环氧基材料影响导体/固体绝缘界面电-热-力耦合效应的机理研究

Interface between metal conductor and solid insulating materials are found in large amount in power equipment. As the concentration zone of electrical/thermal/mechanical field, numerous insulation damage accidents especially UHV accidents occurred from these interface. However, there is no systematized research for multi-physics field coupling effects and the regulatory mechanism of the conductor/ solid insulating materials interface so far. This research based on the multi-field coupling effects of the interface between conductor and solid insulating materials, and the influence mechanism of epoxy-based materials on these interface will be analyzed, the specific research divided into three aspects are as follows. 1) The samples contain epoxy resin/solid insulation materials interface will be prepared, the interfacial microstructures and its influence on properties of composites will be studied, the interface model for epoxy resin/solid insulating materials will be put forwarded. 2) A simplified coaxial cylindrical model of Gas Insulated Switchgear (GIS) spacer will be fabricated, the systems for monitoring interfacial thermal-force status and partial discharge will be built, and the influence mechanism of epoxy-based interfacial materials on electrical/thermal/mechanical coupling effects for the interface between conductor and solid insulating materials will be analyzed. 3) The stimulation models of Ultra high voltage (UHV) GIS spacer will be designed for calculating the distribution of electric/thermal/mechanical field, the interface characteristics of the UHV GIS spacer will be optimized. This research can provide theoretical basis for the design and manufacture of UHV GIS spacer in China, which has important engineering application value for improving the reliability of UHV GIS.

电力设备中存在大量导体与固体绝缘材料所形成的界面，界面处为电、热、力集中区域，在特高压电力设备的运行中已多次出现由此引发的绝缘破坏。但目前对界面电、热、力多场耦合效应缺乏系统化的研究且尚不明确其多物理场的调控机理。本项目以导体/固体绝缘界面为研究对象，分析环氧基界面材料对界面多物理场的影响机理，开展如下科学问题研究：1）制备含环氧/固体绝缘界面试样，研究界面微观结构及其对材料性能的影响，建立环氧树脂-固体绝缘材料界面模型；2）制备盆式绝缘子简化同轴圆柱试样，改造界面光纤应力-温度测量系统和局部放电测量系统，研究界面材料对导体/固体绝缘界面电-热-力的影响机理；3）建立多物理场耦合模型，对特高压盆式绝缘子导体与盆体绝缘材料之间界面多物理场分布进行仿真计算，优化特高压盆式绝缘子的界面。本研究可为我国特高压盆式绝缘子设计和制造提供理论依据，对提高特高压盆式绝缘子运行可靠性具有重要的工程应用价值。

电力设备中存在大量导体与固体绝缘材料所形成的界面，界面处为电、热、力集中区域，在特高压电力设备的运行中已多次出现由此引发的绝缘破坏。但目前对界面电、热、力多场耦合效应缺乏系统化的研究且尚不明确其多物理场的调控机理。本项目以导体/固体绝缘界面为研究对象，通过试验测试结合数值仿真分析环氧基界面材料对界面多物理场的影响机理，并研制界面涂覆材料抑制界面效应。研究得到的结论如下：1）特高压盆式绝缘子导体与盆体之间界面处应力集中，其上下边沿的水压破坏值达到43.5MPa，同时界面处的电场集中效应显著。2）液态橡胶可以提高基体和金属铝的粘接强度，采用15%含量的HTBN可以使剪切强度达到最大值；通过硅烷偶联剂KH560和KH570对铝导体进行预处理可以大幅提高剪切强度。3）由于先后固化而产生的环氧/环氧界面使材料整体的机械强度下降，但仍保持在同一数量级；界面处的低交联密度使其热学性能有略微的上升，并且界面区域形成的界面势垒抑制电极注入的载流子，使带有界面的试样的交流击穿场强和耐烧蚀性略有提高。4）实验测量和仿真结果都表明，环氧固化过程中的残余应变85%是在冷却降温产生，在生产过程中应采用线性降温同时减缓降温速率，并且在试样固化后采用高温热处理可以使残余应变得到缓释。5）研制的半导体界面涂覆材料由A类环氧树脂、15%的HTBN和2%的炭黑组成，综合特高压盆式绝缘子水压试验值、破坏形态和光纤监测结果，界面材料起到了释缓导体与盆体之间界面应力的作用。本研究可为我国特高压盆式绝缘子设计和制造提供理论依据，对提高特高压盆式绝缘子运行可靠性具有重要的工程应用价值。