A floating type fan wind speed measuring method and a wind wheel equivalent wind speed calculating method

Abstract

This invention relates to the field of wind power generation technology, specifically to a method for measuring wind speed in a floating wind turbine and a method for calculating the equivalent wind speed of the wind turbine rotor. The method includes: constructing a spatial coordinate system based on the tower; obtaining the yaw angle of the wind turbine; obtaining the azimuth angle of the support column; determining the working radar based on the yaw angle of the wind turbine and the azimuth angle of the support column; obtaining the tilt compensation angle of the working radar and adjusting the scanning reference axis of the working radar based on the tilt compensation angle; obtaining the rotation compensation angle of each beam of the working radar and performing position correction on each beam based on the rotation compensation angle; and performing motion compensation on the original radial wind speed measured by the radar to obtain the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component. This method solves the problems of measurement blind spots, platform motion interference, and inaccurate calculation of the equivalent wind speed of the wind turbine rotor in existing floating wind turbine wind speed measurements.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, specifically to a method for measuring wind speed of a floating wind turbine and a method for calculating the equivalent wind speed of the wind turbine rotor. Background Technology

[0002] my country boasts abundant offshore wind energy resources, located close to load centers, making offshore wind power a key focus of my country's energy transformation. However, nearshore areas are limited by external factors such as shipping, fishing, and military operations, resulting in a finite amount of exploitable nearshore wind power resources. With recent development, exploitable nearshore wind power resources are nearly exhausted. my country's exploitable offshore wind power resources in waters deeper than 50 meters are approximately 4-5 times greater than those in waters shallower than 50 meters. In recent years, offshore wind power development has begun to move towards deeper waters. However, greater water depth brings challenges such as increased costs for fixed foundations and difficulties in wind turbine installation. Floating wind turbines can be installed in ports, and their economic viability increases with water depth. Therefore, floating wind power technology has become an important development direction for future deep-sea wind power development.

[0003] Floating wind turbines are used in deep-sea areas, and due to cost considerations, ultra-large wind turbine units are often adopted. Ultra-large wind turbine units have large rotor diameters, and during operation, wind shear effects cause significant differences in wind speed at different altitudes, resulting in significant aerodynamic imbalances throughout the rotor. This places cyclic loads on key components such as the turbine blades, affecting their fatigue life. It also impacts the floating body motion and stability control of the floating wind turbine. Furthermore, the increased rotor surface area causes a significant difference between the wind speed at the hub center height and the equivalent wind speed of the rotor, thus affecting the accuracy of power control and power characteristic testing and evaluation. Therefore, measuring the wind speed across the entire rotor plane is crucial for unloading floating wind turbine components, controlling floating body stability, and tracking and evaluating power performance.

[0004] Currently, offshore wind turbine wind measurement typically uses mechanical or ultrasonic wind measurement equipment mounted on the top of the nacelle. The measured wind speed can only represent the wind speed at a height near the center of the hub. However, methods such as setting up wind measurement towers or using buoy lidar for wind measurement have problems such as high investment and maintenance costs for wind measurement equipment and the risk of buoys capsizing in complex and harsh sea areas. Summary of the Invention

[0005] To address the problems of measurement blind spots, platform motion interference, and inaccurate calculation of the equivalent wind speed of the impeller in existing floating wind turbine wind speed measurements, this invention proposes a method for measuring the wind speed of a floating wind turbine and a method for calculating the equivalent wind speed of the impeller.

[0006] In a first aspect of the present invention, a method for measuring the wind speed of a floating fan is provided, comprising:

[0007] Step 100. Construct a spatial coordinate system based on the tower;

[0008] Step 200. The fan is aligned with the wind to obtain the fan's yaw angle;

[0009] Step 300. Obtain the azimuth of the column;

[0010] Step 400. Determine the working radar based on the yaw angle of the wind turbine and the azimuth angle of the column, obtain the tilt compensation angle of the working radar, and adjust the scanning reference axis of the working radar based on the tilt compensation angle.

[0011] Step 500. Obtain the rotation compensation angle of each beam of the working radar and perform position correction on each beam based on the rotation compensation angle. Perform motion compensation on the original radial wind speed measured by the radar to obtain the eastward horizontal wind speed component, the northward horizontal wind speed component and the vertical wind speed component.

[0012] Step 600. Obtain a wind speed model based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, and obtain the wind speed at the required location based on the wind speed model.

[0013] In a preferred embodiment of the present invention, step 400, determining the working radar based on the yaw angle of the wind turbine and the azimuth angle of the column, specifically includes:

[0014] Step 410. Calculate the cosine value based on the yaw angle of the wind turbine and the azimuth angle of the column; determine whether the cosine value is greater than 0. When there is only one cosine value greater than 0, determine the lidar corresponding to the cosine value greater than 0 as the working lidar.

[0015] Step 420. When there is not only one cosine value greater than 0, calculate the radius comparison distance based on the cosine value greater than 0; determine whether the radius comparison distance is greater than the minimum distance threshold. When the radius comparison distance is greater than the minimum distance threshold, determine the lidar corresponding to the radius comparison distance greater than the minimum distance threshold as the working lidar.

