JP2016169711A - Wind turbine for wind power generation and wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind turbine for wind power generation and a wind power generator having a vertical main shaft and capable of rotating blades even if wind power energy is low.SOLUTION: This wind turbine for wind power generation is a wind turbine for wind power generation having a vertical main shaft 22. This wind turbine comprises a vertical main shaft 22 rotatably arranged around its axis, supporters 23 integrally arranged with the vertical main shaft 22 and blades 24 connected to the vertical main shaft 22 through supporters 23 and rotated around the axis concentric with the axis while receiving wind. A plurality of blades 24 extending in a vertical direction are spaced apart from the vertical main shaft 22 and arranged around the vertical main shaft 22. When this wind turbine is installed at Northern hemisphere of the earth, each of the blades 24 has a sectional shape for generating rotating power rotated in a counter-clockwise direction R1 as seen from its top plan view by wind power. Each of the blades 24 is rotated in the counter-clockwise direction R1 under application of Coriolis force.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wind turbine and a wind power generator for wind power generation having a vertical main shaft, and relates to a technique capable of rotating a blade with a small amount of wind energy.

A vertical axis wind power generator having a vertical main shaft has been proposed (Patent Document 1).
The wind turbine for vertical shaft type power generation is designed with the shape and number of blades so that a certain rotational speed can be obtained even with low speed wind and power can be generated efficiently.

JP 2006-118384 A

  However, in a conventional wind turbine for vertical axis wind power generation, the rotation direction of the blades is not defined, and the clockwise direction in the plan view (clockwise) is the standard. On the other hand, in the wind turbine for vertical axis wind power generation, in order to make the feature of being able to rotate even with low-speed wind even more effective, a technique capable of rotating the blades with less wind energy has been desired.

  An object of the present invention is to provide a wind turbine for wind power generation and a wind power generator capable of rotating blades with a small amount of wind energy in a wind turbine for power generation having a vertical main shaft.

  A wind turbine for wind power generation according to the present invention is a wind turbine for wind power generation having a vertical main shaft, and a plurality of blades extending in the vertical direction are provided around the vertical main shaft apart from the vertical main shaft, The wing is characterized by having a cross-sectional shape in which wind force generates a rotational force that rotates counterclockwise in a plan view when the windmill is installed in the northern hemisphere of the earth.

In the process of developing small wind power generators, it was found that the blades rotate even with a small amount of wind energy by specifying the rotation direction of the blades to a specific direction. Specifically, in Japan in the Northern Hemisphere, we confirmed that the direction of the wings extending in the vertical direction of the vertical axis wind turbine was turned upside down and attached to the main shaft. did. In the Northern Hemisphere, the typhoon, whirlpool, and drainage vortex are all counterclockwise due to the rotation of the earth. This is thought to be due to the Coriolis force acting on the earth's rotation. On the other hand, the direction of rotation of a windmill is determined based on the lift generated by the difference in flow velocity of air flowing on both sides of the blade when the blade receives wind due to the cross-sectional shape of the blade.
According to the wind turbine of this configuration, when installed in the northern hemisphere, each wing has a cross-sectional shape that generates a rotational force that rotates counterclockwise in plan view, so a vertical axis with a conventional clockwise wing. The wind turbine for wind power generation can effectively use the action caused by the rotation of the earth to reduce the rotational resistance and rotate many blades under the same conditions. Therefore, it is possible to generate power from less wind energy using a wind turbine for power generation having a vertical main shaft.

The windmill may be a straight blade vertical axis type windmill. In this case, the ratio of lift and drag acting on the wing can be increased. Also, a large torque can be obtained with a high peripheral speed ratio.
A wind power generator according to the present invention includes any one of the wind turbines according to the present invention and a power generator driven by the wind turbine. According to this configuration, since it is possible to generate power from less wind energy, it is possible to install the wind power generator in a place where installation has conventionally been postponed.

