JPH04365976A - Pitch angle controller of windmill - Google Patents

Abstract

PURPOSE:To prevent a condition in which excessive wind pressure is given to a windmill when wind velocity reaches an excessive level, to prevent that malfunction is generated in driving of the windmill afterwards even when an initial state is restored from a condition of lowered wind velocity, and to facilitate the operation of the restoring. CONSTITUTION:When it is detected by a wind velocity detection sensor 34 that wind velocity exceeds a first set value, the cross sectional surface of a blade 11 is turned into a danger-avoiding position that is almost parallel to the wind direction. When the wind velocity is less than a first set value which is larger than the first set value, the blade 1 can be automatically returned to an initial state. When the wind velocity reaches no less than the second set value, the danger-avoiding position of the blade 11 is maintained under a condition that the automatic returning is not allowed.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to a pitch angle control device for a wind turbine, and more specifically, a device that temporarily stops the operation of the wind turbine to avoid the wind pressure when the wind speed exceeds a certain set value. Regarding.

0002

BACKGROUND OF THE INVENTION Conventionally, pitch angle control devices for wind power generators, which are an example of the above-mentioned wind turbines, have conventionally been disclosed in Japanese Patent Application Laid-Open No. 63-1248.
There is one shown in Publication No. 74. According to this, a hub is provided to be rotatable about a substantially horizontal first axis, and a blade is provided that extends from the hub side substantially radially outward from the first axis. Further, the blade is pivotally supported by the hub so as to be rotatable about a second axis along the longitudinal direction thereof, and pitch angle changing means for changing the pitch angle of the blade about the second axis. is provided. In the event of an emergency, such as loss of generator load or loss of power to the control means for this generator,
The pitch angle of the blade is automatically changed so that the cross section of the blade is in a danger-avoiding position almost parallel to the first axis.In other words, the wind pressure applied to the blade is reduced, and unnecessary wind pressure is not applied to the generator. I'm trying not to give it to you.

0003

[Problem to be Solved by the Invention] By the way, even when the wind speed in the wind direction substantially parallel to the first axis becomes excessive, the above configuration can be applied as an emergency measure to cause the blade to take a danger avoidance position. , it is conceivable to reduce the wind pressure that the blade receives. But after this,
When the wind speed decreases, this blade automatically returns to its original pitch angle from the danger avoidance position, and if the generator has malfunctioned due to overspeed due to the excessive wind speed, this malfunction will continue. , there is an inconvenience that the operation is restarted. Therefore, when the wind speed becomes excessive, it is conceivable to maintain the blade in the danger avoidance position so that the blade cannot automatically return to its original pitch angle. However, simply doing so would require recovery work each time, regardless of whether or not the generator has malfunctioned, which is extremely troublesome.

0004

[Purpose of the Invention] This invention was made with attention to the above-mentioned circumstances, and when the wind speed becomes excessive, the blades of the wind turbine are placed in a danger avoidance position so that excessive wind pressure is not applied to the blades. In addition, even if the blades are returned from the danger avoidance position when the wind speed decreases, the subsequent operation of the wind turbine is not hindered, and this return can be done with a simple operation. The purpose is to do so.

[0005]

[Means for Solving the Problems] The present invention is characterized in that when the wind speed detection means detects that the wind speed exceeds the first set value, the The pitch angle changing means sets the cross section of the blade to a danger avoidance posture substantially parallel to the first axis, and at this time, if the wind speed is less than a second set value that is larger than the first set value, The pitch angle of the blade can be automatically reset, and when the wind speed detecting means detects that the wind speed exceeds the second set value, the pitch angle changing means adjusts the pitch angle of the blade based on the detection signal. The pitch angle is such that the danger avoidance posture is maintained in a state where 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 the first set value (for example, 25 m/s), the pitch angle changing means 16 changes the blade 11 based on the detection signal.
The pitch angle α of the blade 11 is changed so that the cross section (a plane substantially perpendicular to the second axes 14, 14') is in a danger avoidance posture substantially parallel to the first axis 8, which is substantially horizontal;
At this time, the second wind speed is higher than the first set value.
If the pitch angle α of the blade 11 is less than a set value (for example, 40 m/s), the pitch angle α of the blade 11 can be automatically returned to the original pitch angle α. Therefore, the wind having the wind direction Fr substantially parallel to the first axis 8 is prevented from applying excessive wind pressure to the wind power generator (wind turbine) 1 via the blades 11.

