Development and tests of extruded polyethylene insulated superconducting cable

摘要

A superconducting power cable which has a similar structure to the conventional extruded polyethylene cable is proposed. The rated voltage and current are 20 kV and 2 kA, respectively. The design utilizes the excellent electrical properties of polyethylene at cryogenic temperatures and separate helium coolant from the electrical insulation. The outer superconductor layers for magnetic shielding are eliminated for the simplicity of the structure. The thermal shielding consists of multilayer superinsulation and high vacuum. The simplicity of the design reduces the cost. A superconducting cable based on this scheme has been built in Japan. A cooling test down to liquid-helium temperature, a current test up to 2.5 kA, and voltage tests at liquid-nitrogen temperature have been carried out with fair success.