ABSTRACT
Abstract
A wind energy systems includes a shroud for each turbine. The shroud is adapted to direct and accelerate wind towards the turbine. A strong adaptable support assembly is provided for securing turbines to a structure. An air glide yaw assembly facilitates rotational movement of the structure allowing the turbines to face oncoming wind. The turbine blades are optimized for use with a shroud.
Description
RELATED APPLICATION
This application claims the benefit of priority of U.S. provisional application 60/871,135, filed Dec. 21, 2006, the entire contents of which are incorporated herein by this reference.
FIELD OF THE INVENTION
This invention generally relates to devices for use in producing electric power from wind energy, and more particularly, to an elevated shrouded wind turbine adapted for yaw movement facing the wind.
BACKGROUND
Most electricity today is generated by burning fossil fuels and producing steam which is then used drive a steam turbine that, in turn, drives an electrical generator. Unfortunately, however, the world's supply of fossil fuels is large, but finite. Exhaustion of low-cost fossil fuels will have significant consequences for energy sources as well as for the manufacture of plastics and many other things.
More serious are concerns about the emissions that result from fossil fuel burning. Fossil fuels constitute a significant repository of carbon buried deep under the ground. Burning them results in the conversion of this carbon to carbon dioxide, which is then released into the atmosphere. This results in an increase in the Earth's levels of atmospheric carbon dioxide, which enhances the greenhouse effect and contributes to global warming. Depending upon the particular fossil fuel and the method of burning, other emissions may be produced as well. Ozone, SO 2 , NO 2 and other gases are often released, as well as particulate matter. Sulfur and nitrogen oxides contribute to smog and acid rain. Fossil fuels, particularly coal, also contain dilute radioactive material, and burning them in very large quantities releases this material into the environment, leading to low but real levels of local and global radioactive contamination. Coal also contains traces of toxic heavy elements such as mercury, arsenic and others. Mercury vaporized in a power plant's boiler may stay suspended in the atmosphere and circulate around the world.
An alternative source of renewable energy, solar cells, also referred to as photovoltaic cells, use the photovoltaic effect of semiconductors to generate electricity directly from sunlight. Their use has been rather limited because of high manufacturing costs. Disadvantageously, the manufacturing process also consumes considerable fossil fuels, resulting in pollution. Additionally, refined silicon required for the semiconductors is in short supply, making solar cells relatively costly. Solar electricity currently tends to be more expensive than electricity generated by other sources. Furthermore, solar energy is not available at night, may be unavailable due to weather conditions, and may be compromised during winter months; therefore, a storage or complementary power system is required for most applications.
Moreover, solar energy is inefficient. Expensive solar cells made from single crystal silicon are currently limited to about 25% efficiency because they are most sensitive to infrared light, and radiation in this region of the electromagnetic spectrum is relatively low in energy. Polycrystalline solar cells are made by a casting process in which molten silicon is poured into a mould and allowed to cool, then sliced into wafers. This process results in cells that are significantly less expensive to produce than single crystal cells, but whose efficiency is limited to less than 20% due to internal resistance at the boundaries of the silicon crystals. Amorphous cells are made by depositing silicon onto a glass substrate from a reactive gas such as silane (SiH 4 ). This type of solar cell can be applied as a thin film to low cost substrates such as glass or plastic. Thin film cells have a number of advantages, including easier deposition and assembly, the ability to be deposited on inexpensive substrates, the ease of mass production, and the high suitability to large applications. Since amorphous silicon cells have no crystal structure at all, their efficiencies are presently only about 10% due to significant internal energy losses.
Another attractive alternative source of renewable energy, wind power, produces electricity from the flow of air over the surface of the earth. Wind rotates a rotor mechanically to an electric generator to produce electricity. Unlike solar cells, properly located wind turbines can generate the energy used in its construction within just months of operation. Greenhouse gas emissions and air pollution produced by construction of a wind turbine are small and declining. There are no emissions or pollution produced by operation of a wind turbine. Modern wind turbines are almost silent and rotate so slowly (in terms of revolutions per minute) that they are rarely a serious hazard to birds. Aesthetic, landscape and heritage issues may be a significant issue for certain wind farms. However, when appropriate planning procedures are followed, these risks are minimal and should be weighed against the need to address the threats posed by climate change and the opinions of the broader community.
Unfortunately, conventional wind turbines suffer several serious shortcomings. For example, they rely exclusively on ambient wind speed. Nothing is done to accelerate the wind and thereby attempt to improve efficiency of the turbine. Known prior art wind energy systems do not include a shroud.
Another shortcoming is serviceability. Conventional rotors, blades and adjacent components are unreachable from the tower for maintenance. Mechanisms configured to retract the rotor towards a tower, or a yaw assembly configured to facilitate rotational movement of the shroud and rotor to face oncoming wind.
Yet another shortcoming is the stationary structure supporting the nacelle. While many wind turbines include yaw mechanisms to orient the nacelle into the wind, no prior art wind turbine rotates the structure supporting the nacelle. Thus the structure is stationary and typically designed with a circular or similar cross section, which exhibits similar aerodynamic properties from every angle. Such designs exhibit marginal aerodynamic performance, making the structure more prone to drag and susceptible to failure than a streamlined structure.
Still another shortcoming of conventional wind turbines is the required blade size to drive a particular generator. As conventional wind turbines do nothing to augment wind speed, power requirements are met by sizing the rotor. A large generator, of course, requires substantial power provided by a large rotor to turn. This approach ignores the relationship of wind speed to power, whereby an increased wind speed augments power output. Disadvantageously, a larger rotor increases manufacturing and construction costs, stresses on the support structure, wear and tear on bearings, and maintenance costs.
The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.
SUMMARY OF THE INVENTION
To solve one or more of the problems set forth above, in an exemplary implementation of the invention a wind energy systems is provided with a shroud for each turbine. The shroud is adapted to direct and accelerate wind towards the turbine.
In one aspect of the invention, an exemplary wind turbine system includes a shroud having an entrance, throat and exit, the entrance having an entrance diameter, the throat having a throat diameter and the exit having an exit diameter, wherein the entrance diameter is greater than throat diameter. A rotor assembly includes a hub and a plurality of blades attached to the hub. The rotor assembly has a diameter less than the throat diameter and is centered at the throat of the shroud. The rotor assembly is configured to convert wind energy into rotary mechanical movement of the rotor assembly. The rotor assembly is operably coupled to a nacelle, which includes an electric generator configured to produce electric power from rotary mechanical movement. In a preferred embodiment, the plurality of blades consists of five identical blades equally spaced on the hub seventy two degrees apart. The throat diameter is 2% to 20% larger than the diameter of the diameter of the rotor assembly, allowing rotation and deflection of the rotor assembly without contact between the blades and shroud. The transition from inlet diameter to throat diameter is smooth and gradual, with a shroud pitch of 15 degrees to 60 degrees. The shroud receives wind and accelerates the received wind to a throat wind velocity, of 1.25 to 2.5 times the entrance wind velocity. A support structure supports the nacelle, rotor assembly and shroud. Each of the plurality of blades has a twist of approximately 15° to 25°, with a pitch that varies from 1° to 5° near the tip to 15° to 25° near the root, and a chord length that tapers about 75% to 33% from the root the tip.
In another aspect of the invention, a horizontal actuator for moving the nacelle is provided. The nacelle is operably coupled to the horizontal actuator and the horizontal actuator is operably coupled to the support structure. The horizontal actuator is adapted to controllably move the nacelle from a deployed operational position to a retracted maintenance position.
