Standardization of control facilities for the British grid: communications, indications and telemetering

During 1932¿57, different telephone, general indicating, and telemetering systems were used to control the British Grid. These systems served their purpose, but improvisations had to be made from time to time to cater for expansion of the Grid. Since 1938, the Grid has been operated as one interconnected system; it is now of 22,000 MW capacity and the rate of expansion shows no sign of diminishing. A readily extensible and standard system became necessary, and in 1949 the then British Electricity Authority embarked on a programme to re-equip about 300 stations, 8 Grid Control Centres and the National Control Centre with a `standardized system¿ which provided many new features that operating experience had proved to be necessary. The standardized system was developed by certain telephone manufacturers in consultation with the Authority. A full description of the facilities it provides is given in the paper. Reasons are also given why with few exceptions rented Post Office circuits are used for the control networks. A brief description is included of control facilities afforded by switchgear-reclosing equipment provided at unattended stations controlled by the standardized system. The principal design features of the system are described in the companion paper.