An efficient wind energy converter that requires neither a gearbox nor a multi-pole generator.

Abstract

A vertical axis turbine having a first rotor and at least one second rotor, wherein the first rotor is configured to rotate around a first axis of rotation that is vertical or more vertical than horizontal during use. The first rotor may be configured to be driven and / or rotated by fluid movement, for example, wind or water current. The at least one second rotor is provided on or coupled to the first rotor such that the first rotor is operable to move the second rotor through a fluid, thereby driving the second rotor upon rotation of the first rotor. The second rotor is operable to drive a power take-off system. Optionally, rotation of the first rotor around the first axis of rotation moves the second rotor around the first axis of rotation. Each second rotor may be angled or perpendicular to the first rotor's first axis of rotation, and optionally rotates around a respective second axis of rotation that is a horizontal axis or at least more horizontal than vertical during use. The first rotor and the second rotor are configured to provide direct drive power take-off without the need for a gearbox or multi-pole generator, and the first rotor and the second rotor are configured to provide efficient power conversion, converting mechanical power at the first rotor to mechanical power at the second rotor. [Selected Figure] Figure 1

Description

Technical Field

[0001] This specification describes a wind energy converter (WEC) that can be used as a wind turbine for generating electricity, optionally rather than necessarily. The invention also relates to related methods of generating power from a vertical axis turbine, and methods of controlling a vertical axis turbine.

Background Art

[0002] A turbine can be driven to rotate and thereby function. For example, a wind turbine can be driven by wind, and a generator can produce electricity when the turbine rotates. Most wind turbines have blades driven by wind around a horizontal axis. Since the blades of a horizontal axis wind turbine can directly contact the wind when rotating, the efficiency of the blades is improved.

[0003] Conventional vertical axis wind turbines generate electricity from the rotation of a rotor centered on the vertical axis in use. The design of conventional vertical axis wind turbines is such that they can operate aerodynamically efficiently only when rotating at a relatively low speed compared to horizontal axis wind turbines. As a result, the rotor of such a turbine will create high torque on the main transmission shaft. These high torques also require a large, heavy, and expensive power train to convert the high torque and low speed rotation of the rotor into electricity.

[0004] A V-type vertical axis wind turbine comprises a vertical axis wind turbine having blades that project upward in a V-shape from a central point or center. Thereby, the power train will be located near the ground rather than at a high location. However, a large and expensive drive train is still required.

[0005] At least one object of one embodiment of the present invention is to provide an improved vertical-axis turbine for power generation that is highly efficient and avoids having a gearbox or generator with a large number of poles. [Overview of the project]

[0006] According to a first embodiment, a turbine is provided comprising a first rotor configured to rotate around a first axis of rotation, and at least one second rotor. The first axis of rotation of the first rotor may be vertical or at least more vertical than horizontal during use. At least one second rotor may be provided with, included in, or coupled to the first rotor. The first rotor may be configured to be driven and / or rotated by fluid motion, for example, by wind or water flow. The first rotor may be operable to drive the second rotor, for example, by moving the second rotor through a fluid when the first rotor is rotating. The second rotor may be provided with, included in, or coupled to the first rotor so that the rotation of the first rotor around the first axis of rotation can move the second rotor, for example, around the first axis of rotation. The second rotors may be operable to drive a power takeoff system, or each second rotor may be operable to drive its own power takeoff system. The power take-off system may comprise at least a generator and optionally a gearbox. Preferably, the generator may be directly driven by each second rotor, or optionally, the generator may be indirectly driven by each second rotor via each gearbox.

[0007] Each second rotor may be configured to rotate around its own second axis of rotation. The second axis of rotation of at least one second rotor may be angled, for example, approximately perpendicular to the first axis of rotation of the first rotor. At least one or each of the second axes of rotation around which the second rotor rotates may be a horizontal axis, or at least an axis more horizontal than vertical, or comprise such axes during use. In other words, at least one or each of the second rotors may be a horizontal axis rotor. The first and second rotors may be positioned such that the second axis of rotation of at least one or each of the second rotors is tangential to the circular track on which the second rotor is moved by the first rotor.

[0008] In an exemplary configuration, the turbine may comprise a primary (first) rotor driven by wind or other fluid flow, the primary (first) rotor having one or more secondary or second rotors (preferably directly, without the use of a gearbox) that drive power take-off systems. The second rotors are driven by the rotation of the primary (first) rotor, and as a result, the motion of the second rotor through the fluid by the primary rotor may rotate and drive each power take-off system of the second rotor. Many configurations exist that do not result in an efficient and effective turbine. The turbine must be properly configured to be usable, and the primary rotor, second rotor, and power take-offs must be selected so that, when combined, they result in a particularly efficient and effective turbine. Without a power takeoff that requires a gearbox or generator with multiple pole pairs, the range of choices for many turbine parameters such as torque, tip speed or rotational speed, and power coefficient of the first and / or second rotors is narrow in order to efficiently and effectively combine the rotor, second rotor, and power takeoff.

[0009] The maximum aerodynamic efficiency of a horizontal-axis turbine (for example, when the primary rotor rotates around the horizontal axis during operation) is achieved at a tip-velocity ratio close to 7 (i.e., the ratio of the blade tip velocity to the wind velocity perpendicular to the wind velocity). A combination of a second horizontal-axis rotor mounted on a first horizontal-axis rotor, both operating at a tip-velocity ratio of 7, would have a combined tip-velocity ratio close to 49. At a wind speed of 10 m / s, the blade tip velocity is 490 m / s, well above the speed of sound. At a tip velocity of 490 m / s, the second rotor is operating far beyond the usable operating range of the secondary rotor.

[0010] The rotation of the first rotor moves the second rotor along a circular path at a forward speed relative to the ground, resulting in thrust in the second rotor. The mechanical force required to overcome the thrust and maintain the rotation of the first rotor and the forward speed of the second rotor is the product of the thrust and the rotor's forward speed. The second rotor then supplies mechanical force to the power takeoff. The efficiency of the transmission of mechanical force from the first rotor to the second rotor, and therefore to the power takeoff, is the ratio of the mechanical force supplied by the second rotor to the mechanical force that maintains the rotation of the first rotor. If the second rotor is designed to have aerodynamic properties similar to a conventional HAWT rotor and operates at maximum aerodynamic efficiency, the efficiency of the transmission of mechanical force from the first rotor to the second rotor is close to the theoretical limit of 2 / 3. To compensate for such low efficiency, a larger, heavier, and more expensive first rotor is required.

[0011] However, in a system that includes a first rotor on a vertical axis driven by wind or water flow, but where the power takeoff is not driven by the primary / first rotor, but rather the first rotor moves one or more second rotors through air or other fluid, and the rotation of the second rotors resulting from their motion through air or other fluid drives the power takeoff, many of the above drawbacks can be reduced, eliminated, or used to one's advantage.