In a further aspect of the invention a yaw system is provided to rotate the rotor assembly, support structure and nacelle. The support structure is mounted atop the yaw system. The yaw system may include an air glide bearing turntable, a gearbox, a drive gear, and a motor. The motor drives the gear box, which drives the drive gear, which drives the turntable. A central air chamber sandwiched between the air glide bearing turntable and the base is adapted to receive pressurized gas with a lubricant sufficient to exert an upward force equal to 0.5 to 1.5 times a weight of the air glide bearing turntable plus the weight supported by the air glide bearing turntable. A gasket may be sandwiched between the air glide bearing turntable and the base. The gasket is a low friction polytetrafluoroethylene (PTFE)-based gasket.
In yet another aspect of the invention the generator includes a servo motor with a position encoder. The position encoder produces output signals corresponding to position of the input shaft. A speedup assembly has a speedup input shaft and an output speedup shaft. The output speedup shaft is adapted to rotate at about 1,500 rpm when the speedup input shaft rotates at about 30 to 60 rpm. The output speedup shaft is coupled to the motor input shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where:
FIG. 1 is a front plan view of an exemplary wind turbine, without a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 2 is a profile view of an exemplary wind turbine, without a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 2A is an profile view of an exemplary mechanical actuator assembly adapted for linearly moving the nacelle from an operational use position to a maintenance position according to principles of the invention; and
FIG. 3 is a top plan view of an exemplary wind turbine, without a shroud, adapted for yaw movement facing the wind according to principles of the invention; and
FIG. 4 is a top plan view of an exemplary tower yaw assembly adapted for yaw movement according to principles of the invention; and
FIG. 4A is a section view of an exemplary tower yaw assembly adapted for yaw movement according to principles of the invention; and
FIG. 5 is an exploded profile view of an exemplary nacelle assembly according to principles of the invention; and
FIG. 6 is a front plan view of an exemplary wind turbine, with a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 6A is a profile view of an exemplary wind turbine, with a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 6B is a profile view of an exemplary shroud with velocity vectors to conceptually illustrate how the shroud affects wind speed according to principles of the invention; and
FIG. 7 is a front plan view of a first exemplary truss support assembly according to principles of the invention; and
FIG. 7A is a profile view of a first exemplary truss support assembly according to principles of the invention; and
FIG. 8 is a front plan view of a second exemplary truss support assembly according to principles of the invention; and
FIG. 8A is a profile view of a second exemplary truss support assembly according to principles of the invention; and
FIG. 9 is a front plan view of a third exemplary truss support assembly according to principles of the invention; and
FIG. 9A is a profile view of a third exemplary truss support assembly according to principles of the invention; and
FIG. 10A is a front plan view of an exemplary concrete support structure supporting a framework comprising a plurality of wind turbines, each with a shroud, wherein the framework is adapted for controlled yaw movement according to principles of the invention; and
FIG. 10B is a side plan view of an exemplary concrete support structure supporting a framework comprising a plurality of wind turbines, each with a shroud, wherein the framework is adapted for controlled yaw movement according to principles of the invention; and
FIG. 11 is a side plan view and section views of an exemplary blade according to principles of the invention; and
FIG. 12A is a top plan view and section views of an exemplary blade according to principles of the invention; and
FIG. 12B is a side plan view and section views of an exemplary blade according to principles of the invention; and
FIG. 12C is a side plan view and section views of an exemplary blade according to principles of the invention.
Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the shapes, relative sizes, ornamental aspects or proportions shown in the figures.
DETAILED DESCRIPTION
Referring to the Figures, in which like parts are indicated with the same reference numerals, various views of exemplary wind turbine systems and assemblies and components thereof according to principles of the invention are shown. An exemplary wind turbine system according to principles of the invention includes a tower construction, a yaw drive assembly, a shroud, a rotor with rotor blades, a nacelle with a drive train and miscellaneous components.
A foundation (not shown in the drawings) anchors the system to the ground. In order to guarantee stability, one or more piles and/or a flat foundation may be used, depending on the consistency of the underlying ground. A flat foundation comprises a large reinforced concrete slab which forms the footing of the generator. In a pile foundation, foundation plates (plate foundations) are fixed with piles into the earth. This is particularly necessary in soft subsoil.
A tower construction, exemplary embodiments of which are described below, carries the weight of the supported equipment, such as the <figure-callout id="120" label="support frame" filenames="US08257019-20120904-D00001.png,U
RELATED APPLICATION
This application claims the benefit of priority of U.S. provisional application 60/871,135, filed Dec. 21, 2006, the entire contents of which are incorporated herein by this reference.
FIELD OF THE INVENTION
This invention generally relates to devices for use in producing electric power from wind energy, and more particularly, to an elevated shrouded wind turbine adapted for yaw movement facing the wind.
BACKGROUND
Most electricity today is generated by burning fossil fuels and producing steam which is then used drive a steam turbine that, in turn, drives an electrical generator. Unfortunately, however, the world's supply of fossil fuels is large, but finite. Exhaustion of low-cost fossil fuels will have significant consequences for energy sources as well as for the manufacture of plastics and many other things.
More serious are concerns about the emissions that result from fossil fuel burning. Fossil fuels constitute a significant repository of carbon buried deep under the ground. Burning them results in the conversion of this carbon to carbon dioxide, which is then released into the atmosphere. This results in an increase in the Earth's levels of atmospheric carbon dioxide, which enhances the greenhouse effect and contributes to global warming. Depending upon the particular fossil fuel and the method of burning, other emissions may be produced as well. Ozone, SO 2 , NO 2 and other gases are often released, as well as particulate matter. Sulfur and nitrogen oxides contribute to smog and acid rain. Fossil fuels, particularly coal, also contain dilute radioactive material, and burning them in very large quantities releases this material into the environment, leading to low but real levels of local and global radioactive contamination. Coal also contains traces of toxic heavy elements such as mercury, arsenic and others. Mercury vaporized in a power plant's boiler may stay suspended in the atmosphere and circulate around the world.
An alternative source of renewable energy, solar cells, also referred to as photovoltaic cells, use the photovoltaic effect of semiconductors to generate electricity directly from sunlight. Their use has been rather limited because of high manufacturing costs. Disadvantageously, the manufacturing process also consumes considerable fossil fuels, resulting in pollution. Additionally, refined silicon required for the semiconductors is in short supply, making solar cells relatively costly. Solar electricity currently tends to be more expensive than electricity generated by other sources. Furthermore, solar energy is not available at night, may be unavailable due to weather conditions, and may be compromised during winter months; therefore, a storage or complementary power system is required for most applications.
Moreover, solar energy is inefficient. Expensive solar cells made from single crystal silicon are currently limited to about 25% efficiency because they are most sensitive to infrared light, and radiation in this region of the electromagnetic spectrum is relatively low in energy. Polycrystalline solar cells are made by a casting process in which molten silicon is poured into a mould and allowed to cool, then sliced into wafers. This process results in cells that are significantly less expensive to produce than single crystal cells, but whose efficiency is limited to less than 20% due to internal resistance at the boundaries of the silicon crystals. Amorphous cells are made by depositing silicon onto a glass substrate from a reactive gas such as silane (SiH 4 ). This type of solar cell can be applied as a thin film to low cost substrates such as glass or plastic. Thin film cells have a number of advantages, including easier deposition and assembly, the ability to be deposited on inexpensive substrates, the ease of mass production, and the high suitability to large applications. Since amorphous silicon cells have no crystal structure at all, their efficiencies are presently only about 10% due to significant internal energy losses.
Another attractive alternative source of renewable energy, wind power, produces electricity from the flow of air over the surface of the earth. Wind rotates a rotor mechanically to an electric generator to produce electricity. Unlike solar cells, properly located wind turbines can generate the energy used in its construction within just months of operation. Greenhouse gas emissions and air pollution produced by construction of a wind turbine are small and declining. There are no emissions or pollution produced by operation of a wind turbine. Modern wind turbines are almost silent and rotate so slowly (in terms of revolutions per minute) that they are rarely a serious hazard to birds. Aesthetic, landscape and heritage issues may be a significant issue for certain wind farms. However, when appropriate planning procedures are followed, these risks are minimal and should be weighed against the need to address the threats posed by climate change and the opinions of the broader community.
