高速气流环境车顶绝缘子积污特性及其对闪络的影响机理研究

发布时间：2018-05-14 08:33

本文选题：高速铁路 + 复合绝缘子　；参考：《西南交通大学》2014年博士论文

【摘要】：列车运行时,车顶绝缘子处于高速气流环境中,污秽在绝缘子表面分布不均匀,容易引起车顶绝缘子闪络。同时,在雾、雨环境中接触网上可能凝结水滴,列车运行时,车顶受电弓与接触网接触,水滴沿受流设备流动、滴落,引起车顶电场畸变,诱发闪络。尤其是近几年来,雾、雨环境造成车顶绝缘子闪络的问题更加突出。当前,电气化铁路复杂环境绝缘闪络问题的理论研究尚不深入,工程上还没有很好解决该问题的系统方案,成为制约列车安全、稳定运行的潜在威胁。在电气化铁路快速发展背景下,研究高速气流环境车顶绝缘子积污特性及闪络机理对保证高速铁路的安全运行具有重要的意义。本文对高速列车强气流环境车顶绝缘子积污特性及其对闪络的影响机理进行了探索,根据车顶电场分析提出车顶设备优化方法。分析了高速气流环境污秽颗粒受力特点；建立多相流体模型,讨论了污秽颗粒在高速气流中的运动状态；引入聚团流化理论分析污秽在绝缘子表面的粘附特性；结合试验,研究了污秽颗粒、气流流速、来流角度等对绝缘子表面积污分布的影响；依据分析,得到了高速气流环境绝缘子表面积污分布函数,提出一种分布函数测量方案；比较绝缘子伞裙倾角、伞裙间距、伞裙组合类型等不同的伞裙设计时绝缘子积污状况；在减小表面积污角度,提出绝缘子的设计方法。在电气化铁路车顶绝缘子污秽组成及污秽分布研究的基础上,分析了污秽性质及污秽分布对绝缘子表面电场的影响。讨论了接近实际分布状况时,不同伞裙设计对沿面电场的影响；在降低电场畸变的角度,提出绝缘子设计优化方法。根据高速气流环境车顶绝缘子沿绝缘子方向及环绕绝缘子方向污秽的不均匀性,提出污秽非均匀分布闪络时剩余电阻的计算方法；比较不同污秽分布状况绝缘子闪络特性,得到污秽沿面分布与环绕绝缘子非均匀分布对闪络电压的影响特性。采集成都一青城山高速铁路沿线犀浦段污秽,建立了污秽失水模型,结合实验分析了电气化铁路污秽失水过程中的电学特性；得出绝缘子染污程度的表征参量及表征方法。根据高速列车车顶受流设备的结构特点,分析了接触网上水滴在车顶部件降落过程,比较了有效导电水滴对车顶空间电场影响,提出了一种车顶电场整体畸变状况的表征方法；计算了沿接触网水滴分布,降落位置、车顶绝缘、列车速度等对车顶电场的影响程度；比较车顶不同设计方式电场分布状况,提出了车顶高压设备优化方案。
[Abstract]:When the train is running, the roof insulator is in the high speed airflow environment, and the contamination is distributed unevenly on the insulator surface, which can easily cause the roof insulator to flashover. At the same time, in the fog and rain environment, the contact network may condensate water droplets. When the train is running, the pantograph of the roof contacts with the catenary, and the water droplets flow along the receiving equipment and drop, which causes the electric field distortion of the roof and induces the flashover. Especially in recent years, the problem of roof insulator flashover caused by fog and rain environment is more prominent. At present, the theoretical research on complex environment insulation and flashover of electrified railway is not deep, and there is no systematic scheme to solve this problem in engineering, which becomes a potential threat to train safety and stable operation. In the context of the rapid development of electrified railway, it is of great significance to study the fouling characteristics and flashover mechanism of roof insulators in high-speed airflow environment to ensure the safe operation of high-speed railway. In this paper, the fouling characteristics of roof insulators and its influence on flashover in high speed train are explored, and the optimization method of roof equipment is put forward according to the analysis of roof electric field. The stress characteristics of polluted particles in high speed airflow environment are analyzed, the multiphase fluid model is established, and the motion state of polluted particles in high speed airflow is discussed. The adhesion characteristics of contamination on insulator surface are analyzed by introducing cluster fluidization theory. Based on the analysis, the pollution distribution function of insulator surface area in high speed airflow environment is obtained, and a measuring scheme of distribution function is put forward. This paper compares the insulator fouling in the design of the insulator skirt with different inclination angle, the distance between the parachute skirt and the combination type of the umbrella skirt, and puts forward the design method of the insulator in order to reduce the surface area pollution angle. Based on the study of pollution composition and pollution distribution of roof insulators in electrified railway, the influence of pollution properties and pollution distribution on the surface electric field of insulators is analyzed. The influence of different design of umbrella skirt on the electric field along the plane is discussed, and the optimization method of insulator design is put forward in order to reduce the distortion of electric field. According to the pollution inhomogeneity of roof insulator along the direction of insulator and surrounding insulator in high speed airflow environment, the calculation method of residual resistance for flashover of polluted non-uniform distribution is put forward, and the flashover characteristics of insulator with different pollution distribution are compared. The influence of contamination distribution along the surface and non-uniform distribution of the surrounding insulator on the flashover voltage is obtained. The pollution of Xiupu section along Chengdu-Qingchengshan high-speed railway is collected, the model of polluted water loss is established, the electrical characteristics in the process of polluted water loss of electrified railway are analyzed, and the characterization parameters and methods of pollution degree of insulator are obtained. According to the structural characteristics of the roof receiving equipment of high-speed train, the falling process of water droplets in the roof parts on the contact network is analyzed, the effect of effective conductive water drops on the space electric field of the roof is compared, and a representation method of the overall distortion of the roof electric field is put forward. The influence of water droplet distribution, landing position, roof insulation and train speed along the catenary on the roof electric field is calculated, and the optimum scheme of roof high-voltage equipment is put forward by comparing the electric field distribution of different design modes of the roof.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U264.3;TM216

【参考文献】