Wind turbine generator and method for controlling wind turbine generator

Abstract

To provide a wind power generation device and a control method of the wind power generation device capable of preventing an excessive load from acting on a yaw driving device by detecting a load directly acting on the yaw driving device by a simple method without adding a load sensor or the like.SOLUTION: A yaw-controllable wind turbine power generating apparatus includes a rotor 14 and a nacelle 3, and further includes a state quantity acquisition unit configured to acquire a state quantity that varies in accordance with a yaw-direction behavior of the wind turbine power generating apparatus, and a control device 15 configured to determine a yaw high load state of the wind turbine power generating apparatus on the basis of the state quantity.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a wind turbine generator, and more particularly to a wind turbine generator having a yaw drive device for changing the direction of a rotor made up of blades and a hub, and a control device for the yaw drive device. [Background technology]

[0002] Wind power generation systems, which are becoming increasingly popular as a form of renewable energy, generally use wind power to rotate a rotor equipped with blades, which then generates electricity using a generator. The housing (nacelle) to which the rotor and generator are attached is rotatably supported at the top of a columnar tower, and its direction is controlled by a yaw drive device according to the wind direction.

[0003] When such a system is used, there is a concern that the load on the rotor from the wind increases during strong winds, causing an excessive load to act on the yaw drive device. As a solution to this problem, for example, Patent Document 1 discloses a configuration in which a control device that controls the yaw drive device and the braking mechanism detects the occurrence of a high wind speed condition based on wind speed while the nacelle is being rotated by the yaw drive device, and applies a braking force to the nacelle using the braking mechanism in response to the detection of the occurrence of a high wind speed condition. Furthermore, Patent Document 2 discloses an acquisition unit that acquires information about load, and controls the drive device so that the force generated by the drive device is reduced or zero based on the load information acquired by the acquisition unit during a stop period in which two structures are stopped relative to each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 096078 [Patent Document 2] Patent Publication No. 2021-102936 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology disclosed in Patent Document 1, a high load acting on the yaw drive device is detected based on wind speed. However, it is conceivable that the load on the yaw drive device may increase not only due to fluctuations in wind speed, but also due to a combination with other factors, such as the nacelle azimuth angle or yaw angular velocity, and no consideration is given to detecting the load acting on the yaw drive device more directly. Furthermore, Patent Document 2 uses a load sensor such as a strain sensor to directly detect the load, making the use of such a load sensor essential.

[0006] Therefore, the present invention provides a wind turbine generator and a control method for a wind turbine generator that can detect the load acting on the yaw drive device directly in a simple manner without adding a load sensor or the like, and prevent an excessive load from acting on the yaw drive device. [Means for solving the problem]

[0007] In order to solve the above problems, the wind turbine generator of the present invention is a yaw-controllable wind turbine generator having a rotor and a nacelle, and is equipped with a state quantity acquisition unit that acquires a state quantity that varies depending on the yaw direction behavior of the wind turbine generator, and a control device that determines whether the wind turbine generator is in a high yaw load state based on the state quantity, and is characterized in that the control device determines that the wind turbine generator is in a high load state when the state quantity exceeds a predetermined value and the time that the state quantity exceeds the predetermined value continues for a predetermined length of time or more.

[0008] Furthermore, the control method for a wind turbine generator according to the present invention is a control method for a wind turbine generator having a rotor and a nacelle and capable of yaw control, characterized in that it comprises a state quantity acquisition step in which a state quantity acquisition unit acquires a state quantity that fluctuates according to the yaw direction behavior of the wind turbine generator, and a step in which a control device determines that a high load state exists when the state quantity exceeds a predetermined value and the time that the state quantity exceeds the predetermined value continues for a predetermined length of time or more. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a wind turbine generator and a control method for a wind turbine generator that can directly detect the load acting on the yaw drive device in a simple manner without adding a load sensor or the like, and prevent an excessive load from acting on the yaw drive device. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall view showing the appearance of a wind turbine generator; [Figure 2] 1 is a configuration diagram showing an example of internal equipment of a wind turbine generator according to a first embodiment of the present invention. [Figure 3] FIG. 4 is a time chart showing a high load state according to the first embodiment. [Figure 4] FIG. 2 is a functional block diagram of a control device according to the first embodiment. [Figure 5] 3 is a flowchart showing a control flow of the wind turbine generator according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing a time chart at the time of high load according to a modification of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Example]

