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Morphing segmented wind turbine and related method — University Of Virginia Patent Foundation (US11466660B2)

University Of Virginia Patent Foundation · Google Patents

Google Patents · Patents · License: Open Access

patent, google patents, intellectual property, US11466660B2, University Of Virginia Patent Foundation, Eric Loth, en, 2022

ABSTRACT

Abstract

A downwind morphing rotor that exhibits bending loads that will be reduced by aligning the rotor blades with the composite forces. This reduces the net loads on the blades which therefore allow for a reduced blade mass for a given maximum stress. The downwind morphing varies the amount of downstream deflection as a function of wind speed, where the rotor blades are generally fully-aligned to non-azimuthal forces for wind speeds between rated and cut-out conditions, while only the outer segments of the blades are generally aligned between cut-in and rated wind speeds. This alignment for large (MW-scale) rated turbines results in much larger downstream deflections of the blades at high wind speeds as compared to that of a conventional rigid single-piece upwind turbine blade.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application under 35 U.S.C. Â§ 120 of U.S. patent application Ser. No. 15/649,794, filed Jul. 14, 2017, which is a continuation application under 35 U.S.C. Â§ 120 of U.S. patent application Ser. No. 13/528,753, filed Jun. 20, 2012, which claims priority from U.S. Provisional Application Ser. No. 61/499,507, filed Jun. 21, 2011, entitled âMorphing Segmented Wind Turbine and Related Methodâ and U.S. Provisional Application Ser. No. 61/661,513, filed Jun. 19, 2012, entitled âMorphing Segmented Wind Turbine and Related Method;â the disclosures of which are hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

Wind energy is a key to the nation's 2030 goals of increased energy independence and reduced environmental impact stemming from power generation (Lindenberg et al. 2008). It is projected to account for as much as 20% of U.S. power by 2030. This sustainable source will improve the nation's energy independence and allow a low environmental impact as compared to traditional fossil fuels in many ways. Firstly, it can reduce energy related emissions since the 20% wind penetration by 2030 is estimated by the U.S. Department of Energy (DOE) to avoid 2,100 million metric tons of carbon into the atmosphere. Secondly, estimates by Jacobsen (2009) indicate that 300 GW of wind power primarily used for charging electric-battery vehicles would eliminate 15,000 emissions-related deaths per year by 2020. This would also eliminate 15 million barrels per day of imported oil in the United States, reducing the amount of imported energy and increasing our energy independence and security.

Maintaining or lowering cost of energy while simultaneously ramping up total installed penetration may benefit from revolutionary advances in turbine concepts at extreme-scales (diameters of 120 meters and beyond) with improved efficiency. This increase in scale and efficiency has been evident in recent wind turbine design. The average wind turbine rated power has increased twenty-fold since 1985, with present systems averaging 2 MW. Economies of scale and higher winds aloft are driving systems to power levels of 5 MW and beyond with rotor diameters (D) nearing 120 m and greater. While larger systems are needed in the future, blade weight (currently proportional to D 2.35 ) has become a constraining design factor due to high gravity loads (Ashwill, 2009). This scaling is important since system costs generally scale linearly with system weight and the rotor itself accounts for about 23% of the initial total system cost (Fingersh, 2006). In addition, noise (and visual) production is likely to be very significant for extreme-scale systems indicating that such systems are best suited for off-shore siting. Such siting may also reduce many existing environmental impacts but leads to complications in terms of installation and maintenance. These problems are compounded by upwind turbine configurations since such designs necessitate stiff blades to avoid rotor-blade tower strikes. Moreover, overly rigid rotor/tower systems lead to problematic high frequency fatigue loads.

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

A morphing segmented concept is submitted herein as an embodiment of the present invention for future extreme-scale wind turbine systems. Both âtwist morphingâ and âdownwind morphingâ can be employed.

The twist morphing pertaining to an embodiment of the present invention may be accomplished by using segmented blades connected by screw sockets and a tension cable system (as well as other available coupling mechanisms and tension control systems). At low wind and rotor speeds, the segmented blades may be, for example, fully tensioned and set at high pitch to ensure start-up and maximum power at low speeds. At high rotor rpm, the cable tension can be designed such that centrifugal forces drive the blade segments outward so as to unwind/feather the rotor and prevent over-speed. This effectively acts like a passive pitch control for rotor speeds. Perhaps more importantly, still referring to the âtwist morphingâ rotor the airfoils of the blade segments can be designed with a center of pressure downstream of the socket axis. This will cause an aerodynamic moment at high wind speeds which will serve to unwind the blade segments to prevent torque spikes and blade stall. For a given rotor diameter and torque, such stall prevention can permit operation at higher average lift coefficient with a reduced blade chord length which can reduce blade and overall system weight. In addition, the segmented blade concept can alleviate manufacturing and shipping constraints for extreme-scale systems. In the proposed concepts, the bending loads will be carried by the segmented rotor spar and not the blade skin. This may result in much larger downstream deflections of the blades at high wind speeds as compared to that of a conventional rigid single-piece turbine blade.

Pertaining to an embodiment of the âdownwind morphingâ rotor, the bending loads will be reduced by aligning the rotor blades with the composite forces. This reduces the net loads on the blades, which therefore allow a reduced blade mass for a given maximum stress. The downwind morphing varies the amount of downstream deflection as a function of wind speed, where the rotor blades are generally fully-aligned to non-azimuthal forces for wind speeds between rated and cut-out conditions, while only the outer segments of the blades are generally aligned between cut-in and rated wind speeds. This alignment for large (MW-scale) rated turbines results in much larger downstream deflections of the blades at high wind speeds as compared to that of a conventional rigid single-piece upwind turbine blade. Therefore, a downstream design would be needed for the downwind morphing to avoid potential strike of the blades with the tower. This will require a more aerodynamic tower to reduce wake interactions, but a downstream system may eliminate yaw-control and substantially relax blade rigidity constraints, thus further reducing blade weight. An aspect of an embodiment of the present invention rotor provides an aligned concept that employs a geometry that orients the loads (i.e., net force) along the blade length of the blade so that the structural loads primarily act in the tension mode. The blade may have two or more blade segments or portions that may be joined at blade segment joints so as to be able to fold or close (partially or fully) downwind. In general, for speeds significantly below rated conditions, the blades could be fixed on the vertical plane in order to maximize the swept area allowed with the longer length blades. As the wind speed approaches rated conditions, the blades could be gradually released in semi-alignment to reduce stresses. For rated speeds and above, the blades could be fully-aligned, though a dashpot-damper system may be needed to avoid problematic dynamics. Finally, at speeds significantly above cut-out conditions, the stopped blades could be closed-up towards the horizontal to allow a stow configuration for hurricane level winds.

