Critical current measurements of a tape in the hybrid multi-stacking high T_c superconducting tapes

A new 200 m high T_c superconducting DC cable test facility was successfully constructed in 2010. This cable is composed of two superconducting layers of the DI-BSCCO® tapes spirally and closely surrounding a copper former. The number of the tapes in each layer is different due to their different radii. We have investigated the effect of the way of the tape winding on the critical current (I_c) of the tapes in order to optimize the cable configuration for the DC transmission.

This paper presents the measurements of I_c of DI-BSCCO® in a hybrid multi-stacking configuration composed of YBCO and BSCCO tapes by controlling the transport current in each tape independently. The I_c measurements were performed with the standard four-probe method at the liquid nitrogen temperature. The magnetic field distribution around the tapes was calculated by the finite element method to demonstrate the effects of the self field from the adjacent tapes. The enhancement and degradation of Ics in the hybrid multi-stacking tapes were observed in contrast to that of single tape. Through the experiments, we started to investigate optimized tape configuration of the DC power cable to enhance the superconducting characteristics.