| 摘要 |
PURPOSE:To shorten current limiting time by connecting two sets of noninductively wound superconducting coils having the same critical current value in series with normally closed and open contacts, and connecting inductive superconducting coils having higher critical current value than the previous coil in parallel. CONSTITUTION:A normally closed contact 10 to be opened by the output of a quench signal detector 9 is connected to a trigger coil in which noninductively wound superconducting coils 6a, 6b having the same critical current value (IC1) are connected in series. Noninductively wound superconducting coils 7 having the same critical current value IC1 are connected to a normally open contact 11. Further, a current limiting coil 5 made of inductive superconducting coil having higher critical current value (IC2) than the IC1 is connected in parallel with the trigger coil. If a load 12 is short-circuited so that the overcurrent exceeds the IC1, the trigger coil is quenched to show a high resistance, the current is commutated to the coil 6 to detect the voltage at both ends by the detector 9, thereby opening the contact 10. If an accident is vanished, the contact 11 is closed to commutate the current from the coil 6 to the coil 7. Thus, its current limiting time is shortened. |
