WO2004099608A1 - Wind turbine blade with lift-regulating means - Google Patents

Wind turbine blade with lift-regulating means Download PDF

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Publication number
WO2004099608A1
WO2004099608A1 PCT/DK2004/000294 DK2004000294W WO2004099608A1 WO 2004099608 A1 WO2004099608 A1 WO 2004099608A1 DK 2004000294 W DK2004000294 W DK 2004000294W WO 2004099608 A1 WO2004099608 A1 WO 2004099608A1
Authority
WO
WIPO (PCT)
Prior art keywords
blade
wind turbine
lift
flap
wind
Prior art date
Application number
PCT/DK2004/000294
Other languages
French (fr)
Inventor
Bernt Ebbe Pedersen
Jørgen DAHL VESTERGAARD
Peter Grabau
Ib Frydendal
Original Assignee
Lm Glasfiber A/S
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lm Glasfiber A/S filed Critical Lm Glasfiber A/S
Priority to EP04730202A priority Critical patent/EP1623111B1/en
Priority to PL04730202T priority patent/PL1623111T3/en
Priority to DK04730202T priority patent/DK1623111T3/en
Priority to US10/555,579 priority patent/US7293959B2/en
Priority to DE602004016649T priority patent/DE602004016649D1/en
Publication of WO2004099608A1 publication Critical patent/WO2004099608A1/en

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D7/00Controlling wind motors 
    • F03D7/02Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor
    • F03D7/022Adjusting aerodynamic properties of the blades
    • F03D7/0232Adjusting aerodynamic properties of the blades with flaps or slats
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D1/00Wind motors with rotation axis substantially parallel to the air flow entering the rotor 
    • F03D1/06Rotors
    • F03D1/0608Rotors characterised by their aerodynamic shape
    • F03D1/0633Rotors characterised by their aerodynamic shape of the blades
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D7/00Controlling wind motors 
    • F03D7/02Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor
    • F03D7/022Adjusting aerodynamic properties of the blades
    • F03D7/024Adjusting aerodynamic properties of the blades of individual blades
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D7/00Controlling wind motors 
    • F03D7/02Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor
    • F03D7/04Automatic control; Regulation
    • F03D7/042Automatic control; Regulation by means of an electrical or electronic controller
    • F03D7/043Automatic control; Regulation by means of an electrical or electronic controller characterised by the type of control logic
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00Components
    • F05B2240/20Rotors
    • F05B2240/30Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05B2240/305Flaps, slats or spoilers
    • F05B2240/3052Flaps, slats or spoilers adjustable
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00Components
    • F05B2240/20Rotors
    • F05B2240/30Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05B2240/31Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor of changeable form or shape
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00Control
    • F05B2270/10Purpose of the control system
    • F05B2270/20Purpose of the control system to optimise the performance of a machine
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2270/00Control
    • F05B2270/30Control parameters, e.g. input parameters
    • F05B2270/331Mechanical loads
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/70Wind energy
    • Y02E10/72Wind turbines with rotation axis in wind direction

