METHODS AND APPARATUS FOR BALANCING A ROTOR

• US 20070294049A1
• Filed: 06/19/2006
• Published: 12/20/2007
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Slack, Robert, Pierce, Kirk
• Granted Patent: US 7,437,264 B2
• Time in Patent Office: Days
• US Class Current: 702/151
• CPC Class Codes: F03D 13/35 Balancing static or dynamic imbalances
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F03D 7/024 of individual blades
• CPC Class Codes: F03D 7/0296 to prevent, counteract or reduce noise emissions
• CPC Class Codes: F03D 7/042 by means of an electrical or electronic controller
• CPC Class Codes: F05B 2270/1095 by limiting mechanical stresses
• CPC Class Codes: F05B 2270/331 Mechanical loads
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A method for balancing a rotor of a rotary machine, wherein the rotor includes at least two rotor blades and a rotor shaft, includes receiving at least one measurement of either a load, an acceleration, or a displacement that pertains to at least one bending moment acting on the rotor shaft, determining at least one value of the at least one bending moment acting on the rotor shaft based, at least in part, on the received at least one measurement, and determining a pitch offset angle value of at least one rotor blade that facilitates reducing the at least one bending moment acting on the rotor shaft.

Claims

1. A method for balancing a rotor of a rotary machine, wherein the rotor includes at least two rotor airfoil blades and a rotor shaft, said method comprising:

receiving at least one measurement of at least one of a load, an acceleration, and a displacement that pertains to at least one bending moment acting on the rotor shaft;

determining at least one value of the at least one bending moment acting on the rotor shaft based, at least in part, on the received at least one measurement;

determining a pitch offset angle value of at least one rotor airfoil blade that facilitates reducing the at least one bending moment acting on the rotor shaft; and

changing a pitch angle of the at least one rotor airfoil blade using the pitch offset angle value.

2. A method in accordance with claim 1 wherein determining a pitch offset angle value of at least one rotor airfoil blade comprises determining a pitch offset angle value that facilitates changing the at least one bending moment acting on the rotor shaft to about zero.

3. A method in accordance with claim 1 wherein receiving at least one measurement of either a load, an acceleration, or a displacement that pertains to at least one bending moment acting on the rotor shaft comprises receiving at least one measurement of either a load, an acceleration, or a displacement within a non-rotating component of the rotary machine.

4. A method in accordance with claim 1 wherein receiving at least one measurement of either a load, an acceleration, or a displacement that pertains to at least one bending moment acting on the rotor shaft comprises receiving at least one measurement of either a load, an acceleration, and a displacement within at least one of the rotor shaft, at least one rotor airfoil blade, and a housing of a bearing coupled to the rotor shaft.

5. A method in accordance with claim 1 wherein receiving at least one measurement of either a load, an acceleration, or a displacement that pertains to at least one bending moment acting on the rotor shaft comprises receiving a plurality of measurements, and wherein determining at least one value of the at least one bending moment acting on the rotor shaft based, at least in part, on the received at least one measurement comprises filtering out one of the plurality of received measurements.

6. A method in accordance with claim 5 wherein filtering out one of the plurality of received measurements comprises reducing an effect of a variation in a surface of the rotor shaft on the at least one determined value of the at least one bending moment acting on the rotor shaft.

7. A method in accordance with claim 1 further comprising mapping a surface of the rotor shaft as a function of azimuth at least one of at least one predetermined wind speed and at least one predetermined rotational speed of the rotor shaft.

8. A method in accordance with claim 7 wherein determining at least one value of the at least one bending moment acting on the rotor shaft comprises determining the at least one bending moment value based, at least in part, on the received at least one measurement, the surface map of the rotor shaft, and an azimuthal position of the rotor shaft at a time the received at least one measurement was taken.

9. A method in accordance with claim 1 wherein determining at least one value of the at least one bending moment acting on the rotor shaft comprises determining the at least one bending moment value based, at least in part, on the received at least one measurement and an azimuthal position of the rotor shaft at a time the received at least one measurement was taken.

10. A method in accordance with claim 1 wherein determining at least one value of the at least one bending moment acting on the rotor shaft based, at least in part, on the received at least one measurement comprises determining a mean value of at least one bending moment acting on the rotor shaft over a predetermined amount of time.

