|ZHU Yuyong,Lü Feipeng,LIAO Xiaojun,LI Yaoyi,ZANG Tianlei.Fault line selection of small current grounding system based on GFT spectral similarity of path graph[J].Electric Power Automation Equipment,2023,43(11):89-94,116
|关键词: 小电流接地系统 故障选线 图傅里叶变换 离散弗雷歇距离 余弦相似度
|Fault line selection of small current grounding system based on GFT spectral similarity of path graph
ZHU Yuyong1, Lü Feipeng1, LIAO Xiaojun2, LI Yaoyi1, ZANG Tianlei1
1.College of Electrical Engineering, Sichuan University, Chengdu 610065, China;2.State Grid Sichuan Technical Training Center, Chengdu 610072, China
|Aiming at the problem of line selection when a single-phase grounding fault occurs in the existing small current grounding system, a fault line selection method based on the graph Fourier transformation(GFT) spectrum similarity of path graph is proposed. The path graph GFT analysis of the transient zero-sequence current of each outgoing line is carried out. The analytical results show that the spectral GFT of the path graph of the non-fault lines is similar while different from that of the fault line. The difference between GFT spectrum of the fault line and the non-fault line is comprehensively characterized by the synthetic discrete Fréchet distance and the synthetic cosine similarity, so as to screen out the fault line. The simulative results show that the proposed method is simple to implement, has high reliability of fault line selection, and is not easily affected by factors such as grid topology, transition resistance and initial fault conditions.
|Key words: small current grounding system fault line selection graph Fourier transformation discrete Fréchet distance cosine similarity