DE102019114529A1 - Modeling and prediction of wake vortices and wind shear with fiber optic sensors in wind turbines - Google Patents

Abstract

An arrangement of sensors on a rotor blade and a method for determining wind currents on one or more rotor blades of a wind turbine are disclosed. The arrangement consists of at least two strain sensors which detect the blade bending moments of at least one rotor blade of a wind energy installation in at least two different spatial directions. The arrangement further comprises a first acceleration sensor for detecting accelerations of the rotor blade in a first spatial direction and at least one second acceleration sensor for detecting accelerations of the rotor blade in a second spatial direction, different from the first spatial direction. An evaluation device is also included, which is designed to read in analog or digital signals from the voltage measurement sensors and the acceleration sensors via inputs of the evaluation device, to evaluate the signals and to provide an evaluation result with regard to wake vortices or wind shear impacting the rotor blade.

Description

TECHNICAL AREA

The registration is in the field of wind turbine technology. The present application discloses in particular systems and methods for the improved prediction and evaluation of unfavorable flow conditions, such as wake vortices and / or wind shear, with regard to wind energy generation plants, in particular with regard to their effects in wind parks, consisting of a number of wind generation plants.

TECHNICAL BACKGROUND

Wind turbines are commercial enterprises that are supposed to generate a steady financial return by selling the energy they generate.

Yields of expected wind energy production are given with probabilities of P50, P75 and P90. In other words, this means that probability values for an expected yield from wind power can be predicted with probabilities of 50, 75 or 90%. You can see that these estimates are quite rough.

In addition to predictions about the expected wind energy yield, statements about loads that can lead to material fatigue and failure of the system are of interest. Both the minimum value for an expected wind energy production and the maximum fatigue load that is tolerated are therefore among the parameters in the design of a wind turbine.

It is known that systems are stressed during operation by the influences of the surrounding environment, which can lead to a limited service life and in the worst case, namely the premature failure of a system, thus to sensitive financial losses for the system operator.

Better estimates of wind loads and flow conditions can therefore lead to a reduction in risk and to a better financial result for wind farm operators.

Particularly during their operation, wind turbines are exposed to large and, above all, changing loads, depending on the changing wind conditions, which can lead to material fatigue and failures. The estimated life of a wind turbine is therefore preferably based on the resistance to such harsh operating conditions.

An improved, better description of such loads, which lead to the fatigue of the material, can therefore lead to an improved use of the wind turbine (WKA). An estimate of the loads that can lead to a fatigue of the rotor or the wind turbine tower can be based on chronologically successive wind conditions at different areas of the rotor or areas of the tower.

Mostly, cost-intensive measurements of at least one year duration are carried out using meteorological (Met) masts including several anemometers in order to describe wind flow fields (mathematically a vector field) during the location selection, as well as to carry out wind energy estimates and layout optimization.

Since local, i.e. Wind turbine-specific conditions are dependent on the geographic conditions around each of the turbines, a generic, representative wind field estimate has so far been carried out first with measurements over the meteorological masts of the WKAs, in order to then extrapolate them for each turbine position. Limitations of the procedures and their informative value or relevance of measurements are included in the probability estimates.

Wind flow conditions are to be understood as the excitation of a mechanical system, the system response of which is simulated using physical models. Therefore, the approaches proposed in the industry focus on a direct measurement of the system response i.e. on the generation of energy, mechanical loads or structural deformation of system parts with a certain wind flow (excitation).

The estimation of wind conditions is therefore the by-product of reverse modeling in which the system response is used to infer or estimate an expected deflection. This estimate of the wind conditions takes place via meteorology (mead) masts or nacelle-based facilities, i.e. in the tower nacelle that encloses the generator and possibly the gearbox.

However, the large areas covered by the rotor blades also mean that there are different conditions along different areas of the blade.

