JP2908906B2 - Wind turbine pitch angle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind turbine pitch angle control device, and more particularly to a device for temporarily stopping the operation of a wind turbine while avoiding the wind pressure when the wind speed exceeds a certain set value. About.

[0002]

2. Description of the Related Art Conventionally, a pitch angle control device for a wind power generator, which is an example of the above-mentioned wind turbine, has been disclosed in, for example,
No. 74 is disclosed. According to this, a hub is provided so as to be rotatable around a substantially horizontal first axis, and a blade is provided from the hub side to extend substantially radially outward of the first axis. Further, the blade is pivotally supported by the hub so as to be rotatable around a second axis along the longitudinal direction, and pitch angle changing means for changing a pitch angle of the blade around the second axis. Is provided. In an emergency such as when the load of the generator is lost or the power of the control means for the generator is lost,
By automatically changing the pitch angle of the blade, the cross section of the blade is set to a danger avoiding posture substantially parallel to the first axis, that is, the wind pressure received by the blade is reduced, and unnecessary wind pressure is applied to the generator. I try not to be given.

[0003]

By the way, even when the wind speed in the wind direction substantially parallel to the first axis becomes excessive, the above configuration is applied as an emergency measure to bring the blade into the danger avoiding posture. It is conceivable to reduce the wind pressure received by the blade. But after this,
If the blade automatically returns to the original pitch angle from the above-mentioned danger avoidance posture when the wind speed decreases, if the generator is over-rotated due to the excessive wind speed and has failed, this failure remains unchanged. Inconvenience that operation is restarted occurs. Therefore, when the wind speed becomes excessive, it is conceivable to hold the blade in the danger avoiding posture so that the blade cannot automatically return to the original pitch angle. However, simply doing so requires a return operation each time, regardless of whether or not the generator has failed, which is extremely complicated.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. When the wind speed becomes excessive, the blade of the wind turbine is set to a danger avoiding posture, and an excessive wind pressure is not applied to the blade. Then, even if the blade is returned from the danger avoidance posture when the wind speed decreases, the subsequent operation of the wind turbine is prevented from being hindered, and the return can be performed with a simple operation. The purpose is to be.

[0005]

A feature of the present invention to achieve the above object is that when the wind speed detecting means detects that the wind speed has exceeded a first set value, the wind speed detecting means detects the wind speed based on the detection signal. The pitch angle changing means sets the blade in a danger avoiding posture in which the cross section of the blade is substantially parallel to the first axis. At this time, when the wind speed is less than a second set value which is larger than the first set value, The pitch angle of the blade can be automatically reset. On the other hand, when the wind speed detecting means detects that the wind speed is equal to or higher than the second set value, the pitch angle changing means detects the blade angle based on the detection signal. Is maintained in the above-mentioned danger avoiding posture in a state where the automatic return is impossible.

[0006]

[Operation] The operation of the above configuration is as follows. When the wind speed detection sensor 34 detects that the wind speed exceeds a first set value (for example, 25 m / s), the pitch angle changing means 16 determines the cross section (second axis) of the blade 11 based on the detection signal. The pitch angle α of the blade 11 is changed so that the danger avoiding posture is substantially parallel to the first axis 8 which is substantially horizontal with respect to the centers 14 and 14 ′. If the value is smaller than a second set value (for example, 40 m / s) larger than the first set value, the pitch angle α of the blade 11 can be automatically returned to the original pitch angle α. For this reason, the wind having the wind direction Fr substantially parallel to the first axis 8 is prevented from applying an excessive wind pressure to the wind power generator (windmill) 1 via the blade 11.

On the other hand, when the above-mentioned wind speed detecting sensor 34 detects that the above-mentioned wind speed has become equal to or higher than the second set value, the above-mentioned pitch angle changing means 16 based on the detection signal.
The blade 11 holds the blade 11 in the danger avoiding posture in a state where the blade 11 cannot automatically return to the original pitch angle α. For this reason, if the second set value is set to a value until the failure rate due to wind pressure increases,
When the wind speed does not reach the second set value and falls below the first set value, the blade 11 automatically returns to the original pitch angle α from the danger avoidance posture, and the operation of the wind power generator 1 continues. Will be done. Then, in this case, the blade 11 is kept in a state where the wind power generator 1 is hardly damaged.
Automatically returns, the operation after the return is performed without any trouble.