On the other hand, when the wind speed detection sensor 34 detects that the wind speed exceeds the second set value, the pitch angle changing means 16 changes the pitch angle according to the detection signal.
The blade 11 is held in the danger avoidance position in a state where the blade 11 cannot automatically return to its original pitch angle α. Therefore, if the second set value is set to a value that will cause a high failure rate due to wind pressure,
When the wind speed does not reach the second set value and falls below the first set value, the blades 11 automatically return from the danger avoidance posture to the original pitch angle α, and the wind power generator 1 continues to operate. It will be. In this case, the blades 11 are in a state where the wind power generator 1 is unlikely to have a failure.
Since it automatically returns, operation after this restoration can be carried out without any trouble.

On the other hand, if the wind speed exceeds the second set value, the failure rate increases, but in this case, as described above, the blade 11 is held in the danger avoidance position without being able to return automatically. Therefore, when this state occurs, the wind power generator 1 must be checked to see if there is a malfunction or not before it is restored.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. In FIGS. 1 to 3, reference numeral 1 indicates a wind power generator, which is an example of a windmill. Further, an arrow Fr in the figure indicates the wind direction, and for convenience of explanation below, the downstream direction of this wind direction is assumed to be the front. The wind power generator 1 has a vertical support 2 erected on the ground, and a generator main body (not shown) is provided in the upper part of the support 2. A transmission 3 is disposed above this column 2, and a casing 4 of this transmission 3 is attached to the column 2.
It is supported on the upper end of the column 2 and is rotatable around the axis of the column 2. Inside the casing 4 is a speed change gear mechanism 5.
is contained therein, and an output shaft (not shown) of this transmission gear mechanism 5
is connected to the generator main body.

The input shaft 7 of the speed change gear mechanism 5 projects forward and approximately horizontally.
The casing 4 is rotatably supported by the casing 4 about a first axis 8 passing through the center of the casing 4. A rotor 9 is attached to the protruding end of the input shaft 7. The rotor 9 is comprised of a box-shaped hub 10 screwed onto the protruding end of the input shaft 7, and a pair of blades 11, 11' that protrude from the hub 10. The first axis 8
They protrude substantially radially outward in opposite directions from each other. 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 about second axes 14, 14' along the longitudinal direction. 15
, 15' are counterweights.

Pitch angle changing means 16 is provided for changing the pitch angle α of the blades 11, 11'. This pitch angle changing means 16 is adapted to each stem 12, 12'.
It has bracket plates 17, 17' attached to the ends of the bracket. Casings 18a of planetary gear type reducers 18, 18' are attached to these bracket plates 17, 17', and these reducers 18, 18' are attached to the stems 12, 12.
' is provided on the second axes 14, 14'. The output shafts 19, 19' of the reduction gears 18, 18' are connected to the hub 1.
0, and this output shaft 19, 19' has the same second
Rotating bars 20, 20 extending in the radial direction of the axes 14, 14'
′ is fixed in the center. Further, when each of these rotating bars 20, 20' rotates around the second axis 14, 14', an engaging protrusion 21 that engages with this rotating bar 20, 20'
, 21' project from the bracket plates 17, 17'.

On the other hand, support shafts 22 and 22' are provided between adjacent blades 11 and 11' in the circumferential direction of the first axis 8, and each of these support shafts 22 and 22' is connected to the first axis 8. The hub 10 is located on an axis substantially orthogonal to the hub 8 and protrudes from the hub 10 . Weights 23 and 23' are respectively fitted to these support shafts 22 and 22' so as to be slidable in the axial direction thereof, and each of the weights 23 and 23'
Spring 24, 24' is provided which biases 3, 23'.

