Over-rating control of wind turbines and power plants

• US 9,599,096 B2
• Filed: 09/30/2011
• Issued: 03/21/2017
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Spruce, Christopher, Turner, Judith, Evans, Martin, Bowyer, Robert
• Primary Examiner(s): KASENGE, CHARLES R
• Application Number:
  US13/876,430
• Publication Number:
  US 20130257051A1
• Time in Patent Office: 1,999 Days
• US Class Current: 1/1
• CPC Class Codes: F03D 7/028 controlling wind motor output power
• CPC Class Codes: F03D 7/0292 to reduce fatigue
• CPC Class Codes: F03D 7/048 controlling wind farms
• CPC Class Codes: F05B 2270/1033 Power (if explicitly mentioned)
• CPC Class Codes: F05B 2270/332 Maximum loads or fatigue criteria
• CPC Class Codes: H02P 9/008 wherein the generator is controlled by the requirements of the prime mover
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A wind turbine power plant comprises a plurality of wind turbines, each having a rated output and under the control of a power plant controller. The power plant also has a rated output which may be over-rated in response to one or more electricity pricing data, power plant age and operator demand. This may comprise a schedule of output set point changes which effect seasonal or intraday changes in electricity prices or which reflect aging of the power plant. It may also reflect the price of electricity on spot or futures markets. Once the over-rating of the power plant has been set, the output may be increased by over-rating individual turbines or operating turbines at rated power if the sum of the rated outputs of the turbines exceeds or is equal to the new power plant output set point.

Claims

1. A controller for a wind turbine power plant, the wind turbine power plant comprising a plurality of wind turbines, the wind turbine power plant producing an output power and having a rated output power, the controller comprising:

a power plant set point control (PPSC) unit configured to schedule, based on received electricity price data, a plurality of set point values for the output power, wherein at least one scheduled set point value corresponds to an output power value greater than the rated output power;

an optimizer unit configured to determine a plurality of overrating values reflecting an overrating capability of each of the plurality of wind turbines; and

a power plant control (PPC) unit coupled with the PPSC unit and the optimizer unit, wherein the PPC unit is configured to;

select, based on the plurality of overrating values, one or more wind turbines of the plurality of wind turbines for overrating; and

communicate, based on the output power value and the plurality of overrating values, an amount of overrating to each of the selected one or more wind turbines,

wherein each wind turbine of the selected one or more wind turbines processes the communicated amount of overrating through a corresponding response function to produce a respective processed overrating amount, the response function having a slope value or an offset value based on a determined fatigue amount of the wind turbine, and

wherein each wind turbine changes an amount of power production by the respective processed overrating amount.

2. The controller according to claim 1, wherein the plurality of scheduled set point values includes at least one set point value reflecting seasonal changes or intraday changes in the electricity price data.

3. The controller according to claim 1, wherein the plurality of scheduled set point values includes at least one set point value reflecting the age of the power plant.

4. The controller according to claim 3, wherein the plurality of scheduled set point values comprises a respective set point value for each month of a lifetime of the power plant.

5. The controller according to claim 1, wherein the PPSC unit is further configured to receive real-time electricity price data for a spot market corresponding to the power plant, or to receive forward electricity price data corresponding to a defined future time.

6. The controller according to claim 5, wherein the PPC unit is further configured to increase, upon determining the real-time electricity price data exceeds a predetermined threshold value, the output power to greater than the rated output power.

7. The controller according to claim 5, wherein the PPC unit increases the output power by an amount proportional to the real-time electricity price data.

8. The controller according to claim 1, wherein communicating the amount of overrating to each of the selected one or more wind turbines comprises transmitting a common over-rating signal to the selected one or more wind turbines.

9. The controller according to claim 1, wherein selecting the one or more wind turbines is further based on at least one of a determined rate of fatigue damage to individual wind turbines of the plurality of wind turbines and a determined accumulated amount of fatigue damage to individual wind turbines of the plurality of wind turbines.

10. The controller according to claim 9, wherein the fatigue damage to an individual wind turbine is determined for one or more critical turbine components of the individual wind turbine with respect to at least one of rotational speed and torque.

