| 摘要 |
PURPOSE:To attain a higher precision for detection of accident in an on-load tap changer by forming the meltable conductor for cutting the accident current from a meterial mainly consisting of aluminum and disposing the same in a vessel charged with sulfur hexafluoride gas. CONSTITUTION:The tap changer has a vessel accomodating the tap changing switch and charged with SF6 gas. The vessel accomodates a first electric line, a second electric line and a first continuous conducting contact 11 connected in parallel to one another. The first electric line includes a first vacuum switch 7 for main arc and a meltable conductor 14 connected in series to each other, while the second line includes a vacuum switch 9 for auxiliary arc and a current-limit relay 10. The line consisting of the parallel connection is connected at its one end to a first input terminal 5 and at its other end to an output terminal 13. An electric line having a series connection of a second main arc vacuum switch 8 and a meltable conductor 14 is connected in parallel to a continuous conducting contact 12. One end of this parallel connection is connected to a second input terminal while the other end is connected to the output terminal 13. The meltable conductor 14 is made from a material consisting mainly of aluminum. According to this arrangement, it is possible to obtain a greater pressure rise when the arc is generated in the vessel and, hence, to increase the precision of detection. |
