Floating wind power generation system

Abstract

To obtain an aquatic wind power generation system for improving power generation efficiency.SOLUTION: An aquatic power generating system includes a hull for navigating on water and a kite connected to the hull through a tether, and comprises: a power generation system repeatedly carrying out a power generation mode A in which wind power is generated by unwinding operation of the tether when the kite ascends and a retraction mode B in which the tether is retracted by winding operation of the tether; and a controller for carrying out control to direct a bow of the hull in a leeward direction in the retraction mode B.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an offshore wind power generation system.

Background Art

[0002] Patent Document 1 discloses an offshore wind power generation system that generates wind power by flying a kite via an engine from an offshore floating body such as a hull equipped with a propulsion device. In this offshore wind power generation system, a power generation mode of generating wind power by paying out a tether connected to the kite and a recovery mode of recovering the tether by winding up the tether are alternately performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above offshore wind power generation system in which the power generation mode and the recovery mode are alternately performed, when the kite is recovered against the wind direction during the recovery mode, the energy required for winding up the tether increases, resulting in poor cost performance and room for improvement.

[0005] In consideration of the above facts, an object of the present invention is to obtain an offshore wind power generation system capable of improving the overall power generation efficiency.

Means for Solving the Problems

[0006] The floating wind power generation system according to claim 1 comprises a hull that sails on the water and a kite connected to the hull via a tether, and the power generation system alternately performs a power generation mode in which wind power is generated by the unwinding of the tether as the kite flies, and a retrieval mode in which the tether is retrieved by the winding of the tether, and in the retrieval mode, the bow of the hull is controlled to face downwind. Furthermore, when the direction of travel of the hull is at an angle to the direction of the natural wind, the relative speed to the hull, which is the combined speed of the hull's travel speed and the wind speed of the natural wind, is controlled so that it is perpendicular to the hull's travel speed. It comprises a control unit and Here, "orthogonal" includes not only perfectly orthogonal connections but also a certain degree of tolerance.

[0007] In the floating wind power generation system according to claim 1 of the present invention, a power generation mode is performed alternately, in which wind power is generated by the tether being extended as the kite flies, and a retrieval mode is performed in which the tether is retrieved by the tether being retracted. In the retrieval mode, the bow of the vessel is controlled to face downwind. Therefore, when retrieving the tether, the bow of the vessel faces downwind, which reduces the relative wind speed to the kite. This reduces the energy consumption required for the tether retraction operation, thereby increasing the overall power generation efficiency.

[0009] Also, Claim 1 In the floating wind power generation system according to the present invention described herein, when the direction of travel of the hull is at an angle with the direction of the natural wind, the speed of the hull is controlled so that the relative speed to the hull is perpendicular to the speed of the hull, thus the relative speed to the hull can be minimized. As a result, by minimizing the relative speed to the hull, the relative wind speed to the kite can be minimized, and the energy consumption required for the tether winding operation can also be minimized, thereby increasing the overall power generation efficiency.

[0010] Claim 2The floating wind power generation system according to the present invention, as described in claim 1, wherein in the recovery mode, the control unit controls the direction of the bow so that, when viewed from above the hull, the vector direction of the tension of the kite coincides with the direction of travel of the hull. Here, "coincides" means not only a perfect coincidence but also includes a certain tolerance.

[0011] Claim 2 In the floating wind power generation system according to the present invention described herein, when retrieving the tether, the hull moves in the direction of the kite tension vector, so the relative wind speed to the kite can be efficiently reduced. As a result, the energy consumption required for the tether winding operation can also be efficiently reduced, and the overall power generation efficiency can be efficiently increased.

[0012] Claim 3 The floating wind power generation system according to the present invention described in claim 1 or claim 2 In the configuration described above, the control unit controls the bow of the hull to face into the wind during the power generation mode.

[0013] Claim 3 In the floating wind power generation system according to the present invention described herein, when generating wind power using a kite, the bow of the vessel is facing into the wind, so the vessel moves against the natural wind. Therefore, the relative wind speed to the kite can be increased, and by increasing the tether payout speed, the amount of power generated can be increased.