[0012] The aerodynamic efficiency of vertical-axis turbines is generally lower than that of their corresponding horizontal-axis turbines. They also tend to have slower rotational speeds and higher torque. In fact, in conventional vertical-axis turbines, the lower aerodynamic efficiency relative to the corresponding horizontal-axis turbine can be problematic, as it necessitates a larger vertical-axis turbine to produce the same power as a horizontal-axis turbine of equivalent rating, resulting in associated disadvantages in terms of cost, weight, and complexity. Furthermore, higher torque in the transmission shaft used to couple the rotor to power takeoff makes the transmission system heavier and more expensive.

[0013] Many of the aforementioned drawbacks of known vertical-axis turbines can also be reduced, eliminated, or advantageously utilized in systems comprising a first vertical-axis rotor and one or more second rotors.

[0014] In exemplary configurations, a specific design for the vertical-axis first rotor is combined with a specific design for the second rotor to mitigate, eliminate, or advantageously utilize both the drawbacks of the vertical-axis wind turbine and the drawbacks of the second rotor. Aerodynamic considerations specify a maximum value for the tip velocity of the second rotor blades. Furthermore, when each secondary rotor directly drives the generator without requiring a gearbox or multi-pole generator, generator considerations specify a minimum value for the rotational speed of the second rotor.

[0015] In the first exemplary configuration, the rotor comprises an upper section with two V-shaped upper blades and a lower section with two inverted V-shaped lower blades. One secondary rotor and an associated generator, optionally, are mounted on the tip of each lower blade. Each secondary rotor directly drives an associated generator, which may have four pole pairs and a nominal frequency of 25 Hz, without requiring a gearbox. The rotor speeds of the first and second rotors are variable and increase with the wind speed. The mechanical force P supplied by the first rotor F This is related to the ambient wind speed, and the rated wind speed V RIt reaches its maximum at a tip-speed ratio of 4.65. The first rotor has maximum aerodynamic efficiency at a tip-speed ratio of 4.65. The second rotor operates at a tip-speed ratio of 3.13, with an aerodynamic power coefficient of 0.27 and an aerodynamic thrust coefficient of 0.3375. The combined tip-speed ratio, which is the product of the tip-speed ratios of the first and second rotors, is 14.57. The mechanical force extracted from the wind by the first rotor is According to TIFF0007864483000001.tif7170, the ambient wind speed V R , and the rotational speed of the second rotor This relates to TIFF0007864483000002.tif7170. When the rotational speed of the second rotor is 39.21 rad / s and the rated wind speed is 12.66 m / s, the tip speed of the secondary rotor is 184.3 m / s, and the mechanical force extracted from the wind by the first rotor is 5.99 MW. When the turbine is operated by changing the rotational speed of the second rotor, the second rotor supplies a mechanical force of 5.02 MW, which is 84% ​​of the mechanical force extracted from the wind by the first rotor, to the generator at a wind speed of 12.66 m / s, and increases to 5.50 MW, which is 92% of the mechanical force supplied by the first rotor, at a wind speed of 20 m / s. The area of ​​the first rotor is 12,351 square meters, and the maximum value of the aerodynamic power coefficient is 0.39. The combined area of ​​the second rotor is 138.8.

[0016] In the second exemplary configuration, the rotor comprises an upper section with two V-shaped blades and a lower section with two inverted V-shaped blades. Two secondary rotors, and optionally associated generators, are mounted to the tips of each lower blade. Each secondary rotor directly drives an associated generator, which may have a 4-pole pair and a nominal frequency of 25 Hz, without requiring a gearbox. The first rotor has maximum aerodynamic efficiency at a tip-to-speed ratio of 4.65. The second rotor operates at a tip-to-speed ratio of 3.13, with an aerodynamic power coefficient of 0.27 and an aerodynamic thrust coefficient of 0.3375. The mechanical force extracted from the wind by the first rotor is: The code is TIFF0007864483000003.tif7170. When the rotational speed of the second rotor is 39.21 rad / s and the rated wind speed is 11.79 m / s, the tip speed of the secondary rotor is 171.6 m / s and the mechanical force supplied by the first rotor is 8.41 MW. The second rotor supplies a mechanical force of 7.05 MW, which is 84% ​​of the mechanical force supplied by the first rotor, to the generator at a wind speed of 11.79 m / s, and increases it to 7.91 MW, which is 94% of the mechanical force supplied by the first rotor, at a wind speed of 20 m / s. The area of ​​the first rotor is 21,470 square meters and the maximum value of the aerodynamic power coefficient is 0.39. The combined area of ​​the second rotor is 242.3 square meters.

[0017] In the first and second exemplary configurations, the selection of the rated wind speed and the tip speed of the second rotor determines all other parameters, including the mechanical force supplied by the first rotor, the mechanical force supplied to the generator by the second rotor, the area of ​​the first rotor, and the combined area of ​​the second rotor. Modifying either of the exemplary configurations by increasing the rotational speed of the second rotor without changing the rated wind speed reduces the power supplied to the generator, the area of ​​the first rotor, and the combined area of ​​the second rotor by the same coefficient, i.e., the ratio of the square of the rotational speed. In the second configuration, increasing the rotational speed of the second rotor from 39.21 rad / s to 46.46 rad / s reduces the mechanical force supplied by the first rotor from 8.41 MW to 5.99 MW. By modifying either of the exemplary configurations, while keeping the number of secondary rotors attached to the tips of the blades and the total mechanical force supplied to the generator the same, by increasing the number of blades constituting the lower part of the first rotor from two to three, the rotational speed of the secondary rotor increases to 48.02 rad / s and the nominal frequency of the generator increases to 30 Hz.

[0018] The combined efficiency of the first and second rotors when supplying mechanical force to the generator is between 84% and 94%. This high combined efficiency is achieved by having a first rotor with high aerodynamic efficiency, where the maximum value of the aerodynamic power coefficient at a tip speed ratio of 4.65 is 0.39, and a second rotor with low aerodynamic efficiency, where the aerodynamic power coefficient is 0.27 at a tip speed ratio of 3.13 and the ratio of the aerodynamic power coefficient to the aerodynamic thrust coefficient is 0.8. The tip speed ratio at which the first rotor has maximum aerodynamic efficiency is higher for a V-rotor vertical-axis turbine than for an H-rotor vertical-axis turbine, and in the case of a V-rotor, a value of 4.65 is easily obtained. The ratio of the aerodynamic power coefficient to the aerodynamic thrust coefficient of 0.8 can be achieved by designing the secondary rotor to maximize the mechanical force extracted from the wind speed while keeping the bending moment at the root of the blades constant. A value of 0.27 for the aerodynamic power coefficient at a tip speed ratio of 3.13 is within the normal range for low-efficiency rotors designed to meet this standard.

[0019] A specific configuration that results in an efficient and effective turbine has the following characteristics:

[0020] The first (primary) rotor may rotate around a generally vertical axis of rotation and is configured to drive one or more secondary rotors having axes of rotation oriented generally horizontally.

[0021] The first rotor may have at least one upper blade and / or at least one lower blade.

[0022] At least one second rotor may be configured such that the power takeoff is either directly driven, i.e., without a gearbox, or semi-directly driven, i.e., with a single-stage gearbox.

[0023] The power takeoff may be configured to provide variable speed operation of the first and second rotors by the rotational speed of the first rotor, which increases with the wind speed until the rated wind speed is reached.

[0024] The first rotor may be configured to operate at a maximum value or a value close to the maximum value of its aerodynamic output coefficient at wind speeds below the rated wind speed.

[0025] The first rotor may be configured to have a maximum aerodynamic efficiency at a tip speed ratio value within the range of 4 to 5, which is the normal range of a vertical axis turbine.

[0026] The combined first rotor and second rotor may be configured to be more efficient in supplying mechanical force to the generator when at least one second rotor is operating inefficiently.

[0027] At least one second rotor may be configured to operate at a tip speed ratio within the range of 3 to 4 at wind speeds below the rated wind speed.

[0028] At least one second rotor may be configured to operate at a high value of the ratio of the aerodynamic output coefficient to the aerodynamic thrust coefficient, which has a value higher than 0.75 at wind speeds below the rated wind speed.

[0029] The first rotor and the second rotor may be configured such that, at wind speeds below the rated wind speed, the product of the tip speed ratio of the first rotor and the tip speed ratio of the second rotor is within the range of 14 to 16, and the tip speed of the second rotor is within the range of 0.4 to 0.6 times the speed of sound at the rated wind speed.

[0030] The characteristics of the first rotor, specifically the tip speed ratio and aerodynamic power coefficient, as well as the characteristics of the second rotor, specifically the tip speed ratio, aerodynamic power coefficient, and aerodynamic thrust coefficient, are all subject to strict limitations. Selecting the rated wind speed and rotational speed values ​​for the second rotor determines the values ​​of all remaining variables, including the area of ​​the first rotor and the total area of ​​the second rotor. While the rated wind speed itself should be limited to a range of 11 m / s to 13.5 m / s, and the nominal rotational speed of the generator should also be limited to above 20 Hz, sufficient design flexibility remains to obtain efficient and effective turbines as demonstrated by the first and second exemplary configurations.

[0031] The first rotor, at a wind speed below its rated speed, has a maximum aerodynamic power coefficient (C pmax ) or a coefficient close to it, for example, it may be configured to operate within 5%. Aerodynamic power coefficient (C pmax ) varies depending on the design and configuration of the first rotor and associated blades, but it will be understood that this can be easily determined by those skilled in the art for any given rotor and blade configuration / design.

[0032] At least one second rotor may be configured to operate such that the ratio of the aerodynamic power coefficient to the aerodynamic thrust coefficient is greater than 0.75 below the rated wind speed.

[0033] At least one second rotor may be configured to operate such that the tip speed ratio is in the range of 3 to 4 below the rated wind speed.

[0034] The first rotor and at least one second rotor may be configured such that the rated wind speed is in the range of 11 m / s to 13.5 m / s.

[0035] The first rotor and at least one second rotor may be configured such that the rotational speed of the second rotor is fast enough to drive power takeoff, for example, direct drive. However, if the rotational speed of the second rotor is too high, the ratio of the aerodynamic power coefficient to the aerodynamic thrust coefficient will be less than 0.75. The first rotor and / or at least one second rotor may be configured such that the product of the tip speed ratio of the first rotor and the tip speed ratio of the second rotor is in the range of 14 to 16, and the tip speed of the second rotor is in the range of 0.4 to 0.6 times the speed of sound at the rated wind speed.

[0036] The power takeoff may be configured such that the rotational speed of the generator exceeds 20 Hz at the rated wind speed.

[0037] The first rotor may have at least one upper blade and / or at least one lower blade.

[0038] The turbine may be configured to operate as a wind turbine and / or a tidal turbine. It will be understood that the axis of rotation of the first rotor may be vertical, within 10° of vertical, or at an angle closer to vertical than horizontal during use. If the angle of the first rotor is adjustable or modifiable, the axis of rotation of the first rotor may be vertical, within 10° of vertical, or at an angle closer to vertical than horizontal at at least some or all of the adjustable or modifiable angles of the rotor during use.

[0039] At least one second rotor may be configured to convert power from the rotation of the first rotor to the rotation of the second rotor. The second rotor may be configured such that at least 80% of the mechanical force extracted from the wind by the first rotor is supplied to the generator under all operating conditions, i.e., the turbine can have high efficiency during use.

[0040] The first rotor may be configured to have maximum aerodynamic efficiency at a tip speed ratio value within the normal range of 4 to 5 for a vertical-axis turbine.

[0041] At least one second rotor may be configured to drive a power takeoff system. For example, at least one second rotor may be configured to drive a generator. Each of one or more second rotors may be configured to drive a power takeoff system. The power takeoff system may include an AC generator. The AC generator can be a generator having several pole pairs, such as eight pole pairs or fewer, or four pole pairs or fewer. The power takeoff system can be a synchronous generator, for example, a 25Hz, four-pole-pair, 2.5MW synchronous generator.

[0042] The power takeoff system may generate power during use by the rotation of at least one second rotor. For example, the rotation of at least one second rotor during use may drive an associated power takeoff system, which may generate power such as electricity. The power takeoff system may be driven during use by the second rotor, for example, by direct drive.

[0043] Direct drive may mean that the power takeoff system rotates at the same speed as at least one second rotor. For example, each rotation of at least one second rotor in use may result in one rotation of the power takeoff system.

[0044] The power take-off system may be coupled to the second rotor, for example, by direct coupling. For instance, the coupling between at least one second rotor and the power take-off system may, advantageously, not involve a gearbox. In other words, the turbine can be a gearboxless or directly driven turbine.

[0045] The power takeoff may be configured to provide variable speed operation of the first and second rotors by the rotational speed of the first rotor, which increases with the wind speed until the rated wind speed is reached.

[0046] At least one second rotor may be provided on or included in at least one of the blades. The lower blades may have at least one second rotor or be provided with at least one second rotor. Each lower blade may have a second rotor or be provided with a second rotor. At least some of the lower blades may each have two or more second rotors or be provided with two or more second rotors. The turbine may be configured such that during use, for example, during the overall operation of the turbine, the second rotors are no more than 25 m above the ground or sea level.

[0047] At least one second rotor may have a second axis of rotation, such as a substantially horizontal axis of rotation during use. At least one second rotor may be a turbine, include a turbine, or be part of a turbine, such as a second turbine.

[0048] The turbine may comprise at least one support structure. At least one second rotor may be provided on or included in at least one support structure. At least one support structure may comprise at least one second rotor, or may be provided with at least one second rotor. Each of the at least one support structure may comprise a second rotor, or may be provided with a second rotor. At least some of the at least one support structure may comprise two or more second rotors, or may be provided with two or more second rotors.

[0049] There may be two or more second rotors. At least one second rotor may be mounted on or incorporated into the blades of the first rotor. At least one second rotor may be mounted on or incorporated into a separate rotating structure coupled to the first rotor, such that the separate rotating structure is rotatable by the first rotor, for example, by the rotation of the first rotor. At least some or all of the second rotors may be at the same distance along and / or relative position on the blades of the first rotor in which the second rotor is supported and / or incorporated. At least some or all of the second rotors may be at the tip and / or vicinity of the blades of the first rotor in which the second rotor is supported. The tip of the blade may be the end furthest from the axis of rotation of the first rotor, for example, the distal end of the blade. At least some or all of the second rotors may be at the same distance and / or radius from the first axis of rotation of the first rotor, for example, substantially perpendicular during use.

