Vertical axis wind turbine with controllable rotation moment

Abstract

The vertical axis wind turbine includes a central turbine axle configured to be attached to an electrical generator, and at least two blades extending radially from the central turbine axle. Each blade includes a wing including a wing axle and a wing control hub. The wing control hub is connected to the wing axle and configured to rotate the wing axle. A yaw control system is in communication with the wing control hub and is configured to control the wing control hub of each blade. A central control system is in communication with the yaw control system and is configured to control the yaw control system based on feedback data from user input, a position sensor, a wind turbine performance sensor and a material failure sensor connected to the vertical axis wind turbine.

Description

VERTICAL AXIS WIND TURBINE WITH CONTROLLABLE ROTATION MOMENTFIELD OF THE INVENTION

[0001] The present embodiments described in this specification relate generally to vertical axis wind turbines, and specifically to a wind turbine with adjustable blades allowing for the manipulation of rotational moment relative to passing wind conditions.BACKGROUND OF THE INVENTION

[0002] In the developmental history of devices for conversion of wind energy to mechanical or electrical energy, two types of wind turbines are most common: horizontal axis wind turbines (HAWT) and vertical axis wind turbines (VAWT). HAWTs have turbines with the main rotor shaft positioned horizontally, while VAWTs have turbines with the main rotor shaft positioned vertically. Each type of generator for developing power from wind has its own advantages and drawbacks.

[0003] HAWTs have the main rotor shaft, gearbox or another type of transmission, electrical generator, yaw control mechanism, and servo motors located in the nacelle on the top of the tower. Because most components are located on the top of the tower, the tower must have a robust structure to be strong enough to support the heavy weight of the components, cyclic load from rotating blades, wind pressure, and vibration. In addition, the location of all the equipment at the top of the tower makes installation and service difficult, requiring large and expensive cranes or helicopters as well as skilled operators.

[0004] HAWTs require an additional yaw control mechanism to turn the blades towards the wind. This yaw control mechanism creates difficulties with transferring electricity through solid cables. Slip rings or complicated computerized yaw systems for counting rounds in the same rotation direction to wind and unwind power transmission and control cable structures are necessary to avoid damaging internal cables in HAWTs. These remedies have drawbacks. For example, running contacts between the brush and slip ring cause electrical current instability and excessive heat emission leading to fire hazard, especially in high current conditions. Counting systems, on the other hand, contain expensive computerized controllers, servo motors, and mechanical transmission.

[0005] The turbine blades of HAWTs can rotate at high speeds - sometimes reaching 200 miles per hour at the blade tips. Such high rotation speeds can cause emission of acoustic noise at a wide range of frequencies and amplitudes. Moreover, when the turbine blades of HAWTs pass across the tower body they can create shock waves with frequencies in the infra-sound range. Acoustic noise at these frequencies and amplitudes are known to cause vibroacoustic diseases (VAD) in the population of surrounding areas as well as harm animal and bird habitats around HAWT installation sites.

[0006] High mechanical stresses occur in HAWT blades as a result of their high speed of rotation. Specifically, angular momentum of the blades combined with their varying position with respect to the gravitational force vector affects the lifespan of the advanced composite materials used in HAWT blade structures. These advanced composite materials are nearly impossible to recycle at a reasonable cost and the accumulation of worn turbine blades creates a serious environmental problem.

[0007] Variants of vertical axis wind turbines (VAWTs) have been developed to avoid the drawbacks of HAWTs. VAWTs can be divided into several sub-classes; each subclass has its own parameters and features, but some advantages and drawbacks are shared amongst these VAWT variants.

[0008] Large tower structures are not required for VAWTs due to the fact that most components may be located near the ground and are easily accessible for installation and service. Similarly, since the axis of the turbine for VAWTs is vertical, VAWTs do not require a complicated yaw mechanism to sustain the integrity of power and to control cable systems. VAWTs also have a lower startup wind speed and a significantly lesser noise pollution level.

[0009] However, the blades of a VAWT move towards the airflow of wind direction each half revolution, thereby creating losses due to their drag force. This drag causes significant power loss and makes large-scale VAWTs not as economically viable as HAWTs. Specifically, the blades of VAWTs endure stress from both sides as they turn with and against wind direction. As such, the stresses experienced by these blades complicates the design of larger scale turbines, which are generally capable of higher energy output than smaller turbines. Accordingly, there is a need for an improved VAWT able to overcome the drawbacks inherent in most VAWT designs while maintaining the advantages that VAWTs have with respect to HAWTs.SUMMARY OF THE INVENTION

[0010] In broad form, the object of the present invention is an improved vertical axis wind turbine. Specifically, the invention allows for maximizing utilization of wind energy at any blade position relative to airflow direction. The invention uses blades with adjustable wings to minimize the aerodynamic drag related to the movement of blades when moving in the direction against the airflow. The wind energy transformation process is controllable with the present invention, thereby allowing a user to maximize energy transformation efficiency from the wind turbine, reduce efficiency, or minimize energy transformation efficiency to control turbine rotation speed or stall the vertical axis turbine without the need of using brakes. The use of adjustable and segmented wings also helps minimize the load on structural elements of the turbine by minimizing stresses associated with aerodynamic drag while also minimizing production and maintenance costs associated with the replacement of blades and the materials necessary to withstand lesser stresses.

[0011] In one embodiment, a vertical axis wind turbine includes a central turbine axle with a proximal end configured to be attached to an electrical generator. The vertical axis wind turbine further includes at least two blades extending radially from the central turbine axle. Each blade includes a lower arm, an upper arm, a wing including a wing axle, and wing control hub. The lower arm extends radially outwards from a proximal part of the central turbine axle and is pivotally attached to the wing at a distal end. The upper arm extends radially outwards from a distal part of the central turbine axle and is pivotally attached to the wing at a distal end. The wing axle of the wing extends between the distal end of the lower arm and the distal end of the upper arm. The wing control hub is connected to the wing axle and configured to rotate the wing axle. A yaw control system is in communication with the wing control hub and is configured to control the wing control hub of each blade. The yaw control system is configured to control the wings of each blade based on feedback data received by a central control system from a position sensor and a turbine performance sensor connected to the vertical axis wind turbine.

[0012] In a further embodiment, the wing of each blade is connected to the upper arm by a first fastener and is connected to the lower arm by a second fastener such that the wing is removeable from the respective blade of the at least two blades. The vertical axis wind turbineincludes a central control hub in communication with each wing control hub of each blade and a wind direction sensor in communication with the yaw control system. The wind direction sensor is configured to sense a relative direction of the wind with respect to the vertical axis wind turbine. A central control system may be configured to receive wind direction data from the wind direction sensor and control an angle of each wing with respect to the wind direction via the yaw control system, the central control hub, and each wing control hub of each blade.

[0013] In yet another embodiment, each blade includes a central arm extending radially outwards from a center part of the of the central turbine axle and is pivotally attached to the corresponding wing axle of the blade. In addition, the central arm may bisect the corresponding wing of the blade.

[0014] In yet another embodiment, the wing control hub of each blade is configured to rotate the wing axle such that the wing of each blade is oriented at an angle with respect to the wind direction to maximize, reduce, or minimize a resulting rotational force on the central turbine axle. The yaw control system is further configured to receive inputs from a central control system to reduce wind energy transmission efficiency of the vertical axis wind turbine or minimizing wind energy transmission efficiency of the vertical axis wind turbine, and the yaw control system is configured to control the wings of each blade based on the received inputs from the central control system.

[0015] In a further embodiment, a vertical axis wind turbine includes a central turbine axle having a proximal end configured to be attached to an electrical generator or any other energy conversion device, a yaw control shaft extending within the central turbine axle, and a set of blades extending radially from the central turbine axle. The yaw control shaft is connected to a yaw control system on a proximal end and connected to a central control hub on a distal end. Each blade of the set of blades includes an arm extending radially outwards from the central turbine axle and pivotally attached to a wing axle at a distal end of the arm, a wing affixed to the wing axle, and a wing control hub connecting the wing axle to the central control hub and configured to rotate the wing axle.

