Damping system and method for wind turbine installation

Abstract

The invention relates to a damping system (1) for damping movement of a tower (2) of a wind turbine (3), comprising a rope (4) for attachment to the tower (2) for applying a pulling force to the tower (2). The damping system (1) further comprises a traction device (5) for providing a defined traction force on the cord (4) and a control device (6) for controlling the traction device (5). The invention also relates to a method for attenuating movement of a tower (2) of a wind turbine (3).

Description

Technical Field

[0001] The present invention relates to a damping system for reducing the movement of a wind turbine tower, in particular during the installation process of a wind turbine (such as placing a nacelle or placing rotor blades). The present invention also relates to a method for reducing the movement of a wind turbine tower. Background Art

[0002] A wind turbine tower is exposed to environmental influences, which may cause the tower to move, such as swaying, vibration, etc. The excitation of the tower can be wind-induced vibration, such as interference galloping (IG) or vortex-induced vibration (VIV). Offshore waters may also cause vibrations through current-driven VIV or waves acting on the substructure of the wind turbine.

[0003] When installing components of a wind turbine (such as placing a nacelle on the tower or placing rotor blades on the hub of the wind turbine), the movement of the wind turbine tower can cause difficulties, especially in aligning the components and maintaining the alignment during the fixing process.

[0004] In addition, for such installation processes, large auxiliary vehicles, such as onshore cranes or offshore lifting vessels, are typically used. Since the operating costs of these vehicles are very high, reducing the installation duration of such wind turbine components is a general objective of the wind turbine industry. For this purpose, various systems and methods have been developed.

[0005] For onshore wind turbines, anchoring the tower is a well-known method for reducing tower movement. The tower is fixed to the ground by means of a combination of ropes and anchoring devices. By tensioning the ropes, the stiffness of the tower is increased, and thus the movement of the tower can be reduced. In addition, by arranging the ropes to provide friction when pulled back and forth by the tower, the movement of the tower can also be attenuated. The disadvantage of the anchoring system is that the positive effect of reducing and attenuating tower movement is very limited. In addition, for offshore applications, such a system can only be implemented with great effort and is therefore not advisable for economic reasons.

[0006] Another technique for onshore and offshore wind turbines is a mass damper system, which is placed on top of the tower during installation. Such a mass damper system can be passive or active. In addition, it can be designed to be rotationally or linearly arranged. The disadvantage of using such an active mass system is that it requires additional lifting by a crane and thus increases the installation time. Another disadvantage is that the active mass damper system requires a rather expensive advanced controller.

[0007] Different methods for improving the alignment of rotor blades with the hub are known from the art. The central part of the rotor blade is connected to the hoisting cable of a crane, while the alignment cables of the alignment system are attached to the rotor blade from both sides of the central part. By lifting the rotor blade and performing defined operations on the alignment cables, the orientation of the rotor blade relative to the hub can be precisely controlled. Such a system requires complex control equipment and incurs relatively high costs. Documents WO 2021 / 121501 A1 and WO 2021 / 175398 A1 disclose additional methods for damping the movement of a wind turbine tower. Summary of the Invention

[0008] Accordingly, it is an object of the present invention to eliminate or at least partially eliminate the disadvantages described above in the case of installing a wind turbine. In particular, it is an object of the present invention to produce a damping system and a damping method that provide a reduced installation time for wind turbine components, such as placing a nacelle on a tower or placing a rotor blade on a hub, in a simple and inexpensive manner.

[0009] The above object is achieved by the claims. Thus, the problem is solved by a damping system for damping the movement of a wind turbine tower having the features of independent claim 1 and by a method for damping the movement of a wind turbine tower having the features of dependent claim 7. Further features and details of the present invention emerge from the dependent claims, the description, and the drawings. The features and details described with respect to the damping system for damping the movement of a wind turbine tower according to the first aspect of the present invention naturally also apply to the method for damping the movement of a wind turbine tower according to the second aspect of the present invention, and vice versa, such that the disclosure regarding the individual aspects of the present invention always refers to each other or can always refer to each other.

[0010] According to a first aspect of the present invention, the object is achieved by a damping system for damping the movement of a wind turbine tower. The damping system includes a cable attached to the tower for applying a tensile force to the tower. According to the present invention, the damping system further includes a pulling device for providing a defined tensile force on the cable and a control device for controlling the pulling device. In addition, the pulling device includes a hydraulic pulling system for providing the tensile force.

