SYSTEM AND METHOD FOR PREVENTING ROTOR BLADE TOWER STRIKE

• US 20150147172A1
• Filed: 11/22/2013
• Published: 05/28/2015
• Est. Priority Date: 11/22/2013
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Chacon, Joseph Lawrence
• Granted Patent: US 9,765,757 B2
• Time in Patent Office: Days
• US Class Current: 416/1
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F03D 7/0244 for braking
• CPC Class Codes: F03D 7/0264 for stopping; controlling in emergency situations orientating out of wind F03D7/0208
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A system and method for preventing a rotor blade from striking a tower of the wind turbine is disclosed. The system includes a pitch adjustment mechanism, at least one electrical switch, and a mechanically-actuated positional switch. The pitch adjustment mechanism is configured to rotate the rotor blade about a pitch axis. Further, the pitch adjustment mechanism includes a motor and a brake. The electrical switch is configured with the motor, the brake, or both. The mechanically-actuated positional switch is fixed within a hub of the wind turbine. Further, the positional switch is configured with the electrical switch such that if the rotor blade rotates to an unsafe region, the positional switch is configured to trigger the electrical switch to implement one of tripping power to the motor of the pitch adjustment mechanism or actuating the brake of the pitch adjustment mechanism.

Claims

1. A system for preventing a rotor blade from striking a tower of the wind turbine, the system comprising:

a pitch adjustment mechanism configured to rotate the rotor blade about a pitch axis, the pitch adjustment mechanism comprising a motor and a brake; and

,

at least one electrical switch configured with one of the motor or the brake;

a mechanically-actuated positional switch fixed within a hub of the wind turbine, the positional switch configured with the electrical switch such that if the rotor blade rotates to an unsafe region, the positional switch is configured to trigger the electrical switch to implement one of tripping power to the motor of the pitch adjustment mechanism or actuating the brake of the pitch adjustment mechanism.

2. The system of claim 1, further comprising a first striker plate and a second striker plate, wherein the first and second striker plates define limits of the unsafe region for the rotor blade, and wherein the first and second striker plates rotate with the rotor blade.

3. The system of claim 2, wherein the positional switch is configured between the first striker plate and the second striker plate, and wherein, if the positional switch contacts one of the striker plates as the rotor blade rotates about the pitch axis, the positional switch is configured to trigger the electrical switch to implement one of tripping power to the motor or actuating the brake.

4. The system of claim 2, wherein the first and second striker plates are spaced 180 degrees apart from one another so as to define the unsafe region for the rotor blade.

5. The system of claim 1, wherein the mechanically-actuated positional switch comprises a limit switch.

6. The system of claim 1, further comprising an additional electrical switch, wherein one of the electrical switches is configured with the motor of the pitch adjustment mechanism and the other electrical switch is configured with the brake of the pitch adjustment mechanism.

7. The system of claim 6, wherein the electrical switches comprise contactors, wherein when the positional switch enters the unsafe region, one of the contactors is configured to open so as to trip power to the motor of the pitch adjustment mechanism and the other contactor is configured to open so as to actuate the brake of the pitch adjustment mechanism.

8. The system of claim 7, further comprising a safety controller configured with the positional switch and the contactors, wherein the safety controller comprises a relay.

9. The system of claim 8, further comprising a reset switch configured with the safety controller.

10. The system of claim 8, further comprising a bypass switch configured with the safety controller.

11. A rotor blade assembly for a wind turbine, the rotor blade assembly configured to prevent a rotor blade from striking a tower of the wind turbine, the assembly comprising:

a rotor blade extending from a blade root to a blade tip, the rotor blade comprising a pressure side surface and a suction side surface, the pressure side surface and the suction side surface each extending between a leading edge and a trailing edge;

a pitch bearing configured between the rotor blade and a hub of the wind turbine, the pitch bearing configured to rotate the rotor blade about a pitch axis;

a pitch adjustment mechanism configured to rotate the pitch bearing about the pitch axis, the pitch adjustment mechanism comprising a motor and a brake;

at least one electrical switch configured with one of the motor or the brake;

a mechanically-actuated positional switch fixed within a hub of the wind turbine, the positional switch configured with the electrical switch such that if the rotor blade rotates to an unsafe region, the positional switch is configured to trigger the electrical switch to implement one of tripping power to the motor of the pitch adjustment mechanism or actuating the brake of the pitch adjustment mechanism.

12. A method for preventing a rotor blade from striking a tower of the wind turbine, the method comprising:

determining an unsafe region for the rotor blade, the unsafe region defined by at least two different pitch angles of the rotor blade;

monitoring, via a mechanically-actuated positional switch, a pitch angle of the rotor blade to determine if the rotor blade enters the unsafe region; and

,

implementing, via an electrical switch, one of tripping power to a motor of a pitch adjustment mechanism or actuating a brake of the pitch adjustment mechanism if the positional switch determines that the pitch angle is in the unsafe region.

13. The method of claim 12, wherein the unsafe region is defined by a first striker plate and a second striker plate located on a blade root of the rotor blade, wherein the first and second striker plates rotate with the rotor blade.

15. The method of claim 13, wherein the positional switch is configured to contact one of the first and second striker plates if the rotor blade enters the unsafe region.

16. The method of claim 12, further comprising at least two electrical switches, wherein the electrical switches comprise contactors, wherein when the positional switch enters the unsafe region, one of the contactors is configured to open so as to trip power to the motor of the pitch adjustment mechanism and the other contactor is configured to actuate the brake of the pitch adjustment mechanism.

17. The method of claim 16, further comprising utilizing a safety controller configured with the positional switch and the contactors, wherein the safety controller comprises a relay.

18. The method of claim 12, wherein the mechanically-actuated positional switch comprises a limit switch.

19. The method of claim 17, further comprising a bypass switch configured with the safety controller.

20. The method of claim 17, further comprising resetting the positional switch via a reset switch, wherein the reset switch is configured with the safety controller.

14. The method of claim 14, wherein the first and second striker plates are spaced 180 degrees apart from one another so as to define the unsafe region for the rotor blade.