KR101204178B1 - Wind power generating apparatus and nacelle rotating method - Google Patents

Abstract

The wind power generator includes a nacelle equipped with a windmill rotor, a yaw driving device for generating a driving force for yawing the nacelle, a braking mechanism for generating a braking force for braking the nacelle, and a yaw driving device and a braking mechanism for controlling the yaw. A control device and a wind speed measuring device for measuring the wind speed are provided. When the control device detects the occurrence of the high wind speed state based on the wind speed while the nacelle is being rotated by the yaw drive device, the control unit applies the braking force to the nacelle by the brake mechanism in response to detecting the occurrence of the high wind speed state. Consists of.

Description

Wind power generation device and nacelle turning method {WIND POWER GENERATING APPARATUS AND NACELLE ROTATING METHOD}

The present invention relates to a wind power generator and a nacelle turning method, and more particularly, to yaw control of a nacelle of a wind power generator.

The nacelle of the wind power generator needs to control the direction in the horizontal plane in accordance with the wind direction and the wind speed. Such control is generally called yaw control, and a mechanism for performing yaw control is generally called a yaw control mechanism. The yaw control mechanism is typically configured with a yaw drive device that generates a driving force for turning the nacelle in a desired direction and a yaw brake that fixes the nacelle in the direction after the nacelle is directed in the desired direction. . As a yaw drive device, the drive mechanism of the structure which drives the pinion gear meshing with the gear provided in the yaw motor, the reducer, and the tower is used typically. Such a wind turbine is disclosed, for example, in US patent application publication US2008 / 0131279 A1. As the yaw brake, the hydraulic brake is most commonly used. A wind power generator using a hydraulic brake as a brake is disclosed in, for example, Japanese Patent Laid-Open No. 2006-307653.

In general, yaw drives are designed to generate a driving force capable of turning the nacelle even under sudden strong winds (such as 50-year gusts, eg wind speeds greater than 35 m / s) that occur only once every 50 years. do. This is to allow the windmill rotor to face the wind blowing even if any strong wind occurs. In general, since the wind load is the smallest when the windmill rotor is on the wind blowing side, it is preferable to point the windmill rotor to the wind blowing side to reduce the wind load during strong wind. If the nacelle is designed to generate a driving force capable of turning the nacelle even for a 50-year gust, the wind load can be reduced by directing the windmill rotor toward the blowing wind in almost all cases.

 Here, according to the inventor's review, the frequency of sudden strong winds such as 50-year gusts is very rare for the 20-year windmill life that is usually required, and the specification of the yaw control mechanism as described above is about normal operation. It is over-specified. The specification of such yaw control mechanism is undesirable because it leads to an increase in cost. Therefore, the inventors are considering a design that allows the nacelle not to turn when the driving force of the yaw control mechanism is reduced and a sudden wind external force is generated.

However, if the driving force of the yaw drive is reduced, there is a possibility that the yaw motor may be damaged if a momentary abnormal wind occurs while turning the nacelle so that the windmill rotor faces the wind blowing. Specifically, if a momentary abnormal wind such as a 50-year gust occurs while turning the nacelle, the nacelle may be suddenly pushed back due to the lack of turning torque. At this time, the nacelle turns at a high speed momentarily. Since the driving force of the yaw motor is generally transmitted to the nacelle via a speed reducer, if the nacelle is turned at a high speed momentarily, the yaw motor may be damaged by over-rotation.

United States Patent Application Publication US2008 / 0131279A1 Japanese Patent Application Publication No. 2006-307653

It is therefore an object of the present invention to provide a technique for effectively preventing damage to a yaw motor caused by a nacelle being pushed back by a strong wind.

In view of the present invention, a wind power generator includes a nacelle on which a windmill rotor is mounted, a yaw driving device for generating a driving force for yawing the nacelle, a braking mechanism for generating a braking force for braking the nacelle, and a yaw driving device. And a control device for controlling the braking mechanism, and a wind speed measuring device for measuring the wind speed. When the control device detects the occurrence of the high wind speed condition based on the wind speed while the yaw drive is turning the nacelle, the control unit applies the braking force to the nacelle by the braking mechanism in response to detecting the occurrence of the high wind speed condition. . In one embodiment, the control device controls the braking mechanism so that the braking force is not applied to the nacelle when the occurrence of the high wind speed state is not detected during the turning of the nacelle.