In other words, it can be assumed that the wind conditions within this large area that the rotor blade sweeps are no longer homogeneous. This area is too big for that, assuming current rotor diameters of more than 130 m. The The area covered by a rotor with a diameter of 100 m, for example, is around 7,800 m ² , for comparison: the area of a standard football field is just over 7,100 m ² . This clarifies the standards and shows that within such a swept area, different wind conditions or wind flow conditions can prevail at different locations on the area.

Both temporal and spatial dependencies as well as statistical models can be used to estimate the change in wind flow conditions along the rotor blades, also known as “turbulent wind models”. The US6909198B2 (2000-07-07) discloses a method and a device for processing and predicting the flow parameters of turbulent media. The US20090311096A1 (2008-06-13) describes a method and a device for measuring air flow conditions on a blade of a wind turbine.

Since modern wind turbines also reach heights at which atmospheric influences can definitely have an effect on these models, the long-term description can be influenced by daily and regional differences.

Newer approaches in industry are aimed at a better description of wind conditions in front of the rotor, such as with LiDAR technology (acronym for Light Detection And Ranging), anemometers that are mounted in the rotor hub and cameras in the rotor blades that make their deformations visible. However, each of these approaches has advantages and disadvantages:

LiDARs are dependent on atmospheric conditions and are more suitable for wind energy forecast than for load estimation, since they preferably scan an area in front of the turbine, i.e. the rotor, rather than a certain point. For example, the US7281891B2 (2003-02-28) carried out a wind turbine control with a LiDAR-based wind speed measuring device.

Anemometers on the rotor hub provide better estimates than currently common, Nacellen-based measurements. A “nacelle” is the housing in a wind power plant in which, for example, the generator, the gearbox, control devices or cooling systems are housed. The nacelle is rotatably mounted on the top of the tower of the wind farm.

Cameras installed in the rotor blades represent a further improvement in the determination. Here they can be arranged in the direct area of the wind-to-leaf interaction. However, your line of sight is limited to the blade tip, namely when the rotor blades bend out of the field of view of the cameras. An optical measuring device for measuring the deformation of a rotor blade of a wind turbine is for example in the DE102011011392A1 (2011-02-17) disclosed.

A special problem, which has not been dealt with so far, arises when operating such a system when currents change very quickly or discontinuously or when wind conditions arise in which the rotors are simultaneously coming from different directions, e.g. laterally and at the same time vertically from bottom to top as in a wind shear.

Shear winds are local wind phenomena, resulting from the local topography, local and large-scale weather conditions and the resulting growing, in particular unexpected, transverse movements of the air masses. The wind shear is a wind whose wind strength or wind direction changes in a small geographic area.

The description of horizontally and vertically acting winches is only possible to a limited extent with previous methods.

Another problem that should be considered in the design and operation of wind turbines is that, especially when operating several wind turbines such as those arranged in wind parks, wind turbines influence each other, with a negative effect on durability and energy yield. This can happen, for example, through wake vortices that form behind the rotors of a wind turbine.

Wind turbines are developed as individual systems, but mostly built in a network. The individual systems are brought together as far as possible so that they bring the greatest possible yield with minimized system costs.

In a network, however, a number of systems does not bring the amount that could be expected from a single system multiplied by the number of systems. One of the most important reasons for this is turbulence (wake vortices), which considerably reduce the yield of the downstream systems. The wake vortices also have a negative impact on the service life of the systems.

The wind power plants are not designed for strong turbulence caused by the wake vortices, nor for locations with high ambient turbulence, forest locations or where there are gaps in existing wind farms. Turbulence, however, plays a major role in terms of yields, lifespan and impact on the environment. Rotor blades, gears and generators are made by the Turbulence heavily burdened by vibrations. This can increase the need for repairs and lead to a serious cost factor, especially at sea.

Wake vortex propagation models are used to show how wake vortices move along a wind farm. The US20130255363A1 deals with the detection of wake vortices in a wind farm using load sensors.

So far, wake vortices in wind farms have been represented using simple computational models, such as a loss of wind speed and / or an increase in the intensity of turbulence. On the one hand, these reduce the energy production of the system and, on the other hand, since the rotor is the most important point of application for forces, they lead to an increased load on the system and thus to a greater risk of faster material fatigue.

