微水含量及老化状态对绝缘硅油介电特性的影响

长期电、热复合应力及潮湿环境作用下的绝缘硅油老化和受潮问题严重威胁电缆充油终端安全稳定运行.研究硅油的微水含量以及老化状态对其介电特性的影响,有利于推进介电测试手段在充油终端内填充硅油绝缘状态诊断的应用.因此,通过对未老化硅油实施自然吸湿实验与电热联合老化实验,分别制备得到6组不同水分含量及6组不同老化状态的硅油试样....

Effect of Moisture Content and Aging State on the Dielectric Properties of Silicone Oil

The aging and dampness of silicone oil caused by long-term electrical and thermal combined stress and humid environment seriously threatens the safe and stable operation of the oil-filled cable terminals. Studying the influence of the moisture content and aging state of silicone oil on its dielectric properties is conducive to promoting the application of dielectric testing methods in the diagnosis of the insulation state of the silicone oil in oil-filled terminals. Therefore, unaged silicone is selected for testing on natural moisture absorption and electric-heat combined aging, and 6 groups of silicone oil samples with different moisture content and 6 groups of silicone oil samples with different aging states are prepared respectively. And then, the oil samples are tested on polarization and depolarization current (PDC). Based on the PDC testing results, the silicone oil with different insulation states are analyzed on DC conductivity and polarization loss factor spectra. Finally, the oil carrier migration and distribution model is used to calculate the relaxation parameter, which can sensitively characterize the concentration of moisture content in the silicone oil and the concentration of the by-products of silicone oil degradation. Thereafter, a quantitative relationship is established between this parameter and the insulation state of silicone oil.