Unfortunately, conventional wind turbines suffer several serious shortcomings. For example, they rely exclusively on ambient wind speed. Nothing is done to accelerate the wind and thereby attempt to improve efficiency of the turbine. Known prior art wind energy systems do not include a shroud.
Another shortcoming is serviceability. Conventional rotors, blades and adjacent components are unreachable from the tower for maintenance. Mechanisms configured to retract the rotor towards a tower, or a yaw assembly configured to facilitate rotational movement of the shroud and rotor to face oncoming wind.
Yet another shortcoming is the stationary structure supporting the nacelle. While many wind turbines include yaw mechanisms to orient the nacelle into the wind, no prior art wind turbine rotates the structure supporting the nacelle. Thus the structure is stationary and typically designed with a circular or similar cross section, which exhibits similar aerodynamic properties from every angle. Such designs exhibit marginal aerodynamic performance, making the structure more prone to drag and susceptible to failure than a streamlined structure.
Still another shortcoming of conventional wind turbines is the required blade size to drive a particular generator. As conventional wind turbines do nothing to augment wind speed, power requirements are met by sizing the rotor. A large generator, of course, requires substantial power provided by a large rotor to turn. This approach ignores the relationship of wind speed to power, whereby an increased wind speed augments power output. Disadvantageously, a larger rotor increases manufacturing and construction costs, stresses on the support structure, wear and tear on bearings, and maintenance costs.
The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.
SUMMARY OF THE INVENTION
To solve one or more of the problems set forth above, in an exemplary implementation of the invention a wind energy systems is provided with a shroud for each turbine. The shroud is adapted to direct and accelerate wind towards the turbine.
In one aspect of the invention, an exemplary wind turbine system includes a shroud having an entrance, throat and exit, the entrance having an entrance diameter, the throat having a throat diameter and the exit having an exit diameter, wherein the entrance diameter is greater than throat diameter. A rotor assembly includes a hub and a plurality of blades attached to the hub. The rotor assembly has a diameter less than the throat diameter and is centered at the throat of the shroud. The rotor assembly is configured to convert wind energy into rotary mechanical movement of the rotor assembly. The rotor assembly is operably coupled to a nacelle, which includes an electric generator configured to produce electric power from rotary mechanical movement. In a preferred embodiment, the plurality of blades consists of five identical blades equally spaced on the hub seventy two degrees apart. The throat diameter is 2% to 20% larger than the diameter of the diameter of the rotor assembly, allowing rotation and deflection of the rotor assembly without contact between the blades and shroud. The transition from inlet diameter to throat diameter is smooth and gradual, with a shroud pitch of 15 degrees to 60 degrees. The shroud receives wind and accelerates the received wind to a throat wind velocity, of 1.25 to 2.5 times the entrance wind velocity. A support structure supports the nacelle, rotor assembly and shroud. Each of the plurality of blades has a twist of approximately 15° to 25°, with a pitch that varies from 1° to 5° near the tip to 15° to 25° near the root, and a chord length that tapers about 75% to 33% from the root the tip.
In another aspect of the invention, a horizontal actuator for moving the nacelle is provided. The nacelle is operably coupled to the horizontal actuator and the horizontal actuator is operably coupled to the support structure. The horizontal actuator is adapted to controllably move the nacelle from a deployed operational position to a retracted maintenance position.
In a further aspect of the invention a yaw system is provided to rotate the rotor assembly, support structure and nacelle. The support structure is mounted atop the yaw system. The yaw system may include an air glide bearing turntable, a gearbox, a drive gear, and a motor. The motor drives the gear box, which drives the drive gear, which drives the turntable. A central air chamber sandwiched between the air glide bearing turntable and the base is adapted to receive pressurized gas with a lubricant sufficient to exert an upward force equal to 0.5 to 1.5 times a weight of the air glide bearing turntable plus the weight supported by the air glide bearing turntable. A gasket may be sandwiched between the air glide bearing turntable and the base. The gasket is a low friction polytetrafluoroethylene (PTFE)-based gasket.
In yet another aspect of the invention the generator includes a servo motor with a position encoder. The position encoder produces output signals corresponding to position of the input shaft. A speedup assembly has a speedup input shaft and an output speedup shaft. The output speedup shaft is adapted to rotate at about 1,500 rpm when the speedup input shaft rotates at about 30 to 60 rpm. The output speedup shaft is coupled to the motor input shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where:
FIG. 1 is a front plan view of an exemplary wind turbine, without a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 2 is a profile view of an exemplary wind turbine, without a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 2A is an profile view of an exemplary mechanical actuator assembly adapted for linearly moving the nacelle from an operational use position to a maintenance position according to principles of the invention; and
FIG. 3 is a top plan view of an exemplary wind turbine, without a shroud, adapted for yaw movement facing the wind according to principles of the invention; and
FIG. 4 is a top plan view of an exemplary tower yaw assembly adapted for yaw movement according to principles of the invention; and
FIG. 4A is a section view of an exemplary tower yaw assembly adapted for yaw movement according to principles of the invention; and
FIG. 5 is an exploded profile view of an exemplary nacelle assembly according to principles of the invention; and
FIG. 6 is a front plan view of an exemplary wind turbine, with a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 6A is a profile view of an exemplary wind turbine, with a shroud, adapted for controlled yaw movement according to principles of the invention; and
FIG. 6B is a profile view of an exemplary shroud with velocity vectors to conceptually illustrate how the shroud affects wind speed according to principles of the invention; and
FIG. 7 is a front plan view of a first exemplary truss support assembly according to principles of the invention; and
FIG. 7A is a profile view of a first exemplary truss support assembly according to principles of the invention; and
FIG. 8 is a front plan view of a second exemplary truss support assembly according to principles of the invention; and
FIG. 8A is a profile view of a second exemplary truss support assembly according to principles of the invention; and
FIG. 9 is a front plan view of a third exemplary truss support assembly according to principles of the invention; and
FIG. 9A is a profile view of a third exemplary truss support assembly according to principles of the invention; and
FIG. 10A is a front plan view of an exemplary concrete support structure supporting a framework comprising a plurality of wind turbines, each with a shroud, wherein the framework is adapted for controlled yaw movement according to principles of the invention; and
FIG. 10B is a side plan view of an exemplary concrete support structure supporting a framework comprising a plurality of wind turbines, each with a shroud, wherein the framework is adapted for controlled yaw movement according to principles of the invention; and
FIG. 11 is a side plan view and section views of an exemplary blade according to principles of the invention; and
FIG. 12A is a top plan view and section views of an exemplary blade according to principles of the invention; and
FIG. 12B is a side plan view and section views of an exemplary blade according to principles of the invention; and
FIG. 12C is a side plan view and section views of an exemplary blade according to principles of the invention.
Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the shapes, relative sizes, ornamental aspects or proportions shown in the figures.
DETAILED DESCRIPTION
Referring to the Figures, in which like parts are indicated with the same reference numerals, various views of exemplary wind turbine systems and assemblies and components thereof according to principles of the invention are shown. An exemplary wind turbine system according to principles of the invention includes a tower construction, a yaw drive assembly, a shroud, a rotor with rotor blades, a nacelle with a drive train and miscellaneous components.
A foundation (not shown in the drawings) anchors the system to the ground. In order to guarantee stability, one or more piles and/or a flat foundation may be used, depending on the consistency of the underlying ground. A flat foundation comprises a large reinforced concrete slab which forms the footing of the generator. In a pile foundation, foundation plates (plate foundations) are fixed with piles into the earth. This is particularly necessary in soft subsoil.
A tower construction, exemplary embodiments of which are described below, carries the weight of the supported equipment, such as the support frame 120 , nacelle 115 and rotor blades 105 , while withstanding the huge static loads caused by the varying power of the wind. The tower construction elevates the system to a desired height, e.g., thirty feet or more above ground level. A tower construction of concrete, steel or other building materials may be used. The tower construction may be a containment structure suitable for housing equipment, a lattice or truss assembly, or other suitable stable form. In the case of concrete, the tower may be constructed on site, which simplifies transport and fitting. Alternatively, pre-cast concrete segments may be shipped and assembled on site.
Referring to FIGS. 1 , 2 and 3 , front plan, profile and top plan views of an exemplary wind turbine 110 , without a shroud, adapted for controlled yaw movement according to principles of the invention are shown. A support structure, e.g., support frame 120 , is mounted on a turntable 130 of a yaw drive assembly 135 , controllably driven by a motor 125 . A nacelle 115 and rotor assembly, which comprises a hub 580 and plurality (e.g., five) of rotor blades 105 , are supported by the frame 120 . The motor 125 may be manually actuated by a switch and/or automatically operated using a programmable logic controller, microcontroller or other control means, to maintain in a direction facing the wind.
In the exemplary embodiment, the frame 120 is comprised of a framework of beams forming a rigid A-shaped support structure. However, the invention is not limited to such a support frame. Any structure suitable for supporting the nacelle 115 and rotor assembly on the yaw drive assembly 135 may be utilized and comes within the scope of the invention. Such structures may, for example, include tubular steel, concrete post and lattice structures.
The rotor assembly, with the help of the rotor blades 105 , converts the energy in the wind into rotary mechanical movement. In an exemplary implementation, a five-blade, horizontal axis rotor assembly is utilized. The rotor blades 105 may be comprised of fiber reinforced (e.g., glass, aramid or carbon-fiber reinforced) plastics (GRP, CFRP), aluminum, alloys, combinations thereof, or other suitable material. The blade profile (airfoil shape) is similar to that of an aircraft wing and uses the same aerodynamic principles to generate lift, which cause the rotor to rotate.
The rotor comprises multiple rotor blades 105 attached to a hub 580 ( FIG. 5 ). The rotor converts the wind energy into a rotation. In an exemplary embodiment, the rotor has five blades, a horizontal axis, and a diameter of approximately fifteen (15) feet or more. The use of five (5) rotor blades 105 allows for a better distribution of mass than conventional two (2) or three (3) blade designs, which makes rotation smoother. A five (5) blade design also allows a smaller diameter, than conventional two (2) or three (3) blade designs that produce similar forces.
The hub 580 is the center of the rotor assembly to which the rotor blades 105 are attached. The hub 580 directs the energy from the rotor blades 105 on to the generator. If the wind turbine has a gearbox, the hub 580 is connected to the gearbox shaft, converting the energy from the wind into rotation energy. If the turbine has a direct drive, the hub 580 passes the energy directly to a ring generator. Each rotor blade 115 can be attached to the hub 580 in various ways: either in a fixed position or with pitch adjustment. A fixed hub 580 is sturdy, reduces the number of movable components that can fail, and is relatively easy to construct. Pitch adjustment enables manual or remote adjustment of blade pitch to improve efficiency.
The hub 580 thus locates and captures the five rotor blades 105 . The hub 580 correctly positions the rotor blades 105 for correct tilt and angular placement. The blades are locked in position using heavy duty mechanical clamps and a locking pin. The locking pin uses two hardened pins locating in a recess in the rotor blade and further locating in the hub 580 to provide positive locking. The blades can be manually adjusted for pitch in the hub 580 .
In a preferred embodiment, each individual rotor blade 115 can be infinitely adjusted manually, electromechanically or hydraulically, by turning into or out of the wind. In such an embodiment, the rotor blades may be positioned at a pitch angle suitable for generating acceptable lift, such as maximum lift, at a design wind speed (e.g., average prevailing local wind speed for the location of the turbine).
Alternatively, each individual rotor blade 115 can be adjusted automatically. Actuators for automated or remote pitch adjustment may be either hydraulic or electro-mechanical. In an automated embodiment, a controller monitors the turbine's power output and/or rotational speed. If the wind is too strong, the rotor blades 105 may be pitched slightly to reduce lift, so that the rotor continues to generate power at rated capacity even at high wind speeds. Otherwise, the system may maintain the rotor blades at a pitch angle suitable for generating acceptable lift, such as maximum lift, for the design or detected wind speed.
Referring now to FIGS. 2 and 2A , an exemplary horizontal actuator assembly 205 adapted for linearly moving the nacelle 115 from an operational use position to a maintenance position 230 according to principles of the invention is shown. The nacelle is operably coupled to the horizontal actuator and the horizontal actuator is operably coupled to the support structure. The horizontal actuator is adapted to controllably move the nacelle from a deployed operational position to a retracted maintenance position. Any manual or automatic linear actuator suitable for reliably moving the nacelle 115 may be utilized. By way of example and not limitation, in an exemplary embodiment, the actuator assembly 205 includes a hand wheel with a handle 210 operably coupled to a rotatable threaded lead screw 220 . The leadscrew is screw specialized for the purpose of translating rotational to linear motion. The mechanical advantage of a leadscrew is determined by the screw pitch or lead. A higher performing, and more expensive, alternative is a ball screw comprising a threaded shaft that provides a spiral raceway for ball bearings which act as a precision screw. Due to inherently high static friction, the lead screw is self-locking (i.e., when stopped, a linear force on the nut will not apply a torque to the screw) thus avoiding backdriving. A threaded flange 215 (e.g., a flange with a threaded nut) coupled to the nacelle 115 by a cradle 225 receives the lead screw 220 . The threaded flange 215 threadedly travels along the length of the lead screw 220 as the lead screw is rotated, thereby causing the cradle 225 to glide in a clamp rail, and consequently cause the nacelle 115 to move linearly and horizontally. The lead screw is rotatably fixed to the support frame 120 . Aside from rotational motion, the lead screw 220 does not move relative to the support frame 120 . The range of motion of the nacelle extends from a deployed operation position to a retracted maintenance position 230 . In the maintenance position 230 , the rotor blades 105 are closest to and accessible from the support frame 120 . In the deployed position, the rotor blades 105 are furthest from the support frame 120 . Thus, the nacelle 115 may be driven from a deployed position to a retracted maintenance position 230 by rotating the hand wheel with a handle 210 . Other means for controlled horizontal linear movement of the nacelle, including (without imitation) hydraulic, pneumatic and electromechanical actuators, also come within the scope of the invention.
To ensure maximum power output from the generator, a wind turbine according to principles of the invention is equipped with a yaw system 400 , as shown in FIGS. 4 and 4A . The yaw system 400 may also be used to better position the rotor assembly and nacelle at a position for servicing. The yaw system 400 allows the rotor assembly, nacelle and support frame to rotate (i.e., yaw) to face wind. The exemplary yaw system 400 comprises an air glide bearing turntable 445 , a gearbox 415 , a drive gear 405 (e.g., pinion gear) on a bearing 425 , and an electric motor 410 (e.g., a servo motor controlled via a communicatively coupled PLC) as a prime mover, i.e., the ultimate source of all mechanical movement in the system. A mechanical or hydraulic braking system may be provided to prevent drift and lock the turntable securely in position when there is no yaw operation. The yaw system is mounted beneath the support frame, and may be mounted atop a tower. The motor 410 drives the gear box 415 , which drives the drive gear 405 . The drive gear 405 meshes with gear teeth of a bull gear 445 coupled to the circumference of the turntable 445 . Thus, rotation of the drive gear 405 causes rotation of the turntable 445 . The turntable 445 is rotatably supported atop a yaw assembly support base 430 between a plurality of roller bearings 440 . The roller bearings 440 maintain the turntable 445 in proper radial alignment with the pinion gear 405 and limit upward movement of the turntable 445 to prevent separation of the turntable 445 from the base 430 .
To greatly facilitate rotation, the exemplary yaw system includes an air glide bearing subsystem. The air glide bearing subsystem comprises a central air chamber 435 sandwiched between the turntable 445 and base 430 . A gasket 420 is sandwiched between the flanged periphery of the turntable 445 and the base 430 . Compressed air with a lubricant may be pumped into the chamber 435 through an inlet port at a pressure (e.g., about 100 psi) sufficient to exert a substantial upward force, e.g., 0.5 to 1.5 the total supported weight, including the weight of the turntable. In a preferred implementation, the upward force is less than the supported weight (e.g., sum total weight of the turntable, frame, nacelle and rotor assembly), but is sufficient to offset the supported weight enough to greatly facilitate rotation without breaking the seal maintained by the gasket 420 between the turntable 445 and the base 430 . In a preferred embodiment, one layer or a plurality (e.g., 2 or more) layers of a polytetrafluoroethylene (PTFE)-based gasket, such as a PTFE tape impregnated with brass or bronze (e.g., Garlock® #426 Multifil Bearing Tape), may be utilized, to maintain a high integrity low friction seal. The air glide bearing assembly 400 thus floats while controlled motion is supplied via a motor.
In an exemplary embodiment a servo motor with a 2:1 belt reduction drives a 60:1 dodge worm gear further reduced 18:1. Thus, every 6 turns of the servo motor provides 1° of rotation of the turntable. At 2,160 rpm, the servo motor will rotate the turntable 360° in one minute.
The nacelle 115 holds turbine machinery, as shown in the exemplary exploded view of FIG. 5 . In the exemplary embodiment, an acorn nut 590 secures a spinner 110 to a spinner standoff 585 . Hex safety bolts 505 lock blades 105 to the hub 580 . A blade clamp 510 with a retaining pin 520 is secured to the hub 580 by a hex safety bolt 515 . The hub is coupled to the input shaft of a speedup assembly 560 (i.e., a gearbox) via a spindle 565 with a retaining pin 525 spindle keeper 570 and head cap screw 575 . A bushing 535 , head cap screw 530 and nut are provided to couple the cradle 225 to the speedup assembly 560 . A coupling 540 joins the keyed output shaft of the speedup assembly 560 to the keyed input shaft of the turbine assembly 550 . The turbine assembly 550 employs an integral servo motor, position encoder and brake in one complete package. The integral motor design assures maximum efficiency, while keeping the overall footprint sleek and out of the air flow. A head cap screw connects the cradle 225 to the turbine assembly 550 . For some embodiments, an asynchronous generator may be used. Other embodiments may use a synchronous generator. A grid connection of synchronous generator is made via a transformer, due to the fixed rotation behavior.
The speedup assembly 560 takes on the task of matching the rotation speeds of the slow-moving rotor and the fast-moving generator. By way of example, the speedup assembly 560 increases the rotation speed from 30 to 60 rpm (which is insufficient for producing electrical energy) to 1,500 rpm. The preferred speedup assembly 560 has gears generally in parallel on the input side and a planetary gear stage on the output side, thereby using fewer rotating components than a conventional system and reduces mechanical stresses and at the same time increases the technical service life of the equipment.
Advantageously, a wind turbine system according to principles of the invention may utilize conventional commercially available electronic equipment, including a generator, a system for grid in-feed of the electricity, and various sensors and controls. The system for feeding electricity into the grid depends upon the generator used. In a variable speed turbine embodiment with a synchronous generator, alternating current generated fluctuates constantly in frequency and quantity. In order for the electricity to be fed into the grid, it is converted into direct current using a rectifier, filtered and then converted back into alternating current using an inverter. Voltage is converted for connection to the level of the grid using a transformer. Sensors for monitoring and control may be provided on and in the nacelle 115 to measure wind speed and wind direction, speed of the rotors and the generator, the ambient temperature and temperature of individual components, oil pressure, pitch and azimuth angle (yaw mechanism based on the wind direction) and electrical values, as well as vibrations or vibrations in the nacelle 115 . Data from sensor signals may be used to control operation. For example, in response to signals corresponding to wind direction, the yaw mechanism may be activated. An exemplary wind turbine system according to principles of the invention may also contain components lighting, cooling, heating, lightning protection, lifting gear (e.g. winches for spare parts), communications equipment and fire extinguishing equipment.
The nacelle may optionally include temperature control features. The temperatures inside a nacelle 115 can be quite high due to the waste heat from the speedup assembly and the generator. Cooling elements such as heat sinks, fans and vents may therefore be installed in the nacelle 115 to help keep it cool. Heaters may also be provided to warm up the oil in the gearbox in cold climates. Rotor blades 105 may be heated in cold climate conditions to prevent them from icing over. Anemometers and weather vanes may also be heated in cold regions to prevent them from malfunctioning.
Referring now to FIGS. 6 and 6A , front plan and profile views of an exemplary wind turbine, with a shroud, adapted for controlled yaw movement according to principles of the invention are shown. The shroud 600 comprises a forward entrance-defining portion 605 , a center throat portion 610 and a rear exit-defining portion 615 , with the inner surfaces of all three portions defining a circular passageway, and with each section differing in radius. Thus, the shroud comprises an axisymmetric tubular structure, converging to a minimum radius in the middle, making somewhat of an hourglass-shape, with a smooth bell shaped venturi inlet, a circular throat, and a flared exit. The diameter of the inlet, d i , is larger than the throat diameter, d t . The diameter of the exit, d e , is also larger than the throat diameter, d t , but equal to or less than the diameter of the inlet, d i . The diameter of the throat 610 of the shroud, d t , is slightly larger (e.g., 2% to 20% larger) than the diameter of the rotor assembly with the blades, thereby enabling the rotor with blades to be positioned in or nearby (e.g., at or slightly aft of) the throat section and allowing blade rotation and deflection without scraping or otherwise contacting the interior surface of the shroud. By way of example and not limitation, for a rotor with blades having a diameter of 15 feet, the shroud may feature a throat diameter, d t , of about 17 feet, an inlet diameter, d i , of about 25 feet, and an exit diameter, d e , of about 20 feet. In general, the larger the ratio of inlet diameter to throat diameter, i.e., d i /d t , the greater the increase in wind speed.
To provide a smooth transition from ambient wind speed V i to throat wind speed V t , the transition from inlet diameter, d i , to throat diameter, d t , should be smooth and gradual. Discontinuities and sudden changes in diameter facilitate early transition from laminar to undesired turbulent flow. Turbulent flow, is dominated by recirculation, eddies, unsteady vortices, increased drag due to increased boundary layer skin friction, and chaos, including low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time. Thus turbulence compromises wind speed at the throat, V t , and decreases overall system performance and efficiency.
To militate against the onset of turbulence, in an exemplary embodiment, the transition from inlet diameter, d i , to throat diameter, d t , occurs over a minimum shroud inlet length, l i , equal to about 25% to 75% of the difference between inlet diameter, d i , and throat diameter, d t . Thus, the minimum length increases as the difference between the inlet diameter, d i , and throat diameter, d t increases. In a particular exemplary embodiment, for a shroud tapering from a 25 foot inlet diameter, d i , to a 17 foot throat diameter, d t , a minimum shroud inlet length, l i , equal to about 50% of the difference between inlet diameter, d i , and throat diameter, d t , i.e., 4 feet which is 50% of 8 feet, is preferred. In such an exemplary embodiment, a transition length l i of 4 feet or greater (e.g., 4.75 feet) may be used. This gradual tapering results in an acute shroud pitch, α, preferably less than 60°.
In addition, the transition to and from the throat diameter d t is smooth, gradual and curvaceous. Illustratively, the throat may feature a curved section having a radius, r t , of approximately 25% to 65% of the total shroud length, l i +l e , and a center of curvature in line with the throat, as shown in FIG. 6A . In a particular exemplary embodiment, for a shroud with a total length of approximately 7 feet, a radius of curvature, r t , for the throat section of approximately 2 feet may be provided.
