MEASURING ASSEMBLY ON A WIND TURBINE

Abstract

The disclosure relates to a measuring arrangement of a wind power plant having a tower and an aerodynamic rotor with at least one rotor blade, for sensing wind conditions, comprising at least a first and a second measuring device for arrangement at different heights on the tower, and wherein each measuring device is prepared so as to sense, at the respective height at which it is to be arranged, wind values for different horizontal directions, said values being representative of a wind pressure from the respective direction.

Claims

1. A measuring arrangement of a wind turbine having a tower and an aerodynamic rotor with at least one rotor blade, for sensing wind conditions, the measuring arrangement comprising a first measuring device and a second measuring device for arrangement at different heights on the tower, wherein the first and second measuring devices are prepared so as to sense, at the respective height at which it is to be arranged, wind values for different horizontal directions, said wind values being representative of a wind pressure from the respective direction.

2. The measuring arrangement according to claim 1, wherein the first and second measuring devices are prepared for arrangement around the tower and configured to sense wind pressure.

3. The measuring arrangement according to claim 1, wherein the first and second measuring devices comprise a pressure sensor film which is prepared so as to sense a direction-dependent pressure profile.

4. The measuring arrangement according to claim 1, wherein the pressure sensor film is a piezo-electric film or a nanosensor film.

5. The measuring arrangement according to claim 1, wherein the first measuring device is arranged on the tower of the wind turbine at a height at which a rotor blade tip passes the tower during the rotation of the rotor.

6. The measuring arrangement according to claim 5, wherein the second measuring device is arranged above the first measuring device and below the nacelle of the wind turbine.

7. The measuring arrangement according to claim 6, further comprising a third measuring device for arrangement on the tower at a height between the first and second measuring devices.

8. The measuring arrangement according to claim 1, wherein the measuring arrangement is configured to sense at least one value of: a wind shear over the height and at least one value of a change in wind direction over the height (wind veer).

9. The measuring arrangement according to claim 1, wherein the measuring arrangement is configure to determine a measure of wind turbulence from the wind values.

10. A method comprising: sensing wind conditions at a wind turbine having a tower and an aerodynamic rotor with at least one rotor blade, wherein sensing comprises: sensing wind values at different heights on the tower; and recording direction-dependent wind values for different horizontal directions at the different heights, wherein the wind values are representative of a wind pressure from the respective horizontal direction.

11. The method according to claim 10, further comprising operating the wind turbine, wherein the wind turbine is operated as a function of the wind values sensed.

12. The method according to claim 10, further comprising determining a wind direction at the first height and at the second height, respectively, and determining a change of wind direction over the height (wind veer).

13. The method according to claim 10, wherein at least at the respective height, the horizontal direction with the largest wind value is determined to be the wind direction at the respective height.

14. The method according to claim 12, comprising at the first height and the second height, determining a wind speed, and deriving a wind shear over the height from the wind speed.

15. The method according to claim 10, comprising deriving a wind speed at the respective height in each case from the largest wind value at the respective height.

16. The method according to claim 14, comprising calculating a wind veer profile or a wind shear profile from the change of wind direction over the height (wind veer) and/or the wind shear over the height for a swept rotor area of the wind turbine.

17. The method according to claim 10, wherein at least one of: an azimuth angle and a pitch angle of the wind turbine is changed as a function of at least one of the following: a wind shear value, a wind veer value, a wind shear profile, and a wind veer profile.

18. A wind turbine comprising: a tower; a nacelle; an aerodynamic rotor; at least one rotor blade; and first and second measuring devices arranged at different heights on the tower, the first and second measuring devices being configured to sense wind from different directions.

19. The wind turbine according to claim 18, wherein the first measuring device is arranged at a height on the tower at which a blade tip of the at least one rotor blade passes the tower during the rotation of the rotor.

20. The wind turbine according to claim 19, wherein the second measuring device is arranged on the tower at a height that is above the first measuring device and below the nacelle.

21. The wind turbine according to claim 20, wherein the second measuring device is arranged on the tower directly below the nacelle.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0063] The present invention will now be explained in more detail below by way of example using exemplary embodiments and with reference to the accompanying figures.

[0064] FIG. 1 shows a schematic view of a wind turbine having a measuring arrangement.

[0065] FIG. 2 shows a schematic view of a pressure sensor film.

[0066] FIG. 3 shows a schematic view of a wind turbine having a particularly preferred embodiment of a measuring arrangement.

[0067] FIG. 4 shows a schematic view of a profile of the wind pressure at a piezo-electric pressure sensor film.

[0068] FIG. 5 shows a schematic view of a profile of the wind pressure at three piezo-electric pressure sensor films which are arranged around a tower.

[0069] FIG. 6 shows a schematic view of a profile of the wind pressure at a piezo-electric pressure sensor film in cross section.

[0070] FIG. 7A shows a profile of wind turbulence at a wind turbine.

[0071] FIG. 7B shows a profile of wind shear and wind veer at a wind turbine.

[0072] FIG. 7C shows a profile of wind veer at a wind turbine over several weeks.