Each of the weights 23, 23' is attached to the support shaft 22,
They are arranged in an X-shape when viewed from the axial direction of 22'. Then, the rear end of one weight 23 and one rotation bar 2
The rear end of one of the weights 23 and the front end of the rotating bar 20' are connected to the second link 26.
They are connected by 7. Further, the front end of the other weight 23' and the front end of one of the rotation bars 20 are connected by a third link 28, and the rear end of the other weight 23' and the front end of the other rotation bar 20 are connected by a third link 28.
' is connected to the rear end by a fourth link 29. In addition,
Each of the links 26 to 29 has a threaded structure so that the length can be adjusted.

The reduction gears 18, 18' are connected to DC electric motors 32, 32 via electromagnetic brake means 31 (the reduction gear 18' is not shown).
'The output shafts 33 (the electric motor 32' is not shown) are connected, and the brake means 31 and the electric motors 32, 32' are also connected to the second axes 14, 14' within the stems 12, 12'. is placed above. In other words, the reduction gears 18, 18' and the electric motors 32, 32' are connected to the stems 12, 12.
Compactness is achieved by utilizing the space within '.

When the electric motors 32, 32' operate, this power is transmitted to the reduction gears 18, 18'. in this case,
Each output shaft 19, 19' of each reduction gear 18, 18' is capable of forward and reverse rotation, that is, the rotating bar 20,
20' is capable of forward and reverse rotation. Moreover, if the brake means 31 is operated, both output shafts 19, 3
3 is fixed to the casing 18a of the speed reducer 18. In this case, the brake means 31, 31' are configured to operate the brake when demagnetized (OFF) and release the brake operation when excited. For this reason, the electric motors 32, 3
If the power supply to the electric motors 32, 32' or the brake means 31 is suddenly cut off during the operation of the blades 11, 11', each brake means 31 adjusts the blades 11, 11' to the pitch angle α at that time. Hold. Therefore, these two blades 1
This prevents an unbalance in the pitch angle α between 1 and 11'.

In particular, in FIG. 1, 34 is a wind speed detection sensor, and 35 is a rotation speed detection sensor that detects the rotation speed of the rotor 9. Further, 36 is an acceleration sensor in the front-rear direction, and 37 is an acceleration sensor in the left-right direction.In other words, by providing these acceleration sensors in the X and Y directions,
The acceleration detection accuracy of the Free Yaw wind power generator 1 is improved.

In addition, especially in FIGS. 2 and 3, limit switches 38 and 38' are attached to each rotating bar 20 and 20', and each bracket plate 1
Engaging bodies 39, 39' are attached to 7, 17'. As shown in FIG. 1, the electric motors 32, wind speed detection sensor 34, etc. are connected to each other via an electronic control device 40. As shown in FIG. Reference numeral 42 denotes a commercial power source, which is used as a control power source for the control device 40 and the like. Further, 43 is a battery, which is used as a power source for the electric motors 32, 32', and can supply electric power to the electric motors 32, 32' even when power is not supplied from the commercial power supply 42 due to a power outage or the like. There is. Note that since the electric motors 32 and 32' are used infrequently, a small capacity battery 43 is sufficient, and since the battery 43 supplies all the driving power for the electric motors 32 and 32', the consumption of the control device 40 is reduced. The power supply equipment (not shown) that shares the current and the charging current for the battery 43 is also of small capacity.

In FIGS. 1 to 3, each blade 11,
11' from the first axis 8 side to its respective second axes 14, 14'
When viewed in the direction along, each of these blades 11, 11'
are interlocked so that the postures of their cross sections (planes substantially orthogonal to the second axes 14, 14') are the same. Therefore, the configuration and operation related to one blade 11 will be mainly explained, and the explanation of the common components of the other blade 11' will be omitted.

