1.School of Electrical Engineering, Southeast University, Nanjing 210096, China;2.State Grid Wuxi Power Supply Company of Jiangsu Electric Power Co., Ltd., Wuxi 214000, China;3.Guangdong Power Grid Co., Ltd., Guangzhou 510600, China

In view of the possible problem of wrong user-transformer relationships in the topology file of the low-voltage distribution station area, this paper proposes a user-transformer relationship identification method based on multi-feature symbolic aggregate approximation (MF-SAX) and hierarchical clustering. First, the symbolic aggregate approximation expression method is used to convert the user voltage time series into string series, and two additional parameters, i.e., the voltage fluctuation coefficient and the voltage change trend, are introduced to strengthen its feature expression. Then, the similarity matrix of the user voltage curves is generated based on the edit distance, and the hierarchical clustering algorithm is combined to realize the identification of the user-transformer relationships. Finally, the results of the practical case show that, compared with some existing methods, the proposed method achieves higher accuracy and fewer false alarms, which can directly respond to missing data situations, and has higher efficiency.