On the other hand, when the wind speed becomes equal to or higher than the second set value, the failure rate increases. At this time, however, the blade 11 is held in the danger avoiding posture such that the blade 11 cannot return automatically as described above. For this reason, when this state is reached, the wind power generator 1 is checked once for any failure and then returned.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 to FIG. 3, reference numeral 1 denotes a wind power generator which is an example of a wind turbine. The arrow Fr in the drawing indicates the wind direction, and for the convenience of the following description, the downstream direction of the wind direction is defined as the front. The wind power generator 1 has a vertical support 2 erected on the ground, and a generator body (not shown) is provided in an upper portion of the support 2. A transmission 3 is provided above the support 2.
The casing 4 of the transmission 3 is supported on the upper end of the column 2 and is rotatable about the axis of the column 2. A transmission gear mechanism 5 is provided in the casing 4, and an output shaft (not shown) of the transmission gear mechanism 5 is connected to the generator body.

The input shaft 7 of the transmission gear mechanism 5 projects substantially horizontally forward, and the input shaft 7 is connected to the input shaft 7.
Is supported by the casing 4 so as to be rotatable around a first axis 8 passing through the center of the casing 4. A rotor 9 is attached to a protruding end of the input shaft 7. The rotor 9 includes a box-shaped hub 10 screwed to the protruding end of the input shaft 7 and a pair of blades 11 and 11 ′ protruding from the hub 10. The first shaft center 8
Project in the directions opposite to each other substantially radially outward. The stems 12, 12 'of the blades 11, 11' are supported on the hub 10 by bearings 13, 13 ', respectively, and each blade 11, 11' passes through the center of the stem 12, 12 '. It is rotatable around the second axes 14, 14 'along the longitudinal direction. 1
5, 15 'are counterweights.

A pitch angle changing means 16 for changing the pitch angle α of the blades 11, 11 'is provided. The pitch angle changing means 16 is provided with the stems 12 and 12 '.
Have bracket plates 17 and 17 'attached to the end of the bracket. The casings 18a of the planetary gear speed reducers 18, 18 'are attached to the bracket plates 17, 17', and the speed reducers 18, 18 'are mounted on the stems 12, 1'.
In 2 ', it is provided on the second shaft center 14, 14'. The output shafts 19, 19 'of the speed reducers 18, 18' protrude into the hub 10, and the output shafts 19, 19 'have a rotating bar 20, which extends in the radial direction of the second shaft center 14, 14'.
The center of 20 'is fixed. When each of the pivot bars 20, 20 'pivots around the second axis 14, 14', the engaging projections 21, 21 'engaging with the pivot bars 20, 20' engage with the bracket plate 17. , 17 '.

On the other hand, support shafts 22, 22 'are provided between blades 11, 11' which are adjacent to each other in the circumferential direction of the first shaft center 8, and these support shafts 22, 22 'are connected to the first shaft center. The projection 10 is provided on the hub 10 at a position substantially perpendicular to the axis 8. Weights 23, 23 'are respectively slidably fitted in the respective support shafts 22, 22' in the axial direction thereof, and the weights 2, 2 'are directed toward the first shaft center 8 side.
Springs 24, 24 'for urging the members 3, 23' are provided.

Each of the weights 23, 23 'is connected to the support shaft 22,
It is arranged so as to be X-shaped when viewed from the axial direction of 22 '. Then, the rear end of one weight 23 and one rotating bar 2
0 is connected to a first link 26, and the front end of one weight 23 and the front end of the pivot bar 20 'are connected to the second link 2
7 are connected. Further, the front end of the other weight 23 'and the front end of the one rotation bar 20 are connected by a third link 28, and the rear end of the other weight 23' and the other rotation bar 2
The rear end of 0 'is connected by a fourth link 29. Each of the links 26 to 29 has a screw structure so that the length can be adjusted.

