Nacelle for a wind turbine

Abstract

A wind turbine nacelle configured to be mounted on a wind turbine tower and to support a rotor support assembly, the nacelle including a main unit and at least one auxiliary unit. The auxiliary unit houses at least one component, such as an inverter or a transformer. To provide efficient transportation, lower costs, and easier assembly, the working components are directly suspended from the main unit.

Description

Technical Field

[0001] The present disclosure relates to a nacelle for a wind turbine. The nacelle includes a main unit and at least one auxiliary unit mounted on a side of the main unit. The nacelle of the present disclosure is particularly suitable for large wind turbines. The present disclosure further relates to a method for manufacturing a wind turbine including such a nacelle. Background Art

[0002] In terms of rated power output and in terms of the physical dimensions of the various components of a wind turbine, the size of wind turbines is continuously increasing. Accordingly, the size of the nacelle must also be increased to accommodate the required wind turbine components. Wind turbines are typically transported from the manufacturing location or locations of the various components to the work site where the wind turbine is to be erected by road, rail, ship, or a combination thereof. Summary of the Invention

[0003] An object of embodiments of the present disclosure is to facilitate further modularization, ease of design and manufacture, and allow for improved maintenance of the wind turbine. Another object of embodiments of the present disclosure is to provide a nacelle that can be transported using common transport means and reduce transportation and handling costs without limiting the possible size of the nacelle.

[0004] In accordance with these and other objects, the present disclosure provides a wind turbine nacelle configured to be mounted on a wind turbine tower and support a rotor support assembly. The rotor support assembly supports a rotor that drives a generator. In addition, the nacelle houses a power conversion assembly.

[0005] The nacelle includes:

[0006] a main unit that can be connected to the wind turbine tower, for example via a yaw device, and that houses the rotor support assembly and optionally a generator, and

[0007] at least one auxiliary unit that houses working components forming part of the power conversion assembly.

[0008] The main unit and the auxiliary unit are independent units assembled by a unit fixing structure at an interface, and the working components are directly suspended from the main unit.

[0009] Since the auxiliary unit houses working components directly suspended from the main unit, and since the main unit can be connected to the wind turbine tower, the main unit forms a load path for the working components into the wind turbine tower.

[0010] If desired, the auxiliary unit can be released from the main unit without releasing the working part, and the auxiliary unit can be designed for a smaller load compared to the main unit. It can for example be dimensioned and designed for storage and transport of the working part, but not for carrying the full load of the working part on the tower.

[0011] Examples of the main unit and / or the auxiliary unit include units of any size and shape and configured to be assembled.

[0012] The auxiliary unit and / or the main unit can be formed to have a size and / or shape comparable or equal to the size and outer shape of a shipping container. Each unit thus inherits the advantages of a shipping container with respect to handling, transportation, and storage. Shipping containers can for example be handled anywhere in the world by ship, train, and truck, etc., and are less costly compared to bulk transportation.

[0013] When the main unit and / or the auxiliary unit is a shipping container, the cost savings are even more significant. Shipping containers are also known as intermodal containers, standard cargo containers, box containers, marine containers, or ISO containers, and generally refer to containers for storing and moving materials and products in the global containerized intermodal transportation system for intercontinental traffic. Shipping containers can follow the size and structural specifications in the ISO standard ISO 668:2013 for series 1 freight containers.

[0014] The main unit and the auxiliary unit can be arranged side by side in a direction away from the axis of rotation defined by the rotor support assembly, rather than one after another in the direction of the axis of rotation.

[0015] In one embodiment, the nacelle includes for example two auxiliary units arranged on opposite sides of the main unit. In this embodiment, each of the two auxiliary units can have half the size of one shipping container following the size and structural specifications in the ISO standard ISO 668:2013 for series 1 freight containers, and is arranged such that these two halves of the container can be assembled during transportation to form one container, and are divided into two auxiliary units to be arranged on opposite sides of the main unit. The container can specifically be divided at an interface extending along the longitudinal direction of the container (i.e., the longest dimension of the container).

[0016] The nacelle can be carried directly by the tower or indirectly by the tower via an intermediate tower structure. If the wind turbine is of the conventional horizontal axis type, the nacelle is typically carried by a yaw device between the top of the tower and the nacelle. However, the present disclosure can also relate to the following type of multi-rotor wind turbine, in which more than one nacelle is carried by a crossbeam structure, which in turn is carried by the tower via a yaw device between the tower and the crossbeam structure.

[0017] The present disclosure can relate to an upwind wind turbine or a downwind wind turbine.

[0018] The main unit is a component that directly or indirectly connects the nacelle to the tower via the intermediate tower structure or a plurality of intermediate tower structures. The main unit can in particular be the central part of the nacelle and accommodate parts of the drivetrain, for example at least a part of the rotor shaft.

[0019] The wind turbine can be a direct drive wind turbine in which the generator is typically placed outside the nacelle, or the wind turbine can be one in which the generator is located in the main unit. The main unit supports the rotor via the rotor shaft.

[0020] Depending on the type of wind turbine, the main unit can include additional components, such as a gearbox, a bearing system, and various types of peripheral equipment for lubrication, cooling, and control purposes, for example. The main unit can specifically include a main frame, which forms part of the rotor support assembly and forms a load path from the rotor into the tower or the intermediate tower structure, for example via a yaw device. The main frame can in particular be a cast component.

[0021] In addition to the main frame, the rotor support assembly can include, for example, a bearing structure and other components that support the rotor in the wind turbine.

[0022] The working components accommodated in the auxiliary unit can in particular be directly suspended from the main frame, i.e., such that the main frame forms a load path from the working components into the tower. In particular, the working components can be suspended from the main frame via a first suspension structure and can be suspended such that the auxiliary unit does not form part of the load path from the working components into the tower.

[0023] The nacelle can rotate relative to the tower via a yaw device. This can be facilitated by connecting the nacelle to the tower via a yaw device, or in a multi-rotor wind turbine, by connecting at least two main frames of the respective nacelle structures to the tower via the intermediate tower structure, which in turn engages with the tower via a yaw device.

[0024] The nacelle can include a second suspension structure that is configured to suspend the working components on the auxiliary unit.

[0025] The unit fixing structure may be configured to fix the auxiliary unit to the main unit in the assembled position of the auxiliary unit relative to the main unit. The first suspension structure may be configured to take over the suspension of the working part from the second suspension structure when the auxiliary unit moves to the assembled position.

[0026] In one example, the working part is carried on the auxiliary unit, such as on a bottom plate or a wall, by the second suspension structure, and when the auxiliary unit is lowered into the assembled position, the first suspension structure hoists the working part out of the supporting relationship with the auxiliary unit. From that moment on, the working part is suspended on the main frame via the second suspension structure and is preferably freely liftable from the bottom plate of the auxiliary unit.