[0050] At least some or all of the second rotors may be in the same relative position with respect to the first axis of rotation of the first rotor. For example, at least some or all of two or more second rotors may be arranged rotationally symmetrically about the first axis of rotation of the first rotor. At least some or all of two or more rotors may follow the same path during use. At least some of two or more rotors may be arranged in a plane or configured to rotate in a circle substantially perpendicular to the first axis of rotation of the first rotor.

[0051] The first rotor may be driven during use by air (e.g., wind) or a fluid such as water acting on the upper and / or lower blades. The upper and / or lower blades may be configured, configurable, reconfigurable, or dynamically reconfigurable to maximize the efficiency of rotation of the first rotor.

[0052] At least some of the upper and / or lower blades may be aerodynamically and / or hydrodynamically designed. At least some of the upper and / or lower blades may be in the shape of a fin, at least partially, a plate, such as an airfoil or hydrofoil. For example, at least some of the upper and / or lower blades may be in the shape of a plate along at least a portion of the blade length.

[0053] The turbine may have two or more upper blades. The turbine may have two or more pairs of lower blades. The turbine may have the same number of upper blades as lower blades. The tips or distal ends of some or all of the upper blades and / or lower blades may be, for example, independent or not connected to other upper blades and / or lower blades.

[0054] The upper and lower blades may be configured, or can be configured, to at least partially equilibrate the turbine. For example, each upper blade may be paired with a lower blade, and each pair of upper and lower blades may lie in a plane. The plane in which the pairs of upper and lower blades lie may be parallel to the first axis of rotation of the first rotor. The upper and / or lower blades, such as the pairs of upper and lower blades, may be arranged symmetrically, such as rotationally, around the axis of rotation of the first rotor. The moments generated from the upper and lower blades to the main bearings act in opposite directions and thus partially cancel each other out.

[0055] The turbine may include a support or tower for supporting a first rotor. The first rotor may be mounted, for example, rotatably mounted and / or fixed to the top of the tower or support. The first rotor may be fixed and / or mounted to the tower by a first bearing. The first axis of rotation of the first rotor may be along the axis of the tower.

[0056] The first rotor may be rotatable on the first bearing. Blades, such as an upper blade and / or a lower blade, may be mounted on and / or fixed to the first bearing. The blades may be positioned and / or configurable to reduce and / or minimize the overturning moment acting on the first rotor and / or the first bearing. For example, the overturning moment acting on the first bearing from the upper blade may be substantially or completely canceled out by the overturning moment acting on the first bearing from the lower blade. The overturning moment acting on the first bearing by the upper blade during use may act in the opposite direction to the overturning moment acting on the first bearing by the lower blade during use.

[0057] At least one second rotor may comprise at least one second blade, for example, five second blades. At least one second blade may drive the rotation of at least one second rotor in use, for example, around each second rotation axis in use. At least one second blade and / or second rotor may be driven by the rotation of the first rotor. For example, the rotation of the first rotor in use may drive at least one second rotor through a fluid such as water and / or air, and the fluid may act on the second rotor and / or at least one second blade to rotate the second rotor. At least one second blade may be configurable to turn, rotate, and / or drive at least one second rotor.

[0058] At least one second rotor may have a rotor stiffness of 0.07 to less than 0.09, for example, 0.082. Rotor stiffness is the total area of ​​the rotor blades relative to the swept area of ​​the rotor.

[0059] At least some of the blades may be positioned and / or configurable to extract energy from the fluid acting on them. At least some of the upper blade and / or lower blade and / or second blades may be positioned and / or configurable to extract energy from the fluid acting on them.

[0060] At least some of the blades, such as the blades of the first rotor, may be pittable. Preferably, for example, at least some of the upper and / or lower blades of the first rotor may be pittable. At least some of the blades may be individually pittable. At least some of the blades may be full-span pittable. At least some of the blades may be substantially linear and / or linear. At least some of the blades may be pittable around their linear or longitudinal axis, for example, rotatable around their linear or longitudinal axis. The turbine may include actuators that can be operated to pitch the blades. The actuators may be located at the base of at least some of the blades, or coupled to their bases. For example, the actuators may be located at the ends of at least some of the blades closest to the first bearing, or coupled to their ends. Each blade may be operable by its respective actuator. Each upper and / or lower blade without the second rotor may be operable by an actuator. Each upper and / or lower blade without the second rotor may be pittable. The actuator may be replaceable and / or accessible during use, for example, by being easily accessible from the base of the turbine.

[0061] At least one second blade may be configured to extract energy from the fluid acting on those second blades.

[0062] The first rotor may include a support member. The support member may be attached to and / or fixed to the first bearing. Blades, such as the upper blade and / or lower blade, may be attachable to and / or fixed to the support member.

[0063] The support member may be substantially planar and / or longitudinal or elongated, or comprise such a support member. The support member may be a rod, a circle, a triangle, a square, or other polygon, or comprise such a support member. The support member may be a polygon, such as a regular polygon, having the same number of angles as the number of pairs of upper and lower blades. The support member may comprise a plurality of rods, each rod supporting at least one upper blade and / or at least one lower blade. The support member may be substantially horizontal and / or perpendicular to the axis of rotation of the first rotor in use.

[0064] The support member may have an aerodynamic and / or hydrodynamic shape. The support member may have a plate shape, at least partially, such as the shape of a wing and / or hydrofoil. For example, the support member may have a plate shape along at least a portion of one length of its rod. The support member may be rotationally symmetric.

[0065] For example, the upper and / or lower blades of the first rotor may be attached to and / or fixed to the ends of a support member, e.g., each end or its vicinity. For example, each upper blade may extend generally upward and / or outward from each end of the support member, and each lower blade may also extend generally downward and / or outward from each end of the support member. Since the upper blades extend from the support member, they may be angled or inclined away from each other. Since the lower blades extend from the support member, they may be angled or inclined away from each other. The upper and / or lower blades may be mounted on the support member such that their blades are rotationally symmetrical about the axis of rotation of the first rotor. The upper blades may be mounted on the upper surface of the support member in use. The lower blades may be mounted on the lower surface of the support member in use.

[0066] The turbine and / or the first rotor may be rotationally symmetric, for example, about the axis of rotation of the first rotor.

[0067] The upper blade may rotate on the tower during use. The lower blade may rotate around the tower during use. The upper blade and / or lower blade may protrude away from the tower. The tips of the upper blade and / or lower blade may be further away from the axis of rotation, which is perpendicular during use, than the base of the blade, which is mounted, mountable, and / or fixed or fixable, to, for example, a first bearing and / or support member.

[0068] The upper blade may protrude generally upward during use. The upper blade may protrude generally upward from the support member and / or the first bearing during use. The upper blade may protrude at an angle to the vertical during use. For example, the upper blade may be at an angle of less than 90° to the vertical during use, preferably between 0° and 45° to the vertical during use, more preferably between 15° and 40° to the vertical during use, and more preferably between 25° and 35° to the vertical during use.

