Method and apparatus for monitoring the state of a wind turbine by means of vibration analysis

Abstract

The invention relates to a method for monitoring the state of a wind turbine (1) by means of an analysis of vibrations of at least one rotor blade (6) of a rotor (4) of the wind turbine (1). The method comprises the following steps: - sensing vibrations of the at least one rotor blade (6) by means of at least one vibration sensor disposed in or on the rotor blade (6); - sensing at least one acceleration value and / or rotation rate value at at least one position of an acceleration sensor (11, 21) and / or gyrosensor (12, 22) which is disposed in or on the rotor blade (6); - determining an operating state of the rotor (4) and / or the rotor blade (6) on the basis of the at least one acceleration value and / or rotation rate value; - analyzing the vibrations of the at least one rotor blade (6) taking into account the operating state of the rotor (4) and / or the rotor blade (6). The invention also relates an assembly for monitoring the state of a wind turbine (1), comprising at least one vibration sensor for sensing vibrations of the at least one rotor blade (6), said vibration sensor being disposed in or on at least one rotor blade (6) of the wind turbine (1). The assembly is characterized in that an acceleration sensor (11, 21) and / or a gyrosensor (12, 22) is disposed in or on the rotor blade (6), and in that an evaluation device for carrying out a method of this type in order to analyze the sensed vibrations is provided.

Description

[0001] Method and device for monitoring the condition of a wind turbine using vibration analysis

[0002] The invention relates to a method for monitoring the condition of a wind turbine by analyzing vibrations detected in or on at least one rotor blade of the wind turbine. The invention further relates to a device comprising at least one vibration sensor arranged in or on a rotor blade.

[0003] Vibrations of a rotor blade during operation of a wind turbine can provide information about the condition of the rotor blade itself and possibly also of connected components such as the drive train of a wind turbine, as described, for example, in the document WO 2006 / 012827 A1. By analyzing the measured oscillations, also called vibrations, e.g. with regard to amplitudes and / or occurring frequencies, an aging assessment of the rotor blade and / or damage detection can be carried out. In addition, bearing damage of the drive train can also be detected in the rotor blade. Furthermore, it is possible for the occurrence of damage events, such as a blade collision or lightning strike, to be immediately detected via vibration detection. The growth of ice on the rotor blade can also be detected.

[0004] Vibration analysis typically involves comparing measured vibration spectra with reference spectra. It has been shown that detected deviations can be more reliably assigned to typical fault patterns and causes if information about the operating condition of the turbine, the rotor, and especially the blades is available and taken into account. Typically, the operating condition data is provided as process data by the turbine control system. However, this data is usually not blade-specific; it is often only time-averaged RMS values ​​and is also subject to latency. The process data from the turbine control system therefore only provides indirect information about the condition of the rotor and the rotor blades. This type of process data usage is sufficient for condition monitoring of steady-state operating conditions.In practice, however, the assessment of transient conditions is also required to ensure continuous monitoring. Furthermore, arrangements and methods for monitoring the condition of wind turbine rotor blades are known that utilize strain gauges and / or acceleration sensors in the rotor blades to determine rotor blade deflection under a load situation, for example, as described in WO 2013 / 097860 A1 or EP 3 191 791 B1. Information can be extracted from the load situation that is used to control the wind turbine, e.g., to adjust collective or individual pitch angles (i.e., the angle of rotation of the blades around their longitudinal axis) or to align the rotor into the wind by rotating the tower.

[0005] It is an object of the present invention to provide improved condition monitoring by means of an analysis of vibrations of at least one rotor blade, which allows condition, in particular damage and event detection with increased accuracy, thereby expanding the monitoring options of the wind turbine.

[0006] This object is achieved by a method or arrangement having the features of the respective independent claim. Advantageous embodiments and further developments are the subject of the dependent claims.

[0007] A method according to the invention for monitoring the condition of a wind turbine by analyzing vibrations detected in or on at least one rotor blade of the wind turbine comprises the following steps: Vibrations of the at least one rotor blade are detected by means of at least one vibration sensor arranged in or on the rotor blade. Furthermore, at least one acceleration and / or yaw rate value is detected at at least one position of an acceleration sensor and / or gyro sensor arranged in or on the rotor blade. An operating state of the rotor and / or the rotor blade is determined based on the at least one acceleration and / or yaw rate value. Finally, the vibrations of the at least one rotor blade are analyzed taking into account the operating state of the rotor and / or the rotor blade.

