【作者】 郑顾平；

【导师】 杨以涵；

【作者基本信息】 华北电力大学 ， 电力系统及其自动化， 2012， 博士

【摘要】 配网自动化系统故障监控模块对线路故障进行监控,配电网80%以上的故障是单相接地故障,然而由于技术的原因,我国配网自动化系统在处理小电流故障定位方面存在严重缺陷,这对配电网安全运行形成潜在威胁。本文重点研究中性点非有效接地系统小电流故障区段定位问题。中性点非有效接地系统小电流故障定位最重要的问题是采集和处理微弱且不稳定的故障电流信号,捕捉故障特征信息。本文提出了配电网广域零序相量测量方法,在配电网线路上设置基于广域相量测量的零序电流测点,当发生单相接地故障时,克服故障电流幅值和相位在线路分布上存在的差异性,故障路径上距离故障点最近的零序电流测点可以获取幅值大、测量准确的故障电流特征信息,为故障定位提供信息技术支持。本文提出消弧、故障选线和故障定位一体化的思想,调控消弧线圈脱谐度在故障路径产生电流突变量,引入当量概念计算脱谐度变化前后电流的差值,给出了基于广域相量测量和电流突变量的识别小电流故障特征信息的相量判据、相位判据和幅值判据。本文充分利用并联电抗器组合式消弧线圈的功能,研究快速有效调控消弧线圈脱谐度的方法,为识别小电流故障特征信息的判据提供了可靠的技术基础。本文系统地提出基于配电网广域零序相量测量的小电流故障区段定位理论。采用配电网广域零序相量测点划分配电线路区段,引入测点相邻矩阵、区段起始测点标识向量和故障路径标识向量概念,表述线路故障路径与非故障路径线路分支的差异。针对配电网线路负载不对称导致不对称运行的情况,设定线路零序电压故障阈值ε,作为判断中性点非有效接地系统有无小电流故障的依据。给出求取故障区间边界节点算法,标识配电线路故障路径,计算线路故障区域节点集合和可能的故障支路。挂网运行结果和配电网物理模拟实验分析证明了基于配电网广域零序相量测量的区段定位理论的正确性和有效性。本文基于智能诊断和人工智能理论提出小电流故障选线装置智能状态诊断方法,依据专家维护选线装置的流程、故障录波数据和故障选线备案信息等信息,诊断选线装置选线出错的原因,对现场选线装置的质量、现场设备的可靠性和现场数据的真伪给出客观的评价,为技术人员使用和维护小电流故障选线装置提供技术保障。本文给出基于相平面原理和小波分析辨识原理的小电流接地故障类型辨识方法。研究提取不同类型小电流接地故障的故障特征的算法,利用模式识别理论和方法进行分类,针对故障录波实验数据有效识别出稳定型故障、电弧型故障、高阻电弧型故障、高阻放电型故障和间隙放电型故障,为巡线人员查找小电流故障点提供有益的信息支持。依据本文提出的基于配电网广域零序相量测量的小电流故障区段定位理论,设计实现了移动式中性点不接地系统小电流故障定位系统和中性点非有效接地系统小电流故障区段定位系统,物理模拟实验结果印证了本文提出的配电网广域相量测量方法的有效性和故障定位系统研究方法的合理性。在此基础上,设计实现的中性点非有效接地系统小电流故障区段定位系统已投入电网运行,经过评审验收,使用效果良好。更多还原

【Abstract】 More than80percent of the fault in the distribution network is single-phase grounded fault, however, China’s distribution automation system is seriously flawed in dealing with the small current fault’s location due to the reason of technology which is a potential threat for the safe operation of power grids. This paper focuses on the problem of current fault section location in the neutral point non-effectively grounded system.The most important issue of current fault location for neutral point grounding system is the collection and processing of the weak and unstable fault current signal to capture the fault information. This paper presents with the method of distribution network wide-area zero-sequence-phasor measurement, which sets the zero sequence current measurement points on the distribution network line based on wide-area zero-sequence-phasor measurement, to overcome the differentiation of the fault current magnitude and phase in the line, when the single-phase grounded fault occurs in the distribution grid, fault path from the point of failure the most recent zero-sequence current measurement points can obtain the amplitude and accurate measurement of the fault current characteristics of information, providing support for fault location.In this paper, the idea that integration of arc and fault line selection and fault location is proposed. Changing can make the mutation of current on the fault path, the author imported the concept of equivalent to calculate the difference of the current when the arc suppression coil off Degree vary, and accomplished the phasor criterion to Identify the small current fault information based on mutation method and wide-area phasor measurement. This article makes full use of the function of the shunt reactor combined arc suppression coil, to realize the fast and effective regulation of the arc suppression coil off Degree, to provide a reliable technical basis for the identification of low current fault information.In this paper proposed a fault section location theory of the small current based on the distribution network wide area zero sequence phasor measurements. To divide the distribution line section adopted with the zero-sequence phase wide-area measurement point. The introduction of the measuring point adjacency matrix, marking vector of segment starting points and fault path to identify vector is to express the difference of the line fault path and the path of the non-fault circuit branch. For with the power grid line load asymmetry lead to asymmetry run, set the zero-sequence voltage fault threshold□, as the basis to determine the neutral point non-effectively grounding system with or without a small current failure. Give an algorithm to strike the boundary nodes of the fault interval, to identify the distribution line fault path, calculate the line fault a collection of regional nodes and possible fault slip. The distribution network physical simulation experiments and the hanging net operating results prove the correctness and validity of section location based on the distribution grid wide area zero sequence phasor measurement.Proposed smart state diagnostic methods of small-current fault line selection device based on intelligent diagnostics and artificial intelligence theory, according to the experts’maintaining process of selecting device, fault recorder data and the fault line selection for the record information, to diagnosis error reasons of the selecting device line selection, to give an objective evaluation on-site selecting device quality, reliability and authenticity of the site data of the field devices, to provide technical support for technicians to use and maintain a small current fault line selection device.In this paper, a small current grounding fault type identification method based on the recognition principle of the phase plane theory and wavelet analysis is proposed. Extract the fault characteristics of the different types of small current grounding fault algorithm, to classify them based on the theory and method of pattern recognition, and identify stable Fault, Arc Fault, high resistance arc-type failure, high impedance discharge type failure and gap discharge fault effectively based on the experimental data for the fault recorder, to provide useful information support to find small current point of failure for the line patrol officersDesign and implement the mobile neutral non-effectively grounded grid current fault location system and the neutral non-effectively grounded grid current fault section location system, based on the proposed distribution network wide area zero sequence current phasor measurement fault section location theory in this paper, and the physical simulation results confirms the effectiveness of the proposed distribution network wide-area phasor measurement methods and fault section location system is reasonable. On this basis, the neutral point non-effectively grounded grid current fault section location system designed and achieved has been put into the power grid after review and acceptance with favorable results.更多还原