[0016] In yet another embodiment, a wind direction sensor is in communication with the yaw control system via a central control system. The wind direction sensor is configured to sense a relative direction of the wind with respect to the vertical axis wind turbine. The central control system may be configured to receive wind direction data from the wind direction sensor andcontrol an angle of each wing of the set of blades with respect to the wind direction via the central control hub and the wing control hub of each blade.

[0017] In yet another embodiment, each blade of the set of blades includes a central arm extending radially outwards from a center part of the of the central turbine axle and pivotally attached to the corresponding wing axle of the blade. The central arm may bisect the corresponding wing of the blade.

[0018] In yet another embodiment, the wing control hub of each blade is configured to rotate the wing axle such that the corresponding wing of each blade is oriented at an angle with respect to the wind direction to maximize, reduce, or minimize a resulting rotational force on the central turbine axle. The central control hub is in communication with each wing control hub of each blade of the at least two blades via a link. The link may be any one of a mechanical connection, electrical connection, pneumatic connection, or electromechanical connection.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For a complete understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:

[0020] FIG. l is a perspective view of a vertical axis wind turbine in accordance with an embodiment of the present invention;

[0021] FIG. 2 is a perspective view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention;

[0022] FIG. 3 is a perspective view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention;

[0023] FIG. 4 is a close-up view of the attachment of wings to a blade in accordance with an embodiment of the present invention;

[0024] FIG. 5 is a close-up view of an embodiment of the connections between a wing on a blade and the yaw control shaft;

[0025] FIG. 6A is a top view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention;

[0026] FIG. 6B is a top view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention;

[0027] FIG. 6C is a top view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention;

[0028] FIG. 6D is a top view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention;

[0029] FIG. 6E is a top view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention; and

[0030] FIG. 6F is a top view of a vertical axis wind turbine with adjusted wing orientation with respect to a wind direction in accordance with an embodiment of the present invention.DETAILED DESCRIPTION OF EMBODIMENTS

[0031] Preferred embodiments of the present invention will be described with reference to the accompanying drawings. It will be readily understood that the components of the present embodiments, as generally described and illustrated in the Figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the brassiere of the present embodiments, as presented in the Figures, is not intended to limit the scope of the embodiments, as claimed, but is merely representative of selected embodiments.

[0032] Reference throughout this specification to “a select embodiment,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described herein. Thus, appearances of the phrases “a select embodiment,” “in one embodiment,” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment.

[0033] As depicted in FIG. 1, an embodiment of the present invention is in the form of a vertical axis wind turbine 100 having a central turbine axle 102 extending vertically. The central turbine axle 102 is connected to a set of blades 200. The set of blades 200 has a minimum of two blades. In the embodiment depicted in FIG. 1, the set of blades 200 includes four blades (220, 240, 260, and 280). Each of the blades 220, 240, 260, 280 is connected to the central turbine axle 102 via an upper arm and a lower arm. For example, the first blade 220 is connected to the central turbine axle 102 via the upper arm 221 and the lower arm 222. The second blade 240 is connected to the central turbine axle 102 via the upper arm 241 and thelower arm 242. As shown in FIG. 1, the blades may also include a middle arm such as the middle arm 223 for blade 220 and the middle arm 243 for blade 240.

[0034] Each blade incudes at least one wing attached to a wing axle. Focusing on blade 240, the blade 240 includes a wing axle 244 extending between the upper arm 241 and the lower arm 242. The wing axle 244 is affixed to a wing 245. In the embodiment depicted in FIG. 1, the wing 245 is bisected by the middle arm 243. The wing axle 244 is pivotably attached to each of the upper arm 241, the lower arm 242, and the middle arm 243. The junction between the wing axle 244 and the arms 241-243 may be by a bearing allowing for pivotable attachment with minimal friction. For example, the embodiment shown in FIG. 1 includes a bearing 246 at the junction between the wing axle 244 and the upper arm 241, a bearing 247 at the junction between the wing axle 244 and the lower arm 242, and a bearing 248 at the junction between the wing axle 244 and the middle arm 243. Awing control hub 249 is connected to an end of the wing axle 244 and is configured to rotate the wing axle 244 with respect to the arms 241-243. The yaw control system 104 has position sensor (not shown) for acquiring yaw system control position information. The wing control hub 249 may control the wing axle 244 by mechanical means, electrical means, pneumatic means, or electromechanical means.

[0035] The central turbine axle 102 is hollow. Within the central turbine axle 102, there is a yaw control shaft 103 extending along the axis of the central turbine axle 102. The yaw control shaft 103 is connected to a yaw control system 104 on a proximal end and to a central control hub 105 on a distal end. The central control hub 105 is connected to the wing control hub of each blade 220, 240, 260, and 280 via links. As such, the central control hub 105 is connected to the wing control hub 249 via link 250. The yaw control system 104 is configured to receive wind direction information, yaw control system position information from the position sensor, and send commands to the central control hub 105 to control the wing control hubs of each blade 220, 240, 260, and 280.

[0036] A wind direction sensor 106, as depicted in FIGs. 2 and 3, is in communication with the yaw control system 104 and is configured to obtain wind direction information from the environment and provide the wind direction information to the yaw control system 104. The wind direction information collected by the wind direction sensor 106 is the wind direction relative to the orientation of the vertical axis wind turbine 100. A central control system 108 (depicted in FIGs 2 and 3) is in communication with the yaw control system 104 and isconfigured to receive inputs from a user and / or from sensors (not shown) on the vertical axis wind turbine 100 itself. For example, sensors distributed along the vertical axis wind turbine 100 may be triggered by increased stresses on the central turbine axle 102, the yaw control shaft 103, or another component of the vertical axis wind turbine 100. In response, the central control system 108 may direct the yaw control system 104 to orientate the wings of each blade via the wing control hub 249 to reduce the efficiency of the transmission of wind energy to rotational energy, thereby decreasing the stress on the respective component. Alternatively, a user may input a command via an interface (not shown) to slow or stop the rotation of the vertical axis wind turbine 100. In this case, the central control system 108 may direct the yaw control system 104 to orientate the wings of each blade via the wing control hub 249 to minimize the efficiency of the transmission of wind energy to rotational energy, thereby allowing the vertical axis wind turbine 100 to come to a stop even in windy conditions.

[0037] As shown in FIG. 2 and FIG. 3, the wind direction information collected by the wind sensor 106 and yaw control system position sensor information collected may be used to orientate the wings of each blade to maximize the amount of resulting rotational force on the central turbine axle, to minimize the amount of resulting rotational force on the central turbine axle, or to provide wings’ position adjustment to achieve a constant controllable turbine rotation speed.

[0038] With respect to FIG. 2, an example of the vertical axis wind turbine 100 being subjected to a wind having a wind direction 107 and configured to maximize the amount of resulting rotational force on the central turbine axle is shown. Specifically, the wings of the set of blades 200 and their orientation with respect to the wind direction 107 provide a combined resulting rotational force on the central turbine axle that is clockwise in this example. The central control system 108 is positioned in parallel to the wind direction 107 signifying that it is directing the yaw control system 104 to orientate the wings of each blade via the wing control hub 249 to maximize the efficiency of the transmission of wind energy to rotational energy. The wing for blade 260 is positioned at a 45-degree angle with the direction of the wind 107 to maximize a tangential force vector in the clockwise direction. The wing for blade 280 is positioned at an opposite 45-degree angle with the direction of the wind 107 to maximize a tangential force vector in the clockwise direction from the opposite side of the vertical axis wind turbine 100 from blade 260. The wing for blade 240 is positioned to facethe wind direction 107. In other words, the wing for blade 240 sits on a plane directly facing the wind direction 107 because the resulting tangential force vector to be maximized from blade 240 is in the same direction as the wind direction 107. The wing for blade 220 is positioned to minimize drag from wind coming from the wind direction 107. In other words, the wing for blade 220 sits on a plane facing a direction orthogonal to the wind direction 107 so that the resulting tangential force vector in the counterclockwise direction and created by air resistance is minimized for blade 240.