[0008] Because the operating state of the rotor and / or the rotor blade is determined directly in or on the rotor blade itself using the acceleration sensor and / or gyro sensor, information about the current and actual operating state is immediately available and can be taken into account when evaluating the vibrations of the rotor blade individually for this rotor blade and with the correct temporal correlation. In one embodiment of the method, the operating state relates to a rotational position of the rotor and thus the basic position of the rotor blade, e.g. whether the blade is pointing vertically upwards or downwards or whether the blade is pointing horizontally to the right or left. The rotational position of the rotor can be determined from the measured acceleration values ​​of the acceleration sensor in or on the rotor blade using a gravitational component of the acceleration values ​​that changes sinusoidally with the rotor rotation.

[0009] The vibration spectra can vary slightly for different blade positions. If damage to the rotor blade or ice buildup needs to be detected, for example, a comparison with reference spectra can be performed. Small deviations from the reference spectrum can be detected particularly sensitively if the reference spectrum was recorded at the same blade position or is available for different blade positions.

[0010] In a further embodiment of the method, the operating state relates to an axial rotational position and / or axial torsion and / or bending of the rotor blade. These operating states of the rotor blade also influence its (natural) vibrations and thus vibration spectra. Small deviations from the reference spectrum can be detected particularly sensitively if the reference spectrum was recorded under the same or at least comparable operating states of the blade.

[0011] The axial rotational position of the rotor blade, also known as the pitch angle, can be measured directly on or in the blade, for example, using a gyro sensor, also known as a rotation rate sensor. According to the invention, information is therefore available about the current pitch angle of the rotor blade in question, rather than merely information about a setpoint value for the pitch angle that can be retrieved from a higher-level control system (turbine control) with a possible time delay. Since the vibration behavior during the pitch angle adjustment process is fundamentally different (clamping changes during movement and the blade twists) compared to stationary operation, this information is essential for correctly assigning and evaluating the vibration spectra. Misinterpretations of the vibration spectra and potentially resulting false alarms can be avoided.In addition, pitch angle misalignments can be directly measured and, if necessary, signaled. A particular advantage of using the gyro sensor is that a sample stream with an equidistant rotation angle relative to the rotor can be derived simultaneously from a time-equidistant sample stream of measured values ​​from other sensors, e.g., the acceleration sensor. This allows speed-synchronous kinematic vibrations such as tooth mesh frequencies from the gear stages to be identified and measured at any time, even on a rotor that does not have a precisely constant rotation rate. In addition to monitoring the drive train itself, signal components that originate from the kinematics of the drive train can be largely eliminated from the signal in order to analyze blade-related frequencies without interference.

[0012] Furthermore, the operating condition can affect a bending or bending moment at a rotor blade root. The bending or bending moment indicates the load condition of the rotor blade.

[0013] The load on a rotor blade changes dynamically depending on the wind conditions and the subsequent actions of the turbine control system, which attempts to generate optimal electrical power by aligning the rotor in the wind and adjusting the pitch angle of the rotor blades. Due to this dynamic nature, the measured vibration spectrum is subject to constant changes. Individual states, which may also be reflected differently in the individual blades, cannot be clearly differentiated using latency-based and averaged information about operating states, which would otherwise compensate for their influence on the frequency spectrum using discrete-time calculations.

[0014] According to the invention, vibration analysis can be improved using current information about the rotor blade load measured on the respective blade. The vibration spectra of the individual blades can be assigned to the current load state of the individual blades. Without this current load information, however, only an assignment to the overall operating state of the turbine would be possible.

[0015] In a preferred embodiment of the method, information from the at least one vibration sensor, on the one hand, and from the at least one acceleration sensor and / or the at least one gyro sensor, on the other hand, is acquired and evaluated synchronously with one another. The synchronous and thus phase-locked data acquisition of all measured variables enables correct consideration of the various operating states when evaluating the vibration spectra. Preferably, the measured values ​​of the vibration sensor and the at least one acceleration sensor and / or the at least one gyro sensor are acquired with a time resolution and time correlation to one another in the range of less than 10 milliseconds (ms), and more preferably of less than 250 microseconds (ps), and more preferably in the range of 1 ps.

