基于分形理论与聚类分析的小电阻接地系统高阻接地保护方法  

Protection method based on fractal theory and cluster analysis for grounding fault with high resistance of low resistance grounding system

作　　者：曹文思 吴擎 徐铭铭 牛荣泽 CAO Wensi;WU Qing;XU Mingming;NIU Rongze(School of Electric Power,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;State Grid Henan Electric Power Research Institute,Zhengzhou 450002,China)

机构地区：[1]华北水利水电大学电力学院,河南郑州450045 [2]国网河南省电力公司电力科学研究院,河南郑州450002

出　　处：《电力自动化设备》2020年第4期204-209,224,共7页Electric Power Automation Equipment

基　　金：2019年度河南省重点研发与推广专项(科技攻关)项目(192102210229);河南省高等学校重点科研项目(19A-470006);2019年度河南省高等学校青年骨干教师培养计划(2019GGJS104)。

摘　　要：针对目前小电阻接地系统保护由于整定值过大而对高阻接地故障易出现拒动的问题,基于分形理论和聚类分析提出了高阻接地保护新方法。该方法提取故障线路和非故障线路零序电流的相似性特征,利用零序电流比值和分形维数对相似度进行量化计算,构建了接地故障特征矩阵,采用K-means聚类算法对接地故障特征矩阵进行分析,避免了保护整定困难的问题。经真型实验录波数据验证,所提方法将保护的耐阻能力提高到2000Ω,具有一定的应用价值。Because the setting value of the protection in low resistance grounding system is too large,the protection in low resistance grounding system easily refuses to operate when a high-impedance grounding fault occurs.Aiming at this problem,a novel protection method based on fractal theory and cluster analysis for grounding fault with high resistance of low resistance grounding system is proposed.The similarity cha-racteristics of zero-sequence current between fault line and normal lines are extracted.The characteristic matrix of grounding fault is constructed by the similarity of zero-sequence currents that quantified by ratio of zero-sequence currents and fractal dimension,and analyzed by K-means clustering algorithm.The pro posed method avoids the difficulty of protection setting.The true-mode experimental recording data verify that the high resistance capacity of protection is improved to 2000Ωby the proposed method,which has certain application value.

关 键 词：小电阻接地系统 高阻接地 分形理论 相似性 聚类分析 继电保护 

分 类 号：TM771[电气工程—电力系统及自动化]