含水量对变压器油介电性能影响的研究

Effects of Moisture Content on Dielectric Properties of Transformer Oil

变压器油是油浸式变压器内部重要的液体绝缘介质,油中含有的水分会影响变压器油的绝缘性能。文中通过搭建测试平台,对不同温度下含水量对变压器油的电阻率及频域介电特性的影响进行测试研究。研究结果表明:变压器油的电阻率随温度的增大而减小,随含水量的增大呈现指数下降趋势;水分对变压器油的介电常数和介质损耗因数的影响主要反映在低频段。在低频范围内,变压器油的相对介电常数和介损因数随频率增加而减小,随温度和含水量的增大而增大。因此,利用低频段的相对介电常数和介质损耗因数变化可间接对变压器油中的含水量进行诊断。

Transformer oil is important liquid dielectric of oil-immersed transformer. Moisture in oil will bring a harm effect on the transformer insulation. In this paper, the effects of moisture content on resistivity and frequency properties of transformer oil are studied though test platform with different temperature. According to the results, the transformer oil resistivity decreases with the increase of temperature, as well as moisture content The effects of moisture content on dielectric constant and dielectric loss factor mainly reflect in the low frequency band. In low frequency band, the relative dielectric constant and dielectric loss factor of transformer oil decreases with the increase of frequency, but increases with the increase of temperature and moisture content. This orderliness can be indirectly used for diagnosis of transformer oil moisture content.