Lightweight and Large-Current HTS Stacked Tape Conductor

More electric aircraft (MEA) is one of the technical trends in the aviation field, and its merits are high safety, lightweight, easy to control, and good economy. Boeing 787 consumes almost ten times more electric power than conventional aircraft, so the power cable weight is ∼ ten times heavier than that of traditional aircraft. As a result, we need a lightweight and large current power cable for MEA. The power cable's conductor weight is heavy because of low voltage and large current in airplanes. We proposed developing high-temperature superconducting (HTS) dc cables because dc cables are more lightweight than ac cables. Its structure is a stacked conductor, and the current direction of each layer is opposite, and HTS tapes are insulated from each other. We also do not use the heavy copper former. We use the current lead resistance to make the current balance of each HTS tape. We made several types of stacked conductors in the laboratory using Bi2223 and RE123 tapes and tested them. Here, we report two experimental results; one is a twelve-layer stacked conductor using the Bi2223 tapes, and its shape is straight. The second one is to test the bending and twisting of a six-layer stacked conductor. Bending and twisting are necessary to lay the stacked conductor in any direction. The critical currents are 1196 A for the twelve-layer conductor, 639 A for the six-layer straight conductor, 607 A for the six-layer bent conductor, and 615 A for the six-layer twisted conductor.