MEASURING DEVICE FOR WIND TURBINES

Abstract

A measuring arrangement for detecting deformations, in particular bending of the outer surface, of a wind turbine structural element, includes: at least two measurement sites on the structural element spaced apart from one another toward a structural element extension, each having at least one acceleration sensor, that can be communication-connected—preferably via a wireless interface—to an evaluation device. The measuring arrangement—has at least two speed sensors, in particular angular speed sensors, on the structural element and spaced apart from one another toward a structural element extension, preferably the longitudinal extension, and/or the measuring arrangement has at least two position sensors, in particular magnetic field sensors, on the structural element and spaced apart from one another toward a structural element extension, preferably the longitudinal extension. The speed sensors and/or the position sensors can be communication-connected to the evaluation device—preferably via a wireless interface.

Claims

40-40 (canceled).

41. A measuring arrangement (10) for detecting deformations, in particular bending of the outer surface, of a structural element (12, 14, 15, 16) of a wind turbine (11), wherein the structural element is a rotor blade (12) of the wind turbine (11), comprising: at least three, preferably at least five, measurement sites (1) arranged on the structural element (12, 14, 15, 16), the at least two measurement sites (1) being spaced apart from one another in the direction of the longitudinal extension, of the structural element (12) and each having at least one acceleration sensor (2), wherein the acceleration sensors (2) can be communication-connected—preferably via a wireless interface (5)—to an evaluation device (6), wherein the measuring arrangement (10) has at least two speed sensors (3), in particular angular speed sensors, arranged on the structural element (12) and spaced apart from one another in the direction of longitudinal extension, of the structural element (12), and/or wherein the measuring arrangement (10) has at least two position sensors (4), in particular magnetic field sensors, arranged on the structural element (12) and spaced apart from one another in the direction of the longitudinal extension, of the structural element (12, 14, 15, 16) wherein the measurement sites (1) each have at least one speed sensor (3) and/or at least one position sensor (4)—in addition to the acceleration sensor (2)—, and, wherein the speed sensors (3) and/or the position sensors (4) can be communication-connected to the evaluation device (6)—preferably via a wireless interface (5), and wherein at least one, preferably at least two, of the measurement sites (1) is/are arranged in the region of the rotor blade tip and/or at a distance from the rotor blade tip, which distance is at the most as great as 20% of the total length of the rotor blade (12), and wherein at least one measurement site (1) is arranged away from the connecting line between the outermost measurement sites (1) of the measuring arrangement (10), preferably between the measurement site (1) closest to the rotor blade root and the measurement site (1) closest to the rotor blade tip, wherein preferably the normal distance from the connecting line amounts to at least 20 cm, preferably at least 50 cm, and/or at least 0.5%, preferably at least 1%, of the longitudinal extension of the structural element (12), and/or wherein at least one measurement site (1) is arranged on a first side, in particular the front side, of the structural element (12), and at least one measurement site (1) is arranged on a second side opposite the first side, in particular on the rear side, of the structural element (12).

42. The measuring arrangement according to claim 41, wherein the distance between an acceleration sensor (2) and a speed sensor (3) and/or position sensor (4) belonging to the same measurement site (1) amounts to a maximum of 5 cm, preferably a maximum of 1 cm, particularly preferably a maximum of 5 mm, and/or wherein the acceleration sensor (2) of a measurement site (1), together with a speed sensor (3) belonging to the same measurement site (1) and/or a position sensor (4) belonging to the same measurement site (1), is integrated in a measuring unit (17) and/or is accommodated in a common housing.

43. The measuring arrangement according to claim 41, wherein the acceleration sensors (2) are each configured to detect the acceleration in 3 spatial directions, and/or wherein the speed sensors (3) are each configured to detect the speed in 3 spatial directions, and/or wherein the position sensors (4) are configured to detect the position or orientation in 3 spatial directions.

44. The measuring arrangement according to claim 41, wherein the measuring unit (17) has a flat base which carries the sensors (2, 3, 4), wherein the flat base is preferably formed by a film-like and/or pliant material and preferably carries at least one additional functional element, in particular a wireless interface (5) connected to the sensors (2, 3, 4) for transmitting the sensor data to an evaluation unit (6) and/or an energy conversion device (7) for supplying the sensors (2, 3, 4) with energy, wherein the flat base is preferably adhered to the surface of the rotor blade (12) of the wind turbine (11).

