AC loss reduction of a 6.6kV superconducting fault current limiter
- Toshiba Corp., Kawasaki (Japan). Research and Development Center
- Tokyo Electric Power Co., Yokohama (Japan). Power Engineering R and D Center
The authors have been investigating a 6.6kV superconducting fault current limiter (SCFCL) for use in power distribution systems. For practical application, heat load at 4.2 K must be reduced to a level which can be compensated by a small refrigerator. This paper describes AC loss reduction of a SCFCL coil, which is comprised of a conductor and junctions. The conductor is a cable of double-twisted multi-filament NbTi strands in a high-resistivity CuNi matrix. The filament diameter in strands and the filament twist pitch were reduced for AC loss reduction. Current junctions made of copper generate eddy current loss because an alternating magnetic field is applied on them by the conductor. It was confirmed experimentally that cylindrical-shaped junctions effectively reduced the loss. A total coil loss of 0.8 W at 1 kA has been achieved, which value is sufficiently low for the development of a closed cryostat of superconducting fault current limiter compensated by a small refrigerator.
- OSTI ID:
- 287654
- Report Number(s):
- CONF-950691-; ISSN 0018-9464; TRN: IM9639%%243
- Journal Information:
- IEEE Transactions on Magnetics, Vol. 32, Issue 4Pt1; Conference: 14. international conference on magnet technology, Tampere (Finland), 11-16 Jun 1995; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Internally cooled cable superconductor (ICCS) for TF and PF coils of FED
50-Hz ac losses in inductive coils with mixed matrix fine filament NbTi composites at fields up to 1 T