The reduction effect of transmission losses in filamented REBCO coils

High-temperature superconducting (HTS) motors offer high power density and efficiency and have broad application prospects in the aerospace sector, while transmission losses under high-frequency transport currents limit motor performance and increase cooling system requirements. This study investigates the transmission loss suppression effect of REBCO racetrack coils by fabricating coils with non-filamented and four-filament REBCO tapes, and measuring their losses using the calorimetric method. Furthermore, two-dimensional T-A models were established for coils with 2, 4, 6, 10, and 20 filaments to study the dependence of loss suppression on filament number and transport current frequency. The results indicate that the loss reduction ratio increases with both filament number and transport current. These findings provide critical data for optimizing HTS motor winding structures and operational conditions, and offer a theoretical basis for improving motor efficiency and reducing cooling system load.