Definitions

  • the invention relates to a wind turbine blade provided with adjustable lift-regulating means arranged on or at the surface of the wind turbine blade and extending in the longitudinal direction of the blade, and with activating means by means of which the lift-regulating means may be adjusted to change the aerodynamic properties of the blade, the lift-regulating means and the activating means being adapted and arranged such that by activation of the activating means the lift can be reduced in a zone extending from a first position adjacent the blade tip to a second position between the first position and the blade root, and this second position being variable in the longitudinal direction of the blade by activating the activating means.
  • the invention further relates to a wind turbine rotor including such wind turbine blades, to a wind tur- bine and to a method of controlling such a wind turbine.
  • Modern wind mills also called wind turbines or wind engines, are used to produce electricity. They are often very large structures with blades of up to and in excess of 60 metres and made from fibre-reinforced polymer shells.
  • These wind turbines are provided with control devices which may prevent a overloading of the wind turbine and the blades at wind gusts and high wind speeds. Such control devices can also be used to brake the turbine and bringing it to a complete halt, if the wind speed becomes too high.
  • the turbine may comprise a braking device arranged in communication with the main shaft of the wind turbine.
  • the control devices may be formed of pitch-controlled blades mounted such on the hub that they are able to turn about the longitudinal axis.
  • the blades may thus be continuously adjusted to provide the lift rendering the desired power.
  • so-called stall-controlled wind turbines the blades are fixedly mounted on the hub and thus unable to turn about their longitudinal axis. The stall properties of the blades are used to reduce the aerodynamic lift and thus the power output.
  • the wind turbine according to US 6.361.275 is, however, encumbered by the drawback that the adjustment cannot be made particularly fast, the conventional pitch hydraulics of the blade being used for this purpose.
  • the hydraulics is not adapted for fast and almost instantaneous movements since a wind turbine blade, whose dead lo- ad may exceed 10 tons, has a comparatively large inertia.
  • the wind speed may vary greatly locally in the area swept by the rotor.
  • the rotor may have a diameter of more than 120 metres for which reason the wind speed may vary greatly due to local wind gusts and turbulence both in height and width.
  • US 4.692.095 discloses a wind turbine blade according to the preamble to claim 1.
  • the object of the invention is to provide a wind turbine blade of the modern, aerodynamic type with improved regulating properties to enhance the adjustment of the wind turbine to various wind conditions.
  • this object is attained in that the lift-regulating means of the wind turbine blade stated in the introduction are formed of at least one flexible flap extending in the longitudinal direction of the blade and being adjustable by means of one or more activating means to allow the lift-altering setting thereof to be changed gradually in the longitudinal direction of the flap.
  • the wind turbine may operate at high wind speeds as the lift from the blade tip and inwards can be reduced as the wind speed increases.
  • the turbine is operational at wind speeds above the so-called "cut-out wind speed" at which the turbine otherwise would have been stopped due to an excessive load.
  • These options make it possible to provide a wind turbine with longer blades than usual, said blades being relieved of the load as the wind speed increases, whereby the operating range of the wind turbine as regards wind speed is increased.
  • a considerable advantage is that the bending moment to which the blade root is subjected can be reduced.
  • the forces acting on the outermost portion of the blade adjacent the blade tip have a comparatively heavy impact on the bending moment at the blade root for which reason it is advantageous to reduce the lift in the outermost portion of the blade.
  • the lift-regulating means of the blade may be formed of at least two flaps displaced in relation to each other in the longitudinal direction of the blade. This is a particularly simple embodiment.
  • the flap(s) is/are fixedly supported along a line in the longitudinal direction of the blade and flexibly shaped.
  • the activating means may for instance be driven by hydraulics, electromagnetism, pneumatics or piezoelectric fibres.
  • a piezoelectric activating means is capable of activating a flap at a significantly higher rate than the rate at which for instance a hydraulic activating means operates.
  • the rate of the above type of piezoelectric activating means is practically instantaneous enabling a fast adjustment of the aerodynamic properties of the blade.
  • it is easy and mechanically simple to install piezoelectric activating means the only installation required is the supply of power to each or to a series of activating means. Such a solution is thus without mechanical elements and is in practice maintenance-free.
  • the flap may be shaped as a stall-generating flap adjacent the leading edge of the blade, when activated said flap altering the stall properties of the blade.
  • Such means promote the stall tendency of the blade, ie. the formation of separated air flows on the aerodynamic suction side of the blade, whereby the lift is reduced.
  • the blade includes load sensors arranged in or on the blade, said sensors measuring the loads on the blade in form of for instance wind pressure or strain. These sensors may suitably be used to adjust the lift- regulating means.
  • the wind turbine blade includes a control system with a control unit communicating with the activating means and the load sensors such that the control unit can activate the activating means and thus ad- just the flap(s) in accordance with the measurements made by the load sensors.
  • a control unit communicating with the activating means and the load sensors such that the control unit can activate the activating means and thus ad- just the flap(s) in accordance with the measurements made by the load sensors.
  • the control system thereof may be adapted such that it may be linked with other corresponding wind turbine blades on the same wind turbine to allow activation of the ac- tivating means on the basis of the load measurements from one or more of the other blades.
  • the blade may more easily attain optimum lift properties based on the load data received from another blade before it is subjected to the loads to which the other blade just has been subjected.
  • the blades are subjected to higher wind speeds when they are in the upper portion of the rotor plane during their rotation than when they are in the lower portion of the rotor plane.
  • a blade may thus receive date from an upwardly facing blade and make adaptation before it per se reaches its upward position during rotation.
  • the blades are also subjected to loads, which vary according to their position in the rotational plane. Such varying loads may also be compensated by means of the blade according to the invention.
  • a second aspect of the invention relates to a wind turbine rotor having a number of such wind turbine blades, preferably three, said rotor comprising a central control system with a control unit, eg. built-in in the rotor hub, and connected with the load sensors and flap(s) of each blade to allow the control unit to adjust the flap(s) of one or more of the other blades based on the load measurements from each blade and/or the setting of the flap(s) of each blade.
  • a control unit eg. built-in in the rotor hub
  • the invention also relates to a wind turbine comprising the above wind turbine blades or the above rotor.
  • the invention relates to a method of controlling such a wind turbine, wherein the second position between the first position and the blade root is varied in the longitudinal direction of the blade by adjusting the activating means on the basis of the measured loads or measured wind speeds.
  • the method is particularly suitable for controlling a wind turbine having pitch- controlled blades and wherein the rotational speed of the blades is kept substantially constant.
  • Figure 1 shows a wind turbine
  • Figure 2 is an isometric view of a part of an area of a blade profile provided with regulating means according to an embodiment
  • Figure 3 is an isometric view of a part of an area of a blade profile according to a second embodiment