[0016] In the context of the registration, “time synchronous” means that the measurements are either actually carried out at the same time, or that the measurements are each provided with a time stamp so that measurements can be interpolated to the same point in time.

[0017] In a further development of the method, the time-synchronized signals and / or data can originate from a root measuring module in the region of a blade root of at least one rotor blade. In further developments, time-synchronized measurements are also recorded within the same rotor blade, which are recorded by a blade measuring module arranged at a radial distance within the same rotor blade. Finally, in a further advantageous embodiment, measurements are taken synchronously on at least two, preferably all, rotor blades, wherein at least one root measuring module is arranged in the blade root region for measuring at least vibration data and acceleration data, optionally supplemented in each case by a blade measuring module mounted radially spaced within the same rotor blade.

[0018] Thus, in this embodiment, not only the measurement of vibrations and operating states via the acceleration sensor and / or gyro sensor within a module can be evaluated synchronously with each other, but also measurements taken at different radial positions within the at least one rotor blade.

[0019] The time-synchronous recording of comparable measured values ​​at different positions within the individual sheets and a comparison of the measured values ​​with each other also enables a plausibility check of the measured data or the information and / or events extracted from it.

[0020] In a further preferred embodiment of the method, the at least one acceleration sensor also serves as a vibration sensor. In this case, one and the same sensor can be used for the two different measuring tasks. This is possible if the at least one acceleration sensor covers a wide frequency range. For the vibration analysis of the blade vibrations, frequencies in the range from 0 to 2 kilohertz (kHz) are of interest. For the determination of the operating states, in particular those operating states that relate to the position of a rotor blade in space or are correlated with it, low frequencies down to 0 hertz (Hz), i.e. the static case, are particularly relevant.

[0021] Further preferably, the at least one acceleration sensor measures acceleration values ​​in three spatial directions.

[0022] An arrangement according to the invention of the type mentioned above is characterized in that an acceleration sensor and / or a gyro sensor is arranged in or on the at least one rotor blade, and in that an evaluation device is provided for carrying out a previously described method for analyzing the detected vibrations. This results in the advantages described in connection with the method.

[0023] In an advantageous embodiment of the arrangement, the acceleration sensor, from whose measured values ​​the operating states of the rotor and / or rotor blade are derived, is also used to detect the vibrations to be evaluated. Alternatively or additionally, piezo sensors and / or microphones can be used as vibration sensors to detect structure-borne and / or airborne sound.

[0024] The acceleration sensor is preferably a MEMS (Micro Mechanical System) sensor. This has the advantage of a wide frequency range, extending down to a static measurement at the cutoff frequency of 0 Hz. The static measurement, or a measurement at a very low frequency, is relevant for determining operating conditions. MEMS sensors are also maintenance-free and reliable and allow a high measurement repetition frequency. They are also cost-effective. Acceleration measurements are preferably taken in at least two, particularly preferably three, spatial directions in order to determine rotor rotational positions and blade bending and torsion. The gyro sensor, which is used alternatively or in addition to the acceleration sensor, is also preferably a MEMS sensor.

[0025] In a further advantageous embodiment of the arrangement, a first measuring module, hereinafter also called root measuring module, is arranged in the region of the blade root in the at least one rotor blade, which first measuring module has the at least one acceleration sensor and / or the at least one gyro sensor.

[0026] Preferably, the root measurement module is connected via an electrical line for power supply and / or data exchange to a distribution module arranged in a hub of the rotor or in one of the rotor blades. Further preferably, the root measurement module is arranged in the region of a blade bulkhead, either on the side of the hub of the blade bulkhead or in an area immediately radially outside the blade bulkhead.

[0027] A power supply or data connection via electrical cable is particularly advantageous for installations near the blade root. This is robust and cost-effective, and at least in the blade root area, it is safe from interference radiation and the influence of strong fields, for example, caused by lightning near the wind turbine.

[0028] In a further advantageous configuration of the arrangement, at least one second measuring module is arranged within the at least one rotor blade, which is connected to the root measuring module and positioned radially spaced from the root measuring module in the rotor blade. The second measuring module is also referred to below as the blade measuring module. The blade measuring module preferably has at least one further acceleration sensor and / or at least one further gyro sensor. Further preferably, a field strength sensor, e.g., an induction loop and / or a magnetic field sensor, can be present in order to be able to detect and record strong field strength changes caused by lightning strikes, which are accompanied by induced voltages and magnetic fields, in the vicinity of the wind turbine.