An alternative embodiment to downwind morphing is a âpre-alignedâ configuration, where the rotor geometry and orientation does not change with wind speed, and instead is fixed at a constant downwind deflection consistent with alignment at or near the rated wind speed conditions.

Another embodiment is morphing based on twist, where the airfoil-shapes around the spars twist relative to the wind due to aerodynamic forces so as to unload the rotors when there is a gust. This can help reduce unsteady stresses on the blade and therefore may allow for reduced blade mass and cost. It should be appreciated that twist morphing may be combined with either downwind morphing or it may be combined with pre-alignment.

An aspect of an embodiment of the present invention provides, but not limited thereto, a rotor blade for a wind turbine. The blade may comprise: a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; a plurality of spar members extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication with the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; a tension member extending longitudinally through the aligned spar members; and the aligned spar members are configured to at least partially unwind due to centrifugal forces exerted on the blade segments and aligned spar members, the unwound spar members causing the blade segments to twist and provide twist morphing relative to the spar members.

An aspect of an embodiment of the present invention provides, but not limited thereto, a method of manufacturing a rotor blade for a wind turbine. The method may comprise: providing a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; providing a plurality of spar members extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; providing a tension member extending longitudinally through the aligned spar members; and the aligned spar members are configured to at least partially unwind due to centrifugal forces exerted on the blade segments and aligned spar members, the unwound spar members causing the blade segments to twist and provide twist morphing relative to the spar member.

An aspect of an embodiment of the present invention provides, but not limited thereto, a rotor blade kit for forming rotor blade on a wind turbine. The kit may comprise: a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; a plurality of spar members for extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; a tension member for extending longitudinally through the aligned spar members; and the aligned spar members are configured to at least partially unwind due to centrifugal forces exerted on the blade segments and aligned spar members, the unwound spar members causing the blade segments to twist and provide twist morphing relative to the spar member.

An aspect of an embodiment of the present invention provides, but not limited thereto, an individual blade segment for a wind turbine that is formed from a plurality of the individual blade segments, whereby the individual blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; wherein a plurality of spar members extend longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; a tension member extends longitudinally through the aligned spar members; and wherein the aligned spar members are configured to at least partially unwind due to centrifugal forces exerted on the blade segments and aligned spar members, the unwound spar members causing the blade segments to twist and provide twist morphing relative to the spar members.

An aspect of an embodiment of the present invention provides, but not limited thereto, a rotor blade for a wind turbine. The blade may comprise: a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; a plurality of spar members extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication with the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

An aspect of an embodiment of the present invention provides, but not limited thereto, a method of manufacturing a rotor blade for a wind turbine. The method may comprise: providing a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; providing a plurality of spar members extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

An aspect of an embodiment of the present invention provides, but not limited thereto, a rotor blade kit for forming rotor blade on a wind turbine. The kit may comprise: a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; a plurality of spar members for extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

An aspect of an embodiment of the present invention provides, but not limited thereto, an individual blade segment for a wind turbine that is formed from a plurality of the individual blade segments, whereby the individual blade segments comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; wherein a plurality of spar members extend longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and wherein the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

These and other objects, along with advantages and features of various aspects of embodiments of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.

<head

CROSS-REFERENCE TO RELATED APPLICATIONS

BACKGROUND OF THE INVENTION

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

An aspect of an embodiment of the present invention provides, but not limited thereto, a rotor blade for a wind turbine. The blade may comprise: a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; a plurality of spar members extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication with the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

An aspect of an embodiment of the present invention provides, but not limited thereto, a method of manufacturing a rotor blade for a wind turbine. The method may comprise: providing a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; providing a plurality of spar members extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

An aspect of an embodiment of the present invention provides, but not limited thereto, a rotor blade kit for forming rotor blade on a wind turbine. The kit may comprise: a plurality of blade segments for use as part of a rotor; the plurality of blade segments may comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; a plurality of spar members for extending longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

An aspect of an embodiment of the present invention provides, but not limited thereto, an individual blade segment for a wind turbine that is formed from a plurality of the individual blade segments, whereby the individual blade segments comprise an internal passage extending longitudinally from a first end to a second end of each of the blade segments; wherein a plurality of spar members extend longitudinally through the internal passages of each of the blade segments such that the plurality of the spar members are aligned and in communication end-to-end through the internal passages and the plurality of blade segments are aligned and in communication the aligned spar members and define a complete rotor blade from a root that connects to a rotor hub to a blade tip of the rotor blade; and wherein the aligned spar members and blade segments are configured to pivot due to centrifugal forces exerted on the blade segments and aligned spar members, the pivoted spar members and blade segments causing the blade segments to provide a curvature defining a deflection angle relative to the axis of rotation plane of the rotor blade.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the present invention, as well as the invention itself, will be more fully understood from the following description of preferred embodiments, when read together with the accompanying drawings.

FIG. 1A provides a perspective view of a modern conventional turbine.

FIG. 1B provides a schematic view of the associated net forces summed at quarter elements on a respective conventional blade of FIG. 1A .

FIG. 1C provides a perspective view of an aspect of an embodiment of the present invention downwind morphing wind turbine.

FIG. 1D provides a schematic view of the associated net forces summed at quarter elements on a respective blade of FIG. 1C .

FIG. 1E provides an illustration of palm tree in high winds.

FIG. 1F provides a schematic view of the associated net forces summed at quarter elements on two respective blades of FIG. 1C along with the deflection of curvature angles Î² and hub angle Î¸.

FIG. 2A provides a schematic view of the associated net forces on a respective conventional blade of FIG. 1A .

FIG. 2B provides a schematic view of the associated net forces on a respective blade of an embodiment of the present invention which demonstrates a free-coning blade so side-forces align with the blade.

FIG. 3A schematically illustrates the various forces acting on turbine blade(s) in general from the front view.

FIG. 3B schematically illustrates the various forces acting on turbine blade(s) in general from the side view.

FIG. 3C schematically illustrates the various forces acting on turbine blade(s) in general from the chord view.

FIG. 4 provides a graphical representation of the average load-path angles (Î²) (i.e., deflection curvature angle with the axis of rotation plane of the blade) in degrees at rated conditions as a function of rated turbine power (P rated ) in MW.

FIG. 5A schematically illustrates an exemplary downwind morphing schedule as a function of wind speed for no morphing.

FIG. 5B schematically illustrates an exemplary downwind morphing schedule as a function of wind speed for partial downwind morphing.