11. A method of controlling an output power of a wind power plant, the wind power plant comprising a plurality of wind turbines and a control arrangement, the wind power plant producing an output power and having a rated output power, the method comprising:

scheduling, based on received electricity price data, one or more set point values for the output power including at least one set point value corresponding to an output power value greater than the rated output power;

determining a plurality of overrating values reflecting an overrating capability of each of the plurality of wind turbines;

selecting, based on the plurality of overrating values, one or more wind turbines of the plurality of wind turbines for overrating; and

communicating, based on the output power value and the plurality of overrating values, an amount of overrating to each of the selected one or more wind turbines,

wherein each wind turbine of the selected one or more wind turbines processes the communicated amount of overrating through a corresponding response function to produce a respective processed overrating amount, the response function having a slope value or an offset value based on a determined fatigue amount of the wind turbine, and

wherein each wind turbine changes an amount of power production by the respective processed overrating amount.

12. The method according to claim 11, wherein the one or more scheduled set point values includes at least one set point value reflecting seasonal changes in the electricity price data.

13. The method according to claim 11, wherein the one or more scheduled set point values include at least one set point value reflecting the age of the power plant.

14. The method according to claim 13, wherein the plurality of scheduled set point values comprises a respective set point value for each month of a lifetime of the power plant.

15. The method according to claim 11, further comprising receiving, as an input to the control arrangement, real-time electricity price data for a spot market corresponding to the power plant or receiving electricity price data corresponding to a futures marker.

16. The method according to claim 15, further comprising:

increasing, upon determining the real-time electricity price data exceeds a predetermined threshold value, the output power to greater than the rated output power.

17. The method according to claim 15, further comprising increasing the output power of the power plant in proportion to the real-time electricity price data to an amount greater than the rated output power.

18. The method according to claim 11, wherein communicating an amount of overrating to each of the selected one or more wind turbines comprises transmitting, via the control arrangement, a common over-rating signal to the selected one or more wind turbines.

19. The method according to claim 11, wherein selecting the one or more wind turbines is further based on at least one of a determined rate of fatigue damage to individual wind turbines of the plurality of wind turbines and a determined accumulated amount of fatigue damage to individual wind turbines of the plurality of wind turbines.

20. The method according to claim 19, wherein the fatigue damage to an individual wind turbine is determined for one or more critical turbine components of the individual wind turbine with respect to at least one of rotational speed and torque.

21. The method according to claim 19, wherein at least one of the selected one or more wind turbines is operated with an overrating level less than an overrating level requested by the control arrangement, based on at least one of the determined rate of fatigue damage and the determined accumulated fatigue damage of the at least one wind turbine.

22. The method according to claim 21, further comprising:

updating an amplifier gain value of the controller arrangement based on the at least one of the at least one of the determined rate of fatigue damage and the determined accumulated fatigue damage of the at least one wind turbine.

23. The method of claim 11, wherein the response function is based on the determined fatigue amount of the wind turbine relative to an expected fatigue amount.

24. A method of controlling an output power of a wind power plant, the power plant comprising a plurality of wind turbines and a control arrangement and having a rated output power, the method comprising:

scheduling, based on received electricity price data, one or more set point values for the output power including at least one set point value corresponding to an output power value greater than the rated output power;

communicating, based on the output power value, an amount of overrating to each of a selected one or more of the plurality of wind, wherein the selected one or more wind turbines are selected based on at least one of a determined rate of fatigue damage to individual wind turbines of the plurality of wind turbines and a determined accumulated amount of fatigue damage to individual wind turbines of the plurality of wind turbines, wherein at least one of the selected one or more wind turbines is operated with an overrating level less than an overrating level requested by the control arrangement, based on at least one of the determined rate of fatigue damage and the determined accumulated fatigue damage of the at least one wind turbine; and

updating an amplifier gain value of the controller arrangement based on the at least one of the at least one of the determined rate of fatigue damage and the determined accumulated fatigue damage of the at least one wind turbine.