Coupling time constants and ac loss characteristics of spiral copper-plated striated coated-conductor cables (SCSC cables)
Yusuke Sogabe, Yudai Mizobata, Naoyuki Amemiya
Abstract
Abstract We conducted electromagnetic field analyses of spiral copper-plated striated coated-conductor cable (SCSC cable), where the striated (multifilament) and copper-plated coated conductors were twisted spirally around a round core in order to decouple the filaments. We used a numerical model which was formulated with current vector potential and in which thin-strip approximation was applied to the superconductor layer of the coated conductors. The nonlinear conductivity obtained from measured electric field–current density characteristics was used to represent the superconducting properties. To confirm the effect of the spiral twist in the SCSC cables, we determined their coupling time constants from the frequency dependences of their calculated magnetisation losses, under an ac transverse magnetic field with a small amplitude. Moreover, we calculated the ac losses in the SCSC cables under simultaneous application of ac transverse magnetic fields and ac transport currents, which represent practical operating conditions for electrical power devices and magnets.