[0039] Feedback data 109 is collected from yaw control system position sensors and turbine performance sensors in connection with the vertical axis wind turbine 100 and sent to the central control system 108. The central control system 108 is configured to control the yaw control system 104 so as to manipulate the wings on the blades based on the feedback data 109 from the sensors in connection with the vertical axis wind turbine 100 as well as wind direction data from the wind direction sensor 106. The central control system 108 may be in communication with a variety of sensors which provide it with input data to optimize control of the vertical axis wind turbine 100 in a variety of scenarios. One such sensor may be one or more material failure sensor(s) connected to the vertical axis wind turbine at strategic locations such that stress or strain on a component may be identified before the component fails and compromises the vertical axis wind turbine 100. For example, the material failure sensor may be a strain gauge, force sensor, force transducer, blade rpm gauge, etc. Another form of sensor that may be in communication with the central control system 108 is a wind turbine performance sensor, which is a sensor configured to detect performance metrics of the vertical axis wind turbine as it runs. Examples of wind turbine performance sensors include anemometers and electronic devices for measuring electrical output, blade speed, and calculating power coefficients. An additional form of sensor that may be in communication with the central control system 108 is a yaw control system position sensor, or ‘position sensor.’ A yaw control system position sensor detects the relative position of the blades to the wind direction and the angular orientation of the wings in relation to the blades and with respect to their position in the circular path taken during the revolution of the blades. An example of a yaw control system position sensor is an absolute position encoder sensor, located on the yaw control shaft 103 such that it is able to detect the relative position of the blades of the vertical axis wind turbine 100. The feedback data 109 received by the centralcontrol system 108 from these sensors enables for the manipulation of turbine efficiency and turbine rotational speed regardless of wind speed.

[0040] With respect to FIG. 3, an example of the vertical axis wind turbine 100 being subjected to a wind having a wind direction 107 and configured to minimize the amount of resulting rotational force on the central turbine axle is shown. The central control system 108 is positioned perpendicular to the wind direction 107 signifying that it is directing the yaw control system 104 to orientate the wings of each blade via the wing control hub 249 to minimize the efficiency of the transmission of wind energy to rotational energy. One may wish to minimize the amount of resulting rotational force on the central turbine axle when their intention is to slow or stop the vertical axis wind turbine 100. Feedback data from material failure sensors in connection to the vertical axis wind turbine 100 may detect strains or stresses that result in an automatic reduction of rotational speed of the vertical axis wind turbine 100. Alternatively, a need to obtain consistent power transmission from the vertical axis wind turbine 100 in variable wind conditions may require a reduction in wind energy transmission efficiency to compensate for wind variances. In this configuration (z.e., a stall configuration), the wings of the set of blades 200 and their orientation with respect to the wind direction 107 provide a combined resulting rotational force that is zero due to the canceling of tangential forces resulting from each blade of the set of blades 200. The wing for blade 240 is positioned at a 45-degree angle with the direction of the wind 107 while the wing for blade 220 is positioned at an opposite 45-degree angle with the wind direction 107. As such, the resulting tangential force vectors of both blades 220, 240 cancel each other and result in a combined resulting tangential force vector of zero. The wing for blade 280 is positioned to face the wind direction 107. In other words, the wing for blade 280 sits on a plane directly facing the wind direction 107, but because blade 280 is fully downwind with respect to the wind direction 107 and in relation to the other blades of the set of blades 200, the resulting tangential force vector is zero. The wing for blade 260 is positioned at the most upstream location, but the wing of blade 260 is orientated to minimize drag from wind coming from the wind direction 107. In other words, the wing for blade 260 sits on a plane facing a direction orthogonal to the wind direction 107 so that the resulting tangential force vector is minimized for blade 260. In this configuration, the rotational speed of the verticalaxis wind turbine 100 may be reduced without the need of mechanical or electrical brakes, which are prone to failure, and sometimes, fire.

[0041] FIG. 4 is a close-up view of a blade of another embodiment of a vertical axis wind turbine. In this embodiment, the vertical axis wind turbine has a central turbine axle 302 and three blades: blade 360, and blades 320 and 340 (not shown). In addition, the blade 360 includes a wing 365 extending along a wing axle 364 and segmented into at least three wing segments: 365A, 365B, and 365C. Between wing segments 365A and 365B, there is a lower- middle arm 361 attached to the central turbine axle 302 on a first end and pivotably attached to the wing axle 364 via a bearing 366 on a second end. Between wing segments 365B and 365C, there is an upper-middle arm 362 attached to the central turbine axle 302 on a first end and pivotably attached to the wing axle 364 via a bearing 367 on a second end. Blades 320 and 340 (not shown) have similar lower-middle arms 321 and 341, respectively, and similar upper-middle arms 322 and 342, respectively.