[0014] Claim 4 The floating wind power generation system according to the present invention described herein is Claim 1 or Claim 2 In the configuration described above, the control unit controls the direction of the bow in the power generation mode so that, when viewed from above the hull, the direction of the natural wind and the direction of the hull's movement are perpendicular. Here, "perpendicular" means not only perfectly perpendicular but also includes a certain tolerance.

[0015] Claim 4In the offshore wind power generation system according to the present invention described in [reference], by making the advancing direction of the hull orthogonal to the direction of the natural wind, the advancing direction of the hull can be made the same as the direction of the wind beam, so the advancing speed of the hull can be increased. As a result, the propulsive force of the hull increases, so the lateral force applied to the hull increases, and the tension of the kite can be reduced. Thereby, the relative speed to the kite can be efficiently increased, so that the payout speed of the tether can be increased, and the power generation amount can be increased.

Advantages of the Invention

[0016] As described above, the offshore wind power generation system according to the present invention has an excellent effect of being able to improve the overall power generation efficiency.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic configuration diagram schematically showing the configuration of the offshore wind power generation system according to the first embodiment of the present invention. [Figure 2] It is a course diagram showing the movement locus of the hull when the hull moves downwind. [Figure 3] It is a diagram showing three-dimensionally the maximum flight range line within which the kite can fly. [Figure 4] It is a diagram showing two-dimensionally the maximum flight range line within which the kite can fly. [Figure 5] It is a plan view showing the relationship between the wind direction and the force applied to the hull in the power generation mode. [Figure 6] It is a diagram showing the relationship between the relative wind speed to the hull, the advancing speed, and the wind speed. [Figure 7] It is a plan view showing in coordinates the relationship between the relative wind speed and the propulsive force with respect to the sail angle. [Figure 8] It is a graph showing, for each sail angle, the relationship between the relative angle between the Xo axis and the relative wind speed, and the aerodynamic coefficient. [Figure 9] It is a plan view showing the relationship between the wind direction and the force applied to the hull in the recovery mode. [Figure 10]This diagram shows the relationship between relative wind speed to the hull and the ship's speed and wind speed. [Figure 11] This is a navigation chart showing the trajectory of a ship's movement while maintaining its position. [Figure 12] This is a navigation chart showing the trajectory of a ship as it moves into the wind. [Figure 13] This is a navigation chart showing the trajectory of a ship's movement when it moves laterally relative to natural wind. [Modes for carrying out the invention]

[0018] The floating wind power generation system 10 according to one embodiment of the present invention will be described below with reference to Figures 1 to 13. In each figure, the arrow UP indicates the upper side in the vertical direction of the hull, and the arrow FR indicates the front in the longitudinal direction of the hull. The arrow W indicates the width direction of the hull. In addition, in each figure, only some of the reference numerals are listed, and others are omitted, prioritizing the readability of the drawings.

[0019] As shown in Figure 1, the floating wind power generation system 10 comprises a sailing vessel 12 having a hull 16 that operates on the sea, lakes, rivers, etc., a power generation system 20 that generates electricity, and a control device 30 that performs steering control of the sailing vessel 12 and drive control of the power generation system 20. The control device 30, which acts as the control unit, is not shown in the figure, but includes various electrical equipment (electrical components) and control units. The control unit consists of a CPU (Central Processing Unit: processor), ROM (Read Only Memory), RAM (Random Access Memory), storage, a communication interface (communication I / F), and an input / output interface (input / output I / F). A generator 22A, which will be described later, is connected to the input / output I / F.

[0020] (Configuration of power generation system 20) The power generation system 20 includes, for example, a power generator 22 mounted on the hull 16 and a kite 26 connected to the hull 16 via a tether 24. The kite 26 is made up of a kite body and is moored to the hull 16 by the tether 24.

[0021] The power generation device 22 comprises a generator 22A and a winch 22B. A rotating shaft body 22C is connected to the rotating shaft of the generator 22A, and the generator 22A rotates the rotating shaft body 22C based on a command from the control device 30. The winch 22B uses the rotating shaft body 22C as its axis of rotation, and a tether 24 is wrapped around the rotating shaft body 22C. The power generation device 22 unwinds the tether 24 from the winch 22B or winds the tether 24 onto the winch 22B by rotating the rotating shaft body 22C clockwise or counterclockwise.

