Differentiated vibration control method and device for wind turbine generator

Abstract

The application discloses a differential vibration control method and device for a wind turbine. The method comprises: obtaining wind speed data in a first height range in front of a wind wheel; determining a current wind condition type according to longitudinal wind speed data and vertical wind speed data; when a downburst is encountered, determining a position state relative to the downburst according to a longitudinal-to-lateral wind speed ratio, and executing a corresponding shutdown strategy; when a low-level jet is encountered, obtaining cabin vibration acceleration or blade load spectrum feature data, and when it is determined that an abnormal vibration triggering condition is met, generating an additional variable pitch angle instruction, and superimposing the variable pitch angle instruction on a variable pitch reference instruction to execute a variable pitch action. The application solves the technical problem that in the related art, due to the fact that both the low-level jet and the downburst are characterized by nonlinear changes in wind speed with height in the vertical wind profile and cause significant wind speed differences in the wind wheel plane, it is difficult to accurately distinguish between the two by simply relying on traditional wind measurement data, and thus precise control strategies cannot be executed.

Description

Technical Field

[0001] This invention relates to the field of wind power generation control technology, and more specifically, to a differentiated vibration control method and device for wind turbine generators. Background Technology

[0002] Wind turbine generators are often exposed to complex and unsteady atmospheric environments. In particular, as the single-unit capacity of wind turbine generators continues to increase and the hub height continues to rise, the probability of the generators encountering complex wind conditions such as low-level jets and downbursts has increased significantly. Load control under extreme wind conditions has become a key technical challenge for the safe operation of wind turbine generators. Low-level jets refer to strong, narrow, and fast-moving air currents characterized by a significant gradient in horizontal wind speed along a vertical direction, exhibiting a non-linear wind speed distribution with height. Their load characteristics are primarily manifested in the following ways: when a low-level jet occurs within the height range of the wind turbine, under certain jet height, intensity, and width conditions, large wind turbines experience vibration problems distinct from those under other general airflow conditions. Specifically, the excitation on the nacelle and tower, at three times the rotor rotation frequency, is further enhanced, leading to resonance; the excitation on the blade flapping bending moment, at twice the rotor rotation frequency, is further enhanced, causing periodic load abrupt vibration problems. Therefore, the occurrence of low-level jets can cause large wind turbines to frequently trigger vibration over-limit fault alarms, resulting in turbine shutdowns and power generation losses. The inability to control vibration phenomena in a timely manner also poses a significant challenge to turbine safety and fatigue damage. Downbursts, on the other hand, are strong descending air currents generated by severe convective weather such as thunderstorms. When these air currents impact the ground, they radiate outwards, forming highly destructive near-surface strong winds. Current technologies face a key bottleneck in identifying these two types of wind conditions: low-level jets and downbursts exhibit certain similarities in their vertical wind profiles, both displaying nonlinear wind speed variations with height and potentially causing significant wind speed differences within the rotor surface. Simply relying on traditional wind speed profile measurements or hub height anemometer data often fails to accurately distinguish between low-level jets and downbursts. This identification challenge directly hinders the precise matching of control strategies, directly impacting the safe operation of the generator unit.

[0003] Previous studies have often addressed unit vibration by installing dampers. However, dampers are designed based on the first or second order frequency of the tower, and then control the resonance of the first or second order frequency of the tower. When a low-level jet occurs, the nacelle and tower vibrate at three times the rotor rotation frequency. In addition, frequency tuning of the damper is very difficult and complex to operate. Using a damper cannot respond in time and perform vibration reduction control. Therefore, the method of adding a damper cannot reduce the vibration caused by the low-level jet.

[0004] Furthermore, existing wind turbine control technologies lack effective solutions that can accurately distinguish between downbursts and low-level jets and implement differentiated vibration control accordingly. While some existing technologies address turbine protection under extreme wind conditions, they typically employ uniform safety strategies (such as uniform shutdown). This may lead to unnecessary power generation losses under low-level jet conditions and fails to fully leverage the potential of independent pitch control in load mitigation.

[0005] There is currently no effective solution to the above problems. Summary of the Invention

[0006] This invention provides a differentiated vibration control method and apparatus for wind turbines, which at least solves the technical problem in the related art of identifying low-level jets and downbursts. Since both exhibit nonlinear wind speed changes with height in the vertical wind profile and cause significant wind speed differences within the rotor surface, it is difficult to accurately distinguish them by simply relying on traditional wind measurement data, thus making it impossible to execute precise control strategies.

[0007] According to one aspect of the present invention, a differentiated vibration control method for a wind turbine is provided, comprising: acquiring wind speed data within a first height range in front of the wind turbine rotor, wherein the wind speed data includes wind direction data and height data, and the wind direction data includes longitudinal wind speed data, lateral wind speed data, and vertical wind speed data; determining the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data; when the current wind condition type is a downburst, determining the position state of the wind turbine relative to the downburst based on the ratio of longitudinal to lateral wind speeds at the hub height of the wind turbine, and executing a shutdown strategy corresponding to the position state; when the current wind condition type is a low-level jet stream, acquiring nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine; when determining that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, generating an additional pitch angle command, and superimposing the additional pitch angle command with a pitch reference command to drive a pitch actuator to perform a pitch action.

[0008] Optionally, determining the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data includes: determining whether a vertical wind shear anomaly exists based on the longitudinal wind speed data sequence corresponding to the longitudinal wind speed data; determining whether the downburst characteristic conditions are met based on the vertical wind speed data to obtain a judgment result; determining the current wind condition type as the downburst when the judgment result indicates that the vertical wind speed data meets the downburst characteristic conditions; and determining the current wind condition type as the low-level jet when the judgment result indicates that the vertical wind speed data does not meet the downburst characteristic conditions.

[0009] Optionally, determining the existence of vertical wind shear variation based on the vertical wind speed data sequence corresponding to the vertical wind speed data includes: determining the maximum vertical wind speed in the vertical wind speed data sequence and determining the height at which the maximum vertical wind speed is located; obtaining the minimum vertical wind speed within a second height range above the height; and determining the existence of the vertical wind shear variation when the difference between the maximum and minimum vertical wind speeds is greater than or equal to a vertical wind speed difference threshold.

[0010] Optionally, when the current wind condition is a downburst, determining the position of the wind turbine relative to the downburst based on the ratio of longitudinal to transverse wind speeds at the hub height includes: acquiring the longitudinal wind speed and the transverse wind speed at the hub height; determining the ratio of the longitudinal wind speed to the transverse wind speed to obtain the longitudinal-transverse wind speed ratio; if the longitudinal-transverse wind speed ratio is within a preset range, then the position is determined to be the center region of the downburst; if the longitudinal-transverse wind speed ratio is not within the preset range, then the position is determined to be the non-center region of the downburst.

[0011] Optionally, the shutdown strategy corresponding to the position state is executed, including: when the position state is in the center of the downburst, executing a first shutdown strategy, wherein the first shutdown strategy is: controlling the pitch actuator of the wind turbine to perform a pitch-up operation at a preset pitch-up rate; and when the position state is in the non-center of the downburst, executing a second shutdown strategy, wherein the second shutdown strategy is: controlling the pitch actuator to perform a pitch-up operation at the preset pitch-up rate, and controlling the pitch actuator to perform a yaw action.

[0012] Optionally, when it is determined that the nacelle vibration acceleration or the blade load spectrum characteristic data meets the abnormal vibration triggering condition, an additional pitch angle command is generated, including: when the average value of the vibration peaks of the forward acceleration and backward acceleration in the nacelle vibration acceleration is greater than or equal to a vibration peak threshold, it is determined that the nacelle vibration acceleration meets the abnormal vibration triggering condition, and the additional pitch angle command is generated; spectral analysis is performed on the blade load spectrum characteristic data, and when it is determined that the energy ratio of twice the vibration energy to one times the vibration energy of any blade is greater than or equal to an energy ratio threshold, it is determined that the blade load spectrum characteristic data meets the abnormal vibration triggering condition, and the additional pitch angle command is generated.

[0013] Optionally, generating additional pitch angle commands includes: performing bandpass filtering on the blade root flapping moment or main shaft moment signal of the wind turbine with a center frequency of twice the wind turbine rotation frequency to extract the twice frequency component signal; and generating the additional pitch angle command for each blade based on the twice frequency component signal through a proportional-resonant controller or phase compensation.

[0014] Optionally, the additional pitch angle command is superimposed with the pitch reference command to drive the pitch actuator to perform pitching action, including: algebraically superimposing the additional pitch angle command of each blade with the pitch reference command to obtain the target pitch command of each blade; sending the target pitch command to the pitch actuator of each blade to control the pitch actuator to perform pitching action.

[0015] According to another aspect of the present invention, a differentiated vibration control device for a wind turbine is also provided, comprising: a first acquisition module, configured to acquire wind speed data within a first height range in front of the wind turbine rotor, wherein the wind speed data includes wind direction data and height data, and the wind direction data includes longitudinal wind speed data, lateral wind speed data, and vertical wind speed data; a first determination module, configured to determine the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data; and a second determination module, configured to, when the current wind condition type is a downburst, determine the wind condition type based on the wind direction data and the vertical wind speed data. The longitudinal and lateral wind speed ratio at the hub height of the wind turbine determines the position of the wind turbine relative to the downburst and executes a shutdown strategy corresponding to the position. The second acquisition module is used to acquire the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine when the current wind condition is a low-level jet. When it is determined that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated and superimposed with the pitch reference command to drive the pitch actuator to perform pitch action.

[0016] Optionally, the first determining module includes: a judging unit, configured to determine whether a downburst characteristic condition is met based on the vertical wind speed data sequence corresponding to the vertical wind speed data when a vertical wind shear anomaly is determined to exist, and obtain a judging result; a first determining unit, configured to determine the current wind condition type as a downburst when the judging result indicates that the vertical wind speed data meets the downburst characteristic condition; and a second determining unit, configured to determine the current wind condition type as a low-level jet stream when the judging result indicates that the vertical wind speed data does not meet the downburst characteristic condition.

[0017] Optionally, the determination unit includes: a first determining subunit, configured to determine the maximum longitudinal wind speed in the longitudinal wind speed data sequence and determine the height at which the maximum longitudinal wind speed is located; an acquisition subunit, configured to acquire the minimum longitudinal wind speed within a second height range above the height; and a second determining subunit, configured to determine that the vertical wind shear variation currently exists when the longitudinal wind speed difference between the maximum and minimum longitudinal wind speeds is greater than or equal to a longitudinal wind speed difference threshold.

