A Retrofit Turbine Automatic Control for Large Steam Turbine-Generators

The present trend of upgrading older turbine-generator sets for extended operating life and cycling has generated the need for automatic startup capability in existing power plants. This paper describes a new automatic control system which will interface with existing mechanical-hydraulic or electro-hydraulic controls on large steam turbine-generators in central power stations. It provides push-button control for startup from turning gear through synchronization to a preset load demand. Stresses in high temperature rotors are controlled during this startup operation by automatic selection of appropriate acceleration rates, speed holds, and loading rates. Stresses are controlled during unloading as well. The system utilizes a commercial minicomputer connected to an operating panel, thus providing the versatility necessary to interface with the many variations of turbine-generator Sets in operation.