A fan blade flutter protection method, system, medium, and apparatus

Abstract

The application discloses a fan blade flutter protection method, system, medium and equipment. The method is to add a blade flutter strategy in an original main control program of a fan, that is, to realize detection of a blade flutter state by extracting eigenvalues of a variable pitch motor of the fan. If it is detected that the extracted eigenvalues of the variable pitch motor meet flutter characteristics, yaw is executed to reduce blade vibration, so that the blade is protected. The application creatively uses the eigenvalues (current, voltage or torque) of the variable pitch motor to judge whether the blade appears flutter without adding any additional hardware device in advance, and has a positive effect on the safety of the fan blade.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power generation, in particular to a wind turbine blade flutter protection method and system based on a variable pitch system and a yaw system, a storage medium and a computing device. BACKGROUND

[0002] With the increasing diameter of the impeller of wind turbine generators (also referred to as wind turbines), the threat of blade flutter to the safety of wind turbines in extreme wind conditions is also increasing. The existing technologies for detecting wind turbine blade flutter mostly achieve this by adding hardware devices, which is costly. Moreover, the existing technologies only detect whether the blade is fluttering when it is stationary, and do not detect blade flutter when the blade is not stationary in special cases.

[0003] For example, in Chinese patent application CN115573868A, a blade multi-state monitoring system based on optical fiber MEMS sensing and a working method thereof are disclosed. The method adds a sensor for detecting the state of the blade, and detects data such as blade acceleration, blade load and lightning current through the numerical value of the sensor to determine whether the blade is normal. This method requires a complete set of sensors, signal processing and transmission devices, etc., which is costly.

[0004] In Chinese patent application CN116971921A, a wind turbine generator blade flutter control method and system under power grid outage conditions are disclosed. The method uses supercapacitors or batteries in the variable pitch system of the wind turbine to provide power when the wind turbine is powered off, and starts the variable pitch action to eliminate vortex-induced vibration when an abnormal wind turbine vibration value is detected. This method can provide some protection, but it is not accurate to distinguish between blade flutter and flutter of other parts by using the vibration value of the wind turbine.

[0005] In summary, most of the existing technologies require the addition of extra detection devices, which is costly. Among the methods that do not require the addition of extra hardware devices, the existing detection schemes only use vibration values to determine whether the wind turbine blade is fluttering. Since there is no vibration sensor installed separately in the wind turbine blade, this method is not accurate. The existing methods basically detect the wind turbine when it is stationary, such as when the wind turbine is powered off or has stopped and the variable pitch is no longer in motion. However, the method does not monitor and protect the wind turbine when the variable pitch is still in motion. When the existing method detects that the blade may flutter, it starts to perform the set action. However, it does not further analyze and determine whether the blade is truly protected during the execution process. 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 blade flutter protection method based on a variable pitch system and a yaw system, which creatively uses the characteristic values (current, voltage or torque) of the variable pitch motor to determine whether the blade is fluttering without adding any additional hardware devices in advance, and has a positive effect on the safety of the wind turbine blade.

[0007] The second object of the present application is to provide a wind turbine blade flutter protection 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 blade flutter protection method, which adds a blade flutter strategy in the original main control program of the wind turbine, that is, the characteristic values of the variable pitch motor of the wind turbine are extracted to detect the blade flutter state, and when the wind turbine is not powered off, if the extracted characteristic values of the variable pitch motor meet the flutter characteristics, yaw is performed to reduce blade vibration, thereby protecting the blade safety.

[0011] Further, the characteristic values are current, voltage or torque.

[0012] Further, since blade flutter generally only occurs in special strong winds, when detecting and determining whether the blade is fluttering, in addition to the characteristic values of the variable pitch motor meeting the conditions, the external wind speed also needs to meet the set conditions, that is, the judgment of the wind speed condition is added.

[0013] Further, since blade flutter generally occurs after the wind turbine is stopped, when detecting and determining whether the blade is fluttering, in addition to the characteristic values of the variable pitch motor meeting the conditions, the angle of the variable pitch motor also needs to meet the set conditions, that is, the judgment of the blade angle value is added.

[0014] Further, the method is programmed and implemented in the PLC main controller of the wind turbine.

[0015] Further, under the non-grid-connected condition of the wind turbine, the following operations are performed:

[0016] The blade angle value is used to determine whether the wind turbine has been stopped and is in a state where blade flutter may occur, that is, whether the blade angle of the wind turbine is greater than a threshold value a, and if it is greater, the wind turbine has been stopped and is in a state where blade flutter may occur;

[0017] The wind speed value is used to determine whether the external environment may cause the blade to flutter, that is, whether the wind speed is greater than a threshold value b, and if it is greater, the external environment may cause the blade to flutter;

[0018] When the blade angle of the wind turbine is greater than the threshold a and the wind speed is greater than the threshold b, the maximum value of the characteristic value of each variable pitch motor in a preset time period t is compared with the threshold c respectively to determine whether the condition greater than the threshold c occurs in the time period t, and the effective value obtained by filtering the characteristic value of each variable pitch motor is compared with the threshold d respectively to determine whether the condition greater than the threshold d occurs.

[0019] When any one of the characteristic values of each variable pitch motor is greater than the threshold c and any one of the effective values of the characteristic values of each variable pitch motor is greater than the threshold d, it is determined that the blade may vibrate in the above-mentioned time period t, and if the blade is determined to possibly vibrate in a plurality of continuous time periods t, the wind turbine is controlled to start yawing to reduce the vibration of the blade.

[0020] The second object of the application is achieved by the following technical scheme: a wind turbine blade vibration protection system for implementing the wind turbine blade vibration protection method described above, comprising:

[0021] A variable pitch angle detection module determines whether the wind turbine has stopped and is in a state where the blade may vibrate by the blade angle value, i.e., whether the blade angle of the wind turbine is greater than the threshold a, and if it is greater, the wind turbine has stopped and is in a state where the blade may vibrate.

[0022] A wind speed detection module determines whether the external environment may cause the blade to vibrate by the size of the wind speed value, i.e., whether the wind speed is greater than the threshold b, and if it is greater, the external environment may cause the blade to vibrate.

[0023] A variable pitch motor characteristic value detection module is used to compare the maximum value of the characteristic value of each variable pitch motor in a preset time period t with the threshold c respectively when the blade angle of the wind turbine is greater than the threshold a and the wind speed is greater than the threshold b to determine whether the condition greater than the threshold c occurs in the time period t, and the effective value obtained by filtering the characteristic value of each variable pitch motor is compared with the threshold d respectively to determine whether the condition greater than the threshold d occurs.

[0024] A yaw determination module is used to determine that the blade may vibrate in the above-mentioned time period t when any one of the characteristic values of each variable pitch motor is greater than the threshold c and any one of the effective values of the characteristic values of each variable pitch motor is greater than the threshold d, and if the blade is determined to possibly vibrate in a plurality of continuous time periods t, the wind turbine is controlled to start yawing to reduce the vibration of the blade.

[0025] The third object of the application is achieved by the following technical scheme: a storage medium storing a program, which is executed by a processor to implement the wind turbine blade vibration protection method described above.

[0026] The fourth object of the present application is achieved by a computing device comprising a processor and a memory for storing processor-executable programs, wherein the processor implements the fan blade flutter protection method as described above when executing the programs stored in the memory.

[0027] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0028] The present application is added in the main control program of the fan after the fan is put into use, and the required related signals already exist in the fan itself based on the pitch system and the yaw system, without the need for additional hardware.

[0029] The present application can execute yaw action when detecting the risk of possible blade flutter in the non-power-off shutdown state of the fan, thereby reducing the degree of blade flutter and protecting the fan.

[0030] The present application only works when the fan has stopped in special extreme cases, and has no effect on the normal operation and power generation of the fan. After detecting the blade flutter condition, the processing action is only to control yaw, which does not exist risk, and can effectively improve the safety of the fan. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The figure is the architecture diagram of the method of the present application.

[0032] Figure 2 The figure is the control flow chart of the method of the present application.

[0033] Figure 3 The figure is the architecture diagram of the system of the present application. DETAILED DESCRIPTION

[0034] The present application will be further described in detail below in combination with embodiments and drawings, but the embodiments of the present application are not limited thereto.