DC motors 32, 3 are respectively connected to the speed reducers 18, 18 'via electromagnetic brake means 31 (the ones for the speed reducer 18' are not shown).
The output shafts 33 of the motor 2 '(not shown for the motor 32') are connected, and these brake means 31 are connected.
And the electric motors 32, 32 'are also provided on the second shaft centers 14, 14' in the stems 12, 12 '. That is, the reduction gears 18, 18 'and the electric motors 32, 32' are connected to the stems 12, 1 '.
By providing using the space in 2 ', compactness is achieved.

When the motors 32, 32 'operate, this power is transmitted to the speed reducers 18, 18'. in this case,
Each output shaft 19, 19 'of each speed reducer 18, 18' can be rotated forward and reverse, that is, the rotating bar 20,
20 'is forward and reverse reversible. Further, if the brake means 31 is operated by a brake, both output shafts 19, 3
3 is fixed to a casing 18 a of the speed reducer 18. In this case, the brake means 31 and 31 'are configured to perform a brake operation by demagnetizing (OFF) and release the brake operation by excitation. For this reason, the motors 32, 3
If the power supply to the electric motors 32, 32 'and the brake means 31 is suddenly interrupted during the operation of 2', each brake means 31 moves each blade 11, 11 'to the pitch angle α at that time. Hold. Therefore, these two blades 1
An imbalance is prevented from occurring in the pitch angle α between the first and the 11 ′.

In particular, in FIG. 1, reference numeral 34 denotes a wind speed detection sensor, and reference numeral 35 denotes a rotation speed detection sensor for detecting the rotation speed of the rotor 9. 36 is a front-back direction acceleration sensor, 37 is a left-right direction acceleration sensor, that is,
By providing these acceleration sensors in the X and Y directions, the acceleration detection accuracy of the free yaw wind generator 1 is improved.

In particular, in FIGS. 2 and 3, limit switches 38, 38 'are attached to the respective rotating bars 20, 20', and the respective bracket plates 1 correspond to these.
Engagement bodies 39, 39 'are attached to 7, 17'. As shown in FIG. 1, the electric motors 32 and the wind speed detection sensor 34 are connected to each other via an electronic control unit 40. 42 is a commercial power supply, which is
It is used as a control power supply for use. Reference numeral 43 denotes a battery, which is used as a power source for the electric motors 32 and 32 '.
Even when electric power is not supplied from the commercial power supply 42 due to a power failure or the like, electric power can be supplied to the electric motors 32 and 32 '. Since the frequency of use of the motors 32 and 32 'is low, a small capacity battery is sufficient for the battery 43, and
Since all the driving power of the electric motors 32 and 32 'is supplied from the battery 43, the current consumption of the control device 40 and the battery 43
The power supply device (not shown) that shares the charging current with a small capacity is also of a small capacity.

1 to 3, each of the blades 11,
11 'from the first shaft center 8 side to the respective second shaft centers 14, 14'.
When viewed in the direction along, each of these blades 11, 11 '
Cooperate with each other so that the postures of their cross sections (planes substantially perpendicular to the second axis centers 14 and 14 ') are the same. Therefore, the configuration and operation related to one blade 11 will be mainly described, and the description of the other blade 11 'common to this will be omitted.

In FIG. 3, the pitch angle α of the blade 11 is 0 ° when a reference specific cross section is parallel to an imaginary plane orthogonal to the first axis 8. When it is rotated around the second axis 14 in the direction of arrow A in the figure and its cross section is turned to a position parallel to the first axis 8, the pitch angle α becomes 90 °. The attitude of the blade 11 in which the pitch angle α is substantially 90 ° is referred to as a danger avoiding attitude. In this state, the rotational torque due to the wind pressure given to the blade 11 by the wind in the direction indicated by Fr in the drawing becomes substantially zero. Therefore, the blade 11 is prevented from rotating around the first axis 8, and the wind power generator 1 is in a stopped state. When the wind direction changes in the horizontal direction, the rotor 9 rotates around the vertical axis of the column 2 by the wind pressure received by the blades 11 and 11 ', and the first axis 8 is always substantially parallel to the wind direction. It is becoming.