Simpler and improved methods and a device for predicting rapidly changing wind flow conditions, in particular wake vortices and wind shear on a rotor, is therefore desirable.

SUMMARY

In a first aspect, an arrangement of sensors on a rotor blade for determining wind currents on one or more rotor blades of a wind turbine is disclosed.

The arrangement can include at least one strain sensor (advantageously also at least two strain sensors), with which blade bending moments of at least one rotor blade of a wind turbine can be detected in at least two different spatial directions.

The arrangement can comprise a first acceleration sensor for detecting accelerations of the rotor blade in a first spatial direction. The arrangement can further comprise at least one second acceleration sensor for detecting accelerations of the rotor blade in a second spatial direction, the second spatial direction being different from the first spatial direction.

Furthermore, the arrangement can comprise an evaluation device which is designed to read in analog or digital signals from the voltage measurement sensors and the acceleration sensors via inputs of the evaluation device, to evaluate the signals and to provide an evaluation result.

In another aspect, a method for determining wind currents on one or more rotor blades of a wind turbine is disclosed. The method can include the determination of voltage and acceleration values at at least two locations on a rotor blade surface.

The method can further include converting the determined voltage and acceleration values into at least one electronically processable signal, as well as accepting the at least one electronically processable signal in an electronic evaluation unit. Furthermore, the evaluation of the at least one electronically processable signal and further the determination of one or more parameters from the group: intensity values of wake vortices, in particular wake vortices that are generated by neighboring wind turbines, intensity values of wind shear can be included.

In a further aspect, a rotor blade with an arrangement of sensors according to one of the other aspects can be disclosed.

Another aspect can disclose a wind power plant with one or more rotor blades with an arrangement of sensors according to one of the other aspects.

Figure list

• 1: skizzenhaft einen Einfluss einer Art von Windströmungen auf eine Windkraftanlage;
• 2: skizzenhaft einen Einfluss einer weiteren Art von Windströmungen auf eine Windkraftanlage;
• 3: Windströmungsverteilungen an Windkraftanlagen/in Windparks;
• 4: Sensoranordnung an einem Rotorblatt gemäss Ausführungsformen der Erfindung;
• 5: Sensoranordnungen an einem Rotorblatt gemäss Ausführungsformen der Erfindung; und
• 6: ein Verfahren gemäss Ausführungsformen der Erfindung.

Exemplary embodiments are shown in the drawings and explained in more detail in the following description. In the drawings show:

• 1 : a sketch of an influence of a type of wind currents on a wind turbine;
• 2 : a sketch of the influence of another type of wind currents on a wind turbine;
• 3 : Wind flow distributions at wind turbines / in wind parks;
• 4th : Sensor arrangement on a rotor blade according to embodiments of the invention;
• 5 : Sensor arrangements on a rotor blade according to embodiments of the invention; and
• 6th : a method according to embodiments of the invention.

Description of the preferred embodiments

In particular, the following features are advantageous for embodiments of the present invention.

Fiber optic sensors are advantageously used 400 , 500 at certain points on the rotor blade 110 arranged, the accelerations and mechanical stresses in the rotor blade 110 or on partial areas / partial surfaces 200 of the rotor blade 110 determine.

For example, vertical and horizontal winch shear 120 , 130 can be described better, since the rotation of the leaves is exploited, with which a recognition over the entire leaf surface 220 can be carried out, i.e. the surface swept over by the leaves during rotation, as in 1 to recognize. In principle, measurements are made on the entire rotor and the measurements rotate. Hence it can also be said that the shear (vertical and horizontal wind shear 120 , 130 ) is measured along any coordinate system (Cartesian, polar ...). This gives a realistic picture of the influence of the shear on the rotor blades of the rotor or on the wind turbine 100 per se. The detection is therefore independent of typical assumptions such as: Deterministic form of shear along an axis and spatial-temporal correlation.