[0029] Preferably, the at least one leaf measuring module is connected to the root measuring module via at least one optical fiber, wherein a power supply to the leaf measuring module and / or a data connection between the leaf measuring module and the root measuring module takes place via the at least one optical fiber. In this case, a radiation source, in particular a light-emitting diode (LED) or a semiconductor laser, can be provided in the root measuring module, and a photovoltaic cell can be provided in the leaf measuring module, which converts light received via the optical fiber into electricity used to operate the leaf measuring module. Furthermore, a storage unit for electrical energy can be provided in the leaf measuring module to collect transmitted energy and operate energy-intensive components of the leaf measuring module in a pulsating manner.

[0030] Measuring acceleration values ​​at various radially spaced positions within at least one rotor blade also makes it possible to determine rotor blade torsion. Due to the time synchronicity of the measurements, it is possible to determine, for example, whether the tip of a rotor blade is leading or lagging behind the blade root, which allows the calculation of load moments in the direction of rotor rotation.

[0031] In a further advantageous embodiment of the arrangement, a root measuring module, optionally together with at least one blade measuring module, is present in at least two, preferably all, rotor blades of the rotor. Power is preferably supplied to the root measuring modules and thus also to the blade measuring modules jointly from the distribution module arranged in the hub or in one of the rotor blades.

[0032] The data from the root measurement modules of the various rotor blades and, if applicable, the blade measurement modules is preferably also collected by the common distribution module, from where the data is transmitted via a wired data line, in particular an Ethernet line and particularly preferably a Single Pair Ethernet (SPE) line, if applicable with power transmission (PoE - Power over Ethernet), to another computing unit within a nacelle of the wind turbine or external to the wind turbine. Provision can be made for complete data processing to take place in the distribution module. Alternatively, provision can be made for preprocessing and, if applicable, time synchronization of the data to take place in the distribution module, and for the preprocessed data to then be forwarded to the next computing unit. The next computing unit can also be physically located somewhere other than in the wind turbine.

[0033] It is advantageous here that a signal for time synchronization of the various root measuring modules and thus also of the blade measuring modules is output by the distribution module. Alternatively, a radio signal, in particular a GPS Global Positioning System signal, can be used to perform the measurements synchronously or to provide them with a sufficiently precise time stamp, based on which time-synchronized measured values ​​can be interpolated. Time synchronicity thus exists not only for measurements of different parameters (vibrations, accelerations) within a module (root measuring module or blade measuring module), but also for the modules within a rotor blade and for the measurements taken in the various rotor blades. Information about load conditions and rotational positions of the individual rotor blades can also be derived from this time synchronicity of measurements taken in the different rotor blades.

[0034] The described arrangement and method can be used, for example, to determine the following information or parameters:

[0035] - Wind speed and wind direction on the entire rotor

[0036] - Monitor drivetrain torsion

[0037] - Identify vibration types (blade natural frequencies, rotor natural frequencies)

[0038] - Ice detection on the rotor blade

[0039] - Input for ice distribution models

[0040] - Individual blade angle of rotation (pitch) control through real-time calculation of actual and target control variables with latency-free forwarding to a pitch control (if necessary only for redundant checking)

[0041] - Modeling the rotor

[0042] - Determine the wind field for a subsequent rotor blade, e.g. when passing a tower

[0043] - “Erosion index”: acoustic evaluation, noise level / spectrum depending on operating sizes

[0044] - Input for lifetime models, digital twin of the rotor / blades

[0045] - Analysis of transient operating conditions that cannot be resolved using the operating data of the plant control system.

[0046] The invention is explained in more detail below using an exemplary embodiment and the accompanying figures. The figures show:

[0047] Fig. 1 is a spatial representation of part of a wind turbine;

[0048] Fig. 2 is a schematic representation of an arrangement for monitoring the condition of rotor blades of the wind turbine of Fig. 1; and

[0049] Fig. 3 shows a more detailed schematic representation of an implementation of a branch of the arrangement shown in Fig. 2. In the figures, identical reference numerals identify identical or equivalently functioning elements. For reasons of clarity, not all elements are provided with reference numerals in all figures.