[0069] The lower blade may protrude generally downward during use. The lower blade may protrude generally downward from the support member and / or the first bearing during use. The lower blade may protrude at an angle to the vertical during use. For example, the lower blade may be at an angle of less than 90° to the vertical during use, preferably an angle of 0° to 50° to the vertical during use, more preferably an angle of 25° to 50° to the vertical during use, and more preferably an angle of 45° to 50° to the vertical during use.

[0070] The lower blade may, during use, form a larger angle of acute with respect to the vertical than the angle of acute with respect to the vertical that the upper blade forms during use. The lower blade may, during use, form a smaller angle of acute with respect to the vertical than the angle of acute with respect to the vertical that the upper blade forms during use. The upper and lower blades may, during use, form the same angle of acute with respect to the vertical.

[0071] The upper blade may be longer than the lower blade. The lower blade may be longer than the upper blade. The length of the lower blade may be about two-thirds or less of the length of the upper blade.

[0072] The length of the upper blade may be up to 200m, preferably in the range of 50m to 150m, more preferably in the range of 80m to 120m, for example, 100m. The length of the lower blade may be up to 140m, preferably in the range of 35m to 105m, more preferably in the range of 55m to 75m, for example, 65m.

[0073] The tips of the upper and / or lower blades may have the same radius from the axis of rotation, which is substantially perpendicular during use. Alternatively, the tips of the upper and / or lower blades may have a different radius from the axis of rotation, which is substantially perpendicular during use.

[0074] At least one second rotor may be located on at least one upper blade and / or preferably on at least one lower blade, so that at least one second rotor may rotate around the axis of rotation of the first rotor with a radius up to the radius of the tip of the upper blade and / or the radius of the tip of the lower blade.

[0075] The upper blades may all be the same, for example, the same length and / or shape. The lower blades may all be the same, for example, the same length and / or shape. At least one second blade may all be the same, for example, the same length and / or shape.

[0076] At least some or each of the upper blades may differ from at least some or each of the other upper blades. For example, there may be two first upper blades that are the same as each other, and two second upper blades that are the same as each other but different from the first upper blades. Some upper blades may differ from some other upper blades in at least one or more or all of their shape, size, length, angle to the vertical, number of second rotors, and / or whether they are pitting-capable.

[0077] At least some or each of the lower blades may differ from at least some or each of the other lower blades. For example, there may be two first lower blades that are the same as each other, and two second lower blades that are the same as each other but different from the first lower blades. Some lower blades may differ from some other lower blades in at least one or more or all of their shape, size, length, angle to the vertical, and number of second rotors.

[0078] The first rotor may be equipped with a power takeoff system. The first rotor may be equipped with two or more power takeoff systems, such as two or more generators.

[0079] The first bearing may, advantageously, not have to include a power take-off system. The first bearing may, advantageously, not have to include a drivetrain such as a conventional turbine drivetrain.

[0080] At least one second rotor may be removable and / or replaceable during use, for example, to minimize the time and effort spent on maintenance and repair. At least one secondary rotor may be accessible, such as being easily accessible when the turbine is upright and / or in use. For example, at least one second rotor may be accessible from, for example, the ground, sea level, or the height of the tower base when the turbine is upright and / or in use, and for example, at least one second rotor may be no more than 25 m from the ground or sea level during use, or may always be no more than 25 m. The turbine may be considered upright when the axis of rotation of the first rotor is substantially vertical. At least one second rotor may be located at a low height, for example, substantially lower than the first bearing and / or support members.

[0081] The turbine may be connectable to a power grid. The power grid may include rechargeable power sources such as cells and / or batteries. The power grid may include power grids such as the national power grid.

[0082] The turbine may be equipped with one or more wind speed and / or wind direction measuring instruments, such as an anemometer, LiDAR, wind vane, and / or similar.

[0083] The turbine may be configured to determine the direction of the prevailing wind using at least one second rotor and associated power takeoff system. When at least one second rotor is rotating toward the wind, the power generated is in an increased state and / or maximum, and when it is rotating toward the wind, the power generated is in a decreased state and / or minimum. Thus, the turbine may be operable to analyze the fluctuations in power generated by at least one second rotor and associated power takeoff system in order to determine the direction of the prevailing wind.

[0084] The turbine may be equipped with a power connector. The power connector may include a transformer, such as a rotary transformer or a non-rotating or conventional transformer, which may be connected via slip rings or the like. The power connector may advantageously include a variable frequency transformer or an electrical connection. The power connector may be housed in and / or near the tower, for example, in and / or near the base of the tower, or in the turbine hub. The power connector may connect the turbine to an external power system, such as a grid, for example, the national power grid. The power connector may be accessible, such as being easily accessible from the base of the tower in use.

[0085] The turbine may include a power converter and / or power electronics. The power converter and / or power electronics may connect the power takeoff system to a power connector. The power converter and / or power electronics may regulate the power passing through the power takeoff system, the power connector, and / or between the power takeoff system and the power connector.

[0086] Power converters and / or power electronics may control power connectors. For example, the frequency of AC power supply to a rotary transformer may be controlled to achieve a high-efficiency connection to an external power system with a connection rate higher than 98%.

[0087] The power converter and / or power electronics may control the turbine. For example, the power electronics may control power takeoff and the rotational speed of the generator by using the frequency of the AC power supply to the generator, or by appropriately controlling and / or changing that frequency. For example, below the rated wind speed, the second rotor speed may be controlled to achieve maximum power generation, and above the rated wind speed, the second rotor speed may be controlled to achieve rated power generation.

[0088] The turbine may include a pitch actuator. The pitch actuator may pitch at least some of the blades. The pitch actuator may control at least some of the blades, for example, at least the upper blades of the first rotor, to pitch cyclically in accordance with the rotational position of the blades relative to the direction of the prevailing wind. For example, the pitch actuator may be configured to control the pitch of at least some of the blades to maximize energy when the wind speed is below the rated speed, to regulate the rotational speed when the wind speed is above the rated speed, and / or to provide overspeed protection. The pitch actuator may be housed in and / or near the roots of the upper rotor blades. The pitch actuator may be accessible, such as being easily accessible from the base of the tower in use.

[0089] The turbine's center of mass may be located at a lower position during operation. For example, power connectors and power electronics may be housed at and / or near the base of the tower, thereby lowering the turbine's center of mass and bringing it closer to the base of the tower during operation.

[0090] The tower may be supported by a platform. The platform may be levitable and / or tetherable. The turbine may be configured to reduce the weight and / or size of the platform compared to a conventional floating turbine platform.

[0091] According to a second embodiment, there is a method for generating electricity using the turbine of the first embodiment.

[0092] The power generated may be generated by the rotation of at least one second rotor and / or extracted from the rotation of at least one second rotor.

[0093] The method may include exposing the turbine to a fluid, which may act on the upper and / or lower blades to drive a first rotor. The fluid may be air and / or water. For example, wind and / or wave energy may push the upper and / or lower blades to drive the first rotor. The upper and / or lower blades may be configured to extract energy from the fluid acting on them.