Likewise, the transition from throat diameter, d t , to exit diameter, d e , should be gradual to avoid low speed transition from laminar to undesired turbulent flow dominated by recirculation, eddies and unsteady vortices. Such flow, characterized by swirling and reverse current, can offset the benefit of the accelerated incoming flow and decrease overall system performance and efficiency. In an exemplary embodiment, the transition from throat diameter, d t , to exit diameter, d e , occurs over a minimum shroud exit length, l e , equal to about 25% to 85% of the difference between exit diameter, d e , and throat diameter, d t . Thus, the minimum length increases as the difference between the exit diameter, d e , and throat diameter, d t increases. In a particular exemplary embodiment, for a shroud expanding from a 17 foot throat diameter, d t , to a 20 foot exit diameter, d e , a minimum shroud exit length, l e</sub
CLAIMS
Claims ( 19 )
1. A wind turbine system comprising:
a shroud having an entrance, a throat, and an exit, the entrance having an entrance diameter, the throat having a throat diameter, and the exit having an exit diameter, wherein the entrance diameter is greater than throat diameter; and
a rotor assembly comprising a hub and a plurality of blades attached with the hub, said rotor assembly having a diameter less than the throat diameter and being centered at the throat of the shroud;
said rotor assembly being configured to convert wind energy into rotary mechanical movement of the rotor assembly; and
said rotor assembly being operably coupled with a nacelle, said nacelle comprising an electric generator configured to produce electric power from rotary mechanical movement, said generator comprising a servo motor with a positioning encoder.
2. A wind turbine system according to claim 1 , wherein the plurality of blades consists of five identical blades, the blades spaced on the hub seventy two degrees apart.
3. A wind turbine system according to claim 1 , wherein the throat diameter is about 2% to 20% larger than the diameter of the diameter of the rotor assembly, allowing rotation and deflection of the rotor assembly without contact between the blades and shroud.
4. A wind turbine system according to claim 1 , the transition from inlet diameter to throat diameter being smooth and gradual and the pitch of the shroud being about 15 degrees to 60 degrees.
5. A wind turbine system according to claim 1 , the shroud being adapted to receive wind having an entrance wind velocity and accelerate the received wind to a throat wind velocity, the throat wind velocity being about 1.25 to 2.5 times the entrance wind velocity.
6. A wind turbine system according to claim 1 , further comprising:
a support structure; and
a horizontal actuator, said nacelle being operably coupled with the horizontal actuator and said horizontal actuator being operably coupled with said support structure, and said horizontal actuator being adapted to controllably move the nacelle between deployed operational and retracted maintenance positions.
7. A wind turbine system according to claim 1 , further comprising:
a support structure, said nacelle and shroud being operably coupled with the support structure; and
a yaw system adapted to rotate the rotor assembly, support structure and nacelle.
8. A wind turbine system according to claim 1 , further comprising:
a support structure, said nacelle and shroud being operably coupled with the support structure; and
a yaw system adapted to rotate the rotor assembly, support structure and nacelle, said support structure being mounted atop said yaw system.
9. A wind turbine system according to claim 1 , further comprising:
a support structure, said nacelle and shroud being operably coupled with the support structure; and
a yaw system adapted to rotate the rotor assembly, support structure and nacelle, said support structure being mounted atop said yaw system, said yaw system comprising an air glide bearing turntable.
10. A wind turbine system according to claim 1 , further comprising:
a support structure, said nacelle and shroud being operably coupled with the support structure; and
a yaw system adapted to rotate the rotor assembly, support structure and nacelle, said support structure being mounted atop said yaw system, said yaw system comprising an air glide bearing turntable, a gearbox, a drive gear, and a motor, said motor driving the gear box, which gear box drives the drive gear, which drive gear drives the turntable.
11. A wind turbine system according to claim 1 , said nacelle further comprising a position encoder adapted to produce output signals corresponding to position of the input shaft, and a speedup assembly with a speedup input shaft and an output speedup shaft, said output speedup shaft adapted to rotate at about 1,500 rpm when said speedup input shaft rotates at about 30 to 60 rpm, and said output speedup shaft being coupled with said motor input shaft.
12. A wind turbine system comprising:
a shroud having an entrance, a throat, and an exit, the entrance having an entrance diameter, the throat having a throat diameter and the exit having an exit diameter, wherein the entrance diameter is greater than throat diameter;
a rotor assembly comprising a hub and a plurality of blades attached to the hub, said rotor assembly having a diameter less than the throat diameter and being centered at the throat of the shroud;
said rotor assembly being configured to convert wind energy into rotary mechanical movement of the rotor assembly;
said rotor assembly being operably coupled to a nacelle, said nacelle comprising an electric generator configured to produce electric power from rotary mechanical movement;
a support structure, said nacelle and shroud being operably coupled to the support structure; and
a yaw system adapted to rotate the rotor assembly, support structure and nacelle, said support structure being mounted atop said yaw system, said yaw system comprising a base, an air glide bearing turntable, a gearbox, a drive gear, and a motor, said motor driving the gear box, which gear box drives the drive gear, which drive gear drives the turntable, a central air chamber sandwiched between the air glide bearing turntable and the base, and adapted to receive pressurized gas sufficient to exert an upward force equal to about 0.5 to 1.5 times a weight of the air glide bearing turntable plus a weight supported by the air glide bearing turntable.
13. A wind turbine system according to claim 12 , further comprising:
a gasket sandwiched between the air glide bearing turntable and the base.
14. A wind turbine system according to claim 13 , further comprising:
said pressurized gas being compressed air with a dispersed lubricant.
15. A wind turbine system according to claim 14 , further comprising:
said gasket being a polytetrafluoroethylene (PTFE)-based gasket.
16. A wind turbine system comprising:
a shroud having an entrance, throat and exit, the entrance having an entrance diameter, the throat having a throat diameter and the exit having an exit diameter, wherein the entrance diameter is greater than throat diameter; and
a rotor assembly comprising a hub and a plurality of blades attached to the hub, said rotor assembly having a diameter less than the throat diameter and being centered at the throat of the shroud;
said rotor assembly being configured to convert wind energy into rotary mechanical movement of the rotor assembly; and
said rotor assembly being operably coupled to a nacelle, said nacelle comprising an electric generator configured to produce electric power from rotary mechanical movement, said generator comprising a servo motor having a motor input shaft, and said nacelle further comprising a position encoder adapted to produce output signals corresponding to position of the input shaft.
17. A wind turbine system according to claim 16 , further comprising a speedup assembly with a speedup input shaft and an output speedup shaft, said output speedup shaft adapted to rotate at about 1,500 rpm when said speedup input shaft rotates at about 30 to 60 rpm, and said output speedup shaft being coupled with said motor input shaft.
18. A wind turbine system comprising:
a shroud having an entrance, throat and exit, the entrance having an entrance diameter, the throat having a throat diameter and the exit having an exit diameter, wherein the entrance diameter is greater than throat diameter; and
a rotor assembly comprising a hub and a plurality of blades attached to the hub, said rotor assembly having a diameter less than the throat diameter and being centered at the throat of the shroud;
said rotor assembly being configured to convert wind energy into rotary mechanical movement of the rotor assembly;
said rotor assembly being operably coupled to a nacelle, said nacelle comprising an electric generator configured to produce electric power from rotary mechanical movement, wherein each of said plurality of blades has a twist of approximately 15° to 25°, with a pitch that varies from about 1° to 5° near the tip to about 15° to 25° near the root, and a chord length that tapers about 75% to 33% from the root the tip.
19. A wind turbine system according to claim 18 , further comprising:
a support structure, said nacelle and shroud being operably coupled with the support structure; and
a yaw system adapted to rotate the rotor assembly, support structure and nacelle.
