Abstract An improvement in the operation of an electric power plant utilizing a steam turbine controlled, in an automatic mode, by means of a digital computer, is accomplished by simplifying the interaction between the programmed automatic process control and the manual backup control. The position setpoint for each of a plurality of valves in the system to be controlled is established as a direct digital holding function in a respective bistable relay register. In addition, a single valve control holding register is provided which is coupled to all of the valve position controls in parallel. Automatic operation is then possible in either single valve or programmed sequential valve modes, and the programmed interaction to accomplish switching from manual to automatic control is simplified by updating the automatic control status until the single valve holding register has a setting equal to the manual control representation before consummating the manual to automatic switching. The direct digital holding registers also improve total system operation in eliminating drift with respect to the valve positions represented so as to extend the period of reliable operation in the manual mode, and also make it possible to retain the last valid position setpoints held in the respective registers prior to a computer power failure.
A method for operating a steam turbine system for controlling power output to a generator connected to said turbine as a function of the position of the series of governor valves said method comprising: establishing individual governor valve setpoints for each respective valve during a sequential mode of operation; establishing a single valve setpoint applied in parallel to all of said governor valve controls during a single valve control; applying a single common manual control signal to all of said valves in parallel during a manual mode of operation, said single valve control signal and said manual control signal being switchably combined through an automatic-manual control; and summing the switchably combined automatic and manual control signal with the individual sequential governor valve control signal to form a composite governor valve control signal sUitable for application to respective governor valve actuators.
Claim 2
Independent Claim
140 words
A method for operating a steam turbine system for controlling power output to a generator connected to said turbine as a function of the position of the series of governor valves said method comprising: establishing individual governor valve setpoints for each respective valve during a sequential mode of operation; establishing a single valve setpoint applied in parallel to all of said governor valve controls during a single valve control; applying a single common manual control signal to all of said valves in parallel during a manual mode of operation, said single valve control signal and said manual control signal being switchably combined through an automatic-manual control; and summing the switchably combined automatic and manual control signal with the individual sequential governor valve control signal to form a composite governor valve control signal sUitable for application to respective governor valve actuators.
Claim 3
Independent Claim
88 words
A method for controlling the valves of a turbine to improve automatic-manual interaction, said method comprising: providing individual valve setpoints of digital words during a sequental valve control operation; providing a single valve setpoint during a single valve setpoint operation and applying said single valve setpoint in parallel to all valves; summing said parallel-applied single valve setpoint individually with each respective separate valve setpoint; and switchably introducing a single valve control during manual operation to a point common with said point of application of said single valve setpoint.
Claim 4
Independent Claim
88 words
A method for controlling the valves of a turbine to improve automatic-manual interaction, said method comprising: providing individual valve setpoints of digital words during a sequental valve control operation; providing a single valve setpoint during a single valve setpoint operation and applying said single valve setpoint in parallel to all valves; summing said parallel-applied single valve setpoint individually with each respective separate valve setpoint; and switchably introducing a single valve control during manual operation to a point common with said point of application of said single valve setpoint.
Claim 5
Dependent Claim
71 words
An improved method for automatic turbine valve control comprising: separately producing a governor valve series of setpoint control signals, a single valve setpoint signal, and a manual control signal; selectively switching either said single valve control signal or said manual control signal to a common control point; and summing the signal output of said common control point with individual separate valve control signals to form a plurality of valve actuator signals.
Claim 6
Dependent Claim
71 words
An improved method for automatic turbine valve control comprising: separately producing a governor valve series of setpoint control signals, a single valve setpoint signal, and a manual control signal; selectively switching either said single valve control signal or said manual control signal to a common control point; and summing the signal output of said common control point with individual separate valve control signals to form a plurality of valve actuator signals.