[0016] In a preferred embodiment of the present invention, step 400, which involves obtaining the tilt compensation angle of the working radar and adjusting the scanning reference axis of the working radar based on the tilt compensation angle, specifically includes:

[0017] Step 440. Based on the formula The tilt compensation angle of the working radar is calculated, where For tilt compensation angle, This represents the minimum horizontal distance from the nearest radar measurement point to the wind turbine surface. For wheel hub height, Radar installation height;

[0018] Step 450. Based on the tilt compensation angle, adjust the scanning reference axis of the working radar from the vertical direction to tilt upstream of the wind turbine.

[0019] In a preferred embodiment of the present invention, step 500, which involves obtaining the rotation compensation angle of each beam of the working radar and performing position correction on each beam based on the rotation compensation angle, specifically includes:

[0020] Step 510. Obtain the beam rotation compensation angle of the working radar based on the following formula, and perform beam position correction based on the beam rotation compensation angle:

[0021] ;

[0022] in, The unit vector is obtained based on the radar centerline. This represents the projection component of the tilting intermediate vector onto the plane perpendicular to the central axis. Let be the projection component of the target vector onto the plane perpendicular to the central axis. This is the rotation compensation angle.

[0023] In a preferred embodiment of the present invention, in step 500, the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component are obtained using the following formulas:

[0024] ;

[0025] in, This represents the horizontal wind speed component heading due east. This represents the horizontal wind speed component from due north. This represents the vertical wind speed component. The angle between the eastward beam and the vertical direction. The angle between the north-facing beam and the vertical direction. The angle between the westward beam and the vertical direction. The angle between the south-facing beam and the vertical direction. This is the corrected eastward radial wind speed. This is the corrected northward radial wind speed. This is the corrected westward radial wind speed. This is the corrected southward radial wind speed.

[0026] As a preferred embodiment of the present invention, the angles between the east-facing beam, north-facing beam, west-facing beam, and south-facing beam and the vertical direction are obtained using the following formula:

[0027] ;

[0028] in, This represents the projection component of the eastward beam onto the z-axis. This represents the projection component of the northbound beam onto the z-axis. This represents the projection component of the westward beam onto the z-axis. This represents the projection component of the southbound beam onto the z-axis.

[0029] In a preferred embodiment of the present invention, step 600, which involves obtaining the wind speed model based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, specifically includes:

[0030] Step 610. Adjust the tilt compensation angle. Based on the adjusted tilt compensation angle, obtain the measurement height and measurement horizontal distance. Based on the adjusted tilt compensation angle, calculate the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component. Based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, calculate a corresponding wind speed. Combine the measurement height, measurement horizontal distance, and wind speed as a model construction data set. Repeat step 610 to obtain the required number of model construction data sets.

[0031] Step 620. Construct a wind speed model based on the model-built data set.

[0032] As a preferred embodiment of the present invention, step 620, which involves constructing a wind speed model based on the model construction data set, specifically includes:

[0033] Step 621. Based on the model, construct the data set and obtain the vertical model parameters using the following formula:

[0034] ;

[0035] in, To measure the height is Wind speed at the location, The coefficient of friction, Kalman constant, The length of the surface roughness. This is the atmospheric stability correction function. For atmospheric stratification stability;

[0036] The vertical model parameters include the friction coefficient, surface roughness length, and atmospheric stratification stability.

[0037] Step 622. Construct a dataset based on the model and obtain the horizontal model parameters using the following formula:

[0038] ;

[0039] in, This refers to the horizontal wind shear index. To measure the horizontal distance Wind speed at the location, To measure the horizontal distance Wind speed at the location;

[0040] The horizontal model parameters include the horizontal wind shear index;

[0041] Step 623. Substitute the obtained vertical and horizontal model parameters into the following formula to obtain the wind speed model:

[0042] ;

[0043] in, To measure the height is And the measured horizontal distance is Wind speed at the location, The coefficient of friction, Kalman constant, The length of the surface roughness. For atmospheric stratification stability, For reference horizontal distance, It represents the horizontal wind shear index.

[0044] In a second aspect of the present invention, a method for calculating the equivalent wind speed of a wind turbine is provided, employing the wind speed measurement method of the first aspect. The method for calculating the equivalent wind speed of a wind turbine includes:

[0045] Step 710. Divide the wind turbine swept surface into multiple local blocks;

[0046] Step 720. Calculate the local wind speed corresponding to each local block:

[0047] Step 730. Calculate the equivalent wind speed of the wind turbine based on the local wind speed of all local blocks.

[0048] In summary, the present invention has the following beneficial effects:

[0049] By establishing a spatial coordinate system and calculating the geometric relationship between the yaw angle and the column azimuth in real time, an innovative radar dynamic selection strategy based on free-flow wind sector is proposed. This strategy automatically selects radar combinations and activates radars by judging the relationship between the yaw angle and the azimuth of each column, so as to reduce the interference of the wind turbine itself on the measurement, and optimize the system energy consumption and radar working life while ensuring data quality.

