A techno-economic design study of high-temperature superconducting power transmission cables

The results of a comprehensive techno-economic design study of power transmission cables utilising High-Temperature Superconductors are presented. A cable design is described, based upon superconductors operating at liquid nitrogen temperatures. The dimensions and operating parameters of an optimized underground cable are calculated. Based on this design the manufacture, installation, losses and operating costs of an AC High-Temperature Superconducting (HTSC) Cable are estimated and compared with conventional underground cables for a new power link. Significant conclusions of the study are: for transmitted powers greater than I GVA the HTSC cable transmission costs become the same as for conventional cables when the superconductor critical current density exceeds 200 kA/cm' at liquid nitrogen temperature; the HTSC-based cable is capable of transmitting up to seven times as much power (to 700 MVA at 66 kV) as a conventional cable in a 150 mm fixed diameter duct at the same transmission cost.