DE102021113455A1 - Floating offshore wind turbine - Google Patents

Abstract

The application relates to a buoyant offshore wind turbine (100, 200, 400, 500, 700, 800), comprising at least one buoyant foundation (102, 202, 402, 502, 702, 802), comprising at least one floating body, one on the buoyant a base (102, 202, 402, 502, 702, 802) arranged tower (104, 204, 404, 504, 704, 804), and a nacelle arranged on the tower (104, 204, 404, 504, 704, 804). (106, 206) with a plurality of rotor blades (116, 216), wherein the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) further comprises at least one detection device (125, 225), set up to detect at least a wave parameter, and at least one wind pressure changing device (108, 208, 408, 508, 708, 808), set up to change the wind pressure exerted on the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) by controlling at least one Wind pressure control device (120) of the buoyant offshore wind turbine e (100, 200, 400, 500, 700, 800), comprising a pitch control device (120.1) and/or a converter torque control device (120.2), based on the at least one detected shaft parameter and a shaft criterion.

Description

The application relates to a buoyant offshore wind turbine, comprising at least one buoyant foundation with at least one floating body, a tower arranged on the buoyant foundation and a nacelle with a plurality of rotor blades arranged on the tower. In addition, the application relates to a wind pressure changing device for a buoyant offshore wind turbine, a method and a computer program product.

Wind energy systems or wind farms with at least one wind turbine are increasingly being used to provide electrical energy from so-called renewable energy sources. A wind power plant is set up in particular to convert the kinetic wind energy into electrical energy.

In order to increase the energy yield in such systems, wind farms are increasingly being arranged at locations with a high probability of wind. Offshore locations in particular (e.g. at sea) are usually characterized by relatively continuous wind conditions and high average wind speeds, so that so-called offshore wind energy systems or offshore wind farms are increasingly being erected.

As a rule, an offshore wind farm has a large number of offshore structures, such as a large number of offshore wind turbines and at least one offshore transformer station, via which the offshore wind farm is electrically connected, for example to an onshore transformer station or another offshore transformer station or offshore converter station. Furthermore, an offshore wind farm can have at least one measuring mast, which can have a number of sensors. The sensors can be set up to (continuously) measure local (meteorological) environmental parameters. Local means in particular the conditions prevailing at the offshore location.

An onshore substation, in turn, can be connected to a public power grid. Energy cables are laid in the form of submarine cables to transmit electrical energy between two offshore structures or between an offshore structure and an onshore structure.

While it has hitherto been customary for offshore wind turbines to be anchored by a foundation structure (e.g. monopile, tripod, tripile or jacket foundations) on or in the underwater bottom, in particular a seabed, there are more and more considerations about floating Install offshore wind turbines to install offshore wind farms, especially in areas with a large water depth, for example of more than 150 m.

A buoyant or floating offshore wind turbine has at least one buoyant foundation with at least one floating body. In the case of a wind turbine, at least one tower with a nacelle is arranged on the buoyant foundation, on which a plurality of rotor blades (usually three rotor blades) is arranged.

For (permanent) stationary operation of the offshore wind power plant, it can be fastened to the underwater floor, for example, by at least one anchoring arrangement. The at least one anchoring arrangement can be set up to fasten the offshore structure to an underwater bed when the offshore wind turbine is in an anchored state. For this purpose, the anchoring arrangement has at least one anchor connection running between an anchor, which is at least partially buried in the underwater bed, and the buoyant foundation.

Due to the floating design of such an offshore structure, the offshore wind power plant can be moved by wind and/or waves. In particular, a considerable (periodic) tilting movement can occur in a floating offshore wind turbine, in particular in the main wind direction and/or main wave direction.

With an increasing tilting movement or swaying movement, ie with an increasing tilting angle, of the offshore wind turbine, the risk increases that the blade tip will contact or touch the tower when passing through it.

In order to prevent damage to the offshore wind turbine, in particular due to the tower being touched by a blade tip of a rotor blade, the prior art involves a complex design of the buoyant foundations and, in particular, a relatively deep vertical positioning of the offshore wind turbine during installation. It is also known from internal prior art to regulate a wind pressure control device (e.g. pitch control device) of the buoyant offshore wind turbine, depending on a detected distance between the blade tip of a rotor blade and the tower, in particular the tower outer wall.

The disadvantage of the known regulations, however, is that they are imprecise. This reduces the Operational safety in the well-known offshore wind turbines. In order to nevertheless achieve sufficient operational reliability in practice, the regulations intervene at a very early stage. This in turn often unnecessarily reduces the energy yield of offshore wind turbines.

The application is therefore based on creating a possibility that at least reduces the disadvantages of the prior art and, in particular, in the case of a buoyant offshore wind turbine, reduces the risk of damage and at the same time increases the energy yield.

According to a first aspect of the application, the object is achieved by a buoyant offshore wind power plant according to claim 1. The buoyant offshore wind power plant comprises at least one buoyant foundation, comprising at least one floating body. The buoyant offshore wind turbine includes a tower arranged on the buoyant foundation. The buoyant offshore wind turbine comprises a nacelle arranged on the tower and having a plurality of rotor blades. The buoyant offshore wind turbine includes at least one detection device, set up to detect at least one wave parameter. The buoyant offshore wind turbine comprises at least one wind pressure changing device, set up to change the wind pressure exerted on the buoyant offshore wind turbine by controlling at least one wind pressure control device of the buoyant offshore wind turbine, comprising a pitch control device and/or a converter torque control device, based on the at least a detected wave parameter and a wave criterion.

In contrast to the prior art, the disadvantages of the prior art are at least reduced and, in particular in the case of a buoyant offshore wind turbine, the risk of damage is reduced, i.e. operational safety is increased, and at the same time the electrical energy yield of a buoyant offshore wind turbine is increased by at least one ( local) wave parameter is detected, this is evaluated as a function of a wave criterion and, depending on this evaluation, a wind pressure control device is controlled in such a way that the wind pressure exerted on the tower is changed.

In particular, it has been recognized that the waves hitting the buoyant offshore wind power plant, ie the local water waves, play a significant role in the fact that the buoyant offshore wind power plant is set in an impermissible tilting movement. The buoyant offshore wind turbine or the corresponding overall system has a resonant frequency. The entire system can be excited by the wave motion so that the resonance frequency is reached. A corresponding excitation can be prevented by controlling the wind pressure as a function of the wave movement. In particular, the wind pressure acting on the tower can be reduced as a function of the detected local wave movement in such a way that the resonant frequency of the entire system is not reached and/or the vibration frequency of the entire system is (immediately) changed when the resonant frequency is reached.

The buoyant offshore wind power plant according to the application has a wind power device as the offshore device, comprising a tower, nacelle, rotor, rotor blades, generator or converter, etc.

Furthermore, the buoyant offshore wind turbine has at least one buoyant foundation. The buoyant foundation serves to support the offshore device, ie at least the tower including the gondola. In particular, the tower is placed on the buoyant foundation and the nacelle on the top of the tower.

The at least one floating foundation comprises at least one floating body. A floating body or buoyant body is able to float independently, in particular due to its buoyancy by displacement according to the Archimedean principle. For example, floats can be hollow and filled with air or with a light solid. In particular, the buoyant foundation can essentially form the floating body.

The buoyant foundation can preferably be a so-called barge foundation, semi-submersible foundation, spar foundation and/or tension leg platform (TLP) foundation. It goes without saying that other types of buoyant foundations can also be provided in other variants of the application.

A floating foundation can be fastened or anchored to the underwater bed via at least one anchoring arrangement. In particular, a plurality (e.g. three or four) of anchoring arrangements may be provided for attachment.

According to the application, the offshore wind turbine has at least one (wave parameter) detection device that is set up for detecting at least one (instantaneous and/or local) wave parameter.

The (wave parameter) detection device can preferably comprise at least one measuring or sensor module and/or be communicatively connectable (e.g. via a wireless and/or wired communication network) to at least one measuring or sensor module. The at least one wave parameter is in particular a parameter of the instantaneous wave movement at the installation site of the offshore wind turbine, ie in particular a parameter of the locally occurring water waves that are momentarily impacting the offshore wind turbine. The measurement module can preferably measure the at least one wave parameter at least almost continuously. Particularly preferably, two or more different shaft parameters can be measured, for example by a corresponding number of different measurement modules or sensors.

The at least one measuring module can be arranged on the offshore wind power plant. Alternatively or additionally, a measuring device of the offshore wind farm in which the offshore wind power plant is arranged (such as a measuring mast described above) can comprise the at least one measuring module. In particular, at least one predicted wave parameter can additionally be made available to the detection device, for example by a corresponding service provider. The at least one predicted wave parameter can be used in particular to evaluate the at least one measured wave parameter. For example, at a certain momentary measured maximum wave height, a predicted wave height can be used to evaluate whether this measured wave height will remain a one-off event (because it is significantly (e.g. more than 20%) above or below the predicted wave height) or whether this maximum wave height will be reached regularly in the near future (e.g. the next hour etc.) (because it is essentially in the range of the predicted wave height, for example). In the first-mentioned case, a change in wind pressure can, for example, initially be omitted, while in the second case a change in wind pressure can take place.

In addition, the offshore wind power plant according to the application comprises at least one wind pressure changing device. The wind pressure changing device can include a control module set up to activate at least one wind pressure regulation device. The offshore wind power plant includes at least one wind pressure control device. The at least one wind pressure control device is a pitch control device and/or a converter torque control device.

A wind pressure control device according to the application is a device that can change the wind pressure on the tower, in particular the top of the tower.

A pitch control device is set up to adjust at least one rotor blade (preferably all rotor blades) of the offshore wind power plant. This means in particular that the angle of attack of a rotor blade is changed. The angle of attack can be adapted in particular in accordance with a target angle of attack predetermined by the wind pressure change device.

Alternatively or additionally, a converter torque control device can be controlled. The converter torque controller is configured to change the speed of the converter. This allows the wind pressure on the tower to be changed. In other words, by changing the torque of the converter, the aerodynamic efficiency can be changed. The torque can be adjusted in particular in accordance with a setpoint torque specified by the wind pressure change device.

In particular, the wind pressure can be changed by activating a wind pressure control device, ie in particular reduced (in particular to prevent damage to the offshore wind power plant) or increased (in particular to increase the energy yield). The change in the wind pressure also includes, in particular, switching off the converter.

The wind pressure changing device evaluates in particular the at least one wave parameter based on the at least one (specified) wave criterion. In a variant of the application, an average value/per time unit (e.g. x min) can be determined from the recorded instantaneous values of the at least one wave parameter. Alternatively or additionally, each instantaneous value can be evaluated with the wave criterion.

The wave criterion is in particular a regulation criterion. In one case, one threshold wave value or a plurality of threshold wave values may be predetermined. The evaluation can in particular include a comparison operation. If it is determined during this comparison operation that the at least one limit wave value is exceeded by a detected instantaneous value and/or by the mean value formed, a reduction in the wind pressure can be achieved, for example be effected by controlling the wind pressure control device, for example, with a specific setpoint. If it is determined during this comparison operation that the at least one limit wave value is undershot by a detected instantaneous value and/or by the mean value formed, the wind pressure can be increased by activating the wind pressure control device, for example with a specific target value.

In particular, the wave criterion can determine how great the change in wind pressure should be or with which target value, such as a target angle of attack value and/or target speed value, the wind pressure control device should be controlled, depending on the at least one detected wave parameter. In a (simple) case, the shaft parameter values above a threshold wave parameter can be assigned a first target value and the shaft parameter values below the threshold wave parameter can be assigned a second target value, which can differ from the first target value. A corresponding assignment can preferably be mapped by a lookup table (or the like), in particular for a plurality of limiting wave parameters and/or a plurality of different detectable wave parameters).

Such a wave criterion can be determined in advance, in particular by tests and/or simulations, and stored in a data memory of the wind pressure changing device.

• - (augenblickliche und/oder vorhergesagte) Wellenhöhe,
• - (augenblickliche und/oder vorhergesagte) Wellenrichtung, und
• - (augenblickliche und/oder vorhergesagte) Wellenfrequenz.

According to a preferred embodiment of the buoyant offshore wind turbine according to the application, the at least one (local) wave parameter can be selected from the group comprising:

• - (instantaneous and/or predicted) wave height,
• - (instantaneous and/or predicted) wave direction, and
• - (instantaneous and/or predicted) wave frequency.

Particularly preferably, at least the wave frequency (or wavelength) can be recorded and evaluated. In particular, it has been recognized that the tilting movement is influenced by the wave frequency. Therefore, in order to prevent the case of resonance, the wave frequency can preferably be detected. In particular, an (individual) wave criterion can be determined by prior tests (for example immediately after installation) or simulations for the offshore wind turbine, in which the resonant frequency of the offshore wind turbine is taken into account as a function of the wave frequency. A corresponding wave criterion, the detection of the wave frequency and the corresponding control can prevent (or at least reduce the risk) that the buoyant offshore wind turbine is excited to oscillate in such a way that the resonance frequency is reached.

Preferably, in addition to the wave frequency, at least the wave height can be recorded and evaluated. Alternatively or in addition, the wave direction can be recorded and evaluated.

A respective (pre-described) wave criterion can be provided for each of the wave parameters mentioned. A common shaft criterion (such as the lookup table described above or the like) can also be provided, in which the different shaft parameters can be set in a mathematical relationship with one another.

As already described, in one case the at least one wave criterion can comprise one or more limit wave values. At least one control command or setpoint can be assigned to each threshold value range. If the limit wave value is reached or exceeded or fallen below, the at least one wind pressure control device can be controlled with the at least one associated control command or target value (for example via a wireless and/or wired communication network).

The at least one limit wave value range can be between 0 and 2 Hz, in particular between 0.005 and 0.7 Hz, preferably between 0.05 and 0.4 Hz and particularly preferably between 0.05 and 0.2 Hz be provided as previously described. For example, a first control command or desired value can be assigned to a first range between, for example, 0.7 Hz and 2 Hz, which in particular brings about a first reduction in the wind pressure exerted on the buoyant offshore wind turbine. A second control command or target value can be assigned to a second range between eg 0.2 Hz and 0.7 Hz, which causes in particular a second reduction in the wind pressure exerted on the buoyant offshore wind turbine, the second reduction being higher than the first reduction . For example, a third control command or desired value can be assigned to a third range of, for example, 0.05 Hz to 0.2 Hz, which in particular represents a third reduction in the wind pressure exerted on the buoyant offshore wind turbine causes. The third reduction can in particular be an (emergency) shutdown.

According to a preferred embodiment of the buoyant offshore wind turbine according to the application, the at least one wave criterion can be a linear control criterion or a non-linear control criterion. In particular, a control curve can be specified. In particular, a control curve specifies the relationship between shaft parameter values of a shaft parameter and the desired values or control commands.

The regulation criterion can particularly preferably contain a dead band and/or a hysteresis. In particular, an unnecessary reduction in the wind pressure (for example due to a one-time or brief exceeding or reaching of a wave limit value) can be avoided by means of a deadband. A hysteresis or minimum time can be provided in a corresponding manner, after which an increase in the effective wind pressure is allowed again. As already described, a linear control criterion or a non-linear control criterion can also be mapped in the form of a lookup table.

According to a further embodiment of the buoyant offshore wind power plant according to the application, the buoyant offshore wind power plant can comprise at least one further detection device. The at least one further detection device can preferably comprise at least one measuring or sensor module and/or be communicatively connectable (e.g. via a wireless and/or wired communication network) to at least one measuring or sensor module.

• - Abstand zwischen einer Blattspitze eines Rotorblatts und der Turmaußenwand,
• - Kippwinkels des Turms,
• - Kippfrequenz des Turms,
• - Biegewinkel eines Rotorblatts,
• - (augenblickliche und/oder vorhergesagte) Windgeschwindigkeit,
• - (augenblickliche und/oder vorhergesagte) Windrichtung.

The at least one additional detection device can be set up to detect at least one additional parameter selected from the group comprising:

• - distance between a blade tip of a rotor blade and the outer wall of the tower,
• - tilting angle of the tower,
• - pitch frequency of the tower,
• - bending angle of a rotor blade,
• - (instantaneous and/or predicted) wind speed,
• - (instantaneous and/or predicted) wind direction.

Preferably, two or more of the aforementioned additional parameters can be recorded and evaluated. The at least one further parameter allows at least indirect conclusions to be drawn about the current distance between the tip of the blade and the outer wall of the tower. The operational reliability can be further improved by detecting at least one additional parameter.

To detect the distance between a blade tip of a rotor blade and the outer wall of the tower, the detection device can include at least one optical distance sensor and/or at least one magnetic distance sensor and/or at least one electro-optical distance sensor. The at least one distance sensor can be arranged, for example, on a blade tip and/or the outer wall of the tower. A plurality of distance sensors can preferably be provided for reasons of redundancy.

A sensor in the form of a light barrier can also be provided for detecting the passage of the blade tip through one or more optical barriers (in particular a light barrier, preferably a laser barrier). The at least one optical barrier can be attached, for example, between the foundation and the nacelle.

Alternatively or additionally, at least one sensor module can be provided, set up to measure the instantaneous (maximum) angle of inclination of the tower. The Seica NTT system, for example, can be used as a measuring module. The distance between a blade tip of a rotor blade and the outer wall of the tower can be determined, in particular calculated, from the angle of inclination.

The at least one parameter criterion can preferably indicate that the wind pressure is reduced by at least one first target parameter at a detected angle of inclination between 2° and 5°, by at least one second target parameter (which indicates a greater reduction in wind pressure than the causes first set parameters). In particular, with a detected angle of inclination between 5° and 15°, the regulation of a ballast tank, an anchor connection and/or a weight element, as described below, can also take place. If the angle of inclination is greater than 15°, preferably greater than 35°, it can be switched off.

In one embodiment, the minimum permissible distance between the blade tip of a rotor blade and the outer wall of the tower can be between 1 m and 4 m, preferably 1 m, in particular specified by the at least one parameter criterion.

In addition, at least one sensor module can be provided as an alternative or in addition, set up to measure the (instantaneous) bending angle of the rotor blade. The at least one sensor module can preferably be at least one strain gauge arranged on the rotor blade.

Furthermore, a local (instantaneous) meteorological parameter (preferably wind speed and/or wind direction) can be recorded as a further parameter, for example using a measuring device already provided in the wind farm, such as a measuring mast. It goes without saying that other (local) meteorological parameters that influence wind pressure can be taken into account, such as precipitation parameters, temperature, etc.

The at least one further parameter can be additionally (or alternatively) evaluated by the wind pressure change device. Depending on this evaluation, the at least one wind pressure control device can also be controlled.

According to a preferred embodiment, the wind pressure changing device can be set up to change the wind pressure exerted on the offshore wind turbine by controlling the at least one wind pressure control device, additionally based on the at least one additional parameter detected and at least one additional parameter criterion. The parameter criterion can be a control criterion, which can be formed in accordance with the at least one wave criterion that has already been described.

It has also been found that under certain (extreme) (weather) conditions, a reduction in wind pressure solely by the pitch control device and/or the converter torque control device may not be sufficient to reduce the risk of damage caused by contact between the tower and Reduce rotor blade sufficiently. In such a case, only the emergency shutdown of the wind turbine remains in the state of the art.

In order to prevent an emergency shutdown and in particular to improve the energy yield (even under such conditions/conditions), according to a particularly preferred embodiment of the buoyant offshore wind turbine, regulation of at least one ballast tank is provided. In particular, the buoyant offshore wind turbine can (further) comprise at least one ballast tank that can be filled with a ballast medium (preferably water, in particular seawater) and at least one ballast medium delivery device, set up to change the filling level of the ballast tank. The wind pressure changing device can be set up to control the ballast medium conveying device based on the at least one recorded wave parameter or the at least one recorded further parameter and at least one ballast criterion. The ballast criterion can be a control criterion, which can be formed in accordance with the at least one wave criterion that has already been described.

The at least one ballast tank can preferably be integrated in the at least one foundation. A ballast tank can also be attached to the outside of a foundation.

If two or more foundations or foundation elements are provided, each foundation can have a ballast tank. The at least one ballast tank can be arranged in particular in such a way that filling/emptying leads to a specific vertical and/or horizontal orientation of the foundation. In the case of a plurality of ballast tanks, the filling/emptying can in particular be controlled so that the at least two ballast tanks can be filled/emptied in a specific manner.

The at least one ballast medium delivery device can be set up to change the filling level of the ballast tank in order in particular to stabilize the position of the offshore structure. This means in particular that the tilting or swaying movement of the offshore wind turbine can at least be reduced. This in turn can reduce the risk of damage to the offshore wind turbine due to a rotor blade touching the tower.

The ballast medium conveying device can be arranged in or on the foundation. A change in the fill level changes, in particular, a vertical distance from the water line or from the underwater bottom surface. As a result, the position of the offshore wind turbine can be stabilized. In this embodiment, a target position parameter may be a target fill level (e.g., full, half full, empty, x liters, etc.). This can be specified by the wind pressure changing device according to the at least one (specified) ballast criterion by controlling the ballast medium delivery device. The ballast medium conveying device can change the filling level of the ballast tank in accordance with a predetermined position setpoint parameter of this type in order to change the said vertical distance.

Particularly preferably, the ballast medium conveying device can comprise at least one pumping device configured to change the fill level of the ballast tank by actively conveying the ballast medium into the ballast tank and/or by actively conveying the ballast medium out of the ballast tank. In particular, if an active delivery of the ballast medium out of the ballast tank is provided, filling can take place passively by opening a tank opening. In particular, if active delivery of the ballast medium into the ballast tank is provided, emptying can take place passively by opening a tank opening. Preferably, however, at least one pump device can be provided both for filling and for emptying. As a result, faster emptying and filling can be achieved.

The setting of a specific fill level can be controlled or regulated by a local control module of the ballast medium conveying device. A level measuring element can be used to monitor the level. As a result, a predefined target position parameter can be set in a reliable manner in the form of a target filling quantity.

As an alternative or preferably in addition to the regulation of at least one ballast tank, regulation of a weight element can be provided according to a further preferred embodiment of the buoyant offshore wind turbine according to the application. The buoyant offshore wind turbine can include at least one weight element connected to the buoyant foundation, which can be changed at least between a state lowered on the underwater ground surface and a state raised from the underwater ground surface, and at least one weight adjustment device, set up to adjust the weight element between the lowered state and the detached state. The wind pressure changing device can be set up to control the weight adjustment device based on the at least one recorded wave parameter or the at least one recorded additional parameter and at least one weight criterion. The weight criterion can be a control criterion, which can be formed in accordance with the at least one wave criterion, which has already been described.

In particular, a weight connection (e.g. an anchor cable and/or an anchor chain) can be provided which can be connected to the buoyant foundation. The other end of the weight connection can be connected to the at least one weight element. In a lowered state, the weight element can at least be placed or lowered on the underwater floor surface. In this state, in particular almost no weight can be exerted on the floatable foundation by the at least one weight element.

In a lifted state, the weight element can be off or raised from the underwater ground surface, that is to say no longer (almost) contact the underwater ground surface. In this state, in particular, a weight (corresponding to the weight of the weight element) is exerted on the foundation by the at least one weight element.

An adjustment between the stated states can bring about a change in the vertical distance between the foundation and the underwater bottom surface, and as a result the position of the offshore wind turbine can be (positively) influenced. In particular, the wind pressure changing device can control the weight adjustment device (for example a winch or a similar device) in order to bring about an adjustment of the at least one weight element. As a result, the operational safety can be further increased and at the same time the energy yield can be improved.

Alternatively or preferably in addition to the regulation of at least one ballast tank and/or the regulation of a weight element, according to a further preferred embodiment of the buoyant offshore wind turbine according to the application, the length of at least one anchor connection can be regulated. The buoyant offshore wind turbine can comprise at least one anchoring arrangement set up for fastening the buoyant offshore wind turbine to an underwater bed in an anchored state of the buoyant offshore wind turbine. The anchoring arrangement may include at least one anchor connection extending between an anchor and the buoyant foundation. The buoyant offshore wind turbine can comprise at least one length changing device set up to change the length of the anchor connection between the anchor and the buoyant foundation in the anchored state. The wind pressure changing device can be set up to control the length changing device based on the at least one recorded wave parameter or the at least one recorded additional parameter and at least one length criterion. The length criterion can be a control criterion, which can be formed in accordance with the at least one wave criterion that has already been described.

