The control system of the national grid and its communication links

The C.E.G.B. generates power to meet the instantaneous demands of the eleven Electricity Boards in England and Wales (maximum 35 800 MW in January 1968). With 230 generating stations and grid transmission at 400, 275 and 132 kV and with 700 grid switching and/or high voltage transforming stations, the C.E.G.B.´s integrated power system is the largest in the world under unified control. To control and protect this countrywide power system, the C.E.G.B. requires a correspondingly large network of more than 2000 communication links. The paper briefly describes the CE.G.B.´s three-tier control system which operates at district, area and national levels, and was arrived at over 30 years of control of the British ´Grid´. Some of the philosophy which has gone into the planning of the networks and into the design of the associated speech, remote control, general indication, telemetering and high-speed protection installations is explained.