[0012] Figure 1 is an overall view showing the appearance of a wind turbine generator. As shown in Figure 1, the wind turbine generator is generally composed of a rotor 14 having blades 1 and a hub 2 that rotate when exposed to wind, a nacelle 3 that supports the load of the rotor 14, and a tower 4 that supports the nacelle 3. The nacelle 3 is supported on the tower 4 so that it can rotate in a substantially horizontal plane, and can change its orientation according to the wind direction.

[0013] Fig. 2 is a configuration diagram showing an example of internal equipment of a wind turbine generator according to a first embodiment of the present invention. As shown in Fig. 2, the wind turbine generator according to this embodiment includes a rotor 14 having blades 1 and a hub 2, a nacelle 3 that supports the load of the rotor 14, a tower 4 that rotatably supports the nacelle 3, a yaw drive unit 5 that has an electric motor and a gearbox and is fixed to the nacelle 3 or the tower 4 and rotates the nacelle 3 relative to the tower 4, a brake 13 that is installed on the nacelle 3 or the tower 4 and applies a braking force to the rotational motion of the nacelle 3, a yaw control unit 6 that controls the yaw drive unit 5 and the brake 13, a ring gear 7 that is fixed to the tower 4 or the nacelle 3, and a nacelle azimuth angle detection unit 8 that is installed on the nacelle 3.

[0014] The yaw drive device 5 has an electric motor 5a, an electric motor brake 5d, and a gearbox 5b, and a pinion gear 5c is attached to the output rotating shaft. The rotating shafts of the electric motor 5a and the gearbox 5b are rotatably supported by bearings. The yaw drive device 5 is attached to the tower 4 or the nacelle 3, and the electric motor 5a rotates in response to power supply and control instructions from the yaw control unit 6. When the pinion gear 5c of the yaw drive device 5 rotates while meshed with the opposing ring gear 7, the direction of the nacelle 3 on the tower 4 changes. This rotates the nacelle 3, and moves the rotor 14, which includes the blades 1 and hub 2, to an appropriate position relative to the wind. The pinion gear 5c and ring gear 7 mesh with each other with a specified tooth gap (backlash). The blades 1 are attached so that they can rotate around an axis in the longitudinal direction, and are controlled to any angle (pitch control) by the power generation control unit 12. When the blades 1 receive wind and the rotor 14 rotates, the rotational torque is transmitted to a generator (not shown) through a speed increaser (not shown) housed in the nacelle 3, and power generation is performed by driving the rotor of the generator.

[0015] 3 shows a time chart for a high load according to Example 1. Due to recent rapid climate change, if an unexpected wind load is applied due to a gust of wind or the like, there is a concern that the nacelle 3 may be forced to rotate even in a yaw-stop state. In this case, a high load is applied to the drive system, including the gearbox 5b and the electric motor brake 5d provided in the yaw drive device 5, which is undesirable. Figure 3 shows, from the top to bottom, a time chart of wind load, nacelle azimuth angle, and the yaw angular velocity calculated by differentiating it with respect to time. It is believed that the nacelle azimuth angle fluctuates due to backlash between the gears as the wind load direction reverses and acts alternately. On the other hand, when the nacelle 3 is forcibly rotated due to a high load, as circled by a dotted line in Figure 3, it is believed that the nacelle azimuth angle fluctuates in one direction over a certain time span. This can also be seen from the change in yaw angular velocity; whereas a sudden change is seen in the oscillation due to backlash, the yaw angular velocity changes over a certain time span in the forced rotation caused by a high load.

[0016] In this embodiment, in order to detect only forced turns due to a high load in such a situation, a high load state is determined when the yaw angular velocity exceeds a predetermined value and the time that the value exceeds the predetermined value continues for a predetermined period of time or more. This makes it possible to accurately and directly determine a high load state without providing an additional sensor for obtaining load information.

