Wind turbine generator blade imbalance identification method and system

Abstract

The invention provides a wind turbine generator blade imbalance identification method and system, and the method comprises the steps: arranging a laser range finder at the front part of a cabin of a wind turbine generator, and enabling a laser light source of the laser range finder to be perpendicular to the ground plane; in the process that the fan blades rotate by one circle, the point cloud three-dimensional coordinates of the blade tip part of each blade are measured through a laser range finder when each blade in the wind turbine generator rotates to the direction perpendicular to the ground plane; calculating the horizontal distance between the blade tip part of each blade and the perpendicular bisector of the laser range finder according to the corresponding point cloud three-dimensional coordinates; and calculating the blade unbalance degree of the wind turbine generator based on the horizontal distances corresponding to all the blades in the wind turbine generator. According to the method, the unbalance degree among the blades in the rotating process of the blades of the fan can be accurately calculated, and safe operation of the fan can be guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation, and in particular to a method and system for identifying imbalance of blades of a wind turbine generator set. Background Art

[0002] Currently, industrial development is driving an ever-increasing demand for energy and electricity. However, due to growing environmental awareness, green power generation projects such as wind power and photovoltaic power generation are being vigorously developed within renewable energy sources to reduce carbon dioxide emissions. Wind power generation is showing positive development trends, with wind turbines gradually becoming larger and more intelligent. Units larger than 5MW have already been demonstrated in offshore wind farms.

[0003] Large turbines with a capacity of 5MW and above are typically equipped with blades with a rotating diameter of more than 140 meters. In actual applications, due to factors such as measurement errors in the calibration of the blade installation inflow angle, the working angles of the three blades cannot remain completely synchronized during the pitch change process. If there is a large deviation between the three blade angles or one blade is cracked or damaged, the forces on the three blades will be asynchronous, causing aerodynamic imbalance of the entire wind turbine. This will increase the load on the entire unit, affecting the life of the entire unit and the safety of equipment operation. Therefore, how to identify wind turbine blade imbalance becomes particularly important.

[0004] In related technologies, turbine blade imbalance detection typically involves analyzing vibration signals from the nacelle to determine if an imbalance exists. For example, images of the blades on the ground can be used to determine if wind force is balanced. However, these approaches require analysis and comparison of historical turbine data, resulting in large amounts of data and complex calculations. Furthermore, the results can contain errors, making identification less accurate than required. Summary of the Invention

[0005] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, the first purpose of this application is to propose a method for identifying imbalance of wind turbine blades, which can monitor the imbalance of blades in real time, improve the accuracy and convenience of wind turbine blade imbalance identification, reduce the amount of calculation, and ensure the safety of the unit.

[0007] The second object of this application is to provide a wind turbine blade imbalance identification system;

[0008] A third object of the present application is to provide a non-transitory computer-readable storage medium.

[0009] To achieve the above-mentioned objectives, a first embodiment of the present application provides a method for identifying blade imbalance of a wind turbine, the method comprising the following steps:

[0010] A laser rangefinder is arranged at the front of the nacelle of the wind turbine, wherein the laser light source of the laser rangefinder is perpendicular to the ground plane;

[0011] During one rotation of the wind turbine blade, the laser rangefinder measures the three-dimensional coordinates of the tip of each blade of the wind turbine when the blade rotates to a position perpendicular to the ground plane;

[0012] Calculate the horizontal distance between the tip of each blade and the perpendicular bisector of the laser rangefinder according to the corresponding three-dimensional coordinates of the point cloud;

[0013] The blade imbalance of the wind turbine generator set is calculated based on the horizontal distances corresponding to all blades in the wind turbine generator set.

[0014] Optionally, in one embodiment of the present application, the blade imbalance of the wind turbine generator set is calculated based on the horizontal distances corresponding to all the blades in the wind turbine generator set, including: calculating the average value of the horizontal distances corresponding to all the blades in the wind turbine generator set; subtracting the minimum distance from the maximum distance among the horizontal distances corresponding to all the blades to obtain a target difference; and comparing the target difference with the average value to obtain the blade imbalance of the wind turbine generator set.

[0015] Optionally, in one embodiment of the present application, after calculating the blade imbalance of the wind turbine, it also includes: comparing the blade imbalance with a preset safety threshold; when the blade imbalance is greater than the safety threshold, controlling the propeller system of the wind turbine to retract to 90 degrees and controlling the blade speed to decrease.

[0016] Optionally, in one embodiment of the present application, the laser rangefinder is set at the front of the nacelle of the wind turbine generator, including: setting the laser rangefinder on the bottom outer wall of the front of the nacelle of the wind turbine generator, wherein the Z axis in the three-dimensional coordinate system constructed for the laser rangefinder is perpendicular to the ground plane; adjusting the horizontal position of the laser rangefinder so that the position of each blade when it is rotated to be perpendicular to the ground plane is within the detection range of the laser rangefinder.

[0017] Optionally, in one embodiment of the present application, the laser rangefinder is a laser radar with a detection distance of 500 meters, the detection range of the laser rangefinder is a 60-degree cone, and the laser rangefinder distributes 240,000 points of point cloud data within the detection range per second.

[0018] Optionally, in one embodiment of the present application, the method further includes: calculating the real-time distance between the tip of each blade and the outer wall of the tower of the wind turbine generator system based on the three-dimensional coordinates of the point cloud corresponding to each blade.

[0019] To achieve the above objectives, the second embodiment of the present application further proposes a wind turbine blade imbalance identification system, comprising the following modules:

[0020] A setting module is used to set a laser rangefinder at the front of the nacelle of the wind turbine generator, wherein the laser light source of the laser rangefinder is perpendicular to the ground plane;

[0021] a measurement module, configured to measure, by means of the laser rangefinder, the three-dimensional coordinates of the point cloud of the tip of each blade of the wind turbine when each blade rotates to a position perpendicular to the ground plane during one rotation of the wind turbine blade;

[0022] A first calculation module is used to calculate the horizontal distance between the tip of each blade and the perpendicular bisector of the laser rangefinder according to the corresponding three-dimensional coordinates of the point cloud;

[0023] The second calculation module is configured to calculate the blade imbalance of the wind turbine generator set based on the horizontal distances corresponding to all blades in the wind turbine generator set.

[0024] Optionally, in one embodiment of the present application, the second calculation module is specifically used to: calculate the average value of the horizontal distances corresponding to all the blades in the wind turbine; subtract the minimum distance from the maximum distance among the horizontal distances corresponding to all the blades to obtain a target difference; and compare the target difference with the average value to obtain the blade imbalance of the wind turbine.

[0025] Optionally, in one embodiment of the present application, the system further includes a control module, which is specifically used to: compare the blade imbalance with a preset safety threshold; when the blade imbalance is greater than the safety threshold, control the propeller system of the wind turbine to retract to 90 degrees and control the blade speed to decrease.

[0026] In order to implement the above embodiments, the third aspect of the present application further proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for identifying imbalance of wind turbine blades in the above embodiments is implemented.

[0027] The technical solutions provided by the embodiments of the present application bring at least the following beneficial effects: The present application sets up a laser rangefinder to measure the three-dimensional coordinates of the blade tip when each blade rotates to the 6 o'clock position, then calculates the distance between the blade tip and the mid-perpendicular line of the laser rangefinder based on the measured three-dimensional coordinates, and detects blade imbalance based on the distance of each blade. Thus, by monitoring the real-time distance from the blade tip to the rangefinder within a cycle, the present application can accurately calculate the imbalance between each blade during the wind turbine's blade rotation. The recognition result is consistent with the actual situation, the recognition time is short, and the recognition result within the current rotation cycle can be obtained, thereby improving the accuracy, reliability, and real-time performance of wind turbine blade imbalance recognition. Furthermore, the recognition process does not require other historical data, reducing the computational complexity and complexity of the recognition process. The present application can control the wind turbine accordingly based on the recognition results, which helps reduce the wind turbine load and ensure the normal and safe operation of the wind turbine.