At this time, the drive torque Mzt _ALL generated by the drive device and the brake torque Mzt _BRK generated by the brake mechanism are related to the torque (absolute value) | Mzt | _MAX acting on the nacelle by a 50-year gust:

Mzt _ALL ─Mzt _BRK <| Mzt | _MAX <Mzt _ALL + Mzt _BRK ,

It is desirable to be adjusted so that

In one embodiment, the said wind power generator is further equipped with the rapid turning detection apparatus which detects the rapid turning of the nacelle by wind. In this case, when detecting the sharp turn of the nacelle during the turning of the nacelle, it is preferable that the control device controls the braking mechanism to give the nacelle a braking force higher than the braking force given in response to detecting the occurrence of a high wind speed condition.

The yaw drive device preferably includes a yaw motor, a swing mechanism for turning the nacelle using the torque generated by the yaw motor, and a torque control device for controlling the torque generated by the motor.

In another aspect of the present invention, the nacelle turning method of the wind turbine generator detects the occurrence of the high wind speed condition when the wind speed is detected based on the step of monitoring the wind speed while the nacelle is being turned, and the wind speed. In response to this, the step of providing a braking force to the nacelle is provided.

According to the present invention, it is possible to effectively use the driving force of the yaw drive device, while effectively preventing damage to the yaw motor due to the nacelle being pushed back by the strong wind.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows the structure of the wind turbine generator of one Embodiment of this invention.
It is sectional drawing which shows the structure of the yaw control mechanism in embodiment of this invention.
FIG. 3 is a top view illustrating the arrangement of the inner ring, outer ring, and pinion gear in the yaw control mechanism of FIG. 2.
It is a block diagram which shows the structure of the control system of the yaw control mechanism in one Embodiment of this invention.
5 is a graph showing an example of yaw control in one embodiment of the present invention.
It is sectional drawing which shows the structure of the yaw control mechanism in other embodiment of this invention.
It is a top view which shows the structure of the yaw control mechanism of FIG.
8 is a conceptual diagram showing the configuration of a yaw control mechanism according to still another embodiment of the present invention.
9 is a graph showing the slip output torque curve of the yaw motor in the case where an induction voltage is used as the yaw motor.

FIG. 1: is a side view which shows the structure of the wind turbine generator 1 in one Embodiment of this invention. The wind turbine generator 1 includes a tower 2 mounted on a foundation 6, a nacelle 3 provided at an upper end of the tower 2, and a rotor head rotatably mounted to the nacelle 3. (4) and the windmill blade | wing 5 attached to the rotor head 4 are provided. The rotor head 4 and the windmill vane 5 form a windmill rotor. When the windmill rotor is rotated by the wind, the wind power generator 1 generates electric power and supplies power to the electric power system connected to the wind power generator 1.

2 is a diagram illustrating a configuration of a yaw control mechanism for performing yaw control of the nacelle 3. Referring to FIG. 2, the nacelle 3 includes a nacelle base 11 on which a main shaft, a speed increaser, a generator, and other mechanisms used for power generation are mounted. The nacelle base 11 includes a yaw drive device ( 12) is attached.

The bearing attachment part 21 is provided in the upper end of the tower 2, and the outer ring 22 is attached to the bearing attachment part 21. As shown in FIG. In addition, the inner ring 23 is attached to the lower surface of the nacelle base plate 11. A steel ball 24 is inserted between the outer ring 22 and the inner ring 23, and the yaw pivot bearing 25 is formed by the outer ring 22, the steel ball 24, and the inner ring 23. Consists of. By the yaw slewing bearing 25, the nacelle base plate 11 can be swiveled in a horizontal plane. A tooth surface is formed on the outer circumferential surface of the outer ring 22.

 The yaw drive device 12 includes a pinion gear 26, a speed reducer 27, a yaw motor 28, and a motor brake 29. The pinion gear 26 meshes with the tooth surface provided on the outer circumferential surface of the outer ring 22. As shown in FIG. 3, when the pinion gear 26 rotates, the nacelle 3 and the inner ring mounted to the nacelle 3 are rotated. 23 turns. That is, the outer ring 22 also functions as an annular gear meshing with the pinion gear 26. 3 shows the relationship between the rotational direction of the pinion gear 26 and the rotational directions of the nacelle 3 and the inner ring 23. Returning to FIG. 2, the pinion gear 26 is coupled to the output shaft of the reducer 27. The reducer 27 is configured to transmit to the output shaft while decelerating the rotation of the input shaft, and the input shaft of the reducer 27 is coupled to the rotor of the yaw motor 28. Accordingly, the pinion gear 26 is mechanically coupled to the rotor of the yaw motor 28 via the speed reducer 27.

