Thermo-Electromagnetic Stability of Ultrafine Multifilamentary Superconducting Cables for Industrial Frequency Use
The development from 1983 onwards of Nb-Ti ultrafine multifilamentary wires for 50—60 Hz applications has opened up many interesting perspectives in electrotechnology. The AC losses have been greatly reduced due to decreasing the filament diameter to values of 0.1 to 0.2 µm and by using a highly resistive CuNi matrix with a 30% nickel content. The low thermal conductivity and specific heat of this CuNi matrix and the very high critical current densities induce a very acute problem of thermoelectromagnetic stability. As the electromagnetic diffusivity is much higher than the thermal diffusivity, the stability is governed by an adiabatic criterion. The last experiments about various coils and different assembly configurations of industrial cables give us a large panel of results which permit us to check the validity of the theoretical calculations.
KeywordsCritical Current Density Saturated Layer High Critical Current Density Fault Current Limiter Critical Transport Current Density
Unable to display preview. Download preview PDF.
- P. Dubots, A. Février, J.C. Renard, J.C. Goyer and Hoang Gi Ky - Behaviour of multifilaments under A.C. magnetic fields. Journal de Physique, sup. 1 (1984) pp. 467–470.Google Scholar
- J.R. Cave, A. Février, T. Verhaege, A. Lacaze, Y. Laumond - Reduction of AC losses in ultra-fine multifilamentary NbTi wires. Applied Superconductivity Conference. San Francisco (1988).Google Scholar
- P. Dubots, A. Février and Hoang Gia Ky -Specific properties of NbTi ultra-fine filaments wires. International Symposium on flux pinning and electromagnetic properties in superconductors (1985). Fukuoka, Japan.Google Scholar
- A. Février, A. Guéraud, J.P. Tavergnier Thermo-electromagnetic stability of ultra-fine multifilamentary superconducting wires for 50–60 Hz uses. Applied Superconductivy Conference, San Francisco (1988).Google Scholar
- A. Février, T. Verhaege, J.P. Tavergnier, Y. Laumond, M. Bekhaled, M. Collet, V.D. Pham - 25 kV superconducting fault current limiter. This conference.Google Scholar
- J.L. Duchateau - Les instabilités magnétiques dans les composites supraconducteurs multifilamentaires. Thése Orsay (1975).Google Scholar
- J.Y. Georges, A. Février, Y. Laumond, A. Lacaze and P. Bonnet. - Performances of industrial superconducting wires for 250–60 Hz applications. This conference.Google Scholar