[0042] The wing segments 365 A, 365B, and 365C are detachable from the blade 360. For example, wing segment 365B may be removed for maintenance or replacement by disengaging fasteners 371 and 372. Fasteners 371, 372 affix the wing segment 365B so that it is aligned with wing segments 365A and 365C and maintains the same planar orientation as wing segments 365 A and 365C. Removing wing segment 365 A would require at least disengaging the fastener 373 and removing wing segment 365C would require at least disengaging the fastener 374.

[0043] As shown in FIG. 5, an embodiment of the vertical axis wind turbine may have a central control hub 105 connected to the wing control hubs (e.g., 249) via mechanical means including bevel gears. Specifically, the central control hub 105 may include a bevel gear 105a attached to the yaw control shaft 103 and in communication with the links 250 of each blade via pinion bevel gears 105b of each blade. Each link 250 has the pinion bevel gear 105b on a proximal end and a pinion bevel gear 249b on a distal end. In addition, each link 250 is held in place by link support 251, which includes bearings to allow the link 250 to rotate along its axis with minimal friction. The pinion bevel gear 249b on the distal end of each link 250 is in communication with a bevel gear 249a, thereby forming the wing control hub 249. Bevel gear 249a is attached to the wing axle of blade 240. As such, the mechanical means depicted in FIG. 5 shows an example of how the control of the yaw control shaft 103 may be transmittedto control of the wings of each blade via mechanical means. However, note that as mentioned above, control the wing axle by the yaw control shaft 103 may be made by other forms of mechanical means as well as by electrical means, pneumatic means, or electromechanical means.

[0044] With respect to FIGs 6A-6F, a top view perspective shows the orientations of the wings of each blade of the vertical axis wind turbine 100 with respect to the wind direction 107 in various scenarios. A first scenario is depicted by FIGs 6A-6D whereby the vertical axis wind turbine 100 is configured to maximize the transmission of wind energy. In this configuration, the central control system 108 is positioned parallel to the wind direction 107. Having the central control system 108 positioned parallel to the wind calibrates the wings of each blade to be orientated differently with respect to the wind direction 107 depending on the position of the corresponding blade in the circular path taken by the blades. For example, as shown in FIG 6A, blade 220 is positioned upwind of the vertical axis wind turbine 100 and has wings angled at 45 degrees with the wind direction 107 to enable a maximum resultant force in the clockwise direction of rotation of the vertical axis wind turbine 100. Similarly, blade 260, which is positioned downwind of the vertical axis wind turbine 100, has wings angled at 45 degrees with the wind direction 107 to enable a maximum resultant force in the clockwise direction of rotation of the vertical axis wind turbine 100. Because the resultant force of blade 240 is to be in the same direction as that of the clockwise rotation, the wings of blade 240 are orientated to face the wind direction 107 (z.e., 0 degrees or 180 degrees). The opposite situation is true for blade 280, which must travel upwind to continue the clockwise rotation of the vertical axis wind turbine 100. To minimize drag in traveling upwind, blade 280 has wings orientated to face perpendicularly to the wind direction 107 (z.e., 90 degrees or 270 degrees).

[0045] As the vertical axis wind turbine 100 rotates, the position of the blades with respect to the wind direction 107 changes as well. As such, the orientation of the wings of each blade are simultaneously adjusted to maximize the respective resultant forces based on the respective positions of the wings in the clockwise rotation of the vertical axis wind turbine 100. As shown in FIG. 6B, the vertical axis wind turbine 100 is 30 degrees offset from its previous position in FIG. 6 A. To maintain an optimal angle with respect to the wind direction 107, the wings of each blade are rotated at half the rotation speed of the vertical axis wind turbine 100 (z.e., 15 degrees). As such, the wings of blade 220 are rotated to have an angle of 30 degreeswith respect to the wind direction 107, the wings of blade 240 are rotated to have an angle of 15 degrees with respect to the wind direction 107, the wings of blade 260 are rotated to have an angle of 60 degrees with respect to the wind direction 107, and the wings of blade 280 are rotated to have an angle of 75 degrees with respect to the wind direction 107.

