Dielectric design validation of a helium gas cooled superconducting DC power cable

Successful validation of the dielectric design of high temperature superconducting DC cables cooled with pressurized helium gas circulation is reported. The dielectric design features were developed based on the tests of several short sample cables. The features were adapted for the dielectric design of the cable and termination components such as high voltage bushings. A high voltage DC withstand test followed by AC partial discharge measurements on a 30-m long superconducting DC cable cooled with helium gas operating at 50-60 K showed that the dielectric design is suitable for the cable system.