Study On Fault Locating Of 10 KV Automatic Blocking And Continuous Transmission Lines Of Railway Based On Traveling Wave Method

With the rapid development of society and economy,the railway automatic blocking and continuous transmission line shoulders a major responsibility in the railway power system,providing power for the automatic blocking signal along the railway line and the load of the station.It is the economic lifeline of the power system.When the line fails,it directly threatens the safe operation of power system.,therefore,it is possible to accurately locate the fault,timely eliminate the fault,improve the reliability of the power supply,and have important significance for the safe and stable operation of the railway power system.This thesis chooses traveling wave method as fault location method of automatic blocking and continuous transmission lines.Firstly,the catadioptric characteristics of traveling wave are analyzed according to the propagation law of traveling wave,Phase-mode transformation is used to eliminate the coupling effect between three-phase lines,then the positioning principle of two common ranging methods,A and D,is analyzed in detail.On this basis,two different wave velocity processing schemes are given for the problem of uncertain traveling wave velocity.The theory of traveling wave ranging has been proposed many years ago,but the accurate identification of the wave head is the key to research.In recent years,wavelet transform has been widely used as a signal processing tool.Secondly,in this thesis,the singularity detection theory of wavelet transform is used to determine the abrupt point of the traveling wave signal,and the fault traveling wave head is extracted.First built a simulation model of a single line,the single-ended ranging method independent of the wave velocity is used to theoretically avoid the ranging error caused by the uncertainty of the wave velocity,the effects of three different types of fault types,transition resistance and initial phase angle of fault voltage on the fault location of traveling wave are studied.In order to verify the reliability of ranging method,several groups of ranging results are given in each case.Then the method of two-terminal ranging with single wave velocity is adopted for overhead line-cable hybrid line.The simulation results show that the good positioning effect is achieved and the ranging accuracy is high.Thirdly,based on the GUI interface of MATLAB as the platform,the interface design of the fault location system is completed.When a fault occurs,the fault information such as the measured fault distance and the absolute error of the ranging can be displayed on the interface,it is convenient for the user to intuitively grasp the situation of the fault on the line.Finally,a single-phase ground fault simulation test was performed using the existing conditions of the laboratory.