Research On Wide Area Traveling Wave Fault Location Technology For 10KV Distribution Network

The grid structure of 10 kV distribution line is complex,and the overhead line cable hybrid line is often used for power supply,and the overhead line and cable have different feeder branch structures.In addition,the small fault current in the small current grounding mode makes the fault detection difficult,so the research on fault location has been a major difficulty for scholars.As a primary power grid directly connected with the load,the fault location and search of 10 kV distribution line is related to the normal production and domestic power consumption of the people,so we must pay attention to it.Fast and accurate location research is of great significance to improve the reliability and safety of power grid operation.Traveling wave location method is not affected by the system parameters,the size of the transition resistance and the operation mode of the system.It has been widely used in the transmission network.However,there are many branches in the distribution network,and the structure is complex.The traveling wave single ended method needs to accurately identify the subsequent reflected wave head of the fault point,which will have some difficulties in the distribution network.So the research content of this paper is based on the two terminal method of wide area traveling wave information of distribution network fault location,in which the wide area traveling wave information mainly includes wide area traveling wave time difference and wide area traveling wave energy.The main work of this paper is as follows:1.Firstly,the topology of distribution network and the distribution characteristics of wide area traveling wave are analyzed,and the time difference relationship of the initial traveling wave and the attenuation characteristics of the traveling wave energy of wide area fault are mainly studied.Thus,two fault location methods based on wide area traveling wave information are proposed.2.Based on the study of the wide area traveling wave time difference,a fault location method of distribution network based on multi terminal traveling wave time difference is proposed.Based on the traveling wave information obtained by high sampling at both ends of trunk line and branch line terminal,the fault distance matrix is constructed,and the fault interval is defined according to the nature of the matrix,so as to accurately locate the fault location.3.On the basis of studying the characteristics of wide area traveling wave energy,a fault location method based on wide area traveling wave energy is proposed.Based on the fault information obtained by the detection points,the traveling wave energy is calculated by the energy function constructed by the wavelet energy spectrum to determine the fault section directly;then the program is edited to visit the detection points on both sides of the fault section,which is expanded into a multi-level effective fault location network,and the three terminal fault location method is proposed to calculate the multi-level fault distance;the Grubbs test method is used to process the multiple fault location results to determine the fault point.4.The PSCAD software is used to establish the distribution network model,and MATLAB is used to process the data.Simulation analysis is carried out under different fault types to verify the two fault location methods proposed in this paper.Finally,the fault location method of 10 kV distribution network based on wide area information is summarized,and the future research is prospected.