基于形态滤波的谐振接地系统故障选线新方法  

A New Transient Method for Earth Fault Line Selection in Resonant Grounded Power System Based on Morphological Filtering

作　　者：曲轶龙[1] 谭伟璞[1] 杨以涵[1] 

机构地区：[1]华北电力大学电气与电子工程学院,北京市102206

出　　处：《电力系统自动化》2008年第12期73-77,共5页Automation of Electric Power Systems

基　　金：北京市自然科学基金资助项目(3062018)~~

摘　　要：分析了基于小波理论暂态选线方法的现状后,提出一种基于形态滤波和相关分析的暂态选线新方法。与故障线不同,故障时在中性点零序电压作用下,非故障线暂态零序电流的暂态特性主要由自身对地电容充放电特性决定。将所有馈线零序电流对中性点电压的导数进行归一化处理,再利用相关分析得出每条馈线的综合相关系数,选出符合故障判据的故障线。其中,为有效地抑制各种干扰对算法的影响,对归一化后的零序电流利用改进的多结构元素复合形态学滤波器进行滤波处理。高压物理模拟实验及现场试验结果验证了本算法的可靠性和实用性。The limitations of the existing wavelet theory based transient methods for earth fault line selection in the resonant grounded system are analyzed and a new transient method based on correlation analysis and morphological filtering is proposed. The characteristics of the transient zero-sequence current of normal lines, which mainly reflect the transient charge and discharge process of its own equivalent zero-sequence capacitance, differ largely from those of the fault line. Accordingly, in order to distinguish the fault line, this paper normalizes all lines＇ zero-sequence currents with the derivative of zero-sequence neutral voltage and then obtains the integrated correlation coefficients of each line by correlation analysis. Finally the line that matches the fault criterion is selected as the fault line. An improved composite morphological filter with multi-structure elements is designed to filter all normalized zero-sequence currents to restrain the negative effects of various random disturbances. The research results of high voltage physical simulation and on-site actual fault data analysis verify the reliability and feasibility of the proposed method.

关 键 词：谐振接地系统 故障选线 形态滤波 相关分析 

分 类 号：TM862[电气工程—高电压与绝缘技术]