[0035] Embodiment 1

[0036] The embodiment discloses a fan blade flutter protection method based on a pitch system and a yaw system. The method is programmed in a PLC main controller and adds a blade flutter strategy in the original main control program of the fan. The blade flutter state is detected by extracting the characteristic value (specifically, current, voltage or torque) of the pitch motor of the fan. When the fan is not powered off, if the extracted characteristic value of the pitch motor meets the flutter characteristics, yaw is executed to reduce blade vibration, thereby protecting the safety of the blade. Figure 1 and Figure 2 As shown in the figures, taking the current of the pitch motor as an example, the specific implementation of the method is as follows:

[0037] In the non-grid-connected condition of the fan, whether the fan has stopped and is in a state in which blade flutter may occur is determined by the blade angle value, that is, whether the blade angle of the fan is greater than a, and a is 80 degrees in the running fan. If it is greater, the fan has stopped and is in a state in which blade flutter may occur.

[0038] Whether the external environment may cause the fan blades to flutter is determined by the size of the wind speed value, that is, whether the wind speed is greater than b, and b is 8 meters per second in the running fan. If it is greater, the external environment may cause the fan blades to flutter.

[0039] When the above conditions are met (that is, the blade angle of the fan is greater than the threshold value a and the wind speed is greater than the threshold value b), the maximum current of each pitch motor in a preset time period t is compared with the threshold value c, t is 1 minute and c is 50 amperes in the running fan. Determine whether the condition greater than the threshold value c occurs in the time period t, and filter the current of each pitch motor and take the effective value. The effective value obtained is compared with the threshold value d, d is 10 amperes in the running fan, and it is determined whether the condition greater than the threshold value d occurs.

[0040] When the above conditions are met, that is, any one of the current values of each pitch motor is greater than the threshold value c, and any one of the effective values of the current of each pitch motor is greater than the threshold value d, it is determined that the fan blades may flutter in the time period t. If the fan blades are determined to possibly flutter in three consecutive time periods t, the fan is immediately controlled to yaw to reduce the flutter of the blades.

[0041] Example 2

[0042] The embodiment discloses a fan blade flutter protection system for implementing the fan blade flutter protection method described in Example 1, as shown in Figure 3 The system includes the following functional modules:

[0043] A pitch angle detection module determines whether the fan has stopped and is in a state in which blade flutter may occur by the blade angle value, that is, whether the blade angle of the fan is greater than the threshold value a. If it is greater, the fan has stopped and is in a state in which blade flutter may occur.

[0044] A wind speed detection module determines whether the external environment may cause the fan blades to flutter by the size of the wind speed value, that is, whether the wind speed is greater than the threshold value b. If it is greater, the external environment may cause the fan blades to flutter.

[0045] The pitch motor characteristic value detection module is configured to compare the maximum value of the characteristic value of each pitch motor in a preset time period t with a threshold value c respectively when the blade angle of the wind turbine is greater than a threshold value a and the wind speed is greater than a threshold value b, determine whether the maximum value is greater than the threshold value c in the time period t, filter the characteristic value of each pitch motor and take the effective value, and compare the effective value with a threshold value d to determine whether the effective value is greater than the threshold value d.

[0046] The yaw determination module is configured to determine that the blade may vibrate in the time period t when any one of the characteristic values of the pitch motors is greater than the threshold value c and any one of the effective values of the characteristic values of the pitch motors is greater than the threshold value d, and control the wind turbine to yaw to reduce the vibration of the blade if the blade is determined to vibrate in a plurality of time periods t.

[0047] Embodiment 3

[0048] The embodiment discloses a storage medium, which stores a program. The program is executed by a processor to implement the wind turbine blade vibration protection method in the embodiment 1.

[0049] 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, or the like.

[0050] Embodiment 4

[0051] The embodiment discloses a computing device, which includes a processor and a memory for storing a program executable by the processor. The processor executes the program stored in the memory to implement the wind turbine blade vibration protection method in the embodiment 1.

[0052] 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.