[0011] The cable can be configured as a rope, wire, belt, etc., or a combination thereof. To fix the cable to the tower, the cable can be configured to wind around the tower. Alternatively or additionally, the damping system can include a holding element that can be attached to the tower. The holding element is configured for attachment to the cable. Alternatively, the cable can already be attached to the holding element. The holding element can be configured as a loop for winding around the tower.

[0012] The rope is configured to provide a pulling force to the tower. Therefore, preferably, the rope is configured for a force of at least 50 kN, more preferably at least 500 kN, and even more preferably at least 1 MN. In addition, preferably, the rope has a relatively high stiffness to avoid movement of the tower due to the elastic properties of the rope.

[0013] The pulling device is connected to the rope to provide a defined pulling force on the rope. Preferably, the pulling device includes an anchoring device for anchoring the pulling device to the ground. For onshore applications, preferably, the pulling device has a device weight significantly higher than the pulling force to be provided. Thus, during the installation process, the pulling device can be kept in a fixed position. The pulling device can be configured as a lateral pulling device (e.g., having a pulling piston, rod, etc.), a rotary pulling device (e.g., a winch), or a combination thereof.

[0014] The control device is configured to control the pulling device. Within the scope of the present invention, controlling the pulling device preferably means controlling it in such a way as to provide a defined pulling force. Further preferably, the control also means that the defined pulling force can be maintained or adjusted, particularly with respect to the movement of the tower. The control device can be, for example, a programmable logic controller (PLC), having an input sensor signal of the tower movement and an output signal to the pulling device.

[0015] The damping system is preferably configured to keep the rope taut using a predetermined first force (e.g., between 10 and 30 kN) when the tower moves towards the rope. The damping system is preferably configured to pull the rope with a predetermined pulling force (e.g., between 150 and 400 kN) when the tower moves away from the rope. Thus, the movement of the tower can be attenuated and thereby the movement reduced.

[0016] The pulling device includes a hydraulic pulling system for providing the pulling force. The hydraulic pulling system includes a hydraulic actuator. The hydraulic actuator can include a hydraulic cylinder, a piston, and / or a hydraulic motor or a winch, etc. This has the advantage of being able to provide a defined pulling force in an effective and reliable manner in a simple and inexpensive way.

[0017] The damping system according to the present invention has the advantage over conventional damping systems: being able to attenuate the movement of the wind turbine tower in a simple and inexpensive way. Thus, the installation time of components for the wind turbine (such as nacelle to tower, rotor blade to hub, etc.) can be reduced because the alignment process time can be shortened due to the reduced movement of the tower. This has the further advantage that the usage time of expensive auxiliary vehicles (such as lifting vessels) can be reduced and costs can be saved.

[0018] According to a preferred further extension of the invention, the damping system comprises sensing means for sensing the movement of the tower, wherein the control means is configured to control the pulling means relative to the movement of the tower or the sensed movement of the tower, respectively. The sensing means may be configured to be mounted on the tower, for example on the top of the tower. Alternatively, the sensing means may be configured to operate spaced apart from the tower, for example to sense the movement of the tower from a distance by means of optical and / or mechanical means. Preferably, the sensing means is configured to sense the movement of a number of towers from one location without the need to reposition the sensing means. Within the scope of the present invention, sensing may be understood as measuring, detecting, determining, etc. The sensing means is preferably configured to sense the speed of movement of the tower. This has the advantage that a defined pulling force can be better provided in a simple and inexpensive manner relative to reducing the movement of the tower.

[0019] According to the invention, preferably, the sensing means is configured to sense the acceleration of the tower, wherein the control means is configured to control the pulling means relative to the sensed acceleration of the tower. By sensing the acceleration of the tower, the degree of movement of the tower can be better predicted. In addition, the influence of the pulling force exerted by the pulling means on the movement of the tower can be better determined. Therefore, the pulling force can be optimized to more effectively reduce the movement of the tower. This has the advantage that the damping action of the damping system for damping the movement of the tower can be further improved in a simple and inexpensive manner.