45. The measuring arrangement according to claim 41, wherein the acceleration sensors (2) and/or the speed sensors (3) and/or the position sensors (4) are arranged on, preferably adhered to, an outer surface of the rotor blade (12).

46. The measuring arrangement according to claim 41, wherein the acceleration sensors (2) and/or the speed sensors (3) and/or the position sensors (4) are embodied as micro-electro-mechanical systems (MEMS).

47. The measuring arrangement according to claim 41, wherein the evaluation device (6) is configured to link the acceleration data of the acceleration sensors (2) to the speed data of the speed sensors (3) and/or position data of the position sensors (4) and to identify deformations of the structural element (12) based thereon.

48. The measuring arrangement according to claim 41, wherein the sensors (2, 3, 4) of the different measurement sites (1) of the measuring arrangement (10) may be synchronized in time by means of the evaluation device (6)—preferably by means of a signal transmitted from the evaluation device (6) to the sensors (2, 3, 4), in particular in the form of a data package—, in particular with respect to the point in time of the measurement carried out by the respective sensors (2, 3, 4) and/or the point in time of the transmission of the sensor data from the sensors (2, 3, 4) to the evaluation device (6).

49. The measuring arrangement according to claim 41, wherein the evaluation device (6) is configured to transmit a signal to the sensors (2, 3, 4) of the measurement sites (1), by means of which signal the sensors (2, 3, 4) of the different measurement sites (1) are synchronized in time, so that the thusly synchronized sensors (2, 3, 4) each carry out at least one measurement within a common time frame, which is preferably at most 500 μs, preferably at most 100 μs, particularly preferably at most 50 μs.

50. The measuring arrangement according to claim 41, wherein the evaluation device is configured to identify at least one, preferably multiple, of the following values and/or properties from the sensor data of the sensors (2, 3, 4), in particular by linking the acceleration data of the acceleration sensors (2) to the speed data of the speed sensors (3) and/or position data of the position sensors (4): the absolute pitch angle of at least one rotor blade, and/or the relative pitch angle of at least two rotor blades to one another, and/or the torsion of at least one rotor blade and/or at least two rotor blades to one another, and/or the load and/or load cycle acting o at least one rotor blade, and/or a source for increase noise emissions, and/or an early sign of damage or faulty regulating state of the wind turbine, and/or the type, force, dynamics and/or direction of winds, and/or a change of the oscillation behavior of the structural element, and/or damage to the rotor blade, wherein the identification of the value(s) and properties preferably comprises a comparison between current data and historical data and/or a comparison between the data of a rotor blade and the data of at least one other rotor blade.

51. The measuring arrangement according to claim 41, wherein the evaluation device (6) is configured to identify the deformations and/or the values and/or properties from that sensor data which was gathered by the synchronized sensors (2, 3, 4) within a common time frame, which preferably amounts to a maximum of 500 μs, preferably a maximum of 100 μs, particularly preferably a maximum of 50 μs.

52. A wind turbine (11) comprising: a rotor (13) having at least two, preferably three, rotor blades (12), and at least one measuring arrangement (10) for detecting deformations of at least one structural element of the wind turbine (11), wherein the structural element is a rotor blade (12) of the wind turbine (11), and a control device (8), wherein the at least one measuring arrangement (10) is formed according to claim 41.

53. The wind turbine according to claim 52, wherein for at least two rotor blades (12) of the wind turbine (11), in particular for each rotor blade (12) of the rotor (13), a measuring arrangement (10) is provided, wherein the sensors (2, 3, 4) of the measuring arrangements (10) are preferably communication-connected—preferably via a wireless interface (5)—to a central evaluation device (6).

54. The wind turbine according to claim 52, wherein the control device (8) is configured to control the wind turbine (10) depending on the sensor signals generated by the measurement sites (1) of the measuring arrangement (10), in particular to adjust the rotor (13) with respect to the wind direction and/or to set the pitch of the rotor blades (12).

