Abstract :
The paper is divided into two parts. The first part (Section 2) deals with design conditions for overhead lines in India. Each basis of design is examined separately and current practice in the subcontinent is indicated and commented on. Certain changes in this practice are recommended. The second part (Section 3) deals with choice of conductor size and voltage for long primary lines. It is suggested that tabulations of the natural powers of lines, and the distance they can be transmitted for given power losses, will provide useful and reliable guides to the choice of optimum conductor sizes and voltages. It is shown how these tabulations can be prepared on the basis of conditions which prevail in India, and in the process, conductor materials, conductor spacing, and insulation and corona voltages are discussed in relation to these conditions. The performances of three examples of long h.v. transmission lines, as calculated by rigorous methods, are tabulated in order to show that the assumptions which have been made in arriving at the simple formulae which are used to calculate natural power, and the distance it can be transmitted for given power loss, are sufficiently close for all practical purposes.
