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 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.

Abstract: A steam turbine is provided with inlet throttle and governor valves which are positioned by an electrohydraulic control. A digital computer includes a speed control and a load control which respond to turbine speed and load signals and an electrical load signal to generate position control setpoints for the valves. A load reference is generated from an input load demand, and the reference is modified by a speed correction and selectively acted upon by a megawatt control and an impulse pressure control in the generation of the valve position setpoints. On the insertion of the megawatt control or the impulse pressure control into service, or on its removal from service, the computer instantly resets control parameters as required to provide for bumpless control loop switching.

Abstract: The 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.

Abstract: Inplant sensors in the boiler and turbine units sense present values of a number of physical parameters designated process variables, and of certain control variables. Set points are developed, and deviations therefrom of the control and process variables are calculated. Utilizing a mathematical model, state variable deviations are estimated and translated into corresponding physical parameter estimates, which are used to evaluate model inaccuracy. State variable and model error estimates are translated into desired control deviations, which in turn are combined with fed forward values of the control variable set points. The combined control terms actuate controllers in the boiler and turbine units.

Abstract: An improved automatic fuel shutoff system is provided for a turbine type power plant which incorporates (1) sensing means responsive to a preselected abnormal engine operating condition for initially cutting off fuel flow to the engine and (2) latching means for maintaining the cutoff until engine conditions favorable for a normal restart are obtained.

Abstract: A turbine control system for changing two speed governing operations of a steam turbine from a throttle governing operation to a nozzle governing operation and vise versa by controlling steam control valves comprises function generators grouped according to the two speed governing operations and operated by a main control flow-rate request signal to produce function outputs which are applied to respective low-value gate circuits, means for comparing the sum of the outputs of the gate circuits and the main control flowrate request signal, and means for varying the main control flowrate request signal with the aid of the difference between the signals thus compared in such a manner that while one of the outputs of the gate circuits decreases, the other output increases to supplement the decrease, whereby the steam control valves are gradually operated with the output of the turbine being kept unchanged during the operating mode changing operation.

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Abstract: An automatic control system for high pressure blower applications prevents surging under variable supply flow rate requirements and achieves maximum efficiency of operation. The supply flow rate establishes the set point of a proportional plus reset controller, the latter receiving a feedback signal corresponding to the static discharge pressure of the supply blower and responding thereto for controlling the output of the supply blower. A return blower is controlled either through a characterizer relay in proportion to the control of the supply blower to maintain a fixed precalibrated relationship between supply and return flow rates or by a further proportional plus reset controller responsive to the supply flow rate, for establishing the set point thereof, and to the return flow rate, as a feedback signal thereto, for controlling the output of the return blower.