55. A method for operating a wind turbine (11), which has a rotor (13) having rotor blades (12) and at least one measuring arrangement (10) for detecting deformations, in particular bending of the outer surface, of a structural element of the wind turbine (11), which structural element is a rotor blade (12), wherein acceleration data is gathered by means of the at least one measuring arrangement (10) on at least one rotor blade (12), preferably in each case on all of the rotor blades (12) of the rotor (13), at least two measurement sites (1) arranged on the rotor blade (12), the at least two measurement sites (1) being spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the rotor blade (12), wherein speed data and/or position data is gathered at least two sites arranged on the structural element (12, 14, 15, 16) and spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the structural element (12, 14, 15, 16), and wherein the acceleration data is linked to the speed data and/or position data for identifying the deformations of the rotor blade (12)—preferably by means of an evaluation device (6) communication-connected to the sensors (2, 3, 4), and wherein the measuring arrangement (10) is formed according to claim 41.

56. The method according to claim 55, wherein the speed data and/or position data is, in each case, detected at the same measurement sites (1) at which the acceleration data is detected.

57. The method according to claim 55, wherein the position of the measurement site (1) is determined based on the acceleration data detected at a measurement site (1) and the speed data and/or position data detected at the same measurement site (1), wherein the determined position of the measurement site (1) is a relative position to a reference point, in particular the rotor blade root and/or the rotor axis, and/or an absolute position.

58. The method according to claim 55, wherein the deformation of the structural element (12), in particular a bending profile along an extension, preferably the longitudinal extension, of the structural element (12), is identified based on the determined positions of multiple measurement sites (1), wherein the deformation of the structural element (12) is preferably identified in 3 dimensions.

59. The method according to claim 55, wherein the positions of the measurement sites (1) are determined as a function of the time on the basis of the identified acceleration data as well as the speed data and/or position data, and/or wherein the deformations of the structural element (12) are identified as a function of time and/or depending on the rotation angle of the rotor (13).

60. The method according to claim 55, wherein, subject to the acceleration data as well as the speed data and/or position data, the wind turbine (11) is controlled, in particular the rotor (13) is adjusted with respect to the wind direction and/or the pitch of the rotor blades (12) is set.

61. The method according to claim 55, wherein the control of the wind turbine (11) is carried out such that the setting of the pitch of one or multiple rotor blades (12) takes place dependent on the rotation angle of the rotor (13).

62. The method according to claim 55, wherein the identified deformations are compared to a number of stored deformation patterns, which may particularly comprise bending shapes and/or temporal dependencies, wherein preferably, that deformation pattern is selected which has the smallest deviations from the deformations identified.

63. The method according to claim 55, wherein the evaluation device (6) transmits a signal to the sensors (2, 3, 4) of the measurement sites (1), by means of which signal the sensors (2, 3, 4) of the different measurement sites (1) are synchronized in time, so that the thusly synchronized sensors (2, 3, 4) each carry out at least one measurement within a common time frame, which is preferably at most 500 μs, preferably at most 100 μs, particularly preferably at most 50 μs, and/or wherein the evaluation device (6) identifies the deformations and/or the values and/or properties from that sensor data which was gathered by the synchronized sensors (2, 3, 4) within a common time frame, which preferably amounts to a maximum of 500 μs, preferably a maximum of 100 μs, particularly preferably a maximum of 50 μs.

Description

[0084] These show in a respectively very simplified schematic representation:

[0085] FIG. 1 a wind turbine with measuring arrangements according to the invention on the rotor blades

[0086] FIG. 2 a wind turbine with measuring arrangements according to the invention on the nacelle, the tower, and the foundation

[0087] FIG. 3 a measurement site in detail

[0088] FIG. 4 an embodiment of a measurement site

[0089] FIG. 5 the evaluation of the sensor data of individual measurement sites in a schematic view

[0090] FIG. 6 three different deformation states of a rotor blade and the effective rotor blade radius along a complete revolution

[0091] FIG. 7 the determination of the deformation from acceleration data and speed data

[0092] FIG. 8 an alternative measuring arrangement on a rotor blade

[0093] First of all, it is to be noted that in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclosures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position.

