The 4-probe method with a voltage tap on terminals has been used for the measurement of the critical current of multi-strand high-Tc superconducting (HTS) cables. The critical current of cables is obtained as the measured total current divided by the number of conductors when the terminal voltage exceeds the predetermined criterion of critical current. However, because of the nonuniform current share due to the different critical currents, shapes, and other characteristics of each conductor, this method is not applicable to the multi-strand HTS cable. To determine the critical current of multi-strand HTS cable, the critical current of each conductor must be measured with different method. In this paper, the current share and the critical current of each conductor in multi-strand cable were measured with specially made pick-up coils and voltage taps. It is presented that the real critical current of multi-strand is smaller than sum of each critical current of each path. Different resistances appeared in each HTS wire are the main cause of nonuniform current share.
Bibliographical noteFunding Information:
Manuscript received October 21, 2003. This work was supported by a grant from the Center for Applied Superconductivity Technology of the 21st Century Frontier R&D Program funded by the Ministry of Science and Technology, Republic of Korea.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering