Progress in Production and Performance of Second Generation (2G) HTS Wire for Practical Applications

Rare earth (RE) based second generation (2G) high temperature superconducting (HTS) wire is an emerging material that has been commercially available to a wide range of energy, scientific, industrial and medical applications including high-field magnets, fault current limiters, motors and generators, transformers, and power cables. High engineering critical current density, high mechanical strength, and high irreversibility field are the major advantages of 2G HTS wires over low temperature superconducting (LTS) wires and bismuth-based first generation (1G) HTS wires. 2G HTS wires with critical current I_c (77K, self-field) of 300 ~ 500 A/cm-w and piece lengths of a few hundred meters are being routinely produced. Past and ongoing demonstration projects using the 2G HTS wires suggest that the practical application of this new material is appealing, promising and challenging. Further improvement in wire performance is desired and wire price is to be reduced. In this paper, important properties of 2G wires such as uniformity, in-field Ic and electromechanical behaviors are described. Recent technology advancements in using 2G HTS wire for practical applications are discussed.