Wind turbine blade series

Abstract

In a first aspect of the invention, a series of wind turbine blades for cable-supporting a wind turbine rotor is provided. The series comprises a plurality of blades of different lengths. Each blade extends in a spanwise direction between a blade root and a blade end for connection to a hub of the cable support rotor. A blade length of each blade is defined by a spanwise distance between a blade root and a blade end. Each blade further includes an inboard portion defining a blade root, an outboard portion defining a blade end, and an intermediate portion located between the inboard portion and the outboard portion. The intermediate portion includes a cable connection point at a spanwise distance r from the blade root. The inboard portion of each blade is identical to the inboard portions of the other blades in the series. And the outer side part of each blade is the same as the outer side parts of the other blades in the series. The middle portion of each blade has a different spanwise length than the middle portions of the other blades in the series. The spanwise distance r between the cable connecting point of each blade in the series and the root of the blade is different from the spanwise distance r between the connecting point of each other blade in the series and the root of the blade. And the spanwise distance r is increased along with the increase of the blade length.

Description

Technical Field

[0001] The present invention relates generally to wind turbine blades and, more particularly, to a series of wind turbine blades for use with a cable-stayed wind turbine rotor. Background Art

[0002] There is a continuing desire to generate higher levels of electricity from both onshore and offshore wind farms. One way to achieve this is to provide modern wind turbines with larger wind turbine blades. Providing larger blades increases the swept area of ​​the rotor, enabling the wind turbine to capture more energy from the wind. However, increasing the length of the wind turbine blades increases the magnitude of the loads that the blades, hub, and blade bearings must withstand during use. For example, the flapping (flapping) loads caused by wind pressure on the blades and the edgewise loads caused by the weight of the blades are both greater with larger blades.

[0003] Wind turbine blades include a blade root that is configured to connect the blade to a hub of the wind turbine. To help withstand increased loads in use, longer blades typically have a reinforced blade root that is increased in size, e.g., a larger root diameter. However, manufacturing blades with larger reinforced blade roots increases costs and can make manufacturing and shipping such blades more difficult.

[0004] In addition to these challenges, because blade loads vary with blade length, designing and manufacturing wind turbine blades of different lengths for different wind farms or different wind turbine sites within a wind farm typically involves designing and manufacturing entirely new blades. The significant cost and engineering complexity involved in designing and manufacturing new blades limits the commercial viability of such site-specific blades. In many cases, an average or “best fit” blade may be used across an entire wind farm or across different wind farms with similar wind characteristics. This means that many turbines in a wind farm may not be able to extract the maximum available energy from the wind due to the use of suboptimal blades. Therefore, there is an opportunity to extract energy from the wind more efficiently if the cost and engineering challenges of manufacturing site-specific blades can be overcome.

[0005] It is in this context that the present invention has been developed. Summary of the invention

[0006] 2022P00046WOCN(JPHEN)

[0007] In a first aspect of the invention, a series of wind turbine blades for cable-supported wind turbine rotors is provided. The series includes a plurality of blades of different lengths, such as two, three, four, five, six or more blades of different lengths. Each blade extends in a spanwise direction (spanwise direction) between a blade root and a blade end, the blade root being used to connect to a hub of a cable-supported rotor. The blade length of each blade is defined by the spanwise distance between the blade root and the blade end. Each blade also includes an inner portion defining the blade root, an outer portion defining the blade end, and an intermediate portion located between the inner portion and the outer portion. The intermediate portion includes a cable connection point at a spanwise distance r from the blade root. The inner portion of each blade is identical to the inner portion of the other blades in the series. The outer portion of each blade is identical to the outer portion of the other blades in the series. The intermediate portion of each blade has a different spanwise length than the intermediate portions of the other blades in the series. The cable connection point of each blade in the series is different from the spanwise distance r from the connection point of each other blade in the series to the blade root. The spanwise distance r increases with the increase of blade length.

[0008] The cable connection point is configured to connect a cable of a cable-supported rotor to a wind turbine blade. The cable connection point is preferably configured to connect a cable between a blade and another blade of the cable-supported rotor. The cable may be directly connected to the cable connection point of another wind turbine blade, or may be indirectly connected, for example via another cable. The cable is configured to transfer some of the loads borne by the blade in use to another wind turbine blade and / or the hub of the wind turbine. Specifically, the cable reduces the load borne by the inner portion of the blade, thereby also reducing the amount of blade load transferred from the blade to the hub via the blade root. In addition, this reduces the weight of the inner portion of the blade compared to a blade of the same length of a non-cable supported rotor because the mechanical requirements on the inner portion of the blade are reduced. This is because some of the blade loads are transferred to the cable at the cable connection point, and then these loads are transferred to another blade and / or the hub via a separate path, thereby bypassing the blade root.

[0009] Thus, the use of cables (i.e. blade connection cables) at least reduces the extent to which the blade root size of longer blades may increase (compared to blades of a wind turbine that does not include blade connection cables), and in preferred examples, the use of blade connection cables may advantageously facilitate increasing blade length without increasing blade root size. As described above, this is because some of the blade loads are unloaded (i.e. transferred) to the cables at the cable connection point. In this way, the swept area of ​​the rotor may be increased, which means that more energy may be captured from the wind without having to increase the diameter of the blade root.

[0010] In this context, "cable" should be interpreted broadly to include examples such as flexible connecting members and rigid connecting members. For example, in this context, a "cable" can be a metal wire (e.g. steel 2022P00046WOCN (JPHEN)

[0011] The term "cable" may be a braided or laid rope of a rope made of nylon, polymer fibers (e.g. (ultra-high molecular weight) polyethylene, polypropylene, nylon, polyester, aramid fibers), inorganic fibers (e.g. carbon fibers) or a hybrid rope of these materials. It will be understood that "cable" as referred to herein also includes a rigid connecting member configured to be connected between the connection points of two blades of a wind turbine. Thus, "cable" as referred to herein may include a composite member (such as a pultrusion), or may include a metal rod, just to name a few possible examples.

[0012] For longer blades in the series, the cable connection point is located further outboard, i.e. further away from the blade root in the spanwise direction. For each blade in the series, as the blade length increases, the load on the inner part and the blade root can be kept constant, or nearly constant, by positioning the cable connection point further outboard. For example, although the blade load increases due to the increase in blade length, positioning the cable connection point further outboard means that a larger proportion of the blade load can be transmitted to the cable via the cable connection point. Therefore, the blade load changes caused by changes in blade length are mitigated by the location of the cables and the cable connection point, so that the load on the inner part and the blade root can be kept constant, or nearly constant. Therefore, positioning the cable connection point further outboard helps to provide longer wind turbine blades without having to have different inner parts and blade roots for structural purposes. Therefore, the same hub, the same blade bearings and the same blade-to-hub interface can be used for an entire rotor series in which the rotor includes blades of different lengths than the wind turbine blade series.

[0013] Each blade in the series preferably comprises a shell defining an aerodynamic profile that varies along the length of the blade. It will be understood that reference to the inner portion of each blade being identical to the inner portion of the other blades in the series means that in the inner portion of each blade in the series, at least the outer dimensions (i.e. profile) of the shell are identical to the outer dimensions (i.e. profile) of the shell of the inner portion of the other blades in the series. Thus, reference to the outer portion of each blade being identical to the outer portion of the other blades in the series means that in the outer portion of each blade in the series, at least the outer dimensions (i.e. profile) of the shell are identical to the outer dimensions (i.e. profile) of the shell of the outer portion of the other blades in the series.

[0014] In a preferred example, the "same" parts of different blades in the series may have further similarities, except that at least the outer dimensions (i.e., the profile) of the housing are identical to the corresponding parts of the blades in the series. By way of brief example only, in some examples, the "same" parts of different blades in the series may each have additional equivalent features, such as structural elements, sensors, heating elements, lightning conductors, etc.

[0015] In some examples, different blades in the series may include different supplemental features, such as vortex 2022P00046WOCN (JPHEN)

[0016] flow generators, gurney flaps, stall fences, serrated edges or other additional features attached to the outer shell of the blade. It will be understood that reference to a particular portion of each blade being identical to a corresponding portion of another blade in the series refers to the blade itself, without regard to any supplementary features that may be attached to the blade. For example, it will be understood that a blade in the series may include vortex generators arranged on a blade shell in the inboard portion of the blade, and such inboard portion may still be referred to as being "identical" to the inboard portion of another blade in the series that does not include vortex generators. It will be understood that this is just one of many possible examples.

[0017] In some examples, the outer portion of each blade may include at least 30% of the length of the blade. In a preferred example, the outer portion of each blade may include at least 35% to 70% of the length of the blade. For example, the outer portion of each blade may include at least 40% of the length of the blade. In other examples, the outer portion of each blade may include at least 45% or at least 50% of the length of the blade. Configuring each blade in the series so that the outer portion includes at least 30% of the length of the blade reduces the production cost of the blade series because a considerable portion of each blade is the same, thereby enabling the use of large-scale manufacturing techniques to manufacture the outer portion of each blade, and / or facilitating the reuse of blade molds or mold parts for blades of different lengths in the blade series. Since mold costs and lead times for new molds may be high, this design feature of the blade series greatly reduces the blade manufacturing cost and flexibility of the blade series. In particular, this greatly enhances the use of multiple members of a blade series instead of a single blade (or multiple blades that have been significantly redesigned and use completely independent molds) in a wind turbine fleet.

[0018] In some examples, the blade root of each blade may include a bolt circle. Preferably, the bolt circle of each blade has the same diameter. The term "bolt circle" may refer to an arrangement of bolts extending from the blade root to connect the blade to the hub of a cable-supported rotor. Alternatively, the term "bolt circle" may refer to an arrangement of holes or drill holes configured to facilitate the arrangement of bolts to connect the blade to the hub of a cable-supported rotor. Configuring each blade in a series of wind turbine blades to have a bolt circle of the same diameter means that each blade can be attached to the same hub, i.e., to a hub of the same design, despite different blade lengths. Providing the same interface for connecting the blade to the hubs of different rotors can reduce cost and engineering complexity, as the same rotor hub can be used for rotors of a variety of different diameters.

[0019] It will be understood that references to the "same hub" or "same rotor hub" refer to the main configuration of the rotor hub, i.e. the structural features of the hub and the interfaces for connecting the blades to the hub (same). It will therefore be understood that different examples of the "same rotor hub" may include different supplementary features, for example features for attaching different components, such as blade connection cable tensioning systems and / or aerodynamic devices.

[0020] As previously mentioned, each blade preferably includes a housing defining a space that varies along the length of the blade.

[0021] Aerodynamic profile. Each blade may have a substantially constant aerodynamic profile across the spanwise section of the intermediate portion. In some examples, the length of the spanwise section may increase as the blade length increases. For example, the series may include a plurality of blades of different lengths, where the different blade lengths are caused by different lengths of the spanwise section of each blade having a constant aerodynamic profile. As will be described in more detail later with reference to other examples, it will be appreciated that varying the length of the spanwise section having a constant aerodynamic profile is only one of a number of different ways to achieve different blade lengths for blades in the series.

