The conduction-cooled cryogenic cooling system for 1.2 kV/80 A inductive Superconducting Fault Current Limiter (SFCL) was fabricated and tested for its cooling characteristics in 2002. The observed thermal stability of the conduction-cooled system was very unreliable and precarious for the applied superconducting equipment with very large variation of currents like SFCL. Therefore, we replaced the conduction-cooled system with the sub-cooled nitrogen system for the 6.6 kV/200 A SFCL. In this paper, the design techniques and test results of cooling characteristics were introduced. The conditions for achieving the sub-cooled nitrogen state were 1 atm and 64 K. First, the temperature of 64 K was achieved by using the rotary pump and then the pressure of 1 atm was achieved by GHe. The characteristics of liquid nitrogen were strongly enhanced in these conditions. This fabricated cryogenic system merely for the short run operation test SFCL. Finally, the cryogenic system for the long run operation test SFCL was introduced.
Bibliographical noteFunding Information:
Manuscript received October 20, 2003. This work was supported by a grant from the Center for Applied Superconductivity Technology of the 21st Century Frontier R&D Program funded by the Ministry of Science and Technology, Republic of Korea. H. Kang, M. C. Ahn, and T. K. Ko are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea (e-mail: email@example.com). H. J. Kim is with the Hong-Ik University Research Institute of Science and Technology, Seoul, Korea. H.-M. Chang is with the Department of Mechanical and System Design Engineering, Hong-Ik University, Seoul, Korea. Digital Object Identifier 10.1109/TASC.2004.830309
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering