DIFFER
DIFFER Publication

Simulation of Non-Uniform Current Distribution in Stacked HTS Tapes

Author
Abstract

Low-Temperature Superconductors (LTS) are sensitive to non-uniform current distribution, which produces quenching. So, transposition of strands is indispensable in LTS cables to help current redistribution. In contrast, High-Temperature Superconductors (HTS) have higher thermal stability, which is expected to help current redistribution among strands (tapes) without quenching. Generally, HTS cable designs consider transposition to reduce quench likelihood and better handling AC operation. However, transposition causes mechanical strain in the tapes, reducing their performance. Recently, a 20-kA-class Stacked Tapes Assembled in Rigid Structure (STARS) conductor is being developed at NIFS, for the next-generation helical devices. To weigh the simple stacking feasibility of HTS tapes, a previous experiment confirmed, that 5 non-transposed HTS tapes can stably conduct a worst-case non-uniform current distribution without quenching. This further suggests that when using HTS tapes for DC HTS cables, transposition may be optional, but not strictly required. A numerical simulation was developed, dealing with the current distribution among the HTS tapes in a worst-case scenario, reproducing the previous experimental observation, and a second experiment was performed to give insights into the contact resistance between HTS tapes. The self-magnetic field effect and temperature fluctuations are to be explored for quench scenarios.

Year of Publication
2022
Journal
Plasma and Fusion Research
Volume
17
Number of Pages
2405066
Date Published
07/2022
DOI
10.1585/pfr.17.2405066
PId
9a2c70f38c0a55e4db3efb60288afb42
Alternate Journal
Plasma Fusion Res.
Label
OA
Journal Article
Download citation