Wind power generation device

Abstract

To provide a wind power generation device that is improved in startup property of wind turbine rotation with a simple configuration.SOLUTION: A wind power generation device includes: a vertical shaft type principal wind turbine 11; a power generator 13 for generating power by being transmitted with the rotation of the principal wind turbine 11; a startup wind turbine 17 connected to the principal wind turbine 11 and having a wind velocity necessary for rotation startup that is lower than that of the principal wind turbine 11. The principal wind turbine 11 starts up the rotation with the rotation force that is transmitted from the startup wind turbine 17 starting up the rotation with a wind with a low wind speed at the time of low wind speed that is lower than a wind velocity necessary for the rotation startup of the principal wind turbine.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Wind power generation equipment that generates electricity using wind power is known (for example, Patent Document 1). In the wind power generation device of Patent Document 1, a windmill is rotated by wind power, and a generator is driven by the rotational driving force obtained thereby to generate electricity. However, a propeller-type horizontal axis windmill can only capture wind in one direction, and moreover, since vibration is likely to occur, there are many restrictions on the installation of the windmill.

[0003] On the other hand, lift-type windmills such as Darrieus-type windmills, which are vertical axis windmills, can rotate efficiently at high speed because they do not select the wind direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, lift-type windmills such as Darrieus-type windmills belong to the category of windmills with relatively high rotational speeds and have the characteristic of high rotational efficiency. However, once a lift-type windmill stops, the rotational torque obtained from the wind is extremely small, so self-rotation startup may become difficult.

[0006] For this reason, in order to start rotation even with weak wind, there is also a method of rotating with a starting motor. In that case, the generator can also function as a starting motor, but in order to function as a starting motor, a detector for detecting the rotational position and a drive circuit for driving the generator as a starting motor are required. Therefore, the configuration becomes complicated as a small windmill.

[0007] Therefore, an object of the present invention is to provide a wind power generation device that has a simple structure and improved starting performance of windmill rotation.

Means for Solving the Problems

[0008] The present invention has the following configuration. A vertical-axis main windmill, A generator that generates electricity when the rotation of the main windmill is transmitted, A starting windmill that is connected to the main windmill and has a lower wind speed required for rotational startup than the main windmill, and the main windmill starts rotating by the rotational force transmitted from the starting windmill that has started rotating by the low wind speed when the wind speed is less than the wind speed required for rotational startup. Wind power generation device.

Effects of the Invention

[0009] According to the wind power generation device of the present invention, the starting performance of windmill rotation can be improved with a simple structure.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (First Embodiment) First, the first embodiment will be described. FIG. 1 is a schematic configuration diagram of a wind power generation device 100 according to the first embodiment. The wind power generation device 100 according to the first embodiment includes a main wind turbine 11, a generator 13, a starting wind turbine 17, and a one-way clutch 19. This wind power generation device 100 is a wind power generation device provided with a vertical-axis type main wind turbine 11 having a rotating shaft 15 erected in the vertical direction. In the wind power generation device 100, the rotation of the main wind turbine 11 is transmitted to the generator 13 via the rotating shaft 15, and the generator 13 generates electricity by the transmitted rotation.

[0012] The main wind turbine 11 is a Darrieus-type lift wind turbine. This main wind turbine 11 has a plurality (three in this example) of blades 21. The blades 21 are formed in a curved shape, and both ends are connected to the rotating shaft 15. Each blade 21 is arranged at equal intervals around the axis of the rotating shaft 15. When the blades 21 of the main wind turbine 11 receive wind, the main wind turbine 11 rotates in one direction around the axis of the rotating shaft 15.

[0013] The starting wind turbine 17 is connected to the main wind turbine 11 via the rotating shaft 15. The starting wind turbine 17 is provided on the side opposite to the generator 13 side of the main wind turbine 11. That is, separately from the power transmission path from the main wind turbine 11 to the generator 13, the starting wind turbine 17 is provided to rotationally drive the main wind turbine 11. The starting wind turbine 17 rotates in the same direction as the main wind turbine 11. This starting wind turbine 17 is a wind turbine that requires a lower wind speed for rotational startup than the main wind turbine 11.

[0014] The starting windmill 17 is, for example, a Savonius drag-type windmill. The starting windmill 17 includes end plates 23 provided at both axial ends and a plurality (two in this example) of blades 25 provided between these end plates 23. The end plates 23 are formed in a disk shape. The blades 25 are plate materials with an arcuate horizontal cross-section, and their outer circumferences of the arcs face opposite sides to each other, and the centers of the arcs are displaced from each other in the radial direction. When the blades 25 of the starting windmill 17 receive wind, the starting windmill 17 rotates about the axis of the rotating shaft 15.

