AC Losses Analysis of HTS Composite Conductors With Different Current Ramp Rates.

High-temperature superconducting (HTS) composite conductors with high carry-current abilities become a preferable choice for superconducting devices to meet the requirements of the power system. In actual operation conditions of superconducting power devices, it is always accompanied by variational current ramp rates, which may cause the ac loss in the conductors. Therefore, this work carries out research on the ac losses of a stacked conductor and a twisted stacked-tape cable (TSTC) with different current ramp rates by changing their structural parameters. Critical current measurements at multiple rates of HTS tapes are initially investigated. Furthermore, the influence of the number of stacked tapes and the twist pitch on the critical current of the conductors is studied. Based on the experimental results, the ac losses of the samples are calculated in COMSOL multiphysics by using a T–A method. This work provides variation trend references of the critical current in HTS tapes and conductors under several rates. Moreover, the ac losses of a stacked-tape conductor and a TSTC with different structural characteristics have been presented in detail. [ABSTRACT FROM AUTHOR]