US11/845,094
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Shrouded wind turbine system with yaw control
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WO2009029691A1
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2007-08-27
2008-08-27
Shrouded wind turbine system with yaw control
US13/431,206
US8794903B2
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2012-03-27
Shrouded wind turbine system with yaw control
US13/485,227
US9194362B2
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2006-12-21
2012-05-31
Wind turbine shroud and wind turbine system using the shroud
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US20130175804A1
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Wind turbine shroud and wind turbine system using the shroud
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Cited By (11)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US20110133453A1
( en )
*
2007-01-17
2011-06-09
Merswolke Paul H F
Multiple generator wind turbine and method of operation thereof
US20130272842A1
( en )
*
2012-04-11
2013-10-17
Flodesign Wind Turbine Corp.
Fluid turbine with hybrid yaw
US20140073477A1
( en )
*
2012-09-10
2014-03-13
Charles Van Buchan
Fixture, maintenance assembly, and method for maintaining wind turbine gearbox
US20140216680A1
( en )
*
2011-09-09
2014-08-07
Areva Wind Gmbh
Wind turbine with tower climatisation system using outside air
US20150110599A1
( en )
*
2007-12-10
2015-04-23
V Squared Wind, Inc.
Efficient systems and methods for construction and operation of mobile wind power platforms
US9777707B2
( en )
*
2015-07-03
2017-10-03
Darell Allen Williams
Windmill that generates exceptional amounts of electricity
USD803782S1
( en )
*
2015-08-11
2017-11-28
Teral Inc.
Wind power generator
USD803781S1
( en )
*
2015-08-11
2017-11-28
Teral Inc.
Wind power generator
CN107829878A
( en )
*
2017-11-06
2018-03-23
å京éé£ç§åé£çµè®¾å¤æéå ¬å¸
Yaw control device and method for wind power generating set
US10364795B2
( en )
2015-07-03
2019-07-30
Darell Allen Williams
Wind turbine for use in high winds
US11111900B2
( en )
*
2019-07-03
2021-09-07
Tarbiat Modares University
Wind turbine augmented by a diffuser with a variable geometry
Families Citing this family (47)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US20060205554A1
( en )
*
2003-08-12
2006-09-14
Osamu Nohara
Speed reducer for use in yaw drive apparatus for wind power generation apparatus, and yaw drive method and apparatus for wind power generation apparatus using the speed reducer
NO320948B1
( en )
*
2004-07-01
2006-02-20
Owec Tower As
Device for low torque linkage
US7368828B1
( en )
*
2006-03-29
2008-05-06
Calhoon Scott W
Wind energy system
US7453168B2
( en )
*
2007-04-02
2008-11-18
Lanie Robert C
Wind-powered generator system for generating electric power over a wide range of wind conditions
JP5072427B2
( en )
*
2007-05-11
2012-11-14
ä¸è±éå·¥æ¥æ ªå¼ä¼ç¤¾
Wind power generator and lightning energy level determination method thereof
DE102007058746A1
( en )
*
2007-06-18
2008-12-24
Hanning & Kahl Gmbh & Co. Kg
Locking device for a wind turbine
US20090249707A1
( en )
*
2008-04-08
2009-10-08
Curme Oliver D
Supporting a wind-driven electric generator
AU2009260465B2
( en )
*
2008-05-28
2014-09-25
Stephen David Boyd
Wind diverter
US20110012360A1
( en )
*
2008-06-10
2011-01-20
Mitsubishi Heavy Industries, Ltd.
Wind turbine generator and method for constructing the same
CA2643587A1
( en )
*
2008-11-10
2010-05-10
Organoworld Inc.
Turbine annular axial rotor
DE102009008340A1
( en )
*
2008-12-19
2010-06-24
Robert Bosch Gmbh
Flow turbine
US20100166556A1
( en )
*
2008-12-30
2010-07-01
General Electric Company
Partial arc shroud for wind turbine blades
US8063503B2
( en )
*
2009-05-28
2011-11-22
Btpatent Llc
Clusters of small wind turbines diffusers (CSWTD) a renewable energy technique
LT2443340T
( en )
*
2009-06-19
2018-04-25
New World Energy Enterprises Limited
A pressure controlled wind turbine enhancement system
EP2273104B1
( en )
*
2009-06-30
2013-06-19
Vestas Wind Systems A/S
A wind turbine with improved yaw control
US8106528B2
( en )
*
2009-07-08
2012-01-31
Houly Co., Ltd.
Horizontal axis wind turbine with rotatable tower
US8482147B2
( en )
*
2009-07-21
2013-07-09
George Moser
Wind turbine with powered synchronization system
WO2011024670A1
( en )
*
2009-08-27
2011-03-03
ãããã¹ã³æ ªå¼ä¼ç¤¾
Yaw driving device for wind turbine
US20110158787A1
( en )
2010-03-15
2011-06-30
Thacker Ii Andrew Carlton
Wind turbine
US8378516B2
( en )
2010-04-07
2013-02-19
Tai Koan Lee
Continuous wind power system with auxiliary blades
US8939724B2
( en )
*
2010-05-31
2015-01-27
Green Earth Power Company Limited
System and methods for wind energy recapture from a non natural wind source
US9234081B2
( en )
2010-06-08
2016-01-12
King Abdulaziz City For Science And Technology
Method of manufacturing a nitro blue tetrazolium and polyvinyl butyral based dosimeter film
US8203230B2
( en )
*
2010-06-29
2012-06-19
General Electric Company
Yaw bearing system
US9774198B2
( en )
*
2010-11-08
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Brandon Culver
Wind and solar powered heat trace with homeostatic control
US9932959B2
( en )
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King Abdulaziz City For Science And Technology
Shrounded wind turbine configuration with nozzle augmented diffuser
CA2831395A1
( en )
*
2011-03-30
2012-10-04
Flodesign Wind Turbine Corp.
