Control Method, Device and Wind Turbine Generator Set of Wind Turbine

Abstract

The present application provides a control method, device and wind turbine generator for a wind turbine generator set. The wind turbine generator set includes a plurality of blades, and each blade includes a root. The method includes: when the wind turbine generator set adopts a first load reduction strategy, obtaining the load values of each root detected by a load sensor at different moments within the current control period of the wind turbine generator set (S11); determining the pitch angle increment value of the current control period according to the load values of each root at different moments (S12); controlling the real-time pitch angle size of the wind turbine generator set in the next control period according to the sum of the pitch angle increment value and the minimum pitch angle value of the wind turbine generator set in the current control period (S13). The present application achieves the purpose of reducing the windward area of the blade and reducing the load on the blade root.

Description

Technical Field

[0001] The present application relates to the field of control of wind turbines, and particularly to a control method, device and wind turbine of a wind turbine. Background Art

[0002] For a wind turbine, the blades convert wind energy into mechanical energy and transmit it to the hub. With the continuous progress of wind turbine technology, the blade length of the wind turbine is getting longer and longer. As the most basic and crucial component of the wind turbine, the blade is required to have good performance, and the blade load level should be within the permitted range, otherwise it will cause damage to the blade, ultimately resulting in irreversible economic losses.

[0003] Currently, there is no effective control means for the load level at the blade root, and the load at the blade root often remains high. If the load at the blade root does not meet the standard, the blade needs to be redesigned to meet the load requirements. Whether it is increasing the blade stiffness or increasing the blade weight, it will lead to an increase in cost. Too many cyclic iterations will also lead to an extension of the product development cycle, unable to keep up with the market pace, bringing great market pressure to the production and design units. With the continuous increase of the MW number of wind turbines and the continuous popularization of the independent pitch technology, there are more and more sensors at the blade root, and currently most wind turbines do not use the load at the blade root as the input variable for control, but only use it for monitoring the load at the blade root. Summary of the Invention

[0004] The present application provides a control method, device and wind turbine of a wind turbine.

[0005] Specifically, the present application is implemented through the following technical solutions:

[0006] In the first aspect of the embodiments of the present application, a control method of a wind turbine is provided. The wind turbine includes a plurality of blades, and each blade includes a root. The method includes:

[0007] When the wind turbine adopts the first load reduction strategy, obtain the load values of each root detected by the load sensor at different moments within the current control period of the wind turbine;

[0008] Determine the pitch angle increment value of the current control period according to the load values of each root at different moments;

[0009] Control the real-time pitch angle size of the wind turbine in the next control period according to the sum of the pitch angle increment value and the minimum pitch angle value of the wind turbine in the current control period.

[0010] Optionally, determining the pitch angle increment value of the current control cycle according to the load values of each root at different times includes:

[0011] Obtaining the maximum load value at each time according to the load values of each root at each time;

[0012] Performing an asymmetric filtering process on the maximum load values at different times to obtain the load filtering value of the wind turbine generator set in the current control cycle, wherein the sliding average time constant of the asymmetric filtering is negatively correlated with the rising and falling trend of the maximum load value;

[0013] Determining the pitch angle increment value of the current control cycle according to the load filtering value, wherein the pitch angle increment value is positively correlated with the load filtering value.

[0014] Optionally, determining the pitch angle increment value of the current control cycle according to the load filtering value includes:

[0015] Searching in a preset relationship table for the pitch angle increment value corresponding to the load filtering value according to the load filtering value, wherein the relationship table is used to store the load filtering value and the pitch angle increment value in a one-to-one correspondence.

[0016] Optionally, determining the pitch angle increment value of the current control cycle according to the load filtering value includes:

[0017] When the load filtering value is less than a preset load threshold, the pitch angle increment value of the current control cycle is zero.

[0018] Optionally, the method further includes:

[0019] Obtaining a user instruction;

[0020] Controlling the wind turbine generator set to adopt the first load reduction strategy according to the user instruction.

[0021] Optionally, the sliding average time constant of the asymmetric filtering being negatively correlated with the rising and falling trend of the maximum load value further includes:

[0022] Judging the rising and falling trend of the maximum load value in the current control cycle;

[0023] When the maximum load value in the current control cycle shows an upward trend, the sliding average time constant of the current control cycle is T1;

[0024] When the maximum load value in the current control cycle shows a downward trend, the sliding average time constant of the current control cycle is T2;

[0025] Wherein, T1 is less than T2.

