EP3491241A1

EP3491241A1 - Recording of measured values for a wind turbine

Info

Publication number: EP3491241A1
Application number: EP17749123.0A
Authority: EP
Inventors: René MERTENS; Albrecht Brenner; Frank Knoop; Uwe HELMKE
Original assignee: Wobben Properties GmbH
Current assignee: Wobben Properties GmbH
Priority date: 2016-07-29
Filing date: 2017-07-11
Publication date: 2019-06-05
Also published as: CN109563815A; JP2019523363A; CA3030993A1; WO2018019560A1; DE102016114051A1; KR20190032555A; BR112019001561A2; RU2019105104A; RU2019105104A3; US20190170123A1

Abstract

The invention relates to a method for recording at least one measured value, wherein the measured value is recorded by means of at least one measuring drone (2), and the measuring drone (2) for recording the measured values flies into a predeterminable position, is held in the predeterminable position by a position controller, or the measuring drone's change relative to the predeterminable position is recorded, and the measuring drone records the at least one measured value and transmits the at least one recorded measured value or at least one value representative thereof to an evaluation unit (10) and/or stores said value.

Description

Measured value acquisition for a wind energy plant

The present invention relates to a method for acquiring at least one measured value, in particular for use for controlling a wind energy plant. Moreover, the present invention relates to a method for operating at least one wind turbine based on at least one detected measured value. Furthermore, the present invention relates to a measuring drone and an arrangement of several measuring drones. Moreover, the present invention relates to a wind turbine and a wind energy system with one or more wind turbines.

Wind turbines are well known and they are used to generate electrical energy from wind. At least it can be helpful for their control to detect wind properties. This includes in particular the wind speed and the wind direction, which is also referred to below as wind value or wind values. In addition, it is helpful to know the sound emissions radiated by the wind energy plant, in particular during the current operation, in order to reduce noise pollution by wind turbines, for example by adjusting the operating point, if necessary.

For example. It is also possible to carry out measurements for determining power curves, which are usually carried out with the aid of a wind measuring mast arranged upstream of the wind energy plant. However, such a wind measuring mast is firmly anchored and that requires that the measurements can only be correct for a single wind direction and require correction for deviating wind directions. Also, the installation of the wind measuring mast is complicated because of the necessary anchors and guying. In the case of sound measurements, only the sound radiation in one direction can be detected with the measured value, so that a two-dimensional or three-dimensional measurement for determining a sound field is impossible.

Alternatively, measurements, in particular for the determination of wind values, could also be carried out with measuring devices on the relevant wind energy plant. In particular, however, the use of a so-called gondola anemometer is very inaccurate, also due to the fact that the operation of the wind power plant disturbs this measuring device, namely in particular the rotation of the rotor, in which the rotor blades pass the measuring device.

The use of measuring devices on the nacelle of a wind turbine also regularly have the problem that they can determine the wind speed only in the area of the nacelle, but not in the entire area of the rotor surface, ie in the area swept by the rotor blades during operation of the wind turbine. Thus, the detection of a wind field is regularly not or only insufficiently possible.

Even technically complex measurements such as ultrasound measurement come into consideration, but are very expensive and costly.

The invention is therefore based on the object, at least one of the o.g. To address problems. In particular, a solution is to be proposed with which a wind field or a sound field for a wind turbine can be detected from different directions in a simple manner. Such a solution should be as flexible and inexpensive as possible. At least should be proposed to previously known solutions an alternative solution.

According to the invention, a method according to claim 1 is proposed. The method is intended to detect at least one measured value. Such a measurement may be a wind value, such as a wind speed, a wind direction, a wind gust, or a sound measurement, such as a sound pressure level or frequencies of the sound. For detecting it is suggested to use a measuring drone. The measuring drone can also be called a drone for simplicity. This measuring drone, although several can be used, flies to detect the wind value, or multiple wind values, in a predetermined position. This predefinable position can be, for example, at the height of the nacelle of a wind energy plant, wherein a predetermined distance, such as 100 meters, is maintained. This position in front of the wind turbine can mean in particular that this position is directly in luv before the wind turbine, so the wind turbine is located directly behind this drone with respect to the present in the wind direction. However, other positions may also be considered, especially if a wind field or a sound field is to be measured, and especially if several measuring drones are used, which simultaneously operate in different positions.

The now considered measuring drone is now held in this predetermined position by a position control. This allows the measured values to be recorded at this position. In addition or as an alternative, a change in the position of the measuring drones with respect to the predeterminable position can also be detected. As a result, this change in the position of this measuring drone can be taken into account in the evaluation and, if necessary, eliminated to determine a wind measurement value. This may involve intentional or unwanted changes in the position of the measuring drone. For example. It can also be provided that the position forms a position path to be removed. The at least one measured value is now detected by the measuring drone and transmitted to an evaluation device. For this purpose, the wind value, that is, for example, the wind speed and / or the wind direction, or the sound measurement value, for example the sound pressure level, namely the volume or frequencies of the sound, can be calculated and transmitted already in the measuring drone from the recorded values, ie from raw data become. It also comes into consideration that the raw data are transmitted and only from the evaluation device, the corresponding wind values or sound measurements are calculated. An intermediate solution is also considered, in which a first preliminary evaluation takes place at the measuring drone, or only part of the wind values or sound measurement values are calculated, or a calculation without standardization takes place, to name just a few examples. Particularly, for example, even a gustiness can only be determined in the evaluation device from a plurality of values of the wind speed. Alternatively or in addition to the transfer, it is also provided to store the measured values in a memory of the drone in order to evaluate them only after the drone has landed. The measurement drones can also be used to determine wind conditions at planned locations to determine the suitability of the site, which can also be referred to as a site assessment. Here, properties of the location can be determined, such as yield forecasts, altitude profiles, wind shear and turbulence intensity.

An embodiment of the invention proposes an autonomous detachment of a measuring drone by a further measuring drone as soon as the battery of the first measuring drone has been used up. Due to such a cyclical change, measuring phases of any length can be carried out indefinitely despite limited flight times of a measuring drone. According to one embodiment, it is proposed that the measuring drone is held in the predeterminable position by means of a position control. Additionally or alternatively, it is proposed that the measuring drone is held in a predetermined position by means of a position control. This is to be understood in particular in which direction the measuring drone is aligned, in which horizontal direction the measuring drone thus points. A position control can also relate to the position of the measuring drone in a plane, ie whether the measuring drone is tilted to a plane and, if so, in which direction and how strongly.

For the position control or the position control control variables or manipulated variables are constantly generated, such as the thrust of a propeller of the measuring drone and the orientation of the propeller or the measuring drone. From these control variables or manipulated variables can be deduced the wind speed and wind direction and possibly other wind values. Preferably, the at least one measured value to be detected is derived therefrom.

If, for example, the measuring drone is controlled in its position in such a way that it holds an oblique position and corresponding thrust of its propellers in their vorgebaren position against the wind, the wind direction can be determined from the direction of the inclination. From the degree of skew and the set thrust force also the wind speed or wind speed can be determined. Possibly. Accuracy can be improved by taking into account other values such as air temperature, precipitation, precipitation, humidity and / or air pressure. However, this is only explained as an illustrative example and there are other options into consideration, such as the use of a measuring drone, in which instead of an inclination of the measuring drone or in addition to the one or more propellers inclined and these data allow conclusions about the wind speed and wind direction. In particular, a wind value determined in this way, which can also be referred to as wind measurement, can likewise be taken into account in the determination of the sound measurement value. In particular, sound pressure levels at a specific relative location to the wind turbine are in fact also dependent on the prevailing wind values.

Thus, from the position control and also or alternatively from the position control of the at least one drone, a measured value can be derived.

According to one embodiment, the measuring drone has, in particular as a measuring means, at least one measuring sensor for detecting a wind value in order to detect the wind values or a part thereof by means of this at least one measuring sensor. The or at least one of the measuring sensors is a microphone according to another embodiment. Since the operation of the measuring drone can also influence such a measuring device, this operation of the measuring drone may be taken into account when the at least one wind value is detected by the measuring sensor in order to calculate out possible distortions.

If the or at least one of the measuring sensors is embodied as a microphone, that is to say as a sound sensor, then, according to a further embodiment, it is fastened with a cable or a spacer by a base body of the drone, on which the propellers are arranged, and thus spaced from the propellers , As a result, the sound that hits the microphone is reduced by the propellers in terms of its amplitude.

According to a further embodiment, a sound-proof plate is arranged on the cable or the spacer between the measuring sensor, that is to say in particular at least one microphone, and the base body. This reduces the sound of the propellers at the measuring sensor.

Preferably, at least two measuring drones are used to acquire the measured values, which alternate to record the measured values without interruption. This is particularly suitable for the use of measuring drones in battery mode. As a result, in the simplest case, a measuring drone can be in the air and record the measured values and the other measuring drone can be charged in a charging station during this. Preferably, several measuring drones are in use at the same time, and detecting the wind values in different predeterminable positions. In this case, it is particularly possible for a plurality of measuring drones to be arranged at a distance from one another in order to be able to record measured values at different heights. As a result, especially a height profile of the wind or the sound can be detected.

Preferably, a wind characteristic is recorded and this includes the recording of a windshear, so recording the change in wind speed as a function of altitude. This includes the recording of a wind sweeper, namely a change in the wind direction as a function of altitude. In addition or alternatively, wind field can also be recorded. Thus, not only a change of the wind values with the height, but also in the horizontal direction is evaluated. In particular, such a wind field can be recorded for the rotor field or an area in front of it. As a result, a specific measurement of the wind conditions relevant to the relevant wind energy plant is possible in particular. The position control of the measuring drone preferably takes place by means of a GPS data-evaluating measuring system. The position of the measuring drone can thus be detected via the GPS data and thus a position control of the measuring drone can be carried out. In addition or in addition, a change in the position of the measuring drone can also be detected and taken into account. In addition or in addition, a GPS data-evaluating measuring system can be used which is supplemented by one or more stationary reference receivers. As a result, the accuracy can sometimes be significantly improved and this system can be designed as a so-called. Differential GPS or work. This system is commonly known as the Differential Global Positioning System DGPS. In addition or alternatively, a system can be used which detects or provides position data by means of ultrasound measurements, that is to say a measuring system evaluating ultrasound measurements. The use of a measuring system that evaluates radar measurements is also an option. It should be noted that measuring systems evaluating such ultrasound measurements and measuring systems evaluating radar measurements can in principle be complex and expensive, but the costs are limited by the fact that these measuring systems only have to be designed for targeted position detection of the at least one measuring drone. This particularly affects the range and directional spectrum of the system. The detection of a wind field, a sound field or at least one height profile can alternatively or in addition to the use of multiple measuring drones also take place in that the measuring drones or at least one measuring drone changes its position. In other words, here a measuring drone can fly off the wind field, the sound field or a part thereof and thereby measure the wind field, the sound field or the corresponding part.

Preferably, the method is characterized in that further weather information is detected by the least one measuring drone or otherwise. This can be improved especially the measurement quality. On the one hand, the detection of the sound or wind values, in particular of the wind speed, may depend on further weather information, namely especially if the wind speed is derived from control variables or manipulated variables of a position control. However, it is also or alternatively possible to assign further weather information to the wind values or to use it as wind values in order to improve the database of the detected wind values. Such additionally recorded weather information can then possibly improve a dependent regulation or control of the wind turbine.

Such further weather information may be air temperature, precipitation type, precipitation amount, humidity, air density and / or air pressure.

Preferably, a plurality of measuring drones are held at different heights to each other by a position control, and each of the measuring drones detects measured values in their height. This common position control of the multiple measuring drones is carried out in particular so that these multiple measuring drones together form a virtual measuring mast. These measuring drones then record measured values at different heights, which are otherwise recorded by a measuring mast. Since these measuring drones are not mechanically fixed, but only by a coordinated or coordinated position control are positioned to each other, they can form a virtual measuring mast or be regarded as such. Preferably, an evaluation can be carried out here, as is usually known with a measuring mast, without a measuring mast having to be erected. Preferably, this at least one measuring drone, in particular the virtual measuring mast, is positioned as a function of a wind direction, in particular in the wind turbine of the wind energy plant. Preferably, in this case the at least one measuring drone or the virtual measuring mast is tracked with changing wind direction of the wind direction, in particular such that this at least one measuring drone or the virtual measuring mast is held substantially in the wind turbine of the wind energy plant. As a result, an evaluation of the sound profile or of the wind profile in front of the wind power plant or of the sound field or of the wind field in front of the wind energy plant can be carried out in spite of changing wind directions. A correction calculation, which may be required for a windmill that can not track the wind, is not necessary here.

