JP2003056446A - Wind power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind power generation device that can improve generating efficiency by reducing a wind velocity capable of starting a windmill via a relatively simple structure. SOLUTION: A frame 15a of a generating set 15 houses a main generator 16 and an auxiliary generator 17, and the main generator 16 has an extended rotor shaft 18. A disklike main hub 20 mounted with three platelike blades 21 is integrally rotatable mounted on a tip portion of the rotor shaft 18 passed through a cylindrical part 19 fixed to the outside of the frame 15a to constitute a part of the frame 15a, to constitute a main windmill 22. An auxiliary hub 27 mounted with two blades 28 having the same size and shape as the blades 21 is integrally rotatably mounted on an outer ring part 26a of a radial bearing 26 fixed on the circumference of the cylindrical part 19, to constitute an auxiliary windmill 29. The auxiliary windmill 29 is arranged in such proximity to the main windmill 22 as precludes contact, and is designed to rotate in the opposite direction to the main windmill 22.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wind turbine generator.

[0002]

2. Description of the Related Art Some wind turbines mounted on a wind turbine generator or the like start to rotate by a wind force equal to or higher than a predetermined starting wind speed (cut-in wind speed) when in a stopped state. Some wind turbines that are once in a rotating state can continue to rotate even if the wind speed becomes lower than the cut-in wind speed. Therefore, in order to improve the power generation efficiency of the wind turbine generator, it is important to generate electricity by using wind at a relatively low speed.

Therefore, as a wind turbine generator that starts a wind turbine with a relatively low-speed wind, there is, for example, one that performs pitch control to change the blade mounting angle (pitch angle).

[0004]

However, there is a problem in that the structure of the wind power generator for pitch control is complicated and the pitch control is troublesome if the size of the wind turbine is large.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a wind turbine generator capable of reducing the wind speed at which a wind turbine can be started with a relatively simple structure and improving power generation efficiency. Especially.

[0006]

In order to achieve the above object, the invention according to claim 1 is a main wind turbine capable of driving a generator, and an auxiliary wind turbine whose rotation axis is coaxial with the main wind turbine. Are rotatably supported independently of each other, the starting wind speed of the auxiliary wind turbine is set to be lower than the starting wind speed of the main wind turbine, and the main wind turbine is slower than the starting wind speed due to the influence of the rotating auxiliary wind turbine. The gist is that the auxiliary wind turbine is arranged close to the main wind turbine so that the auxiliary wind turbine can be activated.

According to the present invention, when the wind speed lower than the starting wind speed of the main wind turbine blows, the auxiliary wind turbine is rotated, and the main wind turbine is rotated and activated by the influence of the rotation of the auxiliary wind turbine. Therefore, with a relatively simple configuration in which an independently rotatable auxiliary wind turbine is arranged close to the main wind turbine, the main wind turbine is started with a wind speed lower than the startup wind speed in the independent state, and the operating rate of the generator is increased. It is possible to improve the power generation efficiency.

A second aspect of the present invention is based on the first aspect, wherein the auxiliary wind turbine is configured to be rotatable in a direction opposite to the main wind turbine.
According to the present invention, the main wind turbine is started at a lower speed than when the auxiliary wind turbine rotates in the same direction as the main wind turbine. Also, compared to the case where the auxiliary wind turbine rotates in the same direction as the main wind turbine while both the auxiliary wind turbine and the main wind turbine are rotating,
The auxiliary wind turbine is rotated at a higher speed. Therefore, the power generation efficiency can be further improved by using the rotation of the auxiliary wind turbine to generate power by another power generator.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the auxiliary wind turbine is supported by a frame supporting the main wind turbine via a bearing. And

According to the present invention, the main wind turbine and the auxiliary wind turbine are rotatably supported independently of each other with a relatively simple structure. Further, since the auxiliary wind turbine is supported by the frame, the load caused by supporting the auxiliary wind turbine is not applied to the main wind turbine, so that the main wind turbine can be easily rotated and the power generation efficiency can be further improved.

