Electrical Characteristics of Second Generation High Temperature Superconducting Wires for Power Device Application

Abstract

Three kinds of second generation (2G), high temperature superconducting(HTS) wires were characterized for critical current density and over-current behavior under over-current conditions cooled by liquid nitrogen. The critical current density and over-current behavior were measured as a function of increasing temperature and current ramping rate, respectively. The critical current density of HTS wire proportionally decreased with increasing temperature. The critical temperature of the GdBCO HTS wires was higher than that of the YBCO HTS wires. An instantaneous breakdown was observed after 30A/sec of the current ramping rate. Stabilizers were delaminated after the over-current test. Over-current behavior is particularly important in HTS power device applications because the short circuit current can be much larger than the steady state value. These results are in the context of important design and fabrication considerations of HTS power devices application.