In FIG. 3, when the wind is almost no wind and the rotor 9 is hardly rotating, the weights 23 and 23 'are urged by the springs 24 and 24' as shown by arrows A in the figure. It moves to the first axis 8 side, and accordingly, each link 2
The pivot bar 20 pivots through 6 to 29 to the position shown by the dashed line in FIG. In this case, the weights 23, 23 'abut against the stoppers 44, 44' at the bases of the support shafts 22, 22 ', and are prevented from further moving to the first shaft center 8 side. Although not shown, the stoppers 44 and 44 'are adjustable in height. At this time, the output shaft 19 of the speed reducer 18 is rotated forward by the operation of the electric motor 32 as shown by the arrow B in FIG.
8a rotates together with the bracket plate 17 as shown by an arrow B 'in FIG. 3 opposite to the arrow B, and the engaging projection 21 which rotates together with the bracket plate 17 is in contact with the rotary bar 20. . Then, in this state, the brake means 31 performs the brake operation and the operation of the electric motor 32 is stopped. And in this case, the pitch angle α of the blade 11
Is the minimum pitch angle, which is 4 ° in the illustrated example.

The value of the minimum pitch angle can be arbitrarily adjusted by adjusting the heights of the stoppers 44 and 44 'and the lengths of the links 26 to 29. When the wind speed increases from the above state, the blades 11 and 11 'receive wind pressure, and the rotor 9 rotates in the direction indicated by the arrow C in FIG. Then, this rotation is transmitted to the transmission 3 via the input shaft 7, where the speed is increased, power is generated by the generator main body, and the wind power generator 1 enters the operating state.

1 to 3, when the wind speed increases, a centrifugal force is generated in each of the weights 23 and 23 ', which opposes the urging force of the springs 24 and 24' as shown by solid lines in each of the figures. As a result, the rotary bar 20 moves away from the first axis 8, and accordingly, the rotary bar 20 rotates via the links 26 to 29. Then, the engagement projection 21 pressed by the rotation bar 20 rotates the bracket plate 17, that is, the blade 11 is rotated in a direction indicated by an arrow D in each drawing, and the blade 1 is rotated.
The pitch angle α of 1 gradually increases.

When the pitch angle α increases to some extent, the wind pressure received by the blade 11 decreases, and the rotation speed of the rotor 9 decreases accordingly. Therefore, the weight 23,
The centrifugal force of 23 'is also reduced. In this way, even if the wind speed fluctuates, the rotation speed of the rotor 9 is maintained at a certain value, and power generation is continued. That is, the weights 23, 23 '
The springs 24, 24 'constitute a centrifugal governor for the blade 11.

In FIG. 3, the state where the blade 11 is indicated by a two-dot chain line indicates the state when the blade 11 is in the danger avoiding posture. The operation of each device in this posture will be described with reference to FIGS. That is, first,
The brake means 31 is released, and the output shaft 19 of the speed reducer 18 is reversed by the operation of the electric motor 32 as shown by an arrow E in FIG. At this time, the rotating bar 20 connected to the output shaft 19 applies the centrifugal force of the weights 23 and 23 'and the spring 2
Since the output shaft 19 is rotated in the reverse direction as described above, the casing 18a of the speed reducer 18 moves with the bracket plate 17 due to the reaction force when the output shaft 19 reverses as described above. Will rotate as shown by the arrow E 'in FIG. Then, when the blade 11 assumes the danger avoiding posture, the operation of the electric motor 32 is stopped by turning on the limit switch 38 by an engagement body (not shown) different from the engagement body 39 provided on the bracket plate 17. At the same time, the brake means 31 is operated by a brake. When the motor 32 is started, a slow start is performed to reduce the starting current, so that abnormal torque is not generated in the motor 32 and the speed reducer 18 and the power supply capacity is reduced.

The control device 40 of the pitch angle changing means 16
When the wind speed detection sensor 34 detects that the wind speed has exceeded a first set value and / or has become equal to or greater than a second set value greater than the first set value, The blade 11 is configured to be in a danger avoiding posture.

Referring to FIGS. 4 and 5, the control device 40 will be described. These figures show flowcharts of the control device 40, and (P-1) to (P-23) in the figures show steps of the program. Also, A,
The symbols B and C mean that the same symbols are connected to each other. In FIG. 4, when the wind speed U exceeds a first set value of 25 m / s (P-2), this wind speed U
Is less than 40 m / s (P-3), the pitch angle α is 9
The angle is set to 0 °, that is, the blade 11 is set to the danger avoidance posture by the operation of each device described above (P-4).

In FIG. 5, each of the acceleration sensors 3
6, 37, the acceleration detected is less than 0.5 g (P
-5) Regardless of whether the wind speed is 5 m / s or less (P-6), regardless of whether the rotation speed of the rotor 9 detected by the rotation speed detection sensor 35 is 100 rpm or less. (P-7), the commercial power supply 42 is not on (ON) (P-8), and the capacity of the battery 43 is sufficient (P-
9) If the wind speed is less than the second set value of 40 m / s (P-1
0), when the rotation speed of the rotor 9 is 2500 rpm or less (P−
11) If the inverter as the power converter for power generation is normal (P-13), the program returns to (P-5), and the state where the pitch angle α is 90 ° is maintained.

On the other hand, in (P-8), if the commercial power supply 42 is ON, it is determined whether or not the capacity of the battery 43 is sufficient (P-14). If not, charging is performed. (P-15). Then, after this, the pitch angle α is 4 °
(P-16). Specifically, when (P-16) is shown, when the capacity of the battery 43 becomes sufficient, the brake operation of the brake means 31 is first released, and the output shaft 19 of the speed reducer 18 is operated by the operation of the electric motor 32. It rotates forward as indicated by arrow B in FIG. Then, the reaction force causes the casing 18a of the above-described speed reducer 18 to move the bracket plate 1
7, the blade 11 rotates in the direction opposite to the arrow B as shown by the arrow B 'in FIG. 3, and the blade 11 is returned until the pitch angle α becomes 4 ° (shown by a dashed line in FIG. 3).

Then, after this, the program is (P-1)
Return to That is, when the wind speed becomes 5 m / s or less, which is lower than the first set value, from the state in which the blade 11 is in the danger avoiding posture, the rotor 9 automatically switches to the normal operation state in which the rotor 9 is controlled by the weight 23 and the spring 24. It is designed to return.

In FIG. 5, at (P-5), the acceleration is set to 0.
5 g or more, the capacity of the battery 43 is insufficient at (P-9), the wind speed is 40 m / s or more at (P-10), and the rotation speed of the rotor 9 is 2500 rpm at (P-11). pm
And the acceleration is 0.5g or more at (P-12),
If any one of the inverters is abnormal in (P-13), an abnormal mode is displayed (P-1).
7). In this case, the brake means 31 is held in the brake operating state, that is, the blade 11 is held in the danger avoiding posture such that the blade 11 cannot return automatically. Returning to (P-16) is manually performed. At this time, the wind power generator 1 may be inspected.

In FIG. 4, at (P-3), the wind speed is 40 m /
s or more, the pitch angle α becomes 90 as in (P-4).
° (P-18), and further referred to as (P-17). In FIG. 4, when the commercial power supply 42 is turned off (P-19), the battery 4 for backup is used.
3 is used, and the pitch angle α is 90 °.
(P-4). Thus, reliability is secured.

As shown in FIG.
5 has an abnormality (P-20), the acceleration is 0.5g
At this time (P-21), the rotation speed of the rotor 9 is 2500
rpm (P-22) or when the inverter trips (P-23),
-18). In the above (P-16), when the pitch angle α of the blade 11 reaches just 4 °, the brake means 31 and the electric motor 32 are controlled as shown in FIG.

In FIG. 6, the rotating bar 20 and the engaging projection 2
The pitch angle α of the blade 11 when it comes into contact with 1 is 4 °
It is. When the pitch angle α reaches 10 ° from a value larger than 10 °, the limit switch 38 comes into contact with the engagement body 39 and turns ON (point a in the figure).
Then, with this signal, the drive voltage of the electric motor 32 is reduced, and the rotation speed is controlled so as to gradually decrease (b in the figure).
Department). Next, after a lapse of time required for the rotation bar 20 to come into contact with the engagement protrusion 21, the brake means 31 operates the brake (point c in the drawing).