According to a fourth aspect of the present invention, a main wind turbine capable of driving a generator and an auxiliary wind turbine whose rotation axis is coaxial with the main wind turbine are rotatably supported in the same direction. The starting wind speed is set to be lower than the starting wind speed of the main wind turbine, and the main wind turbine can be started by transmitting the rotational force of the auxiliary wind turbine in a rotating state, and the rotation force is maintained when the main wind turbine is activated. The gist is to provide a transmission switching means capable of canceling the transmission of.

According to the present invention, when the wind speed lower than the starting wind speed of the main wind turbine blows, the auxiliary wind turbine is rotated, the rotational force of the auxiliary wind turbine is transmitted to the main wind turbine by the transmission switching means, and the main wind turbine rotates. Is activated. Therefore, it is possible to improve the operating rate of the generator by starting the main wind turbine with a wind speed lower than the starting wind speed in the independent state, and improve the power generation efficiency.
Further, after the main wind turbine is activated, the transmission switching means is operated to cancel the transmission of the rotational force, so that the main wind turbine is separated from the auxiliary wind turbine and efficiently rotates, so that the power generation efficiency can be further improved.

A fifth aspect of the present invention is characterized in that, in the invention according to any one of the first to fourth aspects, the auxiliary wind turbine is arranged leeward of the main wind turbine. According to this invention, the main wind turbine faces the wind before the auxiliary wind turbine. Therefore, compared to the case where the auxiliary wind turbine is arranged on the windward side of the main wind turbine and the main wind turbine is rotated by the wind after rotating the auxiliary wind turbine and losing energy.
The power generation efficiency can be further improved.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the auxiliary wind turbine is operated in a state in which the rotation speed of the main wind turbine is equal to or higher than a predetermined speed. The gist is to provide a connection switching means that can be connected to another generator.

According to the present invention, after the main wind turbine is started due to the influence of the rotation of the auxiliary wind turbine and the rotation speed of the main wind turbine becomes equal to or higher than the predetermined speed, the auxiliary wind turbine is connected to another generator by the connection switching means. , This other generator also produces electricity. Therefore, the rotation of the auxiliary wind turbine can be used for power generation to further improve the power generation efficiency.

The invention according to claim 7 is, in the invention according to any one of claims 1 to 6, characterized in that the number of blades of the auxiliary wind turbine is smaller than the number of blades of the main wind turbine. To do.

According to the present invention, the starting wind speed of the auxiliary wind turbine can be set to be lower than the starting wind speed of the main wind turbine easily at low cost.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 shows a schematic perspective view of the wind turbine generator.

As shown in FIG. 2, the wind turbine generator 11 is
A pillar 13 made of a metal pipe is erected vertically from a fixed portion 12 fixed to the ground. A support case 14 that is rotatable with respect to the column 13 is arranged at the upper end of the column 13. The support case 14 is provided with a tail fin 14a that can drive the support case 14 in a predetermined direction by receiving wind. A power generator 15 is attached to the upper part of the support case 14.

FIG. 1 shows a schematic sectional view of a power generator. Figure 1
As shown in, inside the frame 15a of the power generator 15,
A main generator 16 as a generator and an auxiliary generator 17 as another generator are housed. Main generator 1
A rotor shaft 18 is horizontally extended at 6. A disk-shaped main hub 20 is integrally rotatably attached to the tip of a rotor shaft 18 that is fixed to the outside of the frame 15a and that penetrates a tubular portion 19 that forms a part of the frame 15a.

On the main hub 20, as shown in FIG.
Three plate-shaped blades 21 are mounted at intervals of 120 ° on a circle concentric with the rotor shaft 18. Main hub 20,
The blade 21 forms a main wind turbine 22.

A radial bearing 26 is mounted as a bearing at a predetermined position on the peripheral surface of the tubular portion 19. An annular auxiliary hub 27 having the same diameter as the main hub 20 is integrally rotatably attached to the outer ring portion 26a of the radial bearing 26. The auxiliary hub 27 has two blades 28 of the same size and shape as the blade 21,
They are mounted on a circle concentric with the rotor shaft 18 at 0 ° intervals. The auxiliary hub 27 and the blade 28 form an auxiliary wind turbine 29. As described above, the main wind turbine 22 and the auxiliary wind turbine 29 have their axes of rotation coaxial with each other and are rotatably supported independently of each other. In addition, the main windmill 22
The auxiliary wind turbine 29 and the auxiliary wind turbine 29 are arranged close to each other, and are set at intervals such that they do not contact each other during rotation.

