| 摘要 |
PURPOSE:To improve current limit performance, by providing a section for heating a current limit element, i.e. a superconductor. CONSTITUTION:A tubular bottomed thermal reflector 7 is arranged in a low temperature container 9 containing low temperature liquid 15. A long superconductor rod 3 is arranged in the center of the thermal reflector 7 and an arc generator comprising electrodes 4, 4 facing each other is arranged at the lower section. Current flows normally through the superconductor 3. Upon occurrence of overcurrent, a current sensor 10 detects the overcurrent and provides a signal for producing arc between the facing electrodes 4, 4. Consequently, the low temperature liquid 15 is heated and evaporated thus heating the superconductor 3, while a thermal insulation layer is formed to lower cooling capacity, and thereby the superconductor 3 is brought to high temperature and exhibits high resistance thus limiting current. When the superconductor 3 is brought to high temperature, it is brought to higher temperature by the heat reflected from the thermal reflector 7 thus providing quick response. |