[0022] In some examples, the cable connection point for each blade may be located in a spanwise section having a constant aerodynamic profile. The spanwise section having a constant aerodynamic profile may be structurally reinforced or may have greater strength than surrounding portions of the blade where the aerodynamic profile changes. Thus, the spanwise section having a constant aerodynamic profile may provide a structurally advantageous location for the cable connection point to transfer loads between the blade and the connecting cable.

[0023] In some examples, the blade is a modular wind turbine blade (also called a split blade) that includes an inner blade module and an outer blade module. The inner blade module preferably defines an inner portion of the blade and at least a portion of a middle portion of the blade. The entire outer portion of each blade is preferably defined by the outer blade module. This configuration reduces manufacturing complexity, meaning that tools and blade molds or mold parts can be reused to form different blade portions of different lengths in a blade series.

[0024] In particular, providing the blades in a series of wind turbine blades as modular components may improve transport convenience. For example, blade modules may be transported individually to a wind turbine site and then assembled to form a modular blade. Thus, modular blades may be transported to wind turbine sites that are inaccessible to conventional (i.e. non-modular) blades of the same length. Providing wind turbine blades in a series as modular wind turbine blades may be particularly advantageous for blades having a length of more than 80 m.

[0025] Conventional, i.e., non-modular wind turbine blades may be referred to herein as “full-length blades”. It will be understood that “full-length blades” as used herein refer to blades in which the main body of the wind turbine blade shell is manufactured (e.g., molded) in a blade manufacturing facility before the blade is transported to the wind turbine site. In some examples, the full-length blade may be formed from two half shells joined together. Alternatively, in other examples, the full-length wind turbine blade may be formed as a single molded body. It will be understood that the terms “full-length blade” or “conventional blade” are used herein only as a distinction between typical wind turbine blades and modular wind turbine blades, i.e., modular wind turbine blades are not full-length or 2022P00046WOCN(JPHEN)

[0026] Conventional wind turbine blades.

[0027] The outer blade module of each blade can be identical to the outer blade modules of other blades in the series of wind turbine blades. Therefore, in some examples, a large number of outer blade modules can be manufactured using mass production techniques as standard components common to the series of blades. This can help promote cost-effective manufacturing of wind turbine blades in the series.

[0028] Alternatively, in some examples, the outboard blade module of each blade may have a different spanwise length compared to the outboard blade modules of other blades in the series of wind turbine blades. In this case, the outboard blade module includes an outboard portion of the blade and a portion of the middle portion of the blade. Thus, the blade length variation of the blades in the series may be at least partially caused by the outboard blade modules of different lengths. This may help facilitate a greater variation in the length of the blades in the series.

[0029] In some examples, the inner blade module of each blade may have a different spanwise length compared to the inner blade modules of other blades in the series of wind turbine blades. Thus, the blade length variation of the blades in the series may be caused at least in part by the inner blade modules of different lengths. In particular, this facilitates the use of the same outer blade modules on blades of different lengths in the series. As previously mentioned, this may mean that a large number of outer blade modules may be manufactured using mass production techniques as standard components common to the blade series.

[0030] In some examples, the inner blade module of each blade can have a different pre-bend compared to the inner blade modules of other blades in the wind turbine blade series. The pre-bend refers to the angle at which the inner blade module can be bent or flexed, that is, the angular offset between the relative first and second ends of the inner blade module. Changing the pre-bend of the inner blade module changes the angle at which the blade extends from the hub when the cable-supported rotor is assembled, and therefore, changing the pre-bend changes the taper angle of the cable-supported rotor. Therefore, advantageously, this can facilitate providing site-specific cable-supported rotors with different taper angles, wherein each rotor has blades from the wind turbine blade series.

[0031] In some examples where the blades are modular wind turbine blades, each blade preferably includes a joint connecting an outer blade module to another blade module. The cable connection point of each blade can be located at the joint. The joint can be reinforced to safely and efficiently transfer loads between the blade modules. Therefore, the joint can provide a structurally advantageous location for transferring loads from the blade to the cable via the cable connection point. In addition, in some examples, the joint may disrupt the airflow over the blade, and the cable connection point may also disrupt the airflow over the blade. Therefore, it may be advantageous to provide the cable connection point and the joint at the same location to minimize the overall disturbance of the airflow over the blade during use. When cable 2022P00046WOCN(JPHEN)

[0032] When a cable connection point is arranged at a joint between blade modules, both modules are considered to include the cable connection point.

[0033] In some examples, the inner blade module of each blade may include a cable connection point. Because the inner blade module is relatively close to the rotor axis, it generally covers a smaller swept area than the outer blade module during use. Therefore, the configuration of the inner blade module may have a smaller impact on the overall aerodynamic performance of the blade than the outer blade module. Therefore, the inner blade module may be configured more specifically for structural performance rather than aerodynamic performance, while the outer blade module may be configured primarily for aerodynamic performance. Therefore, providing a cable connection point on the inner module may be beneficial for transferring loads between the blade and the cable, and may also reduce noise and reduce the impact of drag generated by the cable connection point.

[0034] Alternatively, in some examples, the outboard blade module of each blade may include a cable connection point. In such examples, changes in blade length and changes in spanwise positions of cable connection points may be achieved by changing the spanwise length of the inboard blade module.

[0035] In some examples, each modular wind turbine blade may also include an intermediate blade module connected between the inner blade module and the outer blade module. The intermediate blade module of each blade may include a cable connection point. Including the intermediate blade module may facilitate an expansion of the blade length range of the blades in the series. In addition, including the intermediate blade module may facilitate standardization of a greater proportion of each blade in the series of blades, as will be explained later.

[0036] In some examples, each blade in the series may include an intermediate blade module having a different spanwise length than the intermediate blade modules of other blades in the series of wind turbine blades. Thus, variations in blade length and spanwise location of cable connection points may be achieved at least in part by providing different intermediate blade modules for different blades in the series.

[0037] Thus, in some examples where the blades in the series include an intermediate blade module, the inner blade module of each blade may be identical to the inner blade module of the other blades in the series of wind turbine blades. Furthermore, in some examples where the blades in the series include an intermediate blade module, the outer blade module of each blade may be identical to the outer blade module of the other blades in the series of wind turbine blades. Thus, a series of wind turbine blades may include inner and / or outer blade modules that are common to each blade in the series. By including a different intermediate blade module for each blade in the series, this may reduce cost and part count while still achieving different blade lengths for each blade and different spanwise locations of cable connection points.

[0038] 2022P00046WOCN(JPHEN)

[0039] In some examples, the spanwise distance r may be between 25% and 60% of the total blade length. In a preferred example, the spanwise distance r may be between 40% and 50% of the total blade length. Positioning the cable connection point at the spanwise distance r between 25% and 60% of the total blade length facilitates favorable transfer of loads from the blade to the cable via the cable connection point, while also making the majority of the spanwise portion of each blade identical to the other blades in the series.

[0040] In some examples, the outer portion of each blade comprises a winglet. In particular, the end of the blade can be formed by a winglet. The example in which the outer portion of each blade comprising a winglet is defined by an outer blade module is found to be particularly advantageous, and the outer blade module is generally more flexible than the full-length blade and has a lower maximum thickness and chord length, which makes the transportation of the outer blade module with the winglet much easier than the transportation of the full-length blade with the winglet.

[0041] In another aspect of the present invention, a cable-supported wind turbine rotor is provided, the cable-supported wind turbine rotor comprising a plurality of wind turbine blades from the series of wind turbine blades as described above. The cable-supported rotor further comprises a rotor hub and a plurality of blade connection cables, each blade connection cable being connected between corresponding cable connection points of a pair of wind turbine blades.

[0042] In a preferred example, the blades in the series are configured to be attached to the hub of the cable supported rotor via respective pitch mechanisms. Hence, the blades in the series of wind turbine blades may be referred to as variable pitch wind turbine blades, and the series may be referred to as a series of variable pitch wind turbine blades. Hence, the cable supported wind turbine rotor may be referred to as a cable supported variable pitch rotor (CSPR). BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Examples of the present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0044] Figure 1 is a schematic perspective view of a wind turbine comprising a cable-supported rotor equipped with a plurality of wind turbine blades from a series of wind turbine blades;

[0045] Figure 2 A series of wind turbine blades of different lengths are schematically shown, comprising blade portions common to each blade in the series;

[0046] Figure 3 A family of wind turbine blades of different lengths is schematically shown, comprising blades having span-wise sections of constant aerodynamic profile of different lengths;

[0047] Figure 4A family of modular wind turbine blades of different lengths is schematically shown, wherein each blade comprises an inboard module having a different spanwise length;

[0048] Figure 5 Schematic diagram of a series of modular wind turbine blades of different lengths, each of which is 2022P00046WOCN (JPHEN)

[0049] The blade’s cable connection points are located at the joints between blade modules;

[0050] Figure 6 A series of modular wind turbine blades of different lengths is schematically shown, wherein each blade has an inner module, the inner sections having different pre-cambers;

[0051] Figure 7 schematically illustrates a family of modular wind turbine blades of different lengths, wherein each blade comprises outer modules having different spanwise lengths; and

[0052] Figure 8 A series of wind turbine blades of different lengths is schematically shown, wherein each blade comprises an intermediate module of different lengths located between an inner module and an outer module. DETAILED DESCRIPTION

[0053] Figure 1 A wind turbine 10 is shown, which comprises a tower 12 and a nacelle 14 mounted on the tower 12. A rotor 16 is mounted on the nacelle 14, the rotor 16 comprising a hub 18 and a plurality of wind turbine blades 20. In this example, the wind turbine 10 comprises three wind turbine blades 20. The blades 20 may be variable pitch wind turbine blades 20, i.e. the pitch of the blades 20 may be adjustable. Thus, the wind turbine blades 20 may be connected to the hub 18 via respective pitch mechanisms (not shown), by means of which the blades 20 may be rotated relative to the hub 18. Thus, in a preferred example, the pitch of the wind turbine blades 20 may be controlled and adjusted depending on the relative speed of the incident wind to ensure that the blades 20 are oriented at a favorable angle of attack in order to capture energy from the wind.

[0054] The wind turbine blades 20 will be described in more detail later with reference to the remaining figures, but by way of brief description, each wind turbine blade 20 extends in a spanwise direction between a blade root 22 and a blade tip 24. The blade root 22 is preferably configured to be directly connected to the hub 18 (e.g., Figure 1 ), or connected to the hub 18 via another wind turbine component such as a blade root extension (not shown). Figures 2 to 8, each blade 20 includes a cable connection point 26 that is configured to facilitate connecting a blade connection cable 28 to the wind turbine blade 20. It will be appreciated that the cable connection point 26 is a means for connecting the blade connection cable 28 to the wind turbine blade 20, and the present invention is not limited to any particular configuration of the cable connection point 26. Accordingly, the cable connection points 26 shown in the drawings are provided by way of example only.

[0055] like Figure 1 As shown, the wind turbine 10 may include a plurality of blade connection cables 28, and each blade connection cable 28 is preferably connected between corresponding cable connection points 26 of a pair of wind turbine blades 20. The blade connection cable 28 is configured to transfer some of the loads to which the blade 20 is subjected during use to another wind turbine blade 20 and / or the hub 18. Therefore, the blade connection cable 282022P00046WOCN(JPHEN)

[0056] The loads borne by the inboard portion 30 of the blade 20 may be reduced, and thus the amount of blade load transferred from the blade 20 to the hub 18 via the blade root 22 may also be reduced. This is because some of the blade loads are transferred to the blade connection cables 28 at the cable connection points 26, and these loads are then transferred to another blade 20 or the hub 18 via a separate path, thereby bypassing the inboard portion 30 and the blade root 22. A wind turbine rotor 16 that includes cables 28 connected between the blades 20 of the rotor 16 may be referred to as a cable-supported rotor 16.

[0057] Also refer to Figure 2 , the cable-supported rotor 16 may be equipped with blades 20 from a series 32 of wind turbine blades 20. The series 32 of wind turbine blades includes blades 20 having different lengths R. Thus, different blades 20 from the series 32 may be selected for use with different wind turbines 10 depending on a variety of factors, such as wind characteristics at a particular wind turbine site, to optimize the wind turbine 10 to capture energy from the wind at the particular site. As will be described in greater detail later, each blade 20 in the series 32 of wind turbine blades includes blade portions that are identical to corresponding portions of other blades 20 in the series, which helps facilitate cost-effective manufacturing of the blades 20 in the series 32.

[0058] The blades 20 preferably each include an outer shell 34 that defines an aerodynamic profile configured to generate lift when wind strikes the blades 20 in use. The aerodynamic profile of each blade 20 varies along the spanwise length R of the blade 20. For example, the blade 20 may include a relatively thicker airfoil profile near the blade root 22 to increase strength, and a relatively thinner airfoil profile near the blade tip 24 to reduce blade mass and generate more lift from incident wind.

[0059] like Figure 2 As shown, each blade 20 in the series 32 includes an inner portion 30 defining a blade root 22, and the end 24 of each blade 20 is defined by an outer portion 36. Each blade 20 has a blade length R defined by a spanwise distance between the blade root 22 and the blade end 24. Each blade 20 in the series 32 also includes an intermediate portion 38 located between the inner portion 30 and the outer portion 36. The intermediate portion 38 includes a cable connection point 26 that is spaced a spanwise distance r from the blade root 22.

[0060] Still refer to Figure 2 , the cable connection point 26 of each blade 20 in the series 32 is located at a different spanwise distance r from the blade root 22 than other blades 20 in the series 32. It is noteworthy that the spanwise distance r increases with increasing blade length R, i.e., the cable connection point 26 is located further outboard on longer wind turbine blades 20 in the series 32. In a preferred example, the cable connection point 26 of each blade 20 in the series 32 is located at a spanwise distance r from the blade root 22 of between 25% and 60% of the total blade length R. Positioning the cable connection point 26 further outboard of the longer blades 202022P00046WOCN(JPHEN) in the series 32 helps to ensure that the blade loads in the inner portion 30 and the loads transmitted to the hub 18 via the blade root 22 remain substantially consistent on all blades 20 in the series 32, despite the differences in blade length R. This means that the blades 20 in the series 32 may be manufactured with a blade portion 30 , 36 that is common to all blades 20 in the series 32 , despite the fact that the blade length R varies.

[0061] like Figure 2 As shown, the inboard portion 30 of each blade 20 is identical to the inboard portion 30 of the other blades 20 in the series 32. As described above, by using the blade connection cables 28 (which help to keep the blade loads in the inboard portion 30 of each blade 20 substantially the same despite the differences in blade length R), it is possible to provide an identical inboard portion 30 on each blade 20 in the series 32. This means that the blade root 22 (i.e., the interface for connecting the blade 20 to the hub 18) can be identical on each blade 20 in the series 32. For example, the blade root 22 of each blade 20 can include a bolt circle (i.e., an arrangement of bolts extending from the blade root 22 or an arrangement of drill holes for receiving bolts) arranged around the blade root 22. Preferably, the bolt circle of each blade 20 has the same diameter. This means that, despite the differences in blade length R, each blade 20 in the series 32 can be assembled to a rotor hub 18 having the same style or design, which reduces design costs and simplifies manufacturing.

[0062] The outer portion 36 of each blade 20 is identical to the outer portions 36 of the other blades 20 in the series 32. Providing the same outer portion 36 for each blade 20 in the series 32 may mean that the same blade molding equipment may be used to manufacture the outer portions 36 of blades 20 of different lengths. In addition, in some examples, manufacturing each blade 20 with the same outer portion 36 may facilitate the use of high-volume manufacturing methods to manufacture the outer portions 36 of the blades 20. In some preferred examples, the outer portion 36 of each blade 20 may include at least 30% of the total blade length R. Therefore, a substantial portion of each blade 20 may be identical, thereby facilitating cost-effective manufacturing of blades 20 of different lengths in the series 32.

[0063] Still refer to Figure 2 , the middle portion 38 of each blade 20 has a different spanwise length compared to the middle portions 38 of the other blades 20 in the series 32. Thus, while each blade 20 in the series 32 has the same inboard portion 30, and each blade 20 in the series 32 has the same outboard portion 36, the difference in blade length R is achieved by varying the spanwise length of the middle portion 38 of each blade 20.

[0064] As will be described in more detail later with reference to the remaining figures, the length variation of the intermediate portion 38 can be achieved in a variety of different ways. For example, the blades 20 in the series 32 can be modular 2022P00046WOCN (JPHEN)

[0065] Leaves, as later referred to Figures 4 to 8 As described in the example of , or alternatively, the blade 20 may be formed as a full-length blade in a manufacturing facility.

[0066] Although not shown in the drawings, one possible method of manufacturing the full-length blade series 20 may involve the use of a modular blade mold. For example, the modular blade mold may include an inner mold part for molding the inner portion 30 of the blade 20, and an outer mold part for molding the outer portion 36 of the blade 20. The same inner mold part and outer mold part can be used to mold the inner portion 30 and the outer portion 36 of each blade 20 in the series 32. The modular blade mold may also include one or more intermediate mold parts for molding the middle portion 38 of the blade 20. Different intermediate mold parts can be used to mold blades 20 of different lengths R, each blade 20 having a middle portion 38 of different lengths. The chord length and thickness of the middle section can decrease monotonically with the extension of the blade; however, the middle section can have a section with a constant thickness and / or chord length or even increasing with the extension. Specifically, the thickness and / or chord length of the blade can have a local maximum at the cable connection point 26.

[0067] Although in one example the inner and outer mould parts may be identical for the entire blade series, it has been found that advantageously the inner and outer mould parts may advantageously be arranged with different twists for individual members of the blade series. In particular, it has been found that the longer the middle mould part (and therefore the longer the distance between the inner and outer mould parts), the greater the twist between the inner and outer mould parts, as this allows a closer fit to the perfect aerodynamic profile of the blade. Such a mould may be used for a wind turbine blade series, wherein each blade in the wind turbine blade series has a first chord length of the blade at the interface between the inner part and the middle part, and a second chord length of the blade at the interface between the outer part and the middle part, wherein for each blade the first chord length is rotated at a different twist angle relative to the second chord length, and the twist angle increases with increasing blade length R.

[0068] Figure 3 An example of a series 32 of wind turbine blades 20 for a cable-supported wind turbine rotor 16 is shown, wherein each blade 20 in the series 32 has a spanwise section 40 of a mid-portion 38, and the aerodynamic profile of the shell 34 is substantially constant throughout the spanwise section 40. Figure 3 As shown, the cable connection point 26 of each blade 20 may be located in a spanwise section 40 having a constant aerodynamic profile. Variation of the blade length R may be achieved by varying the length of the spanwise section 40. For example, the length of the spanwise section 40 may increase as the blade length R increases.

[0069] In some examples, a blade 20 having a spanwise section 40 of constant aerodynamic profile may be manufactured using a modular blade mold as described above. In such an example, the modular blade mold 2022P00046WOCN (JPHEN)

[0070] The mold may include one or more intermediate mold parts that define a mold surface having a substantially constant profile across the entire spanwise section of the mold. In some examples, such a modular blade mold may include one or more intermediate mold parts, each of which has a constant profile, and the number of such constant profile mold parts and / or the combined spanwise length of such constant profile mold parts may be varied to form blades 20 of different lengths R having spanwise sections 40 of constant aerodynamic profile of different lengths. The inboard section 30 of each blade 20 is identical to the inboard sections 30 of the other blades 20 in the series 32, for Figure 3In the series of blades in FIG. 1 , the inner portion 30 includes the region where the chord length of the blade 20 is the largest. When the middle portion 38 has a spanwise section of constant aerodynamic profile, then that section may be arranged next to the inner portion (not shown), or the section of the middle portion that does not have a constant aerodynamic profile may be arranged between the inner portion and the portion of the middle portion that has a constant aerodynamic profile (e.g. Figure 3 shown).

[0071] Reference now Figure 4 In some examples, the wind turbine blade series 32 may be a modular wind turbine blade series 20. For example, the blade 20 may include an inner blade module 42 and an outer blade module 44. The inner blade module 42 may be connected to the outer blade module 44 at a joint 46. The inner blade module 42 preferably defines at least a portion of the inner portion 30 of the blade 20 and the middle portion 38 of the blade 20. In the example shown in FIG. Figure 4 In the preferred example shown, the entire outboard portion 36 of each blade 20 is preferably defined by the outboard blade module 44 .

[0072] In some examples, the outboard blade module 44 of each blade 20 may be identical to the outboard blade modules 44 of the other blades 20 in the series 32, such as Figure 4 This configuration may facilitate cost-effective manufacturing of the blades 20 in the series 32 because the outboard modules 44 may be manufactured in large quantities as a standard component common to all blades 20 in the series 32 .

[0073] Still refer to Figure 4 Variation of the blade length R of the blades 20 in the series 32 may be achieved at least in part by providing different inner blade modules 42 for different blades 20. For example, the inner blade module 42 of each blade 20 may have a different spanwise length compared to the inner blade modules 42 of other blades 20 in the series 32. Figure 4 In the illustrated example, the inboard blade module 42 of each blade 20 includes a cable connection point 26, however, it will be appreciated that in some other examples, the outboard blade module 44 of each blade 20 may include a cable connection point 26. Furthermore, in some examples (not shown), the series 32 may include blades 20 having inboard blade modules 42 of varying lengths and outboard blade modules 44 of varying lengths.

[0074] Brief reference Figure 5 In some examples, the cable connection point 2022P00046WOCN (JPHEN) of each blade 20 in the series 32

[0075] The connection point 26 may be located at a joint 46 connecting the inner blade module 42 and the outer blade module 44. The modular blade 20 may be reinforced in the area near the joint 46 to ensure safe and efficient transfer of loads between the blade modules 42, 44 in use. Thus, the joint 46 may present an advantageous location for transferring loads from the modular blade 20 to the blade connection cables 28 via the connection point 26.

[0076] exist Figure 5 In the example shown, the series 32 includes blades 20 having identical outboard modules 44 and different length inboard modules 42. However, it will be appreciated that in other examples where the blades 20 in the series 32 have different inboard blade modules 42 and different outboard blade modules 44, the cable connection points 26 may be similarly located at the joints 46 between the blade modules 42, 44.

[0077] Figure 6 Another example of a series 32 of wind turbine blades 20 of different lengths for cable-supported rotors 16 is shown. In this example, different blades 20 in the series 32 have different pre-cambers. For example, Figure 6 As shown, in some examples, the inboard blade module 42 of each blade 20 may have a different pre-camber than the inboard blade modules 42 of other blades 20 in the series 32. Thus, different inboard blade modules 42 may include different angular offsets between the inboard ends 48 and outboard ends 50 of the inboard modules 42. This configuration may advantageously enable assembly of site-specific blades 20 for different cable-supported wind turbine rotors 16 having different tapers.

[0078] Although Figure 6 Each blade 20 in the blade series 32 shown by way of example in FIG. 1 includes the same outboard module 44 , but it will be appreciated that in other examples, the blades 20 in the series 32 may include a combination of different outboard blade modules 44 and inboard blade modules 42 having different pre-cambers.

[0079] Figure 7 An example of a series 32 of modular wind turbine blades 20 is shown in which the outboard blade modules 44 of each blade 20 have a different span-wise length than the outboard blade modules 44 of the other blades 20 in the series of wind turbine blades 32. In some examples, such as Figure 7 As shown, the series 32 may include blades 20 each having the same inboard blade module 42 , and thus variations in blade length R and spanwise position r of the cable connection point 26 may be achieved by providing different outboard blade modules 44 .

[0080] It will be appreciated that although in this example, the spanwise length of each outboard blade module 44 may be different for different blades 20, the outboard portion 36 of each blade 20 in the series 32 is the same. This facilitates the reuse of blade molds and / or blade mold components to form outboard blade modules 44 of different lengths. Thus, in such an example, the outboard blade modules 44 may define at least a portion of the middle portion 38 of the blade 20 to provide a variation in blade length R. Thus, as shown in FIG. Figure 7 As shown, the outer blade module 44 of each blade 20 may include a cable connection point 26 and change the outer mold 2022P00046WOCN (JPHEN)

[0081] The spanwise length of block 44 may also change the spanwise location r of cable connection point 26 .

[0082] Now refer to Figure 8 In some examples, the blade series 32 may include a blade 20 having an intermediate blade module 52 connected between the inner blade module 42 and the outer blade module 44. In such an example, the intermediate blade module 52 of each blade 20 may include a cable connection point 26. Providing the cable connection point 26 on the intermediate blade module 52 facilitates a variety of different blade configurations by which the blade length R and the spanwise position r of the cable connection point 26 can be varied.

[0083] For example, Figure 8 As shown, each blade 20 in the series 32 may include an intermediate blade module 52 having a different spanwise length than the intermediate blade modules 52 of other blades 20 in the wind turbine blade series 32. Thus, variations in blade length R and spanwise position r of cable connection points 26 may be achieved at least in part by providing different intermediate blade modules 52 for different blades 20. In addition, although Figure 8 Not shown, but in some examples, one or more blades 20 in the series 32 may include a plurality of intermediate blade modules 52 .

[0084] In some examples, such as Figure 8In the example shown in , the inner blade module 42 of each blade 20 can be the same as the inner blade module 42 of other blades 20 in the series 32. In addition, in some preferred examples, the outer blade module 44 of each blade 20 can be the same as the outer blade module 44 of other blades 20 in the series. Therefore, in some examples, the inner module 42 and the outer module 44 can be the same in different blades 20 in the series. In such an example, the change in blade length R and the change in the spanwise position r of the cable connection point 26 can be completely achieved by the change of the middle blade module 52. This configuration facilitates the use of standardized inner blade modules 42 and outer blade modules 44 in blades 20 of different lengths in the series 32. This in turn enables the use of large-scale manufacturing methods to make the inner blade modules 42 and the outer blade modules 44, thereby reducing costs.

[0085] Although not shown in the figures, in some examples, the blades 20 in the series 32 may each include the same intermediate module 52. In such examples, the blades 20 in the series 32 may each include a different inner module 42 and / or a different outer module 44 compared to the inner / outer modules 42 / 44 of other blades 20 in the series 32. Moreover, in some other examples, the blades 20 in the series 32 may each alternatively include a different intermediate module 52 and / or a different inner module 42 and / or a different outer module 44 compared to the intermediate, inner and outer modules 52, 42, 44 of other blades 20 in the series 32. It will be understood that the description of the examples of the inner blade modules 42 and the outer blade modules 44 provided previously also applies to the blade 20 also including one or more intermediate modules 2022P00046WOCN(JPHEN)

[0086] Example of 52.

[0087] The description provided herein is used to illustrate multiple possible examples of the present invention. The examples above and the examples in the accompanying drawings are used to illustrate a non-exhaustive list of non-limiting examples. In particular, it will be understood that the features described with respect to any of the examples above can be easily combined with any other features described with reference to different examples without departing from the scope of the present invention defined in the appended claims.

[0088] For example, it will be appreciated that the location of the cable connection point 26 on a particular blade module 42, 44, 52 or at the joint 46 between blade modules is not necessarily limited to or linked to other features described in the corresponding examples above. For example, although not shown in the figures, in some examples, the cable connection point 26 may be located at the joint between the outer module 44 and the middle module 52, so that both the outer module 44 and the middle module 52 include the cable connection point 26.

[0089] Additionally, in some examples, the series 32 of wind turbine blades 20 may include one or more modular wind turbine blades 20 (eg, Figures 4 to 8 ), and one or more full-length wind turbine blades 20 (e.g. Figure 2 shown).

[0090] Although attached Figures 2 to 8 Three different blades 20 from a respective wind turbine blade series 32 are each shown, but it will be understood that each wind turbine blade series 32 may include any number of a plurality of different wind turbine blades 20. Furthermore, it will be understood that in a preferred example, each cable-supported rotor 16 equipped with blades 20 from a wind turbine blade series 32 includes a plurality of identical blades 20. For example, a first cable-supported rotor 16 may include a plurality of identical blades 20 from a wind turbine blade series 32, such as three identical blades 20. A second cable-supported rotor 16 may include the same plurality of second wind turbine blades 20 from the same series 32 as the blades 20 of the first rotor 16, and the blades 20 of the second rotor 16 may be different than the blades 20 of the first rotor 16, such as having a different length R and / or a different pre-camber.

Claims

1. A wind turbine blade series (32) for a cable-supported wind turbine rotor (16), the series (32) comprising a plurality of blades (20) of different lengths, each blade extending in a spanwise direction between a blade root (22) and a blade end (24), the blade root (22) being adapted to be connected to a hub (18) of the cable-supported rotor (16), the blade length R of each blade being defined by the spanwise distance between the blade root and the blade end; Each blade also includes: an inner portion (30) defining a root of the blade; an outer portion (36) defining an end of the blade; as well as an intermediate portion (38) between the inner portion and the outer portion, the intermediate portion comprising a cable connection point (26) at a spanwise distance r from the blade root; wherein the inner portion of each blade is identical to the inner portions of the other blades in the series, the outer portion of each blade is identical to the outer portions of the other blades in the series, and the middle portion of each blade has a different spanwise length than the middle portions of the other blades in the series; and wherein the cable connection point of each blade in the series has a different spanwise distance r from the blade root than the connection point of each other blade in the series, and wherein the spanwise distance r increases as the blade length R increases.

2. The wind turbine blade series (32) according to claim 1, wherein: The outer portion (36) of each blade (20) comprises at least 30% of the length R of said blade, preferably comprises from 35% to 70% of the length R of said blade.

3. A series of wind turbine blades (32) according to claim 1 or claim 2, wherein: The outboard portion (36) of each blade (20) includes a winglet.

4. A series of wind turbine blades (32) according to any preceding claim, wherein: Each blade (20) includes a shell (34) defining an aerodynamic profile that varies along the length of the blade; 2022P00046WOCN(JPHEN) wherein each blade has a substantially constant aerodynamic profile across a spanwise section (40) of the intermediate portion; and The length of the spanwise section increases as the length R of the blade increases.

5. The series of wind turbine blades (32) according to claim 4, wherein: The cable connection point (26) of each blade (20) is located in a spanwise section (40) having a constant aerodynamic profile.

6. A series of wind turbine blades (32) according to any one of the preceding claims, wherein: Each blade in the series of wind turbine blades (32) has a first chord length of the blade at an interface between the inner portion and the middle portion, and a second chord length of the blade at an interface between the outer portion and the middle portion, For each blade, the first chord length is rotated at a different twist angle relative to the second chord length, and the twist angle increases as the blade length R increases.

7. A series (32) of wind turbine blades according to any preceding claim, wherein: The blade (20) is a modular wind turbine blade comprising an inner blade module (42) and an outer blade module (44), wherein the inner blade module defines an inner portion (30) of the blade and at least a portion of a middle portion (38) of the blade, and wherein the entire outer portion (36) of each blade is defined by the outer blade module (44).

8. The series (32) of wind turbine blades according to claim 7, wherein: The outer blade module (44) of each blade (20) is identical to the outer blade modules of other blades in the series of wind turbine blades.

9. The series of wind turbine blades (32) according to claim 7, wherein: The outboard blade module (44) of each blade (20) has a different span-wise length compared to the outboard blade modules of other blades in the series of wind turbine blades.

10. A series (32) of wind turbine blades according to any one of claims 7 to 9, 2022P00046WOCN (JPHEN) in, The inner blade module (42) of each blade (20) has a different span-wise length compared to the inner blade modules of other blades in the series of wind turbine blades.

11. A series of wind turbine blades (32) according to any one of claims 7 to 10, wherein: The inner blade module (42) of each blade (20) has a different pre-camber compared to the inner blade modules of other blades in the series of wind turbine blades.

12. A series (32) of wind turbine blades according to any one of claims 7 to 11, wherein: Each blade (20) comprises a joint (46) connecting the outer blade module (44) to another blade module (42, 52), and wherein the cable connection point (26) of each blade is located at the joint.

13. A series of wind turbine blades (32) according to any one of claims 7 to 12, wherein: The inboard blade module (42) of each blade (20) comprises the cable connection point (26).

14. A series of wind turbine blades (32) according to any one of claims 7 to 13, wherein: The outboard blade module (44) of each blade (20) comprises the cable connection point (26).

15. A series (32) of wind turbine blades according to any one of claims 7 to 14, wherein: Each blade (20) further comprises an intermediate blade module (52) connected between the inner blade module (42) and the outer blade module (44), and wherein the intermediate blade module of each blade comprises the cable connection point (26), preferably, each blade (20) comprises an intermediate blade module (52), and the intermediate blade module (52) has a different span length compared to the intermediate blade modules of other blades in the wind turbine blade series.

16. A series of wind turbine blades (32) according to claim 14 or claim 15, wherein: The inner blade module (42) of each blade (20) is identical to the inner blade modules of other blades in the series of wind turbine blades.

17. A series (32) of wind turbine blades according to any preceding claim, wherein: The spanwise distance r is between 25% and 60% of the total blade length R, preferably between 40% and 50% of the total blade length R.

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