Manual/automatic system for synchronizing multiple turbines in a

Abstract

A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. In the control system, an automatic digital computer control generates position setpoints for the gas turbine fuel valves and the steam turbine inlet valves to control turbine speed and load. A synchronizer system includes an automatic synchronizer subsystem and a manual synchronizer subsystem. The automatic synchronizer subsystem includes a sequencer which is largely embodied in the digital computer and it further includes a synchronizer which is external to the automatic control. The automatic sequencer connects the synchronizer to synchronize the three generators in a sequence which depends on the startup and loading operation of the turbines, the synchronization operation of the synchronizer and the operation of the breakers. The manual synchronizer subsystem responds to operator inputs to generate a speed reference for the synchronization of each turbine. The synchronization system further includes logic structure needed to permit synchronization to occur and to define the synchronization mode. Turbine speed changes are initiated by the speed/load control under synchronizer system control.