System and method for estimating rotor blade loads of a wind turbine

Patent metadata

Field	Value
Publication number	US-2016138571-A1
Application number	US-201414540275-A
Country	US
Kind code	A1
Filing date	Nov 13, 2014
Priority date	Nov 13, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

The present subject matter is directed to a method for estimating rotor blade loads, e.g. a blade root resultant moment, of a wind turbine. In one embodiment, the method includes measuring, via one or more sensors, a plurality of operating parameters of the wind turbine. Another step includes estimating out-of-plane and in-plane forces acting on the rotor blade based at least partially on the plurality of operating parameters. Further, the method includes determining an application point for the out-of-plane and in-plane forces along a span of the rotor blade. A further step includes estimating out-of-plane and in-plane moments of the rotor blade based at least partially on the out-of-plane and in-plane forces and the respective application points. Thus, the method includes calculating the load acting on the rotor blade based at least partially on the out-of-plane and in-plane moments.

First claim

What is claimed is:

1 . A method for estimating a load acting on a rotor blade of a wind turbine, the method comprising:
measuring, via one or more sensors, a plurality of operating parameters of the wind turbine, estimating, via a processor, an out-of-plane and in-plane force acting on the rotor blade based at least partially on the plurality of operating parameters; determining, via the processor, an application point of the out-of-plane and in-plane force on a span of the rotor blade; estimating, via the processor, 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, via the processor, 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, via the processor, the load acting on the rotor blade based at least partially on the out-of-plane moment and the in-plane moment.

2 . The method of claim 1 , wherein the load acting on the rotor blade corresponds to a blade root resultant moment.

3 . The method of claim 1 , wherein the plurality of operating parameters of the wind turbine comprise at least one of the following: a thrust, a power, a speed, a torque, a pitch angle, a nodding moment, an overhang moment, a rotor azimuth angle, or a yawing moment.

4 . The method of claim 3 , further comprising estimating the thrust utilizing at least one of the following: a plurality of equations, one or more aerodynamic performance maps, or one or more look-up tables.

5 . The method of claim 1 , wherein estimating the out-of-plane force further comprises:
determining an out-of-plane force distribution from a blade root to a blade tip of the rotor blade; and integrating the out-of-plane force distribution to obtain an equivalent out-of-plane force.

6 . The method of claim 1 , wherein determining the application point of the out-of-plane force further comprises:
determining a plurality of application points of a plurality of out-of-plane forces during operation of the wind turbine for a plurality of wind speeds; and storing the plurality of application points in an aerodynamic performance map.

7 . The method of claim 1 , wherein the application point of the out-of-plane force comprises a constant value.

8 . The method of claim 3 , further comprising estimating the in-plane moment of the rotor blade as a function of at least one of a weight of the rotor blade, a mechanical torque load of the rotor blade, a speed of the rotor blade, a power of the rotor blade, or an inertial load of the rotor blade.

9 . The method of claim 8 , further comprising calculating the gravity load of the rotor blade as a function of at least one of the rotor azimuth angle, a mass of the rotor blade, gravity, a hub radius, or a center of gravity location of the rotor blade.

10 . The method of claim 9 , further comprising calculating the mechanical torque load of the rotor blade as a function of at least one of a low-speed shaft torque, a blade radius, or the hub radius.

11 . The method of claim 10 , further comprising calculating the inertial load of the rotor blade as a function of at least one of a rotor acceleration or a rotor inertia.

12 . The method of claim 11 , further comprising determining the rotor acceleration based at least partially on a rate of change of a rotor speed signal and filtering the speed signal via a low pass filter.

13 . The method of claim 3 , further comprising:
estimating an in-plane shear force of the rotor blade as a function of at least one of the rotor azimuth angle, a rotor blade mass, a rotor blade radius, the application point, torque, filtered rotor acceleration, rotor inertia, gravity, aerodynamic drag, wind speed, or a center of gravity location; and calculating the load acting on the rotor blade based at least partially on the in-plane shear force.

14 . A system for maintaining rotor blade loads of a wind turbine within predetermined limits while also maximizing power output, the system comprising:
one or more sensors configured to measure a plurality of operating parameters of the wind turbine; a controller configured with the one or more sensors, the controller comprising a processor configured to perform one or more operations, the operations comprising: 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 load acting on the rotor blade based at least partially on the out-of-plane moment and the in-plane moment.

15 . The system of claim 14 , wherein the plurality of operating parameters of the wind turbine comprise at least one of the following: a thrust, a power, a speed, a torque, a pitch angle, a nodding moment, an overhang moment, a rotor azimuth angle, or a yawing moment.

16 . The system of claim 14 , wherein estimating the out-of-plane root moment further comprises:
determining an out-of-plane force distribution from a blade root to a blade tip of the rotor blade; and integrating the out-of-plane force distribution to obtain an equivalent out-of-plane force.

17 . The system of claim 14 , wherein determining the application point of the out-of-plane force further comprises:
calculating a plurality of application points of a plurality of out-of-plane forces during operation of the wind turbine, wherein the plurality of application points correspond to a plurality of wind speeds; and storing the plurality of application points in an aerodynamic performance map.

18 . The system of claim 14 , wherein the application point of the out-of-plane force comprises a constant value.

19 . The system of claim 13 , further comprising estimating the in-plane blade root moment of the rotor blade as a function of at least one of a weight of the rotor blade, a mechanical torque load of the rotor blade, a speed of the rotor blade, a power of the rotor blade, or an inertial load of the rotor blade.

20 . A method for estimating an out-of-plane blade root moment of the rotor blade, the method comprising:
measuring, via one or more sensors, a plurality of operating parameters of the wind turbine; estimating, via a processor, an out-of-plane force acting on the rotor blade based at least partially on the plurality of operating parameters; and determining an application point on the rotor blade of the out-of-plane force.

Assignees

• Gen Electric

Inventors

• Perley Thomas Franklin
• Gerber Brandon Shane
• Gerloff Tim Robert

Classifications

• F03D1/06

  Rotors · CPC title

• F03D11/0091 Primary

  Mechanical Engineering · mapped topic

• G01N3/24 Primary

  by applying steady shearing forces (G01N3/26, G01N3/28 take precedence) · CPC title

• F03D7/043 Primary

  characterised by the type of control logic · CPC title

• F05B2270/331

  Mechanical loads · CPC title