A bevel gear 31 is attached to the outer ring portion 26a of the radial bearing 26 on the frame 15a side. The bevel gear 31 can be connected to the drive shaft 17a of the auxiliary generator 17 via a gear mechanism 32 attached to the frame 15a. An electromagnetic clutch 33 is provided between the gear mechanism 32 and the drive shaft 17 a, and transmission of the rotational force of the auxiliary wind turbine 29 to the auxiliary generator 17 can be switched by the electromagnetic clutch 33. The electromagnetic clutch 33 is configured to be switched based on a signal from a sensor 33a that detects the rotation speed of the rotor shaft 18. Specifically, the electromagnetic clutch 33 connects the gear mechanism 32 and the drive shaft 17a while the rotor shaft 18 is rotating at a speed higher than a predetermined rotation speed, and the rotor shaft 18 is lower than the predetermined rotation speed or is stopped. Then, the gear mechanism 32 and the drive shaft 17a are separated from each other. The electromagnetic clutch 33 and the sensor 33a constitute a connection switching unit.

FIG. 3 is a schematic enlarged view of the mounting portion of the blade. As shown in FIGS. 1 to 3, the base ends of the blades 21 and 28 are attached to the main hub 20 or the auxiliary hub 27 by an attachment member 35 including two L-shaped metal plates 35a and 35b. The L-shaped metal plate 35a screwed to each blade 21 and 28 and the L-shaped metal plate 35b screwed to the main hub 20 or the auxiliary hub 27 are connected by a bolt 36a and a nut 36b. The mounting member 35 can adjust the mounting angle (pitch angle) α of each blade 21, 28 to the main hub 20 or the auxiliary hub 27 by loosening the fastening between the bolt 36a and the nut 36b.

As shown in FIG. 3, the blade 21 has one end 21a in the width direction attached to the L-shaped metal plate 35a.
Thus, the pitch angle α is set so that the other end 21b is separated from the main hub 20. Also, the blade 28
Means that the other end 28b is separated from the auxiliary hub 27 from the one end 28a in the width direction attached to the L-shaped metal plate 35a, and the blade 28 tilts in the direction opposite to the direction in which the blade 21 tilts with respect to the main hub 20. Thus, the pitch angle α is set. Therefore, the auxiliary wind turbine 29 is set to rotate in the opposite direction to the main wind turbine 22, and specifically, in FIG. 2, the main wind turbine 22 rotates counterclockwise and the auxiliary wind turbine 29 rotates clockwise. It is configured to rotate. If the pitch angle α is set so that the blade 28 inclines in the same direction as the blade 21 inclines with respect to the main hub 20, as indicated by the alternate long and short dash line in FIG. 3, the auxiliary wind turbine 29 is in the same direction as the main wind turbine 22. Can be rotated (counterclockwise).

Next, the operation of the wind turbine generator configured as described above will be described. When the wind blows, the wind hits the tail fins 14a, and the supporting winds the support case 14. Then, the support case 14 stops at the position where the tail fin 14a has the least wind resistance. At this time, the tail fins 14a are positioned to project in the leeward direction, and the main wind turbine 22 faces in the upwind direction. In this way, the tail fins 14a keep the main wind turbine 22 facing upwind.

The wind speed is low, and the main wind turbine 22 and the auxiliary wind turbine 2
When both 9 and 9 are stopped, the electromagnetic clutch 3
3 is not connected. When the wind speed rises from such a low wind speed, first, the auxiliary wind turbine 29 is activated and rotates. The number of blades of the auxiliary wind turbine 29 is 2
There are less than three main wind turbines 22. Further, as compared with the main wind turbine 22 that is connected to the main generator 16 and is under load, the auxiliary wind turbine 29 is separated from the auxiliary generator 17 by the electromagnetic clutch 33 that is not connected. It is started at a lower speed than the main windmill 22.

