Stability evaluation of a conduction-cooled prototype LTS pulse coil for UPS-SMES

Akifumi Kawagoe, Fumio Sumiyoshi, Toshiyuki Mito, Hirotaka Chikaraishi, Ryuji Maekawa, Kazutaka Seo, Tomosumi Baba, Tsutomu Henmi, Kagao Okumura, Masataka Iwakuma, Kazuo Hayashi, Ryo Abe

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The stability of a prototype conduction-cooled LTS pulse coil for UPS-SMES of 100 kJ was evaluated. This coil has been developed as a first step of a project to develop a 1 MW, 1 UPS-SMES to protect semiconductor chip production equipment and nuclear fusion experimental devices, etc, from momentary voltage drop and power failure. The winding conductor is an NbTi/Cu Rutherford cable, which is extruded with aluminum. This conductor has both low AC losses and high stability under specified orientation of changing transverse magnetic fields. The 100 kJ-coil are wound by the new winding method. In order to improve the heat conduction properties in the coil, Dyneema FRP and Litz wires are used as spacers. Litz wires were connected with the cryocooler as cooling paths. On the pulse operation, the operating current is reduced from 1000 A to 707 A in 1 s. In this paper, the thermal properties of the 100 kJ-coil are calculated by finite element method under pulse operation. In order to estimate the stability, a calibration experiment was carried out. Results indicated that our prototype LTS pulse coil has high stability to enable to allow over 10 times as large heat as AC losses.

Original languageEnglish
Pages (from-to)1891-1894
Number of pages4
JournalIEEE Transactions on Applied Superconductivity
Issue number2 PART II
Publication statusPublished - Jun 2005

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Stability evaluation of a conduction-cooled prototype LTS pulse coil for UPS-SMES'. Together they form a unique fingerprint.

Cite this