基于频域参数识别方法的配电网单相接地故障选线  

Fault Line Selection in Distribution Networks Based on Parameter Identification Method in Frequency Domain

作　　者：索南加乐[1] 李宗朋[1] 王莉[1,2] 焦在滨[1] 马超[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049 [2]许继电气股份有限公司技术中心,河南省许昌市461000

出　　处：《电力系统自动化》2012年第23期93-97,125,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51037005);国家重点基础研究发展计划(973计划)资助项目(2009CB219704)~~

摘　　要：国内配电网大多采用中性点不接地或经消弧线圈接地的方式运行,在这种系统发生单相接地故障时,尽快选出故障线路对电网运行有重要意义。提出一种基于参数识别的频域方法进行小电流接地选线。通过矩阵束方法提取故障后零序电压和零序电流的频点信息,解决了传统离散傅里叶变换方法提取频域信号不准确的问题。提取频点信息后,利用频域方程求解线路对地电容值并进行选线。与时域参数识别方法相比,该方法对采样频率要求低、计算精度高。同时,频带分析表明该方法比传统的首容性频带滤波方式具有更宽的频带,理论上不需要滤波。经ATP-EMTP仿真和实时数字仿真器录波数据验证,该方法选线正确、有效,耐过渡电阻能力强,不受消弧线圈的影响。The distribution networks in China are mostly the ungrounded neutral system or the resonant grounded system.Timely selection of the fault line is of great significance to power systems after fault.This paper proposes a parameter identification method in frequency-domain to solve this problem.By using the matrix pencil method to extract frequency-points and their information in zero-sequence voltage and zero-sequence current,spectral leakage in discrete Fourier transformation is avoid.With the estimated frequency points,an equation is established in frequency-domain,which will help to calculate the capacitance value and further identify the fault line.Compared with the time-domain method,this method requires a lower sampling rate and has higher accuracy.Moreover,the frequency-band in this new method is wider than the traditional frequency-band of the first capacitive frequency band filtering method.In theory,a filtering process is not needed in this method.Verified by simulation in ATP-EMTP and data from real time digital simulator（RTDS）,the new method is quite effective in fault line selection with an ability to overcome transition resistor and is free from the impact of arc-suppression.

关 键 词：配电网 故障选线 矩阵束算法 最小二乘估计 模型参数识别 

分 类 号：TM862[电气工程—高电压与绝缘技术]