[0015] The one-way clutch 19 is provided between the main windmill 11 and the starting windmill 17. When the rotational speed of the main windmill 11 reaches the cut-in speed, which is higher than that of the starting windmill 17, the power transmission is cut off and the one-way clutch 19 idles. As a result, when the main windmill 11 rotates at a speed higher than the cut-in speed, the rotation of the starting windmill 17 is disconnected by the one-way clutch 19, and the rotational resistance caused by the starting windmill 17 rotating at a lower speed than the main windmill 11 is blocked. As a result, the main windmill 11 rotates efficiently without receiving rotational resistance from the starting windmill 17.

[0016] Here, the axial-type generator and the radial-type generator used as the generator 13 will be described.

[0017] Figure 2 is a schematic cross-sectional view of an axial-type generator. Figure 3 is a schematic cross-sectional view of a radial-type generator. The axial-type generator shown in Figure 2 has a shaft body 41, a plurality of rotor plates 43, and a stator 45. The rotor plates 43 are fixed to the shaft body 41 and rotate together with the shaft body 41. The rotor plates 43 are arranged at intervals in the axial direction, and the stator 45 is arranged between these rotor plates 43. The rotor plates 43 have permanent magnets 47 on the stator 45 side. These permanent magnets 47 are arranged opposite to the stator 45 and are arranged in the circumferential direction so that the magnetic poles alternate. The stator 45 is provided with coils 49 and is formed in an annular shape. This axial-type generator generates electricity by receiving a rotating magnetic field from the rotor plates 43 when the shaft body 41 is rotated, causing the coils 49 of the stator 45 to generate an electromotive force. This axial-type generator is used as a generator when the rotational speed is relatively low. Incidentally, this axial-type generator can cope with an increase in output by stacking the configurations of the rotor plates 43 and the stator 45 in the axial direction.

[0018] The radial-type generator shown in Figure 3 has a shaft body 51, a rotor 53, and a stator 55. The rotor 53 is a plurality of permanent magnets and is fixed around the shaft body 51 so that the magnetic poles alternate. The stator 55 is provided with coils 59 and is formed in a cylindrical shape. This radial-type generator generates electricity by receiving a rotating magnetic field from the rotor 53 when the shaft body 51 is rotated, causing the coils 59 of the stator 55 to generate an electromotive force. This radial-type generator can generate electricity efficiently at high speeds.

[0019] Next, the power generation in the wind power generation device 100 will be described. (At the time of rotational startup) When the wind is weak and the rotational force of the main wind turbine 11 cannot be sufficiently generated, first, the starting wind turbine 17 starts to rotate with the weak wind. Then, due to the rotational force of this starting wind turbine 17, the main wind turbine 11 connected to the starting wind turbine 17 starts to rotate. In this way, in the wind power generation device 100, even when the wind speed is low and the wind is weak such that the main wind turbine 11 does not start to rotate, the main wind turbine 11 is started to rotate by the rotational force of the starting wind turbine 17 that has been started to rotate by this weak wind. Thereby, the main wind turbine 11 can be smoothly started to rotate.

[0020] (During normal power generation) When the wind speed of the wind increases, the main wind turbine 11 that has been started to rotate by the rotational force of the starting wind turbine 17 rotates with the blades 21 receiving the wind. Then, when the rotational speed of this main wind turbine 11 reaches the cut-in speed that is faster than that of the starting wind turbine 17, the one-way clutch 19 idles. As a result, when the main wind turbine 11 rotates faster than the cut-in speed, the rotation of the starting wind turbine 17 is disengaged by the one-way clutch 19. Consequently, with the resistance of the starting wind turbine 17 blocked, the main wind turbine 11 rotates efficiently. Therefore, the rotation of the main wind turbine 11 is transmitted to the generator 13 and power is generated with high efficiency.

[0021] Here, FIG. 4 schematically shows the relationship between the tip speed ratio and the torque coefficient of the main wind turbine 11 and the starting wind turbine 17. Also, FIG. 5 schematically shows the relationship between the tip speed ratio and the power coefficient of the main wind turbine 11 and the starting wind turbine 17. As shown in FIG. 4, the output region Tm of the torque coefficient of the main wind turbine 11 composed of a Darrieus-type lift wind turbine and the output region Ts of the torque coefficient of the starting wind turbine 17 composed of a Savonius-type drag wind turbine are in different rotation regions from each other. Also, as shown in FIG. 5, the output region Pm of the power coefficient of the main wind turbine 11 composed of a Darrieus-type lift wind turbine and the output region Ps of the power coefficient of the starting wind turbine 17 composed of a Savonius-type drag wind turbine are in different rotation regions from each other. Specifically, with respect to the output region Ts of the torque coefficient and the output region Ps of the power coefficient of the starting wind turbine 17, the output region Tm of the torque coefficient and the output region Pm of the power coefficient of the main wind turbine 11 are in the high rotation region.