An anchoring arrangement preferably comprises an anchor connection, in particular in the form of an anchor cable and/or an anchor chain. One end of the anchor connection is attached to the foundation and the other end to at least one anchor (eg, weight anchor, torpedo anchor, etc.). The anchor may be at least partially buried in the underwater bed.

The state in which the foundation and thus the offshore structure are fastened to the underwater soil by the at least one anchoring arrangement is referred to here in particular as the anchoring state of the foundation or the offshore wind power plant.

According to the application, it has been recognized that critical positions of the offshore structure, in which at least the above-described damage to the offshore wind turbine threatens, can at least be reduced if a possibility is created to change the length of an anchor connection of an anchoring arrangement in the anchored state, i.e. in proper operation of the offshore wind turbine. In particular, by shortening (but possibly also by lengthening; this can (also) change the oscillation frequency of the system) the length at least causes a tilting or swaying movement of the offshore wind turbine compared to a longer (or shorter) length reduced.

In order to change the length, one embodiment proposes providing a length-changing device. This can be arranged at least partially in and/or on the buoyant foundation. In the case of variants of the application, this can also be arranged at least partially in the offshore device, such as the tower of the offshore wind turbine.

The at least one length changing device is preferably set up to change the length of the anchor connection between the anchor and the buoyant foundation (in particular the point at which the anchor connection reaches the foundation) in the anchoring state, based on at least one target parameter (specified by the wind pressure control device).

The at least one target parameter (in particular a target length parameter) specifies in particular a vertical position (and/or horizontal position) of the offshore wind power plant that is to be set. A local control module of the length-changing device can change the instantaneous length of an anchor connection in accordance with the specified target parameter.

According to a preferred embodiment, the length-changing device can comprise at least one winch device coupled to the anchor connection. The winch device can be arranged to change the length of the anchor connection between the anchor and the buoyant foundation. In particular, the winch device comprises a substantially cylindrical and rotatable drum.

In the present context, coupled means in particular that the at least one anchor connection in the form of an anchor cable or an anchor chain can be wound up and unwound on the drum (in particular between a minimum and maximum length). One end of the anchor connection can hereby be firmly attached to the drum or another attachment point of the winch device.

Preferably, the winch device can comprise at least one controllable and motor-based drive, in particular an electric motor that can be supplied with electrical energy by the offshore wind turbine. The drive can be controlled by the local control module in particular in such a way that the length is changed in such a way that the length of the anchor connection (substantially) corresponds to the at least one target parameter.

According to a further embodiment, the winch device can comprise at least one parking brake. The parking brake may be releasable (and lockable once changed) to change the length of the anchor linkage. If the length of the anchor connection is to be changed, the control module can, for example, activate the parking brake so that it is released. The length of the anchor connection can then be changed, in particular by the drive, as has been described. The parking brake can then be locked (again) either automatically or by being activated again, e.g. by the control module. The load on the drive can be reduced as a result.

According to a further embodiment of the buoyant offshore wind turbine, at least one vertical anchor connection running essentially in the vertical direction can be fastened to the buoyant foundation and at least one angle anchor connection running at an angle to the vertical direction of at least 2°, preferably at least 5°, on the buoyant foundation be attached. The wind pressure changing device can be set up to control the length changing device in such a way that the length of the vertical anchor connection and/or the length of the angle anchor connection is changed based on the at least one detected Shaft parameters or the at least one further parameter detected and the at least one length criterion.

In particular, it can be advantageous if the respective lengths of the vertical anchor connection(s) and the angle anchor connection(s) are changed differently.

In particular, if the vertical plane in which the angle of the angle anchor connection lies to the vertical direction (vertical axis) extends in a direction parallel to the prevailing wind direction and/or main wave direction (or within a range of ±20°) (and in particular the anchor of this angle anchor connection itself located on the side hitting the wind and/or waves), it can be specified in particular by the at least one target position parameter that the anchor connection of the said angle anchor connection is shortened more (e.g. 2 to 10 m more) than the at least one vertical anchor connection, in particular in such a way that without wind and waves, there would be a tilt in the direction of the main wind direction and/or main wave direction. Additionally or alternatively, it could be provided that in at least one other angle anchor connection, in which the anchor is on the side facing away from the wind and/or waves, the length is left unchanged or lengthened, so that without wind and waves there is an inclination in the direction of the Main wind direction and/or main wave direction would result.

Particularly in the event that a ballast tank as described above is/are provided with a ballast conveying device and/or a weight element as described above, at least one tracking module can be provided according to one embodiment of the offshore wind turbine, set up for tracking the anchor connection (i.e. changing the length of the Anchor connection), in particular with a change in the vertical distance between an underwater bottom surface of the underwater bottom and the buoyant foundation (or between the foundation and the waterline or water surface).

In order to prevent a desired (minimum and/or maximum) voltage between anchor and foundation from being undershot or exceeded, each anchor connection can in particular be coupled to a tracking module in order to track the anchor connection accordingly. In other variants, a tracking device can also be dispensed with.

• - mindestens eine Überwachungseinrichtung eingerichtet zum Detektieren eines Ausfalls mindestens einer Windkraftanlagenkomponente, umfassend die mindestens eine Erfassungseinrichtung, die Winddruckänderungseinrichtung, die Längenänderungseinrichtung, die Gewichtsverstelleinrichtung, die Ballastmediumfördereinrichtung und/oder die mindestens eine Winddruckregelungseinrichtung,
• - wobei die Überwachungseinrichtung ein Alarmmodul umfasst, eingerichtet zum Ausgeben einer Alarmmeldung bei Detektion eines Ausfalls einer der überwachten Windkraftanlagenkomponenten.

According to a further preferred embodiment of the buoyant offshore wind turbine according to the application, the buoyant offshore wind turbine can also include:

• - at least one monitoring device set up to detect a failure of at least one wind turbine component, comprising the at least one detection device, the wind pressure changing device, the length changing device, the weight adjustment device, the ballast medium conveying device and/or the at least one wind pressure control device,
• - Wherein the monitoring device comprises an alarm module set up to output an alarm message upon detection of a failure of one of the monitored wind turbine components.

The monitoring device can be connected to and/or include at least one monitoring sensor. The monitoring sensor can be a sensor that is provided (in any case) and is set up to monitor the functionality of at least one of the devices mentioned at least almost continuously. In one case, the at least one monitoring sensor can detect whether at least one of the devices is (currently) functional or not, ie in particular whether there is a malfunction.

If a monitoring sensor reports a malfunction to a monitoring device and/or the monitoring device determines a malfunction from the sensor data provided, an alarm module of the monitoring device can output at least one alarm message. In one case, a central controller and/or a user can be informed of the malfunction. Measures to eliminate the malfunction can then be initiated.

In addition, the outputting of an alarm message can preferably include the activation of at least one (still) functional device (from the above-mentioned devices). For example, the detected malfunction and the at least one recorded wave parameter or the at least one recorded additional parameter and at least one predefined emergency rule can be evaluated by the monitoring device (or by the wind pressure changing device).

The at least one emergency rule can specify how to proceed in the event of a malfunction of a specific device of the offshore wind power plant and a specific parameter value that is currently present (eg shaft parameter value and/or another parameter value). For example, upon detection of a radio If a malfunction occurs in the form of a failure of a wind pressure control device, such as the pitch control device, the at least one other wind pressure control device can be activated (regardless of the current at least one parameter value) and/or a brake on the wind turbine can be activated.

Preferably additionally (if present), the length change device and/or the weight adjustment device and/or the ballast medium conveying device can be controlled in such a way that the vertical distance between the foundation and the bottom of the water is reduced (in particular minimized), i.e. for example the ballast tank is filled and/or the weight element is raised and / or the length of the at least one anchor connection is shortened.

A further aspect of the application is a wind pressure changing device for a buoyant offshore wind turbine, in particular a buoyant offshore wind turbine according to one of the preceding claims. The wind pressure changing device comprises at least one receiving module, set up to receive at least one recorded wave parameter. The wind pressure changing device comprises at least one control module, set up to change the wind pressure exerted on the buoyant offshore wind turbine by controlling at least one wind pressure control device of the buoyant offshore wind turbine, comprising a pitch control device and/or a converter torque control device, based on the at least one received wave parameter and a wave criterion.

In particular, the receiving module can be communicatively connectable to the at least one detection device. In variants of the application, the at least one detection device and/or the at least one monitoring device can be at least partially integrated in the wind pressure change device.

• - Ansteuern mindestens einer Winddruckregelungseinrichtung der schwimmfähigen Offshore-Windkraftanlage, umfassend eine Pitch-Regelungseinrichtung und/oder eine Umrichterdrehmoment-Regelungseinrichtung, basierend auf mindestens einem bereitgestellten Wellenparameter und einem Wellenkriterium, derart, dass der auf die schwimmfähige Offshore-Windkraftanlage ausgeübte Winddruck geändert wird.

A further aspect of the application is a method, in particular for controlling a buoyant offshore wind turbine (described above). The procedure includes:

• - Activation of at least one wind pressure control device of the buoyant offshore wind turbine, comprising a pitch control device and/or a converter torque control device, based on at least one provided wave parameter and a wave criterion, such that the wind pressure exerted on the buoyant offshore wind turbine is changed.

The method can be carried out in particular by a wind pressure control device as described above. Furthermore, the method can include receiving (and in particular detecting) the at least one wave parameter, as described above.

Yet another aspect of the application is a computer program product (or computer program), comprising instructions which, when the computer program is executed by a computer (in particular the wind pressure control device), cause the latter to carry out the method described above.

The computer program product, in particular the instructions or program instructions, can be stored in a computer program memory, in particular a program memory. For example, program memory is non-volatile memory such as flash memory, magnetic memory, EEPROM memory (Electrically Erasable Programmable Read Only Memory), and/or optical memory.

In addition, a wind pressure control device may comprise a main memory, for example a volatile or non-volatile memory, in particular a random access memory (RAM), such as a static random access memory (SRAM), a dynamic random access memory (DRAM), a ferroelectric RAM memory (FeRAM) and/or magnetic random access memory (MRAM). The processor of the control device can, for example, store intermediate results or the like in the main memory.

In the present case, a device, a module or a device can be formed at least partially from software and/or at least partially from hardware. In particular, a device/element may include appropriate computing elements (e.g., processor, memory, etc.).

The features of the buoyant offshore wind turbines, wind pressure control devices, methods and computer program products can be freely combined with one another. In particular, features of the description and/or the dependent claims, even if features of the independent claims are completely or partially bypassed, can be independently inventive on their own or freely combined with one another.

• 1 eine schematische Ansicht eines Ausführungsbeispiels einer schwimmfähigen Offshore-Windkraftanlage gemäß der vorliegenden Anmeldung mit einem Ausführungsbeispiel einer Winddruckänderungseinrichtung gemäß der vorliegenden Anmeldung,
• 2 eine schematische Ansicht eines weiteren Ausführungsbeispiels einer schwimmfähigen Offshore-Windkraftanlage gemäß der vorliegenden Anmeldung,
• 3 ein Diagramm eines Ausführungsbeispiels eines Verfahrens gemäß der vorliegenden Anmeldung,
• 4 eine schematische Ansicht eines weiteren Ausführungsbeispiels einer schwimmfähigen Offshore-Windkraftanlage gemäß der vorliegenden Anmeldung,
• 5 eine schematische Ansicht eines weiteren Ausführungsbeispiels einer schwimmfähigen Offshore-Windkraftanlage gemäß der vorliegenden Anmeldung,
• 6 eine beispielhafte über die Zeit aufgetragene Kippbewegung eines schwimmfähigen Offshore-Bauwerks,
• 7a eine schematische Ansicht eines weiteren Ausführungsbeispiels einer schwimmfähigen Offshore-Windkraftanlage gemäß der vorliegenden Anmeldung mit einem ersten eingestellten Abstand,
• 7b eine schematische Ansicht des Ausführungsbeispiels nach 5a mit einem weiteren eingestellten Abstand,
• 8a eine schematische Ansicht eines weiteren Ausführungsbeispiels einer schwimmfähigen Offshore-Windkraftanlage gemäß der vorliegenden Anmeldung mit einem ersten eingestellten Abstand, und
• 8b eine schematische Ansicht des Ausführungsbeispiels nach 6a mit einem weiteren eingestellten Abstand.

There are now a large number of possibilities for embodying the buoyant offshore wind turbine according to the application, the wind pressure control device according to the application, the method according to the application and the computer program product according to the application to develop. In this regard, reference is made on the one hand to the claims subordinate to the independent claims and on the other hand to the description of exemplary embodiments in conjunction with the drawing. In the drawing shows:

• 1 a schematic view of an embodiment of a buoyant offshore wind turbine according to the present application with an embodiment of a wind pressure change device according to the present application,
• 2 a schematic view of another embodiment of a buoyant offshore wind turbine according to the present application,
• 3 a diagram of an embodiment of a method according to the present application,
• 4 a schematic view of another embodiment of a buoyant offshore wind turbine according to the present application,
• 5 a schematic view of another embodiment of a buoyant offshore wind turbine according to the present application,
• 6 an exemplary tilting motion of a buoyant offshore structure plotted against time,
• 7a a schematic view of another embodiment of a buoyant offshore wind turbine according to the present application with a first set distance,
• 7b a schematic view of the embodiment 5a with a further set distance,
• 8a a schematic view of another embodiment of a buoyant offshore wind turbine according to the present application with a first set distance, and
• 8b a schematic view of the embodiment 6a with a further set distance.

In the figures, the same reference numbers are used for the same elements. Furthermore, z generally denotes a vertical axis or direction and x denotes a horizontal axis or direction.

the 1 shows a schematic view of an embodiment of a buoyant offshore wind turbine 100 according to the present application with an embodiment of a wind pressure change device 108 according to the present application.

The buoyant offshore wind turbine 100 has at least one buoyant foundation 102 comprising at least one float. In the present exemplary embodiment, the buoyant foundation 102 is a barge foundation 102.

As can be seen, a tower 104 with a gondola 106 is arranged on the foundation 102 . Furthermore, the buoyant offshore wind turbine 100 has a hub 118 , a plurality of rotor blades 116 , a gearbox 126 , a brake 124 and a converter 122 . In addition, the offshore wind power plant 100 in the present case has a wind pressure control device 120, comprising a pitch control device 120.1 and/or a converter torque control device 120.2.

Pitch control device 120.1 is set up to adjust at least one rotor blade 116 (preferably all rotor blades 116). This means in particular that the angle of attack of a rotor blade 116 is changed.

The converter torque control device 120.2 is set up in particular to change the speed of the converter 122. By changing the torque of the converter 122, the aerodynamic efficiency and thus the wind pressure can be changed in particular.

In addition, the offshore wind power plant 100 in the present case comprises a (wave parameter) detection device 125 which can be communicatively connected (via a wireless and/or wired communication network, not shown) to the wind pressure change device 108 . In other variants, the detection device can also be at least partially integrated in the wind pressure change device. Furthermore, an above-described monitoring device can optionally be provided.

In the example shown, the detection device 125 can be communicatively connected (via a wireless and/or wired communication network, not shown) to at least one sensor 114 (arranged on or in the foundation 102, for example).

The at least one detection device 125 is set up to detect at least one (local) wave parameter, such as the (current (maximum or average) wave height (see reference number 140), the (current (average)) wave direction (indicated by the arrow 165) and/or the (instantaneous (through average)) wave frequency (f= 1/T, where T is indicated by reference numeral 138). In the present case, the height difference (see reference number 140) between the high point of a wave crest and the low point of a wave trough is referred to as the height of the water waves.

Exemplary and non-exhaustive sensors 114 or measuring modules 114 for measuring a wave parameter described above are those that characterize the waves by means of position angle measurement (e.g. using GPS), depth measurement (e.g. using sonar) and acceleration measurement (e.g. piezoceramic sensor plates or spring-mass systems).

The wind pressure changing device 108 comprises at least one receiving module 110, set up to receive at least one wave parameter recorded (by the recording device 125).

In addition, the wind pressure changing device 108 comprises at least one control module 112, set up to change the wind pressure exerted on the buoyant offshore wind turbine 100 by controlling the at least one wind pressure control device 120 (via a wireless and/or wired communication network, not shown), comprising a pitch control device 120.1 and/or a converter torque control device 120.2, based on the at least one received wave parameter and a wave criterion.