[0018] Optionally, the second determining module includes: an acquisition unit, configured to acquire the longitudinal wind speed and the lateral wind speed at the hub height; a third determining unit, configured to determine the wind speed ratio of the longitudinal wind speed to the lateral wind speed, thereby obtaining the longitudinal-lateral wind speed ratio; a fourth determining unit, configured to determine the position state as the center region of a downburst if the longitudinal-lateral wind speed ratio is within a preset ratio range; and a fifth determining unit, configured to determine the position state as a non-center region of a downburst if the longitudinal-lateral wind speed ratio is not within the preset ratio range.

[0019] Optionally, the second determining module includes: a first execution unit, configured to execute a first shutdown strategy when the position state is the center region of the downburst, wherein the first shutdown strategy is to control the pitch actuator of the wind turbine to perform a pitch-up operation at a preset pitch-up rate; and a second execution unit, configured to execute a second shutdown strategy when the position state is the non-center region of the downburst, wherein the second shutdown strategy is to control the pitch actuator to perform a pitch-up operation at the preset pitch-up rate and to control the pitch actuator to perform a yaw action.

[0020] Optionally, the second acquisition module includes: a sixth determining unit, configured to determine that the nacelle vibration acceleration meets the abnormal vibration triggering condition when the average value of the vibration peaks of the forward and backward accelerations in the nacelle vibration acceleration is greater than or equal to a vibration peak threshold, and generate the additional pitch angle command; and a seventh determining unit, configured to perform spectral analysis on the blade load spectral characteristic data, and determine that the blade load spectral characteristic data meets the abnormal vibration triggering condition when the energy ratio of twice the vibration energy to one times the vibration energy of any blade is greater than or equal to an energy ratio threshold, and generate the additional pitch angle command.

[0021] Optionally, the second acquisition module includes: a filtering unit, used to perform bandpass filtering on the blade root flapping moment or main shaft moment signal of the wind turbine with a center frequency of twice the wind turbine rotation frequency, so as to extract the twice frequency component signal; and a generation unit, used to generate the additional pitch angle command for each blade based on the twice frequency component signal through a proportional-resonant controller or phase compensation.

[0022] Optionally, the second acquisition module includes: a superposition unit, used to algebraically superimpose the additional pitch angle command of each blade with the pitch reference command to obtain the target pitch command of each blade; and a control unit, used to send the target pitch command to the pitch actuator of each blade and control the pitch actuator to perform pitch action.

[0023] According to another aspect of the present invention, a wind turbine generator is also provided, wherein the wind turbine generator uses the differentiated vibration control method for wind turbine generators described in any of the preceding embodiments.

[0024] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein the program executes the differentiated vibration control method for wind turbines described in any of the preceding embodiments.

[0025] According to another aspect of the present invention, a processor is also provided, the processor being configured to run a program, wherein the program, when running, executes the differentiated vibration control method for wind turbine generators as described in any of the preceding embodiments.

[0026] According to another aspect of the present invention, a computer program product is also provided, including computer instructions that, when executed by a processor, perform the differentiated vibration control method for wind turbines described in any one of the above embodiments.

[0027] In this embodiment of the invention, wind speed data within a first height range in front of the wind turbine rotor is acquired. The wind speed data includes wind direction data and height data. The wind direction data includes longitudinal wind speed data, lateral wind speed data, and vertical wind speed data. The current wind condition type of the wind turbine is determined based on the longitudinal and vertical wind speed data. When the current wind condition type is a downburst, the position of the wind turbine relative to the downburst is determined based on the ratio of longitudinal to lateral wind speeds at the hub height, and a shutdown strategy corresponding to the position is executed. When the current wind condition type is a low-level jet stream, the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine is acquired. When the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated, and the additional pitch angle command is superimposed on the pitch reference command. The pitch control mechanism is driven to perform pitch control actions. By utilizing the characteristic differences between downbursts and low-level jets on the vertical wind profile and the positional judgment based on the longitudinal and transverse wind speed ratio at the hub height, a differentiated emergency shutdown strategy is implemented for downbursts. When the low-level jet triggers specific vibration conditions, an additional pitch control command based on the 2P frequency is generated for active load suppression. This achieves the goal of accurately distinguishing between the two extreme wind conditions and implementing targeted control. This maximizes power generation efficiency while ensuring the structural safety of the unit, and avoids malfunctions and excessive wear. Furthermore, it solves the technical problem in related technologies where it is difficult to accurately distinguish between low-level jets and downbursts because both exhibit nonlinear wind speed changes with height on the vertical wind profile and cause significant wind speed differences within the rotor surface. This makes it difficult to implement precise control strategies by simply relying on traditional wind measurement data. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0029] Figure 1 This is a hardware structure block diagram of a mobile terminal for a differentiated vibration control method for wind turbines according to an embodiment of the present invention.

[0030] Figure 2 This is a flowchart of a differentiated vibration control method for wind turbines according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of a laser wind-measuring radar and a nacelle acceleration sensor installed on the hub of a wind turbine according to an embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram of a differentiated vibration control method for wind turbines according to an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram comparing the spectrum of blade root flapping (My) under normal wind shear and abnormal vibration of blade root flapping (My) in low-altitude jet stream according to an embodiment of the present invention.

[0034] Figure 6 This is a schematic diagram of the entire wind measurement sample of the differentiated vibration control method for wind turbines according to an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of a low-altitude jet stream early warning sample of a differentiated vibration control method for wind turbines according to an embodiment of the present invention.

[0036] Figure 8 This is a schematic diagram of a sample requiring additional pitch angle control according to an embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of the effect of controlling the vibration acceleration in the nacelle in the forward and backward directions by superimposing an independent pitch angle based on 2P on the unified pitch according to an embodiment of the present invention.

[0038] Figure 10 This is a schematic diagram of the blade root My flapping load control effect based on the unified pitch of the present invention and the superposition of independent pitch based on 2P with additional pitch angle.

[0039] Figure 11 This is a schematic diagram comparing the blade root My flapping load spectrum analysis based on the unified pitch of the present invention and the additional pitch angle based on 2P independent pitch.

[0040] Figure 12 This is a schematic diagram of the effect of controlling the vibration acceleration in the fore-and-aft direction of the nacelle by superimposing an additional independent pitch angle based on 2P on the traditional independent pitch angle for 1P vibration according to an embodiment of the present invention.

[0041] Figure 13 This is a schematic diagram of the blade root My flapping load control effect based on the traditional independent pitch angle for 1P vibration superimposed on the independent pitch angle based on 2P according to an embodiment of the present invention.

[0042] Figure 14 This is a schematic diagram comparing the blade root My flapping load spectrum analysis based on the traditional independent pitch angle for 1P vibration superimposed on the independent pitch angle based on 2P according to an embodiment of the present invention.

[0043] Figure 15 This is a schematic diagram comparing the combined bending moment load at the tower base under the operating and shutdown states of the unit in the case of a downburst flow according to an embodiment of the present invention;

[0044] Figure 16This is a schematic diagram comparing the blade root combined bending moment load under the downburst flow condition of the unit in operation and shutdown states according to an embodiment of the present invention;

[0045] Figure 17 This is a schematic diagram of a differentiated vibration control device for a wind turbine according to an embodiment of the present invention.

[0046] The above figures include the following reference numerals:

[0047] 102. Processor; 104. Memory; 106. Transmission equipment; 108. Input / output equipment; 301. Wind turbine; 302. Nacelle acceleration sensor; 303. Laser wind measurement radar. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] From the perspective of hazard mechanism, low-level jets have three characteristics: jet height, jet intensity, and jet width. Only under certain specific combinations of these three structural characteristics can low-level jets trigger abnormal vibrations in the nacelle and periodic abrupt changes in blade root loads. This primarily causes fatigue accumulation damage to critical components such as blades and the tower through continuous 2P and 3P cyclic loads. The corresponding countermeasures should focus on active load suppression, i.e., adjusting the pitch angle of each blade through independent pitch control of the three blades to reduce unbalanced loads. Downbursts, on the other hand, manifest as sudden extreme loads. Their vertical downdraft component may cause instantaneous blade stall, while the horizontal divergence component may cause the tower to experience enormous bending moments. The countermeasures should prioritize emergency avoidance and immediate shutdown. If not located at the center of the downburst, yaw should be used to reduce the load on the unit from the wind, with structural safety as the primary objective. Therefore, differentiated control strategies are needed for low-level jets and downbursts, rather than a single control logic.

[0051] As described in the background section, related technologies suffer from drawbacks in identifying low-level jets and downbursts. Both exhibit nonlinear wind speed variations with height in the vertical wind profile, resulting in significant wind speed differences within the rotor surface. This makes it difficult to accurately distinguish them using traditional wind measurement data, thus hindering the implementation of precise control strategies. In this invention, a differentiated vibration control method and device for wind turbines, a wind turbine, a computer-readable storage medium, a processor, and a computer program product are provided in the embodiments.

[0052] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0053] The methods and embodiments provided in this invention can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a differentiated vibration control method for wind turbines according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0054] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the differentiated vibration control method for wind turbines in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the aforementioned method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one instance, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0055] According to an embodiment of the present invention, a method embodiment of a differentiated vibration control method for wind turbine generators is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0056] Figure 2 This is a flowchart of a differentiated vibration control method for wind turbines according to an embodiment of the present invention, such as... Figure 2 As shown, the method includes the following steps:

[0057] Step S202: Obtain wind speed data within a first height range in front of the wind turbine rotor. The wind speed data includes wind direction data and height data. The wind direction data includes longitudinal wind speed data, lateral wind speed data, and vertical wind speed data.

[0058] In this embodiment, by acquiring multi-dimensional wind speed data and corresponding height data within the first height range in front of the wind turbine rotor, the three-dimensional spatial characteristics of the wind field can be fully captured, especially the vertical distribution pattern of longitudinal wind speed and the vertical downdraft characteristics. This provides a key data foundation for accurately distinguishing between low-level jets and downbursts that have similar vertical wind shear characteristics but different physical mechanisms.

[0059] Low-level jet streams typically refer to strong winds occurring at low altitudes (usually below 1000 meters) that have vertical wind shear. Downbursts refer to strong downdrafts within thunderstorm clouds that impact the ground.

[0060] Figure 3 This is a schematic diagram of a laser wind-measuring radar and a nacelle acceleration sensor installed on the hub of a wind turbine according to an embodiment of the present invention. Figure 3 As shown, a nacelle acceleration sensor 302 and a laser wind-measuring radar 303 are installed on the hub of the wind turbine 301. The laser wind-measuring radar 303 is used to monitor wind speeds at different heights in front of the rotor, and the nacelle acceleration sensor 302 is used to monitor nacelle vibration acceleration. Figure 3 As shown, the nacelle acceleration sensor 302 is installed in the nacelle in the fore-and-aft direction to collect the fore-and-aft acceleration signal a. x The blade root bending moment sensors (not shown in the figure) are installed at the roots of the three blades respectively, using a full-bridge strain gauge array, to measure the flapping bending moment M at the blade root of each blade. y1 M y2 M y3 A lidar sensor, such as a pulsed or continuous wave type, is installed at the center height of the wind turbine hub to acquire wind speed components and height information at various heights in front of the turbine. The acquired height range should at least cover the entire height range of the turbine. The sensor scans forward from the hub to acquire the longitudinal wind speed *u*, lateral wind speed *v*, and vertical wind speed *w*, covering at least the entire height range of the turbine from bottom to top. The average value of the sampled data is calculated every 10 minutes to obtain the average value sequence *u*. i v i w i and corresponding height h i Where i = 1, 2, ..., n, the maximum crosswind speed u is determined. i The height h i and obtain a value higher than h i Minimum lateral wind speed u within the height range j This yields the sequence (u1, v1, w1, h1), (u2, v2, w2, h2), ..., (u n v n w n h n ), where h i Let be the height of the i-th measurement point.

[0061] It should be noted that the aforementioned lidar is installed at the wind turbine hub or on top of the nacelle, with preference given to installation at the hub. Compared to pulsed Doppler lidar, its scanning beam is directed in front of the rotor, and the scanning range covers at least one complete rotor height interval from bottom to top, for example, 0.5D below and 0.5D above the hub center, where D is the rotor diameter. This lidar is used to measure the three-dimensional wind speed profile in real time, including longitudinal wind speed u, lateral wind speed v, and vertical wind speed w, and outputs the average value sequence u at each height every 10 minutes. i , v i , w i and corresponding height h i .

[0062] Step S204: Determine the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data.

[0063] In this embodiment, by identifying vertical wind shear anomalies based on longitudinal wind speed data and combining the vertical wind speed data to determine whether the characteristics of a downburst are met, the essential difference between low-level jet streams and downbursts—which have similar longitudinal wind speed gradients but different vertical airflow characteristics on the vertical wind profile—can be utilized to accurately distinguish the current wind condition type, providing an accurate decision-making basis for subsequently implementing targeted differentiated control strategies.

[0064] Step S206: When the current wind condition is a downburst, determine the position of the wind turbine relative to the downburst based on the ratio of longitudinal to transverse wind speeds at the hub height of the wind turbine, and execute the shutdown strategy corresponding to the position.

[0065] In this embodiment, by using the ratio of longitudinal to transverse wind speeds at hub height to determine the relative position of the unit to the downburst center, it is possible to accurately identify whether the unit is in the downburst center or non-center area, and then execute differentiated shutdown strategies. This ensures the structural safety of the unit while minimizing the mechanical stress caused by unnecessary yaw movements, thereby improving the safety protection efficiency under downburst conditions.

[0066] Step S208: When the current wind condition is a low-altitude jet stream, acquire the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine. When it is determined that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, generate an additional pitch angle command and superimpose the additional pitch angle command with the pitch reference command to drive the pitch actuator to perform pitch action.

[0067] In this embodiment, by real-time monitoring of nacelle vibration acceleration and blade load spectrum characteristics under low-altitude jet flow conditions, and generating and superimposing additional pitch angle commands for twice the rotor rotation frequency when specific abnormal vibration triggering conditions are met, it is possible to actively suppress nacelle and tower 3P resonance and blade 2P periodic load mutation caused by low-altitude jet flow, effectively reduce fatigue damage and abnormal vibration amplitude of key components, avoid frequent unit shutdowns due to excessive vibration, and thus reduce power generation losses while ensuring safe unit operation.

[0068] As described above, in this embodiment of the invention, wind speed data within a first height range in front of the wind turbine rotor is acquired. This wind speed data includes wind direction data and height data. The wind direction data includes longitudinal wind speed data, lateral wind speed data, and vertical wind speed data. The current wind condition type of the wind turbine is determined based on the longitudinal and vertical wind speed data. When the current wind condition type is a downburst, the position of the wind turbine relative to the downburst is determined based on the ratio of longitudinal to lateral wind speeds at the hub height, and a shutdown strategy corresponding to the position is executed. When the current wind condition type is a low-level jet stream, the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine is acquired. This data is then used to determine the nacelle vibration acceleration or blade load spectrum characteristic data. When the load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated and superimposed with the pitch reference command to drive the pitch actuator to perform pitch action. By utilizing the characteristic differences between downburst and low-level jet on the vertical wind profile and the position judgment based on the longitudinal and transverse wind speed ratio at hub height, a differentiated emergency shutdown strategy is implemented for downburst. When the low-level jet triggers specific vibration conditions, an additional pitch command based on the 2P frequency is generated for active load suppression. This achieves the goal of accurately distinguishing between the two extreme wind conditions and implementing targeted control, thereby maximizing power generation efficiency while ensuring the structural safety of the unit and avoiding malfunctions and excessive wear.

[0069] The technical solutions provided by the embodiments of the present invention solve the technical problem in the related art of identifying low-level jet streams and downbursts. Since both exhibit nonlinear wind speed changes with height on the vertical wind profile and cause significant wind speed differences within the wind turbine surface, it is difficult to accurately distinguish them by simply relying on traditional wind measurement data, thus making it impossible to execute precise control strategies.

[0070] According to the above embodiments of the present invention, determining the current wind condition type of the wind turbine based on longitudinal wind speed data and vertical wind speed data includes: determining whether a vertical wind shear anomaly exists based on the longitudinal wind speed data sequence corresponding to the longitudinal wind speed data; determining whether the characteristic conditions of a downburst are met based on the vertical wind speed data; obtaining a judgment result; determining the current wind condition type as a downburst when the judgment result indicates that the vertical wind speed data meets the characteristic conditions of a downburst; and determining the current wind condition type as a low-level jet stream when the judgment result indicates that the vertical wind speed data does not meet the characteristic conditions of a downburst.

[0071] In this embodiment, by first identifying vertical wind shear anomalies based on longitudinal wind speed data sequences, and then using vertical wind speed data to determine whether there are strong downdraft characteristics, it is possible to accurately distinguish between the significant vertical negative wind speed component unique to downbursts and the horizontal airflow dominated by low-level jets, under the premise that both exhibit vertical wind shear anomalies. This provides an accurate basis for determining the wind condition type for subsequent implementation of differentiated shutdown or vibration reduction control strategies.

[0072] According to the above embodiments of the present invention, determining the existence of vertical wind shear variation based on the vertical wind speed data sequence corresponding to the vertical wind speed data includes: determining the maximum vertical wind speed in the vertical wind speed data sequence and determining the height at which the maximum vertical wind speed is located; obtaining the minimum vertical wind speed within a second height range above the height; and determining the existence of vertical wind shear variation when the difference between the maximum and minimum vertical wind speed is greater than or equal to a vertical wind speed difference threshold.

[0073] In this embodiment, by determining the maximum wind speed and its height in the longitudinal wind speed sequence, and calculating the minimum wind speed difference in the area above that height, the wind speed gradient change characteristics in the vertical direction in front of the wind turbine can be accurately quantified. Utilizing the significant vertical wind shear characteristics caused by the "nose-shaped" wind speed distribution that exists in both downbursts and low-level jets, the longitudinal wind speed difference is used as a preliminary screening criterion to effectively identify abnormal wind fields with extreme wind disturbances, providing a prerequisite for further distinguishing specific wind condition types by combining vertical wind speed.

[0074] Figure 4 This is a schematic diagram of a differentiated vibration control method for wind turbines according to an embodiment of the present invention, as shown below. Figure 4 As shown, u is collected by lidar. i and h i Sequence, determine the maximum longitudinal wind speed u i =max(u1, ..., u n ) and its height h i At a height greater than h i Within the range (i.e., the second altitude range), find the minimum longitudinal wind speed u. j =min{uk |h k h i}, calculate the difference Δu=u i -u j If u i -u j If the wind speed is ≥2 m / s (i.e., the longitudinal wind speed difference threshold), then wind pattern identification is performed to obtain w. i Sequence, determine the vertical wind speed w between any two consecutive sampled data points at all heights. i w j Are all values ​​less than -3 m / s when the vertical wind speeds at all heights are w1, ..., w n In the above, the vertical wind speed at any two different heights and at two consecutive sampling times satisfies w i <-3 m / s and w j If the wind speed is less than -3 m / s, it is determined to be a downburst; otherwise, it is determined to be a low-level jet stream, and the jet stream velocity u is output. i and the height of the jet stream h i It issues a low-altitude jet stream warning to alert maintenance personnel or upper-level systems.

[0075] According to the above embodiments of the present invention, when the current wind condition is a downburst, the position state of the wind turbine relative to the downburst is determined based on the ratio of the longitudinal and lateral wind speeds at the hub height of the wind turbine, including: obtaining the longitudinal wind speed and the lateral wind speed at the hub height; determining the ratio of the longitudinal wind speed to the lateral wind speed to obtain the longitudinal-lateral wind speed ratio; if the longitudinal-lateral wind speed ratio is within a preset ratio range, the position state is determined to be the center region of the downburst; if the longitudinal-lateral wind speed ratio is not within the preset ratio range, the position state is determined to be the non-center region of the downburst.

[0076] In this embodiment, by calculating the ratio of longitudinal wind speed to lateral wind speed at the hub height, the spatial position of the unit relative to the center of the downburst can be accurately determined by taking advantage of the difference in flow field characteristics between the radial divergence of the airflow in the central region of the downburst, the relatively balanced longitudinal and lateral wind speed components, and the strong directionality of the airflow in the non-central region. This provides a reliable spatial positioning basis for the subsequent implementation of targeted differentiated shutdown strategies, ensuring that the most appropriate safety protection measures are taken under extreme wind conditions.

[0077] like Figure 4 As shown, the identification of the relative position between the downburst center and the turbine unit involves determining whether the ratio of longitudinal to lateral wind speeds at the hub height is between 0.8 and 1.25, and determining the relative position between the downburst center and the turbine unit, while also receiving the longitudinal wind speed u at the hub height. hub With cross wind speed v hub Calculate the longitudinal wind speed u at the hub height. hub With cross wind speed v hubThe ratio, i.e., the longitudinal and lateral wind speed ratio, is used to determine whether this ratio satisfies 0.8 ≤ hub height wind speed u. hub / v hub ≤1.25. When Δu ≥ 2m / s and the vertical wind speed w of any two consecutively sampled data at all heights. i w j <-3m / s and 0.8≤u hub / v hub When ≤ 1.25 (i.e., the preset ratio range), the unit is located at the center of the downburst and an alarm is triggered; when Δu ≥ 2m / s and the vertical wind speed w of any two consecutive sampled data at all heights... i w j < -3m / s but u hub / v hub If the above ratio is not met, the unit will trigger a downburst alarm; when Δu ≥ 2m / s but any w exists i or w j When the speed is ≥ -3m / s, output a low-level jet stream warning and output the jet stream velocity u. i and the height of the jet stream h i .