[0094] The method may include configuring the upper and / or lower blades such that the tip speed ratio and the rotational speed of the first rotor are high during use, for example, such that the tip speed ratio is in the range of 4 to 5.

[0095] The method may include configuring the first rotor and / or at least one second rotor such that the tip speed ratio and rotational speed are low during use, for example, such that the tip speed ratio is in the range of 3 to 5. The maximum tip speed of at least one second blade during use may be high, such as 160 m / s to 200 m / s at the rated wind speed, for example, 180 m / s.

[0096] The method may include arranging the turbine such that the rotation of a first rotor through a fluid drives at least one second rotor through a fluid, for example, air or water. The fluid may act on at least one second rotor to drive at least one second rotor. For example, the fluid may act on the second blades of at least one second rotor to rotate at least one second rotor.

[0097] The rotation of at least one second rotor may drive at least one power takeoff system, which may generate power, for example, electricity. At least one second rotor may drive the power takeoff system without a gearbox or multipole generator. For example, the rotation of at least one second rotor may directly drive at least one power takeoff system. The rotation of at least one second blade in use may directly drive the power takeoff system.

[0098] The power generated by at least one second rotor may be cyclic, sinusoidal, and / or periodic. For example, at least one second rotor may be driven either against the fluid flow or in accordance with the fluid flow when the first rotor is rotating. The power generated by at least one second rotor may be greater when at least one second rotor is driven against the fluid flow than when at least one second rotor is driven in accordance with the fluid flow. Cyclic, sinusoidal, and / or periodic power generated by at least one second rotor can increase the efficiency of the power generated by the second rotor. For example, cyclic, sinusoidal, and / or periodic power generated by at least one second rotor can increase the energy extracted from the fluid acting on at least one second rotor. Amplitude A and mean flow velocity In the case of sinusoidal fluctuations in the fluid velocity on the second rotor of TIFF0007864483000004.tif7170, the extracted energy is coefficient It increases by TIFF0007864483000005.tif13170. The determination of cyclic, sinusoidal, and / or periodic power generated by at least one second rotor may be used to determine the direction of the prevailing wind.

[0099] The cyclic, sinusoidal, and / or periodic power generated by at least one second rotor may be used to calculate and / or determine the rotational speed and / or frequency of the first rotor.

[0100] The power generated by the first rotor may be cyclic, sinusoidal, and / or periodic. The point of maximum power generation by the first rotor may coincide with the point of minimum power generation by at least one second rotor. The cyclic, sinusoidal, and / or periodic nature of the power generated by at least one second rotor may be reduced by the phase-shifted cyclic, sinusoidal, and / or periodic power generated by the first rotor.

[0101] According to a third aspect, there is a method for controlling the turbine of the first or second aspect.

[0102] A turbine may be configured to have maximum efficiency under specific conditions. For example, when a fluid is blowing against the turbine at a specific desired speed or within a specific desired speed range, the turbine may be most efficient at extracting energy from the fluid acting against it. The turbine may be rated to produce maximum power under these conditions. The turbine may be rated or configurable to extract maximum energy from the fluid acting against it under these conditions.

[0103] For example, when the turbine is operating as a wind turbine, it may be configured to operate most efficiently at wind speeds below its rated wind speed, ranging from 11 m / s to 13.5 m / s. The turbine may also be configured to generate megawatts of power, for example, several megawatts, such as up to 10 MW, or 5.9 MW.

[0104] When the turbine is operating as a wind turbine, the method may include configuring at least one second rotor to operate most efficiently at an effective wind speed of up to 65 m / s, for example 59 m / s. The effective wind speed of at least one second rotor is the sum of the wind speed and the relative speed of at least one second rotor when the first rotor is rotating. The method may also include configuring at least one second rotor to generate several megawatts of power, such as up to 5 MW, for example 2.5 MW.

[0105] The method may include pitching at least some of the blades, for example, upper blades and / or lower blades without a second rotor. The method may include pitching the upper blades. The method may include pitching the upper blades so that the orientation of each upper blade is fixed to the fluid flow as the first rotor rotates. For example, the upper blades may be pitched cyclically. At least some of the blades may be pitched at the same frequency as the rotation of the first rotor. At least some of the blades may be pitched when the turbine is operating below its maximum energy rating, for example, when the wind is blowing against the turbine below a certain desired speed or a certain desired speed range. Pitching at least some of the blades, such as the upper blades, may increase the energy generated by the turbine. For example, pitching at least some of the blades, such as the upper blades, may increase the energy extracted from the wind blowing against the turbine.

[0106] At least some of the blades may be pitched to increase or optimize the efficiency of energy transfer from the fluid acting on the vertical axis turbine to the turbine, compared to the energy transfer from the fluid to the vertical axis turbine when the blades are not pitched and / or when the blades have a fixed pitch relative to the turbine's rotation. For example, at least some of the blades may be pitched to increase or optimize the rotational speed of the first rotor. When the turbine is operating as a wind turbine, at least some of the blades may be pitched to fix the orientation of those blades to the wind. For example, at least some of the blades may be cyclically pitched to maximize energy transfer from the wind to those blades.

[0107] The method may include determining the direction of the fluid flow acting on the turbine. The direction of the fluid flow may be determined from the position of the first rotor when the cyclic, sinusoidal, and / or periodic power generated by at least one second rotor is maximum. For example, when the power generated by at least one second rotor is maximum, at least one second rotor is directly driven by the first rotor to the fluid flow.

[0108] The pitching speed and / or frequency of at least some of the upper and / or lower blades can be based on the cyclic power generated by at least one second rotor. For example, at least some of the upper and / or lower blades, such as the upper blades, may pitch at the same frequency as the power generated by at least one second rotor.

[0109] At least some of the blades may be pitched to reduce the efficiency of energy transfer from the fluid acting on the turbine to the turbine compared to the energy transfer from the fluid to the turbine when the blades are not pitched and / or when the blades have a fixed pitch relative to the rotation of the turbine. For example, at least some of the blades may be pitched to reduce the rotational speed of the first rotor and / or to stop the rotation of the first rotor. At least some of the blades may be pitched to provide overspeed protection. For example, at least some of the blades may be pitched to prevent the first rotor from rotating too fast, for example, to prevent damage to the first rotor and / or the first bearing.

[0110] The method may include controlling the rotor speed of at least one second rotor. The method may also include controlling the rotor speed of each second rotor individually. The rotor speed of at least one second rotor may be controlled by controlling the frequency of the voltage across the ends of at least one second rotor, for example, across the power take-off system of at least one second rotor. The drag force of at least one second rotor may be used to control and / or influence the rotational speed of the first rotor.

[0111] The rotor speed of the first rotor may be variable and controlled by collectively pitching the upper blades when the turbine is operating beyond its maximum energy rating, for example, when the wind is blowing against the turbine beyond a specific desired speed or a specific desired speed range. The upper blades may be pitched to control the rotor speed of the first rotor in response to relatively low frequency changes in wind speed. The rotor speed of at least one second rotor may be controlled, for example, by controlling the frequency of the voltage across at least one second rotor in response to relatively high frequency changes in wind speed.

