Installation of nacelle and rotor blade of wind turbine

Abstract

In the installation of a wind turbine, an integrated device configured for nacelle lifting and for blade positioning is used, the integrated device having a nacelle lifting structure and a blade positioning assembly. The method includes connecting the integrated device to the nacelle, then lifting the nacelle to the top of the tower, and then securing the nacelle to the top of the tower. After fastening the nacelle, the load connector of the crane is disconnected from the integrated device, which then remains connected to the nacelle in a stable position. The blade positioning assembly is used for positioning the blade root relative to a blade mounting structure of the blade hub so as to fix the blade root to the blade mounting structure.

Description

Technical Field

[0001] The present invention relates to the installation of wind turbines, such as offshore wind turbines. Background Art

[0002] In a known method for installing a wind turbine, one or more cranes are used to lift a nacelle, which contains a generator and a blade hub that drives the generator, onto the top of the wind turbine's tower. Typically, the hub is provided with multiple blade mounting structures, for example three, each configured to secure a rotor blade to the blade mounting structure. At a later stage in the installation process, the rotor blades are assembled one by one to their respective blade mounting structures. Here, each rotor blade is lifted by a crane to a height at which the blade root can be secured to the blade mounting structure.

[0003] Today, wind turbine nacelles are typically very large and heavy. In the wind energy industry, nacelle weights of several hundred tons have become commonplace. The nacelle of an SG14-222DD wind turbine with a design capacity of 14 MW weighs approximately 500 tons. The nacelle of a 12 MW Haliade-X wind turbine weighs 675 tons.

[0004] To lift the heavy nacelle to the top of a wind turbine tower, one or two tall, high-capacity cranes are required. For this operation, it is known to utilize specialized nacelle hoisting tools suspended from a load connector of one crane or from two cranes. The nacelle hoisting tools themselves are quite large and can weigh tens of tons in order to handle the weight of the nacelle.

[0005] The nacelle is typically provided with anchor points configured to connect to a nacelle lifting tool, typically via a sling. For example, three or four anchor points may be provided, such as three anchor points arranged in a triangular configuration when viewed from above. For example, one anchor point may be located further forward on the hub on the nacelle's centerline, while two anchor points may be located further aft on opposite sides of the nacelle.

[0006] In prior art methods, once the nacelle has been lifted onto and secured to the top of the tower, the nacelle lifting tool is disconnected from the nacelle, for example by disconnecting the lifting slings from the anchor points. When installing an offshore wind turbine, the nacelle lifting tool is then brought back down, for example to the ground or the deck of a vessel, and disconnected from the crane.

[0007] The installation process of the rotor blades is then typically performed using the same crane or one of the cranes that has been used to install the nacelle on top of the tower.

[0008] The rotor blade has a blade body having a blade root, a blade tip, a length between the root and the tip, and a mass. The rotor blade is usually made primarily of composite materials.

[0009] In a common design for a wind turbine rotor blade, the blade root is configured as a blade mounting structure that is secured to the wind turbine's hub by one or more fasteners. In a well-known embodiment, a series of bolts, for example in the form of so-called T-bolts, protrude from the trailing surface of the hollow blade root. The hub's mounting structure is provided with a circular flange that is provided with a matching series of bolt holes. For example, the flange is part of or integral with the pitch bearing of the blade mounting structure. Once the bolts have been inserted through these bolt holes, nuts are fitted over the bolts to secure the blade root to the hub.

[0010] The size of wind turbines has steadily increased over the years, primarily for economically efficient energy production. Consequently, wind turbines now have very large rotor blades, for example exceeding 75 meters in length, or even exceeding 100 meters. For example, each blade of the Vestas 15V236 wind turbine measures 115.5 meters in length. Siemens Gamesa's SG 14-222DD direct-drive wind turbine has rotor blades 108 meters in length. This market development has further increased the requirements for mounting rotor blades onshore or offshore wind turbines. The blade root can have a diameter greater than 5 meters. The mass of a single rotor blade can well exceed 50 tons.

[0011] To mount a rotor blade to a wind turbine's hub, the blade is typically lifted by a crane using a blade lifting tool attached to the crane's load connector. In a typical method, the crane is operated to lift the rotor blade to a height substantially flush with the blade mounting structure while maintaining the rotor blade in a horizontal orientation, with the blade mounting structure positioned at the so-called three or nine o'clock position. The crane is then operated to bring the rotor blade closer to the hub's blade mounting structure, for example with the aid of the crane's guy wire system, in order to stabilize and align the rotor blade so that bolts can be introduced into the bolt holes.

[0012] It should be noted that, in addition to the increased size and mass of rotor blades, so-called six o'clock mounting has become quite problematic due to the difficulty in holding the blades in a vertical position by means of blade lifting tools.

[0013] Matching all the bolts on the blade root with the bolt holes of the mounting structure is difficult, and in light of the developments discussed above, this matching has become even more difficult. The main factor in this context is the presence of excessive relative motion between the blade mounting structure and the blade root. This factor and the problem of matching bolts and bolt holes are discussed, for example, in the article "Effects of Wind-Wave Misalignment on a Wind Turbine Blade Mating Process: Impact Velocities, Blade Root Damages and Structural Safety Assessment" by Verma et al. in the Journal of Marine Science and Applications, 2019, https: / / doi.org / 10.1007 / s11804-020-00141-7. In that article, it is described that the hub of an offshore wind turbine may be subject to motion caused by sea conditions, such as waves impacting the foundation on which the tower is mounted, such as a monolithic pile or other foundation.

[0014] A rotor blade lifted by a crane can obviously be subject to wind-induced motions, as long as it is not completely fixed to the hub. In practice, crane-induced motions, such as vibrations of the crane boom, may also occur during the installation of the rotor blade.

[0015] The relative movement between the root end of the rotor blade and the blade mounting structure of the hub may be a source of undesired impacts or collisions between one or more bolts and other parts of the hub or the nacelle. This may be a head-on impact or a side impact, or a combination thereof. Such impacts may cause damage to the blade root, even hidden damage, such as (minimum) cracking of the laminated composite material, and / or damage to one or more bolts, etc. The same problem may arise if some of the bolts are initially replaced by longer guide rods, which extend beyond the bolts and are to be introduced into the corresponding holes as guides. For example, see EP2918969.

[0016] The aforementioned article discusses that at sea, wind and wave directions can be the same, but they can also differ. The latter is known as wind-wave misalignment. As discussed, in both cases, the impact velocity at the blade root can cause excessive damage upon impact. The article shows a graph depicting the cyclical hub motion in the horizontal, or XY, plane for different angles between wave and wind. Due to the waves striking the base, the amplitude of this cyclical hub motion can be approximately 1 meter. At the same time, the blades, suspended from the crane, undergo their own cyclical motion, resulting in significant relative motion during the mating process. Summary of the Invention

[0017] It is an object of the present invention to provide a more efficient method and related apparatus for installing a wind turbine, either offshore or onshore.

[0018] The present invention provides a method according to claim 1 .

[0019] In the method of the invention, an integrated device configured for nacelle lifting and for blade positioning is used, the integrated device having a nacelle lifting structure and a blade positioning assembly.

[0020] The method comprises connecting the integrated device to the nacelle and load connector of the crane.As discussed, in embodiments, two cranes may be employed to lift the nacelle, however a single crane is preferably used.

[0021] Connecting the integrated device to the nacelle can be accomplished after the integrated device has first been connected to the load connector of a crane, such as one used to bring the integrated device into position relative to the nacelle to allow it to be connected to the nacelle. In another approach, the integrated device is first connected to the nacelle, for example using a different crane than the one used to actually lift the nacelle. This other crane can be significantly smaller in size and capacity than the crane required to lift the nacelle.

[0022] The nacelle is then lifted to the top of the tower and subsequently secured to the top of the tower.

[0023] After securing the nacelle to the top of the tower, the crane's load connector is disconnected from the integrated device, which then remains connected to the nacelle. This is in contrast to prior art methods, in which a dedicated nacelle hoisting tool is disconnected from the nacelle and then removed by crane operation.

[0024] The integrated device is configured to have a stable position relative to the nacelle, at least when disconnected from the load connector of the crane. The stable position is required in view of the use of the blade positioning assembly of the integrated device during the subsequent installation of at least one rotor blade. The stable position can be provided in many different ways, for example, the integrated device is rigidly connected to the nacelle, for example to an anchoring point of the nacelle. The stable position can also be provided by a stabilizing member, which is used to stabilize the integrated device relative to the nacelle, for example, the stabilizing member is different from the load transfer connector member. For example, as in the prior art, a sling is used as the load transfer connector member together with an additional stabilizer member for stabilizing the integrated device. For example, one or more stabilizer members can be operated between an inactive state and / or position and an active state and / or position. For example, the integrated device is provided with one or more operable stabilizers.

[0025] In an embodiment, stabilization of the integrated device is obtained by engaging one or more stabilizers on the nacelle only.In another embodiment, the integrated device is configured to provide a stable position by, for example, engaging on the top end of a tower in addition to engaging on the nacelle.

[0026] Once the nacelle has been mounted on top of the tower, the method continues with the installation of at least one rotor blade, preferably all rotor blades, for example all three rotor blades. It should be noted that the method of the present invention is also applicable, for example, to the so-called "rabbit ears method", in which the nacelle is already equipped with two rotor blades before being lifted to the top of the tower, so that only one rotor blade needs to be installed on the nacelle at the top of the tower.

