高海拔特高压换流站复合支柱绝缘子积污和污闪特性研究

发布时间：2019-05-27 11:32

【摘要】：国内多条特高压直流线路都需经过高海拔地区，对高海拔地区复合支柱绝缘子积污和污闪特性展开研究具有重要意义。目前积污特性研究主要依靠自然积污试验，对积污过程中复合支柱绝缘子周围流体力学特性、污秽颗粒撞击情况等方面的研究较少。本文结合仿真计算和自然积污试验，从微观机理和实际测量两方面入手，研究高海拔地区复合支柱绝缘子自然积污规律，并在高海拔地区对复合支柱绝缘子开展人工污秽试验研究其直流污闪特性，结果具有一定的理论和工程实用价值。本文首先建立不同伞形结构、伞裙参数复合支柱绝缘子三维模型，利用流体力学仿真软件Fluent对其积污过程绝缘子外流场进行分析；将各绝缘子分为上、中、下三部分，每一部分又分大伞上、下表面，小伞上、下表面、杆径五个部位，计算绝缘子不同位置污秽颗粒撞击密度；在特高压工程技术（昆明）国家工程实验室开展自然积污试验测得绝缘子不同部位盐密、灰密值，并与仿真结果进行对比验证，得出相关规律。最后对复合支柱绝缘子进行直流污闪试验，对海拔、加压方式、盐密、灰密等因素对直流污闪特性的影响展开分析研究。通过以上研究，，可得主要成果如下：（1）一大一小伞形积污情况比一大两小伞形严重；合理增加绝缘子伞伸出值可提高防污水平；在旱季或雨水较少的高海拔地区，复合支柱绝缘子上表面污秽情况比下表面严重；同一复合支柱绝缘子越往下积污情况越严重；仿真和自然积污试验分别认为杆径和小伞的积污情况最严重。（2）污秽颗粒粒径大于5μm时，随粒径增加，污秽颗粒撞击密度增加；两种伞形绝缘子污秽颗粒撞击密度随风速增大均先减小后增大，趋势改变的临界点为5m/s。（3）复合支柱绝缘子直流污闪电压与海拔高度的线性关系可表示为：U/U0=1-0.054H；直流污闪电压随污秽程度、盐密、灰密的增大均呈不同程度的非线性的下降趋势；升压法可用于污秽试验中作定性分析，定量研究建议采用升降法。
[Abstract]:It is of great significance to study the pollution and flashover characteristics of the composite column insulator in the high-altitude area through the high-altitude area. At present, the research of the pollution characteristic mainly depends on the natural accumulation test, and has little research on the fluid dynamics and the impact of the pollution particles in the composite post insulator during the deposition process. Combined with the simulation calculation and the natural fouling test, this paper starts from the two aspects of the micro-mechanism and the practical measurement, and studies the natural soil-accumulation rule of the composite post insulator in the high-altitude area, and studies the direct-current pollution flashover characteristic of the composite post insulator in the high-altitude area. The result has a certain theory and practical value. In this paper, the three-dimensional model of the composite post insulator of the umbrella structure and the umbrella skirt is established, and the external flow field of the insulator is analyzed by the fluid dynamics simulation software Fluent. The insulators are divided into upper, middle and lower three parts, each part of which is divided into a large umbrella, and the following table The impact density of the dirty particles at different positions of the insulator is calculated by the five parts of the upper surface, the lower surface and the rod diameter of the surface, the small umbrella, the lower surface and the rod diameter, and the salt density and the ash density value of different parts of the insulator are measured in the high-voltage engineering (Kunming) national engineering laboratory and compared with the simulation results. The relevant rules are obtained. The influence of the factors such as altitude, pressure, salt density and ash density on the characteristics of the direct current pollution flashover is analyzed and research on the influence of the factors such as altitude, pressure, salt density and ash density on the characteristics of the DC pollution flashover. by the above-mentioned study, it is possible to obtain the main product The results are as follows: (1) a large small umbrella-type sewage is more serious than a big two-small umbrella; a reasonable increase of the extension value of the insulator can improve the anti-pollution level; in the dry season or the rain is less In the high-altitude area, the surface pollution of the composite column insulator is serious than that of the lower surface; the more serious the contamination of the insulator of the same composite column is, the more serious the simulation and the natural fouling test consider the accumulated pollution of the rod diameter and the small umbrella (2) When the particle size of the dirty particles is more than 5. m u.m, the impact density of the dirty particles is increased with the increase of the particle size, and the impact density of the dirty particles of the two umbrella-type insulators increases with the increase of the wind speed, and the trend is changed. The linear relation between the DC pollution flashover voltage and the altitude of the composite column insulator can be expressed as: U/ U0 = 1-0.054H; the direct current pollution flashover voltage with the degree of pollution, the density of the salt and the increase of the density of the gray density all show a different degree of non-linear decreasing trend; the step-up method can be used for sewage treatment. Qualitative analysis and quantification in the laboratory test
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM721.1

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