[0078] Specifically, wind speed determination involves checking whether the difference between the maximum longitudinal wind speed at all heights and the minimum longitudinal wind speed at heights above it is ≥2 m / s, and the vertical wind speeds at all heights are w1, ..., w n Vertical wind speed w at any two consecutive sampling data points at any two heights i w j If all speeds are less than -3 m / s, a low-altitude jet stream warning or downburst alarm will be issued. The method for determining whether the unit is located in the center of the downburst is as follows: if the unit is currently in the center area of ​​the downburst, then execute rapid pitch recovery, i.e., the pitch recovery rate is 5° / s, and the unit will stop urgently without yaw; otherwise, execute rapid pitch recovery, i.e., the pitch recovery rate is 5° / s, and the unit will stop urgently and yaw to make the unit face the wind.

[0079] According to the above embodiments of the present invention, executing a shutdown strategy corresponding to the position state includes: when the position state is in the center of a downburst, executing a first shutdown strategy, wherein the first shutdown strategy is: controlling the pitch actuator of the wind turbine to perform a pitch-up operation at a preset pitch-up rate; when the position state is in the non-center of a downburst, executing a second shutdown strategy, wherein the second shutdown strategy is: controlling the pitch actuator to perform a pitch-up operation at a preset pitch-up rate, and controlling the pitch actuator to perform a yaw action.

[0080] In this embodiment, by implementing differentiated shutdown strategies based on the unit's position relative to the center or non-center of the downburst, namely, performing emergency pitch control shutdown only in the center region to avoid additional mechanical stress caused by yaw or loss of control during strong shear, while in the non-center region, combining emergency pitch control with active yaw to reduce asymmetric loads, optimal safety response measures can be taken for different risk levels, ensuring the structural safety of the unit under extreme strong winds, avoiding equipment wear caused by unnecessary yaw actions, and maximizing safety and equipment protection effectiveness.

[0081] Specifically, upon receiving an alarm signal from the wind condition type identification and alarm unit, if the position is in the center of a downburst, an emergency stop command is generated, and the propellers are immediately and rapidly retracted at a rate of 5° / s. An emergency stop is initiated without yaw, and yaw is prohibited. If the position is in the non-center of a downburst, an emergency stop command is generated, and the propellers are immediately and rapidly retracted at a rate of 5° / s. Simultaneously with the emergency stop, a yaw command is generated to yaw the unit to align with the wind, ensuring that the nacelle axis is aligned with the prevailing wind direction, thereby reducing asymmetric loads.

[0082] According to the above embodiments of the present invention, when it is determined that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering condition, an additional pitch angle command is generated, including: when the average value of the vibration peaks of the forward acceleration and backward acceleration in the nacelle vibration acceleration is greater than or equal to the vibration peak threshold, it is determined that the nacelle vibration acceleration meets the abnormal vibration triggering condition, and an additional pitch angle command is generated; spectrum analysis is performed on the blade load spectrum characteristic data, and when it is determined that the energy ratio of twice the vibration energy to one times the vibration energy of any blade is greater than or equal to the energy ratio threshold, it is determined that the blade load spectrum characteristic data meets the abnormal vibration triggering condition, and an additional pitch angle command is generated.

[0083] In this embodiment, by combining two monitoring indicators—the average time-domain peak value of nacelle vibration acceleration and the frequency-domain energy ratio of blade load spectrum—abnormal vibrations caused by low-altitude jets and sudden load changes at twice the rotor rotation frequency can be accurately captured from both macroscopic structural response and microscopic load characteristics. The dual triggering mechanism effectively avoids erroneous or missed actions caused by fluctuations in data from a single sensor, ensuring that additional pitch commands are generated only when the unit is confirmed to be under substantial abnormal vibration threat. This provides an accurate and reliable control triggering basis for subsequent targeted load suppression.

[0084] Figure 5 This is a schematic diagram comparing the spectrum of blade root flapping (My) under normal wind shear and abnormal vibration conditions of low-level jet stream according to an embodiment of the present invention. Figure 5 As shown, during normal operation or low-altitude jet stream warnings, the following three conditions are continuously monitored: 1) Forward and backward acceleration of the cabin. The average value of the vibration peak (positive peak value) within a 60-second time window. ≥0.08g (i.e., the vibration peak threshold), where g=9.8 m / s; 2) the flapping moment M at the root of the three-bladed blade within a 60-second time window. y1 M y2 M y3 Perform Fast Fourier Transform (FFT) on each blade to calculate the ratio E2 / E1 of the 2P frequency energy E2 to the 1P frequency energy E1, where 2P frequency... =2 × rotor rotation frequency. If the ratio E2 / E1 ≥ 0.8 for any blade, then the trigger condition is met; 3) A comparison of the spectrum diagrams of blade root flapping My under normal wind shear and low-level jet abnormal vibration conditions shows that the energy corresponding to the 2P frequency of the blade root flapping moment under severe low-level jet is significantly increased. When any of the above conditions are met, 2P frequency band load suppression pitch control is performed; otherwise, conventional pitch control continues.

[0085] It should be noted that 2P refers to twice the rotor rotation frequency, 1P refers to once the rotor rotation frequency, and the flapping moment refers to the flapping moment at the blade root. Alternatively, instead of using the FFT sliding window, an adaptive notch filter can be used to estimate the 1P and 2P energies in real time. Second-order notch filters with center frequencies of f1P and f2P are set respectively, and the real-time energy is calculated through the residual signal output by the filter. This method has a faster response and is suitable for rapidly changing wind conditions.

[0086] According to the above embodiments of the present invention, generating additional pitch angle commands includes: performing bandpass filtering on the blade root flapping moment or main shaft moment signal of the wind turbine with a center frequency of twice the wind turbine rotation frequency to extract the twice frequency component signal; and generating additional pitch angle commands for each blade based on the twice frequency component signal through a proportional-resonant controller or phase compensation.

[0087] In this embodiment, by bandpass filtering the blade root flapping moment or main shaft moment signal with a center frequency of twice the rotor rotation frequency, the specific 2P periodic vibration component caused by the low-altitude jet can be accurately extracted, eliminating background noise and other frequency interferences. Then, by utilizing the high gain characteristics of the proportional-resonant controller or the in-phase control principle of the phase compensation method, an independent pitch angle command that can effectively counteract the vibration of this specific frequency can be generated, thereby achieving active and precise suppression of abnormal vibrations of the nacelle and tower and sudden changes in blade load caused by the low-altitude jet.

[0088] Specifically, a sliding window peak detection is performed on the ax signal, and the average peak value over 60 seconds is calculated. For each blade root flapping moment signal or main shaft moment signal, a second-order bandpass filter with a center frequency of 2P is designed, with a passband width of ±10%×2P, to extract the 2P periodic load component. The passband width for the main shaft moment signal can be set to ±25%×2P. For the blade root flapping moment signal M of the three blades... y1 M y2 M y3 Or the principal shaft bending moment signal M shaft Performing at a center frequency of f 2P Bandpass filtering. When the load signal is the blade root flapping moment signal, a bandpass filter with a center frequency of 2p and a second- or fourth-order Butterworth design is used, with a passband width of [f]. 2P -0.1f 2P ,f 2P +0.1f 2P When the load signal is the main shaft bending moment signal, the passband width is [f]. 2P -0.25f 2P ,f 2P +0.25f 2P A fourth-order Chebyshev bandpass filter is used to suppress adjacent frequency interference. The additional pitch angle generation controller employs a proportional-resonant controller or a phase compensator; its input is the filtered 2P bending moment signal, and its output is the independent additional pitch angles Δβ1, Δβ2, and Δβ3 for each blade. The controller parameters are adjusted online according to the current operating conditions of the unit. The filtered signal is input to the proportional-resonant controller, whose transfer function is: ,in, For the Laplace operator, , The cutoff frequency is used to control the width of the resonant peak. , To control the proportional gain and resonant gain; , The gain is tuned using the root locus or Ziegler-Nichols method. The proportional-resonant controller provides high gain at the 2P frequency, effectively tracking and suppressing this frequency component. Alternatively, a phase compensation method can be used: the amplitude and phase of the filtered bending moment signal are calculated to generate an additional pitch angle in phase with the vibration velocity. ,in For adaptive gain, This refers to the filtered blade root flapping moment or main shaft moment. It also generates the additional pitch angle command θ for each blade. add,1 θ add,2 θ add,3 .

[0089] It should be noted that the proportional-resonant controller can also be replaced with optimal control based on the linear quadratic regulator (LQR). A state-space equation containing a 2P disturbance model can be established, the disturbance state can be estimated using a Kalman filter, and the feedback gain matrix can be designed through LQR to generate additional pitch commands. Theoretically, this scheme has better control performance, but it requires more computation and is suitable for large units with ample computing resources.

[0090] According to the above embodiments of the present invention, superimposing the additional pitch angle command with the pitch reference command to drive the pitch actuator to perform pitch action includes: algebraically superimposing the additional pitch angle command of each blade with the pitch reference command to obtain the target pitch command of each blade; sending the target pitch command to the pitch actuator of each blade to control the pitch actuator to perform pitch action.

[0091] In this embodiment, by algebraically superimposing the additional pitch angle command for vibrations at a specific frequency with the pitch reference command for maintaining normal unit operation, the independent pitch control function can be seamlessly embedded and executed without changing the basic power control or speed control logic of the unit. This ensures that the pitch actuator applies compensation actions to counteract 2P periodic loads while responding to conventional control requirements, thereby effectively reducing nacelle vibration and blade fatigue loads and ensuring the stable operation of the unit under complex wind conditions.

