基于故障指示器的小电流接地故障定位研究

发布时间：2018-03-03 08:44

本文选题：故障指示器　切入点：小电流接地　出处：《山东理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着现代化与智能化时代的到来,电力电网对国民经济的重要性也越来越突出,良好的电能质量已经成为了社会生活必不可少的一部分。因此,如何应对突发事故做出快速的反应也越发值得人们深究。配电网的覆盖面广和分支众多的特性,使得故障排查作业难度大大提高,尤其是单相接地故障的发生,其可预判性一直都是电力作业的重中之重。由于单相接地故障量的不突出、不稳定以及不确定等问题,小电流故障定位存在较大困难,该领域也一直缺乏完善的技术方法。为了更好的应对和解决这一困难,帮助工作人员快速找到故障位置,缩短故障时间,使电网及时恢复正常工作状态,故障指示设备已大量使用于配电网中。然而,目前使用的一些故障定位方法虽取得了很好的成效,但仍存在不足。针对配电网中经消弧线圈接地系统存在小电流接地故障定位困难这一问题,本文在现有相关系数法的基础上,提出了一种改进的基于暂态零模电流相关系数的故障定位方法。本文的主要研究内容有:(1)概述了配电网中性点的接地方式及特点,介绍了故障指示器的工作原理及功能特点,总结了应用于故障指示器的传统接地故障检测技术,并分析了其存在的问题。(2)分析了小电流单相接地故障的暂态信息,重点分析了现有的基于相关系数法故障判据的不足,并在此基础上提出了改进的基于暂态零模电流相关系数的故障定位方法。(3)结合改进后的故障定位方法设计了一套完整的故障定位方案;为了降低故障指示器因通信设备延迟造成数据不同步的问题,利用馈线监测单元中的双向无线传输通信模块,设计了多种定位系统无线通信拓扑关系。(4)搭建了小电流单相接地故障的MATLAB仿真模型,验证了现有相关系数法在出线上故障分界点处存在着定位盲区的推理,证实了改进后的方法能够有效地消除该盲区的结论。实验结果表明:改进后的故障定位方法在利用接地点上游与下游间暂态零模电流存在相似性的基础上,将工频电流极性与暂态零模电流的相关系数相结合,进而避免了在故障点两侧暂态电流相关系数为负相关时出现误判的情况,最终解决了目前相关系数法中存在定位盲区的问题。本文不仅指出了位于故障线路上距母线1/2处存在故障分界点的情况,还进一步分析了故障分界点处发生单相接地故障时故障点两侧暂态零模电流的高相似度对故障判据的准确性的影响,并在此基础上对现有的相关系数法提出了改进,从根本上消除了原方法故障定位存在的盲区。研究结果对完善配电网故障定位方法、提高供电可靠性具有十分重要的意义。
[Abstract]:With the modernization and the arrival of the era of intelligent power grid, the importance of the national economy has become increasingly prominent, good power quality has become an essential part of social life. Therefore, how to deal with the emergency rapid response is more worth studying. The distribution network coverage and many branches of the characteristics. Troubleshooting work difficulty is greatly improved, especially the single-phase grounding fault occurs, the pre sentence has been the priority among priorities of power operation. Because of the single-phase grounding fault was not prominent, unstable and uncertain, small current fault location is difficult, the field has been the lack of technology perfect. In order to deal with and solve this problem, help the staff to quickly find the location of the fault, shorten the time of fault, the power return to normal working condition timely, fault Indicating devices have been widely used in the distribution network. However, some fault location methods used at present has achieved good results, but there are still shortcomings. According to the distribution network with arc suppression coil grounding system is difficult to locate the small current grounding fault of this problem, based on the correlation coefficient method. The proposed fault location method, an improved correlation coefficient based on the transient zero mode current. The main research contents of this paper are: (1) an overview of the distribution network neutral grounding modes and characteristics, introduces the working principle and function characteristics of the fault indicator, summarizes the application on fault indicator of traditional grounding fault detection technology, and analyzes its problems. (2) of small current single-phase ground fault transient information, analyzes the lack of correlation coefficient method based on the criterion of fault current, and put forward the reform Fault location method in transient zero mode current based on correlation coefficient. (3) a complete set of fault location scheme design based on fault location method is improved; in order to reduce the fault indicator for communication equipment caused by the delay of data synchronization, the feeder monitoring unit in two-way wireless communication module design a variety of positioning system wireless communication topology. (4) to build a ground fault simulation model of single phase MATLAB small current, verify the existing correlation coefficient method in fault line on the boundary are positioning blind reasoning, proved that the improved method can effectively eliminate the blind spot of the conclusion. The experimental results show that the fault the improved positioning method in the presence of the similar ground between upper and lower level transient zero mode current on the basis of the correlation coefficient of AC current polarity and transient zero mode current phase Combined, and avoid the misjudgment of the situation appears in both transient current of fault point correlation coefficient is negative correlation, finally solved the correlation coefficient method in positioning blind area problem. This paper not only points out in the fault line fault point away from the bus at 1/2, further analysis of the fault occurred at the boundary point single phase affects the accuracy of high similarity at the fault point of transient zero mode current of the fault criterion of ground fault, and on the basis of correlation coefficient method is proposed to improve the existing, fundamentally eliminate the blind area existing fault location method. The research results to improve the distribution network fault location method is very important the significance of improving the reliability of power supply.

【学位授予单位】：山东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM862

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