JP2005273642A - Wind power generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium/small-sized wind power generator suppressing an increase in the number of revolution of a windmill at the time of strong wind without using a mechanical mechanism, greatly decreasing a mechanical failure, and eliminating the need of maintenance. <P>SOLUTION: A windmill blade is structured as a smart blade 1 from laminated material of aluminum alloy thin plate and CFRP having an inverse symmetry structure. An excessive electric current at the time of strong wind is made to pass through the smart blade 1. Joule heating is carried out, and a load is increased to suppress the number of revolution. If wind velocity is increased further, and a surplus current that cannot be completely consumed by air-cooling is generated, the smart blade is twisted and deformed by temperature rise to reduce dynamic lift to suppress output. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wind turbine generator, and more particularly to a device capable of suppressing an increase in the rotational speed of a windmill in a strong wind in a medium-sized and small-sized wind turbine generator for the purpose of spreading to urban areas and homes.

  Wind power generators that convert wind energy into electrical energy are expected to spread as an energy source with an extremely low environmental load. In addition to large-scale power generation facilities such as wind farms, wind power generation has been proposed as a small-scale distributed energy source for small and medium-sized installations intended for installation in urban areas and homes.

However, in such small and medium-sized wind power generators, the windmill rotates at high speed during strong winds, and the generation of wind noise is a cause that hinders the spread to urban areas and homes. It has been demanded.
In a strong wind such as a typhoon, a method of stopping the rotation by short-circuiting the output side current of the power generator is generally taken, but as a method of suppressing the rotation of a small and medium-sized wind power generator during a strong wind that does not reach that point 1) A rotor deflection type, 2) a pitch control type, or 3) a method of controlling the distance between the rotor and the stator of the power generation apparatus disclosed in Patent Document 1 is used or proposed.

  JP2003-324896

However, any of the conventional methods described above requires an elaborate mechanical mechanism, which increases the manufacturing cost. At the same time, the probability of failure increases due to sophistication. And, as a wind power generator that is constantly exposed to wind and rain, maintenance is indispensable, and it takes time and effort to maintain it.
The present invention relates to a method for suppressing an increase in the rotational speed of a windmill during a strong wind of a small and medium-sized wind power generation device without using any mechanical mechanism, and particularly enables quiet operation of the small and medium-sized wind power generation device. The present invention provides a wind power generator that can be installed in an urban area and a home, and particularly a small and medium wind power generator.

In the present invention, in a wind turbine generator that attaches a windmill blade to one end side of the rotating shaft and connects a rotor to the other end side, and drives the rotor by rotation of the windmill blade to generate power.
The rotating blades are laminated in the thickness direction with a metal thin plate and a CFRP thin plate, and an insulating FRP thin plate or an insulating film for electrically insulating the metal thin plate and the CFRP thin plate, and a CFRP thin plate and an insulating FRP thin plate, Alternatively, the CFRP thin plate and the insulating film are configured as smart blades arranged inversely symmetrically with respect to the blade central surface in the thickness direction of the rotary blade,
A rotation state detection device is provided that detects the rotation state of at least one member of the rotor blade, the rotation shaft, and the rotor, and flows the current generated by the rotor to the CFRP of the smart blade when the detected rotation state exceeds a preset threshold value. The above-described problem is achieved by a wind power generator characterized by being provided.

  In the present invention, the smart blade is further provided with a temperature sensor, and when the detected temperature of the temperature sensor exceeds a preset limit temperature, a current is passed from the power source different from the rotor to the smart blade to greatly deform the smart blade. There may be provided a controller for causing the vehicle to stall.

  As the metal thin plate in the present invention, an aluminum alloy plate, a titanium plate, a titanium alloy plate, an iron plate such as an iron plate and a stainless steel plate, or one or more of a copper plate or a copper alloy plate can be used. Pneumatic alloy plates are preferred because of their high strength and thermal expansion coefficient and large deformation with respect to temperature changes.

CFRP is a carbon fiber reinforced resin (carbon fiber reinforced plastic), and insulating FRP is a fiber reinforced plastic made of non-conductive fibers and resin. Here, the CFRP thin plate and the insulating FRP or CFRP thin plate and the insulating film are disposed in an antisymmetric manner with respect to the blade central surface in the thickness direction of the rotary blade. That is, the CFRP thin plate and the insulating FRP are arranged such that the elastic principal axis direction forms an angle with respect to the longitudinal axis of the rotary blade, and the inclination angle is smaller than the blade central surface when viewed in the thickness direction of the rotary blade. The upper side is + θ and the lower side is −θ, and their absolute values are equal and the directions are reversed.
In the present invention, the rotating blades can be deformed without providing a mechanical actuator or the like by supplying current to the CFRP arranged in an opposite symmetry to perform Joule heating. Refers to a blade having such characteristics as a smart blade.

  The rotational state detection device of the present invention detects the rotational state of at least one member of the rotary blade, the rotary shaft, and the rotor. Here, the rotation state includes a rotation speed, a rotation speed, or a generated current value of the rotor.

  In the present invention, the rotation state detection device detects the rotation state of at least one member of the rotating blade, the rotation shaft, and the rotor, and if the detected rotation state exceeds a preset threshold value, the current generated in the rotor is smartly detected. Pour into the CFRP of the blade. As a result, the smart blade generates heat. Since the rotating blade rotates at the tip of the rotating shaft, the peripheral speed is higher than the wind blown to the windmill, and the smart blade of the rotating blade is efficiently cooled and consumes surplus current of the power generator. Thereby, rotation of a rotor can be suppressed to an appropriate value. Note that the smart blade generates heat up to a certain value of the flowing current, but hardly deforms.

  Further, when the current flowing to the smart blade is increased, the CFRP thin plate and the insulating FRP thin plate, or the CFRP thin plate and the insulating film are arranged in reverse symmetry with respect to the blade central surface in the thickness direction of the rotary blade. Causes torsional deformation with increasing temperature. As a result, surplus power that cannot be consumed even by heat dissipation is consumed to cause torsional deformation, and the torsional deformation causes a reduction in lift of the smart blade, thereby slowing down the rotation of the rotating blades. By these, rotation of a rotor is suppressed and it becomes a suitable value.

  Preferably, as shown in the embodiment, the smart blade is provided with a temperature sensor, and the detected temperature of the temperature sensor has a preset limit temperature when the wind is so strong that the rotation speed of the rotor cannot be controlled. When exceeding, in addition to flowing current from the rotor to the smart blade as described above, by directly applying current to the smart blade from another power source such as a storage battery, the smart blade is greatly twisted and deformed, so that the rotating blade is A stalled state may be introduced so that a limit value such as a limit rotational speed, a limit speed, or a limit current value is not exceeded.

The smart blade according to the present invention is not only a heat generator but also a heat radiator, and the balance between heat generation and heat radiation is lost, and when its temperature rises, its own twist angle can be changed accordingly.
By using this blade, when the wind turbine speed rises to a predetermined value during strong winds and exceeds the required power, the surplus power is first used to heat the blade itself. A load is applied to the power generator, and the rotation of the wind turbine is suppressed by increasing the rotational torque of the rotor due to the load.
To further increase the wind speed, the torsion angle of the smart blade is changed to reduce the lift, and the balance between the rotational torque of the windmill and the rotational torque of the rotor is lost to suppress the rotational speed of the windmill.
For further strong winds, current can be supplied from a separate power source such as a battery, and the twist of the smart blade can be increased to stall, thereby suppressing rotation.
For strong winds that still cannot suppress rotation, the output of the power generator is short-circuited to stop rotation completely.

As described above, regarding the rotational speed control of the wind turbine according to the present invention, since no mechanical mechanism for speed control is required, mechanical failure is greatly reduced, and a maintenance-free system can be constructed.
It can also be set to maintain low speed rotation by lowering the threshold value of the shunt circuit at night and lowering the starting value of rotation suppression, enabling operation control that suits installation conditions and purpose of use. is there.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings illustrating examples of the present invention. FIG. 1 is a perspective view showing the structure of a smart blade used in the present invention.
In FIG. 1, a metal thin plate 2, an insulating layer 3 made of an insulating FRP thin plate or an insulating film, an inversely symmetric laminated CFRP 4, an insulating layer 3 and a metal thin plate 2 are laminated in the thickness direction.
The metal thin plate 2 is made of an aluminum alloy plate and serves as a heat dissipation member, and at the same time, compensates for a decrease in bending rigidity due to the temperature rise of the antisymmetric laminated CFRP 4 and the insulating layer 3.
The CFRP section 4 is constituted by a CFRP unidirectional prepreg, and the CFRP is laminated so that the upper and lower fiber directions are + θ and −θ, respectively, with respect to the plate thickness center plane. In this example, θ was set to 45 °.

In FIG. 1, a copper foil positive electrode 7 is attached to the left end of the laminated upper insulating layer 3, and a copper foil conductive circuit that penetrates the layer from left to right is laminated together. The right end of the laminated CFRP 4 is inserted into the right side of the blade central surface in the thickness direction. Also, a copper foil minus electrode 5 is mounted on the left side of the blade central surface in the thickness direction of the laminated CFRP 4.
When a voltage is applied between the plus electrode 7 and the minus electrode 5, the current flowing from the plus electrode 7 through the conductive circuit in the insulating layer to the CFRP 4 joules the CFRP part and flows to the minus electrode 5. .

  At the time of production, the laminated material such as the thin metal plate 2, the insulating layer 3, the reverse symmetrical laminated CFRP4, the insulating layer 3 and the thin metal plate 2, and other electrode materials laminated as described above are sandwiched between flat plate molds, heated, Press to cure. If this is cooled to room temperature and then removed from the mold, a torsionally deformed smart blade 1 according to a predetermined design intention can be obtained.

  If an insulating unidirectional prepreg is used as the insulating layer 3, the FRP portion as a whole can have an inversely symmetric structure of ± θ by laminating the fiber direction with the fiber direction of the CFRP layer. . Thereby, it is possible to increase the degree of freedom in designing the magnitude of torsional deformation.

  Among the two insulating layers 3, a temperature sensor 8 such as an ultrafine thermocouple or an optical fiber is embedded in the insulating layer 3 shown on the lower side in FIG. 1. Thereby, the temperature of the smart blade 1 can be measured in real time, and the twist angle of the blade 1 at that time can be known.

  FIG. 3 shows the operation of the smart blade 1 produced in this way in a diagram of the temperature-twist angle of the smart blade. That is, in FIG. 1, Joule heat is generated in the CFRP layer by passing a direct current from the electrodes 5 and 7 to the CFRP layer. This Joule heat is measured by the sensor 8 and the twist angle of the smart blade with respect to the temperature is measured. It is expressed as a change in the twist angle with respect to the temperature of the smart blade.

FIG. 4 shows the principle of operation of the power generator equipped with the smart blade. In order to detect the rotation state of at least one member of the rotary blade (smart blade 1), the rotation shaft, and the rotor 17, a rotation sensor 10 is provided as one aspect of the rotation state detection device. In the embodiment illustrated in FIG. 5, the rotation sensor 10 detects the number of rotations of the rotor 17.
Based on information from the rotation sensor 10, the controller 9 causes a current from a separately provided power source such as the generator 11 or the storage battery 12 to flow through the CFRP layer of the smart blade 1 and joule-heats the CFRP layer. This causes the blade to convert power into heat and strain energy. This operation principle enables the rotational speed control of the wind power generator as described below.

Normally, the electric power generated by the rotation of the rotary blades is consumed by the controller 9 by a load (tradition, electric motor, etc.) connected to the power generation device, or stored in the storage battery 12 as surplus power.
However, when the wind speed increases and the rotational speed of the rotor 17, the rotational speed of the windmill, or the generated current value exceeds a predetermined value, the detection device 10 detects that the state has been reached. When the detected value rises beyond a predetermined value, surplus current is caused to flow to the smart blade 1 through the slip ring 18 by the controller 9, the smart blade 1 is heated, and the surplus current is cooled by simultaneously blowing wind. By consuming it, the rotation of the rotor 17 is suppressed to an appropriate value. Note that the smart blade generates heat up to a certain value of flowing current, but hardly deforms.