The motor brake 29 has a function of applying a braking force to the rotor of the yaw motor 28. Since the rotor of the yaw motor 28 is mechanically coupled to the pinion gear 26, the yaw turning of the nacelle 3 is braked by the braking force provided by the motor brake 29. In one embodiment, as the motor brake 29, a non-excited actuation type electromagnetic brake that operates when supply of current for excitation is stopped is used. As the motor brake 29, an electromagnetic brake of a type that operates when supply of current for excitation is started may be used.

In this embodiment, the yaw brake 30 is provided in addition to the motor brake 29 as a means for braking the turning of the nacelle 3. The yaw brake 30 is a braking mechanism for braking the yaw turning of the nacelle 3 using hydraulic pressure, and includes a yaw brake disc 31 and a yaw brake caliper 32. The yaw brake disc 31 is attached to the tower 2, and the yaw brake caliper 32 is attached to the nacelle base plate 11 by the mounting bracket 33. The yaw brake caliper 32 is driven by hydraulic pressure and sandwiches the yaw brake disc 31, thereby braking the yaw turning of the nacelle 3.

In addition, although the yaw drive device 12 is attached to the nacelle base plate 11 in this embodiment, it is also possible to mount the yaw drive device 12 to the tower 2. In this case, the tooth surface is formed in the inner peripheral surface of the inner ring 23, and the pinion gear 26 meshes with the tooth surface. In addition, the yaw brake disc 31 may be attached to the nacelle base plate 11, and the yaw brake caliper 32 may be attached to the tower 2.

4 is a block diagram showing the configuration of a control system of the yaw control mechanism according to the present embodiment. In the present embodiment, the wind power generator 1 is provided with a yaw brake drive mechanism 13, a control device 14, and a wind direction anemometer 15. The yaw brake drive mechanism 18 drives the yaw brake caliper 32 by hydraulic pressure. The controller 14 controls the turning and stopping of the nacelle 3 in response to the wind direction and wind speed measured by the wind direction anemometer 15. Control of turning and stopping of the nacelle 3 is performed by operating the yaw motor 2, the motor brake 29, and the yaw brake caliper 32.

When the nacelle 3 is fixed (that is, when the nacelle 3 is not turned), the controller 14 operates the motor brake 29 and the yaw brake caliper 32 to operate the nacelle 3. Braking

On the other hand, when the nacelle 3 is rotated, the controller 14 operates the yaw motor 28. The driving force generated by the yaw motor 28 is transmitted to the pinion gear 26 via the reducer 27, whereby the nacelle 3 is rotated. When turning the nacelle 3, the motor brake 29 and the yaw brake caliper 32 are basically released.

However, during turning of the nacelle 3, the control device 14 monitors the wind speed measured by the wind direction anemometer 15, and if determined to be in a high wind speed state, the motor brake 29 and / or the yaw brake caliper ( While operating 32, the mode shifts to the mode of turning the nacelle 3 (high wind speed mode). By this control, the occurrence of the situation in which the nacelle 3 is pushed back in an instant when an abnormal abnormal wind is generated is prevented, and damage of the yaw motor 28 due to over-rotation is prevented. The braking force applied to the nacelle 3 when it is in a high wind speed state is smaller than the braking force applied to the nacelle 3 when the nacelle 3 is fixed. For example, when the nacelle 3 is fixed, both the motor brake 29 and the yaw brake caliper 32 are operated. When the nacelle 3 is in a high wind speed, only the yaw brake caliper 32 may be operated. Do. In addition, the braking force generated by the yaw brake caliper 32 when it is in a high wind speed state may be different from the braking force generated by the yaw brake caliper 32 when the nacelle 3 is fixed.

Various logics can be considered about judging the transition to the high wind speed mode. As parameters to be considered in logic, the average wind speed and duration time can be considered. For example, when the average wind speed of the past predetermined time is larger than a predetermined value, it may be judged that it is in a high wind speed state. Moreover, when the maximum wind speed of the past predetermined time became larger than predetermined value, it may be judged that it is in the high wind speed state.

At this time, when the high wind speed state is canceled, the motor brake 29 and the yaw brake caliper 32 are released to the mode (normal swing mode). For example, when the conditions for shifting to the high wind speed mode are not satisfied, the shift to the normal swing mode may be performed. In addition, when the state in which the average wind speed of the predetermined time in the past continues below the set value continues for a predetermined time, the device may shift to the normal turning mode.

5 is a graph for explaining an example of yaw control in the present embodiment. In one embodiment, when the absolute value of the torque (that is, the maximum torque assumed by design) given to the nacelle 3 by 50-year gust is | Mzt | _MAX , the yaw drive device 12 is generated as a whole. The drive torque Mzt _ALL and the brake torque Mzt _BRK applied to the nacelle 3 in a high wind speed state are adjusted to satisfy the following conditions.