[0022] That is, the starting windmill 17 composed of a drag-type windmill can generate rotational torque even at low wind speeds, so it can be rotationally started even at low wind speeds. However, since the tip speed ratio is approximately 1, it does not rotate faster than the wind speed. Therefore, when the main windmill 11 with a tip speed ratio greater than 1 rotates at high speed, if the starting windmill 17 is rotating while connected, the starting windmill 17 acts as a resistance to the rotation of the main windmill 11, resulting in losses.

[0023] As described above, in this configuration example, when the wind is weak, the main windmill 11 is smoothly rotationally started by the rotational force of the starting windmill 17. When the main windmill 11 exceeds the rotational speed of the starting windmill 17, the one-way clutch 19 idles and the starting windmill 17 is disconnected from the main windmill 11. Thereby, the loss due to the resistance of the starting windmill 17 to the main windmill 11 can be reduced, and high power generation efficiency can be maintained.

[0024] As described above, according to the wind power generation device 100 according to the first embodiment, even when the wind is weak at low wind speeds where the main windmill 11 does not start rotating, the main windmill 11 can be rotationally started by the rotational force of the starting windmill 17 that has been rotationally started by this weak wind. That is, the main windmill 11 can be smoothly rotationally started and efficiently generate electricity with the generator 13.

[0025] Also, stable rotation can be obtained even in an environment where the wind speed and wind direction change easily. Since it is provided with the main windmill 11 composed of a Darrieus-type lift-type windmill that rotates under low wind speed conditions and rotates from low wind speed to high wind speed, high-efficiency power generation can be achieved.

[0026] In the above embodiment, the case where the main windmill 11 is provided with a Darrieus-type lift-type windmill and the starting windmill 17 is provided with a Savonius-type drag-type windmill is exemplified. However, the main windmill 11 and the starting windmill 17 may be of other types. For example, the main windmill 11 may be a straight blade-type lift-type windmill in which a plurality of straight blades are supported in parallel at intervals with respect to the rotation shaft 15. Also, the starting windmill 17 may be a cross-flow type drag-type windmill in which a plurality of blades are arranged along the outer peripheral edge of the end plates between a pair of end plates.

[0027] Here, Darrieus or straight airfoil lift wind turbines have the characteristics of high rotational speed and high efficiency. However, since the rotational torque obtained from the wind in the stopped state is small, it may be difficult to start up by themselves. On the other hand, Savonius or cross-flow drag wind turbines have a large starting torque obtained from the wind in the stopped state, so they can start even with a weak wind.

[0028] In this embodiment, by providing a starting wind turbine 17 composed of a Savonius or cross-flow drag wind turbine that rotates and starts with a weak wind to the main wind turbine 11 composed of a Darrieus or straight airfoil lift wind turbine, the starting wind turbine 17 can smoothly rotate and start the main wind turbine 11, and the generator 13 can generate electricity with high efficiency.

[0029] Next, the second to fifth embodiments will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0030] (Second Embodiment) FIG. 6 is a schematic configuration diagram of a wind power generation device 200 according to the second embodiment. The wind power generation device 200 according to the second embodiment is provided with a clutch 61 for disconnecting and connecting the rotation transmitted from the main wind turbine 11 to the generator 13 between the main wind turbine 11 and the generator 13 in the wind power generation device 100 according to the first embodiment. Also, a rotation sensor (speed detection unit) 31 and a control unit 33 are provided.

[0031] The rotation sensor 31 is connected to the control unit 33. Also, the control unit 33 is connected to the clutch 61. The clutch 61 is, for example, an electromagnetic clutch and has a mechanism for disconnecting and connecting power transmission by using the electromagnetic force generated by energizing the coil. The clutch 61 is not limited to this, and known ones can be used.

[0032] The rotation sensor 31 detects the rotational speed of the main windmill 11 and transmits a detection signal to the control unit 33. As the rotation sensor 31, for example, a known configuration such as one that reads the rotation of a rotary encoder by an optical or magnetic sensor and detects the position of the rotary encoder can be used. The control unit 33 transmits a control signal to the clutch 61 and controls the drive unit (not shown) of the clutch 61. The control unit 33 operates the clutch 61 according to the rotational speed of the main windmill 11 detected by the rotation sensor 31, and disconnects and connects the rotation transmitted from the main windmill 11 to the generator 13.