[0092] Specifically, it receives pitch reference command β from the main controller. base , will Δβ i (i.e., additional pitch angle command) and β base Superimposed to generate the target pitch command β for each blade. icmd = β base + Δβ i It receives the final pitch angle commands for each of the three blades and drives the blades to independently adjust the pitch. That is, the additional pitch angle of the power or speed control loop of the future autonomous control system will be superimposed with the pitch reference command at a value of θ. final,i =θ base,i +θ add,i Given i=1, 2, 3, the final pitch angle command for each blade is obtained and sent to the pitch actuator, such as an electric or hydraulic pitch system. The pitch actuator receives the pitch control command and drives the blades to the 90° limit position at a rate of 5° / s. The yaw drive mechanism receives the yaw alignment command and actively yaws to align the nacelle with the incoming flow direction. Afterwards, the lateral wind speed difference Δu = u is continuously monitored. i -u j : if u i -u jIf the wind speed is less than 2 m / s and the duration exceeds the set verification period, such as three consecutive 10-minute windows, it is determined that the extreme wind condition has subsided, the additional pitch overlay function is exited, and the output of the additional pitch angle generator controller, i.e., Δβ, is cleared. i Forced zeroing, the propeller angle superposition module is restored to β. icmd = β base That is, the blade pitch actuator only executes the pitch reference command, while clearing the low-altitude jet stream warning status, and the unit returns to normal operating mode. The pitch actuator only executes θ. base,i If the conditions are not met, or if the additional pitch control has been discontinued, only the baseline pitch control command is executed, and the unit operates in normal power generation or standby mode.

[0093] Furthermore, it should be noted that the above functions are integrated through the wind turbine main controller (Programmable Logic Controller, PLC). The main controller has a state machine inside, whose states include normal operation, low-altitude jet warning operation, downburst emergency shutdown, and downburst center emergency shutdown. It performs data refresh and command output at a rate of 20ms-100ms to meet real-time control requirements. Each module can be deployed inside the wind turbine main controller, or some functions (such as spectrum analysis and proportional-resonant controller) can be implemented through independent high-performance computing units (such as embedded digital signal processors or field-programmable gate arrays) and then communicate with the main controller. Specifically, the lidar first measures the wind profile data in real time, and the wind field characteristic monitoring and identification subsystem determines the current wind condition type. If it is not the center of a downburst or is the center of a downburst, the differentiated shutdown control subsystem is triggered to execute emergency shutdown with different strategies. If it is a low-level jet warning, the vibration monitoring and additional pitch control subsystem is activated to actively suppress 2P load when the vibration exceeds the limit. When the low-level jet weakens (Δu<2m / s), the control mode management and exit module automatically switches the system back to normal operation.

[0094] The differentiated vibration control method for wind turbines provided in this invention will be described in detail below with reference to specific embodiments. It mainly includes the following steps:

[0095] Step 1: Data Acquisition and Preprocessing

[0096] A lidar sensor (such as a pulsed or continuous wave type) is installed at the center height of the wind turbine hub. Scanning forward from the hub, it acquires the longitudinal wind speed *u*, lateral wind speed *v*, and vertical wind speed *w*, covering at least the entire height of the wind turbine from bottom to top. The average value of the sampled data is calculated every 10 minutes, resulting in the sequence: (u1, v1, w1, h1), (u2, v2, w2, h2), ..., (u... n v n w n h n), where h i Let be the height of the i-th measurement point.

[0097] Step 2: Initial assessment of low-level jet streams and downbursts:

[0098] Find the maximum longitudinal wind speed u i =max(u1, ..., u n ) and its height h i At a height greater than h i Within the range, find the minimum longitudinal wind speed u j =min{u k |h k h i}

[0099] If: u i -u j If the speed is ≥2 m / s, proceed to step 3.

[0100] Step 3: Wind pattern identification:

[0101] Vertical wind speeds w1, ..., w at all heights n In the above, the vertical wind speed at any two different heights and two consecutive sampling times satisfies: w i <-3 m / s and w j If the wind speed is less than -3 m / s, it is determined to be a downburst wind condition, and proceed to step 4; otherwise, proceed to step 7.

[0102] Step 4: Determine the relative position of the storm center and the generator set:

[0103] Calculate the longitudinal wind speed u at the hub height hub With cross wind speed v hub Does the ratio satisfy 0.8 ≤ hub height wind speed u? hub / v hub ≤1.25; if satisfied, proceed to step S5; if not satisfied, proceed to step S6;

[0104] Step S5: The unit is located at the center of the downburst and alarms. Immediately and quickly retract the propellers, i.e., retract the propellers at a rate of 5° / s, and shut down the unit in an emergency without yawing.

[0105] Step S6: When the unit encounters a downburst alarm, immediately and quickly retract the propellers, i.e., the retraction rate is 5° / s. At the same time as the emergency shutdown, perform a yaw action to bring the unit into the wind and reduce asymmetric load.

[0106] Step 7: Determine it as a low-altitude jet stream, and output the jet stream velocity u. i and the height of the jet stream h i The system issues a low-altitude jet stream warning, alerting maintenance personnel or upper-level systems, and proceeds to step 8 for judgment.

[0107] Step 8: Vibration and load monitoring triggers additional pitch control:

[0108] During normal operation or during a low-level jet stream warning, continuously monitor the following three conditions:

[0109] (1) Forward and backward acceleration of the cabin The average value of the vibration peak (positive peak value) within a 60-second time window. ≥0.08g, where g=9.8 m / s;

[0110] (2) The flapping moment M at the root of the three-bladed blade within a 60-second time window y1 M y2 M y3 Perform Fast Fourier Transform (FFT) separately to calculate the 2P frequency of each blade. =2 × wind turbine rotation frequency) energy E2 to 1P frequency energy E1, the ratio E2 / E1, if the ratio of any blade is ≥0.8, then the trigger condition is; comparison of the spectrum diagrams of blade root flapping My under normal wind shear and low-level jet flow abnormal vibration conditions, for example. Figure 5 As shown, the energy corresponding to the 2P frequency of the blade root flapping moment is significantly increased under severe low-altitude jet streams.

[0111] If any of the above conditions are met, proceed to step 9; otherwise, continue with conventional pitch control.

[0112] Step 9: 2P band load suppression pitch control:

[0113] (1) The flapping moment signal M at the root of the three blades y1 M y2 M y3 Or the principal shaft bending moment signal M shaft Performing at a center frequency of f 2P Bandpass filtering. When the load signal is the blade root flapping moment signal, a bandpass filter with a center frequency of 2p and a second- or fourth-order Butterworth design is used, with a passband width of [f]. 2P -0.1f 2P , f 2P +0.1f 2P When the load signal is the main shaft bending moment signal, the passband width is [f]. 2P -0.25f 2P ,f 2P +0.25f 2P A fourth-order Chebyshev bandpass filter is used to suppress interference at adjacent frequencies.

[0114] (2) The filtered signal is input into the proportional-resonant controller, whose transfer function is: ,in For the Laplace operator, , The cutoff frequency is used to control the width of the resonant peak. , To control the proportional gain and resonant gain; , The gain is tuned using the root locus or Ziegler-Nichols method. The proportional-resonant controller provides high gain at the 2P frequency, effectively tracking and suppressing this frequency component.

[0115] Alternatively, a phase compensation method can be used: the amplitude and phase of the filtered bending moment signal are calculated to generate an additional pitch angle that is in phase with the vibration velocity. ,in For adaptive gain, This refers to the leaf root flapping moment or main shaft moment after filtering.

[0116] (3) Generate additional pitch angle command θ for each blade add,1 θ add,2 θ add,3 .

[0117] Step 10: Instruction stacking and execution:

[0118] The additional pitch angle generated in step 9 is superimposed on the pitch reference command (from the power or speed control loop of the main control system): θ final,i =θ base,i +θ add,i i=1, 2, 3, obtain the final pitch angle command for each blade, and send it to the pitch actuator (such as an electric or hydraulic pitch system).

[0119] Step 11: Exit Conditions:

[0120] Continuously monitor the wind speed difference u in step 2 i -u j :

[0121] If u i -u j If the wind speed is less than 2 m / s, it is determined that the extreme wind condition has subsided, the additional pitch overlay function is deactivated, and the pitch actuator only executes θ. base,i If the conditions in step 2 are not met, or if the additional pitch control has been discontinued, only the baseline pitch control command is executed, and the unit operates in normal power generation or standby mode.

[0122] This embodiment is basically the same as the above embodiment, except that the spectrum analysis method in step S8 and the controller implementation method in step S9 (2) are different.

[0123] Alternative implementation of step S8: This embodiment does not use an FFT sliding window, but instead uses an adaptive notch filter to estimate the 1P and 2P energies in real time. Specifically, the center frequencies are set to f1 and f2 respectively. 1P and f 2P The second-order notch filter calculates real-time energy through the residual signal output by the filter, has a faster response, and is suitable for rapidly changing wind conditions.

[0124] Alternative implementation of step S9(2): In this embodiment, the proportional-resonant controller is replaced with optimal control based on linear quadratic (LQR). A state-space equation containing a 2P disturbance model is established, the disturbance state is estimated using a Kalman filter, and the feedback gain matrix is ​​designed using LQR to generate additional pitch commands. Theoretically, this scheme has better control performance, but requires more computation and is suitable for large-scale units with ample computing resources.

[0125] Furthermore, an embodiment of the present invention also provides a control system, comprising:

[0126] 1) Wind field characteristic monitoring and identification subsystem:

[0127] The lidar measurement unit is installed at the wind turbine hub or on top of the nacelle, with the hub being the optimal location. This is preferable to using a pulsed Doppler lidar. Its scanning beam is pointed in front of the rotor, and the scanning range covers at least one complete rotor height interval from bottom to top (e.g., 0.5D below and 0.5D above the hub center, where D is the rotor diameter). This unit is used to measure the three-dimensional wind speed profile in real time, including longitudinal wind speed u, lateral wind speed v, and vertical wind speed w, and outputs the average value sequence u at each height every 10 minutes. i , v i , w i and corresponding height h i , where i = 1, 2, ..., n.

[0128] Longitudinal wind speed gradient calculation module: Receives the u output from the lidar measurement unit. i and h i A sequence used to determine the maximum crosswind speed u i Location at height h i and obtain a value higher than h i Calculate the difference Δu = u, which is the minimum longitudinal wind speed u within the height range. i -u.

[0129] Vertical wind speed determination module: receives w i Sequence, determine the vertical wind speed w between any two consecutive sampled data points at all heights. i Are w all less than -3m / s?

[0130] Wind speed ratio calculation module: Receives the longitudinal wind speed u at the hub height.hub With cross wind speed v hub Calculate the ratio u hub / v hub And determine whether the ratio is within the range of 0.8-1.25.

[0131] Wind condition type identification and alarm unit:

[0132] When Δu ≥ 2m / s and the vertical wind speed w of any two consecutively sampled data at all heights i w < -3m / s and 0.8 ≤ u hub / v hub When ≤ 1.25, output "Unit is located at the center of downburst alarm";

[0133] When Δu ≥ 2m / s and the vertical wind speed w of any two consecutively sampled data at all heights i w < -3m / s but u hub / v hub If the above ratio is not met, output "Unit encountered downburst alarm";

[0134] When Δu ≥ 2m / s but there exists any w i When w ≥ -3m / s, output a low-altitude jet stream warning and output the jet stream velocity u. i and the height of the jet stream h i .