[0050] By deeply coupling the motion monitoring data of the floating wind turbine platform with the lidar measurement, a motion speed compensation mathematical model was established. This accurately separated the velocity coupling component introduced by the platform motion in the radial direction of the lidar, fundamentally solving the problem of wind speed measurement distortion caused by the continuous motion of the floating wind turbine.

[0051] The Monin-Obukhov similarity theory model based on atmospheric boundary layer physics is used for wind profile inversion and extrapolation. By fitting key atmospheric parameters, this model can accurately describe the vertical and horizontal distribution of wind speed under different stability conditions, and realize the reliable reconstruction and prediction of the wind field of the complete wind turbine swept surface and the incoming flow region.

[0052] When calculating the equivalent wind speed of the wind turbine, a weighting coefficient based on aerodynamic characteristics is introduced. By discretizing the integration, the three-dimensional spatially distributed wind field is equivalent to a single wind speed value with high fidelity. This can most realistically reflect the total aerodynamic load and energy capture potential acting on the entire wind turbine, providing accurate input for wind turbine control and performance evaluation.

[0053] Further or more detailed beneficial effects will be described in conjunction with specific embodiments in the detailed implementation. Attached Figure Description

[0054] Figure 1 A schematic diagram of the northward rotation compensation angle of the northward beam of the working radar is shown in an embodiment of the present invention.

[0055] Figure 2 A schematic diagram illustrating the acquisition of measured height and measured horizontal distance is shown in an embodiment of the present invention;

[0056] Figure 3 This diagram illustrates how the wind turbine sweep surface is divided into multiple local blocks in an embodiment of the present invention. Detailed Implementation

[0057] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0058] In the description of embodiments of the present invention, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0059] This invention provides a method for measuring the wind speed of a floating wind turbine. The wind speed measurement is based on a wind measurement system, which includes: a central column, a first column, a second column, and a third column arranged around the central column, a first lidar mounted on the top of the first column, a second lidar mounted on the top of the second column, a third lidar mounted on the top of the third column, a tower mounted on the top of the central column, a wind turbine mounted on the top of the tower, and an industrial control computer mounted at the bottom of the tower and communicatively connected to the first lidar, the second lidar, the third lidar, and the wind turbine.

[0060] In this embodiment, the first, second, and third lidars are all base-mounted lidars. These base-mounted lidars are equipped with servo mechanisms that control the adjustment of the lidar's pitch angle and the rotation of the lasers within the lidar around its central axis. An industrial control computer is located at the bottom of the tower, receiving operating status signals from the wind turbine and attitude signals from the floating body, and is responsible for the communication and control of the lidars. In this embodiment, each lidar contains four lasers, which are optically switched lasers.

[0061] Wind speed measurement methods include:

[0062] Step 100. Construct a spatial coordinate system based on the tower. Specifically, take the intersection of the tower centerline and the bottom flange surface of the tower as the origin to establish a spatial coordinate system. The x-axis is due east, the y-axis is due north, and the z-axis is the axis perpendicular to the x and y axes.

[0063] Step 200. The wind turbine is aligned with the wind to obtain its yaw angle. In this embodiment, the wind direction is the direction from which the wind is blowing, measured by the wind vane on the top of the nacelle; the yaw angle is the actual azimuth angle of the wind turbine nacelle (measured by a yaw encoder / sensor installed at the connection between the tower and the nacelle). This embodiment assumes that after the wind turbine is aligned with the wind, the nacelle is completely facing the wind, at which point the yaw angle and wind direction are perfectly matched. When the wind turbine is facing due north, its yaw angle is 0°; when the wind turbine is facing due east, its yaw angle is 90°; when the wind turbine is facing due south, its yaw angle is 180°; and when the wind turbine is facing due west, its yaw angle is 270°.

[0064] Step 300. Obtain the azimuth angle 1 of the first pillar, the azimuth angle 2 of the second pillar, and the azimuth angle 3 of the third pillar, wherein azimuth angle 2 is 120° greater than azimuth angle 3, and azimuth angle 3 is 120° greater than azimuth angle 2. In this embodiment, the azimuth angle 1 of the first pillar, the azimuth angle 2 of the second pillar, and the azimuth angle 3 of the third pillar can be obtained directly by a satellite positioning system; alternatively, the azimuth angle 1 of the first pillar, the azimuth angle 2 of the second pillar, and the azimuth angle 3 of the third pillar can be obtained by inertial navigation and gyroscope measurement.

[0065] Step 400. Based on the yaw angle of the wind turbine and the azimuth angles of the first column, the second column, and the third column, determine the working radar from the first lidar, the second lidar, and the third lidar, obtain the tilt compensation angle of the working radar, and adjust the scanning reference axis of the working radar based on the tilt compensation angle.

[0066] In step 400 of this embodiment, determining the working radar from the first lidar, the second lidar, and the third lidar specifically includes:

[0067] Step 410. Based on the formula The first cosine value, the second cosine value, and the third cosine value are calculated, where Yaw angle for or or , For azimuth angle 1, For azimuth angle two, For azimuth angle 3; determine whether the first cosine value, second cosine value, and third cosine value are greater than 0. When only the first cosine value, second cosine value, or third cosine value is greater than 0, the first laser radar corresponding to the first cosine value greater than 0, the second laser radar corresponding to the second cosine value greater than 0, or the third laser radar corresponding to the third cosine value greater than 0 is identified as the working radar.

[0068] In this embodiment, we assume a yaw angle of 30°, azimuth angle 1 is 0° (corresponding to the first lidar), azimuth angle 2 is 120° (corresponding to the second lidar), and azimuth angle 3 is 240° (corresponding to the third lidar). Therefore, the first cosine value (corresponding to the first lidar) is 0.866, the second cosine value (corresponding to the second lidar) is 0, and the third cosine value (corresponding to the third lidar) is -0.866. Since only the first cosine value is greater than 0, the first lidar is determined to be the working lidar.

[0069] In this embodiment, we further assume a yaw angle of 50°, azimuth angle 1 is 0° (corresponding to the first lidar), azimuth angle 2 is 120° (corresponding to the second lidar), and azimuth angle 3 is 240° (corresponding to the third lidar). Then, the first cosine value (corresponding to the first lidar) is 0.643, the second cosine value (corresponding to the second lidar) is 0.342, and the third cosine value (corresponding to the third lidar) is -0.985. Since both the first and second cosine values ​​are greater than 0, we proceed to step 420.

[0070] Step 420. When there is not only a first cosine value, a second cosine value, or a third cosine value greater than 0, based on the formula... The distances 1 and 2 are calculated, where For radius comparison distance one or radius comparison distance two, The distance from the center of the column to the center of the tower. The radius of rotation of the wind turbine. for or , It is a cosine value greater than 0. The value is a cosine value greater than 0. It is determined whether the radius comparison distance one is greater than the minimum distance threshold. When the radius comparison distance one is greater than the minimum distance threshold, the first, second, or third lidar corresponding to the radius comparison distance one is identified as the working lidar. At the same time, it is determined whether the radius comparison distance two is greater than the minimum distance threshold. When the radius comparison distance two is greater than the minimum distance threshold, the first, second, or third lidar corresponding to the radius comparison distance two is identified as the working lidar.

[0071] In this embodiment, it is assumed that It is 100m. It is 20m. It is 0.643 (corresponding to the first cosine value). The value is 0.342 (corresponding to the second cosine value). The final calculated radius comparison distance is 43.3m for the first distance and 14.2m for the second distance. In this embodiment, we further assume a minimum distance threshold of 15m. Because the radius comparison distance one (corresponding to the first cosine value) is greater than the minimum distance threshold, the first lidar is determined to be the working lidar. Because the radius comparison distance two (corresponding to the second cosine value) is less than the minimum distance threshold, the second lidar is not determined to be the working lidar.

[0072] In step 400 of this embodiment, obtaining the tilt compensation angle of the working radar and adjusting the scanning reference axis of the working radar based on the tilt compensation angle specifically includes:

[0073] Step 440. Based on the formula The tilt compensation angle of the working radar is calculated, where For tilt compensation angle, This represents the minimum horizontal distance from the nearest radar measurement point to the wind turbine surface. For wheel hub height, The installation height for the radar.

[0074] This embodiment assumes that the working radar is only the first lidar, so this step directly obtains the tilt compensation angle of the first lidar through the formula in step 440.

[0075] Step 450. Based on the tilt compensation angle, adjust the scanning reference axis of the working radar from the vertical direction to tilt upstream of the wind turbine.

[0076] To minimize the impact of the platform wake on the measurement results, this embodiment will trigger the ranging compensation mode, which controls the working radar to adjust its scanning reference axis from the vertical direction to an upstream tilt compensation angle towards the wind turbine. This tilt causes the nearest measurement point of the radar scanning cone to move upstream of the wind turbine, thereby ensuring that the horizontal distance from the nearest measurement point to the wind turbine surface meets the requirements.

[0077] Step 500. Obtain the rotation compensation angle of each beam of the working radar and perform position correction on each beam based on the rotation compensation angle. Introduce the three-dimensional motion velocity vector of the floating platform to perform motion compensation on the original radial wind speed measured by the radar to obtain the eastward horizontal wind speed component, the northward horizontal wind speed component and the vertical wind speed component.

[0078] The operating radar has four beams. Before tilting, each shock beam has a fixed exit angle relative to the radar's scanning reference axis (i.e., the radar's central axis). The projections of each beam onto the horizontal plane point to the four directions of due north, due east, due south, and due west.

[0079] After the scanning reference axis of the working radar is tilted, the servo mechanism drives the entire working radar to tilt. At this time, the angle between the radar's scanning reference axis and the vertical direction is... Furthermore, the azimuth angle of the radar's scanning reference axis projected onto the horizontal plane is the same as the yaw angle of the wind turbine. Maintain consistency.

[0080] In step 500 of this embodiment, obtaining the rotation compensation angle of each beam of the working radar and performing position correction on each beam based on the rotation compensation angle specifically includes:

[0081] Step 510. Obtain the beam rotation compensation angle of the working radar based on the following formula, and perform beam position correction based on the beam rotation compensation angle:

[0082] ;

[0083] ;

[0084] ;

[0085] ;

[0086] in, For tilt compensation angle, Yaw angle The unit vector is obtained based on the radar centerline. The beam's exit angle relative to the radar's central axis. The intermediate vector of the follower tilt is obtained based on the beam without rotation compensation. The target vector is obtained based on the beam after rotation compensation. This represents the projection component of the tilting intermediate vector onto the plane perpendicular to the central axis. Let be the projection component of the target vector onto the plane perpendicular to the central axis. This is the rotation compensation angle.

[0087] Step 510 specifically includes obtaining the northward rotation compensation angle of the northward beam of the working radar based on the following formula, and performing position correction on the northward beam based on the northward rotation compensation angle, combined with... Figure 1 understand:

[0088] ;

[0089] ;

[0090] ;

[0091] ;

[0092] in, For tilt compensation angle, Yaw angle The unit vector is obtained based on the radar centerline. The emission angle of the north-facing beam relative to the radar's central axis. The northward servo tilt intermediate vector is obtained based on the northward beam without rotation compensation. The northward target vector is obtained based on the northward beam after rotation compensation. This represents the projection component of the northward-following tilted intermediate vector onto the plane perpendicular to the central axis. This represents the projection component of the northward target vector onto the plane perpendicular to the central axis. This is the northward rotation compensation angle. Once the northward rotation compensation angle is obtained, the internal servo mechanism of the lidar will drive the northward beam to rotate relative to the central axis of the lidar to complete the position correction. Figure 1 The dashed circle in the diagram represents the trajectory of the laser beam rotating around the central axis.

[0093] The eastward rotation compensation angle of the working radar's eastward beam is obtained based on the following formula, and the position of the eastward beam is corrected based on the eastward rotation compensation angle:

[0094] ;

[0095] ;

[0096] ;

[0097] ;

[0098] in, For tilt compensation angle, Yaw angle The unit vector is obtained based on the radar centerline. The emission angle of the eastward beam relative to the radar's central axis. The eastward servo tilt intermediate vector is obtained based on the eastward beam without rotation compensation. The eastward target vector is obtained based on the eastward beam after rotation compensation. This represents the projection component of the eastward-moving, tilting intermediate vector onto the plane perpendicular to the central axis. This represents the projection component of the eastward target vector onto the plane perpendicular to the central axis. This is the eastward rotation compensation angle. Once the eastward rotation compensation angle is obtained, the internal servo mechanism of the lidar will drive the eastward beam to rotate relative to the central axis of the lidar to complete the position correction.

[0099] The southward rotation compensation angle of the working radar's southward beam is obtained based on the following formula, and the position of the southward beam is corrected based on the southward rotation compensation angle:

[0100] ;

[0101] ;

[0102] ;

[0103] ;

[0104] in, For tilt compensation angle, Yaw angle The unit vector is obtained based on the radar centerline. This represents the exit angle of the south-facing beam relative to the radar's central axis. The southward servo tilt intermediate vector is obtained based on the southward beam without rotation compensation. The target vector for the south is obtained based on the south-facing beam after rotation compensation. This represents the projection component of the southward-following tilting intermediate vector onto the plane perpendicular to the central axis. This represents the projection component of the southward target vector onto the plane perpendicular to the central axis. This is the southward rotation compensation angle. Once the southward rotation compensation angle is obtained, the internal servo mechanism of the lidar will drive the southward beam to rotate relative to the central axis of the lidar to complete the position correction.

[0105] The westward rotation compensation angle of the working radar's westward beam is obtained based on the following formula, and the position of the westward beam is corrected based on the westward rotation compensation angle:

[0106] ;

[0107] ;

[0108] ;

[0109] ;

[0110] in, For tilt compensation angle, Yaw angle The unit vector is obtained based on the radar centerline. The emission angle of the westward beam relative to the radar's central axis. The westward servo tilt intermediate vector is obtained based on the westward beam without rotation compensation. The westward target vector is obtained based on the westward beam after rotation compensation. This represents the projection component of the westward-moving, tilting intermediate vector onto the plane perpendicular to the central axis. Let be the projection component of the westward target vector onto the plane perpendicular to the central axis. This is the westward rotation compensation angle. Once the westward rotation compensation angle is obtained, the internal servo mechanism of the lidar will drive the westward beam to rotate relative to the central axis of the lidar to complete the position correction.

[0111] In this embodiment, the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component are obtained using the following formulas:

[0112] ;

[0113] in, This represents the horizontal wind speed component heading due east. This represents the horizontal wind speed component from due north. This represents the vertical wind speed component. The angle between the eastward beam and the vertical direction. The angle between the north-facing beam and the vertical direction. The angle between the westward beam and the vertical direction. The angle between the south-facing beam and the vertical direction. This is the corrected eastward radial wind speed. This is the corrected northward radial wind speed. This is the corrected westward radial wind speed. This is the corrected southward radial wind speed.