[0046] In FIG. 6C, the vertical axis wind turbine 100 has continued rotating in a clockwise direction until it is 45 degrees offset from the position in FIG. 6A. To maintain an optimal angle with respect to the wind direction 107, the wings of each blade keep rotating at half the rotation speed of the vertical axis wind turbine 100. As such, the wings of blade 220 are rotated to have an angle of 22.5 degrees with respect to the wind direction 107, the wings of blade 240 are rotated to have an angle of 22.5 degrees with respect to the wind direction 107, the wings of blade 260 are rotated to have an angle of 67.5 degrees with respect to the wind direction 107, and the wings of blade 280 are rotated to have an angle of 67.5 degrees with respect to the wind direction 107.

[0047] In FIG. 6D, the vertical axis wind turbine 100 has continued rotating in a clockwise direction until it is 60 degrees offset from the position in FIG. 6A. To maintain an optimal angle with respect to the wind direction 107, the wings of each blade keep rotating at half the rotation speed of the vertical axis wind turbine 100. As such, the wings of blade 220 are rotated to have an angle of 15 degrees with respect to the wind direction 107, the wings of blade 240 are rotated to have an angle of 30 degrees with respect to the wind direction 107, the wings of blade 260 are rotated to have an angle of 75 degrees with respect to the wind direction 107, and the wings of blade 280 are rotated to have an angle of 60 degrees with respect to the wind direction 107.

[0048] In FIG. 6E, the vertical axis wind turbine 100 is configured to minimize the transmission of wind energy (z.e., a stall configuration). In this configuration, the central control system 108 is positioned perpendicular to the wind direction 107. Having the central control system 108 positioned perpendicular to the wind calibrates the wings of each blade to be orientated differently with respect to the wind direction 107 depending on the position of the corresponding blade in the circular path taken by the blades to slow or stop the vertical axis wind turbine 100. For example, as shown in FIG. 6E, blade 220 is positioned upwind of the vertical axis wind turbine 100 and has orientated to face the wind direction 107 (z.e., 0 degrees or 180 degrees) to have a resultant force that does not contribute to the rotation of the verticalaxis wind turbine 100. Similarly, blade 260, which is positioned downwind of the vertical axis wind turbine 100, has wings orientated to face perpendicularly to the wind direction 107 (z.e., 90 degrees or 270 degrees) to minimize its resultant force. Blades 240 and 280 are orientated at 45 degrees with respect to the wind direction 107 but have resultant forces with vectors that cancel each other in the rotation direction.

[0049] In FIG. 6F, the vertical axis wind turbine 100 is configured to have an approximately 50% reduced transmission of wind energy. In this configuration, the central control system 108 is positioned at 45 degrees with respect to the wind direction 107. As with the example scenarios provided in FIGs 6A-E, having the central control system 108 positioned at 45 degrees to the wind calibrates the wings of each blade to be orientated differently with respect to the wind direction 107 depending on the position of the corresponding blade in the circular path taken by the blades. Specifically, each blade 220, 240, 260, and 280 has its respective wings orientated in such a way that the resulting force created by the angle of each wing with respect to the wind direction 107 is approximately half of what the corresponding resulting force is in FIG. 6A for each blade. By being able to reduce the efficiency of the vertical axis wind turbine 100 based on feedback data 109 obtained by sensors across the vertical axis wind turbine 100, a constant rotational speed is able to be achieved despite gusts of wind and other variances in wind direction and speed.

Claims

What is claimed is:

1. A vertical axis wind turbine comprising: a central turbine axle extending from a proximal end to a distal end, the proximal end being configured to be attached to an electrical generator or other energy conversion device; at least one blade extending radially from the central turbine axle, the blade including: a lower arm extending radially outwards from a proximal part of the central turbine axle and pivotally attached to a wing at a distal end of the lower arm, an upper arm extending radially outwards from a distal part of the central turbine axle and pivotally attached to the wing at a distal end of the upper arm, the wing including a wing axle extending between the distal end of the lower arm and the distal end of the upper arm, and a wing control hub connected to the wing axle and configured to rotate the wing axle; a yaw control system in communication with the central control hub and configured to control the wing control hub of each blade of the at least one blades; and a central control system in communication with the yaw control system and configured to control the yaw control system based on at least user input, feedback data from a position sensor, and a turbine performance sensor connected to the vertical axis wind turbine.

