Steam turbine system with digital computer position control having improved automatic manuel interaction

Claim 3

The control system defined in claim 1 wherein said manual control means includes: an up-down counter; a converter for translating the digital state of said counter into said manual control signal; and logic and comparison means for incrementing or decrementing said counter during automatic operation so as to track the level of said single valve setpoint and means for raising or lowering the value in said counter during manual operation in response to corresponding operator signals.

Claim 4

The control system defined in claim 1 wherein said manual control means includes: a track and hold amplifier; a comparison network; a switching element operative during automatic operation to connect said comparison network to said track and hold amplifier; and means for applying manual raise and lower control signals to said switching element for application to said track and hold amplifier during manual operation.

Claim 5

The control system defined in claim 1 wherein said valve setpoint registers comprise bistable relays operable to hold the last digital value entered therein after removal of power and switching means are provided for disconnecting switching power from said valve setpoint registers during manual control operation.

Claim 6

The control system defined in claim 4 wherein network means includes at least first and second summing resistors, the first summing resistor being connected to a converter producing an analog signal representing a governor valve setpoint and the second summing resistor being connected to said control point.

Claim 7

The control system defined in claim 5 wherein said network means further includes a third resistor for applying a feedback signal representing the actual position of a valve being controlled.

Claim 8

A control system for apparatus having a plurality of devices with each device being characterized with at least one controllable variable which affects the operation of the apparatus, said control system comprising a digital computer system operative to generate at one of its outputs control words defining setpoints for the variables associated with the respective devices, an improved auto-manual control system comprising: a plurality of digital setpoint storage registers and associated digital-to-analog converters; a digital multiplexer for directing digital representations of the setpoint control words to said storage registers; a plurality of control networks coupling certain of said converters to a corresponding plurality of device controllers; manual control means including circuits for producing a manual control output signal having a value variable in response to raise and lower operator input signals during a manual mode of operation and further circuits for increasing or decreasing said manual control signal during an automatic mode of operation to correspond to the setpoint value of one of said setpoint storage registers; and auto-manual switching means for selectively coupling either the converted output of said one setpoint storage register or the output of said manual control means to said control networks.

Claim 9

A control system for apparatus having a plurality of devices with each device being characterized with at least one controllable variable which affects the operation of the apparatus, said control system comprising a digital computer system operative to generate at one of its outputs control words defining setpoints for the variables associated with the respective devices, an improved auto-manual control system comprising: a plurality of digital setpoint storage registers and associated digital-to-analog converters; a digital multiplexer for directing digital representations of the setpoint control words to said storage registers; a plurality of control networks coupling certain of said converters to a corresponding plurality of device controllers; manual control means including circuits for producing a manual control output signal having a value variable in response to raise and lower operator input signals during a manual mode of operation and further circuits for increasing or decreasing said manual control signal during an automatic mode of operation to correspond to the setpoint value of one of said setpoint storage registers; and auto-manual switching means for selectively coupling either the converted output of said one setpoint storage register or the output of said manual control means to said control networks.

Claim 10

The control system defined in claim 7 wherein said devices are valves and converters DAC-G1...DAC-Gn (where n represents a number of valves) are coupled individually through separate summing impedances to respective control networks, and a converter DAC-SV is applied to one terminal of a switch in said auto-manual switching means, the other terminal of which is connected to a converter DAC-M constituting the output means for said manual control means.

Claim 11

The control system defined in Claim 7 wherein said manual control means comprises: a comparator coupled to one of said digital-to-analog converters for producing increase and decrease signals as a function of the comparison of the analog value of said one analog converter and the output of said manual control means; an up-down counter; a converter for translating the counter state into said output; and logic for applying said increase and decrease signals to said counter during automatic operation and for applying raise and lower control signals during manual operation.

Claim 12

A steam turbine system for generating electric power wherein the level of power produced is controlled as a function of the position setting of a plurality of valves, said system comprising: a plurality of hydraulic valve actuators coupled to said valves, respectively, and a corresponding plurality of position controls each of which produces a signal specifying the absolute value of the position of a corresponding valve; a plurality of digital setpoint registers coupled to a corresponding plurality of digital to analog converting means producing first input signals for said position controls, respectively; means for digitally processing data having a programmed digital computer central processor; a manual control circuit and said digital means including a single valve register, digital to analog converter coupled to said digital means, means for tracking an electrical signal connected to said converter, a manual control circuit connected to said tracking means, and a switch connected to said tracking means whereby switching between a manual control state and an automatic control state is permitted, said manual control circuit producing a common control signal applied to said position controls in parallel, said tracking means connected to an input of said digital means whereby a signal from said tracking means can be monitored by said digital means, said central processor being programmed to permit manual to automatic switching such that the setpoint value placed in said single valve register is made to equal the existing manual control signal level at said tracking means prior to actuating said switch to an automatic state, the output signal derived through said switch providing a means of controlling all of said valves in parallel.

Claim 13

A steam turbine system for generating electric power wherein the level of power produced is controlled as a function of the position setting of a plurality of valves, said system comprising: a plurality of hydraulic valve actuators coupled to said valves, respectively, and a corresponding plurality of position controls each of which produces a signal specifying the absolute value of the position of a corresponding valve; a plurality of digital setpoint registers coupled to a corresponding plurality of digital to analog converting means producing first input signals for said position controls, respectively; means for digitally processing data having a programmed digital computer central processor; a manual control circuit and said digital means including a single valve register, digital to analog converter coupled to said digital means, means for tracking an electrical signal connected to said converter, a manual control circuit connected to said tracking means, and a switch connected to said tracking means whereby switching between a manual control state and an automatic control state is permitted, said manual control circuit producing a common control signal applied to said position controls in parallel, said tracking means connected to an input of said digital means whereby a signal from said tracking means can be monitored by said digital means, said central processor being programmed to permit manual to automatic switching such that the setpoint value placed in said single valve register is made to equal the existing manual control signal level at said tracking means prior to actuating said switch to an automatic state, the output signal derived through said switch providing a means of controlling all of said valves in parallel.

Claim 14

The steam turbine system defined in claim 10 wherein each of said position controls includes a summing network for combining said common signal individually with each of the other valve control signals.

Claim 15

The steam turbine system defined in claim 11 wherein each of said networks further includes means for summing a valve position feedback signal and a servo-amplifier coupled to the summing junction for producing a driving signal for the corresponding valve actuator.