[0022] In the power generation system 20, when the kite 26 rises, the tether 24 is extended from the winch 22B in conjunction with the rise of the kite 26. This extension of the tether 24 causes the rotating shaft 22C to rotate, and the rotation of the generator 22A rotates in conjunction with the rotation of the rotating shaft 22C, thereby generating electricity. The amount of electricity Q generated by the rise of the kite 26 is the value obtained by multiplying the tension of the tether 24 by the extension speed of the tether 24.

[0023] Then, once the tether 24 has been extended to a predetermined length, or after a predetermined time has elapsed, the control device 30, based on a command, rotates the rotating shaft 22C in the opposite direction, i.e., in the direction to rewind the tether 24, via the generator 22A, for example, by a motor (not shown). As a result, the tether 24 is rewinded, and the kite 26 descends.

[0024] As shown in Figure 2, the power generation system 20 alternately performs two modes: power generation mode A, in which wind power is generated by the unwinding of the tether 24 as the kite 26 flies, and retrieval mode B, in which the tether 24 is retrieved by the winding of the tether 24. In this embodiment, the time required for power generation mode A in the power generation system 20 is set to be longer than the time required for retrieval mode B, so that the amount of power generated Q in power generation mode A is greater than the amount of power consumed in retrieval mode B. Also, as shown in Figure 2, in the power generation system 20, wind power generation in power generation mode A and retrieval of the tether 24 in retrieval mode B are performed while the sailboat 12 is moved F in order to increase power generation efficiency. This movement F will be explained in detail later.

[0025] (12 components of a sailing ship) As shown in Figure 1, the sailing ship 12 has a hull 16 equipped with sails 14. The hull 16 is the main body of a floating vessel configured to float on the water surface S in the sea, lakes, rivers, etc., and generates buoyancy, which is an upward force equivalent to the weight of the water displaced by the bottom of the hull 16 located in the water. The hull 16 also has a rudder 18 as a steering device and a lateral force generating unit 40 located below the water surface S that generates a lateral force, which will be described later.

[0026] Sail 14 is made of a membrane material and is composed of a soft sail formed of an elastic material that expands in the wind. In this embodiment, sail 14 is composed of a soft sail as an example, but the present invention is not limited to this, and may be composed of a hard sail formed of a rigid material having an airfoil shape, for example. Also, there may be more than one sail 14.

[0027] The sail 14 is fixed to the hull 16 via the mast 15, and the base of the mast 15 is rotatable relative to the hull 16. By rotating the base of the mast 15 relative to the hull 16, the sail angle αs, described later, can be set to any angle. The mast 15 is driven and controlled by the control device 30 described above. If the mast 15 is operated manually, the control device 30 will notify the amount of rotation required to set the sail angle αs to the desired angle via a display unit, voice notification, or other notification means (not shown). In this embodiment, as an example, the sail angle αs is changed by rotating the base of the mast 15 relative to the hull 16, but the present invention is not limited to this, and the method of changing the sail angle αs can be changed as appropriate.

[0028] As shown in Figure 1, the rudder 18 has a flat surface and is located on the rear side of the bottom surface of the hull 16, controlling the direction of the bow 16A of the hull 16. Specifically, the rudder 18 is configured to be rotatable, and by rotating, it changes the direction of the water flow, which in turn changes the direction of the bow 16A. The rudder 18 is driven and controlled by the control device 30 described above. If the rudder 18 is operated manually, the control device 30 notifies the amount of movement required to move the bow 16A of the hull 16 in the desired direction using the notification means (not shown).

[0029] Furthermore, the method for controlling the direction of the bow 16A of the hull 16 is not limited to the rudder 18; known technologies such as thrusters (propulsion devices) that generate a moment in the direction of the bow 16A can be used.

[0030] As shown in Figure 1, the lateral force generating section 40 is provided on the bottom surface of the hull 16 and, in this embodiment, has a board 42 as a plate material fixed to the center of the width direction of the hull 16 so as to extend in the front-rear direction. The board 42 generates a lateral force Fb, which will be described later, in a direction substantially perpendicular to the direction of travel of the hull 16.

[0031] As described above, in the power generation system 20, wind power generation using power generation mode A and retrieval of the tether 24 using retrieval mode B are performed while the sailing ship 12 is moved F in order to increase power generation efficiency.

[0032] (Downwind movement pattern) Here, we will describe a downwind movement pattern in which power is generated while moving the sailing ship 12 as a whole downwind. As shown in Figure 2, in power generation mode A, the control device 30 moves the hull 16 in a direction perpendicular to the natural wind direction WD, i.e., in the wind-a-beam direction, and in recovery mode B, it moves the hull 16 in approximately the same direction as the wind direction WD.

[0033] (Power generation mode A) Generally, the kite 26 has a flight range within which it can generate electricity. As shown in Figure 3, in this embodiment, this flight range is represented by the angle ψ between the wind axis W and the tether 24 (see Figures 1 and 4). The angle ψ is the angle based on the average position of the tether 24 when the kite 26 is flying during wind power generation in power generation mode A. In Figure 3, the arc indicated by K shows the flight path of the kite 26, and the colored area indicates the flight range. Note that the value of the flight range, i.e., the angle ψ, depends on the inherent performance of the kite 26.

[0034] As shown in Figure 4, when the flyable range shown in color in Figure 3 is projected onto the azimuth angle, the azimuth angle at which the kite 26 can fly most directly toward the bow 16A of the hull 16 is defined as the maximum flight azimuth angle, i.e., the azimuth angle at the position of the tether 24 shown in Figure 4. In this embodiment, in power generation mode A, the control device 30 maintains the position of the kite 26 so that the tether 24 is positioned in the direction of the maximum flight azimuth angle. However, because the kite 26 may unintentionally move outside the flyable range, the control device 30 flies the kite 26 with a margin within the flyable range. That is, the control device 30 flies the kite 26 such that the tether 24 is slightly inward from the direction of the maximum flight azimuth angle.

[0035] (Direction of movement of hull 16) As shown in Figure 5, in power generation mode A, the sail 14 generates thrust by utilizing the wind power of the natural wind. In Figures 5 and 6, the direction of the vector represents the wind direction, and the magnitude of the vector represents the speed. As shown in Figure 6, the relative speed Vw with respect to the hull 16, shown by the dashed line, is represented by the combined speed of the natural wind Vwd, shown by the solid line, and the forward speed V of the hull 16, shown by the dotted line. This relative speed Vw is detected by a wind direction and speed sensor (not shown) mounted on the hull 16. Specifically, the wind direction and speed sensor detects the relative angle γw, which is the wind direction relative to the hull 16, and the relative speed Vw.

[0036] As shown in Figure 5, the thrust Ps from the sail 14 changes with the change in the sail angle αs, which is the angle of attack between the sail 14 and the relative velocity Vw. The thrust Ps increases as the sail angle αs increases, and the greater the thrust Ps, the faster the sailing ship 12 moves.

[0037] Furthermore, a lateral force Fb is generated on the hull 16 by the board 42 in a direction substantially perpendicular to the direction of travel of the hull 16. The control device 30 generates the lateral force Fb in a direction that counteracts the tension T generated by the kite 26. In this embodiment, as an example, the control device 30 changes the rudder angle αr so that the lateral force Fb acts in the opposite direction to the tension T generated by the kite 26. Note that the means for generating the lateral force Fb is not limited to this, and known techniques such as making the board 42 movable can be used.

[0038] Furthermore, the lateral force Fb generated by the board 42 increases as the speed of the hull 16 increases. In other words, the lateral force Fb increases as the thrust Ps increases. In this embodiment, the control device 30 controls the sail angle αs so that the thrust Ps is maximized. Here, we will describe the sail angle αs that can obtain the maximum thrust Ps.

