Modular Wind Turbine Blade with Vibration Damping

Abstract

According to a first aspect of the present invention, there is provided a wind turbine blade having a split blade configuration, the wind turbine blade comprising: a first blade module defining an airfoil profile and a second blade module defining an airfoil profile; a damping module located intermediate the first blade module and the second blade module; wherein the damping module includes a first blade interface for engagement with the first blade module and a second blade interface for engagement with the second blade module. The damping module includes a vibration damping unit. Advantageously, the present invention provides a useful way of integrating a motion damping function into a modular wind turbine blade.

Description

Technical Field

[0001] The present invention generally relates to a modular wind turbine blade, and more particularly to a modular wind turbine blade that can better withstand edgewise vibration. Background Art

[0002] To take advantage of economies of scale in wind energy, there is a general desire to make wind turbines larger to reduce the overall energy cost. Larger wind turbines have longer wind turbine blades, and the larger wind turbine blades provide a larger swept area, enabling the wind turbine to capture more energy from the wind.

[0003] One problem associated with long wind turbine blades is the challenge of transporting them efficiently to the installation site. Due to the constraints imposed by the road network, the transportation of long wind turbine blades over land becomes problematic.

[0004] To address these issues, it is known to design wind turbine blades as modular components. Thus, a wind turbine blade can be divided into two or more modules that are more easily transported and then assembled on site, for example, by gluing or bolting the modules together.

[0005] Despite their modularity, modular wind turbine blades tend to be slender articles that are vulnerable to vibration. Of particular concern are edgewise vibration modes, because slender blades tend to exhibit less inherent aerodynamic damping in the edgewise direction compared to the flapwise direction (where the lift generated by the blade tends to damp out flapwise oscillations).

[0006] It is in this context that the present invention has been developed. Summary of the Invention

[0007] According to a first aspect of the present invention, there is provided a wind turbine blade having a split blade construction, the wind turbine blade comprising: a first blade module defining an airfoil profile and a second blade module defining an airfoil profile; a damping module located intermediate the first blade module and the second blade module; wherein the damping module includes a first blade interface for engaging with the first blade module and a second blade interface for engaging with the second blade module. The damping module includes a vibration damping unit.

[0008] Advantageously, the present invention provides a useful way of integrating a motion damping function into a modular wind turbine blade. Preferably, the vibration damping unit is configured to attenuate the edgewise vibration of the wind turbine blade. The vibration damping unit can include various configurations and can include one or more selected damping devices, the damping devices including viscous dampers, spring devices including elastically mounted masses, tuned mass dampers; fluid filled volumes, etc. Preferably, the vibration damping unit is configured to act on the shear center of the blade section in which the damping module is located.

[0009] The damping module can be shaped to define an airfoil profile. In this way, the damping module can be more efficiently integrated into the overall shape of the blade. In this case, the airfoil profile of the damping module at the first blade interface can correspond to the airfoil profile of the first blade module. Additionally, the airfoil profile of the damping module at the first blade interface can match the adjacent airfoil profile of the first blade module. Thus, the damping module can have a profile at each interface that matches the adjacent portion of the associated blade module. In contrast, the interfaces of the blade modules can correspond to the respective adjacent faces of the blade modules, but can be of different sizes such that the airfoil profile of the damping module has a larger cross-sectional area than the cross-sectional area of the first blade module and / or the second blade module.

[0010] The vibration damping unit can be configured to act such that it applies a force to the damping module and thus also to the first blade module and the second blade module. The force is applied to the shear center of the section of the wind turbine blade in which the vibration damping unit is located. This minimizes the torsional force applied by the damping module to the wind turbine blade.

[0011] Although the vibration damping unit can be housed inside the body of the damping module, in other embodiments, the vibration damping unit can be supported outside the body of the damping module.

[0012] At least one of the first interface and the second interface can be connected to the connection faces of the respective first blade module and second blade module by a bolted connection. In other embodiments, the respective connection faces are defined by a scarf joint. The connection can be an adhesive connection or a bolted connection.

