An advanced superconducting fault current limiter (SFCL) using $high-T_c$ superconducting (HTS) wire has been developed. The SFCL has a non-inductively wound magnet for reducing loss in normal state. Two types of non-inductively wound magnets, the solenoid type and the pancake type, were designed and manufactured by using Bi-2223 wire in this research. Short-circuit tests of the magnets were performed in sub-cooled $LN_2$ cooling system of 65 K. The magnets are thermally more stable and have a higher critical current in 65 K sub-cooled $LN_2$ cooling system than in 77 K saturated one. Because the resistivity of matrix at 65 K is lower than the resistivity at 77 K, the magnets generate a small resistance to reduce the fault current when the quench occurs. The magnets could limit the fault current to low current level with such a small resistance. The current limiting characteristic of the magnets was analyzed from the test result. The solenoid type was wound in parallel to make it non-inductive. The pancake type was also connected in parallel to be compared with the solenoid type in the same condition. The solenoid type was found to have a good thermal stability compared with the pancake type. It also had as large resistance as the pancake type to limit the fault current in sub-cooled $LN_2$ cooling system.
Giese R F, Runde M. Assessment study of superconducting fault-current limiters operating at 77 K. IEEE Trans Power Delivery 1993; Vol 8 Issue 3: 1138-47
M C Ahn, S Lee, H Kang, D K Bae, M Joo, H S Kim, T K Ko. Design, fabrication, and test of high-$T_c $ superconducting DC reactor for inductive superconducting fault current limiter. IEEE Trans Appl Superconduct 2004; Vol 14 Issue 2: 827-830
M C Ahn, S Lee, H Kang, D K Bae, H SKim, T K Ko. Fabrication and Characteristic Test of the DC Reactor for 6.6kV/200A Inductive Superconducting Fault Current Limiter. Journal of the Korea Institute of Applied Superconductivity and Cryogenics 2003; 5(2): 36-40
H Kang, H J Kim, D K Bae, M C Ahn, H-M Chang, T K Ko. Sub-cooled nitrogen cryogenic cooling system for superconducting fault current limiter by using GM-cryocooler. Cryogenics 2005;45:65-69
H Kang, H J Kim, D K Bae, M C Ahn, Y S Yoon, H-M Chang, T K Ko Characteristics of Sub-cooled Nitrogen Cryogenic System for Applied High- $T_c $ Superconducting Devices. Journal of the Korea Institute of Applied Superconductivity and Cryogenics 2004; 6(1): 38-42
D K Park, M C Ahn, S Park, H Kang, D K Bae, S E Yang, T K Ko. An Analysis and Short Circuit Test of Various Types of Bi-2223 Bifilar Winding Fault Current Limiting Module. 19th International Conference Magnet Technology