[0027] In another example, the working part is carried on the auxiliary unit, such as on a bottom plate or a wall, by the second suspension structure, and when the auxiliary unit is in the assembled position, the first suspension structure is attached between the working part and the main frame. At this time point, both the first suspension structure and the second suspension structure support the working part. In some embodiments, the second suspension structure can be removed so that the suspension is achieved only by the first suspension structure directly located on the main frame.

[0028] The first suspension structure may include at least one bracket connected to the working part and the main frame, and each bracket may extend through a corresponding wall opening in the outer wall of at least one of the main unit and the auxiliary unit.

[0029] Each wall opening may have a size larger than the cross-sectional dimension of the corresponding bracket to define a gap between the edge around the wall opening and the bracket. This allows the load on the bracket to be carried by the main frame without affecting the outer walls of the main unit or the auxiliary unit.

[0030] The gap between the wall opening and the bracket may be sealed by a sealing structure, such as a rubber gasket extending between the edge of the wall and the bracket.

[0031] In one embodiment, the first suspension structure may constitute or form part of the unit fixing structure. In this embodiment, the first suspension structure holds the auxiliary unit in place on the main unit.

[0032] The power conversion assembly converts the power from the generator into a desired energy form. The power conversion assembly may be configured to deliver electric power, for example, in the form of AC or DC.

[0033] In the case of electrical energy, the power conversion assembly may be configured to link the generator to, for example, an external power grid. In this case, the power conversion assembly may be constituted by, for example, an inverter and / or a transformer and / or switchgear. Any such components may be included in the power conversion assembly.

[0034] Thus, the working components can consist of an inverter and / or a transformer and / or switchgear, etc. Such components can be suitably accommodated in the auxiliary unit and advantageously be carried directly by the main unit, as they are relatively heavy components. The load path from such components to the tower can thus be as short as possible, and it is therefore advantageous to directly suspend such components on the main unit and thereby directly carry at least part of the weight of these components through the main unit connected to the tower.

[0035] In addition, the components mentioned are often supplied to the site where the wind turbine is erected by external suppliers not involved in the drivetrain and other parts of the wind turbine. Therefore, it may be advantageous to enclose them in a separate unit away from the drivetrain and reduce the risk of accidental access by unauthorized personnel.

[0036] In addition, the inverter and the transformer are high-voltage components, and for safety reasons, the high-voltage components can be separated from the main unit.

[0037] In addition, the components mentioned are expensive and complex components, and for these components, they can be suitably repaired or replaced by specially trained personnel, for example, by lowering these working components to the ground when they are accommodated in the auxiliary unit, or at least by working in a work area isolated from the rotating and potentially dangerous drivetrain.

[0038] As an example, the generator can be an asynchronous or synchronous generator, for example, an asynchronous or synchronous generator, and the inverter voltage can be in the same range as the generator voltage (sometimes called the stator voltage).

[0039] In another example, the generator can be a doubly-fed induction generator (DFIG). In this case, the voltage on the inverter can be different from the generator stator voltage. The inverter is connected to the generator rotor and is usually the same voltage or a voltage lower than the stator voltage.

[0040] Low voltage can be considered, for example, as a voltage up to 1000V. Medium voltage can be considered as a voltage from 1 kV to about 60 kV. The generator voltage can be low voltage or medium voltage.

[0041] The main unit and the auxiliary unit are assembled at the interface by a unit fixing structure. The unit fixing structure can fix the auxiliary unit to the main unit when the auxiliary unit is in the assembled position, and it can be adapted to allow the auxiliary unit to be released from the main unit at a later date after the main unit is assembled on top of the tower, for example, for performing repairs or replacements. For this purpose, the unit fixing structure can include interlocking structural features located on the main unit and on the auxiliary unit. Examples of such interlocking features can be protrusions on one of the main unit and the auxiliary unit and notches or holes on the other of the main unit and the auxiliary unit. The unit fixing structure can form a bolt interface that allows the main unit and the auxiliary unit to be releasably engaged, or the auxiliary unit can be held in place on the main unit by a cable through which the auxiliary unit can be lowered to the ground for component repair, replacement, or for the transportation of components and personnel between the ground and the nacelle. In one embodiment, the unit fixing structure is configured such that the auxiliary unit can be received by the main unit when the auxiliary unit is lowered close to the main unit. Such a unit fixing structure can be constituted by hooks or interlocking structures on the main unit and the auxiliary unit. This can in particular be combined with a first suspension structure that is configured to receive the load of the working component when the auxiliary unit is moved to the position where the unit fixing structure fixes the auxiliary unit to the main unit.

[0042] The working component is housed in the auxiliary unit but is directly suspended on the main unit, for example, directly on the main frame in the main unit. Here, this means that at least a part of the load of the working component is directly transferred to the main unit without loading the auxiliary unit or the unit fixing structure. This load is referred to herein as the direct load.

[0043] The direct load does not necessarily constitute the entire load caused by the working component housed in the auxiliary unit, but rather its main part. Thus, the direct load can constitute, for example, anything from 50% to 100% of the total load, such as the total load caused by the working component housed in the auxiliary unit and the suspension direction on the main unit. In particular, the direct load can constitute 100% of the total load, which means that the working component is fully borne by the main unit. For example, the weight of the working component in a 5 MW wind turbine can be 25 to 30 tons (transformer and / or inverter), and the weight of the auxiliary unit used to house such a component can be 5 to 15 tons. Therefore, it would be advantageous to transfer at least part of the load of the working component to the main unit and in particular to the main frame.

[0044] The direct load is neither transferred to the auxiliary unit nor via the auxiliary unit to the main unit. Instead, the direct load is directly transferred to the main unit, for example, directly to the main frame.

[0045] The main unit and the auxiliary unit can be arranged side by side in a direction away from the axis of rotation. This means that the auxiliary unit is laterally displaced relative to the main unit away from the axis of rotation. The auxiliary unit can be, for example, in a direction perpendicular to the axis of rotation of the wind turbine rotor. This provides an advantageous modularization of the nacelle, in which an advantageous distribution of the main wind turbine components enables both the main bearing system and the drivetrain system to be assembled in the main unit and other components in the auxiliary unit to be laterally displaced away from the drivetrain. Thus, the interface between the main unit and the auxiliary unit can extend particularly in the direction of the axis of rotation.

[0046] In one embodiment, a plurality of working components are accommodated in the auxiliary unit and are directly suspended on the main unit. The working components can be, for example, a transformer and an inverter that are thereby accommodated in the same auxiliary unit.

[0047] The first suspension structure can be configured to releasably suspend the working components, thereby facilitating the direct suspension of the working components on the main unit. The first suspension structure can be particularly suitable for allowing the working components to be released from the main unit. For this purpose, the first suspension structure can include mutually interlocking structural features located on the main unit and the working components. Examples of such mutually interlocking features can be protrusions on one of the main unit and the working components and notches or holes on the other of the main unit and the working components. The first suspension structure can include a bolt interface that allows the working components to be releasably engaged with the main unit, or the working components can be held in place on the main unit by a cable through which the working components can be lowered to the ground for repair or replacement. The first suspension structure can also constitute an interface for holding the auxiliary unit on the main unit. That is, the auxiliary unit can be held in place on the main unit via the first suspension structure.