The wave criterion is in particular a regulation criterion and can be stored, for example, in a data memory of the wind pressure changing device 108 . In one case, a limit wave value or a plurality of limit wave values can be specified as the wave criterion. In preferred variants, a linear control criterion or a non-linear control criterion can be specified. In particular, a control curve can be specified. A control curve indicates in particular the relationship between wave parameter values of a wave parameter (e.g. wave height, wave frequency and/or wave direction) and the target values for the at least one wind pressure control device 120.

The regulation criterion can particularly preferably contain a dead band and/or a hysteresis. In particular, an unnecessary reduction in the wind pressure (for example due to a one-time or brief exceeding or reaching of a wave limit value) can be avoided by means of a deadband. A hysteresis or minimum time can be provided in a corresponding manner, after which an increase in the effective wind pressure is allowed again.

The evaluation, preferably carried out by the control module 112, can in particular include a comparison operation. If it is determined during this comparison operation that the at least one limit wave value is exceeded by a detected instantaneous value of the wave parameter and/or by the formed mean value of a plurality of wave parameter values of the at least one wave parameter recorded during a specific period of time, a reduction in the wind pressure can be achieved, for example, by the actuation of the wind pressure control device 120, e.g. with a specific desired value. For example, activation can take place with a specific target angle value (e.g. specified by the control curve and/or the lookup table described above) and/or a specific target speed or torque (e.g. specified by the control curve and/or the lookup table described above).

If it is determined during this comparison operation that the at least one limit wave value is undershot by a detected instantaneous value of the shaft parameter and/or by the average value formed of a plurality of shaft parameter values of the at least one shaft parameter recorded during a specific period of time, no activation can take place or, for example, an increase in the wind pressure by controlling the wind pressure control device 120, e.g. with a specific target value. For example, activation can take place with a specific target angle value (e.g. specified by the control curve and/or the lookup table described above) and/or a specific target speed or torque (e.g. specified by the control curve and/or the lookup table described above).

Furthermore, in the 1 the underwater bottom surface with the reference number 132, the water surface or (still) waterline with the reference number 128, the underwater bottom with 136 and the wave direction with 165.

the 2 shows a schematic view of a further exemplary embodiment of a buoyant offshore wind turbine 200 according to the present application with an exemplary embodiment of a wind pressure change device 208 according to the present application. In order to avoid repetition, essentially only the differences from the previous exemplary embodiment are explained below and otherwise the explanations relating to FIG 1 referred.

First, it can be seen that the buoyant foundation 202 is a tension leg platform foundation 202 in the present exemplary embodiment. In other variants of the application, the foundation can also be a semi-submersible foundation, a savings foundation or the like.

In addition, the offshore wind turbine 200 in the present case includes two detection devices 225, 213. It goes without saying that in variants of the application, the at least two detection devices 225, 213 can be formed by a common device or three or more detection devices can be provided. The at least two detection devices 225, 213 can be communicatively connected to the wind pressure change device 208 in the manner described above.

The first detection device 225, designed to detect the at least one shaft parameter, includes the at least shaft sensor 214. The further detection device 213, designed to detect at least one further parameter, can be communicatively connected to a plurality of sensors in the present exemplary embodiment. In the present example, a strain gauge 213.2 is arranged on each rotor blade 216. The at least one strain gauge 213.1 is set up in particular to measure the (instantaneous) bending angle of the rotor blade 216.

To detect the distance between a blade tip 217 of a rotor blade 216 and the outer wall of the tower 204, the further detection device 213 can be communicatively connectable to at least one optical distance sensor 213.1 and/or at least one magnetic distance sensor 213.1 and/or at least one electro-optical distance sensor 213.1. In the present case, the at least one distance sensor 213.1 is arranged on or in the outer wall of the tower, in particular at the height of the passage of a blade tip 217. A plurality of distance sensors can preferably be provided for reasons of redundancy.

Other sensors can be provided alternatively or additionally, as previously described. In particular, at least one sensor module can be provided, set up to measure the instantaneous (maximum) angle of inclination of the tower 204. The Seica NTT system, for example, can be used as a measuring module. The distance between a blade tip 217 of a rotor blade 216 and the outer wall of the tower can be determined, in particular calculated, from the angle of inclination.

Wind parameters, such as (measured and/or predicted) wind direction (in particular (current) main wind direction) and/or (measured and/or predicted) wind strength of detection device 213, for example by a measuring mast of the wind farm of the offshore wind turbine and/or a meteorological service providers are provided.

The at least one further parameter can also be evaluated by wind pressure change device 208 . Depending on this evaluation, the at least one wind pressure control device (not shown here for the sake of a better overview) can also be controllable. In particular, the wind pressure changing device 208 can be set up to change the wind pressure exerted on the offshore wind turbine 200 by activating the at least one wind pressure control device, additionally based on the at least one further parameter detected and at least one further parameter criterion. The parameter criterion can be a control criterion, which can be formed in accordance with the at least one wave criterion that has already been described. The parameter criterion and the wave criterion can also be a common criterion, such as a lookup table and/or a control curve.

Furthermore, in the present case, the buoyant foundation 202 is fastened or anchored to the underwater floor 236 via a plurality of anchoring arrangements 250 . An illustrated anchoring assembly 250 has an anchor link 246, particularly in the form of an anchor cable 246 or an anchor chain 246. One end of the anchor link 246 is attached to the foundation 202 and the other end to at least one anchor 244 (e.g. weight anchor, torpedo anchor, etc.). The anchor 244 may be at least partially buried in the underwater bed 236 .

In addition, the offshore wind power plant 200 can preferably include a length changing device 260 (in particular a winch device 260) that can be controlled by the wind pressure changing device 208 (via a wireless and/or wired communication network). The length changing device can be set up to change the length 248 of an anchor connection 246 between the anchor 244 and the floating foundation 202 in the anchored state (shown) based on at least one predetermined target parameter. The wind pressure changing device 208 can be set up in particular to control the length changing device 260, based on the at least one recorded wave parameter or the at least one recorded additional parameter and at least one length criterion as previously described.

As can be seen, the length 248 presently extends from the point of attachment of the anchor link 246 to the anchor 244 and the point where the anchor link 246 enters the foundation 202 . The vertical distance between the underwater floor 232 and the foundation 202 is denoted by 215 and can differ from the length 248 .

the 3 FIG. 12 shows a diagram of an embodiment of a method according to the present application. The method can be carried out in particular by a wind pressure changing device (e.g. a computer with a processor configured to run a computer program product), such as the wind pressure changing device 108 or 208.

In a first step 301, at least one detected shaft parameter can be provided by a detection device, as previously described. Preferably, at least one additional recorded parameter can be provided by at least one additional recording device, as described above.

In a further step 302, at least one wind pressure control device of the buoyant offshore wind turbine is activated, comprising a pitch control device and/or a converter torque control device, based on the at least one provided wave parameter and a wave criterion, such that the Wind turbine exerted wind pressure is changed, as previously described. If at least one further parameter is provided, the activation can also take place on the basis of the at least one further parameter and a parameter criterion. The at least two criteria can be linked to one another in an overall regulation criterion.

It goes without saying that steps 301, 302 can be carried out at least almost continuously and at least partially in parallel.

the 4 FIG. 4 shows a schematic view of another embodiment of a buoyant offshore wind turbine 400 according to the present application. To avoid repetition, essentially only the differences from the previous exemplary embodiments are explained below and otherwise reference is made to the statements relating to the previous figures. Details that are already known, such as the at least one detection device, the gondola, etc., have only been omitted for the sake of a better overview.

The offshore wind energy installation 200 includes a length change device 212 which can be controlled by a wind pressure control device 408 via a communication link.

In the present case, the length-changing device 460 comprises at least one winch device 462, preferably three winch devices 462.1, 462.2, 462.3. In particular, each anchoring arrangement 450.1, 450.2, 450.3 can be assigned a winch device 462.1, 462.2, 462.3. Each anchor connection 446.1, 446.2, 446.3 can preferably be coupled to a respective winch device 462.1, 462.2, 462.3. In particular, an anchor connection 446.1, 446.2, 446.3 can be coupled to a cylindrical drum (winch) of a winch device 462.1, 462.2, 462.3 in order to wind and unwind the anchor connection 446.1, 446.2, 446.3 at least between a minimum and a maximum length.

