To design a large scale superconducting fault current limiter (SFCL) for power grids, a single long-length YBCO coated conductor (CC) wire is preferred. However this single YBCO CC wire can cause a problem of unequal voltage distribution between the parts on the long wire at quench by the faults. Inhomogeneous critical current of the YBCO CCs in the SFCL is a possibility. Furthermore, sub-cooled liquid nitrogen (LN2) condition is usually used to increase current capacity of the SFCL. However, this sub-cooled condition can worsen the inhomogeneity between the YBCO CCs. Therefore, it is important to understand the relation between the unequal voltage distribution and the inhomogeneous critical currents in the single long length YBCO CC. In this paper, experiments with the same single YBCO CC wire were conducted in various temperature conditions, LN2 and sub-cooled LN2. In both experiments, the critical currents and voltage distributions generated by faults at short-circuit tests were measured. It was observed that the inhomogeneous condition impacts on the unequal voltage distribution.
Bibliographical noteFunding Information:
Manuscript received August 03, 2010; accepted November 02, 2010. Date of publication December 17, 2010; date of current version May 27, 2011. This work was supported by the Human Resources Development Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korea Government Ministry of Knowledge Economy (2007-P-EP-HM-E-08-0000).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering