US3934128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for operating a steam turbine with improved organization of logic and other functions in a sampled data control
Assignee: Westinghouse Electric Corp
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Filing: 1973-10-16
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Granted: 1976-01-20
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Expires: 1993-10-16
Abstract
Abstract The throttle and governor valves of a steam turbine are operated by a digital computer control system to provide speed and load control for the turbine. The computer includes a speed and load control which periodically generates control outputs and a separate logic control which responds to panel and contact inputs to generate logicals which structure the speed and load control. An analog scan periodically enters feedback parameters into the computer for use by the controls. An input contacts scan enters feedback logicals into the computer on demand, or under certain conditions periodically. A monitor operates with an auxiliary synchronizer to control the execution of the scans and the controls. The speed and load controls are bid for execution once each second to generate the control outputs which are applied to an external electrohydraulic control for the valves. The analog scan is bid for execution once each half second and the logic control is bid for execution on demand for performance of a logic function. The auxiliary synchronizer is bid for execution once each tenth of a second. The monitor controls the execution with a priority order of auxiliary synchronizer, speed and load control, analog scan and logic control. Certain logic and controller functions are performed commonly by a single programmed element as needed at different points in time by multiple parts of the controls.
Inventors
- 👤 Robert Uram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:21
CPC Classifications
F; F01; F01D; F01D17/00; F01D17/20; F01D17/22; F01D17/24
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
374 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying steam to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, a logic control for generating mode control outputs for operating said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, said digital controller including means for generating synchronous outputs to trigger the operation of said speed and load controls on a periodic basis, and means for operating said logic control on demand in response to changes in the panel or turbine contact signals.
Claim 2
Independent Claim
374 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying steam to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, a logic control for generating mode control outputs for operating said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, said digital controller including means for generating synchronous outputs to trigger the operation of said speed and load controls on a periodic basis, and means for operating said logic control on demand in response to changes in the panel or turbine contact signals.
Claim 3
Dependent Claim
59 words
A steam turbine operating system as set forth in claim 1 wherein said digital controller is embodied with a digital computer which further includes monitor means for controlling the execution of said logic control and said speed and load controls and other predetermined program elements in response to program run bids and in accordance with a predetermined priority system.
Claim 4
Dependent Claim
80 words
A steam turbine operating system as set forth in claim 2 wherein said synchronous generator output means includes an auxiliary synchronizer which generates trigger outputs for speed and load control program execution for which periodic bids are placed for its own execution at a rate substantially more frequent than the rate at which the control program is to be executed, said monitor means placing a higher priority on execution of said auxiliary synchronizer than on said speed and load controls.
Claim 5
Dependent Claim
41 words
A steam turbine operating system as set forth in claim 3 wherein bids are placed for execution of said logic control on demand and said monitor means places a higher priority on control program execution than on logic control program execution.
Claim 6
Dependent Claim
69 words
A steam turbine operating system as set forth in claim 3 wherein said auxiliary synchronizer further generates trigger outputs for said analog scan at a rate faster than the execution rate for said speed and load controls and slower than the auxiliary synchronizer execution rate, and wherein said monitor means places priorities on execution bids in the other auxiliary synchronizer, speed and load control, analog scan and logic control.
Claim 7
Dependent Claim
79 words
A steam turbine operating system as set forth in claim 2 wherein said synchronous generator output means includes an auxiliary synchronizer which generates trigger outputs for operating said periodic analog scanning means and for which periodic bids are placed for its own execution at a rate substantially more frequent than the rate at which the analog scan is to be executed, said monitor means placing a higher priority on execution of said auxiliary synchronizer than on said analog means.
Claim 8
Dependent Claim
56 words
A steam turbine operating system as set forth in claim 2 wherein the input contact signals are normally scanned on demand initiated by a contact signal change wherein said computer includes means for scanning the input contact signals periodically if computer duty above a predetermined level is being applied to contact scanning on a demand basis.
Claim 9
Dependent Claim
27 words
A steam turbine operating system as set forth in claim 1 wherein the input contact signals are normally scanned on demand initiated by a contact signal change.
Claim 10
Dependent Claim
33 words
A steam turbine operating system as set forth in claim 1 wherein said speed and load control functions approximately once each second and said analog scanning means functions approximately once each half second.
Claim 11
Dependent Claim
102 words
A steam turbine operating system as set forth in claim 1 wherein said speed and load controls include a proportional plus reset controller, means for coupling said porportional plus reset controller to each of said control elements which require a proportional plus reset function when such control elements are to be operated, means for uncoupling said proportional plus reset controller for each of the latter control elements when an output has been provided for each of such control elements, and means for registering the outputs from said proportional plus reset controller for use in the operation of the speed and load concontrols.
