System and method for operating a wind turbine based on rotor blade margin

Patent metadata

Field	Value
Publication number	US-9863402-B2
Application number	US-201514621853-A
Country	US
Kind code	B2
Filing date	Feb 13, 2015
Priority date	Feb 13, 2015
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

The present subject matter is directed to a method for operating a wind turbine. The method includes calculating one or more blade root loads, e.g. a blade root resultant moment, of at least one rotor blade of the wind turbine. Another step includes estimating a span-wise loading of the rotor blade based at least partially on the one or more blade root loads. The method also includes determining a deformation margin of the rotor blade based at least partially on the span-wise loading and one or more estimated deformations occurring on the rotor blade. Another step includes controlling the wind turbine based on the deformation margin.

First claim

What is claimed is:

1. A method for operating a wind turbine, the method comprising:
calculating, via a processor, one or more blade root resultant moments of at least one rotor blade of the wind turbine as a function of a tip speed ratio and a pitch angle of the rotor blade;
estimating, via the processor, a span-wise loading of the rotor blade based on the one or more blade root resultant moments;
determining, via the processor, a deformation margin of the rotor blade based at least partially on the span-wise loading and one or more real-time deformations occurring on the rotor blade; and
controlling, via the processor, the wind turbine based on the deformation margin.

2. The method of claim 1 , wherein calculating the one or more blade root resultant moments of at least one rotor blade of the wind turbine further comprises:
measuring, via one or more sensors, a plurality of operating parameters of the wind turbine;
estimating an out-of-plane and in-plane force acting on the rotor blade based at least partially on the plurality of operating parameters;
determining an application point of the out-of-plane and in-plane force on a span of the rotor blade;
estimating an out-of-plane moment of the rotor blade based at least partially on the out-of-plane force and the out-of-plane application point;
estimating an in-plane blade moment of the rotor blade based at least partially on the in-plane force and the in-plane application point; and,
calculating the one or more blade root resultant moments acting on the rotor blade based at least partially on the out-of-plane moment and the in-plane moment.

3. The method of claim 1 , wherein estimating the span-wise loading of the rotor blade based on the one or more blade root resultant moments further comprises:
determining a real-time operating point of the wind turbine;
determining corresponding curve fit coefficients based on the operating point;
generating a non-dimensional load shape curve based on the coefficients offline; and
scaling the non-dimensional load shape curve up or down based on the one or more blade root resultant moments to create a dimensional curve online.

4. The method of claim 1 , further comprising storing, via a memory device, at least one of the one or more blade root resultant moments, the span-wise loading, or the deformation margin.

5. The method of claim 1 , wherein determining the deformation margin of the rotor blade further comprises:
applying a predetermined load distribution to the rotor blade;
measuring one or more corresponding margins in response to the predetermined load distribution; and
storing the measured corresponding margins in at least one of a map or look-up-table.

6. The method of claim 5 , wherein determining the deformation margin of the rotor blade further comprises:
determining an actual load distribution of the rotor blade in real-time; and
scaling the measured corresponding margins based on the actual load distribution.

7. The method of claim 1 , wherein the one or more real-time deformations comprise at least one of a strain deformation or a buckling deformation.

8. The method of claim 1 , wherein controlling the wind turbine based on the deformation margin further comprises determining a control parameter based on at least one of a maximum deformation or the deformation margin.

9. The method of claim 8 , further comprising calculating a deformation error as a function of the control parameter and a predetermined threshold and implementing a corrective action based on the error.

10. The method of claim 9 , wherein the corrective action comprises at least one of altering the pitch angle of a rotor blade, modifying a generator torque, modifying the generator speed, modifying the power output, yawing a nacelle of the wind turbine, braking one or more wind turbine components, or activating an airflow modifying element on a rotor blade.

11. A method for controlling loads of a rotor blade of a wind turbine, the method comprising:
storing a predetermined deformation margin for the rotor blade in a processor of a controller of the wind turbine;
calculating, via the processor, a blade root load of the rotor blade as a function of a tip speed ratio and a pitch angle of the rotor blade;
determining, via the processor, a span-wise loading of the rotor blade based at least partially on the blade root load;
updating, via the processor, the predetermined deformation margin based at least partially on the span-wise loading or one or more real-time deformations occurring on the rotor blade; and,
implementing a corrective action based on the deformation margin.

12. A system for operating a wind turbine, the system comprising:
a controller comprising a processor configured to perform one or more operations, the one or more operations comprising:
calculating one or more blade root resultant moments of at least one rotor blade of the wind turbine as a function of a tip speed ratio and a pitch angle of the rotor blade;
estimating a span-wise loading of the rotor blade based at least partially on the one or more blade root resultant moments;
determining a deformation margin of the rotor blade based at least partially on the span-wise loading and one or more estimated deformations occurring on the rotor blade; and
controlling the wind turbine based on the deformation margin.

13. The system of claim 12 , wherein calculating the one or more blade root resultant moments of at least one rotor blade of the wind turbine further comprises:
measuring, via one or more sensors, a plurality of operating parameters of the wind turbine;
estimating an out-of-plane and in-plane force acting on the rotor blade based at least partially on the plurality of operating parameters;
determining an application point of the out-of-plane and in-plane force on a span of the rotor blade;
estimating an out-of-plane moment of the rotor blade based at least partially on the out-of-plane force and the out-of-plane application point;
estimating an in-plane blade moment of the rotor blade based at least partially on the in-plane force and the in-plane application point; and
calculating the one or more blade root resultant moments acting on the rotor blade based at least partially on the out-of-plane moment and the in-plane moment.

14. The system of claim 12 , wherein estimating span-wise loading of the rotor blade based on the one or more blade root resultant moments further comprises:
determining a real-time operating point of the wind turbine;
determining corresponding curve fit coefficients based on the operating point;
generating a non-dimensional load shape curve based on the coefficients offline; and
scaling the non-dimensional load shape curve up or down based on the one or more blade root resultant moments to create a dimensional curve online.

15. The system of claim 12 , wherein determining the deformation margin of the rotor blade further comprises:
applying a predetermined load distribution to the rotor blade;
measuring one or more corresponding margins in response to the predetermined load distribution; and
storing the measured corresponding margins in at least one of a map or look-up-table.

16. The system of claim 15 , wherein determining the deformation margin of the rotor blade further comprises:
determining an actual load distribution of the rotor blade in real-time; and
scaling the measured corresponding margins based on the actual load distribution.

17. The system of claim 12 , wherein the one or more deformations comprise at least one of a strain deformati

Assignees

• Gen Electric

Inventors

• Perley Thomas Franklin
• Caruso Christopher Daniel
• Yarbrough Aaron

Classifications

• F05B2270/332

  Maximum loads or fatigue criteria · CPC title

• F03D7/0288 Primary

  in relation to clearance between the blade and the tower, i.e. preventing tower strike · CPC title

• F03D17/00

  Monitoring or testing of wind motors, e.g. diagnostics (testing during commissioning of wind motors F03D13/30) · CPC title

• F03D7/028

  controlling wind motor output power · CPC title

• F03D7/047 Primary

  characterised by the controller architecture, e.g. multiple processors or data communications · CPC title