  • Figure 4 is a cross-sectional view through a wind turbine blade with regulating means according to the invention
  • Figure 5 is a diagrammatic view of a wind turbine rotor with a control system
  • Figure 6 is a side view of a wind turbine blade
  • Figure 7 is a graph showing the lift of a wind turbine blade profile as a function of the distance to the blade root
  • Figure 8 is a graph as the one shown in fig. 7, the lift being here reduced in a zone along an outer portion of the blade.
  • FIG. 1 illustrates a conventional modern wind turbine with a tower 4, a nacelle 6 and a rotor including a hub 8 and three blades 10 extending therefrom.
  • the blades 10 may be provided with lift-regulating means, which by activation of the activating means at high wind speeds can gradually reduce the lift of the blade in a zone extending from the blade tip 14 to a position between the blade tip and the blade root 16.
  • the blade 10 is relieved in a zone extending from the blade tip 14 and inwardly towards the root 16 such that a wind turbine 2 with a given blade 10 can remain in operation at higher wind speed than usual.
  • the invention also renders it possible to provide a wind turbine 2 with longer blades 10' than usually, said blades merely being relieved by the lift-regulating means at increasing wind speeds and thus at increasing loads such that an overloading of the turbine and the blade is prevented.
  • FIG 2 is a sectional view of a blade profile, various embodiments of the lift- regulating means in form of two adjustable flaps 12 adjacent the trailing edge 22 of the blade being shown on the aerodynamic suction side 20 and a single comparatively long stall-generating flap 13 on the suction side of the blade adjacent the lead- ing edge 23 of the blade.
  • the shown flaps are integrally formed with the blade material and connected along fixedly-supported edges 25.
  • Not-shown activating means are provided on the lower face of the flaps 12, 13. When these activating means are activated the flap is pushed upwards to change the surface profile of the suction side 20.
  • the activating means may for instance be in form of hydraulic, pneumatic, electromagnetic or piezoelectric means (actuators).
  • the activating means are able to react relatively fast, especially if the flaps have to be adjusted one or more time for each rotation of the wind turbine blade.
  • Piezoelectric activating means based on piezoelectric fibres are especially interesting. Such means are virtually maintenance-free due to the lack of parts being worn caused by friction.
  • the two flaps 12 along the trailing edge 22 may each be provided with a single activating means.
  • the flap 13 positioned adjacent the leading edge 23 of the blade is fixedly supported to the blade along two edges 25, 26 and provided with an activating means in one end. Due to the flexibility of the flap material the flap 13 renders a gradually increasing lift-reducing effect in the direction of the end of the flap 13 being furthest to the right in Figure 2.
  • the flap 13 may, however, also be fixedly sup- ported only along the long edge 25 and be provided with activating means in both ends.
  • the flap 13 may have a stall- generating effect by ensuring when activated that the air flow is separated over the suction side 20 of the blade and thus reducing the lift of the blade.
  • Figure 3 illustrates a second embodiment, wherein a plurality of small flaps 17, 15 is provided along the trailing edge 22 of the blade and adjacent the leading edge 23 of blade.
  • the non-shown activating means may be of a simple type adjustable in two or three step or step-less. If a plurality of small flaps 15, 17 as used, as shown in Figure 3, simple on/off activating means may optionally be used.
  • a first area with a number of flaps adjacent the blade root may have inactivated activating means, an area between the first area and the blade tip may have a number of flaps of which every other flap is activated, and a third area adjacent the blade tip, where all flaps are activated.
  • the active flaps 19, 21 may be arranged on the pressure side 18 and/or on the suction side 20 of the blade profile.
  • active flaps 21 By placing active flaps 21 on the pressure side 18 and specifically at the trailing edge 22 of the blade on the pressure side it is possible to adjust the blade 10 to an optimum lift at varying wind speeds. It is thus possible at increasing wind speeds to make adjustments by means of the flaps 21 on the pressure side 18 of the blade for reducing the lift.
  • the lift may further be reduced with the flaps 19 on the suction side 20 of the blade adjacent the leading edge 23 of the blade by generating stall on the suction side 20 of the blade.
  • FIG. 5 is a diagrammatic view of a rotor with a hub 8 and three wind turbine bla- blades 10 extending from the hub 8.
  • Each blade 10 is provided with a control system including an electronic control unit 3 connected to the activating means of the lift- regulating means 12, 13, 15, 17, 19, 21.
  • the control unit 3 is further connected to load sensors 5 measuring the load on the wind turbine blade.
  • the load sensors 5 may for instance be strain gauges mounted on the inner face of the blade shell or a bracing interconnecting the inner faces of the blade shell and thus measures the strain caused by the wind load.
  • pressure gauges measuring the wind pressure on the blade may be used as load sensors.
  • control units 3 of each blade 10 may be interconnected such that data about the load on a first blade 10 or the flap setting thereof is transmitted to the other blades 10.
  • the flaps 12 thereof can be adjusted to the wind action to which they are subjected when they adopt the position of the first blade 10 during rotation.
  • control systems of the blades may be interconnected in such a manner that a single control unit 3 controls all of the lift-regulating means of the blades 10.
  • This control unit 3 may be placed in one of the blades, in the hub, in the nacelle, in the turbine tower 4 or outside of the turbine.
  • Figure 6 is a side view of a wind turbine blade.
  • Figure 7 shows a graph diagram- matically illustrating the lift L of the blade as a function of the distance X from the blade root. The lift of the blade thus increases gradually along the blade and decreases to 0 at the blade tip.
  • Figure 8 illustrates a situation in which the lift-regulating means 12, 13, 15, 17, 19, 21 are activated along an outer zone of the blade. In this zone the lift has been reduced to nearly 0.
  • the length of this zone is adjustable depending on the wind load, the abrupt transition can be moved inwards towards the blade root - to the left in fig- ure 8 - or outwards towards the blade tip - to the right in figure 8.
  • the lift-regulating means and the activating means may be formed and/or adjustable such that the lift is gradually reduced in the direction towards the blade tip.
  • the graph in the activated zone may be shaped as a flight of steps.
  • power output data from the generator in the nacelle may also be used to adjust the flaps.
  • Wind predictions may also be performed using the solution described in WO 98/42980, in which the wind speed at a certain distance in front of the wind turbine is measured by means of laser equipment. This method is advantageously combined with the flaps described above, the blades thus being “ready” when the predetermined wind situation occurs in the rotor plane.
  • the method of adjusting the aerodynamic properties of the blades described above makes it easier - particularly with pitch-controlled wind turbines - to maintain a substantially constant rotational speed even if the wind turbine is affected by wind gusts, eg due to turbulence, and other variations in the wind speed. Furthermore, the load on the blades is significantly more uniform in that variations in the speed profile of the wind can be part of the regulating parameters such that corrections for wind variations in the rotor plane can be made. It is also possible to make corrections for the wind shade exerted by the wind turbine tower on the rotor.
  • the invention may be used in connection with stall-controlled wind turbines with a constant speed of revolution and in connection with wind turbines with a varying speed of revolution.
  • the invention is, however, particularly advantageous when used to operate pitch-controlled wind turbines with a substantially constant rate. The cost of the expensive electric components required for converting the alternating current of varying frequency generated by wind turbines with variable rotational speed to an alternating current of constant frequency is thus saved.

