Science and Technology Program of State Grid Jiangsu Electric Power Maintenance Company(J2018036);Science and Technology Program of State Grid(J2018078)
The structure of distribution network is becoming more and more complex.In this paper, based on the research on the distribution characteristics of the zero sequence current in the selected frequency band (SFB), a new method of single phase grounding faultyline selection based on the difference of the transient zero sequence current waveform is proposed. The method introduces the zero sequence currentcharacteristic component of feeder based on SFB by utilizing wavelet packet transform. By defining the absolute sums of the mutual deviations of the zerosequence currentcharacteristic components filtered out by sign function as the waveform difference coefficient of the zero-sequence current of each feeder, the faulty feeder is selected according to the maximum waveform difference coefficient of the zero sequence current of faulty feeder, which highlights the difference between faulty feeder and healthy feeder. A lot of PSCAD simulations show that the proposed method has high accuracy and reliability, and is not affected by fault resistance, fault distance, neutral grounding mode, arc and noise.