The main wind turbine 22 is activated by the influence of the auxiliary wind turbine 29 thus rotated. That is, the main wind turbine 22 is started by wind having a speed lower than the predetermined start wind speed.

When the rotational speeds of the main wind turbine 22 and the rotor shaft 18 increase above a predetermined speed, the electromagnetic clutch 33 is switched to the connected state based on the increase in the rotational speed, and the gear mechanism 32 is connected to the drive shaft 17a. Then, the rotating force of the auxiliary wind turbine 29 causes the auxiliary generator 17 to generate electric power.

When the wind speed decreases and the rotation speeds of the main wind turbine 22 and the rotor shaft 18 decrease below a predetermined speed, the electromagnetic clutch 33 is switched to the disengaged state based on the decrease in the rotation speed, and the auxiliary wind turbine 29 is applied. The load that is applied is reduced. Therefore, the rotation speed of the auxiliary wind turbine 29 increases, and the rotation speed of the main wind turbine 22 increases due to the influence of the auxiliary wind turbine 29 having the increased rotation speed, so that the amount of power generated by the main generator 16 is secured.

Next, an experimental example of this embodiment will be described. FIG. 4 shows a schematic diagram of the experimental apparatus. As shown in FIG. 4, the wind tunnel device 51 is installed on the front surface of the wind turbine generator 11. The wind tunnel device 51 includes a cylindrical wind tunnel 52, and an air blower 53 is arranged at an opening on the upstream side thereof. The blower 53 can synchronize the number of revolutions per second with the frequency of the drive current, and can be driven by changing the number of revolutions by changing the frequency by the power supply device 54 having an inverter. A rectifying plate 55 is provided at the downstream opening of the wind tunnel 52 to rectify the flow of air to be sent out. Further, a voltmeter 56 is connected to the wind turbine generator 11 so that the generated voltage of the main generator 16 can be observed. The electromagnetic clutch 33 is fixed in a non-connected state.

In this experimental apparatus, the distance from the end of the wind tunnel 52 to the main wind turbine 22 was set to 150 cm, and the pitch angle α of the main wind turbine 22 was set to 15 °. The distance between the main wind turbine 22 and the auxiliary wind turbine 29 was set to 2.5 cm. The blade is a plate with a length of 20 cm and a width of 4 cm,
It is a pentagonal shape that is obliquely cut away from a position 2 cm from the base end so that the width of the tip portion becomes 1.7 cm.

The following experiment was conducted using the experimental apparatus having the above-mentioned configuration. Hereinafter, when the auxiliary wind turbine 29 is set so as to rotate in the same direction as the main wind turbine 22, the value of the pitch angle α of the auxiliary wind turbine 29 is described by adding “+”,
When it is set to rotate in the opposite direction, "-" is added.

In this experiment, (Example 1) No auxiliary wind turbine (Example 2) α = −30 ° (Example 3) α = −20 ° (Example 4) α = −10 ° (Example 5) α = + 10 ° Experiments were performed by changing the conditions as follows.

First, in each of Examples 1 to 5, the frequency of the power supply device 54 (power supply frequency) is increased by, for example, 1 Hz from 15 Hz to increase the wind speed, and the start wind speed (cut-in) of the main wind turbine 22 in the stopped state is cut. Wind speed). After obtaining the starting wind speed, set the frequency of the power supply device 54 to 1H.
The voltmeter 56 measured the generated voltage (V) of the main generator 16 with respect to each wind speed by decreasing z.

Table 1 shows the experimental results, and FIG. 5 shows a graph of the experimental results.

[0037]

[Table 1]

Repeated experiments were carried out for (Example 2) to (Example 4), but the results are shown only in Table 1, and the results of repeated experiments are omitted in FIG. Next, the experimental results and what has been clarified from the experimental results will be described.

As shown in Table 1 and FIG. 5, the auxiliary wind turbine 29
When there is no (Example 1), the power supply frequency corresponding to the starting wind speed is 31 Hz, whereas in (Example 2), (Example 3), (Example 4), and (Example 5), 28 Hz, 26 Hz, Two
6 Hz and 27 Hz. From this, the frequency with the auxiliary wind turbine 29 is lower than that without the auxiliary wind turbine 29,
That is, it can be seen that the main windmill 22 was started at a low wind speed.

Further, (Example 1), (Example 2), (Example 3),
According to the experiment of (Example 5), the auxiliary wind turbine 29 is the main wind turbine 22.
It was found that the voltage generated by rotating in the opposite direction is slightly higher than that generated by rotating in the same direction.

Further, according to the experiments of (Example 2), (Example 3), and (Example 4), in this wind turbine generator 11, the one having the smaller absolute value of the pitch angle α, that is, the pitch angle α is less than −30 °. −
Auxiliary windmill 29 at -10 ° rather than at 20 ° -20 °
It was confirmed that the rotation speed of was higher. Further, as in (Example 4), it was found that when the rotation speed of the auxiliary wind turbine 29 became higher than the predetermined speed, the generated voltage of the main generator 16 decreased.

Not only when the distance between the main wind turbine 22 and the auxiliary wind turbine 29 is set to 2.5 cm, but it is 3.0 c.
An experiment was also performed in the case of setting m and 3.5 cm. From these experimental results, it became clear that the closer the main wind turbine 22 and the auxiliary wind turbine 29 are to each other, the more the main wind turbine 22 is activated at a lower wind speed. Further, in the experimental results in the case of the intervals of 3.0 cm and 3.5 cm, it is preferable that the absolute value of the pitch angle α is made smaller and the rotation speed of the auxiliary wind turbine 29 is made higher so that the main wind turbine becomes slower. Two
It turned out more clearly that 2 was activated. Further, it was revealed that rotating the auxiliary wind turbine 29 in the opposite direction to the main wind turbine 22 starts the main wind turbine 22 at a lower wind speed than in the case of rotating the auxiliary wind turbine 29 in the same direction as the main wind turbine 22. .

The rotation of the auxiliary wind turbine 29 causes the main wind turbine 22 to be started by a wind having a speed lower than the predetermined starting wind speed in the independent state, because the wind is drawn by the rotation of the auxiliary wind turbine 29 to the main wind turbine 22. It is considered that the input angle of the wind changes. Therefore, when the absolute value of the pitch angle of the auxiliary wind turbine 29 becomes smaller, the rotation speed of the auxiliary wind turbine 29 becomes higher, and the change in the wind input angle becomes larger, so that the main wind turbine is driven by the lower speed wind. 22 is activated.

Further, when both the main wind turbine 22 and the auxiliary wind turbine 29 rotate, the auxiliary wind turbine 29 is faster when the auxiliary wind turbine 29 rotates in the opposite direction than when the main wind turbine 22 rotates in the same direction. Is rotated. This is because the input angle of the wind to the auxiliary wind turbine 29, which is affected by the rotation of the main wind turbine 22, is the angle at which the auxiliary wind turbine 29 rotates more easily when the auxiliary wind turbine 29 rotates in the opposite direction to the main wind turbine 22. It is thought to be because.

Further, when the blade pitch angle α of the auxiliary wind turbine 29 is set to, for example, -10 °, the power generation efficiency of the main generator 16 decreases because the auxiliary wind turbine 29 rotates at a high speed above a predetermined speed. It looks like a wall,
This is probably because the flow of wind is blocked. The decrease in the output of the main generator 16 due to the high speed rotation of the auxiliary wind turbine 29 causes the electromagnetic clutch 33 to be in the connected state and the auxiliary wind turbine 2
9 is connected to the auxiliary generator 17 and loaded to prevent it.

According to this embodiment, the following effects are obtained. (1) The starting wind speed of the wind turbine generator 11 is the main wind turbine 2
An auxiliary wind turbine 29 having a speed lower than that of No. 2 is arranged close to the main wind turbine 22. Therefore, with the relatively simple configuration in which the auxiliary wind turbine 29 is arranged close to the main wind turbine 22, the main wind turbine 22 can be started with a wind speed lower than the starting wind speed in the independent state, and the power generation efficiency of the main generator 16 is improved. it can. The rotation direction of the auxiliary wind turbine 29 may be set to be the same as or opposite to the rotation direction of the main wind turbine 22.

(2) By rotating the auxiliary wind turbine 29 in the opposite direction to the main wind turbine 22, the main generator 16 can be started at a lower speed than in the case of rotating the auxiliary wind turbine 29 in the same direction as the main wind turbine 22. Further, when the rotation direction of the auxiliary wind turbine 29 is set to be opposite to that of the main wind turbine 22, the auxiliary generator 17 can generate power efficiently, and the power generation efficiency of the main generator 16 and the auxiliary generator 17 combined can be improved.

(3) The auxiliary wind turbine 29 is supported by the tubular portion 19 supporting the main wind turbine 22 via the radial bearing 26. Therefore, the main wind turbine 22 and the auxiliary wind turbine 2
9 and 9 can be rotatably supported independently of each other with a relatively simple structure. Further, since the auxiliary wind turbine 29 is supported by the tubular portion 19, the load of the auxiliary wind turbine 29 is not applied to the rotor shaft 18, so that the main wind turbine 22 can be easily rotated and the power generation efficiency can be further improved.

(4) Since the auxiliary wind turbine 29 is arranged leeward of the main wind turbine 22, the main wind turbine 22 faces the wind before the auxiliary wind turbine 29, and the power generation efficiency can be further improved. (5) The auxiliary wind turbine 29 is connected to the auxiliary generator 17 by the electromagnetic clutch 33 when the rotation speed of the main wind turbine 22 is equal to or higher than the predetermined speed. Therefore, the rotation of the auxiliary wind turbine 29 is also used for power generation, and the power generation efficiency can be further improved. Also,
Auxiliary wind turbine 29 is connected to the auxiliary generator 17, and the auxiliary wind turbine 29 is connected.
By applying a load to the motor, it is possible to prevent the rotation speed of the auxiliary wind turbine 29 from becoming higher than a predetermined speed and prevent the power generation efficiency of the main wind turbine 22 from being lowered.

(6) Number of blades of the auxiliary wind turbine 29 (two)
Is set to be smaller than the number of blades of the main wind turbine 22 (three blades), so that the starting wind speed of the auxiliary wind turbine 29 can be set to be lower than the starting wind speed of the main wind turbine 22 easily at low cost. Further, unlike the case where the number of blades of the auxiliary wind turbine 29 and the number of blades of the main wind turbine 22 are the same, it is possible to prevent the auxiliary wind turbine 29 from not being sufficiently exposed to wind depending on the rotational position.

(7) By disposing the auxiliary wind turbine 29 closer to the main wind turbine 22, the main wind turbine 22 can be started at a lower wind speed. (8) By reducing the absolute value of the pitch angle α of the blades of the auxiliary wind turbine 29 to increase the rotation speed of the auxiliary wind turbine 29, the influence on the main wind turbine 22 is strengthened and the wind speed is reduced. The main windmill 22 can be activated.

The embodiment is not limited to the above embodiment, but may be modified as follows. The main wind turbine 22 and the auxiliary wind turbine 29 are not limited to being rotatably supported independently of each other. For example, as shown in FIG. 6, on the rotor shaft 18, a disk 71 having substantially the same diameter as the auxiliary hub 27 is formed on the main wind turbine 22 side of the auxiliary hub 27. An electromagnet 72 is attached to the frame 15a at a position facing the auxiliary hub 27 via a bracket 15b. The electromagnet 72 is configured to be excited when the rotation speed of the rotor shaft 18 becomes equal to or higher than a predetermined speed. A leaf spring (not shown) is attached between the electromagnet 72 and the auxiliary hub 27. The auxiliary hub 27 is configured to be slightly slidable with respect to the radial bearing 26 in the axial direction of the rotor shaft 18. The auxiliary hub 27, the disc 71, and the electromagnet 72 constitute transmission switching means. The auxiliary wind turbine 29 is set to rotate in the same direction as the main wind turbine 22.

In this case, when the wind speed is low and both the main wind turbine 22 and the auxiliary wind turbine 29 are stopped, the electromagnetic clutch 33 is disengaged and the electromagnet 72 is demagnetized. The auxiliary hub 27 is in contact with the disc 71 by the biasing force of the leaf spring. In this state, the auxiliary hub 27 is rotatable relative to the disc 71.

When the wind speed rises from the low wind speed, the auxiliary wind turbine 29 is first activated and rotates. The rotational force of the auxiliary wind turbine 29 is transmitted to the rotor shaft 18 by the friction between the auxiliary hub 27 and the disc 71, and the main wind turbine 22 is activated. That is, the main windmill 22
It is started by wind that is lower than the predetermined start wind speed.

When the rotation speeds of the main wind turbine 22 and the rotor shaft 18 rise above a predetermined speed, the electromagnet 72 is excited based on the rise of the rotation speed, and the auxiliary hub 27 resists the biasing force of the leaf spring. Attracted to the electromagnet 72 side,
The contact between the auxiliary hub 27 and the disc 71 is released. For this reason, the main wind turbine 22 rotates efficiently because the connection with the auxiliary wind turbine 29 is released. The auxiliary wind turbine 29 whose contact with the disc 71 is released can be used for power generation of the auxiliary generator 17 by putting the electromagnetic clutch 33 into the connected state.

Therefore, even in this case, when the main wind turbine 22 is stopped and the auxiliary wind turbine 29 is started with a wind speed lower than the starting wind speed of the main wind turbine 22, the main wind turbine 22 can be started by the rotation of the auxiliary wind turbine 29. In order to make it easier to rotate the auxiliary wind turbine 29 in contact with the disk 71 and under load, the blade pitch angle α of the auxiliary wind turbine 29 is approximately +
It is preferably set to 30 °.

The number of blades of the main wind turbine 22 is not limited to three, and another number may be attached. In addition, auxiliary windmill 2
The number of blades of 9 is not limited to two, and other number may be attached, but it is preferable that the number of blades is smaller than that of the main wind turbine 22.

The number of blades of the auxiliary wind turbine 29 is not limited to be set smaller than the number of blades of the main wind turbine 22. For example, the blade of the auxiliary wind turbine 29 is used as the main wind turbine 2
If the starting wind speed of the auxiliary wind turbine 29 can be set to be lower than the starting wind speed of the main wind turbine 22 by making it smaller than the second blade, the number of blades of the auxiliary wind turbine 29 may be equal to or more than the number of blades of the main wind turbine 22. .

The size of the blade of the auxiliary wind turbine 29 is not limited to be set to be the same as the blade of the main wind turbine 22, and may be smaller or larger, but the same size as the blade of the main wind turbine 22. It is preferable to make it small or small.

The auxiliary generator 17, the bevel gear 31, the gear mechanism 32, and the electromagnetic clutch 33 need not be attached to the power generator 15. The auxiliary wind turbine 29 is not limited to being connected to the auxiliary generator 17 when the rotation speed of the main wind turbine 22 becomes equal to or higher than a predetermined speed, and the auxiliary wind turbine 29 brakes in response to an increase in the rotation speed of the main wind turbine 22, for example. The auxiliary wind turbine 29 may be decelerated or stopped by a mechanism or the like. Even in this case,
It is possible to prevent a decrease in the power generation efficiency of the main wind turbine 22 due to the rotation speed of the auxiliary wind turbine 29 rising above a predetermined speed.

The structure for supporting the auxiliary wind turbine 29 so that the load caused by supporting the auxiliary wind turbine 29 is not applied to the main wind turbine 22 is the tubular portion 19 as a part of the frame 15a.
The configuration is not limited to the configuration in which the auxiliary wind turbine 29 is supported via bearings. For example, a support member having a penetrating portion through which the rotor shaft 18 penetrates is provided in the support case 14 separately from the frame 15a, and the auxiliary wind turbine 29 is attached to this support member so that the auxiliary wind turbine 29 rotates coaxially with the main wind turbine 22. It may be supported via a bearing. Even in this case, the main wind turbine 22 can be easily rotated.

The structure for supporting the auxiliary wind turbine 29 so that the load is not applied to the main wind turbine 22 is not limited to the above case. For example, another support member may be attached to the housing of the main generator 16 to support this other support. Main windmill 2 for parts
The auxiliary wind turbine 29 may be supported via a bearing so as to rotate coaxially with the second wind turbine 2.

The auxiliary wind turbine 29 is the radial bearing 2
It is not limited to be rotatably supported by the tubular portion 19 by 6, but may be rotatably supported by, for example, a thrust bearing.

The blade may have a twisted shape. The auxiliary wind turbine 29 is not limited to be placed and set downwind of the main windmill 22, and the auxiliary windmill 29 may be placed and set upwind of the main windmill 22.

The technical ideas that can be understood from the above-described embodiments will be added below. (1) In the invention according to claim 6, the connection switching means includes an electromagnetic clutch that is switched based on a signal from a sensor that detects the rotation speed of the main wind turbine.

(2) In the invention according to any one of claims 1 to 7, the auxiliary wind turbine can be stopped or decelerated while the rotation speed of the main wind turbine is equal to or higher than a predetermined speed.

(3) In the invention described in claim 1 or 2, the auxiliary wind turbine is supported via a bearing by a supporting member provided at a position other than a frame supporting the main wind turbine. .

[0068]

As described in detail above, according to the invention described in claims 1 to 7, the wind speed at which the wind turbine can be started can be reduced by the relatively simple structure, and the power generation efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a power generator.

FIG. 2 is a schematic perspective view of a wind turbine generator.

FIG. 3 is a schematic enlarged view of a blade mounting portion.

FIG. 4 is a schematic diagram of an experimental device.

FIG. 5 is a graph showing experimental results.

FIG. 6 is a schematic partial cross-sectional view showing another example.

[Explanation of symbols]

11 ... Wind power generator, 15a ... Frame, 19 ... Cylindrical part which constitutes a part of frame, 16 ... Main generator as a generator, 17 ... Auxiliary generator as another generator, 21 ...
Main wind turbine blades, 26 ... Radial bearings as bearings, 22 ... Main wind turbine, 28 ... Auxiliary wind turbine blades, 29 ... Auxiliary wind turbines, 33 ... Electromagnetic clutch that constitutes connection switching means, 33a ... Similarly sensor, 71 ... Transmission switching A disk constituting the means, 72 ... Similarly an electromagnet.

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Claims (7)

[Claims] 1. A main wind turbine capable of driving a generator and an auxiliary wind turbine having a rotation shaft coaxial with the main wind turbine so as to be rotatable independently of each other, and the starting wind speed of the auxiliary wind turbine is the main wind turbine. Is set lower than the starting wind speed, and the auxiliary wind turbine is arranged close to the main wind turbine so that the main wind turbine can be started at a lower speed than the starting wind speed due to the influence of the auxiliary wind turbine in a rotating state. A characteristic wind power generator. 2. The wind turbine generator according to claim 1, wherein the auxiliary wind turbine is configured to be rotatable in a direction opposite to the main wind turbine. 3. The wind turbine generator according to claim 1, wherein the auxiliary wind turbine is supported by a frame that supports the main wind turbine via a bearing. 4. A main wind turbine capable of driving a generator and an auxiliary wind turbine whose rotation axis is coaxial with the main wind turbine are rotatably supported in the same direction, and the starting wind speed of the auxiliary wind turbine is controlled by the main wind turbine. Transmission that is set to a speed lower than the starting wind speed and that can transmit the rotational force of the auxiliary wind turbine in the rotating state to start the main wind turbine, and that can release the transmission of the rotational force when the main wind turbine is activated. A wind turbine generator comprising switching means. 5. The wind turbine generator according to claim 1, wherein the auxiliary wind turbine is arranged leeward of the main wind turbine. 6. The connection switching means capable of connecting the auxiliary wind turbine to another generator in a state where the rotation speed of the main wind turbine is equal to or higher than a predetermined speed, and any one of claims 1 to 5 is provided. The wind power generator according to claim 1. 7. The wind turbine generator according to claim 1, wherein the number of blades of the auxiliary wind turbine is smaller than the number of blades of the main wind turbine.