Abstract

Wind turbine blade (10) including adjustable lift-regulating means (12, 13, 15, 17, 19, 21) arranged on or at the surface of the wind turbine blade (10), said lift-regulating means being provided with activating means by means of which they can be adjusted and thus alter the aerodynamic properties of the blade (10). The lift-regulating means (12, 13, 15, 17, 19, 21) and the activating means are adapted and arranged such that by activation of the activating means, the lift can be reduced in a zone extending in the longitudinal direction of the blade (10) from a first position adjacent the blade tip (14) to a second position between the first position and the blade root (16) and this second position is variable in the longitudinal direction of the blade (10) by adjusting the activate means. The lift-regulating means are formed of at least one flexible flap (12, 13, 15, 17, 19, 21). The invention further relates to a wind turbine rotor including such wind turbine blades, to a wind turbine and to a method of controlling the wind turbine.

Description

Title: wind turbine blade with lift-regulating means.
Technical Field
The invention relates to a wind turbine blade provided with adjustable lift-regulating means arranged on or at the surface of the wind turbine blade and extending in the longitudinal direction of the blade, and with activating means by means of which the lift-regulating means may be adjusted to change the aerodynamic properties of the blade, the lift-regulating means and the activating means being adapted and arranged such that by activation of the activating means the lift can be reduced in a zone extending from a first position adjacent the blade tip to a second position between the first position and the blade root, and this second position being variable in the longitudinal direction of the blade by activating the activating means. The invention further relates to a wind turbine rotor including such wind turbine blades, to a wind tur- bine and to a method of controlling such a wind turbine.
Modern wind mills, also called wind turbines or wind engines, are used to produce electricity. They are often very large structures with blades of up to and in excess of 60 metres and made from fibre-reinforced polymer shells. These wind turbines are provided with control devices which may prevent a overloading of the wind turbine and the blades at wind gusts and high wind speeds. Such control devices can also be used to brake the turbine and bringing it to a complete halt, if the wind speed becomes too high. In addition to these devices the turbine may comprise a braking device arranged in communication with the main shaft of the wind turbine.
The control devices may be formed of pitch-controlled blades mounted such on the hub that they are able to turn about the longitudinal axis. The blades may thus be continuously adjusted to provide the lift rendering the desired power. In so-called stall-controlled wind turbines the blades are fixedly mounted on the hub and thus unable to turn about their longitudinal axis. The stall properties of the blades are used to reduce the aerodynamic lift and thus the power output. Background Art
US 6.361.275 (Wobben) discloses a wind turbine, wherein the pitch angles of each wind turbine blade can be adjusted independently such that corrections for varying wind speeds in the swept area of the wind turbine blades can be made. The wind speed often increases with the distance to the surface of the ground and it may thus be advantageous to adjust the lift power of the blades such that the load on the blade is substantially uniform during its entire rotation. However, this solution may also be used to compensate for other types of variations in the wind speed in the rotor plane.
The wind turbine according to US 6.361.275 is, however, encumbered by the drawback that the adjustment cannot be made particularly fast, the conventional pitch hydraulics of the blade being used for this purpose. The hydraulics is not adapted for fast and almost instantaneous movements since a wind turbine blade, whose dead lo- ad may exceed 10 tons, has a comparatively large inertia.
As mentioned above, particularly at large wind turbines, eg offshore wind turbines, the wind speed may vary greatly locally in the area swept by the rotor. The rotor may have a diameter of more than 120 metres for which reason the wind speed may vary greatly due to local wind gusts and turbulence both in height and width.
In WO 97/01709 (Bonus Energy A/S) reference is made to wind turbine blades with active, adjustable flaps for changing the aerodynamic properties of the blade.
US 4.692.095 discloses a wind turbine blade according to the preamble to claim 1.
According to a first aspect, the object of the invention is to provide a wind turbine blade of the modern, aerodynamic type with improved regulating properties to enhance the adjustment of the wind turbine to various wind conditions. Description of the Invention
In accordance with the invention, this object is attained in that the lift-regulating means of the wind turbine blade stated in the introduction are formed of at least one flexible flap extending in the longitudinal direction of the blade and being adjustable by means of one or more activating means to allow the lift-altering setting thereof to be changed gradually in the longitudinal direction of the flap. As a result a particularly smooth and gradual change in the lift of the blade is obtained in a simple manner.
The wind turbine may operate at high wind speeds as the lift from the blade tip and inwards can be reduced as the wind speed increases. As a result, the turbine is operational at wind speeds above the so-called "cut-out wind speed" at which the turbine otherwise would have been stopped due to an excessive load. These options make it possible to provide a wind turbine with longer blades than usual, said blades being relieved of the load as the wind speed increases, whereby the operating range of the wind turbine as regards wind speed is increased. A considerable advantage is that the bending moment to which the blade root is subjected can be reduced. The forces acting on the outermost portion of the blade adjacent the blade tip have a comparatively heavy impact on the bending moment at the blade root for which reason it is advantageous to reduce the lift in the outermost portion of the blade.
According to an embodiment, the lift-regulating means of the blade may be formed of at least two flaps displaced in relation to each other in the longitudinal direction of the blade. This is a particularly simple embodiment.
According to particularly simple embodiment the flap(s) is/are fixedly supported along a line in the longitudinal direction of the blade and flexibly shaped. This is a particularly simple and secure way of providing the flap, the use of mechanical hinge members thereby further being avoided. The activating means may for instance be driven by hydraulics, electromagnetism, pneumatics or piezoelectric fibres. Especially a piezoelectric activating means is capable of activating a flap at a significantly higher rate than the rate at which for instance a hydraulic activating means operates. The rate of the above type of piezoelectric activating means is practically instantaneous enabling a fast adjustment of the aerodynamic properties of the blade. Furthermore, it is easy and mechanically simple to install piezoelectric activating means, the only installation required is the supply of power to each or to a series of activating means. Such a solution is thus without mechanical elements and is in practice maintenance-free.
According to an embodiment the flap may be shaped as a stall-generating flap adjacent the leading edge of the blade, when activated said flap altering the stall properties of the blade. Such means promote the stall tendency of the blade, ie. the formation of separated air flows on the aerodynamic suction side of the blade, whereby the lift is reduced.
According to a preferred embodiment the blade includes load sensors arranged in or on the blade, said sensors measuring the loads on the blade in form of for instance wind pressure or strain. These sensors may suitably be used to adjust the lift- regulating means.
According to an advantageous embodiment, the wind turbine blade includes a control system with a control unit communicating with the activating means and the load sensors such that the control unit can activate the activating means and thus ad- just the flap(s) in accordance with the measurements made by the load sensors. Such a wind turbine blade may thus be "automatically controlled" in that it per se adapts its lift according to the load and thus requires no external control.
According to a particularly advantageous embodiment of the wind turbine blade, the control system thereof may be adapted such that it may be linked with other corresponding wind turbine blades on the same wind turbine to allow activation of the ac- tivating means on the basis of the load measurements from one or more of the other blades. As a result, for instance when the turbine is hit by a wind gust, the blade may more easily attain optimum lift properties based on the load data received from another blade before it is subjected to the loads to which the other blade just has been subjected. In a typical situation the blades are subjected to higher wind speeds when they are in the upper portion of the rotor plane during their rotation than when they are in the lower portion of the rotor plane. A blade may thus receive date from an upwardly facing blade and make adaptation before it per se reaches its upward position during rotation. At yaw errors, ie when the nacelle is not adjusted in the opti- mum manner in relation to the wind direction, the blades are also subjected to loads, which vary according to their position in the rotational plane. Such varying loads may also be compensated by means of the blade according to the invention.
A second aspect of the invention relates to a wind turbine rotor having a number of such wind turbine blades, preferably three, said rotor comprising a central control system with a control unit, eg. built-in in the rotor hub, and connected with the load sensors and flap(s) of each blade to allow the control unit to adjust the flap(s) of one or more of the other blades based on the load measurements from each blade and/or the setting of the flap(s) of each blade.
