A method and system for reducing the load of a fixed hub of a wind turbine

Abstract

The application discloses a kind of wind generating set fixed wheel hub My limit load unloading method and system, wind generating set encounters extreme turbulence above rated wind speed, the following steps are executed: 1) blade position correction;2) obtain wind speed signal and the pitch angle signal of unit;3) obtain blade azimuth angle signal;4) if fixed wheel hub My limit load maximum value, namely Mymax is over limit, then step 6) is executed, if fixed wheel hub My limit load minimum value, namely Mymin is over limit, then step 5) is executed;5) establish interpolation table of lower half plane azimuth angle-pitch angle;6) establish interpolation table of upper half plane azimuth angle-pitch angle;7) according to the interpolation table result of azimuth angle-pitch angle Dynamic calculation superimposed pitch angle;8) execute variable pitch control;9) exit strategy.The application can effectively solve the problem of fixed wheel hub My limit load over limit under extreme turbulence working condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power generation, and particularly refers to a wind turbine generator set fixed hub My limit load reduction method, system, storage medium and computing device. BACKGROUND

[0002] The load of the wind turbine generator set mainly comes from aerodynamic load, gravity load, inertia load and other loads (temperature load and icing load, etc.), which is an important factor affecting the cost and efficiency of the entire wind power generation system. The limit load of the wind turbine generator set generally occurs under fault conditions, extreme gusts, extreme turbulence, once-in-a-decade or once-a-year limit wind speed.

[0003] According to the IEC61400-1 standard, all extreme conditions and general possibilities that may occur during the service life of the wind turbine generator set must be considered during the design evaluation stage of the unit, such as the possibility of extreme gusts or extreme turbulence wind, power grid outage, and variable pitch failure. The occurrence of the limit load of the wind turbine generator set is often under extreme wind conditions or fault conditions.

[0004] When the unit encounters extreme turbulence wind, the traditional method is to strengthen each subsystem and component of the wind turbine generator set to ensure that the components do not fail or break, but this will limit the wind wheel diameter and manufacturing cost of the unit, or adopt a power reduction load reduction method under extreme turbulence wind, which will seriously affect the power generation performance of the unit and cause a loss of power generation capacity of the unit.

[0005] The present application mainly aims to solve the problem of fixed hub My limit load overrunning under extreme turbulence conditions. There are two traditional ways to reduce the fixed hub My: 1. Increase the redundancy of the fixed hub My limit load by replacing hardware, which will increase the cost; 2. Reduce the limit load of the fixed hub My by reducing the speed of the impeller or reducing the power when detecting extreme turbulence conditions, which will cause a loss of power and affect the power generation capacity of the unit. SUMMARY

[0006] The first object of the present application is to overcome the shortcomings and deficiencies of the prior art, and to provide a safe and reliable wind turbine generator set fixed hub My limit load reduction method, which can effectively solve the problem of fixed hub My limit load overrunning under extreme turbulence conditions.

[0007] The second object of the present application is to provide a wind turbine generator set fixed hub My limit load reduction system.

[0008] The third object of the present application is to provide a storage medium.

[0009] The fourth object of the present application is to provide a computing device.

[0010] The first object of the present application is achieved by the following technical solution: a wind turbine fixed hub My limit load unloading method, when the wind turbine encounters extreme turbulence above the rated wind speed, the following steps are performed:

[0011] 1) blade position correction;

[0012] The correction method adopts an inverted "Y" shape, that is, the azimuth angle of blade 1 is 0° when it is at the top, correspondingly, the azimuth angle of blade 2 is 120° at this time, and the azimuth angle of blade 3 is 240° at this time, and after the azimuth angle correction is completed, step 2) is performed;

[0013] 2) obtaining a wind speed signal and a pitch angle signal of the unit;

[0014] If the wind speed is greater than the wind speed threshold and the pitch angle is greater than the angle threshold, step 3) is performed, and if not, step 9) is performed;

[0015] 3) obtaining a blade azimuth angle signal;

[0016] After the wind turbine enters the normal power generation mode, the azimuth angle of blade 1 is read from the azimuth angle sensor The azimuth angles of blade 2 and blade 3 are calculated And After obtaining the blade azimuth angle information, step 4) is performed;

[0017] 4) if the maximum fixed hub My limit load Mymax is over limit, step 6) is performed, and if the minimum fixed hub My limit load Mymin is over limit, step 5) is performed;

[0018] 5) establishing an interpolation table of the lower half plane azimuth angle-pitch angle;

[0019] 6) establishing an interpolation table of the upper half plane azimuth angle-pitch angle;

[0020] 7) dynamically calculating the superimposed pitch angle according to the interpolation table results of the azimuth angle-pitch angle;

[0021] 8) performing pitch control;

[0022] According to the existing pitch angle command value θ of each blade PIout And the pitch angle command value of the superimposed azimuth angle FinePitch, the final pitch angle control value of each blade is determined;

[0023] 9) exit strategy;

[0024] If the wind speed is not greater than the wind speed threshold and the pitch angle is not greater than the angle threshold, the normal power generation mode is performed.

[0025] Furthermore, in step 3), the azimuth angles of blade 2 and blade 3 are and The calculation formula is as follows:

[0026]

[0027]

[0028] Further, in step 5), an interpolation table is established according to the correspondence between the azimuth angle and the pitch angle. In order to reduce the thrust of the lower half plane of the impeller, that is, to increase the limit load of the fixed hub Mymin, it is necessary to superimpose a preset pitch angle on the lower half plane of the impeller. The superposition rule is: when the blade azimuth angle is 0°-90°, the superimposed pitch angle is 0°, when the blade azimuth angle is 180°, the superimposed pitch angle is 1°, and when the blade azimuth angle is 270°-360°, the superimposed pitch angle is 0°, that is, the superimposed pitch angle gradually increases from 90°-180° of the blade azimuth angle, and gradually decreases from 180°-270° of the blade azimuth angle; execute step 7) according to the result of the interpolation table.

[0029] Furthermore, in step 6), an interpolation table is established based on the correspondence between the azimuth angle and the pitch angle. In order to reduce the thrust of the upper half plane of the impeller, that is, to reduce the limit load of the fixed hub Mymax, it is necessary to superimpose a preset pitch angle on the upper half plane of the impeller. The superposition rule is: when the blade azimuth angle is 0°, the superimposed pitch angle is 1°, and when the blade azimuth angle is 90°-270°, the superimposed pitch angle is 0°, that is, the superimposed pitch angle gradually decreases from 0° to 90°, and the superimposed pitch angle gradually increases from 270° to 360°; execute step 7) according to the result of the interpolation table.

[0030] Further, in step 7), the table result of step 5) or 6) is used to adjust the pitch angle command value θ of blades 1, 2, and 3 in real time according to the superposition rule of blade azimuth angles. Az1 ,θ Az2 ,θ Az3 , execute step 8) according to the superimposed pitch angle command value).

[0031] Further, in step 8), according to the existing pitch angle command value θ of each blade PIout and the pitch angle command value θ of the superimposed azimuth angle FinePitch Az1 ,θ Az2 ,θ Az3 , determine the final pitch angle control value θ of blades 1, 2, and 3 PitchDemand1 ,θ PitchDemand2 ,θ PitchDemand3The value is applied to a pitch actuator of the wind turbine generator set to control each blade to perform a corresponding pitch action to adjust the limit load of the fixed hub My of the wind turbine generator set.

[0032] θ PitchDemand1 = θ PIout + θ Az1

[0033] θ PitchDemand2 = θ PIout + θ Az2

[0034] θ PitchDemand3 = θ PIout + θ Az3

[0035] In the formula, θ PIout is a pitch angle instruction value of the pitch PI control.

[0036] The second object of the application is achieved by the following technical solution: a wind turbine generator set fixed hub My limit load reduction system for implementing the wind turbine generator set fixed hub My limit load reduction method described above, comprising:

[0037] A blade position correction module adopts a reverse "Y" shape correction method, that is, the azimuth angle of blade 1 is 0° when it is at the top, and correspondingly, the azimuth angle of blade 2 is 120° at this time, and the azimuth angle of blade 3 is 240° at this time, and the azimuth angle correction is completed to execute the first signal acquisition module;

[0038] The first signal acquisition module is used to acquire a wind speed signal and a pitch angle signal of the generator set, and if the wind speed is greater than a wind speed threshold value and the pitch angle is greater than an angle threshold value, the second signal acquisition module is executed, and if not, the exit strategy module is executed;

[0039] The second signal acquisition module is used to acquire a blade azimuth angle signal, and after the wind turbine generator set enters a normal power generation mode, the azimuth angle of blade 1 is read out from the azimuth angle sensor The azimuth angles of blade 2 and blade 3 are calculated and After the blade azimuth angle information is acquired, the judgment module is executed;

[0040] The judgment module executes the second interpolation table module if the maximum fixed hub My limit load value, that is, Mymax, is over limit, and executes the first interpolation table module if the minimum fixed hub My limit load value, that is, Mymin, is over limit;

[0041] The first interpolation table module is used to establish an interpolation table of the lower half plane azimuth angle-pitch angle, and the calculation module is executed according to the result of the interpolation table;

[0042] A second interpolation table module is configured to establish an interpolation table of the azimuth angle-pitch angle in the upper half plane, and the calculation module is configured to perform calculation according to the result of the interpolation table;

[0043] A calculation module is configured to dynamically calculate the superimposed pitch angle according to the result of the interpolation table of the azimuth angle-pitch angle;

[0044] A pitch control module is configured to determine the final pitch angle control value of each blade according to the existing pitch angle control value θ PIout of each blade and the pitch angle instruction value of the superimposed azimuth angle FinePitch.

[0045] An exit strategy module is configured to execute a normal power generation mode if the wind speed is not greater than the wind speed threshold value and the pitch angle is not greater than the angle threshold value.

[0046] The third object of the application is achieved by the following technical solution: a storage medium storing a program, the program being executed by a processor to implement the wind turbine generator set fixed hub My limit load reduction method.

[0047] The fourth object of the application is achieved by the following technical solution: a computing device including a processor and a memory for storing a program executable by the processor, the processor executing the program stored in the memory to implement the wind turbine generator set fixed hub My limit load reduction method.

[0048] Compared with the prior art, the application has the following advantages and beneficial effects:

[0049] 1. The limit load of the fixed hub My is solved by software without increasing hardware cost.

[0050] 2. The implementation is simple and reliable.

[0051] 3. It is enabled under strong wind conditions without loss of power generation capacity. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 It is one of the azimuth angle-pitch angle corresponding relationship diagrams.

[0053] Figure 2 It is the second of the azimuth angle-pitch angle corresponding relationship diagrams.

[0054] Figure 3 It is a curve diagram of the azimuth angle and the superimposed pitch angle.

[0055] Figure 4 It is a curve diagram of the pitch angle control value of blades 1, 2 and 3.

[0056] Figure 5 It is an architecture diagram of the system of the application. DETAILED DESCRIPTION

[0057] The application will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the application are not limited thereto.

[0058] Embodiment 1

[0059] This embodiment discloses a method for reducing the limit load of a fixed hub My of a wind turbine when the wind turbine encounters extreme turbulence above the rated wind speed, and the following steps are performed:

[0060] 1) blade position correction;

[0061] The correction mode is inverted "Y", that is, the azimuth angle of blade 1 is 0° when it is at the top, and the azimuth angle of blade 2 is 120° and the azimuth angle of blade 3 is 240° at this time. After the azimuth angle correction is completed, step 2) is performed.

[0062] 2) obtaining the wind speed signal and the pitch angle signal of the wind turbine;

[0063] If the wind speed is greater than the wind speed threshold and the pitch angle is greater than the angle threshold, step 3) is performed, otherwise, step 9) is performed.

[0064] 3) obtaining the blade azimuth angle signal;

[0065] After the wind turbine enters the normal power generation mode, the azimuth angle of blade 1 is read from the azimuth angle sensor The azimuth angles of blade 2 and blade 3 are calculated And The calculation formula is as follows:

[0066]

[0067]

[0068] After obtaining the blade azimuth angle information, step 4) is performed.

[0069] 4) if the maximum limit load of the fixed hub My (i.e. Mymax) is over limit, step 6) is performed, and if the minimum limit load of the fixed hub My (i.e. Mymin) is over limit, step 5) is performed.

[0070] 5) establishing an interpolation table of the lower half plane azimuth angle-pitch angle;

[0071] According to the corresponding relationship of the azimuth angle-pitch angle, an interpolation table is established. In order to reduce the thrust of the lower half plane of the impeller, that is, to increase the limit load of the fixed hub Mymin, a preset pitch angle needs to be superimposed on the lower half plane of the impeller. The superimposition rule is: for example Figure 1As shown, when the blade azimuth angle is 0°-90°, the superimposed pitch angle is 0°, when the blade azimuth angle is 180°, the superimposed pitch angle is 1°, when the blade azimuth angle is 270°-360°, the superimposed pitch angle is 0°, that is, the superimposed pitch angle gradually increases from 90°-180°, and the superimposed pitch angle gradually decreases from 180°-270°; step 7) is performed according to the results of the interpolation table.

