Methods of system control in a large interconnection

This paper describes the principles used in controlling the load in a large interconnected system. Automatic frequency controllers with time-error correction and tie-line controllers with frequency bias and time-error correction have been developed for co-ordinating the operations of interconnected systems of any size and geographical extent. Automatic control of two or more stations simultaneously within a group is described, and the relation of the auxiliary frequency controllers to the speed governors is also discussed.