| 摘要 |
PURPOSE:To increase the withstand voltage of a transformer filled with oil by providing an insulation cylinder of 0.5-1.0 time thick against the thickness of the insulator of a lead wire in an aperture when a high voltage lead wire is connected to the lower terminal of a bushing through the aperture opened in an insulation barrier enveloping around a winding. CONSTITUTION:In the grounded tank 11 of a direct current transformer filled with oil, a winding 12 wound around an iron core 12a is housed, the outside is enveloped with plural layer insulation barriers 16 which have an aperture 18 and the lower terminal 21 of a bushing in the bushing fixture 13 provided on the tank 11 and the winding 12 are connected with a high voltage lead wire 17 through the aperture 18. In this construction, the aperture 18 is not left intact and an insulation cylinder 19 of 0.5-1.0 time thick of the thickness of the insulation layer of the lead wire 17 is inserted in the aperture 18. The other filling of the insulation oil 11b, an insulation shield 22 provided at the lower terminal 21 of the bushing 15, etc. are as usual. In this way, the electric field distribution generated around the aperture 18 is made gentle. |
