Rotor resonance disturbance rejection controller

Patent metadata

Field	Value
Publication number	US-2016348533-A1
Application number	US-201615170024-A
Country	US
Kind code	A1
Filing date	Jun 1, 2016
Priority date	Nov 2, 2012
Publication date	Dec 1, 2016
Grant date	—

Abstract

A speed control system for an engine comprising at least one rotary load is provided. The speed control system may include a rotor speed controller configured to regulate speed in the rotary load based on a sensed rotor speed, exclusive of resonant mode speed oscillations, in closed loop feedback with a commanded rotor speed. To provide active damping of resonant mode speed oscillations, a resonance disturbance rejection controller may be configured to compensate a speed control signal by observing a component of the sensed rotor speed that is due to resonant mode oscillations. Based on the observed resonance component, the resonance disturbance rejection controller may compute an adjustment value for the speed control signal. In the particular case of gas turbine engines, the resonance disturbance rejection controller may effect active damping by compensation of a fuel flow request for a gas generator.

First claim

1 . A speed control system for an engine comprising at least one rotary load, the speed control system comprising:
a rotor speed controller configured to generate a speed control signal based on a rotor speed signal so as to regulate speed in the rotary load, wherein the rotor speed signal is representative of a sensed speed in the rotary load; and a resonance disturbance rejection controller configured to generate a resonance compensation signal based on a resonance component of the rotor speed signal, wherein the resonance component is representative of speed oscillations in the rotary load caused by development of a resonance condition wherein the resonance disturbance rejection controller comprises:
an acceleration estimator configured to estimate an acceleration component associated with the speed oscillations based on the resonance component of the rotor speed signal, wherein the acceleration estimator comprises a state observer configured to observe the resonance component of the rotor speed signal, and to estimate the acceleration component based on the observed resonance component and a state model of the speed oscillations; and
a speed control compensator configured to generate the resonance compensation signal so as to provide an adjustment value for the speed control signal determined based on the estimated acceleration component; and
a summing junction to adjust the speed control signal based on the resonance compensation signal so as to effect active damping of the speed oscillations.

2 .- 3 . (canceled)

4 . The speed control system of claim 1 , wherein the state model comprises a second order oscillator.

5 . The speed control system of claim 1 , wherein the speed control compensator comprises a gain multiplier configured to calculate the adjustment value by applying a gain factor to the estimated acceleration component.

6 . The speed control system of claim 1 , further comprising a signal separator configured to filter the rotor speed signal into the resonant component and an average speed component that is representative of an average speed in the rotary load determined exclusive of the speed oscillations, and wherein the rotor speed controller is configured to generate the speed control signal based on the average speed component.

7 . The speed control system of claim 1 , wherein the engine comprises a gas generator coupled to at least one turbine for driving the rotary load, and the speed control signal determined by the rotor speed controller is configured to regulate speed in the turbine-driven rotary load by controlling fuel flow to the gas generator.

8 . A method of controlling speed in an engine comprising at least one rotary load, the method comprising:
regulating speed in the rotary load based on a sensed speed of the rotary load; determining a resonance component of the sensed speed that is representative of speed oscillations in the rotary load caused by development of a resonance condition; and adjusting the regulated speed based on the determined resonance component so as to effect active damping of the speed oscillations i estimating an acceleration component associated with the speed oscillations based on the resonance component of the sensed speed; determining an adjustment value for the regulated speed based on the estimated acceleration component; observing the resonance component of the sensed speed; and estimating the acceleration component based on the observed resonance component and a state model of the speed oscillations.

9 .- 10 . (canceled)

11 . The method of claim 8 , wherein the rotor speed oscillations are modeled as a second order oscillator.

12 . The method of claim 8 , further comprising calculating the adjustment value by applying a gain factor to the estimated acceleration component.

13 . The method of claim 8 , further comprising filtering the sensed speed into the resonant component and an average speed component that is representative of an average speed in the rotary load determined exclusive of the speed oscillations, and regulating speed in the rotary load based on the average speed component.

14 . The method of claim 8 , wherein the engine comprises a gas generator coupled to at least one turbine for driving the rotary load, and speed in the turbine-driven rotary load is regulated by controlling fuel flow to the gas generator.

15 . A resonance disturbance rejection controller for an engine comprising at least one rotary load the speed of which is regulated using a speed control signal, the resonance disturbance rejection controller implemented by at least one processor configured to generate a resonance compensation signal based on a resonance component of a rotor speed signal, wherein the rotor speed signal is representative of a sensed speed of the rotary load, and the resonance component is representative of speed oscillations in the rotary load caused by development of a resonance condition, and the processor further configured to adjust the speed control signal based on the resonance compensation signal so as to effect active damping of the speed oscillations;
wherein the resonance disturbance resection controller comprises:
an acceleration estimator configured to estimate an acceleration component associated with the speed oscillations based on the resonance component of the rotor speed signal; and
a speed control compensator configured to generate the resonance compensation signal so as to provide an adjustment value for the speed control signal determined based on the estimated acceleration component; and
wherein the acceleration estimator comprises a state observer configured to observe the resonance component of the rotor speed signal, and to estimate the acceleration component based on the observed resonance component and a state model of the speed oscillations.

16 .- 17 . (canceled)

18 . The resonance disturbance rejection controller of claim 15 , wherein the state model comprises a second order oscillator.

19 . The resonance disturbance rejection controller of claim 15 , wherein the speed control compensator comprises a gain multiplier configured to calculate the adjustment value by applying a gain factor to the estimated acceleration component.

20 . The resonance disturbance rejection controller of claim 15 , wherein the engine comprises a gas generator coupled to at least one turbine for driving the rotary load, and the speed control signal adjusted by the resonance compensation signal is configured to regulate speed in the rotary load by controlling fuel flow to the gas generator.

Assignees

• Pratt & Whitney Canada

Inventors

• Ficklscherer Peter

Classifications

• F01D25/04 Primary

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• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F05D2220/329

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• F05D2240/35

  Combustors or associated equipment · CPC title

• F05D2270/304

  Spool rotational speed · CPC title