66kV-2kA peak load test of high-T-c superconducting model cable

The superconducting power transmission cable is one of the most feasible applications for oxide superconductors. One case of introducing superconducting cables into power cable systems is as a replacement type in cable ducts, so that it is necessary to develop a compact superconducting cable which can be installed in existing ducts of diameter 150 mm. For this purpose, long-length Bi-2223 phase multifilamentary silver-sheathed wires with high critical current densities, such as over 7000 A cm(-2), have been developed and the effects of mechanical strain were investigated. As the next step, we have designed a 66 kV-2 kA superconducting cable of outer diameter 124 mm and developed a 5 m long model cable having a flexible conductor assembled by winding the foregoing wires in layers around a former. Furthermore, two different types of termination have been developed for a simultaneous current and voltage withstand test. As a result, we have been able to successfully perform a 66 kV-2 kA withstand test on an oxide superconducting power cable. The AC loss of the cable measured by the four-probe method was about 35 W m(-1). Moreover, generation of partial discharge in the cable was not observed at the test voltage. (C) 1996 Elsevier Science Limited