[0114] In this embodiment, the angles between the east-facing beam, north-facing beam, west-facing beam, and south-facing beam and the vertical direction are obtained using the following formula:

[0115] ;

[0116] in, This represents the projection component of the eastward beam onto the z-axis. This represents the projection component of the northbound beam onto the z-axis. This represents the projection component of the westward beam onto the z-axis. This represents the projection component of the southbound beam onto the z-axis.

[0117] The projection components of the eastward, northward, westward, and southward beams on the z-axis are obtained using the following formula:

[0118] ;

[0119] in, This represents the projection component of the eastward beam onto the z-axis. This represents the projection component of the northbound beam onto the z-axis. This represents the projection component of the westward beam onto the z-axis. This represents the projection component of the southbound beam onto the z-axis. The beam's exit angle relative to the radar's central axis. For tilt compensation angle, This is the yaw angle.

[0120] In step 500 of this embodiment, the motion compensation of the original radial wind speed measured by the radar by introducing the three-dimensional motion velocity vector of the floating platform is specifically obtained by using the following formulas to obtain the corrected eastward radial wind speed, northward radial wind speed, westward radial wind speed, and southward radial wind speed:

[0121] ;

[0122] in, This is the corrected eastward radial wind speed. This is the corrected northward radial wind speed. This is the corrected westward radial wind speed. This is the corrected southerly radial wind speed. The eastward radial wind speed detected by the working radar. The northward radial wind speed detected by the working radar. The westward radial wind speed detected by the working radar. The southward radial wind speed detected by the working radar. The three-dimensional velocity vector of the floating wind turbine platform. The unit vector of the eastward beam. The unit vector of the northbound beam. The unit vector of the westward beam. This is the unit vector of the southbound beam;

[0123]

[0124] in, The three-dimensional velocity vector of the floating wind turbine platform. For the eastward velocity component of the floating wind turbine platform. For the northward velocity component of the floating wind turbine platform, This represents the vertical velocity component of the floating wind turbine platform.

[0125] Because floating wind turbines generate six degrees of freedom motion under the coupling effect of wind, waves, and currents, the lidar measurement coordinate system continuously moves with the platform. This causes the measured radial wind speed to include a coupled component of the platform's motion velocity and the actual atmospheric wind speed, resulting in a significant deviation in the wind speed measurement results. Therefore, this embodiment requires obtaining the platform's motion velocity. Specifically, the platform's motion velocity is obtained in the following way: each column of the platform is equipped with an accelerometer, gyroscope, and a global satellite navigation system to collect the platform's linear acceleration, angular velocity, and absolute position information in real time. The acquired sensor data is uploaded in real time to an industrial control computer installed at the bottom of the wind turbine tower, which calculates and outputs a high-precision three-dimensional motion velocity vector of the platform in the geographic coordinate system.

[0126] By combining high-precision three-dimensional motion velocity vectors with the eastward, northward, westward, and southward radial wind speeds detected by the working radar, the true eastward, northward, westward, and southward radial wind speeds can be obtained. In other words, by utilizing the existing motion monitoring data of the floating wind turbine platform, the velocity measurement error introduced by the platform's six degrees of freedom motion is effectively eliminated, ensuring the accuracy of the wind speed measurement results.

[0127] Step 600. Obtain a wind speed model based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, and obtain the wind speed at the required location based on the wind speed model.

[0128] In step 600 of this embodiment, obtaining the wind speed model based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component specifically includes:

[0129] Step 610. Adjust the tilt compensation angle, obtain the measurement height and measurement horizontal distance based on the adjusted tilt compensation angle, calculate the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component based on the adjusted tilt compensation angle, calculate a corresponding wind speed based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, and use the measurement height, measurement horizontal distance, and wind speed as a model construction data set; repeat step 610 to obtain the required number of model construction data sets.

[0130] Taking a certain tilt compensation angle as an example, the corresponding measurement height and measurement horizontal distance can be calculated using the following formula, combined with... Figure 2 understand:

[0131] ;

[0132] in, To measure height, To measure horizontal distance, For radar installation height, For tilt compensation angle, The beam's exit angle relative to the radar's central axis. denoted as the vector of the laser beam. Figure 2 The dashed circle in the diagram represents the trajectory of the laser beam rotating around the central axis.

[0133] At this tilt compensation angle, the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component can also be obtained through the aforementioned steps. A corresponding wind speed can be calculated, where, For wind speed, This represents the horizontal wind speed component heading due east. This represents the horizontal wind speed component heading due north.

[0134] In this embodiment, the measured height, measured horizontal distance, and wind speed obtained at a certain tilt compensation angle are used as a model construction data set. By continuously adjusting the tilt compensation angle, multiple model construction data sets can be obtained.

[0135] Step 620. Construct a wind speed model based on the model-built data set.