  In the generator, either one of the output core around which the output winding is wound and the field core around which the main field winding and the sub field winding are wound serves as a stator, and the other serves as a rotor. A rectifying means is connected to the magnetic winding, the blades rotate, and the stator and the rotor rotate relative to each other. The self-excited type obtains generated power, and generates an initial magnetic force necessary for the initial excitation of power generation. It may have excitation means. In this case, since it is a self-excited type that performs excitation using the main field winding, power generation can be performed without the need for a normal permanent magnet for power generation or an external power source that supplies power for external excitation from the outside. . Self-excited generators do not require external excitation during normal rotation, but require some excitation at the start of rotation. Since the initial excitation means generates a magnetic force necessary for the initial excitation of such power generation, a normal magnetic force for obtaining generated power at normal time is not necessary. Therefore, the cogging torque is not a problem in practical use, and the rotor can be rotated with a small torque.

A wind turbine for power generation according to the present invention is a wind turbine for wind power generation having a vertical main shaft, and a plurality of blades extending in the vertical direction are provided around the vertical main shaft away from the vertical main shaft, and each of the blades When this windmill is installed in the northern hemisphere of the earth, it has a cross-sectional shape that generates a rotational force that rotates counterclockwise in plan view with wind power, so that the wing can be rotated even with a small amount of wind energy.
Since the wind power generator according to the present invention includes any one of the wind turbines according to the present invention and the power generator driven by the wind turbine, the blades can be rotated even with a small amount of wind energy.

1 is a cutaway plan view of a wind turbine for wind power generation according to an embodiment of the present invention. It is a front view of the windmill. (A) is the front view of the blade | wing of the windmill, (B) is the IIIB-IIIB sectional view taken on the line of FIG. 3 (A). It is the IV-IV sectional view taken on the line of FIG. It is explanatory drawing which combined the fracture | rupture front view and circuit diagram of the generator main body of the generator which concerns on embodiment of this invention. It is explanatory drawing which expands and shows the generator main body linearly. It is a circuit diagram which shows the electric circuit structure of the generator main body.

  A wind turbine and a wind power generator for wind power generation according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cutaway plan view of a wind turbine 18 for wind power generation according to this embodiment. FIG. 2 is a front view of the wind turbine 18. The wind turbine 18 is a so-called straight blade vertical axis wind turbine in which the blades 24 extend in the vertical direction. This windmill 18 is installed in the northern hemisphere. As shown in FIGS. 1 and 2, the wind power generator 19 includes a windmill 18 and a power generator 26 (described later) driven by the windmill 18. The windmill 18 includes a support plate 20, a frame 21, a vertical main shaft 22, a support 23, wings 24, and a base 25. The support plate 20 is a flat plate placed on the ground surface, and a base 25 is installed on the upper surface of the support plate 20. Inside the base 25, a generator 26 described later is provided.

  The frame body 21 has a plurality of (four in this example) support columns 21a extending upward from the support plate 20, a plurality of connection members 21b for connecting these support columns 21a in the horizontal direction, and a plurality of installation members 21c. . These connecting members 21b include a plurality of upper connecting members 21b that connect the upper ends of the adjacent columns 21a to each other, and a plurality of lower connecting members 21b that connect the vicinity of the lower ends of the adjacent columns 21a to each other. An erection member 21c is installed over the linking member 21b defined among the upper linking members 21b (upper side in FIG. 2) and the linking member 21b facing the linking member 21b. In addition, the erection member 21c is installed over the linking member 21b defined in the lower linking member 21b (the lower side in FIG. 2) and the linking member 21b facing the linking member 21b.

  A vertical main shaft 22 is rotatably supported via a bearing 27 at an intermediate portion in the longitudinal direction of each erection member 21c. The vertical main shaft 22 extends in the vertical direction, and the lower end portion of the vertical main shaft 22 is connected to the inside of the base 25. A plurality of supports 23 are respectively provided so as to extend outward in the radial direction from the middle portion in the longitudinal direction of the vertical main shaft 22. These supports 23 are provided, for example, so as to be parallel in the front view of the windmill and in phase in the plan view of the windmill.

