Method for monitoring the vibrational state of a wind turbine

Patent metadata

Field	Value
Publication number	US-10465661-B2
Application number	US-201716076860-A
Country	US
Kind code	B2
Filing date	Feb 15, 2017
Priority date	Feb 25, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

The invention relates to a method for monitoring the vibrational state of a wind turbine comprising detecting a plurality of acceleration values that represent accelerations which a component of the wind turbine is subject to at different respective points in time within a specified time interval, storing the acceleration values in an acceleration data set; generating a sum frequency distribution on the basis of the acceleration data set, comparing a first sum frequency value of the sum frequency distribution with a second sum frequency value of a threshold sum frequency distribution for at least one acceleration value, and outputting a warning signal if the second sum frequency value is greater than the first sum frequency value.

First claim

The invention claimed is:

1. A method for monitoring the vibration state of a wind turbine comprising:
detecting a plurality of acceleration values, which represent accelerations to which a component of the wind turbine is subjected, each at different points in time within a predefined time interval;
storing the acceleration values in an acceleration dataset;
generating a cumulative frequency distribution based on the acceleration dataset;
comparing a first cumulative frequency value of the cumulative frequency distribution to a second cumulative frequency value of a limiting cumulative frequency distribution for at least one acceleration value; and
outputting a warning signal if the second cumulative frequency value is greater than the first cumulative frequency value.

2. The method of claim 1 , wherein the limiting cumulative frequency distribution is generated by the steps of
detecting a plurality of acceleration values, which represent accelerations to which the component of the wind turbine is subjected, each at different points in time within a predefined initial time interval;
storing these acceleration values in an initial acceleration dataset;
generating an initial cumulative frequency distribution based on the initial acceleration dataset; and
generating the limiting cumulative frequency distribution based on the determined initial cumulative frequency distribution;

wherein the steps are executed in a time interval before the detection of the plurality of acceleration values for generating the first cumulative frequency value of the cumulative frequency distribution.

3. The method of claim 1 , wherein the limiting cumulative frequency distribution for a wind turbine of a wind turbine fleet consisting of a plurality of structurally-equivalent wind turbines is generated by the steps of:
for at least two wind turbines of the wind turbine fleet, detecting a plurality of acceleration values, which represent accelerations to which the component of the respective wind turbine is subjected, each at different points in time within a predefined initial time interval;
storing these acceleration values in an initial acceleration dataset;
generating an initial cumulative frequency distribution based on the initial acceleration dataset; and
generating the limiting cumulative frequency distribution based on the determined initial cumulative frequency distribution;

wherein the steps are executed in a time interval before detecting the plurality of acceleration values for generating the first cumulative frequency value of the cumulative frequency distribution.

4. The method of claim 1 , wherein the limiting cumulative frequency distribution is generated by the steps of:
generating a limiting acceleration dataset by adding an additional acceleration value to each of the acceleration values detected in the initial time interval and stored in the initial acceleration dataset;
storing the limiting acceleration dataset; and
generating the limiting cumulative frequency distribution based on the limiting acceleration dataset.

5. The method of claim 1 , further comprising:
determining a wind strength range and/or a wind direction of the wind to which the wind turbine is subjected;
selecting a limiting cumulative frequency distribution from a plurality of different limiting cumulative frequency distributions which are each associated with different wind strength ranges and/or different wind directions, wherein the limiting cumulative frequency distribution is selected as a function of the wind strength range and/or the wind direction to which the wind turbine is subjected;
comparing a first cumulative frequency value of the cumulative frequency distribution to a second cumulative frequency value of the limiting cumulative frequency distribution for at least one acceleration value; and
outputting a warning signal if the second cumulative frequency value is greater than the first cumulative frequency value.

6. The method of claim 1 , further comprising:
determining a wind direction of the wind to which the wind turbine is subjected;
selecting a limiting cumulative frequency distribution from a plurality of different limiting cumulative frequency distributions which are each associated with different wind directions, wherein the limiting cumulative frequency distribution is selected as a function of the wind direction to which the wind turbine is subjected;
comparing a first cumulative frequency value of the cumulative frequency distribution to a second cumulative frequency value of the limiting cumulative frequency distribution for at least one acceleration value; and
outputting a warning signal if the second cumulative frequency value is greater than the first cumulative frequency value.

7. The method of claim 1 , further comprising:
determining a blade angle of rotor blades of the wind turbine;
selecting a limiting cumulative frequency distribution from a plurality of different limiting cumulative frequency distributions which are each associated with different blade angles, wherein the limiting cumulative frequency distribution is selected as a function of the blade angle which the rotor blades have;
comparing a first cumulative frequency value of the cumulative frequency distribution to a second cumulative frequency value of the limiting cumulative frequency distribution for at least one acceleration value; and
outputting a warning signal if the second cumulative frequency value is greater than the first cumulative frequency value.

8. The method of claim 1 , wherein the limiting cumulative frequency distribution is generated by the steps of:
continuously detecting a plurality of acceleration values, which represent accelerations to which the component of the wind turbine is subjected, each at different points in time within a predefined initial time interval;
storing these acceleration values in an initial acceleration dataset, which is stored in a ring memory having a predefined memory size, and therefore, after reaching the memory size, the acceleration values stored last in the ring memory overwrite the acceleration values stored first;
generating an initial cumulative frequency distribution based on the initial acceleration dataset; and
generating the limiting cumulative frequency distribution based on the determined initial cumulative frequency distribution;

wherein the steps are executed in a time interval before the detection of the plurality of acceleration values for generating the first cumulative frequency value of the cumulative frequency distribution.

9. The method as claimed in any one of the preceding claims, further comprising:
determining a power range of the wind turbine;
selecting a limiting cumulative frequency distribution from a plurality of different limiting cumulative frequency distributions which are each associated with different power ranges, wherein the limiting cumulative frequency distribution is selected as a function of the power range of the wind turbine;
comparing a first cumulative frequency value of the cumulative frequency distribution to a second cumulative frequency value of the limiting cumulative frequency distribution for at least one acceleration value; and
outputting a warning signal if the second cumulative frequency value is greater than the first cumulative frequency value.

10. A wind turbine comprising at least one acceleration sensor and a data processing unit connected thereto via a data line, wherein the data processing unit is configured to execute the method of claim 1 .

Assignees

• Innogy Se

Inventors

• Franke Jan-Bernd
• Kulse Sebastian

Classifications

• F05B2260/80

  Diagnostics · CPC title

• F05B2270/334

  Vibration measurements · CPC title

• F03D17/00 Primary

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

• F05B2270/807

  Accelerometers · CPC title

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title