The invention also relates to a wind turbine comprising the above wind turbine blades or the above rotor.
Finally the invention relates to a method of controlling such a wind turbine, wherein the second position between the first position and the blade root is varied in the longitudinal direction of the blade by adjusting the activating means on the basis of the measured loads or measured wind speeds.
The method is particularly suitable for controlling a wind turbine having pitch- controlled blades and wherein the rotational speed of the blades is kept substantially constant. Brief Description of the Drawings
The invention is explained in greater detail below with reference to the drawing illustrating embodiments of the invention and in which
Figure 1 shows a wind turbine,
Figure 2 is an isometric view of a part of an area of a blade profile provided with regulating means according to an embodiment,
Figure 3 is an isometric view of a part of an area of a blade profile according to a second embodiment,
Figure 4 is a cross-sectional view through a wind turbine blade with regulating means according to the invention,
Figure 5 is a diagrammatic view of a wind turbine rotor with a control system,
Figure 6 is a side view of a wind turbine blade,
Figure 7 is a graph showing the lift of a wind turbine blade profile as a function of the distance to the blade root, and
Figure 8 is a graph as the one shown in fig. 7, the lift being here reduced in a zone along an outer portion of the blade.
Best Modes for Carrying Out the Invention
Figure 1 illustrates a conventional modern wind turbine with a tower 4, a nacelle 6 and a rotor including a hub 8 and three blades 10 extending therefrom. The blades 10 may be provided with lift-regulating means, which by activation of the activating means at high wind speeds can gradually reduce the lift of the blade in a zone extending from the blade tip 14 to a position between the blade tip and the blade root 16. As a result, at high wind speeds the blade 10 is relieved in a zone extending from the blade tip 14 and inwardly towards the root 16 such that a wind turbine 2 with a given blade 10 can remain in operation at higher wind speed than usual. The invention also renders it possible to provide a wind turbine 2 with longer blades 10' than usually, said blades merely being relieved by the lift-regulating means at increasing wind speeds and thus at increasing loads such that an overloading of the turbine and the blade is prevented.
Figure 2 is a sectional view of a blade profile, various embodiments of the lift- regulating means in form of two adjustable flaps 12 adjacent the trailing edge 22 of the blade being shown on the aerodynamic suction side 20 and a single comparatively long stall-generating flap 13 on the suction side of the blade adjacent the lead- ing edge 23 of the blade. The shown flaps are integrally formed with the blade material and connected along fixedly-supported edges 25. Not-shown activating means are provided on the lower face of the flaps 12, 13. When these activating means are activated the flap is pushed upwards to change the surface profile of the suction side 20. The activating means may for instance be in form of hydraulic, pneumatic, electromagnetic or piezoelectric means (actuators). It is advantageous that the activating means are able to react relatively fast, especially if the flaps have to be adjusted one or more time for each rotation of the wind turbine blade. Piezoelectric activating means based on piezoelectric fibres are especially interesting. Such means are virtually maintenance-free due to the lack of parts being worn caused by friction.
The two flaps 12 along the trailing edge 22 may each be provided with a single activating means. The flap 13 positioned adjacent the leading edge 23 of the blade is fixedly supported to the blade along two edges 25, 26 and provided with an activating means in one end. Due to the flexibility of the flap material the flap 13 renders a gradually increasing lift-reducing effect in the direction of the end of the flap 13 being furthest to the right in Figure 2. The flap 13 may, however, also be fixedly sup- ported only along the long edge 25 and be provided with activating means in both ends. In contrast to the flaps 12 adjacent the trailing edge 22 of the blade which primarily alter the lift of the blade without generating stall, the flap 13 may have a stall- generating effect by ensuring when activated that the air flow is separated over the suction side 20 of the blade and thus reducing the lift of the blade.
Figure 3 illustrates a second embodiment, wherein a plurality of small flaps 17, 15 is provided along the trailing edge 22 of the blade and adjacent the leading edge 23 of blade. As a result a more accurate adjustment of the lift properties of the blade is ob- tained. The non-shown activating means may be of a simple type adjustable in two or three step or step-less. If a plurality of small flaps 15, 17 as used, as shown in Figure 3, simple on/off activating means may optionally be used. For obtaining a gradually reduced lift in the direction from the blade tip, a first area with a number of flaps adjacent the blade root may have inactivated activating means, an area between the first area and the blade tip may have a number of flaps of which every other flap is activated, and a third area adjacent the blade tip, where all flaps are activated. As a result three zones are obtained, in which a first zone has unchanged lift, a second zone has partially reduced lift and a third zone adjacent the blade tip has heavily reduced lift.
As evident in figure 4, which is cross-sectional view of a blade profile, the active flaps 19, 21 may be arranged on the pressure side 18 and/or on the suction side 20 of the blade profile. By placing active flaps 21 on the pressure side 18 and specifically at the trailing edge 22 of the blade on the pressure side it is possible to adjust the blade 10 to an optimum lift at varying wind speeds. It is thus possible at increasing wind speeds to make adjustments by means of the flaps 21 on the pressure side 18 of the blade for reducing the lift. The lift may further be reduced with the flaps 19 on the suction side 20 of the blade adjacent the leading edge 23 of the blade by generating stall on the suction side 20 of the blade.
Figure 5 is a diagrammatic view of a rotor with a hub 8 and three wind turbine bla- blades 10 extending from the hub 8. Each blade 10 is provided with a control system including an electronic control unit 3 connected to the activating means of the lift- regulating means 12, 13, 15, 17, 19, 21. The control unit 3 is further connected to load sensors 5 measuring the load on the wind turbine blade. The load sensors 5 may for instance be strain gauges mounted on the inner face of the blade shell or a bracing interconnecting the inner faces of the blade shell and thus measures the strain caused by the wind load. Optionally pressure gauges measuring the wind pressure on the blade may be used as load sensors.
As evident in figure 5, the control units 3 of each blade 10 may be interconnected such that data about the load on a first blade 10 or the flap setting thereof is transmitted to the other blades 10. As a result the flaps 12 thereof can be adjusted to the wind action to which they are subjected when they adopt the position of the first blade 10 during rotation.
The control systems of the blades may be interconnected in such a manner that a single control unit 3 controls all of the lift-regulating means of the blades 10. This control unit 3 may be placed in one of the blades, in the hub, in the nacelle, in the turbine tower 4 or outside of the turbine.
Figure 6 is a side view of a wind turbine blade. Figure 7 shows a graph diagram- matically illustrating the lift L of the blade as a function of the distance X from the blade root. The lift of the blade thus increases gradually along the blade and decreases to 0 at the blade tip.
Figure 8 illustrates a situation in which the lift-regulating means 12, 13, 15, 17, 19, 21 are activated along an outer zone of the blade. In this zone the lift has been reduced to nearly 0. The length of this zone is adjustable depending on the wind load, the abrupt transition can be moved inwards towards the blade root - to the left in fig- ure 8 - or outwards towards the blade tip - to the right in figure 8. The lift-regulating means and the activating means may be formed and/or adjustable such that the lift is gradually reduced in the direction towards the blade tip. By using a number of step- wise adjustable flaps, the graph in the activated zone may be shaped as a flight of steps.
In addition to wind speed registrations and strain measurements, power output data from the generator in the nacelle may also be used to adjust the flaps.
Wind predictions may also be performed using the solution described in WO 98/42980, in which the wind speed at a certain distance in front of the wind turbine is measured by means of laser equipment. This method is advantageously combined with the flaps described above, the blades thus being "ready" when the predetermined wind situation occurs in the rotor plane.
The method of adjusting the aerodynamic properties of the blades described above makes it easier - particularly with pitch-controlled wind turbines - to maintain a substantially constant rotational speed even if the wind turbine is affected by wind gusts, eg due to turbulence, and other variations in the wind speed. Furthermore, the load on the blades is significantly more uniform in that variations in the speed profile of the wind can be part of the regulating parameters such that corrections for wind variations in the rotor plane can be made. It is also possible to make corrections for the wind shade exerted by the wind turbine tower on the rotor.
The invention may be used in connection with stall-controlled wind turbines with a constant speed of revolution and in connection with wind turbines with a varying speed of revolution. The invention is, however, particularly advantageous when used to operate pitch-controlled wind turbines with a substantially constant rate. The cost of the expensive electric components required for converting the alternating current of varying frequency generated by wind turbines with variable rotational speed to an alternating current of constant frequency is thus saved.