[0136] In step 620 of this embodiment, constructing the wind speed model based on the model construction data set specifically includes:

[0137] Step 621. Based on the model, construct the data set and obtain the vertical model parameters using the following formula:

[0138] ;

[0139] ;

[0140] ;

[0141] ;

[0142] in, To measure the height is Wind speed at the location, The coefficient of friction, Kalman constant, The length of the surface roughness. This is the atmospheric stability correction function. For atmospheric stratification stability;

[0143] Vertical model parameters include friction coefficient Surface roughness length and atmospheric stratification stability .

[0144] The friction coefficient can be obtained by fitting a dataset based on a model and using the least squares method. Surface roughness length and atmospheric stratification stability The optimal solution.

[0145] Step 622. Construct a dataset based on the model and obtain the horizontal model parameters using the following formula:

[0146] ;

[0147] in, This refers to the horizontal wind shear index. To measure the horizontal distance Wind speed at the location, To measure the horizontal distance Wind speed at the location;

[0148] Horizontal model parameters include horizontal wind shear index .

[0149] The horizontal wind shear index can be obtained by constructing a dataset based on the model and calculating using the above formula. .

[0150] Step 623. Substitute the obtained vertical and horizontal model parameters into the following formula to obtain the wind speed model:

[0151] ;

[0152] in, To measure the height is And the measured horizontal distance is Wind speed at the location, The coefficient of friction, Let be the Karman constant (taken as 0.4). The length of the surface roughness. For atmospheric stratification stability, For reference horizontal distance, It represents the horizontal wind shear index.

[0153] The model construction data set in step 610 is obtained within a limited measurement area. When calculating wind speed, it is only necessary to input the height and horizontal distance into the wind speed model to obtain the wind speed corresponding to the measurement height and horizontal distance. Even if the input height and horizontal distance are not within the measurement area, the corresponding wind speed can still be calculated through the wind speed model, thereby realizing the wind speed measurement of the floating wind turbine without blind spots.

[0154] This invention also provides a method for calculating the equivalent wind speed of a floating wind turbine rotor, employing the wind speed measurement method described in the first embodiment. This method for calculating the equivalent wind speed of the rotor includes:

[0155] Step 710. Divide the wind turbine swept surface into multiple local blocks, and use polar coordinates for each local block. It means that, among them, Indicates the polar radius. Indicates the polar angle. Combined with... Figure 3 Understand that the local blocks are fan-shaped or fan-shaped rings. Taking a local block as an example, its distance from the center of the wind turbine is the polar radius, and its arc angle in the whole circle is the polar angle (for example, if it is between 10° and 16°, then its polar angle is 13°).

[0156] Step 720. Calculate the local wind speed corresponding to each local block using the following formula:

[0157] ;

[0158] ;

[0159] in, For polar coordinates The local wind speed of a local block. For height is Wind speed at the location, Indicates the polar radius. Indicates the polar angle. Indicates the radius of the wind turbine. It is the aerodynamic constant. This refers to the wheel hub height.

[0160] Knowing polar coordinates After that, the altitude can be obtained. Thus, it is possible to obtain high altitude The wind speed at the location is then substituted into the local wind speed calculation formula to obtain the polar coordinates. The local wind speed of a local block.

[0161] Step 730. Calculate the equivalent wind speed of the wind turbine based on the local wind speeds of all local blocks using the following formula:

[0162] ;

[0163] in, This indicates the equivalent wind speed of the wind turbine. Indicates the swept area of ​​the wind turbine and , Indicates the radius of the wind turbine. For polar coordinates The local wind speed of a local block. This represents the aerodynamic weighting coefficient.

[0164] The aerodynamic weighting coefficient is a conventionally known parameter in the field of wind turbine aerodynamic design. This coefficient characterizes the contribution of airflow at different positions on the rotor plane to the overall wind energy capture of the turbine. In practice, this coefficient does not require real-time system measurement or inverse calculation, but is directly read from the blade aerodynamic design drawings or aerodynamic parameter tables (including chord length, twist angle, and airfoil lift and drag coefficients of each section) of the target wind turbine at the time of manufacture, and is obtained through discretization calibration using the classic blade element momentum theory (BEM).

[0165] Once the local wind speed of each local block is calculated, the required equivalent wind speed of the wind turbine can be obtained by substituting the local wind speed into the formula for calculating the equivalent wind speed of the wind turbine.

[0166] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A method of measuring wind speed with a floating wind turbine, characterized in that, include: Step 100. Construct a spatial coordinate system based on the tower; Step 200. The fan is aligned with the wind to obtain the fan's yaw angle; Step 300. Obtain the azimuth of the column; Step 400. Determine the working radar based on the yaw angle of the wind turbine and the azimuth angle of the column, obtain the tilt compensation angle of the working radar, and adjust the scanning reference axis of the working radar based on the tilt compensation angle. Step 500. Obtain the rotation compensation angle of each beam of the working radar and perform position correction on each beam based on the rotation compensation angle. Perform motion compensation on the original radial wind speed measured by the radar to obtain the eastward horizontal wind speed component, the northward horizontal wind speed component and the vertical wind speed component. Step 600. Obtain a wind speed model based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, and obtain the wind speed at the required location based on the wind speed model.

