【2017年整理】10kV架空线路单相接地故障定位方法的研究与实现.doc

东北农业大学学士学位论文 学号：05510kV架空线路单相接地故障定位方法的研究与实现 Research and Implementation of the 10kV overhead line single-phase ground fault location method 学生姓名：郑全爽 指导老师：吴雅芹 所在院系：网络教育学院 所学专业：电气工程及其自动化 研究方向：电气工程及其自动化 东 北 农 业 大 学 中国·哈尔滨 2012年4月 摘要 配电网输电线路单相接地故障也称为小电流接地故障，是6～1 0 KV配电网系统最常发生的故障。配电网发生单相接地故障的选线和定位一直是备受关注的研究课题。本文综合多种近年来一些小电流接地故障选线和定位方法的研究文献，分析了它们的优缺点，提出了一种全新的小电流接地故障选线和定位的方案，并开展一些前期的实验工作。 在配电系统中变电站通过PT向电网注入相位差为120度的三相正弦信号，作为故障诊断信号，在正常情况下注入的三相诊断信号从线路分布的电容和其它变电站的CT经大地返回信号注入点，返回的信号两相抵消，和为零：当有小电流接地故障发生时，对故障相的诊断信号将从故障接点经大地返回，破坏了原三相信号的抵消性，在信号注入点的CT将检测到失衡电流。根据故障发生的相线可实现单相接地故障选线，应用锁相技术对返回的信号提纯、放大，并得到注入信号与返信号的相位差，可进一步计算得到接地故障发生点的距离，从而实现故障点的定位。 文章分四个部分说明了《l 0 K V配电网单相接地故障选线定能方案》的研究意义和背景、系统的整体结构原理、系统各部分的实现和总结。 关键词： 配电网 10KV线路 接地 Abstract Power distribution network one-phase ground fault also called the small current grounding fault, it is 6 ~ 1 0 KV power distribution network system the most often the fault occurred unique original. Single-fault to liver failure. Ground fault location and orientation of has been of concern research subject. WenZong sets in various in recent years a few small current spindle fault location positioning method to design the research literature, this paper analyzes current ground fault location and the location of the project, and to develop some of the early experiments. In the distribution system through to power substation PT into the phase difference is 120 degrees of triphase signal, as a fault diagnosis signal, in normal conditions of the three-phase permeability broken into the signal from the line distributed capacitance and other transformer substation of the return signal into the CT point, return signal two phase offset, and zero: when there is the small current grounding faults, the fault phases, diagnosis signal will return to the earth from the fault contacts, damaged the three-phase signal offset sex, in signal into the CT screening states will point to the current imbalance.