2. The vertical axis wind turbine of claim 1, wherein the wing is connected to the upper arm by a first fastener and is connected to the lower arm by a second fastener such that the wing is removeable from the blade.

3. The vertical axis wind turbine of claim 1, further comprising:a central control hub in communication with the wing control hub, the central control hub being configured to transmit configuration commands between the yaw control system and the wing control hub; and a wind direction sensor in communication with the central control system, the wind direction sensor being configured to sense a relative direction of the wind with respect to the vertical axis wind turbine.

4. The vertical axis wind turbine of claim 3, wherein: the central control system is further configured to receive inputs with respect to reducing wind energy transmission efficiency of the vertical axis wind turbine or minimizing wind energy transmission efficiency of the vertical axis wind turbine, and the central control system is configured to control the yaw control system based on the received inputs together with the feedback data from the position sensor and the turbine performance sensors.

5. The vertical axis wind turbine of claim 1, wherein each blade of the at least two blades includes a central arm extending radially outwards from a center part of the of the central turbine axle and pivotally attached to the corresponding wing axle of the blade, the central arm bisecting the corresponding wing of the blade.

6. The vertical axis wind turbine of claim 3, wherein the central control hub is in communication with the wing control hub via a link, the link being any one of a mechanical connection, electrical connection, pneumatic connection, or electromechanical connection.

7. The vertical axis wind turbine of claim 3, wherein the central control hub is connected to a yaw control system via a yaw control shaft, the yaw control system being in electronic communication with the central control system.

8. The vertical axis wind turbine of claim 1, wherein the central control system is further configured to control the yaw control system based on feedback data from a material failure sensor connected to the vertical axis wind turbine.

9. A vertical axis wind turbine comprising: a central turbine axle extending from a proximal end to a distal end, the proximal end configured to be attached to an electrical generator or other energy conversion device; a yaw control shaft extending within the central turbine axle, the yaw control shaft being connected to a yaw control system on a proximal end and connected to a central control hub on a distal end; a central control system in communication with the yaw control system; and a set of blades extending radially from the central turbine axle, each blade of the set of blades including: an arm extending radially outwards from the central turbine axle and pivotally attached to a wing axle at a distal end of the arm, a wing affixed to the wing axle, and a wing control hub connecting the wing axle to the central control hub and configured to rotate the wing axle, wherein the central control system is configured to control the central control hub via the yaw control system based upon user input and feedback data received from a turbine performance sensor and a position sensor in connection with the vertical axis wind turbine.

10. The vertical axis wind turbine of claim 9, wherein the wing of each blade of the set of blades is connected to the arm by a fastener such that the wing is removeable from the respective blade of the set of blades.

11. The vertical axis wind turbine of claim 9, further comprising a wind direction sensor in communication with the central control system, the wind direction sensor beingconfigured to sense a relative direction of the wind with respect to the vertical axis wind turbine.

12. The vertical axis wind turbine of claim 11, wherein the central control system is further configured to: receive wind direction data from the wind direction sensor together with the feedback data received from user input, the turbine performance sensor and the position sensor, and control an angle of each wing of the set of blades with respect to the wind direction via the central control hub and the wing control hub of each blade of the set of blades.

13. The vertical axis wind turbine of claim 9, wherein each blade of the set of blades includes a central arm extending radially outwards from a center part of the of the central turbine axle and pivotally attached to the corresponding wing axle of the blade, the central arm bisecting the corresponding wing of the blade.

14. The vertical axis wind turbine of claim 11, wherein the central control hub is in communication with each wing control hub of each blade of the set of blades via a link, the link being any one of a mechanical connection, electrical connection, pneumatic connection, or electromechanical connection.

15. The vertical axis wind turbine of claim 9, wherein the central control system is further configured to control the central control hub based on feedback data from a material failure sensor connected to the vertical axis wind turbine.

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