Each winch device 462.1, 462.2, 462.3 can have a drive 464 and a parking brake 466 for this purpose. To change a length 448.1, 448.2, 448.3, a local control module 461 (upon receipt of a corresponding control command, in particular containing a specific desired length value) of the length changing device 460 can first control the corresponding parking brake 466 in order to release this parking brake 466. Then the control module 461 can control the appropriate drive 464 (preferably an electric motor 464) to cause winding or unwinding by a certain length (e.g. according to the desired value). The parking brake 466 can then be locked again, controlled by the control module 461.

In the 4 reference numeral 463 denotes the (current) main wind direction and reference number 465 the (current) main wave direction (generally these directions 463, 465 can be almost identical).

As well as the 4 can be seen, at least one vertical anchor connection 446.2 running essentially in the vertical direction can be fastened to the floating foundation 402. At least one angle anchor connection 446.1, 446.2 running at an angle 429 to the vertical direction of at least 2°, preferably at least 5° (and at most 45°), can be fastened to the floating foundation 402.

The length-changing device 460 can be set up to change the length of the vertical anchor connection 446.2 and/or the angular anchor connection 446.1, 446.3, based on at least one predetermined target parameter. Depending in particular on the at least one shaft parameter and/or the at least one other parameter, it can be advantageous if the respective lengths of the vertical anchor connection 446.2 and the at least one angle anchor connection 446.1, 446.3 are changed differently (this can be done in the at least one shaft and/or length criterion).

In particular, if the vertical plane in which the angle 429 of the angle anchor connection 446.1, 446.3 lies to the vertical direction extends in a direction parallel (±20°) to the main wind direction (±20°) and/or main wave direction (±20°) and in particular the anchor 444 of this angle anchor connection 446.1 is on the side that is exposed to the wind and/or waves, it can be specified in particular by the at least one target length parameter that the anchor connection of the mentioned angle anchor connection 446.1 is shortened more (e.g. 2 to 10 m more) than the at least one Vertical anchor connection 446.2, in particular such that without wind and waves there would be an inclination in the direction of the main wind direction 463 and/or main wave direction 463. In addition or as an alternative, it can be provided that at least one further angle anchor connection 446.3, in which the anchor 444 is on the side away from the wind and/or waves, is left unchanged or lengthened, so that without wind and waves there is an inclination in the direction of the Main wind direction 463 and/or main wave direction 465 would result.

the 5 FIG. 5 shows a schematic view of a further exemplary embodiment of an offshore wind turbine 500 according to the present application. In order to avoid repetition, essentially only the differences from the previous exemplary embodiments according to the previous figures are described below and otherwise reference is made to the previous explanations. It should be noted that a representation of individual details was omitted merely in favor of a better overview.

In particular, in the 5 a tilting or swaying movement (indicated by the arrow 572) of the floating offshore wind turbine 500 is indicated. In the dashed version, the offshore wind power plant 500 is shown at the reversal point of the tilting movement, ie when the tilting angle 573 is at its maximum. In addition, the offshore wind turbine 500 is shown in the vertical state.

This swaying movement or oscillations can be excited in particular by the water waves hitting the offshore wind turbine 500 . This can lead to critical states in particular if the water wave frequency is in the range of the resonant frequency of the offshore wind turbine 500 . In order to prevent this, the water wave frequency is preferably detected and, if necessary, the wind pressure on the tower head is changed, in particular reduced, so that the resonant frequency of the offshore wind turbine 500 is changed, as has been described in particular above.

The time course of the tilt angle α between the maximum tilt angles -676, 676 is in 6 shown. How from the 6 can be seen, the result is an essentially sinusoidal curve.

In the present case, the offshore wind turbine 500 can comprise at least one position detection device 570 (with at least one suitable position sensor) as a further detection device, set up to detect the at least one (instantaneous) position parameter of the offshore wind turbine 500. In other words, in this exemplary embodiment, the offshore wind turbine 500, in particular, additionally determine at least one actual position parameter of the offshore wind turbine 500 by the position detection device 570 itself. In particular, a wind pressure control device or another device can be activated as a function of an additional evaluation (e.g. a difference between the detected position parameter or actual position parameter and a (specified) position setpoint parameter can take place according to a criterion).

The at least one position parameter can be at least one position angle (also called Euler angle) of the offshore wind power plant 500, for example. The at least one position parameter can be, for example, a yaw angle (angle between the current orientation of the offshore wind turbine 500 and the vertical axis (also called the z-axis)), a roll angle (angle between the current orientation of the offshore wind turbine 500 and a longitudinal axis (also called the x axis)) and/or a pitching or pitching angle (angle between the current orientation of the offshore wind turbine 500 and a longitudinal axis (also called the y-axis)).

The position detection device 570 can preferably be a tilt angle detection device 570 set up to detect the (maximum) tilt angle 573 of the offshore wind turbine 500. As shown, the tilt angle 573 is in particular that on a vertical axis 571 or direction z-related (maximum) angle 573 during a tilting or swaying movement 572 of the offshore wind turbine 500. For example, a (maximum) tilt angle 573 can be additionally specified as a position setpoint parameter by a criterion, preferably a permissible tilt angle range. If the actual tilting angle 573 is outside the permissible tilting angle range, the length in particular can be changed in such a way (in particular for so long) that (until) the detected tilting angle 573 is again in the permissible range. The same applies to the at least one recorded shaft parameter.

Alternatively or additionally, the position detection device 570 can be a tilt frequency detection device 570, set up to detect the tilt frequency (f _tilt =1/T _tilt , see 4 ) of the offshore wind turbine 500. It goes without saying that the detection of the tilt frequency f _tilt includes a detection of the tilt period duration T _tilt . This tipping frequency f _tipping can preferably be evaluated in an analogous manner.

the 7a and 7b show another exemplary embodiment of a buoyant offshore wind turbine 700 with differently set vertical distances 790.1, 790.2. In order to avoid repetition, essentially only the differences from the previous exemplary embodiments are described below and otherwise reference is made to the previous explanations. It should be noted that, for the sake of a better overview, the entire wind power device is not shown, for example.

The difference between the distances 790.1, 790.2 in the 7a and 7b is denoted by reference numeral 789. The adjustable difference can preferably be between 10 m and 40 m.

In order to adjust the vertical distance 790.1, 790.2 (to the underwater bottom surface 732 (or to the (still) water line 728)), at least one ballast tank 788 that can be filled with a ballast medium 787 is provided, which is preferably arranged in the foundation 702, and at least one through a wind pressure changing device 708 controllable ballast medium delivery device 782. This is set up in particular to change the fill level 786 of the ballast tank 788.

In the present case, the ballast medium conveying device 782 comprises, in particular, two pumping devices 782. A pumping device 782 is set up in particular to change the fill level 786 of the ballast tank 788 by actively conveying the ballast medium 787 (in particular water) into the ballast tank 788 (indicated by the arrow 783). In particular, an opening 784 can be arranged in the foundation 702 through which the ballast medium 787 can be pumped into the ballast tank 788 .

The additional pumping device 782 is set up in particular to change the fill level 786 of the ballast tank 788 by actively conveying the ballast medium 787 out of the ballast tank 788 (indicated by the arrow 780). In particular, a further opening 781 can be arranged in the foundation 702 through which the ballast medium 787 can be pumped out of the ballast tank 788 .

A control module (not shown) can preferably be provided. The (local) control module of the ballast medium conveying device can be controlled by the wind pressure changing device 708 with a target parameter (e.g. a specific filling quantity (e.g. full, half full, empty, x liters etc.) or the like).

Depending on an instantaneous fill level 786 measurable by a fill level measuring element (not shown) of the control module and a target parameter obtained, a pump device 782 can be controlled in such a way that the fill level 786 is changed according to the target parameter. In particular, the position of an offshore wind turbine 700 can be stabilized by changing the vertical distance 790.1, 790.2. In addition, the power yield in particular can be increased as a result.

Furthermore, at least one tracking module 785 can also be arranged on the offshore wind turbine 700, set up for tracking (i.e. changing the length) of the anchor connection 746, in particular when there is a change in the vertical distance 790.1, 790.2 between an underwater bottom surface 732 of the underwater bottom 736 and the buoyant foundation 702. In order to prevent a desired (minimum and/or maximum) voltage between the anchor 744 and the foundation 702 from being undercut or exceeded, each anchor connection 746 can in particular be coupled to a tracking module 785 in order to track the anchor connection 746 accordingly.

the 8a and 8b 12 show a further exemplary embodiment of a buoyant offshore wind turbine 800 with differently set vertical distances 893. To avoid repetition, essentially only the differences from the previous exemplary embodiments are described below and otherwise reference is made to the previous explanations senior It should be noted that, for the sake of a better overview, a representation of, for example, the entire wind power device was omitted.