[0027] To install the rotor blades, a blade lifting tool is used, which holds the rotor blade and suspends it from the crane's load connector. In some embodiments, this crane is also used to lift the nacelle. Since the rotor blade weighs significantly less than the nacelle, another crane can also be used to install the blade. For example, in an onshore scenario, one or two high-capacity cranes are used to install the nacelle. These one or two cranes are then moved to the next wind turbine in the same wind farm, and another, lower-capacity crane is brought in to install the rotor blades. This approach allows for optimal use of the high-capacity cranes upon completion of the wind farm. For offshore wind turbines in offshore wind farms, a possible approach is to use one vessel equipped with one or two high-capacity cranes to install the nacelle, and possibly the tower, before the nacelle is installed, and then use a second vessel equipped with cranes to install the rotor blades. This second vessel can have a lower-capacity crane, for example, the entire vessel being smaller and / or lighter than the first vessel equipped with one or two high-capacity cranes.

[0028] In one embodiment, to complete a wind farm, multiple wind turbines are equipped with nacelles, each with a corresponding integrated device. These wind turbines are then equipped with at least one rotor blade, or for example, all of their blades. The nacelles can be installed using one or two high-capacity cranes, for example, on a first vessel, while the rotor blades can be installed using lower-capacity cranes, for example, on a second vessel. This allows for optimal use of the first vessel, which, for example, may have a higher day rate than the second vessel.

[0029] An advantage of combining the integrated device described herein with one or two first cranes for installing the nacelle and a second crane for installing at least one rotor blade is that the second crane can be, and preferably is, lighter, e.g., having a lighter boom and a rotating superstructure to which the boom is pivotally mounted. This lighter design can allow for enhanced control over crane motion and / or precision compared to the heavy designs required for lifting the nacelle. This enhanced control can be beneficial when installing the blades, for example, in terms of aligning the blade with the blade mounting structure and / or compensating for wind-induced blade motion.

[0030] In the method, a crane is operated to lift the rotor blade to a height capable of securing the blade root to a corresponding blade mounting structure of the hub. In a practical embodiment, the rotor blade is held horizontally throughout the entire process of lifting and securing the rotor blade to the hub. This corresponds, for example, to a method in which the blade is mounted in the so-called three o'clock or nine o'clock position. In another embodiment, as is known in the art, the blade lifting tool is configured to controllably tilt the lifted blade to an inclined orientation, for example, with the blade root pointing upward or downward, for example, at an angle of up to 30 degrees relative to the horizontal.

[0031] In the method according to the invention, a rotor blade, for example a blade root and / or a blade lifting tool, is brought into engagement with a blade positioning assembly of an integrated device still present on the nacelle.

[0032] The blade positioning assembly is then used to position the blade root relative to the blade mounting structure of the hub to secure the blade root to the blade mounting structure. The appropriately positioned blade root is then secured to the blade mounting structure, for example, by introducing bolts on the blade root through bolt holes and applying nuts to secure the blade root to the hub.

[0033] In the method of the invention, after installation of the at least one rotor blade of the wind turbine, the integrated device is disconnected from the nacelle and removed by a crane. Preferably, this is the same crane that has been used to lift the at least one rotor blade.

[0034] The method of the present invention is believed to provide increased efficiency when installing wind turbines onshore or offshore.

[0035] Since the nacelle lifting structure needs to be strong and robust to fulfil its function of lifting the (very) heavy nacelle, in an embodiment the lifting structure may form a stable base for the blade positioning assembly. Forces that may arise during blade installation will most likely be of limited magnitude and can be easily absorbed by the nacelle lifting structure.

[0036] In an embodiment, the nacelle lifting structure has a front connector that connects the nacelle lifting structure to the nacelle at the front nose end of the hub. Preferably, the front connector is primarily conceived and / or configured for the purpose of stabilizing the structure relative to the nacelle, and not, or only in a limited manner, as a load transfer connector for lifting the nacelle. Preferably, the nacelle lifting structure has at least two connections to the nacelle at a more rearward position for lifting the nacelle. Possibly, a temporary nacelle lifting load transfer connector is used, which is connected to an anchor point located in the nose of the hub, for example via a hatch located in the nose between adjacent blade mounting structures of the hub.

[0037] In one embodiment, the integrated device, and more specifically its nacelle lifting structure, has an upwardly projecting handle with a shoulder at its upper end. One handle of the integrated device is configured to support the weight of the device and the nacelle when lifted by one or two high-capacity cranes. For possible embodiments and operation of this handle and load connector, see WO 2020 / 055249.

[0038] For example, a blade position assembly of an integrated device may be implemented as disclosed in EP2538073.

[0039] For example, the blade positioning assembly is configured to center the blade root relative to the corresponding blade mounting structure.

[0040] In an embodiment, the blade positioning assembly comprises a blade engaging member that is fixedly mounted, and thus stationary relative to the nacelle, such as a static guide, eg a roller, along which the blade slides when mounting the blade root to the mounting structure.

[0041] In an embodiment, the blade positioning assembly comprises:

[0042] a movable blade engaging member, such as a blade coupling, such as a blade root coupling, configured to be coupled to an outer portion of the blade root,

[0043] - a movement mechanism supporting a blade engaging member, such as a movement arm,

[0044] - A controllable actuator assembly comprising one or more actuators associated with a motion mechanism and a controller, the actuator assembly being configured to provide controlled motion of the motion mechanism so as to controllably move the blade engagement member.

[0045] For example, the centering of the blade root is achieved by a movement mechanism, for example, a movement of the blade coupling in a plane perpendicular to the axis of the rotor blade is provided to achieve the centering of the blade root.

[0046] For example, the kinematic mechanism is configured to provide a controlled displacement of at least the movable blade engagement member in the direction of an axis along which the blade root is to be mounted to the blade mounting structure, for example, a controlled displacement perpendicular to the plane of a pitch bearing of said structure. For example, this embodiment is used for coupling to a blade, for example a blade root, and then controllably moving the blade root towards the blade mounting structure, for example, to introduce bolts protruding axially from the blade root into corresponding bolt holes of the blade mounting structure.

[0047] In an embodiment, during the installation phase, the blade to be mounted to the respective blade mounting structure is held horizontally by the crane and the blade lifting device. This corresponds to a three o'clock or nine o'clock orientation. In another embodiment, e.g. Figure 4-Figure 12 As shown, the blades may be maintained at an angle, for example, of approximately 30 degrees relative to the horizontal.

[0048] For example, the movement mechanism is operated to bring the movable blade engaging member into its receiving position so that a rotor blade lifted by a crane can engage with the movable blade engaging member.

[0049] In one embodiment, the blade coupling is configured as a blade root coupling that engages, for example, clamps around, an exterior portion of the blade root of a rotor blade. In another embodiment, the blade coupling is configured and operable to engage another portion of a rotor blade, for example, an airfoil portion thereof. In yet another embodiment, the blade coupling is configured and operable to couple with a blade lifting tool, for example, an extender member of the blade lifting tool that extends toward the blade root.

[0050] The connection of the blade coupling to the blade, such as the root, can be performed in various ways, for example depending on the design of the blade coupling and / or the blade / blade root. For example, the blade coupling can be connected to the outside of the blade or blade root by magnetic connection, vacuum connection, etc.

[0051] Preferably, the blade coupling constrains the rotor blade at least in its longitudinal direction. Possibly, the blade coupling allows (some) rotation of the blade about its longitudinal axis, for example, by suitable design of the blade lifting tool, for example, by aligning the bolts with the bolt holes. Alternatively, such alignment is achieved by rotation of the mounting structure, for example, via its pitch adjustment mechanism.

[0052] For example, the blade coupling is first moved to its receiving position and coupled to the blade. In an embodiment, the motion mechanism is then operated to displace the blade root of the coupled blade to the blade mounting structure.

[0053] In an embodiment, the blade root coupling is an openable clamp configured to clamp around the blade root of the blade. For example, the clamp has a clamp base that is connected to a motion mechanism, such as an arm, for example, via a Z-axis swing axis. For example, the clamp has one or more movable, such as pivoting, clamp jaws, such as one at each circumferential end of the clamp base.

[0054] In an embodiment, the blade root coupling is an openable clamp, the clamp being configured to clamp around a blade root, eg around a blade root having a diameter of at least 3 meters, eg more than 4 meters.

[0055] The initial coupling of the blade to the blade coupling, e.g. the blade root, is preferably performed at a considerable distance, e.g. a safe distance, from the blade mounting structure of the hub, so as to practically exclude the possibility of impacts between the blade root and the mounting structure or other parts of the nacelle, e.g. the outer shell of the nacelle and / or the generator.

[0056] In an embodiment, the movement mechanism is configured to provide controlled movement of the blade engaging member, eg the blade coupling, in two non-parallel horizontal directions only, thus providing controlled movement in a horizontal plane.

[0057] In an embodiment, the kinematic mechanism is or includes an articulated kinematic arm having a plurality of interconnected arm segments, the plurality of interconnected arm segments including an inner arm segment connected to a frame member of the integrated device and an outer arm segment carrying a blade engagement member, such as a blade coupling, and possibly one or more intermediate arm segments between the inner and outer arm segments. In a practical embodiment, the arm segments are connected to each other via Z-axis hinges. In an embodiment, the kinematic arm provides motion only in two non-parallel horizontal directions.

[0058] In a practical embodiment, all arm segments of the articulated arm are fixed-length arm segments. In another embodiment, one or more arm segments are implemented as telescopic arm segments.

[0059] In an alternative embodiment, the motion mechanism, such as a motion arm, is configured to move in and / or rotate about the X, Y and Z axes, so that motion with multiple, such as four, five or six, degrees of freedom can be achieved for the blade engaging member, such as the blade connector.

[0060] In an embodiment of the method of the present invention, the method comprises:

[0061] - operating the controllable actuator assembly to bring the blade coupling into its receiving position,

[0062] - coupling the blade coupling in the receiving position to a rotor blade, for example to the blade root of a rotor blade lifted by a crane,

[0063] - with the blade coupling coupled to the blade - operating the controllable actuator assembly so as to displace the blade root of the coupled blade to a pre-installed position closer to the blade mounting structure than the receiving position,

[0064] - operating the controllable actuator assembly to perform an installation movement, wherein the blade root is moved from a pre-installation position to an installation position, and to maintain the blade root in the installation position during fixation of the blade root, e.g. during fastening of the blade root to a blade mounting structure by one or more fasteners.

