Effect of the neighboring tape´s AC currents on transport current loss of a Bi-2223 tape

Bi-2223 tapes have been developed for low-field power applications at liquid nitrogen temperature. When the Bi-2223 tapes are used in an application such as a power transmission cable or a power transformer, they are supplied with an AC transport-current and exposed to an external magnetic field generated by neighboring tape´s AC currents simultaneously. AC loss. taking into account such real applications. is a crucial issue for power applications of the Bi-2223 tapes to be feasible. In this paper, the transport losses for different AC current levels and arrangements of the neighboring tapes have been measured in a 1.5 m long Bi-2223 tape. The significant increase of the transport losses due to neighboring tape´s AC currents is observed. An increase of the transport losses caused by a decrease of the Bi-2223 tape´s critical current is a minor effect. The measured transport losses could not be explained by a dynamic resistance loss based on DC voltage-current characteristics in combination with the neighboring tape´s AC currents. The transport losses do not depend on the frequency of the neighboring tape´s AC currents but its arrangements in the range of small current especially