[0017] FIG. 4 is a functional block diagram of a control device according to the first embodiment. FIG. 4 shows the arrangement of the yaw drive devices 5 as viewed from below, and the functional blocks of the control device for determining whether a high-load state is present. While an example in which four yaw drive devices 5 are arranged will be described, this is not limiting and any number of yaw drive devices may be used. As shown in FIG. 4, the yaw drive devices 5 are arranged to surround a centrally located ring gear 7, and each pinion gear 5c meshes with the ring gear 7 in parallel. The control device 15 also includes a yaw angular velocity calculation unit 9, a predetermined value comparison unit 10, and an overtime counting unit 11. The yaw angular velocity calculation unit 9, the predetermined value comparison unit 10, and the overtime counting unit 11 are implemented by, for example, a processor such as a CPU (not shown), a ROM (read only memory) for storing various programs, a RAM (random access memory) for temporarily storing data during the calculation process, and a storage device such as an external storage device. The processor such as the CPU reads and executes the various programs stored in the ROM, and stores the execution results in the RAM or the external storage device.

[0018] The yaw angular velocity calculation unit 9 calculates the yaw angular velocity, which is a state quantity used for determining a high load, by time differentiation of the nacelle azimuth angle acquired by the nacelle azimuth angle detection unit 8. The predetermined value comparison unit 10 compares the yaw angular velocity with a predetermined value that has been set in advance. The overload time counting unit 11 starts counting the overload time when the predetermined value comparing unit 10 determines that the yaw angular velocity exceeds a predetermined value. If the counted overload time continues for a predetermined length or longer, it determines that a high load state exists. The overload time counting unit 11 outputs the result of the determination that a high load state exists to the yaw control unit 6 or the power generation control unit 12. Here, the nacelle azimuth angle detection unit 8 and the yaw angular velocity calculation unit 9 are referred to as a state quantity acquisition unit, and the predetermined value comparison unit 10 and the excess time counting unit 11 are referred to as a high load determination unit.

[0019] Fig. 5 is a flowchart showing a control flow of the wind turbine generator according to Example 1. As shown in Fig. 5, in step S1, the nacelle azimuth angle detection unit 8 constituting the state quantity acquisition unit acquires the nacelle azimuth angle. In step S2, the yaw angular velocity calculation unit 9, which constitutes the state quantity acquisition unit, calculates the yaw angular velocity, which is a state quantity used for high load determination, by time differentiation of the nacelle azimuth angle detected by the nacelle azimuth angle detection unit 8.

[0020] In step S3, the predetermined value comparison unit 10 compares the yaw angular velocity calculated by the yaw angular velocity calculation unit 9 with a predetermined value. If the comparison shows that the yaw angular velocity exceeds the predetermined value, the process proceeds to step S4. Details of the predetermined value will be described later. On the other hand, if the comparison shows that the yaw angular velocity does not exceed the predetermined value, the process returns to step S1, and the processes from step S1 to step S3 are repeated.

[0021] In step S4, the overtime counting unit 11 starts counting the overtime. In step S5, the overtime counting unit 11 determines whether the counted overtime has continued for a predetermined length or longer. If the determination result shows that the counted overtime has continued for a predetermined length or longer, the process proceeds to step S6. Details of the predetermined length will be described later. On the other hand, if the determination result shows that the counted overtime has not continued for a predetermined length or longer, the process returns to step S1, and the processes from step S1 to step S5 are repeatedly executed.

[0022] In step S6, the overtime counting unit 11 determines that the load is high, and the process proceeds to step S7. In step S7, the overtime counting unit 11 outputs the determination result that the load is high to the yaw control unit 6 or the power generation control unit 12. In step S8, the yaw control unit 6 or the power generation control unit 12 changes the command value and ends the process.