11. A method in accordance with claim 10 wherein determining a pitch offset angle value of at least one rotor airfoil blade comprises determining a pitch offset angle value that facilitates changing a mean value of the at least one bending moment acting on the rotor shaft to about zero based on the determined mean value of the at least one bending moment acting on the rotor shaft.

12. A method in accordance with claim 1 wherein determining a pitch offset angle value for at least one rotor airfoil blade comprises determining a pitch offset angle value for each of the at least two rotor airfoil blades.

13. A method in accordance with claim 1 further comprising changing a pitch angle of at least one rotor airfoil blade based on the determined pitch offset angle value of at least one rotor airfoil blade to facilitate changing the at least one bending moment acting on the rotor shaft to about zero.

14. A rotary machine comprising:

a rotor comprising a hub, at least two rotor airfoil blades coupled to said hub, and a rotor shaft coupled to said hub for rotation therewith;

at least one blade pitch actuator coupled to said at least two rotor airfoil blades for controlling an angle of pitch of said at least two rotor airfoil blades;

at least one sensor configured to measure at least one of a load, an acceleration, and a displacement that pertains to at least one bending moment acting on said rotor shaft; and

a processor coupled to said at least one blade pitch actuator and coupled to said at least one sensor, said processor configured to balance said rotor by;

receiving, from said at least one sensor, at least one measurement of at least one of a load, an acceleration, and a displacement that pertains to at least one bending moment acting on said rotor shaft;

determining at least one value of the at least one bending moment acting on said rotor shaft based, at least in part, on the received at least one measurement;

determining a pitch offset angle value for at least one rotor airfoil blade that facilitates reducing the at least one bending moment acting on said rotor shaft; and

changing a pitch angle of the at least one rotor airfoil blade using the pitch offset angle value.

15. A rotary machine in accordance with claim 14 wherein said processor is configured to determine a pitch offset angle value for at least one rotor airfoil blade that facilitates changing the at least one bending moment acting on said rotor shaft to about zero.

16. A rotary machine in accordance with claim 14 further comprising at least one non-rotating component, and wherein said processor is configured to receive, from said at least one sensor, at least one measurement of either a load, an acceleration, or a displacement within said at least one non-rotating component.

17. A rotary machine in accordance with claim 14 wherein said processor is configured to receive, from said at least one sensor, at least one measurement of either a load, an acceleration, or a displacement within at least one of said rotor shaft, at least one rotor airfoil blade, and a housing of a bearing coupled to said rotor shaft.

18. A rotary machine in accordance with claim 14 wherein said processor is configured to receive a plurality of measurements of either a load, an acceleration, or a displacement that pertains to at least one bending moment acting on said rotor shaft, and wherein said processor is configured to filter out one of the plurality of received measurements.

19. A rotary machine in accordance with claim 18 wherein said processor is configured to reduce an effect of a variation in a surface of said rotor shaft on the determined value of the at least one bending moment acting on said rotor shaft by filtering out one of the plurality of received measurements.

20. A rotary machine in accordance with claim 14 wherein said processor is configured to map a surface of said rotor shaft as a function of azimuth at at least one of at least one predetermined wind speed and at least one predetermined rotational speed of said rotor shaft.

21. A rotary machine in accordance with claim 20 wherein said processor is configured to determine the at least one bending moment value based, at least in part, on the received at least one measurement and the surface map of said rotor shaft.

22. A rotary machine in accordance with claim 14 wherein said processor is configured to determine the at least one bending moment value based, at least in part, on the received at least one measurement and an azimuthal position of the rotor shaft at a time the received at least one measurement was taken.

23. A rotary machine in accordance with claim 14 wherein said processor is configured to determine a mean value of at least one bending moment acting on said rotor shaft over a predetermined amount of time.

24. A rotary machine in accordance with claim 23 wherein said processor is configured to determine a pitch offset angle value that facilitates changing a mean value of the at least one bending moment acting on said rotor shaft to about zero based on the determined mean value of the at least one bending moment acting on said rotor shaft.

25. A rotary machine in accordance with claim 14 wherein said processor is configured to determine a pitch offset angle value for each of said at least two rotor airfoil blades.