[0135] 2) Differentiated shutdown control subsystem:

[0136] Paddle retraction command generation unit: Receives alarm signals from the wind condition type identification and alarm unit.

[0137] If an alarm is received that "the unit is located in the center of the downburst", an emergency shutdown command is generated, the propeller recovery rate is set to 5° / s, and yaw action is prohibited.

[0138] If an alarm is received that the unit is encountering a downburst, an emergency shutdown command is generated, the propeller recovery rate is set to 5° / s, and a yaw command is generated to align the nacelle axis with the prevailing wind direction.

[0139] Pitch actuator: Receives the pitch control command and drives the blades to the 90° limit position at a rate of 5° / s.

[0140] Yaw drive mechanism: Receives yaw wind control commands and actively yawing to align the nacelle with the direction of the incoming flow.

[0141] 3) Vibration monitoring and additional pitch control subsystem:

[0142] The activation condition for this subsystem is: receiving a low-level jet stream warning and meeting any of the following conditions during continuous operation:

[0143] The average value of the vibration wave peaks in the forward and backward acceleration of the cabin over a 60-second period is ≥ 0.08g;

[0144] The three-bladed blade root flapping moment M within 60 seconds y Spectral analysis showed that the ratio of 2P vibration energy E2 to 1P vibration energy E1 of any blade, E2 / E1, was ≥0.8.

[0145] This subsystem specifically includes:

[0146] Accelerometer sensor: Installed in the fore-and-aft direction inside the cabin to collect acceleration signals a from the front and rear of the cabin. x .

[0147] Blade root moment sensors: Installed at the roots of three blades, using a full-bridge strain gauge array, to measure the flapping moment M at the blade root of each blade. y1 M y2 M y3 .

[0148] Signal processing unit:

[0149] For a x The signal undergoes sliding window peak detection, and the average peak value is calculated over 60 seconds.

[0150] For M y1 -M y3 The signal is subjected to FFT spectrum analysis to extract the energy of 1P and 2P frequency components and calculate their ratio.

[0151] Bandpass filter: For the flapping moment signal of each blade root or the main shaft bending moment signal, a second-order bandpass filter with a center frequency of 2P (i.e., twice the wind turbine rotation frequency) is designed. The passband width can be set to ±10%×2P to extract the 2P periodic load component; the passband width of the main shaft bending moment signal can be set to ±25%×2P.

[0152] Additional pitch angle generation controller: This controller employs a proportional-resonant controller or a phase compensator. Its input is a filtered 2P bending moment signal, and its output is an independent additional pitch angle Δβ1, Δβ2, and Δβ3 for each blade. The controller parameters are adjusted online according to the current operating conditions of the unit (rotor speed and pitch angle).

[0153] Pitch angle superposition module: Receives pitch reference command β from the main controller. base , will Δβ i With β base Superimposed to generate the final pitch angle command β for each blade. icmd = β base + Δβi .

[0154] Independent pitch actuator: It receives the final pitch angle command of each of the three blades and drives the blades to pitch independently.

[0155] 4) Control Mode Management and Exit Module:

[0156] This module continuously monitors the lateral wind speed difference Δu = u i -u. When Δu < 2m / s and the duration exceeds the set verification period (e.g., three consecutive 10-minute windows), the module outputs an exit signal:

[0157] Clear the output of the additional propeller angle generation controller (i.e., Δβ) i Forced reset);

[0158] The propeller angle superposition module is restored to β. icmd = β base That is, the blade pitch actuator only executes the pitch reference command;

[0159] At the same time, the low-altitude jet stream warning status was cleared, and the unit returned to normal operating mode.

[0160] 5) System integration and workflow:

[0161] The aforementioned subsystems are integrated through a wind turbine main controller (PLC). The main controller contains a state machine with states including: normal operation, low-altitude jet warning operation, downburst emergency shutdown, and downburst center emergency shutdown. Each subsystem module performs data refresh and command output at a rate of 20ms-100ms to meet real-time control requirements. The above is a system embodiment corresponding to the claims of this invention. It should be noted that the modules in this system embodiment can be deployed inside the wind turbine main controller, or some functions (such as spectrum analysis and PR controller) can be implemented through independent high-performance computing units (such as embedded DSPs or FPGAs) and then communicate with the main controller. Any system that uses the same or equivalent module division and signal flow implementation as this invention falls within the protection scope of this invention.

[0162] The above system workflow is as follows: The lidar measures wind profile data in real time, and the wind field characteristic monitoring and identification subsystem determines the current wind condition type; if it is not the center of a downburst or the center of a downburst, the differentiated shutdown control subsystem is triggered to execute emergency shutdown with different strategies; if it is a low-level jet warning, the vibration monitoring and additional pitch control subsystem is activated to actively suppress 2P load when the vibration exceeds the limit; when the low-level jet weakens (Δu < 2m / s), the control mode management and exit module automatically switches the system back to normal operation.

[0163] Taking a wind turbine unit with a rotor diameter of 292m and a hub height of 167m as an example, this embodiment is illustrated by collecting wind measurement data at heights of 40m, 60m, 90m, 120m, 145m, 149m, 167m, 170m, 205m, 240m, 270m, and 300m. Figure 6 This is a schematic diagram of the entire wind measurement sample of the differentiated vibration control method for wind turbines according to an embodiment of the present invention. Figure 7 This is a schematic diagram of a low-altitude jet stream early warning sample for a differentiated vibration control method for wind turbines according to an embodiment of the present invention. Figure 8 This is a schematic diagram of a sample requiring additional pitch angle control according to an embodiment of the present invention. The entire sample acquisition is as follows: Figure 6 As shown, where Δu≥2m / s, the sample output for the low-level jet stream warning is as follows. Figure 7 As shown, after vibration and load monitoring triggers additional pitch control, the sample that needs to have an additional pitch angle superimposed is determined as follows. Figure 8 As shown, this demonstrates that the present invention can accurately identify and precisely control low-altitude jet stream phenomena that cause abnormal vibrations in the unit.

[0164] Figure 9 This is a schematic diagram illustrating the effect of superimposed independent pitch angle based on 2P on the unified pitch control according to an embodiment of the present invention, on the vibration acceleration control effect in the fore-and-aft direction of the nacelle. Figure 10 This is a schematic diagram illustrating the blade root My flapping load control effect based on a unified pitch control system according to an embodiment of the present invention, superimposed with an independent pitch control system based on 2P. Figure 11 This is a schematic diagram comparing the blade root My flapping load spectrum analysis based on the unified pitch control according to an embodiment of the present invention, superimposed with an independent pitch control angle based on 2P. The diagram shows the pitch reference command for command superposition and execution. The reference command is a three-bladed unified pitch control, i.e., superimposed with an independent pitch control angle based on 2P on the unified pitch control. The effect of nacelle forward and backward vibration acceleration control is as follows: Figure 9 As shown, the control effect of the blade root My flapping load and the spectrum analysis are compared. Figure 10 and Figure 11 As shown, the forward and backward vibration acceleration of the nacelle was controlled at around 0.05g, and the flapping load of the blade root My was significantly reduced at the same time. In the spectrum analysis, its 2P vibration energy was significantly reduced.

[0165] Figure 12 This is a schematic diagram illustrating the effect of superimposing an additional independent pitch angle based on 2P on the conventional independent pitch angle for 1P vibration according to an embodiment of the present invention, on the control effect of nacelle fore-and-aft vibration acceleration. Figure 13This is a schematic diagram illustrating the blade root My flapping load control effect based on the conventional independent pitch angle for 1P vibration superimposed on the independent pitch angle based on 2P according to an embodiment of the present invention. Figure 14 This is a schematic diagram comparing the blade root My flapping load spectrum analysis based on the conventional independent pitch angle for 1P vibration superimposed with an additional independent pitch angle based on 2P, according to an embodiment of the present invention. Figure 15 This is a schematic diagram comparing the combined bending moment load at the tower base under the conditions of unit operation and shutdown in the event of a downburst flow, according to an embodiment of the present invention. Figure 16 This is a schematic diagram comparing the blade root combined bending moment load under downburst conditions in both operating and shutdown states according to an embodiment of the present invention. The pitch reference command in the command superposition and execution section differs. Traditional independent pitch control targets a single positive or negative wind shear, suppressing load imbalance caused by 1P. However, in low-altitude jet streams, both positive and negative wind shears exist simultaneously. The reference command is the traditional independent pitch angle targeting 1P vibration; that is, an additional independent pitch angle based on 2P is superimposed on the traditional independent pitch angle targeting 1P vibration. The control effect of nacelle fore-and-aft vibration acceleration is as follows: Figure 12 As shown, the control effect of the blade root My flapping load and the spectrum analysis are compared. Figure 13 , Figure 14 As shown, the fore-and-aft vibration acceleration of the nacelle was controlled at around 0.05g, and the blade root My flapping load was significantly reduced simultaneously. The spectral analysis also showed a significant decrease in its 2P vibration energy. This also indicates that the traditional independent pitch control strategy targeting 1P vibration has no effect on controlling abnormal fore-and-aft vibration of the nacelle and the 2P vibration energy in blade root My flapping. Under downburst conditions, the comparison of the tower top combined bending moment and blade root combined bending moment loads under unit operation and shutdown states is as follows: Figure 15 , Figure 16 As shown, therefore, in the case of a downburst.

[0166] As described above, in this embodiment of the invention, based on the common characteristic that both downbursts and low-level jets exhibit a "nose-shaped" longitudinal wind speed distribution on the vertical wind profile, the downburst is distinguished from the other by its additional characteristic of having a significant vertical velocity component. Given the suddenness of downbursts, which can easily trigger extreme instantaneous loads on the unit, leading to risks such as stall, blade contact with tower, or overturning, a rapid pitch retraction and emergency shutdown strategy is implemented for this wind condition. Specifically, the position of the unit relative to the downburst is determined based on the ratio of longitudinal to lateral wind speeds at hub height (0.8-1.25) to decide whether to perform yaw maneuvers. On the other hand, not all low-level jets will cause a significant increase in abnormal vibration and fatigue damage to the unit. Therefore, the identified low-level jets need to be further analyzed, and a three-bladed additional pitch angle strategy is only implemented when specific conditions are met. The judgment criteria include that the average value of the vibration peak of the nacelle's forward and backward acceleration within a 60-second time window is ≥0.08g, or that a spectral analysis of the blade root flapping load within a 60-second time window reveals that the ratio of vibration energy at twice the rotor rotation frequency (2P) to vibration energy at one times the rotor rotation frequency (1P) for any blade is ≥0.8. When the above vibration conditions are triggered, the additional pitch angle of the three blades is calculated using the following method: First, the blade root flapping moment or main shaft moment signal is bandpass filtered at a center frequency of 2P to extract specific frequency components. Then, based on the filtered signal, the additional pitch angle of each blade is generated through a proportional-resonant controller or a phase compensation method. Through the joint judgment of multi-dimensional characteristic parameters, accurate identification of downbursts and low-level jets is achieved, and differentiated control strategies are executed accordingly. This maximizes power generation efficiency while ensuring the safety of the unit, providing a wind turbine differentiated vibration control method and system that can distinguish between downbursts and low-level jets.

