Due to the complex fabrication process, it is currently difficult to produce REBCO coated conductors with completely spatially uniform characteristics, and there is concern that localized characteristic degradation will become a factor of thermal runaway in practical use. In this study, we investigated the possibility that the application of Face-to-Face Double Stacked (FFDS) architecture to REBCO coated conductors could be a solution to this problem. In particular, the time variation of the generated voltage during overcurrent application was measured for DC and AC with various frequencies. As a result, it was found that overcurrent can be applied to a sample with FFDS architecture stably even at a load factor considerably higher than that at which thermal runaway occurs in a single coated conductor without FFDS architecture. This will not only provide a safety margin for conventionally considered applications of REBCO coated conductors, but also will expand their applicability to other applications such as rotating machines which utilize voltage-generating conditions.

This work was supported by JSPS KAKENHI Grant Number JP19H05617 and JP20H02132.