  Wings 24 are provided at the tip portions on both sides of the plurality of supports 23. In this example, one wing 24 is connected to one end of the upper and lower supports 23, 23, and another wing 24 is connected to the other end of the upper and lower supports 23, 23. These blades 24, 24 are provided at positions 180 degrees out of phase with the vertical main shaft 22 as the center. Each wing 24 extends in the vertical direction and is provided in the frame body 21 so as not to interfere with the frame body 21. Each blade 24 receives wind from various directions and rotates about the axis L1 of the vertical main shaft 22.

  3A is a front view of the blade 24 of this windmill, and FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB in FIG. As shown in FIGS. 3A and 3B, the blade 24 includes a straight portion 28 and blade tip portions 29 and 29. The straight portion 28 extends in parallel with the vertical main shaft 22 (FIG. 2), and has the same width at any position in the vertical direction when viewed from the front shown in FIG. 3 (A). Further, as shown in FIG. 3B, the straight portion 28 is formed with the same thickness at any position in the vertical direction.

  As shown in FIGS. 2 and 3, the blade tip 29 has a cross-section obtained by cutting the blade tip 29 along a plane including the axis L1 toward the vertical main shaft L1 side from the base end toward the tip. The cross-sectional shape is inclined so as to reach. As shown in FIG. 3A, the blade tip portion 29 has a tapered shape that becomes narrower from the base end toward the tip. Further, as shown in FIG. 3B, the blade tip portion 29 is formed to have a thickness that becomes thinner from the base end toward the tip.

FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.
As shown in FIGS. 1 and 4, the plurality (two in this example) of blades 24 have a cross-sectional shape that regulates the rotation direction to a specific direction (counterclockwise indicated by arrow R <b> 1 in FIG. 1) regardless of the wind direction. Yes. In other words, each of the plurality of blades 24 has a section that is cut along a plane perpendicular to the axis L1 of the vertical main shaft 22 and is asymmetric with respect to the rotation direction of the blades 24, and is a portion on the thick side in the same section ( The lower part of FIG. 4 is the tip of each blade 24 in the rotational direction. Further, the outer surface 28a of the straight portion 28 of each blade 24 is a curved surface that protrudes radially outward, and the majority of the inner surface 28b of the straight portion 28 of each blade 24 is a flat surface 28ba.

  Instead of the majority of the inner surface 28b being the flat surface 28ba, the inner surface 28b may be a curved surface having a larger radius of curvature than the outer surface 28a. The connecting portion of the inner side surface 28b of the straight portion 28 and one end in the circumferential direction of the outer side surface 28a (the lower side in FIG. 4) forms an arc surface 28bb. The connecting portion between the arc surface 28bb and the flat surface 28ba is formed so as to continue smoothly without a step.

  A connecting portion between the inner side surface 28b of the straight portion 28 and the other circumferential end (upper side in FIG. 4) of the outer side surface 28a is formed at an acute corner. The tip of the support 23 is connected to a portion of the flat surface 28ba on the inner side surface 28b of the straight portion 28 that is closer to the arc surface 28bb. The flat surface 28ba forms a plane perpendicular to the longitudinal direction of the support 23, and this perpendicular plane extends along the up-down direction.

  When such a blade 24 receives wind, the flow velocity along the outer surface 28a is faster than the flow velocity along the inner surface 28b, and the pressure distribution around the blade increases the negative pressure on the outer surface 28a. Therefore, lift L from the inner surface side to the outer surface side is generated as a whole blade. As shown in FIG. 4, let L be the lift generated in the blade by the combined wind speed W of the relative wind speed v and the wind speed U generated by the rotation of the blade 24. Then, the combined component (Lt−Dt) of the lift L and the effectiveness D in the t direction becomes the force in the rotational direction of the blade 24.

