A preliminary study of mechanical switch using high temperature superconducting material

Koichiro Sawa, Masako Suzuki, Masaru Tomita, Masato Murakami

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


A Persistent Current Switch (PCS) is a key component for Superconducting Magnetic Energy Storage (SMES) system because it is used to switch a superconducting coil from storage mode to transfer mode. In past research on a mechanical PCS for SMES, a metallic superconductor made of Nb and NbTi is used as a switching material. However, recently the research of SMES coil of a High-Temperature Superconductor (HTS) is widely carried out, in which a PCS is also expected to work in liquid nitrogen temperature. In this paper, YBCO (Yitrium Boron Copper Oxide) bulk of HTS was proposed as a switch material, and the test on the fundamental characteristics of a mechanical contact between two YBCO bulks was carried out. As a result, a switching phenomenon between low and high resistance ranges is observed at a threshold current value in the V-I characteristics of the YBCO contact. This phenomenon is also observed after the break and make action is carried out in liquid nitrogen. It means a possibility of a superconducting mechanical switch using YBCO bulks. Furthermore, the tests indicate that a certain amount of current needs to flow before the switching phenomenon. Because the discontinuous transition occurred after the surface-insulating layer formed by degradation of YBCO was destroyed in the contact area.

Original languageEnglish
Pages (from-to)128-133
Number of pages6
JournalElectrical Contacts, Proceedings of the Annual Holm Conference on Electrical Contacts
Publication statusPublished - 2001 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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