High-Strength, Low AC-loss High Temperature Superconductor

For motor, generator, transformer, and transmission line applications, demonstration projects have been conducted using Bi:2223 high temperature superconductors. There is the desire to use these conductors in AC applications at temperatures from 20-77K. Currently these conductors use silver or high silver alloys for their sheath material, this high silver content and the bridging of filaments results in tapes with significant AC losses. In addition the silver and silver alloy sheaths have low strength which limits them in high fields, and make coil construction very difficult. This proposal investigates a non-silver sheath material that has several times the yield strength of silver that has been demonstrated to be compatible with the high temperature processing of BSCCO superconductors for DC applications. By the use of this more resistive sheath material, several combinations of tape configurations will be investigated to develop a combination that will result in the reduction of AC losses. In addition to investigating the development of low AC loss tapes, a tape bundling approach will be investigated that will produce a high Ic tape bundle that will also contribute to reducing the AC losses. The results of this work will accelerate the development and commercialization of AC-BSCCO high temperature superconducting motors, generators, transformers, and transmission lines. A high-strength, low AC loss high temperature superconductor for generators, motors, transformers, and AC transmission cables.