Mzt _ALL Mzt _BRK <| Mzt | _MAX <Mzt _ALL + Mzt _BRK . (One)

For example, when three yaw drives 12 are installed, while the braking force (brake torque) applied to the nacelle 3 in a high wind speed is set to the torque generated by one yaw drive 12. The following formula holds:

Mzt _ALL = 3 Mzt _DRV . (2a)

Mzt _BRK = Mzt _DRV . (2b)

Here, Mzt _DRV is the torque which the one yaw drive device 12 generate | occur | produces.

In this case, the torque Mzt _DRV generated by one yaw drive 12 (i.e., the brake torque applied to nacelle 3 at high wind speed) is adjusted to satisfy the following conditions:

2Mzt _DRV <| Mzt | _MAX <4Mzt _DRV . (3)

In this case, when the torque applied to the nacelle 3 by wind is set to Mzt, (a) the nacelle 3 turns when M zt <2Mzt _DRV , and (b) when 2Mzt _DRV <Mzt <4Mzt _DRV . The nacelle 3 stops. In either case, the situation in which the nacelle 3 is pushed back by the wind does not occur. In this way, the nacelle 3 is adjusted by adjusting the torque generated by the yaw drive device 12 and the brake torque applied to the nacelle 3 in a high wind speed state so as to satisfy the equation (1) or (3). It is possible to suppress the occurrence of overrotation of the yaw motor 28 by retraction.

Here, in this embodiment, it should be noted that the motor brake 29 and the yaw brake caliper 32 are not operated in the low wind speed state (that is, the state which is not a high wind speed state). This is because the driving force of the yaw motor 28 is not wasted. In a configuration in which the braking force is always applied to the nacelle 3, only a part of the driving force of the original yaw motor 28 acts effectively. This unnecessarily increases the driving force of the yaw motor 28, which is not preferable. Here, the problem of over-rotation of the yaw motor 28 due to the nacelle 3 being pushed back occurs only in a high wind speed state. Therefore, in this embodiment, since the motor brake 29 and the yaw brake caliper 32 are operated only in a high wind speed state, the driving force of the yaw motor 28 is utilized effectively.

If you want to further reduce the driving force of the yaw drive device 12,

Mzt _ALL + Mzt _BRK <| Mzt | _MAX . (4)

The design may be as follows. Here, Mzt _ALL is a drive torque generated by the yaw drive device 12 as a whole, Mzt _BRK is a brake torque applied to the nacelle 3 in a high wind speed state, and Mzt | _MAX is caused by a 50-year gust. It is an absolute value of the torque applied to the nacelle 3 (that is, the maximum torque assumed by design). If the condition of the formula (4) is allowed, the total torque that the yaw drive device 12 should generate can be reduced, so that the yaw drive device 12 can be miniaturized and the cost can be reduced.

However, in the case where the yaw drive device 12 is designed such that Equation (4) is established, the nacelle 3 may be pushed back by the strong wind and may turn sharply. In order to cope with such a situation, it is preferable to provide a detection mechanism for detecting a sharp turn of the nacelle 3 and to fix the nacelle 3 when the sharp turn of the nacelle 3 is detected. 6 and 7 are diagrams showing an example of the configuration of a detection mechanism that detects a sharp turn of the nacelle 3. As shown in FIG. 6, FIG. 7, the sharpness detection tooth 41 which engages with the tooth surface of the outer ring 22 is provided, and the sharpness detection tooth 41 is attached to the sharpness detection apparatus 42. As shown in FIG. The sharpness detecting device 42 detects the rotation of the sharpness detecting gear 41.

When the nacelle 3 sharply turns, the sharpness detection gear 41 rotates rapidly. When the controller 14 detects the sudden increase in the rotational speed of the rapid turning detection gear 41 (that is, the rapid turning of the nacelle 3) by the rapid turning detection device 42, the motor brake 29 and the yaw brake caliper ( 32) to secure the nacelle (3). Here, the brake torque Mzt _BRK _ _EMG applied to the nacelle 3 when the nacelle 3 is fixed in response to the detection of the sharp turn of the nacelle 3 is applied to the nacelle 3 in response to the detection of the high wind speed state. It is larger than the applied brake torque (brake torque Mzt _BRK mentioned above). However, Mzt _BRK _ _EMG has the same conditions as in the above formula (1):

Mzt _ALL ─Mzt _{BRK EMG} <| Mzt | _MAX <Mzt _ALL + Mzt _{BRK EMG} … (5)

Is set to satisfy. According to such an operation, even when the yaw drive device 12 is designed so that the equation (4) holds, it is possible to suppress the occurrence of overrotation of the yaw motor 28 due to the nacelle 3 being pushed back. Moreover, although the technique of detecting the sharp turning of the nacelle 3 using a gear | wheel is described above, it will be understood by those skilled in the art that various mechanisms can be used as a mechanism of detecting the sharp turning of the nacelle 3.