[0023] The predetermined value to be compared with the yaw angular velocity in step S3 described above is preferably set within a range that can detect the yaw angular velocity that occurs when the high load to be determined is applied and is not affected by external disturbances such as noise. Furthermore, the predetermined length of overtime compared with the counted overtime in step S5 contributes to the response of the determination, and increasing the predetermined length reduces the response, leading to the tolerance of a high-load state. For this reason, it is preferable to determine the predetermined length based on, for example, the allowable load of the device and the number of yaw drive devices 5. This makes it possible to distinguish between the swing caused by the backlash of the gears and the forced rotation caused by the high-load state, and to perform a highly accurate high-load determination.

[0024] Next, the change in the command value for the yaw control unit 6 in step S8 described above will be specifically explained. When a high-load state is determined, controlling the yaw drive unit 5 and other drive units to counteract the high load may result in an overload. For this reason, when a high-load state is determined, the overload may be suppressed by, for example, freeing the drive units, such as the electric motor 5a constituting the yaw drive unit 5, or the braking units, such as the brake 13 or the electric motor brake 5d. Conversely, when a high load acts in a yaw-stop state in which each braking unit is in a holding state, there is a concern that the load may be concentrated on a specific yaw drive unit 5 due to variations in the holding force of the electric motor brake 5d among the multiple yaw drive units 5. In such a case, the electric motor 5a constituting the yaw drive unit 5 may be operated to share the load among all the yaw drive units 5, thereby suppressing the overload. Alternatively, the holding force of the brake 13 may be temporarily increased to prevent the load from being transmitted to the yaw drive unit 5.

[0025] Next, the change in the command value of the power generation control unit 12 in step S8 described above will be specifically explained. When a determination result indicating a high load state is output, one possible cause is an increase in wind load. When wind strikes the blades 1, torque is generated in the rotational direction, which rotates the generator (not shown) and generates electricity. On the other hand, torque generated in a direction other than the rotational direction acts on the nacelle 3, becoming an external force that causes the nacelle 3 to rotate. Therefore, in order to reduce the wind load, which is one of the causes of high load, it is considered effective to change the angle (pitch) of the blades 1 relative to the wind and adjust them so that they are not affected by the wind. In light of the above, when a determination result indicating a high load state is output, for example, the power generation operation may be stopped and the angle (pitch) of the blades 1 relative to the wind may be adjusted to suppress overload.

[0026] In this embodiment, the yaw angular velocity, which is a state quantity used to determine a high load, is calculated by time-differentiating the nacelle azimuth angle as a state quantity. However, the present invention is not limited to this. For example, instead of the yaw angular velocity, the yaw angle based on the nacelle azimuth angle may be used as a state quantity. In this case, the predetermined value compared with the yaw angle may be set within a range that can detect the yaw angle that occurs when the high load to be determined is applied and is not affected by external disturbances such as noise. Alternatively, the nacelle azimuth angle, which is a value from which the yaw angular velocity or yaw angle can be calculated, may be used as a state quantity. In other words, the state quantity includes values ​​from which the yaw angular velocity and the yaw angle can be calculated. In addition, in this embodiment, the control device 15 includes the yaw angular velocity calculation unit 9, the predetermined value comparison unit 10, and the overtime counting unit 11, but this is not limiting. For example, the functions of the control device 15 may be implemented in the yaw control unit 6. The control device 15 may be arranged inside the nacelle 3 or inside the tower 4.

[0027] FIG. 6 is a time chart showing a high-load situation according to a modification of the first embodiment. As shown in FIG. 6, this modification is an example that aims to perform a sign-of-high-load prediction based on the fluctuation of the nacelle azimuth angle before a forced turn actually occurs. The nacelle azimuth angle in the middle of the graph shows a gradual change before a forced turn due to a high load occurs. To capture this, for example, as shown in FIG. 6, the average azimuth angle for a predetermined interval is calculated, and the deviation between this average azimuth angle and the target azimuth angle is calculated by the state quantity acquisition unit. The deviation is compared by the predetermined value comparison unit 10 to determine whether or not this deviation exceeds a predetermined value. The overtime counting unit 11 counts the time the deviation exceeds the predetermined value. If the deviation continues for a predetermined period or longer, the high-load determination unit determines that a high-load prediction has occurred. Here, the number of times the deviation exceeds the predetermined value may be counted instead of the time to determine whether the deviation continues. As described above, by modifying the configuration shown in this embodiment, it can be utilized to predict a high load before it actually occurs.