Deficits in wind speed and increased turbulence can occur in one or more specific areas 200 (Partial surfaces, quadrants) of the rotor blade 110 by evaluating the sensor readings from the sensors 400 , 500 can be determined, for example, to indicate the presence of wake vortices within a wind farm / a wind park. In other words, this means that not only in one area (partial surface, quadrant) of the area swept by the rotor blade 220 can be evaluated, but also in several places. For example, currents or wake vortices can occur simultaneously in different areas of the area swept by the rotor blades 220 exist and be determined.

The present application can therefore determine and take into account, in particular, strong and undesired flow influences on a wind turbine 100 like wind shear 120 , 130 and especially wake vortices 210 allow.

In a first embodiment there is therefore an arrangement of sensors 400 , 500 on a rotor blade 110 to determine wind currents on one or more rotor blades of a wind turbine 100 disclosed. At least one strain sensor 400 be included, the blade bending moments of at least one rotor blade 110 a wind turbine 100 recorded in at least two different spatial directions. An arrangement can advantageously also have at least two strain sensors 400 contain.

Turbulence and wind-dependent loads can be estimated with measurements in the wind direction (“out-of-rotor-plane”).

A first acceleration sensor can also be used 500 for recording accelerations of the rotor blade 110 in a first spatial direction and at least one second acceleration sensor 500 for recording accelerations of the rotor blade 110 be included in a second spatial direction. The second spatial direction can preferably be different from being different from the first spatial direction. An evaluation device 510 can preferably be included, the evaluation device 510 is particularly designed to receive analog or digital signals from the strain sensors 400 and the acceleration sensors 500 via inputs of the evaluation device 510 read in, evaluate the signals and provide an evaluation result.

Preferably three strain sensors 400 be included. The three strain sensors can be arranged in the vicinity of the leaf root, preferably evenly distributed over a circle, that is to say offset by essentially 120 °. In 5 is the arrangement of the sensors 400 shown near the rotor blade root. 4th shows this in detail; for reasons of illustration there are only two sensors 400 shown. Preferably (not shown separately in the figures), only one sensor can be used 400 be used as a minimum, more sensors are advantageous for the measurement accuracy.

At least two acceleration sensors can also preferably be used 500 be included, which can be located in a sheet radius> 5m in particular. The measuring direction of the sensors, in particular the acceleration sensors, can be offset by 90 ° with respect to one another. One sensor 500 can advantageously, in the flapping direction of the rotor blade 110 measure, another in the direction of the edge of the rotor blade 110 . See also the arrangement of the acceleration sensors in 5

This local arrangement overcomes the limitations of previous approaches because it controls the wind conditions along the entire area described by the rotor 220 measures. It is particularly advantageous that this measurement can be carried out at a higher sampling rate.

A measurement of a deflection (e.g. on a quadrant 200 on the rotor blade, i.e. the place of interaction between wind and blade) is therefore the focus of the consideration and not a system response, i.e. how the energy output changes under which wind conditions.

This means a clear advantage in the response time after a suggestion. It is therefore not the system response that is of interest, but rather the measurement of a deflection as a direct reaction to the action of a force caused by the wind. The entire blade length and not just point estimates are used to describe the wind flow.

The determination of the wind conditions with very short system response times, which is possible according to the invention, makes it possible to react more quickly to loads and thus to reduce excessive wear on the system. As a result of the increased service life of the system, better economic efficiency can be achieved.

As in 3 you can see two wind turbines 100 one behind the other in the direction of the wind. One can speak of two “continuous” wind turbines here. The wind turbine 100 , which is flown against first as seen in the wind direction, can thereby validate an estimate of the second, following wind turbine. This can also be done for several subsequent wind turbines.

The impact on each blade quadrant 200 (Surface element or partial surface of the rotor blade 110 ) is used to describe the wind flow; both at the wind turbine and at the wind farm / wind park level (for the entire wind park) and no point estimates. 2 shows an example of a quadrant 200 . The symbols "+" and "-" indicate that the rotor blade is 110 by applying force to the quadrant 200 twisted.