It is also proposed according to the invention a method for operating at least one wind turbine. In this case, the wind energy plant is operated as a function of at least one measured value. For this purpose, it is proposed that the at least one measured value be detected by at least one measuring drone. The detection is preferably carried out as described in accordance with one of the preceding embodiments of the method for detecting at least one measured value by means of a measuring drone.

It is particularly considered that the corresponding measured values are transmitted directly or indirectly from the at least one measuring drone to the wind turbine.

According to the invention, a measuring drone is also proposed for detecting at least one sound value or one wind value, in particular a wind speed and / or a wind direction. Such a measuring drone comprises a flight control device which is prepared so that the measuring drone approaches a predefinable position and is held there in the predeterminable position. The flight control device then performs a position control. In addition or alternatively, as soon as the measuring drone has reached approximately its predeterminable position, a change in the position of the measuring drone relative to the predeterminable position can be detected. The flight control device may in particular include a position detection and position deviation, especially in three coordinate directions. From this, control errors can be determined, for example, by corresponding desired-actual value comparisons for all three position directions and entered into a control algorithm which determines therefrom corresponding thrust setpoint values for the respective directions. Such a nominal thrust value in the vertical direction is primarily relevant for overcoming the deadweight of the measuring drone. The two other desired thrust values of different, especially Cartesian, directions in the horizontal plane can, however, provide information about wind direction and strength, especially if finally, at least for a short time, results in a stationary accuracy for the position control.

A conversion for the desired thrust in the vertical direction can be implemented in particular via a thrust of the propeller, especially on their speed. The other two desired thrusts in the directions in the horizontal plane can be achieved, for example, by corresponding inclinations of the propellers of the measuring drone, or an inclination of the measuring drone, to name just two examples.

According to one embodiment, the drone not only determines its position in the three spatial directions, but also or alternatively its inclination in the sense of rotation about these directions. It has been recognized that this inclination is a measure that correlates with the wind direction and wind force, when simultaneously maintaining the vertical and horizontal positions. For this purpose, it is proposed that this inclination is detected and from this the wind direction and, in addition or alternatively, the wind speed is derived while keeping the horizontal position. The flight control device may also or alternatively detect the change in the position of the measuring drone to the predetermined position. If a position control is activated, such changes are likely to exist as a control error anyway and can be evaluated. However, even if such a control is not activated, such control errors can nevertheless be detected as deviations without necessarily changing the position of the measuring drone.

In addition, the measuring drone comprises a wind detection means, which may also be called Windmesswert- detection means for detecting at least one wind value. This can be done by evaluating the quantities that the flight control device receives and uses especially for position control. In addition or alternatively, however, at least one measuring sensor may also be present on the measuring drone. Alternatively or additionally, the measuring drone comprises a microphone for detecting a sound measurement value.

In addition, according to one embodiment, a transmission means for transmitting the at least one detected measured value to an evaluation device is provided. Instead of the measured value or in addition thereto, representative values can also be transmitted for the measured values, such as, for example, raw data acquired by the measuring drone. The transmission can be wired or by radio. Especially if a variant is chosen in which the measuring drone is supplied by trailing cable with electric power, this trailing cable, for example. Also similar to a d-network, in addition to data transmission. If the measuring drone flies freely with an electric battery, a radio transmission is considered. If measured values are recorded off-line in order to finally configure a wind energy plant or a wind energy plant control, it is also possible to first record and store recorded values and then to transmit the measured drone on landing. Especially when the measuring drone lands at or on the evaluation device and there, for example, also connected to charge their battery. The measuring drone preferably has one or more electrically driven propellers with a substantially vertical axis of rotation. The flight control device may then be prepared to control at least one actuator. Such an actuator may be the one or more propellers, especially a corresponding drive motor of each propeller can be controlled thereby. An actuator in this sense may also be an adjusting means for adjusting the orientation of the vertical axis of rotation of each propeller, provided that the measuring drone used has such adjustable axes of rotation. By a small adjustment of this vertical axis of rotation, so for example. By 5 to 10 degrees, to name just one example, a corresponding advance of the measuring drone in the tilting direction of this axis of rotation may result. With such a low inclination, the lift thrust scarcely changes, but can be adjusted if necessary by appropriate control of the propeller or a motor.

In addition, an actuator may be a position control means for controlling a position of the measuring drone. These may include aerodynamic elements such as baffles. An actuator may also be a direction control means for controlling a direction of flight of the measuring drone. Illustratively speaking, a configuration such as a helicopter may be considered, such as a tail rotor. However, it is also considered that the measuring drone is designed as a quadrocopter and the entire control is carried out via the control of the correspondingly provided four propellers.

Preferably, it is proposed that the measuring drone has an electrical battery for its electrical supply in order to store electrical energy required therein. This is especially true of the electrical energy needed to fly. The battery can also be used to control a computer, including capturing readings. Alternatively, it is proposed that the measuring drone has a trailing cable for supplying the electrical energy. Through the use of such a measuring drone for measuring a wind profile or wind field for a wind turbine, the radius of action of the measuring drone is quite clear outlined and thus the maximum cable length and thus the einzcc, the weight of this cable is well known. The measuring drone can therefore be designed so that it can lift a corresponding tow cable. This configuration has the advantage that a measuring drone can be operated permanently.

According to one embodiment, the measuring drone is characterized by one or more propellers driven by at least one internal combustion engine with a substantially vertical axis of rotation, wherein the flight control device is prepared to control at least one actuator. As an actuator, the one or more propellers, an adjusting means for adjusting the orientation of the vertical axis of rotation of each propeller, a position control means for controlling a position of the measuring drones and a direction control means for controlling a direction of flight of the measuring drone can also be used here. Explanations of the actuator, which were made in connection with the one or more electrically driven propellers, also apply mutatis mutandis to the embodiment with one or more internal combustion engines. It is therefore also contemplated that the measuring drone is driven by one or more internal combustion engines, so that it has one or more propellers, which are driven by one or more internal combustion engines. As a result, she can also work independently. Basically, it can have any functionality which was or will be described above or below in connection with an electrically drivable measuring drone. The above and following descriptions of an electrically drivable measuring drone, especially if it has an electric battery, apply mutatis mutandis to the measuring drone, which is driven by one or more internal combustion engines.

Especially for a variant that uses several measuring drones with at least one internal combustion engine, it can be provided that two or more measuring drones alternate in such a way that at least one measuring drone flies and takes measured values, while at least one other measuring drone is refueled in a base station. For this purpose, the same variants are proposed mutatis mutandis, which also explained above or below for the use of battery-powered measuring drones were or become. Again, a base station may be provided on the ground or on the nacelle of a wind turbine.

A particular advantage of using at least one internal combustion engine is that the measuring drone, and also the method for detecting at least one measured value, is particularly well suited for remote areas, especially if the one or more wind turbines are not yet connected to an electrical supply network are.

In any case, it is proposed that the measuring drone essentially autonomously controls its position and possibly stops. Possibly. For example, a user such as service personnel can specify a new position. In principle, however, it is not intended for a person to permanently engage in the control of the measuring drone, but instead the measuring drone is to autonomously fly and autonomously maintain its position, possibly the positional path, by means of the explained position control.

Preferably, the measuring drone is characterized in that it is prepared to be used in a method according to at least one of the embodiments described above. The measuring drone is therefore prepared to behave as described in connection with at least one of the above-described embodiments of the method for detecting at least one measured value. In addition, a measuring arrangement for detecting at least one measured value by means of a plurality of measuring drones is proposed according to the invention. Such a measuring arrangement comprises a plurality of measuring drones according to one of the embodiments described above. In addition, this measuring arrangement comprises a base station. This base station can be provided for supplying the measuring drone with electrical energy. Towing cables of the measuring drones can be connected to the base station if the measuring drones are wired. Alternatively, the base station can reach the supply by operating as a charging station for the measuring drones or by controlling such a charging station.

Additionally or alternatively, the base station may form the evaluation device and serve to record the acquired measured values. This can be done via the trailing cable or by radio, or offline, when the measuring drones control the base station. Additionally or alternatively, the base station can perform the coordination of the measuring drones with each other. This may include specifying different positions for the measuring drones, which differ particularly in their height. Even if the measuring drones are operated with rechargeable batteries and must alternately control a charging station, specifically at the base station, this change can be coordinated by the base station.

In particular, the measuring arrangement as a whole can form a virtual measuring mast, in which the base station evaluates the acquired data and the plurality of measuring drones receives the measured values, that is to say wind values, in the manner of a plurality of sensors distributed over the height.

The base station can be designed as a vehicle, especially as a service vehicle. Alternatively, a wind turbine can form the base station.

According to the invention, a wind turbine with a nacelle and a rotor with one or more rotor blades for generating electrical power from wind is also proposed. Such a wind turbine can be controlled as a function of at least one measured value. In addition, it has a data transmission means which is set up to receive measured values of at least one measuring drone. This can also or as an alternative to measured values relate to representative values. For example. For this purpose, the wind power installation can have a radio receiver for the at least one measuring drone to be able to transmit the measured values to the wind energy installation by radio. However, it is also contemplated that the wind turbine with the one or more measuring drones is connected by trailing cable when the measuring drones are those with trailing cable. Then the data transmission can take place and furthermore the wind energy plant can supply the at least one measuring drone with electrical energy. Of course, it is also considered that, as is generally the case, despite the use of a trailing cable, the measuring drones transmit the measured values by radio.

Preferably, the wind energy plant is characterized in that the data transmission means is adapted to receive the measured values or the values representative thereof from a measuring drone according to an embodiment described above. Thus, the advantageous properties of a measuring drone described above can be used to supply a wind turbine with corresponding wind values. Preferably, a wind turbine together with several measuring drones can form a virtual measuring mast. For this purpose, the measuring drones are coupled to the wind power plant, so that the measuring drone record the measured values for different positions, particularly different height positions, and transmit them to the wind energy plant for further processing.

Preferably, the wind turbine has a charging station for electrically charging at least one measuring drone. Preferably, the charging station is arranged on the nacelle of the wind turbine. As a result, depending on the design of the wind power plant, comparatively short distances between the charging station and the respective positions of the measuring drone can be achieved.

According to one embodiment, the drone is charged with firmly installed battery. Preferably, however, it is proposed to hold several batteries for exchange and to remove the drone from the used battery to replace it with a freshly charged. This has the advantage that the charging time of a single battery may be longer than the flight time of the drone and you still only need two drones, but several batteries needed.

In addition, a wind energy system for generating electrical power from wind is proposed, which comprises at least one wind energy plant according to an embodiment described above and also has at least one, preferably a plurality of measuring drones, as described according to at least one embodiment described above. According to one embodiment, the wind energy system is designed as a wind farm with multiple wind turbines. Additionally or alternatively, it may be provided to use a plurality of measuring drones, in particular a measuring arrangement with a plurality of measuring drones, as described above in accordance with at least one corresponding embodiment. Preferably, a virtual measuring mast described above is used.

The invention will now be explained in more detail below by way of example with reference to embodiments with reference to the accompanying figures.

Fig. 1 shows a wind turbine in a perspective view. Fig. 2 shows a wind farm in a schematic representation. 3 shows an exemplary control scheme for carrying out a method according to the invention.

Figures 4-7 show different configurations of a wind energy system with a wind turbine and several measuring drones. Fig. 8 shows a measuring drone with microphone.

FIG. 1 shows a wind energy plant 100 with a tower 102 and a nacelle 104. A rotor 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. The rotor 106 is set in rotation by the wind in rotation and thereby drives a generator in the nacelle 104 at. FIG. 2 shows a wind farm 1 12 with, by way of example, three wind turbines 100, which may be the same or different. The three wind turbines 100 are thus representative of virtually any number of wind turbines of a wind farm 1 12. The wind turbines 100 provide their power, namely in particular the electricity generated via an electric parking network 1 14 ready. In this case, the respective generated currents or outputs of the individual wind turbines 100 are added up and usually a transformer 1 16 is provided, which transforms the voltage in the park, to then at the feed point 1 18, which is also commonly referred to as PCC, in the supply network 120th feed. Fig. 2 is only a simplified representation of a wind farm 1 12, for example, shows no control, although of course there is a controller. Also, for example, the parking network 1 14 be designed differently, in which, for example, a transformer at the output of each wind turbine 100 is present, to name just another embodiment.

FIG. 3 shows a simplified control structure of an embodiment for a position control of a measuring drone, including evaluation of control values of the control for acquiring measured values, such as wind speed and wind direction. Therein the measuring drone is included as system 302. During flight operation, the measuring drone 302 can be positioned practically anywhere in space and its position is indicated here by the coordinates x, y and z. In this case, for example, the coordinate x may indicate a position in the north-south direction, the coordinate y a position in the east-west direction, and the coordinate z may indicate a vertical direction and thus the height of the measuring drone 302. These three coordinates x, y and z correspondingly form the output variables of the system for the position control. A predetermined position can be specified by the corresponding setpoint values x _s , y _s and z _s . There now takes place for each of the coordinates x, y and z a desired-actual value comparison at the summing 31 1, 312 and 313, wherein the actual values x, y, and z, received with negative signs. This then results in each case a control error, namely e _x , e _y and e _z . These control errors then enter the first sub-controller 320. The first sub-controller 320 has a single thrust controller for each coordinate, namely an X-thruster 321, a Y-thruster 322, and a Z-thruster 323. Each of these three thrust controllers of the first sub-regulator 320 inputs a thrust to be set, that is, a thrust to be set the corresponding coordinate direction, namely the thrusts or thrust forces S _x , S _y and S _z . The index indicates the respective direction. These three thrusts S _x , S _y and S _z can be referred to as control variables or manipulated variables. The term control variable is preferable here because they are not yet an immediate physical control of an actuator, as will become clear below. For the implementation of this exemplary system of Figure 3 is based on a measuring drone 302, which is controlled by the fact that their propellers in the rotational speed n and in a tilting of the axis of rotation of the propeller can be controlled in two directions Kipprichtungen, namely the tilting directions α and ß.

To control the vertical position z of the measuring drone 302, it can be assumed for the sake of simplification that this can be achieved by setting the rotational speed n. Accordingly, a speed controller 333 is provided. This receives as input the desired vertical thrust S _z and calculates a target speed n _s .

For the position control in the x-direction and y-direction is available as an actuator adjustment of the vertical axis of the propeller with respect to the two tilt angles α and ß available, these two tilt angles α and ß can be adjusted in mutually orthogonal directions. These two tilt angles α and β should be adjusted together, especially if the orientation of the measuring drone 302 can vary with respect to the x-direction and y-direction. Therefore, in the example structure of FIG. 3, the multi-variable controller 331 is provided. This takes into account the two thrusts S _x and S _{y together} in the x or y direction and outputs setpoints for the two tilt angles α and β as common result, namely the setpoint angles a _s and β _s . In the case of an exact alignment of the measuring drone 302, for example, in the north-south direction, when the tilt angle α then refers exactly to the north-south direction and the tilt angle ß exactly to the east West direction, would be a decoupling of this multi-variable controller 331 into two simple controller into consideration, so that the intended thrust in x-direction S _{x would} only change the tilt angle α directly and the thrust in y direction S _{y would} only directly affect the tilt angle ß , Since this requirement is usually not met, by taking into account the orientation of the measuring drone 302, which is characterized here as position L, a corresponding conversion into the multi-variable controller 331 can be made or taken into account. For this purpose, this layer L is input to the multi-variable controller 331.

The multi-variable controller 331 forms so far together with the speed controller 333 a second sub-controller 330.

In any case, the results of this simplified and illustrative structure of Figure 3 of the multi-variable controller 331 and the speed controller 333 are the setpoints a _s and ß _s for two tilt angle of the propeller and the target speed n _s for the speed of the propeller. These three setpoints are input into the system 302 accordingly, so they are passed to the measuring drone 302 for implementation or they are the appropriate actuators for adjusting the propeller axes and the motors for adjusting the speed passed. Of course, these actuators themselves can each have a control structure as an inner control cascade.

For the idealized case that the measuring drone 302 is exactly and immovably in its predetermined position, namely given by the desired coordinates x _s , y _s and z _s , there would be stationary accuracy for this position control and the control errors e _x , e _y and e _z would thus be 0. In this situation, it is then possible to derive wind speed V _w and wind direction R _w from the thrusts of the three coordinate directions, ie S _x , S _y and S _z . Of course, it is to be assumed here, unless it is calm, that these thrusts S _x , S _y and S _z have values different from 0. Accordingly, the first sub-controller 320 has an integral portion in each of its blocks. The x-boost regulator 321, the y-boost regulator 322 and the z-thrust regulator 323 thus each have an integral or integrally acting portion.

In order to calculate the wind speed V _w and the wind direction R _w , the measurement detection block 340 receives the three thrust values S _x , S _y and S _z . In order to assign the wind values calculated therefrom, namely the wind speed V _w and the wind direction L _{w, to} the respective coordinates in which they were detected, these coordinates x, y and z are also input to the measurement detection block 340. Accordingly, the Wind values are assigned to these coordinates x, y and z. Accordingly, the measurement detection block 340 outputs the wind speed V _w (x, y, z) and the wind direction R _w (x, y, z). These wind values can then be further processed and also be used taking into account the coordinates assigned to them for detecting a wind field. For the detection of a wind profile, it may be sufficient to consider only the vertical coordinate z. If the wind field is to be detected, especially for the entire rotor plane, the coordinates and x and y are also required, whereby the coordinates x and y could be converted into a representation with only one varying horizontal coordinate. From the vertical thrust S _z can be closed, for example, on the air density, which is proposed as one aspect.

In addition or as an alternative to this regulation according to the simplified control structure of FIG. 3, at least the wind speed and the wind direction can be derived from the inclination of the measuring drone. When the drive rotors are immovably connected with the measuring drone, the speed of each individual rotor and thus its thrust are adjusted in such a way that the desired inclination and direction of movement are established. As a secondary condition, the requirement can be made that the sum of the individual rotor thrusts to hold the vertical position corresponds exactly to the flight weight, or causes a desired acceleration up or down. For implementation, the software used can output position data and the angle of inclination. This data can be stored and transmitted telemetrically to a ground station. The evaluation can be made, for example, at the ground station.

