Development of a HTS Magnet System for Long-Run Operation Test in Sub-Cooled Nitrogen

Author

Kim, Tae Jung ; Kang, Hyoungku ; Ahn, Min Cheol ; Lee, Chanjoo ; Bae, Duck Kweon ; Seok, Bok-Yeol ; Chang, Ho-Myung ; Ko, Tae Kuk

Author_Institution

Dept. of Human Resources Dev., Korea Found. of Polytech. Colleges, Seoul

Volume

16

Issue

2

fYear

2006

fDate

6/1/2006 12:00:00 AM

Firstpage

1324

Lastpage

1327

Abstract

This paper deals with the development of a 6.6 kV/200A 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

Keywords

critical current density (superconductivity); cryogenics; fault current limiters; high-temperature superconductors; superconducting magnets; 101 kPa; 200 A; 6.6 kV; AC dielectric test; GM-cryocooler; HTS machines; HTS magnet system; HTS transformer; critical current; cryogenic system; electrical insulation tests; gaseous helium; heat transfer; impulse test; inductive superconducting fault current limiter; long-run operation test; saturated liquid nitrogen cooling system; sub-cooled nitrogen cooling system; Cooling; Critical current; Dielectrics and electrical insulation; Fault current limiters; High temperature superconductors; Insulation testing; Nitrogen; Saturation magnetization; Superconducting magnets; System testing; Cryogenic system; HTS magnet; SFCL; sub-cooled nitrogen;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2006.871212

Filename

1643095