Claims

Claims
1. Wind turbine blade (10) including adjustable lift-regulating means (12, 13, 15, 17, 19, 21) arranged on or at the surface of the wind turbine blade and extending in the longitudinal direction of the blade, and activating means by means of which the lift-regulating means (12, 13, 15, 17, 19, 21) can be adjusted and thus alter the aerodynamic properties of the blade (10), the lift-regulating means (12, 13, 15, 17, 19, 21) and the activating means being adapted and arranged such that by activation of the activating means, the lift can be reduced in a zone extending in the longitudinal direction of the blade (10) from a first position adjacent the blade tip (14) to a second position between the first position and the blade root (16) and this second position being variable in the longitudinal direction of the blade by adjusting the activating means characterised in that the lift-regulating means are formed of at least one flexible flap (12, 13, 15, 17, 19, 21) extending in the longitudinal direction of the blade (10) and being adjustable by means of one or more activating means to allow the lift-altering setting of the flap to be changed gradually in the longitudinal direction of the flap (12, 13, 15, 17, 19, 21).
2. Wind turbine blade (10) according to claim 1, characterised in that the lift- regulating means are formed of at least two flaps (12, 15, 17) being displaced in relation to each other in the longitudinal direction of the blade (10).
3. Wind turbine blade (10) according to claim 1 or 2, characterised in that the flap(s) (12, 13, 15, 17, 19, 21) is/are fixedly supported along a line (25) in the longi- tudinal direction of the blade (10).
4. Wind turbine blade (10) according to one of the preceding claims, characterised in that the activating means are driven by hydraulics, electromagnetism, pneumatics or piezoelectric fibres.
5. Wind turbine blade (10) according to one of the preceding claims, characterised in that the flap is a stall-generating flap (13, 15, 19) adjacent the leading edge (23) of the blade (10).
6. Wind turbine blade (10) according to one of the preceding claims, characterised in that it comprises load sensors (5) arranged in or on the blade and measuring wind loads in form of for instance wind pressure or strain.
7. Wind turbine blade (10) according to claim 6, characterised in that it comprises a control system with a control unit (3) connected with the activating means and the load sensors (5) such that the control unit may activate the activating means and thus adjust the flap(s) (12, 13, 15, 17, 19, 21) in accordance with the measurements made by the load sensors (5).
8. Wind turbine blade (10) according to claim 7, characterised in that the control system is adapted such that it can be linked with other corresponding blades (10) on the same wind turbine (2) to allow activation of the activating means on the basis of the load measurements from one or more of the other blades (10).
9. Wind turbine rotor (8, 10) with a plurality of wind turbine blades (10), preferably three, according to claim 8, said wind turbine rotor including a central control system with a control unit, eg built-in in the rotor hub (8), and connected with the load sensors (5) and flap(s) (12, 13, 15, 17, 19, 21) of each blade (10) to allow the control unit to adjust the flap(s) (12, 13, 15, 17, 19, 21) of one or more of the blades (10) based on the load measurements from each blade (10) and/or the setting of the flap(s) (12, 13, 15, 17, 19, 21) of each blade (10).
10. Wind turbine (2) comprising wind turbine blades (10) according to one of the claims 1-8 or a rotor according to claim 9.
11. Method of controlling a wind turbine (2) according to claim 10, wherein the second position between the first position and the blade root (16) is varied in the longitudinal direction of the blade (10) by adjusting the activating means on the basis of the measured loads or measured wind speeds.
12. Method according to claim 11 for controlling a wind turbine, in which the bla- des (10) are pitch-controlled and in which the rotational speed of the blades (10) is kept substantially constant.
PCT/DK2004/000294 2003-05-05 2004-04-29 Wind turbine blade with lift-regulating means WO2004099608A1 (en)

Priority Applications (5)

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EP04730202A EP1623111B1 (en) 2003-05-05 2004-04-29 Wind turbine blade with lift-regulating means
PL04730202T PL1623111T3 (en) 2003-05-05 2004-04-29 Wind turbine blade with lift-regulating means
DK04730202T DK1623111T3 (en) 2003-05-05 2004-04-29 Wind turbine blade with buoyancy regulating organs
US10/555,579 US7293959B2 (en) 2003-05-05 2004-04-29 Wind turbine blade with lift-regulating means
DE602004016649T DE602004016649D1 (en) 2003-05-05 2004-04-29 WIND TURBINE BLADE WITH DRIVE ADJUSTMENT

Applications Claiming Priority (2)

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DK200300670A DK200300670A (en) 2003-05-05 2003-05-05 Wind turbine with buoyancy regulating organs
DKPA200300670 2003-05-05

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EP (1) EP1623111B1 (en)
AT (1) ATE408754T1 (en)
DE (1) DE602004016649D1 (en)
DK (2) DK200300670A (en)
ES (1) ES2314394T3 (en)
PL (1) PL1623111T3 (en)
PT (1) PT1623111E (en)
WO (1) WO2004099608A1 (en)

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006122547A1 (en) * 2005-05-17 2006-11-23 Vestas Wind Systems A/S A pitch controlled wind turbine blade, a wind turbine and use hereof
WO2007043895A1 (en) * 2005-10-13 2007-04-19 Sway As Speed control system for a wind power plant's rotor and an aerodynamic brake
WO2007045940A1 (en) * 2005-10-17 2007-04-26 Vestas Wind Systems A/S Wind turbine blade with variable aerodynamic profile
WO2007105174A1 (en) 2006-03-14 2007-09-20 Tecsis Tecnologia E Sistemas Avançados Ltda Multi-element blade with aerodynamic profiles
WO2007118581A1 (en) * 2006-04-13 2007-10-25 Repower Systems Ag Rotor blade of a wind energy unit
WO2008020242A2 (en) * 2006-08-18 2008-02-21 Insensys Limited Structural monitoring in wind turbine blades
WO2008049426A1 (en) * 2006-10-24 2008-05-02 Vestas Wind Systems A/S A method for damping tower oscillations, an active stall controlled wind turbine and use hereof
EP2017467A1 (en) 2007-07-20 2009-01-21 Siemens Aktiengesellschaft Wind turbine rotor blade and pitch regulated wind turbine
NL2000819C2 (en) * 2007-08-17 2009-02-18 Stichting Energie Wind turbine and rotor blade.
WO2009080316A2 (en) * 2007-12-21 2009-07-02 Vestas Wind Systems A/S Active flow control device and method for affecting a fluid boundary layer of a wind turbine blade
EP2085609A1 (en) * 2007-09-14 2009-08-05 Gamesa Innovation & Technology, S.L. Wind turbine blade with cambering flaps controlled by surface pressure changes
EP2128385A2 (en) 2008-05-16 2009-12-02 Frontier Wind, LLC. Wind turbine with deployable air deflectors
WO2009056136A3 (en) * 2007-10-29 2009-12-03 Vestas Wind Systems A/S Wind turbine blade and method for controlling the load on a blade
NL2001878C2 (en) * 2008-08-07 2010-02-09 Stichting Energie System and method for compensating rotor imbalance for a wind turbine.
WO2010034749A2 (en) * 2008-09-26 2010-04-01 Vestas Wind Systems A/S Flow control device and method of controlling a fluid boundary layer on a rotating wind turbine blade
GB2469854A (en) * 2009-04-30 2010-11-03 Vestas Wind Sys As Wind turbine rotor blade
US7922450B2 (en) 2009-03-26 2011-04-12 Vestas Wind Systems A/S Wind turbine blade comprising a trailing edge flap and a piezoelectric actuator
EP1674723A3 (en) * 2004-12-23 2011-05-04 General Electric Company Active flow modification on wind turbine blades
WO2010106329A3 (en) * 2009-03-17 2011-06-16 Vestas Wind Systems A/S A hinge apparatus for connecting first and second wind turbine blade components comprising a rotary actuator
EP2336555A1 (en) * 2009-12-14 2011-06-22 Lm Glasfiber A/S Magnetic active flap
WO2010135552A3 (en) * 2009-05-20 2011-10-20 Deka Products Limited Partnership Centrifugally driven aerodynamic rotor blade brake assembly
CN102418666A (en) * 2011-11-24 2012-04-18 三一电气有限责任公司 Wind generating set and blade thereof
CN102434394A (en) * 2011-12-31 2012-05-02 深圳市风发科技发展有限公司 Turbulent flow device of Vertical axis wind turbine, bracket and vertical axis wind turbine
WO2011147422A3 (en) * 2010-05-27 2012-07-19 Vestas Wind Systems A/S Method and apparatus for reducing fluid flow induced forces produced by vortex shedding on a wind turbine rotor blade
WO2012095478A1 (en) 2011-01-14 2012-07-19 Lm Wind Power A/S Wind turbine blade, wind turbine and method of controlling such
WO2012093022A3 (en) * 2011-01-06 2012-08-30 Siemens Aktiengesellschaft Load mitigation device for wind turbine blades
US8267654B2 (en) 2008-05-16 2012-09-18 Frontier Wind, Llc Wind turbine with gust compensating air deflector
US8418967B2 (en) 2008-02-21 2013-04-16 Cornerstone Research Group, Inc. Passive adaptive structures
EP2301841A3 (en) * 2009-09-24 2013-05-22 Rolls-Royce plc Variable shape rotor blade
US8517682B2 (en) 2007-04-30 2013-08-27 Vestas Wind Systems A/S Wind turbine blade
EP2664791A2 (en) 2012-05-18 2013-11-20 Manuel Torres Martinez Wind turbine blade of variable geometry with passive control
US8678324B2 (en) 2008-02-21 2014-03-25 Cornerstone Research Group, Inc. Passive adaptive structures
EP2264311A3 (en) * 2009-06-17 2014-04-02 General Electric Company Wind turbine comprising an active flow control device on the rotor blade
US8807940B2 (en) 2007-01-05 2014-08-19 Lm Glasfiber A/S Wind turbine blade with lift-regulating means in form of slots or holes
US8851840B2 (en) 2008-08-29 2014-10-07 Vestas Wind Systems A/S Control system in wind turbine blades
US8876473B2 (en) 2009-03-17 2014-11-04 Vestas Wind Systems A/S Hinged connection apparatus for securing a first wind turbine component to a second
US8899923B2 (en) 2008-10-14 2014-12-02 Vestas Wind Systems A/S Wind turbine blade with device for changing the aerodynamic surface or shape
US9039372B2 (en) 2007-04-30 2015-05-26 Vestas Wind Systems A/S Wind turbine blade
US9039366B2 (en) 2009-11-11 2015-05-26 Vestas Wind Systems A/S Control of wind turbine blade lift regulating means
WO2015132882A1 (en) * 2014-03-04 2015-09-11 中国電力株式会社 Wind power generation device
CN107810140A (en) * 2015-01-24 2018-03-16 迪特尔·勒姆 Multi-functional wing flap as backflow wing flap
US9926911B2 (en) 2014-09-12 2018-03-27 Ge Infrastructure Technology, Llc Wind turbine air deflector system control
CN109162878A (en) * 2018-08-01 2019-01-08 汕头大学 A kind of intelligent blade of wind driven generator investigating method and its system
US11078885B2 (en) 2016-08-30 2021-08-03 Siemens Gamesa Renewable Energy A/S Flow control arrangement for a wind turbine rotor blade