A coordinate system for specifying the coordinates of a flow event on a rotor blade 110 can advantageously be a polar coordinate system with respect to the rotor, in which the center point is a hub of the rotor blade 110 can be. With other known coordinate systems, for example a Cartesian one, it is also possible to describe the location of the flow event on the rotor or rotor blade 110 will be realized.

In a further embodiment of the sensor arrangement according to one or more aspects of the application, the acceleration sensors 500 and / or the strain sensors 400 be fiber optic sensors. The DE 10 2014 210 949 A1 discloses the use of fiber optic pressure sensors on the rotor blade surface.

Compared to sensors based on semiconductors, fiber optic sensors have the advantage that they do not react to electromagnetic fields and are particularly robust. I.e. An optical sensor can withstand a lightning strike in the tower or in the rotor, in contrast to a semiconductor-based sensor unless it is equipped with complex protective mechanisms against overvoltage. Fiber optic sensors are suitable for temperature, strain or acceleration measurements. Examples of this are massless, distributed temperature measurements in the smallest of spaces and at the highest temperatures. When measuring strain, electrical strain gauges are often superior in terms of maximum strain and load cycles. Passive acceleration measurement is possible without an electrical connection between the measuring device and the sensor.

The fact that the wind conditions can be measured locally on the blades or on the rotor blade surface by deflection via the fiber-optic sensors, in particular sensors for measuring acceleration and mechanical tension or expansion pressure sensors, enables more precise statements to be made about the wind energy yield to be achieved or the wind conditions to be expected in the short term are made. This can enable the system to be regulated much more precisely, since the wind conditions on the rotor blades show real-time behavior.

An optimized wind turbine control is thus not implemented via a system response, but can advantageously be implemented directly via the deflection of the fiber-optic sensors attached to the rotor blades in order to control the system.

In a further preferred embodiment, the arrangement according to one or more other aspects can reveal that the first spatial direction and the second spatial direction of the at least two strain sensors 400 enclose an angle of 70 ° to 110 °.

In a further preferred embodiment it is disclosed that in the arrangement according to one of the preceding embodiments, the evaluation device is a computing unit 510 may include, wherein the computing unit can contain an algorithm which is preferably designed to measure acceleration and / or elongation values of at least one surface element 200 one or more rotor blades 110 to determine, the determination based on the signals of the measuring sensors, that is, the strain and acceleration sensors 400 , 500 based. The evaluation unit 510 or arithmetic unit contain a memory area in which an assignment of measured value combinations of the sensors 400 , 500 to one or more quadrants 200 on the rotor blade 110 is filed. In other words, a certain combination of measured values stands for a certain wind configuration (wake vortex / wind shear) at one Quadrant 200 of the rotor blade attacks. The arithmetic unit can "learn" during operation and write further combinations of measured values (acceleration / expansion) into the memory area or overwrite / adapt existing values.

As the sensors 400 , 500 analog measurement, a very large number of combinations of measured values is possible and thus reliable detection of the flow conditions on the rotor blade.

That is to say, the algorithm can preferably use any surface elements or partial surfaces or even quadrants from the sensor data 200 of the rotor blade 110 , Assign exposure values. These loading values can preferably be representative of impinging wake vortices 210 , e.g. wake vortices, generated by rotors (actually: the rotor blade tips) that are in the direction of propagation and the wake vortices.

Equally, these load values determined by the algorithm can also be representative of wind shear 120 , 130 his. Wind shear is understood to be local wind phenomena, resulting from the local topography, local and large-scale weather conditions and the resulting growing unexpected transverse movements of the air masses. The wind shear is a wind whose wind strength or wind direction changes in a small geographic area.

This winch, hence the name, can act simultaneously on the rotor and, of course, the other parts of the wind turbine from different directions. The meeting of the winds itself is called the "wind shear", the resulting wind the "wind shear". As a result of this uneven distribution of force, the wind turbine is exposed to uneven loads.

