屏蔽电缆电磁干扰分析与滤波防护研究

发布时间：2018-05-17 00:42

本文选题：编织电缆 + 传输线方程　；参考：《西南交通大学》2017年硕士论文

【摘要】：随着半导体技术的不断进步,电子系统朝着模块化、高功率、高集成、小型化等的趋势发展,电子系统的电磁兼容性问题日益突出。同时,人为有意和电子设备无意地向空间中辐射电磁波等行为,使得空间电磁环境日趋复杂,其对电子系统的影响不可忽视。特别是其中的强电磁脉冲部分,这种具有高功率、宽频带的电磁波,对电子系统有严重的破坏作用。电缆作为电子系统间的信息传输和供电传输的载体,电缆大部分暴露各种复杂电磁环境下,容易受强电磁脉冲干扰。电缆耦合的电磁干扰经由电缆耦合进系统,可轻易损毁电子系统。因此,屏蔽电缆的耦合机理分析、预测和防护,对提高电子系统的可靠性具有重要意义和工程实用价值,并且能够为设计电子系统提供指导。首先,研究了应用于屏蔽电缆电磁耦合分析的时域混合算法。以近地面上架空的屏蔽电缆作为研究对象,采用时域有限差分(FDTD)方法、传输线方程(TL)和电缆激励场快速计算方法,并结合逆卷积技术,研究了高效的时域混合算法,能够用于屏蔽电缆电磁耦合的快速模拟。将算法结果与文献结果进行对比,验证了算法的正确性和有效性。然后,利用该混合算法分析了电缆屏蔽层不同端接负载、不同电缆架设高度和不同电磁波入射角度对芯线响应的影响。其次,考虑了编织电缆的转移阻抗模型的误差对耦合分析仿真影响,介绍了相关转移阻抗的计算模型。基于现有的编织电缆的转移阻抗计算模型,提出通过电缆编织层覆盖率K对计算模型中的编织角α与屏蔽层直径Dm参数进行优化。根据自行设计的三同轴转移阻抗测量装置对电缆的转移阻抗进行实测,来验证本文优化后的电缆转移阻抗模型的有效性。在此基础上,进一步分析了编织层不同结构参数对电缆转移阻抗的影响。最后,将改进之后的转移阻抗计算模型引入到时域混合算法进行优化,进而提高了算法的计算精度。最后,针对核电磁脉冲对屏蔽电缆的电磁耦合进行滤波防护分析。首先是建立屏蔽电缆的电磁耦合模型,芯线两端均接匹配负载。然后,采用上述研究的时域混合算法计算得到芯线上的电压和电流响应,从而获得响应的幅值、频率等关键参数。在此基础上,以此电压和电流响应作为干扰源,结合电路仿真软件,针对不同类型的干扰源,设计相应的滤波器,然后仿真分析滤波器的防护效果,进而实现了对屏蔽电缆的滤波防护设计。
[Abstract]:With the development of semiconductor technology and the trend of modularization, high power, high integration and miniaturization of electronic system, the electromagnetic compatibility of electronic system is becoming more and more serious. At the same time, the electromagnetic environment in space is becoming more and more complex due to the intentional and unintentional radiation of electromagnetic waves into space by human beings and electronic devices, and its influence on electronic systems cannot be ignored. Especially the strong electromagnetic pulse, which has high power and wide band electromagnetic wave, has a serious damage to the electronic system. As the carrier of information transmission and power supply transmission between electronic systems, most cables are exposed to various complex electromagnetic environments and are vulnerable to strong electromagnetic pulse interference. Cable-coupled electromagnetic interference can easily damage the electronic system by coupling the cable into the system. Therefore, the analysis, prediction and protection of the coupling mechanism of shielded cables are of great significance and practical value in improving the reliability of electronic systems, and can provide guidance for the design of electronic systems. Firstly, the hybrid time domain algorithm for electromagnetic coupling analysis of shielded cables is studied. Taking the overhead shielded cable near the ground as the research object, using the FDTD method, the transmission line equation (TL) and the fast calculation method of the cable excitation field, and combining with the deconvolution technique, an efficient time-domain hybrid algorithm is studied. It can be used for fast simulation of electromagnetic coupling of shielded cables. The correctness and validity of the algorithm are verified by comparing the results of the algorithm with those of the literature. Then, the effects of different terminal loads, different cable mounting heights and different incident angles of electromagnetic wave on the core line response are analyzed by using the hybrid algorithm. Secondly, the influence of the error of the transfer impedance model of the woven cable on the coupling analysis simulation is considered, and the calculation model of the correlation transfer impedance is introduced. Based on the existing transfer impedance calculation model of braided cable, the braiding angle 伪 and the diameter of shield layer D _ m in the calculation model are optimized by the cable braided layer coverage K. In order to verify the validity of the optimized cable transfer impedance model, the transmission impedance of the cable is measured according to the three-axis transfer impedance measurement device designed by ourselves. On this basis, the influence of different structure parameters of braided layer on cable transfer impedance is further analyzed. Finally, the improved transfer impedance calculation model is introduced to the time domain hybrid algorithm for optimization, thus improving the accuracy of the algorithm. Finally, the electromagnetic coupling of shielded cable is analyzed by filter protection against nuclear electromagnetic pulse. First, the electromagnetic coupling model of shielded cable is established, and the core wire is connected with matching load at both ends. Then, the voltage and current responses on the core line are calculated by using the time-domain hybrid algorithm, and the key parameters such as the amplitude and frequency of the response are obtained. On this basis, the voltage and current response as interference source, combined with circuit simulation software, for different types of interference sources, the design of the corresponding filter, and then simulation analysis of the protective effect of the filter, Furthermore, the filter protection design of shielded cable is realized.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN03

【参考文献】