[0050] Fig. 1 initially shows, by way of example, an upper part of a wind turbine 1, in which a nacelle 3 is rotatably mounted on a tower 2. A rotor 4 with a hub 5 and, in this case, three rotor blades 6 is mounted on the nacelle 3, essentially rotatable about a horizontal axis. A drive train with a gearbox and generator is arranged downstream of the rotor 4 in the nacelle 3.

[0051] For condition monitoring of, among other things, the rotor blades 6, an arrangement is provided in the rotor 4, which comprises a first measuring module 10 (root measuring module 10) and a second measuring module 20 (blade measuring module 20) in each of the rotor blades 6. A distributor 30 is arranged in the hub 5 of the rotor 4, which provides power to the modules 10, 20 in the rotor blades 6 and collects and transmits measurement data from the modules 10, 20.

[0052] For this purpose, electrical lines 31 for power and data are led from the distributor 30 to the root measuring modules 10. In the illustrated embodiment, optical fibers 32 lead from the root measuring modules 10 to the blade measuring modules 20, via which energy in the form of light is conducted from the root measuring modules 10 to the blade measuring modules 20 for their supply, and data is transmitted bidirectionally. In this way, the blade measuring modules 20 can be connected deep within the rotor blade 6 without the risk of high voltages being induced in electrical supply lines, for example by lightning, which could destroy the blade measuring modules 20 themselves or components connected to them. "Deep" within the rotor blade here means, for example, at 1 / 3 of the length of the rotor blade 6 or even at the blade tip.

[0053] Fig. 2 shows the arrangement of the root measuring modules 10, the leaf measuring modules 20 and the distributor 30 again schematically.

[0054] In the example shown, the root measurement modules 10 are each positioned directly behind a blade bulkhead 7. Alternatively, it is possible to position them just in front of the blade bulkhead 7, as seen from the hub 5.

[0055] As previously mentioned, the electrical lines 31 lead from the distributor 30 to the root measuring modules 10. Energy and data are transferred from each root measuring module 10 via the at least one optical fiber 32 to the associated leaf measuring module 20. For this purpose, an emitter 13 is arranged in each root measuring module 10, which feeds light into the at least one optical fiber 32. The emitter can be a high-power LED or a semiconductor laser. Each leaf measuring module 20 comprises a receiver for the light with a photovoltaic cell 23, which converts the light back into electrical energy. A DC-DC converter is connected downstream of the photovoltaic cell 23 to provide operating voltage for the leaf measuring module 20.

[0056] For data transmission, additional transceivers, each comprising an emitter and a receiver, are present in each root measurement module 10 and each leaf measurement module 20. Data transmission can take place via the same optical fiber 32 through which the energy is transmitted or, alternatively, via a separate optical fiber 32.

[0057] Data transmitted from the blade measuring modules 20 to the root measuring modules 10 is forwarded from there to the distributor 30. All data can then be output by wire from the distributor 30 via a connection 33 if wired data transmission between the nacelle 3 and the hub 5 is supported by the wind turbine 1. Alternatively, a radio transmission can be set up from the distributor 30 to a receiver in the nacelle 3. The connection 33 can be used for data and power transmission and can be configured, for example, as a PoE (Power over Ethernet) connection. If the data transmission is wireless, the connection 33 can also serve solely for the power supply.

[0058] In order to perform the measurements in the various modules 10, 20 synchronously or to provide them with a sufficiently accurate time stamp that allows interpolation to the same point in time, a time signal can be output from the distributor to the root measurement modules 10 and thus indirectly also to the leaf measurement modules 20. Alternatively, another time base can be used that is available with the appropriate accuracy at all modules 10, 20, e.g., a GPS signal.

[0059] Each root measuring module 10 and each blade measuring module 20 comprises at least one acceleration sensor 11 or 21 for measuring acceleration values. In the illustrated embodiment, the acceleration sensor 11 or 21 is a MEMS sensor that records acceleration values ​​in three dimensions and over a wide frequency range in a compact housing. In this embodiment, the acceleration sensor 11, 21 provides both vibration data at higher frequencies and acceleration values ​​at low frequencies down to 0 Hz, which are used to determine operating states of the rotor 4 and the rotor blade 6. The operating states relate, for example, to a rotational position of the rotor 4 and thus the basic position of the rotor blade 6. Furthermore, the operating states can include an axial rotational position (pitch angle) and / or an axial torsion and / or a bending of the rotor blade 6. A load on the rotor blade 6 can be derived from the bending.