FIG. 4 schematically shows a wind energy system 1 with a wind energy plant 100 and a plurality of measuring drones 2. The measuring drones 2 are shown in FIG. 4 in front of the wind energy plant 100, ie in FIG. 4, with reference to the schematically indicated wind 4, which is here characterized by corresponding arrows Windward wind turbine 100 arranged. The measuring drones 2 are arranged substantially vertically above one another and thereby form a virtual measuring mast 6. According to this variant of FIG. 4, a supply cable 8 is provided, via which the measuring drones 2 are supplied with electrical energy. The measuring drones share a common supply cable 8, which can also be referred to as a tow cable. By using this common supply cable 8 can the total weight that must be borne in total by the measuring drones 2 in addition by the supply cable 8, to be kept as low as possible. The supply takes place here via a base station 10, which is designed here as a service car. The measuring drones 2 with the supply cable 8 and the base station 10 thus also form a measuring arrangement 12 for detecting at least one measured value by means of the measuring drones 2.

Thus, according to this embodiment, measurement of measurement values in a desired position with respect to the wind turbine 100 can be easily achieved. In particular, this makes it possible in a simple manner always in the windward wind turbine 100 not only individual measurements, but a wind profile or a wind field or in the case that a microphone is provided to record sound profiles or sound fields. This is possible in principle for each occurring wind direction, in that only the measuring drones 2 have to be controlled to the corresponding position in the wind turbine of the wind power plant. These can also be tracked in a simple manner to the wind, so that even after a change in the wind direction, a measurement can be made in luv. Optionally, the base station 10, which is designed here as a service car and especially makes the electrical supply of the measuring drones 2, also change their position when the wind direction has changed. Alternatively, it may also be provided that the corresponding section of the supply cable 8, in particular that between the base station 10 and the lowest measuring drone 2, is so long that the base station 10 does not have to be changed in position or at least not in its position with smaller changes in the wind direction.

FIG. 5 shows an embodiment in which several measuring drones 2 are likewise supplied via a supply cable 8. However, the supply takes place here via the wind power plant 100, wherein the supply cable 8 is connected to the nacelle 104 or is connected in the region of the nacelle 104 to a corresponding supply unit.

Here, too, various measuring drones 2 are arranged in front of the wind energy plant 100 with respect to the wind 4. In principle, it is also possible to make a measurement not in luv the wind turbine, if this is needed.

In any case, according to this embodiment according to FIG. 5, a virtual measuring mast 6 can be formed in a simple manner with measuring drones 2, which detects measured values and can also detect a vertical profile of the wind 4 in particular. For a cable Guidance the supply cable 8 further measuring drones 2 are provided, which leads the supply cable from the nacelle 104 via the rotor 106 to the desired position in which the measurement is to take place, namely in this example in the windward wind turbine 100. The terms supply cable and trailing cable used here synonymously.

Recorded data, in particular measured values or values corresponding thereto, can be transmitted to the wind energy plant 100 or additionally or alternatively to the service wagon 1 1. From the service vehicle 1 1 can also be done a coordination of the measuring drones 2 and especially the virtual measuring mast 6. A partial task of a base station, namely the power supply, can be taken over here by the wind energy plant 100, in particular a corresponding device in the nacelle 104.

It should be noted that in this detailed description of the figures, particularly in the description of FIGS. 4 to 7, like reference numerals are used for similar, possibly non-identical elements. For example, the service car 1 1 between Figure 4 and Figure 5 and other figures differ, because he takes over the electrical supply of the measuring drones 2 in one case, but not in another case. The measuring drones 2 may be identical in the embodiments of FIGS. 4 to 7, but may also differ. For example, it could be provided that, according to the embodiment of FIG. 5, the measuring drones 2, which are arranged in front of the wind energy plant 100, have a different evaluation functionality than the measuring drones 2, which are provided essentially only for guiding the supply cable 8. If necessary, the measuring drones can also differ in their size. In particular, a measuring drone 2, which does not have to carry a trailing cable, may possibly be made smaller than those measuring drones 2 which have to carry a cable. Preferably, however, identical measuring drones 2 are used for each position in order to simplify especially the handling of the measuring arrangement 12.

The measuring arrangement 12 of FIG. 6, and thus also the wind energy system 1, differs from the measuring arrangement 12 or the wind energy system 1 of FIG. 5 essentially only in that another guidance of the supply cable 8 is provided, namely by the nacelle 104 and by the nacelle Rotor 106 of the wind turbine 100 through to the position of the virtual measuring mast 6 before the wind energy Otherwise, reference is made to the embodiment of FIG. 5 for further explanation.

Finally, FIG. 7 shows a wind energy system 1 and thus also a measuring arrangement 12 in which the measuring drones 2 operate without supply cables. For this purpose, each measuring drone 2 has an accumulator or similar storage of electrical energy. The measuring drones 2 can then be arranged independently of each other in space. However, this also makes it possible to form a virtual measuring mast 6. Such a virtual measuring mast 6 is also formed here, namely in this example from four measuring drones 2, which are also positioned in an exemplary manner with respect to the wind 4 in front of the wind energy plant 100. Thus, these measuring drones 2 of Figure 7 can perform the same tasks, as well as the measuring drones 2 with supply cable 8 according to the embodiments of Figures 4 to 6 can. However, the measuring drones 2 of the embodiments of FIGS. 4 to 6 can basically fly into their position for as long as desired, thereby permanently carrying out measurements and forwarding the measurement results. Instead, two charging stations 14 are provided for the measuring drones 2. In each case one measuring drone 2, that is to say a total of two measuring drones 2, can be charged in these charging stations 14. If at least one measuring drone 2 is charged, an exchange process 16 can be carried out in which a charged measuring drone 2 leaves one of the charging stations 14 and assumes the position of a measuring drone 2, which can then approach the charging station 14 and be charged there. Coordination can also take place here from the service vehicle 1 1. The charging stations 14, together with the service trolley 11, can form a base station 10 for the measuring drones 2 and thus for the entire measuring arrangement 12.

