Extreme load control

Patent metadata

Field	Value
Publication number	US-2018171978-A1
Application number	US-201615737621-A
Country	US
Kind code	A1
Filing date	Jun 22, 2016
Priority date	Jun 30, 2015
Publication date	Jun 21, 2018
Grant date	—

Abstract

Methods for calculating a maximum safe over-rated power demand for a wind turbine operating in non-standard conditions include the steps of determining a value indicative of a risk of exceeding an ultimate design load during operation in a standard operating condition, and establishing a maximum over-rated power demand corresponding to a maximum power that the turbine may produce under the non-standard operating condition without incurring an increased risk of exceeding the ultimate design load, with respect to operation in the standard condition. A method of over-rating a wind turbine, a wind turbine controller, a wind turbine and a wind power plant are also claimed.

First claim

1 . A method for calculating a maximum safe over-rated power demand for a wind turbine operating in a non-standard operating condition, the method comprising the steps of:
determining a value indicative of a risk of exceeding an ultimate design load during operation in a standard operating condition; and establishing a maximum over-rated power demand corresponding to a maximum power that the turbine may produce under the non-standard operating condition without incurring an increased risk of exceeding the ultimate design load, with respect to operation in the standard condition.

2 . The method of claim 1 , wherein establishing the maximum over-rated power demand comprises:
determining, for each of a plurality of over-rated power demands, a value indicative of the risk of exceeding the ultimate design load during operation in the non-standard operating condition; and selecting the largest of the plurality of over-rated power demands for which the determined risk is not greater than the determined risk of exceeding the design load in the standard operating condition.

3 . The method of claim 1 , wherein the operating condition comprises one or more of wind speed, yaw error, air density, vertical wind shear, horizontal wind shear, inflow angle and turbulence intensity.

4 . The method of claim 1 , wherein determining the value indicative of the risk of exceeding the ultimate design load comprises calculating a maximum value of the ultimate load experienced by the turbine during operation in an extreme event.

5 . The method of claim 4 , wherein the extreme event is an extreme design load case.

6 . The method of claim 1 , wherein determining the value indicative of the risk of exceeding the ultimate design load comprises:
calculating a maximum value of the ultimate load experienced by the turbine during operation in each of a plurality of extreme events; and selecting the largest of the calculated maximum ultimate load values.

7 . The method of claim 1 , wherein the ultimate load comprises one or more of a tower base over-turning moment, a flapwise bending moment on a blade of the wind turbine, an edgewise bending moment on a blade of the wind turbine, a torque of the drive train, a tilt bending moment on a rotor of the wind turbine, and a yaw-wise bending moment on a rotor of the wind turbine.

8 . The method of claim 4 , wherein calculating the maximum value of the ultimate load experienced in the extreme event comprises:
performing a plurality of simulations of operation of the turbine in the extreme event; for each of the simulations, establishing the maximum value of the ultimate load experienced during the extreme event; and selecting the largest of the plurality of established maximum values.

9 . The method of claim 4 , wherein calculating the maximum value of the ultimate load experienced in the extreme event comprises:
performing a plurality of simulations of operation of the turbine in the extreme event; for each of the simulations, establishing the maximum value of the ultimate load experienced across the extreme event; and calculating the average of the plurality of established maximum values.

10 . The method of claim 8 , wherein each of the plurality of simulations is characterised by different wind series starting points.

11 . The method of claim 1 , wherein determining the value indicative of the risk of exceeding the ultimate design load comprises:
calculating a baseline value of the ultimate load, the baseline value comprising the maximum value of the ultimate load experienced by the turbine in an extreme design load case during standard operation; and for each of a plurality of time intervals in the extreme design load case, simulating operation of the turbine for a pre-determined time period, to determine a probability of exceeding the baseline ultimate load value.

12 . A method of populating a look-up table for a wind turbine controller, the method comprising calculating a maximum safe over-rated power demand for a wind turbine for each of a plurality of non-standard operating conditions of the wind turbine, the calculating comprising:
determining a value indicative of a risk of exceeding an ultimate design load during operation in a standard operating condition; and establishing the maximum over-rated power demand corresponding to a maximum power that the turbine may produce under the non-standard operating condition without incurring an increased risk of exceeding the ultimate design load, with respect to operation in the standard condition.

13 . A method of over-rating a wind turbine, the method comprising:
determining an operating condition of the wind turbine; and determining a maximum safe over-rated power demand for the wind turbine given the determined operating condition by interrogating a look-up table; wherein the look-up table is populated by calculating a maximum safe over-rated power demand for the wind turbine for each of a plurality of non-standard operating conditions of the wind turbine, the calculating comprising: determining a value indicative of a risk of exceeding an ultimate design load during operation in a standard operating condition; and establishing a maximum over-rated power demand corresponding to a maximum power that the turbine may produce under the non-standard operating condition without incurring an increased risk of exceeding the ultimate design load, with respect to operation in the standard condition.

14 . The method of claim 13 , further comprising reducing the determined maximum safe over-rated power demand in response to a warning from a condition monitoring system for the wind turbine.

15 . The method of claim 13 , further comprising the steps of:
establishing a frequency of exceedance of a load level for a wind turbine component that is close to an ultimate load level for the wind turbine component; and reducing the determined maximum safe over-rated power demand based on the established frequency.

16 . The method of claim 13 , further comprising the steps of:
establishing a frequency of triggering of one or more ultimate load control features for the turbine; and reducing the determined maximum safe over-rated power demand based on the established frequency.

17 . (canceled)

18 . (canceled)

19 . (canceled)

20 . A controller for a wind power plant, the controller configured to perform an operation of over-rating a wind turbine in the wind power plant, the operation comprising:
determining an operating condition of the wind turbine; and determining a maximum safe over-rated power demand for the wind turbine given the determined operating condition by interrogating a look-up table; wherein the look-up table is populated by calculating a maximum safe over-rated power demand for the wind turbine for each of a plurality of non-standard operating conditions of the wind turbine, the calculating comprising: determining a value indicative of a risk of exceeding an ultimate design load during operation in a standard operating condition; and establishing a maximum over-rated power demand corresponding to a maximum power that the turbine may produce under the non-standard operating condition without incurring an increased risk of exceeding the ultimate design load, with respect to operation in the standard condition.

21 . (canceled)

22 . (canceled)

Assignees

• Vestas Wind Sys As

Inventors

• Spruce Chris

Classifications

• F05B2270/321

  Wind directions · CPC title

• F05B2270/1033

  Power (if explicitly mentioned) · CPC title

• F05B2270/1095

  by limiting mechanical stresses · CPC title

• F05B2270/332

  Maximum loads or fatigue criteria · CPC title

• F05B2270/329

  Azimuth or yaw angle · CPC title