空间电磁场对屏蔽电缆电磁干扰的研究

发布时间：2019-03-09 14:32

【摘要】：随着科技的飞速发展,电磁干扰源的不断增多,空间电磁环境变得越来越复杂。通常,屏蔽电缆作为设备间传输信号的载体,经常受到空间电磁干扰的影响。因此,研究屏蔽电缆场线耦合问题具有非常重要的意义。本文在研究时域有限差分法和多导体传输线理论的基础上,将屏蔽电缆场线耦合问题划分为内系统和外系统模型,通过Matlab编程计算,分析了不同因素对屏蔽电缆芯线响应的影响。首先,本文研究了时域有限差分法的理论,通过时域有限差分法的计算区域的划分、Maxwell基本方程的离散迭代、数值稳定性的条件、边界条件的设置、激励源的选取等方面介绍了外系统建模时应注意的问题。计算分析了屏蔽层接地方式不同和土壤电导率的不同对屏蔽层耦合响应的影响。随后,介绍了屏蔽电缆相关参数的计算和多导体传输线的基本理论。对内系统运用传输线模型进行分析,通过对屏蔽电缆相关参数的计算,传输线方程进行差分推导,设置边界条件和算法稳定性条件进而对电缆芯线上的响应进行求解。计算分析了不同端接电阻对终端电流响应的影响。最后,通过对同轴电缆场线耦合问题建立内系统和外系统模型,分析求解了电缆接地方式不同、土壤电导率不同、土壤介电常数不同、电磁波入射方位角不同时,对电缆芯线上耦合感应电流的影响。通过对感应电流的分析,得出了一些有益的结论,对于工程实践提供了理论指导。
[Abstract]:With the rapid development of science and technology and the increasing number of electromagnetic interference sources, the space electromagnetic environment becomes more and more complex. Usually, shielded cable, as the carrier of transmission signal between equipments, is often affected by space electromagnetic interference. Therefore, it is very important to study the field-wire coupling of shielded cable. Based on the finite-difference time-domain method (FDTD) and multi-conductor transmission line (MTL) theory, the coupling problem of shielded cable field and wire is divided into internal and external system models, which are calculated by Matlab programming. The influence of different factors on the response of shielded cable cored wire is analyzed. Firstly, this paper studies the theory of the finite-difference time-domain method (FDTD). By dividing the computational region of the FDTD, the discrete iteration of the Maxwell basic equation, the condition of numerical stability and the setting of the boundary condition, The selection of excitation sources and other aspects of the external system modeling should be paid attention to. The effects of different grounding modes of shielding layer and soil conductivity on the coupling response of shielding layer are calculated and analyzed. Then, the calculation of relevant parameters of shielded cable and the basic theory of multi-conductor transmission line are introduced. The transmission line model is used to analyze the internal system. By calculating the relevant parameters of the shielded cable, the transmission line equation is derived by differential method, and the boundary conditions and the stability conditions of the algorithm are set up to solve the response of the cable core wire. The influence of different terminal resistors on terminal current response is calculated and analyzed. Finally, the internal and external system models are established for the field-wire coupling problem of coaxial cable. The different grounding modes, different soil conductivity, different soil dielectric constant and different incident azimuth of electromagnetic wave are analyzed and solved. The effect on the coupling induced current on the cable core wire. Based on the analysis of induced current, some useful conclusions are drawn, which provide theoretical guidance for engineering practice.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM246

【参考文献】