Mitigation of 50 Hz magnetic field produced by an overhead transmission line

Power transmission utilities are challenged by the need to expand transmission system capacity to meet growing energy demands. The impact of high voltage overhead transmission lines on the environment represents a hot topic in the context of transport and distribution of electrical energy. In particular, interest towards the effects of extra low frequency (ELF) magnetic fields generated by high-voltage power transmission lines has been increasing significantly during the last decade, giving rise to a number of policy initiatives and research activities. Therefore, the evaluation of the magnetic field generated by conductors of overhead lines is of primary importance in order to develop methods for mitigating the influence of overhead lines on the surrounding environment. In this paper, some technical solutions that are used nowadays to reduce 50 Hz magnetic fields generated by power lines are analyzed; simulation results concerning a case study on an actual 150 kV Italian power transmission line are also presented.