| 摘要 |
PROBLEM TO BE SOLVED: To decrease the rate of change di/dt of short-circuit current when a short-circuit fault occurs, by increasing the inductance of a main circuit conductor when the short-circuit fault occurs. SOLUTION: Currents of the same magnitude flow in directions reverse to each other in a pair of conductors 1a, 1b. A movable portion 5 holds the conductors 1a, 1b in parallel in such a way as to be movable. Springs 3 urge the conductors 1a, 1b in directions for an insulator 2 to be interposed inbetween. The urging force of the springs 3 is smaller than repulsive force generated between the conductors 1a, 1b by electromagnetic force by short-circuit current which flows in the conductors 1a, 1b, when a short-circuit fault occurs. When normally operated, the conductors 1a, 1b touch the insulator 2 and their gaps become narrower, and the inductance of the main circuit conductor 10 becomes smaller. When the short-circuit fault occurs, the conductors 1a, 1b open and their gap becomes wider, and the inductance of the main circuit conductor 10 becomes larger. |