[0020] More preferably, the damping system further comprises a relay, wherein the control means is configured to operate the relay relative to the sensed movement of the tower. Preferably, the damping system comprises a plurality of relays. The control means may be configured to set the internal relay on or off according to a sensor input signal. When the internal relay is on, the device relay of the pulling means is activated, and when the internal relay is off, the device relay is not activated, or vice versa. This has the advantage that the pulling means can be easily controlled by the control means in a simple and inexpensive manner.

[0021] In a particularly preferred embodiment, the control means is configured to operate the relay relative to the predicted movement of the tower based on the sensed movement of the tower. The control means is configured to predict the movement of the tower by analyzing the sensed movement of the tower. For example, when the acceleration of the tower movement increases, the control means may determine that the driving force for the tower movement is relatively high, and from that point in time, further movement of the tower in a specific direction is expected. The control means is also configured to operate the relay and thus control the pulling means to pre-adjust the pulling force relative to the expected movement of the tower. This has the advantage that the response of the pulling means to the movement of the tower can be improved in a simple and inexpensive manner, wherein the offset between the tower movement and the action of the pulling means for damping the tower movement can be reduced. Therefore, the movement of the tower can be damped in a more effective manner.

[0022] According to a preferred embodiment of the present invention, a relay is connected to at least one valve for operating a hydraulic pulling system. By operating the valve, pressurized hydraulic fluid provided by a hydraulic motor - pump unit of the pulling device can be provided to a hydraulic actuator in a defined manner. Preferably, the valve is configured as a two - way valve for selectively providing hydraulic fluid to a high - pressure hydraulic circuit and a low - pressure hydraulic circuit. The control device is preferably configured to set the valve for the low - pressure circuit to tighten the rope when the tower moves towards the rope, and to set the valve for the high - pressure circuit to provide a higher pulling force when the tower moves away from the rope. This has the advantage that a defined pulling force can be provided in a simple and inexpensive way, and in an effective and reliable manner.

[0023] In a particularly preferred embodiment, the damping system further includes a winch which is connected to one or more ropes of the tower during blade installation to ensure that the ropes remain taut. Additionally, at least one hydraulic actuator is also connected to the winch through a movable sliding device on the main frame (frame support). The sliding device can be a slide rail. By actuating one or more hydraulic actuators (such as a hydraulic cylinder actuator), the movement of the tower is attenuated by the pulling force generated by the hydraulic actuator.

[0024] By combining the winch with a hydraulic cylinder, it is ensured that the ropes remain taut because the winch may be able to quickly pull several meters of rope. When the ropes are kept taut by the winch, the hydraulic cylinder or cylinders can be used to generate the pulling force of the ropes.

[0025] According to a further extension of the present invention, regarding offshore blade installation, the damping system is installed on the deck of a jack - up vessel. Regarding onshore blade installation, the damping system can also be used. By attenuating the turbine tower oscillations during blade installation, it increases the weather window, thus allowing the installation of wind turbines at higher wind speeds.

[0026] According to another preferred embodiment of the present invention, the tower is connected to an installation vessel (or land on the ground) by ropes, and damping is provided by having a higher tension in the ropes when the tower oscillates away from the vessel, while reducing the tension when the tower may move towards the vessel. Alternating between these tension forces and the tower frequency, the tower amplitude is reduced. The degree of suppressing this displacement may impose a load on the damping system.

[0027] According to a further embodiment of the present invention, the damping system is stored inside a container to facilitate the storage and transportation of the damping system. Additionally, it protects the container from damage caused by impacts during transportation or storage, as well as exposure to weather and environmental conditions.

[0028] According to a second aspect of the present invention, the object is achieved by a method for attenuating the movement of a tower of a wind turbine. The method includes:

[0029] - Provide a damping system according to the first aspect of the present invention, wherein the damping system includes a sensing device for sensing the movement of the tower, and wherein the control device is configured to control the pulling device relative to the sensed movement of the tower.

[0030] - Attach the rope to the tower.

[0031] - Sense the movement of the tower by the sensing device, and

[0032] - Provide a defined pulling force on the rope relative to the sensed movement by operating the pulling device with the control device.

