Verification tests of a 100 m high-Tc superconducting cable

The authors have started a project to develop a 100 m three-core 66 kV/1 kA/114 MVA HTS cable system to certify the manufacturing capability and the practicability of an HTS cable system as actual power system equipment. The HTS cable has three cable cores housed in one cryostat and is cooled by sub-cooled liquid nitrogen (LN₂). The cable core is composed of a former, superconducting conductor, LN₂ impregnated polypropylene laminated paper (PPLP) electrical insulation and a superconducting electromagnetic shield. The conductor and the shield are wound spirally with Bi-2223 tapes along the former and insulation respectively. The cable system is composed of a 100 m HTS cable, two splitter boxes, six terminations and two cooling systems. The cable is bent at its center and forms a U-shape. The cable and the apparatuses have been developed and set at CRIEPI´s test site and one year long tests including first to fourth term have started since June, 2001. By the end of the year 2001, first and second tests had been completed and third test has been under way. The first cooling tests proved that the cable has good performance in terms of critical current, shield current and heat loss. The second and third cooling tests showed that the cable did not undergo any serious damage during the cooling cycle. Concerning the electrical tests, 40 kV and 1 kA in the three-phase have been loaded successfully to the cable for more than 1300 hours. This paper describes the design of the cable and some test results.