[0167] The technical solutions provided by the above embodiments of the present invention solve the following technical problems: 1) Integrating lidar wind measurement data with unit response characteristics to construct a multi-level, multi-dimensional wind condition identification system, wherein the lidar wind measurement data includes longitudinal, lateral, and vertical wind speeds, and the unit response characteristics include nacelle vibration acceleration peak value and blade root flapping load spectrum energy ratio; 2) Implementing differentiated control strategies based on the differences in hazards between the two types of wind conditions, focusing on active load suppression for low-altitude jet flow conditions and focusing on emergency avoidance control for downburst conditions. Depending on the unit's position relative to the downburst center, including the central or non-central area, different safety protection strategies are implemented. In the central area, the unit immediately shuts down without yaw, while in the non-central area, it immediately shuts down and yaws against the wind, in order to minimize the catastrophic risks such as blade contact with the tower and tower overturning caused by extreme loads; 3) Establishing an adaptive exit mechanism for the control strategy, setting wind condition dissipation judgment conditions, and allowing the unit to return to normal operating mode after the extreme wind conditions disappear, avoiding excessive wear and energy loss of the pitch system caused by long-term intervention of additional control.

[0168] Meanwhile, it has the following beneficial effects: 1) Accurate situation identification: By combining the vertical shear of longitudinal wind speed and the descending vertical airflow as a joint criterion, and combining the longitudinal / lateral wind speed ratio, it accurately distinguishes between low-level jet streams and downbursts, avoiding false alarms; 2) Differentiated response strategy: Different shutdown and yaw strategies are adopted for the center and non-center areas of downbursts to improve safety. Low-level jet streams only require warnings without shutting down the generator, reducing power generation losses; 3) Active load suppression: Based on the dual triggering of nacelle acceleration or 2P / 1P energy ratio, an additional pitch angle is generated using a proportional-resonant controller or phase compensation method to effectively suppress 2P periodic vibration and reduce abnormal vibration and fatigue load on the tower and blades; 4) Adaptive exit: The additional pitch control automatically exits after the wind speed returns to normal, avoiding unnecessary wear on the actuator pitch system; 5) Strong engineering compatibility: It reuses existing sensors of the unit, and the algorithm is lightweight, which can be easily embedded into mainstream pitch control systems; 6) Utilizing a 10-minute average wind speed and a 60-second load window, it balances stability and response speed.

[0169] In other words, the technical solution provided by the embodiments of the present invention comprehensively considers multiple factors, performs the superposition of three additional blade angles under the screening conditions of low-level jet streams, and establishes an adaptive exit mechanism for the control strategy. At the same time, it sets the wind condition dissipation judgment condition. When the extreme wind condition disappears, the unit returns to the normal operation mode, avoiding excessive wear and energy loss of the pitch system caused by long-term intervention of additional control, thus ensuring the maximization of power generation efficiency. After the downburst executes an emergency shutdown, compared with the operating state, the combined bending moment at the blade root and the combined bending moment at the tower bottom are significantly reduced, ensuring the safety of the unit. The problem of large-amplitude abnormal vibration of the nacelle and periodic sudden changes in blade root load under low-level jet stream conditions is significantly solved. Regardless of whether the independent pitch strategy for 1 times the rotor rotation frequency was activated before, the abnormal vibration control effect is very significant after superimposing the additional pitch angle for 2 times the rotor rotation frequency. It solves the problem of confusion between low-level jet streams and downbursts on the vertical wind profile, and the problem that the height, intensity, and width of low-level jet streams only cause abnormal vibration of the unit under certain specific combinations of conditions.

[0170] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0171] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0172] According to embodiments of the present invention, a differentiated vibration control device for a wind turbine for implementing the above-described differentiated vibration control method for wind turbines is also provided. Figure 17 This is a schematic diagram of a differentiated vibration control device for a wind turbine according to an embodiment of the present invention, such as... Figure 17 As shown, the device includes: a first acquisition module 1701, a first determination module 1703, a second determination module 1705, and a second acquisition module 1707. The differentiated vibration control device for this wind turbine will be described below.

[0173] The first acquisition module 1701 is used to acquire wind speed data within a first height range in front of the wind turbine rotor. The wind speed data includes wind direction data and height data. The wind direction data includes longitudinal wind speed data, lateral wind speed data and vertical wind speed data.

[0174] The first determining module 1703 is used to determine the current wind condition type of the wind turbine based on longitudinal wind speed data and vertical wind speed data.

[0175] The second determining module 1705 is used to determine the position state of the wind turbine relative to the downburst based on the ratio of longitudinal to transverse wind speeds at the hub height of the wind turbine when the current wind condition is a downburst, and to execute a shutdown strategy corresponding to the position state.

[0176] The second acquisition module 1707 is used to acquire the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine when the current wind condition is a low-altitude jet stream. When it is determined that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated and superimposed with the pitch reference command to drive the pitch actuator to perform pitch action.

[0177] It should be noted that the first acquisition module 1701, the first determination module 1703, the second determination module 1705 and the second acquisition module 1707 mentioned above correspond to steps S202 to S208 in the above embodiments. The four modules and the corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in the above embodiments.

[0178] As can be seen from the above, in the scheme described in the above embodiments of the present invention, firstly, the first acquisition module can be used to acquire wind speed data within a first height range in front of the wind turbine rotor, wherein the wind speed data includes wind direction data and height data, and the wind direction data includes longitudinal wind speed data, lateral wind speed data and vertical wind speed data; then, the first determination module can be used to determine the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data; secondly, when the current wind condition type is a downburst, the second determination module can be used to determine the position state of the wind turbine relative to the downburst based on the ratio of longitudinal to lateral wind speeds at the hub height of the wind turbine, and execute a shutdown strategy corresponding to the position state; finally, when the current wind condition type is a low-level jet stream, the second acquisition module can be used to acquire the nacelle vibration of the wind turbine. When the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated. This additional pitch angle command is then superimposed on the pitch reference command to drive the pitch actuator to perform pitch control. By utilizing the characteristic differences between downbursts and low-level jets on the vertical wind profile and the position judgment based on the longitudinal and transverse wind speed ratio at hub height, a differentiated emergency shutdown strategy is implemented for downbursts. When the low-level jet triggers specific vibration conditions, an additional pitch command based on the 2P frequency is generated for active load suppression. This achieves the goal of accurately distinguishing between the two extreme wind conditions and implementing targeted control, thereby maximizing power generation efficiency while ensuring the structural safety of the unit and avoiding malfunctions and excessive wear.

[0179] The technical solutions provided by the embodiments of the present invention solve the technical problem in the related art of identifying low-level jet streams and downbursts. Since both exhibit nonlinear wind speed changes with height on the vertical wind profile and cause significant wind speed differences within the wind turbine surface, it is difficult to accurately distinguish them by simply relying on traditional wind measurement data, thus making it impossible to execute precise control strategies.

[0180] In one optional embodiment, the first determining module includes: a judging unit, configured to determine whether the vertical wind shear anomaly is met based on the vertical wind speed data sequence corresponding to the vertical wind speed data, and obtain a judging result; a first determining unit, configured to determine the current wind condition type as a downburst when the judging result indicates that the vertical wind speed data meets the downburst characteristic conditions; and a second determining unit, configured to determine the current wind condition type as a low-level jet when the judging result indicates that the vertical wind speed data does not meet the downburst characteristic conditions.

[0181] In one optional embodiment, the determination unit includes: a first determining subunit, configured to determine the maximum longitudinal wind speed in the longitudinal wind speed data sequence and determine the height at which the maximum longitudinal wind speed is located; an acquiring subunit, configured to acquire the minimum longitudinal wind speed within a second height range above the height; and a second determining subunit, configured to determine that a vertical wind shear variation exists when the longitudinal wind speed difference between the maximum and minimum longitudinal wind speeds is greater than or equal to a longitudinal wind speed difference threshold.

[0182] In one optional embodiment, the second determining module includes: an acquisition unit for acquiring the longitudinal wind speed and the lateral wind speed at the hub height; a third determining unit for determining the wind speed ratio of the longitudinal wind speed to the lateral wind speed, thereby obtaining the longitudinal-lateral wind speed ratio; a fourth determining unit for determining the location state as the center region of a downburst if the longitudinal-lateral wind speed ratio is within a preset ratio range; and a fifth determining unit for determining the location state as a non-center region of a downburst if the longitudinal-lateral wind speed ratio is not within the preset ratio range.

[0183] In one optional embodiment, the second determining module includes: a first execution unit, configured to execute a first shutdown strategy when the position state is in the center of a downburst, wherein the first shutdown strategy is to control the pitch actuator of the wind turbine to perform a pitch-up operation at a preset pitch-up rate; and a second execution unit, configured to execute a second shutdown strategy when the position state is in the non-center of a downburst, wherein the second shutdown strategy is to control the pitch actuator to perform a pitch-up operation at a preset pitch-up rate and to control the pitch actuator to perform a yaw action.

[0184] In one optional embodiment, the second acquisition module includes: a sixth determining unit, configured to determine that the nacelle vibration acceleration meets the abnormal vibration triggering condition when the average value of the vibration peaks of the forward and backward accelerations in the nacelle vibration acceleration is greater than or equal to the vibration peak threshold, and generate an additional pitch angle command; and a seventh determining unit, configured to perform spectral analysis on the blade load spectral characteristic data, and determine that the blade load spectral characteristic data meets the abnormal vibration triggering condition when the energy ratio of twice the vibration energy to one times the vibration energy of any blade is greater than or equal to the energy ratio threshold, and generate an additional pitch angle command.

[0185] In one optional embodiment, the second acquisition module includes: a filtering unit, used to perform bandpass filtering on the blade root flapping moment or main shaft moment signal of the wind turbine with a center frequency of twice the wind turbine rotation frequency, so as to extract the twice frequency component signal; and a generation unit, used to generate additional pitch angle commands for each blade based on the twice frequency component signal through a proportional-resonant controller or phase compensation.