[0026] Optionally, the method further includes:

[0027] When the wind turbine adopts the second load reduction strategy, according to the minimum pitch angle value, control the real-time pitch angle size of the wind turbine in the next control cycle.

[0028] Optionally, the minimum pitch angle value is obtained from the maximum pitch angle allowed for the wind turbine in the current control cycle determined according to the static thrust reduction strategy or the turbulence monitoring strategy.

[0029] Optionally, the load sensors include at least three, and at least one load sensor is installed at each root, and at least three of the load sensors are located on the same circumference.

[0030] Optionally, the load sensors are attached to the corresponding roots.

[0031] Optionally, the load value is the combined torque of the root in the first direction and the second direction of the blade root coordinate system, where the third direction of the blade root coordinate system is along the radial direction of the blade, and the first direction and the second direction are respectively perpendicular to the third direction.

[0032] In an aspect of the embodiments of the present application, a control device for a wind turbine is provided, including one or more processors for implementing the control method of the wind turbine described in any one of the first aspects.

[0033] In a third aspect of the embodiments of the present application, a wind turbine is provided, including:

[0034] A plurality of blades, each blade including a root; and

[0035] The control device of the wind turbine described in the aspect.

[0036] In a fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, it implements the control method of the wind turbine described in any one of the first aspects.

[0037] According to the technical solution provided by the embodiments of the present application, load sensors are used to monitor the load value of the blade root. According to the monitored load value of the blade root, the pitch angle increment value is determined, and then the additional pitch angle increment value is added to the minimum pitch angle value to ensure that the pitch angle of the wind turbine in the next control cycle is maintained at a relatively high level, so as to achieve the purpose of reducing the wind-facing area of the blade and reducing the load on the blade root.

[0038] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Description of the Drawings

[0039] The accompanying drawings here are incorporated into the description and form a part of this description, showing embodiments consistent with this application, and are used together with the description to explain the principles of this application.

[0040] Figure 1 It is a schematic flowchart of a control method for a wind turbine shown in an exemplary embodiment of this application;

[0041] Figure 2 It is a schematic diagram of a root coordinate system of a wind turbine shown in an exemplary embodiment of this application;

[0042] Figure 3A It is a schematic diagram of an implementation process for determining the pitch angle increment value of the current control cycle according to the load values of each root at different moments shown in an exemplary embodiment of this application;

[0043] Figure 3B It is a curve graph of the maximum load shown in an exemplary embodiment of this application;

[0044] Figure 3C It is a curve graph of the load filter value shown in an exemplary embodiment of this application;

[0045] Figure 4 It is a schematic flowchart of a specific control method for a wind turbine shown in an exemplary embodiment of this application;

[0046] Figure 5 It is a structural block diagram of a control device for a wind turbine shown in an exemplary embodiment of this application. Detailed implementation manners

[0047] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with this application. On the contrary, they are merely examples of devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0048] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a", "the", and "said" used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0049] It should be understood that although terms such as first, second, and third may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to a determination".

[0050] The control method, device, and wind turbine generator of this application will be described in detail below with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners may be combined with each other.

[0051] The wind turbine generator in the embodiments of this application may include a plurality of blades, and each blade includes a root. Specifically, the wind turbine generator includes three blades.

[0052] Figure 1 is a schematic flowchart of a control method for a wind turbine generator shown in an exemplary embodiment of this application; the control method for the wind turbine generator in the embodiments of this application may be applied to the controller of the wind turbine generator or an independent controller provided on the wind turbine generator or a combination of the controller of the wind turbine generator and the above-mentioned independent controller. Refer to Figure 1 The control method for a wind turbine generator provided in the embodiments of this application may include steps S11 to S13.

[0053] Among them, in S11, when the wind turbine generator adopts the first load reduction strategy, the load values of each root detected by the load sensor at different moments within the current control period of the wind turbine generator are obtained.

[0054] The wind turbine generator in the embodiments of this application is periodically controlled. Optionally, the duration corresponding to each control period is 20 ms (unit: millisecond). It should be understood that the duration corresponding to each control period may also be set to other duration sizes according to needs.

[0055] There may be at least three load sensors, and at least one load sensor is installed on each root. In this embodiment, at least three load sensors are located on the same circumference to unify the position reference for load value monitoring and ensure the effectiveness of control. Exemplarily, there are three load sensors, and one load sensor is installed on each root.