[0112] When the wind is blowing against the turbine at a specific desired speed or a specific desired speed range, it may be possible to store a portion of the power of the rotating first rotor as a reserve in, for example, a flywheel, compressed air reservoir, electrochemical cell, and / or similar. When the wind speed decreases, power may be drawn from the reserve later.

[0113] The method may include monitoring the power generated by the turbine. The method may also include controlling the turbine in response to the power generated by the turbine. The power generated by the turbine may be monitored by power electronics, and / or the control of the turbine may be performed by power electronics. The power electronics may be controlled by a programmable computer.

[0114] It should be understood that the individual features and / or combinations of features defined above in accordance with any aspect of the present invention, or defined below in relation to any particular embodiment of the present invention, may be used separately and individually, alone, or in combination with other defined features in other aspects or embodiments of the present invention.

[0115] Furthermore, the present invention is intended to cover apparatus configured to perform any of the features described herein in relation to methods of using or producing and / or using or manufacturing any of the features of the apparatus described herein.

[0116] Next, at least one embodiment of the present invention will be described simply as an example with reference to the accompanying drawings. [Brief explanation of the drawing]

[0117] [Figure 1] This is a perspective view of a vertical-axis turbine. [Figure 2] This is a plan view of a vertical-axis turbine. [Figure 3] This is a diagram showing a wind power plant with a vertical-axis turbine. [Figure 4] This diagram shows the planar shapes of the upper blade, the lower blade, and the second blade. [Modes for carrying out the invention]

[0118] Throughout the following description, the same reference number will be used to identify the same part.

[0119] Figure 1 shows a vertical-axis turbine 5 comprising a tower 10 and a first rotor 12. The first rotor 12 is mounted to the tower 10 at a first bearing 13. The first rotor 12 rotates on the first bearing 13. The first bearing 13 is located at the top of the tower 10. The first rotor 12 has a support member 15. The first rotor 12 is mounted to the first bearing 13 at the center of the support member 15.

[0120] Two upper blades 20 are attached to a support member 15, and the upper blades 20 protrude diagonally upward away from the tower 10. Two lower blades 25 are attached to the support member 15, and the lower blades protrude diagonally downward away from the tower 10. The upper blades 20 and lower blades 25 are attached to the support member 15 by mounting points 30. The mounting points 30 of the upper blades 20 include actuators that can pitch the upper blades 20. Since the first rotor 12 rotates relatively slowly during use, the pitching of the upper blades 20 is also relatively slow, and therefore the duty cycle of the actuator is low. Therefore, the maintenance cost of the actuator is low.

[0121] Each lower blade 25 includes a second rotor 35 and an associated generator 37 at its end. The second rotor 35 includes a second blade 40. Each second rotor 35 is configured to drive the associated generator 37. The second rotors 35 are oriented in opposite directions, so that when the first rotor 12 rotates, both second rotors 35 are driven in the same direction and along the same path during use.

[0122] The upper blades 20, lower blades 25, and support members 15 are configured such that when wind blows toward the vertical axis turbine 5, the first rotor 12 rotates clockwise around the first bearing 13 (however, it will be understood that a configuration in the opposite direction of rotation may be realized). This rotation drives the second rotor 35 via air. The air acts on the second blades 40 of the second rotor 35, causing the second rotor 35 to rotate. This rotation then supplies power to the generator 37, which is driven by the second rotor 35. Thus, the first rotor 12 acts to rotate the second rotor 35, and the rotation of the second rotor 35 drives the generator 37. Therefore, it is primarily the rotation of the second rotor 35, not the rotation of the first rotor 12, that drives the generator 37.

[0123] The second rotor 35 of the horizontal axis is different from the usual, and in contrast to conventional horizontal axis wind turbines, it has a low C P Value and high C P vs C T The first rotor 25 is designed to operate at a low blade tip speed ratio. The second rotor 35 is also designed to operate at a fast blade tip speed of about 160 m / s. If the blade tip speed of the second rotor 25 is too high, the second rotor 35 will be unsuitable for the required high lift and low drag aerodynamic characteristics.

[0124] Because the second rotor operates at a relatively fast blade tip speed due to its relatively short second blades 40, the second rotor 35 rotates at high speed, for example, up to 50 rad / s. As a result, each second rotor 35 can directly drive its associated generator 37 without the need for a gearbox or multipole generator. This simplifies the second rotor 35 and consequently reduces its cost.

[0125] Since the first bearing 13 does not have a power take-off system, a large, heavy, and expensive drivetrain is not required for the first bearing 13. This significantly simplifies the vertical shaft turbine 5 and drastically reduces its cost.

[0126] The power electronics 41 are located at the base of the tower 10 and are easily accessible. Because the power electronics 41 are easily accessible, maintenance costs are relatively low. The power electronics 41 are used to monitor and control the vertical axis turbine 5 and the power generated by the vertical axis turbine 5.

[0127] The power electronics 41 is connected to the power connector 42. The power connector 42 connects the vertical-axis turbine 5 to a power grid 43, such as the national power grid.

[0128] Since the power electronics 41 are located at a low height, they can be easily accessed from the height of the base of the tower 10. This facilitates maintenance and reduces maintenance costs.

[0129] Figure 2 is a plan view of the vertical-axis turbine 5 shown in Figure 1. The rotation axis 45 of the first rotor is indicated by a dashed line.

[0130] The tips of the upper blade 20 and the lower blade 25 are at the same distance from the rotation axis 45 of the first rotor and rotate at the same radius from the rotation axis 45 of the first rotor. The second rotor 35 is at the tip of the lower blade 25. The second rotor 35 is at the same height from the base of the tower 10. The second rotor 25 is at the same distance from the rotation axis 45 of the first rotor and rotates at the same radius from the rotation axis 45 of the first rotor.

[0131] The second rotor 35 is positioned at a low height (e.g., 25m or 20m or less from the ground or sea level) so that it can be easily accessed from the height of the base of the tower 10. The second rotor 35 is also lightweight and replaceable so that it can be easily replaced. This simplifies maintenance and reduces maintenance costs.

[0132] The upper blade 20 forms a smaller acute angle with respect to the vertical than the lower blade 25. The upper blade 20, the lower blade 25, and the support member 15 are all in a plane.

[0133] Figure 3 shows an offshore wind farm 105 with a vertical-axis turbine 5. The tower 10 supports a first rotor 12 above the sea 110. The tower 10 may be supported by a floating platform or fixed to the seabed.

[0134] The lower blade 25 protrudes downward toward the sea 110, and the second rotor 35 is located at the tip of the lower blade 25. Therefore, the second rotor 35 is at a relatively low height and relatively close to the surface of the sea 110. Thus, since the second rotor 35 is not in a significantly high position, maintenance and / or replacement of the second rotor 35 from the boat is relatively easy.

