Inductive Superconducting Fault Current Limiters With Y123 Thin-Film Washers Versus Bi2223 Bulk Rings as Secondaries

We present the comparison between the performance of an inductive superconducting fault current limiter operating with bulk
$hboxBi_1.8hboxPb_0.26hboxSr_2hboxCa_2hboxCu_3hboxO_10+x$
rings or
$hboxY_1hboxBa_2hboxCu_3hboxO_7-delta$
thin-film washers as secondaries. We have measured the impedance offered by the limiter under current faults and the recovery time once the faults are cleared. Our results show that the use of thin films can improve the impedance response of these devices and especially their recovery time, which can be about two orders of magnitude shorter than that of bulk samples.