Properties of a prototype Bi-based HTS composite with a high resistivity sheath for resistive fault current limiting applications

Prototype Bi-2223 based composite conductors have been fabricated to provid e inherent passive fault current limiting functionality in devices. An HTS insert strand possessing a high resistivity sheath (HRS) was laminated to t wo metallic strips to provide additional capacity to absorb the heat genera ted during a fault. Sheath resistivities up to 45 times that of pure Ag wer e achieved, We summarize the electrical response of 10 to 100 cm straight s ections of conductor to pulsed de and ae currents several times the critica l current. DC pulsed I-V characteristics have been obtained over 7 to 8 ord ers of magnitude of voltage, For electric field levels around 10 V/m, the I -V curves demonstrate the advantage of the HRS conductor in facilitating fa ult current limiting over the conventional Ag-sheathed Bi-2223 approach. Th e recovery time for ac faults of 10 V/m was mapped out for various fault ho ld times. Instantaneous operational recovery was observed for fault hold ti mes up to 3 seconds.