Fluid turbine with variable pitch shroud segments
JP5492832B2
( en )
*
2011-07-25
2014-05-14
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Transformer and wind power generation system
DE102011080228B3
( en )
*
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CN102913385A
( en )
*
2012-06-08
2013-02-06
åæ¹å·¥ä¸å¤§å¦
Active yaw control system of small/ medium-sized wind generating set
EP2754886B1
( en )
*
2013-01-14
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ALSTOM Renewable Technologies
Method of operating a wind turbine rotational system and wind turbine rotational system
US9372201B2
( en )
*
2014-03-31
2016-06-21
Alstom Renewable Technologies
Yaw and pitch angles
KR20160083120A
( en )
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2014-05-12
2016-07-11
ìì½íë§ ê³ ë¬´ ê°ë¶ìí¤ê°ì´ì¤
Power generation system
CN104481803B
( en )
*
2014-11-13
2018-06-22
çåå·¥å¦é¢
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US9885340B2
( en )
*
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( en )
*
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Ultracapacitor real-time detecting system and method for variable pitch control system of wind generating
US9699967B2
( en )
*
2015-09-25
2017-07-11
Deere & Company
Crosswind compensation for residue processing
US10563635B2
( en )
*
2015-11-18
2020-02-18
Clarkson University
Aft rotor ducted wind turbine
SI3443224T1
( en )
*
2016-04-15
2020-08-31
Pur Wind Aps
Gasket for wind turbine
WO2017184106A1
( en )
*
2016-04-18
2017-10-26
Star Wind Turbines, Llc
High torque, low rpm horizontal axis wind turbine
IT201600130230A1
( en )
*
2016-12-22
2018-06-22
Nuovo Pignone Tecnologie Srl
PLANT MODULE WITH SENSOR ARRANGEMENT
DE102017123935A1
( en )
2017-10-13
2019-04-18
Rosen Swiss Ag
Sealing arrangement for a connection of two fasteners of an offshore structure and method for producing the same
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( en )
*
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éå²èªå¤©å导ä½ç 究ææéå ¬å¸
Power generation control method based on gyroscope automatic navigation system
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( en )
*
2019-10-15
2025-09-05
éç¨çµæ°å¯åçè½æºè¥¿ççæéå ¬å¸
System and method for locking a wind turbine rotor during extended maintenance
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( en )
*
2019-12-20
2020-04-10
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( en )
*
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2024-08-27
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Wind gathering and efficiency improving device of low wind speed wind turbine
EP4466456A1
( en )
*
2022-01-18
2024-11-27
Basf Se
Gasket for a transition piece of a wind turbine and method for mounting such a gasket
CN116292096B
( en )
*
2023-04-18
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Positioning device and positioning method for head of wind driven generator
Citations (53)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US2137559A
( en )
1935-07-16
1938-11-22
Lucian C Algee
Windmill
US3339078A
( en )
1964-12-17
1967-08-29
Crompton George
Wind turbine electro-generators
US3883750A
( en )
*
1974-01-30
1975-05-13
Natural Energy Systems Inc
Method and apparatus for generating power from wind currents
US4075500A
( en )
1975-08-13
1978-02-21
Grumman Aerospace Corporation
Variable stator, diffuser augmented wind turbine electrical generation system
US4086498A
( en )
1975-04-25
1978-04-25
Joseph Szoeke
Wind powered rotary electric generator
US4132499A
( en )
1976-01-29
1979-01-02
Ben Gurion University Of The Negev
Wind driven energy generating device
US4140433A
( en )
*
1975-07-10
1979-02-20
Eckel Oliver C
Wind turbine
US4213734A
( en )
1978-07-20
1980-07-22
Lagg Jerry W
Turbine power generator
US4309146A
( en )
1980-03-12
1982-01-05
The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
Amplified wind turbine apparatus
US4323331A
( en )
*
1979-04-27
1982-04-06
Charles Schachle
Windmill tower
US4411588A
( en )
1978-04-28
1983-10-25
Walter E. Currah
Wind driven power plant
US4482290A
( en )
1983-03-02
1984-11-13
The United States Of America As Represented By The United States Department Of Energy
Diffuser for augmenting a wind turbine
US4616973A
( en )
1984-12-31
1986-10-14
Souchik Jr Nicholas
Wind driven turbine
US4684316A
( en )
1982-12-30
1987-08-04
Kb Vindkraft I Goteborg
Improvements in wind turbine having a wing-profiled diffusor
US4720640A
( en )
1985-09-23
1988-01-19
Turbostar, Inc.
Fluid powered electrical generator
US4781522A
( en )
1987-01-30
1988-11-01
Wolfram Norman E
Turbomill apparatus and method
US5669758A
( en )
1996-01-24
1997-09-23
Williamson; Larry D.
Wind turbine
US6053700A
( en )
1997-09-24
2000-04-25
Fosdick High-Tek Wind Turbines, Inc.
Ducted turbine
US6064123A
( en )
*
1995-10-13
2000-05-16
Gislason; Nils Erik
Horizontal axis wind turbine
US6246126B1
( en )
*
1996-10-22
2001-06-12
Germaine Van Der Veken
Hooded wind power engine
US20020047071A1
( en )
1999-05-21
2002-04-25
Lewis Illingworth
Lifting platform with energy recovery
US6382904B1
( en )
1998-03-25
2002-05-07
Igor Sergeevich Orlov
Windmill powerplant
JP2003003944A
( en )
2001-06-21
2003-01-08
Akira Nagashiro
Hybrid wind generator
US20030133783A1
( en )
2001-03-20
2003-07-17
Brock Gerald E.
Fluid driven generator
US20030175109A1
( en )
2002-03-18
2003-09-18
Brock Gerald E.
Fluid driven vacuum enhanced generator
US6710468B1
( en )
*
1999-11-23
2004-03-23
Marrero O'shanahan Pedro M.
Flow accelerating wind tower
US20040096327A1
( en )
2002-11-14
2004-05-20
Kari Appa
Method of increasing wind farm energy production
US6756696B2
( en )
*
2002-03-22
2004-06-29
Kyusho Tlo Company, Limited
Wind power generator
US6786697B2
( en )
2002-05-30
2004-09-07
Arthur Benjamin O'Connor
Turbine
US20050002783A1
( en )
2003-04-16
2005-01-06
Clement Hiel
Diffuser-augmented wind turbine
US6849965B2
( en )
1999-05-12
2005-02-01
Compagnie Internationale De Turbines Atmospheriques
Wind machine with slanted blades
US6887031B1
( en )
2004-03-16
2005-05-03
Angus J. Tocher
Habitat friendly, pressure conversion, wind energy extraction
US6903466B1
( en )
1999-09-01
2005-06-07
Alstom
Wind-power generator pod constituted by the body of an electricity generator
US6981839B2
( en )
2004-03-09
2006-01-03
Leon Fan
Wind powered turbine in a tunnel
US7018166B2
( en )
2001-06-28
2006-03-28
Freegen Research Ltd.
Ducted wind turbine
US7094018B2
( en )
2004-05-07
2006-08-22
Grubb Kelly W
Wind power generator
US7118344B2
( en )
2001-08-08
2006-10-10
Gudrun Wieser
Wind power plant for generating energy
US7160083B2
( en )
*
2003-02-03
2007-01-09
General Electric Company
Method and apparatus for wind turbine rotor load control
US7176584B1
( en )
2005-09-23
2007-02-13
Green C Raymond
Wind power apparatus
US7220096B2
( en )
2004-03-16
2007-05-22
Tocher Angus J
Habitat friendly, multiple impellor, wind energy extraction
US7230348B2
( en )
2005-11-04
2007-06-12
Poole A Bruce
Infuser augmented vertical wind turbine electrical generating system
US7365448B2
( en )
2006-08-17
2008-04-29
X Blade Systems Lp
Wind driven power generator
US20080258467A1
( en )
2007-04-18
2008-10-23
Wilson Samuel B
Methods, Systems, and Devices for Energy Generation
US20090087308A2
( en )
2007-03-23
2009-04-02
Presz Walter Jr
Wind turbine with mixers and ejectors
US7550864B2
( en )
2003-03-18
2009-06-23
Renewable Devices Swift Turbines Limited
Wind turbine
US20090230691A1
( en )
2007-03-23
2009-09-17
Presz Jr Walter M
Wind turbine with mixers and ejectors
US20090256359A1
( en )
2006-05-12
2009-10-15
Mmi Trust Holding S.A.
Wind turbine and wind power installation
US20090263244A1
( en )
2007-03-23
2009-10-22
Presz Jr Walter M
Water Turbines With Mixers And Ejectors
US7633177B2
( en )
2005-04-14
2009-12-15
Natural Forces, Llc
Reduced friction wind turbine apparatus and method
US20100028132A2
( en )
2007-03-23
2010-02-04
Flodesign Wind Turbine Corporation
Wind turbine with mixers and ejectors
US7679206B1
( en )
2005-09-23
2010-03-16
Green C Raymond
Wind power apparatus
US20100247289A1
( en )
2007-03-23
2010-09-30
Flodesign Wind Turbine Corporation
Segmented wind turbine
US20100270802A1
( en )
2007-03-23
2010-10-28
Flodesign Wind Turbine Corporation
Wind turbine
Family Cites Families (27)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US984599A
( en )
1906-02-24
1911-02-21
Stephane Pichault
Apparatus for storing and distributing wind-power.
GB1450348A
( en )
1973-10-11
1976-09-22
Gronager J
Windturbine
DE2451965A1
( en )
1974-10-30
1976-05-06
Siemens Ag
Tripping circuit for an asynchronously running synchronous machine - using induced slip frequency currents as trip signal switches off machine when overload occurs
US4021135A
( en )
1975-10-09
1977-05-03
Pedersen Nicholas F
Wind turbine
US4258271A
( en )
1977-05-19
1981-03-24
Chappell Walter L
Power converter and method
<tr itemprop="backwardReferencesFamily" item