Analysis on the low-frequency electromagnetic pulse coupling to horizontal electrically short lines

Abstract

In this study, we investigated the coupling features of the nuclear electromagnetic pulse (NEMP) on overhead cables in the middle-and-far regions, different from the transmission line model commonly used for field-line coupling in high-frequency cases, using a simpler lumped approximation to solve the electrically small size model in low-frequency cases. To verify its effectiveness, a simulation model with the same conditions was set up using the software of Computer Simulation Technology (CST), and cable coupling experiments were performed in a laboratory environment using a bounded-wave electromagnetic pulse simulator. The calculated results of the lumped approximation circuit were compared with the CST simulation and measured results, and the agreement was good. The results also shows that the load exhibits a differential response in the case of the low impedance and it is consistent with the excitation signal in the case of the high impedance. Finally, some more experiments were constructed to analyzed the effect of different cable parameters on the cable load response through experiments, and the experimental results are also in general agreement with the theoretical analysis, in which the induced signal of the low-impedance load is mainly determined by the magnetic field in the direction normal to the cable and the ground loop and the induced signal of the high-impedance load is mainly determined by the electric field in the direction of the height of the cable erection.