| 摘要 |
<p>PURPOSE:To improve a DC flashover voltage by eliminating a high electric field at a gap between shield upper and lower bushings and lead wires by arranging a solid insulator composed of an oil impregnated paper at the peripheral area of a conductor. CONSTITUTION:Filling material of solid insulators 13, 14 is filled in each gap between a bushing 12 and a shield 25 and between the shield 25 and a lead wire 24. A cap winding by means of an oil impregnated paper tape or an oil impregnated oil sheet is formed at the peripheral area of the solid insulators 13, 14 and the shield 25, and a solid state insulator 15 having a drum shape and a tapering toward the point at the lower part is formed. An oil gap 16 is formed within the shield 25 and the potential is allotted partially to the solid state insulator 14, therefore, the potential is low at this part. And as a result thereof, a high electric field is generated in the solid state insulators 13, 14. However, since the magnitude of a DC breakdown electric field is approximately 10 times as large as that of an insulating oil, the solid state insulators 13, 14 can be prevented from a dielectric breakdown, and the DC flashover voltage between the bushing 12 and the busing pocket tank can be improved.</p> |