[0013] The vibration damping unit generally acts in the chordwise direction. This means that any movement of the vibration damping unit or a part of the vibration damping unit moves in a substantially chordwise direction.

[0014] Within the scope of the present application, it is the express intention that the various aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, claims, and / or the following description and drawings, particularly their respective features, can be implemented independently or in any combination. That is to say, all embodiments and / or features of any embodiment can be combined in any manner and / or combination, unless these features are incompatible. Description of the Drawings

[0015] The above and other aspects of the present invention will now be described by way of example only with reference to the drawings, in which:

[0016] Figure 1 is a perspective view of a wind turbine having a wind turbine blade that can incorporate an embodiment of the present invention;

[0017] Figure 2 is an exploded perspective view of a modular wind turbine blade according to an embodiment of the present invention, the wind turbine blade including a damping module;

[0018] Figure 3 is an exemplary cross-section through the wind turbine blade by way of example to illustrate the structural components;

[0019] Figure 4 is according to an embodiment of the present invention as Figure 2 shown in a schematic diagram of the damping module;

[0020] Figure 5 is a schematic diagram of a damping module according to another embodiment of the present invention;

[0021] Figure 6 is an exploded perspective view of a modular wind turbine blade according to another embodiment of the present invention; and

[0022] Figure 7a and Figure 7b is a view of the connection arrangement for a damping module according to an embodiment of the present invention.

[0023] In the drawings, the same reference numerals are used to denote features common to the drawings. Detailed Description

[0024] Figure 1is a schematic view of a modern utility-scale wind turbine 10, which includes a tower 12 that supports a nacelle 14. A rotor 16 is mounted to the nacelle 14. The rotor 16 includes a plurality of radially extending wind turbine blades 18 that are attached to a central hub 22 at their respective root ends 20. In this example, the rotor 16 includes three blades 18, but the rotor 16 can have any number of blades 18. The wind turbine blades 18 are of a type sometimes known as a "split" or "modular" blade design. Thus, in this example, the wind turbine blade 18 includes a first blade module and a second blade module, although in other embodiments each blade 18 can use more than two modules. As explained in the background art, modular blade components can be assembled at a wind farm site to facilitate easier transportation of large components.

[0025] Reference Figure 2 , which shows a schematic exploded view of a modular wind turbine blade 18 according to a first embodiment of the present invention. The modular wind turbine blade 18 includes a first blade module 24 and a second blade module 26. The blade modules 24, 26 are configured to be joined end-to-end at a joint region 28 to form a complete wind turbine blade 18.

[0026] In Figure 2 , axes S and C respectively represent the spanwise direction and the chordwise direction of the wind turbine blade 18 and of each module of the blade 18. The first blade module 24 and the second blade module 26 form spanwise (S) sections of the modular wind turbine blade 18. Each module extends in the chordwise direction between a leading edge 30 and a trailing edge 32 and defines an airfoil profile.

[0027] In the illustrated embodiment, the first blade module 24 includes the tip 34 of the blade 18 and the second blade module 26 includes the root end 20 of the blade, although for purposes of scale the root end of the blade is depicted as a dashed line in Figure 2 . In other embodiments, the first module 24 can include the root 20 of the blade and the second module 26 can include the tip 34 of the blade. Additionally, in other embodiments, the modular blade 18 can include more than two modules, for example additional modules can be connected inside or outside the first blade module 24 and / or the second blade module 26, and these additional modules can include the blade root 20 and / or the blade tip 34.

[0028] The general construction of the blade modules 24, 26 is known to those skilled in the art. Figure 3 shows a cross-sectional view of a typical construction of a wind turbine blade for reference. The features of the wind turbine blade will be referred to in the singular, but it will be understood that these features will apply equally to the various modules of the modular blade, as will be described. Thus,Figure 3 The cross-sectional view of the blade module in [reference] includes a housing 36 that defines a generally hollow interior 38. In this example, the housing 36 is mainly formed of glass fiber reinforced plastic (GFRP). The housing 36 has a laminated structure that includes an outer skin 40 that defines the outer surface 41 of the blade 18 and an optional inner skin 42 that defines the inner surface 43 of the blade 18. Each of the outer skin 40 and the inner skin 42 includes one or more layers of fiber material (not shown) embedded in a cured matrix material such as epoxy resin. In regions of the blade housing 36 where increased stiffness is required, a lightweight core material such as a foam board may be provided between the skins 40, 42.

[0029] Although not shown here, those skilled in the art will understand that the blade 18 will also include a spar structure, which may generally be embodied as a box spar extending longitudinally along the blade, or by means of spar caps embedded in the housing, which are connected by shear webs. However, the structural details of the spar arrangement of the blade are not essential for the present invention, and further discussion will be omitted for the sake of clarity, although an example of such a shear web structure is shown in [reference] in dashed lines. Figure 3 in dashed lines.

[0030] In known modular blade designs, the first blade module 24 will be directly connected to the second blade module 26 in an end-to-end manner. This can be achieved by a bolted butt joint between the blade modules or by means of an adhesive scarf joint. However, it is apparent from [reference] that the modular wind turbine blade 18 includes an additional module 50 located intermediate or between the first blade module 24 and the second blade module 26. It will become apparent from the following discussion that the additional module 50 is a damping module and will hereinafter be referred to as the damping module. The damping module 50 is configured to apply a force between the leading edge 30 and the trailing edge 32 of the wind turbine blade 18 during use to attenuate edgewise oscillations. Figure 2 in [reference] that the modular wind turbine blade 18 includes an additional module 50 located intermediate or between the first blade module 24 and the second blade module 26. It will become apparent from the following discussion that the additional module 50 is a damping module and will hereinafter be referred to as the damping module. The damping module 50 is configured to apply a force between the leading edge 30 and the trailing edge 32 of the wind turbine blade 18 during use to attenuate edgewise oscillations.

[0031] Referring first to [reference], it will be understood that the damping module 50 is similar to a relatively short spanwise section of the wind turbine blade 18 and thus has an aerodynamic body section 51, the profile of which is similar to the profile of the remainder of the wind turbine blade 18. In this way, when the first blade module 24, the second blade module 26, and the damping module 50 are joined together, they form a complete wind turbine blade that, in appearance, looks like a conventional wind turbine blade made as a single-piece large article with a minimum number of joint lines. Figure 2 Referring first to [reference], it will be understood that the damping module 50 is similar to a relatively short spanwise section of the wind turbine blade 18 and thus has an aerodynamic body section 51, the profile of which is similar to the profile of the remainder of the wind turbine blade 18. In this way, when the first blade module 24, the second blade module 26, and the damping module 50 are joined together, they form a complete wind turbine blade that, in appearance, looks like a conventional wind turbine blade made as a single-piece large article with a minimum number of joint lines.

[0032] The damping module 50 has an airfoil profile defined by its outer skin extending between a leading edge and a trailing edge. The damping module 50 further includes lateral sides defining respective first interface 52 and second interface 54. The first interface 52 is on the outer side of the damping module 52 in the spanwise direction of the blade, and the second interface 54 is on the inner side of the damping module 50 in the spanwise direction of the blade. In this context, the "spanwise direction" is considered as an indication reference system for the blade, where the reference to "inner" means towards the root of the blade and "outer" means towards the tip of the blade.

[0033] The first interface 52 is joined to a corresponding connection interface 56 of the first blade module 24, and the second interface 54 is joined to a corresponding connection interface 58 of the second blade module 26.

