Research on zero sequence voltage transient characteristic identification algorithm for single-phase grounding fault

Inhalt:
For 10kV line outgoing line, the neutral point of transformer adopts arc suppression coil grounded or ungrounded distribution network, in case of single-phase grounding, the zero sequence fault current is weak, and the single-phase grounding fault line selection protection is difficult. This paper presents an algorithm to identify the sudden change of zero sequence voltage signal in the process of single-phase grounding fault by using the principle of time series singularity detection, determine the fault occurrence time, and detect single-phase grounding fault according to the size and polarity direction characteristics of zero sequence voltage and zero sequence current fault components at the occurrence time of grounding fault. The results of real-time digital simulation and dynamic simulation experiments of power system show that the algorithm can detect the mutation point of zero sequence voltage signal, and correctly identify the grounding fault line combined with the polarity direction characteristics of zero sequence voltage and zero sequence current fault components. RTDS simulation experiments verify the effectiveness of the algorithm.