In the present case, at least one weight element 894 connected to the buoyant foundation 802 is provided. In particular, the weight element 894 can be connected to the foundation 802 via a weight connection 895 (e.g. an anchor cable 895 and/or an anchor chain 895).

In a lowered state of the weight element 894, in particular almost no weight force is exerted on the foundation 802 by the at least one weight element 894. When weight element 894 is in a raised state, for example caused by a weight adjustment device 892 (e.g. a winch 892), a weight force g (corresponding to the weight of weight element 894) is exerted on foundation 802 by the at least one weight element 894. In particular, the wind pressure changing device 808 can control the weight adjustment device 892 with a corresponding setpoint parameter in the manner described above.

By adjusting the weight adjustment device 892 between the mentioned states of the weight element 894, a change in the mentioned vertical distance 820 can be brought about at least between two discrete values.

A control module (not shown) can also be provided here, which can control the weight adjustment device 892 as a function of the setpoint parameter received (e.g. lowering or not lowering).

It is understood that the embodiments according to the 1 , 2 , 4 , 7a , 7b and/or 8a, 8b can be combined with one another.

Claims (14)

Floatable offshore wind turbine (100, 200, 400, 500, 700, 800), comprising: - at least one buoyant foundation (102, 202, 402, 502, 702, 802) comprising at least one float, - one on the buoyant foundation (102, 202, 402, 502, 702, 802) arranged tower (104, 204, 404, 504, 704, 804), and - a nacelle arranged on the tower (104, 204, 404, 504, 704, 804). (106, 206) with a plurality of rotor blades (116, 216), characterized in that the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) further comprises: - at least one detection device (125, 225) , set up for detecting at least one wave parameter, and - at least one wind pressure changing device (108, 208, 408, 508, 708, 808), set up for changing the on the floatable offshore wind turbine (100, 200, 400, 500, 700, 800) exerted wind pressure by controlling at least one wind pressure control device (120) of the buoyant offshore Windkr ftanlage (100, 200, 400, 500, 700, 800), comprising a pitch control device (120.1) and / or a converter torque control device (120.2), based on the at least one detected shaft parameter and a shaft criterion. Floating offshore wind turbine (100, 200, 400, 500, 700, 800) according to claim 1 , characterized in that - the at least one wave parameter is selected from the group comprising: - wave height, - wave direction, and - wave frequency. Floating offshore wind turbine (100, 200, 400, 500, 700, 800) according to claim 1 or 2 , characterized in that - the at least one wave criterion is a linear control criterion or a non-linear control criterion. Floating offshore wind turbine (100, 200, 400, 500, 700, 800) according to claim 3 , characterized in that - the regulation criterion contains a dead band and/or hysteresis. Floatable offshore wind turbine (100, 200, 400, 500, 700, 800) according to one of the preceding claims, characterized in that - the floatable offshore wind turbine (100, 200, 400, 500, 700, 800) at least one further detection device (213), - wherein the at least one further detection device (213) is set up to detect at least one further parameter, selected from the group comprising: - distance between a blade tip (217) of a rotor blade (116, 216) and the outer wall of the tower, - pitch angle of the tower (104, 204, 404, 504, 704, 804), - pitch frequency of the tower (104, 204, 404, 504, 704, 804), - bending angle of a rotor blade (116, 216), - wind speed, - wind direction. Floating offshore wind turbine (100, 200, 400, 500, 700, 800) according to claim 4 , characterized in that - the wind pressure changing device (108, 208, 408, 508, 708, 808) is set up to change the wind pressure exerted on the offshore wind turbine (100, 200, 400, 500, 700, 800) by controlling the at least a wind pressure control device (120), additionally based on the at least one detected additional parameter and at least one additional parameter criterion. A buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) according to any one of the preceding claims, characterized in that the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) comprises: - at least one a ballast tank (788) that can be filled with a ballast medium (787), and - at least one ballast medium conveying device (782), set up to change the filling level (786) of the ballast tank (788), - the wind pressure changing device (108, 208, 408, 508, 708, 808) is set up to control the ballast medium conveying device (782) based on the at least one recorded shaft parameter or the at least one recorded additional parameter and at least one ballast criterion. A buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) according to any one of the preceding claims, characterized in that the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) comprises: - at least one a weight element (894) connected to the buoyant foundation (102, 202, 402, 502, 702, 802) and movable at least between a state lowered onto the underwater bottom surface (132, 232, 432, 732, 832) and a state suspended from the underwater bottom surface (132 , 232, 432, 732, 832) can be changed in the raised state, and - at least one weight adjustment device (892), set up for adjusting the weight element (894) between the lowered state and the raised state, - the wind pressure changing device (108, 208, 408 , 708, 808) is set up to control the weight adjustment device (892) based on the at least one detected shaft parameter or the at least one detected additional parameter and at least one em weight criterion. A buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) according to any one of the preceding claims, characterized in that the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) comprises: - at least one Anchoring arrangement (250, 450) set up for fastening the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) to an underwater bed (136, 236, 436, 736, 836) in an anchored state of the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800), - wherein the anchoring arrangement (250, 450) comprises at least one between an anchor (244, 444) and the buoyant foundation (102, 202, 402, 502, 702, 802) running anchor connection (246, 446), - at least one length changing device (260, 460) set up to change the length of the anchor connection (246, 446) between the anchor (244, 444) and the buoyant foundation (104, 204, 304, 504 , 604) in the anchored condition, - the wind pressures a Changing device (108, 208, 408, 708, 808) is set up to control the length changing device (260, 460), based on the at least one detected shaft parameter or the at least one detected additional parameter and at least one length criterion. Floatable offshore wind turbine (100, 200, 400, 500, 700, 800) according to one of the preceding claims, characterized in that - at least one vertical anchor connection (446.2) running essentially in the vertical direction on the floatable foundation (102, 202, 402 , 502, 702, 802) and - at least one angle anchor connection (446.1, 446.3) running at an angle to the vertical direction of at least 2°, preferably at least 5°, on the buoyant foundation (102, 202, 402, 502, 702, 802) is attached, - the wind pressure changing device (108, 208, 408, 708, 808) being set up to control the length changing device (260, 460) in such a way that the length of the vertical anchor connection (446.2) and/or the length of the Angular anchor connection (446.1, 446.3) is changed based on the at least one recorded shaft parameter or the at least one recorded additional parameter and at least one length criterion. A buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) according to any one of the preceding claims, characterized in that the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) comprises: - at least one Monitoring device turned on for detecting a failure of at least one wind turbine component, comprising the at least one detection device (125, 213, 225), the wind pressure changing device (108, 208, 408, 708, 808), the length changing device (260, 460), the weight adjusting device (894), the ballast medium conveying device (782) and/or the at least one wind pressure control device (120), - the monitoring device comprising an alarm module set up to output an alarm message when a failure of one of the monitored wind turbine components is detected. Wind pressure changing device (108, 208, 408, 708, 808) for a buoyant offshore wind turbine (100, 200, 400, 500, 700, 800), in particular a buoyant offshore wind turbine (100, 200, 400, 500, 700, 800 ) according to any one of the preceding claims, comprising: - At least one receiving module (110), set up to receive at least one detected wave parameter, and - at least one control module (112), set up to change the wind pressure exerted on the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) by controlling at least one wind pressure control device (120) of the buoyant offshore wind turbine (100, 200 , 400, 500, 700, 800) comprising a pitch control device (120.1) and/or a converter torque control device (120.2), based on the at least one received wave parameter and a wave criterion. Method, in particular for controlling a buoyant offshore wind turbine (100, 200, 400, 500, 700, 800), comprising: - Controlling at least one wind pressure control device (120) of the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800), comprising a pitch control device (120.1) and/or a converter torque control device (120.2), based on at least one provided wave parameters and a wave criterion such that the wind pressure exerted on the buoyant offshore wind turbine (100, 200, 400, 500, 700, 800) is changed. Computer program product, comprising instructions which, when the program is executed by a computer, cause it to carry out the method according to Claim 13 to execute.

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