Hybrid Cooling System Installation for the KEPCO HTS Power Cable

In Korea, the KEPCO (Korea Electric Power Corporation) HTS power cable system has been successfully operated for evaluating the technical and economic feasibility as well as accumulating the operation experience since 2006. A cooling system composed of a liquid nitrogen decompression cooling unit and a closed-circulation system of subcooled liquid nitrogen at the KEPCO's Gochang power testing center. As the next step, we adjusted the cooling system for the purpose of testing a different cooling system using a cryocooler unit with cooling capacity of 4 kW at 77 K in the existing cooling system. It was designed to be used as a hybrid cooling system. In other words, it has as an each system of cryocooler unit or decompression pump unit. In this paper, the performance test results are summarized and the outline of the hybrid cooling system is introduced.