Research And Application On The Detection And Positioning Of Distribution Network Fault Based On Feature Electrical Extraction

The main function of distribution network is to provide users with stable and safe power,the distribution network load,topology is complex,etc.lead to the distribution network easy to fail.The fault type is mostly single-phase grounding,the fault current is small and easy to cause the power supply system to malfunction,if the voltage breakdown,will affect the work of the distribution network seriously.Therefore,when there are something happed to distribution network,it is necessary for us to locate and troubleshoot in a timely and accurate manner.The current fault positioning method mainly has problems such as slow positioning speed and low positioning accuracy,so it is of great significance to carry out accurate and timely positioning for the safety of distribution network.In this paper,a distribution grid fault location method based on characteristic electrical volume extraction is proposed for the distribution ground fault location problem.This context of the article is as follows: First,the existing fault location methods are described,comparing the advantages and disadvantages of different fault location methods.Under the mode of operation of the neutral point change,the single-phase ground fault of the power grid is presented and the fault monitoring method based on the characteristic electrical quantity is used to deal with it.The fault-located feeder terminal is de-noiseed,the different de-noise methods are compared,the wavelet transformation method is selected as the denoise method of the characteristic component,and the fault component waveform after denoise is obvious.Secondly,the transient process after SLG failure in the power grid is analyzed,and the transient current component can be used as the criterion for determining the fault location.According to the fault location characteristics of the fault positioning flow chart,began to build PSCAD simulation model,in the main feeder different branches set up fault detection point,determine the start-up adjacent position,collect the data monitored after the fault,and export the transient current waveform map according to the data,compare the fault monitoring point upstream and downstreamcharacteristic stakes,so as to fault location.Finally,the characteristics of the fault when the frequency characteristic failure occurs are analyzed,and the analysis conditions are different grounding mode of power grid failure.Design the fault location system of the distribution network,according to the same detection point,the transient zero sequence current and the frequency zero sequence current mutation to determine the fault section of the power grid.The model is constructed by PSCAD,and the distribution network with voltage of 10 kV is used to verify the field fault location.When the distribution network failure,collect useful fault characteristic electrical components,and the characteristic electrical quantity for denoise and purification treatment,compared with the initial set threshold,to determine the distribution network fault segment.The feasibility of fault location based on the distribution network fault positioning algorithm based on characteristic electrical quantity is verified.