According to a variant, the charging stations, which in the simplest case could also extend to a charging station, are arranged on the nacelle of the wind energy plant 100. As a result, among other things, it can be achieved that the charging stations are thereby protected against unauthorized access. The measuring drones can then work completely autonomously and require no monitoring.

According to one embodiment, a solution may be provided in which the measuring drones have accumulators or similar stores of electrical energy which are exchanged for charging. For this purpose, a series of several accumulators, which can also be referred to as rechargeable batteries, for example five or more rechargeable batteries, are charged on the same number of recharging stations. The one or more fully charged batteries stand at the end of the row for docking to a drone. The used battery is removed from the drone and placed at the rear end of the row on a charging station and loaded there. This requires fewer drones with the same functionality and has more time to recharge, which extends the life of the battery. Such an arrangement may also be provided on the nacelle of the wind turbine.

Thus, a solution is now created with which wind measurements can be performed in front of the wind turbine even from changing wind directions. The invention thus avoids problems that are known from fixed wind measuring masts, in which no permanently installed wind measuring mast is required, but at the same distance in the flow direction before the wind turbine an autonomously flying device with automatic position and position control is used. This autonomously flying device is referred to here as a measuring drone.

The flying object, so the measuring drone, is preferably equipped with electrically driven propellers with vertical axis of rotation, which provide the necessary propulsion. This measuring drone can be designed according to the principle of a multicopters. According to one embodiment, deviating from the technique of free-flying drones for the purpose of the invention can be dispensed with the entrainment of batteries or accumulators as an energy source and instead done the power supply wired. However, the altitude is then limited by the weight of such a cable, namely supply cable, while the duration of flight can be unlimited.

Alternatively, it is also possible to use accumulator-operated flying objects, that is to say especially measuring drones with accumulator. Because of the limited duration of flight, a cyclical detachment of the flying object can take place through another, freshly loaded object. In this case, the detaching object, that is, the measuring drone, flies from a charging station mounted on the ground or on the nacelle, such as the charging station 14, to the position of the object to be detached, while the object to be detached flies back to the charging station. The flying objects described here are also referred to as measuring drones and these terms can be used interchangeably insofar. If the loading times are greater than the flight times, it is proposed to arrange correspondingly more charging stations and objects per object position in order to maintain as long as possible continuous operation. For attitude control, conventional systems are proposed, such as gyroscopes, including gyros, and optical systems or combinations thereof.

The position control is intended to hold the object rigidly at a predetermined position and height, whereby the position can still be changed. For this purpose, GPS-based systems and for height measurement and possibly ultrasound and radar devices are used. The accuracy of GPS-based systems can be significantly improved by using stationary reference receivers on or near the wind turbine. It is also known by the term Differential GPS. Since the wind direction and the wind speed are the primarily required measured variables, one can use the control variables calculated by the flight controller for position keeping directly as a measuring signal. Alternatively or additionally, the flying object could also carry conventional sensors.

In particular, it is proposed to station a plurality of these objects, that is to say flying objects, on a geometrical position but at different heights and thus to form a virtual wind measuring mast, namely in particular a virtual wind measuring mast 6 illustrated in FIGS. 4 to 7.

If a wind tracking of the wind turbine, so if the wind changes in its direction, such a column of flying objects, which can form said virtual wind measuring mast, be transferred to a corresponding new position, in particular in the then new position in luv the wind turbine ,

The disadvantage of such tracking could be here also nachzuführende wired power supply. This can be avoided by a preferred embodiment of the invention, in which the power supply of the flying objects, so the measuring drones 2, takes place from the nacelle. Figures 5 and 6 show such a variant in which the cables are guided around the rotor. This can be done, for example, above or below the rotor, that is below the rotor diameter or below the rotor surface.

Cyclical detachment of battery-powered flying objects, ie battery-powered measuring probes, avoids the disadvantages of cable operation as a whole, but may require a higher one Number of flying objects and additional charging stations with correspondingly higher costs. Such a cyclic detachment is described by way of example in FIG.

The invention has been particularly described for surveying for the use of wind turbines. But other measuring tasks in the atmosphere, which are about currents in the range of 0 to 300 meters above ground, and must necessarily be stationary, can be performed if necessary.

However, it is especially envisaged to use the invention as a replacement for stationary wind measuring masts.

Thus, it is particularly proposed to arrange an arrangement of flying platforms, that is to say so-called flying objects or measuring drones, on fixed positions, in particular specifiable positions, for measuring purposes. It is advantageous to combine several such platforms to virtual wind measuring masts. By a wired energy supply an unlimited flight time is at least theoretically achievable. An energy supply can take place from the ground or from a nacelle of a wind energy plant. Position control signals or position control signals can be used as the measured value. Particularly preferred is a telemetric wireless data transmission to a central station. Such a central station can be part of a described base station. However, an evaluation of the transmitted data can also take place instead or in addition at other locations, such as in a process computer of a wind turbine or in a parking controller in a wind farm in a central evaluation unit, which does not have to be directly in the vicinity of the measuring drones or said flying platforms , It should be noted that the term flying platforms is used here in order to emphasize that it is important for such flying platforms that they do not fly for their own ends, but in particular carry out measuring tasks and to this extent form a platform for carrying out these measuring tasks.

FIG. 8 shows a measuring drone 2 with a microphone 80. The microphone 80 is used to record measured values, namely sound measurement values, such as the sound pressure or frequencies of the sound. The microphone 80 is suspended by a cable 82 below the drone 2 on the base body 84 of the drone 2. The main body 84 of the drone 2 is the part of the drone on which the propellers 85 are arranged. The cable 82 is located above the microphone 80, a reverberant plate 86, the noise of the drone 2 shields.

Claims

claims

1. A method for detecting at least one measured value, wherein the measured value is detected by means of at least one measuring drone (2), and the measuring drone (2)

flies to a predetermined position to acquire the measured value,

is held in the predetermined position by a position control or its change is detected to the predetermined position,

- The at least one measured value detected and

- stores the at least one detected measured value or at least one value representative thereof and / or transmits it to an evaluation device (10).

2. The method according to claim 1, characterized in that as a measured value at least one sound reading, in particular with a microphone (80) formed measuring sensor of the drone (2), is detected.