DESCRIPTION OF FIGURES.

[0094] The exemplary embodiments show possible embodiment variants, and it should be noted in this respect that the invention is not restricted to these particular illustrated embodiment variants of it, but that rather also various combinations of the individual embodiment variants are possible and that this possibility of variation owing to the technical teaching provided by the present invention lies within the ability of the person skilled in the art in this technical field.

[0095] The scope of protection is determined by the claims. Nevertheless, the description and drawings are to be used for construing the claims. Individual features or feature combinations from the different exemplary embodiments shown and described may represent independent inventive solutions. The object underlying the independent inventive solutions may be gathered from the description.

[0096] All indications regarding ranges of values in the present description are to be understood such that these also comprise random and all partial ranges from it, for example, the indication 1 to 10 is to be understood such that it comprises all partial ranges based on the lower limit 1 and the upper limit 10, i.e. all partial ranges start with a lower limit of 1 or larger and end with an upper limit of 10 or less, for example 1 through 1.7, or 3.2 through 8.1, or 5.5 through 10.

[0097] Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size.

[0098] FIG. 1 and FIG. 2 show wind turbines 11, which are each equipped with measuring arrangements 10 according to the invention for detecting deformations, in particular bending of the outer surface, of a structural element. In FIG. 1, the measuring arrangements 10 formed by individual measurement sites 1 are arranged on the rotor blades 12 of the rotor 13. In FIG. 2, the measuring arrangements 10 formed by individual measurement sites 1 are arranged on the nacelle 14, on the tower 15, and on the foundation 16. A variety of combinations and extensions of the measuring arrangements shown in FIGS. 1 and 2 (as well as omissions of measuring arrangements or individual measurement sites) are of course possible. The measuring arrangement according to the invention comprises at least two measurement sites 1 arranged on the structural element 12, 14, 15, 16, the at least two measurement sites 1 being spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the structural element 12, 14, 15, 16 and each having at least one acceleration sensor 2 (see FIGS. 3 and 4). The acceleration sensors 2 are communication-connected—here, via a wireless interface 5—to an evaluation device 6, so that the sensor data can be transmitted to the evaluation device 6—preferably directly after being generated.

[0099] The evaluation device is preferably a central evaluation device, which preferably communi-cates with multiple measuring arrangements 10, each being arranged on different structural elements 12, 14, 15, 16.

[0100] The evaluation device 6 may be integrated in the control device 8 of the wind turbine 11 (FIG. 2) or be provided as a separate device and/or module (FIG. 1).

[0101] The measuring arrangement 10 has at least two speed sensors 3, in particular angular speed sensors—in addition to the acceleration sensors 2—, which speed sensors 3 are arranged on the structural element 12, 14, 15, 16 and spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the structural element 12, 14, 15, 16.

[0102] Additionally or alternatively, the measuring arrangement 10 can have at least two position sensors 4, in particular magnetic field sensors, arranged on the structural element 12, 14, 15, 16 and spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the structural element 12, 14, 15, 16.

[0103] The speed sensors 3 and/or the position sensors 4 are also communication-connected—preferably via a wireless interface 5—to the evaluation device 6.

[0104] The speed sensors 3 may be spaced from the acceleration sensors 2 (just like the position sensors 4) (FIG. 8). However, in a preferred embodiment, the additional sensors, i.e. the speed sensors 3 and/or the position sensors 4, are in each case combined with the acceleration sensors at a measurement site 1 (FIGS. 3 and 4 in combination with FIGS. 1 and 2).

[0105] In other words: the at least two speed sensors 3 and/or the at least two position sensors 4 are arranged on the speed sensor 12, 14, 15, 16 such that the at least two measurement sites 1, each having at least one acceleration sensor 2, each additionally have at least one speed sensor 3 and/or at least one position sensor 4 (FIGS. 3 and 4).

[0106] In any case, position sensors may also be provided—instead of or in addition to the speed sensors 3 shown in FIGS. 3 and 8.

[0107] Using acceleration data (recorded directly on site) in combination with speed or position data (recorded directly on site) allows a significantly more precise detection of deformations, especially since information on acceleration, speed, and position makes it possible to resolve different timescales.