[0072] As shown in the figure, the azimuth angle changes from 0-360°, the superimposed pitch angle changes from 0-1°, the superimposed pitch angle gradually increases from 90°-180°, and the superimposed pitch angle gradually decreases from 180°-270°. Figure 3

[0073] 6) Establish an interpolation table of the upper half plane azimuth angle-pitch angle;

[0074] According to the corresponding relationship of the azimuth angle-pitch angle, an interpolation table is established, in order to reduce the thrust on the upper half plane of the impeller, that is, to reduce the limit load of the fixed hub Mymax, a predetermined pitch angle needs to be superimposed on the upper half plane of the impeller, and the superimposition rule is: as shown in the figure, when the blade azimuth angle is 0°, the superimposed pitch angle is 1°, when the blade azimuth angle is 90°-270°, the superimposed pitch angle is 0°, that is, the superimposed pitch angle gradually decreases from 0°-90°, and the superimposed pitch angle gradually increases from 270°-360°; step 7) is performed according to the results of the interpolation table. Figure 2

[0075] 7) Dynamically calculate the superimposed pitch angle according to the interpolation table results of the azimuth angle-pitch angle;

[0076] Using the table results of step 5) or 6), the blade 1, 2, 3 needs to adjust the superimposed pitch angle command value θ Az1 , θ Az2 , θ Az3 according to the superimposed pitch angle command value, and step 8) is performed according to the superimposed pitch angle command value.

[0077] 8) Perform variable pitch control;

[0078] According to the existing pitch angle command value θ PIout and the superimposed azimuth angle FinePitch pitch angle command value θ Az1 , θ Az2 , θ Az3 of each blade, the final pitch angle control value θ PitchDemand1 , θ PitchDemand2 , θ PitchDemand3 of the blade 1, 2, 3 is determined, as shown in the figure, which is the final pitch angle control value θ Figure 4 ​​​PitchDemand1 , θ PitchDemand2 , θ PitchDemand3 , the value is applied to the variable pitch actuator of the wind turbine generator set, and each blade performs corresponding variable pitch action to adjust the limit load of the fixed hub My of the wind turbine generator set;

[0079] θ PitchDemand1 = θ PIout + θ Az1

[0080] θ PitchDemand2 = θ PIout + θ Az2

[0081] θ PitchDemand3 = θ PIout + θ Az3

[0082] In the formula, θ PIout is the pitch angle command value of the variable pitch PI control.

[0083] 9) exit strategy;

[0084] If the wind speed is greater than the wind speed threshold and the pitch angle is greater than the angle threshold, the normal power generation mode is executed.

[0085] Embodiment 2

[0086] The embodiment discloses a wind turbine generator set fixed hub My limit load reduction system for realizing the wind turbine generator set fixed hub My limit load reduction method described in embodiment 1, as shown in the figure, the system includes the following functional modules: Figure 5

[0087] The blade position correction module adopts an inverted “Y” shape correction method, that is, the azimuth angle of blade 1 is 0° when it is at the top, and correspondingly, the azimuth angle of blade 2 is 120° at this time, and the azimuth angle of blade 3 is 240° at this time. After the azimuth angle correction is completed, the first signal acquisition module is executed;

[0088] The first signal acquisition module is used to acquire the wind speed signal and the pitch angle signal of the unit, and if the wind speed is greater than the wind speed threshold and the pitch angle is greater than the angle threshold, the second signal acquisition module is executed, and if not, the exit strategy module is executed;

[0089] The second signal acquisition module is used to acquire the blade azimuth angle signal, and after the wind turbine generator set enters the normal power generation mode, the azimuth angle of blade 1 is read out from the azimuth angle sensor The azimuth angles of blade 2 and blade 3 are calculated and After the blade azimuth angle information is acquired, the judgment module is executed; ​

[0090] a judging module, if the maximum value of the fixed hub My limit load, i.e. Mymax, is out of limit, the second interpolation table module is executed, if the minimum value of the fixed hub My limit load, i.e. Mymin, is out of limit, the first interpolation table module is executed;