[0033] Next, the power generation in the wind power generation device 200 will be described. (At startup) When the wind is weak and the wind speed is such that the rotational force of the main windmill 11 is not sufficiently generated, first, the starting windmill 17 starts to rotate with the weak wind. Then, due to the rotational force of this starting windmill 17, the main windmill 11 to which the starting windmill 17 is connected starts to rotate. In this way, in the wind power generation device 200, even when the wind is weak at a low wind speed where the main windmill 11 does not start to rotate, the main windmill 11 is started to rotate by the rotational force of the starting windmill 17 that has started to rotate with this weak wind. Also, at the time of this rotation startup, the control unit 33 cuts off the transmission of the rotation of the main windmill 11 by the clutch 61 to the generator 13, and makes the main windmill 11 rotate freely with respect to the generator 13. Thereby, the resistance of the generator 13 to the main windmill 11 at startup can be suppressed, and the main windmill 11 that rotates by the rotational force of the starting windmill 17 can be started more smoothly.

[0034] (During normal power generation) When the wind speed increases, the main windmill 11 that is rotationally started by the rotational force of the starting windmill 17 rotates with the blades 21 receiving the wind. Then, when the rotational speed of this main windmill 11 reaches the cut-in speed that is higher than that of the starting windmill 17, the one-way clutch 19 blocks the rotational transmission from the starting windmill 17 to the main windmill 11. As a result, when the main windmill 11 reaches a rotational speed higher than the cut-in speed, the rotational resistance of the main windmill 11 caused by the starting windmill 17 is suppressed, and the main windmill 11 rotates efficiently. And when it is detected by the rotation sensor 31 that the main windmill 11 has reached the cut-in speed, the control unit 33 activates the clutch 61, and the rotation of the main windmill 11 is transmitted to the generator 13 by the clutch 61. Thereby, power is efficiently generated by the generator 13.

[0035] (Third Embodiment) FIG. 7 is a schematic configuration diagram of a wind power generation device 300 according to the third embodiment. The wind power generation device 300 according to the third embodiment includes a clutch 61, a rotation sensor 31, and a control unit 33, similar to the second embodiment. Further, in the wind power generation device 300, a clutch 62 that can be disconnected and connected by an external signal is provided between the main windmill 11 and the starting windmill 17 instead of the one-way clutch 19. Similar to the clutch 61 described above, the clutch 62 can be a known one such as an electromagnetic clutch. This clutch 62 is connected to the control unit 33. The control unit 33 transmits a control signal to the clutch 62 and controls the drive unit (not shown) of the clutch 62. The control unit 33 activates the clutch 62 according to the rotational speed of the main windmill 11 detected by the rotation sensor 31, and disconnects and connects the rotational transmission between the main windmill 11 and the starting windmill 17.

[0036] Next, the power generation in the wind power generation device 300 will be described. (During Rotational Startup) When the wind speed is low and the rotational force of the main windmill 11 is insufficient to be generated, first, the starting windmill 17 starts to rotate with the weak wind. At this time, the rotation between the main windmill 11 and the starting windmill 17 can be transmitted by the clutch 62. Therefore, due to the rotational force of the starting windmill 17, the main windmill 11 connected to the starting windmill 17 starts to rotate. In this way, in the wind power generation device 300, even when the wind is weak at a low wind speed where the main windmill 11 does not start to rotate, the main windmill 11 is started to rotate by the rotational force of the starting windmill 17 that has started to rotate with this weak wind. Also, at the time of this starting rotation, the transmission of the rotation of the main windmill 11 to the generator 13 by the clutch 61 is blocked by the control unit 33, and the main windmill 11 rotates idly with respect to the generator 13. Thereby, the resistance of the generator 13 to the main windmill 11 at the time of starting is suppressed, and the main windmill 11 that rotates by the rotational force of the starting windmill 17 can be started more smoothly.

[0037] (During normal power generation) When the wind speed of the wind increases, the main windmill 11 that has started to rotate by the rotational force of the starting windmill 17 rotates with the blades 21 receiving the wind. Then, when it is detected by the rotation sensor 31 that the rotational speed of this main windmill 11 has reached the cut-in speed that is faster than the starting windmill 17, the power transmission by the clutch 62 is blocked by the control signal output from the control unit 33, and the power transmission by the clutch 61 is connected. Thereby, the transmission of rotation between the starting windmill 17 and the main windmill 11 by the clutch 62 is blocked, and the rotation of the main windmill 11 is transmitted to the generator 13 by the clutch 61. Also, when the main windmill 11 rotates at a speed higher than the cut-in speed, the rotation from the starting windmill 17 is disconnected by the clutch 62, and since the rotation of the starting windmill 17 is blocked, the main windmill 11 rotates efficiently with the rotational resistance from the starting windmill 17 blocked. The rotation of this main windmill 11 is transmitted to the generator 13 via the clutch 61. Thereby, power is efficiently generated by the generator 13.

