Development and Test of a Cooling System for a 154 kV Superconducting Fault Current Limiter

Title & Authors
Development and Test of a Cooling System for a 154 kV Superconducting Fault Current Limiter
Kim, Heesun; Han, Young Hee; Yang, Seong-Eun; Yu, Seung-Duck; Park, Byung Jun; Park, Kijun; Yoo, Jaeun; Kim, Hye-Rim; In, Sehwan; Hong, Yong Joo; Yeom, Hankil;

Abstract
The superconducting fault current limiter (SFCL) is an electric power device that limits the fault current immediately in a power grid. Korea Electric Power Corporation (KEPCO) has been developing a 154 kV, 2 kA SFCL since 2011 to protect power grids from increasing fault current and improve the stability and quality of electric power. This SFCL adopts 2G YBCO wires and operates at 71 K and 5 bars. In this paper, a cooling system for the 154 kV SFCL and its cooling test results are reported. This cooling system uses a Stirling-type cooler to make sub-cooled liquid nitrogen ($\small{LN_2}$), which cools the superconductor modules of the SFCL. The $\small{LN_2}$ is circulated between the cooler and the cryostat that contains superconductor modules. The $\small{LN_2}$ also plays the role of a high voltage insulator between the modules and the cryostat, so the pressure was maintained at 5 bars for high insulation performance. After installation in a test site, the cooling characteristics of the system were tested. In this operation test, some important data were measured such as temperature distribution in $\small{LN_2}$, pressure change, performance of the heat exchanger, and cooling capacity of the total system. Consequently, the results indicate that the cooling system operates well as designed.
Keywords
superconducting fault current limiter;cooling system;test operation;liquid nitrogen;YBCO;
Language
English
Cited by
References
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