With the sensor arrangement according to the invention and the corresponding evaluation, a very brief wind energy forecast (less than 10 minutes gate time) is possible. In contrast to previous procedural measures, this enables very effective and rapid regulation of the wind power plant and can thus contribute to optimized wind energy generation. The load values measured directly on the blades of the plant due to the wind flow can be used advantageously for the operation and also in the design of wind power plants.

The influence of the wind speed on the rotor can be determined directly at the measurement location and used for pitch angle and blade torsion calibration.

In a further embodiment of the arrangement according to further embodiments of the application it is disclosed that the evaluation device 510 from the acceleration and / or elongation values of the at least one surface element 200 Intensity values of one or more on the rotor blade 110 hitting wake vortex 210 or a strength of wind shear 120 , 130 certainly.

In a further embodiment of the arrangement according to further embodiments of the application, it is disclosed that the evaluation device 510 is further adapted to the intensity values of the wake vortices by means of a data interface 210 and / or windshear 120 , 130 to neighboring wind turbines 100 to submit. This can be used for individual determination and a blade angle adjustment (pitch) and / or a rotor angle adjustment (yaw) of the neighboring wind turbines 100 to be used.

In the event of wind shear or when wake turbulences hit the rotor, a blade angle of the rotor or a yaw adjustment of the rotor can take place, in particular in the case of systems that are located in the wind flow direction behind the system that determined the measured value. In this way, increased mechanical stress on the systems can be reduced. At the same time, the adjustment can be kept in such a way that the wind energy yield, taking into account the intensity values, can be kept to a maximum. In other words, in order to protect the system or the systems located one behind the other in the wind direction, the load is reduced as much as necessary in order to still obtain an optimal energy yield from the system. At the same time, increased stress, which can lead to premature material fatigue, is reduced as far as possible.

3 shows two wind turbines at a distance d. A flow channel 310 a wake vortex has its origin in the wind turbine on the left or has just passed this turbine. During the movement of the drag towards the second wind turbine on the right, the flow channel widens. The speed of the wake vortex is reduced by one value due to aerodynamic principles V ₁ on the value V ₂ on the following system.

In the center of the flow channels (hatched area in the ellipse) the air pressure is low, towards the edges of the channel it is high. The wake vortex reefs on the rotor blade 110 of the turbine on the right, the area of the rotor blade that is hit by the hatched area of the drag, the area of the rotor blade that is affected by the Edge areas of the train is hit, heavily polluted. In comparison to a normal, even wind flow on the blades, this represents a good thing for the rotor blade 110 and of course for the indentation system 100 an extraordinary load. By recognizing this load directly on partial surfaces 200 the rotor blades 110 the rotor blade and / or the machine housing with the rotor can be turned out of the load using the pitch / yaw adjustment.

The evaluation device 510 with a computing unit and a control unit that is configured to output corresponding adjustment commands for pitch and yaw controls, for example in a rotor blade 110 , the rotor hub or at another point on the wind turbine 100 be arranged.

Evaluation device 510 and control unit can also be arranged at different positions of the wind power plant, for example the external device can be in a rotor blade 110 be arranged and the control unit in the tower of the wind turbine 100 or a machine housing (“nacelle”), ie part of a wind turbine 100 , in the generator, gearbox etc. are housed.

Advantageously, several or all of the rotor blades 110 a rotor with sensors 400 , 500 be equipped according to the present invention.

In a further embodiment of the arrangement according to further embodiments of the application it is disclosed that the surface elements have one or more quadrants 200 on the rotor blade surface 110 are. The algorithm that processes the sensor data in the processing unit is able to use the sensor measurement values to determine in which area (quadrant) 200 the force exerted by a wake vortex 210 or wind shear 120 , 130 he follows. This is a real-time measurement which, compared to previous prediction models, allows a quick reaction to changed flow conditions.

In a further embodiment of the arrangement according to one or more other embodiments, the evaluation device 510 be further adapted to determine a load prediction of one or more mechanical components of the wind turbine from the evaluation data. The mechanical components can be one or more of the wind turbine tower group 100 , Rotor blades 110 of the wind turbine, gears of the wind turbine include.

