Novel Design Concept and Demonstration of a Superconducting Gas-Insulated Transmission Line

A new and novel design concept for superconducting cables that uses the gaseous cryogen as the dielectric medium is presented. This novel design addresses the challenges in developing a dielectric design of a superconducting cable that is cooled by a gaseous cryogen such as gaseous helium (GHe). This design has the added benefit of improving thermal aspects and for dc applications should reduce the possibility of space charge accumulation. The paper provides an overview of design criteria which is necessary to successfully implement this design. A proof of concept experiment was also developed to demonstrate how the voltage rating of such a design is dependent on the dielectric strength of the cryogen being used. The new design has the potential to offer a solution for high power density superconducting medium voltage dc cables that are cooled with GHe and operate in the temperature range of 5-80 K.