[0186] In one optional embodiment, the second acquisition module includes: a superposition unit, used to algebraically superimpose the additional pitch angle command of each blade with the pitch reference command to obtain the target pitch command of each blade; and a control unit, used to send the target pitch command to the pitch actuator of each blade and control the pitch actuator to perform the pitch action.

[0187] According to another aspect of the present invention, a wind turbine generator is also provided, wherein the wind turbine generator uses the differentiated vibration control method of any of the above-described wind turbine generators.

[0188] According to another aspect of the present invention, a processor is also provided, which is used to run a program, wherein the program executes the differentiated vibration control method for wind turbines described above.

[0189] According to another aspect of the present invention, a computer program product is also provided, including computer instructions, which, when executed by a processor, perform the differentiated vibration control method for a wind turbine generator described above.

[0190] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein the program executes the differentiated vibration control method for wind turbines described in any of the above embodiments.

[0191] Optionally, in this embodiment, the computer-readable storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any communication device in a group of communication devices.

[0192] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: acquiring wind speed data within a first height range in front of the wind turbine rotor, wherein the wind speed data includes wind direction data and height data, and the wind direction data includes longitudinal wind speed data, lateral wind speed data, and vertical wind speed data; determining the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data; when the current wind condition type is a downburst, determining the position state of the wind turbine relative to the downburst based on the ratio of longitudinal to lateral wind speeds at the hub height of the wind turbine, and executing a shutdown strategy corresponding to the position state; when the current wind condition type is a low-level jet stream, acquiring the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine, and when determining that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, generating an additional pitch angle command, and superimposing the additional pitch angle command with the pitch reference command to drive the pitch actuator to perform pitch action.

[0193] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: when a vertical wind shear anomaly is determined based on the vertical wind speed data sequence corresponding to the vertical wind speed data, whether the downburst characteristic conditions are met is determined based on the vertical wind speed data, and a judgment result is obtained; when the judgment result indicates that the vertical wind speed data meets the downburst characteristic conditions, the current wind condition type is determined to be: downburst; when the judgment result indicates that the vertical wind speed data does not meet the downburst characteristic conditions, the current wind condition type is determined to be: low-level jet stream.

[0194] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: determining the maximum longitudinal wind speed in the longitudinal wind speed data sequence and determining the height at which the maximum longitudinal wind speed is located; obtaining the minimum longitudinal wind speed within a second height range above the height; and determining that a vertical wind shear variation exists when the longitudinal wind speed difference between the maximum and minimum longitudinal wind speed is greater than or equal to a longitudinal wind speed difference threshold.

[0195] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: obtaining the longitudinal wind speed and the lateral wind speed at the hub height; determining the wind speed ratio of the longitudinal wind speed to the lateral wind speed to obtain the longitudinal-lateral wind speed ratio; if the longitudinal-lateral wind speed ratio is within a preset ratio range, then determining the location state as the center region of the downburst; if the longitudinal-lateral wind speed ratio is not within the preset ratio range, then determining the location state as the non-center region of the downburst.

[0196] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: when the position state is in the center of a downburst, executing a first shutdown strategy, wherein the first shutdown strategy is: controlling the pitch actuator of the wind turbine to perform a pitch-up operation at a preset pitch-up rate; when the position state is in the non-center of a downburst, executing a second shutdown strategy, wherein the second shutdown strategy is: controlling the pitch actuator to perform a pitch-up operation at a preset pitch-up rate, and controlling the pitch actuator to perform a yaw action.

[0197] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: when the average value of the vibration peaks of the forward and backward accelerations in the nacelle vibration acceleration is greater than or equal to the vibration peak threshold, determine that the nacelle vibration acceleration meets the abnormal vibration triggering condition, and generate an additional pitch angle command; perform spectral analysis on the blade load spectral characteristic data, and when it is determined that the energy ratio of twice the vibration energy to one vibration energy of any blade is greater than or equal to the energy ratio threshold, determine that the blade load spectral characteristic data meets the abnormal vibration triggering condition, and generate an additional pitch angle command.

[0198] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: performing bandpass filtering on the blade root flapping moment or main shaft moment signal of the wind turbine with a center frequency of twice the wind turbine rotation frequency to extract the twice frequency component signal; and generating additional pitch angle commands for each blade through a proportional-resonant controller or phase compensation based on the twice frequency component signal.

[0199] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: algebraically superimposing the additional pitch angle command of each blade with the pitch reference command to obtain the target pitch command of each blade; sending the target pitch command to the pitch actuator of each blade to control the pitch actuator to perform the pitch action.

[0200] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0201] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0202] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0203] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0204] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0205] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0206] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0207] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A differentiated vibration control method for wind turbine generators, characterized in that, include: The wind speed data within a first height range in front of the wind turbine rotor is obtained, wherein the wind speed data includes wind direction data and height data, and the wind direction data includes longitudinal wind speed data, lateral wind speed data and vertical wind speed data; The current wind condition type of the wind turbine is determined based on the longitudinal wind speed data and the vertical wind speed data; When the current wind condition is a downburst, the position of the wind turbine relative to the downburst is determined based on the ratio of longitudinal to transverse wind speeds at the hub height of the wind turbine, and a shutdown strategy corresponding to the position is executed. When the current wind condition is a low-level jet stream, the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine are acquired. When it is determined that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated and superimposed with the pitch reference command to drive the pitch actuator to perform pitch action.

2. The differentiated vibration control method for wind turbine generators according to claim 1, characterized in that, The current wind condition type of the wind turbine is determined based on the longitudinal wind speed data and the vertical wind speed data, including: When a vertical wind shear anomaly is determined based on the vertical wind speed data sequence corresponding to the vertical wind speed data, it is then determined whether the downburst characteristic conditions are met based on the vertical wind speed data, and the determination result is obtained. When the judgment result indicates that the vertical wind speed data meets the downburst characteristic conditions, the current wind condition type is determined to be the downburst; When the judgment result indicates that the vertical wind speed data does not meet the downburst characteristic conditions, the current wind condition type is determined to be the low-level jet stream.

3. The differentiated vibration control method for wind turbine generators according to claim 2, characterized in that, Based on the longitudinal wind speed data sequence corresponding to the aforementioned longitudinal wind speed data, it is determined that there is currently a vertical wind shear variation, including: Determine the maximum longitudinal wind speed in the longitudinal wind speed data sequence, and determine the height at which the maximum longitudinal wind speed is located; Obtain the minimum longitudinal wind speed within a second height range above the stated height; When the difference between the maximum and minimum longitudinal wind speeds is greater than or equal to a longitudinal wind speed difference threshold, it is determined that the vertical wind shear variation currently exists.

4. The differentiated vibration control method for wind turbine generators according to claim 1, characterized in that, When the current wind condition is a downburst, the position of the wind turbine relative to the downburst is determined based on the ratio of longitudinal to transverse wind speeds at the hub height of the wind turbine, including: The longitudinal wind speed and the lateral wind speed at the hub height are obtained. The ratio of the longitudinal wind speed to the transverse wind speed is determined to obtain the longitudinal-transverse wind speed ratio; If the longitudinal and transverse wind speed ratio is within a preset range, then the location state is determined to be the center region of a downburst. If the longitudinal and transverse wind speed ratio is not within the preset ratio range, then the location state is determined to be a non-central area of ​​a downburst.

5. The differentiated vibration control method for wind turbine generators according to claim 4, characterized in that, Execute the shutdown policy corresponding to the stated position state, including: When the position is in the center of the downburst, a first shutdown strategy is executed, wherein the first shutdown strategy is: controlling the pitch actuator of the wind turbine to perform a pitch-up operation at a preset pitch-up rate; When the position state is in the non-central area of ​​the downburst, a second shutdown strategy is executed, wherein the second shutdown strategy is to control the pitch actuator to perform a pitch recovery operation at the preset pitch recovery rate, and to control the pitch actuator to perform a yaw action.

6. The differentiated vibration control method for wind turbine generators according to claim 1, characterized in that, When the nacelle vibration acceleration or the blade load spectrum characteristic data is determined to meet the abnormal vibration triggering conditions, an additional pitch angle command is generated, including: When the average value of the forward and backward accelerations in the nacelle vibration acceleration is greater than or equal to the vibration peak threshold, the nacelle vibration acceleration is determined to meet the abnormal vibration triggering condition, and the additional pitch angle command is generated. Spectral analysis is performed on the blade load spectral characteristic data. When the energy ratio of twice the vibration energy to one time the vibration energy of any blade is greater than or equal to the energy ratio threshold, the blade load spectral characteristic data is determined to meet the abnormal vibration triggering condition, and the additional pitch angle command is generated.

7. The differentiated vibration control method for wind turbine generators according to claim 1, characterized in that, Generate additional pitch angle commands, including: The blade root flapping moment or main shaft bending moment signal of the wind turbine is subjected to bandpass filtering with a center frequency of twice the wind turbine rotation frequency to extract the twice frequency component signal. Based on the twice-frequency component signal, the additional pitch angle command for each blade is generated through a proportional-resonant controller or phase compensation.

8. The differentiated vibration control method for wind turbine units according to any one of claims 1 to 7, characterized in that, The additional pitch angle command is superimposed on the pitch reference command to drive the pitch actuator to perform pitching action, including: The additional pitch angle command for each blade is algebraically superimposed with the pitch reference command to obtain the target pitch command for each blade. The target pitch command is sent to the pitch actuator of each blade to control the pitch actuator to perform pitch control.

9. A differentiated vibration control device for wind turbine generators, characterized in that, include: The first acquisition module is used to acquire wind speed data within a first height range in front of the wind turbine rotor, wherein the wind speed data includes wind direction data and height data, and the wind direction data includes longitudinal wind speed data, lateral wind speed data and vertical wind speed data. The first determining module is used to determine the current wind condition type of the wind turbine based on the longitudinal wind speed data and the vertical wind speed data; The second determining module is used to determine the position state of the wind turbine relative to the downburst based on the longitudinal and transverse wind speed ratio at the hub height of the wind turbine when the current wind condition type is a downburst, and to execute a shutdown strategy corresponding to the position state. The second acquisition module is used to acquire the nacelle vibration acceleration or blade load spectrum characteristic data of the wind turbine when the current wind condition is a low-altitude jet stream. When it is determined that the nacelle vibration acceleration or blade load spectrum characteristic data meets the abnormal vibration triggering conditions, an additional pitch angle command is generated and the additional pitch angle command is superimposed with the pitch reference command to drive the pitch actuator to perform pitch action.

10. A wind turbine generator set, characterized in that, The wind turbine uses the differentiated vibration control method for wind turbines as described in any one of claims 1 to 8.

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