ABSTRACT

The electricity produced in the stator windings of the generators is at 25 kV and is fed through a transformer which steps up the voltage to 132, 275 or 400 kV. The original 'grid' established in the 1930s was designed to work at 132 kV and was strengthened by the 275 kV system in 1953. In 1960, the CEGB decided to use the 400 kV system for major new lines in order to increase the carrying capacity and to reduce the number of new lines needed: one 400 kV line has three times the carrying capacity of one 275 kV line and eighteen times the carrying capacity of a 132 kV line. A 160 MW direct current cross-Channel link with France, enables some exchange of supply between the two countries which is particularly useful during peak demands.