In FIG. 3, the pitch angle α of the blade 11 is 0° when the specific cross section serving as its reference is parallel to a virtual plane perpendicular to the first axis 8, and from this, When it rotates about the second axis 14 in the direction of the arrow A in the figure until the cross section thereof is parallel to the first axis 8, the pitch angle α becomes 90°. The posture of the blade 11 in which this pitch angle α is approximately 90° is called the danger avoidance posture, and in this state, the rotational torque due to the wind pressure applied to the blade 11 by the wind in the wind direction indicated by Fr in the figure becomes approximately 0. Therefore, the blade 11 is prevented from being rotated around the first axis 8, and the wind power generator 1 is brought into a state where the operation is stopped. Note that when the wind direction changes in the horizontal direction, the rotor 9 rotates around the vertical axis of the support column 2 due to the wind pressure applied to each blade 11, 11', so that the first axis 8 is always substantially parallel to the wind direction. It's supposed to be.

In FIG. 3, when there is almost no wind and the rotor 9 is hardly rotating, the weights 23, 23' are biased by the springs 24, 24' as shown by arrow A in the figure. Moves to the first axis 8 side, and accordingly each link 2
6 to 29, the rotation bar 20 rotates to the position shown by the dashed line in FIG. In this case, each weight 23, 23' comes into contact with a stopper 44, 44' at the base of the support shaft 22, 22', and is prevented from moving further toward the first axis 8 side. Although not shown, the height of the stoppers 44, 44' is adjustable. At this time, the output shaft 19 of the reducer 18 rotates forward as shown by arrow B in FIG. 2 due to the operation of the electric motor 32, and the reaction force causes the casing 1 of the reducer
8a rotates together with the bracket plate 17 as shown by arrow B' in FIG. . In this state, the brake means 31 performs a brake operation, and the operation of the electric motor 32 is stopped. In this case, the pitch angle α of the blade 11 is
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 height of the stoppers 44, 44' and the length of each link 26-29. When the wind speed increases from the above state, each blade 11, 11' receives wind pressure, and the rotor 9 rotates in the direction shown by arrow C in FIG. Then, this rotation is transmitted to the transmission device 3 via the input shaft 7, where the speed is increased, the generator main body generates electricity, and the wind power generator 1 is put into operation.

In FIGS. 1 to 3, when the wind speed increases, centrifugal force is generated in each of the weights 23 and 23', which resists the biasing force of the springs 24 and 24' as shown by solid lines in each figure. and moves away from the first axis 8, and accordingly, the rotation bar 20 rotates via each link 26-29. Then, the engagement protrusion 21 pressed by the rotation bar 20 rotates the bracket plate 17, that is, the blade 1
1 in the direction shown by arrow D in each figure, and
The pitch angle α gradually increases.

When the pitch angle α increases to a certain extent, the wind pressure applied to the blades 11 decreases, and the rotational speed of the rotor 9 decreases accordingly. For this reason, the weight 23,
The centrifugal force at 23' also becomes smaller. In this way, even if the wind speed fluctuates, the rotational speed of the rotor 9 is kept at a certain value, and power generation continues. That is, the weights 23, 23'
The blade springs 24, 24' constitute a centrifugal cabana for the blade 11.

In FIG. 3, the state of the blade 11 indicated by the two-dot chain line shows the state in which the blade 11 assumes the danger avoidance attitude. The operation of each device when taking this posture will be explained with reference to FIGS. 1 to 3. That is, first,
When the brake means 31 is released and the electric motor 32 is activated, the output shaft 19 of the reduction gear 18 is rotated in the reverse direction as shown by arrow E in FIG. At this time, the rotating bar 20 connected to the output shaft 19 is operated by the centrifugal force of the weights 23, 23' and the spring 24.
, 24' are held in a certain position by the balance of
7, it rotates as shown by arrow E' in FIG. 3, opposite to the above-mentioned arrow E. Then, when the blade 11 assumes the danger avoidance posture, the operation of the electric motor 32 is stopped by turning on the limit switch 38 by an engaging body (not shown) that is different from the engaging body 39 provided on the bracket plate 17. At the same time, the brake means 31 is operated. Note that when starting the electric motor 32, a slow start is performed to reduce the starting current, so that abnormal torque is not generated in the electric motor 32 and the reduction gear 18, and the power supply capacity is reduced.

Control device 40 for the pitch angle changing means 16
is based on the detection signal when the wind speed detection sensor 34 detects that the wind speed exceeds the first set value and/or becomes equal to or higher than the second set value, which is larger than the first set value. , the blade 11 is configured to take a danger avoidance position.