[0073] FIG. 7D shows an averaged wind veer between the height of the hub and the tip, during the day and at night, on a wind turbine.

[0074] FIG. 8 shows a block diagram of system incorporating measuring devices.

DETAILED DESCRIPTION

[0075] FIG. 1 shows a wind turbine 100 with a tower 102 and a nacelle 104. An aerodynamic rotor 106 with rotor blades 108, which each have a blade tip 109, and a spinner 110, are arranged on the nacelle 104. The rotor 106 is made by the wind to move in rotation during operation and as a result drives a generator in the nacelle 104.

[0076] In addition, two measuring devices 120 and 122 are arranged at different heights on the tower 102 of the wind turbine 100 in such a way that they sense wind values for different horizontal directions at the respective height at which they are arranged, said wind values being representative of a wind pressure from the respective direction.

[0077] The first measuring device 120 is arranged here on the tower and underneath the second measuring device 122 in such a way that both the first and the second measuring devices 120 and 122 lie within the swept rotor area. The first measuring device 120 is arranged far below in a region in which the respective blade tips 109 pass the tower. The second measuring device 122 is arranged directly underneath the nacelle 104.

[0078] In addition, the first and second measuring devices 120 and 122 are arranged as a belt around the tower in such a way that each measuring device can sense a direction-dependent pressure profile over 360 in the horizontal direction.

[0079] The first and second measuring devices 120 and 122 therefore essentially form a measuring arrangement according to one embodiment, wherein elements for transmitting data and evaluating data can also be added.

[0080] FIG. 2 shows a schematic view of a section of a pressure sensor film 200 which can be arranged as a measuring device on the tower.

[0081] The pressure sensor film 200 is embodied here, in particular, as a piezo-electric film or as a nanosensor film and has a thin and essentially web-like design which permits particularly simple installation on the tower of the wind turbine, for example by bonding on. Piezo-electric films can have a thinness of less than 100 m here, a width of over 30 cm and virtually any desired length.

[0082] FIG. 3 shows a schematic view of a wind turbine 300 according to a further embodiment which has a measuring arrangement which comprises three measuring devices, specifically three piezo-electric pressure sensor films 320, 322 and 324. The three piezo-electric pressure sensor films are arranged here as a belt around the tower 302.

[0083] The first piezo-electric pressure sensor film 320 is also arranged on the tower 302 at a height at which the blade tip 309, which can also be referred to as a tip, passes the tower 302 during the rotation of the rotor 306. Accordingly, the first piezo-electric pressure sensor film 320 is arranged at the lower edge of the swept rotor area over which the rotor blades 308 pass.

[0084] The second piezo-electric pressure sensor film 322 is arranged on the tower 302, around the tower directly underneath the nacelle 304.

[0085] The third piezo-electric pressure sensor film 324 is arranged on the tower 302, around the tower centrally between the first and second piezo-electric pressure sensor films.

[0086] The measuring arrangement is therefore prepared so as to sense at least one value of the wind shear over the height and/or at least one value of the change in the wind direction over the height.

[0087] In this arrangement, higher accuracy can be achieved compared to the embodiment in FIG. 1. Wind veer values and wind shear values can be recorded with good accuracy even though the design is embodied in a comparatively simple and cost-effective way. Only three pressure sensor films and one evaluation unit are required.

[0088] FIG. 4 shows a schematic view, in different representations, of distribution of the wind pressure 400, or 440, of a pressure sensor film 420 which runs around the tower. The illustration in FIG. 4and the same applies to the illustrations in FIG. 5respectively shows, in an upper part of the figure, a plan view of the respective pressure sensor film, and illustrates the respective pressure namely in a type of illustration a pressure intensity on the respective pressure sensor film 420 or 520, 522 and 524 by means of corresponding black color intensity or density of the black points. In each case, in an illustration located below, the sensed pressure P is plotted as a diagram against the length of the pressure sensor film 420 or 520, 522 and 524.

[0089] The pressure sensor film 420 runs completely around the tower here, that is to say from 0 to 360 in the horizontal direction, but is illustrated as an unrolled pressure sensor film 420 or pressure sensor film 520, 522 and 524 in FIG. 4 and in FIG. 5. This pressure sensor film is therefore prepared so as to map the distribution of the wind pressure around the tower, specifically through 360 in the horizontal direction. A pressure sensor film which is arranged around the tower in this way has a multiplicity of wind values which are each representative of a wind pressure. In addition, the multiplicity of wind values has a maximum wind value 430, which is assumed as a wind direction and which is at approximately 180 here.

[0090] FIG. 5 shows a schematic view, in different types of illustration, of in each case a profile of the wind pressure 500 or 540, 542 and 544 at three pressure sensor films 520, 522 and 524 which are arranged at different heights around a tower. The three piezo-electric pressure sensor films 520, 522 and 524 run completely around the tower here from 0 to 360 in the horizontal direction, but at different heights, as shown in FIG. 3, wherein the films 520, 522 and 524 correspond to the films 320, 322 and 324 according to FIG. 3. Each of the pressure sensor films has a maximum wind value 530, 532 and 534 in different horizontal directions. This respective direction is adopted as a wind direction at the respective height at which the pressure sensor film is actually arranged.

