs), the conductor is wound in a coil configuration. For a coil of finite length, the magnetic field orientation is axial in the middle of the coil, while the field contains a substantial radial component at the coil ends. In a superconducting BSCCO/Ag tape, the ac losses depend strongly on the orientation of the magnetic field. In this study, we present experimental results of the ac losses in a multifilamentary silver-sheathed Bi-2223 HTSs tape, carrying alternating transport currents in externally applied alternating magnetic fields at different orientations, with respect to the face of the tape and perpendicular to the transport current. The ac losses were measured calorimetrically, at fixed temperature and frequency. The results are compared to semi-empirical models of the ac losses in HTSs tape. We present a more general model of the angular dependence of the ac losses.
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