2. The wind speed measurement method according to claim 1, characterized in that, In step 400, determining the working radar based on the yaw angle of the wind turbine and the azimuth angle of the support column specifically includes: Step 410. Calculate the cosine value based on the yaw angle of the wind turbine and the azimuth angle of the column; determine whether the cosine value is greater than 0. When there is only one cosine value greater than 0, determine the lidar corresponding to the cosine value greater than 0 as the working lidar. Step 420. When there is not only one cosine value greater than 0, calculate the radius comparison distance based on the cosine value greater than 0; determine whether the radius comparison distance is greater than the minimum distance threshold. When the radius comparison distance is greater than the minimum distance threshold, determine the lidar corresponding to the radius comparison distance greater than the minimum distance threshold as the working lidar.

3. The wind speed measurement method according to claim 1, characterized in that, In step 400, obtaining the tilt compensation angle of the working radar and adjusting the scanning reference axis of the working radar based on the tilt compensation angle specifically includes: Step 440. Based on the formula The tilt compensation angle of the working radar is calculated, where For tilt compensation angle, This represents the minimum horizontal distance from the nearest radar measurement point to the wind turbine surface. For wheel hub height, Radar installation height; Step 450. Based on the tilt compensation angle, adjust the scanning reference axis of the working radar from the vertical direction to tilt upstream of the wind turbine.

4. The wind speed measurement method according to claim 1, characterized in that, In step 500, obtaining the rotation compensation angle of each beam of the working radar and performing position correction on each beam based on the rotation compensation angle specifically includes: Step 510. Obtain the beam rotation compensation angle of the working radar based on the following formula, and perform beam position correction based on the beam rotation compensation angle: ; in, The unit vector is obtained based on the radar centerline. This represents the projection component of the tilting intermediate vector onto the plane perpendicular to the central axis. Let be the projection component of the target vector onto the plane perpendicular to the central axis. This is the rotation compensation angle.

5. The wind speed measurement method according to claim 1, characterized in that, In step 500, the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component are obtained using the following formulas: ; in, This represents the horizontal wind speed component heading due east. This represents the horizontal wind speed component from due north. This represents the vertical wind speed component. The angle between the eastward beam and the vertical direction. The angle between the north-facing beam and the vertical direction. The angle between the westward beam and the vertical direction. The angle between the south-facing beam and the vertical direction. This is the corrected eastward radial wind speed. This is the corrected northward radial wind speed. This is the corrected westward radial wind speed. This is the corrected southward radial wind speed.

6. The wind speed measurement method according to claim 5, characterized in that, The angles between the east-facing, north-facing, west-facing, and south-facing beams and the vertical direction can be obtained using the following formulas: ; in, This represents the projection component of the eastward beam onto the z-axis. This represents the projection component of the northbound beam onto the z-axis. This represents the projection component of the westward beam onto the z-axis. This represents the projection component of the southbound beam onto the z-axis.

7. The wind speed measurement method according to claim 1, characterized in that, In step 600, obtaining the wind speed model based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component specifically includes: Step 610. Adjust the tilt compensation angle. Based on the adjusted tilt compensation angle, obtain the measurement height and measurement horizontal distance. Based on the adjusted tilt compensation angle, calculate the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component. Based on the eastward horizontal wind speed component, the northward horizontal wind speed component, and the vertical wind speed component, calculate a corresponding wind speed. Combine the measurement height, measurement horizontal distance, and wind speed as a model construction data set. Repeat step 610 to obtain the required number of model construction data sets. Step 620. Construct a wind speed model based on the model-built data set.

8. The wind speed measurement method according to claim 7, characterized in that, In step 620, constructing the wind speed model based on the model construction data set specifically includes: Step 621. Based on the model, construct the data set and obtain the vertical model parameters using the following formula: ; in, To measure the height is Wind speed at the location, The coefficient of friction, Kalman constant, The length of the surface roughness. This is the atmospheric stability correction function. For atmospheric stratification stability; The vertical model parameters include the friction coefficient, surface roughness length, and atmospheric stratification stability. Step 622. Construct a dataset based on the model and obtain the horizontal model parameters using the following formula: ; in, This refers to the horizontal wind shear index. To measure the horizontal distance Wind speed at the location, To measure the horizontal distance Wind speed at the location; The horizontal model parameters include the horizontal wind shear index; Step 623. Substitute the obtained vertical and horizontal model parameters into the following formula to obtain the wind speed model: ; in, To measure the height is And the measured horizontal distance is Wind speed at the location, The coefficient of friction, Kalman constant, The length of the surface roughness. For atmospheric stratification stability, For reference horizontal distance, It represents the horizontal wind shear index.

9. A method for calculating the equivalent wind speed of a floating wind turbine rotor, employing the wind speed measurement method described in claim 8, characterized in that... The method for calculating the equivalent wind speed of the wind turbine includes: Step 710. Divide the wind turbine swept surface into multiple local blocks; Step 720. Calculate the local wind speed corresponding to each local block: Step 730. Calculate the equivalent wind speed of the wind turbine based on the local wind speed of all local blocks.

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