Sensor assembly for measuring at least a first torsion of a rotor blade of a wind turbine generator system

Patent metadata

Field	Value
Publication number	US-12031886-B2
Application number	US-202218076434-A
Country	US
Kind code	B2
Filing date	Dec 7, 2022
Priority date	Dec 8, 2021
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A sensor assembly for measuring a torsion of a rotor blade of a wind turbine generator system includes a first light source configured to generate light and a first transmitter-side polarizer disposed downstream thereof in a direction of light propagation and configured to generate linearly polarized light as a first transmission light. A second light source is configured to generate unpolarized light as a second transmission light. First and second detector elements are arranged and adapted to receive the first and second transmission light. A first receiver-side polarizer is disposed upstream of the first detector element in the direction of light propagation and a second receiver-side polarizer is disposed upstream of the second detector element in the direction of light propagation. An orientation of a polarization plane of the first receiver-side polarizer and an orientation of a polarization plane of the second receiver-side polarizer are different from one another.

First claim

What is claimed is:

1. A sensor assembly for measuring at least a first torsion of a rotor blade of a wind turbine generator system, the sensor assembly comprising:
a first light source configured to generate light;
a first transmitter-side polarizer disposed downstream of the first light source in a direction of light propagation and configured to generate linearly polarized light as a first transmission light;
a second light source configured to generate unpolarized light as a second transmission light;
a first detector element and a second detector element arranged and adapted to receive the first transmission light and the second transmission light; and
a first receiver-side polarizer disposed upstream of the first detector element in the direction of light propagation and a second receiver-side polarizer disposed upstream of the second detector element in the direction of light propagation, an orientation of a polarization plane of the first receiver-side polarizer and an orientation of a polarization plane of the second receiver-side polarizer being different from one another,
wherein the sensor assembly has first through third operating modes, the sensor assembly being configured to switch cyclically among the first through third operating modes.

2. The sensor assembly as recited in claim 1 , wherein no transmitter-side polarizer is disposed between the second light source and a pair formed by the first and second detector elements.

3. The sensor assembly as recited in claim 1 , wherein, in the first operating mode, the first and second light sources are switched off, wherein, in the second operating mode, the first light source is switched off and the second light source is switched on, and wherein, in the third operating mode, the first light source is switched on and the second light source is switched off.

4. The sensor assembly as recited in claim 1 , further comprising a transmitter-side color filter disposed downstream of the first light source in the direction of light propagation and a receiver-side color filter disposed upstream of the first and second detector elements in the direction of light propagation, a pass-wavelength of the transmitter-side color filter and a pass-wavelength of the receiver-side color filter being the same.

5. The sensor assembly as recited in claim 4 , wherein the transmitter-side color filter is associated with both the first and the second light sources.

6. The sensor assembly as recited in claim 1 , wherein the sensor assembly is configured to modulate each of the first and/or second light source(s) with a predetermined frequency to generate the respective first and/or second transmission light(s) as a modulated transmission light in order to obtain a first modulated measurement signal generated by the first detector element and a second modulated measurement signal generated by the second detector element.

7. The sensor assembly as recited in claim 1 , further comprising:
a first transmitter-side optical waveguide coupled to the first light source and a second transmitter-side optical waveguide coupled to the second light source;
a first transmitter-side lens element coupled to the first transmitter-side optical waveguide and a second transmitter-side lens element coupled to the second transmitter-side optical waveguide; and
a first receiver-side optical waveguide coupled to the first detector element and a second receiver-side optical waveguide coupled to the second detector element, wherein the first and second light sources and the first and second detector elements are each disposed outside a longitudinally extending portion of the rotor blade.

8. The sensor assembly as recited in claim 1 , further comprising a retroreflector disposed downstream of the first light source in the direction of light propagation and fixedly connected with the first transmitter-side polarizer, wherein the first light source, the first detector element and the second detector element are arranged side-by-side in a first direction perpendicular to a longitudinal axis of the rotor blade, and wherein the second light source is disposed between a pair formed by the first and second detector elements and the retroreflector.

9. The sensor assembly as recited in claim 1 , further comprising a transmitter unit disposed at a first position and a plurality of transmitter/receiver units disposed along a bending line of the rotor blade at second through nth positions, wherein the transmitter unit includes the first light source, the first transmitter-side polarizer, and the second light source, wherein a first transmitter/receiver unit of the transmitter/receiver units includes the first and second detector elements and the first and second receiver-side polarizers, wherein the first transmitter/receiver unit includes a third light source configured to generate light and a second transmitter-side polarizer disposed downstream of the third light source in the direction of light propagation, wherein the third light source and the second transmitter-side polarizer are configured to generate linearly polarized light as a third transmission light, and wherein the first transmitter/receiver unit includes a fourth light source configured to generate unpolarized light as a fourth transmission light.

10. The sensor assembly as recited in claim 9 , wherein the transmitter unit is configured such that the first and second transmission lights are generated with a predetermined first wavelength, wherein the first transmitter/receiver unit is configured such that the third and fourth transmission lights are generated with a predetermined second wavelength, and wherein the predetermined first wavelength and the predetermined second wavelength are different from each other.

11. The sensor assembly as recited in claim 1 , wherein the first light source and the first transmitter-side polarizer are configured to generate the linearly polarized light as the first transmission light in such a way that a polarization direction of the linearly polarized light is parallel or perpendicular to a second direction, the second direction being defined by a predetermined curvature of the rotor blade.

12. The sensor assembly as recited in claim 1 , further comprising an analysis unit configured to generate an output signal representative of a measure of the first torsion as a function of a first measurement signal generated by the first detector element and as a function of a second measurement signal generated by the second detector element.

13. The sensor assembly as recited in claim 1 , wherein the first and second light sources are arranged relative to each other in such a way that the first and second light sources radiate substantially into the same solid angle.

14. The sensor assembly as recited in claim 1 , wherein the first and/or second light source(s) are each an incoherent light source.

15. The sensor assembly as recited in claim 1 , further comprising a beam-splitting element disposed downstream of the first light source in the direction of light propagation and configured to split a beam of the first transmission light into at least a first sub-beam and a second sub-beam, wherein the first sub-beam and the second sub-beam have the same intensity or a fixed ratio of intensity, and wherein the first detector element and the second detector element are arranged and adapted such that the first detector element receives the first sub-beam and the second detector element receives the second sub-beam.

16. The sensor assembly as recited in claim 15 , further comprising an aperture stop disposed upstream of the beam

Assignees

• Heidenhain Gmbh Dr Johannes

Inventors

• Meissner Markus
• Langrieger Franz
• Reichhuber Siegfried
• Gilg Stefan

Classifications

• G01D5/28

  with deflection of beams of light, e.g. for direct optical indication (G01D5/40 takes precedence; {mechanical adjustment G01D5/264}) · CPC title

• F05B2260/83

  Testing, e.g. methods, components or tools therefor · CPC title

• F03D17/00 Primary

  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

• G01M5/0091

  by using electromagnetic excitation or detection · CPC title