This paper deals with the development of a 6.6 kV/200 A HTS magnet for inductive superconducting fault current limiter (SFCL) that uses a sub-cooled nitrogen cooling system which is expected to be very useful to the applied HTS machines. The several characteristics of the HTS magnet such as critical current, electrical insulation and heat transfer can be enhanced in the sub-cooled nitrogen cooling system rather than in saturated liquid nitrogen (LN2) cooling system. To obtain sub-cooled nitrogen, LN2 was cooled down to 64 K with GM-cryocooler and its pressure was kept at 101 kPa with gaseous helium. In this investigation, the HTS magnet for a 6.6 kV/200 A SFCL was developed and its long-run operation characteristics were measured and analyzed. The characteristics of the sub-cooled nitrogen system like temperature, level of LN2 and pressure of cryogenic system were not degraded in spite of the several over current tests, electrical insulation tests, and even long-run operation tests with rated transport current.
Bibliographical noteFunding Information:
Manuscript received September 20, 2005. 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. T. J. Kim is with the Dept. of Human Resources Development, Korea Foundation of Polytechnic Colleges, Seoul, Korea. H. Kang, C. Lee, and B.-Y. Seok are with the Electro-Mechanical Research Institute, Hyundai Heavy Industries Co., Ltd., Yongin-si, Gyeonggi-do, Korea (e-mail: email@example.com). M. C. Ahn, D. K. Bae, and T. K. Ko are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea. H.-M. Chang is with the Department of Mechanical and System Design Engineering, Hong-Ik University, Sangsu-dong, Mapo-gu, Seoul, Korea. Digital Object Identifier 10.1109/TASC.2006.871212
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering