Electromagnetic shielding calculation of the communication cable armor and buried pipelines

Based on the combination of the circuit theory and the field theory, a calculation method of the electromagnetic shielding effect of pipelines, which takes the inductive coupling and resistive coupling between power lines and underground telecommunication lines into account, is presented. After the discretization of the pipeline and the cable, the equation group is set up by the loop current method of the circuit theory, and pertinent parameters and equivalent voltage sources are calculated by the electromagnetic field theory. By using the current distribution figured out from simultaneous equations, the electromagnetic shielding effect of pipeline can be obtained easily.