When the windmill 18 having the plurality of blades 24 whose rotation direction is defined counterclockwise regardless of the wind direction is installed in the northern hemisphere, the wind turbine for vertical axis wind power generation having the conventional clockwise blades is By effectively utilizing the Coriolis force generated by the rotation of the blade, the rotational resistance can be reduced, and the blades 24 can be rotated a lot under the same conditions. Therefore, it is possible to generate power from less wind energy by using the wind turbine 18 for power generation having the vertical main shaft 22.
Since the wind force 18 is a straight blade vertical axis type wind turbine, the ratio of lift and drag acting on the blade 24 can be increased. Also, a large torque can be obtained with a high peripheral speed ratio.

The generator 26 will be described with reference to FIGS.
Inside the base 25 (FIG. 2), there is provided a generator 26 that generates electricity by rotating a rotor 5 described later by rotation of the vertical main shaft 22 (FIG. 2). FIG. 5 is an explanatory diagram in which a broken front view and a circuit diagram of the generator body 1 of the generator 26 are combined. In FIG. 5, the generator body 1 of the generator 26 includes an annular stator 4 and a rotor 5 that is installed inside the stator 4 so as to be rotatable around the center of the stator 4. For example, the rotor 5 and the above-described vertical main shaft (FIG. 2) are connected coaxially. The stator 4 has an output iron core 6 and an output winding 7. This embodiment is an example applied to a two-pole generator, and the output iron core 6 is formed with tooth-shaped magnetic pole portions 6b protruding inward at two locations in the circumferential direction of an annular yoke portion 6a. The output winding 7 is wound around each magnetic pole portion 6b.

  As shown in FIG. 6, the output windings 7 of the magnetic pole portions 6 b are connected in series such that different magnetic poles appear on the magnetic pole surfaces facing the inner diameter side of the adjacent magnetic pole portions 6 b of the output iron core 6. Both ends of the output winding 7 become terminals 7a and 7b, and an external load 3 is connected to these terminals 7a and 7b as shown in FIG. 5, and current is taken out from the generator.

  As shown in FIGS. 5 and 6, the rotor 5 has a field iron core 8, and a main field winding 9 and a subfield winding 10 wound around the field iron core 8. The field iron core 8 is provided with a plurality of tooth-shaped magnetic pole portions 8b protruding in the circumferential direction on the outer periphery of an iron core body 8a having a center hole. Three magnetic pole portions 8 b are provided for each magnetic pole portion 6 b of the output iron core 6.

  The main field winding 9 is wound around two adjacent magnetic pole portions 8b and 8b, and each main field winding 9 wound around the two magnetic pole portions 8b and 8b is a set of two. The adjacent magnetic pole groups are connected in series so that different magnetic poles appear on the magnetic pole surfaces. The sub-field winding 10 is shifted in phase by the amount of the main field winding 9 and one magnetic pole portion 8b, and is spread over two adjacent magnetic pole portions 8b and 8b in the same manner as the main field winding 9. It is rolled up. The subfield windings 10 wound around the two magnetic pole portions 8b and 8b are connected in series so that different magnetic poles appear on the magnetic pole surfaces of adjacent magnetic pole pairs that are in pairs. Yes. Terminals at both ends of each series connection body of the main field winding 9 and the sub field winding 10 are shown in FIG. 6 by reference numerals 9a, 9b, 10a, 10b, respectively.

  As shown in FIG. 7, a rectifying element (rectifying means) 11 is connected in parallel to the main field winding 9, and a current in a direction that allows the rectifying element 11 to flow flows through the main field winding 9. The sub-field winding 10 is connected in series with the main field winding 9, and a rectifying element (rectifying means) 12 is connected in series, and the sub-field winding 10 has the same direction as the main field winding 9. Only current flows. The arrows in the figure indicate the direction of current flow.

  This generator 26 includes an initial excitation means 2 that generates a magnetic force necessary for initial excitation of power generation in a self-excited generator having such a subfield winding 10. As shown in FIG. 5, a magnetizing power source 14 is connected to the output winding 7 in parallel with the external load 3 via the switching means 13. The magnetizing power supply 14 and the switching means 13 constitute the initial excitation means 2. The switching means 13 is a semiconductor switching element or a contact switch. The magnetizing power source 14 is a storage means such as a secondary battery or a capacitor. When the external load 3 is a secondary battery, it may be used as a magnetizing power source.

