运行后复合绝缘子的理化分析

为了获得复合绝缘子在运行后老化的状况,选取了3个厂家生产的6支绝缘子试样,分别对这6支试样进行了憎水性测试、Fourier红外光谱分析、热分析和扫描电镜(SEM)检测。结果表明:硅橡胶表层的憎水性基团Si-CH3、-CH3各自与-Si-O-Si-基团的摩尔比明显低于中心层,而-OH未见明显规律;憎水性基团Si-CH3、-CH3摩尔比的相对变化能较好地表征憎水性,而-OH不宜作为复合绝缘子的憎水性表征指标。新复合绝缘子表层和中心层的组成基本相同。投运后复合绝缘子表层和中心层中无机化合物的质量规律性不明显;表层及中心层中高分子物质的质量随运行时间的延长而呈下降趋势,且中心层中高分子物质的质量高于表层;表层中低分子物质的质量高于中心层。投运时间对试样的扫描电镜结果具有一定的影响。新复合绝缘子试样喷水后的憎水性级别为HC1,运行后试样的憎水性级别处于HC3～HC4,同一复合绝缘子试样中不同伞裙、不同位置的憎水性也略有不同。研究结果对复合绝缘子老化评估具有参考价值。

Physics and Chemistry Analysis on Composite Insulators After Operated

To obtain ageing conditions of composite insulators after being operated,six composite insulators of three manufacturers are selected to perform hydrophobicity test,Fourier infrared spectroscopic analysis,thermoanalysis,and scanning electron microscope(SEM) detection.The results indicate that,hydrophobic groups,Si-CH3 and-CH3,of silicone rubber surface are less than those of inner part.-OH group has not obvious rule between surface and inner.Hydrophobic groups,Si-CH3 and-CH3,can be used as indicator of hydrophobicity variation,but-OH can not be used for this purpose.The composition of surface and inner layers of new composite insulator is similar.The inorganic compound of surface and inner layers of operated insulator has not obvious rule.The high polymer of surface and inner decreases with time,and the mass of inner is more than that of surface layer.For low molecular weight compound,the mass of surface layer is more than that of inner layer.Operation time affects SEM result to some extent.The hydrophobic level of new composite insulators belongs to HC1,and the hydrophobic level of operated composite insulators belongs to HC2~HC3.Different sheds or different positions of composite insulator may have different hydrophobicity.