In order to handle increasing demand for electric power and protection against fires in large cities, larger-capacity and higher voltage SF/sub 6/ gas-insulated transformers have been developed and are in practical use. They use high pressure gas to enhance cooling and insulating performance. However, they have some drawbacks such as higher noise and heavier tank. We carried out developments to enlarge the ranges of capacity and voltage to which low pressure gas can be applied. Firstly, its interior structures and cooling system were designed using thermo-fluid and gas flow analyses. Secondly, electric field stresses in the transformer were kept under control by the adjustment of relative permittivities and position of insulators. Thirdly, a low-noise type gas blower was developed after careful tests. As a result, 100 MVA 154 kV SF/sub 6/ gas-insulated transformer of 65 dB class using low pressure SF/sub 6/ gas (0.24 MPa at 20/spl deg/C) has been developed.
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机译：为了在大城市中应对不断增长的电力需求并防止火灾，已经开发出了更大容量和更高电压的SF / sub 6 /气体绝缘变压器。他们使用高压气体来增强冷却和绝缘性能。但是，它们具有一些缺点，例如噪音较高和油箱较重。我们进行了一些开发，以扩大可应用低压气体的容量和电压范围。首先，利用热流体和气流分析设计了其内部结构和冷却系统。其次，通过调节相对介电常数和绝缘子的位置，可以控制变压器中的电场应力。第三，经过仔细测试，研制出了低噪音型气体鼓风机。结果，已经开发出使用低压SF / sub 6 /气体（20 / spl deg / C时为0.24 MPa）的65等级的100 MVA 154 kV SF / sub 6 /气体绝缘变压器。
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