[0048] The second suspension structure can be configured to releasably suspend the working components on the auxiliary unit. In one embodiment, the second suspension structure is a support structure configured to make the working components stand on the bottom plate of the auxiliary unit. Such a support structure can include, for example, legs, beams, or similar structures arranged between the bottom plate of the auxiliary unit and the working components.

[0049] The second suspension structure can be particularly suitable for allowing the working components to be released from the auxiliary unit. For this purpose, the second suspension structure can include mutually interlocking structural features located on the auxiliary unit and the working components. Examples of such mutually interlocking features can be protrusions on one of the auxiliary unit and the working components and notches or holes on the other of the auxiliary unit and the working components. The second suspension structure can include a bolt interface that allows the working components to be releasably engaged with the auxiliary unit, or the working components can be held in place in the auxiliary unit by a cable through which the working components can be lowered to the ground for repair or replacement. The second suspension structure can particularly allow the auxiliary unit to carry the working components during transportation via the second suspension structure.

[0050] As described above, the first suspension structure and the second suspension structure can be configured such that when the auxiliary unit is attached to the main unit (i.e., when it moves towards the assembly position), the load is transferred from the second suspension structure to the first suspension structure. Alternatively or additionally, the first suspension structure and the second suspension structure can be configured to suspend the working component to both the main unit and the auxiliary unit simultaneously, thereby allowing the working component to be carried by both the main unit and the auxiliary unit, for example, such that the main frame in the main unit carries a larger percentage of the load, and the auxiliary unit carries a smaller percentage, less than 50% or less than 10%. In addition, the first suspension structure and the second suspension structure can be configured to automatically switch between the main unit carrying the working component and the auxiliary unit carrying the working component, and vice versa.

[0051] Below, three different assembly processes will be outlined.

[0052] a) The main unit and the auxiliary unit are joined via a unit fixing structure at the ground. Subsequently, they are lifted and attached to the tower as an assembled nacelle. Once attached to the nacelle, the working component is directly attached to the main unit via the first suspension structure, thus being directly suspended on the main unit. If the working component is sufficiently sheltered to be exposed on the outer surface of the main unit, the auxiliary unit can be released and used for subsequent transportation of other components, or the auxiliary unit can remain fixed to the main unit and form part of the nacelle for continued encapsulation of the working component.

[0053] b) The main unit and the auxiliary unit are joined via a unit fixing structure at the ground. Subsequently, the working component is directly attached to the main unit via the first suspension structure, thus being directly suspended on the main unit. Now, the auxiliary unit can be released and used for subsequent transportation of other components, or it can remain fixed to the main unit and form part of the nacelle for continued encapsulation of the working component. The nacelle is lifted and attached to the tower as an assembled nacelle.

[0054] c) The main unit is lifted and attached to the tower. Subsequently, the auxiliary unit is lifted and joined to the main unit via a unit fixing structure. When the two units are assembled, the working component is directly attached to the main unit via the first suspension structure, thus being directly suspended on the main unit. At this time, the working component can be attached to both the main unit and the auxiliary unit simultaneously via both the first suspension structure and the second suspension structure. Now, the auxiliary unit can be released and used for subsequent transportation of other components, or it can remain fixed to the main unit and form part of the nacelle for continued encapsulation of the working component.

[0055] In all three cases, the auxiliary unit can be used as a guide for the correct positioning of the working part relative to the main unit, i.e., when the auxiliary unit is attached via the unit fixing structure, the working part is correctly positioned to be attached to the main unit via the first suspension structure. Subsequently, the working part can be released from the auxiliary unit via the second suspension structure, whereby the auxiliary unit only serves as a weather protection shield and / or forms an indoor working platform for maintaining the working part. The working part can be released from the auxiliary unit, for example, to establish a load path from the working part directly into the main frame in the main unit.

[0056] In all three cases, the auxiliary unit can be attached directly to the main unit via an interface.

[0057] The interface can provide a sealed connection, thereby preventing the intrusion of air, water, and dust into the main unit.

[0058] The auxiliary unit can also be carried by an adapter inserted between the yaw device and the main unit.

[0059] The nacelle can include at least two auxiliary units. The two auxiliary units can be arranged on opposite sides of the main unit. In this embodiment, the two auxiliary units can be located on opposite sides of a vertical plane in which the axis of rotation extends.

[0060] The two auxiliary units can be arranged one above the other or one after the other on one side or on two sides of the main unit. In this case, the two auxiliary units can be located, for example, on opposite sides of a horizontal plane in which the axis of rotation extends. Such a plane will be determined by the axis of rotation and a point horizontally adjacent to the axis of rotation.

[0061] The two auxiliary units can be arranged one after the other to form a row of auxiliary units and are thus separated by a vertical plane extending perpendicular to the axis of rotation.

[0062] If the two auxiliary units are arranged one above the other or one after the other, the nacelle can include a third fixing structure for releasably fixing one of the auxiliary units to the other of the auxiliary units. In this way, one of these auxiliary units can form a load path for the other auxiliary units to enter the main unit and thus enter the wind turbine tower.

[0063] The third fixing structure can allow one of the auxiliary units to be released from the other of the auxiliary units. For this purpose, the third fixing structure can include mutually interlocking structural features on the two auxiliary units, for example, in the form of a protrusion on one unit and a notch or hole on the other unit.

[0064] The third fixing structure can include a bolt interface that allows the auxiliary units to be releasably joined to each other.

[0065] If two auxiliary units are arranged one above the other, the lower auxiliary unit among these auxiliary units can be held in place on the upper auxiliary unit among these auxiliary units by cables, and the lower auxiliary unit among these auxiliary units can be lowered to the ground by these cables for maintenance or replacement.

[0066] Two auxiliary units can be arranged one above the other or one after another on one side of the main unit, and two auxiliary units can be arranged one above the other or one after another on the opposite side of the main unit.

[0067] The working component can include an electrical connector configured to be electrically connected to a generator. The electrical connector can be connected via an interface between the main unit and the auxiliary unit. In particular, this interface can be operated from the main space in the main unit, thereby allowing connection or disconnection without entering the auxiliary unit. Alternatively, this interface can be operated from the auxiliary space in the auxiliary unit, and thereby allowing connection or disconnection without entering the main unit.

[0068] The main unit can be specifically configured to isolate a rotor support assembly physically separated from the working component. The isolation can be, for example, airtight (i.e., air-impermeable), fireproof or waterproof isolation that isolates or prevents the spread of fire or water.

