摘要
中性点经消弧线圈接地配电网发生单相接地故障,各线路的零序电流暂态含量丰富,在理论分析单相接地故障零序电流特性的基础上,提出一种基于动态模式匹配距离(DPM)的零序电流波形相似性度量聚类选线方法。首先将单相接地后线路暂态零序电流以等分段点和极值点作端点进行动态分段,根据各分段均值及其变化趋势实现子分段序列形态模式符号化表达,以模式之间的异同性定义模式匹配距离,其次运用动态时间弯曲(DTW)规划原理,获得线路零序电流波形间的动态模式匹配距离矩阵,最后利用模糊C均值聚类算法,实现单相接地选线。对不同故障初相角、非同步采样、信息缺失、两点接地故障、电弧故障等情况进行仿真。结果表明,所提出的方法较DTW有更高的故障区分度,且能够有效地提高配电网故障选线的准确性和容错性,对配网安全运行具有一定实际意义。
When a single-phase earth fault occurs in the distribution network with neutral earthing via arc suppression coil,the zero-sequence current of each line is rich in transient content.On the basis of a theoretical analysis of the zero sequence current characteristics of single-phase ground faults,a clustering line selection method is proposed through zerosequence current waveform similarity measurement based on Dynamic Pattern Matching distance(DPM).Firstly,the transient zero-sequence current of the line after single-phase grounding is dynamically segmented with equal segment points and extreme points as the end points,the segmented sequence configurational patterns are expressed symbolically according to each segment average and variation trend,and the pattern matching distance is defined by the similarities and differences among patterns.Secondly,the dynamic pattern matching distance matrix among zero-sequence current waveforms is obtained using the Dynamic Time Warping(DTW)principle.Finally,the single-phase grounded line selection is realized by using the fuzzy C-mean clustering algorithm.Many kinds of cases such as different fault initial angle,asynchronous sampling,information loss,two-point ground faults,arc faults are simulated.The results show that the proposed method has higher fault discrimination than DTW and effectively improves the accuracy and fault tolerance of fault line selection in the distribution network,and has certain practical significance for the safe operation of the distribution network.
作者
吴春阳
倪良华
汤智谦
朱方博
倪诚
吕干云
WU Chunyang;NI Lianghua;TANG Zhiqian;ZHU Fangbo;NI Cheng;LÜGanyun(School of Electric Power Engineering,Nanjing Institute of Technology,Nanjing 211167,Jiangsu,China;Zhenjiang Power Supply Branch,State Grid Jiangsu Electric Power Co.,Ltd.Zhenjiang 212000,Jiangsu,China;Guodian Nanjing Automation Co.,Ltd.,Nanjing 210000,Jiangsu,China)
出处
《电网与清洁能源》
北大核心
2022年第2期1-9,共9页
Power System and Clean Energy
基金
江苏“六大人才高峰”创新团队(2019-TD-XNY004)
江苏省高等学校自然科学研究重大项目(2019052)
关键词
零序电流
单相接地
形态模式
动态模式匹配距离
模糊C均值聚类
zero-sequence currents
single-phase grounding
configurational pattern
dynamic pattern matching distance
fuzzy C-means clustering
