Wind power generation device

Abstract

To provide a wind power generation device capable of substantially eliminating power cables disposed in a tower.SOLUTION: A rotor 3 rotates due to wind power. A nacelle 4 rotatably supports the rotor 3. A tower 2 is hollow, and supports the nacelle 4 at its upper part. The nacelle 4 has a generator 43 that converts rotational energy of the rotor 3 into power, and a microwave power transmitter 46 that converts the power into microwaves and emits them downward through a hollow part 22 in the tower 2. Additionally, a microwave power receiving device 23 is provided at the bottom part of the tower 2, which receives microwaves, converts them into power, and outputs it.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a wind power generation device.

Background Art

[0002] A wind power generation device that generates electricity using wind generally includes a nacelle that houses a generator that generates electricity by wind, and a tower that supports the nacelle at the top. Electric power from the generator in the nacelle is sent to a power converter provided at the bottom through a power cable disposed in the tower from the top to the bottom, and further sent from the power converter to the outside of the wind power generation device through a transmission line (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The height of the tower of a wind power generation device is relatively high, and it is not uncommon for it to be 100 meters or more. Therefore, the power cable disposed in the tower is often long. For this reason, the weight of the power cable increases, and its installation cost also increases. In addition, since the weight of the entire wind power generation device also increases, it is necessary to thicken the structure for stably fixing the tower to the ground or the like, and the costs related to its installation and maintenance are also considerable.

[0005] In view of the above problems, the present disclosure aims to provide a wind power generation device capable of substantially eliminating the power cable disposed in the tower.

Means for Solving the Problems

[0006] A wind power generation device according to an aspect of the present disclosure includes a nacelle having a generator, and a hollow tower that supports the nacelle at an upper portion. The nacelle includes a power transmission device that converts generated power from the generator into an electromagnetic wave for power transmission (for example, a microwave) and emits it downward through a hollow portion in the tower. The tower has, at its bottom, a power reception device that receives the electromagnetic wave (for example, a microwave) and converts it into power for output. The wind power generation device may have an electromagnetic shield that electromagnetically isolates its exterior from the space through which the electromagnetic wave (microwave) in the tower passes. The tower itself may be made of a material (for example, a steel tube) or a structure (for example, reinforced concrete) that functions as an electromagnetic shield, or a foil, sheet, mesh, or coating film made of a material that functions as an electromagnetic shield may be provided inside, on the inner surface, within the thickness, on the outer surface, or outside the wall of the tower. The electromagnetic shield may have a function of reflecting the electromagnetic wave on an inner surface facing the power transmission path through which the electromagnetic wave passes.

Advantages of the Invention

[0007] According to the present invention, it becomes possible to substantially eliminate the need for long power transmission cables running inside the tower.

Brief Description of the Drawings

[0008]

Figure 1

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] FIG. 1 is a diagram schematically showing a wind power generation device according to an embodiment of the present disclosure. As shown in FIG. 1, the wind power generation device 1 includes a tower 2, a rotor 3, and a nacelle 4.

[0011] Tower 2 is a hollow column extending upward provided on the ground or at sea and functions as a support member for supporting nacelle 4. Tower 2 is manufactured, for example, from steel, reinforced concrete, or a combination thereof.

[0012] Rotor 3 rotates by the wind force and has a plurality of blades 31 that receive the wind and a hub 32 that serves as the rotation axis of blades 31. Blades 31 are connected to hub 32 and extend radially from hub 32.

[0013] Nacelle 4 rotatably supports rotor 3 and is rotatably supported via a slewing device 5 at the upper part (the top part in this embodiment) of tower 2. The slewing axis of nacelle 4 is substantially vertical. Nacelle 4 houses therein a drive train unit 40 that converts the rotational force (torque) of rotor 3 into electric power.

[0014] Drive train unit 40 has a main shaft 41, a speed increaser 42, a generator 43, a brake 44, a first power converter 45, and a microwave power transmission device 46.

[0015] Main shaft 41 connects hub 32 of rotor 3 and speed increaser 42. When blades 31 receive the wind, they rotate integrally with hub 32, and the rotational force of hub 32 is transmitted to speed increaser 42. Speed increaser 42 increases the rotational speed of main shaft 41 to a rotational speed suitable for driving generator 43 and transmits the rotational power of hub 32 to generator 43. Generator 43 converts the rotational power transmitted from speed increaser 42 into electric power and outputs it.

[0016] Brake 44 stops the rotation of rotor 3 as necessary to stop power generation by generator 43. Brake 44 is used, for example, during maintenance of wind power generation device 1 and during strong winds. Brake 44 is operated by manual operation of an operator in wind power generation device 1 and / or by a wireless signal from a remote control base far away from wind power generation device 1.

[0017] The first power converter 45 converts the power output from the generator 43 into microwave drive power in a form suitable for driving the microwave power transmission device 46 and outputs it to the microwave power transmission device 46.

[0018] The microwave power transmission device 46 is arranged facing the opening 21 provided at the top of the tower 2. The microwave power transmission device 46 converts the microwave drive power from the first power converter 45 into a microwave beam 50 for power transmission and emits it downward from the opening 21 of the tower 2 through the hollow portion 22, that is, toward the bottom of the tower 2.

[0019] At the bottom of the tower 2, a microwave power receiving device 23 and a second power converter 24 are arranged. The microwave power receiving device 23 receives the microwave beam 50 from the microwave power transmission device 46, converts it into power in a predetermined form, and outputs it to the second power converter 24. The second power converter 24 converts the power from the microwave power receiving device 23 into power in a form suitable for power transmission to the outside and transmits it to the outside through the power transmission line 100.

[0020] Also, in the hollow portion 22 inside the tower 2, a lifting device 25 is provided that enables a person such as a worker to move up and down. The lifting device 25 is used for a worker to move up and down between the bottom of the tower 2 and the nacelle 4. The lifting device 25 is, for example, an elevator, a ladder, or a staircase. At the bottom of the wall 26 of the tower 2, there is a door 27 for a worker to enter and exit the tower 2.

[0021] Also, an electromagnetic shield 51 is provided on the wall 26 (or in the vicinity of the wall 26) of the tower 2 as schematically shown by a dashed line. The electromagnetic shield 51 is provided over substantially the entire wall surface 26 of the tower 2 so as to surround the entire or substantially the entire periphery of the microwave power transmission path through which the microwave beam 50 passes. The electromagnetic shield 51 shields strong electromagnetic wave noise generated outside the wind power generation device 1 such as lightning and protects the microwave beam 50 passing through the hollow portion 22 inside the tower 2. The electromagnetic shield 51 also prevents the microwave beam 50 inside the tower 2 from leaking outside the tower and protects people and organisms outside the tower from high-power microwaves.

[0022] The electromagnetic shield 51 is realized by, for example, a conductor mesh, a conductor film, a conductor sheet, a conductive paint, etc. The electromagnetic shield 51 may be provided inside or on the inner surface of the wall 26 of the tower 2, may be provided on the outer surface or outside, or may be provided within the thickness of the wall 26. For example, when the wall 26 of the tower 2 is made of reinforced concrete, if the mesh formed by the vertical and horizontal intersections of the reinforcing bars has sufficient density and overall conductivity due to mutual connection, the mesh of the reinforcing bars becomes an electromagnetic wave shield. Also, if the wall 26 of the tower 2 is made of a conductive tube such as steel, the wall surface 26 of the tower 2 itself becomes the electromagnetic shield 51. Further, if almost the entire inner surface or outer surface of the wall 26 of the tower 2 is coated with a conductive paint or a conductive sheet or mesh is pasted, it functions as the electromagnetic shield 51.

[0023] Also, instead of or in addition to the electromagnetic shield 51 provided on the wall 26 of the tower 2, a cylindrical electromagnetic wave shield surrounding the periphery of the power transmission path through which the microwave beam in the hollow portion 22 in the tower 2 passes may be provided. Also, the electromagnetic shield is not limited to the tower 2 and may be provided on the nacelle 4, the slewing device 5, etc. as illustrated by the dashed line 52.

[0024] Also, an electromagnetic shield 53 schematically shown by a dashed line may be provided between the space in the door 27 and the hoisting device 25 in the tower 2 and the space through which the microwave beam 50 passes so as to partition both spaces. The electromagnetic shield 53 may be in the form of a curtain or a wall. Alternatively, when the hoisting device 25 is an elevator, the electromagnetic shield 52 may be provided around the wall of the elevator cage, the door 27, and the passage from the door to the car. For example, if the elevator cage is made of metal, the cage itself functions as the electromagnetic shield 52.

[0025] According to the present embodiment described above, since power is transmitted by microwaves from the top to the bottom of the tower 2, it is possible to transmit the generated power to the bottom of the tower 2 without using a long and heavy power cable. Therefore, it is possible to substantially eliminate the power cable disposed in the tower 2. For this reason, the weight of the wind power generation device can be reduced, and it is also possible to reduce various costs such as installation costs and maintenance costs.

[0026] Further, in the present embodiment, an electromagnetic shield 51 is provided between the space through which the microwave beam 50 passes and the space outside the tower 2. For this reason, it is possible to reduce both of the two weaknesses of microwave power transmission, that is, the first weakness that microwave power transmission is affected by strong electromagnetic wave noise such as lightning occurring outside, and the second weakness that high-power microwaves can affect people and organisms outside. Usually, since an outsider cannot enter the tower 2, it is easily possible to suppress the influence on people outside by microwaves.

[0027] When the tower 2 is made of a metal tube such as steel or reinforced concrete in order to obtain sufficient mechanical strength, the tower 2 itself can be used as the electromagnetic shield 51. Further, the electromagnetic shield 51 surrounding the power transmission path of the microwave may have a function of reflecting the microwave on the inner surface facing the microwave power transmission path, so as to return the portion of the microwave beam that tries to spread out of the power transmission path back toward the power transmission path.

[0028] Further, in the present embodiment, an electromagnetic shield 52 is provided between the power transmission path of the microwave and the lifting device 25. Alternatively, when the elevator cage is made of metal, the cage itself functions as the electromagnetic shield 52. Usually, when a worker enters the tower 2 for maintenance and inspection, etc., the power generation and transmission are stopped by the brake 44 or the like. However, in the case of this configuration, even if a microwave beam is accidentally emitted when a worker is in the tower 2, it is possible to suppress the influence on the worker.

[0029] In the above-described embodiments of the present disclosure, power transmission is performed inside the tower using microwaves. However, instead of microwaves, other propagation waves suitable for power transmission, particularly electromagnetic waves, for example, electromagnetic waves having a higher frequency than microwaves, such as light like a laser with excellent directivity and easy to obtain a high energy density, can also be used. When a light beam is used for power transmission inside the tower, for the electromagnetic shield 51 surrounding the power transmission path of the light beam, one having a function of shielding or reflecting light on the inner surface facing the light power transmission path can be used.

[0030] The above-described embodiments of the present disclosure are examples for explaining the present disclosure, and are not intended to limit the scope of the present disclosure only to those embodiments. Those skilled in the art can implement the present disclosure in various other modes without departing from the scope of the present disclosure.

Explanation of Reference Numerals

[0031] 1: Wind power generation device 2: Tower 3: Rotor 4: Nacelle 5: Swivel device 21: Opening 22: Hollow part 23: Microwave power receiving device 24: Second power converter 25: Lifting device 26: Tower wall 31: Blade 32: Hub 40: Drive train unit 41: Main shaft 42: Speed increaser 43: Generator 44: Brake 45: First power converter 46: Microwave power transmission device 50: Microwave beam 51, 52, 53: Electromagnetic shield 100: Power transmission line

Claims

1. A nacelle having a generator, and a hollow tower that supports the nacelle at the top, wherein the nacelle has a power transmission device that converts the generated power from the generator into microwaves or electromagnetic waves for power transmission and emits the converted waves downward through the hollow portion inside the tower, and the tower has a power reception device at its bottom that receives the microwaves or the electromagnetic waves, converts them into power, and outputs the power. A wind power generation device.

2. The wind power generation device according to claim 1, further comprising an electromagnetic shield disposed so as to surround a power transmission path through which the microwaves or the electromagnetic waves pass.

3. The wind power generation device according to claim 2, wherein the electromagnetic shield is provided inside, on the inner surface, within the thickness, on the outer surface, or outside the wall of the tower.

4. The wind power generation device according to claim 2, wherein the wall of the tower is formed of a material or structure that functions as the electromagnetic shield.

5. The wind power generation device according to claim 2, wherein the electromagnetic shield has an inner surface facing the power transmission path, and reflects the microwaves or the electromagnetic waves on the inner surface.

6. The tower has a lifting device that enables a person to move up and down inside the hollow portion, and the wind power generation device according to claim 1, further comprising a second electromagnetic shield that protects the person using the lifting device from the microwaves or the electromagnetic waves.

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