[0091] the first interpolation table module, for establishing an interpolation table of the lower half plane azimuth angle-pitch angle, and executing the calculation module according to the result of the interpolation table;

[0092] the second interpolation table module, for establishing an interpolation table of the upper half plane azimuth angle-pitch angle, and executing the calculation module according to the result of the interpolation table;

[0093] the calculation module, for dynamically calculating the superimposed pitch angle according to the result of the interpolation table of the azimuth angle-pitch angle;

[0094] the pitch control module, for determining the final pitch angle control value of each blade according to the existing pitch angle control value θ PIout and the pitch angle instruction value of the superimposed azimuth angle FinePitch.

[0095] the exit strategy module, for executing the normal power generation mode if the wind speed is not greater than the wind speed threshold value and the pitch angle is not greater than the angle threshold value.

[0096] Embodiment 3

[0097] The embodiment discloses a storage medium, which stores a program, and the program is executed by a processor to realize the wind turbine fixed hub My limit load reduction method in the embodiment 1.

[0098] The storage medium in the embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a U disk, a mobile hard disk, and the like.

[0099] Embodiment 4

[0100] The embodiment discloses a computing device, which comprises a processor and a memory for storing a program executable by the processor, and the processor executes the program stored in the memory to realize the wind turbine fixed hub My limit load reduction method in the embodiment 1.

[0101] The computing device in the embodiment can be a desktop computer, a notebook computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0102] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A method for reducing the limit load of the fixed hub My of a wind turbine generator set, characterized in that: When a wind turbine encounters extreme turbulence above rated wind speed, perform the following steps: 1) Blade position correction; Use an inverted "Y"-shaped correction method, that is, when blade 1 is at the top, the azimuth angle is 0°, and accordingly, the azimuth angle of blade 2 at this time is 120°, and the azimuth angle of blade 3 at this time is 240°. After the azimuth angle correction is completed, proceed to step 2); 2) Obtain wind speed signal and pitch angle signal of the unit; If the wind speed is greater than the wind speed threshold and the pitch angle is greater than the angle threshold, then execute step 3); if not, execute step 9); 3) Obtain blade azimuth angle signal; After the wind turbine enters the normal power generation mode, the azimuth angle of blade 1 is read from the azimuth angle sensor. Calculate the azimuth angles of blades 2 and 3 and After obtaining the blade azimuth information, execute step 4); 4) If the maximum limit load of the fixed hub My, i.e., Mymax, exceeds the limit, execute step 6); if the minimum limit load of the fixed hub My, i.e., Mymin, exceeds the limit, execute step 5); 5) Establish an interpolation table of the lower half plane azimuth angle-pitch angle; 6) Establish an interpolation table of upper half plane azimuth angle-pitch angle; 7) Dynamically calculate the superimposed pitch angle based on the interpolation table results of the azimuth angle-pitch angle; 8) Execute pitch control; According to the existing pitch angle command value θ of each blade PIout The final pitch angle control value of each blade is determined by the pitch angle command value of the superimposed azimuth angle FinePitch; 9) Exit strategy; If the wind speed is not greater than the wind speed threshold and the pitch angle is not greater than the angle threshold, the normal power generation mode is executed.

2. The method for reducing the limit load of the fixed hub My of a wind turbine generator set according to claim 1, characterized in that: In step 3), the azimuth angles of blades 2 and 3 are and The calculation formula is as follows:

3. The method for reducing the limit load of the fixed hub My of a wind turbine generator set according to claim 2, characterized in that: In step 5), an interpolation table is established according to the correspondence between the azimuth angle and the pitch angle. In order to reduce the thrust of the lower half plane of the impeller, that is, to increase the limit load of the fixed hub Mymin, it is necessary to superimpose a preset pitch angle on the lower half plane of the impeller. The superposition rule is: when the blade azimuth angle is 0°-90°, the superimposed pitch angle is 0°, when the blade azimuth angle is 180°, the superimposed pitch angle is 1°, and when the blade azimuth angle is 270°-360°, the superimposed pitch angle is 0°, that is, the superimposed pitch angle gradually increases from 90°-180° of the blade azimuth angle, and gradually decreases from 180°-270° of the blade azimuth angle; execute step 7) according to the result of the interpolation table.

