The Control System of a 225,000-Kw Double-Automatic Extraction Steam Turbine and Related Reducing Stations

Three variables must be controlled on a double-automatic extraction turbine—speed (or power output), and the two process-header pressures—by controlling the flow of steam at different pressure levels. This has been done in a satisfactory manner on a large number of extraction turbines. However, the designs which had been developed for turbines of 50,000-kw capacity and smaller were not suitable for a turbine nearly five times as large, and a completely new control-system design had to be created.