High-T-c superconducting materials for electric power applications

Large-scale superconducting electric devices for power industry depend crit ically on wires with high critical current densities at temperatures where cryogenic losses are tolerable. This restricts choice to two high-temperatu re cuprate superconductors, (Bi, Pb)(2)Sr2Ca2Cu3Ox and YBa2Cu3Ox, and possi bly to MgB2, recently discovered to superconduct at 39 K. Crystal structure and material anisotropy place fundamental restrictions on their properties , especially in polycrystalline form. So far, power applications have follo wed a largely empirical, twin-track approach of conductor development and c onstruction of prototype devices. The feasibility of superconducting power cables, magnetic energy-storage devices, transformers, fault current limite rs and motors, largely using (Bi, Pb)(2)Sr2Ca2Cu3Ox conductor, is proven. W idespread applications now depend significantly on cost-effective resolutio n of fundamental materials and fabrication issues, which control the produc tion of low-cost, high-performance conductors of these remarkable compounds .