3. The method according to claim 1 or 2,

characterized in that after detecting the measured value, the measuring drone flies into a further predeterminable position and is held in the further predeterminable position by a position control or its change is detected to the further predetermined position and detects at least one further measured value.

4. The method according to any one of the preceding claims,

characterized in that at least one measured wind value, in particular with a measuring sensor of the drone (2) designed as a wind value detection means, is detected as the measured value.

5. The method according to claim 4,

characterized in that as the at least one wind measurement value at least one value is selected from the list comprising:

a wind speed,

- a wind direction and

- a gust of wind.

Method according to claim 4 or 5,

characterized in that the measuring drone - Is held by means of a position control in the predetermined position and / or

- Is held by means of a position control in a predetermined position, and that - is derived from the position control or the position control or both of the at least one wind value.

7. The method according to any one of the preceding claims,

characterized in that at least two measuring drones (2) alternate during the detection of the measured values in order to record the measured values without interruption.

8. The method according to any one of the preceding claims,

characterized in that a plurality of measuring drones (2) are used simultaneously and detect the measured values in different predeterminable positions.

9. The method according to any one of the preceding claims,

characterized in that at least one wind characteristic is picked up, selected from the list comprising:

- at least one windshear,

- at least one Windveer and

- a wind field.

10. The method according to any one of the preceding claims,

characterized in that the position control of the measuring drone (2) takes place by means of at least one measuring system selected from the list

- a GPS data evaluating measuring system,

a GPS data evaluating measuring system supplemented by one or more stationary reference receivers,

- An ultrasound measurements evaluating measuring system and

- a radar measurement evaluating measuring system.

1 1. A method according to any one of the preceding claims,

characterized in that further weather information is detected by the at least one measuring drone or otherwise, and the further weather information relates to at least one weather information selected from the list

- air temperature,

- precipitation type,

- rainfall, - humidity,

- Airtight and

- Air pressure.

12. The method according to any one of the preceding claims,

characterized in that a plurality of measuring drones (2) are held at different heights to each other by a position control and each of the measuring drones (2) detects measured values of their height, in particular so that the plurality of measuring drones (2) together form a virtual measuring mast (6).

13. The method according to any one of the preceding claims,

characterized in that the at least one measuring drone (2) is positioned as a function of a wind direction, in particular in the wind turbine of the wind turbine (100).

14. A method for operating at least one wind turbine (100), wherein the wind turbine (100) is operated as a function of at least one wind value and the at least one wind value is detected by at least one measuring drone (2), in particular that the at least one wind value by means of a measuring drone (2) is detected by a method according to any one of the preceding claims.

15. Measuring drone (2) for detecting at least one measured value, and the measuring drone (2) comprises

a flight control device is prepared so that the measuring drone (2) approaches a predefinable position and is held there in the presettable position and / or that the change in the position of the measuring drone (2) to the predeterminable position is detected,

- A measuring means for detecting the at least one measured value, and

- A transmission means for transmitting to an evaluation device (10) or a storage means for storing the at least one detected measured value or at least one value representative thereof.

16. measuring drone (2) according to claim 15,

characterized in that the measuring means comprises at least one microphone (80) for detecting sound measurements.

17. Measuring drone (2) according to claim 15 or 16,

characterized in that the measuring means is connected to a cable (82) or a spacer, for example a rod, with a main body (84) on which, in particular, the propellers (85) are arranged, in order to keep a distance from the propellers ( 85).

18. measuring drone (2) according to claim 17,

characterized in that on the cable (82) or the spacer between the measuring means and the base body (84) a plate (86) is arranged, wherein the plate (86) is preferably a reverberant plate.

19. Measuring drone (2) according to one of claims 15 to 18,

characterized in that the measuring means comprises at least one Windmesswerterfas- means.

20. Measuring drone (2) according to one of claims 15 to 19,

characterized by one or more electrically driven propellers having a substantially vertical axis of rotation, the flight control device being adapted to control at least one actuator selected from the list comprising:

- the one or more propellers,

an adjusting means for adjusting the orientation of the vertical axis of rotation of each propeller,

a position control means for controlling a position of the measuring drone and

a direction control means for controlling a direction of flight of the measuring drone.

21. Measuring drone (2) according to one of claims 15 to 20,

characterized in that the measuring drone for their electrical supply

- Has an electric battery, for storing required electrical energy or

- A tow cable (8) for supplying electrical energy.

22. Measuring drone (2) according to one of claims 15 to 19,

characterized by one or more propellers driven by at least one internal combustion engine and having a substantially vertical axis of rotation, the flight control device being prepared to control at least one actuator selected from the list comprising:

- the one or more propellers, an adjusting means for adjusting the orientation of the vertical axis of rotation of each propeller,

a position control means for controlling a position of the measuring drone and

23. Measuring drone (2) according to one of claims 15 to 22,

characterized in that it is prepared to be used in a method according to one of claims 1 to 12 as a measuring drone (2) described therein.

24. Measuring arrangement for detecting at least one measured value, in particular a sound measurement value or a wind measurement value by means of a plurality of measuring drones (2), and the arrangement comprises

- Several measuring drones (2) according to one of claims 15 to 23, and

- A base station (10) for performing at least one function from the list comprising the functions

Supplying the measuring drones (2) with electrical energy,

- Recorded measured values and

- Coordinate the measuring drones (2) with each other.

25. Wind energy plant (100) with a nacelle (104) and a rotor (106) with rotor blades (108) for generating electrical power from wind, wherein

- The wind turbine (100) in response to at least one measured value can be controlled, and

- Has a data transmission means, adapted for receiving measured values or representative values, which are detected and transmitted by at least one measuring drone (2).

26. Wind energy plant (100) according to claim 25,

characterized in that the data transmission means is adapted to receive the measured values or the values representative thereof from a measuring drone (2) according to any one of claims 15 to 23.

27. Wind energy plant (100) according to one of claims 25 or 26,

characterized in that a charging station (14) is provided for electrically charging at least one measuring drone (2) according to one of Claims 15 to 19, wherein the charging station (14) is preferably arranged on the nacelle (104) of the wind energy plant (100).

28. Wind energy system (1), in particular wind farm (1 12), for generating electrical power from wind, comprising

- At least one wind turbine (100) according to one of claims 25 to 27 and

- A measuring drone (2) according to any one of claims 15 to 23.