TVA Co-ordinated Communication System

This paper describes communication and control systems used by the Tennessee Valley Authority, principally to expedite the operation of its multiple-purpose dams, electric power generating stations, transmission lines, and substations. Seventy per cent of the 10,000-mile communication and control system is obtained by carrier channels superimposed upon power lines. This paper explains relationships which exist between carrier channels that are utilized for pilot relay, remote trip, telemeter, automatic load-frequency control, and telephone purposes. Close engineering co-ordination of 45 telephone switchboards, including 13 of the automatic type, and a variety of kinds of telephone circuits, totaling over 6,000 miles in length, permits the rapid handling of 2,500,000 telephone calls each year. The basic equipment used in establishing these circuits and their flexible interconnecting arrangements is standardized and the units are applicable to systems of any size.