[0039] When the coordinates are defined as shown in Figure 7, the lift force Ls and drag force Ds change with the change in the sail angle αs, which is the angle of attack between the sail 14 and the relative velocity Vw. The lift force Ls occurs in a direction perpendicular to the relative velocity Vw, and the drag force Ds occurs in the same direction as the relative velocity Vw. Here, the values ​​of lift force Ls and drag force Ds for a given sail angle αs are unique characteristics of each sailing ship 12. Therefore, the values ​​of lift force Ls and drag force Ds for a given sail angle αs are obtained in advance by wind tunnel tests and CFD (Computational Fluid Dynamics).

[0040] The thrust force Ps with respect to the relative angle γw between the Xo axis and the relative velocity Vw is shown in the graph in Figure 8 for each sail angle αs. In Figure 8, the aerodynamic coefficient Cx is a dimensionless coefficient of the thrust force Ps in the Xo axis direction of the hull 16. As shown in Figure 8, when the relative angle γw is 140° or less, the thrust force Ps is maximized when the sail angle αs at which the lift Ls is maximized is 15°. Also, when the relative angle γw is greater than 140°, the thrust force Ps is maximized when the sail angle αs at which the drag Ds is maximized is 90°. Note that the above threshold of 140° for the relative angle γw and the maximum sail angle αs vary depending on the shape of the sail 14, but are generally around the values ​​described above.

[0041] (Recovery Mode B) (Direction of movement of hull 16) As shown in Figures 2 and 9, in recovery mode B, the hull 16 is moved in approximately the same direction as the wind direction WD. Specifically, the control device 30 rotates the rudder 18 to change the rudder angle αr, thereby controlling the bow 16A of the hull 16 to face downwind.

[0042] As shown in Figure 9, in this embodiment, since the direction of travel D of the hull 16 is approximately the same as the wind speed Vwd of the natural wind, the vector direction of the hull 16's travel speed V is also approximately the same as the wind speed Vwd direction. When the wind speed Vwd is constant, the relative speed Vw of the hull 16 changes according to the speed of travel speed V. That is, as the travel speed V increases, the relative speed Vw decreases, so the control device 30 controls the sail angle αs so that the thrust force Ps becomes smaller. Specifically, since the relative angle γw is 180°, the control device 30 controls the sail angle αs so that the sail angle αs becomes 90°, referring to the graph in Figure 8.

[0043] Furthermore, as shown in Figure 9, the control device 30 flies the kite 26 so that, when viewed from above the hull 16, the tether 24 is in approximately the same direction as the wind speed Vwd. The control device 30 also winds up the tether 24 at an appropriate winding speed Vt that maximizes the average power generation.

[0044] In the downwind movement pattern described above, the direction of travel D of the hull 16 is in the same direction as the wind speed Vwd of the natural wind, hence the movement direction described above. However, as shown in Figure 10, when the direction of travel D of the hull 16 is at an angle with the wind speed Vwd of the natural wind, there is a speed V of the hull 16 that minimizes the relative speed Vw of the hull 16 when the hull 16 is sailing downwind. Specifically, this occurs when the vector of the hull 16's speed V and the vector of the relative speed Vw are orthogonal. Next, the movement pattern of the hull 16 when the direction of travel D of the hull 16 is at an angle with the wind speed Vwd of the natural wind will be explained.

[0045] In the patterns shown below, the azimuth angle of the tether 24 of the kite 26 and the sail angle αs are the same as in the downwind movement pattern described above, in both power generation mode A and recovery mode B. Furthermore, the azimuth angle of the hull 16 in the upwind or downwind direction is determined considering the need for movement, taking into account the performance such as the maximum wind speed of the natural wind and the amount of power generated relative to the azimuth angle.

[0046] (Position-holding movement pattern) As shown in Figure 11, when wind power generation is performed while the hull 16 remains within a predetermined range, the direction of travel of the hull 16 in power generation mode A and the direction of travel of the hull 16 in recovery mode B are in opposite directions.

[0047] (Upwind movement pattern) As shown in Figure 12, when wind power generation is performed while the hull 16 moves downwind overall, the hull 16 is moved such that the amount of movement of the hull 16 upwind in power generation mode A is greater than the amount of movement of the hull 16 downwind in recovery mode B.

[0048] (Horizontal movement pattern) As shown in Figure 13, when the hull 16 performs wind power generation while moving lateral (perpendicular to) the natural wind direction WD, in power generation mode A, the hull 16 moves upwind, but only in the set direction of travel. In recovery mode B, the hull 16 moves in approximately the same direction as downwind, and is moved to the position in the wind direction from which the hull 16 began sailing in power generation mode A.

[0049] (If the external environment deteriorates) Furthermore, if the external environment deteriorates, such as due to bad weather, the control device 30 will perform one or more of the following processes (1) to (3).

[0050] (1) The speed V of the hull 16 is reduced. Specifically, the control device 30 reduces the speed V of the hull 16 by increasing or decreasing the sail angle αs. (2) Stop the flight motion of Kite 26. (3) Have Kite 26 recovered.

[0051] (In the event of a sudden change in the external environment) Furthermore, if the external environment changes rapidly, such as when the weather changes suddenly, the control device 30 will perform one or more of the following processes (4) to (7). (4) The strength of the kite 26 and tether 24 is maintained by increasing the deployment speed of tether 24. (5) Change the direction of travel of the hull 16 to the downwind side. (6) Reduce the speed V of the hull 16. Note that (6) is the same process as (1) above. (7) Stop the flight motion of Kite 26. Note that (7) is the same procedure as (2) above.

[0052] (Effects and effects of the above embodiment) Next, the effects and advantages of the above embodiment will be described.

[0053] In the floating wind power generation system 10 according to the above embodiment, a power generation mode A is performed by the unwinding of the tether 24 as the kite 26 flies, and a retrieval mode B is performed by the winding of the tether 24. In retrieval mode B, the bow 16A of the hull 16 is controlled to face downwind. As a result, when retrieving the tether 24, the bow 16A of the hull 16 faces downwind, which reduces the relative wind speed to the kite 26. This reduces the energy consumption required for the winding of the tether 24, thereby increasing the overall power generation efficiency.

[0054] Furthermore, in the floating wind power generation system 10 according to the above embodiment, when the direction of travel D of the hull 16 is approximately the same as the direction of the natural wind, the thrust force Ps of the hull 16 and the tension T of the tether 24 are in the same direction. Also, the winding speed Vt of the tether 24 is set to be as slow as possible within the feasible range compared to the unwinding speed of the tether 24 in power generation mode A. The amount of power Qr required to recover the kite 26 is the value obtained by multiplying the tension T of the tether 24 by the winding speed Vt of the tether 24. Therefore, by setting the thrust force Ps of the hull 16 and the tension T of the tether 24 in the same direction, the tension T is used to pull the hull 16, so the tension T can be reduced. As a result, the amount of power Qr can be reduced by further reducing the tension T and further slowing down the winding speed Vt.

[0055] Furthermore, in the floating wind power generation system 10 according to the above embodiment, when retrieving the tether 24, the hull 16 moves in the direction of the tension T vector of the kite 26, so the relative wind speed to the kite 26 can be efficiently reduced. As a result, the energy consumption required for winding up the tether 24 can also be efficiently reduced, and the overall power generation efficiency can be efficiently increased.

[0056] Furthermore, in the floating wind power generation system 10 according to the above embodiment, when the direction of travel D of the hull 16 is at an angle with the direction of the natural wind, the travel speed V of the hull 16 is controlled so that the relative speed Vw with respect to the hull 16 is perpendicular to the travel speed V of the hull 16, so that the relative speed Vw with respect to the hull 16 can be set to the minimum speed. As a result, by setting the relative speed Vw with respect to the hull 16 to the minimum speed, the relative wind speed to the kite 26 can be minimized, and the energy consumption required for the winding operation of the tether 24 can also be minimized, so that the overall power generation efficiency can be further increased.

[0057] Furthermore, in the floating wind power generation system 10 according to the above embodiment, when generating wind power with the kite 26, the bow 16A of the hull 16 is facing into the wind, so the hull 16 moves against the natural wind. Therefore, the relative wind speed to the kite 26 can be increased, and by increasing the payout speed of the tether 24, the amount of power generated can be increased.

