Upon the Contribution of Image Currents on the Magnetic Fields Generated by Overhead Power Lines

In the first part of the paper we have synthesized a theoretical breviary that finalizes with an analytical calculation method aiming to find out the depth at which the image current (of its air correspondent) is established. For a straightforward case (single wire), it is easier to verify the match between the result obtained by analytical calculation and the one acquired by simulation. The CST Studio simulation software mainly provides the required simulations. It has been developed a model that allows the choice of the soil conductivity value. Higher values for magnetic fields were obtained by up to 70% in the case of good ground conductivity (σ = 100S/m), compared with the practically insulating soil (σ = 0.1 S/m). For mutual validation, these simulations were compared with those obtained using EMFACDC software. It then went on to a more common but complicated case, precisely, the three-phase, double, high voltage network. The simulations showed less influence of image currents due to mutual compensation. In the end, concrete recommendations have been done on methods for reducing the magnetic emissions due to Overhead High Voltage Power Lines (OhHVPL) from the soil conductivity perspective.