  In order to magnetize, a current of a predetermined magnitude may be passed for a very short time. The degree of magnetization may be such that residual magnetism necessary for initial excitation for the start of power generation is obtained, and is determined by the magnitude of current and the ON time of the switching means 13. The opening / closing operation of the switching means 13 is performed by the opening / closing control means 15. For example, the opening / closing control means 15 monitors the detection signal of the rotation detection means 16 that detects the rotation of the rotor 5. When it is detected that the rotor 5 has started rotating from a stationary state, the switching means 13 is magnetized. Turn it on only for the required setting time.

  When the rotation stop time of the rotor 5 is short, sufficient residual magnetism remains, so that the opening / closing control means 15 turns on the switching means 13 only when the rotation starts after the rotor 5 stops for a set time or longer. For example, the switching unit 13 may be turned on according to the set conditions. Further, the magnetizing may be performed only when the power generation is not started even when the predetermined rotational speed is reached, or the magnetizing may be performed when the rotation of the generator is stopped every predetermined time. .

  In this embodiment, the magnetizing power source 14 is connected to the output winding 7. However, as shown in FIG. 7, the magnetizing power source 14 may be connected to the field windings 9 and 10 via the switching means 13. good. Also in this example, the magnetizing power source 14 is a secondary battery or a capacitor. In order to magnetize, a current of a predetermined magnitude may be passed for a very short time. The switching means 13 is controlled to be opened and closed by the opening / closing control means 15 as in the embodiment of FIG.

The operation when the rotor 5 is rotating and generating power will be described.
As shown in FIG. 7, since the rectifying element 11 is connected in parallel to the main field winding 9, a current in a direction that allows the rectifying element 11 to flow flows through the main field winding 9. Therefore, a magnetic flux having a direction determined by a current that can be passed through the main field winding 9 is generated. In addition, due to electromagnetic induction, a current flows in a direction that prevents a decrease in magnetic flux in the same direction as a magnetic flux generated by the current, but a current does not flow in a direction that prevents an increase in magnetic flux. Therefore, the decrease of the magnetic flux is prevented, but the increase of the magnetic flux is not prevented. A rectifying element 12 is connected in series to the sub-field winding 10, and only a current in the same direction as the main field winding 9 flows.

  As shown in FIGS. 5 to 7, a current flows through the main field winding 9 due to the residual magnetism of the output iron core 6 or the field iron core 8. With this current, the magnetic flux generated by the main field winding 9 changes the magnetic flux linked to the sub field winding 10, and a voltage is generated in the sub field winding 10. With this voltage, the sub-field winding 10 supplies a current through the main field winding 9 and increases the current flowing through the main field winding 9. When no voltage is induced in the subfield winding 10 and no current is supplied, a return current flows through the commutator 11 in the main field winding 9 to maintain the magnetic flux of the main field winding 9.

  Since the current is supplied to the main field winding 9 and the magnetic flux generated by the main field winding 9 is increased, the magnetic flux linked to the subfield winding 10 is also increased, and a larger current is supplied to the main field winding 9. 9 is supplied. In this manner, the current in the main field winding 9 gradually increases, and a field magnetic flux necessary for power generation is created. Due to the relative motion of the output iron core 6 and the field iron core 8, the flux linkage of the output winding 7 changes to generate a voltage.

  As described above, power is generated while the rotor 5 is rotating. However, if the rotor 5 is stopped for a long time to some extent, there is no residual magnetism in either the output iron core 6 or the field iron core 8, Alternatively, the residual magnetism is insufficient and power generation cannot be started. Therefore, in this embodiment, at the start of rotation after the rotor 5 is stopped, the switching means 13 of the initial excitation means 2 is turned on so that a magnetizing current flows from the magnetizing power supply 14 to the output winding 7, and the output iron core 6. Magnetize. Since the magnetic flux gradually increases as the rotation continues as described above, the degree of magnetization may be such that the residual magnetism necessary for the initial excitation for the start of power generation is obtained. For this reason, in order to magnetize, a current of a predetermined magnitude may be passed for a very short time. By this magnetization, even after the rotor 5 is stopped for a long time, power generation is reliably started by resuming the rotation.

