Abb Schweiz Ag

Abb Automation Gmbh

Abb Technology Ag

Abb Inc.

Kevin Dowdell

Steve Miller

Camilo Lopez

Mark Foltz

Mark Wieland

Alan Majors

Anthony M DiTommaso

Xudong Yang

Ljubisa Milojevic

Anthony M Di Tommaso

Michael J Kleya

William J Kline

Mark Stephen Wieland

Steve Lee Miller

A system for controlling a turbine valve is provided. The system includes a hydraulic pilot valve section being moveable in a first direction and a second direction; a main hydraulic valve section being moveable in a first direction to close the turbine valve and a second direction to open the turbine valve; a position demand indicating a desired position of the turbine valve; a first feedback indicating an actual position of the hydraulic pilot valve section; and aa second feedback indicating an actual position of the main hydraulic valve section. The system also includes a pilot valve error; a main valve error; a turbine valve error; and a pilot valve adjustment moving the hydraulic pilot valve section in response to the turbine valve error. The turbine valve error is repeatedly determined and the pilot valve adjustment repeatedly moves the hydraulic pilot valve section to minimize the turbine valve error.

Valve position control

A control system is provided for a turbine valve. The turbine valve has a first coil and a second coil to control or sense movement of a mechanical valve positioner. Two valve positioners are provided with each valve positioner having two drive circuits to drive the first and second coils. Switches are provided such that only one drive circuit is connected to each coil at a time. The control system may also include a hydraulic pilot valve section and a main hydraulic valve section. Feedbacks are used to determine a pilot valve error and a main valve error which are combined to determine a turbine valve error. The turbine valve error is repeatedly determined to minimize the error.

A turbine speed probe diagnostic system is provided. The turbine includes a speed probe and a speed reading circuit. A speed lead connects the speed probe and speed reading circuit together to transmit speed signals from the speed probe to the speed reading circuit. A speed probe diagnostic circuit is also provided for connection to the speed lead. An isolation switch is provided to isolate the speed probe diagnostic circuit during normal operation when the speed reading circuit is receiving speed signals from the speed probe. When no speed signals are being received, the isolation switch closes and the speed probe diagnostic circuit performs a test on the speed probe or speed lead.

Turbine diagnostics

A speed control system and a power load balance detector for a turbine is provided. The speed control system includes a speed wheel with a plurality of teeth. A timer stores a time stamp when each of the teeth passes by a speed probe. A first speed estimate is determined for overspeed protection, and a second speed estimate is determined for operational speed control. The power load balance detector trips or shuts down the turbine when an unbalance is above a first threshold and the speed of the turbine is above a second threshold.

Turbine speed detection and use

A breaker between two electrical circuits is provided that is closed when electrical properties in both of the electrical circuits are matching. Two check circuits are provided for comparing electrical properties of the two electrical circuits. Each of the check circuits sets a corresponding authorization to close the breaker. The breaker is only closed if both check circuits set an authorization to close the circuit.

Breaker auto-synchronizer

A method is disclosed for monitoring the vibration of a rotating shaft including, measuring a current shaft position and determining a centroid of the shaft. The current shaft sector is then determined. The current distance between the centroid and the current shaft position may then be determined. The current distance is compared with a previously stored maximum distance for that sector, and if greater, the current shaft position and current distance is stored as the new maximum for that sector. After a predetermined period of time, the maximum displacement between the stored maximum positions is calculated, which represents the maximum shaft displacement peak to peak. This value may then be visually displayed or automatically monitored by shaft control computers.

Method and apparatus for calculating the maximum displacement of a rotating shaft

A sampled data system for computing the amplitude of a signal received from a vibration sensing probe minus the fundamental frequency associated with the running speed of a rotating machinery shaft. This signal is known as the Not 1X waveform and variations in its amplitude can signal problems with bearings, rotors, cracks or mechanical looseness, and/or fluids of the rotating machine. The amplitude of the Not 1X waveform can be provided in either peak to peak amplitude, peak amplitude, absolute average or root mean square.

Method and apparatus for calculating the amplitude of a complex waveform associated with a rotating machine shaft after removing the running speed frequency

A method and apparatus for analyzing and signal conditioning the pulsation signal derived from combustion of fuel in a turbine. There are one or more user defined frequency bands and the method and apparatus provides a digital signal for the true RMS value of each of the user defined bands. Turbine protection logic has as its input the digital true RMS values for each such band and inspects that value to determine if the frequencies in that band exceed a predetermined level for a predetermined period of time.

Method and apparatus for digital analysis and signal conditioning in a turbine generator silo combustor

An event marker is generated from the periodic input voltage received from the notch in a shaft of a rotating machine. Positive and negative peak voltages each attenuated by &frac12; are detected from the periodic input voltage. The attenuated detected positive and negative peak voltages are combined to provide a bias voltage which is subtracted from the periodic input voltage to give an output voltage representative of the event marker.

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Pittsburgh, PA, United States of America

Kevin Dowdell