复合绝缘子硅橡胶成分分析方法

Study on component analysis schemes for silicone rubber of composite insulator

复合绝缘子硅橡胶伞裙护套属于高分子有机材料,在长期的户外运行条件下不可避免出现褪色、粉化、龟裂、变脆、憎水性变差等老化现象,影响到输电线路的安全运行。硅橡胶老化与运行环境和自身耐老化性能相关,直接表现为硅橡胶主要成分的变化,运维单位需定期对运行复合绝缘子进行抽检分析。提出复合绝缘子硅橡胶成分分析方法,定义胶含量。首先,为对硅橡胶主要成分进行标定,制作13种硅氧烷含量一定、氢氧化铝和白炭黑填料含量不同的硅橡胶平板样,利用密度和热失重2种方法对其进行研究。然后,运用线性回归方法对结果进行拟合。最后,选取不同生产厂家退运复合绝缘子伞裙内层样品进行验证。试验分析结果表明,基于硅橡胶的密度,和基于硅橡胶热失重过程中关键转折点的质量剩余比例,均可推算出硅橡胶样品的胶含量,2种方法具有结果的一致性,运维人员可以根据情况进行现场或者实验室离线分析,实现复合绝缘子快速、可靠的评估,保障了输电线路的安全运行。

The silicone rubber of composite insulator shed and housing is a kind of polymer organic material.Due to the effect of environmental stress under the long-term operating,aging phenomena such as the color fading,chalking,cracking,brittleness and decline of hydrophobicity will appear on it inevitably.The performance of insulators affects the safe operation of transmission lines directly.The aging of silicone rubber is related to the complex operating environment and the aging resistance ability,and it is represented as the change of key components directly.Therefore,the sampling inspection for composite insulators should be carried out by operating maintenance departments.In this paper,the key components of silicone rubber analysis schemes are proposed and the rubber content is defined.To measure the components of silicone rubber,13 kinds of flat silicone rubber samples with certain content of siloxane and different content of aluminum hydroxide and white carbon black are prepared.Methods of density and thermos gravimetric analysis are adopted,then the results are fitted by the linear regression.Silicone rubber samples of the shed inner layer from different manufacturers are selected to verify the consistency of the results obtained by the two methods.It is shown that the rubber content of silicone rubber can be calculated by either the density or the remaining mass ratios at the critical turning point of thermal gravimetric(TG)curve.The field or off-line analysis can be carried out according to the actual situation.The operating status of composite insulators can be assessed by the proposed schemes conveniently and reliably,then safe operation of transmission line can be promoted.