Method for operating a wind turbine and a wind turbine system

Patent metadata

Field	Value
Publication number	US-10837424-B2
Application number	US-201916531494-A
Country	US
Kind code	B2
Filing date	Aug 5, 2019
Priority date	Aug 3, 2018
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A method for operating a wind turbine for generating electrical energy is provided comprising the steps as described below. The wind turbine comprises a nacelle being rotatably supported on a tower of the wind turbine, in particular wherein at least one tower cable is provided in the tower for electrically connecting the nacelle and/or components thereof to e.g. an electrical installation on a ground of the tower. In one step of the method an early untwist operation for untwisting the tower cables of the wind turbine is initiated at a first specific time. In addition, a future power generation of the wind turbine is predicted for a certain prediction period at least by analyzing a prediction of the wind, in particular by analyzing at least wind direction forecast information and/or wind speed forecast information. The first specific time for initiating the early untwist operation is determined such that an overall predicted energy generation of the wind turbine over the certain prediction period is maximized or that a predicted energy loss caused by an untwist operation is minimized.

First claim

The invention claimed is:

1. A method for operating a wind turbine having a nacelle being rotatably supported about a vertical yaw axis on a tower of the wind turbine, wherein at least one tower cable is provided between the nacelle and the tower, comprising:
initiating an early untwist operation for untwisting the tower cable at a first specific time:
predicting a future power generation of the wind turbine for a certain prediction period by analyzing a prediction of the wind;
wherein the first specific time is determined such that an overall predicted energy generation of the wind turbine over the certain prediction period is maximized, or
that a predicted energy loss caused by the early untwist operation is minimized.

2. The method according to claim 1 , wherein the first specific time is determined such that a first predicted energy loss caused by the early untwist operation initiated at the first specific time is less than a second predicted energy loss caused by a possible untwist operation which would be performed at a second specific time.

3. A method for operating a wind turbine having a nacelle being rotatably supported about a vertical yaw axis on a tower of the wind turbine, wherein at least one tower cable is provided between nacelle and the tower, comprising:
initiating an early untwist operation for untwisting the tower cable at a twist angle threshold of the nacelle, wherein the twist angle threshold is smaller than a maximum twist angle threshold, and if a first condition is fulfilled;
wherein the early untwist operation is initiated also upon fulfillment of a first condition, the first condition being that a current power generation or a predicted power generation of the wind turbine is less than a specific power generation threshold of the wind turbine, or if a current wind speed or a predicted wind speed is less than a wind speed threshold.

4. The method according to claim 3 , comprising predicting the predicted power generation of the wind turbine for a certain prediction period by analyzing a prediction of the wind, including one or both of wind direction forecast information and wind speed forecast information.

5. The method according to claim 4 , wherein the early untwist operation is initiated only if a second condition is also fulfilled, the second condition being that the current power generation is less than the predicted power generation, or a current wind speed is less than a predicted wind speed.

6. The method for operating a wind turbine having a nacelle being rotatably supported about a vertical yaw axis on a tower of the wind turbine, wherein at least one tower cable is provided between the nacelle and the tower, comprising:
initiating an early untwist operation for untwisting the tower cable when a current twist angle of the nacelle exceeds a twist angle threshold, wherein the twist angle threshold is smaller than a maximum twist angle threshold; and
wherein the twist angle threshold is dependent on a current power generation of the wind turbine such that the twist angle threshold increases or at least remains constant with an increasing current power generation of the wind turbine.

7. The method according to claim 6 , comprising predicting a predicted twist angle of the tower cable for a certain prediction period by analyzing a prediction of the wind, including one or both of wind direction forecast information and wind speed forecast information.

8. The method according to claim 7 , wherein the predicting of the predicted twist angle takes into consideration an execution of at least one untwist operation.

9. The method according to claim 7 , wherein the certain prediction period is at least as long as an untwist time period required for an untwist operation of about 360°.

10. The method according to claim 7 , wherein the certain prediction period is at least as long as the predicted twist angle having reached the maximum twist angle threshold, including time for executing an untwist operation.

11. The method according to claim 6 , wherein duration of the untwist operation or a number of rotations of the untwist operation is determined such that an overall predicted energy generation of the wind turbine over a certain prediction period is maximized.

12. The method according to claim 6 , wherein a number of untwisting rotations of the nacelle during the untwist operation is less than a number of necessary rotations for bringing the nacelle into a rotational position of less than 360° with respect to the tower, or wherein the untwist operation comprises less than three rotations of the nacelle.

13. The method according to claim 6 , comprising automatically providing a control request for executing the early untwist operation to a control center of the wind turbine.

14. A wind turbine system, comprising:
a wind turbine, wherein the wind turbine comprises a tower, a nacelle rotatably supported about a vertical yaw axis on the tower, a tower cable provided between the nacelle and the tower, a yaw drive mechanism for rotation of the nacelle around the yaw axis, a rotor rotatably supported by the nacelle;
a control system integrated in the wind turbine or at an external control arrangement, wherein the control system is configured to operate the wind turbine in accordance with the method of claim 1 .

Assignees

• Gen Electric

Inventors

• Torbohm Gert

Classifications

• F03D7/0204 Primary

  for orientation in relation to wind direction · CPC title

• F03D7/028

  controlling wind motor output power · CPC title

• F05B2260/821

  Parameter estimation or prediction · CPC title

• F05B2270/321

  Wind directions · CPC title

• F05B2270/32

  Wind speeds · CPC title