[0108] The deformation may be detected in the form of a deviation from the resting or normal state, as an elongation and/or compression, as a (spatial) change in relation to a reference point, as an oscillation (amplitude), in the form of a curvature, as a one—or multidimensional bending parameter, as a normalized representation, as a one—or multidimensional deformation pattern, as a time dependency, etc., and is thus to be interpreted broadly in its meaning.

[0109] Additionally, it is preferred if the measuring arrangement 10 comprises at least three, preferably at least five, measurement sites 1 arranged on the structural element 12, 14, 15, 16, the at least three measurement sites 1 being spaced apart from one another in the direction of the longitudinal extension of the structural element 12, 14, 15, 16, and each having at least one acceleration sensor 2. In this regard, each measurement site 1 is equipped with at least one speed sensor 3 and/or at least one position sensor 4—in addition to the acceleration sensor 2. The sensor data of all sensors are transmitted to the (central) evaluation device 6.

[0110] In this regard, the distance between an acceleration sensor 2 and a speed sensor 3 and/or position sensor 4 belonging to the same measurement site 1 are to amount to, where possible, a maximum of 5 cm, preferably a maximum of 1 cm, particularly preferably a maximum of 5 mm

[0111] In the case of a rotating rotor blade 12, at least one, preferably at least two, of the measurement sites 1 are arranged in the region of the rotor blade tip and/or at a distance from the rotor blade tip, which distance is at the most as great as 50%, preferably at most as great as 20%, of the total length of the rotor blade 12 (see FIG. 1). It is additionally preferred if at least one measurement site 1 is arranged away from the connecting line between the outermost measurement sites 1 of the measuring arrangement 10, preferably between the measurement site 1 closest to the rotor blade root and the measurement site 1 closest to the rotor blade tip. The normal distance from the connecting line preferably amounts to at least 20 cm, preferably at least 50 cm.

[0112] Likewise, at least one measurement site 1 may be arranged on a first side, in particular the front side, of the structural element 12, 14, 15, 16 and at least one measurement site 1 is arranged on a second side opposite the first side, in particular on the rear side, of the structural element 12, 14, 15, 16.

[0113] In order to be able to characterize a deformation and/or a deformation pattern more precisely, the acceleration sensors 2 are each configured to detect the acceleration in 3 spatial directions. The same also applies to the speed sensors 3 and/or the position sensors 4. For this purpose, the respective sensor 2, 3, 4 may have three (sub) units. However, a single unit configured to measure in all three spatial directions would also be conceivable.

[0114] FIG. 4 shows that the acceleration sensor 2 of a measurement site 1 together with a speed sensor 3 belonging to the same measurement site 1 and/or a position sensor 4 belonging to the same measurement site 1 may be integrated in a measuring unit 17 and/or be accommodated in a common housing.

[0115] It is preferred if the measuring unit 17 has a flat base which carries the sensors 2, 3, 4. The flat base may be formed by a film-like and/or pliant material. Furthermore, the flat base may carry additional functional elements, such as, e.g., a wireless interface 5 connected to the sensors for transmitting the sensor data to a (central) evaluation unit 6 and/or an energy conversion device 7, preferably in miniature form, for supplying the sensors 2, 3, 4 and possibly the wireless interface 5 with (electrical) energy. The flat base is preferably adhered to the surface of the structural element (to be monitored) of the wind turbine 11.

[0116] Preferably, each measurement site 1 is formed on a separate measuring unit 17.

[0117] The acceleration sensors 2 and/or the speed sensors 3 and/or the position sensors 4 may be arranged on, preferably adhered to an outer surface of the structural element 12, 14, 15, 16 (see, e.g., FIG. 1). In FIG. 4, it is adumbrated that the measurement sites 1 and/or the sensors 2, 3, 4 forming the measurement sites 1 are energy-self-sufficient and/or can each be connected to at least one local energy conversion device 7, which preferably converts mechanical energy, chemical energy, thermal energy and/or light into electrical energy, in particular a photovoltaic device.

[0118] The acceleration sensors 2 and/or the speed sensors 3 and/or the position sensors 4 are preferably embodied as micro-electro-mechanical systems (MEMS).

