A comprehensive design procedure is presented for the current leads in HTS fault current limiters continuously refrigerated by a cryocooler. Two specific aspects are focused here in addition to the standard lead-design. The first is an optimization with taking into account the heat conduction through electrical insulator needed for high-voltage applications. Through a rigorous analysis, it is verified that the standard design should be modified in order to minimize the overall heat leak. The second is the transient thermal behavior that may be caused by excessive current. A numerical analysis is performed to estimate the peak temperature after a short current-limiting period, including the effect of fins as enhanced local heat capacity. Some of the design details are demonstrated for the specifications of FCL's under development in Korean R&D Programs.
Bibliographical noteFunding Information:
Manuscript received August 29, 2006. This work was supported by the Center for Applied Superconductivity Technology (CAST) under the 21st Century Frontier R&D Program in Korea. H.-M. Chang and Y. S. Kim are with the Department of Mechanical and System Design Engineering, Hong Ik University, Seoul 121-791, Korea (e-mail: firstname.lastname@example.org). H. M. Kim is with the LS Industrial Systems Inc., Cheongju 361-720, Korea. H. Lee is with the Department of Material Science and Engineering, Korea University, Seoul 136-713, Korea. T. K. Ko is with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Korea. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2007.898486 Fig. 1. Schematic of FCL cryostats continuously refrigerated by a cryocooler. (a) Re-entry cryostat; (b) suspended LN vessel.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering