WO2018079863A1

WO2018079863A1 - Blade pitch adjustment device for wind power generator

Info

Publication number: WO2018079863A1
Application number: PCT/KR2016/011974
Authority: WO
Inventors: 홍순원
Original assignee: 주식회사 와이이씨
Priority date: 2016-10-24
Filing date: 2016-10-24
Publication date: 2018-05-03
Also published as: KR101723175B1

Abstract

Disclosed is a blade pitch adjustment device of a wind power generator, the device comprising: a hub connected to a power generator shaft rotatably provided at the front of a nacelle of the wind power generator; a plurality of blades provided at the hub so as to be arranged symmetrically to each other around the rotational center of the power generator shaft; a pitch adjustment part provided at the hub and linking the plurality of blades to each other such that the blades can rotate relative to the hub according to wind velocity, thereby enabling the pitch angles of the blades to be adjusted; an elastic member provided between the pitch adjustment part and the hub and providing an elastic restoring force such that the plurality of blades return to the initial positions thereof when the positioning thereof is changed from the initial positions thereof; and an electronic brake selectively regulating the operation of the pitch adjustment part so as to control the relative rotations of a hub of the blades, wherein the blade includes: a blade shaft rotatably provided at the hub, and connected to the pitch adjustment part; and inner and outer blades provided at the blade shaft, and arranged at different pitch angles so as to have different resistance values for wind directions.

Description

[Calibration according to Rule 26.11.2016] Blade pitch control device for wind power generator

The present invention relates to a blade pitch adjusting device for a wind power generator, and more particularly, an outer blade and an inner blade having a different pitch angle from an outer blade on the same wing shaft line, so that the pitch of the blade is variable according to the wind speed. It is made by itself to prevent the overload of the generator and the damage of the blade to the high power, as well as the wind power generation by the inner blade only in the strong wind of 25 meters per second speed, and control the pitch of the blade as the electromagnetic brake when the wind speed changes from strong wind to low speed It relates to a blade pitch adjusting device for a wind turbine so that this can be done.

As is well known, wind power refers to the generation of electricity by converting wind energy into mechanical energy through a device such as a wind turbine and operating a generator as this energy.

Wind turbines are installed on land and at sea depending on the installation site. Horizontal wind turbines (lift type) and vertical shaft wind turbines (drag type) are classified according to the direction of rotation.

Blades applied to recent wind generators are wind power generation of the pitch regulated type (Pitch regulated type).

Wind power of the wing angle control type has a range of rotational speeds by adjusting the wing angle (pitch) because the cross section has a streamlined wing angle. Using this principle, the blade angle is adjusted to control the torque of the rotational speed, so that the required wind energy can be efficiently converted into mechanical energy, enabling efficient output control above the rated wind speed, which is almost essential in modern wind turbine facilities. It is adopted.

Wind power generation can theoretically convert up to 59.3% of wind energy into electrical energy, but in reality there are losses due to the shape of the blades, mechanical friction, and the efficiency of the generator. have.

Wind power is a kind of renewable energy, and it is a promising alternative energy source for fossil energy depletion because it is rich in resources, constantly regenerated, distributed in a wide range of regions, and has no greenhouse gas emission during operation.

Looking at the structure of recent wind generators, a blade that converts wind energy into rotational force, a hub that connects it to the main shaft, and a rotational shaft that transmits the rotational force of the wing to the gearhead or generator, or Spindle, gearbox to increase rotation speed, generator to convert mechanical energy into electrical energy, brake (brake), pitch control system to adjust wing angle, nacelle to adjust blade to wind direction Yawing system that rotates the shaft, and a tower that supports the wind turbine.

Such a wind turbine may be classified into a large wind turbine and a small wind turbine according to the capacity or scale of the generator. Large wind turbines usually use a variable pitch or tip control. The small wind power generator uses a control method that stops the braid by generating electric power in stall state or stopping the braid at high wind speed by making the lift drag match at high speed of blade rotation.

The variable pitch control method can control the overall pitch of the blade to operate the efficiency of the rotor to the maximum state, but there is a disadvantage in that the structure of the hub is complicated. In addition, since the actuator system must be applied in preparation for sufficient power, failure occurs frequently, and when it is applied to small wind power generation, installation cost increases, so it is difficult to commercialize due to low economic feasibility.

In addition, the tip control method is a pitch control method of the blade tip only, the hub and blade installation structure is simple, but there is a problem that the cost increases because the actuator or the tip bearing must be used and the actuator must be added. In addition, there is a need for a space for installing the actuator inside the blade, in particular, a thin blade of high speed rotation is difficult to control, it is difficult to balance the blade, there is a problem to apply to a small wind generator.

In addition, the stall control method is the simplest and most inexpensive control system, which can use a simple hub or integrated blade and does not require an auxiliary machine for using a power actuator. However, the rotor speed cannot be controlled independently and over-rotation can not be prevented. Therefore, an aerodynamic brake device is required, and the stall control is characterized by a small area of wind from the middle of the blade to the tip. Because of this very high speed, the blade receives the wind at a low wind speed (wind speed of 4 m / s or less), which is suitable for high wind speeds because it is not started.

An example of the prior art related to the pitch adjusting device of such a blade is disclosed in Korean Patent Registration No. 10-737407 (hereinafter referred to as 'Patent Document 1').

Blade pitch adjusting device of Patent Literature 1, the pitch of the blade is automatically adjusted by the wind speed, it is possible to continuously develop by the required rotational force, the blade pitch is automatically adjusted by the wind speed more than a certain value to block the rotation of the generator It is configured to prevent overload.

However, there is a problem that such a pitch adjusting device is not suitable for a small wind turbine of low wind speed.

The wind turbine starts generating power at the starting wind speed and increases the power in proportion to the square of the wind speed until the rated wind speed is reached, and the blade control system operates after reaching the rated power. The wind speed ranges from 1 m / s to several tens of m / s, so the control range is very wide and expensive to control this wide range.

In Korea, the wind speed in most areas except for some coasts is less than 4m / s, instantaneous wind speed is more than 25 m / s, the blade does not rotate when installing a small wind turbine.

Normally, the output coefficient of wind energy is known by Betz's law that the maximum energy conversion theoretically has an output coefficient of 0.593. However, the wind speed range is very wide, the efficiency of the system configuration is up to 40% -50% in the large generator, the small 20% ~ 25% system efficiency, which decreases rapidly as the system becomes smaller.

In particular, small wind turbines do not stand high on the tower, so the wind speed varies greatly due to the influence of the terrain, and the variable pitch device must be installed on the rotor, but the cost of the rise is low. Equipped with a stop system is the mainstream.

Therefore, the efficiency is very limited because it has reactive energy at low wind speed and reactive energy at high wind speed. In addition, wind power generators are proportional to the blade area and proportional to three squares of the wind speed, so wind turbines are advantageous in size. The small wind power generator can compensate to some extent the disadvantages of the large wind power generator, but it is uneconomical because the efficiency is very low as described above.

In addition, the Republic of Korea Patent Publication No. 10-2010-0035206 (hereinafter referred to as "Patent Document 2") discloses a technology for an automatic pitch control device for a wind power generator for converting a strong wind, a middle wind, a small wind into power.

The automatic pitch adjusting device in Patent Document 2 has a structure in which blades are automatically adjusted by using springs inside the rack rod and shock absorber blades by wind pressure when wind is applied to the blades.

However, since the spring is put into the blade, the reality is poor, the structure is complicated, and the cost is not only high. In addition, the use of the spring for pitch adjustment causes a change in strength depending on the use period, which is a problem in long-term use. In addition, since a rack rod or shock absorber is applied to the blade fixing part (hub), the size of the rotor hub is increased, so that a wide hub is needed and weight is heavy to be applied to a small wind power generator. In addition, since the blade control is made separately, there is a concern that blade damage may occur due to incomplete rotation (rotational center of rotation) during high-speed rotation, and it is pointed out that a disadvantage is to supply oil after a certain period of time because the gear and the shock absorber are used.

The present invention was devised to solve the above-mentioned problems, and the pitch angles of the outer blade and the inner blade are differently installed on the same wing shaft line, so that the pitch of the blade is varied in the blade itself according to the wind speed. In addition to preventing the overload of the generator and damage to the blades, wind power can be generated by the inner blade only in the strong winds of 25 meters per second. It is an object of the present invention to provide a blade pitch adjusting device for a wind turbine.

Blade pitch adjusting device for a wind turbine of the present invention for achieving the above object, the hub is connected to the generator shaft rotatably installed in front of the nacelle of the wind turbine; A plurality of blades installed in the hub to be symmetrically disposed with respect to the rotation center of the generator shaft; A pitch adjusting unit installed at the hub to adjust the pitch angle of the blades by interlocking the plurality of blades with each other to allow relative rotation of the blades according to wind speed; An elastic member installed between the pitch adjusting unit and the hub to provide an elastic restoring force so that the plurality of blades return to the initial position when the posture changes from the initial position; And an electronic brake for selectively controlling the pitch adjusting unit to control the rotation of the blade relative to the hub, wherein the blade is rotatably installed at the hub and connected to the pitch adjusting unit. ; It is installed on the wing shaft, characterized in that it comprises an inner and outer blades disposed at different pitch angles to have different resistance values for the wind direction.

Here, the outer blade and the inner blade is preferably arranged to have a wing angle of 15 to 30 degrees of deviation from each other.

In addition, the electromagnetic brake is controlled on and off based on the measured value output from any one of the anemometer, tachometer, and output meter to control the operation of the pitch adjusting unit.

In addition, the pitch adjustment unit, the main bevel gear is installed on the blade shaft of each blade; First and second rotation shafts rotatably installed at the hub and disposed coaxially with each other; A sub bevel gear installed on each of the first and second rotation shafts; And a connecting gear connecting the main bevel gear and the sub bevel gear of any one of the first and second rotation shafts, wherein the electromagnetic brake selectively interrupts any one of the first and second rotation shafts. Is installed so that, one end of the elastic member is connected to any one of the first and second rotary shaft, the other end is connected to a fixed plate fixed to the hub, the fixed blade is the outer blade has a pitch adjustment range It is preferable that a stopper is provided to limit the rotation range of the first and second rotary shafts without departing.

Blade pitch adjusting device for a wind power generator according to the present invention, the outer blade in the high wind speed range (approximately 25 meters per second at about 25 meters per second) in the wind speed corresponding to the wind power generation range is folded in parallel to the horizontally located power generation shaft is a blade by high power There is an advantage in that the wind power generation can be prevented, and only by rotating the inner blade forming a predetermined angle with the outer blade with respect to the wing shaft.

In addition, when switching from high wind speed to low wind speed, the second rotating shaft of the sub bevel gear meshed with the main bevel gear and the neutral gear of the wing shaft is operated by the electromagnetic brake to maintain the pitch angle of the blade by braking according to the current wind speed. In addition, the structure is simpler than the existing complicated mechanical pitch adjusting device by adjusting and maintaining the angle of the blade by the magnetic force according to the corresponding wind speed by the return operation of the spring elastically supporting the second rotating shaft with the tension spring. Efficient wind energy can be obtained.

1 is a schematic front view of a blade pitch adjusting apparatus for a wind turbine according to an embodiment of the present invention.

Figure 2 is a schematic side cross-sectional view of a blade pitch adjusting device for a wind turbine according to an embodiment of the present invention.

Figure 3 is a cross-sectional view A-A showing the wing angle of the inner blade and the outer blade in FIG.

4 is a cross-sectional view taken along the line B-B in FIG.

5 is a side view showing an extract of the pitch adjustment unit shown in FIG.

6 (a), (b) and (c) are schematic diagrams illustrating a variable pitch of inner and outer blades according to wind speed.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all of the technical idea of the present invention, these can be replaced at the time of the present application It should be understood that there may be various equivalents and variations.

1 and 2, the blade pitch adjusting device according to the present invention is installed to the hub 10, which is connected to the generator shaft 1 of the tower constituting the wind turbine, the reciprocating rotation at a predetermined angle to the hub (10) A plurality of blades 20, the pitch adjusting unit 30 for adjusting the rotation angle relative to the hub 10 of the plurality of blades 20, the fixing plate 40, the elastic member 50 and the electromagnetic brake 60 do.

The hub 10 is connected to the generator shaft (1) is rotated together when the blade 20 receives the resistance of the wind to rotate the generator shaft (1) to the center of rotation. On the outside of the hub 10 a plurality of blades 20 are installed symmetrically with respect to the rotation center of the generator shaft (1).

The blade 20 includes a blade shaft 21 rotatably installed on the hub 10, an inner blade 22 and an outer blade 24 installed on the blade shaft 21. The outer blade 24 has a larger air resistance area than the inner blade 22. As shown in FIG. 3, the inner blade 22 and the outer blade 24 are arranged to have different wing angles so as to shift from 15 to 30 degrees. That is, as shown in Figure 6, the inner blade 22 is disposed to have a pitch angle that can receive more wind resistance than the outer blade 24 when the same area reference, the outer blade 24 is the wind of It is arranged to have a pitch angle that is relatively low in resistance.

Therefore, the blowing wind is subjected to great resistance in the inner blade 22, and flows toward the outer blade 24 having a relatively low resistance. Accordingly, when the same resistance is received, the wind can be induced to flow to the outer blade 24 which generates a relatively large rotational torque as compared with the inner blade 22. Therefore, at low wind speeds it is possible to increase the output by inducing the direction of the wind toward the outer blade (24). At high wind speeds, the pitch of the blades 20 is adjusted by the operation of the pitch adjusting unit 30 so that the angle of the blade 20 is less resistance to wind, that is, as shown in FIG. Therefore, at high wind speeds, the outer blade 24 receives little wind resistance, and the rotational force capable of rotating the generator shaft 1 can be obtained only by the air resistance received by the inner blade 22.

The blade angle of the inner blade 22 with respect to the outer blade 24 is formed 15 to 30 degrees based on the blade shaft 21 to which the outer blade 24 is fixed.

As described above, the width of the inner blade 22 having the blade angle with the outer blade 24 is formed on the basis of the wind speed 25m / s, which is preferably formed in proportion to the capacity of the generator.

The angle to the wind direction, that is, the pitch angle of the blade 20 may be adjusted by the pitch adjusting unit 30 installed in the hub 10.

The pitch adjusting unit 30 includes a main bevel gear 30a installed on the blade shaft 21 of the blade 20, first and

second rotation shafts

31 and 33 rotatably installed on the hub 10, Sub bevel gears (31a, 33a), the main bevel gear (30a) and the connecting gear (32a) for connecting the sub-bevel gears (33a) are provided on the first and second rotary shafts (31, 33), respectively.

The first and second

rotary shafts

31 and 33 are disposed coaxially with each other, and the

sub bevel gears

31a and 33a provided at the end thereof are disposed to face each other. The sub bevel gear 33a is rotated in conjunction with the main bevel gear 30a by the connecting gear 32a, and the remaining sub bevel gear 31a is directly connected to the main bevel gear 30a and rotated. The shaft 32 of the connecting gear 32a is installed in the hub 10 so as to be freely rotatable.

According to the above configuration, when the blade shaft 21 is rotated, the main bevel gear 30a is rotated while the

sub bevel gears

31a and 33a are interlocked in the same direction. Therefore, the blade shafts 21 of the plurality of blades 20 are simultaneously rotated in conjunction with each other. However, since the blades 20 coaxially disposed to face each other are rotated in opposite directions, the pitch angles of the inner and

outer blades

22 and 24 may be equally adjusted based on the wind direction.

The fixing plate 40 is installed on one side of the hub 10.

In the center of the fixed plate 40, the rotating body 42 is rotatably supported by the second rotating shaft 33 is installed. Here, the second rotating shaft 33 and the rotating body 42 may be coupled to each other by a fastening screw S to be rotated together. The fastening screw S may be fixed to at least two points with respect to the rotating body 42.

An elastic member, that is, a tension spring 50 is installed to connect one of the fastening screws S and the fixing plate 40 of the fastening screws to fix the rotating body 42. When the blade 20 is rotated and the second rotation shaft 33 is rotated according to the variable pitch, the tension spring 50 is stretched in proportion to the rotation angle to generate an elastic force. The elastic force of the tension spring 50 allows the blade 20 to be returned to its initial position in a pitch-variable state.

In addition, the fixing plate 40 is provided with a stopper 44 on one side where the rotating body 42 is installed to limit the tension distance of the tension spring 50, that is, the pitch adjustment range of the blade 20. Therefore, the blade 20 is prevented from rotating beyond the pitch adjusting range even at high wind speeds, thereby controlling the pitch adjusting range of the blade 20.

The tension spring 50 causes the pitch angle of the blade 20 to gradually return to the initial position when switching from the high wind speed to the low wind speed.

In addition, one end of the second rotation shaft 33 disposed through the fixing plate 40 is provided with an electromagnetic brake 60 for selectively intermittently stopping or releasing the rotation of the second rotation shaft 33. The electromagnetic brake 60 may apply a brake that brakes the rotation shaft by compressing the brake shoe to the brake disc using an electromagnetic force. The electronic brake 60 may be installed inside the cover 70 fixed to the hub 10 to be protected from the outside.

The electronic brake 60 is controlled on and off by comparing the measured value output from any one of an anemometer, a tachometer, and an output meter installed in the wind power generator with a set reference value to selectively control the rotation of the second rotary shaft 33. can do.

When the wind speed gradually increases and the output of the generator exceeds the reference value, when the electromagnetic brake 60 is kept on for a predetermined time, the control of the second rotating shaft 33 is released for a predetermined time (several seconds to several tens of seconds). . Then, the blade 20 is rotated with respect to the blade axis 21 by receiving a large resistance of the wind, the pitch angle is adjusted while the tension spring 50 is tensioned and elastically deformed.

After the set time, the electromagnetic brake 60 is turned off and the blade shaft 21 of the blade 20 is fixed in the pitch adjusted state. Therefore, in the pitch-adjusted state, the blade 20 is able to output at an appropriate level by receiving wind resistance.

On the contrary, when the output is below the rated value, the electromagnetic brake 60 is driven again to release the interruption of the second rotary shaft 33 for the set time. Then, in a state where the wind resistance is reduced, the blade 20 is rotated in the initial posture direction by the elastic restoring force of the tension spring 50 to change the posture to maintain a pitch angle that receives a lot of wind resistance. Therefore, the wind resistance can be properly received to maintain the output above the rated output.

Referring to the effect of the blade pitch adjustment device for a wind turbine according to an embodiment of the present invention having the configuration as described above are as follows.

Wind power is usually produced according to the size of the wind turbine, the production of wind energy varies, the blade 20 of the wind turbine according to the present invention to the wind power corresponding to the wind speed corresponding to 5 to 25 meters per second to the medium-sized class or more Can be generated.

The wind turbine installed on the ground or at sea rotates the blade 20 including the hub 10 in response to the wind speed at a predetermined height of the tower.

When the blade 20 rotates, the dynamic pressure blowing from the front is converted to the static pressure through the blade. At this time, the outer blade 24 is attached to the blade shaft 21 against the wind speed received from the point of time more than 12 meters per second. In Figure 6 (a) to (b) is made. When switching to the high wind speed in the state of FIG. 6A, as described above, the cracking of the electromagnetic brake 60 is momentarily released. While the clamping of the electromagnetic brake 60 is released, the blade 20 is twisted by the resistance of the wind so that the pitch angle is adjusted as shown in FIG. 6B, and then the posture is fixed by the clamping of the electromagnetic brake 60. Can be.

On the other hand, when it is maintained in the state of FIG. 6 (a), the wind of low wind speed blows. At this time, the wind receives the resistance from the inner blade 22 is guided toward the outer blade 24 to smoothly rotate the outer blade 24 at low wind speeds to achieve efficient wind power generation. That is, the wind is moved to the outer blade 24 located at a distant position with respect to the generator shaft 1 to concentrate the wind, thereby effectively rotating the blade 20 even at a low wind speed.

6B illustrates a state where the inner blade 22 and the outer blade 24 are positioned at a point where the outer blade 24 is flipped toward the generator shaft 1 from the hub 10 at a high wind speed. It is illustrated.

As described above, the pitch of the blade 20 is equal to or greater than the reference output, or when the reference wind speed or more, or when the rotation speed of the generator shaft 1 is equal to or more than the reference speed, the electromagnetic brake 60 is operated to rotate the second rotation shaft. This is achieved by releasing the interruption of 33 at the moment. That is, when the interruption of the second rotary shaft 33 is released, the angle change of the blade 20 is made by air resistance, but the blades 20 are interlocked with each other by the pitch adjusting unit 30. The tension spring 50 is elastically deformed as shown in FIG. 4 by the rotation of the second rotary shaft 33. In this state where the blade 20 is distorted and the pitch angle is adjusted as shown in FIG. 6 (b), when the interruption of the electromagnetic brake 60 is performed, the blade angle is adjusted. ) Posture is maintained.

The tension of the tension spring 50 is made within the pitch adjustment range of the blade (20). As such, by limiting the tension range of the tension spring 50, that is, the twist angle of the blade 20, the blade 20 does not go out of the set pitch adjustment range, so that unnecessary pitch adjustment of the blade is no longer performed at high wind speeds. This can prevent damage to the blade.

As described above, the blade shaft 21 of the blade 20 in response to the wind speed, as shown in the arrow direction shown in Figure 6 the blade shaft 21 is rotated in conjunction with each other, the pitch adjustment is made of magnetic force, the second rotating shaft 33 is interrupted by the electromagnetic brake 60 and is fixed in posture without being rotated.

In other words, the electromagnetic brake and the tension spring allows the blade's pitch with respect to the current wind speed to be converted to an angle that is easy to develop.

Such pitch adjustment of the blade can prevent damage to the blade 20 and overload of the generator, which may occur due to the high output range caused by the rotation of the blade 20 with respect to the high wind speed, while the wind pressure received by the inner blade 22 alone. By rotating the blade 20 it is possible to generate the required wind energy.

For example, if the pitch of the inner blade 22 is not controlled by the wind in a gust or typhoon of 30 meters per second, the power generation is stopped by the main brake system provided in the generator. Wind turbines can be protected from

FIG. 6C illustrates that when the high wind speed is changed from the low wind speed, the pitch angle of the blade 20 is adjusted by releasing the intermittent state of the electromagnetic brake 60 holding the second rotating shaft 33. It showed the state. That is, in the state (b) of FIG. 6, when the wind speed is reduced so that the output does not reach the reference value, the rotation speed is less than the reference speed, or the wind speed is less than the reference value, the electromagnetic brake 60 temporarily releases the interruption. Then, the second rotating shaft 33 is returned to the position corresponding to the current wind speed by the elastic restoring force of the tension spring 50, and in that state, the electromagnetic brake 60 is turned off, and the pitch angle of the blade is adjusted. By maintaining it, the wind power generation for wind speed is made stable.

Blade pitch adjusting device according to an embodiment of the present invention, there is no need to install a dedicated motor that is conventionally installed to adjust the blade pitch, and adopts a method of transmitting the power to the electromagnetic force without going through the slip ring which is the contact portion of the motor. Because it can be operated by, it provides an advantage that can significantly reduce the failure rate due to the pitch adjustment of the wind turbine.

In the present invention as described above has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents and equivalents of the claims, as well as the following claims, will fall within the scope of the present invention. .

[Description of the code]

1: generator shaft 10: hub

20: blade 21: wing shaft

22: inner blade 24: outer blade

30: pitch adjusting unit 30a: main bevel gear

31: 1st rotation shaft 31a: sub bevel gear

32: rotating shaft 32a: connecting gear

33: 2nd rotating shaft 33a: sub bevel gear

40: fixed plate 42: rotating body

44: stopper 50: tension spring

60: electromagnetic brake 70: cover

S: Tightening Screw

Claims

A hub connected to the generator shaft rotatably installed in front of the nacelle of the wind turbine;

A plurality of blades installed in the hub to be symmetrically disposed with respect to the rotation center of the generator shaft;

A pitch adjusting unit installed at the hub to adjust the pitch angle of the blades by interlocking the plurality of blades with each other to allow relative rotation of the blades according to wind speed;

An elastic member installed between the pitch adjusting unit and the hub to provide an elastic restoring force so that the plurality of blades return to the initial position when the posture changes from the initial position; And

And an electronic brake for selectively controlling the pitch adjusting unit to control the rotation of the blade relative to the hub.

The blade,

A wing shaft rotatably installed at the hub and connected to the pitch adjusting unit; And

The blade pitch adjusting device of the wind turbine is installed on the blade shaft, characterized in that it comprises an inner and outer blades arranged at different pitch angles to have different resistance values for the wind direction.
The method of claim 1,

The outer blade and the inner blade blade pitch control device for wind turbines, characterized in that arranged to have a wing angle of 15 to 30 degrees deviation from each other.
The method of claim 1,

The electromagnetic brake is on, off based on the measured value output from any one of the anemometer, tachometer, output meter to control the operation of the blade pitch for wind turbine blades, characterized in that for controlling.
The pitch adjusting unit according to any one of claims 1 to 4, wherein

A main bevel gear installed on the blade shaft of each blade;

First and second rotation shafts rotatably installed at the hub and disposed coaxially with each other;

A sub bevel gear installed on each of the first and second rotation shafts;

And a connecting gear connecting the main bevel gear and the sub bevel gear of any one of the first and second rotary shafts.

The electromagnetic brake is installed to selectively interrupt any one rotation of the first and second rotation shafts,

One end of the elastic member is connected to any one of the first and second rotation shaft, the other end is connected to a fixed plate fixed to the hub,

Blade fixing device for a wind turbine, characterized in that the fixing plate is provided with a stopper for limiting the rotation range of the first and second rotary shaft so that the outer blade does not leave the pitch adjustment range.