Westinghouse Electric Corporation

Wu-Shi Shung

Eddie Y Hwang

Andras I Szabo

Robert L Osborne

Louis G Ottobre

In a steam turbine control system three overspeed protection circuits (OPC) are provided, each one being identical to the others and each having a programmable digital computer in two-way data communication with a master controller, as well as with the other OPCs. Speed transducers adjacent the turbine shaft provide speed indicative signals to the respective OPCs which calculate extremely precise RPM values utilizing an adaptive filter in the derivation process.

Overspeed protection control arrangement for a steam turbine generator

A sine wave generator which utilizes a PROM for storing a predetermined bit pattern which is converted to a corresponding pulse waveform generated in response to a very accurate and stable clock pulse. The pulse waveform is shifted to a very exacting voltage level and is filtered by a band-pass filter to derive the desired fundamental frequency sine wave. The amplitude and frequency stable sine wave may be utilized in linear variable differential transformer (LVDT) apparatus for measuring the position of a controlled object such as a turbine valve. The arrangement may also be utilized for generating additional sine waves bearing some predetermined phase relationship with respect to one another for other control or signal processing applications.

Stable sine wave generator

A steam turbine control system which includes a manual panel with pushbuttons for operator control of the steam admission valves. Each valve has its own control means and is responsive to pushbutton activation to govern its valve movement. If a pushbutton indicating valve opening or closing gets stuck, the operator pushes a pushbutton indicating opposite movement and the control means switches to a special control mode after a predetermined period of time. In the special mode valve movement stops after removal of the operator's finger pressure and valve movement is accomplished by activation of predetermined pairs of pushbuttons.

Stuck pushbutton contingency operation for a steam turbine control system

Hydraulically operated turbine steam admission valves wherein each valve has its own microcomputer control. In the event the valve gets stuck due to possible contamination in the hydraulic system, the microcomputer control provides an oscillatory control signal to dither the valve. If the valve remains stuck after dithering action it is provided with a control signal of an initial magnitude greater than that normally required to close the valve.

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South Windsor, CT, United States of America

Wu-Shi Shung