[0056] In some embodiments, the load sensor is detachably fixed to the corresponding root. For example, the load sensor is attached to the corresponding root, or the load sensor is fixed to the corresponding root through a quick-release structure, which facilitates the disassembly of the load sensor, thereby facilitating the replacement or repair of the load sensor. In the embodiments of the present application, the load sensor is attached to the corresponding root, and the attachment method is simple and easy to implement.

[0057] In some embodiments, the load sensor is fixedly arranged on the corresponding root, and it is necessary to use a destructive force to disassemble the load sensor.

[0058] The load value is the combined torque of the root in the first direction and the second direction of the root coordinate system of the blade root. Among them, the third direction of the root coordinate system of the blade root is along the radial direction of the blade, and the first direction and the second direction are respectively perpendicular to the third direction. Among them, the root coordinate system of the blade root is as Figure 2 shown, where the third direction ZB is along the radial direction of the blade, and the third direction ZB is the pitch axis of the blade. The first direction XB is perpendicular to the third direction ZB. Among them, for an upwind wind turbine, the first direction XB points to the tower; for a downwind wind turbine, the first direction XB is away from the tower. The second direction YB is perpendicular to the pitch axis ZB of the blade and the main shaft of the wind turbine, providing a right-handed coordinate system, independent of the rotation direction and the position of the impeller of the upwind or downwind tower. Figure 2 where F is the force and M is the torque. In addition, it should be noted that for steady-state calculations, the wind is considered to blow from the north.

[0059] In an exemplary embodiment of the present application, load sensors are attached to the roots of all three blades to respectively monitor the combined torque M xy (M xB and M yB of the combined torque).

[0060] In some embodiments, the control method of the wind turbine further includes: obtaining a user instruction; and controlling the wind turbine to adopt a first load reduction strategy according to the user instruction. That is, the user can select whether the wind turbine adopts the first load reduction strategy according to needs. For example, the wind turbine can be provided with a virtual switch, and the user generates the above user instruction by operating the virtual switch, or sets the virtual switch to be turned on in the software program, thereby controlling the wind turbine to adopt the first load reduction strategy. Of course, the user can also cut the wind turbine out of the first load reduction strategy by operating the above virtual switch, or set the virtual switch to be turned off in the software program, thereby cutting the wind turbine out of the first load reduction strategy. Optionally, when the virtual switch is turned off, the wind turbine adopts a second load reduction strategy.

[0061] In some other embodiments, when the wind turbine generator starts, the wind turbine generator automatically adopts the first load reduction strategy. During the operation of the wind turbine generator, the first load reduction strategy can be switched to the second load reduction strategy.

[0062] In S12, according to the load values of each root at different moments, determine the pitch angle increment value of the current control cycle.

[0063] See Figure 3A , a realization process of determining the pitch angle increment value of the current control cycle according to the load values of each root at different moments may include the following steps:

[0064] S31. According to the load values of each root at each moment, obtain the maximum load value at each moment;

[0065] Through S11, obtain the load values Mxy of the three roots at each moment. Take the maximum value among the three load values at each moment to obtain the maximum load value MxyBRmax at each moment.

[0066] S32. Perform asymmetric filtering on the maximum load values at different moments to obtain the load filtering value of the wind turbine generator in the current control cycle, where the sliding average time constant of the asymmetric filtering is negatively correlated with the rising and falling trend of the maximum load value;

[0067] In some embodiments, establish an asymmetric filtering function F1. F1 is a sliding average function, which means performing filtering processing on the corresponding multiple consecutive maximum load values at each moment using the sliding average time constant. For example, if the sliding average time constant of the current control cycle is T, then perform an averaging process on the maximum load values at each moment within the adjacent T time period before the current control cycle to obtain the load filtering value of the current control cycle.

[0068] In some embodiments, when the maximum load value shows an upward trend, the sliding average time constant of the asymmetric filtering is T1; when the maximum load value shows a downward trend, the sliding average time constant of the asymmetric filtering is T2, and T1 < T2. Adopting a smaller T1 represents a faster response, which is beneficial for the load filtering value obtained by the filtering process to increase rapidly; a larger T2 makes the load filtering value not fluctuate frequently, and the blades do not pitch frequently. Figure 3B Is a curve graph of a maximum load value shown in an exemplary embodiment of the present application, Figure 3C Is a curve graph of a load filtering value shown in an exemplary embodiment of the present application. It can be seen that after performing asymmetric filtering on the maximum load values at each moment, a relatively stable load filtering value is obtained.