That is, by reducing the speed of the electric motor 32 as described above, when the engaging projection 21 comes into contact with the rotating bar 20 due to the torque generated by the electric motor 32, the contact force is reduced, and Abnormal torque is prevented from being generated in the speed reducer 18. Then, immediately after the contact, the motor 32 is turned off (point d in the figure). On the other hand, the sensor abnormality detection in (P-20) is performed as shown in FIG. That is, although the wind speed is 8 m / s or more, the wind power generator 1
When the number of revolutions of the rotor 9 is 0, an abnormal signal is output.

[0035]

According to the present invention, when the wind speed detecting sensor detects that the wind speed exceeds the first set value, the pitch angle changing means, based on the detection signal, makes the cross section of the blade substantially horizontal. The pitch angle of this blade is changed so that the danger avoidance posture is substantially parallel to the first axis center,
At this time, the second wind speed is larger than the first set value.
When the value is less than the set value, since the pitch angle of the blade can be automatically returned, the wind having a wind direction substantially parallel to the first axis is prevented from applying an excessive wind pressure to the windmill via the blade. The protection of this windmill is achieved.

On the other hand, when the wind speed detection sensor detects that the wind speed has become equal to or higher than the second set value, the pitch angle changing means, based on the detection signal, determines that the blade cannot be automatically returned. Since the blade is held in the above-mentioned danger avoiding posture, if the second set value is set to a value until the failure rate due to wind pressure increases, the wind speed reaches this second set value. Don't, first
When the value falls below the set value, the blade automatically returns from the danger avoidance posture, and the operation of the windmill is continued.In this case, the blade automatically returns in a state where the failure of the windmill is unlikely to occur. Therefore, the operation after the return is performed without any trouble, and the return is performed without any additional work.

On the other hand, when the wind speed becomes equal to or higher than the second set value, the failure rate increases. At this time, however, the blade is held in the danger avoiding posture such that the blade cannot return automatically as described above. For this reason, when this state is reached, the wind turbine is once checked for any failure and then returned. Therefore, it is possible to prevent the inconvenience that the operation is automatically restarted while the wind turbine is still broken.

That is, according to the present invention, when the wind speed becomes excessive, the blade is prevented from being in the danger avoiding posture, and an excessive wind pressure is prevented from being applied to the windmill through the blade. Further, if the blade is returned from the danger avoiding posture when the wind speed decreases thereafter, the subsequent operation is performed without any trouble, and the return can be performed by a simple operation.

[Brief description of the drawings]

FIG. 1 is a perspective view.

FIG. 2 is a plan sectional view.

FIG. 3 is a view taken along line 3-3 in FIG. 2;

FIG. 4 is a flowchart.

FIG. 5 is a flowchart.

FIG. 6 is a time chart.

FIG. 7 is a logic circuit diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wind power generator (windmill) 2 Prop 8 First shaft 9 Rotor 10 Hub 11 Blade 14 Second shaft 16 Pitch angle changing means 34 Wind speed detection sensor

Claims (1)

(57) [Claims] A hub is provided rotatably about a substantially horizontal first axis, and a blade is provided extending from the hub side substantially radially outward of the first axis. Pitch of a windmill provided with pitch angle changing means for pivotally supporting the blade so as to be rotatable about a second axis along the hub and changing a pitch angle of the blade about the second axis. In the control device, the first
A wind speed detecting means in a wind direction substantially parallel to the axis is provided,
When the wind speed detecting means detects that the wind speed exceeds a first set value, the pitch angle changing means avoids danger that the cross section of the blade is substantially parallel to the first axis based on the detection signal. At this time, when the wind speed is less than a second set value which is larger than the first set value, the pitch angle of the blade can be automatically reset, while the wind speed is set to the second set value. When the wind speed detecting means detects that it has become equal to or greater than the set value, the pitch angle of the blade is held by the pitch angle changing means based on the detection signal in the danger avoiding posture in a state where the blade cannot be automatically returned. Wind turbine pitch angle control device.