In a further embodiment of the present application, a method for determining, in particular, undesirable or highly stressful wind currents on one or more rotor blades of a wind power plant is disclosed. The procedure can include:

Determine 610 of voltage and acceleration values at at least two locations on a rotor blade surface and converting 620 the previously determined voltage and acceleration values into at least one electronically processable signal. The method can further include that the at least one electronically processable signal is sent to an electronic evaluation unit 510 can be read 630 . The evaluation unit 510 can evaluate 640 or analyze the at least one electronically processable signal and determine one or more parameters from the signal 650 .

The parameters can be, for example, intensity values of wake vortices 210 especially wake vortices caused by neighboring wind turbines 100 or intensity values of wind shear 120 , 130 that hit the rotor blades 110 of the rotor. However, parameters other than those mentioned can also be determined, as long as these parameters have information that is relevant to them. For example “proxy parameters”, which are similar to the parameters mentioned.

The importance for optimization is to find “proxy parameters”. These “proxy parameters” and not necessarily the exact parameters themselves can make it possible to make appropriate decisions when designing wind turbines. An approximation of the turbulence intensity can, for example, be sufficient to create a hypothesis / improvement that can optimize a wind farm.

• übermitteln bestimmter Intensitätswerte der Wirbelschleppen 210 und/oder Scherwinde 120, 130 mittels einer Datenschnittstelle an benachbarte Windturbinen 100;

In a further embodiment, the method for determining wind parameters according to one or more other aspects can further comprise:

• transmit certain intensity values of the wake vortices 210 and / or windshear 120 , 130 by means of a data interface to neighboring wind turbines 100 ;

Determination of an individual blade angle adjustment (pitch) and / or a rotor angle adjustment (yaw) of the neighboring wind turbines 100 a load on the wind turbine or its rotor blades 110 to be kept below a predefinable limit value, taking into account the maximum wind energy yield that can be achieved under the given intensity values. The intensity

According to a further embodiment, a rotor blade 110 with an array of sensors 400 , 500 according to one or more other embodiments.

According to a further embodiment, a wind turbine 100 with one or more rotor blades 110 with an array of sensors 400 , 500 disclosed in accordance with one or more embodiments.

In summary, the processes and facilities presented enable new applications. A continuous wake vortex detection on rotor quadrants 200 or individual surface elements or partial areas of a rotor or rotor blade 110 serves to confirm and verify the wake vortex direction in wind farms and therefore for an optimal use of the yaw and pitch controls of the wind turbines in wind farms. Forecast times are very short (<10min)

The influence of the wind speed on the rotor can be determined directly at the measuring location (pitch angle and blade torsion calibration)

The description of the winds at the site is used to predict the power output and the load on the wind turbine.

A wind / load dependency can be measured in real time (hybrid model correction for aero-elastic models) and can contribute to an improved design in wind turbine development.

An optimized turbine control is not, as before, implemented via its system response but directly via its deflection, in particular via deflections, expansions, and / or accelerations, measured on partial surfaces or surface elements of the rotor blade in order to control the wind power turbine and, if necessary, with regard to material fatigue and Wind power yield to achieve an optimized operating position.

The measuring device according to the present disclosure and corresponding methods thus overcome problems and limitations of alternative approaches:

The wind speed vector, turbulence intensity and wind shear can be measured as surfaces with high sampling rates.

Turbulent wind field models can be better validated and further improved. Wind energy probability estimates can be improved in accuracy and precision.

In particular, the spread of wake vortices from wind farms is determined by analyzing wind deficits, i.e. lack of wind and increased load on wind turbines, in the same wind direction.

