Single-phase Grounded Line Selection Based On Transient Information In Distribution System With Neutral Point Grounding Via Arc Suppression Coil

With the development of the power distribution system turning into smart grid, itputs forward higher requirements for the distribution system automation. Thesingle-phase grounded fault line selection of the distribution network is the foundationto realize grid automation control. However, the results of single-phase grounded faultline selection are unsatisfactory in distribution network today. So far, the study ofsingle-phase grounded fault line selection in the distribution network is mainly dividedinto the research for new fault feature and the line selection algorithm for the studiedfault feature. In this paper, the main contents are:①From the basic principle of line twists and turns reflection, this paper deducesand analyzes the transient traveling wave head of zero sequence current of thedistribution network when single-phase grounded fault occurs. For the problem ofcorrelation analysis cannot be applicated in the hybrid system when the single-phase isgrounded fault, the multi-resolution singular value decomposition is introduced to detectthe initial wave head of zero sequence current, and the detected wave head position isused as a benchmark to obtain related analysis data window. Then the pearsoncorrelation analysis method is used to carry on the analysis for getting the faultmeasurement data for fault line selection. Through the validation of fault line selectionunder different conditions in the hybrid system, the correctness of the method is proved.Through a large number of simulation example, the change rule of fault characteristicsis concluded and corresponding suggestions for reliable routing algorithm is given.②The selected frequency band (SFB) and the determination method of SFB isdeduced and provided when the single-phase is grounded in the hybrid system withneutral point grounding via arc suppression coil. The same and different faultcharacteristics are deduced and analyzed in the SFB of the system with2and3or abovefeeders with neutral point grounding via arc suppression coil.For the problem of faultmeasure method based on zero sequence current phase filter cannot be applied in thesystem with2feeders, zero sequence transient voltage of the bus is seeked as acomparison reference to solve. This paper uses porous algorithm wavelet packet toextract the transient zero sequence voltage and current of the SFB. According to thefault characteristics of the SFB, a fault line selection algorithm is proposed based on thetransient zero sequence current of the two largest energy feeders and transient zero sequence voltage difference phase filtering measure in the SFB. Respectively for thesystem with2,3and4feeders, the correctness of the algorithm is demonstrated.Through a large number of examples analysis, the change rule of fault characteristics isconcluded and corresponding suggestions for reliable routing algorithm is given.