Optimization of Overhead Transmission Lines Power Transfer Capability with Minimizing Electric and Magnetic Fields

The electric and magnetic fields generated by transmission lines, at ground level, must be carefully analyzed to ensure low levels of induced voltage in surrounded metallic elements. Additionally, whenever possible, one main concern on transmission lines projects should be improving maximum line power transfer capability. Thus, this paper aims to present multi-objective optimization studies applied to improve the use of overhead transmission lines by conductor rearrangement. As objectives of the optimization problem are considered the maximization of line power transfer capability and the minimization of resulting electric and magnetic fields at ground level. An efficient multi-objective evolutionary algorithm method is updated and used as a result of the technical conflicts inherent to the physical process. Symmetry strategies for the overhead transmission line geometric configuration are considered in the optimization process. The results illustrate the robustness and physical consistency of the adopted methodology. According to results, verified from real overhead transmission lines, one of the cases studies showed that by rearranging the conductors, it is possible to obtain, simultaneously, an improvement of 17.5% in the maximum line power transfer capability with a reduction of 31.8% and 32.8%, respectively, of electric and magnetic fields.