Catenary Fault And Train Location Technology Of Urban Rail Power Supply System

In recent years,the rapid development of urban rail transit in China has gradually become the main passenger transport mode in major cities,and its safety and reliability in the process of operation have been paid more and more attention.Traction power supply system provides power support for the operation of urban rail transit train.If the short circuit fault occurs in the power supply region,it will cause power failure and affect the operation of the train.Therefore,it is particularly important to find the fault location in a short time.In addition,the current train positioning is mainly completed by the signal system.When the signal system fails,the train operation is maintained mainly through the judgment of the dispatcher and the train driver,which tends to increase the risk of accident.Therefore,it is necessary to build a train positioning method independent of the signal system.Firstly,the structure and basic working principle of traction substation,train and traction network in traction power supply system are analyzed in this thesis.MATLAB/Simulink is used to model these three parts,and the data parameters and calculation process are given.Secondly,the influence of skin effect on the parameters of the traction network is considered in this thesis,and the finite element analysis is carried out on the rail as an example.The calculation method of rail impedance under skin effect is given,and the ratio of rail resistance inductance at different frequencies to DC resistance inductance is obtained.In this thesis,the influence of the reflux system on the rail is considered,the traction reflux system is simplified,and the calculation formula of the reflux is given.Based on the above contents and the calculation of the inductance outside the traction network,the range and typical values of the parameters of the traction network are finally given.Thirdly,the short circuit fault of traction power supply system is simulated in this thesis.And the variation characteristics of the output voltage and current of traction power supply station after short circuit fault are summarized.A short-circuit fault location method based on double-terminal transient electrical volume is proposed,and the results are obtained by solving the equation with least square method.In order to solve the problem that the double-ended electrical and pneumatic quantities are not synchronized,a fault location method based on the single-ended electrical and pneumatic quantities is proposed in this thesis.The genetic algorithm,particle swarm optimization algorithm and simulated annealing algorithm were used to solve the fault location,and the advantages of particle swarm optimization algorithm in fault location were confirmed by comparative analysis.Finally,the feasibility analysis is made on whether the single-ended positioning method and the double-ended positioning method in the short-circuit fault calculation can be applied to the train positioning.A train positioning method based on double-terminal electric gas volume is selected.The simulation and location calculation are carried out for three different operation modes in the power supply region,and the actual data of the train running on the dynamic simulation platform is substituted into the location calculation method,which verifies the feasibility of the proposed method.The influence of three different situations on the train positioning results is considered,and the influence of each situation on the train positioning error is obtained through simulation analysis and calculation.