Method and system for managing loads on a wind turbine

Patent metadata

Field	Value
Publication number	US-9745958-B2
Application number	US-201414319904-A
Country	US
Kind code	B2
Filing date	Jun 30, 2014
Priority date	Jun 30, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A method and a system for managing loads on a wind turbine are provided. The method includes receiving a signal relative to a yaw misalignment of the wind turbine, generating a yaw error signal based on the yaw misalignment, and comparing the yaw error signal to a first predetermined yaw error threshold value. The method also includes regulating a speed of the rotor to a value determined by a predetermined tip speed ratio, reducing the yaw misalignment using a yaw control system, and restarting the wind turbine if the yaw error signal is reduced to less than a second predetermined yaw error threshold value within a predetermined period of time. The method further includes shutting down the wind turbine if the yaw error signal remains greater than the second predetermined yaw error threshold value beyond the predetermined period of time.

First claim

What is claimed is:

1. A computer-implemented method for managing loads on a wind turbine including a rotor having rotatable blades and coupled to an electrical generator through at least one rotor shaft, the method implemented using one or more processors coupled to one or more memory devices, the method comprising:
operating the wind turbine at a first power output level;
receiving a signal representing a yaw misalignment of the wind turbine, the yaw misalignment defined as an angle between a direction of wind at the wind turbine and a longitudinal axis of the rotor;
generating a yaw error signal based on the yaw misalignment;
comparing the yaw error signal to a first predetermined yaw error threshold value;
operating the wind turbine at a second power outlet level if the yaw error signal is greater than the first predetermined yaw error threshold value by regulating a speed of the rotor to a value determined by an optimal tip speed ratio (TSR) based on a measure of prevailing wind speeds, the TSR defined by dividing a tip speed of the blades by the prevailing wind speed;
reducing the yaw misalignment using a yaw control system if the yaw error signal is greater than the first predetermined yaw error threshold value;
returning the wind turbine to operation at the first power output level if the yaw error signal is reduced to less than a second predetermined yaw error threshold value within a predetermined period of time, the second predetermined yaw error threshold value being less than the first predetermined yaw error threshold value; and
shutting down the wind turbine if the yaw error signal remains greater than the second predetermined yaw error threshold value beyond the predetermined period of time.

2. The method of claim 1 , further comprising regulating the speed of the rotor between an upper setpoint, which is lower than the rated speed of the wind turbine and a lower setpoint, which is higher than the cut-out rotor speed by using one of a counter torque on the rotor, a blade pitch control system, and the yaw control system.

3. The method of claim 2 , wherein regulating the speed of the rotor using a counter torque on the rotor comprises regulating an electrical load on the wind turbine.

4. The method of claim 2 , wherein regulating the speed of the rotor using a counter torque on the rotor comprises ramping a maximum counter torque limit down to a predetermined low value.

5. The method of claim 1 , wherein shutting down the wind turbine further comprises:
ramping down a rotor speed reference; and
completing a closed loop shutdown using coordinated torque-pitch control.

6. The method of claim 1 , wherein shutting down the wind turbine further comprises minimizing yaw misalignment using the yaw control system.

7. The method of claim 1 , wherein returning the wind turbine to operation at the first power output level comprises increasing a speed of the rotor using a rotor speed reference.

8. The method of claim 1 , wherein returning the wind turbine to operation at the first power output level comprises increasing an electrical load of the wind turbine.

9. A load management system configured to manage loads on a wind turbine operating at a first power output level, the wind turbine including a rotor having rotatable blades and coupled to an electrical generator through at least one rotor shaft, said load management system comprising:
a first sensor configured to generate a yaw misalignment signal relative to a yaw misalignment of the wind turbine, the yaw misalignment defined as an angle between a direction of wind at the wind turbine and a longitudinal axis of a rotor of the wind turbine;
a yaw control system configured to adjust a yaw angle of the bladed rotor;
one or more processors communicatively coupled to one or more memory devices, the processor programmed to:
receive the yaw misalignment signal;
generate a yaw error signal based on the yaw misalignment;
compare the yaw error signal to a first predetermined yaw error threshold value;
operate the wind turbine at second power output level if the yaw error signal is greater than the first predetermined yaw error threshold value by regulating a speed of the rotor to a value determined in real-time by an optimal tip speed ratio (TSR) based on a measure of prevailing wind speeds, the TSR defined by dividing a tip speed of the blades by the prevailing wind speed;
reduce the yaw misalignment using a yaw control system if the yaw error signal is greater than the first predetermined yaw error threshold value;
return the wind turbine to the first power output level if the yaw error signal is reduced to less than a second predetermined yaw error threshold value within a predetermined period of time; and
shut down the wind turbine if the yaw error signal remains greater than the second predetermined yaw error threshold value beyond the predetermined period of time.

10. The system of claim 9 , wherein said processor is further programmed to reduce a speed of the rotor to a value determined by a predetermined tip speed ratio (TSR), the TSR defined by dividing a tip speed of the blades by the incoming wind speed.

11. The system of claim 9 , wherein said processor is further programmed to receive an indication of electrical load of the wind turbine.

12. The system of claim 9 , wherein said processor is further programmed to regulate the speed of the rotor by using one of a counter torque on the rotor, a blade pitch control system, and the yaw control system.

13. The system of claim 9 , wherein said processor is further programmed to regulate the speed of the rotor by regulating an electrical load on the wind turbine.

14. The system of claim 9 , wherein said processor is further programmed to ramp a maximum counter torque limit down to a predetermined low value.

15. The system of claim 9 , wherein said processor is further programmed to shut down the wind turbine by:
ramping down a rotor speed reference; and
completing a closed loop shutdown using coordinated torque-pitch control.

16. The system of claim 9 , wherein said processor is further programmed to shut down the wind turbine by minimizing yaw misalignment using the yaw control system.

17. The system of claim 9 , wherein said processor is further programmed to restart the wind turbine by increasing a speed of the rotor using a rotor speed reference.

18. The system of claim 9 , wherein said processor is further programmed to restart the wind turbine by increasing an electrical load of the wind turbine.

19. One or more non-transitory computer-readable storage media having computer-executable instructions embodied thereon, wherein when executed by at least one processor, the computer-executable instructions cause the processor to:
receive a signal relative to a yaw misalignment of a wind turbine rotor during operation of the wind turbine at a first power output level, the yaw misalignment defined as an angle between a direction of wind at the wind turbine and a longitudinal axis of the wind turbine rotor;
generate a yaw error signal based on the yaw misalignment;
compare the yaw error signal to a first predetermined yaw error threshold value;
operate the wind turbine at a second power output level if the yaw error signal is greater than the first predetermined yaw error threshold value by regulating a speed of the rotor to a value determined in real-time by an optimal tip speed ratio (TSR) based on a measure of prevailing wind speeds, the TSR defined by dividing a tip speed of the blades by the prevailing wind

Assignees

• Gen Electric

Inventors

• Agarwal Pranav
• Mehendale Charudatta Subhash
• Holsonback Christopher Ryan

Classifications

• F03D7/0276

  controlling rotor speed, e.g. variable speed · CPC title

• F03D7/044 Primary

  with PID control · CPC title

• F03D7/0264

  for stopping; controlling in emergency situations (orientating out of wind F03D7/0208) · CPC title

• F03D7/0212

  the rotating axis remaining horizontal · CPC title

• Y02E10/723

  Cross-Sectional Technologies · mapped topic