Location Scheme of Broken Line Section of Distribution Line Based on Line Voltage Characteristics

Aiming at the problem that a single-phase break is difficult to locate in 10 kV ungrounded distribution system, this paper proposes a single-phase disconnection location method based on the DTW distance coefficient. After the single-phase disconnection of the line is not grounded or one end is grounded, the line voltage on the power supply side is three-phase symmetrical, while the phase of the line voltage on the load side is significantly different. This paper uses the phase information of the low-voltage side line voltage of the local intelligent terminal of each distribution transformer on the line to construct the corresponding fault section scheme. In order to characterize this difference, the DTW distance is used to characterize the phase relationship of the line voltage of each monitoring point, and the fault section location method and criterion based on the DTW distance are further designed. When the distance coefficients of the upstream monitoring point are lower than the threshold value and the distance coefficients of the downstream monitoring point are higher than the threshold value, Therefor the distance between the two monitoring points is the fault section. The MATLAB / Simulink software is used to build a 10 kV neutral point ungrounded system model, and the disconnection faults in different scenarios are simulated to verify the scheme's effectiveness.