METHOD FOR MONITORING A WIND TURBINE

Abstract

A method for monitoring a wind power installation having a nacelle is provided. The method includes recording a sound using at least one acoustic sensor arranged outside and on the nacelle and evaluating the recorded sound to detect an operating state of the wind power installation.

Claims

1. A method for monitoring a wind power installation having a nacelle, comprising: recording a sound using at least one acoustic sensor arranged outside and on the nacelle, and evaluating the recorded sound to detect an operating state of the wind power installation.

2. The method as claimed in claim 1, wherein the acoustic sensor is arranged atop the nacelle.

3. The method as claimed in claim 1, comprising: detecting the operating state using a sound power level of the recorded sound of the wind power installation.

4. The method as claimed in claim 1, wherein recording the sound includes recording the sound in a directionally sensitive fashion.

5. The method as claimed in claim 1, wherein recording the sound includes recording the sound in at least one frequency band in which sounds occur that are attributable to ice formation on a rotor blade of the wind power installation.

6. The method as claimed in claim 1, wherein at least one of: recording the sound includes recording the sound when the wind power installation is at a standstill or evaluating the recorded sound includes evaluating the sound recorded when the wind power installation is at the standstill.

7. The method as claimed in claim 1 comprising: evaluating of the recorded sound to detect the operating state externally, by a monitoring center.

8. The method as claimed in claim 1, wherein evaluating the recorded sound to detect the operating state includes performing spectral analysis on the recorded sound.

9. A method for controlling operation of at least one wind power installation, comprising: recording a sound of the at least one a-wind power installation using an acoustic sensor arranged outside and on a nacelle of the at least one wind power installation, evaluating the recorded sound to detect an operating state of the at least one wind power installation including the acoustic sensor, and controlling the operation of the at least one wind power installation based on the detected operating state of the at least one wind power installation including the acoustic sensor.

10. The method as claimed in claim 9, comprising: controlling, based on the recorded sound, at least one state from a list including: at least one pitch angle of a rotor blade of the at least one wind power installation, a yaw angle of the at least one wind power installation, a rated power of the at least one wind power installation, and a rated speed of the at least one wind power installation.

11. The method as claimed in claim 9 comprising: receiving, by the acoustic sensor arranged on the nacelle, external inquiry from an external unit, and transmitting the recorded sound externally to the external unit.

12. The method as claimed in claim 9, wherein the acoustic sensor is a self-sufficient sensor having a standalone arrangement, and wherein the at least one wind power installation is controlled externally based on the recorded sound.

13. (canceled)

14. A monitoring apparatus for monitoring a wind power installation having a nacelle, comprising: an acoustic sensor arranged outside and on the nacelle for recording a sound, and an evaluation device for evaluating the recorded sound to detect an operating state of the wind power installation.

15. The monitoring apparatus as claimed in claim 14, wherein the acoustic sensor has multiple microphones arranged as an array of microphones.

16. The monitoring apparatus as claimed in claim 14, comprising: a data interface for transmitting the sound recorded by the acoustic sensor or for transmitting data evaluated by the evaluation device.

17. A wind power installation having a nacelle and at least one acoustic sensor arranged on the outside of the nacelle for recording sounds, comprising: the monitoring apparatus as claimed in claim 14.

18. A wind farm, comprising at least two wind power installations including the wind power installation as claimed in claim 17.

19. The wind farm having as claimed in claim 17 in which the two wind power installations are networked with each other and are configured to exchange data via the monitoring apparatus.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0087] The present invention is now explained in more detail below by way of example using exemplary embodiments with reference to the accompanying figures.

[0088] FIG. 1 shows a schematic depiction of a wind power installation.

[0089] FIG. 2a shows a schematic depiction of the wind power installation in a plan view.

[0090] FIG. 2b shows the schematic depiction of the wind power installation in a plan view as shown in FIG. 2a, the wind power installation having an ice formation on the rotor blade.

[0091] FIG. 3 shows a diagram of a method for monitoring a wind power installation according to an embodiment.