[0069] In some embodiments, first determine the rising and falling trend of the maximum load value in the current control period; when the maximum load value in the current control period shows an upward trend, set the sliding average time constant of the current control period to T1; when the maximum load value in the current control period shows a downward trend, set the sliding average time constant of the current control period to T2. For example, when the maximum load value shows an upward trend, set the time constant to a smaller T1 (such as 1 second or other value), which can keep the load filtered value relatively accurate all the time, so as to respond quickly. When the maximum load value shows a downward trend, set the time constant to a larger T2 (such as 20 seconds or other value greater than T1), which can make the load filtered value more stable. By setting asymmetric filtering, not only can it respond in time, but also it can stabilize the maximum load value with large fluctuations, and obtain a relatively smooth load filtered value Filter_MxyBRmax.

[0070] In some embodiments, the rising and falling trend is judged by multiple consecutive maximum load values. In other embodiments, the rising and falling trend can be judged by comparing the maximum load value in the current control period with the load filtered value in the previous period. The present invention is not limited thereto.

[0071] S33. Determine the pitch angle increment value of the current control period according to the load filtered value, wherein the pitch angle increment value is positively correlated with the load filtered value.

[0072] That is, according to Filter_MxyBRmax obtained in S32, determine the pitch angle increment value △MinPitch of the current control period. Specifically, a look-up table or a mathematical model can be used.

[0073] Exemplarily, an implementation process of determining the pitch angle increment value according to the load filtered value may include: looking up the pitch angle increment value corresponding to the load filtered value in a preset relationship table according to the load filtered value. This way of determining the pitch angle increment value △MinPitch by looking up the table is simple to implement. Among them, the relationship table is used to store the load filtered value and the pitch angle increment value in one-to-one correspondence. For example, in the relationship table, the pitch angle increment values corresponding to load values greater than or equal to 30000 N*m are stored. For example, when the load value is 31000 N*m, the corresponding minimum pitch angle value is 5 degrees; when the load value is 32000 N*m, the corresponding minimum pitch angle value is 5.3 degrees; when the load value is 33000 N*m, the corresponding minimum pitch angle value is 5.6 degrees. By adopting the first load reduction strategy of the embodiments of the present application, the load at the root can be controlled below 30000 N*m. It should be noted that the load filtered value and the pitch angle increment value are positively correlated, that is, the larger the load filtered value, the larger the pitch angle increment value. Optionally, the load filtered value and the pitch angle increment value are non-linearly positively correlated.

[0074] In some embodiments, the pitch angle increment value in the relationship table can be set to achieve different load reduction effects. Of course, in some other embodiments, the relationship table cannot be modified.

[0075] In some embodiments, the minimum pitch angle value is obtained from the maximum pitch angle allowed for the wind turbine generator set in the current control cycle according to the static thrust reduction strategy or the turbulence monitoring strategy. Of course, the minimum pitch angle value can also be determined according to other algorithms.

[0076] In some embodiments, when the load filtering value is less than the preset load threshold, the pitch angle increment value in the current control cycle is zero.

[0077] In some embodiments, when the load filtering value is greater than or equal to the preset load threshold, the pitch angle increment value is determined according to the load filtering value, and then proceed to S13; when the load filtering value is less than the preset load threshold, the real-time pitch angle of the wind turbine generator set in the next control cycle is controlled according to the minimum pitch angle value of the wind turbine generator set in the current control cycle. The size of the minimum pitch angle value in the next control cycle is the minimum pitch angle value in the current control cycle, without adding the pitch angle increment value in the current control cycle.

[0078] In some other embodiments, whether the load filtering value is greater than or equal to the preset load threshold or less than the preset load threshold, it will proceed to S13. In this embodiment, the pitch angle increment value △MinPitch corresponding to the load filtering value greater than or equal to the preset load threshold is not equal to 0, and the pitch angle increment value △MinPitch corresponding to the load filtering value less than the preset load threshold is equal to 0.

[0079] The preset load threshold is related to the maximum load value allowed at the root. Optionally, the preset load threshold is less than the maximum load value allowed at the root; optionally, the preset load threshold is equal to the maximum load value allowed at the root.

