| 摘要 |
PURPOSE:To obtain a higher shielding effect with less magnetic shield amount as a whole, by mounting a shield frame surrounding a bushing pocket part to an inside wall of a transformer tank and further covering the shield frame excepting the pocket part with a shield plate. CONSTITUTION:A silicon steel plate frame 21 made of materials with high permeability surrounding a bushing pocket part 8a of a tank is mounted to an inside wall of a transformer tank 1. Aluminum plates 23a, 23b are mounted to the steel plate 21 by screw threads 24 on the upper and lower positions of the pocket part 8a. Reverse eddy currents i1, i2... i1', i2' are to be flowed to the aluminum plates 23a, 23b with symmetrical directions so that magnetic flux is concentrated around the aluminum plates 23a, 23b utilizing the reactional skin effect of the aluminum plates 23a, 23b. These concentrated magnetic flux is to be received by the steel plate frame 21 so that a higher shielding effect with less magnetic shield amount as a whole can be obtained. |
