| 摘要 |
PROBLEM TO BE SOLVED: To make flow a rated current even immediately after an accident of short-circuit, by setting the cross section area of a protection conductor and value of critical current under optimum condition. SOLUTION: For the superconductor, a protection conductor is electrically connected to the superconducting layer in parallel, and the protection conductor is composed of one or more kinds of low resistance metal chosen from copper, copper alloy, aluminum, and aluminum alloy. When regardingαas a coefficient between 1-20, Is (kA) as a short-circuit current flowing through a superconducting cable at an accident of short-circuit or ground fault, and t (s) as a duration of time that the short-circuit current is flowing, the cross section area of the protection conductor isα×Is×√t (mm) or more, and the critical current (Ic) of the superconductive layer is 1.4 times the peak current (Ip) of alternating current at rated operation. |