[0119] The wind turbine may be designed such that for at least two structural elements 12, 14, 15, 16 of the wind turbine 11, in particular for each rotor blade 12 of the rotor 13, a measuring arrangement 10 according to the invention is provided. In this regard, the sensors 2, 3, 4 of the measuring arrangement 10 are each communication-connected to the central evaluation device 6—preferably via a wireless interface 5.

[0120] The control device 8 may be configured to control the wind turbine 10 in accordance with the sensor signals generated by the measurement sites 1 of the measuring arrangement 10, in particular to adjust the rotor 13 with respect to the wind direction (e.g., rotation about a vertical or nearly vertical axis) and/or to set the pitch of the rotor blades 12.

[0121] The method for operating a wind turbine 11 having a rotor 13 with rotor blades 12 and at least one measuring arrangement 10 for detecting deformations, in particular bending of the outer surface, of a structural element 12, 14, 15, 16 of the wind turbine 11, in particular of a rotor blade 12, comprises the following steps: by means of the at least one measuring arrangement 10, acceleration data is gathered on at least one structural element 12, 14, 15, 16 (e.g. On all rotor blades 12 of the rotor 13) on at least two measurement sites 1 arranged on the structural element 12, 14, 15, 16, which measurement sites 1 are preferably spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the structural element 12, 14, 15, 16. Additionally, speed data and/or position data is gathered on at least two sites arranged on the structural element 12, 14, 15, 16 and spaced apart from one another in the direction of an extension, preferably the longitudinal extension, of the structural element 12, 14, 15, 16.

[0122] The acceleration data is linked to the speed data and/or position data for identifying the deformations of the structural element 12, 14, 15, 16. This preferably takes place by means of an algorithm. The linking and identification of the deformations preferably takes place by means of the evaluation device 6.

[0123] As already explained above, it is preferred if the speed data and/or position data is, in each case, detected at the same measurement sites 1 at which the acceleration data is detected, as well.

[0124] In the following, the principle is explained in more detail. FIG. 6 shows a rotor blade in various deformation states a, b and c as well as, to the right thereof, the effective radius along a complete rotation, i.e. depending on the rotor angle of rotation. The effective radius is obtained by a projection of the bent rotor blade—in the direction of the rotation axis of the rotor —into the rotor blade that is not bent. State a means “no deformation” (resting state), state b means “constant deformation”, and state c means asymmetrical deformation, e.g. in the case of wind shear. Such deformation patterns may be identified as follows:

[0125] FIG. 7 shows a schematic approach. Firstly, the (absolute or relative) positions x1(t), x2(t), of the individual measurement sites is determined from the acceleration data a1(t), a2(t), . . . as well as the speed data v1(t), v2(t), . . . of the individual measurement sites with the designation 1, 2, . . . by applying an algorithm A. Additionally to the acceleration and speed data (or instead of the speed data), position data (e.g. with information on the orientation) may be used in this step.

[0126] Subsequently, the deformation V (bending, torsion, oscillations, etc.) can be identified from these positions x1(t), x2(t), . . . of the individual measurement sites.

[0127] In other words, the position of the measurement site 1 is determined based on the acceleration data detected at a measurement site 1 and the speed data and/or position data detected at the same measurement site 1, wherein the determined position of the measurement site 1 may be a relative position to a reference point, in particular the rotor blade root and/or the rotor axis, and/or an absolute position.

[0128] A possibility consists in, e.g., assuming the following model, which firstly considers the static acceleration As, which is essentially a function of the gravitational acceleration ag and the centrifugal acceleration a.sub.c.

[00001]$A_s=R_x.Math.R_z.Math.\left(R_y.Math.\left(\begin{array}{c}{a}_g\\ 0\\ 0\end{array}\right)+\left(\begin{array}{c}-a_c\\ 0\\ 0\end{array}\right)\right)$

[0129] R.sub.x is the rotation matrix of a measurement site about the x-axis due to the pitch. R.sub.z is the rotation matrix of the measurement site about the z-axis due to the orientation of the rotor and/or the measurement site. R.sub.y is the rotation matrix of the measurement site about the y-axis, which corresponds to the rotation of the rotor 13 about its rotations axis.

