Railway Automatic Blocking Line Fault Location

In this paper, since the railway automatic blocking and continuous transmission lines of cable lines and overhead lines in distribution network transmission mode of application of this hybrid line traveling wave method of fault location. Traveling wave in the application of the mixed lines there are three major problems to be solved, one for traveling wave determine the exact time of first arrival; the second is the logical choice for traveling wave velocity; finally, how to solve the mixed line problem of inconsistency in velocity.First introduced the line of wavelet theory and the basic principle of traveling wave, respectively, of the overhead lines and cable lines BOC Wave Propagation and select the double-end method for traveling wave mixing line; describes the basic phase mode transformation theory and the overhead lines and cable lines modulus communication parameters, as calculated after the analysis of the theoretical basis; introduced the wavelet transform principle and the principle of HHT, and compare the cubic B-spline wavelet and HHT transform fault traveling wave identification first to determine the arrival time of the first wave.Then in the PSCAD a single cable line, respectively, and a single overhead line structures simulation model, using simulation software in the calculation of the line parameter matrices of the two lines in the wave propagation velocity respectively, and given the velocity of two lines fitting curve.Finally the wave double-end method for fault location on the mixing line, by using the equivalent circuit velocity method to solve the mixed problem of inconsistent velocity of several typical hybrid circuit simulation and analysis, show that the algorithm for hybrid circuits ranging superiority, and the algorithm is improved to improve the accuracy of the distance.Through theoretical analysis and a large number of simulation show that the fault line for the first wave arrival times using wavelet cubic B-spline wavelet transform can be more accurately determine the fault line of the first wave arrival time; use of matrix analysis of line parameters calculated Select the fault band velocity on the mixing line under the traveling wave fault simulation shows that the velocity accuracy required to meet the distance, to achieve the accuracy of the hybrid line fault location; velocity ranging method using equivalent circuit for the hybrid fault location, a good mix of lines to solve the problem of inconsistent velocity, but also found in the simulation methods of the deficiencies that occurred in the cable for the line if the use of overhead lines in the velocity equivalent, the error would be more large, and even lead to the failure of distance, using the improved algorithm, the distance was more accurate.