Abstract Body

We are developing SCSC cable, in which copper-plated multifilament (striated) coated conductors are wound spirally on a round core. In SCSC cable, winding the coated conductors spirally allows the quick decay of coupling current through copper, so that the magnetization loss can be reduced effectively.

In our recent studies, we measured magnetization losses of various SCSC cables at the temperature of 77 K and the magnetic field up to 0.1 T. Meanwhile, for actual applications of SCSC cable, it is essential to evaluate the magnetization loss when operated at practical conditions, in which the temperature should be lower than 77 K, and the field amplitude should be higher than 0.1 T. Since it is difficult and expensive to conduct measurements at such conditions, we propose a method to evaluate the magnetization loss by using the experimental results at 77 K and the magnetic field up to 0.1 T.

We decompose the measured magnetization loss at 77 K and the magnetic field up to 0.1 T per cycle along frequency dependences into hysteresis loss, which is independent of frequency, and coupling loss, which depends on frequency. Then, we normalize the hysteresis loss, so that the normalized hysteresis loss at different conditions can be compared directly. Also, we identify the coupling time constant and the geometry factor, which characterize the coupling loss, and evaluate the coupling loss at different conditions. We will discuss the possibility of evaluating the magnetization loss at practical conditions using the normalized hysteresis loss and the evaluated coupling loss.

References

[1] N. Amemiya et al., “Effective reduction of magnetization losses in copper-plated multifilament coated conductors using spiral geometry,” Supercond. Sci. Technol., vol. 35, no. 2, Feb. 2022, Art. no. 025003, doi: 10.1088/1361-6668/ac3f9c.

Acknowledgment

This work was supported by JST-Mirai Program Grant Number JPMJMI19E1, Japan.