[0065] In an embodiment of the method of the present invention, for example, as discussed in the mentioned scientific article, the tower top is subjected to a movement of the tower top in at least one direction in the horizontal plane caused by sea conditions and / or wind. In an embodiment, the integrated device is configured and operated to perform a method comprising the following steps:

[0066] - operating the controllable actuator assembly to bring and maintain the blade coupling into its motion-compensated receiving position, wherein the motion mechanism is operated to compensate for tower top motion in at least one horizontal direction, such as in multiple horizontal directions, such as in two orthogonal horizontal directions,

[0067] - coupling the blade coupling in the receiving position to the rotor blade lifted by the crane, for example to the blade root of the rotor blade,

[0068] - with the blade coupling coupled to the blade - operating the controllable actuator assembly to gradually cause the coupled blade, e.g. the blade root, to undergo a horizontal movement synchronized with the movement of the tower top and then to maintain the horizontal movement, and

[0069] - possibly simultaneously with said synchronization, operating the controllable motion arm actuator assembly to displace the blade root of the coupled blade to a pre-installation position closer to the blade mounting structure than the receiving position,

[0070] - operating the controllable actuator assembly to perform an installation movement, wherein the blade root is moved from a pre-installation position to an installation position, and to maintain the blade root in the installation position during fixation of the blade root, e.g. during fastening of the blade root to a mounting structure by one or more fasteners.

[0071] In the motion-compensated receiving position, a blade coupling, such as a blade root coupling, substantially compensates for tower top motion through appropriate operation of a controllable actuator assembly, such as, in one embodiment, the folding and extending of a kinematic arm, so that the coupling exhibits no tower top motion. This compensation allows the blade coupling to assume a stationary or stable position in space. This greatly facilitates the process of engaging a suspended rotor blade, such as the outer portion of a blade root, with the blade root coupling. This engagement process can involve operating a crane to move the rotor blade, but can also define a controlled engagement motion of the blade coupling.

[0072] For example, the blade coupling is motion-compensated at such a position that only a slewing movement of the crane, for example without a pitching movement of the crane boom, brings the blade root into position for the initial coupling. Thus, any disturbance of the blade stability caused by the pitching of the crane boom, which in practical implementations can be over 100 meters long, is avoided.

[0073] Once coupling is achieved, the controllable actuator assembly is operated to gradually cause the coupled blade to undergo horizontal movement synchronized with the movement of the tower top and then maintain this horizontal movement.

[0074] In a preferred embodiment, the movement mechanism, for example comprising or embodied as an arm, such as an articulated arm, is configured—under control of the actuator assembly—to selectively apply a force that pulls the blade, such as the root portion, toward the mounting structure and a force that pushes the blade, such as the root portion, away from the blade mounting structure. In an embodiment, this allows for the aforementioned synchronization with the nacelle.

[0075] The use of a blade coupling and an associated kinematic mechanism allows for a controlled, gradual approach of the blade root toward the blade mounting structure (e.g., including a pitch bearing), which is desirable given the large mass of the rotor blade. For example, a rapid or even sudden approach would result in excessive inertia-based forces, e.g., thereby creating an excessively heavy kinematic mechanism, and / or could result in excessive strain at the location where the blade coupling engages the blade, e.g., at the outer portion of the blade root.

[0076] Under some practical conditions, the tower top movement primarily coincides with a horizontally extending installation axis defined by the blade mounting structure during blade installation. When the blade is then preferably lifted by a crane so that the longitudinal axis of the blade coincides with this axis, in embodiments, the movement mechanism can then be operated to synchronize along this axis, thereby synchronizing along the longitudinal axis of the blade suspended from the crane. As will be discussed in more detail below, the blade lifting tool and / or crane can be configured and operated to synchronize the blade with this movement, thereby not being constrained by the crane or being excessively pulled by the crane, for example to avoid or reduce vibrations in the boom caused by synchronization of the blade movement.

[0077] In some practical conditions, as described above, tower top motion has a component that extends perpendicular to the mounting axis, or even completely perpendicular to it. In these cases, the blade root coupling will synchronize the blade roots, but long, heavy blades may not follow this synchronized motion. As will be explained herein, it is preferred that the blade root coupling oscillate about the Z-axis, or vertical axis, to avoid excessive torsional loads on the kinematic mechanism, such as the kinematic arm, caused by the inertia of the massive rotor blades.

[0078] In an embodiment, the method comprises, with the blade root gripper in its motion-compensated receiving position, opening the gripper such that coupling or engaging the blade root comprises resting the blade root on the gripper base, for example by lowering the blade slot of a crane, and then closing the gripper around the blade root by actuating one or more movable, for example pivoting, gripper jaws. For example, the one or more gripper jaws are hydraulically actuated.

[0079] In an embodiment, during the engagement action of the blade root, the kinematic mechanism is operated so that the blade coupling, on the one hand, compensates for the movement of the tower top and, on the other hand, follows the movement, e.g., sway, of the blade root, which is not yet engaged, when the blade is suspended from the crane. It should be noted that such movement of the blade (which effectively makes engagement even more problematic) can also be (partially) counteracted by means associated with the crane and / or the blade hoisting tool. For example, one or more guy wires and associated winches can be employed to counteract the sway of the blade suspended from the crane. For example, the blade hoisting tool can be equipped with means for counteracting the sway, e.g., one or more gyroscopes, thrusters generating air thrust, etc.

[0080] In one embodiment, synchronization of the coupled blade with the tower top movement is achieved before the coupled blade root is shifted to the pre-installation position. For example, the articulating arm initially behaves / operates as a soft, flexible arm to compensate for tower top movement while stabilizing the blade coupling in the receiving position, and then gradually stiffens or becomes more rigid, such that the blade gradually assumes the tower top movement and no longer compensates for it. It will be appreciated that, given the mass of the blade, a gradual reduction in the arm's compensating operation is preferred, so that the blade gradually enters synchronized movement without inducing excessive stress / loads in the process.

[0081] In an embodiment, synchronization of the coupled blade movement with the tower top is at least partially achieved simultaneously with displacing the coupled blade root to the pre-installation position.

[0082] In an embodiment, a rotor blade lifted by a crane is subjected to motion, such as wind-induced motion, such as cyclical motion, in at least one direction in a horizontal plane before being coupled to a blade coupling. For example, wind or gusts may cause the blade to exhibit cyclical motion. In an embodiment, the integrated device is configured and operable to perform a method comprising the following steps:

[0083] - in a case where the blade coupling is not yet coupled to the blade - operating the controllable actuator assembly to gradually cause the blade coupling, such as the blade root coupling, to perform a horizontal movement synchronized with the movement of the blade in at least one direction, such as in a plurality of horizontal directions, such as in two orthogonal horizontal directions, and then to maintain the horizontal movement,

[0084] - coupling the motion-synchronizing blade coupling to the rotor blade, for example to the blade root of the rotor blade,

[0085] - operating a controllable actuator assembly to displace a blade root of the coupled blade to a pre-installed position closer to the blade mounting structure,

[0086] - operating the controllable actuator assembly to perform an installation movement, wherein the blade root is moved from a pre-installation position to an installation position, and to hold the blade root in the installation position during fixation of the blade root, e.g. during fastening of the blade root to a mounting structure by one or more fasteners.

[0087] In this method, before actually being coupled to the blade, the blade coupling is effectively made to follow the blade in (periodic) motion, such as the blade root. Once the coupling is made, a motion mechanism, such as a motion arm, is operated to move the blade root towards the blade mounting structure in a controlled process.

[0088] In an embodiment, the method comprises a verification step performed with the blade root in a pre-installation position and before the installation movement is started, the verification step comprising verifying the synchronization and / or alignment of the blade root with the blade mounting structure. As explained, the consequences of a collision between the blade root, in particular any bolts thereon, and the blade mounting structure or other parts of the hub and / or the nacelle may be violent and irreversible. For example, a collision may damage the blade root, for example a rupture of the laminate structure, such that installation of the blade is no longer possible, for example the blade needs to be shipped back to the factory for repair. The verification step attempts to avoid this situation, for example by accurately measuring the alignment of the blade with the axis along which the installation movement is to be carried out, and / or the position of any bolts and / or temporary guides (for example, which will be replaced by bolts later) relative to the mounting structure, for example, using measuring equipment.

[0089] In one embodiment, a crane used in the lifting of a rotor blade has a boom and is equipped with a load connector active position control system configured and operable to actively control the position of the load connector relative to the boom in at least one horizontal direction, preferably in at least two non-parallel horizontal directions. Examples of cranes with this capability are disclosed in WO2019156556, WO2018199743, and WO2018106105. In one embodiment, a method includes operating the crane's load connector active position control system synchronously with the blade connector when the blade connector is coupled to the blade, for example, when the blade root connector moves synchronously with the tower top movement, for example, when the blade root is controllably advanced toward a pre-installation position and / or installation position. This method effectively seeks to reduce or eliminate the effects of the blade's suspension from the crane interfering with the moving arm and / or applying excessive loads or stresses to the moving arm. In one embodiment, the load connector active position control system is configured and operable to move the blade lifting tool synchronously with the tower top movement, for example, in at least one horizontal direction, and possibly in two non-parallel directions in the horizontal plane.

[0090] In an embodiment, a blade lifting tool comprises a frame attached to a load connector of a crane involved in the installation of a rotor blade, wherein the blade lifting tool comprises a blade holding assembly movably mounted relative to the frame, e.g., movable relative to the frame in at least one horizontal direction, e.g., along the length of a rotor blade held by the blade holding assembly, preferably movable in two non-parallel horizontal directions, wherein the blade lifting tool comprises a controllable motion actuator arrangement between the frame and the blade holding assembly. For example, the method comprises operating the controllable motion actuator arrangement to move the blade holding assembly relative to the frame, e.g., synchronously with the blade coupling when coupled to an exterior portion of the blade root.

[0091] For example, a blade lifting tool includes an active center of gravity (COG) balancing system having a counterweight movably mounted relative to a frame and a controlled motion actuator arrangement between the frame and the counterweight, wherein the method includes moving the counterweight relative to the frame so as to maintain a common center of gravity of the blade mass and the blade lifting tool stable in a horizontal plane as the blade holding assembly and a blade held thereby move relative to the frame.

[0092] In an embodiment, one or more sensors are used, the one or more sensors measuring the distance and / or position and / or angular orientation of the blade root relative to the mounting structure, for example, the one or more sensors are linked to a controller of a controllable motion arm actuator assembly and / or a load connector active position control system and / or a controllable motion actuator device that moves the blade holding assembly relative to the frame.

[0093] In an embodiment, the method comprises controlling the motion mechanism using a control unit, for example operated by an operator present in or on the nacelle or on a platform or cabin on or near the nacelle.

[0094] In one embodiment, communication means are provided to enable communication between a controller of the kinematic mechanism of the blade positioning assembly and a crane involved in lifting the rotor blade, such as a crane controller and / or crane drive. Alternatively or additionally, such communication may occur with a blade lifting tool involved in lifting the rotor blade. For example, the controller may communicate with a load connector position control system, for example in two directions, for multi-axis (e.g., xyz) control of the position of a load connector of a crane used to lift the rotor blade.

[0095] In one embodiment, the blade positioning assembly is provided with one or more force sensors configured to measure the forces exerted by the rotor blade on the assembly or its components. For example, force feedback is used to control the operation of a crane and / or blade lifting tool involved in lifting the rotor blade. The force feedback can be automatically processed and / or signaled to the crane driver, for example, to provide a warning signal when one or more forces become excessive.

[0096] In an embodiment, the blade positioning assembly may be provided with one or more sensors configured to provide a signal, such as a feedback signal, for controlling the operation of a crane and / or a blade lifting tool involving lifting of the rotor blade.

[0097] In an embodiment, after completing fastening of the rotor blade to the hub of the wind turbine, the blade engagement member, such as a blade coupling, is released from the blade, such as from the blade root, and the movement mechanism is then operated to move into its retracted configuration, wherein clearance is provided for the mounted rotor blade during rotation of the hub, and in this way another of the blade mounting structures is brought into position for mounting another rotor blade to the wind turbine.

[0098] In an embodiment, the method includes an emergency away routine, wherein, for example in the event of an abnormality in power and / or control signals, such as a power outage, and / or in the event of abnormal wind conditions and / or sea conditions, such as gusts, abnormal waves, etc., the motion mechanism is operated to quickly move the blade root away from the nacelle.

[0099] The invention further relates to an integrated device configured for nacelle lifting and for blade positioning, the integrated device having a nacelle lifting structure and a blade positioning assembly.

[0100] An integrated device may have one or more features as discussed herein.

[0101] The invention also relates to the use of the integrated device in the installation of a wind turbine.

[0102] The present invention further relates to a vessel carrying a plurality of nacelles, each nacelle being configured to be mounted on a respective offshore wind turbine tower, such as a respective offshore wind turbine tower of an offshore wind farm, wherein each nacelle is pre-assembled with an integrated device configured for nacelle lifting and blade positioning, the integrated device comprising a nacelle lifting structure and a blade positioning assembly. For example, the vessel is a ship having one or two cranes for lifting the nacelles, or a dedicated transport vessel, such as a barge. BRIEF DESCRIPTION OF THE DRAWINGS

[0103] The present invention will now be discussed with reference to the accompanying drawings. In the drawings:

[0104] Figure 1 The top of an offshore wind turbine with an integrated device according to the invention for mounting rotor blades is schematically shown in a view from the front of the nacelle.

[0105] Figure 2 The use of the integrated device according to the invention in the installation of a rotor blade is schematically shown in a top view.

[0106] Figure 3 Schematically shows the installation of a rotor blade with the integrated device of the present invention and a blade lifting tool for lifting the rotor blade,

[0107] Figure 4 Another embodiment of the integrated device and the nacelle of the present invention is schematically shown,

[0108] Figure 5 Shown is the installation on the nacelle Figure 4 integrated device,

[0109] Figure 6 Shown Figure 5 The connection between the integrated device and the cabin,

[0110] Figure 7 shows the nacelle having been lifted and secured to the top of the tower of a wind turbine, wherein the integrated device remains on the nacelle after having been disconnected from the crane,

[0111] Figure 8 Shown Figure 4-Figure 7 The operation of the blade positioning assembly of the integrated device in installing the rotor blades,

[0112] Figure 9 shows the rotation of the hub after the rotor blades have been fastened to the corresponding blade mounting structures of the hub,

[0113] Figure 10 shows the operation of the blade positioning assembly when installing the second rotor blade,

[0114] Figure 11 shows the rotation of the hub after the second rotor blade has been fastened to the corresponding blade mounting structure of the hub,

[0115] Figure 12 shows the operation of the blade positioning assembly when installing the third rotor blade,

[0116] Figure 13 shows the integrated device being removed from the nacelle once installation of the rotor blades is complete, and

[0117] Figure 14 The top of the wind turbine is shown when installation of the wind turbine is complete and the wind turbine is ready to generate electricity. DETAILED DESCRIPTION

[0118] exist Figure 1 The top of a wind turbine is schematically shown in FIG. A wind turbine comprises:

[0119] a foundation (not shown), for example fixed to the seabed, such as a monolithic pile foundation or a jacket foundation, or a floating foundation,

[0120] - a tower 2, which is mounted on a base and has Figure 1 The top of the tower shown in

[0121] - A nacelle 3 , which is located on top of the tower.

[0122] The nacelle 3 is provided with a horizontal axis hub 4 having a plurality of blade mounting structures 5a, 5b, 5c, here three, each blade mounting structure being configured for securing a rotor blade 7, 8 thereto.

[0123] As is known in the art, the mounting structures 5a, b, c may each include a pitch bearing, thereby allowing the pitch of the rotor blades to be adjusted by a pitch regulator mechanism.

[0124] As is known in the art, the rotation of the hub 4 causes the generator of the nacelle 3 to generate electricity. The generator may be, for example, a direct drive generator. In another embodiment, the drive train of the generator includes a gearbox.

[0125] Now refer to Figure 1-Figure 3 To illustrate the method of the present invention.

[0126] As mentioned above, the nacelle 3 is large and heavy and at least one large capacity crane (not shown) is used in order to lift the nacelle 3. The crane has a load connector 75, here a crane hook 75, suspended from a winch drive cable of the crane.

[0127] To install an offshore wind turbine at an offshore location, a crane is mounted on a vessel, such as a jack-up vessel or a floating vessel, such as a semi-submersible vessel. Optionally, the nacelle 3 is transported to the wind turbine site on the same vessel. Alternatively, the nacelle 3 is transported to the site on a different vessel, such as a barge or other supply vessel.

[0128] In the method of the invention, for lifting the nacelle 3 to the tower top, an integrated device 100 is used which is configured not only for nacelle lifting but also for blade positioning during the stage or progress of mounting the rotor blades to the hub of the nacelle.

[0129] The integrated device 100 has a nacelle lifting structure 110 and a blade positioning assembly 130 .

[0130] The nacelle lifting structure 110 is configured to support the weight of the nacelle 3 when the nacelle 3 is lifted by a crane.

[0131] The blade positioning assembly 130 is used to assist and / or control the positioning of the blade relative to the blade mounting structure during the installation process of the blade.

[0132] In order to lift the nacelle 3, the integrated device 100 is here suspended from the load connector 75 of the crane by means of a sling 80. Other connections to the load connector of the crane are also possible, e.g. Figure 4 shown.

[0133] The method comprises connecting the integrated device 100 to the nacelle 3, then lifting the nacelle 3 to the top of the tower 2 by a crane and subsequently securing the nacelle 3 to the top of the tower. Various ways of connecting the device 100, and in particular its structure 110, to the nacelle 3 are discussed herein.

[0134] After fastening the nacelle 3 to the top of the tower 2 , the load connector 75 of the crane is disconnected from the integrated device 100 , which then remains connected to the nacelle 3 .

[0135] The integrated device 100 is configured to have a stable position relative to the nacelle 3 at least when disconnected from the load connector 75 of the crane.

[0136] For installing the rotor blades 7, 8, preferably a blade lifting tool 20 is used, which holds the rotor blade 8 and is suspended from the load connector of a crane, which for example has also been used for lifting the nacelle, but can be suspended from the load connector of another crane, for example a crane installed on another second vessel.

[0137] The crane is operated to lift the rotor blade 8 to a height enabling the blade root to be fixed to the corresponding blade mounting structure 5 c of the hub 4 .

[0138] During the blade installation phase of the method, the rotor blade 8 , for example the blade root 8 a , is brought into engagement with the blade positioning assembly 130 of the integrated device 100 present on the nacelle 3 .

[0139] The blade positioning assembly 130 is used to position the blade root 8a relative to the blade mounting structure 5c of the hub 4 using bolts 10 to secure the blade root 8a to the blade mounting structure 5c. The positioned blade root 8a is then secured to the blade mounting structure 5c, for example, by inserting the bolts 10 through corresponding bolt holes in the structure 5c and then attaching nuts to the bolts 10.

[0140] After all rotor blades 7 , 8 of the wind turbine have been installed (here three), the integrated device 100 is disconnected from the nacelle 3 and then removed by a crane (eg a crane that has also been used for lifting the rotor blades).