  By adjusting the stacking angle ± θ of the CFRP portion 4 and the insulating layer 3 of the smart blade 1, the structure is such that appropriate torsional deformation is caused as the temperature rises. When surplus power that cannot be consumed even by heat radiation is generated, the smart blade 1 is twisted by flowing this current through the smart blade 1. By twisting in this way, a large amount of current is consumed. Further, the deformation of the smart blade 1 causes the lift of the smart blade 1 to decrease, and this is used to further suppress the rotation of the rotor 17.

  When the wind is so strong that the rotational speed cannot be controlled even by the above method, current is directly supplied from the storage battery 12 to the smart blade 1 to greatly twist and deform the smart blade 1. As a result, the blades can be brought into a stalled state, and the rotating blades can be prevented from exceeding the limit rotation speed (or limit speed or limit current value).

  If the wind speed further increases and the rotational speed of the rotating blade continues to increase, the blade temperature at that time is detected by the temperature measuring device 13 such as the thermal sensor 8 embedded therein, and it reaches a predetermined limit temperature. For example, the output short-circuit device 20 short-circuits the power generator output to stop the rotation of the wind turbine.

  It is a perspective view which shows the outline of the structure of the smart blade used for this invention.   It is a cross-sectional view of the smart blade shown in FIG.   It is a diagram which shows the experimental example of the temperature-twist angle of a smart blade.   It is a flowchart explaining the working principle of a smart blade.   It is a flowchart which shows an example of a structure of the wind power generator using the smart blade which concerns on this invention.

Explanation of symbols

1 Windmill blade (smart blade)
2 Thin metal plate 3 Insulating material 4 Reverse symmetrical laminated CFRP
5, 6, 7 Copper foil electrode 8 Temperature sensor 16 Rotating shaft 17 Rotor 18, 19 Slip ring

Claims (2)

In a wind turbine generator that attaches a windmill blade to one end side of the rotating shaft and connects a rotor to the other end side, and drives the rotor by rotation of the windmill blade to generate power,
The rotating blades are laminated in the thickness direction with a metal thin plate and a CFRP thin plate, and an insulating FRP thin plate or an insulating film for electrically insulating the metal thin plate and the CFRP thin plate, and a CFRP thin plate and an insulating FRP thin plate, Alternatively, the CFRP thin plate and the insulating film are configured as smart blades arranged inversely symmetrically with respect to the blade central surface in the thickness direction of the rotary blade,
A rotation state detection device is provided that detects the rotation state of at least one member of the rotor blade, the rotation shaft, and the rotor, and flows the current generated by the rotor to the CFRP of the smart blade when the detected rotation state exceeds a preset threshold value. The wind power generator characterized by the above-mentioned. In a wind turbine generator that attaches a windmill blade to one end side of the rotating shaft and connects a rotor to the other end side, and drives the rotor by rotation of the windmill blade to generate power,
The rotating blades are laminated in the thickness direction with a metal thin plate and a CFRP thin plate, and an insulating FRP thin plate or an insulating film for electrically insulating the metal thin plate and the CFRP thin plate, and a CFRP thin plate and an insulating FRP thin plate, Alternatively, the CFRP thin plate and the insulating film are configured as smart blades arranged inversely symmetrically with respect to the blade central surface in the thickness direction of the rotary blade,
A rotation state detection device is provided that detects the rotation state of at least one member of the rotor blade, the rotation shaft, and the rotor, and flows the current generated by the rotor to the CFRP of the smart blade when the detected rotation state exceeds a preset threshold value. And
A temperature sensor is installed in the smart blade, and if the temperature detected by the temperature sensor exceeds a preset limit temperature, a controller that causes the smart blade to deform greatly by causing current to flow from the power source different from the rotor to the smart blade will be A wind power generator characterized by being provided.

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