Research On Current Distribution Law Of Overhead Catenary Contact Suspension Based On Finite Element Method

The electrical energy required by the electrified railway is provided by the traction power supply system.In the traction power supply system,the contact suspension is the power supply equipment in the catenary that directly contacts the pantograph and completes the currentcarrying and current collection.In order to ensure the quality of power supply,the contact suspension must have good electromechanical characteristics.However,with the continuous increase in the annual transportation volume of electrified railways and the gradual increase in operating years,the contact suspension parts have been exposed to electrical loads for more and more time,and the phenomenon of parts burning has also occurred.Exploring the current distribution of the contact suspension can improve its electrical performance by optimizing the cue matching and selection during the design or transformation stage.At the same time,it has very important significance for the current-carrying fatigue test of the contact suspension parts and the fault location of the catenary.Therefore,it is necessary to study the law of current distribution in the contact suspension.This paper takes the overhead catenary contact suspension as the research object,and comprehensively uses the methods of theoretical analysis,simulation modeling,and experimental verification to study the current distribution law of the contact suspension.Contact suspension is a complex circuit with multiple meshes.Traditional analysis methods often use equivalent simplified circuits and Simulinlk for circuit simulation.The results have certain errors.In order to improve the accuracy,this paper analyzes the electrical characteristics of the contact suspension,and summarizes the main factors that affect the current distribution of the contact suspension,such as contact suspension clue resistivity,operating temperature,electromagnetic environment,etc.Then use the ANSYS finite element analysis modeling method to model the contact suspension and conduct the coupling analysis of electric-magneticthermal and other multi-physics fields,by imposing corresponding constraints to simulate the actual working conditions of the contact suspension,and setting up a contact suspension current distribution test bed,the obtained test data and the simulation results are compared and analyzed to verify the correctness of the contact suspension finite element modeling method At the same time,it also proves that the method has high accuracy.Finally,using the contact suspension finite element modeling method,a three-dimensional finite element model of the contact suspension was established in ANSYS to analyze the changes in the current distribution law of the connection suspension under the influence of different factors.At the same time,by simulating the dynamic current drawing process of the pantograph and the contact suspension,the current load spectrum of the clues inside the contact suspension is extracted,and suggestions are provided for carrying out the current-carrying fatigue test of catenary components.In the analysis of the factors affecting the current distribution of contact suspension,by changing the line structure or parameters,the influence of factors such as electrical connection,strengthening wire,contact wire wear and clue matching on the current distribution are discussed,and the changes are analyzed accordingly.In the dynamic operation simulation,by simulating the process of dynamic current extraction between the pantograph and the contact suspension,the current load spectrum of each clue at different positions of the contact suspension is analyzed,and the final conclusions are as follows:The contact wire and the load-bearing cable are mainly responsible for carrying the current of the locomotive.The dropper only flows when the pantograph passes.The addition of a transverse electrical connection can reduce the electrical load of the dropper when the pantograph passes,but it only diverts the three hanging strings nearby.The addition of a strengthening wire can effectively reduce the electrical load of the contact wire,and the closer the pantograph is to the parallel connection point of the strengthening line and the contact suspension,the more obvious its shunting effect is.The contact line can meet the working requirements under the maximum current carrying condition under the working condition that the wear is less than 20%.The peak value of the dropper current is related to the position of the dropper in the contact suspension,and has nothing to do with the running speed of the train,but the duration of the dropper impulse current is related to the running speed of the train.Droppers at different positions in the contact suspension have different current load spectra.When carrying out the current-carrying fatigue test of the droppers,different current loads can be applied to the dropper at the contact suspension position to simulate the actual working conditions.