Method of optimizing the power recovered by a wind turbine by reducing the mechanical impact on the structure

Patent metadata

Field	Value
Publication number	US-10041473-B2
Application number	US-201213491686-A
Country	US
Kind code	B2
Filing date	Jun 8, 2012
Priority date	Jun 17, 2011
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

A method of optimizing the power recovered by a wind turbine by reducing the mechanical impact on the structure is disclosed. A first angle of inclination of the blades allowing the recovered power to be optimized is determined. The aerodynamic force produced on the nacelle when the blades are directed with a first angle is determined. A second angle of inclination of the blades allowing obtaining an aerodynamic force setpoint value is then determined by inverting the aerodynamic force model and using a wind velocity measurement, a rotor velocity measurement and the aerodynamic force setpoint value. Finally, the blades are directed to the second angle.

First claim

The invention claimed is:

1. A method of optimizing electrical power production of a horizontal axis wind turbine comprising a tower supporting a nacelle provided with a rotor to which blades are fastened with an angle of inclination of the blades being controlled, comprising:
a) determining a first angle of inclination of the blades allowing recovered power to be maximized as a function of wind velocity by generating an electrical torque setpoint value as a function of a rotor measurement, generating a rotor velocity setpoint value as a function of a wind velocity measurement using mappings, generating an aerodynamic torque setpoint value which follows the rotor velocity setpoint value and the electrical torque setpoint value; and determining the first angle of inclination allowing achieving the aerodynamic torque setpoint value and providing regulation of a rotor velocity;
b) providing a model of an aerodynamic force produced on the nacelle as a function of a wind velocity, of the angle of inclination of the blades and of a velocity of the rotor;
c) determining the aerodynamic force produced on the nacelle when the blades are directed with the first angle of inclination;
d) determining a setpoint value for the aerodynamic force produced on the nacelle when the blades are directed with the first angle of inclination by decreasing the aerodynamic force determined in c) by a term defined to minimize velocity variations at a top of the tower to lessen structural fatigue of the tower for electrical power generation during wind speed variation;
e) determining a second angle of inclination of the blades allowing obtaining the aerodynamic force by inverting the model of the aerodynamic force while using a wind velocity measurement, a rotor velocity measurement and the setpoint value of the aerodynamic force; and
f) directing the blades to the second angle to provide maximum power generation during the wind speed variation while minimizing the velocity variations at the top of the tower.

2. The method as claimed in claim 1 , wherein the term defined to decrease velocity variations at the top of the tower is proportional to a difference between a current tower position and velocity values and a reference tower position and velocity values with a reference position value depending on the aerodynamic force determined in c), and a zero reference velocity value.

3. The method as claimed in claim 2 , wherein the model of aerodynamic force depending on wind velocity Vw, on the angle of inclination θ of the blades and on the velocity of the rotor Ωr is expressed as an equation:

F
aero

=

0.5
⁢
ρΠ
⁢

⁢

R
b
2

⁢

c
t

(

θ
,

R
b

⁢

Ω
r

V
w

)

⁢

V
w
2

with:
Rb being rotor radius;
p being air density; and
ct being a mapping parameter.

4. The method as claimed in claim 3 , wherein a term proportional to torsion of the tower is added to the term defined to decrease velocity variations at the top of the tower.

5. The method as claimed in claim 4 , wherein the first angle of inclination of the blades allowing recovered power to be optimized is determined by:
a) providing a model of aerodynamic torque produced on the nacelle in an equation which is a function of a wind velocity Vw, of the angle of inclination of the blades and of velocity Ωr of the rotor;
b) determining the aerodynamic torque setpoint value from the model of the aerodynamic torque; and
c) determining the first angle of inclination of the blades for obtaining the aerodynamic torque setpoint value by inverting the model of the aerodynamic torque while using a wind velocity measurement, a rotor velocity measurement and the aerodynamic torque setpoint value.

6. The method as claimed in claim 5 , wherein the model of the aerodynamic torque is expressed as an equation:

T
aero

=

0.5
⁢
ρΠ
⁢

⁢

R
b
3

⁢

c
q

(

θ
,

R
b

⁢

Ω
r

V
w

)

⁢

V
w
2

)

with:
Rb being rotor radius;
p being air density;
cq being a mapping parameter;
Vw being wind velocity; and
Ωr being rotor velocity.

7. The method as claimed in claim 3 , wherein the first angle of inclination of the blades allowing recovered power to be optimized is determined by:
a) providing a model of aerodynamic torque produced on the nacelle in an equation which is a function of a wind velocity Vw, of the angle of inclination of the blades and of velocity Ωr of the rotor;
b) determining the aerodynamic torque setpoint value from the model of the aerodynamic torque; and
c) determining the first angle of inclination of the blades for obtaining the aerodynamic torque setpoint value by inverting the model of the aerodynamic torque while using a wind velocity measurement, a rotor velocity measurement and the aerodynamic torque setpoint value.

8. The method as claimed in claim 7 , wherein the model of the aerodynamic torque is expressed as an equation:

T
aero

=

0.5
⁢

Assignees

• Chauvin Jonathan
• Creff Yann
• Ifp Energies Now

Inventors

• Chauvin Jonathan
• Creff Yann

Classifications

• F03D7/045

  with model-based controls · CPC title

• F03D7/0292

  to reduce fatigue · CPC title

• F03D7/0224 Primary

  Adjusting blade pitch · CPC title

• Y02E10/723

  Cross-Sectional Technologies · mapped topic

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title