多分辨形态学梯度—相关函数理论在特高压直流输电线路故障测距上的应用

发布时间：2018-05-13 15:52

本文选题：特高压工程 + 直流　；参考：《山东大学》2017年硕士论文

【摘要】：我国资源与负荷逆向分布的特点,清洁能源须增大能源占比的发展形势,亟需发展特高压。而高压直流输电系统中间不落点,可点对点、大功率、远距离直接将电力送往负荷中心,因此成为我国发展特高压工程的首选。尤其是对经营区域覆盖26个省(自治区、直辖市)、覆盖国土面积的88%以上、供电人口超过11亿人的国家电网公司,更是把发展特高压作为构建全球能源互联网,攻坚智能电网的发展方向。由于我国发展特高压直流输电技术的目的就是远距离、大容量的输送、调节电能。大都横跨多个省市,且为减少对群众生产生活的影响,特高压线路通道一般就规划在偏远路上,经过地形地貌复杂多变,防外破压力大,线路运行维护困难。同时,因担负着大容量的符合,一旦发生故障或缺陷,造成的经济损失和不良影响极大。因此,选取一种方便、可靠并易于操作的故障点距离测量和成熟的计算方法迫在眉睫。利用在输电线路一侧的方法进行对故障点距离测算的单端算法是当前推进高压直流故障测距的重要研究方向。利用此类方法,可以及时、有效的进行故障波的提取检测,并用传统的行波故障点测距算法进行距离测算。但此种算法是在理论条件下,面对实现复杂环境和诸多干扰波,以上算法难以在实际中进行操作应用,其测算结果也往往会出现诸多误差。本篇论文正是基于以上问题,创造性的引入数学形态学梯度变换函数,结合传统距离测量算法完成对外界干扰因素的过滤,及待测算行波的极值剔除,进而极大降低测距误差,使操作方法更具有实用性和准确性。基于以上思路,本文重点从一下过程进行优化完善:(1)对研究对象进行分析研究,即将直流输电线路上发生故障的条件、种类及过程进行提取(假设)分析,对搜集到的各类行波浪涌进行对比,找出关键需要分析的行波,并推导出关键行波本身存在的干扰因素和不足。(2)开展建模分析,对实际运行的特高压直流线路网及设备进行研究,总结其关键部位构成及特点为数学建模提供思路和现实参考。上述工作完成后,应用PSCAD电力系统仿真成熟软件组建高压直流输电网模型及有可能发生故障点的模拟数据。分别研究正常运行状态、发生外力破坏情况(断线或对地放电)以及雷电干扰等情形进行逐一分析。试验结果表明,上述观点符合实际需求。(3)引入新算法,解决传统计算方法面临的误差大的问题,利用数学形态学中梯度变换的优点,构造出一个既可以过滤干扰波,又可以修正(剔除)带分析行波的波峰和波谷上的极值,因此提出了"多分辨形态学梯度-相关函数理论在特高压直流输电线路故障测距上的应用"这一最终研究课题。计算过程就是通过引入两个类型的结构元素,分离出所需要进行计算的行波,再利用直流输电线路上故障点行波的测距方法进行相应函数的构造,最后实现利用单侧测量点完成高压直流输电线路故障点的定位和测距。本论文通过两种仿真数据软件(即电力系统PSCAD和MATLAB数学软件)对建立的模型进行仿真实验。通过最终测算,得出以上计算方法的能够大范围的消除误差,距离判定缩小至0.2公里的范围内。因此,本文涉及到新型测距方法可以在故障线路的单侧进行故障测距,并且能够有效甄别外部干扰,净化带测量行波纯度,进而极大提高故障点距离测量的准确性和现实可操作性。
[Abstract]:With the characteristics of reverse distribution of resources and load in China, clean energy needs to increase the development situation of energy occupation, and it is urgent to develop ultra high voltage. However, there is no drop in the middle of HVDC transmission system. It can be directly sent to the load center by point to point, high power and long distance, so it has become the first choice for the development of UHV project in China. The national Power Grid Corp covering 26 provinces (autonomous regions and municipalities), covering more than 88% of the land area and the power supply population of more than 1 billion 100 million people, is the development direction of developing the ultra high voltage as the global energy Internet to build the smart grid. The purpose of developing the technology of UHVDC transmission is long distance, large capacity transmission and regulation. Electrical energy, mostly across provinces and cities, and to reduce the impact on the production and life of the masses, the UHV route channel is generally planned in the remote road, through the complex terrain and geomorphology, the prevention of external breakage pressure and the difficulty of the line operation and maintenance. At the same time, the economic loss and malfunction caused by the large capacity and failure or defect occur. Therefore, it is imminent to select a convenient, reliable and easy to operate fault point distance measurement and mature calculation method. Using the method of one side of the transmission line to calculate the distance of the fault point is an important research direction for the current high voltage DC fault location. It performs the extraction and detection of the fault wave, and calculates the distance with the traditional traveling wave fault location algorithm. However, under the theoretical condition, the algorithm is difficult to operate in the actual environment and many interference waves, and the calculation results often have many errors. This paper is based on this paper. In the above problems, we creatively introduce mathematical morphology gradient transform function, combine the traditional distance measurement algorithm to filter the external interference factors and eliminate the extreme value of the traveling wave, thus greatly reducing the distance error, making the operation method more practical and accurate. Based on the above ideas, this paper focuses on the optimization of the process. (1) the research object is analyzed and studied. The condition, the type and the process of the fault in the DC transmission line are extracted (hypothesis) analysis, the collection of all kinds of wave surges are compared, the key need analysis traveling wave is found, and the interference factors and shortcomings of the key traveling wave itself are derived. (2) to carry out the modeling division. Analysis of the actual operation of the UHVDC line network and equipment, and summarize the key parts and characteristics for the mathematical modeling and practical reference. After the completion of the above work, the application of PSCAD power system simulation mature software to form a HVDC model and the possible failure point of the simulation data, respectively. The normal operation state, the occurrence of external force damage (broken line or ground discharge) and lightning interference and other cases are analyzed one by one. The results show that the above viewpoint is in line with the actual demand. (3) introducing a new algorithm to solve the problem of large error faced by the traditional calculation method, and using the advantages of the gradient transformation in mathematical morphology to construct an existing one. It is possible to filter the interference waves and to correct the extremes on the wave peaks and the valleys of the traveling wave. Therefore, the final research topic of "the application of the multi-resolution morphological gradient correlation function theory to the fault location of UHVDC transmission lines" is proposed. The calculation process is separated by introducing two types of structural elements. The traveling wave needs to be calculated, and the corresponding function is constructed by using the fault location method on the fault point on the DC transmission line. Finally, the location and distance measurement of the fault point of the HVDC transmission line are completed by the single side measurement point. This paper is built by two kinds of simulation data software (i.e., the power system PSCAD and the MATLAB mathematical software). The simulation experiment is carried out by the vertical model. Through the final calculation, the above calculation method can be eliminated in a wide range and the distance is reduced to 0.2 km. Therefore, this paper involves the new method of measuring the single side of the fault line, and can effectively identify the external interference and clean the belt to measure the traveling wave. Purity, thus greatly improving the accuracy and practical operability of fault point distance measurement.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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