[0033] First, provide a damping system according to the first aspect of the present invention. The damping system includes a rope, a pulling device, a control device, and a sensing device for sensing the movement of the tower. The control device is configured to control the pulling device relative to the sensed movement of the tower. Using this preferred embodiment of the damping system, the damping force can better adapt to the movement of the tower.

[0034] Subsequently, attach the rope to the tower. Preferably, the rope is wound around the tower and tightened such that the connection height of the rope at the tower remains at a constant level.

[0035] Then, sense the movement of the tower by the sensing device. For this purpose, preferably the sensing device is arranged at the tower, in particular at a position above the attachment portion of the rope. The relatively high attachment portion of the sensing device has the advantage that the sensed movement is also relatively high, since the movement of the tower generally increases from the bottom section to the top section of the tower. As the movement, for example, the movement speed and / or the movement acceleration can be sensed.

[0036] The control device then operates the pulling device based on the sensed movement to provide a defined pulling force. Preferably, the pulling force is provided such that a relatively low pulling force is provided when the tower approaches the rope to just tighten the rope, and when the tower moves away from the rope, a relatively high pulling force is provided to actively reduce the movement of the tower. In addition, preferably, a defined pulling force is provided relative to the predicted movement of the tower to improve the damping effect on the tower movement.

[0037] The method for damping the movement of the tower of a wind turbine according to the second aspect of the present invention has all the advantages already described for the damping system for damping the movement of the tower of a wind turbine according to the first aspect of the present invention. Thus, the method according to the present invention has advantages over conventional methods: the movement of the tower of the wind turbine can be damped in a simple and inexpensive manner. Thus, the installation time of components for the wind turbine (such as nacelle to tower, rotor blade to hub, etc.) can be reduced because, due to the reduced movement of the tower, the alignment process time can be shortened. This has the further advantage that the use time of expensive auxiliary vehicles (such as lifting vessels) can be reduced and costs can be saved.

[0038] Particularly preferably, the rope is attached to an intermediate section of the tower such that the rope lies outside the range of the rotor blades mounted to the wind turbine. The height at which the rope is attached to the tower represents the attachment height. Further preferably, the attachment height is as high as possible and outside the range of the rotor blades to improve the influence of the pulling device on the movement of the tower. This has the advantage that the movement of the tower can be damped in a simple and inexpensive manner without the risk of the rotor blades colliding with the rope.

[0039] According to the present invention, preferably, the sensing device is arranged to sense the movement of the top section of the tower. Naturally, the movement of the tower at the top end of the tower is the highest movement of the tower. Thus, sensing the movement in this area at or near the top end is useful for sensing the movement of the tower very reliably and accurately. This has the advantage that the damping of the movement of the tower can be further improved in a simple and inexpensive manner. Description of the Drawings

[0040] Further advantages, features and details of the present invention emerge from the following description, in which working examples of the present invention are described in detail with reference to the drawings. Thus, the features from the claims as well as those mentioned in the description may be necessary for the present invention, either taken alone or in any combination. In the drawings:

[0041] Figure 1 A schematic side view of a tower of a wind turbine with a damping system according to a preferred embodiment of the present invention is shown,

[0042] Figure 2 A schematic structural view of a hydraulic pulling system of a damping system according to a preferred embodiment of the present invention is shown, and

[0043] Figure 3 A schematic process diagram of a method according to a preferred embodiment of the present invention is shown, and

[0044] Figure 4Schematic structural view of a tower of a wind turbine with a damping system according to a preferred embodiment of the present invention, and

[0045] Figure 5 Top view of a damping system according to a preferred embodiment of the present invention, and

[0046] Figure 6 Schematic structural view of a tower of a wind turbine with a damping system in a container according to a preferred embodiment of the present invention, and

[0047] Figure 7 Schematic structural view of a tower of a wind turbine with a damping system in a jack-up vessel according to a preferred embodiment of the present invention.

[0048] Elements having the same function and effectiveness are denoted by the same reference numerals in Figures 1 to 3 the drawings. Detailed Description

[0049] In Figure 1 the drawings, a tower 2 of a wind turbine 3 with a damping system 1 according to a preferred embodiment of the present invention is shown in a schematic side view. The tower 2 includes a bottom section 14, an intermediate section 11 disposed on top of the bottom section 14, and a top section 13 disposed on top of the intermediate section 11. A nacelle 15 is located on top of the top section 13. The wind turbine 3 is in a placed state, and the rotor blades are not shown. When assembled, the rotor blades facing downward can move within a predefined range 12.