[0060] To record structure-borne sound, a piezo sensor can be used, for example, while airborne sound can be recorded using a condenser microphone, an electromagnetic microphone and / or a MEMS microphone.

[0061] Furthermore, each root measuring module 10 and each leaf measuring module 20 in the example shown comprises a gyro sensor 12 or 22, which can be used in support of or as an alternative to the respective acceleration sensor 11, 21 to determine the operating states.

[0062] Fig. 3 shows a branch of the arrangement of Fig. 2, ie the distributor 30 and the root measuring module 10 or the blade measuring module 20 of one of the rotor blades 6, schematically in a possible implementation.

[0063] In the implementation shown in Fig. 3, the root measurement module 10, like the leaf measurement module 20, each has a MEMS board 17, 27, which allows for the inclusion of up to two MEMS components 18, 28. In one embodiment of the root measurement module 10, the MEMS board 17 can be equipped with only one MEMS component 18, which includes the aforementioned acceleration sensor 11 and the gyro sensor 12. The acceleration sensor 11 can have a sufficiently high temporal resolution to be able to detect frequencies up to several kHz and thus also be used as a vibration sensor.

[0064] The blade measuring module 20 has a comparable MEMS component 28, which includes the acceleration sensor 21. Additionally, a second MEMS component 28 is used here, for example, which includes the gyro sensor 22. Alternatively, separate MEMS components 18 for the acceleration sensor 11 and the gyro sensor 12 can also be used in the root measuring module 10. Conversely, the blade measuring module 20 can also use only one MEMS component 28, which includes the acceleration sensor 21 integrated with the gyro sensor 22.

[0065] The MEMS board 17, 27 is connected to a control board 14, 24 of the root or leaf measuring module 10, 20 via a bus 16, 26. The control board 14, 24 includes a processor and / or FPGA (Field Programmable Gate Array) for controlling and processing data for the respective module 10, 20. The emitter 13 or photovoltaic cell 23 for energy transmission via the optical fiber 32 is also arranged on the control board 14, 24.

[0066] Both modules 10, 20 include a microphone 15 as an additional sensor for recording airborne sound. For example, it may be provided to provide a user with a "sound sample" from the rotor blade 6 in order to acoustically assess the condition of the wind turbine 1. In addition to such manual acoustic evaluation, an automated evaluation can also be performed using a spectral analysis of the signals from the microphone 15, in particular using pattern recognition using adaptive algorithms.

[0067] Both modules 10, 20 can also include additional sensors, e.g., for measuring temperatures. In this way, the provided infrastructure for power supply and data transmission can be comprehensively utilized for all information to be recorded within the rotor blades 6.

[0068] The blade measuring module 20 also includes an induction loop 29 as an electric field strength sensor for detecting lightning events in the vicinity of the wind turbine 1. Alternatively or additionally, a sensor for measuring magnetic fields may be present, e.g., a Hall sensor, which can also detect lightning events.

[0069] As Fig. 3 further shows, a controller 34 with a processor and / or FPGA is also present in the distributor 30. Data and power are distributed via a data and power distribution bus 35, in particular an SPE bus with PoE, to three ports 36, to which, for example, only one branch for one of the rotor blades 6 is connected. Reference numerals

[0070] 1 wind turbine

[0071] 2 tower

[0072] 3 gondolas

[0073] 4 Rotor

[0074] 5 Hub

[0075] 6 rotor blades

[0076] 7 Leaf bulkhead

[0077] 10 first measuring module (root measuring module)

[0078] 11 Accelerometer

[0079] 12 Gyro sensor

[0080] 13 emitters

[0081] 14 Control board

[0082] 15 microphones

[0083] 16 buses

[0084] 17 MEMS board

[0085] 18 MEMS module

[0086] 20 second measuring module (leaf measuring module)