[0141] The integrated device 100 is configured to have a stable position relative to the nacelle, at least when disconnected from the load connector of the crane that lifts the nacelle. This stable position is required in order to allow for the use of the blade positioning assembly 130 of the integrated device 100 during subsequent rotor blade installation. The stable position can be provided in a number of different ways, for example, by rigidly connecting the integrated device 100 to the nacelle, for example, to an anchoring point (also referred to as a hardpoint) of the nacelle 3. For example, a removable rigid connector 101 is provided between the device 100 and the anchoring point of the nacelle. The rigid connector can include, for example, a connecting rod that is resistant to tensile loads.

[0142] The stable position of the device 100 can also be provided by a stabilizing member that is used to stabilize the integrated device relative to the cabin, for example, the stabilizing member 102 is distinct from the load transfer connector member 101. For example, as in the prior art, a sling is used as the load transfer connector member 101 together with an additional stabilizer member for stabilizing the integrated device. For example, one or more stabilizer members can be operated between an inactive state and / or position and an active state and / or position. For example, the integrated device 100 is provided with one or more operable stabilizers.

[0143] In one embodiment, stabilization of the integrated device 100 is achieved by one or more stabilizers engaging only on the nacelle 3. In another embodiment, the integrated device is configured to provide a stable position by, for example, engaging on the top end of a tower in addition to the nacelle. For example, see WO 2006 / 076920, in which a nacelle hoisting tool is provided with one or more movable stabilizer arms engaging on the top end portion of a tower.

[0144] In the figures, the blade positioning assembly 130 is shown to the side of the nacelle 3. Other locations of the assembly 130 are possible, for example generally above the nacelle 3, for example extending above the nose of the hub where the mounting structures 5a, 5b, 5c are provided.

[0145] In the figures, it is shown that the integrated device 100 may include a counterweight 105 opposite a blade positioning assembly 130 .

[0146] In an embodiment, the integrated device 100 has a front connection piece that is connected to the nacelle 3 at the front nose end of the hub, such as an anchor point at said location. For example, here, the integrated device also has two further rear connections to the nacelle.

[0147] exist Figure 1 , two of the three blades 6, 7 are shown already mounted on the hub 4. It should be noted that at this stage the load connector 75 has been disconnected from the integrated device 100, for example to allow the same crane to be used to lift the rotor blades to be installed, or to allow a vessel with a nacelle lifting crane to be moved away from that particular wind turbine and a second vessel with a rotor blade lifting crane to be positioned near that particular wind turbine.

[0148] In the installation of the blades 6, 7, as is also known in the art, a vessel provided with a crane may be used, the crane having a load connector suspended from a cable driven by one or more winches of the crane, wherein a blade lifting tool 20 attached to the load connector engages the rotor blade 8 in a horizontal orientation. Figure 3 It is preferably shown that the center of gravity (COG) of the blade 8 is located within the area where the tool 20 holds the blade 8 .

[0149] Similar to the blade 8 , each rotor blade has a blade body with a blade root 8 a , a blade tip, a length and a rotor blade weight.

[0150] The blade root 8a has an outer portion and is configured to be fixed to a blade mounting structure 5c of a hub of an offshore wind turbine in the mounted position of the blade root 8a by one or more fasteners, such as bolts 10 protruding from the root as is known in the art. For example, the structure 5c has bolt holes into which the bolts are introduced and after which nuts are fastened on the bolts.

[0151] A crane is operated to lift the blade lifting tool 20 and thereby the rotor blade 8 from the deck and / or storage rack of a vessel or from a barge to a height substantially flush with the blade mounting structure 5c of the offshore wind turbine, e.g. while holding the blade lifting tool 20 and thereby the rotor blade 8 in a horizontal orientation.

[0152] The blade mounting structure 5c to which the blade 8 is mounted is oriented horizontally and is therefore at either the 3 o'clock or 9 o'clock position.

[0153] The figures show that the integrated device 100 includes a blade positioning assembly 130, and more specifically includes an advanced blade motion synchronization and positioning assembly 130, which includes:

[0154] a base frame 131 , which is integral with or fixed to the nacelle hoisting frame structure 110 of the integrated device 100 ,

[0155] a blade coupling, here a blade root coupling 132 , which is configured to be coupled to the outside of the blade root 8 a ,

[0156] - a movement mechanism, here a movement arm 140 , located between the base frame 131 and the blade coupling 132 ,

[0157] - A controllable actuator assembly comprising a controller 160 and one or more actuators 150 , 151 , 152 associated with the motion mechanism, the assembly being configured to provide controlled motion of the motion mechanism.

[0158] For example, in case of wind turbines installed offshore, the tower top is subject to sea state and / or wind induced tower top movements in at least one direction in the horizontal plane, eg as discussed in detail in the documents mentioned in the introduction.

[0159] The illustrated motion arm 140 is an articulated motion arm having a plurality of interconnected arm segments including an inner arm segment 141 connected to the base frame 131 and an outer arm segment 142 carrying the blade coupler 132 .

[0160] Inner arm segment 141 is connected to base frame 131 via z-axis hinge 143 .

[0161] In this embodiment, the base frame 131 has a vertically adjustable coupler member 131 c, here guided on a vertical beam 131 d of the base frame, and an associated height adjustment actuator 131 e, which allows setting the height of the arm 140 and thereby the blade root coupler 132. The inner arm section 141 is connected to the coupler member 131 c via a vertical axis hinge 143.

[0162] The arm segments 141 , 142 are connected to each other via a Z-axis hinge 144 .

[0163] In this example, the arm segments 141 , 142 are rigid arm segments having a fixed length.

[0164] In order to control the (pivoting) movement of the arm segment 141 relative to the base frame, an actuator 150 is provided.

[0165] In order to control the (pivoting) movement of the arm segment 142 relative to the arm segment 141 , an actuator 151 is provided.

[0166] The blade root coupling 132 is carried on an outer arm section 142 of the kinematic arm so as to pivot relative to the kinematic arm at least about a Z-axis swing pivot 145, e.g., freely pivoting or provided with a damping device, thereby allowing a rotor blade 8 suspended from a crane to swing about the Z-axis swing axis when coupled to the blade root coupling 132. As a result, the coupling 132 is movable relative to the tower top in two non-parallel directions in a horizontal plane.

[0167] The blade root coupling 312 is shown to be an openable clamp configured to clamp around the blade root 8a.

[0168] The gripper has a gripper base 132b connected to the motion arm via a Z-axis swing shaft 145 and has one or more pivoting gripper claws 132c, for example one at each circumferential end of the gripper base 132b.

[0169] As an example, the gripper base 132 is shown articulated not only about the vertical swing axis 145 but also about the horizontal swing axis 146. To this end, the coupling 132 includes a subframe 132a between the arm (here, via the section 142 of the swing axis 145) and the base 132b. The subframe 132a swings about the axis 145, and the base 132b swings relative to the subframe 312a about the horizontal axis 146. For example, actuator 146a controls the swinging motion of the base 132a about the horizontal (swing) axis 146. Similarly, actuator 152 controls the swinging motion about the vertical axis 145.

[0170] exist Figure 1 In FIG. 1 , the blade 8 has been correctly installed, so the clamp 132 has been opened.

[0171] The clamp 132 can be opened so that coupling of the blade root 8a comprises placing the blade root on the clamp base 132b, here also on one of the jaws 132c, and then closing the clamp by actuating one or more pivoting clamp jaws 132c.

[0172] Mounting the blades 8 to the hub 4 includes:

[0173] - operating the controllable actuator assemblies 150, 151, 152, 160 to bring and maintain the blade coupling 132 into its motion-compensated receiving position, e.g. Figure 2 shown or slightly outward, wherein the motion arm 140 is operated to compensate for the tower top motion,

[0174] - coupling the blade coupling 132 in said receiving position to a rotor blade, here to the blade root 8a of a rotor blade suspended from a crane substantially flush with the mounting structure 5c of the hub of the wind turbine,

[0175] - with the blade coupling 132 coupled to the blade root 8a - operating the controllable actuator assemblies 150, 151, 152, 160 so as to gradually cause the coupled blade, e.g. the blade root 8a, to undergo a horizontal movement synchronized with the tower top movement and then maintain this horizontal movement, and

[0176] - possibly simultaneously with said synchronization, operating the controllable actuator assembly 150, 151, 512, 160 to displace the blade root 8a of the coupled blade to a pre-installed position (pm, see Figure 2 ),

[0177] - operating the controllable actuator assemblies 150, 151, 152 to perform a mounting movement, wherein the blade root 8a is moved from the pre-mounting position pm to the mounting position (see Figure 3 ), and holds the blade root 8a in the mounted position during fastening of the blade root to the mounting structure 5c by means of one or more fasteners 10.

[0178] It should be noted that Figure 3 The retracted position of the arm 140 is also shown.

[0179] In an embodiment, synchronization with the tower top movement is achieved before the blade root 8a of the coupled blade is displaced to the pre-installation position by operation of the arm 140 .

[0180] In an embodiment, the method comprises a verification step, which is performed when the blade root 8a is in the pre-installation position pm and before starting the installation movement, here in the axial direction of the blade 8, as defined by the extension of the bolts 10 and their introduction into the bolt holes of the mounting structure 5c, the verification step consisting in verifying the synchronization and / or alignment of the blade root with the mounting structure.

[0181] Verification may require the use of one or more position detectors, eg contactless, eg from the nacelle to the blade root, such as cameras, radar, infrared distance measurement and / or satellite-based position sensing.

[0182] Preferably, in an embodiment, the crane for lifting the rotor blade 8 has a boom, and the crane is provided with a load connector active position control system, which is configured and operated to actively control the position of the load connector relative to the boom in at least one horizontal direction, preferably two non-parallel horizontal directions, wherein the method includes operating the load connector active position control system synchronously with the blade coupler 132, for example the blade root coupler when coupled to the outside of the blade root 8a.