FIG. 5C schematically illustrates an exemplary downwind morphing schedule as a function of wind speed for full downwind morphing.

FIG. 5D schematically illustrates an exemplary downwind morphing schedule as a function of wind speed for stowed configuration.

FIG. 6 schematically illustrates the blade segments joined or coupled as desired or required.

FIG. 7 schematically shows an exploded view of the alignment of adjacent blade segments for a twist morphing embodiment.

FIG. 8A schematically shows a perspective view of the alignment of adjacent blade segments for a twist morphing embodiment.

FIG. 8B schematically shows a perspective partial view of the alignment of adjacent blade segments shown in FIG. 8A .

FIG. 9A schematically shows a perspective view of the alignment of adjacent blade segments in a fully-wound (together) condition for a twist morphing embodiment.

FIG. 9B schematically shows a perspective view of the alignment of adjacent blade segments in an unwound (separated) condition for a twist morphing embodiment.

FIG. 10A provides a finite element analysis (FEA) of downwind morphing rotor blades at rated conditions for a 10 MW turbine showing surface meshes for conventional blades.

FIG. 10B provides a finite element analysis (FEA) of downwind morphing rotor blades at rated conditions for a 10 MW turbine showing surface meshes for morphed blades.

FIG. 10C shows von Mises stress for a conventional blade according to the stress color map in MPa provided in FIG. 10F .

FIG. 10D shows von Mises stress for a morphed blade with the same mass according to the stress color map in MPa provided in FIG. 10F .

FIG. 10E shows von Mises stress for a morphed blade with 50% less mass according to the stress color map in MPa provided in FIG. 10F .

FIG. 10F shows the stress color map in MPa.

FIG. 11A schematically shows downwind morphing method to ensure zero moment nodes.

FIG. 11B schematically shows downwind morphing resulting downstream blade curvature.

FIG. 12 provides a graphical representation of the downwind morphing deflection angle at each node and the resulting fit vs. the radial position for fixed-mass and fixed-length.

FIG. 13 Aerodynamic shroud around the tower for reduced tower wake effects on the blades, wherein for illustration purposes the nacelle is translucent (outlined with dashed lines) in context of the tower, hub and blades.

FIG. 14 schematically shows a perspective view of Tripod floating embodiment of the present invention (pre-alignment aspects or morphing not shown).

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

The wind turbine 100 illustrated in FIG. 1A is a modern conventional turbine 100 that comprises a tower 104 supporting a nacelle 106 . A substantially horizontal main shaft projects from the nacelle 106 , a rotor 102 being mounted on the shaft, the rotor comprising a hub 108 and two or more blades 110 . The rotor 102 can be made to rotate by the wind. In this example, the wind turbine is a so-called upwind turbine, where the wind impinges on the rotor 102 before it impinges on the tower 104 , and where the nacelle 106 is able to yaw, i.e. rotate around a vertical axis with respect to the tower 104 , the rotor thereby adjusting itself to the wind direction at any given moment. Moreover, the wind turbine is preferably provided with three blades 110 extending substantially radially outwards from the hub 108 . Each blade 110 comprises a root section 116 near the hub 108 and a blade tip 114 . Still referring to FIG. 1A , upwind turbine configurations typically employ blades with fiberglass shells (or more expensive carbon fiber) to carry the gravity, acceleration and aerodynamic loads. Designing the blades to be stiff enough to resist the forces at rated conditions ( FIG. 1B ) leads to the blade mass problems. As shown in FIG. 1B , the associated net forces summed at quarter elements and are schematically shown by force arrows 109 on a respective blade shown in FIG. 1A . The angle of the blade 110 is essentially aligned with the axis of rotation plane 132 of the blade. Load-adaptable blade geometry is not a new concept and in fact has been used on many successful (and unsuccessful) systems by introducing flexibility. An example load-adaptable geometry is the Soft Rotor concept [See Rasmussen, F., Petersen, J. T., Volund, P. Leconte, P, Szechenyi, E and Westergaard, C. âSoft rotor design for flexible turbines.â in Riso National Laboratory . Roskilde, Denmark: Contract JOU3-CT95-0062, of which is hereby incorporated by reference herein in its entirety.], which employed flexible downwind blades that eliminated the need for mechanical yaw control. A two-bladed 15 kW (13 meter diameter) design was fabricated and field tested and it was found that the rotor loads were reduced by 25-50% during operation (compared to rigid upwind blades) while aerodynamic efficiency was approximately retained. Moreover, such a soft design can mitigate problematic high-frequency fatigue loads, a concept already demonstrated for tower design [See Sear, D., âWind turbine technology: Fundamental concepts in wind turbine engineering,â ASME 2009 (New York, N.Y.), of which is hereby incorporated by reference herein in its entirety.]. Other examples of adaptability to forces include coning designs, where typically two downstream blades are hinged at the hub. However, such systems are not widespread due to dynamics concerns with two-bladed designs, and structural designs for highly flexible blades.

The stiffness constraint can be relaxed if a downwind morphing concept is employed as per the aspects of the various embodiments of the present invention. An aspect of an embodiment of the present concept does not necessitate the use of a flexible rotor nor conventional coning, but instead as shown in FIG. 1C , employs a rotor 202 having three segmented blades with stiff elements whose joints can be unlocked at high-speeds to allow substantial downstream movement, i.e., downwind morphing. It should be appreciated that the present invention flexible rotor may employ two or more blade segments.

FIG. 1C provides a perspective view of an aspect of an embodiment of the present invention downwind morphing wind turbine 200 including among other things, a nacelle 206 , a rotor 202 being mounted on the shaft, the rotor comprising a hub 208 and two or more segmented blades 210 . Also shown is the deflection curvature angle Î² with the axis of rotation plane 232 of the blade. The rotor 202 is a downwind turbine from the tower 204 and nacelle 206 regarding the prevailing wind 203 . Moreover, the wind turbine is preferably provided with three blades 210 extending substantially radially outwards from the hub 208 . Each blade 210 comprises a root section 216 near the hub 208 and a blade tip 214 . Although not specifically called out due to the limitations of the illustration, each blade is comprised of two or more blade segments (of which will be discussed in detail in this disclosure). Between each the segments (not specifically called out in FIG. 1C ), the segments may be coupled with a hinge-like mechanism such as a ball joint, flex joint, pin joint, tension cabling, trunnion joint, or the like between them so as to be able to rotate or close downwind to provided downwind morphing.

As can be seen in FIG. 1C , the tower 204 and the nacelle 206 may be provided with an aerodynamic design, such as an aerodynamic shroud for instance. Similarly, an enlarged view as shown in FIG. 13 will be discussed below.

As schematically shown in FIG. 1D , the associated net forces summed at quarter elements, which align along the blade 210 are schematically shown by force arrows 209 on a respective blade shown in FIG. 1C . The blade 210 has three blade segments 240 that may be joined at blade segment joints 241 . Also shown is the deflection curvature of angle Î² with the axis of rotation plane 232 of the blade.

This concept has the advantage, but not limited thereto, in that it can still employ low-cost low-deflection fiberglass materials and furthermore, allows direct control of the degree of geometry change. At rated conditions, the joints are designed to eliminate any downstream moment so that gravity, centrifugal and aerodynamic loads only yield mass-efficient tensile loads (and avoid mass-consuming cantilever loads). The result is a dramatic reduction in structural stresses so that the blade mass may be dramatically reduced. As shown in FIG. 1E , this concept can be, for example, compared to the flow adaptability of the palm tree, whose light-weight segmented trunk can be considered as a series of cylindrical shells which can bend in the wind. FIG. 1E provides an illustration of palm tree in high winds. In contrast, the oak tree trunk is more like a solid (and much heavier) single-element beam which resists bending in moderate winds (like a conventional rotor). However, monsoon storms and hurricanes will blow and uproot most âstiffâ trees away. In contrast, the segmented morphing palm tree can bend all the way to the ground and survives hurricane strength winds. This adaptability to aerodynamic load via an extremely lightweight structural design and thus, provides some of the principles of an embodiment of the present inventionâSegmented Ultralight Morphing Rotor (SUMR).

Referring to FIG. 1F , the associated net forces summed at quarter elements, which align along the blade 210 are schematically shown by force arrows 209 on a respective blade shown in FIG. 1C . The blade 210 has three blade segments 240 that may be joined at blade segment joints 241 . Also shown is the deflection of curvature angle Î² with the axis of rotation plane 232 of the blade. For a particular example, but not limited thereto, at rated conditions, the maximum deflection angles at the top and bottom blade positions reach values of 18Â° (Î² up ) and 12Â° (Î² down ), respectively. These angles are a primarily a function of blade weight, rotor rpm, and rotor power. In particular, the angles tend to increase as rotor power increases, especially for turbines which are greater than 1 MW of rated power. To avoid cyclic variations of blade angle of the blade 210 with respect to the rotating hub, i.e., axis rotation of the blade 232 , teetering can be employed whereby the effective rotation hub axis (Î¸) is inclined downward at a net angle, e.g. Î¸=Â½ (Î² up âÎ² down )=3Â°. This adaptability is quite beneficial since it removes gravity cycling stresses, and the associated reduction in dynamic loads and fatigue in the entire system also reduces cost and improves reliability. Teetering is most commonly used for two two-bladed systems, and various embodiments of the present invention morphing can be applied to one or more bladed turbines. In such cases, the rotor axis can also be changed by titling the rotor shaft with respect to the gravitational plane. This may be driven and controlled with motors or may be achieved using the downwind load forces to tilt the entire tower, e.g. for the case of a floating platform. It should be appreciated that the deflection of curvature angle Î² (Î² up and Î² down ) and hub angle Î¸ may be designed to curve and align at any desired or required angle to achieve the intended or desired objective of turbine or rotor operation.

Furthermore, the downwind orientation may eliminate the need for mechanical yaw. Another key point of the morphing concept is aerodynamic fairing of the nacelle and tower (as shown in FIG. 1C ), minimizing tower wake effects [See Loth, E., Selig, M. S., and Moriarty, P. âMorphing segmented wind turbine concept,â in AIAA Applied Aerodynamics Conference. 2010. Chicago, Ill. AIAA-2010-4400 paper, of which is hereby incorporated by reference herein in its entirety.]. In addition, the segment pin-joints are designed to prevent deflection in the torque-wise direction since such moments (albeit small compared to the downstream cantilever moment for a conventional rotor blade) are needed for power extraction. Circumferential stiffness also allows conventional pitch control, e.g. so blades can be faired above rated wind speeds. The addition of joints results in a small but finite weight penalty, but allows morphing to be locally focused at the blade tips where aerodynamic and centrifugal forces are much higher than near the hub. In contrast, a coning rotor that cannot adapt along the blade will have reduced aerodynamic performance.

An aspect of the present invention pre-aligned rotor blade or downwind morphing rotor blade is that it provides, among other things, an aero-elastic design that reduces the downwind cantilever aerodynamic load to help reduce structural mass. Turning to FIG. 2 , the distribution of forces at rated conditions for a conventional upwind rotor blade ( FIG. 2A ) and an embodiment of the present invention aligned downwind blade ( FIG. 2B ) and that demonstrates a free-coning blade so side-forces align with the blade, which eliminates downwind cantilever hub moments. This concept can be used for an embodiment of the present invention wind turbine to minimize rotor mass by avoiding the conventional stiffness constraint and instead adapting a downwind geometry to align with the load path, i.e., net force

109 , 209 as shown in FIGS. 2A-2B . As shown in FIG. 2A , it can be seen that the conventional blade 110 that is subjected to the prevailing wind 103 has loading that leads to cantilever forces (i.e., net forces 109 ) in the downstream direction. In contrast, referring to FIG. 2B , an aspect of an embodiment of the present invention rotor having the aligned concept employs a geometry that orients the loads (i.e., net force 209 ) along the blade length of the blade 210 so that the structural loads primarily act in the tension mode. The blade 210 , as shown, has four blade segments 240 that may be joined at blade segment joints 241 to be able to fold or close (partially or fully) downwind or may be fixed in âpre-alignedâ or âalignedâ fashion. The resulting load-path angles (Î²) (i.e., deflection of curvature angle with the axis of rotation of the blade) will vary as a function of radius and azimuthal angle, but these changes are minor. By converting loads to a tensile direction, this concept effectively uses design principles of cabled-stayed bridges and the kite rotors to reduce mass by minimizing cantilever-based shear loads. However, the present downwind rotor design (for example, as shown in FIG. 2B ) is unique in that it can avoid direct use of cables to direct loads in the tensile direction, and instead incorporates aeroelastic adaptability bio-inspired by the palm tree. If this alignment is fixed (independent of wind speed) and based on eliminating cantilever loads at the rated condition (where peak loads occur), it is termed herein as a âpre-alignedâ or âalignedâ rotor. Note that an embodiment of the pre-aligned rotor (or âalignedâ rotor) present invention provides, among other things, a design that is fixed in advanced. In contrast, an embodiment of the morphing rotor of the present invention is as a function of wind speed. It should be appreciated that a morphing rotor can achieve the positions achieved by pre-aligned (aligned) rotor by implementing the appropriate coupling, materials, and structure as desired or required as is contemplated within the context of the present invention. And vice versa, whereby it should be appreciated that a pre-aligned rotor can achieve the positions achieved by a morphing rotor by implementing the appropriate design criteria as discussed herein.

To determine the typical angles needed to align a rotor blade with the rated load conditions, an aspect of an embodiment of the present invention considers a decomposition of the forces which act on a turbine blade in general as shown in FIG. 3 . These forces include the gravity force (G), the centrifugal force (C), the downstream aerodynamic thrust force (T), and the in-plane aerodynamic torque-wise force (F Q ). Note that the latter two forces result from the aerodynamic drag force (D) and the lift force (L). FIGS. 3A, 3B, and 3C schematically illustrate the various forces acting on the turbine blades in general from the front view, side view and chord view, respectively.

An aspect of an embodiment of the present invention entails the estimation of the net load-path angle (Î²) (i.e., deflection curvature angle with the axis of rotation plane of the blade) in terms of these net forces and the azimuthal blade angle (Ï, defined as 0 for a blade that is pointed vertically upwards and Ï for a blade that is downwards) as:

Î² =

tan

- 1

â¡

(

C -

G â¢

â¢ cos â¢

â¢ Ï

)

( 1 )

This load-path angle is shown in FIG. 4 for the blade pointed upwards (Î² up , where Ï=0) and downwards (Î² down , where Ï=Ï=Ï) as a function of turbine rated power. For moderate-size turbines (less than 1 MW), the load-path angle at rated conditions is small (typically less than 5 deg.) so that some of this can be accommodated by aeroelastic deflection for an upwind conventional rotor. This indicates that aligned blades do not benefit small systems. However, for large- and extreme-scale turbines the load-path angles can be large, e.g. more than 20 degrees for a 20 MW system. This trend of increasing Î² with increasing P is a result of size-scaling for a constant tip-speed (ÏËR â1 ) such that CËR 1.2 (Eqs. 2 and 5), TËR 2 (Eqs. 1, 6 and 13), while GËR 2.2 (Eqs. 2 and 4).

Since cantilever loads are more significant at extreme-scales, alignment allows a larger reduction in the moments experienced by the blade (per FIG. 2 ). Furthermore, aligning the blade geometry at these large angles downstream necessitates a downwind rotor. Thus, scaling will drive extreme-scale systems to downwind aligned rotors. One may also note that there is a significant difference in the upwards and downwards load-path angles in FIG. 4 , which is due to the increased importance of gravity loads at extreme-scales. Additional differences in these load path angles can occur if there is a vertical wind-shear across the rotor causing higher wind speeds at higher altitudes. To avoid cyclic appearance of cantilever loads while maintaining a fixed rotor geometry with respect to the hub, the hub axis can be tilted relative to the horizon as a function of wind speed by Î¸ as shown in FIG. 1F . If a two-bladed design is used, this tilting can instead be achieved by tilting the hub-axis or by teetering the rotor. For two- or three-bladed designs, individual pitch control and/or trailing edge surfaces (flaps or tabs) may accommodate tilt-pitch coupling as well as rapid changes in wind angle or speed caused by gusts. It should be noted that rotor speeds above rated conditions will result in only a small reduction in the load path angles, such that pre-alignment at rated conditions will be nearly ideal. For rotor speeds below rated conditions, the load path angles will generally not be aligned with those at rated conditions, but at these lower speeds the loads on the blades are substantially reduced so that the adaption is not needed to avoid peak stresses on the blades.

A qualitative downwind morphing schedule is shown in FIGS. 5A-D for an aspect of an embodiment of the present invention morphing wind turbine 200 including among other things, a nacelle 206 , a rotor 202 , hub 208 , blades 210 , and tower 204 while exposed to a given prevailing wind 203 . Referring to FIG. 5A , for parked conditions and low-wind speeds, the turbine blades 210 are un-morphed since the stresses are generally small and dominated by gravity loads. For example, there is no morphing at the range for about 0-8 m/s. Although not specifically called out, all of the blade segments 240 are generally shown substantially in the same plane. At low wind speeds below the cut-in wind speed, the rotor will be in a parked state where the rotor is perfectly vertical). As the wind speed increases above the cut-in speed, the rotor will start to turn and produce power. Referring to FIG. 5B , as the wind speed increases further, centrifugal and aerodynamic loads can dominate gravity loads such that the load path does vary strongly with azimuthal angle. Once a segment has reached a loading level that leads to a moderate downstream deflection angle (e.g. 18Â° or less), the joints (starting first with the outermost joint) are sequentially are unlocked so the segment is free to deflect downstream. The initial downwind morphing will have the outermost blade segment 252 angled compared to both the middle blade segment 253 and inner blade segment 254 , which remain substantially in the same plane. As the wind speed increases more and more of the segments will be free to align. Referring to FIG. 2C , at rated conditions, all jointed segments of the blade are aligned so the rotor is fully morphed to minimize the stresses induced by the high aerodynamic and centrifugal loads. The most outer blade segment 252 , middle blade segment 253 , and inner blade segment 254 are all angled relative to one another. As the wind speeds increases above rated condi

CLAIMS

Claims ( 14 )

The invention claimed is:

1. A wind turbine comprising:

at least two downwind-morphing rotor blades, each rotor blade configured to aeroelastically deflect flapwise in a downwind direction in a load-dependent manner to establish a specified downwind deflection angle at rated load using the aeroelastic deflection, to align the rotor blade with a load path defined by a contribution of forces including aerodynamic thrust force, centrifugal force, and gravitational force; and

a support tower;

wherein each of the at least two downwind-morphing rotor blades comprises a segmented configuration including at least two segments, the two segments including a first segment defining a root section and a second segment defining a blade tip; and

wherein respective segments amongst the at least two segments controllably unlock in a sequential matter to establish respective angles of load-aligned deflection.

2. The wind turbine of claim 1 , wherein the deflection of the rotor blades is established at least in part using a hub coupling to set the rotor blades at an angle extending in the downwind direction.

3. The wind turbine of claim 2 , wherein the respective rotor blades are set at an initial downwind angle at the hub, relative to an axis of a rotation plane about the hub in the downwind direction.

4. The wind turbine of claim 2 , wherein the hub is tilted with respect to a gravitational plane to establish a specified rotor angle.

5. The wind turbine of claim 1 , wherein the downwind deflection of the respective rotor blades vary within the specified range depending on rotational positions of the respective blades about a hub.

6. The wind turbine of claim 1 , wherein the at least two segments are coupled together to define a pre-aligned configuration oriented in the downwind direction.

7. The wind turbine of claim 1 , wherein the second segment is configured to unlock first.

8. The wind turbine of claim 1 , wherein at least the blade tip of the rotor blade is configured to deflect into a stowed configuration toward a horizontal alignment.

9. The wind turbine of claim 1 , wherein the support tower comprises an aerodynamic fairing.

10. The wind turbine of claim 9 , wherein a rotational position of the aerodynamic fairing is variable in response to an incident wind direction.

11. The wind turbine of claim 1 , wherein the support tower comprises a truss structure.

12. The wind turbine of claim 11 , wherein the truss structure includes a tripod-configuration of elongated supports extending from a generator housing to a surface below the wind turbine.

13. The wind turbine of claim 12 , wherein the surface comprises water and wherein the support tower is configured as a floating platform.

14. The wind turbine of claim 13 , wherein the floating platform is moored using a cable.

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Morphing segmented wind turbine and related method

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Morphing segmented wind turbine and related method

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Families Citing this family (40)

* Cited by examiner, â Cited by third party

Publication number

Priority date

Publication date

Assignee

Title

US9709029B2

( en )

2011-06-21

2017-07-18

University Of Virginia Patent Foundation

Morphing segmented wind turbine and related method

US9534580B2

( en )

2013-02-27

2017-01-03

General Electric Company

Fluid turbine blade with torsionally compliant skin and method of providing the same

EP3011174B1

( en )

2013-06-20

2018-11-14

The University of Virginia Patent Foundation

2-d fairing for a wind turbine tower

US20150161860A1

( en )

2013-12-05

2015-06-11

Frank G. Pringle

Security System and Associated Methods

ITBZ20140002U1

( en )

2014-03-13

2015-09-13

Frassinelli Ernesto

WIND FOLDER WITH ADAPTIVE PROFILE ABLE TO MODIFY ITS STRUCTURE ON THE BASIS OF THE AERODYNAMIC PRESSURE THAT INVESTS IT, THE CLIMATE AND METEOROLOGICAL CHARACTERISTICS OF THE INSTALLATION SITE AND, COMPOSING A SINGLE ROTOR WITH ONE OR MORE ELEMENTS, WITH A MICRO-WIND GENERATOR WITH ROTATION AXIS PARALLEO AT THE AERODYNAMIC FLOW.

CN105003395B

( en )

2015-07-24

2018-07-20

ä¸å½è½æºå»ºè®¾éå¢å¹¿ä¸ççµåè®¾è®¡ç ç©¶é¢æéå¬å¸

A kind of test model and test method of floating wind turbine movenent performance

BR102015024612A2

( en )

2015-09-24

2017-03-28

Monteiro De Barros Marcelo

wind blade, tubular structure for wind blade, wind turbine and wind harness control method

CN105760629A

( en )

2016-03-25

2016-07-13

å°å·çå·¥å¤§å¦

Lamination optimum design method of wind turbine blade main beam

US10740507B2

( en )

2016-12-20

2020-08-11

General Electric Company

Wind turbine tower placement and orientation

JP6783212B2

( en )

2017-10-20

2020-11-11

ä¸è±éå·¥æ¥æ ªå¼ä¼ç¤¾

How to position the vortex generator on the wind turbine wing, how to manufacture the wind turbine wing assembly and the wind turbine wing assembly

US10830207B2

( en )

2018-08-28

2020-11-10

General Electric Company

Spar configuration for jointed wind turbine rotor blades

US11149709B2

( en )

2018-09-24

2021-10-19

General Electric Company

Method to reduce noise and vibration in a jointed wind turbine blade, and associated wind turbine blade

DK3870834T3

( en )

2018-10-25

2024-09-30

Lm Wind Power As

Beam flange construction for a joined wind turbine blade

PL3874155T3

( en )

2018-10-31

2023-11-20

General Electric Company

Jointed wind turbine rotor blade having varying material combinations along its span for pin reinforcement

EP3874144B1

( en )

2018-11-01

2023-08-02

General Electric Company

Method for installing and retaining a bushing in a bearing block of a rotor blade joint

JP7221384B2

( en )

2018-11-01

2023-02-13

ã¼ãã©ã«ã»ã¨ã¬ã¯ããªãã¯ã»ã«ã³ããã¤

Wind turbine jointed rotor blades with hollow chordally extending pins

US11536246B2

( en )

2018-11-01

2022-12-27

General Electric Company

Span-wise extending pin for joining rotor blade segments

EP3874143B1

( en )

2018-11-01

2026-04-01

General Electric Renovables EspaÃ±a, S.L.

Compliant structures for jointed rotor blades

CN112955646B

( en )

2018-11-01

2024-10-11

éç¨çµæ°å¯åçè½æºè¥¿ççæéå¬å¸

Scarf joint for wind turbine rotor blades

CN113286696A

( en )

2018-11-01

2021-08-20

éç¨çµæ°å¬å¸

Spacer material for reducing a bond gap between a beam structure and a blade shell of a segmented rotor blade

CN113165285A

( en )

2018-12-11

2021-07-23

éç¨çµæ°å¬å¸

Method for manufacturing a structural component for a blade segment of a rotor blade of a wind turbine

CA3121890A1

( en )

2018-12-11

2020-06-18

Louis Rondeau

Method for manufacturing a hollow composite structure, particularly a spar beam for a wind turbine rotor blade, and an associated mandrel

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( en )

2018-12-11

2023-10-02

Gen Electric

METHOD OF MANUFACTURE OF WIND COMPONENTS FOR WIND TURBINE ROTOR BLADES

US11542917B2

( en )

2018-12-11

2023-01-03

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Beam structure for a segmented rotor blade having a transitioning shape

BR112021009996B1

( en )

2018-12-11

2023-10-17

General Electric Company

METHOD FOR PREVENTING MANUFACTURE AND STRUCTURAL COMPONENT DEFECTS FOR A BLADE SEGMENT OF A ROTOR BLADE OF A WIND TURBINE

DK3894691T3

( en )

2018-12-13

2025-05-19

General Electric Renovables Espana Sl

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( en )

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( en )

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( en )

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( en )

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DE102019112945A1

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( en )

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2022-05-06

æ±è¥¿æ´ªé½èªç©ºå·¥ä¸éå¢æéè´£ä»»å¬å¸

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( en )

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( en )

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2022-03-01

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US12011771B2

( en )

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CN114396975B

( en )

2022-01-05

2023-05-23

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CN115127792B

( en )

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2025-10-28

ä¸å½èªåè´µé³åå¨æºè®¾è®¡ç ç©¶æ

A high-low cycle composite fatigue test device for aircraft engine blades

US12180938B2

( en )

2023-03-22

2024-12-31

General Electric Renovables Espana, S.L.

System and method for reducing wind turbine loads caused by rotor imbalance

CN119203664B

( en )

2024-09-09

2025-09-16

åäº¬èªç©ºèªå¤©å¤§å¦

A method for efficiently obtaining gust loads of UAVs

Citations (36)

* Cited by examiner, â Cited by third party

Publication number

Priority date

Publication date

Assignee

Title

US3981613A

( en )

1973-07-11

1976-09-21

Gori-Vaerk A/S

Foldable propellers

US4095918A

( en )

1975-10-15

1978-06-20

Mouton Jr William J

Turbine wheel with catenary blades

US4105363A

( en )

1976-06-14

1978-08-08

Loth John Lodewyk

Overspeed control arrangement for vertical axis wind turbines

US4197056A

( en )

1977-08-22

1980-04-08

Ulrich Hutter

Wind-driven power plant

DE3107252A1

( en )

1981-02-26

1982-09-09

Erno Raumfahrttechnik Gmbh, 2800 Bremen

Floating wind-power installation

DE3126677A1

( en )

1981-07-07

1983-01-20

Erno-Raumfahrttechnik Gmbh, 2800 Bremen

Rotor blade design for high-speed rotors

US4403916A

( en )

1980-09-02

1983-09-13

Chicago Province Of The Society Of Jesus

Wind turbines

US4469956A

( en )

1983-01-24

1984-09-04

U.S. Windpower, Inc.

Windmill support structure

US4522561A

( en )

1980-07-30

1985-06-11

Carter Wind Power

Wind-driven generator apparatus

US4533297A

( en )

1982-09-15

1985-08-06

Bassett David A

Rotor system for horizontal axis wind turbines

DE3637678A1

( en )

1986-10-31

1988-05-11

Siegfried Herbert Gaertner

Warping blade for driving wind-power plants

US4878808A

( en )

1987-05-14

1989-11-07

Anton Wildenauer

Airfoil for a wind-driven wheel

GB2353825A

( en )

1999-09-01

2001-03-07

David Lovett Ewbank Teal

Wind turbine tower having rotatable shroud/fairing

JP2005147085A

( en )

2003-11-19

2005-06-09

Fuji Heavy Ind Ltd

Blade of horizontal axis wind mill

US6979171B2

( en )

2000-03-28

2005-12-27

Per Lauritsen

Maritime energy generating device

US7186083B2

( en )

2002-06-06

2007-03-06

Elliott Bayly

Wind energy conversion device

US20070098555A1

( en )

2004-09-18

2007-05-03

Aerodyn Energiesysteme Gmbh

Wind turbine comprising elastically flexible rotor blades

US20080124216A1

( en )

2006-11-27

2008-05-29

Ning Liao

Turbine blade assembly

EP1953383A1

( en )

2005-10-28

2008-08-06

Gamesa Innovation & Technology, S.L.

Split-blade for wind generators

US20080240923A1

( en )

2007-03-27

2008-10-02

Laurent Bonnet

Rotor blade for a wind turbine having a variable dimension

US20090162208A1

( en )

2007-12-19

2009-06-25

General Electric Company

Multi-segment wind turbine blade and method for assembling the same

US20090208337A1

( en )

2006-05-18

2009-08-20

Epl Composite Solutions Limited

Turbine blade support assembly

WO2009130212A1

( en )

2008-04-21

2009-10-29

Lm Glasfiber A/S

Upwind wind turbine with blades supported on the leeward side

WO2009135902A2

( en )

2008-05-07

2009-11-12

Vestas Wind Systems A/S

A sectional blade

US20100028161A1

( en )

2008-08-01

2010-02-04

Vestas Wind Systems A/S

Segmented Rotor Blade Extension Portion

US20100040477A1

( en )

2007-03-05

2010-02-18

Manfred Moehring

Wind turbine with additional blade-end support

US20100086407A1

( en )

2007-03-14

2010-04-08

Vidar Holmoy

Wind turbine rotor

FR2937687A1

( en )

2008-10-23

2010-04-30

Astrium Sas

WINDBREAD BLADES AND METHOD OF MANUFACTURING THE SAME

US20100132884A1

( en )

2009-05-28

2010-06-03

General Electric Company

Method for assembling jointed wind turbine blade

US20100143143A1

( en )

2009-04-28

2010-06-10

General Electric Company

Segmented wind turbine blade

US20100143131A1

( en )

2008-08-22

2010-06-10

Natural Power Concepts, Inc.

Folding blade turbine

US20100172759A1

( en )

2009-01-08

2010-07-08

Sullivan John T

Retractable wind turbines

US20110038726A1

( en )

2009-08-14

2011-02-17

Elkin Benjamin T

Independent variable blade pitch and geometry wind turbine

US20110255974A1

( en )

2010-04-15

2011-10-20

General Electric Company

Configurable winglet for wind turbine blades

US20130064663A1

( en )

2011-06-21

2013-03-14

University Of Virginia Patent Foundation

Morphing segmented wind turbine and related method

US20200173422A1

( en )

2017-06-20

2020-06-04

Exponential Renewables, S.L.

Floating structure for offshore wind turbine

2012

2012-06-20

US13/528,753

patent/US9709029B2/en

active

Active

2017

2017-07-14

US15/649,794

patent/US20180003151A1/en

not_active

Abandoned

2019

2019-12-18

US16/719,612

patent/US11466660B2/en

active

Active

Patent Citations (38)

* Cited by examiner, â Cited by third party

Publication number

Priority date

Publication date

Assignee

Title

US3981613A

( en )

1973-07-11

1976-09-21

Gori-Vaerk A/S

Foldable propellers

US4095918A

( en )

1975-10-15

1978-06-20

Mouton Jr William J

Turbine wheel with catenary blades

US4105363A

( en )

1976-06-14

1978-08-08

Loth John Lodewyk

Overspeed control arrangement for vertical axis wind turbines

US4197056A

( en )

1977-08-22

1980-04-08

Ulrich Hutter

Wind-driven power plant

US4522561A

( en )

1980-07-30

1985-06-11

Carter Wind Power

Wind-driven generator apparatus

US4403916A

( en )

1980-09-02

1983-09-13

Chicago Province Of The Society Of Jesus

Wind turbines

DE3107252A1

( en )

1981-02-26

1982-09-09

Erno Raumfahrttechnik Gmbh, 2800 Bremen

Floating wind-power installation

DE3126677A1

( en )

1981-07-07

1983-01-20

Erno-Raumfahrttechnik Gmbh, 2800 Bremen

Rotor blade design for high-speed rotors

US4533297A

( en )

1982-09-15

1985-08-06

Bassett David A

Rotor system for horizontal axis wind turbines

US4469956A

( en )

1983-01-24

1984-09-04

U.S. Windpower, Inc.

Windmill support structure

DE3637678A1

( en )

1986-10-31

1988-05-11

Siegfried Herbert Gaertner

Warping blade for driving wind-power plants

US4878808A

( en )

1987-05-14

1989-11-07

Anton Wildenauer

Airfoil for a wind-driven wheel

GB2353825A

( en )

1999-09-01

2001-03-07

David Lovett Ewbank Teal

Wind turbine tower having rotatable shroud/fairing

US6979171B2

( en )

2000-03-28

2005-12-27

Per Lauritsen

Maritime energy generating device

US7186083B2

( en )

2002-06-06

2007-03-06

Elliott Bayly

Wind energy conversion device

JP2005147085A

( en )

2003-11-19

2005-06-09

Fuji Heavy Ind Ltd

Blade of horizontal axis wind mill

US20070098555A1

( en )

2004-09-18

2007-05-03

Aerodyn Energiesysteme Gmbh

Wind turbine comprising elastically flexible rotor blades

EP1953383A1

( en )

2005-10-28

2008-08-06

Gamesa Innovation & Technology, S.L.

Split-blade for wind generators

US20090208337A1

( en )

2006-05-18

2009-08-20

Epl Composite Solutions Limited

Turbine blade support assembly

US20080124216A1

( en )

2006-11-27

2008-05-29

Ning Liao

Turbine blade assembly

US20100040477A1

( en )

2007-03-05

2010-02-18

Manfred Moehring

Wind turbine with additional blade-end support

US20100086407A1

( en )

2007-03-14

2010-04-08

Vidar Holmoy

Wind turbine rotor

US20080240923A1

( en )

2007-03-27

2008-10-02

Laurent Bonnet

Rotor blade for a wind turbine having a variable dimension

US20090162208A1

( en )

2007-12-19

2009-06-25

General Electric Company

Multi-segment wind turbine blade and method for assembling the same

US7740453B2

( en )

2007-12-19

2010-06-22

General Electric Company

Multi-segment wind turbine blade and method for assembling the same

WO2009130212A1

( en )

2008-04-21

2009-10-29

Lm Glasfiber A/S

Upwind wind turbine with blades supported on the leeward side

WO2009135902A2

( en )

2008-05-07

2009-11-12

Vestas Wind Systems A/S

A sectional blade

US20100028161A1

( en )

2008-08-01

2010-02-04

Vestas Wind Systems A/S

Segmented Rotor Blade Extension Portion

US20100143131A1

( en )

2008-08-22

2010-06-10

Natural Power Concepts, Inc.

Folding blade turbine

FR2937687A1

( en )

2008-10-23

2010-04-30

Astrium Sas

WINDBREAD BLADES AND METHOD OF MANUFACTURING THE SAME

US20100172759A1

( en )

2009-01-08

2010-07-08

Sullivan John T

Retractable wind turbines

US20100143143A1

( en )

2009-04-28

2010-06-10

General Electric Company

Segmented wind turbine blade

US20100132884A1

( en )

2009-05-28

2010-06-03

General Electric Company

Method for assembling jointed wind turbine blade

US20110038726A1

( en )

2009-08-14

2011-02-17

Elkin Benjamin T

Independent variable blade pitch and geometry wind turbine

US20110255974A1

( en )

2010-04-15

2011-10-20

General Electric Company

Configurable winglet for wind turbine blades

US20130064663A1

( en )

2011-06-21

2013-03-14

University Of Virginia Patent Foundation

Morphing segmented wind turbine and related method

US9709029B2

( en )

2011-06-21

2017-07-18

University Of Virginia Patent Foundation

Morphing segmented wind turbine and related method

US20200173422A1

( en )

2017-06-20

2020-06-04

Exponential Renewables, S.L.

Floating structure for offshore wind turbine

Non-Patent Citations (45)

* Cited by examiner, â Cited by third party

Title

" Machine Translation of DE 3126677 A1 ", Accessed by the Examiner from the EPO dated Mar. 12, 2019, (Retrieved Mar. 18, 2020), 3 pgs.

" Machine Translation of FR 2,937,687 A1 ", Accessed by the Examiner from the EPO dated Mar. 12, 2019, (Retrieved Mar. 18, 2020), 5 pgs.

" Machine Translation of JP2005-147085 ", Accessed by the Examiner from the EPO dated Mar. 12, 2019, (Retrieved Mar. 18, 2020), 4 pgs.

" U.S. Appl. No. 13/528,753, Final Office Action dated Oct. 20, 2015 ", 9 pgs.

" U.S. Appl. No. 13/528,753, Non Final Office Action dated Mar. 2, 2015 ", 12 pgs.

" U.S. Appl. No. 13/528,753, Non Final Office Action dated May 24, 2016 ", 7 pgs.

" U.S. Appl. No. 13/528,753, Notice of Allowance dated Mar. 28, 2017 ", 5 pgs.

" U.S. Appl. No. 13/528,753, Response filed Apr. 20, 2016 to Final Office Action dated Oct. 20, 2015 ", 12 pgs.

" U.S. Appl. No. 13/528,753, Response filed Nov. 23, 2016 to Non Final Office Action dated May 24, 2016 ", 9 pgs.

" U.S. Appl. No. 13/528,753, Response filed Sep. 2, 2015 to Non Final Office Action dated Mar. 2, 2015 ", 10 pgs.

" U.S. Appl. No. 15/649,794, Non Final Office Action dated Mar. 15, 2019 ", 9 pgs.

" U.S. Appl. No. 15/649,794, Notice of Non-Compliant Amendment dated Oct. 29, 2019 ", 4 pgs.

" U.S. Appl. No. 15/649,794, Preliminary Amendment filed Jul. 14, 2017 ", 6 pgs.

" U.S. Appl. No. 15/649,794, Preliminary Amendment filed Sep. 25, 2017 ", 5 pgs.

" U.S. Appl. No. 15/649,794, Response filed Sep. 12, 2019 to Non Final Office Action dated Mar. 15, 2019 ", 12 pgs.

Ashwill, " Materials and Innovations for Large Blade Structures: Research Opportunities in Wind Energy Technology ", 50th AIAA Structures, Structural Dynamics, & Materials Conference, Paper AIAA-2009-2407, American In

Morphing segmented wind turbine and related method — University Of Virginia Patent Foundation (US11466660B2)

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