DocumentCode :
1313530
Title :
Development of superconducting mechanical persistent current switch
Author :
Tsuda, Y. ; Ohara, Atsushi ; Nakamura, Shigenari ; Oomyou, N. ; Tsukamoto, Osami ; Numato, T. ; Yamamoto, Manabu
Author_Institution :
Mitsubishi Electric Corp., Amagasaki, Japan
Volume :
10
Issue :
1
fYear :
2000
fDate :
3/1/2000 12:00:00 AM
Firstpage :
804
Lastpage :
807
Abstract :
The authors developed and tested a superconducting mechanical persistent current switch for SMES applications. For the purpose of improving electric current carrying capacity of one contact up to the kA level, multiple rods of NbTi with a copper matrix were selected. Pre-experiments surveyed current carrying capacity and electrical resistance of valuable contact samples, that were different in diameter of NbTi, shape of contacts and surface treatment. Vacuum valves were manufactured on trial with most suitable contacts for this purpose, and tested in liquid helium. A quench current up to 1900-2000 A DC at single valves, and 4570 A DC at four parallel valves, resulted. The electrical contact resistance before quench was lower than the measuring resolution (<1/spl times/10/sup -10/ ohm). Vacuum valve open/close speed was improved using coned disk springs and electromagnetic repulsion coils for the driving mechanism. With repeating open/close cycles, quench currents were observed to decrease. Therefore the closing mechanism should be improved.
Keywords :
contact resistance; electrical contacts; superconducting coils; superconducting magnet energy storage; superconducting switches; NbTi-Cu; SMES applications; closing mechanism; coned disk springs; contact shape; electric current carrying capacity; electrical contact resistance; electrical resistance; electromagnetic repulsion coils; quench currents; superconducting mechanical persistent current switch; surface treatment; vacuum valves; Contacts; Electric resistance; Niobium compounds; Persistent currents; Samarium; Superconducting magnetic energy storage; Switches; Testing; Titanium compounds; Valves;
fLanguage :
English
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8223
Type :
jour
DOI :
10.1109/77.828353
Filename :
828353
Link To Document :
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