[0130] Furthermore, dynamic accelerations A.sub.d, such as Coriolis acceleration and the Euler acceleration, which are dependent on, inter alia, the rotation speed and the position of the respective measurement site, may be included in the model: A=A.sub.s+A.sub.d.

[0131] From the above model, it is evident that particularly the speeds, possibly, however, also the positions and/or orientations of the measurement site, in particular in the form of the rotation matrixes, have a significant importance in the modelling of the acceleration and/or the deformation to be detected. By means of the concept according to the invention of measuring the speeds and/or positions directly on site—i.e. directly on the structural element itself that is moving, oscillating, or subjected to any other deformations, preferably in each case on a measurement site, the accuracy of the deformation detection can be increased significantly. A reason for this is that the treatment of a measurement site—e.g., by means of a model or algorithm—can be carried out individually and based on the data recorded directly at the measurement site (acceleration data as well as speed and/or position data).

[0132] The acceleration data as well as the speed data and/or position data can be detected continuously, wherein the deformations of the structural element 12, 14, 15, 16 are preferably also identified continuously.

[0133] From the determined positions of multiple measurement sites 1, the deformation of the structural element, in particular a bending profile along an extension, preferably the longitudinal extension of the structural element, can be determined. This preferably takes place in 3 dimensions. The values schematically shown in FIG. 17 are, in this case, vectors and/or matrixes. Based on the identified acceleration data as well as the speed data and/or position data, the positions of the measurement sites 1 can also be determined as a function of time. It is also possible to identify the deformations of the structural element 12, 14, 15, 16 as a function of time and/or depending on the rotation angle of the rotor 13.

[0134] In FIG. 5, it is additionally adumbrated that, subject to the acceleration data as well as the speed data and/or position data, the wind turbine 11 can be controlled, in particular the rotor 13 can be adjusted with respect to the wind direction and/or the pitch of the rotor blades 12 is set. In this regard, control commands S can be generated as a function of the determined positions (of the measurement sites) and deformations V of the structural element, which control commands S are forwarded from the evaluation device 6 and/or control device 8 to appropriate actuators of the wind turbine 11.

[0135] FIG. 6 shows that in state c, an asymmetrical deformation (i.e. one that depends on the angle of rotation) occurs. In such cases, the control of the wind turbine 11 can then be carried out such that the setting of the pitch of one or multiple rotor blades 12 takes place depending on the rotor blade of the rotor 13 in order to handle such an asymmetrical deformation in the best possible way. Depending on the rotation angle means that different settings can be made within one revolution of the rotor (at least two, preferably any number).

[0136] The advantages of a setting in real time have already been extensively explained above.

[0137] Moreover, the identified accelerations, speeds and/or positions of the individual measurement sites 1 and/or the identified deformations of the structural element 12, 14, 15, 16, in particular the rotor blade 12, can be compared to a model, wherein deviations from the model are preferably used for recognizing deformation patterns.

[0138] The identified deformations may also be compared to a number of stored deformation patterns, which may particularly comprise bending shapes and/or temporal dependencies. In this regard, that deformation pattern can be selected which has the least deviations from the deformations identified.

[0139] The stored deformation patterns may each be assigned at least one predefined setting of the wind turbine 11. The setting, in particular a certain orientation of the rotor 13 with respect to the wind direction and/or a setting of the pitch of the rotor blades 12, assigned to the selected deformation pattern is then carried out and/or maintained.

[0140] Lastly, a self-learning algorithm may be stored in the control device 8, which algorithm is configured to adjust and/or maintain settings, in particular setting parameters, of the wind turbine 11 based on one or multiple deformation patterns, preferably based on deformation patterns identified with time lags, wherein the self-learning algorithm preferably draws on stored reference data with deformation patterns and/or settings.

[0141] The following variants relate to the preferred possibility of bringing the sensors belonging to different measurement sites spaced apart from one another into a temporal common mode. Thus, the sensors 2, 3, 4 of the different measurement sites 1 can be synchronized in time by means of the evaluation device 6—preferably by means of a signal transmitted from the evaluation device 6 to the sensors 2, 3, 4, in particular in the form of a data package—, in particular with respect to the point in time of the measurement carried out by the respective sensors 2, 3, 4 and/or the point in time of the transmission of the sensor data from the sensors 2, 3, 4 to the evaluation device 6.