[0028] As described above, according to this embodiment, it is possible to provide a wind turbine generator and a control method for a wind turbine generator that can directly detect the load acting on the yaw drive device in a simple manner without adding a load sensor or the like, and prevent an excessive load from acting on the yaw drive device.

[0029] Furthermore, it is possible to detect or predict the application of an excessive load to the yaw drive device and prevent it.

[0030] It should be noted that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations. [Explanation of symbols]

[0031] 1...Blade 2. Hub 3... Nacelle 4. Tower 5...Yaw drive unit 5a...Electric motor 5b…Gearbox 5c...Pinion gear 5d...Electric brake 6...Yaw control section 7...Ring gear 8... Nacelle azimuth angle detection unit 9...Yaw angular velocity calculation section 10...Predetermined value comparison section 11...Excess time counter 12...Power generation control unit 13...Brake 14...Rotor 15...Control device

Claims

1. A wind turbine generator having a rotor and a nacelle and capable of yaw control, a state quantity acquisition unit that acquires a state quantity that varies depending on the behavior of the wind turbine generator in a yaw direction; a control device that determines a high yaw load state of the wind turbine generator based on the state quantity, The control device determines that the wind power generation device is in a high load state when the state quantity exceeds a predetermined value and the time during which the state quantity exceeds the predetermined value continues for a predetermined length of time or more.

2. The wind turbine generator according to claim 1, The wind turbine generator, wherein the state quantity is one of a yaw angular velocity and a value from which the yaw angular velocity can be calculated, and a yaw angle and a value from which the yaw angle can be calculated.

3. The wind turbine generator according to claim 2, The predetermined value is set within a range that can detect the state quantity that occurs when a high-load state to be determined is applied and is not affected by external disturbances including noise.

4. The wind turbine generator according to claim 3, The wind turbine generator is characterized in that the predetermined length is determined based on the number of yaw drive devices.

5. The wind turbine generator according to claim 4, The wind turbine generator is characterized in that the control device determines that the wind turbine generator is in a high load state when a yaw brake is operating.

6. The wind turbine generator according to claim 4, A yaw control unit and a power generation control unit are provided, The wind turbine generator is characterized in that the control device outputs a determination result of the high load state to a yaw control unit or a power generation control unit.

7. The wind turbine generator according to claim 6, The wind turbine generator is characterized in that the yaw control unit changes a command value in accordance with a result of determining that the load state is high.

8. The wind turbine generator according to claim 6, The wind power generating device is characterized in that the power generation control unit changes the command value in accordance with the result of determining that the load state is high.

9. A control method for a wind turbine generator having a rotor and a nacelle and capable of yaw control, comprising: a state quantity acquiring step in which a state quantity acquiring unit acquires a state quantity that varies depending on the yaw direction behavior of the wind turbine generator; a step in which the control device determines that the state quantity is in a high load state when the state quantity exceeds a predetermined value and the time during which the state quantity exceeds the predetermined value continues for a predetermined length of time or more.

10. A control method for a wind turbine generator according to claim 9, The control method for a wind turbine generator, wherein the state quantity is one of a yaw angular velocity and a value from which the yaw angular velocity can be calculated, and a yaw angle and a value from which the yaw angle can be calculated.

11. A control method for a wind turbine generator according to claim 10, A control method for a wind turbine generator, characterized in that the predetermined value is set within a range that can detect the state quantity that occurs when the high load state to be determined is applied and is not affected by external disturbances including noise.

12. A control method for a wind turbine generator according to claim 11, A method for controlling a wind turbine generator, wherein the predetermined length is determined based on the number of yaw drive devices.

13. A control method for a wind turbine generator according to claim 12, 10. A control method for a wind turbine generator, wherein the control device determines that the wind turbine generator is in a high load state when a yaw brake is operating.

14. A control method for a wind turbine generator according to claim 12, A control method for a wind turbine generator, comprising the step of: the control device outputting a determination result that the load state is high to a yaw control unit or a power generation control unit.

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