Study on Thermal-Quench Behaviors of GdBCO Coils Wound with Silicon Grease as an Insulation Material

Seong Gyeom Kim, Yoon Hyuck Choi, Dong Gyu Yang, Seol Hee Jeong, Ji Hyung Kim, Ho Min Kim, Yeon Suk Choi, Haigun Lee

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

This paper investigated quench initiation and propagation characteristics of grease insulation coils by conducting thermal-quench tests for two GdBCO single-pancake coils, namely a coil co-wound with silicon grease (termed as the SiG coil) and the other coil co-wound with Kapton tape (termed as the INS coil), as turn-to-turn insulation. The test results confirmed that the SiG coil exhibited better thermal and electrical stabilities when compared with the INS coil because the operating current could be bypassed in the radial direction through the turn-to-turn contacts when a local hot spot was generated. The SiG coil had superior thermal and electrical stabilities. However, a nonrecovering resistive zone could be generated because excessive Joule heat energy could be induced by radial current flow due to the existence of radial resistance that was mainly generated by silicon grease and nonsuperconducting materials including the substrate, stabilizer, and buffer layers within the high-temperature superconductor (HTS). Therefore, it is essential to consider critical Joule heat energy that is influenced by operating current and stored magnetic energy as well as the radial resistance to achieve self-protective 2G HTS coils.

Original languageEnglish
Article number7805225
JournalIEEE Transactions on Applied Superconductivity
Volume27
Issue number4
DOIs
Publication statusPublished - 2017 Jun 1

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Keywords

  • GdBCO coils
  • grease insulation
  • high-temperature superconductor (HTS)
  • thermal and electrical stabilities
  • thermal-quench behavior

ASJC Scopus subject areas

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

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