[0092] FIG. 4 shows a diagram of a method for controlling a wind power installation according to an embodiment.

[0093] FIG. 5 shows a schematic depiction of a spectral analysis.

[0094] FIG. 6 shows a monitoring apparatus.

DETAILED DESCRIPTION

[0095] FIG. 1 shows a wind power installation 100 having a tower 102 and a nacelle 104. Arranged on the nacelle 104 is a rotor 106 having three rotor blades 108 and a spinner 110. The rotor 106 is set in a rotary motion by the wind during operation and thereby drives a generator in the nacelle 104. Arranged outside and on the nacelle is an acoustic sensor 114, or alternatively there may even be two acoustic sensors 114 provided, for example.

[0096] FIG. 2a shows a wind power installation 200 as shown in FIG. 1 in a plan view, the rotor 206 rotatably mounted on the nacelle 204 having only one of the three rotor blades 208 in a 12-o'clock position for the purposes of illustration. Further, mounted above and on the nacelle 204 is an instrument carrier 212 that has an acoustic sensor 214, in particular a monitoring apparatus 214.

[0097] The rotor blade 208, together with the rotor 206, is arranged rotatably in relation to the rest of the nacelle 204. The wind W causes the rotor blade 208 to rotate in the direction of rotation 216 denoted by the arrow. In so doing, the rotor blade 208 causes a stall 218 that, as seen from the wind direction W, is behind the rotor blade 208. It is pointed out that the depiction is schematic and particularly depicts the stall only schematically.

[0098] The laminar stall 218, which is, therefore, depicted only in simplified fashion in this case, is measurable in the form of a sound and is captured by the acoustic sensor 214, which is configured as a microphone. Depending on the angle of attack and position of the rotor blade 208 in relation to the wind W, the stall 220 can vary.

[0099] By way of example, the separation of the laminar flow takes place at another point on the rotor blade surface, or the laminar flow envelopes the rotor blade to produce a turbulent flow. Such and further alterations in the stall, which are caused in particular by the pitch angle, can be captured by the acoustic sensor and evaluated.

[0100] FIG. 2b, which is essentially based on FIG. 2a, shows the same depiction of a wind power installation 200 as shown in FIG. 1, the rotor blade 208 having icing 230, which can also be referred to as ice formation 230.

[0101] The ice formation 230, in contrast to an ice-free rotor blade 208, causes an altered stall 238, which is likewise depicted only in simplified fashion. This altered stall 238 is likewise measurable in the form of a sound and is captured by the microphone 214. The sound recorded in this manner differs perceptibly from a sound of an ice-free rotor blade, which means that the ice formation 230 on the rotor blade 208 is detected by means of a simple collation.

[0102] Both FIG. 2a and FIG. 2b show just one example of a capture of an operating state of a resource of a wind power installation. The acoustic sensor and the proposed methods are also suitable for capturing further operating states of other resources, such as the generator and the nacelle, for example. The capture of further operating states can accordingly take place at the same time using the same recorded sound.

[0103] FIG. 3 uses an overview 300 to illustrate a method for monitoring a wind power installation according to a preferred embodiment. The wind power installation has an acoustic sensor outside and on, in particular atop, the nacelle for the purpose of monitoring an operating state of the wind power installation.

[0104] The acoustic sensor is switched on in response to a signal. The signal used is an internal signal in the wind power installation 301 or an external signal from the control room 302. After it has been switched on 304, the acoustic sensor, that is to say the microphone, begins to record the sound 306 that surrounds the nacelle of the wind power installation. What is recorded 306 is subsequently transferred 307 to a filter in order to eliminate spurious signals in what is recorded. The filtering 308 takes place either internally, namely in particular in the monitoring apparatus having the sensor or externally. The monitoring apparatus comprises at least one sensor and may further also comprise a filter and an evaluation unit. Alternatively, the filtering can take place externally in a control room. For external filtering, the recorded sound is then transmitted to the control room by means of a stream via a wireless local area network (WLAN), for example.