4. The method for reducing the limit load of the fixed hub My of a wind turbine generator set according to claim 3, characterized in that: In step 6), an interpolation table is established based on the correspondence between the azimuth angle and the pitch angle. In order to reduce the thrust of the upper half plane of the impeller, that is, to reduce the limit load of the fixed hub Mymax, it is necessary to superimpose a preset pitch angle on the upper half plane of the impeller. The superposition rule is: when the blade azimuth angle is 0°, the superimposed pitch angle is 1°, and when the blade azimuth angle is 90°-270°, the superimposed pitch angle is 0°, that is, the superimposed pitch angle gradually decreases from 0° to 90°, and the superimposed pitch angle gradually increases from 270° to 360°; execute step 7) according to the result of the interpolation table.

5. The method for reducing the limit load of the fixed hub My of a wind turbine generator set according to claim 4, characterized in that: In step 7), the table result of step 5) or 6) is used to adjust the pitch angle command value θ of blades 1, 2, and 3 in real time according to the superposition rule of blade azimuth angles. Az1 ,θ Az2 ,θ Az3 , execute step 8) according to the superimposed pitch angle command value).

6. The method for reducing the limit load of the fixed hub My of a wind turbine generator set according to claim 5, characterized in that: In step 8), according to the existing pitch angle command value θ of each blade PIout and the pitch angle command value θ of the superimposed azimuth angle FinePitch Az1 ,θ Az2 ,θ Az3 , determine the final pitch angle control value θ of blades 1, 2, and 3 PitchDemand1 ,θ PitchDemand2 ,θ PitchDemand3 , this value is applied to the pitch actuator of the wind turbine generator set to control each blade to perform the corresponding pitch action to adjust the ultimate load of the fixed hub My of the wind turbine generator set; i PitchDemand1 =θ PIout +θ Az1 i PitchDemand2 =θ PIout +θ Az2 i PitchDemand3 =θ PIout +θ Az3 Where θ PIout is the pitch angle command value of the pitch PI control.

7. A wind turbine fixed hub My limit load reduction system, characterized in that: The method for reducing the limit load of the fixed hub My of a wind turbine generator set according to any one of claims 1 to 6 comprises: The blade position correction module uses an inverted "Y"-shaped correction method, that is, when blade 1 is at the top, the azimuth angle is 0°. Correspondingly, the azimuth angle of blade 2 at this time is 120°, and the azimuth angle of blade 3 at this time is 240°. After the azimuth angle correction is completed, the first signal acquisition module is executed; A first signal acquisition module is used to obtain a wind speed signal and a pitch angle signal of the unit. If the wind speed is greater than a wind speed threshold and the pitch angle is greater than an angle threshold, the second signal acquisition module is executed. If not, the exit strategy module is executed; The second signal acquisition module is used to obtain the blade azimuth angle signal. After the wind turbine enters the normal power generation mode, the azimuth angle of blade 1 is read from the azimuth angle sensor. Calculate the azimuth angles of blades 2 and 3 and After obtaining the blade azimuth information, the judgment module is executed; The judgment module executes the second interpolation table module if the maximum limit load of the fixed hub My, i.e., Mymax, exceeds the limit; and executes the first interpolation table module if the minimum limit load of the fixed hub My, i.e., Mymin, exceeds the limit; A first interpolation table module is used to establish an interpolation table of the lower half plane azimuth angle-pitch angle, and execute the calculation module according to the result of the interpolation table; A second interpolation table module is used to establish an interpolation table of the upper half plane azimuth angle-pitch angle, and execute the calculation module according to the result of the interpolation table; A calculation module dynamically calculates the superimposed pitch angle based on the interpolation table results of the azimuth angle and pitch angle; The pitch control module controls the pitch angle of each blade according to its value θ. PIout The final pitch angle control value of each blade is determined by the pitch angle command value of the superimposed azimuth angle FinePitch; The exit strategy module executes the normal power generation mode if the wind speed is greater than the wind speed threshold and the pitch angle is greater than the angle threshold.

8. A storage medium storing a program, characterized in that: When the program is executed by a processor, the method for reducing the limit load of the fixed hub My of a wind turbine generator set according to any one of claims 1 to 6 is implemented.

9. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the method for reducing the limit load of the fixed hub My of the wind turbine generator set according to any one of claims 1 to 6 is implemented.

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