[0142] Here, it is preferred if the evaluation device 6 is configured to transmit a signal to the sensors 2, 3, 4 of the measurement sites 1, by means of which signal the sensors 2, 3, 4 of the different measurement sites 1 are synchronized in time, so that the thusly synchronized sensors 2, 3, 4 each carry out at least one measurement within a common time frame, which is preferably at most 500 μs, preferably at most 100 μs, particularly preferably at most 50 μs.

[0143] In other words: The sensors are brought into common mode via data packages transmitted from the base such that they measure simultaneously within a tolerance of preferably <100 μs, in an advantageous embodiment <50 μs or below. Thus, the approximately same, simultaneous sampling at multiple positions is possible—even if the transmission between base/evaluation device is wireless and the sensors depend on one another (i.e. in the case of sensors which do not or at least do not necessarily communicate with one another).

[0144] Additionally and alternatively to the deformations, at least one, preferably multiple, of the following values and/or properties can be identified from the sensor data of the sensors 2, 3, 4, in particular by linking the acceleration data of the acceleration sensors 2 to the speed data of the speed sensors 3 and/or position data of the position sensors 4: [0145] the absolute pitch angle of at least one rotor blade, and/or [0146] the relative pitch angle of at least two rotor blades to one another, and/or [0147] the torsion of at least one rotor blade and/or at least two rotor blades to one another, and/or [0148] the load and/or load cycle acting o at least one rotor blade, and/or [0149] a source for increase noise emissions, and/or [0150] an early sign of damage or faulty regulating state of the wind turbine, and/or [0151] the type, force, dynamics and/or direction of winds, and/or [0152] a change of the oscillation behavior of the structural element, and/or [0153] damage to the rotor blade, [0154] wherein the identification of the value(s) and properties preferably comprises a comparison between current (sensor) data and historical (sensor) data and/or a comparison between the (sensor) data of a rotor blade and the (sensor) data of at least one other rotor blade.

[0155] The measurement of the torsion of the blades may take place statically, dynamically and/or with respect to the individual rotor blades relative to one another. Thus, blade loads and load cycles may also be determined. Measuring vibration patterns may also take place locally, globally and/or with respect to the individual rotor blades relative to one another. Based on this, e.g. a source for increased noise emissions or an early sign of damage or faulty regulating state can be identified. Moreover, the detection/characterization of wind shears, turbulences, gusts of wind, oblique incoming flow and/or incorrect azimuth angles of the wind turbine is possible. Rotor damage may be recognized, e.g. based on an altered oscillation behavior of the rotor blade (e.g. by comparing a sensor position to historical data at the same position or comparing a radial position to current data gathered from other rotor blades).

[0156] Here, as well the evaluation device 6 is preferably configured to identify the deformations and/or the values and/or properties from that sensor data which was gathered by the sensors 2, 3, 4 within a common time frame, which preferably amounts to a maximum of 500 μs, preferably a maximum of 100 μs, particularly preferably a maximum of 50 μs.

[0157] List of reference numbers [0158] 1 Measuring site [0159] 2 Acceleration sensor [0160] 3 Speed sensor [0161] 4 Position sensor [0162] 5 Wireless interface [0163] 6 Evaluation device [0164] 7 Photovoltaic device [0165] 8 Controller [0166] 9 — [0167] 10 Measuring arrangement [0168] 11 Wind turbine [0169] 12 Rotor blade [0170] 13 Rotor [0171] 14 Nacelle [0172] 15 Tower [0173] 16 Foundation [0174] 17 Measuring unit [0175] a No bend [0176] b Constant bend [0177] c Bend in wind shear [0178] P Position [0179] S Control command [0180] A Algorithm [0181] a.sub.1(t), a.sub.2(t) Acceleration data [0182] v.sub.1(t), v.sub.2(t) Speed data [0183] x.sub.1(t), x.sub.2(t) Position data [0184] V Deformation