Economical power-line terminal-voltage ratio

THE PURPOSE OF this study was to determine the most economical terminal voltages to use on a 230-kv transmission line. To do this, annual transmission costs per unit of transmitted load were calculated and plotted as a function of receiver voltage. This was done for several sender voltages, receiver loads, line lengths, and so forth. The minimum points of the cost curves gave the most economical receiver voltage for the assumed conditions. The receiver-to-sender voltage ratio (only voltage magnitude is significant in this ratio) was determined for the minimum cost points. A plot then was made of terminal voltage ratio ER/ES versus receiver load for maximum economy; see Figure 1.