AC losses in a flexible 10 m long conductor model for a HTS power transmission cable

To demonstrate the possibility of manufacturing a HTS power transmission ca ble with low AC losses, we fabricated a 10 m long cable conductor and a cry osystem. The conductor was wound in a four-layer design out of 2 km Ag/Bi-2 223 tapes. We determined a critical current of 5000 A. Loss measurements we re performed with an electric method which detects the voltage drop along t he conductor with a lock-in technique and a calorimetric method which measu res the temperature rise along the conductor. Both methods yield the same l ow loss values of only 0.8 W/m at 77 K and 2000 A(rms)/50 Hz. This is due t o the low loss winding scheme we used which assures an equal current distri bution in all four layers through transformatoric coupling. We applied the uniform current distribution model and added the nonlinear V-l curve to des cribe quantitatively the obtained results. (C) 1998 Elsevier Science B.V. A ll rights reserved.