[0050] The damping system 1 includes a cord 4 having one end attached to the intermediate section 11 of the tower 2. The other end of the cord 4 is attached to a hydraulic piston 17 of a hydraulic traction system 9 of a traction device 5 of the damping system 1. The hydraulic piston 17 is partially surrounded by a hydraulic cylinder 16 of the hydraulic traction system 9. The cord 4 is attached to the tower 2 such that the cord 4 is outside the range 12 of the rotor blades. A sensing device 7 of the damping system 1 is located on top of the top section 13 of the tower 2. To control the traction device 5, the damping system 1 further includes a control device 6.

[0051] In Figure 2 the drawings, a hydraulic traction system 9 of a damping system 1 according to a preferred embodiment of the present invention is shown in a schematic structural view. The hydraulic traction system 9 includes a hydraulic motor 18 for operating a hydraulic pump 19 to provide hydraulic pressure. The hydraulic traction system 9 further includes a two-way valve 10 operated by a relay 8. The relay 8 can be connected to the sensing device 7. The hydraulic traction system 9 further includes a valve 10 for a low-pressure circuit and a valve 10 for a high-pressure circuit. In addition, in this drawing, a hydraulic cylinder 16 and a hydraulic piston 17 are shown.

[0052] InFigure 3 In the following, a method according to a preferred embodiment of the present invention is schematically illustrated in a process diagram. In a first step 100, a damping system 1 according to the present invention is provided. In a second step 200, a cord 4 of the damping system 1 is attached to the tower 2, preferably to an intermediate section 11 of the tower 2.

[0053] In a third step 300, the movement of the tower 2 is sensed by a sensing device 7 of the damping system 1. In a fourth step 400, a control device 6 operates a pulling device 5 to provide a defined pulling force on the cord 4 relative to the sensed movement.

[0054] In Figure 4 A damping system for attenuating the movement of a tower (2) includes at least one cord (4) which is coupled to a connecting device (20) before being introduced into the damping system through a guiding device (21) and ultimately attached to a winch (22). The winch (22) is attached to a translatably movable sliding device (23) placed on rollers (24). At least one hydraulic cylinder (25) is mounted on the winch (22), and a main frame (26) is connected to a translatable sliding device (24) of the main frame (26) of the structure. The main frame (26) ultimately transfers the load to the ship deck or the ground through a fastening device (27). In addition, a tensioning device (28) is utilized to attach the container to the ship deck or the ground, thereby reducing the load on the corner castings of the container. A distance d is maintained between the tower and the ship deck or the floor. The cord (4) is long enough to connect the tower to the damping system and maintain the distance d between the tower and the ship deck or the ground.

[0055] The damping system is placed inside a container (dashed lines), which can be reconfigured to accommodate the damping system. The container can have a size of 20 feet.

[0056] The damping system operates at various tower positions relative to the installation ship. The horizontal range is ±45°, and the vertical range is -10° / +25°. The at least one hydraulic cylinder (25) can be restricted by a hydraulic valve which generates a pressure on each cylinder that generates a damping force. More specifically, the hydraulic valve can generate a pressure equal to 20 tons on each cylinder that generates a maximum damping force of 40 tons and a total of 10 tons as the minimum damping force. The winch (22) can be equipped with a mechanical brake which can have a capacity of 50 tons, thereby allowing the sliding device (23) to translate during operation. In the event of an unexpected overload of the load, the brake can be released, thereby allowing the sliding device (23) to translate freely to effectively eliminate any tower damping and thus unload the damping system.

[0057] In Figure 5The top view of the damping system is shown. The rope (4) is introduced into the damping system inside the container through a guiding device (21) (such as a wire guide). The rope (4) is attached to a winch (22). The winch (22) can quickly pull several meters of the rope (4), and when the rope (4) is held taut by the winch (4), the large pulling force of the rope (4) can be easily achieved by the hydraulic cylinder (25).

