电磁脉冲对装备机箱搭接缝耦合的研究

Analyses of Electromagnetic Coupling through Joint Lap on Equipment Enclosure under EM Pulse

摘要: 本文建立了装备机箱的物理模型，依据时域有限差分法原则对机箱和搭接缝进行网格剖分。在Fortran软件中编程仿真，通过数值计算得到了电磁脉冲通过搭接缝的耦合。通过分析机箱内的电场分布情况和时域波形分析，可以看到进入机箱内的电磁干扰产生谐振，谐振频率和机箱的几何尺寸有关。机箱对高功率电磁脉的屏蔽作用非常有限，机箱内峰值场强高达1415 dBV/m。此外，垂直于搭接缝方向的耦合电场大于平行与搭接缝方向的耦合电场。因此，电子器件应该尽量沿平行与搭接缝方向布置。

Abstract: In this paper, the computer enclosure model is established, and both the enclosure and the joint lap are modeled by finite-difference time-domain method (FDTD) cells. Programs are written in Fortran Software and the electromagnetic coupling through joint lap is obtained from numerical simulation. From analyses of the field distribution and waveforms, it can be seen that resonance occurs and the resonant frequency depends on the enclosure dimension. Secondly, the shielding effectiveness of the enclosure is limited under the EM pulse, and the amplitude of the coupled electric field can reach as high as 1415 dBV/m. Finally, the coupled electric field in the joint lap width direction is larger than that in the length direction. Thus the electronic devices are supposed to locate in the joint lap length direction rather than the width direction.