Families Citing this family (86)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004074681A1 (en) * 2003-02-18 2004-09-02 Forskningscenter Risø Method of controlling aerodynamic load of a wind turbine based on local blade flow measurement
GB0510417D0 (en) * 2005-05-21 2005-06-29 Rotech Holdings Ltd Improved turbine
DK1915514T4 (en) * 2005-07-15 2019-02-11 Vestas Wind Sys As Wind turbine blade
US20070231151A1 (en) * 2005-10-10 2007-10-04 General Electric Company Active flow control for wind turbine blades
ES2261100B1 (en) * 2006-03-29 2007-08-01 Gamesa Corporacion Tecnologica, S.A. ANTI-NOISE AEROGENERATOR.
US20090249779A1 (en) * 2006-06-12 2009-10-08 Daw Shien Scientific Research & Development, Inc. Efficient vapor (steam) engine/pump in a closed system used at low temperatures as a better stirling heat engine/refrigerator
US8608441B2 (en) 2006-06-12 2013-12-17 Energyield Llc Rotatable blade apparatus with individually adjustable blades
US20080296906A1 (en) * 2006-06-12 2008-12-04 Daw Shien Scientific Research And Development, Inc. Power generation system using wind turbines
US20090044535A1 (en) * 2006-06-12 2009-02-19 Daw Shien Scientific Research And Development, Inc. Efficient vapor (steam) engine/pump in a closed system used at low temperatures as a better stirling heat engine/refrigerator
US20090211223A1 (en) * 2008-02-22 2009-08-27 James Shihfu Shiao High efficient heat engine process using either water or liquefied gases for its working fluid at lower temperatures
US20100215502A1 (en) 2007-03-30 2010-08-26 Distributed Thermal Systems Ltd. Multistage wind turbine with variable blade displacement
ES2324002B1 (en) * 2007-06-22 2010-05-13 GAMESA INNOVATION & TECHNOLOGY, S.L. AIRLINER SHOVEL WITH DEFLECTABLE ALERONS.
ES2337645B1 (en) * 2007-09-14 2011-03-11 GAMESA INNOVATION & TECHNOLOGY, S.L. SENSORIZED SHOVEL UNION.
ES2343397B1 (en) * 2008-03-07 2011-06-13 GAMESA INNOVATION & TECHNOLOGY, S.L. AN AIRWOOD SHOVEL.
US20100045037A1 (en) * 2008-08-21 2010-02-25 Daw Shien Scientific Research And Development, Inc. Power generation system using wind turbines
GB2465975B (en) 2008-12-02 2010-10-13 Vestas Wind Sys As Wind turbine control surface hinge
GB2468693A (en) * 2009-03-18 2010-09-22 Vestas Wind Sys As Wind turbine blade control
US8137066B2 (en) * 2009-04-16 2012-03-20 Frontier Wind, Llc Pressure based load measurement
EP2253838A1 (en) * 2009-05-18 2010-11-24 Lm Glasfiber A/S A method of operating a wind turbine
GB2470589A (en) * 2009-05-29 2010-12-01 Vestas Wind Sys As Branching spar wind turbine blade
US8011886B2 (en) * 2009-06-30 2011-09-06 General Electric Company Method and apparatus for increasing lift on wind turbine blade
US8475129B2 (en) * 2009-12-10 2013-07-02 General Electric Company Systems and methods for assembling an air distribution system for use in a rotor blade of a wind turbine
US8876064B2 (en) 2009-12-21 2014-11-04 Ramot At Tel-Aviv University Ltd. Oscillatory vorticity generator and applications thereof
GB2479413A (en) 2010-04-09 2011-10-12 Vestas Wind Sys As Wind Turbine Independent Blade Control Outside The Rated Output
GB2479415A (en) 2010-04-09 2011-10-12 Vestas Wind Sys As Wind Turbine Independent Blade Control Outside The Rated Output
US8061986B2 (en) * 2010-06-11 2011-11-22 General Electric Company Wind turbine blades with controllable aerodynamic vortex elements
CN101865081B (en) * 2010-07-01 2012-02-29 北京大学 Device for utilizing front edge rudder pieces to adjust output power of rotating blade and method thereof
US20110142595A1 (en) 2010-07-02 2011-06-16 General Electric Company Wind turbine blades with controlled active flow and vortex elements
US8011887B2 (en) * 2010-07-21 2011-09-06 General Electric Company Rotor blade assembly
US8868261B2 (en) * 2010-09-08 2014-10-21 Airbus Operations Gmbh Monitoring device for an actuation system of an aircraft, actuation system and method for reconfiguring the actuation system
DK2479423T3 (en) * 2011-01-24 2018-05-28 Siemens Ag Wind turbine rotor blade element
US8167554B2 (en) * 2011-01-28 2012-05-01 General Electric Corporation Actuatable surface features for wind turbine rotor blades
DK2715122T3 (en) * 2011-06-03 2018-08-13 Vestas Wind Sys As A WAY TO OPERATE A WINDMILL
ES2640954T3 (en) * 2011-06-09 2017-11-07 Pp Energy Aps Lifting device to connect two rotor blade segments of a wind turbine
US8444384B2 (en) * 2011-08-25 2013-05-21 General Electric Company Rotor blade assembly and method for adjusting loading capability of rotor blade
US8491262B2 (en) * 2011-10-27 2013-07-23 General Electric Company Method for shut down of a wind turbine having rotor blades with fail-safe air brakes
US20120134814A1 (en) * 2011-10-27 2012-05-31 General Electric Company Wind turbine rotor blade with fail-safe air brake flaps
US8434996B2 (en) 2011-12-06 2013-05-07 General Electric Company System and method for detecting and/or controlling loads in a wind turbine
US8936435B2 (en) * 2011-12-16 2015-01-20 General Electric Company System and method for root loss reduction in wind turbine blades
US9816384B2 (en) * 2011-12-28 2017-11-14 Orville J. Birkestrand Power generation apparatus
US9816383B2 (en) * 2011-12-28 2017-11-14 Orville J. Birkestrand Power generation apparatus
US20140076419A1 (en) * 2012-02-27 2014-03-20 Sinhatech Self adjusting deturbulator enhanced flap and wind deflector
DK2647835T3 (en) 2012-04-04 2017-02-20 Siemens Ag Flexible flap arrangement for a wind turbine rotor blade
DE102012216804B4 (en) * 2012-09-19 2015-06-03 Senvion Se Damping system and rotor blade
US20150003985A1 (en) * 2013-06-27 2015-01-01 General Electric Company Moveable surface features for wind turbine rotor blades
US9267491B2 (en) 2013-07-02 2016-02-23 General Electric Company Wind turbine rotor blade having a spoiler
US9638164B2 (en) 2013-10-31 2017-05-02 General Electric Company Chord extenders for a wind turbine rotor blade assembly
CN104747374A (en) * 2013-12-25 2015-07-01 深圳市泰玛风光能源科技有限公司 Intelligent variable pitch speed regulation method and system for wind driven generator
US9752559B2 (en) 2014-01-17 2017-09-05 General Electric Company Rotatable aerodynamic surface features for wind turbine rotor blades
US9670901B2 (en) 2014-03-21 2017-06-06 Siemens Aktiengesellschaft Trailing edge modifications for wind turbine airfoil
US9476406B2 (en) 2014-04-14 2016-10-25 Siemens Aktiengesellschaft Vortex generators aligned with trailing edge features on wind turbine blade
US9422915B2 (en) 2014-05-08 2016-08-23 Siemens Aktiengesellschaft Customizing a wind turbine for site-specific conditions
EP3146201A1 (en) * 2014-05-23 2017-03-29 Siemens Aktiengesellschaft Aerodynamic device of a rotor blade of a wind turbine
US10385826B2 (en) 2014-09-12 2019-08-20 Ge Infrastructure Technology, Llc Wind turbine air deflector system control
DE102015113347A1 (en) 2015-01-24 2016-07-28 Dieter Röhm Multifunctional flaps for improving energy efficiency and safety
DE102015101763A1 (en) 2015-02-06 2016-09-01 Airbus Operations Gmbh Vertical stabilizer for an aircraft
DE102015101765A1 (en) * 2015-02-06 2016-08-11 Airbus Operations Gmbh Vortex generator arrangement
US10683845B2 (en) * 2015-03-12 2020-06-16 Rensselaer Polytechnic Institute Modular active structural vibration suppression for wind turbine blades
JP2016194280A (en) * 2015-04-01 2016-11-17 株式会社東芝 Wind power generation system and control method of the same
DE102015113404A1 (en) 2015-08-13 2017-02-16 Dieter Röhm Multifunctional flap system to improve energy efficiency
CN106050556A (en) * 2016-08-15 2016-10-26 上海理工大学 Self-adaptive flexible blade of vertical-shaft wind turbine
DE102016116138A1 (en) * 2016-08-30 2018-03-01 Wobben Properties Gmbh Actuator device for a wind turbine, wind turbine and assembly method
US11384734B1 (en) 2017-04-07 2022-07-12 Orville J. Birkestrand Wind turbine
EP3517773B1 (en) * 2018-01-29 2020-08-12 Siemens Gamesa Renewable Energy A/S Trailing edge assembly
EP3587799A1 (en) 2018-06-27 2020-01-01 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
EP3587798B1 (en) * 2018-06-27 2020-10-14 Siemens Gamesa Renewable Energy A/S Aerodynamic structure
DE102018127801A1 (en) 2018-11-07 2020-05-07 fos4X GmbH Improvement or optimization of the yield of a wind energy plant through aerodynamic adaptation in the event of a stall
EP3667063A1 (en) 2018-12-13 2020-06-17 Siemens Gamesa Renewable Energy A/S Device for draining humidity in wind turbines
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EP3667072A1 (en) 2018-12-13 2020-06-17 Siemens Gamesa Renewable Energy A/S Adaptable spoiler for a wind turbine blade
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EP3730779A1 (en) 2019-04-25 2020-10-28 Siemens Gamesa Renewable Energy A/S Fluid convey tubing system for wind turbine rotor blade
EP3832127A1 (en) 2019-12-05 2021-06-09 Siemens Gamesa Renewable Energy A/S Wind turbine blade flow regulation
AU2021227962A1 (en) 2020-02-27 2022-08-18 Orville J. Birkestrand Toroidal lift force engine
EP3913212A1 (en) 2020-05-19 2021-11-24 Siemens Gamesa Renewable Energy A/S Blade for a wind turbine comprising means for retaining a spoiler at a retracted position
EP3919737A1 (en) * 2020-06-05 2021-12-08 Siemens Gamesa Renewable Energy A/S Device and method of controlling an operation of a wind turbine to reduce load at yaw misalignment
EP4050205A1 (en) * 2021-02-25 2022-08-31 Siemens Gamesa Renewable Energy A/S Rotor blade with controllable aerodynamic device for a wind turbine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4692095A (en) * 1984-04-26 1987-09-08 Sir Henry Lawson-Tancred, Sons & Co. Ltd. Wind turbine blades
US20020047275A1 (en) * 1997-07-25 2002-04-25 Aloys Wobben Wind energy installation
FR2826066A1 (en) * 2001-06-19 2002-12-20 Jean Pierre Tromelin Device for regulating windmill blade rotation comprises flap articulated around axis parallel to blade longitudinal axis able to open between positions in plane perpendicular to blade and retracted in blade

