The research on the current capability and insulating properties of 35 kV/1 kA CD HTS cable witness samples

Due to the high capacity and low loss, high temperature superconducting (HTS) cable using Liquid N2 as the coolant has attracted the widespread attention in the field of the modern power technology. A 35 kV/1 kA cold dielectric (CD) high temperature superconducting (HTS) cable demonstration line, which is in the length of 100 m, has been established. To verify the design of the superconducting cable structure, the witness samples in the length of ~1.0 m were fabricated to evaluate the current capability and insulating properties, such as lightning impulse voltage and alternating voltage tests. The results showed that the critical current (IC ) of the superconducting layer and superconducting shield layer was measured to be 1650 A and 3000 A respectively, and the voltage waveform of superconducting layer revealed no apparent increase during the testing process. Meanwhile, it could be also indicated from the results of high voltage tests that the insulating properties of HTS cable conform to the requirements of the standard GB/T3048.8-94.