[0028] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0030] Figure 1 A flow chart of a method for identifying imbalance of wind turbine blades proposed in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of a laser rangefinder configuration method proposed in an embodiment of the present application;

[0032] Figure 3 This is a schematic diagram of the architecture of a wind turbine blade imbalance identification system proposed in an embodiment of the present application;

[0033] Figure 4 A flowchart of a specific method for identifying imbalance of wind turbine blades proposed in an embodiment of the present application;

[0034] Figure 5 This is a schematic diagram of the structure of a wind turbine blade imbalance identification system proposed in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0036] A method and system for identifying imbalance in blades of a wind turbine generator system according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0037] It should be noted that blade imbalance refers to the relative distance offset of each blade relative to the rotation plane when the wind turbine hub in the wind turbine rotates to drive the three blades in the unit to rotate. This application identifies whether the unit has blade imbalance by calculating the value of the imbalance of the blades of the computer group, that is, the degree of relative distance offset.

[0038] Figure 1 This is a flow chart of a method for identifying wind turbine blade imbalance proposed in an embodiment of the present application, such as Figure 1 As shown, the method includes the following steps:

[0039] Step S101: a laser rangefinder is arranged at the front of the nacelle of the wind turbine generator, wherein the laser light source of the laser rangefinder is perpendicular to the ground plane.

[0040] Specifically, this application installs a laser rangefinder on the blade rotation plane of the unit for real-time scanning. The installed laser rangefinder can detect in real time the deviation distance of each blade from the rotation plane when it enters the laser radar scanning field of view, so as to subsequently calculate the imbalance of the three blades in the wind turbine.

[0041] During specific implementation, the laser rangefinder is set at the front of the nacelle of the wind turbine according to the special circumstances of the structure of the wind turbine, the assembly method of each component and the operation process of the turbine. When installing the laser rangefinder, ensure that the laser light source of the laser rangefinder is perpendicular to the ground plane, that is, the horizontal plane, to facilitate subsequent measurements.

[0042] As a possible implementation, Figure 2 As shown, a laser rangefinder 20 is installed on the outer wall of the bottom end of the front portion of the nacelle of the wind turbine 10. The Z-axis of the three-dimensional coordinate system constructed by the laser rangefinder 20 during distance measurement is perpendicular to the earth plane. That is, the direction of the laser light source emitted by the laser rangefinder 20 is the Z-axis direction in the three-dimensional coordinate system. Furthermore, before fixing the position of the laser rangefinder 20, the horizontal position of the laser rangefinder 20 is adjusted so that the position of each blade when rotated to be perpendicular to the earth plane is within the detection range of the laser rangefinder 20.

[0043] It should be noted that if Figure 2As shown, a laser rangefinder is installed at the front of the nacelle, perpendicular to the nacelle and pointing downward. The laser radar rangefinder can detect objects in its scanning line of sight in real time and determine the three-dimensional coordinates of reflective objects within its detection range by receiving reflected light. This embodiment determines the horizontal position of the laser rangefinder on the lower housing of the nacelle based on the dimensions of components such as the blades and nacelle of the wind turbine and the detection range of the laser rangefinder. This ensures that each blade, when rotated to the 6 o'clock position, is within the laser rangefinder's detection range, enabling the acquisition of blade position data.

[0044] It should also be noted that the 6 o'clock position to which the blades rotate in the embodiments of the present application refers to the position where the blades are perpendicular to the ground plane.

[0045] In one embodiment of the present application, attribute information of a laser rangefinder is determined based on specific parameters of the wind turbine blades, such as length and rotational speed. In this embodiment, the laser rangefinder is a lidar with a detection range of 500 meters. The detection range of the laser rangefinder is a 60-degree cone, and the laser rangefinder can distribute 240,000 points of point cloud data per second within its detection range.