[0038] (Fourth Embodiment) FIG. 8 is a schematic configuration diagram of a wind power generation device 400 according to the fourth embodiment. The wind power generation device 400 according to the fourth embodiment adds a speed increaser 27 between the main windmill 11 and the generator 13 in the wind power generation device 100 according to the first embodiment. The speed increaser 27 increases the rotation speed of the main windmill 11 and transmits it to the generator 13. As the speed increaser 27, a known one such as a speed increasing mechanism having a structure in which a plurality of planetary gears revolve while rotating around a sun gear can be used.

[0039] In the wind power generation device 400 according to this fourth embodiment, by providing the speed increaser 27 between the main windmill 11 and the generator 13, while achieving miniaturization, weight reduction, and cost reduction, the rotation of the main windmill 11 is increased in speed by the speed increaser 27, and the increased speed rotation is transmitted to the generator 13 to enable efficient power generation.

[0040] When the main windmill 11 is a Darrieus-type lift windmill, it is generally designed to be combined with an axial-type generator suitable for power generation at low-speed rotation so as to be able to cope with different wind conditions. However, since the axial-type generator has a large diameter and a large mass, the cost tends to be high. Moreover, the power generation efficiency decreases at extremely low-speed rotation.

[0041] In the wind power generation device 400 according to the fourth embodiment, by providing the speed increaser 27 between the main windmill 11 and the generator 13, a high-speed rotation type radial generator using radially opposed magnets can be used as the generator 13, and the power generation efficiency can be improved by high-speed rotation.

[0042] Note that in the wind power generation device 200 according to the second embodiment and the wind power generation device 300 according to the third embodiment in which a clutch 61 is provided between the main windmill 11 and the generator 13, a speed increaser 27 may also be provided between the main windmill 11 and the generator 13. Also in this case, while achieving miniaturization, weight reduction, and cost reduction, the rotation of the main windmill 11 can be increased in speed by the speed increaser 27 and transmitted to the generator 13 to enable efficient power generation.

[0043] In addition, when providing the speed increaser 27, it is preferable to provide the clutch 61 described above on the upstream side of the power transmission to the speed increaser 27. By disconnecting the clutch 61 at the start of rotation, the windmill can be started rotating without being subjected to the resistance of the speed increaser 27 even at a low wind speed.

[0044] (Fifth Embodiment) FIG. 9 is a schematic configuration diagram of the wind power generation device 500 according to the fifth embodiment. The wind power generation device 500 according to the fifth embodiment adds a mechanical brake 63 between the speed increaser 27 and the generator 13 in the wind power generation device 400 according to the fourth embodiment.

[0045] The mechanical brake 63 adjusts the rotational speed of the main windmill 11 by its operation. As the mechanical brake 63, for example, a known mechanism such as a mechanism that sandwiches a disk rotating together with the rotating shaft 15 axially by pads operated by a driving unit and decelerates by the friction generated thereby can be used.

[0046] In addition, the wind power generation device 500 may further include a rotation sensor (speed detection unit) 31 and a control unit (speed adjustment unit) 33, and may further include a short-circuit circuit (electromagnetic brake circuit) 35. The rotation sensor 31 and the short-circuit circuit 35 are respectively connected to the control unit 33. Further, the control unit 33 is connected to the mechanical brake 63.

[0047] The rotation sensor 31 detects the rotational speed of the main windmill 11 and transmits it to the control unit 33. The control unit 33 transmits a control signal to the mechanical brake 63 and controls a driving unit (not shown) of the mechanical brake 63. The control unit 33 operates the mechanical brake 63 according to the rotational speed of the main windmill 11 detected by the rotation sensor 31 and reduces the rotational speed of the main windmill 11.

[0048] In addition, the control unit 33 transmits a control signal to the short - circuit circuit 35. The short - circuit circuit 35 is a circuit provided in the generator 13 and operates according to the control signal from the control unit 33. The short - circuit circuit 35 short - circuits the output terminals of the generator 13 to activate the electromagnetic brake. Thereby, the rotational speed of the main windmill 11 is suppressed by the electromagnetic brake of the generator 13.

[0049] Next, the control in the wind power generation device 500 will be described. (Normal power generation) When the blades 21 receive the wind and the main windmill 11 rotates, the rotation of the rotating shaft 15 is speed - increased by the speed - increaser 27, and the speed - increased rotation is transmitted to the generator 13 to generate electricity. At this time, if the generator 13 is a radial - type generator, high - efficiency power generation can be achieved by the high - speed rotating shaft 15.

