Second Generation Wire Development at AMSC

TL;DR: HTS Roebel cables from REBCO coated conductors were first manufactured at the Karlsruhe Institute of Technology and have been successively developed in a number of varieties that provide all the required technical features such as fully transposed strands, high transport currents and low AC losses, yet retaining enough flexibility for a specific cable design.

TL;DR: In this article, the authors provide an overview and a succinct and easy-to-consult guide for users, developers, and manufacturers of high-temperature superconductors (HTS) cable.

Abstract: Superconductors are essential components of future fusion power plants. The magnet coils responsible for producing the field required for confining the fusion plasma are exposed to considerable neutron radiation. This makes irradiation studies necessary for understanding the radiation response of the superconductor. High temperature superconductors are promising candidates as magnet coil materials. YBCO and GdBCO tapes of several manufacturers were irradiated to fast neutron fluences of up to 3.9 × 1022 m−2 in the research reactor at the Atominstitut. Low energy neutrons contribute to the fission reactor spectrum but not to the expected spectrum at the fusion magnets. Low energy neutrons have to be shielded in irradiation experiments to avoid their substantial effect on the superconducting properties of tapes containing gadolinium. The critical current (Ic) of the tapes in this study was examined at fields of up to 15 T and down to a temperature of 30 K. Ic first increases upon irradiation and reaches a maximum at a certain fluence, which depends highly on temperature, being highest at low temperature. Ic declines at high fluences and eventually degrades with respect to its initial value. Tapes with artificial pinning centers (APCs) degrade at lower fluences than tapes without them. The n-values decrease in all types of tapes after irradiation even when the critical currents are increased. The field dependence of the volume pinning force differs in pristine tapes with and without APCs but shows the same behavior after irradiation.

TL;DR: In this article, important properties of 2G wires such as uniformity, in-field Ic and electromechanical behaviors are described. But, the authors do not discuss the performance of the 2G HTS wires.

TL;DR: In this article, the authors describe the latest status of the Albany, NY HTS cable project, which was installed between two substations in National Grid's electric utility system and operated successfully in unattended condition through May 1, 2007.

TL;DR: The US Department of Homeland Security is currently funding the design, development and demonstration of an inherently fault current limiting HTS cable, called Secure Super Grids, under the Hydra project with Con Edison as discussed by the authors.

TL;DR: In this paper, a resistive superconducting fault current limiter for the 115kV transmission voltage level has been designed and manufactured by a collaboration of American Superconductor, Siemens, Nexans and Southern California Edison.

TL;DR: The American Superconductor Corporation (AMSC) has developed the base technology and a manufacturing line for initial volume production of low-cost second generation high temperature superconductor (2G HTS) wire for commercial and military applications as discussed by the authors.