When the reduction in the total torque generated by the yaw drive device 12 is allowed, the number of the yaw drive devices 12 may be reduced in order to reduce the cost. Reduction in the number of yaw drives 12 is an effective technique for reducing the cost. However, if the number of yaw drives 12 is reduced, the load acting on each of the yaw drives 12 when the wind load acts on the nacelle 3 during the turning of the nacelle 3 increases, and the load is increased. In order to overcome and to perform yaw turning, the output torque which each yaw drive device 12 should output also increases. At this time, when an electric motor (for example, an induction voltage generator for speed control) that does not perform torque control is used as the yaw motor 28 of the yaw drive device 12, a large torque to the output limit of the yaw motor 28 is achieved. There is a possibility that the mechanism related to yaw turning (for example, the tooth pin 26 and the reduction gear 27 provided on the outer ring 22) may be mechanically damaged.

In order to prevent damage to the mechanism related to yaw turning caused by excessive output torque of the yaw motor 28, it is preferable to provide a torque limiting mechanism for limiting the output torque of the yaw motor 28 to a predetermined torque or less. Do. The torque limiting mechanism may be a mechanical mechanism or an electrical mechanism. One method is to drive the yaw motor 28 with the inverter 40 as shown in FIG. 8 and to perform torque control of the yaw motor 28 with the inverter 40.

9 is a graph showing the relationship between the slip and the output torque when an induction motor is used as the yaw motor 28. The induction motor has a positive output torque when the slip (difference from reducing the rotational speed of the rotor from the synchronous speed) is greater than zero. In this embodiment, when it is going to output the torque beyond predetermined point a, output torque is restrict | limited to the torque T _LIM corresponding to point a. Such torque control can be realized by controlling the yaw motor 28 by vector control.

Claims (6)

Nacelle equipped with a windmill rotor,
A yaw driving device for generating a driving force for yawing the nacelle;
A braking mechanism for generating a braking force for braking the turning of the nacelle;
A control device for controlling the yaw drive device and the braking mechanism;
Equipped with a wind speed measuring device for measuring wind speed,
The braking mechanism is generated while the control device detects the occurrence of a high wind speed condition based on the wind speed while the nacelle is turned by the yaw drive device to turn the windmill rotor toward the wind blowing side. The brake torque is a difference between the drive torque generated by the yaw drive device and the brake torque is less than the absolute value of the maximum design torque given to the nacelle by wind, and the sum of the drive torque and the brake torque is Is adjusted to be greater than the absolute value of the maximum design torque given to the nacelle by wind
Wind power equipment. The method of claim 1,
When the control device detects occurrence of the high wind speed condition, the brake torque is applied by the brake mechanism.
Wind power equipment. delete The method according to claim 1 or 2,
Further provided with a sharpness detection device for detecting the sharpness of the nacelle by the wind,
When the sharp turning of the nacelle is detected during the turning of the nacelle, a predetermined braking force is applied by the braking mechanism,
The brake torque is applied when the control device detects the occurrence of the high wind speed condition and detects the sharp turning of the nacelle by the sharp turning device.
The brake torque is greater than the predetermined braking force
Wind power equipment. The method according to claim 1 or 2,
The yaw drive device,
With yaw motor,
A turning mechanism for turning the nacelle using the torque generated by the yaw motor;
And a torque control device for controlling the torque generated by the yaw motor.
Wind power equipment. The process of monitoring the wind speed while turning the nacelle so that the windmill rotor faces the windward wind,
Detecting the occurrence of a high wind speed condition based on the wind speed, and applying a braking force to the nacelle by a braking mechanism in response to detecting the occurrence of the high wind speed condition,
The brake torque generated by the brake mechanism in the state where the occurrence of the high wind speed condition is detected on the basis of the wind speed while the yaw driver is turning the nacelle so that the windmill rotor is directed toward the wind blowing side, The difference between the drive torque generated by the yaw drive and the brake torque is smaller than the absolute value of the maximum design torque given to the nacelle by wind, and the sum of the drive torque and the brake torque is caused by the wind. Is adjusted to be greater than the absolute maximum design torque given to
Nacelle turning method of wind power generator.

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