Research On Method Of Single-ended Traveling Wave Fault Location For Traction Network Of Electronic Railway

After studying the line structure and operation mode of the Catenary on the electrified railway,based on the research results of the fault location in the transmission line,this paper puts forward the idea of single-end traveling wave fault location algorithm on the electrified railway contactAfter fully understanding the structure and characteristics of traction transformer,electric locomotive load and Catenary line under T R+NF and AT power supply system,a 6-phase line(Two-phase contact line,two-phase return line,two-phase railway)that considering the electromagnetic coupling between upstream and downstream Catenary lines was established.In the case of arbitrary phases transmission lines,the line mode transformation method is deduced by the formula.The current phase mode transformation matrix and the wave velocity of the traveling wave are calculated by using the inductance and capacitance parameters of the Catenary 6 phase line.The current traveling wave signal measured in the simulation model is wavelet transformed and the maximum value is obtained.The position of the initial current traveling wave and the fault point reflection wave front are identified.On this basis,a pre-positioning algorithm based on the main component of the traveling wave natural frequency and precise location algorithm based on traveling wave module are proposed.The T R+NF and AT power supply simulation models of the Catenary are established in EMTP-ATP.Considering the fault type(fault between contact line and railway,fault between contact line and return line,fault between contact line and positive feed line),the electric locomotive load operate situation(considering the number and location of electric locomotives only)and the effect of fault point transition resistance on single-ended traveling wave fault location algorithm,the following conclusions are obtained:When the fault location is constant,the fault results of different fault types are the same,In the event of a failure between the contact line and return line,the traveling wave reflection head of the fault point is difficult to distinguish from the reflection head of other impedance imbalance points.Therefore,a pre-positioning algorithm is needed as an auxiliary method for precise positioning.In the failure between the contact line and positive feed line,the traveling wave reflection head of the fault point is easy to distinguish,When the fault point transition resistance is less than a certain range,it has no effect on the positioning algorithm results,but when the transition resistance exceeds a certain value,The fault location may fail due to the difficulty of identifying the traveling wave reflection head of the fault point.If the traveling wave sampling frequency is set to 10MHz,based on the single-ended traveling wave fault location algorithm proposed in this paper,The simulation results show that the ranging deviation is less than 30m in both T_R + NF and AT modes.,The validity and accuracy of the method are verified.Therefore,the proposed prepositioning algorithm based on the traveling natural frequency and the precise positioning algorithm based on the traveling wave component can be applied to the fault location of the electrified railway Catenary.