Claim 12
Dependent Claim
49 words
A steam turbine operating system as set forth in claim 1 wherein a speed controller is provided for generating a characteristic output in response to speed error, and means are provided for coupling said speed controller in said speed control or said load control according to the control mode.
Claim 13
Dependent Claim
42 words
A steam turbine operating system as set forth in claim 11 wherein the speed controller is a proportional plus integral controller and said speed controller coupling means includes means for applying one characterization in speed control and another characterization in load control.
Claim 14
Independent Claim
373 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying stream to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, means for controlling said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, a flip-flop for generating switch outputs, means for connecting said flip-flop at least into said load and speed controls to function as each of at least some of said mode switching means and to generate a switch output for registration and speed and load control operation when so connected.
Claim 15
Independent Claim
373 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying stream to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, means for controlling said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, a flip-flop for generating switch outputs, means for connecting said flip-flop at least into said load and speed controls to function as each of at least some of said mode switching means and to generate a switch output for registration and speed and load control operation when so connected.
Claim 16
Independent Claim
433 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying steam to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, means for controlling said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, said digital controller being embodied with a digital computer having monitor means for controlling the execution of said speed and load controls and other predetermined program elements in response to program run bids and in accordance with a predetermined priority system said synchronous generator output means including an auxiliary synchronizer which generates trigger outputs for speed and load control program execution for which periodic bids are placed for its own execution at a rate substantially more frequent than the rate at which the control program is to be executed, said monitor means placing a higher priority on execution of said auxiliary synchronizer than on said speed and load controls.
Claim 17
Independent Claim
433 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying steam to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, means for controlling said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, said digital controller being embodied with a digital computer having monitor means for controlling the execution of said speed and load controls and other predetermined program elements in response to program run bids and in accordance with a predetermined priority system said synchronous generator output means including an auxiliary synchronizer which generates trigger outputs for speed and load control program execution for which periodic bids are placed for its own execution at a rate substantially more frequent than the rate at which the control program is to be executed, said monitor means placing a higher priority on execution of said auxiliary synchronizer than on said speed and load controls.
Claim 18
Dependent Claim
65 words
A steam turbine operating system as set forth in claim 14 wherein said auxiliary synchronizer also triggers said analog scan means at a rate faster than the execution rate for said speed and load controls and slower than the auxiliary synchronizer execution rate and wherein said monitor means places priorities on execution bids in the other auxiliary synchronizer, speed and load control, and analog scan.
Claim 19
Independent Claim
414 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying steam to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, means for controlling said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, said speed and load controls including a proportional plus reset controller means for coupling said proportional plus reset controller to each of said control elements which require a proportional plus reset function when such contact elements are to be operated, means for uncoupling said proportional plus reset controller from each of the latter control elements when an output has been provided for each of such control elements, and means for registering the outputs from said proportional plus reset control for use in other operation of the speed and load controls.
Claim 20
Independent Claim
414 words
A system for operating a steam turbine in an electric power plant, said system comprising an arrangement of throttle and governor valves for supplying steam to the turbine, means for actuating said valves to position said valves in accordance with valve position signals, means for generating signals representative of the turbine speed and the turbine load and other turbine variables, a digital controller having means for generating a speed setpoint and means for generating a load setpoint, means for coupling the turbine speed and load signals and the other turbine variable signals to said digital controller on a periodic or demand basis, means for registering the coupled speed and load and other turbine variables in said digital controller, said digital controller including a speed control for periodically generating valve position outputs in response to the turbine speed and speed setpoint during turbine startup, said digital controller further including a load control for periodically generating valve position outputs in response to the turbine load and load setpoint during turbine load operation, means for continuously generating the valve position signals in response to the valve position outputs, said coupling means including means for generating contact signals representative of predetermined turbine variables and for scanning such signals on a predetermined basis for registration in said digital controller, said coupling means further including means for converting input analog signals to digital signals and for periodically scanning the digital signals for registration in said digital controller, an operator panel having switching means for generating control mode and control parameter signals, means for coupling the operator panel signals to said digital controller and for registering such signals in said digital controller, said speed and load controls having a plurality of control elements and mode switching means for determining which elements are operative in the functioning of the controls, means for controlling said mode switching means in response to the registered control mode panel signals and the registered turbine contact signals, said speed and load controls including a proportional plus reset controller means for coupling said proportional plus reset controller to each of said control elements which require a proportional plus reset function when such contact elements are to be operated, means for uncoupling said proportional plus reset controller from each of the latter control elements when an output has been provided for each of such control elements, and means for registering the outputs from said proportional plus reset control for use in other operation of the speed and load controls.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |