Noboru Ishii

Manufacturing and installation of the world's longest HTS cable in the Super-ACE project

The 500 m high temperature superconducting cable (HTS cable) is 77 kV 1 kA single-core cable with LN2-impregnated paper insulation. Demonstration and verification test of 500 m HTS cable has been started from March 2004 and many useful results can be obtained in the test for future practical uses. Furukawa Electric has mainly taken charge of designing, manufacturing and installation of the 500 m cable. In the manufacturing process, the cable could be fabricated without Ic degradation in Ag/Bi-2223 tapes. Moreover, various factory tests were carried out for the 500 m cable. The result of tests showed that the cable has sufficiently satisfied the quality requirement. In the installation, the cable was successfully pulled into a cable duct of 170 m long like actual underground cable installations.

Demonstration and verification tests of 500 m long HTS power cable

A high-temperature superconducting (HTS) power transmission cable is considered as one of the next-generation power transmission technologies. The introduction of HTS cables into the actual power grid requires a long-distance cooling tube, due to the location of the cooling stations at intervals of several kilometers along the cable length. Therefore, it is essential to understand the flow property of the liquid nitrogen as a coolant for the HTS cable, the current flow properties, electrical insulation characteristics, thermal insulation properties and mechanical behavior for the HTS cable taking into account its long length. This paper provides a brief summary of the HTS cable test system with a length of 500 m constructed in the Yokosuka area of CRIEPI.

Insulation design method of cold dielectric type superconducting power cable and its verification tests

A high-Tc superconducting (HTS) power cable is considered to be a major candidate for the bulk power transmission device in the future. The HTS power cable with a cold dielectric type electrical insulation system can make the outer diameter of the HTS cable compact in order to replace the conventional XLPE cable laid in underground ducts. Therefore, establishment of the electrical insulation design, HV testing and evaluation methods is the most important in the realization of the HTS power cable. From these viewpoints, the electrical insulation design method and determination of testing voltages for a 500-m HTS power cable constructed for verification tests are discussed, and the result of the various tests are described in this paper.