[0069] The auxiliary unit can also be configured to isolate a transformer and an inverter from the rotor support assembly. Again, this can be airtight isolation or fireproof isolation or waterproof isolation.

[0070] In one embodiment, the main unit and the auxiliary unit engage at an interface that forms a gap allowing air to pass through, for example, allowing air to pass through the gap from below the nacelle to above the nacelle. Such a gap can increase heat convection and thus increase the cooling of the spaces within the main unit and the auxiliary unit.

[0071] The first suspension structure can extend across the gap through an opening in the walls of both the main unit and the auxiliary unit, and the space between the opening and the first suspension structure can be sealed by a gasket made of, for example, elastic rubber or other flexible material, thereby ensuring that the load of the working component is not transmitted to the walls of the main unit or the auxiliary unit.

[0072] The gasket can also be arranged where an access passage (e.g., a door or passage for cables or busbars) extends across the gap. The gasket can be designed to withstand a pressure exceeding the burst pressure, for example, other pressure relief structures such as the burst panel act on this burst pressure.

[0073] In one embodiment, a damping material is arranged between the main unit and the auxiliary unit. Rubber or foam materials, or materials having similar elastic deformability and damping effects, can be used. The damping material can be particularly compressed between the main unit and the auxiliary unit, and it can be particularly arranged where the main unit and the auxiliary unit are fixed by nails, rivets, bolts or any similar mechanical attachments.

[0074] In one embodiment, the main unit is wider than the auxiliary unit. The main unit being "wider" means that its dimension in the horizontal plane and perpendicular to the axis of rotation is greater than the same dimension of the auxiliary unit. The main unit can specifically be wider than a shipping cargo container that follows the dimensional and structural specifications of the ISO standard in ISO 668:2013 for series 1 cargo containers, while the auxiliary unit can have dimensions as specified for those ISO standard (ISO 668:2013) series 1 cargo containers or be smaller than that.

[0075] The nacelle can include a crane structure that is attached to the main unit and is configured to lift the auxiliary unit vertically from the ground to a position where a unit fixing structure can connect the auxiliary unit to the main unit. This means that the crane structure is configured to lift the auxiliary unit vertically without having to move the auxiliary unit in other directions. This lifting process is particularly suitable for combination with a unit fixing structure that includes rotatable or slidable hooks to facilitate attachment without relative movement between the main unit and the auxiliary unit in directions other than vertical.

[0076] The crane can, for example, include a cantilever beam structure that can move between a suspended configuration and a retracted configuration. In the suspended configuration, the cantilever beam structure forms at least one and optionally several outwardly projecting cantilevers that are configured to carry the auxiliary unit and can be used to lift the auxiliary unit towards and away from the main unit. The outwardly projecting cantilever beam structure can specifically be attached to the top portion of the main unit.

[0077] In one embodiment, the power conversion assembly is configured to convert electrical power from a generator into energy in a chemically storable form, for example, into hydrogen, ammonia or methanol. Thus, the working component can be constituted by an electrolytic cell stack or a battery, etc. Such components can be suitably accommodated in the auxiliary unit and advantageously be directly carried by the main unit as they are relatively heavy components.

[0078] In a second aspect, the present disclosure provides a method of assembling a wind turbine. According to this method, the main unit can be transported to the location where the wind turbine is to be erected. The auxiliary unit can be prepared, for example, by a supplier of the working components and received at the erection site of the wind turbine including the working components, and the working components are attached to the main unit in a state where they are accommodated in the auxiliary unit.

[0079] In particular, the method may include directly attaching a working component to a main frame that forms part of a load path from a rotor to a wind turbine tower.

[0080] During an initial stage of assembly, the working component may be carried by an auxiliary unit. During installation, the working component in a state of being carried in the auxiliary unit is lifted to a position where the auxiliary unit can be attached to the main unit. Here, this position is referred to as the "assembly position". When the assembly position is reached, the load of the working component is transferred from the auxiliary unit to the main unit, in particular to the main frame in the main unit.

[0081] In one embodiment, while moving the auxiliary unit towards the assembly position, the load is transferred from a second suspension structure to a first suspension structure, wherein a unit fixing structure connects the auxiliary unit to the main unit.

[0082] In a third aspect, the present disclosure provides a method for servicing a wind turbine according to the first aspect. According to this method, in a state where the working component is accommodated in the auxiliary unit, the working component is separated from the main unit and lowered to the ground in the auxiliary unit for servicing or replacement at the ground.

[0083] The main unit and the auxiliary unit can be classified into two different safety classes having different rules regarding fire, toxic escape, temperature, or electricity.

[0084] In other aspects, the present disclosure provides a wind turbine nacelle configured to be mounted on a wind turbine tower, the nacelle including:

[0085] a main unit arranged to be connected to the wind turbine tower and accommodating a rotor support assembly, and

[0086] at least one auxiliary unit.

[0087] In this aspect, the main unit and the auxiliary unit are independent units configured to be connected at an interface by a unit fixing structure, and the main unit includes a crane structure attached to the main unit and configured to hoist the auxiliary unit vertically from the ground to a position where the unit fixing structure can connect the auxiliary unit to the main unit. In particular, the unit fixing structure may include a movable support structure, such as in the form of a pivotable or slidable hook disclosed herein.

[0088] List of numbered embodiments

[0089] 1. A wind turbine nacelle (2) configured to be mounted on a wind turbine tower (3) and accommodating a rotor support assembly, a generator (33), and a power conversion assembly, the nacelle including:

[0090] A main unit (20, 72, 101, 121, 192) arranged to be connected to the wind turbine tower (3) and to accommodate the rotor support assembly, and

[0091] at least one auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) that houses working components (34, 35, 77, 104) forming part of the power conversion assembly,

[0092] wherein:

[0093] the main unit (20, 72, 101, 121, 192) and the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) are independent units configured to be connected at an interface by a unit fixing structure, and

[0094] the working components (34, 35, 77, 104) are directly suspended from the main unit (20, 72, 101, 121, 192).

[0095] 2. The nacelle according to embodiment 1, wherein the main unit (20, 72, 101, 121, 192) houses the generator (33).

[0096] 3. The nacelle according to embodiment 1 or 2, wherein the main unit (20, 72, 101, 121, 192) and the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) are arranged side by side in a direction away from the axis of rotation defined by the rotor support assembly.

[0097] 4. The nacelle according to any one of the foregoing embodiments, wherein the working components (34, 35, 77, 104) are directly suspended from a main frame (106) in the main unit (20, 72, 101, 121, 192).

[0098] 5. The nacelle according to any one of the foregoing embodiments, wherein the working components (34, 35, 77, 104) are an electrolytic cell stack, a transformer, or an inverter.

[0099] 6. The nacelle according to any one of the foregoing embodiments, the nacelle including a first suspension structure (78) for releasably suspending the working components (34, 35, 77, 104) to the main unit (20, 72, 101, 121, 192), thereby facilitating directly suspending the working components (34, 35, 77, 104) from the main unit (20, 72, 101, 121, 192).

