Protection system for transferring turbine and steam generator operation to a backup mode especially adapted for multiple computer electric power plant control systems
United States Patent 11 Davis 1 1 PROTECTION SYSTEM FOR TRANSFERRING TURBINE AND STEAM GENERATOR OPERATION TO A BACKUP MODE ESPECIALLY ADAPTED FOR MULTIPLE COMPUTER ELECTRIC POWER PLANT CONTROL SYSTEMS [75] Inventor: Guy E. Davis, Martinez, Calif.  
 [73] Assignee: Westinghouse Electric Corporation,  
 Pittsburgh, Pa.  
 [22] Filed: Nov. 6. 1973 [21] Appl. No: 413,277  
 [52] U.S. Cl 235/1511], 290/40, 60/646 [51] Int. Cl. G051) 15/00, 0061&#39; 15/06, G06f 15/56 [58] Field of Search 235/151.2l, 151.34, 151.3, 235/151; 415/1. 13-15, 17; 60/646; 290/40 A-40C, 40 F; 340/1725 [56] References Cited UNITED STATES PATENTS 0.552.872 1/1971 Giras ct a1. 415/17 3.555.251 1/1971 Shavit 235/151 3561216 2/1971 Moore. Jr. 60/73 3564273 2/1971 Cockrcll 415/17 X 3.588.265 6/1971 Berry 415/17 X OTHER PUBLICATIONS Application of the PRODAC 50 system to direct digital control. .1. C. Belz, G. 1. Kirk &amp; P. S. Radcliffe, IEEE lnt1.Conv. Rec. Part 3, 1965. pp. 102-122. Montioring and automatic control in steam power stations by process computer, E. Doetsch &amp; G. Hirschberg, Siemens Review XXXV (1968) No. 12, pp.  
 GAS OR OIL &#39; 45] Apr- 1975 Primary Examiner-Eugene G. Butz Assistant ExaminerEdward 1. Wise Attorney, Agent, or FirmE. F. Possessky [57] ABSTRACT An electric power plant including a steam generator and a steam turbine is operated by a control system including two redundant digital computers. Switching circuitry is provided for coupling one of the computers through interface equipment to the steam generator and the turbine and a generator according to programmed computer control. A data link is established between the computers to transfer manual/automatic status and other needed data from the control com puter to the standby computer. A system is provided for detecting when certain hardware and software malfunctions have occurred and for responsively transferring control to the standby computer. The standby computer is tracked to the control computer so that control computer transfer can be made reliably without disturbing the electric power generation process. The detection system triggers computer transfers in the event malfunctions occur in input/output equipment including contact closure input and output systems and analog input and output systems. Computer transfers are also triggered on certain software malfunctions including tight loop operation and prescribed task errors. Certain other events such as a data link malfunction permit a computer transfer but limit the computer coming into control status to the manual mode.  
 25 Claims, 41 Drawing Figures 51 EM TO HP TURBINE E Ii ATER TU K5 TO I? TURBIN E F ROM HF TURBINE FE EUWATER eoouomzca AIR INLET &#34;ATENTEU APR 1 19. 5  
 GAS OR OIL sum L2 1? as RHEATEATER TUBES STEAM TO HP TURBINE REHE ATER TUBES TO IP TURBINE COMBUSTION PRODUCTS FROM HP TURBINE FEEDWATER ECONOMIZER COMBUSTION GAS OUT LE T AIR lN LET SHEET 11 6F DL COUNT= DL COUNT &#34;1 IDATFLG=Q CALL SDLYUJI DO l0 I=1.10 FIRST=LOCUU LAST =LOC2(I) 80 CALL DATLNK(5,2,F,L)  
 CALL SDLYU) DO 20 I =1.1O FIRST=LOCHD LAST=LOC2(H 20 CALL DATLNK(5,I,F,L  
 FIG. 8.  
 PZOOO-l N CONTROL (READ MODE) P2000-2 TRACKING P2000-2 IN CONTROL (WRITE MODE) PZOOO-l TRACK&#39;NG F TWAR OR HARDWARE MALFUNCTION TRIGGER DEAD OK ,362 ,360 DEMAND COMPUTER RUN STATUS T R COMPUTER SHEET 12 3F 33 NOT STOP 0 0 CONTACTS DEAD -TOGGLlNG-,DEACTIVATE 0K Aux SYNC STANDB COMPUTER AVAILABLE REJECT TO MANUAL FIG.9  
 PUT M/A STATION ON M OR A PER DATA LINKS SET RETRANSFER TNHIBIT BID BOILER CHASIS AND TURBINE LOGIC CLOSE DEH SPEED LOOP IF OPEN DEH DEMAND CCI SCAN PROCESS GO AND HOLD PANEL PB END FIG. I0  
 CONTROL POINT B UMPLESS TRANSFER VALVE POSITION IIIIL R l IQYS ELNELU SHEET 133% 33 PROCESS TRANSDUCER Illllllll&#39;llll CONVERT ERR TO CCO TIME OUTPUT CCO Tl MED DIGITAL SCAN ROUTINE SHEET 19 0F 38 mwwt. 9; m @I mom NI wow @I mom mom of hOm :I mom N I mom Q1 06 XI :m mi N m mi Em DI