[0058] Furthermore, in the floating wind power generation system 10 according to the above embodiment, by making the direction of travel D of the hull 16 perpendicular to the direction of the natural wind, the direction of travel D of the hull 16 can be made to be the direction of the wind beam, so that the speed V of the hull 16 can be increased. As a result the thrust Ps of the hull 16 increases, the lateral force Fb applied to the hull 16 increases, and the tension T of the kite 26 can be reduced. As a result the relative speed to the kite 26 can be increased efficiently, so the payout speed of the tether 24 can be increased, and the amount of power generated can be increased.

[0059] In the embodiments described above, the sailing ship 12 has one hull 16, but the present invention is not limited thereto. For example, the sailing ship 12 may have a twin-hulled vessel, such as a catamaran and a trimaran, in which two or more hulls are connected in parallel by a deck. The lateral force generating section 40 of the embodiments described above can also be applied to this twin-hulled vessel configuration.

[0060] Furthermore, in the floating wind power generation system 10 according to the above embodiment, in power generation mode A, the control device 30 controls the rudder angle αr so that, when viewed from above the hull 16, the vector direction of the tension T of the kite 26 and the direction of travel D of the hull 16 are approximately perpendicular. However, the present invention is not limited to this. For example, the rudder angle αr may be controlled to be within approximately ±10° of the direction in which, when viewed from above the hull 16, the vector direction of the tension T of the kite 26 and the direction of travel D of the hull 16 are approximately perpendicular. However, this range varies depending on the area of ​​the kite 26 and the magnitude of the wind speed Vwd, and the larger the area of ​​the kite 26 and the wind speed Vwd, the narrower the above range becomes. In the present invention, the control device 30 only needs to be able to control the rudder angle αr so that it can generate a lateral force Fb in a direction that cancels out the tension T of the kite 26.

[0061] Furthermore, in the embodiments described above, the rudder angle αr is controlled to change the direction of travel D of the hull 16, but the present invention is not limited thereto. For example, the direction of travel D of the hull 16 may be changed by controlling the sail angle αs to increase the thrust Ps and generate a larger lateral force Fb. Alternatively, the direction of travel D of the hull 16 may be changed by controlling both the rudder angle αr and the sail angle αs.

[0062] Furthermore, although this embodiment describes a sailing ship 12 equipped with a sail 14, the present invention is not limited thereto, and known means capable of generating propulsion force Ps may be used instead of the sail 14.

[0063] Although one embodiment of the present invention has been described above, the present invention is not limited to these embodiments, and various modifications may be used in appropriate combinations with one embodiment, and of course, the invention can be implemented in various forms without departing from the spirit of the present invention. [Explanation of symbols]

[0064] 10. Floating Wind Power Generation Systems 16 hull 16A Bow 24 tether 26 Kite 30 Control device (control unit) 40 Lateral force generation section A Power generation mode B Recovery Mode D Direction of travel T Tension (Kite tension) V Ship's speed Vwd Natural wind speed Vw Relative wind speed relative to the hull

Claims

1. A ship's hull sailing on the water, A power generation system having a kite connected to the hull via a tether, which alternately performs a power generation mode in which wind power is generated by the unwinding of the tether as the kite flies, and a retrieval mode in which the tether is retrieved by the winding of the tether, In the recovery mode, the control unit controls the bow of the hull to be pointed downwind, and when the direction of travel of the hull is at an angle with the direction of the natural wind, the control unit controls the speed of the hull so that the relative speed to the hull, which is the combined speed of the hull's speed and the wind speed of the natural wind, is perpendicular to the speed of the hull's speed. A floating wind power generation system equipped with [unspecified features].

2. The floating wind power generation system according to claim 1, wherein the control unit controls the direction of the bow of the vessel so that, when viewed from above the vessel, the vector direction of the tension of the kite coincides with the direction of travel of the vessel.

3. The floating wind power generation system according to claim 1, wherein the control unit controls the bow of the hull to face into the wind during the power generation mode.

4. The floating wind power generation system according to claim 1, wherein the control unit controls the direction of the bow of the vessel so that, when viewed from above the vessel, the direction of the natural wind and the direction of travel of the vessel are perpendicular.

Images