First field trials of a superconducting power cable within the power grid of a public utility

The first tests of a superconducting power cable within the power grid of a public utility were conducted at the Steweag power plant in Arnstein, Austria, in 1979. The cable (conceived by Klaudy [1],[2] and manufactured by ATF and Kabelmetal) is 50 m long and consists of seven concentric, longitudinally welded corrugated tubes using the "Wellmantel" technology. The fully flexible cable was shipped on a reel by conventional rail and road transportation means. It was easily installed by technicians familiar with conventional cable laying methods. No problem developed during the evacuation and cooling by liquid helium to about 6.5 K. The shield was cooled by liquid nitrogen to about 77 K. The cable was designed for 110 kV and 1.6 kA. Although transmitting the entire available power output of the station, the full rating of the cable was not attained during the tests. The conductor for these first trials was made of copper-stabilized niobium. The tests were concluded without any problems and all components performed in accordance with their design expectations under actual field conditions.