Superconductor for high power AC transmission - has spacers separating sections of overlapping superconductors in coaxial system

摘要

Super-conducting cable is for high power transmission of a.c. along certain stretches. The cable is resistant to excess current produced by a fault situation and at the same time acts as a protection against excess current for other components in the plant. It consists of concentrically arranged layers of conductors separated by insulating layers. The conductors are separated by spacers (4) with overlapping sections (10, 20) of two normal or super-conducting conductors (1, 2). The sections (20) of a conductor (2) are rigidly linked to another super-conductor section (3) via a ring-flange (22). The capacitive reactance of the conductors divided into sections is less than the resistance of the super-conductors in normal conducting conditions. However, the value of the capacitive inductance at excess current conditions is such as to limit the current to approximately rated value.