Methods and systems for detecting sensor fault modes

Patent metadata

Field	Value
Publication number	US-9447778-B2
Application number	US-201113287946-A
Country	US
Kind code	B2
Filing date	Nov 2, 2011
Priority date	Nov 2, 2011
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A method of detecting a fault mode of a sensor is provided. The sensor may be, for example, a bending moment sensor and may sense a bending moment of a blade on a wind turbine generator (WTG). The method includes comparing data output by a first sensor with reference data indicating what is expected to be output by the first sensor to produce a first comparison result and comparing data output by the first sensor with data output by a second sensor to produce a second comparison result. A determination of whether the first sensor has entered a fault mode is made based at least in part on the first and second comparison results.

First claim

The invention claimed is:

1. A method for detecting fault modes of a bending moment sensor for a blade of a wind turbine generator, the method comprising:
operating the bending moment sensor to generate data representing a bending moment experienced by the blade of the wind turbine generator, wherein the bending moment sensor includes:
a fiber bragg grating configured for placement on a surface of the blade; and
sensor circuitry configured to optically couple to the fiber bragg grating via an optical fiber, the sensor circuitry including:
a light source configured to emit a light signal; and
a light receiver configured to receive a reflection of the light signal from the fiber bragg grating and to convert the reflected light signal into the data generated by the bending moment sensor,

comparing the data generated by the bending moment sensor with reference data indicating what is expected to be generated by the bending moment sensor to produce a comparison result, wherein the reference data includes at least one of: pre-determined data output of the bending moment sensor during a controlled environment, and model data output from a model, wherein the model includes at least one relationship determining the model data output as a function of observed operating conditions and knowledge of properties of the bending moment sensor; and
determining whether the bending moment sensor has entered a fault mode based at least in part on the comparison result; and
upon determining that the bending moment sensor has entered the fault mode, issuing an indication of the fault mode to a controller of the wind turbine generator that configures the controller to issue pitch commands to adjust a blade pitch of the wind turbine generator, wherein the pitch commands are based on the controller performing at least one of: ignoring an output of the bending moment sensor and reducing a reliance on the bending moment sensor,
wherein comparing the data generated by the bending moment sensor with the reference data to produce the comparison result includes comparing a signal power level indicated by the data generated by the bending moment sensor with a signal power level indicated by the reference data to produce a power comparison result.

2. The method of claim 1 , further comprises:
modifying power output by the light source in response to determining that the bending moment sensor has entered a fault mode based at least in part on the power comparison result.

3. A method for detecting fault modes of a bending moment sensor for a blade of a wind turbine generator, the method comprising:
operating the bending moment sensor to generate data representing a bending moment experienced by the blade of the wind turbine generator, wherein the bending moment sensor includes:
a fiber bragg grating configured for placement on a surface of the blade; and
sensor circuitry configured to optically couple to the fiber bragg grating via an optical fiber, the sensor circuitry including:
a light source configured to emit a light signal; and
a light receiver configured to receive a reflection of the light signal from the fiber bragg grating and to convert the reflected light signal into the data generated by the bending moment sensor;

comparing the data generated by the bending moment sensor with reference data indicating what is expected to be generated by the bending moment sensor to produce a comparison result, wherein the reference data includes at least one of: pre-determined data output of the bending moment sensor during a controlled environment, and model data output from a model, wherein the model includes at least one relationship determining the model data output as a function of observed operating conditions and knowledge of properties of the bending moment sensor; and
determining whether the bending moment sensor has entered a fault mode based at least in part on the comparison result; and
upon determining that the bending moment sensor has entered the fault mode, issuing an indication of the fault mode to a controller of the wind turbine generator that configures the controller to issue pitch commands to adjust a blade pitch of the wind turbine generator, wherein the pitch commands are based on the controller performing at least one of: ignoring an output of the bending moment sensor and reducing a reliance on the bending moment sensor, wherein comparing the data generated by the bending moment sensor with the reference data to produce the comparison result includes comparing a mean signal frequency indicated by the data generated by the bending moment sensor with a mean signal frequency indicated by the reference data to produce a mean frequency comparison result.

4. The method of claim 3 , wherein the method further includes:
compensating for a frequency offset of the bending moment sensor in response to determining that the bending moment sensor has entered a fault mode based at least in part on the mean frequency comparison result.

5. A wind turbine generator, comprising:
a blade configured to rotate in response to a wind force;
a first sensor configured to measure a bending moment experienced by the blade, wherein the first sensor includes:
a fiber bragg grating placed on a surface of the blade;
sensor circuitry configured to optically couple to the fiber bragg grating via an optical fiber, the sensor circuitry including:
a light source configured to emit a light signal; and
a light receiver configured to receive a reflection of the light signal from the fiber bragg grating and to convert the reflected light signal into the data representing the bending moment experienced by the blade;

first fault detection circuitry configured to:
compare data output by the sensor during operation with reference data indicating what is expected to be generated by the bending moment sensor to produce a comparison result, wherein the reference data includes at least one of: pre-determined data output of the first sensor during a controlled environment, and model data output from a model, wherein the model includes at least one relationship determining the model data output as a function of observed operating conditions and knowledge of properties of the first sensor; and
determine whether the first sensor has entered a first fault mode based at least in part on the comparison result; and

a controller arranged to adjust a blade pitch of the wind turbine generator by issuing pitch commands to adjust a blade pitch of the wind turbine generator, wherein upon the controller receiving an indication of the first fault mode from the first fault detection circuitry, the controller is configured to perform at least one of: ignoring an output of the first sensor and reducing a reliance on the first sensor,
wherein comparing the data generated by the bending moment sensor with the reference data to produce the comparison result includes comparing a signal power level indicated by the data generated by the bending moment sensor with a signal power level indicated by the reference data to produce a power comparison result.

6. The wind turbine generator of claim 5 , further comprising:
second fault detection circuitry configured to compare data output by the first sensor with data output by a second sensor to determine whether the first sensor has entered a second fault mode,
wherein upon the controller receiving an indication of either the first and the second fault modes, the controller is configured to perform at least one of: ignoring an output of the first sensor and reducing a reliance on the first sensor.

7. The wind turbine generator of claim 6 , further comprising a second blade, wherein the second sensor is configured to measure a bending moment experienced by the second blade.

Assignees

• Caponetti Fabio
• Brath Per
• Hammerum Keld
• Nielsen Johnny
• Vestas Wind Sys As

Inventors

• Caponetti Fabio
• Brath Per
• Hammerum Keld
• Nielsen Johnny

Classifications

• F03G7/00 Primary

  Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for · CPC title

• F03D7/042

  by means of an electrical or electronic controller · CPC title

• F03D17/00

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

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title

• F03D7/0224

  Adjusting blade pitch · CPC title