3D numerical analysis of magnetization loss in twisted filamentary multilayer ReBCO tape

Le résumé fourni par la source

Multifilamentary structure can reduce the magnetization loss of ReBCO tapes by striating them into narrower filaments. But the loss reduction effect will be weakened due to the coupling current between filaments. The twisting of filaments can migrate the coupling effect and achieve further loss reduction. In this work, a 3D multilayer numerical model of the striated twisted (S-T) tape is proposed based on the H-formulation to study its magnetization loss characteristics and inter-layer coupling current behaviors. The S-T tape is compared with the non-striated non-twisted (NS-NT) tape, the non-striated twisted (NS-T) tape, and the striated non-twisted (S-NT) tape in terms of loss values under external AC fields with different amplitudes (20~120 mT) and frequencies (50~1000 Hz) to give suggestions on magnetization loss reduction when the field varies. The loss characteristics and current density distributions of the S-T tape indicate that a coupling current between filaments may flow through the substrate layer and the bottom stabilizer layer, based on which the high-resistivity-bottom-stabilizer S-T tape (H-S-T tape) is proposed to suppress the coupling loss. For a 4-filament HS-T tape, over 99% of the loss components in the REBCO layer caused by coupling is eliminated at 60 mT and 200 Hz, which reduces 73% of the total loss when compared with the NS-NT tape. The results can offer useful insights on designing low-loss HTS conductors. The 3D multilayer model can be a strong tool for magnetization loss analysis of twisted and striated HTS conductors, which will be used for our future modelling of HTS cables.

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