Abstract: A control system for a marine turbine power plant is disclosed wherein the input signal to an electrohydraulic valve positioning circuit for ahead and astern turbines may be directly related to a desired valve position signal input set at a throttle lever. Hence, primary control is by a desired valve position signal. A speed feedback circuit is included and selectively applied to the desired valve position signal as a valve position trimming signal. Another input into the primary control or desired valve position is a malfunction proportional control signal which tracks boiler operation, shaft vibration and overspeed. The valve position signal is applied to the valve positioning circuit through a rate limiter which may be set at a fast, normal, or slow rate depending upon an input from a system interface board.

Abstract: A control system for an extraction type steam turbine driven by steam from a steam generator wherein it is desired to control the steam pressure in the steam generator, at a predetermined level, by varying the position of the steam inlet valve. Turbine speed may be controlled at a predetermined level by varying the position of an extraction control valve. The inlet valve and the extraction valve are independently operable except under a condition where the extraction valve is completely closed and the turbine speed continues to rise. In this instance, means are provided for positioning the inlet valve according to a speed control signal which dominates an inlet pressure control signal for lowering the inlet steam valve until normal conditions are restored.

Abstract: A speed control device is constituted of an acceleration control device used for starting a turbine, a constant speed control device used for the constant speed operation of the turbine and a selection circuit for selecting that one of the outputs of the control devices which makes smaller the opening of an adjustable valve provided at the entrance of the turbine. The output of the selection circuit determines the opening of the valve. The speed control device is so designed that the speed regulation may affect only the loop gain of the constant speed control system. For this purpose, the speed regulation circuit is provided, for example, between the subtractor of the constant speed control device and the selection circuit.

Abstract: A digital transfer system for transferring the operation of a steam turbine between a single and sequential mode of operation is disclosed. A total flow demand signal is applied to all of the valves in parallel for the single mode; and applied to all of the valves through individual function generators for the sequential mode. A digital up/down counter is connected to a rate multiplier for generating pulses at a frequency corresponding to the status of the counter. An electronic switch is connected to conduct either the single or sequential mode signal to the valve operating mechanism to respond to the pulses for repetitively applying alternately the single and sequential mode signal during the transfer.

Abstract: An intermediate intercept valve controlling method and system for use in a heat power plant wherein the occurrence of a fault in a transmission system is detected by an abrupt decrease in generator output, and the intercept valve is closed to a certain opening depending upon the magnitude of an output variation and is then opened when a rotor angle between the internal voltage and terminal voltage of the generator reaches the first peak value.

Abstract: A protection system is provided for a turbine plant to avoid double shock or similar rotor blade operation. A digital computer controller detects excessive blade loading conditions on the basis of governor valve positions and effects bumpless mode transfer from sequential valve operation to single valve operation to avoid excessive blade loading.

Abstract: 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.

Abstract: The stages of a turbine system are independently controlled to produce a desired system power output by monitoring and comparing the power characteristics of each stage to the desired power output. Flow through each of the stages is adjusted until the desired power output is generated, while any flow that is passing through bypass lines about each of the turbine stages is varied inversely to the variations in the flow through the turbine stages. Non-linearities occurring in the system are offset by appropriate modification of the control of each stage and by comparison of the power output of the system with the power requirements to direct continuing control until the power requirements are met.

Abstract: The closed gas turbine plant is fitted with at least one by-pass valve serving as an adjusting member for the working medium cycle, and uses measuring transformers for measuring the working medium cycle high and low pressures as well as the actual and nominal speeds of the turbine. A regulator has a first regulator part including an integrator, and the difference signal, between the speed nominal value and the speed actual value, is processed in this first regulator part. The regulator has a second regulator part in which signals representative of the working medium cycle high pressure and the working medium cycle low pressure are combined in an adding manner and the output signals of the two regulator parts are supplied to a third regulator part which controls the by-pass valve or valves.

Abstract: An electrohydraulic emergency trip system which automatically shuts off the steam supply to a turbine power plant upon the detection of specific operational contingencies is disclosed. The hydraulic portion of the system includes two pair of combined electrical and hydraulically operated pilot trip valves that are so arranged that the opening of any one valve of each pair decreases the hydraulic trip pressure to close rapidly the steam inlet valves to the turbine; that an open or closed failure of a single trip valve does not prevent a valid trip or cause an unwarranted trip; and finally that an open failure of one pair of the valves does not result in an unwarranted trip. Each pair of valves is electrically operated from an independent voltage source such that the electrical failure of one source does not cause or prevent an unwarranted turbine trip.