Title :
Stability and safety estimates and tests of a superconducting bus-line for large-scale superconducting coils
Author :
Mito, T. ; Yamada, S. ; Chikaraishi, H. ; Takahata, K. ; Yanagi, N. ; Iwamoto, A. ; Nishimura, A. ; Tanahashi, S. ; Motojima, O. ; Yamamoto, J. ; Uede, T. ; Hiue, H. ; Ueda, K. ; Itoh, I.
Author_Institution :
Nat. Inst. for Fusion Sci., Gifu, Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
We have been developing a flexible superconducting bus-line as a unit electrical feeder between large-scale superconducting coils and their power supplies away from the coils. The designed superconducting bus-line consists of a pair of +/- aluminum stabilized NbTi/Cu compacted strand cables and a coaxial four-channel transfer line. A full-scale model of the SC bus-line (20 m long) has been constructed and tested successfully up to 40 kA without a quench under the short-circuit condition. Stability tests were also done by inducing a forced quench with heaters. A minimum propagation current larger than 32.5 kA was confirmed. Thus, the bus-line was cryogenically stabilized at the rated current of 30 kA. We have examined the test results and evaluated the stability and safety margins of this bus-line. The design criteria for a superconducting bus-line are also shown for large-scale superconducting coils with operating current as a parameter.<>
Keywords :
copper; fusion reactor instrumentation; fusion reactors; niobium alloys; power supplies to apparatus; quenching (thermal); safety; short-circuit currents; stability; superconducting cables; superconducting coils; superconducting device testing; titanium alloys; 20 m; 30 to 40 kA; Large Helical Device; NbTi-Cu; aluminum stabilized NbTi/Cu compacted strand cables; beliotron/torsatron fusion device; coaxial four-channel transfer line; cryogenically stabilized bus line; forced quench; minimum propagation current; power supplies; safety estimates; short-circuit condition; stability tests; superconducting bus-line tests; superconducting coils; unit electrical feeder; Aluminum; Coaxial cables; Large-scale systems; Niobium compounds; Power supplies; Safety; Stability; Superconducting cables; Superconducting coils; Testing;
Journal_Title :
Applied Superconductivity, IEEE Transactions on