Abstract
The hysteresis losses in commercial type‐II superconductors preclude the use of these materials for acsuperconducting power cables. While recent work has shown that ac cables employing high‐purity Nb may have acceptably low losses, it is clear that dc cables would better exploit existing superconductivity technology and make possible the use of commercial NbTi and Nb3Sn. Coincidentally, there has been a lively interest in dc transmission in the electric power industry due partly to advances in SCR converters and partly to increased emphasis on system stability. In this paper the relevance of these developments is discussed. Several alternative designs for superconductingdc cables utilizing commercial superconductors are discussed and design and cost calculations are presented. Areas where additional experimental work is needed are identified.