Conductor development suitable for HTSC cables

Five leading European electrical companies have been collaborating within the framework of a BRITE/EURAM project with the aim of selecting and developing a production technology for the construction of underground power cables containing high-temperature superconductors. A laser-melting technique was used to form conductors based on the Y-123 phase and the power-in-tube (PIT) and thick-film techniques were used to form (Pi, Pb)-2223/Ag composite superconductors. Thallium-containing superconductors and selected 1212-phase cuprates were also examined for their suitability as HTS conductors. The most promising results were obtained with (Bi, Pb)-2223 multifilamentary PIT tapes, and two d.c. cable models have been designed, built and tested using these tapes. The best of the prototypes carried 430 A at 77 K in self-field.