Low Loss, High Temperature Superconducting Wire For Inductive Energy Storage

This Small Business Innovation Research Phase l project is proposed by American Superconductor Corporation (ASC) to establish the feasibility of hermetically manufacturing small-filament, high temperature superconducting (HTS) composite wires for use above 20 K in AC magnet applications such as inductive energy storage devices. HTS magnet wire applications will typically operate under fluctuating magnetic field conditions where inductive losses can dissipate significant energy at operating current levels that are well below the zero field DC critical current of the superconductor. A resistive barrier layer that electrically isolates the filaments is essential to reduce these losses. But this layer also limits oxygen exchange with the external gas environment during reactions that form the superconductor. To solve this critical problem, a concept is proposed for controlling oxygen activity inside the HTS filament by a novel sheath material, without the need for oxygen exchange with an external gas environment during superconducting oxide formation. The Phase I project will demonstrate the feasibility of fabricating Bi2223 composites with oxygen activity control provided at each filament without the need for oxygen contact with an external gas environment.