[0050] (Brake control) (1) Operation of the electromagnetic brake When the wind speed of the wind received by the main windmill 11 increases and the rotational speed of the main windmill 11 reaches a predetermined first cut - out speed, the control unit 33 transmits a control signal to the short - circuit circuit 35 of the generator 13. Then, the output terminals of the generator 13 are short - circuited and the electromagnetic brake operates, suppressing the rotational speed of the main windmill 11. This first cut - out speed is preferably set to a rotational speed at which damage due to the centrifugal force of the rotating main windmill 11 and burnout of the generator 13 can be sufficiently suppressed. That is, when the rotational speed of the main windmill 11 reaches the first cut - out speed and the electromagnetic brake operates, damage due to the centrifugal force of the rotating main windmill 11 and burnout of the generator 13 are suppressed.

[0051] (2) Operation of the mechanical brake When the wind speed received by the main wind turbine 11 further increases and the electromagnetic brake cannot suppress the rotational speed of the main wind turbine 11 and the speed increases, when the rotational speed of the main wind turbine 11 reaches the second cut-out speed, the control unit 33 transmits a control signal to the mechanical brake 63. Then, the mechanical brake 63 operates and the main wind turbine 11 is mechanically braked, and the rotational speed of the main wind turbine 11 is suppressed. This second cut-out speed is a rotational speed faster than the first cut-out speed, and this second cut-out speed is also set to a rotational speed at which there is no risk of damage due to the centrifugal force of the rotating main wind turbine 11 and burnout of the generator 13. That is, when the rotational speed of the main wind turbine 11 reaches the second cut-out speed and the mechanical brake 63 operates and is mechanically braked, damage due to the centrifugal force of the rotating main wind turbine 11 and burnout of the generator 13 are suppressed.

[0052] As described above, according to the wind power generation device 500 according to the fifth embodiment, by providing the mechanical brake 63 between the speed increaser 27 and the generator 13, while achieving miniaturization, weight reduction, and cost reduction, the rotation of the main wind turbine 11 can be increased in speed by the speed increaser 27 and transmitted to the generator 13, enabling high-efficiency power generation.

[0053] Also, when the wind speed received by the main wind turbine 11 excessively increases, by operating the mechanical brake 63 between the speed increaser 27 and the generator 13, the rotation of the main wind turbine 11 can be suppressed. Thereby, damage due to the centrifugal force of the rotating main wind turbine 11 and burnout of the generator 13 can be suppressed, and power generation can be performed safely.

[0054] Moreover, since the mechanical brake 63 is provided on the rotation shaft 15 on the downstream side of power transmission from the speed increaser 27, that is, on the side opposite to the main wind turbine 11 side of the speed increaser 27, as the braking force required for this mechanical brake 63, a small brake capacity corresponding to the speed increase ratio of the speed increaser 27 is sufficient. Therefore, even with the mechanical brake 63, a compact device structure can be achieved.

[0055] Further, according to the rotational speed of the main windmill 11 detected by the rotation sensor 31, the control unit 33 transmits a control signal to the short - circuit circuit 35 to activate the electromagnetic brake, thereby reducing the rotational speed of the main windmill 11. As a result, damage due to centrifugal force or the like of the rotating main windmill 11 and burnout of the generator 13 can be more reliably suppressed, and power generation can be performed safely.

[0056] In addition, in the above - mentioned wind power generation device 500, as the mechanical brake 63 provided between the speed increaser 27 and the generator 13, for example, a brake of a type that is automatically activated by centrifugal force or the like may be used. In that case, control of the mechanical brake 63 by the control unit 33 becomes unnecessary, and the structure can be simplified.

[0057] Also, the mechanical brake 63 may be disposed between the main windmill 11 and the generator 13 of the wind power generation device 100 of the first embodiment described above. In that case, a rotation sensor 31 for detecting the rotational speed of the main windmill 11 and a control unit 33 for activating the mechanical brake 63 according to the rotational speed of the main windmill 11 detected by the rotation sensor 31 may be provided. Further, the mechanical brake 63 may be disposed between the main windmill 11 and the clutch 61 in the wind power generation devices 200 and 300 of the second and third embodiments. Note that the mechanical brake 63 only needs to be able to attenuate the rotational force of the main windmill 11 and transmit it to the generator 13, and is not limited to the above - mentioned arrangement examples. In any case, damage to the main windmill 11 and burnout of the generator 13 can be suppressed by the mechanical brake 63.

[0058] Thus, the present invention is not limited to the above - mentioned embodiments, and combinations of the respective configurations of the embodiments, as well as changes and applications by those skilled in the art based on the description in the specification and well - known techniques, are also within the scope contemplated by the present invention and are included in the scope for which protection is sought.

