Comparison of the shielding effectiveness between two methods of cable bridge EMP protection

EMP (electromagnetic pulse) has the characteristics of transience, wide spectrum, high intensity and etc. EMP brings severe threaten to the electrical equipments. And conducted interference is produced along the cables of the electrical equipments, which is an important coupling path. As the support of the cables, cable bridges provide electromagnetic shielding as well as cable laying support, which is significant to improve the conducted immunity of the electrical equipments. So it is important to design electromagnetic protection for cable bridges. In this paper, two kinds of electromagnetic hardening techniques are applied to a typical cable bridge on the joint, and the EMP shielding effectiveness of them are measured respectively to analysis the influence of the electromagnetic hardening on the EMP shielding effectiveness.