The control device 40 will be explained with reference to FIGS. 4 and 5. Note that these figures show flowcharts of the control device 40, and (P-1) to (P-23) in the figures indicate each step of the program. In addition, A, B in each figure
, and C mean that the same symbols are connected to each other. In Fig. 4, when the wind speed U exceeds the first set value of 25 m/s (P-2), the pitch angle α becomes 90° even if this wind speed U is less than 40 m/s (P-3). In other words, the blade 11 is brought into the danger avoidance position by the operation of each of the above-mentioned devices (P-4).

In FIG. 5, each of the acceleration sensors 36
, 37, the detected acceleration is less than 0.5g (P-
5), regardless of whether the wind speed is 5 m/s or less (P-6), if the rotation speed of the rotor 9 detected by the rotation speed detection sensor 35 is 100 r. p. m or less (P-7), the commercial power supply 42 is not ON (P-8), and the battery 43 has sufficient capacity (P-8).
-9), when the wind speed is less than the second set value of 40 m/s (
P-10), the rotation speed of the rotor 9 is 2500 r. p. m
In the following (P-11), if the inverter, which is a power conversion device for power generation, is normal (P-13), the program will be executed as described above (P-13).
Returning to -5), the pitch angle α remains at 90°.

On the other hand, in the above (P-8), if the commercial power supply 42 is ON, it is determined whether the capacity of the battery 43 is sufficient (P-14), and if it is insufficient, charging is not performed. (P-15). And after this, the pitch angle α is 4°
(P-16). To specifically illustrate this (P-16), 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 reduction gear 18 is activated by the operation of the electric motor 32. It rotates forward as shown by arrow B in FIG. Then, due to the reaction force, the casing 18a of the reducer 18 is pushed against the bracket plate 17.
3, the blade 11 is rotated as shown by arrow B' in FIG. 3 in the opposite direction to arrow B, and the blade 11 is returned until its pitch angle α becomes 4° (as shown by the dashed line in FIG. 3).

[0029] After this, the program is (P-1)
Return to In other words, if the wind speed becomes 5 m/s or less, which is lower than the first set value, from the state where the blade 11 is in the danger avoidance position, the rotor 9 automatically returns to the normal operating state controlled by the weight 23 and the spring 24. It is set to return.

In FIG. 5, the acceleration is 0 at (P-5).
5 g or more, in (P-9) the capacity of the battery 43 is insufficient, in (P-10) the wind speed is 40 m/s or more, and in (P-11) the rotation speed of the rotor 9 is 2500 r. p
．． m, the acceleration is 0.5 g or more in (P-12), and the inverter is abnormal in (P-13), an abnormal mode is displayed (P-13).
17). In this case, the brake means 31 is maintained in the braking state, that is, the blade 11 is held in the danger avoidance position without being able to automatically return. Then, returning to the above (P-16) is done manually, and at this time, the wind power generator 1 may be inspected.

[0031] In Fig. 4, the wind speed is 40 m at (P-3).
/s or more, the pitch angle α is set to 90° (P-18) as in (P-4), and is further set to (P-17). In FIG. 4, when the commercial power supply 42 is turned off (P-19), the backup battery 43 is used, and the pitch angle α is 9.
It is assumed to be 0° (P-4). This ensures reliability.

In FIG. 4, the rotation speed detection sensor 3
When an abnormality occurs in 5 (P-20), the acceleration is 0.5g.
In the above case (P-21), the rotation speed of the rotor 9 is 2500
r. p. The above (P-18) occurs either when the inverter exceeds m (P-22) or when the inverter trips (P-23). In addition, in the above (P-16), when the pitch angle α of the blade 11 reaches exactly 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 protrusion 2
1, the pitch angle α of the blade 11 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 engaging body 39 and turns on (point a in the figure). Then, in response to this signal, the drive voltage of the electric motor 32 is lowered, and its rotational speed is controlled to gradually decrease (section b in the figure). Next, after the time required for the rotation bar 20 and the engagement protrusion 21 to come into contact with each other, the brake means 31 performs a brake operation (point c in the figure).

