Detecting a wake situation in a wind farm

1. A method for detecting a wake situation in a wind farm comprising a plurality of wind turbines, the method using a map representing a distribution of the wind turbines in the wind farm, wherein one or more of the wind turbines have one or more load sensors, and wherein the wake situation refers to an action of the wind on a wind turbine that produces a wake received by another wind turbine, the method comprising:

obtaining, for one or more of the wind turbines with load sensors, load measurements from the load sensors during a predefined time interval;

obtaining an enriched map of the wind farm by qualifying in the map each wind turbine for which load measurements have been obtained as overloaded or non-overloaded according to the load measurements obtained for the wind turbine;

based on the wind turbines qualified as overloaded in the enriched map, obtaining a set of possible wind directions that could have generated a wake received by at least one of the overloaded wind turbines; and

detecting the wake situation by determining the most likely actual wind direction from the set of possible wind directions.

2. The method according to claim 1 , wherein obtaining the set of possible wind directions comprises:

obtaining, for each of the overloaded wind turbines, a particular set of possible wind directions that could have generated the wake received by the overloaded wind turbine; and

selecting the wind directions that are in all the particular sets of possible wind directions, and taking said selected wind directions as the set of possible wind directions.

3. The method according to claim 1 , wherein determining the most likely actual wind direction from the set of possible wind directions comprises:

for each wind direction of the set of possible wind directions, verifying if said wind direction could have generated a wake received by at least one of the wind turbines qualified as non-overloaded in the enriched map, and

in case of positive result of said verification, excluding said wind direction from the set of possible wind directions.

4. The method according to claim 1 , further comprising:

applying a predefined strategy of adjusting wind turbine operations, wherein the predefined strategy is theoretically suitable for solving the detected wake situation.

5. A method for solving a wake situation comprising iterating the method according to claim 4 until the detected wake situation is solved or an ending condition is satisfied;

wherein determining the most likely actual wind direction comprises excluding the wind directions that have been determined as most likely actual wind directions in previous iterations;

wherein the ending condition is satisfied when all the wind directions of the set of possible wind directions have been determined as most likely actual wind directions in previous iterations; and

wherein the detected wake situation is solved when the enriched map comprises a number of overloaded wind turbines that is less than a predefined threshold of overloaded wind turbines.

6. The method according to claim 5 , further comprising:

if the detected wake situation has not been solved, generating an alarm signal.

7. The method according to claim 1 , wherein qualifying in the map each wind turbine for which load measurements have been obtained as overloaded or non-overloaded comprises:

calculating an average load for each of said wind turbines for which load measurements have been obtained; and

qualifying in the map each of said wind turbines as overloaded or non-overloaded according to the average load calculated for the wind turbine.

8. The method according to claim 7 , wherein obtaining the set of possible wind directions comprises:

obtaining, for each of the overloaded wind turbines, a particular set of possible wind directions that can theoretically generate a wake that can be received by the overloaded wind turbine;

selecting the wind directions that are in all the particular sets of possible wind directions, and taking said selected wind directions as the set of possible wind directions;

wherein determining the most likely actual wind direction from the set of possible wind directions comprises

for each wind direction of the set of possible wind directions, verifying if said wind direction could have generated a wake received by at least one of the non-overloaded wind turbines, and

in case of a positive result of said verification, excluding said wind direction from the set of possible wind directions; and

wherein the method further comprises:

applying a predefined strategy of adjusting wind turbine operations, wherein the predefined strategy is theoretically suitable for solving the detected wake situation.

9. A method for solving a wake situation comprising iterating the method according to claim 8 until the detected wake situation is solved or an ending condition is satisfied;

wherein determining the most likely actual wind direction comprises excluding the wind directions that have been determined as most likely actual wind directions in previous iterations;

wherein the ending condition is satisfied when all the wind directions of the set of possible wind directions have been determined as most likely actual wind directions in previous iterations; and

wherein the detected wake situation is solved when the enriched map comprises a number of overloaded wind turbines that is less than a predefined threshold of overloaded wind turbines.

10. A method for detecting a wake situation in a wind farm comprising a plurality of wind turbines by using a map representing a distribution of the wind turbines in the wind farm, wherein one or more of the wind turbines have one or more load sensors, and wherein the wake situation refers to an action of the wind on a wind turbine that produces a wake received by another wind turbine; the method comprising:

obtaining, for one or more of the wind turbines with load sensors, load measurements from the load sensors during a predefined time interval;

obtaining an enriched map of the wind farm by qualifying in the map each wind turbine for which load measurements have been obtained, as overloaded or non-overloaded according to the load measurements obtained for the wind turbine;

comparing the enriched map with predefined wake situations, and producing a set of matched predefined wake situations according to predefined matching criteria; and

detecting the wake situation by selecting one of the predefined wake situations from the set of matched predefined wake situations according to predefined selection criteria.

