Westinghouse Electric Corporation

Guy E Davis

Jack R Smith

Francesco Lardi

William D Ghrist, Iii

Donald J Jones

An electric power plant, including a fossil fired boiler and a steam turbine, is operated by a control system including a plant unit master. The control system includes a boiler control for determining the inputs of fuel, air and water, and a turbine control for determining the position of the throttle valves introducing steam from the boiler to the turbine. The plant unit master provides a load demand reference in parallel to the boiler control and to the turbine control, whereby the turbine and the boiler are operated in a coordinated manner. Measuring means provide indications of throttle pressure, power generated by the system and turbine rotor speed. Distinct controllers, each including a controller and responsive to one of the aforementioned indications and its corresponding reference, modify the load demand reference before it is applied to the turbine control or to the boiler control. The above-described control system including the plant unit master, boiler control and turbine control is implemented by a single digital computer.

Plant unit master control for fossil fired boiler implemented with a

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 computer 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 turbine control includes a speed control loop which is implemented with computer operations. Startup control is also implemented in startup control loops for the steam generator by means of computer operations. Computer transfers are executed smoothly in the startup control mode at substantially any stage of the startup process.

Wide range system for transferring steam generator and turbine operation

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 computer 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. In order to provide for making a noncontrolling computer available for control in a reliable and fast manner after it has been stopped for any reason, the system is arranged to structure the noncontrolling computer with certain initializing data over the data link. The initialization data includes turbine rotor stress calculated variables and other variables including boiler and turbine logicals and calibration variables.

System for initializing a backup computer in a multiple computer

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 computer 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 turbine control includes a load control loop which is implemented with computer operations. Load control is also implemented in load control loops for the steam generator by means of computer operations. Computer transfers are executed smoothly in the load control mode at substantially any load level of operation.

Wide load range system for transferring turbine or plant operation

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 computer 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. Tracking is produced by a system which includes the data link as well as tracking controls in the noncontrolling computer. Such tracking controls function in the tracking mode of the noncontrolling computer to conform the control outputs of the two computers with little or no offset. On the execution of a computer transfer, the tracking controls are bumplessly switched out of operation as the computer coming into control switches from the tracking mode to the control mode.

System for manually or automatically transferring control between

An electric power plant including a steam generator and a steam turbine is operated by a control system including a turbine control, a boiler control and a plant unit master; each of the aforementioned controls includes integrating or adaptive controllers responsive to error signals to effect a desired control and ramp generators to provide an output against which a control process may be tracked. The integrating controllers include an integrating circuit for integrating an input error signal and a proportional circuit responsive to the error signal for providing an output signal to be summed with the output of the integrating circuit. The constant of the proportional circuit and the time constant of the integrating circuit are changed as a function of an index. In a control for an electric power plant, the index is the load reference provided by the plant unit master. A ramp generator is suggested that is capable of generating linear ramps at a fixed rate toward a known value, e.g. the control reference to be entered, and includes an integrating circuit to which is selectively applied first and second reference signals dependent upon whether the input signal is above or below a predetermined level.

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Martinez, CA, United States of America

Guy E Davis