The component contents of silicone rubber composite insulators play a very important role in their quality and service life, but the detecting method of component contents is still inadequate for the electric power department.In this paper, TG-DSC technology is employed to study the thermal decomposition behavior of silicone rubber and its main components (aluminum hydroxide, organic silicone compounds, inorganic materials such as silica), and a method is developed to calculate the component contents according to the thermal weight loss rate in a certain temperature range.The method has been applied to the quality control, operation state evaluation and aging invalidation analysis for composite insulators.A series of composite insulators from several companies are evaluated by this method, and the results indicate that the contents of organic silicone compounds are about 35.9%~40.7%.Layer by layer sections analyses are conducted to running composite insulator skirts, and it is found that the polydimethylsiloxane (PDMS) contents vary with the depth, which reflects the aging state of the housing surface.In addition, this method also provides the component contents information at a selective silicone rubber housing region around fault locations, which can be used for failure analysis for the broken composite insulator.So TG-DSC method for silicone rubber component contents analysis is helpful for the operation and maintenance management of composite insulators, and also is helpful for ensuring the safety and stability of electric power network.%硅橡胶复合绝缘子组分对绝缘子的质量及使用寿命具有决定性的影响,但目前电力部门缺乏有效的检测方法.采用热重分析-差示扫描量热联用技术,在系统研究硅橡胶及其主组分高温热分解规律的基础上,提出了一种根据硅橡胶在一定温度范围的热失重率推算氢氧化铝、有机硅化合物及白炭黑等稳定无机物组分含量的方法,并应用于复合绝缘子的质量控制、运行状态评估和老化失效分析.利用该方法对国内厂家系列复合绝缘子产品进行组分检测,发现总有机硅含量大多在35.9%~40.7%之间;对运行复合绝缘子伞裙进行逐层切片分析,发现硅橡胶组分随深度呈现规律性梯度变化,较好地反映了伞裙的表面老化状态;对断串复合绝缘子故障部位的组分分析结果也为事故诊断提供了较为可靠的依据.该方法有助于复合绝缘子的运维管理,也有助于保障输电线路的安全运行.
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