11. The method according to claim 10 ,

wherein qualifying in the map each wind turbine for which load measurements have been obtained as overloaded or non-overloaded comprises:

calculating an average load for each of said wind turbines for which load measurements have been obtained; and

qualifying in the map each of said wind turbines as overloaded or non-overloaded according to the average load calculated for the wind turbine; and

wherein the method further comprises:

applying a predefined strategy of adjusting wind turbine operations, wherein the predefined strategy is theoretically suitable for solving the detected wake situation.

12. A method for solving a wake situation comprising iterating the method according to claim 11 until the detected wake situation is solved or an ending condition is satisfied;

wherein selecting one of the predefined wake situations from the set of matched predefined wake situations comprises excluding predefined wake situations selected in previous iterations;

wherein the ending condition is satisfied when all the predefined wake situations of the set of matched predefined wake situations have been selected in previous iterations; and

wherein the detected wake situation is solved when the enriched map comprises a number of overloaded wind turbines that is less than a predefined threshold of overloaded wind turbines.

13. A system configured for detecting a wake situation in a wind farm according to the method of claim 10 .

14. A wind farm comprising a plurality of wind turbines, wherein one or more of the wind turbines have one or more load sensors, and wherein the wind farm also comprises a system according to claim 13 .

15. The method according to claim 10 , further comprising:

applying a predefined strategy of adjusting wind turbine operations, wherein the predefined strategy is theoretically suitable for solving the detected wake situation.

16. A method for solving a wake situation comprising iterating the method according to claim 15 until the detected wake situation is solved or an ending condition is satisfied;

wherein selecting one of the predefined wake situations from the set of matched predefined wake situations comprises excluding the predefined wake situations selected in previous iterations;

wherein the ending condition is satisfied when all the predefined wake situations of the set of matched predefined wake situations have been selected in previous iterations; and

wherein the detected wake situation is solved when the enriched map comprises a number of overloaded wind turbines that is less than a predefined threshold of overloaded wind turbines.

17. A method for solving a wake situation, comprising:

performing the method according to claim 16 , wherein comparing the enriched map with predefined wake situations comprises obtaining the predefined wake situations from a repository; and

iterating a second method for detecting a wake situation in a wind farm until the detected wake situation is solved or an ending condition is satisfied; wherein

based on the wind turbines qualified as overloaded in the enriched map, obtaining a set of possible wind directions that could have generated a wake received by at least one of the overloaded wind turbines,

detecting the wake situation by determining the most likely actual wind direction from the set of possible wind directions,

applying a predefined strategy of adjusting wind turbine operations, wherein the predefined strategy is theoretically suitable for solving the detected wake situation, and

if the detected wake situation has been solved, storing the enriched map as a predefined wake situation into the repository; wherein

determining the most likely actual wind direction comprises excluding the wind directions that have been determined as most likely actual wind directions in previous iterations; wherein

the ending condition is satisfied when all the wind directions of the set of possible wind directions have been determined as most likely actual wind directions in previous iterations; wherein

the detected wake situation is solved when the enriched map comprises a number of overloaded wind turbines that is less than a predefined threshold of overloaded wind turbines.

18. The method according to claim 17 , wherein:

storing the enriched map as the predefined wake situation also comprises storing the predefined strategy that has solved the detected wake situation into the repository; and

wherein applying the predefined strategy of adjusting wind turbine operations comprises obtaining the predefined strategy from the repository.

19. A system for detecting a wake situation in a wind farm comprising a plurality of wind turbines, by using a map representing a distribution of the wind turbines in the wind farm, wherein one or more of the wind turbines have one or more load sensors, wherein the wake situation refers to an action of the wind on a wind turbine that produces a wake received by another wind turbine, and wherein the system is configured to perform a method comprising:

obtaining, for one or more of the wind turbines with load sensors, load measurements from the load sensors during a predefined time interval;

obtaining an enriched map of the wind farm by qualifying in the map each wind turbine for which load measurements have been obtained, as overloaded or non-overloaded according to the load measurements obtained for the wind turbines;

based on the wind turbines qualified as overloaded in the enriched map, obtaining a set of possible wind directions that could have generated a wake received by at least one of the overloaded wind turbines; and

detecting the wake situation by determining the most likely actual wind direction from the set of possible wind directions.

20. A wind farm comprising a plurality of wind turbines, wherein one or more of the wind turbines have one or more load sensors, and wherein the wind farm also comprises a system according to claim 19 .