[0100] 7. The engine nacelle according to any one of the foregoing embodiments, the nacelle including a second suspension structure (78, 91) for releasably suspending the working components (34, 35, 77, 104) to the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191).

[0101] 8. The engine nacelle according to embodiments 6 and 7, wherein the first suspension structure and the second suspension structure are configured to simultaneously suspend the working components (34, 35, 77, 104) to the main unit (20, 72, 101, 121, 192) and the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191).

[0102] 9. The engine nacelle according to any one of the foregoing embodiments, the nacelle including at least two auxiliary units (21, 22, 61, 62, 71, 102, 122, 191).

[0103] 10. The engine nacelle according to embodiment 9, wherein two of the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are arranged on opposite sides of the main unit (20, 72, 101, 121, 192).

[0104] 11. The engine nacelle according to embodiment 10, wherein two of the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are located on opposite sides of a horizontal plane unit to form a lower auxiliary unit and an upper auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191).

[0105] 12. The engine nacelle according to embodiment 11, wherein two of the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are arranged one above the other on one side of the main unit (20, 72, 101, 121, 192), and two of the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are arranged one above the other on an opposite side of the main unit (20, 72, 101, 121, 192) to form a lower auxiliary unit and an upper auxiliary unit (61, 62) on two opposite sides of the main unit (20, 72, 101, 121, 192).

[0106] 13. The engine nacelle according to embodiment 12, wherein the main unit (20, 72, 101, 121, 192) includes a third fixing structure for releasably fixing the lower auxiliary unit (62) to the upper auxiliary unit (61).

[0107] 14. The nacelle according to any one of the foregoing embodiments, wherein the working components (34, 35, 77, 104) include electrical connectors configured to be electrically connected to a generator in the main unit (20, 72, 101, 121, 192), and wherein the electrical connectors are connected via an interface between the main unit (20, 72, 101, 121, 192) and the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191).

[0108] 15. The nacelle according to any one of embodiments 5 to 14, wherein the main unit (20, 72, 101, 121, 192) defines an enclosed space for receiving the rotor support assembly, whereby the transformer and the inverter are physically separated from the main unit.

[0109] 16. The nacelle according to any one of the foregoing embodiments, wherein the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) is configured to isolate the working components (34, 35, 77, 104) from the rotor support assembly.

[0110] 17. The nacelle according to any one of the foregoing embodiments, wherein the interface between the main unit (20, 72, 101, 121, 192) and the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) defines a gap (167) that allows air to pass between the surface of the main unit (20, 72, 101, 121, 192) and the facing surface of the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191).

[0111] 18. The nacelle according to any one of the foregoing embodiments, the nacelle including a crane structure attached to the main unit and configured to lift the auxiliary unit from the ground to a position where the unit fixing structure can connect the auxiliary unit to the main unit.

[0112] 19. The nacelle according to embodiment 18, wherein the crane structure is configured to lift the auxiliary unit in a vertical direction without causing the auxiliary unit to move in a horizontal direction.

[0113] 20. A method of assembling a wind turbine having a nacelle according to any one of embodiments 1 to 19, wherein:

[0114] The main unit (20, 72, 101, 121, 192) is received at the erection site of the wind turbine, and the erection site includes the working components (34, 35, 77, 104).

[0115] The auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are attached to the main unit (20, 72, 101, 121, 192); and

[0116] In a state where the working components (34, 35, 77, 104) are accommodated in the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191), the working components are directly attached to the main unit (20, 72, 101, 121, 192).

[0117] 21. The method according to embodiment 20, wherein the working components (34, 35, 77, 104) are directly attached to the main frame in the main unit (20, 72, 101, 121, 192).

[0118] 22. The method according to embodiment 20 or 21, wherein the main unit is attached to a wind turbine tower, and the auxiliary unit is hoisted onto or lowered from the main unit by using a crane structure attached to the main unit.

[0119] 23. The method according to embodiment 22, wherein the auxiliary unit is hoisted only in a vertical plane by using the crane structure.

[0120] 24. A method for repairing a wind turbine having a nacelle according to any one of embodiments 1 to 19, wherein in a state where the working components (34, 35, 77, 104) are accommodated in the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191), the working components are separated from the main unit (20, 72, 101, 121, 192), and the working components are lowered to the ground in the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) for repair or replacement at the ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0121] Hereinafter, embodiments of the present disclosure will be described in more detail with reference to the drawings, wherein:

[0122] Figure 1a and Figure 1b shows a wind turbine;

[0123] Figure 2 shows the nacelle of a wind turbine;

[0124] Figure 3 shows a perspective view of the Figure 2 engine nacelle;

[0125] Figure 4 shows a Figure 3 view of the engine nacelle from above;

[0126] Figure 5 shows an embodiment in which the left auxiliary unit and the right auxiliary unit house the same components;

[0127] Figure 6 shows an embodiment in which two auxiliary units 61, 62 are positioned one above the other;

[0128] Figure 7 schematically shows details of the interface;

[0129] Figure 8 shows the Figure 7 main unit and the auxiliary unit after the auxiliary unit has been attached to the main unit;

[0130] Figure 9 shows an embodiment in which the first suspension structure consists of a bolt-shaped fixing pin;

[0131] Figure 10 , Figure 11 shows in more detail another embodiment of the first suspension structure and the second suspension structure;

[0132] Figures 12 to 15 shows four different embodiments of the interface between the main unit and the auxiliary unit;

[0133] Figures 16 to 18 shows an embodiment in which the main unit and the auxiliary unit are assembled by a hinge structure;

[0134] Figure 19a , Figure 19b , Figure 19c , Figure 20 shows further details of the hook for attaching the auxiliary unit to the main unit;

[0135] Figure 21 shows the hook in the open position, in which the auxiliary unit can be freely lowered to the ground;

[0136] Figure 22 shows a cross-section having two bolt holes for attaching the auxiliary unit to the main unit;

[0137] Figures 23, 24, 25a, 25b show an embodiment in which the hook is configured for sliding; and

[0138] Figures 26 to 28Shows an embodiment of a crane for hoisting an auxiliary unit on a main unit. Detailed Embodiment

[0139] The detailed description and specific examples, while indicating certain embodiments, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0140] Figure 1a and Figure 1b Shows a wind turbine 1 having a nacelle 2 mounted on a tower 3. A hub 4 carrying three rotor blades 5 forms a rotor and is carried by a rotor support assembly in the nacelle 2. Typically, the rotor support assembly includes a rotor shaft that connects a gearbox and a generator to the hub. However, a gearbox is not always required, since the generator can be directly driven by the shaft. Figure 1b Shows a direct drive wind turbine having a generator 6 located outside the nacelle.

[0141] Figure 2 Shows that the nacelle includes a main unit 20 and two auxiliary units 21, 22. A cooling area 23 is arranged on top of the nacelle. The cooling area is formed by a heat exchanger that can form part of the main unit and / or any of the auxiliary units. The main unit 20 is mounted on the tower 3 via a yaw device (not shown), allowing the nacelle 2 to rotate to direct the rotor into the wind.

[0142] Figure 3 Shows Figure 2 a perspective view of the nacelle 2. In Figure 3 (for illustrative purposes), the outer wall of the nacelle 2 is transparent, revealing the internal parts of the nacelle 2 and the wind turbine components housed therein. The main unit 20 houses a main bearing unit 31, a gearbox 32, and a generator 33 that are sequentially arranged behind the hub 4 along the direction defined by the rotational axis of the hub 4. The main bearing unit 31 supports a main shaft that rotates therein. These components in the main unit mainly form part of the drivetrain.

[0143] The auxiliary unit 22 houses a transformer unit 34 and an inverter unit 35, which together constitute two different working components housed in the auxiliary unit but carried by the main unit. In an alternative embodiment, the working component could be an electrolytic cell stack or a battery.

[0144] Each auxiliary unit 21, 22 is mounted along a side of the main unit 20 by a unit fixing structure. In the disclosed embodiment, these auxiliary units are mounted such that one auxiliary unit 21 is mounted along the right side of the main unit 20 and the other auxiliary unit 22 is mounted along the left side of the main unit 20, as seen from the hub 4 towards the rear wall of the main unit 20 in the direction of the rotational axis of the hub 4.

[0145] The main unit and the auxiliary units are enclosed and optionally sealable units such that the auxiliary units form a compartment defining an auxiliary space and the main unit forms another compartment defining a main space. This allows the drivetrain to be isolated from the inverter and the transformer. The two compartments can be joined by a cooperating opening 36 to allow personnel and equipment to enter the auxiliary space in the auxiliary unit from the main space in the main unit. The opening 36 can be sealed to prevent the spread of fire etc. from one of the main unit and the auxiliary units to the other of the main unit and the auxiliary units.

[0146] Figure 4 The nacelle is shown as seen from above.

[0147] Figure 5 An embodiment is shown in which the left and right auxiliary units house at least one identical component for establishing weight balance and dual functionality. Dual functionality means that the wind turbine includes two components of similar function, one component being housed in each auxiliary unit. These components can be identical in nature and specification. In the event of a failure of a component in one unit, the wind turbine can continue to operate at reduced power while replacing the working component in the other auxiliary unit.

[0148] Figure 4 and Figure 5 A transport system including a track 42 is shown, which extends from the main unit into the auxiliary units and allows easy handling of spare parts etc.

[0149] In Figures 2 to 5 these auxiliary units are constituted by elements generally having the shape and size of a standardized cargo container, such as a 40-foot shipping cargo container, which have the dimensions and structural specifications as provided by the ISO standard (ISO 668:2013) for series 1 cargo containers. These auxiliary units are attached to the main unit by an ISO corner lifting structure, which is typically made of steel and forms a particularly strong interface with the container.

[0150] Figure 6An embodiment is shown in which two auxiliary units 61, 62 are positioned one above the other. In this embodiment, the upper auxiliary unit 61 is formed by a unit having the size and shape of a 40-foot shipping cargo container, and the lower auxiliary unit 62 is formed by a unit having the size and shape of a 20-foot shipping cargo container. Both containers have the dimensions and structural specifications provided by the ISO standard (ISO 668:2013), and the auxiliary units are attached to each other mainly by the corner lifting devices of the 20-foot container and partly by the corner lifting devices of the 40-foot container. Alternatively, the two auxiliary units have the same length.

[0151] Figure 7 Details of the interface are schematically shown. The interface releasably engages the auxiliary unit 71 and the main unit 72 and allows the auxiliary unit to be attached to the main unit after being transported to the installation site or to be replaced, for example, during maintenance. In the disclosed embodiment, the auxiliary unit 71 is attached to the main unit 72 independently of any other unit, and the unit fixing structure is constituted by an inward groove or guide rail 73 in the main unit. The guide rail 73 is shown in dashed lines and defines a notch into the outer surface 75. The guide rail has a C-shaped profile in a horizontal cross-section, that is, when viewed from above, the guide rail is configured to receive a protrusion 74 provided on the auxiliary unit, and in particular, the guide rail can receive the protrusion 74 through the process of the auxiliary unit 71 descending along the outer surface 75 of the main unit 72. This is shown by arrow 76. This process allows the easy replacement of the auxiliary unit and the working components accommodated therein without removing other auxiliary units and the working components accommodated therein.

[0152] The main unit can form a load path from the working components accommodated in the auxiliary unit, for example, downward through the main frame to the tower. In particular, this load path can be different from the load path from the auxiliary unit to the tower. This will be described hereinafter with respect to different embodiments.

[0153] The auxiliary unit 71 houses an inverter 77, which is fixed to the auxiliary unit by a second suspension structure constituted by a bolt-shaped fixing pin 78.

[0154] The main unit has a reinforcing bracket 79, which is attached to the outer wall and is configured to receive the weight of the inverter 77 when the auxiliary unit is received and fixed on the main unit.

[0155] Figure 8 Shown is the main unit and the auxiliary unit after the auxiliary unit has been attached to the main unit Figure 7 In this state, the bolt-shaped fixing pin 78 extends laterally to the left and thereby engages into the reinforcing bracket feature 79. The bracket can be connected to a rigid frame supported by, for example, the main frame in the main unit, so as to directly guide the load from the working components to the tower via the main frame.

[0156] The bolt-shaped fixing pins now form the first suspension structure by which the inverter is directly carried by the main unit. The first suspension structure forms part of the load path from the working component to the tower, and the interface between the main unit and the auxiliary unit forms part of another load path from the auxiliary unit to the tower.

[0157] In Figures 7 to 8 the illustrated embodiment, both the first suspension structure and the second suspension structure are formed by the same set of bolts that extend from the inverter and into one or both of the auxiliary unit or the main unit.

[0158] Figure 9 An embodiment is shown in which the first suspension structure is formed by bolt-shaped fixing pins and the second suspension structure is formed by a support leg 91 between the bottom of the inverter and the bottom of the auxiliary unit.

[0159] Figure 10 Another embodiment of the first suspension structure and the second suspension structure is shown in more detail. In this embodiment, the main unit 101 and the auxiliary unit 102 are joined by a unit fixing structure formed by the corner lifting points 103 of the container constituting the auxiliary unit 102.

[0160] The transformer 104 is carried by the first suspension structure, which in this case is in the form of a support frame 105 resting on the bottom of the auxiliary unit 102 and is directly suspended on the main frame 106 within the main unit 101. Thus, the main frame forms part of the load path for the working component to enter the tower.

[0161] At least 50% of the weight of the transformer 104 is thus carried by the main unit 101, and the remaining weight is carried by the auxiliary unit 102, which is in turn carried by the main unit 101. The remaining part of this heavy object is thus not directly carried by the main unit 101.

[0162] Figure 11 An embodiment is shown that can be compared with the Figure 10 embodiment therein, but in which the suspension structure 105 includes a support frame 105 that is suspended via a bracket structure including a lower bracket 1101 and an upper bracket 1102, and this bracket structure is placed on the main frame 106 within the main unit 101. The main frame thus forms part of the load path for the working component to enter the tower.

[0163] Figures 12 to 15 Four different embodiments of the unit fixing structure forming the interface between the main unit and the auxiliary unit are shown. In each of these four illustrations, the main unit 121 and the auxiliary unit 122 are connected by a cooperation structure that forms the unit fixing structure and will be described in further detail below.

[0164] In Figure 12 Figure 12 , the cooperation structure is constituted by the support 123, and the main unit and the auxiliary unit are joined together by bolts by means of this support.

[0165] In Figure 13 Figure 13 , the cooperation structure is constituted by a lower support 123 similar to the support used in Figure 12 Figure 12 . At the upper edge, the main unit and the auxiliary unit are assembled by hooks 131 pivotally joined to the main unit at the hinge points 132. The hooks can rotate as indicated by the arrow 133 and engage the edge support 134 of the auxiliary unit when in the position shown. When the lower support 123 is removed and the hooks 131 are rotated into the main unit, the auxiliary unit can be lowered to the ground.

[0166] Figure 14 The embodiment in Figure 13 Figure 13 is comparable to the embodiment in

[0167] In Figure 15 Figure 15 , the lower support and the upper support are used to bolt the auxiliary unit to the main unit, and the slidable support 151 supports the lower surface of the auxiliary unit in a state where the bolts have been attached. If it is necessary to lower the auxiliary unit to the ground, for example, for replacing or maintaining working parts, the slidable support can slide to the left, and the auxiliary unit can be lowered, for example, by using a crane built into the main unit.

[0168] In Figures 12 to 15 Figures 12 to 15 shown in any of the embodiments, the support or the hook guides the load from the auxiliary unit into the rigid part of the main unit, for example, into the load-bearing columns such as the corner columns of the main unit. Various structural features can directly connect the support or the hook carrying the auxiliary unit to the main frame in the main unit, thereby establishing a load path into the tower.

[0169] In addition to Figures 12 to 15 Figures 12 to 15 shown in the hook and support unit fixing structure, a first suspension structure (not shown) directly connects the working part (not shown) to the main frame inside the main unit.

[0170] Figures 16 to 18 Figures 16 to 18 shows an embodiment of the unit fixing structure, in which the main unit and the auxiliary unit are assembled by a hinge structure including hinge elements 163, 164, 165, and the hinge elements 163, 164, 165 have holes for receiving a hinge pin 166 extending through the hinge elements. Figure 16An interface forming gap 167 is also shown, allowing air, for example, to pass from below the nacelle through the gap to above the nacelle. The gap is kept open at the bottom by a distance element 168, which can consist of a plurality of pins or an open structure allowing air to pass between the units.

[0171] Such a gap can increase heat convection and thus increase the cooling of the space within the main unit and the auxiliary unit. The gap is not limited to embodiments with a hinged structure but can be combined with any other assembly method. The first suspension structure can extend across the gap.

[0172] Figure 17 and Figure 18 Hinge elements 163, 164, 165 and hinge pins 166 are shown. In Figure 17 , these hinge elements are correctly positioned relative to each other such that the hinge pins can slide into the hinge elements. In Figure 18 , the hinge pins are inserted through the holes of the hinge elements.

[0173] Figure 19a , Figure 19b and Figure 19c Further details of a hook - form unit fixing structure for attaching the auxiliary unit 191 to the main unit 192 are shown. The hook 193 is rotatably suspended at a hinge 194 in the main unit. The hook can rotate through an opening 195 in the auxiliary unit and engage a notch or edge 196 in the auxiliary unit.

[0174] The hook can also be attached in the auxiliary unit and engage a notch or edge in the main unit. In this case, the hook can be attached in the opposite way, i.e., as Figure 20 shown. The position of the hook can be controlled by an actuator.

[0175] Figure 21 A hook in the open position is shown, in which the auxiliary unit can freely lower to the ground.

[0176] Figure 22 A cross - section showing two bolt holes 221 is shown. The bolt holes help attach the auxiliary unit to the main unit using bolts for a firm fixation. In this embodiment, the hook is mainly used to position the auxiliary unit at the correct height relative to the main unit, and the bolts are used to join the units together.

[0177] In Figure 19a , Figure 19b , Figure 19c , Figure 21 and Figure 22 , the hook is preferably supported by the main frame of the main unit, for example, via columns or support bars arranged along the inner surface of the main unit. In Figure 19a , Figure 19b andFigure 19c In Figure 19c , the column 197 extends along the inner surface of the main unit and supports a hook on the main frame in the bottom portion of the main unit.

[0178] In Figure 20 where the hook forms part of the auxiliary unit, the edge in the main unit for the hook to engage with can preferably be carried by the main frame in the main unit. Again, this can be a rod or column arranged along the inner surface of the main unit.

[0179] The hook can be moved between an open position ( Figure 21 ) and a closed position ( Figure 19a , Figure 19b , Figure 19c , Figure 20 , Figure 22 ) by a power driving device (e.g., including a hydraulic driving actuator).

[0180] Figures 23, 24, 25a and 25b show an embodiment in which the hook is not rotatably suspended but slidably suspended. This function is similar to that of Figure 19a , Figure 19b , Figures 19c to 22 . In Figures 23 and 24, the cross-sectional views show bolt holes 231 which can be used to bolt the auxiliary unit firmly to the main unit. The hook in Figure 23 is attached to the main unit and the hook in Figure 24 is attached to the auxiliary unit.

[0181] In Figure 25a, the hook 251 slides to the left, thus disengaging from the edge of the auxiliary unit and allowing the auxiliary unit to be lowered to the ground. In Figure 25b, the hook 251 slides to the right, thus engaging with the edge of the auxiliary unit and keeping the two units fixed to each other. The hook can slide by a power driving device (e.g., by a hydraulic actuator).

[0182] In the above description, Figures 19a to 2 5b is interpreted as part of the unit fixing structure for fixing the auxiliary unit to the main unit. A similar structure can constitute the first suspension structure through which the working part is releasably fixed to the main unit. A similar structure can also constitute the second suspension structure through which the working part is releasably fixed to the auxiliary unit, and a similar structure can constitute the third fixing structure through which the two auxiliary units are fixed to each other.

[0183] Figure 26During maintenance or replacement, the auxiliary unit is lifted up or down. The auxiliary unit is lifted by using a crane 261 that forms part of the main unit. The movement is basically only in the vertical plane shown by arrow 263, and the attachment of the auxiliary unit to the main unit can be assisted by the unit fixing structure as described above, which includes movable fixing features such as hinged or slidable hooks, etc.

[0184] Figure 27 The internal crane 261 is shown in an enlarged view. The crane is attached to the top part of the main unit, and by its position, the crane can lift the auxiliary unit in the vertical direction to a position where the unit fixing structure can form an engagement between the main unit and the auxiliary unit. This process may not require movement in other directions except the vertical direction, and thus contributes to a simple assembly process, reducing the need for external crane assistance. For adjustment in the horizontal plane, the crane 261 can have options for horizontal movement, for example, as shown by arrow 262.

[0185] Figure 28 Another crane structure with a double cantilever beam 281 on top of the main unit 282 is schematically shown. The cantilever beam 281 can extend laterally in the telescopic section 283. The cantilever beam helps in lifting and connecting the auxiliary unit 284 to the main unit 282. Even though the unit fixing structures disclosed herein (including pivotable or slidable hooks) generally facilitate the attachment of the auxiliary unit by lifting only in the vertical direction, the in-and-out movement can facilitate fine adjustment of the horizontal distance between the main unit and the auxiliary unit.

[0186] Definition

[0187] Herein, the term "nacelle" refers to the generally accepted term describing the machine room for a wind turbine, i.e., that part which houses the rotor and the drivetrain and is carried by the wind turbine tower.

[0188] The terms "main unit" and "auxiliary unit" herein refer to units that can be transported separately and can be assembled with one or more other units to form a nacelle.

[0189] Herein, the term "rotor support assembly" refers to those parts of the nacelle that carry the rotor, typically those parts that carry the drivetrain, the main bearing, and the main frame. Depending on the type of wind turbine, the drivetrain can include different components, for example, the rotor shaft, the generator, and optionally a gearbox between the rotor shaft and the generator.

Claims

1. A wind turbine nacelle (2) configured to be mounted on a wind turbine tower (3) and to house a rotor support assembly for supporting a rotor, the nacelle further housing a power conversion assembly, the nacelle comprising: Main units (20, 72, 101, 121, 192), which are arranged to be connected to the wind turbine tower (3) and accommodate the rotor support assembly, and at least one auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191), which accommodates working components (34, 35, 77, 104) forming part of the power conversion assembly, wherein: the main units (20, 72, 101, 121, 192) and the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are independent units configured to be connected at an interface by a unit fixing structure, the working components (34, 35, 77, 104) are directly suspended on the main units (20, 72, 101, 121, 192), the main units (20, 72, 101, 121, 192) and the at least one auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) are arranged side by side in a direction transverse to the axis of rotation defined by the rotor support assembly.

2. The nacelle according to claim 1, the nacelle comprising a first suspension structure that directly suspends the working components (34, 35, 77, 104) from a main frame (106) in the main unit (20, 72, 101, 121, 192), the main frame forming part of a load path from the rotor into the wind turbine tower.

3. The nacelle according to claim 1 or 2, the nacelle comprising a second suspension structure (78, 91) for suspending the working components (34, 35, 77, 104) from the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191).

4. The nacelle according to claim 2, wherein, The nacelle includes a second suspension structure (78, 91) for suspending the working components (34, 35, 77, 104) on the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191), the unit fixing structure being configured to fix the auxiliary units to the main units in the assembled position of the auxiliary units relative to the main units, and wherein the first suspension structure is configured to take over the suspension of the working components from the second suspension structure when the auxiliary units are moved to the assembled position.

5. The nacelle according to claim 2, wherein, The first suspension structure includes at least one bracket connected to the working components and the main frame (106).

6. The nacelle according to claim 5, wherein, Each bracket extends through a corresponding wall opening in the outer wall of at least one of the main unit and the auxiliary unit.

7. The nacelle according to claim 6, wherein, Each wall opening has a size exceeding the cross-sectional dimension of the corresponding bracket to define a gap between the edge around the wall opening and the bracket.

8. The nacelle according to claim 2, wherein, The first suspension structure (78) is configured to releasably suspend the working components (34, 35, 77, 104) to the main frame.

9. The nacelle according to claim 3, wherein, The second suspension structure (78, 91) is configured to releasably suspend the working components (34, 35, 77, 104) on the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191).

10. The nacelle according to claim 1, wherein, The interface between the main unit (20, 72, 101, 121, 192) and the auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191) defines a gap (167) that allows air to pass between the surface of the main unit (20, 72, 101, 121, 192) and the surface of the facing auxiliary unit (21, 22, 61, 62, 71, 102, 122, 191).

11. The nacelle according to claim 10, the nacelle comprising a first suspension structure that directly suspends the working components (34, 35, 77, 104) from a main frame (106) in the main unit (20, 72, 101, 121, 192), the main frame forming part of a load path from the rotor into the wind turbine tower, wherein, The first suspension structure extends across the gap.

12. The nacelle according to claim 1 or 2, wherein,The working components (34, 35, 77, 104) are electrolytic cell stacks, transformers or inverters.

13. The nacelle according to claim 1 or 2, wherein, The rotor drives a generator located outside the nacelle.

14. The nacelle according to claim 1 or 2, wherein, The nacelle also houses a generator (33) driven by the rotor.

15. A method of assembling a wind turbine having a nacelle according to any one of claims 1 to 14, wherein: The main unit (20, 72, 101, 121, 192) is received at an erection site of the wind turbine, the erection site including the working components (34, 35, 77, 104), The auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) are attached to the main unit (20, 72, 101, 121, 192); The main frame in the main unit forms part of a load path from the rotor into the wind turbine tower, and In a state where the working components (34, 35, 77, 104) are housed in the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191), the working components are directly attached to the main frame in the main unit (20, 72, 101, 121, 192).

16. The method according to claim 15, wherein, The working components (34, 35, 77, 104) are configured to be supported by the main frame via a first suspension structure and by the auxiliary units via a second suspension structure.

17. The method according to claim 16, the method comprising: While moving the auxiliary unit towards an assembly position, a load is transferred from the second suspension structure to the first suspension structure, in which assembly position a unit fixing structure connects the auxiliary unit to the main unit.

18. The method according to any one of claims 15 to 17, wherein, The main unit is attached to the wind turbine tower, and the auxiliary unit is hoisted onto or lowered from the main unit by using a crane structure attached to the main unit.

19. The method according to claim 18, wherein, The auxiliary unit is hoisted only in a vertical plane by using the crane structure.

20. A method of servicing a wind turbine having a nacelle according to any one of claims 1 to 14, wherein, In a state where the working components (34, 35, 77, 104) are housed in the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191), the working components are separated from the main unit (20, 72, 101, 121, 192), and the working components are lowered to the ground in the auxiliary units (21, 22, 61, 62, 71, 102, 122, 191) for repair or replacement at the ground.

Images