Westinghouse Electric Corporation

Terry J Reed

Jack R Smith

Robert A Yannone

Roy W Kiscaden

A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. In the automatic and manual modes of operation, the control system develops a fuel reference signal for the throttle valve position control by means of a speed/load control which functions on a feedforward speed control basis without speed feedback correction. An electrical overspeed protection control is directly coupled to the throttle valve position control to limit turbine speed to a first reference value when the breaker is closed and to limit turbine speed to a lower reference value when the breaker is open. Electrical and mechanical overspeed protection systems directly trip the turbine at higher speed references.

Combined cycle electric power plant and a gas turbine having an improved

A hybrid digital computer gas turbine power plant control system which may operate in a multiple control loop arrangement is provided with selected process variable monitoring and control and turbine system failure detection means. More specifically, open, shorted, grounded and reversed thermocouples are detected and alarmed. Problems of any one combustor in a multiple combustor arrangement are similarly detected and alarmed. Additionally, automatic correction of previously computed temperature related control inputs is provided in response to detected variations from a predetermined temperature reasonability criterion. Novel placement and orientation of system thermocouples facilitates achieving improved monitoring, detection and control.

System and method for monitoring and controlling operation of industrial

A hybrid digital computer gas turbine power plant control system which may operate in a multiple-control loop arrangement is provided with selected process variable monitoring means. Control system inputs representative of current values of such variables are continuously available to provide positive highly responsive control over a broad range of gas turbine operating conditions. Predictable process sensor errors are effectively eliminated by means of programmed computer operations to thereby insure highly accurate control variable derivation essential to maintaining gas turbine operation at or near design limits.

System and method for monitoring industrial gas turbine operating

A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. A gas turbine megawatt load control system is included in the control and it includes a feedforward load control which generates a fuel reference equal to the sum of a megawatt load demand and an idle speed fuel demand. The megawatt load control also includes a feedback load trimmer which provides minor corrective action on the operation of the feedforward load control. Gas turbine and combined cycle plant operation results in the generation of megawatts equal to an input demand value.

Combined cycle electric power plant and a gas turbine having improved

A digital computer system provides automatic control for a steam turbine and two gas turbines in a combined cycle electric power plant during startup and load modes of operation. The gas turbine automatic control system provides speed, load and blade path temperature control functions in developing an output fuel control signal for application to each gas turbine fuel valve control. An analog control for each gas turbine selectively provides startup and temperature and load control functions as a backup for the automatic gas turbine control, and further provides gas turbine overspeed, surge and other limit controls continuously. An operator panel functions with the analog and digital controls to provide an operator interface with the plant, and an interface circuit ties the digital and analog controls together for bumpless transfer between manual and automatic modes of operation. A sequencer is provided for each gas turbine and it provides gas turbine startup sequence control, gas turbine trip protection and other functions in both the automatic and the backup modes of operation. A gas turbine monitor develops temperature and vibration signals for the sequencer and the fuel controls.

Combined cycle electric power plant having an improved digital/analog

A gas turbine power plant is provided with an industrial gas turbine which drives a rotating brushless exciter generator coupled to a power system through a breaker. One or more of the turbine-generator plants are operated by a hybrid digital computer control system during sequenced startup, synchronizing, load and shutdown operations. The program system for the computer and external analog circuitry operate in a multiple gas turbine control loop arrangement. Automatic synchronization is achieved with a hybrid subsystem which includes the programmed computer and external phase detection circuitry. An automatic synchronization program for the computer is divided into rough speed and voltage matching, fine speed matching and breaker closure subprograms.

System and method employing a digital computer with improved programmed

A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. A backup control is included for each of the gas turbines with an outlet or preferably blade path temperature limit control which prevents the operator from causing the turbine to operate above a temperature limit reference. The temperature limit control further restricts the rate at which the operator can move the gas turbine operating or load level toward the temperature limit value. When the turbine is operating at a load below the temperature limit value, the operator can freely move the fuel reference until the blade path temperature approaches the temperature limit value.

A combined cycle electric power generating plant, which includes gas and steam turbines, inlet guide vane positioning means for the gas turbines, steam generators, afterburners and a digital/analog control system, is provided with inlet guide vane control apparatus adapted to modulate the position of the inlet guide vanes as a function of load or inlet blade path temperature. The inlet guide vane control apparatus is further adapted to operate in either an automatic or manual mode with additional provision for bumpless transfer therebetween incorporated in the control apparatus.

Control apparatus for modulating the inlet guide vanes of a gas turbine

A combined cycle electric power plant includes gas and steam turbines and steam generators and a digital/analog control system. The control system includes an automatic control and a backup control which are interfaced to operate the gas turbine throttle valve for speed and load control purposes and to provide for manual/auto transfers. The backup control includes a startup control which functions on the basis of a feedforward fuel schedule ramp function. Between ignition speed and 78% synchronous speed, the ramp function is a linear function of fuel demand versus speed with a predetermined slope. From 78% of synchronous speed to idle speed, the ramp function is a linear function with a lesser slope.

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North Huntingdon, PA, United States of America

Terry J Reed