[0080] In S13, the real-time pitch angle of the wind turbine generator set in the next control cycle is controlled according to the sum of the pitch angle increment value and the minimum pitch angle value of the wind turbine generator set in the current control cycle.

[0081] In the embodiments of the present application, the minimum pitch angle value MinPitch in the next control cycle (i+1) has the following calculation formula:

[0082] MinPitch (i+1) = MinPitch (i) + ΔMinPitch (i) (1);

[0083] In formula (1), i represents the serial number of the current control cycle, MinPitch (i)Represents the minimum pitch angle value of the current control cycle, ΔMinPitch (i) Represents the pitch angle increment value of the current control cycle.

[0084] In the next control cycle, control the real-time pitch angle of the wind turbine to be less than the size of MinPitch (i+1) In this way, when the load value at the root is large, the minimum pitch angle value in the next control cycle will be raised, thereby reducing the windward area and achieving the purpose of load reduction.

[0085] For the control method of the wind turbine in the embodiment of the present application, when using the first load reduction strategy, a load sensor is used to monitor the load value at the blade root. According to the monitored load value at the blade root, the pitch angle increment value is determined, and then the additional pitch angle increment value is added to the minimum pitch angle value to ensure that the pitch angle of the wind turbine in the next control cycle is maintained at a high level, thereby achieving the purpose of reducing the windward area of the blade and reducing the load at the blade root.

[0086] As Figure 4 shown, first obtain the load values of the three roots detected by the load sensor at the same moment, M xy BR1, M xy BR2, M xy BR3; then, select the maximum value among M xy BR1, M xy BR2, M xy BR3 as the maximum load value MxyBRmax at the corresponding moment; then perform asymmetric filtering on the maximum load values MxyBRmax at different moments, and then determine the pitch angle increment value △MinPitch corresponding to the filtered load value through look-up table, as the pitch angle increment value △MinPitch of the wind turbine in the current control cycle ( Figure 4 in the current cycle); superimpose the pitch angle increment value △MinPitch on the minimum pitch angle value MinPitch of the current control cycle to obtain the minimum pitch angle value MinPitch of the next control cycle, so as to control the size of the real-time pitch angle of the wind turbine in the next control cycle according to the minimum pitch angle value MinPitch of the next control cycle.

[0087] The inventor practiced using the above control method of the wind turbine and found that the load value at the blade root can be effectively reduced by more than 5%.

[0088] In some embodiments, the control method of the wind turbine further includes: when the wind turbine adopts the second load reduction strategy, controlling the real-time pitch angle of the wind turbine in the next control period according to the minimum pitch angle value. It should be noted that when the wind turbine adopts the second load reduction strategy, the value of the minimum pitch angle in the next control period is the same as the minimum pitch angle value in the current control period, without adding the pitch angle increment value in the current control period.

[0089] Corresponding to the embodiments of the control method of the wind turbine described above, the present application also provides an embodiment of a control device for a wind turbine.

[0090] See Figure 5 , the embodiments of the present application also provide a control device for a wind turbine, including one or more processors for implementing the control method of the wind turbine in the above embodiments.

[0091] The embodiments of the control device of the wind turbine in the present application can be applied to the control of the wind turbine. The device embodiments can be implemented by software, or by hardware or a combination of software and hardware. Taking software implementation as an example, as a logically meaningful device, it is formed by the processor of the wind turbine where it is located reading the corresponding computer program instructions in the non-volatile memory into the memory for operation. From the hardware level, as Figure 5 shown, it is a hardware structure diagram of the wind turbine where the control device of the wind turbine in the present application is located. In addition to Figure 5 the processor, memory, network interface, and non-volatile memory shown, the control of the wind turbine where the device is located in the embodiments usually also includes other hardware according to the actual functions of the wind turbine, which will not be elaborated here.

[0092] The specific implementation processes of the functions and roles of each unit in the above device are specifically described in the implementation processes of the corresponding steps in the above method, which will not be elaborated here.

[0093] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can refer to the partial descriptions of the method embodiments. The device embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of the present application. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0094] An embodiment of the present application further provides a wind turbine generator, which may include a plurality of blades and the control device of the wind turbine generator in the above embodiment. Each blade includes a root portion.

[0095] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the control method of the wind turbine generator according to any one of the first aspects.

