This paper discusses the measurement of critical current IC in three-in-one high-temperature superconducting (HTS) cables. It is difficult to measure the IC of long-length HTS cables by simply connecting a dc power supply to both ends of a single cable core. We propose a go-and-return method, in which the HTS conductor layers of two of the three cores are used to carry current in both directions. A current in the opposite direction is induced in the HTS shield layers. However, the current induction is less than that from ac transmission, and magnetic field leaks from each core. As a result, the measured IC value becomes smaller than the sum of the wires' IC. We used a transient electromagnetic simulation, taking into account the IC-B characteristics of the wires. The estimated I-V waveforms for the 30- and 240-m cable systems are comparable with the measured ones. We have established a practical IC measuring technique that can be used with long-length HTS cable.
- critical current
- High-temperature superconductors
- power cables
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering