WO2016087451A2 - Procédé de détection d'une instabilité en torsion d'une pale de rotor d'éolienne et profilé pour une pale de rotor - Google Patents

Procédé de détection d'une instabilité en torsion d'une pale de rotor d'éolienne et profilé pour une pale de rotor Download PDF

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Publication number
WO2016087451A2
WO2016087451A2 PCT/EP2015/078233 EP2015078233W WO2016087451A2 WO 2016087451 A2 WO2016087451 A2 WO 2016087451A2 EP 2015078233 W EP2015078233 W EP 2015078233W WO 2016087451 A2 WO2016087451 A2 WO 2016087451A2
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WO
WIPO (PCT)
Prior art keywords
rotor blade
acceleration
acceleration sensor
signal
profile
Prior art date
Application number
PCT/EP2015/078233
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German (de)
English (en)
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WO2016087451A3 (fr
Inventor
Mathias Müller
Matthias Schubert
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fos4X GmbH
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Publication date
Application filed by fos4X GmbH filed Critical fos4X GmbH
Publication of WO2016087451A2 publication Critical patent/WO2016087451A2/fr
Publication of WO2016087451A3 publication Critical patent/WO2016087451A3/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03D—WIND MOTORS
    • F03D17/00—Monitoring or testing of wind motors, e.g. diagnostics
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
    • G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
    • G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
    • G01P15/093—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by photoelectric pick-up
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00—Control
    • F05B2270/30—Control parameters, e.g. input parameters
    • F05B2270/325—Air temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00—Control
    • F05B2270/30—Control parameters, e.g. input parameters
    • F05B2270/334—Vibration measurements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00—Control
    • F05B2270/80—Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
    • F05B2270/804—Optical devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00—Control
    • F05B2270/80—Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
    • F05B2270/807—Accelerometers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00—Control
    • F05B2270/80—Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
    • F05B2270/808—Strain gauges; Load cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/72—Wind turbines with rotation axis in wind direction

Definitions

  • Embodiments of the present invention generally relate to a control and / or regulation or monitoring of the operation of wind turbines and the components used for this purpose, such as acceleration sensors and / or the corresponding components of a wind turbine.
  • embodiments relate to a method for monitoring a torsional instability of a rotor blade of a wind turbine, and a profile for a trailing edge of a rotor blade of a wind turbine, a rotor blade of a wind turbine, a rotor of a wind turbine, and a wind turbine.
  • Wind turbines are subject to a complex control, which may be necessary, for example, by changing operating conditions. Due to the conditions associated with the operation of a wind turbine, for example, temperature fluctuations, weather and weather conditions, but also in particular greatly changing wind conditions, as well as the variety of legally required safety measures, the monitoring and necessary for monitoring sensors are subject to a variety of boundary conditions. For example, torsional instability of the rotor blades may occur during operation. In this case, the rotor blade rotates about a substantially along the radius extending torsion axis, and may possibly to a vibration or Oscillation around the torsion axis, the so-called flutter. To control the operation of a wind turbine, it is important to detect or monitor a torsional instability.
  • a plurality of sensors is used. For example, strain measurements for measuring the bending of a rotor blade, acceleration measurements for measuring an acceleration of a rotor blade, or other quantities can be measured.
  • a group of sensors that appear promising for future applications are fiber optic sensors. It is therefore desirable to further improve measurements for monitoring a wind turbine with fiber optic sensors.
  • a method for detecting a torsional instability of a rotor blade of a wind turbine includes measuring an acceleration with a fiber optic acceleration sensor, wherein the acceleration sensor is provided at a radial position in the area of the outer 70% of the radius of the rotor blade and evaluating the acceleration to generate a signal for detecting a torsional instability, in particular flapping, and / or a torsion-bending coupling detection signal.
  • a method for detecting a torsional instability of a rotor blade of a wind turbine is provided.
  • the method includes measuring acceleration with a fiber optic acceleration sensor, wherein the acceleration sensor is provided at a radial position in the range of the outer 70% of the radius of the rotor blade, and wherein the signal is guided with an optical fiber to the blade root of the rotor blade, which extends in particular along a trailing edge of the rotor blade; and evaluating the acceleration to generate a signal for detecting a torsional instability, in particular flutter, and / or a signal for detecting a torsional-bending coupling.
  • a profile for the trailing edge of a rotor blade of a wind turbine comprises at least a first fastening device for a light guide, in particular wherein the profile is designed to extend along at least 10% or at least 30% of the radius of the rotor blade, more particularly wherein one or more segments of the profile along at least 10% or extend at least 30% of the radius of the rotor blade
  • Figure 1 shows schematically a rotor blade of a wind turbine with an acceleration sensor according to embodiments described herein;
  • Figure 2 shows schematically a part of a wind turbine with rotor blades and acceleration sensors according to embodiments described herein;
  • Figure 3 shows schematically a light guide with a fiber Bragg grating for use in acceleration sensors according to embodiments described herein;
  • FIG. 4 schematically shows an embodiment of an acceleration sensor according to embodiments described here or for use in embodiments described here
  • Figure 5 shows schematically a rotor of a wind turbine with rotor blades and acceleration sensors according to embodiments described herein or for use in embodiments described herein;
  • FIG. 6 shows schematically a measurement setup for a fiber-optical acceleration sensor according to embodiments described here or for methods for monitoring and / or control and / or regulation according to embodiments described here;
  • FIG. 7 schematically shows a measurement setup for a fiber-optic acceleration sensor according to embodiments described here or for methods for monitoring and / or control and / or regulation according to embodiments described here;
  • FIG. 7A shows the influence of the measurement with an anti-aliasing filter according to embodiments described here
  • FIGS 8A and 8B schematically show acceleration sensors for use in embodiments described herein;
  • Figures 9A and 9B schematically show a fiber optic acceleration sensor according to embodiments described herein and for use in embodiments described herein;
  • Figure 10 shows schematically a rotor blade of a wind turbine with an acceleration sensor according to embodiments described herein;
  • Figure 11 shows schematically a rotor blade of a wind turbine with an acceleration sensor according to embodiments described herein or for use in embodiments described herein, wherein a profile for a rotor blade according to embodiments described herein is provided;
  • Figure 11A shows a profile for a rotor blade according to embodiments of the present invention;
  • Figures 12, 13A and 13B show schematically a part of a rotor blade of a wind turbine with an acceleration sensor according to embodiments described herein or for use in embodiments described herein;
  • Figure 14 shows schematically another part of a rotor blade of a wind turbine with a connection of an acceleration sensor according to embodiments described herein or for use in embodiments described herein;
  • Figure 15 shows schematically a part of a rotor blade of a wind turbine with an acceleration sensor according to embodiments described herein or for use in embodiments described herein;
  • Figures 16 to 18 show flowcharts of methods for monitoring and / or control and / or regulation of wind turbines according to embodiments described herein.
  • FIG. 1A shows a rotor blade 100 of a wind power plant.
  • the rotor blade 100 has an axis 101 along its longitudinal extent.
  • the length 105 of the rotor blade extends from the blade flange 102 to the blade tip 104.
  • an acceleration sensor 110 in an axial or radial region, that is, a region along the axis 101, there is an acceleration sensor 110, the acceleration sensor being at a radial position in FIG Range of the outer 70% of the radius of a rotor blade of the wind turbine is provided.
  • Sensors have hitherto been mounted near the blade flange 102 in practice. Typically, sensors have in practice been mounted in the inner 20% of the radius of a rotor blade.
  • Sensors in particular acceleration sensors, can provide improved methods for measuring operating states of a wind turbine in the case of radial positioning, which is provided in the range of the outer 70% of the radius of the rotor blade contrary to common practice.
  • positioning of an acceleration sensor along the radius of a rotor blade can be provided as follows.
  • at least one acceleration sensor can be provided at a radial position in the outer 70% of the radius of the rotor blade become.
  • the advantage of mounting on a walk-in position can alternatively be given up.
  • an assembly of an acceleration sensor near the blade tip for example in a Be provided from 30% to 95% of the radius (0% corresponds to the flange at the leaf root).
  • FIG. 2 shows a wind turbine 200.
  • the wind turbine 200 includes a tower 40 and a nacelle 42. On the nacelle 42, the rotor is attached.
  • the rotor includes a hub 44 to which the rotor blades 100 are attached.
  • the rotor has at least 2 rotor blades, in particular 3 rotor blades.
  • the rotor i. the hub with the rotor blades around an axis.
  • a generator is driven to generate electricity.
  • at least one acceleration sensor 110 is provided in a rotor blade 100.
  • the acceleration sensor is connected to a signal line with an evaluation unit 114.
  • the evaluation unit 114 supplies a signal to a control and / or regulation 50 of the wind turbine 200.
  • the acceleration sensor 110 is a fiber optic acceleration sensor, in particular a fiber optic acceleration sensor.
  • a fiber optic acceleration sensor For fiber-optic acceleration sensors, an optical signal is transmitted to the evaluation unit 114 by means of a light conductor 112, for example an optical fiber.
  • the sensor element In a fiber optic acceleration sensor, the sensor element itself can be provided outside of an optical fiber. An example is described in detail with reference to Figs. 9A and 9B.
  • the actual sensor element can be made available within an optical fiber, for example in the form of a fiber Bragg grating. This is described in detail with reference to FIGS. 3 and 4. In FIG.
  • the arrows 201 illustrate a torsion of a rotor blade 100.
  • this torsion may exist along an axis 101.
  • the flapping of the rotor blade 110 can lead to dangerous operating conditions. It is therefore desirable to provide improved methods for monitoring torsional instability of a wind turbine rotor blade.
  • an acceleration with a Acceleration sensor is measured, wherein the acceleration sensor is provided at a radial position in the region of the outer 70% of the radius of the rotor blade.
  • the signal of the acceleration sensor ie the acceleration signal or the acceleration is evaluated in order to generate a warning signal.
  • the warning signal may be a signal for detecting a torsional instability, in particular flutter, and / or a signal for detecting a torsion-bending coupling.
  • the term torsional bending coupling is used.
  • the term bending-torsion coupling can be used.
  • the evaluation of the acceleration signal can take place here in the evaluation unit 114 or in the control and / or regulation 50.
  • the Torsionsinstabilmaschineen or torsional vibrations are not in the nacelle or, the blade root or, the blade flange detectable
  • the rotor blades are poorly damped in this direction, and it can cause a stimulation by dynamic stall effects.
  • torsional instabilities a measurement is made in the blade tip.
  • the torsional instability may occur locally.
  • only the tip of the rotor blade can swing.
  • Each rotor blade may separately have an individual torsional instability.
  • an acceleration sensor is provided in each rotor blade.
  • the sensor can be provided in the blade tip, i. in the outer 30% of the radius of the rotor blade, since a torsional instability can occur only in the rotor blade tip.
  • solutions for the repair, attachment or replacement of the acceleration sensors are made available, wherein in the relevant area of the rotor blade for mounting the acceleration sensor of the rotor blade is not accessible.
  • the problem of torsional instability is difficult to exclude, since this problem may not occur in the test. It can be described by embodiments described here accordingly design risks for large rotor blades or such rotor blades with a constructively provided torsional bending coupling, reduce or exclude.
  • the methods for monitoring torsional instability are also provided in rotor blades that use torsional bending coupling for passive power control.
  • the torsional instability is a problem that occurs in particular for larger leaves, for example with a length of about 40 m or more, or in modern rotor blades, which have a certain ratio of torsional stiffness to the excitation frequencies.
  • the acceleration sensor is provided in the outer 50% of the radius of the rotor blade. Additionally or alternatively, the acceleration sensor may have a distance from the torsion axis of at least 10 cm. Furthermore, it is favorable if the acceleration sensor provides at least one acceleration with a directional component perpendicular to the chord of the rotor blade or perpendicular to the blade surface. A measured acceleration direction may thus be tangential with respect to the traction axis.
  • the radial position according to embodiments made available in the range of the outer 70% of the radius of the rotor blade, in particular the outer 50% of the radius of the rotor blade, in particular the outer 70 to 95% of the radius of the rotor blade, this generates an improved signal the acceleration sensor. This allows a more reliable detection or monitoring of a torsional instability, for example, flutter.
  • fiber optic acceleration sensors in which a signal is transmitted optically via a light guide 12 allow a radial position hitherto considered unfavorable in practice since transmission by means of a light guide or an optical fiber brings a reduced risk of lightning damage with it.
  • FIG. 3 shows a sensor integrated into an optical waveguide or a fiber-optic sensor 310, which has a fiber Bragg grating 306.
  • a fiber Bragg grating 306 is shown in FIG. 3, it is to be understood that the present invention is not limited to data acquisition from a single fiber Bragg grating 306 but that along an optical fiber 112, a transmission fiber , a sensor fiber or an optical fiber, a plurality of fiber Bragg gratings 306 may be arranged.
  • Fig. 3 shows only a portion of an optical waveguide formed as a sensor fiber, optical fiber or light guide 112, which sensor fiber is sensitive to fiber elongation (see arrow 308).
  • optical or “light” is intended to indicate a wavelength range in the electromagnetic spectrum, which may extend from the ultraviolet spectral range over the visible spectral range to the infrared spectral range.
  • a center wavelength of the fiber Bragg grating 306, ie, a so-called Bragg wavelength ⁇ is obtained by the following equation:
  • nk is the effective refractive index of the fundamental mode of the core of the optical fiber and ⁇ the spatial grating period (modulation period) of the fiber Bragg grating 306.
  • a spectral width which is given by a half width of the reflection response, depends on the extent of the fiber Bragg grating 306 along the sensor fiber.
  • the light propagation within the sensor fiber or the light guide 112 is thus by the action of the fiber Bragg grating 306, for example, dependent on forces, moments and mechanical stresses and temperatures, with which the sensor fiber, ie the optical fiber and in particular the fiber Bragg grating 306 are applied within the sensor fiber.
  • electromagnetic radiation 14 or primary light enters the optical fiber or light guide 112 from the left, with a portion modifying the electromagnetic radiation 14 as a transmitted light 16 with one compared to the electromagnetic radiation 14 Wavelength profile emerges.
  • the reflected light 15 can be received at the input end of the fiber (ie at the end where the electromagnetic radiation 14 is also irradiated), the reflected light 15 also having a modified wavelength distribution.
  • the optical signal used for detection and evaluation can be provided according to the embodiments described herein by the reflected light, by the transmitted light, as well as a combination of the two.
  • the electromagnetic radiation 14 or the primary light is irradiated in a wide spectral range, results in the transmitted light 16 at the location of the Bragg wavelength a transmission minmum. In the reflected light arises at this point a reflection maximum.
  • a detection and evaluation of the intensities of the Transmissiorominimums or the reflection maximum, or of intensities in corresponding wavelength ranges generates a signal that can be evaluated in terms of the change in length of the optical fiber or the light guide 112 and thus provides information on forces or accelerations.
  • FIG. 4 shows a device 110 for detecting an acceleration.
  • the device includes a mass 402 attached to a lever arm 406.
  • the lever arm 406 has a fixed point 422, so that a movement of the lever arm and the mass, which is represented by arrow 423, is made possible.
  • an optical fiber or fiber 112 with a fiber Bragg grating 306 is attached to the lever arm 406.
  • the sensor fiber is fastened with a fastening element 412 on the lever arm 406.
  • the fastening element may be a splice or a clamping device.
  • the mass 402 is at a first Lever position is connected to the lever arm 406 and the optical fiber is connected to the lever arm 406 at a second lever position.
  • the fiber Bragg grating 306 generates an altered wavelength characteristic of the optical signal, such as the reflected light 15, that is dependent on the elongation or change in length, that is generated by reflection of the primary light or the electromagnetic radiation 14.
  • the mass is typically limited by a spring mechanism to the design in one or more spatial directions.
  • the mass can only move in one direction.
  • a sensor fiber is attached to the mass, which expands as the mass accelerates.
  • the maximum elongation and thus the sensitivity of the fiber is given by the weight of the mass and the stiffness of the fiber.
  • the resonance frequency f of the fiber-mass system has a dependence f root (k / m), which consequently decreases with increasing mass.
  • k is the spring stiffness of the fiber-mass system. Since the minimum spring stiffness is limited by the stiffness of the fiber, only a limited range can be configured.
  • the movement represented by arrow 423 is a movement of the lever arm 406 and the mass 402 in the plane of the paper of Figure 4.
  • the fixed point 422 may be configured such that a movement occurs only in one plane.
  • a movement can also take place in two levels or even three levels.
  • further optical fibers, each having a fiber Bragg grating 306, can be connected to the lever arm 406, so that acceleration can be detected in several spatial directions.
  • an apparatus for multidimensionally detecting acceleration is performed as described with reference to FIG. 8B.
  • FIG. 5 shows a rotor 500 of a wind power plant.
  • the rotor 500 has a hub 44 and rotor blades 100 mounted thereon.
  • an acceleration sensor 110 is provided in at least one of the rotor blades 100.
  • the signal of the acceleration sensor 110 is passed via a light guide 112 to a distributor 510.
  • the distributor 510 may be, for example, a field distributor to which multiple signals from different sensors are provided.
  • the distributor or field distributor may be attached to the blade bulkhead of the rotor blade.
  • the distributor can be designed for connecting and disconnecting a signal cable of a sensor.
  • a sensor cable can be provided for connection and disconnection from the field distributor to the measuring device or to the evaluation unit.
  • the manifold 510 is provided at the sheet bulkhead or in the blade root. The area of the blade root is illustrated by the dividing line 502. Typically, the blade root extends radially from a blade flange 102 that secures the rotor blade 100 to the hub 44, ie along the length of the rotor blade over a length of 1 m to 3 m.
  • a light guide 512 or an optical fiber can be guided from the distributor 510 to the evaluation unit 114.
  • the light guide 512 can be guided along a spring or a spiral 513 or by a spring or a spiral 513 or a corresponding mechanical element, so that upon rotation of the rotor blade 100 about its longitudinal axis, ie pitching of the rotor blade, the light guide not damaged.
  • the mechanical guidance of the optical waveguide 512 along a spiral or by a spiral 513 permits a torsion of the optical waveguide, so that the optical waveguide is not damaged when the rotor blade is pitched
  • a plurality of the embodiments described in the figures shows an acceleration sensor in each case one of the rotor blades.
  • a measurement of the acceleration at a plurality of positions of a rotor blade in particular at a plurality of radial positions in the region of the outer 70% of the radius of the rotor blade, can be performed.
  • a plurality of acceleration sensors may be provided at the respective radial position. By measuring at several radial positions, on the one hand, the measurement accuracy can be increased.
  • signals for detecting a torsional instability, in particular flutter, and / or signals for instability warning in a torsional bending coupling for different operating conditions at different radial positions can be detected more easily and / or reliably.
  • control and / or regulation of a wind turbine may be triggered by generating a warning signal at at least one radial position or generating it at a predetermined number of radial positions.
  • one or more acceleration sensors may also be combined with at least one other sensor.
  • the at least one more sensor may be selected from one or more sensors from the group consisting of: a strain sensor, a temperature sensor, a pressure sensor, a sound level sensor, and an inclinometer (for measuring the position of rotation of the rotor).
  • a sensor for measuring a pressure fluctuation for example, a sound pressure
  • a sensor for measuring a pressure fluctuation are provided on the rotor blade. In this way, for example, noises that may typically occur when a rotor blade flutters can be detected and used for the generation of warning signals.
  • the measurement of the temperature at the rotor blade for evaluating the signals of the acceleration sensor (s) is advantageous because the sheet properties, such as the natural frequency, are influenced by the temperature.
  • a correlation of the sheet properties with the signals of the acceleration sensor (s) leads to a more precise evaluation in the generation of warning signals or the measurements of the acceleration sensor (s).
  • the measurement of temperature may be made, such as with a temperature sensor, in an acceleration sensor or in an optical fiber.
  • a strain sensor for measuring a static bending moment in particular a static torsional moment, can be provided.
  • a dynamic signal of the acceleration sensor may be combined with a static signal of the strain sensor.
  • a strain sensor can be provided in the area of the blade root.
  • the strain sensor can measure an extension in at least one direction tangential to the torsion axis.
  • an orientation of a strain sensor in a range of 30 ° to 60 °, in particular 45 °, relative to the torsion axis may be advantageous.
  • control and / or regulation 50 of a wind turbine 200 as shown in Figure 2, the signal for flutter warning and / or the signal for instability warning in a torsional bending coupling for the control and / or regulation of Wind turbine to be used.
  • the control and / or regulation may in particular consist of a pitch control of a rotor blade, an adaptation of a generator characteristic of the wind turbine, an emergency shutdown of the wind turbine, or a combination of two or more of these measures.
  • FIG. FIG. 6 shows a typical measurement system for detecting acceleration with a device for detecting acceleration according to the embodiments described herein.
  • the system includes one or more acceleration sensors 110.
  • the system includes an electromagnetic radiation source 602, for example, a primary light source.
  • the source serves to provide optical radiation with which at least one fiber-optic sensor element of an acceleration sensor can be irradiated.
  • an optical transmission fiber or fiber 603 is provided between the primary light source 602 and a first fiber coupler 604.
  • the fiber coupler couples the primary light into the optical fiber or light guide 112.
  • the source 602 may include, for example, a broadband light source, a laser, a light-harvesting diode (LED), an SLD (super-luminescent diode), an amplified spontaneous emission (ASE) light source ) or an SOA (Semiconductor Optical Amplifier). It is also possible to use several sources of the same or different type (see above) for embodiments described here.
  • the fiber optic sensor element such as a fiber Bragg grating (FBG) or an optical resonator, is integrated into a sensor fiber or optically coupled to the sensor fiber.
  • the reflected light from the fiber optic sensor elements is in turn passed through the fiber coupler 604, which directs the light via the transmission fiber 605, a beam splitter 606.
  • the beam splitter 606 divides the reflected light for detection by means of a first detector 607 and a second detector 608.
  • the signal detected on the second detector 608 is first filtered with an optical edge filter 609. By the edge filter 609, a shift of the Bragg wavelength at the FBG or a wavelength change can be detected by the optical resonator.
  • a measuring system as shown in FIG.
  • the detector 607 allows normalization of the acceleration sensor measurement signal with respect to other intensity fluctuations, such as source intensity variations 602, reflections at interfaces between individual fibers, or other intensity variations. This standardization improves the measuring accuracy and reduces the dependence of measuring systems on the length of the optical fibers provided between the evaluation unit and the fiber-optic sensor.
  • An optical filter device 609 or additional optical feed devices may comprise an optical filter which is selected from the group consisting of a thin-film filter, a fiber Bragg grating, an LPG, an Arrayed Waveguide Grating (AWG), an echelle Grids, a grating arrangement, a prism, an interferometer, and any combination thereof.
  • AWG Arrayed Waveguide Grating
  • echelle Grids a grating arrangement
  • prism a prism
  • interferometer an interferometer
  • a method of monitoring a wind turbine includes measuring an acceleration with a fiber optic acceleration sensor, wherein the acceleration sensor is provided at a radial position in the range of the outer 70% of the radius of a rotor blade of the wind turbine and filtering an acceleration signal the fiber optic acceleration sensor with an analog low-pass filter or an analog anti-aliasing filter.
  • Figure 7 shows an evaluation unit 114, wherein a signal of a fiber Bragg grating 306 is guided via an optical fiber to the evaluation unit.
  • FIG. 7 also shows a light source 602, which can optionally be provided in the evaluation unit. However, the light source 602 can also be provided independently or externally by the evaluation unit 114.
  • the optical signal of the fiber optic acceleration sensor 110 is converted into an electrical signal by a detector. The conversion from an optical signal to an electrical signal is represented by the symbol 702 in FIG.
  • the electrical signal is filtered with an analog anti-aliasing filter 710. Following the analog filtering with an analog anti-aliasing filter or low-pass filter, the signal is digitized by an analog-to-digital converter 704.
  • the anti-aliasing filter may have a cut-off frequency of 1 kHz or less, in particular of 500 Hz or less, more particularly of 100 Hz or less. According to embodiments described herein, such filtering takes place prior to digitization. Furthermore, no spectral splitting of the signals takes place for the embodiments described here, an optical digitization already being carried out with a spectrometer and a multichannel detector.
  • analog low pass filtering occurs prior to digitizing a signal of a fiber optic acceleration sensor.
  • the low-pass filter may also be referred to as an analog anti-aliasing filter.
  • the Nyquist frequency is taken into account in the context of a sampling theorem, and a low-pass filtering with signal portions smaller than the Nyquist frequency by means of the analog low-pass filter or analog anti-aliasing filter is made available.
  • a digital evaluation unit 706, which may include, for example, a CPU, memory, and other elements for digital data processing.
  • a digital evaluation unit 706 which may include, for example, a CPU, memory, and other elements for digital data processing.
  • the aspect of improved measurement with fiber optic acceleration sensors on wind turbines by the use of an analog anti-aliasing filter can be used with other embodiments, in particular with regard to the positioning of the acceleration sensors, the use of the signals for flutter warning or torsional instability warning, pitch Regulation; for warning in relation to the tower clearance of a rotor blade, the mounting of acceleration sensors or optical fibers, fiber optic acceleration sensors which are improved for use in wind turbines by a reduced metal content.
  • the improved measurement with fiber-optic acceleration sensors with analog low-pass filtering prior to digitization can be further advantageously designed to perform a digital evaluation in the Stochastic Subspace Identification (SSI) digital evaluation unit 706.
  • SSI Stochastic Subspace Identification
  • eigenvalues of the rotor blade, the eigenvalues in particular the attenuations and the frequencies, i. the natural frequencies of a rotor blade can be calculated.
  • a standing or spinning wind turbine is a wind turbine with no load turning of the rotor.
  • the wind turbine can rotate freely without turning on the generator with foundedppitraum rotor blades.
  • this state may be described by a rotation frequency of the rotor of 0.1 Hz or less.
  • the measurement may be combined with a fiber optic acceleration sensor with a temperature measurement.
  • the temperature affects the properties of the rotor blade.
  • the Eigenvalues typically have a functional dependence on temperature. A deviation or change in the eigenvalues can thus be determined relative to the expected eigenvalue at a predetermined temperature.
  • consideration of a size selected from the group consisting of rotor position, temperature, pitch angle, Yaw acceleration, and rotor rotation rate may be provided in the evaluation ,
  • a method for monitoring a wind turbine by means of a fiber-optic acceleration sensor can be improved by using an analog low-pass filter or an analog anti-aliasing filter.
  • a rotor wind turbine can be provided.
  • the rotor includes at least one rotor blade.
  • a fiber optic acceleration sensor is provided at a radial position in the area of the outer 70% of the radius of the rotor blade.
  • An analog low-pass filter or anti-aliasing filter is designed to filter the acceleration signal of the fiber-optic acceleration sensor, in particular for analog filtering of an electrical signal generated from the fiber-optic acceleration signal.
  • the rotor includes an evaluation unit 114 provided in a hub 44.
  • the evaluation unit 114 may include a converter for converting the optical signal into an electrical signal.
  • a converter for example, a photodiode, photomultiplier (PM), or other opto-electronic detector may be used as the transducer.
  • the evaluation unit further includes an anti-aliasing filter 710, which is connected, for example, to the output of the converter or of the opto-electronic detector.
  • the evaluation content may further include an analog-to-digital converter 704 connected to the output of the anti-aliasing filter 710.
  • the evaluation unit 114 may also include a digital evaluation unit 706, which is set up to evaluate the digitized signals.
  • FIG. 7A shows different acceleration signals for further explanation of the embodiments described here.
  • the upper graph (730) in FIG. 7A shows a real acceleration in a rotor blade or a reference signal which was determined for experimental purposes with a reference sensor.
  • the Power Spectral Density (PSD) is plotted against the frequency to determine, for example, the eigenvalues described here.
  • the middle graph (731) shows the acceleration signal of a fiber optic acceleration sensor, wherein the acceleration signal corresponds to the reference signal.
  • the middle graph was generated without the sequence of the opto-electronic wall of the acceleration signal of the fiber optic acceleration sensor and a filtering of the opto-electronically converted acceleration signal with an analog anti-aliasing filter.
  • the lower graph in FIG. 7A shows the acceleration signal of a fiber-optic acceleration sensor, wherein the acceleration signal corresponds to the reference signal.
  • the lower graph was generated with the sequence of the opto-electronic wall of the acceleration signal of the fiber optic acceleration sensor and a filtering of the opto-electronically converted acceleration signal with an analog anti-aliasing filter. It can be clearly seen that for the lower graph (732) there exists an improved recognition of eigenvalues especially in a frequency range of 0.3 Hz to 20 Hz compared to the middle graph (731).
  • filtering the opto-electronically-converted acceleration signal with an analog anti-aliasing filter may have a cutoff frequency of 10 Hz to 40 Hz, more preferably 15 Hz to 25 Hz.
  • acceleration can be optically measured in a rotor blade.
  • an anti-aliasing filtering is performed, in particular an analog anti-aliasing filter.
  • an acceleration in a rotor blade can be optically measured according to embodiments described here.
  • An aliasing effect is prevented, as opposed to a smoothing of the measured values, whereby in the case of smoothing the measured values only a better control signal is generated.
  • the anti-aliasing filtering is carried out analogously in the embodiments described here, ie, for example, a conversion of the optical acceleration signal into an analog electrical measurement signal is used before analogue anti-aliasing filtering is provided.
  • the analog electrical measurement signal is filtered analogue lowpass, with at least half the Nyquist frequency is used as a limit.
  • the signal filtered with an analog anti-aliasing filter is evaluated by SSI (Stochastic Subspace Identification).
  • SSI Stochastic Subspace Identification
  • An acceleration in a rotor blade is measured, for example, with a fiber optic acceleration sensor described herein. This can be done in a first time interval, for example a short time interval of eg 5 to 30 minutes.
  • the parameters to be compensated can be measured. These parameters may be: a rotor blade temperature, a pitch angle, a wind speed, a power of the wind turbine (eg the power generated or the power delivered to the grid), and / or a rotation rate of the rotor.
  • the temperature of the rotor blade can be measured as an influencing variable on the eigenvalues of the rotor blade.
  • the eigenvalues of the rotor blade can be determined from the acceleration data by means of SSI in the first time interval.
  • the eigenvalues with associated parameter set from one or more of the parameters to be compensated can be stored.
  • the above-described measurement with the determination of the eigenvalues can be repeated several times until a data set is obtained which represents part or all of the parameter space during operation of the respective wind turbine. This second period may, for example, extend over several weeks.
  • the behavior of the eigenvalues above the parameter space can be determined, for example by applying a suitable model (linear model, Taylor approximation, lookup table).
  • the coefficients of the compensation model or the lookup table can be used in a computing unit on the Wind turbine to be stored. It is thus possible to calibrate the eigenvalues as a function of one or more parameters.
  • a measurement can be carried out with compensated or calibrated parameters.
  • the eigenvalues of a rotor blade can be determined by means of an acceleration measurement, for example with a fiber optic acceleration sensor. These can be converted with the help of the calibration model or the parameters, which are determined during the acceleration measurement, can be used for a compensation of the eigenvalues.
  • a deviation of the compensated eigenvalues can be determined.
  • the output of a warning signal can be made available by means of one or more threshold values. Alternatively, multiple threshold values can be provided within the parameter space, so that the output of a warning signal is based on the eigenvalues in the parameter space, i. without previous conversion of eigenvalues.
  • a further aspect or embodiment, independently of other embodiments but also provided in combination with other embodiments, is monitoring a wind turbine with a fiber optic strain sensor.
  • the method of monitoring a wind turbine includes measuring strain with a fiber optic strain sensor.
  • a digitized signal of the strain sensor is subjected, for example, to a digital evaluation in a digital evaluation unit, using an evaluation by means of Stochastic Subspace Identification (SSI).
  • SSI Stochastic Subspace Identification
  • eigenvalues of the rotor blade, the eigenvalues in particular the attenuations and the frequencies, i. the natural frequencies of a rotor blade can be calculated.
  • the eigenvalues thus calculated can also be combined with the eigenvalues from a fiber-optic acceleration sensor or compared with these in order to obtain redundancy with respect to the information on the operating state of the wind turbine.
  • the measurement with a fiber optic strain sensor with a Temperature measurement can be combined. The temperature affects the properties of the rotor blade.
  • the temperature measurement can be used to evaluate the eigenvalues. This can be done for example by a calibration described here.
  • consideration may be given to a size selected from the group consisting of: rotor position, temperature, pitch angle, Yaw acceleration, and rotational rate of the rotor in the evaluation ,
  • the acceleration sensor 110 which is explained in more detail in Figures 8A and 8B, includes a test mass whose acceleration is measured in the sensor.
  • strain sensors used and / or acceleration sensors used may be fiber optic sensors.
  • the strain or the acceleration of the test mass is optically measured by fiber Bragg gratings in a fiber.
  • FIG. 8A shows an acceleration sensor 110 with a test mass 812 attached to an optical fiber 822.
  • a housing 802 is configured such that upon an acceleration of the mass 812, an expansion, ie a relative change in length (lengthening or shortening) of the optical fiber 822, occurs.
  • an expansion ie a relative change in length (lengthening or shortening) of the optical fiber 822.
  • the fiber Bragg grating 824 is changed. This leads to an altered reflection or transmission of the fiber Bragg grating with respect to the reflected or transported wavelengths. This change can be used as a measure of the elongation of the fiber and thus indirectly as a measure of the acceleration of the test mass 812.
  • FIG. 8B shows an acceleration sensor 110.
  • FIGS. 2 and 5 show a part of a wind turbine 200.
  • a nacelle 42 is arranged on a tower 40.
  • Rotor blades 100 are arranged on a rotor hub 44, so that the rotor (with the rotor hub and the rotor blades) rotates in a plane represented by the line 852.
  • FIG. 5 shows a front view of the rotor blades 100 and the rotor hub 44 in the direction of the axis of rotation, wherein coordinates x and y in the blade-fixed coordination system, the gravitational force or gravitational acceleration g, and the sensor 110 are shown.
  • the acceleration sensor 110 measures, inter alia, the gravitational acceleration.
  • This gravitational acceleration is measured in the coordinate system according to FIG. 5 in the y-direction and in the x-direction. Due to the inclination of the rotor, which is shown in FIG. 2, the gravitational acceleration in the coordinate system in FIG. 5 is also superimposed to a certain extent on a signal in the z direction.
  • the measurement signal which is typically measured in the y direction shown in FIG. 5, is superimposed on the gravitational signal. By cleaning up the measurement signal from the gravitational signal, a cleaned signal is obtained.
  • the controllers and / or controls of modern wind turbines typically include a so-called pitch control, wherein the rotor blade is rotated about a longitudinal axis of the rotor blade. Consequently, in a blade-fixed coordination system, the y-direction shown in FIG. 5 changes during a rotation of the rotor blade 100 about the longitudinal axis of the rotor blade.
  • an acceleration sensor 110 which includes the influence of gravitational acceleration on a test mass, it is necessary to consider the different coordinate systems for improved evaluation of the signals.
  • a coordinate system fixed with respect to the rotor hub 44 is. It is a rotating coordinate system that can be used independently of a pitch control.
  • a stationary coordinate system which is fixed with respect to the wind turbine 200 and thus fixed with respect to the gravitational force or gravitational acceleration.
  • a transformation into the stationary coordinate system is performed to correct the signal or signals of the acceleration sensor and / or the strain sensors, ie a signal in the x, y and z direction in the sheet-fixed coordinate system, wherein the rotation of Rotor, the pitch angle of the rotor blade and the inclination of the rotor, are taken into account.
  • the signal can be corrected for gravitational acceleration.
  • a back transformation into the coordinate system, which is fixed with respect to the rotor hub can be performed.
  • this coordinate system which is fixed with respect to the rotor hub, typically an acceleration is determined substantially parallel to the wind direction or substantially parallel to the axis of rotation of the rotor.
  • an acceleration sensor is provided in the outer 70% of the radius of a rotor blade, in particular in a range of 60 to 90% of the radius of the rotor blade.
  • a fiber-optic acceleration sensor such as a fiber-optic acceleration sensor
  • carried an optical signal transmission The optical signal transmission reduces the risk of lightning damage.
  • sensors as close to the blade flange to be made available By the optical signal transmission, a previously existing in practice limitation, sensors as close to the blade flange to be made available. The reduction in the risk of lightning or lightning damage can be further reduced by providing a metal-free or substantially metal-free acceleration sensor.
  • a method for monitoring a wind turbine is provided.
  • the method includes measuring an acceleration with a fiber optic acceleration sensor, wherein the acceleration sensors are available at a radial position in the range of the outer 70% of the radius of the rotor blade wherein the acceleration sensor is less than 10 wt .-% of metal or contains less than 20 g of metal.
  • a rotor blade of a wind turbine includes a fiber optic acceleration sensor, wherein the fiber optic acceleration sensor is provided at a radial position in the range of the outer 70% of the radius of the rotor blade, and wherein the acceleration sensor is less than 10 wt .-% of metal or less than 20 g Contains metal.
  • an optical fiber may be routed from the fiber optic acceleration sensor to a radial rotor blade position where the rotor blade is passable.
  • the fiber optic acceleration sensors may have a maximum extension of 10 mm in a cross section perpendicular to an extension of the light pipe.
  • acceleration sensors may be provided with sufficient metal or metal-free acceleration sensors.
  • metal-free acceleration sensors are provided, which provide a reduced risk of lightning damage.
  • a lightning-proof design or design with a reduced risk of lightning or lightning strikes can meet the high reliability and service life requirements of wind turbines.
  • a fiber optic acceleration sensors are provided as follows.
  • the fiber optic acceleration sensor includes a light guide or optical fiber having a light exit surface. Further, the fiber optic acceleration sensor includes a diaphragm and a mass in communication with the diaphragm.
  • the mass can be provided either in addition to the mass of the membrane available or the membrane can be designed with a suitable sufficiently large mass.
  • the fiber optic acceleration sensor includes an optical resonator formed between the light exit surface and the diaphragm.
  • the resonator may be a Fabry-Perot resonator.
  • the fiber optic acceleration sensor includes a mirror provided in the beam path between the light exit surface and the diaphragm, the mirror being formed at an angle of 30 ° to 60 ° relative to an optical axis of the optical fiber.
  • the mirror may be formed at an angle of 45 °.
  • FIGS. 9A and 9B show a fiber-optic acceleration sensor 910.
  • a primary optical signal is supplied to the acceleration sensor 910 via a light guide 112.
  • the optical fiber may be connected to a substrate 912.
  • the substrate 912 may be made of a non-metallic material.
  • a membrane 914 is formed on the substrate 912 or on the substrate 912.
  • the primary optical signal emerging from the light guide 112 is directed towards the membrane 912 via a mirror 916.
  • the mirror 916 may be provided as a surface formed in the substrate.
  • the substrate may be made of a material that reflects in a predetermined wavelength range, typically the wavelength range of the primary optical signal.
  • the mirror may have an angle in the range of 30 ° to 60 °, for example an angle of 45 °, relative to the axis of the light guide.
  • the primary optical signal is deflected as indicated by the arrow 901 through the mirror 916 and directed to the membrane. At the diaphragm a reflection of the primary optical signal takes place. The reflected light is like through the Arrow 903 shown coupled back into the optical fiber or the light guide 112.
  • an optical resonator 930 is formed between the light exit surface for the exit of the primary optical signal and the diaphragm. It should be noted that in general the light exit surface of the primary optical signal is equal to the light entrance surface for the reflected secondary signal.
  • the optical resonator can thus be designed as a Fabry-Perot resonator.
  • a mass 922 may be provided on the membrane 914.
  • the mass of the membrane itself may serve as ground for the detection of acceleration.
  • the diaphragm 914 is deflected by the inertia of the mass 922. This results in an optically measurable signal in the optical resonator 930.
  • the fiber optic acceleration sensor is configured to provide acceleration with a directional component for measuring, which is a directional component normal to the axis of the fiber or fiber 112. By the directional component perpendicular to the axis of the light guide 112, the fiber optic acceleration sensors 912 can be used for methods for monitoring rotor blades, or be installed in rotor blades of wind turbines or wind turbines, to allow monitoring.
  • Embodiments described herein which may be combined with other embodiments include a fiber optic acceleration sensor, ie, for example, an extrinsic fiber optic acceleration sensor having an optical sensor provided by or adjacent to the fiber, for example, an optical resonator , or an intrinsic fiber-optic acceleration sensor with a sensor provided within the fiber, provided at a radial position of the outer 70% of the radius of the rotor blade.
  • a fiber optic acceleration sensor ie, for example, an extrinsic fiber optic acceleration sensor having an optical sensor provided by or adjacent to the fiber, for example, an optical resonator , or an intrinsic fiber-optic acceleration sensor with a sensor provided within the fiber, provided at a radial position of the outer 70% of the radius of the rotor blade.
  • the radial position of the acceleration sensors described here can also be described by a radial position, at which the rotor blade in the finished state is not accessible.
  • the acceleration sensors in the outer 50% of the radius of the rotor blade or the outer 60-90% of the radius of the rotor blade can be provided. Due to the substantially metal-free design of the fiber-optic acceleration sensor, the risk of lightning strike can be reduced sufficiently to use an acceleration sensor at such a radial position in practice. Due to the outwardly displaced radial position of the acceleration sensor, a sensitivity of the acceleration sensor can be achieved, which allows a variety of monitoring, state determinations, and control options and / or control options.
  • the components of the extrinsic fiber-optic acceleration sensor shown in FIGS. 9A and 9B may consist of the following materials according to exemplary embodiments.
  • the light guide 112 may be, for example, a glass fiber, an optical fiber or an optical waveguide, whereby materials such as optical polymers, polymethyl methacrylate, polycarbonate, quartz glass, ethylene tetrafluoroethylene may be used, optionally doped.
  • the substrate 912 or the mirror 916 configured therein may be made of silicon, for example.
  • the membrane can be made of a plastic or a semiconductor which is suitable to be formed as a thin membrane.
  • the mass 922 may be provided of any non-metallic material, in particular materials having a high density being suitable. Due to a high density, the dimension of the mass can be reduced.
  • the fiber-optic acceleration sensors are in one Cross-section perpendicular to the light guide 112 in Figure 9A and 9B has a small dimensions.
  • a maximum dimension in a cross section perpendicular to the axis of the optical fiber 112 may be 10 mm or less.
  • the fiber-optic acceleration sensor 910 described in FIGS. 9A and 9B can be formed by a further modification into an independent further aspect, which is particularly useful in methods for the Monitoring of rotor blades of wind turbines and can be applied in rotor blades of wind turbines.
  • the membrane 914 may be used to measure static pressure as well as to measure a sound pressure level.
  • the area of the optical resonator 930 is separated from the ambient pressure, so that when the ambient pressure changes, a movement of the membrane takes place.
  • the membrane is designed to perform at a corresponding sound pressure, a movement, in particular an oscillating movement, which is transmitted via the optical resonator in an optical signal.
  • the sound pressure in a direction perpendicular to the longitudinal extent of the light guide 112 is measured.
  • improved acceleration sensors in particular intrinsic or extrinsic fiber-optic acceleration sensors, are provided.
  • intrinsic fiber optic acceleration sensors sensors with a provided within the fiber sensor unit, such as a fiber Bragg grating.
  • Extrinsic fiber optic acceleration sensors have an optical sensor provided by the fiber or on the fiber.
  • extrinsic fiber optic acceleration sensors can also measure acceleration without electrical components by means of an optical fiber and an optical sensor, ie a non-electrical sensor.
  • acceleration sensors can be provided, for example, at a radial position in the area of the outer 70% of the radius of the rotor blade, in particular in the area of the outer 50% of the radius of the rotor blade, for example in the range of 60% to 95% of the radius, where 0% corresponds to the flange on the blade root.
  • Further embodiments for mounting, positioning and guiding the acceleration signals from the acceleration sensor to the blade root are described below. These embodiments for mounting, positioning and for guiding the acceleration signals from the acceleration sensor to the leaf root can be used advantageously for all embodiments described here.
  • Figure 10 shows a rotor blade 100.
  • the rotor blade extends along its length 105, which corresponds to the radius of the rotor blade, from the blade flange 102 to the blade tip.
  • An acceleration sensor 110 is provided at a radial position in the region 107.
  • the acceleration sensor may be, for example, a fiber optic acceleration sensor 110.
  • a signal line from the acceleration sensor 110 to the blade root is guided along the trailing edge of the rotor blade.
  • the signal line may be a light guide 112.
  • the signal line may be provided within the rotor blade along the trailing edge, for example on a newly produced rotor blade, or outside the rotor blade along the trailing edge, for example in a trailing edge mounted profile.
  • acceleration sensors in particular fiber optic acceleration sensors or fiber optic acceleration sensors, near the blade tip, ie in radially outer regions described here in which a rotor blade is not accessible to use, nachzurösten and / or repair in case of repair appropriate maintenance to be able to take.
  • nachzurösten and / or repair in case of repair appropriate maintenance to be able to take.
  • This technical teaching relates on the one hand to the assembly, the guidance of optical fibers, redundant use of components, and / or retrofitting of corresponding sensors, on the other - alternatively or additionally - on the other hand to a data acquisition by means of an analog anti-aliasing filter or an SSI evaluation of the acceleration sensors described here.
  • a technical teaching is made available which allows a practical use of fiber optic acceleration sensors in a radial region of a rotor blade on which the rotor blade is not accessible (for example outer 70%, especially the outer 50%, more particularly the outer 30% of the radius), enable.
  • embodiments described herein allow for good use of measurement signals through the described anti-aliasing filters.
  • the corresponding components can also be provided technically in such a way that the improved control strategies or measuring strategies can also be made available over a sufficiently long service life of, for example, more than 20 years.
  • Embodiments allow, for example, repair and replacement possibilities, without which the use of acceleration sensors is impractical.
  • a puncture is provided in the interior of the rotor blade at a radial position at which the rotor blade is accessible. This may be near the leaf root or at the leaf root. However, it can also be in another radial region of the rotor blade, on which the rotor blade can be walked on.
  • the production of new rotor blades can be made in the context of manufacturing a laying of the signal cable, such as the light guide 112, inside the rotor blade, in particular in the rear of the rotor blade.
  • the sensor can also be mounted inside the rotor blade.
  • the senor can be provided in a separate chamber. This allows protection against loose glue residue and other contaminants.
  • a signal cable such as a light guide can also be guided along the trailing edge, wherein a puncture into the interior of the rotor blade preferably takes place in a walk-on area of the rotor blade. This position of the puncture allows simplified maintenance.
  • the signal line or the optical fiber may be disconnected from a connector that may be provided near the puncture.
  • a signal line provided as a substitute, for example a replacement optical fiber, or an acceleration sensor provided as a substitute can be laid outside in such a case. The original signal line or the original sensor can be abandoned here.
  • the retrofit of a sensor for example for ice detection
  • the optical fiber 112 is also routed outside.
  • a separate profile can be provided according to embodiments described herein.
  • FIG. 11 shows a further rotor blade 100.
  • a profile 150 is provided at the trailing edge of the rotor blade so that the light guide 112 can be guided in the profile.
  • the profile has a fastening device for the optical waveguide 112 or a corresponding signal cable, in particular an optical signal cable.
  • the profile 150 may be, for example, a pultruded profile.
  • the profile may be further adapted to the trailing edge of a rotor blade. It has, for example, a longitudinal extent which corresponds to at least 10% or at least 30% of the radius of the rotor blade.
  • the profile can be provided by segmented elements. For example, multiple segmented elements may extend along at least 30% of the radius of the rotor blade.
  • the profile may have a constant geometry along its length. It may also have a geometry that is designed for different trailing edge thicknesses.
  • the profile may optionally be configured to effect aerodynamic improvements of the rotor blade.
  • the profile 150 can be provided at the trailing edge 109 of the rotor blade.
  • the profile may be attached to the trailing edge with a fastener 151.
  • the profile can be provided by means of an adhesive 152 at the trailing edge.
  • the light guide 112 may be provided in the adhesive, for example, embedded. The light guide 112 extends along the trailing edge 109 of the rotor blade in the profile 150.
  • the profile may have an empty channel 153 to provide a replacement optical fiber for maintenance or repair To make available.
  • the profile 150 may include a structure 157 for aerodynamic flow control. This can be a gurney flap, for example.
  • the structure 157 is shown in dashed lines in FIG. 11A.
  • FIG. 12 shows a further optional embodiment which can be combined with other embodiments.
  • the profile 150 that can be provided at the trailing edge of the rotor blade 100, another mounting device for an acceleration sensor 110.
  • the acceleration sensor 110 may be provided in the profile 150. This allows a particularly simple retrofitting of an acceleration sensor and the corresponding optical signal transmission in the retrofittable profile at the trailing edge of the rotor blade.
  • a profile for the trailing edge of a rotor blade of a wind turbine includes at least one fastening device for a light guide.
  • the profile is configured to extend along at least 30% of the radius of the rotor blade.
  • the at least one fastening device may be one or more splices.
  • a light guide can be glued into the profile.
  • a clamping device for a light guide or an empty channel can be provided as fastening device, through which a light guide can be passed.
  • the profile may include a further attachment device for an acceleration sensor.
  • the further fastening device can be provided as a clamping device, thread or screw, and / or by one or more splices.
  • clamping devices, threads or screws are preferably formed from a non-metallic material.
  • FIG. 13A shows another embodiment that may be combined with other embodiments described herein.
  • the acceleration sensor 110 is provided in a chamber 162.
  • the light guide 112 is guided out of the rotor blade 100 at the trailing edge.
  • the light guide 112 is guided in the profile 150 along the trailing edge in the direction of the blade root or of the blade flange.
  • a plug connection 172 can be made available in a region of the transition between the rotor blade 100 and the profile 150. This allows easy replacement of the light guide 112, if it should be changed as part of maintenance.
  • fiber-optic acceleration sensors in particular fiber-optic acceleration sensors
  • fiber-optic acceleration sensors have a relatively low maintenance requirement or are relatively robust.
  • the operating conditions are extreme due to large temperature fluctuations and / or large accelerations acting on the components, in particular also possibly existing vibrations.
  • a redundancy of components or the simplified possibility for the exchange of components in particular advantageous.
  • Figure 14 illustrates the cable laying, for example the laying of the light guide 112, in a radial region of the rotor blade facing the blade root.
  • the light guide 112 is guided along the trailing edge of the rotor blade 100. This can be made possible for example in a profile as described above.
  • a puncture into the interior of the rotor blade is provided.
  • the radial position of the puncture can be set such that the rotor blade can be walked on at the radial position of the puncture.
  • a further connector 174 are provided in the area of the puncture, for Example, directly at the puncture or near the puncture inside the rotor blade.
  • An optical fiber leads from the connector 174 to a connector 176 on a manifold 510, for example, a field distributor.
  • a further optical fiber 512 leads from the distributor 510 to the evaluation unit 114.
  • the evaluation unit 114 can be provided in the hub of the rotor.
  • the light guide 512 may be guided along a spiral (spring) or through a spiral 513, which does not cause rotation of the rotor blade 100 about its longitudinal axis, for example when pitching Damage to the light guide 512 leads.
  • the light guide 512 is shown in dashed lines in Figure 14 by the spring or spiral.
  • An improved discharge of the light guide can be given by the fact that according to embodiments that can be combined with other embodiments, the light guide is guided parallel to the spiral 513 (symbolized by the dashed line or not explicitly shown).
  • FIG. 15 shows by way of example a further embodiment for the use of an acceleration sensor 110 in a rotor blade 100.
  • the acceleration sensor 110 is provided in a region near the blade tip 104.
  • two light guides are guided in the direction of the blade root or in the direction of the blade flange.
  • a further chamber 164 which can be opened in the course of maintenance, there is a first connector 178 and another connector 179. Through the use of two optical fibers, a redundancy can be provided. In the event of failure of a light guide, the chamber 164 can be opened and the plug connection 178 of the acceleration sensor 110 can be released in order to subsequently connect the acceleration sensor 110 to the plug 179.
  • additional or alternative redundancy may also be provided with respect to the acceleration sensor.
  • the failure of an acceleration sensor can be remedied by changing over.
  • a light guide laid inside can be applied and replaced by a light guide provided in a profile.
  • an empty channel may be provided both within a rotor blade and / or within a profile. In an empty channel, a light guide can be introduced later. This can be particularly advantageously combined with a connector 174, as shown in Figure 14.
  • an empty channel in a profile or in the interior of a rotor blade can also be advantageous with embodiments of acceleration sensors which, as described above, have a small maximum dimension in a cross section perpendicular to the fiber optic axis.
  • a replacement optical fiber may optionally be introduced into the empty channel with a replacement acceleration sensor.
  • acceleration sensors in particular fiber optic acceleration sensors, such as fiber optic acceleration sensors, described in wind turbines, embodiments by the radial positioning, the structure of fiber optic acceleration sensors, as well as the attachment of acceleration sensors and / or Attachment of optical fibers are provided.
  • a method for monitoring a torsional instability of a rotor blade of a wind turbine is provided.
  • a corresponding flow chart is shown in FIG.
  • Acceleration is measured with an acceleration sensor (see reference numeral 962), the acceleration sensor being provided at a radial position in the range of the outer 70% of the radius of the rotor blade.
  • the acceleration becomes Generation of a signal for flutter warning and / or a signal for instability warning in a torsion-bending coupling evaluated (see reference numeral 964).
  • the existence of a torsional instability is recorded or monitored in order to be able to undertake appropriate measures in the regulation of the wind power plant.
  • a method for monitoring a wind turbine is provided.
  • a corresponding flowchart is shown in FIG. 17.
  • Acceleration is measured with a fiber optic acceleration sensor (see reference numeral 972), the acceleration sensor being provided at a radial position in the range of the outer 70% of the radius of a rotor blade of the wind turbine.
  • the acceleration signal of the fiber optic acceleration sensor is filtered with an analog anti-aliasing filter (see reference numeral 974).
  • a method for monitoring a wind turbine is provided.
  • a corresponding flowchart is shown in FIG.
  • Acceleration is measured with a fiber optic acceleration sensor (see reference numeral 982), the acceleration sensor being provided at a radial position in the outer 70% radius of the rotor blade, the acceleration sensor being less than 10% by weight of metal or less than 20 grams of metal.
  • the acceleration sensor may be provided in particular in the outer 50% of the radius of the rotor blade, more particularly in a range of 60% to 90% of the radius of the rotor blade. In this case, it is particularly advantageous if the acceleration sensor consists of less than 10% by weight of metal or contains less than 20 g of metal.
  • Such an acceleration sensor may in particular be the fiber optic acceleration sensor according to one of the embodiments described with reference to FIGS. 9A and 9B.
  • the acceleration sensor or a light guide for signal transmission of the signal of the acceleration sensor according to one of the embodiments can be provided, as described with respect to Figures 10 to 15.

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Abstract

L'invention concerne un procédé de détection d'une instabilité en torsion d'une pale de rotor d'éolienne. Ce procédé comprend la mesure d'une accélération au moyen d'un accéléromètre à fibre optique, l'accéléromètre étant disposé dans une position radiale dans la zone des 70% externes du rayon de la pale de rotor, et l'évaluation de l'accélération en vue de la génération d'un signal de détection d'une instabilité en torsion, en particulier une vibration, et/ou un signal de détection d'un couplage torsion-flexion.
PCT/EP2015/078233 2014-12-04 2015-12-01 Procédé de détection d'une instabilité en torsion d'une pale de rotor d'éolienne et profilé pour une pale de rotor WO2016087451A2 (fr)

Applications Claiming Priority (2)

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DE102014117914.5 2014-12-04
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109416295A (zh) * 2016-07-11 2019-03-01 乌本产权有限公司 转子叶片的扭转角测量
EP3601783B1 (fr) 2017-05-09 2022-04-06 Siemens Gamesa Renewable Energy A/S Pale de rotor d'éolienne avec capteurs incorporés
CN114704439A (zh) * 2022-06-07 2022-07-05 东方电气风电股份有限公司 一种风力发电机组叶片扭转变形在线监测方法

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016116065A1 (de) * 2016-08-29 2018-03-01 fos4X GmbH Optischer magnetfeldsensor
DE102016117691B3 (de) * 2016-09-20 2017-08-03 fos4X GmbH Verfahren und Vorrichtung zur Funktionsprüfung eines faseroptischen Sensors und Computerprogrammprodukt
DE102016118136B4 (de) 2016-09-26 2018-05-17 fos4X GmbH Verfahren zur Funktionsprüfung eines Messsystems für eine technische Anlage
KR101999432B1 (ko) * 2017-04-04 2019-07-11 두산중공업 주식회사 터빈 블레이드의 플러터 측정을 위한 자기장 통신 시스템 및 방법
DE102017123077A1 (de) * 2017-10-05 2019-04-11 Wobben Properties Gmbh Verfahren zur Kalibrierung eines Drucksensors an einer Windenergieanlage sowie Windenergieanlage mit einer Einrichtung zur Kalibrierung eines Drucksensors
DE102020107180A1 (de) 2020-03-16 2021-09-16 fos4X GmbH Faseroptischer Beschleunigungssensor

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8610297D0 (en) * 1986-04-28 1986-10-01 Rolls Royce Turbomachinery
DE4241631C2 (de) * 1992-12-10 1994-11-24 Peter Dipl Ing Frieden Windkraftanlage
DE19939583A1 (de) 1999-02-24 2000-09-14 Siemens Ag Bragg-Gitter-Vorrichtung zum Messen einer mechanischen Kraft sowie Anwendung und Verfahren zum Betrieb der Vorrichtung
FR2798359B1 (fr) * 1999-09-14 2001-11-09 Eurocopter France Perfectionnements aux aeronefs convertibles a rotors basculants
DE10103387A1 (de) * 2001-01-26 2002-08-01 Thorsten Nordhoff Windkraftanlage mit einer Einrichtung zur Hindernisbefeuerung bzw. Nachtkennzeichnung
DK176352B1 (da) * 2005-12-20 2007-09-10 Lm Glasfiber As Profilserie til vinge til vindenergianlæg
DE102006022279B4 (de) * 2006-05-11 2016-05-12 Aloys Wobben Rotorblatt für eine Windenergieanlage
EP2288808A4 (fr) * 2008-05-13 2012-06-20 Purdue Research Foundation Surveillance d'eoliennes
DK2588752T3 (en) 2010-06-30 2015-08-17 Vestas Wind Sys As WIND POWER SYSTEM FOR THE DETECTION OF WINGED-icing
DE102012209935A1 (de) * 2011-12-08 2013-06-13 Wobben Properties Gmbh Hinterkasten, Rotorblatt mit Hinterkasten und Windenergieanlage mit solchem Rotorblatt
DE102011121439A1 (de) * 2011-12-16 2013-06-20 Robert Bosch Gmbh Messvorrichtung und Verfahren zum Erfassen einer Belastung eines Rotorblatts und Regelsystem zum Ansteuern des Rotorblatts

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109416295A (zh) * 2016-07-11 2019-03-01 乌本产权有限公司 转子叶片的扭转角测量
EP3601783B1 (fr) 2017-05-09 2022-04-06 Siemens Gamesa Renewable Energy A/S Pale de rotor d'éolienne avec capteurs incorporés
CN114704439A (zh) * 2022-06-07 2022-07-05 东方电气风电股份有限公司 一种风力发电机组叶片扭转变形在线监测方法
CN114704439B (zh) * 2022-06-07 2022-08-19 东方电气风电股份有限公司 一种风力发电机组叶片扭转变形在线监测方法

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