输电线路绕击多参数几何模型及其在差异化防雷中的应用

发布时间：2018-06-10 06:50

本文选题：差异化防雷 + 绕击多参数几何模型　；参考：《三峡大学》2016年硕士论文

【摘要】：随着我国高压电网的快速发展,输电线路的电压等级越来越高,输送容量的不断提升,电网安全运行在系统中的重要性也越来越高。此外,杆塔高度和线路走廊的尺寸也随之增大,引雷半径自然也增加,电网遭受自然雷害的机率更大。目前,电网中暴露出的弱抗雷击风险能力已对电网的安全运行构成威胁。因此,精确、全面的输电线路防雷性能评估方法对线路设计和针对性地采取防雷措施具有极其重要的指导意义,是减少雷害事故,保证电网安全供电,为建设坚强电网提供有力保障的理论基础。绕击是输电线路防雷性能评估中的关键环节之一,本文针对目前差异化绕击耐雷性能分析中存在的部分关键问题进行了分析和研究,并以此为基础,搭建了考虑多项参数共同影响下的输电线路绕击差异化耐雷性能评估模型,主要研究内容包括:1)基于传统的电气几何模型(EGM),建立输电线路的二维几何坐标系,对传统模型的雷电先导入射角、击距以及暴露距离进行修改,得到改进的电气几何模型,从而推导了基于几何坐标的最大击距和暴露距离计算公式,构建出一套考虑多参数的绕击跳闸率计算模型,并以国外某345kV输电线路为例,利用该模型计算该线路绕击跳闸率,将计算结果与运行经验值、传统方法计算值进行了对比分析,验证了模型的合理性,且误差相对于传统电气几何模型降低了56.15%。2)针对地面落雷密度经典网格统计法存在的“噪点”问题,引入中值滤波理论及其算法,得到了改进的地面落雷密度网格统计法。利用该统计方法对模拟地面落雷密度统计分布图的获取进行了尝试,并将一次三阶、二次三阶滤波统计结果与经典网格法统计值进行对比分析,验证了滤波的有效性;获取中值滤波地面落雷密度统计值后,通过线路走廊网格法估计输电线路走廊地面落雷密度值,采用研究得到的绕击耐雷性能多参数几何模型,对输电线路沿线逐基杆塔进行绕击跳闸率计算,研究并建立了输电线路差异化绕击耐雷性能评估模型。3)基于前文成果,研制开发了输电线路雷击风险评估系统,该系统能够实现线路防雷水平的准确计算,明确雷击薄弱点,为线路防雷工作的开展提供决策依据;以三门峡地区110kV朱明线为例,应用该评估模型对具体输电线路进行了绕击耐雷性能的评估,并将评估结果与实际运行数据进行对比分析,验证了该评估模型的工程适用性。
[Abstract]:With the rapid development of high voltage power grid in our country, the voltage level of transmission line is higher and higher, and the transmission capacity is increasing, the importance of safe operation of power network in the system is becoming more and more important. In addition, the height of the tower and the size of the corridor also increase, the lightning radius increases naturally, and the power grid is more likely to suffer from natural lightning damage. At present, the ability of weak lightning exposure in the power grid has posed a threat to the safe operation of the power grid. Therefore, accurate and comprehensive assessment method of lightning protection performance of transmission lines has an extremely important guiding significance for line design and targeted lightning protection measures, which is to reduce lightning accidents and ensure the safe power supply of power grid. To build a strong power grid to provide a theoretical basis for the protection. Wound strike is one of the key links in the lightning protection performance evaluation of transmission lines. This paper analyzes and studies some key problems existing in the analysis of lightning resistance performance of differential wound strike at present, and based on this analysis, The performance evaluation model of differential lightning resistance for transmission lines under the influence of several parameters is built. The main research contents include: 1) based on the traditional electrical geometry model, the two-dimensional geometric coordinate system of transmission line is established. An improved electrical geometric model is obtained by modifying the incident angle, strike distance and exposure distance of the lightning pilot in the traditional model, and the formulas for calculating the maximum strike distance and exposure distance based on geometric coordinates are derived. A multi-parameter calculation model of tripping rate is established. Taking a 345kV transmission line abroad as an example, the model is used to calculate the tripping rate of the line. The calculated results are compared with the operating experience value and the traditional calculation value. The rationality of the model is verified, and the error is reduced by 56.15. 2 compared with the traditional electrical geometry model. Aiming at the "noise point" problem existing in the classical grid statistical method of ground lightning density, the median filtering theory and its algorithm are introduced. An improved grid statistical method of ground drop density is obtained. The statistical method is used to obtain the statistical distribution map of simulated ground lightning density, and the statistical results of the first third order and the second third order filter are compared with those of the classical grid method, and the validity of the filter is verified. After obtaining the statistical value of ground lightning drop density of median filter, the ground lightning drop density value of transmission line corridor is estimated by the method of line corridor grid, and the multi-parameter geometric model of lightning resistance performance is adopted. Based on the previous results, a lightning risk assessment system for transmission lines is developed based on the calculation of the tripping rate of transmission line towers, and the study and establishment of the lightning performance evaluation model. The system can accurately calculate the lightning protection level of the line, identify the weak points of the lightning strike, and provide the decision basis for the development of the lightning protection work of the line, taking 110kV Zhu Ming line in Sanmenxia area as an example, The evaluation model is used to evaluate the lightning resistance performance of specific transmission lines, and the engineering applicability of the evaluation model is verified by comparing the evaluation results with the actual operation data.
【学位授予单位】：三峡大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM863

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