[0034] The first interface 56 and the second interface 58 of the damping module 50 are shown herein in a planar form and extend in the chordwise direction of the wind turbine blade, and thus can be considered perpendicular to the spanwise axis. In other words, the interfaces 56, 58 are in the form of side walls or partitions of a connection surface defined in the chordwise direction and extending substantially perpendicular to the spanwise axis. Precise perpendicularity is not necessary, but it is a way to achieve a precise docking joint between two adjacent segments of the blade. In other embodiments, the interface may extend at an angle, such as approximately + / - 30 degrees, with respect to the chordwise axis of the blade.

[0035] In this embodiment, the cross-sectional shape of the first interface 56 of the damping module 50 corresponds to the cross-sectional shape of the adjacent portion (i.e., the first connection interface 56) of the first blade module 24. Similarly, the cross-sectional shape of the second interface 54 of the damping module 50 corresponds to the cross-sectional shape of the adjacent portion of the second blade module. It can be seen that the cross-sectional shape is a prominent generally teardrop shape of the airfoil cross-section. More specifically, in this embodiment, the shapes or profiles of the first interface 52 and the second interface 54 of the damping module 50 match the corresponding shapes of the adjacent blade modules such that the blade modules 22, 24 and the damping module 50 fit together without forming any significant surface irregularities or discontinuities that would affect the airflow and thus reduce the aerodynamic efficiency of the blade. However, as will be discussed in a later embodiment, cross-sectional matching is not necessary.

[0036] As already mentioned, the damping module 50 is configured to damp the edgewise vibrations of the wind turbine blade 18 in which it is incorporated. Thus, for this purpose, the damping module 50 includes a vibration damping unit, which is generally indicated by reference numeral 60 in Figure 4 Beneficially, the vibration damping unit 60 is configured such that it can be tuned to focus on attenuating vibrations at a specific frequency of the edgewise vibration.

[0037] In Figure 4In this case, the exemplary vibration damping unit 60 is received within the damping module 50. Here, the vibration damping unit 60 is positioned between the leading edge 30 and the trailing edge 32 of the damping module 50. However, as shown, the vibration damping unit 60 is shown connected to the leading edge 60. It could alternatively be connected to the trailing edge 32. For this purpose, the leading edge 30 and the trailing edge 32 can be constructed with respective mounting brackets 62, 64 on which the vibration damping unit 60 can be mounted.

[0038] During the edgewise vibration of the blade, the leading edge 30 and the trailing edge 32 move substantially in synchronism with each other as the blade oscillates generally in the chordwise direction. Since the vibration damping unit 60 is connected to the damping module 50, it provides a reaction force to the movement, which reduces the extent of the edgewise vibration.

[0039] The vibration damping unit can generally be any article capable of resonating due to the movement of the damping module 50. It can be a tuned mass damper or a mass / rubber article elastically connected inside the damping module 50. In one embodiment, the vibration damping unit can be a mass mounted on a spring inside the damping module 50, where the mass and the spring are selected to act most effectively in attenuating vibrations of a predetermined frequency. In other embodiments, the vibration damping device can include a viscous damper connected inside the damping module 50, which in some embodiments can be configured to apply a force through the shear center of the blade section.

[0040] As Figure 4 shown, the vibration damping unit 60 can be a mass-spring-damper device 66. Thus, the spring-damper device 66 can include a hydraulic damper 70 combined with a spring 72 and a connecting mass 73. The mass-spring-damper device 66 can be configured to be very similar to a coil-over shock absorber used in automotive applications and as will be well understood by those skilled in the art. Thus, the damper 70 includes a cylinder 70a and a slidable piston rod 70b. Other spring-damper units would be acceptable. Note that in a wind turbine blade module having a structural spar in the center of the hollow interior, it is contemplated that the device 66 can be connected to one side of the structural spar from the corresponding leading or trailing edge.

[0041] As discussed, the spring-damper device 66 can be tunable. Such tuning can be constructed during manufacture so as to specify the most suitable damping coefficient and spring constant of the spring-damper device 66, thereby achieving the desired attenuation of the edgewise vibration. Another option is for the spring-damper device 66 to be provided with adjustability. For example, the hydraulic damper 70 can have the required adjustability by means of a hydraulic piston having a variable flow orifice area, thereby changing the damping coefficient. Additionally, the spring 72 can be provided with an adjustable spring constant. The mass 73 can also be configured to provide the required oscillatory characteristics.

[0042] To minimize the torsional effect on the blade, preferably, the vibration damping unit acts generally in the chordwise direction but through the shear center of the blade section in which the vibration damping unit is located. As is known to the person skilled in the art, the shear center is the point on the blade section at which a load applied will cause the blade to bend without any twist. If the vibration damping unit acts on the shear center of the blade section, it should not generate any torque on the blade that would otherwise affect the aerodynamics of the blade.

[0043] Advantageously, the damping module 50 provides a convenient way of integrating a device for damping edgewise vibrations into a modular blade. Known methods of equipping a blade with a vibration damper require the damping mechanism to be incorporated into the wind turbine blade during manufacture. Thus, embodiments of the present invention enable such functionality to be provided to a modular blade after the manufacture of the blade module has been completed. Further, since the damping module is a separate component from the blade module, maintenance can be performed on the damping module in a very convenient manner. For example, the damping module can be removed from the modular wind turbine blade for inspection or repair in the event of a fault. As an option, a replacement damping module can be incorporated into the modular wind turbine blade. A passage can be provided into the interior of the damping module to allow inspection or adjustment after installation; for example, the skin / casing of the damping module 50 can be provided with a hinged access door.

[0044] In Figure 4 an embodiment, it will be noted that the vibration damping unit 60 is housed within the damping module 50. As Figure 5 shown, in an alternative arrangement of the damping module 50, the vibration damping unit 60 is located outside the body of the damping module 50.

[0045] Referring to Figure 5 , the damping module 50 includes an airfoil body section 51 (as in the previous embodiment) connected between a first blade module 24 and a second blade module 26. However, the damping module 50 also includes a nacelle or pod 74 which, in this embodiment, is in an elongated form. The pod 74 is connected to the body section 51 by a pair of struts 76. Other connection structures will be apparent to the person skilled in the art. Similarly, for Figure 4 an embodiment of Figure 5 , the damping module 50 in

[0046] includes a vibration damping unit 60 which is embodied as a mass-spring-damper device 66. However, the spring-damper device 66 includes a suitable linkage mechanism for connecting one end of the spring-damper device 66 to a component of the body section 51 of the damping module 50. More specifically, the linkage mechanism 78 connects the cylinder 70a of the damper unit 70 to the mounting bracket 80 at the leading edge 80 of the body section 51.

[0047] As in the previous embodiments, in the Figure 5 damper module 50 arrangement, the vibration damping unit 60 is connected to the edge of the body section 51 of the damper module 50, thereby acting to provide a force opposite to the oscillatory movement of the damper module 50, thus attenuating the edge vibration. Advantageously, in this embodiment, since the vibration damping unit 60 is located outside the body section 51 of the damper module 50, it provides an opportunity to use a larger damping unit, which may be useful in some cases. Note that in any of the foregoing embodiments, the vibration damping unit may be connected to the leading edge, trailing edge, or another component of the wind turbine blade, but is configured in such a way that the force exerted by the vibration damping unit is directed through the shear center of the wind turbine blade section.

[0048] In the above embodiment, the damper module 50 has an airfoil cross-section at its interface that generally matches the cross-sections of the first damper module 24 and the second damper module 26 to which it is connected. In this context, it will be understood that due to the typical narrowing chordwise taper of the wind turbine blade, the airfoil profile may not be constant along the damper module 50 in the chordwise direction. Thus, the airfoil cross-section of the damper module 50 will gradually decrease in area along its chordwise dimension. In other embodiments, the damper module 50 may have a constant airfoil cross-section along its chordwise direction.

[0049] In other embodiments, the damper module 50 does not have to closely match the shape of the adjacent blade modules 24, 26. In some embodiments, the damper module 50 may have a different shape from the adjacent blade modules. In this case, the damper module 50 does not have to have an airfoil cross-section. For example, the damper module may be in the form of an aerodynamic-shaped torpedo pod or nacelle.

[0050] Figure 6 Another example is shown in, where parts shared with the illustrated embodiments mentioned above will be referred to using the same reference numerals. In Figure 6 , the wind turbine blade includes a first blade module 24 and a second blade module 26 and a damper module 150, as in the previous embodiments, and the damper module 150 is sandwiched between the blade modules 24, 26 in an end-to-end manner.

[0051] As in the previous embodiments, the damping module 150 includes an airfoil profile defined by its outer skin and extending between the leading edge 30 and the trailing edge 32. The airfoil cross-section defined by the damping module 150 at its spanwise ends may correspond to the airfoil cross-section of an adjacent one of the first blade module 24 and the second blade module 26. The term "correspond" means that the airfoil cross-section has the same profile as the airfoil cross-section of the associated blade module, but may be a scaled version thereof. In other words, the overall form of the airfoil cross-section may correspond, but the cross-sectional area may be larger. Alternatively, the blade module 150 may have an airfoil cross-section, although its overall form does not correspond to the airfoil cross-sections of the adjacent blade modules 24, 26.

[0052] As in the previous embodiments, Figure 6 the damping module 150 includes a first interface 52 on the outer side of the damping module 150 in the spanwise direction and a second interface 54 on the inner side of the damping module 150 in the spanwise direction. Note that in Figure 6 the first interface 52 is not visible due to the viewing angle of the damping module 150, but its position can be understood from the position of the second interface 54. In the illustrated embodiment, the connecting means between the damping module 150 and the first blade module 24 and the second blade module 26 are the same as those in Figure 2 the embodiment of Figure 2 the same way as in the embodiment of

[0053] Once the first blade module 24 and the second blade module 26 are coupled to the damping module 150, it will be understood that the outer skin of the damping module 150 will protrude or project from the surrounding airfoil surface of the blade. It should be noted that the details of the form of the oscillatory damping provided by the damping module 150 may be the same as those described above with respect to Figure 4 and Figure 5 and will not be repeated here for further discussion.

[0054] Now turning to Figure 7a and Figure 7b which shows an alternative connection scheme for the damping module 150. As shown, the damping module 150 has a similar enlarged outer profile as in Figure 6 but it should be noted that the connection scheme discussed here is different from that in Figure 7a and Figure 7bThe connection scheme shown also applies to the embodiments discussed previously.

[0055] As mentioned above, in Figure 2 and Figure 6 the connection scheme used between the first blade module 24 and the second blade module 26 and the damping module 50 / 150 in the embodiments is based on a butt joint with a bolted connection. However, in other examples, different joints are envisaged, and different mechanical fasteners are also envisaged. Two examples are lap joints and mortise joints.

[0056] Figure 7a and Figure 7b the connection schemes shown in are in the form of mortise joints, more specifically, in the form of tapered mortise joints.

[0057] In Figure 7a the first blade module 24 can be seen on the left side of the image, the second blade module 26 can be seen on the right side of the image, and the blade module 150 is located between the two blade modules.

[0058] In the previous embodiments, the first and second interfaces of the damping module are planar in form and extend perpendicular to the axis of the blade span, i.e., in the chordwise direction. However, in Figure 7a the embodiments of, the first interface 56 and the second interface 58 define part of a mortise joint. More specifically, the first interface 56 defines the protruding or "male" counterpart of the mortise joint. Thus, the first interface 56 includes two tapered surfaces 160 that extend along the axis of the blade span and thus protrude away from the body section 151 of the blade module 150.

[0059] In contrast, the second interface 58 defines the recessed or "female" counterpart of the mortise joint. In this regard, the second interface 58 is provided with two tapered surfaces 162 that taper in the direction of the body section 151 of the blade module 150 along the axis of the blade span. Thus, the tapered surfaces 162 define the form of a socket for the mating portion 164 of the second blade module 26.

[0060] Returning to the first interface 56, it can be seen that the protruding tapered surface 160 is inserted into a complementary-shaped socket 166 defined by the first blade module 24. The socket 166 thus includes a recessed tapered surface 168 that mates with the protruding surface 160 of the first interface 56. The mating surfaces 160, 168 can be bonded with a suitable adhesive that will firmly couple the first blade module 24 to the first interface 56 of the damping module 150.

[0061] A similar arrangement is provided at the joint between the second interface 58 of the damping module and the blade interface of the second blade module 26, where the tapered surface of the second interface 58 of the damping module 150 mates with the protruding tapered surface 170 of the second interface 164 of the second blade module 26. Again, a suitable adhesive is used to fix the mating surfaces 162, 170.

[0062] Figure 7b Very similar to the arrangement in Figure 7a However, it will be noted that the damping module 150 includes a first interface 56 and a second interface 58, both of which are defined by protruding tapered surfaces 172 that are complementary shaped to the recessed mating surfaces 174 defined by the respective blade interfaces of the first blade module 24 and the second blade module 26.

Claims

1. A wind turbine blade having a split blade construction, comprising: a first blade module defining an airfoil profile and a second blade module defining an airfoil profile; a damping module located between the first blade module and the second blade module; wherein the damping module includes a first blade interface for engaging with the first blade module and a second blade interface for engaging with the second blade module; and wherein the damping module includes a vibration damping unit that acts generally in the chordwise direction of the wind turbine blade to attenuate edgewise vibration, and the vibration damping unit is configured to act on the shear center of the blade section where the damping module is located; and wherein the vibration damping unit is configured to act on the leading edge or the trailing edge of the damping module, rather than on the outer skin of the damping module that extends between the leading edge and the trailing edge.

2. The wind turbine blade according to claim 1, wherein, The damping module is shaped to define an airfoil profile.

3. The wind turbine blade according to claim 2, wherein, The airfoil profile of the damping module at the first blade interface corresponds to the airfoil profile of the first blade module.

4. The wind turbine blade according to claim 3, wherein, The airfoil profile of the damping module at the first blade interface matches the adjacent airfoil profile of the first blade module.

5. The wind turbine blade according to claim 2, wherein The airfoil profile of the damping module at the second blade interface corresponds to the adjacent airfoil profile of the second blade module.

6. The wind turbine blade according to claim 5, wherein, The airfoil profile of the damping module at the second blade interface matches the adjacent airfoil profile of the second blade module.

7. The wind turbine blade according to claim 3 or claim 5, wherein, The airfoil profile of the damping module has a larger cross-sectional area than the cross-sectional area of the first blade module and / or the second blade module.

8. The wind turbine blade according to claim 1, wherein, The vibration damping unit includes at least one of a spring device, a damper device, and a mass block device to damp edgewise vibration.

9. The wind turbine blade according to claim 1, wherein, The damping module has a body, and wherein the vibration damping unit is supported outside the body.

10. The wind turbine blade according to claim 1, wherein, At least one of the first blade interface and the second blade interface of the damping module defines a respective connection surface that extends generally in the chordwise direction.

11. The wind turbine blade according to claim 10, wherein, The respective connection surface is defined by a lateral partition that is substantially perpendicular to the spanwise axis of the wind turbine blade.

12. The wind turbine blade according to claim 10 or 11, wherein, At least one of the first blade interface and the second blade interface is connected to the interfaces of the respective first blade module and second blade module by a bolted connection.

13. The wind turbine blade according to claim 10, wherein, The respective connection surface is defined by a scarf joint.

14. The wind turbine blade according to claim 13, wherein, At least one of the first blade interface and the second blade interface is connected to the interfaces of the respective first blade module and second blade module by an adhesive connection.

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