周军,刘娜,李曙光.基于等效半波注入法的小电流接地故障选线[J].电测与仪表,2020,57(4):55-60. Zhou Jun,Liu Na,Li Shuguang.Small current grounding fault line selection based on equivalent half wave injection method[J].Electrical Measurement & Instrumentation,2020,57(4):55-60.
基于等效半波注入法的小电流接地故障选线
Small current grounding fault line selection based on equivalent half wave injection method
Most of the medium voltage distribution networks in China adopt the operation mode of small current grounding. Because the single-phase grounding fault current of small current grounding system is very small and easily disturbed by external conditions, the problem of fault line selection has not been effectively solved for many years. Based on the analysis of the existing fault line selection methods, the equivalent half-wave injection method was formed on the basis of the original DC injection principle, and it selected the line by comparing the zero sequence current of each line. The theory of line selection and location based on equivalent half-wave injection method was analyzed, which mainly includes determining the flow path of injected half-wave DC signal. After that, a corresponding mathematical model was established. Finally, the correctness of the theory was verified in principle. Finally, a model is built by MATLAB to verify that the method can accurately and reliably achieve fault line selection.
