| 摘要 |
PURPOSE:To ensure the operation of a current breaker to improve reliability by detecting the abnormal voltage, which is generated in a super-conductive coil, through a search coil and an integrator, which are provided near this coil, and breaking the current to the superconductive coil when the abnormal voltage is generated. CONSTITUTION:Superconductive coil 3 is connected to power source 1 through current breaker 2, and protective resistance 4 is inserted between both terminals 5 and 6 of coil 3. Next, integrator 17 is connected to terminals 5 and 6 through search coil 12 and voltage divider 13, and the output terminal of integrator 17 is connected to input terminals 10 and 11 of current breaking signals provided in breaker 2. In this constitution, search coil 12 is arranged closely to superconductive coil 3, and the position of movable tap 16 of voltage divider 13 is so adjusted that the induced voltage may be cancelled in case of a normal voltage. However, since the induced voltage is generated in voltage divider 13 when an abnormal conductive part is generated in superconductive coil 3 and the abnormal voltage appears, this induced voltage is integrated by integrator 17; and when the result exceeds a fixed value, breaker 2 is operated. |