[0059] As described above, the following matters are disclosed in this specification. (1) A vertical - axis type main windmill, and a generator that generates electricity by receiving the rotation of the main windmill, An activation windmill connected to the main windmill and having a lower wind speed required for rotational startup than the main windmill, is provided, wherein the main windmill is a wind power generation device that starts rotating by the rotational force transmitted from the activation windmill that has started rotating by the wind at a low wind speed where the wind does not reach the wind speed required for rotational startup. According to this wind power generation device, even when the wind is weak at a low wind speed such that the main windmill does not start rotating, the main windmill can be started rotating by the rotational force of the activation windmill that has started rotating with this weak wind. That is, the main windmill can be smoothly started rotating and the generator can efficiently generate electricity.

[0060] (2) The wind power generation device according to (1), wherein the main windmill is a lift type windmill of a Darrieus type or a straight blade type. According to this wind power generation device, a main windmill composed of a lift type windmill of a Darrieus type or a straight blade type is provided. A lift type windmill of a Darrieus type or a straight blade type has characteristics of high rotational speed and high efficiency, but since the rotational torque obtained from the wind in a stopped state is small, it may be difficult to start by itself. By providing an activation windmill that starts rotating with a weak wind to the main windmill composed of this Darrieus type or straight blade type lift type windmill, the main windmill composed of the Darrieus type or straight blade type lift type windmill can be smoothly started rotating by the activation windmill and the generator can efficiently generate electricity.

[0061] (3) The wind power generation device according to (1), wherein the activation windmill is a drag type windmill of a Savonius type or a cross flow type. According to this wind power generation device, an activation windmill composed of a drag type windmill of a Savonius type or a cross flow type is provided. A drag type windmill of a Savonius type or a cross flow type has a large starting torque obtained from the wind in a stopped state, so it can be started even with a weak wind. By connecting the Savonius type or cross flow type drag type windmill that starts rotating with this weak wind to the main windmill, the main windmill can be smoothly started rotating by the activation windmill composed of this drag type windmill and the generator can efficiently generate electricity.

[0062] (4) The main windmill is a lift-type windmill of the Darrieus type or the straight blade type, The starting windmill is a drag-type windmill of the Savonius type or the cross-flow type, and the wind power generation device according to (1). According to this wind power generation device, it includes a main windmill composed of a lift-type windmill of the Darrieus type or the straight blade type, and a starting windmill composed of a drag-type windmill of the Savonius type or the cross-flow type. The lift-type windmill of the Darrieus type or the straight blade type has the characteristics of high rotational speed and high efficiency, but since the rotational torque obtained from the wind in the stopped state is small, it may be difficult to start by itself. On the other hand, the drag-type windmill of the Savonius type or the cross-flow type has a large starting torque obtained from the wind in the stopped state, so it can start even with a weak wind. By providing the drag-type windmill of the Savonius type or the cross-flow type that rotates and starts with this weak wind on the main windmill composed of a lift-type windmill of the Darrieus type or the straight blade type, the starting windmill composed of a drag-type windmill can smoothly rotate and start the main windmill composed of a lift-type windmill, and efficiently generate electricity with a generator.

[0063] (5) Between the main windmill and the starting windmill, there is provided a one-way clutch that idles when the rotational speed of the main windmill reaches a cut-in speed faster than that of the starting windmill and releases the connection between the main windmill and the starting windmill. The wind power generation device according to any one of (1) to (4). According to this wind power generation device, when the main windmill, which is difficult to start with a weak wind, is rotated and started by the starting windmill, and when this main windmill rotates sufficiently by itself and reaches a cut-in speed that is faster than the rotational speed of the starting windmill, the one-way clutch idles and the connection between the main windmill and the starting windmill is released. As a result, when the main windmill rotates at a speed higher than the cut-in speed, the rotation from the starting windmill is disconnected by the one-way clutch, and the rotational resistance from the starting windmill that rotates at a lower speed than the main windmill is blocked. As a result, the main windmill can rotate with low resistance and efficiently generate electricity by its rotation.

[0064] (6) A clutch provided between the main windmill and the starting windmill, A speed detection unit that detects the rotational speed of the main windmill, When the rotational speed of the main wind turbine detected by the speed detection unit reaches the cut-in speed, a control unit that activates the clutch to release the connection between the main wind turbine and the starting wind turbine; The wind power generation device according to any one of (1) to (4), comprising: According to this wind power generation device, when the main wind turbine, which is difficult to start in weak winds, is rotationally started by the starting wind turbine and the speed detection unit detects that the main wind turbine has reached the cut-in speed, which is a rotational speed at which the main wind turbine can rotate sufficiently on its own, the control unit activates the clutch to release the connection between the main wind turbine and the starting wind turbine. As a result, when the main wind turbine rotates at a speed higher than the cut-in speed, the rotation from the starting wind turbine is disconnected by the clutch, and the rotational resistance from the starting wind turbine, which rotates at a lower speed than the main wind turbine, is blocked. Consequently, the main wind turbine can rotate with low resistance and can efficiently generate electricity by its rotation.