[0135] Figure 4a shows the planar shapes of the upper blade 20 and the lower blade 25. Both the upper blade 20 and the lower blade 25 are thicker at the base than at the tip. The base of the lower blade 25 is thicker than the base of the upper blade 20. The upper blade 20 is longer than the lower blade 25.

[0136] Figure 4b shows the planar shape of the second blade 40. The planar shape of the second blade 40 is similar to that of the lower blade 25, but the second blade 40 is much smaller than the lower blade 25.

[0137] In the example above, the first and second rotors are configured so that power takeoff is achieved by direct drive without the need for a gearbox or multi-pole generator. The first and second rotors are configured to maximize the efficiency of power conversion, in which the mechanical force in the first rotor is converted into mechanical force in the second rotor.

[0138] While various examples have been provided above, it will be understood that the present invention is not limited to these specific examples and is defined by the claims. For example, it will be understood by those skilled in the art that the turbine may be scaled up or down to different sizes, and the sizes given herein are merely illustrative. Similarly, it will be understood that geometric terms should be interpreted in a purposeful manner. For example, the fact that a blade is a three-dimensional object and that a blade can be linear and / or in a straight line does not preclude, for example, tapering along the length of the blade. The pair of upper and lower blades can be planar, but it will be understood that the pair of upper and lower blades can be planar as an actual three-dimensional object, rather than existing only in a two-dimensional plane. The axis of rotation of the first rotor has been described as substantially perpendicular during use, and it will be understood that this description refers to the axis of rotation during use, which may deviate from perfect perpendicularity during use, for example, at an angle of 15° or less with respect to the perpendicular.

[0139] Those skilled in the art will understand that the turbines disclosed above are equally applicable as onshore and offshore wind turbines, and that the described turbines may also be used in other locations, for example, as tidal turbines. Furthermore, it will be understood that if the turbines disclosed above are used as wave turbines, minor modifications to the embodiments shown in the figures may be necessary, and such modifications are within the scope of this disclosure. For example, the first rotor in Figure 1 may need to be inverted horizontally, resulting in the second rotor being positioned on the upper blades rather than the lower blades. This would bring the second rotor closer to the water surface, resulting in the advantages of easier access and reduced maintenance costs.

Claims

1. A vertical-axis turbine comprising a first rotor and at least one second rotor, The first rotor is configured to rotate around a first rotation axis, the first rotation axis being vertical, The first rotor includes at least one upper blade and at least one lower blade, wherein the at least one second rotor is attached to the tip of each lower blade. The at least one second rotor is operable to drive the power take-off system, The at least one second rotor, or each of the second rotors, has a tip speed ratio in the range of 3 to 4 when used at the rated wind speed. The first rotor and the at least one second rotor have a combined tip velocity ratio in the range of 14 to 16 at wind speeds below the rated speed. The at least one second rotor, when used below the rated wind speed, has an aerodynamic power coefficient (C P ) and the aerodynamic thrust coefficient (C Ｔ The ratio to ) is greater than 0.

75. Vertical-axis turbine.

2. The first rotor has a tip speed ratio in the range of 4 to 5 when used at wind speeds below the rated speed. The combined tip speed ratio of the first rotor and the at least one second rotor at or below the rated wind speed is 15. The first rotor, when used at wind speeds below the rated speed, has an aerodynamic power coefficient within 5% of the maximum value (C pmax). The at least one second rotor has a maximum blade tip velocity in the range of 0.4 to 0.6 times the speed of sound when used at the rated wind speed, and The aforementioned rated wind speed is within the range of 11 m / s to 13.5 m / s during use. One or more of the following, or each of them, The vertical-axis turbine according to claim 1.

3. The vertical-axis turbine according to claim 1 or 2, wherein the power take-off system comprises a generator.

4. The vertical-axis turbine according to any one of claims 1 to 3, wherein the at least one second rotor comprises at least one second blade, and the at least one second blade directly rotates the power takeoff system during use.

5. A vertical-axis turbine according to any one of claims 1 to 4, wherein the first rotor is rotatable on a first bearing, and the first rotor includes at least one upper blade that protrudes substantially upward from the first bearing during use, and at least one lower blade that protrudes substantially downward from the first bearing during use.

6. The vertical-axis turbine according to claim 5, wherein the at least one second rotor is provided on or included in one or more of the lower blades.

7. The vertical-axis turbine comprises a tower supporting the first rotor, and the first bearing is located at the top of the tower. The at least one upper blade protrudes generally upward away from the tower, The at least one lower blade protrudes generally downward, away from the tower. The vertical-axis turbine according to claim 5 or 6.

8. A vertical-axis turbine according to claim 5 or 7, comprising two or more upper blades and two or more lower blades, wherein the upper blades and / or the lower blades are rotationally symmetric about the first axis of rotation of the first rotor.

9. A vertical-axis turbine according to any one of claims 5 to 8, wherein, during use, the overturning moment of the at least one upper blade acting on the first rotor acts in the opposite direction to the overturning moment of the at least one lower blade acting on the first rotor.

10. A vertical-axis turbine according to any one of claims 5 to 9, wherein at least one of the at least one upper blade and / or at least some of the at least one lower blade are pittable.

11. The vertical-axis turbine according to any one of claims 5 to 10, wherein the upper blade and / or the lower blade are not connected to other upper blades and / or lower blades at their distal ends or tips.

12. A vertical-axis turbine according to any one of claims 1 to 11, wherein one or more of the power take-off systems are driven directly by an associated second rotor without being driven via a gearbox, and / or the first rotor rotates on a first bearing, the first bearing not having a drivetrain.

13. The vertical-axis turbine according to any one of claims 1 to 12, wherein the second rotor is configured to be no more than 25 m above the ground or sea level during use and throughout the operation of the vertical-axis turbine.

14. The vertical-axis turbine according to any one of claims 1 to 13, wherein the vertical-axis turbine comprises a variable frequency transformer or electrical connection, and the second rotor and / or the power take-off system is controllable by appropriately controlling the variable frequency transformer or the electrical connection.

15. The vertical-axis turbine according to any one of claims 1 to 14, wherein the vertical-axis turbine is operable to analyze fluctuations in power generated by the at least one second rotor and associated power takeoff system in order to determine the direction of the prevailing wind.

16. A method for generating output using a vertical-axis turbine according to any one of claims 1 to 15, The fluid acts on the upper and / or lower blades to drive the first rotor, and as a result The rotation of the first rotor drives at least one second rotor via the fluid, A fluid acts upon the at least one second rotor to drive the at least one second rotor. Install a vertical-axis turbine. Methods that include...

17. The method according to claim 16, wherein the fluid is air and / or water.

18. The method according to claim 16 or 17, wherein the generation of output is caused by the rotation of the at least one second rotor and / or taken out from the rotation of the at least one second rotor.

19. The method according to any one of claims 16 to 18, wherein the output generated is electric.

20. A method for controlling the rotation of a first rotor of a vertical-axis turbine in use according to any one of claims 1 to 15, or a method for controlling the power generated by the method according to any one of claims 16 to 19, Pitching at least some of the blades, and / or Changing the frequency of an electrical connection or variable frequency transformer coupled to a power takeoff system. Methods that include...

Images