[0183] In an embodiment, a blade lifting tool 20 comprises a frame 21 attached to a load connector of a crane, wherein the blade lifting tool comprises a blade holding assembly 22 movably mounted relative to the frame, e.g., movable in at least one horizontal direction relative to the frame, e.g., along the length of a rotor blade 8 held by the blade holding assembly, preferably movable in two non-parallel horizontal directions, and wherein the blade lifting tool comprises a controllable motion actuator arrangement 23 between the frame and the blade holding assembly. In an embodiment, the method comprises operating the controllable motion actuator arrangement 23 to move the blade holding assembly 22 relative to the frame 21 in synchronization with the blade coupling 132 when coupled to the blade 8 as discussed.

[0184] Preferably, one or more sensors are used which measure the distance and / or position and / or angular orientation of the blade root 8a relative to the mounting structure, for example, said one or more sensors being linked to a controller 60 of a controllable motion mechanism actuator assembly and / or a load connector active position control system and / or a controllable motion actuator device 23 which moves the blade holding assembly 22 relative to the frame 21 of the blade lifting tool 20.

[0185] For example, the method comprises controlling the motion arm 140 using a control unit, for example operated by an operator present in the nacelle 3 .

[0186] Figure 2It is shown that after completing the fastening of the rotor blade 8 to the hub 4 of the offshore wind turbine, a blade coupling 132, for example a blade root coupling, is released from the blade root 8a and then the movement mechanism, here the arm 140, is operated to move to a retracted configuration, wherein clearance is provided for the mounted rotor blade during rotation of the hub, in order to bring another of the mounting structures into position for mounting another rotor blade to the offshore wind turbine.

[0187] As discussed, the method may include, for example, an emergency away routine programmed into the controller 160, wherein, for example in the event of an abnormality in power and / or control signals and / or in the event of abnormal wind conditions and / or sea states, the movement mechanism, here the arm 140, is operated to quickly move the blade root 8a away from the nacelle 3.

[0188] As discussed, when blade 8 is suspended from a crane via hoisting tool 20, some (residual) movement of the rotor blade may still occur, even when other measures are in place to counteract blade movement, such as guy wires. For example, in the horizontal plane, oscillatory rocking of the rotor blade about the Z axis is often observed via the crane's load connector. Other motions are oscillations in the vertical plane about the horizontal axis, typically at the point where hoisting tool 20 is suspended from the crane, in plane X motion along the rotor blade's length, and / or in plane Y motion transverse to the rotor blade's length. This motion is typically wind-induced, but crane motion (e.g., boom vibration) can also be a factor due to the blade's significant mass and the length of the crane boom required for installation. This motion of blade 8 can be the cause of undesirable loads / stresses on the kinematic mechanism, here, arm 140, coupler 132, and / or the location where the coupler engages blade 8, such as at the root. In this regard, providing a swinging support for coupler 132 relative to the mechanism (here, arm 140) alleviates or reduces this problem.

[0189] As mentioned in the cited document, the wind direction can be the same as the wave direction, but they can also be different and not coincident, for example, the waves are still in the direction of the earlier strong wind, when the force decreases and the direction changes. The assembly 130 shown also allows to effectively handle such situations. As mentioned in the cited document, the periodic tower top movements can have a significant amplitude, for example greater than 0.5 meters, or even greater than 1 meter. Considering the precision required to introduce the multiple bolts 10 into their bolt holes, the use of the arm 140 is very effective and at least expands the operating window for blade installation compared to the prior art methods. As discussed, the collision of the bolts 10 can lead to damage to the bolts and / or to the structure of the blade root, for example, which is made of composite material, for example in the form of internal cracks.

[0190] The bolt 10 may be a T-bolt as is known in the art. Other fasteners may also be used.

[0191] During installation, the advancement of the blade 8 by the kinematic mechanism (here the arm 140) can be accompanied by corresponding operation of the crane, for example, such that the suspension point from the crane follows the movement controlled by the arm. For example, the crane follows this movement primarily by slewing the boom about a vertical slewing axis and / or by operating a load connector position control system for xy (and possibly also -z) control of the position of the load connector carrying the blade lifting tool 20.

[0192] The vessel on which the crane is mounted for lifting the rotor blades can be floating, but can also be a jack-up vessel so that the crane is not affected by the motion of the vessel. The crane can also be stabilized, for example mounted on a motion-stabilized platform on a floating vessel.

[0193] In an embodiment, an optical (eg, laser-based) guidance system is provided for controlling the path of the blade coupling relative to the mounting structure to which the blade is to be mounted.

[0194] In an embodiment, the blade root coupler 132 frictionally couples to the exterior of the blade root, for example when the root is clamped by a gripper, such as a friction pad, such as a pneumatic friction pad. Coupling to the blade, such as the blade root, may also involve the use of vacuum, magnetism, etc.

[0195] In an embodiment, the load connector position control system of the crane is operated to align and maintain the longitudinal axis of the blade with the installation axis, and therefore also with the direction of the bolt 10 when it is present, preferably when in the fixed receiving position, and / or when moved to the pre-installation position, or when in the installation position.

[0196] In an embodiment, an angle sensing assembly is present to detect the angle between the mounting axis and the longitudinal axis of the blade, eg the angle in the horizontal plane between the blade root coupling and the motion arm (eg the outer section of the arm).

[0197] In the blade root coupling 132 there may be a blade root engaging member which is elastically mounted and / or associated with a positioning device, for example, thereby allowing adjustment of the coupling 132 according to the transverse dimensions of the blade, for example according to the diameter of the blade root.

[0198] After fastening the blade root to the mounting structure, the blade root coupler 132 is opened and disengaged from the blade root 8a, which involves moving the kinematic mechanism, here the arm 140, to its retracted position so that the hub can be rotated to bring another mounting structure to a horizontal position for mounting the next blade to the hub.

[0199] It should be noted that the motion mechanism can also be implemented in a form different from that shown in the figure. For example, the motion mechanism 140 may include a parallelogram mechanism that acts in a vertical plane and is a motion platform supported by the parallelogram mechanism, such as an XY-θ motion platform. For example, the parallelogram or four-bar linkage is connected to the base frame via a vertical axis hinge and can be rotated or swung around the hinge by an actuator. A motion platform, such as an XY-θ platform, is mounted at the end of the parallelogram mechanism. The blade coupler 132 is mounted on the motion platform. In an embodiment, the motion mechanism can also function without the rotating parts of the XY-θ platform and can therefore be equipped with an XY platform instead.

[0200] In an embodiment, a sensing component is used for sensing the spatial movement of the blade root 8a, such as an inertial-based sensing component, for example only in the horizontal plane, such as two non-parallel directions, such as length and transverse to the length, rotation around the Z axis of the load connector, rotation around the Y axis through the load connector, all oscillations.

[0201] In an embodiment, a mass damper may be provided as part of the tower 2 (eg, permanently mounted or temporarily mounted). A mass damper may also be provided as part of the integrated device 100 to (temporarily) reduce tower motion during blade installation.

[0202] For example, a gyro stabilizer is provided in the device 100 .

[0203] For example, gyroscopic stabilizers are present in the blade lifting tool 20 and / or in the load connector of the crane, for example on a spreader from which the tool 20 is suspended.

[0204] In an embodiment, the blade coupler 132 includes one or more slings, e.g., having one or more sling adjustment devices, each sling being configured to engage with a circumferential portion of the blade, e.g., a circumferential portion of the blade root 8a, e.g., the blade root is gradually tightened between a plurality of slings to couple the blade root.

[0205] In an embodiment, communication means are provided to enable communication between a controller 160 of the mechanism 140 and a crane, such as a crane controller and / or a crane drive, and / or a blade lifting tool involved in the lifting of the rotor blade. For example, the controller 160 communicates with a load connector position control system, such as in two directions, for multi-axis (e.g., xyz-axis) control of the position of a load connector of a crane that is lifting the rotor blade.

[0206] In an embodiment, blade positioning assembly 130 is provided with one or more force sensors configured to measure the forces exerted by the rotor blades on assembly 130 or its components. For example, force feedback is used to control the operation of a crane and / or blade lifting tool involved in lifting the rotor blades. The force feedback can be processed automatically or signaled to the crane driver, for example, to provide a warning signal when one or more forces become too high.

[0207] Typically, the blade positioning assembly 130 may be provided with one or more sensors configured to provide signals, such as feedback signals, for controlling the operation of a crane and / or blade lifting tool involving the lifting of the rotor blades.

[0208] In an embodiment, there is automatic operation of a crane to lift a rotor blade installed in unison with the movement mechanism 140, for example when the root 8a is advanced from the receiving position to the pre-installation position and / or when moved from the pre-installation position to the installation position.

[0209] In an embodiment, there is automatic xy control of the crane lifting the rotor blade to align the longitudinal axis of the blade with the mounting axis, for example based on angles sensed by sensors or arm segments on the motion mechanism (e.g., arm 140) and / or sensors on the motion platform.

[0210] In an embodiment, as shown, there is a gimbal mount of the blade root coupling in order to allow a (limited) rotation of the blade root, for example to avoid overloading the kinematic mechanism 140 due to blade movement.

[0211] In an embodiment, a camera is provided which is directed towards the blade root 8a (eg the protruding bolt 10), the image being displayed to an operator and / or used for automatic image processing, eg to avoid collisions and / or issue warning signals.

[0212] As discussed, one or more guy wires of the crane's guy wire system may be used to orient and / or stabilize the hoisting tool 20 and / or blade 8 primarily in a horizontal plane.

[0213] In an embodiment, a so-called high-wind boom lock or other arrangement may be provided to stabilize the load connector relative to the boom of a crane lifting the rotor blade.

[0214] In an embodiment, the integrated device 100 is provided with an integrated power source, such as a battery, a hydraulic power pack, or the like.

[0215] In an embodiment, the apparatus 100 is provided with a fire suppression system.

[0216] In an embodiment, the apparatus 100 is provided with an auxiliary crane, eg to allow lifting of (hand) tools used by personnel working on and in the nacelle during the installation process.

