要建立基于分解组份分析(DCA)法诊断SF6气体绝缘设备局部过热性故障，其首要问题是如何从过热引发SF6气体分解产生的众多分解特征组份中提取出能有效反映局部过热性故障属性的关键特征量，然后建立科学实用的诊断方法。为此，本课题在已开展的大量实验研究基础上，完善并分析典型局部过热状态下SF6的分解特性及其影响因素，结合分子动力学仿真和同位素示踪技术，剖析主要分解组份的生成条件和物理化学机制，构建含微量杂质气体的高气压局部高温场SF6气体分子过热分解模型，由此提取出能够有效表征SF6气体绝缘设备过热性故障类型、严重程度及发展趋势的关键组份特征量，揭示其所蕴含的物理意义，并对关键组份特征量产生影响的主要因素给出解析校正，最后采用多层二元树逐步归一理论，建立SF6气体绝缘设备局部过热性故障的DCA诊断方法，为最终形成SF6气体绝缘设备相应的安全运行规范或标准，提供理论基础和实用技术。

The method based on the decomposition component analysis(DCA) is developed to diagnosis the partial over-thermal fault of SF6 insulated equipment. However, the primary problem is how to extract the key feature parameter which can effectively reflect the partial over-thermal fault from numerous decomposition component of SF6 under this circumstance and then to establish a scientific and practical diagnosis method. Therefore, the subject on the basis of a lot of existing experimental research, perfecting and analyzing the decomposition characteristics of SF6 under Partial Over-thermal Fault, acquiring influence regularity and correction method about critical influencing factors of generating decomposition characteristics components of SF6, combined with molecular dynamics simulation and isotope tracer technique, dissecting formation conditions and physicochemical mechanisms of the main decomposition components, establishing over-thermal decomposition model of SF6 under partial high temperature field with high pressure including trace of impurity gas, further extracting the key feature parameter which effectively characterizes over-thermal fault type, severity and development trend of SF6 insulated equipment, revealing the physical meaning ,finally using multilayer dual-tree gradual normalization theory, setting up DCA diagnosis method aiming at partial over-thermal fault of SF6 insulated equipment, in the end, provides theoretical basis and practical technology for the norm or standard of corresponding safe operation of the SF6 insulated equipment.