OVER-RATING CONTROL OF WIND TURBINES AND POWER PLANTS

• US 20130257051A1
• Filed: 09/30/2011
• Published: 10/03/2013
• 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, Evans, Martin, Bowyer, Robert, Turner, Judith
• Granted Patent: US 9,599,096 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• 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 power plant comprising a plurality of wind turbines and having a rated output power, the controller comprising a unit for varying the output of the power plant above the rated output in response to at least one of electricity pricing data, power plant age and power plant operator demand.

2. A controller according to claim 1, wherein the controller comprises a store of scheduled changes in the power plant output set point.

3. A controller according to claim 2, wherein the store of scheduled changes in the power plant output set point represents seasonal changes in electricity prices.

4. A controller according to claim 2, wherein the store of scheduled changes in the power plant output set point represents intraday changes in electricity prices.

5. A controller according to claim 2, wherein the store of scheduled changes in the power plant output set point represent the age of the power plant.

6. A controller according to claim 5, wherein the store of scheduled changes in the power point output set point comprises an output set point for each month of the lifetime of the power plant.

7. A controller according to claim 1 wherein the controller receives as an input, a real-time price of electricity on a spot market.

8. A controller according to claim 1 wherein the controller receives as an input, a forward electricity price indicating the price of electricity at a defined future time.

9. A controller according to claim 7, wherein the controller compares the received price with a pre-stored threshold value and, if the received price exceeds the threshold value, the controller varies the output of the power plant above its rated output.

10. A controller according to claim 7 wherein the controller varies the output of the power plant above its rated output by an amount proportional to the received price.

11. A controller according to claim 1, wherein the controller sends an over-rating signal to individual turbines to enable the output of the power plant to reach the over-rated power plant value.

12. A controller according to claim 1, wherein the varying of the output of the power plant above rated power is dependent on fatigue damage and/or fatigue damage rates of individual turbines comprising the power plant.

13. A controller according to claim 12, wherein the fatigue is the fatigue of critical turbine components with respect to rotational speed and/or torque.

14. A method of controlling the output of a wind power plant, the plant comprising a plurality of wind turbines and having a rated output power and a power plant controller, the method comprising varying the output of the power park by the controller above the rated output of the power park in response to at least one of electricity pricing data, power plant age and power plant operator demand.

15. A method according to claim 14, comprising storing a schedule of changes in power plant output set point, the changes reflecting changes in the pricing of electricity generated by the power plant.

16. A method according to claim 15, wherein the stored scheduled changes in the power plant output set point represent seasonal changes in electricity prices.

17. A method according to claim 16, wherein the stored scheduled changes in the power plant output set point represents intraday changes in electricity prices.

18. A method according to claim 15, wherein the stored scheduled changes in the power plant output set point represent the age of the power plant.

19. A method according to claim 18, wherein the stored scheduled changes in the power point output set point comprises an output set point for each month of the lifetime of the power plant.

20. A method according to claim 14, comprising receiving at the controller an input of real time electricity prices on a spot market.

21. A method according to claim 14, comprising receiving at the controller an input of electricity prices as a futures market.

22. A method according to claim 20, comprising comparing the received prices with a threshold, and varying the output of the power plant above its rated output if the threshold price is exceeded.

23. A method according to claim 20, wherein the output of the power plant is varied above its rated output in proportion to the received price.

24. A method according to claim 14, wherein the controller sends an over-rating signal to individual turbines to enable the output of the power plant to reach the over-rated power plant value.

25. A method according to claim 14, wherein the varying of the output of the power plant above rated power is dependent on fatigue damage and/or fatigue damage rates of individual turbines comprising the power plant.

26. A method according to claim 25, wherein the fatigue is the fatigue of critical turbine components with respect to rotational speed and/or torque.