[0053] The above embodiments are preferred embodiments of the present application, but the embodiments of the present application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, which are all included in the protection scope of the present application.

Claims

1. A method of flutter protection for a wind turbine blade, characterized in that, The method is to add a blade flutter strategy in the original main control program of the fan, that is, to realize detection of the blade flutter state by extracting eigenvalues of the variable pitch motor of the fan, and when the fan is not powered off, if the extracted eigenvalues of the variable pitch motor meet the flutter characteristics, yaw is executed to reduce the blade vibration, thereby protecting the blade safety. In addition to the eigenvalues of the variable pitch motor meeting the conditions, the external wind speed also needs to meet the set conditions, that is, the judgment of the wind speed condition is added. In addition to the eigenvalues of the variable pitch motor meeting the conditions, the blade angle also needs to meet the set conditions, that is, the judgment of the blade angle value is added. In the non-grid-connected state of the fan, the following operations are performed: The blade angle value is used to judge whether the fan has stopped and is in a state where the blade flutter may occur, that is, whether the blade angle of the fan is greater than a threshold value a, if greater, the fan has stopped and is in a state where the blade flutter may occur; The size of the wind speed value is used to judge whether the external environment may cause the blade to flutter, that is, whether the wind speed is greater than a threshold value b, if greater, the external environment may cause the blade to flutter; When the blade angle of the fan is greater than the threshold value a and the wind speed is greater than the threshold value b, the maximum value of the eigenvalues of each variable pitch motor in a preset time period t is compared with a threshold value c respectively to judge whether the condition of being greater than the threshold value c occurs in the time period t, and the eigenvalues of each variable pitch motor are filtered and then effective values are taken, and the obtained effective values are compared with a threshold value d respectively to judge whether the condition of being greater than the threshold value d occurs; When any one of the eigenvalues of each variable pitch motor is greater than the threshold value c and any one of the effective values of the eigenvalues of each variable pitch motor is greater than the threshold value d, it is judged that the blade may flutter in the above-mentioned time period t, and if the blade is judged to possibly flutter in a plurality of continuous time periods t, the fan is controlled to start yawing to reduce the blade flutter.

2. A fan blade flutter protection method according to claim 1, characterised in that, The eigenvalues are current, voltage or torque.

3. A fan blade flutter protection method according to claim 1, wherein, The method is realized by programming in the PLC main controller of the fan.

4. A fan blade flutter protection system characterized by, The fan blade flutter protection method of any one of claims 1 to 3 comprises: a variable pitch angle detection module, which judges whether the fan has stopped and is in a state where the blade flutter may occur by the blade angle value, that is, whether the blade angle of the fan is greater than a threshold value a, if greater, the fan has stopped and is in a state where the blade flutter may occur; a wind speed detection module, which judges whether the external environment may cause the blade to flutter by the size of the wind speed value, that is, whether the wind speed is greater than a threshold value b, if greater, the external environment may cause the blade to flutter; a variable pitch motor eigenvalue detection module, which is used to compare the maximum value of the eigenvalues of each variable pitch motor in a preset time period t with a threshold value c respectively to judge whether the condition of being greater than the threshold value c occurs in the time period t when the blade angle of the fan is greater than the threshold value a and the wind speed is greater than the threshold value b, and the eigenvalues of each variable pitch motor are filtered and then effective values are taken, and the obtained effective values are compared with a threshold value d respectively to judge whether the condition of being greater than the threshold value d occurs. The yaw judgment module is configured to determine that the blade may vibrate when any one of the characteristic values of the variable pitch motors is greater than a threshold value c and any one of the effective values of the characteristic values of the variable pitch motors is greater than a threshold value d at the same time, and control the wind turbine to yaw to reduce the vibration of the blade if the blade is determined to possibly vibrate in multiple time periods t.

5. A storage medium storing a program, characterized by comprising: The program is executed by the processor to implement the wind turbine blade vibration protection method in any one of claims 1 to 3.

6. A computing device comprising a processor and a memory for storing a processor-executable program, characterized in that, The processor executes the program stored in the memory to implement the wind turbine blade vibration protection method in any one of claims 1 to 3.

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