Centralized Power Control of 65 000-Horsepower Pump Motors at Grand Coulee Dam

The facilities of the Grand Coulee Pumping Plant and the original starting procedures used for the 65 000-hp synchronous motor-driven pumps are briefly described, followed by a description and schematic diagrams of the controls now used in the automatic centralized power control scheme. The starting, stopping, and remote annunciation systems associated with the pumps are described in detail. A description of the control system for the 108 000-kW generator associated with the pump unit is also included. The system has proved very satisfactory, and after one season of operation with the centralized power control scheme, only two minor modifications were made to provide greater reliability.