| 摘要 |
PURPOSE:To obtain great current-limiting effect, by attracting a superconducting member in a critical magnetic field with a magnetic force generated at the time of excess current from an electromagnet series-connected to the superconducting member kept at a critical or lower temperature and set at a position receiving no critical magnetic field. CONSTITUTION:Superconducting material 1 cooled at a critical or lower temperature is placed between electrodes 3 composed of ferromagnetic materials, and is set at a position receiving no critical magnetic field from an electromagnet 2, and is series- connected to the coil 22 of the electromagnet 2. The ferromagnetic material 21 of the electromagnet 2 is wound up with the coil 22, and a gap G is set. By a spring 4, the superconducting material 1 is energized in the direction separated from the electromagnet 2. When excess current flows to the coil 22 and a strong magnetic field is generated from the electromagnet 2, then the ferromagnetic material 3 and the superconducting material 1 are attracted in the gap G against the force of the spring 4. The superconducting material 1 is exposed in the magnetic field of a critical or higher magnetic field and is transferred in a normal conduction state, and excess current flowing to the coil 22 is suppressed. As a result, great current-limiting effect is certainly obtained. |