[0065] (7) The wind power generation device according to any one of (1) to (6), further comprising a clutch provided between the main wind turbine and the generator for disconnecting and connecting the rotation transmitted from the main wind turbine to the generator. According to this wind power generation device, by blocking the transmission of the rotation of the main wind turbine to the generator by the clutch until the main wind turbine rotates sufficiently, the resistance to the main wind turbine can be suppressed and the rotational starting performance can be improved.

[0066] (8) The wind power generation device according to any one of (1) to (7), wherein the generator is a radial type including a shaft body, a rotor provided around the shaft body, and a stator disposed opposite to the periphery of the rotor. According to this wind power generation device, since it is equipped with a radial type generator that efficiently generates electricity at high rotation speeds, efficient power generation is possible by the rotational force of the main wind turbine.

[0067] (9) The wind power generation device according to any one of (1) to (8), further comprising a speed increaser provided between the main wind turbine and the generator for increasing the rotation speed of the main wind turbine and transmitting it to the generator. According to this wind power generation device, by providing a speed increaser between the main windmill and the generator, while achieving miniaturization, weight reduction, and cost reduction, the rotation of the main windmill can be speeded up by the speed increaser and transmitted to the generator to generate electricity efficiently.

[0068] (10) The wind power generation device according to any one of (1) to (9), comprising a mechanical brake provided between the main windmill and the generator for adjusting the rotational speed of the main windmill. According to this wind power generation device, the rotation of the main windmill can be decelerated by a mechanical brake as necessary, thereby preventing the occurrence of damage to the rotating main windmill and damage to the generator.

Explanation of Signs

[0069] 11 Main windmill 13 Generator 17 Starting windmill 19 One-way clutch 27 Speed increaser 31 Rotation sensor (speed detection unit) 33 Control unit 51 Shaft body 53 Rotor 55 Stator 61, 62 Clutch 63 Mechanical brake 100, 200, 300, 400 Wind power generation device

Claims

1. A vertical-axis main wind turbine, a generator that generates electricity when the rotation of the main wind turbine is transmitted thereto, a starting wind turbine connected to the main wind turbine and having a lower wind speed required for rotational startup than the main wind turbine, comprising: when the wind speed is low and less than the wind speed required for rotational startup, the main wind turbine is rotationally started by the rotational force transmitted from the starting wind turbine that has been rotationally started by the low-speed wind, a wind power generation device.

2. The main wind turbine is a lift-type wind turbine of the Darrieus type or the straight-blade type, The wind power generation device according to Claim 1.

3. The starting wind turbine is a drag-type wind turbine of the Savonius type or the cross-flow type, The wind power generation device according to Claim 1.

4. The main wind turbine is a lift-type wind turbine of the Darrieus type or the straight-blade type, The starting wind turbine is a drag-type wind turbine of the Savonius type or the cross-flow type, The wind power generation device according to Claim 1.

5. Between the main wind turbine and the starting wind turbine, there is provided a one-way clutch that idles when the rotational speed of the main wind turbine reaches a cut-in speed that is higher than that of the starting wind turbine, and releases the connection between the main wind turbine and the starting wind turbine, The wind power generation device according to Claim 1.

6. A clutch provided between the main wind turbine and the starting wind turbine, a speed detection unit that detects the rotational speed of the main wind turbine, a control unit that operates the clutch to release the connection between the main wind turbine and the starting wind turbine when the rotational speed of the main wind turbine detected by the speed detection unit reaches the cut-in speed, The wind power generation device according to Claim 1, comprising:

7. Between the main wind turbine and the generator, there is provided a clutch that disconnects and connects the rotation transmitted from the main wind turbine to the generator, The wind power generation device according to Claim 1.

8. The generator is of a radial type comprising a shaft body, a rotor provided around the shaft body, and a stator disposed opposite to the periphery of the rotor, The wind power generation device according to Claim 1.

9. Between the main wind turbine and the generator, there is provided a speed increaser that increases the rotation of the main wind turbine and transmits it to the generator, The wind power generation device according to any one of Claims 1 to 8.

10. A mechanical brake is provided between the main wind turbine and the generator to adjust the rotational speed of the main wind turbine, The wind power generation device according to any one of Claims 1 to 8.

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