Assessment of mechanical loads on the overhead power transmission lines of 6-35 kV voltage class
The relevance of the research is caused by the need to increase energy efficiency and reliability of operation of overhead power transmission lines using an uninsulated stranded wire in distribution network of 6-35 kV voltage class at external effects. Development of this direction will allow lowering emergencies in distributive network, in particular, in oil and gas branch where lengths of air-lines of 6-35 kV voltage class reach several tens of kilometers. The main aim of the research is to justify the influence of a cross section form of a stranded uninsulated wire of overhead power transmission line of 6-35 kV voltage class, depending on the accepted coefficients of filling the wire full section with material and wire smoothness on values of possible mechanical loadings on wires taking into account weather conditions. Objects: stranded uninsulated wire of overhead power transmission lines of 6-35 kV voltage class. Methods. The method of limit states when determining permissible settlement load was used. Results. The authors have obtained the formulas which allow determining the diameter of a wire depending on the accepted coefficients of filling the wire full section with material and wire smoothness. Based on the formulas obtained the authors showed the dependences of possible mechanical loadings on wires on weather conditions and the taken form of the wire cross section. On the basis of the introduced dependences the authors proposed the algorithm for determining possible mechanical loadings on a wire. This algorithm allows selecting the wire of overhead power transmission lines of 6-35 kV voltage class. The authors assessed the critical spans on the example of using a wire with a nominal section of 120 mm<sup>2</sup>.