[0087] 21 Accelerometer

[0088] 22 Gyro sensor

[0089] 23 photovoltaic cells

[0090] 24 Control board

[0091] 25 microphones

[0092] 26 buses

[0093] 27 MEMS board

[0094] 28 MEMS module

[0095] 29 Induction loop

[0096] 30 distributors

[0097] 31 electrical cable

[0098] 32 optical fibers

[0099] 33 connection

[0100] 34 Control

[0101] 35 Data and power distribution bus

[0102] 36 connection

Claims

Claims 1 . Method for monitoring the condition of a wind turbine (1) by means of an analysis of vibrations of at least one rotor blade (6) of a rotor (4) of the wind turbine (1), comprising the following steps: - detecting vibrations of the at least one rotor blade (6) by means of at least one vibration sensor arranged in or on the rotor blade (6); - detecting at least one acceleration and / or rotation rate value at at least one position of an acceleration sensor (11, 21) and / or gyro sensor (12, 22) arranged in or on the rotor blade (6); - determining an operating state of the rotor (4) and / or the rotor blade (6) based on the at least one acceleration and / or rotation rate value; - analyzing the vibrations of the at least one rotor blade (6) taking into account the operating state of the rotor (4) and / or the rotor blade (6).

2. Method according to claim 1, wherein the operating state relates to a rotational position of the rotor (4).

3. Method according to claim 1 or 2, wherein the operating state relates to an axial rotational position and / or an axial torsion and / or a bending of the rotor blade (6).

4. The method according to claim 3, wherein the operating state relates to a bending moment at a blade root of the rotor blade (6), which is determined based on the bending of the rotor blade (6).

5. Method according to one of claims 1 to 4, in which information from the at least one vibration sensor on the one hand and from the at least one acceleration sensor (11, 21) and / or the at least one gyro sensor (12, 22) on the other hand are recorded and evaluated in a time-synchronous manner with one another.

6. Method according to one of claims 1 to 5, wherein the at least one acceleration sensor (11, 21) also serves as a vibration sensor.

7. Method according to one of claims 1 to 6, wherein the at least one acceleration sensor (11, 21) measures acceleration values ​​in three spatial directions.

8. Arrangement for monitoring the condition of a wind turbine (1), comprising at least one vibration sensor arranged in or on at least one rotor blade (6) of the wind turbine (1) for detecting vibrations of the at least one rotor blade (6), characterized in that an acceleration sensor (11, 21) and / or a gyro sensor (12, 22) is arranged in or on the rotor blade (6), and in that an evaluation device for carrying out a method according to one of claims 1 to 7 for analyzing the detected vibrations is present.

9. Arrangement according to claim 8, in which the acceleration sensor (11, 21) serves to detect the vibrations.

10. Arrangement according to claim 8 or 9, in which at least two, preferably all rotor blades (6) of the wind turbine (1) have at least one acceleration sensor (11, 21) and / or gyro sensor (12, 22).

11. Arrangement according to one of claims 8 to 10, wherein in the at least one rotor blade (6) a first measuring module (10) is arranged in the region of a blade root, which has the at least one acceleration sensor (11, 21) and / or the at least one gyro sensor (12, 22).

12. Arrangement according to claim 11, wherein the first measuring module (10) is connected via an electrical line (31) for power supply and / or data exchange to a distributor (30) which is arranged in a hub (5) of a rotor (4).

13. Arrangement according to claim 11 or 12, wherein the first measuring module (10) is arranged in the region of a blade bulkhead (7).

14. Arrangement according to one of claims 11 to 13, wherein at least one second measuring module (20) is arranged within the at least one rotor blade (6), which is connected to the first module (10) and is positioned in the rotor blade (6) at a radial distance from the first module (10).

15. Arrangement according to claim 14, wherein the at least one second measuring module (20) has at least one further acceleration sensor (21) and / or at least one further gyro sensor (22).

16. Arrangement according to claim 14 or 15, wherein the at least one second measuring module (20) comprises a field strength sensor, in particular an induction loop (29) and / or a magnetic field strength sensor.

17. Arrangement according to one of claims 12 to 16, wherein the distributor (30) is arranged to output a signal for time synchronization to each first measuring module (10) and optionally to each at least one second measuring module (20).

18. Arrangement according to one of claims 14 to 17, in which the at least one second measuring module (20) is connected to the first measuring module (10) via at least one optical fiber (32), wherein a power supply of the at least one second measuring module (20) and / or a data connection of the at least one second measuring module (20) to the first measuring module (10) takes place via the at least one optical fiber (32).

19. Arrangement according to one of claims 8 to 18, wherein the at least one acceleration sensor (11, 21) and / or the at least one gyro sensor (12, 22) are MEMS sensors.

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