Analysis on the transient voltage performance of a DC superconducting cable

Transient voltage distribution in a de superconducting cable, comprising of four concentric metallic cylinders was analyzed. Of the four concentric cylinders, two carry the load current, and the other two comprise the cryogenic enclosure. Analysis was performed with transient current injected either to the innermost or the outermost cylinder. The outermost cylinder was either bare or insulated. The outer three cylinders were either solidly grounded or isolated from ground at the point of current injection. It was concluded that transient voltages will appear across the RETURN cryogen flow and also across the vacuum space in the cryogenic enclosure. As these two systems are designed for their thermal performance, they may suffer permanent damage caused by unwanted electrical transients.