研究复合绝缘子的长期运行性能，可以提高电网安全稳定性，工程意义重大。本文对高温高湿地区运行3-22年的复合绝缘子进行了系统性研究，分析了硅橡胶护套、环氧芯棒以及宏观交界面的运行特性，提出了与运行年限密切相关的18个特征量；针对该地区常见的异常发热缺陷机理展开研究，提出了高温高湿地区端部电场的控制原则；根据该环境下绝缘子的运行性能，提出了高温高湿地区复合绝缘子老化状态与运行寿命的定性评估与定量预测方法。针对硅橡胶护套的运行性能，通过对运行不同年限硅橡胶材料的宏观与微观检测，详细分析了硅橡胶护套在运行过程中的物理、化学变化；并对憎水性下降、ATH填料析出与硅橡胶机械性能下降等核心老化过程展开了深入分析。通过建立塔线仿真模型，对复合绝缘子在运行中的受力过程进行分析；并基于仿真结果，对运行不同年限的芯棒材料进行了静载与动载试验，以分析运行芯棒材料的残余机械性能以及耐动载老化性能；借助声发射技术，研究了芯棒在承受静态载荷时，内部微观结构的变化规律。改进现有的水扩散试验方法，延长水煮时间以更有效地检出交界面粘接性缺陷；并基于太赫兹时域技术提出了复合绝缘子内部缺陷远场无损检测方法，检测精度达到0.4mm。通过对运行绝缘子的污秽闪络、湿雨闪络等电气试验，研究了硅橡胶-空气交界面的运行特性。异常发热是高温高湿地区常见的复合绝缘子紧急缺陷，本文对其机理与控制措施进行了全面研究，通过耐压试验、介损角分析以及化学分析，确定了复合绝缘子的主要致热因素；基于仿真结果与耐压试验结果，提出了高温高湿地区复合绝缘子端部电场的控制原则，并在工程中进行试运行。根据对高温高湿地区复合绝缘子运行性能的分析，分别基于物理模型与统计学模型，在考虑紧急退出机制的基础上，提出了高温高湿地区复合绝缘子的运行状态评估与寿命预测方法，研究结果表明，高温高湿地区复合绝缘子运行15.8年后，存在开裂风险，运行年限超过19.2年后，应逐步更换。
Due to extensive application of composite insulators, there is undoubted significance in research on the long term performance considering the safety of power network. In our study, we systematically analyzed the composite insulators from atypical warm and humid areas, which had been running between 3 to 22 years. We included researches on the silicone rubber sheath, the performance of epoxy core and the macroscopic interface. According to the results, we proposed 18 characteristic quantities in relation to the running years. Meanwhile, we conducted a thorough analysis on the mechanism and quality control measures of the abnormal heating in such areas. Finally, we made a evaluation on the aging status and prediction about the remaining lifespan of composite insulators based on their running performance in atypical warm and humid areas.In the beginning, we studied the performance of silicone rubber sheath. Through macroscopic and microscopic detection of insulators with various running years, we analyzed their physical and chemical change while running online and drilled down the mechanism of aging process, especially the ATH filters migration, decrease of the mechanical properties as well as the water resistant ability.Via the tower-line simulation test results, we analyzed composite insulators while under stress. Based on the results, we conducted static load and dynamic load experiments on the core materials with different running years and analyzed the remaining mechanical properties and dynamic load aging resistant properties. Meanwhile, we studied the variation law of the internal microscopic structures of the core during massive static load with the technology of acoustic emission.In the next section, we improved the water diffusion test to make it more effective in detection of the adhesive defects between interfaces. We also proposed a non destructive far-field monitoring method for the internal delicate gap-like defect as small as 0.4mm based on the THz-TDS technology. In the last, we conducted pollution flashover and rain flashover tests on the running composite insulators and analyzed the performance of interface between silicone rubber and air.Abnormal heating was the most urgent yet widespread emergency in atypical warm and humid areas. In this study, we thoroughly analyzed the mechanism and quality control measures. Via withstand voltage test, dielectric loss angle test and chemical analysis, we locked down several factors in relation to heating. According to the simulation test results and the voltage test, we also proposed quality control measures on the terminal electric field and completed the on-site commissioning.Based on the running performance, in the end, considering the emergent exit, we used two types of models, the physical and the statistical, to propose evaluation on the aging status and prediction about the remaining lifespan of composite insulators from atypical warm and humid areas. According to our prediction, those insulators we used in the study would face the risk of cracking after running for 15.8 years. It is reasonable to gradually replace those insulators which had been running for over 19.2 years.