Although the present invention has been described above on the basis of typical exemplary embodiments, it is not restricted thereto, but rather can be modified in many ways. The invention is also not restricted to the possible applications mentioned.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 6909198 B2 [0015]
• US 20090311096 A1 [0015]
• US 7281891 B2 [0018]
• DE 102011011392 A1 [0020]
• US 20130255363 A1 [0028]
• DE 102014210949 A1 [0057]

Claims (15)

An arrangement of sensors on a rotor blade for determining wind currents on one or more rotor blades of a wind turbine an arrangement of at least two strain sensors (400) which detects blade bending moments of at least one rotor blade (100) of a wind turbine (100) in at least two different spatial directions; a first acceleration sensor (500) for detecting accelerations of the rotor blade (110) in a first spatial direction; and at least one second acceleration sensor (112) for detecting accelerations of the rotor blade (110) in a second spatial direction, the second spatial direction being different from the first spatial direction; an evaluation device (510), which is designed to read in analog or digital signals from the voltage measuring sensors (400) and the acceleration sensors (500) via inputs of the evaluation device (510), to evaluate the signals and to provide an evaluation result. The arrangement according to Claim 1 wherein the acceleration sensors (500) and / or the strain sensors (400) are fiber optic sensors. The arrangement according to one of the Claims 1 - 2 , wherein the first spatial direction and the second spatial direction enclose an angle of 70 ° to 110 °. The arrangement according to one of the preceding claims, wherein the acceleration sensors (500) are arranged in a blade radius> 10m. The arrangement according to one of the preceding claims, wherein the evaluation device (510) comprises a computing unit, wherein the computing unit comprises an algorithm which, based on the evaluation result of the signals of the measurement sensors (400, 500), is designed to accelerate and / or To determine elongation values of at least one surface element (200) of one or more rotor blades (110). The arrangement according to one of the preceding claims, wherein the evaluation device (510) uses the acceleration and / or elongation values of the at least one surface element (200) to use intensity values of one or more wake vortices (210) hitting the rotor blade or a strength of shear winds (120, 130) ) certainly. The arrangement according to one of the preceding claims, wherein the evaluation device (510) is further adapted to transmit the intensity values of the wake vortices (210) and / or wind shear (120, 130) to neighboring wind turbines (100) by means of a data interface for individual determination a blade angle adjustment (pitch) and / or a rotor angle adjustment (yaw) of the neighboring wind turbines (100) in order to keep the load on the systems low, taking into account the maximum wind energy yield to be achieved at the specific intensity values. The arrangement according to one of the preceding claims, wherein the wake vortex (210) is generated by rotor blades (110) of the rotor of an adjacent wind power plant (100), in particular in the same wind direction. The arrangement according to any one of the preceding claims, wherein the surface elements (200) are one or more quadrants on the rotor blade surface. Arrangement according to one of the preceding claims, wherein the evaluation device (510) is further adapted to determine a load prediction of one or more mechanical components of the wind power plant (100) from the evaluation data. Arrangement according to one of the preceding claims, wherein the mechanical components contain one or more of the group consisting of the tower of the wind power plant, rotor blades (110) of the wind power plant, and gears of the wind power plant. Method for determining wind currents on one or more rotor blades of a wind turbine, comprising: Determining (610) stress and acceleration values at at least two locations on a rotor blade surface; Converting (620) the determined voltage and acceleration values into at least one electronically processable signal; Transferring (630) the at least one electronically processable signal to an electronic evaluation unit (510); Evaluating (640) the at least one electronically processable signal and then; Determination (650) of one or more parameters from the group: intensity values of wake vortices, in particular wake vortices that are generated by neighboring wind turbines, intensity values of wind shear (120, 130). Method for determining wind parameters according to Claim 12 , further comprising, transmitting the intensity values of the wake vortices and / or wind shear to neighboring wind turbines by means of a data interface; Determination of an individual blade angle adjustment (pitch) and / or a rotor angle adjustment (yaw) of the neighboring wind turbines in order to keep the load on the wind turbine or its rotor blades below a predefined limit value, taking into account the maximum wind energy yield that can be achieved under the intensity values. Rotor blade with an arrangement of sensors according to one of the preceding claims. Wind power plant with one or more rotor blades with an arrangement of sensors according to one of the preceding claims.

Images