  In the embodiment in which the switching means 13 is provided, at the start of rotation after the rotor 5 is stopped, the switching means 13 of the initial excitation means 2 is turned on to magnetize the main field winding 8 from the magnetizing power supply 14. A current is passed to magnetize the field core 8. Even when the field core 8 is magnetized in this way, power generation is started even after the rotor 5 has been stopped for a long time.

  According to the generator 26 of these embodiments, the following advantages are obtained. Since it is a self-excited type that performs excitation using the main field winding 9, power generation can be performed without the need for a permanent magnet or an external power source that supplies power for external excitation from the outside. Self-excited generators do not require external excitation during normal rotation, but require some excitation at the start of rotation. Since the initial excitation means 2 generates a magnetic force to such an extent that it is necessary for the initial excitation of power generation, a normal magnetic force, that is, a constant magnetic power for obtaining the generated power is not required. Therefore, the cogging torque is not problematic in practical use, and the rotor 5 can be rotated with a small torque. Although it is self-excited, the initial excitation means 2 that magnetizes one of the iron cores of the generator is provided to such an extent that it can generate the magnetic force required for the initial excitation of power generation. Even after or after low speed rotation, power generation can be started reliably. Although the initial excitation means 2 is necessary, the initial excitation means 2 is sufficient if it can be magnetized to such an extent that it can generate a magnetic force necessary for the initial excitation of power generation. Compared to an external power source in, it can be much smaller.

  In the above-described embodiment, the stator 4 side is the output iron core 6 and the rotor 5 side is the field iron core 8. Conversely, the stator 4 side is the field iron cores 9 and 10, and the rotor 5 side is the output iron core. 6 is also acceptable. In the above embodiment, a two-pole generator is used, but a multi-pole generator such as a 4-pole, 8-pole, or 16-pole generator may be used.

A plurality of blades 24 may be provided in the vertical direction with respect to one vertical main shaft 22. In this case, the wind receiving area of the blade 24 can be increased with respect to the installation area of the windmill.
The number of blades is not limited to two per stage, and may be three or more.
The generator 26 may be a synchronous generator using a permanent magnet for generating a field.
It is also possible to provide a plurality of generators 26 for one vertical main shaft 22 and to individually generate power by rotating the one vertical main shaft 22.
The windmill is not limited to a straight blade vertical axis type windmill, and may be a Darrieus type windmill or a Savonius type windmill.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

2 ... Initial excitation means 4 ... Stator 5 ... Rotor 6 ... Output iron core 7 ... Output winding 8 ... Field iron core 9 ... Main field winding 10 ... Sub-field windings 11, 12 ... Rectifying element (rectifying means)
22 ... Vertical spindle 23 ... Support 24 ... Wings 26 ... Generator

Claims (4)

  A wind turbine for wind power generation having a vertical main shaft, wherein a plurality of wings extending in the vertical direction are provided around the vertical main shaft away from the vertical main shaft, and each of the wings is connected to the northern hemisphere of the earth. A wind turbine for wind power generation, characterized in that when installed, the wind turbine generates a rotational force that rotates counterclockwise in plan view.   The wind turbine for wind power generation according to claim 1, wherein the wind turbine is a straight blade vertical axis wind turbine.   A wind turbine generator comprising the windmill according to claim 1 or 2 and a generator driven by the windmill.   4. The wind power generator according to claim 3, wherein the generator is one of an output core around which an output winding is wound and a field core around which a main field winding and a sub field winding are wound. Is a stator, the other is a rotor, a rectifier is connected to each of the field windings, the blades rotate, and the stator and rotor rotate relative to each other. A wind power generator having initial excitation means for generating a magnetic force required for excitation.

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