Research On Crosstalk Of Cables Of Communication System Based On Object-Oriented Technology

High-speed EMU is a large and complex system because of limited space.The system is densely arranged a lot of power electronic equipment,and a variety of related signal cables and power cables.So car signal equipment may be interfered in operation,especially the speed sensor signal.There have been a lot of researches focusing on the measurement instead of the impact on speed signal.Therefore,more meaningful works about the electromagnetic compatibility of speed signal line is deeply needed.In this thesis,it is based on the model of cable coupling.The problem of the electromagnetic compatibility of speed signal line is analyzed by theory,experimental verification and simulation analysis.And relevant suggestions.is put forwardFirstly,in order to research the electromagnetic compatibility of communication systems,object-oriented basic theory and modular concept is put forward.The object-oriented hierarchical modeling method is applied to analyze the electromagnetic compatibility of communication systems.The hierarchical structure model is established.In the analysis of a specific model,only consider the interface properties of the object and the interaction relationship,the analysis result of electromagnetic compatibility of this model can be obtained.Secondly,for the cable coupling module of communication system of EMUs,the Finite Difference Time Domain method is proposed to solve the multi-conductor transmission line equation.And the formulas for the distribution parameters of multi-conductor transmission lines are deduced.On this basis,the model of single-line and unshielded cable,single-line and shielded cable are established for analyzing the transient response of disturbed line by matlab.The simulation results are in good agreement with the theoretical analysis and test results,and the correctness and validity of the model are verified.At last,the influence of shielded cable earthing mode and termination load on signal line is mainly studied.Finally,in order to research the electromagnetic sensitivity of communication cables,the influence of pulse group on signal line is studied emphatically.Taking the speed signal line as an example,the type,working principle,installation position and mode are introduced in detail.Regarding speed signal as digital base-band signal,analysis index is used to analyze the disturbed signal.Then pulse function model based on standard and quantization simulation model is build to analyze pulse burst on speed signal line.The test results are in good agreement with simulation results,and the correctness and validity of the model are verified.At last,the influence of the burst amplitude and repetition frequency on the signal are analyzed in terms of bit error rate and speed error.It is concluded that the speed error has a linear relation with the repetition frequency of pulse group.And the related recommendations are put forward.