[0096] The computer-readable storage medium may be an internal storage unit of the wind turbine generator described in any of the foregoing embodiments, such as a hard disk or a memory. The computer-readable storage medium may also be an external storage device of the wind turbine generator, such as a plug-in hard disk, a Smart Media Card (SMC), an SD card, a Flash Card, etc. equipped on the device. Further, the computer-readable storage medium may also include both an internal storage unit and an external storage device of the wind turbine generator. The computer-readable storage medium is used to store the computer program and other programs and data required by the wind turbine generator, and may also be used to temporarily store data that has been output or is to be output.

[0097] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of protection of the present application.

Claims

1. A control method for a wind turbine generator, the wind turbine generator including a plurality of blades, each blade including a root, characterized in that, the method includes: When the wind turbine generator adopts a first load reduction strategy, obtaining the load values of each root detected by a load sensor at different times within the current control period of the wind turbine generator; Determining the pitch angle increment value of the current control period according to the load values of each root at different times, wherein, according to the load values of each root at each time, obtaining the maximum load value at each time; Performing an asymmetric smoothing filtering process on the maximum load values at different times to obtain the load filtering value of the wind turbine generator in the current control period; Determining the pitch angle increment value of the current control period according to the load filtering value; Controlling the real-time pitch angle size of the wind turbine generator in the next control period according to the sum value of the pitch angle increment value and the minimum pitch angle value of the wind turbine generator in the current control period.

2. The control method for a wind turbine generator according to claim 1, characterized in that, the sliding average time constant of the asymmetric filtering is negatively correlated with the rising and falling trend of the maximum load value; and / or, the pitch angle increment value is positively correlated with the load filtering value.

3. The control method for a wind turbine generator according to claim 2, characterized in that, the determining the pitch angle increment value of the current control period according to the load filtering value includes: Searching in a preset relationship table for the pitch angle increment value corresponding to the load filtering value according to the load filtering value, wherein the relationship table is used to store the load filtering value and the pitch angle increment value in a one-to-one correspondence.

4. The control method for a wind turbine generator according to claim 2, characterized in that, the determining the pitch angle increment value of the current control period according to the load filtering value includes: When the load filtering value is less than a preset load threshold, the pitch angle increment value of the current control period is zero.

5. The control method for a wind turbine generator according to claim 1 or 4, characterized in that, the method further includes: Obtaining a user instruction; Controlling the wind turbine generator to adopt the first load reduction strategy according to the user instruction.

6. The control method for a wind turbine generator according to claim 2, characterized in that, the sliding average time constant of the asymmetric filtering being negatively correlated with the rising and falling trend of the maximum load value further includes: Judging the rising and falling trend of the maximum load value in the current control period; When the maximum load value in the current control period shows an upward trend, the sliding average time constant of the current control period is T1; When the maximum load value in the current control period shows a downward trend, the sliding average time constant of the current control period is T2; wherein, the T1 is less than T2.

7. The control method for a wind turbine generator according to claim 1, characterized in that, the method further includes: When the wind turbine generator adopts a second load reduction strategy, controlling the real-time pitch angle size of the wind turbine generator in the next control period according to the minimum pitch angle value.

8. The control method of a wind turbine according to claim 1, wherein, the minimum pitch angle value is obtained from the maximum pitch angle allowed for the wind turbine in the current control period determined according to a static thrust reduction strategy or a turbulence monitoring strategy.

9. The control method of a wind turbine according to claim 1, wherein, the load sensors include at least three, and at least one load sensor is installed at each root, and at least three of the load sensors are located on the same circumference.

10. The control method of a wind turbine according to claim 9, wherein, the load sensors are attached to the corresponding roots.

11. The control method of a wind turbine according to claim 1, wherein, the load value is the combined torque of the root in the first direction and the second direction of the blade root coordinate system, wherein the third direction of the blade root coordinate system is along the radial direction of the blade, and the first direction and the second direction are respectively perpendicular to the third direction.

12. A control device of a wind turbine, wherein, it includes one or more processors for implementing the control method of the wind turbine according to any one of claims 1 to 11.

13. A wind turbine, wherein, it includes: a plurality of blades, each blade including a root; and the control device of the wind turbine according to claim 12.

14. A computer-readable storage medium having a computer program stored thereon, wherein, when the program is executed by a processor, it implements the control method of the wind turbine according to any one of claims 1 to 11.

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