Magnetic field calculation under EHV transmission lines for more realistic cases

Ground level electric and magnetic fields from overhead power transmission lines are of increasingly important considerations in several research areas. Common methods for the calculation of the magnetic fields created by power transmission lines assume straight horizontal lines parallel to a flat ground and parallel with each other. The influence of the sag due to the line weight is neglected or modeled by introducing an effective height for the horizontal line in between the maximum and minimum heights of the line. Also, the influences of the different heights of the towers, the different distances of the power transmission lines spans and the different angles between the power transmission linespsila spans are neglected. These assumptions result in a model where magnetic fields are distorted from those produced in reality. This paper investigates the effects of the sag in case of different heights of the towers and when the power transmission linespsila spans are not parallel to each other.