In other words, by reducing the speed of the electric motor 32 as described above, when the engaging protrusion 21 abuts against the rotating bar 20 due to the torque generated by the electric motor 32, the abutting force is reduced, and the electric motor 32 and Abnormal torque is prevented from occurring in the reducer 18. Immediately after the above contact, the electric motor 32 is turned off (point d in the figure). On the other hand, the abnormality detection of the sensor in (P-20) is performed as shown in FIG. That is, when the wind speed is 8 m/s or more but the rotational speed of the rotor 9 of the wind power generator 1 is 0, an abnormal signal is output.

[0035]

According to the present invention, when the wind speed detection sensor detects that the wind speed exceeds the first set value, the pitch angle changing means adjusts the pitch angle so that the cross section of the blade is substantially horizontal based on the detection signal. The pitch angle of this blade is changed so that it is in a danger avoidance posture that is almost parallel to the first axis,
At this time, the second wind speed is higher than the first set value.
If the pitch angle of the blade is less than the set value, the pitch angle of the blade can be automatically reset, thereby preventing wind whose direction is approximately parallel to the first axis from applying excessive wind pressure to the wind turbine through the blade. , this windmill will be protected.

On the other hand, when the wind speed detection sensor detects that the wind speed has exceeded the second set value, the pitch angle changing means adjusts the pitch angle in a state where the blade is unable to return automatically based on the detection signal. Since the blade is held in the above-mentioned danger avoidance position, if the second set value is set at a value until the failure rate due to wind pressure becomes high, the wind speed will reach this second set value. If the blades do not do so and the value falls below the first set value, the blades automatically return from the danger avoidance position and the wind turbine continues to operate. Since it automatically returns, operation after this restoration can be carried out without any trouble, and this restoration can be carried out without the need for any separate work.

On the other hand, if the wind speed exceeds the second set value, the failure rate increases, but in this case, as described above, the blade is held in the danger avoidance position without being able to return automatically. Therefore, when this condition occurs, the wind turbine must be inspected to see if there is a malfunction or not before it is restored. This prevents the inconvenience of automatically restarting operation while the wind turbine remains out of order.

That is, according to the present invention, when the wind speed becomes excessive, the blades take a danger-avoiding position, and excessive wind pressure is prevented from being applied to the wind turbine through the blades. Further, even if the blade is returned from the danger avoidance position when the wind speed decreases thereafter, the subsequent operation can be carried out without any problem, and this return can be done with a simple operation.

[Brief explanation of drawings]

FIG. 1 is a perspective view.

FIG. 2 is a plan sectional view.

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

FIG. 4 is a flowchart diagram.

FIG. 5 is a flowchart diagram.

FIG. 6 is a time chart diagram.

FIG. 7 is a logic circuit diagram.

[Explanation of symbols]

1 Wind power generator (windmill) 2　　　　pillar 8 First axis 9 Rotor 10 Hub 11 Blade 14 Second axis 16 Pitch angle changing means 34 Wind speed detection sensor

Claims (1)

[Claims] Claim 1: A hub is provided to be rotatable about a substantially horizontal first axis, and a blade is provided that extends from the hub side substantially radially outward from the first axis, and this blade extends in the longitudinal direction of the hub. A pitch angle of a wind turbine, the blades being pivotally supported on the hub so as to be rotatable about a second axis along the axis, and pitch angle changing means for changing the pitch angle of the blades about the second axis. The control device is provided with a wind speed detecting means in a wind direction substantially parallel to the first axis, and when the wind speed detecting means detects that the wind speed exceeds the first set value, the pitch is adjusted based on the detection signal. The angle changing means sets the cross section of the blade to a danger avoidance posture substantially parallel to the first axis, and in this case, if the wind speed is less than a second set value that is greater than the first set value, , the pitch angle of this blade can be automatically returned,
On the other hand, when the wind speed detecting means detects that the wind speed has become equal to or higher than the second set value, the pitch angle changing means changes the pitch angle of the blade in a state where automatic return is impossible. A pitch angle control device for a wind turbine that maintains it in a danger-avoiding position.