Locating Method of Single-phase Grounding Fault in Small Current Grounding System Based on Distribution Automation

In case of the arc suppression coil for neutral point grounding of small current grounding system, when single-phase grounding fault occurs, due to the arc suppression coil for fault line of the compensation effect of the zero sequence current, the fault features is not obvious, it can't implement the fault line selection and fault point location. This paper puts forward a method of change fault lines zero sequence current shortly, namely a resistance inductance (RL) series branch parallel in arc suppression coil, the series branch acts on the system shortly and changes arc suppression coil compensation degree temporarily in single-phase grounding fault. The change of zero sequence residual current only appears the loop from the neutral point to the fault point via the fault line, using FTU (feeder terminal units) on lines monitor the change of zero sequence current on each nodes for fault regional location. And prove this theory the feasibility of the by using MATLAB software of system modeling simulation method.