Power limits of transmission lines

THIS ARTICLE PRESENTS the results of studies of the factors which influence the power limits or design loadings of transmission lines. Recent investigations have shown the principal factors determining the loading of transmission circuits, particularly those for distances of 100 to 600 miles. Since there is a continuing trend toward the use of higher voltages, it is desirable to study their possibilities more completely over the entire range of distances expected for 230 kv and higher. Hence, the present investigation extends the earlier studies to include lines from 10 to 600 miles in length. The results are general as regards the stability limits (Base kva = 5.0 kv²) and may be applied to lines of any voltage level. The economic comparisons in this study pertain to the 287-kv voltage level, which is about in the middle of the range for 230 to 380 kv and fairly representative of the general economic picture for all voltages 230 kv and above.