[0058] The control of the damping system can be accomplished by a controller (not shown) and can have visual systems of tower acceleration, tower strain, tower position, or similar signals of tower movement as inputs and outputs. Additionally, it can have control signals such that the winch (22) may be able to tighten the rope (4), for example, by activating an electric relay that supplies electric power to the motor of the winch (22) and to the hydraulic actuator, or by activating a hydraulic valve in a hydraulic system driven by a motor - pump unit for moving the sliding device (23) forward or backward. The winch (22) can alternatively be hydraulically driven and thus activated by an input signal of the hydraulic valve.

[0059] In Figure 6 The schematic structural view of the damping system inside the container is shown. At least one rope (4) connected to the connecting device (20) is introduced into the container through the guiding device (21). The container includes holes, and the guiding device (21) is placed there to allow the rope (4) to be introduced into the container.

[0060] The main frame transfers the load to the ship deck or the ground through the fastening device (27). The tensioning device (28) is used to reduce the load on the corner castings of the container. The tensioning device (28) can be a turnbuckle.

[0061] The water tank (29) is placed on top of the container. The controller also activates valves and / or pumps to ensure that water from the water tank (29) flows through the guiding device (21) and thus cools the rope (4) due to the friction between the guiding device (21) and the rope (4) during the pulling of the rope (4).

[0062] The water can be collected in a second water tank (not shown) and pumped back to the water tank (29). The water tank (29) can be provided with a cooler to cool the water returning to the water tank (29). Alternatively, water can be directly pumped from the ocean to the water tank (29) instead of collecting the water and pumping it back to the water tank (29). In this way, depending on the seawater temperature, the cooling of the water can be avoided.

[0063] In Figure 7Schematic structural view of a tower of a wind turbine with a damping system in a jack-up vessel. The tower (2) of the wind turbine is connected to the damping system from an installation vessel by means of a cable (4), and the damping system is placed within a container in the jack-up vessel. The damping system is provided by having a higher tension in the cable (4) when the tower (2) oscillates away from the vessel, while reducing the tension when the tower (2) may move towards the vessel.

Claims

1. A damping system (1) for reducing the movement of a tower (2) of a wind turbine (3), comprising a cord (4) for attachment to the tower (2) for applying a tensile force to the tower (2). Characterized in that, the damping system (1) further comprises a tensioning device (5) for providing a defined tensile force on the cord (4) and a control device (6) for controlling the tensioning device (5), wherein the tensioning device (5) comprises a hydraulic tensioning system (9) for providing the tensile force.

2. The damping system (1) according to claim 1, Characterized in that, the damping system (1) comprises a sensing device (7) for sensing the movement of the tower (2), wherein the control device (6) is configured to control the tensioning device (5) relative to the sensed movement of the tower (2).

3. The damping system (1) according to claim 2, Characterized in that, the sensing device (7) is configured to sense the acceleration of the tower (2), wherein the control device (6) is configured to control the tensioning device (5) relative to the sensed acceleration of the tower (2).

4. The damping system (1) according to claim 2 or 3, Characterized in that, the damping system (1) further comprises a relay (8), wherein the control device (6) is configured to operate the relay (8) relative to the sensed movement of the tower (2).

5. The damping system (1) according to claim 4, Characterized in that, the control device (6) is configured to operate the relay (8) relative to the predicted movement of the tower (2) based on the sensed movement of the tower (2).

6. The damping system (1) according to any one of the preceding claims, Characterized in that, the relay (8) is connected to at least one valve (10) for operating the hydraulic tensioning system (9).

7. A method for reducing the movement of a tower (2) of a wind turbine (3), comprising: - providing a damping system (1) according to any one of the preceding claims, wherein the damping system (1) comprises a sensing device (7) for sensing the movement of the tower (2), wherein the control device (6) is configured to control the tensioning device (5) relative to the sensed movement of the tower (2), - attaching the cord (4) to the tower (2), - sensing the movement of the tower (2) by the sensing device (7), and - operating the tensioning device (5) by the control device (6) to provide a defined tensile force on the cord (4) relative to the sensed movement.

8. The method according to claim 7, Characterized in that, the cord (4) is attached to an intermediate section (11) of the tower (2) such that the cord (4) is located outside the range (12) of the rotor blades mounted to the wind turbine (3).

9. The method according to claim 7 or 8, Characterized in that, the sensing device (7) is arranged to sense the movement of the top section (13) of the tower (2).

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