[0105] After the filtering 308, the sound is evaluated. For evaluation 310, a spectral analysis is performed, for example, which involves the recorded and filtered sound being broken down into individual frequency bands. These frequency bands can then be collated with known frequency bands. In the event of a discrepancy between these frequency bands, a fault signal 311 would then be output, which is processed further.

[0106] The fault signal 311 can be realized by a warning signal in the control room, for example, the personnel in the control room then being able to initiate further steps in order to correct the fault.

[0107] FIG. 4 uses an overview 400 to illustrate a method for controlling a wind power installation according to a preferred embodiment, wherein the wind power installation has an acoustic sensor atop the nacelle for the purpose of control and comprises a method as described above for monitoring a wind power installation, and wherein the wind power installation is controlled externally on the basis of the recorded sound.

[0108] A control room, that is to say an external monitoring center, does this by connecting to a monitoring apparatus 401 on the wind power installation, the monitoring apparatus comprising an acoustic sensor that is arranged atop the nacelle of the wind power installation.

[0109] The acoustic sensor, which is embodied as a microphone, records the sound surrounding the nacelle and transfers it to the control room. What is recorded 404 is thus transmitted 405 to the control room.

[0110] There, the sound is filtered 406 and subsequently evaluated 408, for example by means of a spectral analysis.

[0111] The evaluation 408 establishes whether there is a fault in a resource of the wind power installation 409. If there is no fault, the control room can either disconnect 420 from the sensor or continue to transmit 421 the sound. If there is a fault, a collation is performed with a control database that uses a database to compute the most favorable controlled variable for controlling the wind power installation. This controlled variable 411 is then used to actuate the applicable resource.

[0112] In the simplest case, the control room discovers an incorrect stall at the wind power installation and then controls the yaw angle of the nacelle accordingly. In another exemplary case, the wind power installation is at a standstill and the control room connects to the microphone before the installation is started up. In this case, the control room discovers icing on the rotor blades and uses a collation 410 to decide either to deice the blades by means of heating or not to start up the installation yet.

[0113] FIG. 5 schematically shows an evaluation, in particular a spectral analysis, of a recorded sound 500.

[0114] Accordingly, a sound 502 surrounding the nacelle of the wind power installation is first of all recorded using a microphone arranged atop the nacelle of the wind power installation.

[0115] The sound recorded in this way is subsequently filtered to produce an essentially noise-free sound 504. This can be done by means of high and/or low pass filtering, for example.

[0116] Subsequently, the filtered sound is broken down into determined frequency bands 510 and 520 using a spectral analysis. The breakdown into two frequency bands is intended to convey the principle only simplistically; the evaluation is not restricted to such a breakdown into two bands.

[0117] The determined frequency bands 510 and 520 are collated with the known frequency bands 512 and 522. The frequency band 510 corresponds, by way of example, to the frequency band 510 of the recorded sound of the rotor blades and the frequency band 520 corresponds to the frequency band 520 of the recorded sound of the yaw adjustment. These are collated with the frequency bands 512 and 522 known for the rotor blades and the yaw adjustment. The known frequency bands can be ascertained a priori, for example, by means of simulation or measurement in situ. Alternatively, iterative determination of the known frequency bands 512 and 522 in the course of ongoing operation of the wind power installation is possible.

[0118] If a discrepancy is ascertained during this collation of the frequency bands, said discrepancy is transferred to evaluation logic 530 that then collates potential control processes with one another and outputs a preferred control signal 531.

[0119] FIG. 5 shows an example, and in this case the recorded frequency band 520 for the yaw adjustment has a discrepancy in relation to the known frequency band 522 for the yaw adjustment. This discrepancy is now transferred to the evaluation logic 530, which triggers a preferred control signal 531. By way of example, the angle of attack of the rotor blades is altered in order to correct the discovered discrepancy.

[0120] FIG. 6 shows a monitoring apparatus 602. The monitoring apparatus 602 comprises the acoustic sensor 114 and an evaluation device 604. The monitoring apparatus 602 has a data interface 606 for transmitting data recorded by the acoustic sensor 114 and/or for transmitting data evaluated by the evaluation device 604.