[0217] Figure 4 Another embodiment of the integrated device 100 ′ and the nacelle 3 ′ of the present invention is schematically shown.

[0218] Generally, the apparatus 100 ′ consists of a nacelle lifting structure 110 ′ and a blade positioning assembly 130 ′.

[0219] Figure 4 The integrated device 100 ′ is shown configured to be connected to a load connector 75 , as discussed in referenced WO 2020 / 055249.

[0220] The device 100', and more specifically its nacelle lifting structure 110', has an upwardly projecting handle 111 with a shoulder 112 at the upper end of the handle 111. One handle 111 of the device 100' is configured to support the weight of the device 100' and the nacelle 3' when lifted by one or two high-capacity cranes.

[0221] The load connector 75 includes a plurality of cable pulleys through which one or more winch drive cables pass, such that the load connector 75 is suspended from the one or more winch drive cables in a multi-reel arrangement. The load connector 75 further includes a concave central open body defining a handle receiving channel, the handle receiving channel having a central vertical axis that allows the shoulder 112 of the device 100' to be introduced into the channel from below. A mobile tool holder is provided that is adapted to releasably engage below the shoulder 112 of the handle 111 to suspend the device 100' below the load connector 75. These mobile tool holders are distributed around the handle receiving channel so as to each provide an operative and inoperative position of the mobile tool holder, the mobile tool holder being adapted to - in the inoperative position - allow the handle 111 to be introduced into the receiving channel from below, and - in the operative position - engage below the shoulder 112 of the handle 111 that has been introduced into the channel to suspend the device 100' from the load connector 75. In an embodiment, preferably, a bearing supports the concave center open body in the load connector 75 to allow the concave center open body and the tool holder to swing about a vertical axis, thereby allowing the device 100' and the nacelle 3' held thereby to swing about a vertical axis. In an embodiment, preferably, a rotary drive is provided, which is configured to selectively drive the swinging of the concave center open body and the mobile tool holder mounted thereon, and thereby drive the swinging of the device 100' and the nacelle 3' about the central vertical axis.

[0222] Figure 4The nacelle 3' shown in FIG has two open hatches 3a providing access to anchoring points 3b located within the shell of the nacelle 3' (see FIG. Figure 6 For the sake of clarity, the hub 4' is shown without the blade mounting structure.

[0223] The nacelle lifting structure 110 ′ is depicted as having two rigid connector members 101 ′, here embodied as rods 101 ′, which are configured to be fixed to two anchor points 3 b.

[0224] In the depicted example, the nacelle lifting structure 110' is configured to extend over a nose end of the hub 4' where the blade mounting structures are provided. The bridge portion 1045 of the structure 110' extends over the nose end where the blade mounting structures are provided.

[0225] The structure 110' has a front connection 101' which is connected to the nacelle 3' at the front nose of the hub 4', for example at the anchor point 3c at the location described. As shown in the figure, the integrated device 100' has two further connections 101' to the nacelle 3' located at the rear. When the device 100' is in this position on the nacelle 3', the hub 4' is rotatable.

[0226] In an embodiment, the front connection 101 ″ connecting the nacelle lifting structure 110 ′ to the nacelle 3 ′ at the front nose end of the hub 4 ′ is primarily conceived and / or configured for stabilizing the structure 110 ′ relative to the nacelle 3 ′, and not, or only in a limited manner, as a load transferring connection for lifting the nacelle 3 ′. For example, the load connector is temporarily arranged to engage at an anchor point in the nose of the hub 4 ′ via a hatch 3 d located between adjacent blade mounting structures, e.g. Figure 4 As shown. Once the nacelle 3' has been lifted and secured to the tower top, the load connector is subsequently removed, for example retracted from the hub 4', so that the hub 4' can be rotated during the installation of the rotor blades. Possibly, the load connector associated with the nose of the hub 4' is embodied as a sling, cable, chain, etc., which can be easily disconnected, removed, and / or retracted.

[0227] Figure 5 It is shown that the integrated device 100' has been installed on the nacelle 3'. Figure 6 In the figure, the outer shell of the nacelle 3' has been removed to better illustrate the connection between the connector member 101' of the integrated device 100' and the anchor point 3b of the nacelle 3'. It should be understood that the integrated device 100', and in particular the nacelle lifting structure 110', now remains in a stable position on the nacelle 3'. This stability allows for the proper operation of the blade positioning assembly 130' of the device 100'.

[0228] The nacelle 3' is lifted by one or two cranes to the top of the wind turbine tower 2. The figure shows that the nacelle 3' has been lifted to the top of the tower 2 and then has been fixed to the top of the tower. Figure 7 The integrated device 100' is also shown to remain in a stable position on the nacelle 3' after having been disconnected from the crane. This allows the blade positioning assembly 130' to be used when mounting three rotor blades 6, 7, 8 to the hub 4' of the nacelle 3'.

[0229] As described herein, blade positioning assembly 130' can have various designs and functions.Assembly 130' includes a motion mechanism 140' and an associated actuator assembly with a controller.

[0230] like Figure 8 As shown, the depicted blade positioning assembly 130' is primarily configured to center or centre the blade root of a rotor blade relative to a corresponding blade mounting structure of the hub. As shown, the blade coupling 132' is primarily movable in a plane extending perpendicular to the axis of the rotor blade, here in an orthogonal direction, which allows the blade root to be aligned with the blade mounting structure in this vertical plane.

[0231] Here, the rotor blades 6, 7, and 8 are shown oriented at an angle of 30 degrees relative to the horizontal, with the blade roots pointing downwards for mounting the blades to the hub. For example, a blade lifting tool used in the lifting of the rotor blades allows the blades to be lifted in a horizontal orientation and then tilted to assume an inclined orientation that allows mounting to the hub.

[0232] In another embodiment, the assembly 130' may also have a controlled movement in the direction of the axis of the rotor blade, for example to assist in the controlled displacement of the blade root toward the blade mounting structure, for example during the insertion of the bolts 10 into their corresponding bolt holes on the blade mounting structure. As is known in the art, as an alternative to or in combination with the use of the assembly 130', displacing the blade root toward the hub may also involve the use of a winch and pull-in cable, the operation of a crane to lift the rotor blade, and / or the operation of a suitably designed blade lifting tool.

[0233] The blade positioning assembly 130' can be configured to provide damping for a rotor blade to be attached to a blade mounting structure. For example, the assembly 130' includes an elastic damper or baffle for the blade, such as at the root of the blade. For example, damping is achieved in one or more directions, such as in the longitudinal direction of the rotor blade.

[0234] Damping of blade motion by assembly 130' may be achieved through the design of the kinematic mechanism and / or the operation / design of the associated actuator assembly. For example, there are hydraulic actuator assemblies in which one or more hydraulic throttle components are used to achieve damping of blade motion once engaged by blade coupling 132'.

[0235] Damping of blade motion by assembly 130' may be caused during a specific period, such as during a period of engagement between the blade coupling and the rotor blade, with the damping function then being terminated, e.g., to enable position control of the coupled rotor blade by blade positioning assembly 132', e.g., in view of controlled movement of the blade root toward the blade mounting structure.

[0236] exist Figure 9 , the hub 4 ', equipped with the first rotor blade 6, is shown rotated after the rotor blade 6 has been fastened to the corresponding blade mounting structure of the hub. Rotation of the hub can be achieved in many different ways, for example using a specific drive of the nacelle 3 ', or possibly using a drive 106 present on the integrated device 100 ', for example engaging the nose of the hub. In other embodiments, the rotation is accomplished by a crane that lifts the rotor blade.

[0237] Figure 10 The operation of the blade positioning assembly 130 ′ is shown when installing the second rotor blade 7 . Figure 11 The rotation of the hub 4 ′ is shown after the second rotor blade 7 has been fastened to the corresponding blade mounting structure of the hub. Figure 12 The operation of the blade positioning assembly is shown when the third rotor blade 8 is installed.

[0238] Since all three rotor blades 6 , 7 and 8 are already fixed to the hub 4 ′, there is no need to integrate the device 100 ′ and remove it. Figure 13 Once the installation of the rotor blades is complete, the integrated device 100' is shown removed from the nacelle 3'. The load connector of the crane involved in the removal can be provided with the aforementioned components to allow for coupling with the handle 111 so that the device 100' can be lifted. Other connection arrangements between the crane and the device 100' are also possible during removal, if desired.

[0239] Figure 14 The top of the wind turbine is shown when installation of the wind turbine is complete and the wind turbine is ready to generate electricity.

Claims

1. A method for installing a wind turbine, wherein: A nacelle (3; 3') is mounted on a tower of a wind turbine, the nacelle being provided with a generator and a hub (4; 4') driving the generator, the hub (4; 4') having a plurality of blade mounting structures (5a, 5b, 5c), each blade mounting structure being configured for securing a rotor blade (6, 7, 8) to the hub, and wherein subsequently at least one rotor blade (6, 7, 8) is secured to a respective blade mounting structure of the hub (4; 4'), the rotor blade having a blade body having a blade root (8a), a blade tip and a blade length, wherein the blade root is configured to be secured to the blade mounting structure (5a, 5b, 5c) of the hub, wherein the tower (2) of the wind turbine is mounted on a base and has a tower top, wherein a crane with a load connector (75) is used, Therein, an integrated device (100; 100') configured for nacelle lifting and for blade positioning is used, the integrated device comprising a nacelle lifting structure (110; 100') and a blade positioning assembly (130; 130'), wherein the integrated device (100; 100') is suspended from a load connector (75) of a crane, The method comprises connecting an integrated device (100; 100') to a nacelle (3; 3'), then lifting the nacelle to the top of a tower (2), and subsequently fastening the nacelle to the top of the tower, wherein the method comprises, after fastening the nacelle (3; 3') to the top of the tower (2), disconnecting the load connector (75) of the crane from the integrated device (100; 100'), the integrated device then remaining connected to the nacelle (3; 3'), wherein the integrated device (100; 100') is configured to have a stable position (101, 102; 101'; 104) relative to the nacelle at least when disconnected from the load connector of the crane, wherein, for mounting the rotor blades (6, 7, 8), a crane is used, said crane being operated to lift the rotor blades (6, 7, 8) to a height at which the blade roots can be fixed to the respective blade mounting structures of the hub (4; 4'), wherein preferably, a blade lifting tool (20) is used, said blade lifting tool holding the rotor blades and suspended from a load connector of the crane, wherein the rotor blade (6, 7, 8), for example the blade root (8a), and / or the blade lifting tool engages with a blade positioning assembly (130; 130') of an integrated device (100; 100') present on the nacelle (3), The blade positioning assembly (130; 130') is used to position the blade root (8a) relative to the blade mounting structure (5c) of the hub, so as to fix the blade root to the blade mounting structure. wherein the positioned blade root (8a) is fixed (10) to the blade mounting structure (5c), Therein, after installation of at least one rotor blade (6, 7, 8) of the wind turbine, the integrated device (100; 100') is disconnected from the nacelle (3; 3') and removed by means of a crane, for example, which has also been used to lift the at least one rotor blade (6, 7, 8).

2. The method according to claim 1, wherein The integrated device (100; 100') is rigidly connected to the nacelle (3; 3'), for example to an anchoring point (3b) of the nacelle, and / or wherein the integrated device is provided with a stabilizing member (102; 104), for example a stabilizing member different from the load transfer connector member (101).

3. The method according to claim 1 or 2, wherein: One or two high-capacity first cranes are used for installing a nacelle (3; 3'), and wherein another second crane is used for installing rotor blades (6, 7, 8), wherein the method comprises disconnecting an integrated device (100; 100') from the first crane when installation of the nacelle is completed, wherein the integrated device (100; 100') then remains on the nacelle (3; 3'), and wherein the method comprises disconnecting the integrated device (100; 100') from the nacelle (3; 3') when installation of the blades (6, 7, 8) is completed, wherein the disconnected integrated device (100; 100') is removed by the second crane.

4. The method according to any one or more of claims 1 to 3, wherein: The wind turbine is an offshore wind turbine, wherein a first vessel having one or two first cranes is used to install a nacelle (3; 3'), wherein the method comprises disconnecting the integrated device from the first crane when installation of the nacelle is completed, wherein the integrated device (100; 100') then remains on the nacelle (3), and wherein the first vessel is then moved away from the wind turbine, and wherein a second vessel is positioned close to the wind turbine, the second vessel being equipped with a second crane for installing rotor blades, and wherein the method comprises disconnecting the integrated device (100; 100') from the nacelle (3; 3') when installation of the blades is completed, wherein the disconnected integrated device is then removed by the second crane.

5. The method according to any one or more of claims 1 to 4, wherein: The wind turbine is an offshore wind turbine, wherein a vessel is used which carries a plurality of nacelles (3; 3') configured to be mounted on respective offshore wind turbine towers, wherein each nacelle is pre-assembled with an integrated device (100; 100').

6. The method according to any one or more of claims 1 to 5, wherein: The blade positioning assembly (130; 130') comprises: - a movable blade engaging member, such as a blade coupling (132; 132'), such as a blade root coupling configured to couple to an outer portion of a blade root, - a movement mechanism (140; 140') supporting a blade engaging member, such as a movement arm, - a controllable actuator assembly comprising one or more actuators (150, 151, 152) associated with the motion mechanism and a controller (160), the actuator assembly being configured to provide controlled motion of the motion mechanism to enable controlled movement of the blade engagement member.

7. The method according to claim 6, wherein: The movement mechanism (140) is operated to place the movable blade engaging member in the movable blade engaging member receiving position so that the rotor blade (8) being lifted by the crane engages with the movable blade engaging member in the movable blade engaging member receiving position.

8. The method according to claim 6 or 7, wherein: The blade coupling (132; 132') is configured as a blade root coupling which engages on the exterior of the blade root of the rotor blade, for example clamps around the exterior of the blade root of the rotor blade.

9. The method according to any one or more of claims 6 to 8, wherein: The blade coupling (132) is first moved to its receiving position and then coupled to the rotor blade, e.g. clamping the blade root, and wherein the movement mechanism is then operated to displace the blade root of the coupled blade to the blade mounting structure, e.g. along an axis perpendicular to the plane of the blade mounting structure, e.g. to a pitch bearing of the blade mounting structure.

10. The method according to any one or more of claims 6 to 9, wherein: The method comprises: - operating the controllable actuator assembly to bring the blade coupling into the blade coupling receiving position, - coupling the blade coupling in the receiving position to a rotor blade, for example to the blade root of a rotor blade lifted by a crane, - with the blade coupling coupled to the blade - operating the controllable actuator assembly so as to displace the blade root of the coupled blade to a pre-installed position closer to the blade mounting structure than the receiving position, - operating the controllable actuator assembly to perform an installation movement, wherein the blade root is moved from a pre-installation position to an installation position, and to maintain the blade root in the installation position during fixation of the blade root, e.g. during fastening of the blade root to a blade mounting structure by one or more fasteners.

11. The method according to any one or more of claims 6 to 9, wherein: The tower top is subjected to movement of the tower top in at least one direction in a horizontal plane caused by sea conditions and / or wind, wherein the integrated device is configured and operable to perform a method comprising the steps of: - operating the controllable actuator assembly to bring and maintain the blade coupling into a motion-compensated receiving position of the blade coupling, wherein the motion mechanism is operated to compensate for tower top motion in at least one horizontal direction, such as in multiple horizontal directions, such as in two orthogonal horizontal directions, - coupling the blade coupling in the receiving position to the rotor blade lifted by the crane, for example to the blade root of the rotor blade, - with the blade coupling coupled to the blade - operating the controllable actuator assembly to gradually cause the coupled blade, e.g. the blade root, to undergo a horizontal movement synchronized with the movement of the tower top and then to maintain said horizontal movement, and - possibly simultaneously with said synchronization, operating the controllable motion arm actuator assembly to displace the blade root of the coupled blade to a pre-installation position closer to the blade mounting structure than the receiving position, - operating the controllable actuator assembly to perform an installation movement, wherein the blade root is moved from a pre-installation position to an installation position, and to maintain the blade root in the installation position during fixation of the blade root, e.g. during fastening of the blade root to a mounting structure by one or more fasteners.

12. The method according to any one or more of claims 6 to 9, wherein: The blade lifted by the crane is subjected to movement, such as wind-induced movement, such as cyclic movement, in at least one direction in the horizontal plane before being coupled to the blade coupling, and wherein the integrated device is configured and operative to perform a method comprising the steps of: - in a case where the blade coupling is not yet coupled to the blade - operating the controllable actuator assembly to gradually cause the blade coupling, such as the blade root coupling, to perform a horizontal movement synchronized with the movement of the blade in at least one direction, such as in a plurality of horizontal directions, such as in two orthogonal horizontal directions, and then to maintain said horizontal movement, - coupling the motion-synchronizing blade coupling to the rotor blade, for example to the blade root of the rotor blade, - operating a controllable actuator assembly to displace a blade root of the coupled blade to a pre-installed position closer to the blade mounting structure, - operating the controllable actuator assembly to perform an installation movement, wherein the blade root is moved from a pre-installation position to an installation position, and to hold the blade root in the installation position during fixation of the blade root, e.g. during fastening of the blade root to a mounting structure by one or more fasteners.

13. An integrated device (100; 100') configured for nacelle lifting and for blade positioning, the integrated device comprising a nacelle lifting structure (110; 110') and a blade positioning assembly (130; 130'), wherein: The nacelle lifting structure is configured to support the weight of the nacelle.

14. The integrated device according to claim 13, wherein: The integrated device (100) is provided with a stabilizing member (102), for example a stabilizing member distinct from a load transferring connector member.

15. The integrated device according to claim 13 or 14, wherein: The blade positioning assembly (130) includes: - a movable blade engaging member, such as a blade coupling (132; 132'), such as a blade root coupling configured to couple to an outer portion of a blade root, - a movement mechanism (140; 140') supporting a blade engaging member, such as a movement arm, - a controllable actuator assembly comprising one or more actuators (150, 151, 152) associated with the motion mechanism and a controller (160), the actuator assembly being configured to provide controlled motion of the motion mechanism to enable controlled movement of the blade engagement member.

16. The integrated device according to claim 15, wherein: The movement mechanism (140) is configured to bring the movable blade engaging member into a movable blade engaging member receiving position such that a rotor blade being lifted by a crane can engage with the movable blade engaging member.

17. The integrated device according to claim 15 or 16, wherein: The blade coupling (132; 132') is configured as a blade root coupling which engages on the exterior of the blade root of the rotor blade, for example clamps around the exterior of the blade root of the rotor blade.

18. An integrated device according to any one or more of claims 15 to 17, wherein: The blade positioning assembly (130) is configured to first move the blade coupling (132) to a receiving position of the blade coupling for coupling to a rotor blade (8), and wherein the blade positioning assembly is configured to then operate a motion mechanism for displacing a blade root of the coupled blade to a blade mounting structure of a hub of a nacelle of a wind turbine.

19. Use of an integrated device (100) according to any one or more of claims 13-18 in the installation of a wind turbine.

20. A vessel carrying a plurality of nacelles (3), each of which is configured to be mounted on a respective offshore wind turbine tower, such as a respective offshore wind turbine tower of an offshore wind farm, wherein: Each nacelle is pre-assembled with an integrated device (100; 100') configured for nacelle lifting and for blade positioning, the integrated device (100; 100') having a nacelle lifting structure (110; 110') and a blade positioning assembly (130; 130'), such as for use in the method of any one or more of claims 1-12.

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