System and method for operating a steam turbine with digital control having validity checked data link with higher level digital control

• US 3,937,934 A
• Filed: 12/21/1973
• Issued: 02/10/1976
• Est. Priority Date: 04/26/1972
• Status: Expired due to Term

• Current Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Original Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Inventors: Pasemann, Klaus
• Primary Examiner(s): Gruber, Felix D.
• Assistant Examiner(s): Wise, Edward J.
• Application Number:
  US05/427,281
• Time in Patent Office: 781 Days
• Field of Search: 235/151.21, 235/151.34, 235/151.3, 235/151, 415/17, 415/15, 415/13, 415/1, 60/73, 60/105, 60/39.28 R, 290/40, 340/172.5, 444/1
• US Class Current: 700/290
• CPC Class Codes: F01D 17/24 electrical

Abstract

A digital computer control system is provided for operating a steam turbine in an electric power plant. The computer develops steam valve position signals to control turbine speed and load. Various turbine temperature, pressure and other process parameter signals are coupled to the computer which stores the parameter values along with other parameters such as control loop setpoints in its memory. Another computer at the plant level or at the system dispatch level is coupled to the turbine computer through a data link which includes data link programs in each computer and data transmitter and receiver circuitry connected to the two computers. The higher level computer is the controlling computer on the data link. Control words are used to identify data transmission modes and validity checks are made on transmitted words. Turbine computer core data is accessible and transmittable to either higher level computer. Load demand and load rate are transmitted to the turbine computer from the dispatch computer, and the plant computer transmits setpoints to provide turbine control from the plant level. To check validity, a checksum quantity is generated with respect to predetermined data words at the transmission and receiver ends of the data link. The receiver compares the checksum quantities to validate linked data before such data is permitted to be used for turbine control or other purposes.

Claims

1. 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, a first digital controller having means for generating a speed setpoint and means for generating a load setpoint, said first controller including a speed control for generating valve position signals in response to the turbine speed signal and speed setpoint during turbine startup, said first controller further including a load control for generating valve position signals in response to the turbine load signal and load setpoint during turbine load operation, means for generating signals representative of additional turbine parameters and for coupling the additional signals to said first controller, means for registering the additional signals in said first controller, a second digital controller, means for linking at least digital data signals between said controllers, said data link means including respective first and second means for transmitting data word signals from said first and second controllers, respective first and second means for receiving data word signals in said first and second controllers, said second transmitting means including means for generating setpoint data control and data change word signals for transmittal to said first controller in one of the data link modes to modify at least one of the setpoints operative in said first controller, each of said transmitting means including means for generating a check signal related in a predetermined way to a predetermined group of transmitted digital data signals and each of said receiving means including means for generating a second check representation related in the same way to the group of transmitted data signals as received, and means for comparing the received check signal and the check representation and for generating an indication of a discrepancy between the two.

2. A steam turbine operating system as set forth in claim 1 wherein the check signal is a sum of the transmitted digital data signals.

3. A steam turbine operating system as set forth in claim 1 wherein each of said controllers includes a digital computer system.

4. A steam turbine operating system as set forth in claim 1 wherein the generated indication of a discrepancy includes a control word signal transmitted back to the original transmitting means to indicate a data link error.