Enhanced analytical design method for overhead line conductors in nonlevel spans

This paper presents a practical design method to analyze line conductors deflected by wind in inclined spans. Comparison of the results of the traditional approach (in a vertical plane) and the three-dimensional approach proposed in this paper shows that the shape of the catenary deflected by wind in a nonlevel span may differ significantly from the shape in a vertical plane due to the displacement of its “zero” point. Determination of the true location of the “zero” point in nonlevel spans is very important to determine the accurate clearances to the deflected conductor, the tension at “zero” point, and the three components of line tension at the conductor attachment point. Representing conductor coordinates, loads, and tensions as vectors and their components (projections) allows analysis of the line conductor in any position in space and for any direction of wind or combined “wind plus ice” loadings. This method is most useful when applied to conductors passing through mountainous terrain where determination of the actual state of line conductors using conventional methods is either impossible or impracticable