[0091] As a result, different wind directions are present at different heights and, under certain circumstances, with different pressure values. Different wind strengths can be derived therefrom, said wind strengths varying over the height and therefore being suitable for calculating a wind shear value or a wind shear profile. At least one wind shear value is determined from the respective wind direction at the respective height. The wind shear values and/or wind veer values which are determined in this way can subsequently be extrapolated for the entire swept rotor area. A wind shear profile and/or wind veer profile with which the control of the wind turbine can be improved can also be created from the wind shear values and/or wind veer values which are determined in this way.

[0092] FIG. 6 shows a profile of the wind pressure at a piezo-electric pressure sensor film in cross section 600. The film is arranged over 360 around the tower in the horizontal direction at a height on a wind turbine.

[0093] The pressure curves 610, 620 and 640 show here by way of example the pressure profile transversely with respect to the pressure sensor film, that is to say along the height of the tower.

[0094] Owing to the design and/or the method of functioning of the sensor, it can be found that the sensed wind pressure drops, for example, at the upper edge and/or lower edge of the sensor, that is to say has been measured inaccurately, as is shown for example by the curve 620. However, such absolute measuring inaccuracies, and others like them, can easily be filtered out.

[0095] In addition, the sector through 170 in the horizontal direction has the highest pressures, that is to say this sector corresponds to the wind direction. Accordingly, the wind comes, on average, from 170 in the horizontal direction.

[0096] In addition, FIG. 6 also shows that the highest pressure value is not limited to a single value but instead the highest pressure value is determined from a multiplicity of pressure values above a predetermined threshold value and therefore the wind direction is subsequently determined from the highest pressure value which is determined in this way.

[0097] FIG. 7A shows a profile of wind turbulence at a wind turbine over the time period of one day. In particular, during the day, between 8 am and 8 pm, the wind has a large number of occurrences of turbulence. The occurrence of such wind turbulence is not limited to complex locations. Instead, wind turbulence occurs at all locations which have an unstable or windy atmosphere.

[0098] FIG. 7B shows a profile of the wind shear and wind veer at a wind turbine over the time period of one day. The curve 710 shows the night profile of the wind veer, and the curve 730 shows the day profile. The curve 720 shows the profile of the wind shear at night, and the curve 740 shows it during the day.

[0099] FIG. 7C shows the profile of the wind veer at a wind turbine over several weeks.

[0100] FIG. 7D shows an averaged wind veer profile between the height of the hub and the tip on a wind turbine, for the day 790 and for the night 780. These values have been recorded with a very complex method and show, in particular, the need for a method for sensing the wind veer. The recorded values have been bin-averaged, that is to quantized by means of what is referred to as binning for a statistical statement.

[0101] In order to minimize or compensate the adverse influences on the power curve of a wind turbine, shown in FIGS. 7A to 7D, it is proposed to adapt the control of the wind turbine in such a way that the effect of the wind shear and/or of the change in the wind direction over the height does not have an adverse influence on the output or the coefficients of power of the wind turbine. For this purpose, at least one method and/or one arrangement and/or device according to one of the preceding claims are/is proposed.

[0102] By means of a measuring arrangement as proposed it is possible, for example, to determine the wind direction in a particularly simple way, since the highest or largest pressure measured by a sensor corresponds to the wind direction.

[0103] The proportionalitythe higher the pressure the higher the wind speedcan also be used as an additional indication for determining a corresponding wind speed, for example by means of empirical data collection in combination with a look-up table or by previous calibration of the arrangement, for example by means of an anemometer which has already been previously installed on the roof of the nacelle.

[0104] The absolute accuracy of the measuring sensors used may be secondary here, at any rate if, in particular, the relative profile of the wind veer and of the wind shear by means of the swept rotor area is significant.

[0105] The measured values which are generated by such an arrangement can also additionally be filtered. For example, to minimize the influence of passing rotor blades on the measuring arrangement, the measuring arrangement can be coupled to the rotor blade positioning system of the wind turbine. However, other devices and/or methods for filtering the sensed data are also conceivable.

[0106] The data which is filtered in this way can also be filtered, in particular bin-averaged and used to control the pitch angles and/or azimuth angles.

[0107] For example, the pitch angle of the individual rotor blades can be set as a function of the height by 1 or 3 or more degrees over the height. It is also conceivable, in the case of very strong wind veer and/or wind shear to rotate the entire wind turbine in and/or out of the wind by means of the azimuth, for example through 1 azimuth in the case of 10% wind shear over the height of the swept rotor area.

[0108] FIG. 8 shows a block diagram of a system that incorporates the measuring devices as described herein, such as the measuring devices 120 and 122. The system further includes a controller 220, which may be any control unit including a processor, and performs the functions of the computational and/or evaluation unit described above. The controller 220 is coupled to a memory 222 to record data received by the measuring devices 120 and 122 and generated by the controller 220. The controller 220 may include the memory itself or may be externally coupled to the memory. The controller 220 is coupled to the wind turbine and configured to control the wind turbine based on the determined wind values.

[0109] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.