CAJ | 학술논문

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。
국내배전망대다채용중성점불접지혹경소호선권접지적방식운행,재저충계통발생단상접지고장시,진쾌선출고장선로대전망운행유중요의의。제출일충기우삼수식별적빈역방법진행소전류접지선선。통과구진속방법제취고장후령서전압화령서전류적빈점신식,해결료전통리산부리협변환방법제취빈역신호불준학적문제。제취빈점신식후,이용빈역방정구해선로대지전용치병진행선선。여시역삼수식별방법상비,해방법대채양빈솔요구저、계산정도고。동시,빈대분석표명해방법비전통적수용성빈대려파방식구유경관적빈대,이론상불수요려파。경ATP-EMTP방진화실시수자방진기록파수거험증,해방법선선정학、유효,내과도전조능력강,불수소호선권적영향。
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.