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2622686A (en) * 1942-07-21 1952-12-23 Chevreau Rene Louis Pier Marie Wind motor
DK172932B1 (en) 1995-06-27 1999-10-11 Bonus Energy As Method and device for reducing vibrations in a wind turbine blade.
US6769873B2 (en) * 2002-10-08 2004-08-03 The United States Of America As Represented By The Secretary Of The Navy Dynamically reconfigurable wind turbine blade assembly

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4692095A (en) * 1984-04-26 1987-09-08 Sir Henry Lawson-Tancred, Sons & Co. Ltd. Wind turbine blades
US20020047275A1 (en) * 1997-07-25 2002-04-25 Aloys Wobben Wind energy installation
FR2826066A1 (en) * 2001-06-19 2002-12-20 Jean Pierre Tromelin Device for regulating windmill blade rotation comprises flap articulated around axis parallel to blade longitudinal axis able to open between positions in plane perpendicular to blade and retracted in blade

Cited By (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1674723A3 (en) * 2004-12-23 2011-05-04 General Electric Company Active flow modification on wind turbine blades
CN101223356B (en) * 2005-05-17 2012-06-13 维斯塔斯风力系统有限公司 Pitch control type wind turbine blade, wind turbine and its application
US7927070B2 (en) 2005-05-17 2011-04-19 Vestas Wind Systems A/S Pitch controlled wind turbine blade, a wind turbine and use thereof
EP1886016B1 (en) 2005-05-17 2017-05-10 Vestas Wind Systems A/S A pitch controlled wind turbine blade having turbulence generating means, a wind turbine and use thereof
WO2006122547A1 (en) * 2005-05-17 2006-11-23 Vestas Wind Systems A/S A pitch controlled wind turbine blade, a wind turbine and use hereof
WO2007043895A1 (en) * 2005-10-13 2007-04-19 Sway As Speed control system for a wind power plant's rotor and an aerodynamic brake
WO2007045940A1 (en) * 2005-10-17 2007-04-26 Vestas Wind Systems A/S Wind turbine blade with variable aerodynamic profile
US8157533B2 (en) 2005-10-17 2012-04-17 Vestas Wind Systems A/S Wind turbine blade with variable aerodynamic profile
WO2007105174A1 (en) 2006-03-14 2007-09-20 Tecsis Tecnologia E Sistemas Avançados Ltda Multi-element blade with aerodynamic profiles
US8647063B2 (en) 2006-03-14 2014-02-11 Tecsis Tecnologia Sistemas Avançados S.A. Multi-element blade with aerodynamic profiles
WO2007118581A1 (en) * 2006-04-13 2007-10-25 Repower Systems Ag Rotor blade of a wind energy unit
US8052394B2 (en) 2006-04-13 2011-11-08 Repower Systems Ag Rotor blade of a wind energy unit
WO2008020242A3 (en) * 2006-08-18 2008-04-10 Insensys Ltd Structural monitoring in wind turbine blades
WO2008020242A2 (en) * 2006-08-18 2008-02-21 Insensys Limited Structural monitoring in wind turbine blades
WO2008049426A1 (en) * 2006-10-24 2008-05-02 Vestas Wind Systems A/S A method for damping tower oscillations, an active stall controlled wind turbine and use hereof
US7919880B2 (en) 2006-10-24 2011-04-05 Vestas Wind Systems A/S Method for damping tower oscillations, an active stall controlled wind turbine and use hereof
US8807940B2 (en) 2007-01-05 2014-08-19 Lm Glasfiber A/S Wind turbine blade with lift-regulating means in form of slots or holes
US9039372B2 (en) 2007-04-30 2015-05-26 Vestas Wind Systems A/S Wind turbine blade
US8517682B2 (en) 2007-04-30 2013-08-27 Vestas Wind Systems A/S Wind turbine blade
US8602739B2 (en) 2007-07-20 2013-12-10 Siemens Aktiengesellschaft Wind turbine rotor blade and pitch regulated wind turbine
EP2017467A1 (en) 2007-07-20 2009-01-21 Siemens Aktiengesellschaft Wind turbine rotor blade and pitch regulated wind turbine
NL2000819C2 (en) * 2007-08-17 2009-02-18 Stichting Energie Wind turbine and rotor blade.
ES2326352A1 (en) * 2007-09-14 2009-10-07 GAMESA INNOVATION & TECHNOLOGY, S.L. Wind turbine blade with cambering flaps controlled by surface pressure changes
EP2085609A1 (en) * 2007-09-14 2009-08-05 Gamesa Innovation & Technology, S.L. Wind turbine blade with cambering flaps controlled by surface pressure changes
WO2009056136A3 (en) * 2007-10-29 2009-12-03 Vestas Wind Systems A/S Wind turbine blade and method for controlling the load on a blade
WO2009080316A2 (en) * 2007-12-21 2009-07-02 Vestas Wind Systems A/S Active flow control device and method for affecting a fluid boundary layer of a wind turbine blade
WO2009080316A3 (en) * 2007-12-21 2010-04-29 Vestas Wind Systems A/S Active flow control device and method for affecting a fluid boundary layer of a wind turbine blade
US8678324B2 (en) 2008-02-21 2014-03-25 Cornerstone Research Group, Inc. Passive adaptive structures
US9033283B1 (en) 2008-02-21 2015-05-19 Cornerstone Research Group, Inc. Passive adaptive structures
US8418967B2 (en) 2008-02-21 2013-04-16 Cornerstone Research Group, Inc. Passive adaptive structures
US8267654B2 (en) 2008-05-16 2012-09-18 Frontier Wind, Llc Wind turbine with gust compensating air deflector
US10844837B2 (en) 2008-05-16 2020-11-24 Ge Infrastructure Technology, Llc Wind turbine with deployable air deflectors
EP2128385A3 (en) * 2008-05-16 2012-04-25 Frontier Wind, LLC. Wind turbine with deployable air deflectors
US8192161B2 (en) 2008-05-16 2012-06-05 Frontier Wind, Llc. Wind turbine with deployable air deflectors
EP2128385A2 (en) 2008-05-16 2009-12-02 Frontier Wind, LLC. Wind turbine with deployable air deflectors
NL2001878C2 (en) * 2008-08-07 2010-02-09 Stichting Energie System and method for compensating rotor imbalance for a wind turbine.
US8851840B2 (en) 2008-08-29 2014-10-07 Vestas Wind Systems A/S Control system in wind turbine blades
WO2010034749A2 (en) * 2008-09-26 2010-04-01 Vestas Wind Systems A/S Flow control device and method of controlling a fluid boundary layer on a rotating wind turbine blade
WO2010034749A3 (en) * 2008-09-26 2010-11-11 Vestas Wind Systems A/S Flow control device and method of controlling a fluid boundary layer on a rotating wind turbine blade
US8899923B2 (en) 2008-10-14 2014-12-02 Vestas Wind Systems A/S Wind turbine blade with device for changing the aerodynamic surface or shape
US8876473B2 (en) 2009-03-17 2014-11-04 Vestas Wind Systems A/S Hinged connection apparatus for securing a first wind turbine component to a second
WO2010106329A3 (en) * 2009-03-17 2011-06-16 Vestas Wind Systems A/S A hinge apparatus for connecting first and second wind turbine blade components comprising a rotary actuator
CN102414439A (en) * 2009-03-17 2012-04-11 维斯塔斯风力系统有限公司 A hinge apparatus for connecting first and second wind turbine blade components comprising a rotary actuator
US7922450B2 (en) 2009-03-26 2011-04-12 Vestas Wind Systems A/S Wind turbine blade comprising a trailing edge flap and a piezoelectric actuator
GB2469854A (en) * 2009-04-30 2010-11-03 Vestas Wind Sys As Wind turbine rotor blade
US8827644B2 (en) 2009-04-30 2014-09-09 Vestas Wind Systems A/S Wind turbine rotor blade
WO2010135552A3 (en) * 2009-05-20 2011-10-20 Deka Products Limited Partnership Centrifugally driven aerodynamic rotor blade brake assembly
US8714925B2 (en) 2009-05-20 2014-05-06 Deka Products Limited Partnership Centrifugally driven aerodynamic rotor blade brake assembly
EP2264311A3 (en) * 2009-06-17 2014-04-02 General Electric Company Wind turbine comprising an active flow control device on the rotor blade
EP2301841A3 (en) * 2009-09-24 2013-05-22 Rolls-Royce plc Variable shape rotor blade
US8657561B2 (en) 2009-09-24 2014-02-25 Rolls-Royce Plc Variable shape rotor blade
US9039366B2 (en) 2009-11-11 2015-05-26 Vestas Wind Systems A/S Control of wind turbine blade lift regulating means
WO2011073178A2 (en) 2009-12-14 2011-06-23 Lm Glasfiber A/S Magnetic active flap
CN102741545B (en) * 2009-12-14 2016-03-30 Lm玻璃纤维制品有限公司 For the wind turbine blade of the rotor of wind turbine
EP2336555A1 (en) * 2009-12-14 2011-06-22 Lm Glasfiber A/S Magnetic active flap
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CN102741545A (en) * 2009-12-14 2012-10-17 Lm玻璃纤维制品有限公司 Magnetic active flap
WO2011147422A3 (en) * 2010-05-27 2012-07-19 Vestas Wind Systems A/S Method and apparatus for reducing fluid flow induced forces produced by vortex shedding on a wind turbine rotor blade
WO2012093022A3 (en) * 2011-01-06 2012-08-30 Siemens Aktiengesellschaft Load mitigation device for wind turbine blades
WO2012095478A1 (en) 2011-01-14 2012-07-19 Lm Wind Power A/S Wind turbine blade, wind turbine and method of controlling such
CN102418666A (en) * 2011-11-24 2012-04-18 三一电气有限责任公司 Wind generating set and blade thereof
CN102434394A (en) * 2011-12-31 2012-05-02 深圳市风发科技发展有限公司 Turbulent flow device of Vertical axis wind turbine, bracket and vertical axis wind turbine
EP2664791A2 (en) 2012-05-18 2013-11-20 Manuel Torres Martinez Wind turbine blade of variable geometry with passive control
WO2015132882A1 (en) * 2014-03-04 2015-09-11 中国電力株式会社 Wind power generation device
JPWO2015132882A1 (en) * 2014-03-04 2017-03-30 中国電力株式会社 Wind power generator
US9926911B2 (en) 2014-09-12 2018-03-27 Ge Infrastructure Technology, Llc Wind turbine air deflector system control
CN107810140A (en) * 2015-01-24 2018-03-16 迪特尔·勒姆 Multi-functional wing flap as backflow wing flap
US11078885B2 (en) 2016-08-30 2021-08-03 Siemens Gamesa Renewable Energy A/S Flow control arrangement for a wind turbine rotor blade
CN109162878A (en) * 2018-08-01 2019-01-08 汕头大学 A kind of intelligent blade of wind driven generator investigating method and its system

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DE602004016649D1 (en) 2008-10-30
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