SMES-UPS for large-scaled SC magnet system of LHD

Shuichi Yamada*, T. Mito, H. Chikaraishi, A. Nishimura, H. Kojima, Y. Nakanishi, T. Uede, T. Satow, O. Motojima

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The LHD is an SC experimental fusion device of heliotron type. Eight sets of the helium compressors with total electric power of 3.5 MW are installed in the cryogenic system. The analytical studies of the SMES-UPS for the compressors under the deep voltage sag are reported in this paper. The amplitude and frequency of the voltage decrease gradually by the regenerating effect of the induction motors. The SMES-UPS system proposed in this report has the following functions; (1) variable frequency control, (2) regulations by ACR and AVR, and (3) rapid isolation and synchronous reconnection from the loads to grid line. We have demonstrated that SMES was useful for the large-scaled cryogenic system of the experimental fusion device.

Original languageEnglish
Pages (from-to)1149-1153
Number of pages5
JournalFusion Engineering and Design
Publication statusPublished - 2003 Sept
Externally publishedYes


  • Cryogenic system
  • Induction motor
  • LHD
  • SMES
  • UPS
  • Voltage sag

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • General Materials Science
  • Mechanical Engineering


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