Methodology for selecting optimal wire grade and cross-section based on an integrated technical and economic criterion

The aim was to develop a methodology for selecting an optimal wire grade and cross-section for overhead power lines with a voltage of above 1 kV under intensive development of power grid systems. This aim was solved using the authors’ previously developed methods: selection of an optimal wire grade based on hierarchy analysis and selection of an optimal wire cross-section by optimizing the specific discounted costs during the entire period of construction and operation of overhead power lines. In the present study, these methods are integrated into a single methodology. It is proposed to implement wire inspections prior to the stage of technical and economic calculations, since the necessary data has already been taken into account during the selection of a wire grade and its cross-section. The proposed methodology was tested on a typical example of reconstruction of the Zapadnaya– Davydovka 110 kV overhead line, which creates limitations in the power supply of Primorsky Krai due to insufficient wire capacity and its operation beyond the normative period. SENILEK AT3/C 150/24 wire was selected as a solution for the example under consideration. The application of this wire grade allows not only the overhead line capacity to be increased by 151% without replacing the existing supports, but also active and reactive power losses in the electric network to be reduced by 18.9 and 2.5%, respectively. The proposed methodology enables selection of an optimal grade and cross-section of any wire design, taking the dynamically changing operational conditions of power grid systems into account. The solutions found by the proposed methodology may contribute to a more efficient operation of power lines due to increasing their transmission capacity, reducing the number of used supports, replacing the line wire without replacing supports, decreasing ice formation on wires, and reducing power losses.