[0046] Specifically, the laser rangefinder used in this embodiment utilizes a laser radar (LIDAR) designed for unmanned vehicle detection with a range of up to 500 meters. This laser rangefinder emits multiple laser lines simultaneously for high-speed, non-repetitive scanning. It can distribute up to 240,000 points of point cloud data per second across its approximately 60-degree conical scanning field of view. In just 100 milliseconds, it achieves 99.8% field of view coverage, resulting in a high point cloud density. This ensures that even when blades are moving at high speeds during operation, the laser rangefinder can still quickly detect blades in its field of view and store the three-dimensional coordinates of the measured point cloud in real time.

[0047] Step S102 , during one rotation of the wind turbine blade, the laser rangefinder is used to measure the three-dimensional coordinates of the point cloud of the tip of each blade when each blade in the wind turbine rotates to a position perpendicular to the ground plane.

[0048] Specifically, each fan blade rotates under the drive, and when it rotates to the vertical 6 o'clock position in turn, the laser rangefinder collects the three-dimensional coordinates of the tip of the blade currently located in the detection area, and measures the coordinate information of each blade tip within one cycle of the fan blade rotation.

[0049] Continue to refer to Figure 2 In the example shown, the scanning period of the lidar rangefinder is 100ms. Within each scanning period of 100ms, the lidar rangefinder collects in real time the three-dimensional coordinates of the point cloud at the cross section of the blade tip in the 60-degree conical scanning line of sight when a blade is vertically at 6 o'clock.

[0050] Step S103 , calculating the horizontal distance between the tip of each blade and the perpendicular bisector of the laser rangefinder according to the corresponding three-dimensional coordinates of the point cloud.

[0051] Specifically, since the position of the laser rangefinder's laser light source is known, once the coordinates of the blade tip are determined, the coordinates of the point on the laser rangefinder's perpendicular bisector corresponding to the blade tip can be obtained. This point on the perpendicular bisector and the approximate point of the blade tip are located on the same horizontal line. Furthermore, the horizontal distance between the blade tip and the laser rangefinder's perpendicular bisector can be calculated based on the coordinates of these two points.

[0052] For example, if Figure 2 As shown in the figure, the coordinates of the object measured by the laser rangefinder are the point cloud coordinates at the blade tip section at the vertical distance from the center of the laser rangefinder at the vertical 6 o'clock position of the blade (represented by point A in the figure). According to the coordinates of point A and the coordinates of the laser rangefinder, the coordinates of the corresponding point O on the perpendicular bisector can be obtained, and then the real-time distance of the blade tip relative to point O can be effectively calculated.

[0053] In one embodiment of the present application, when performing data calculation, the blade imbalance identification method of the present application embodiment can be executed by an identification system proposed in the present application. Figure 3 This is a schematic diagram of the architecture of a wind turbine blade imbalance identification system proposed in an embodiment of the present application. Figure 3 As shown, the system Figure 2 The wind turbine 10 and data acquisition device (i.e., laser rangefinder) 20 shown in the figure also include a controller module 30. The controller module 30 can be a programmable logic controller (PLC) pre-installed in the wind turbine, or it can be another intelligent processing terminal. The controller module 30 can be installed inside or outside the turbine and connected to the wind turbine 10 and data acquisition device 20 via wired or wireless means. This application does not limit the configuration method of the controller module 30.

[0054] In this embodiment, the laser radar rangefinder transmits the collected object coordinates to the controller module, and performs data transmission and communication with a sampling period of 50ms. The controller module processes the three-dimensional coordinates of the point cloud of the blade tip at the vertical 6 o'clock position of the blade measured by the laser rangefinder, including data conversion and judgment of whether the correct coordinate data is measured, and then calculates and combines the coordinates of point O to obtain the horizontal distance AO relative to point O on the Z axis of the laser radar.

[0055] Furthermore, when the fan blades rotate one circle, the horizontal distance corresponding to each blade is calculated in sequence according to the above method, and the controller module divides its own memory into three storage intervals, and collects and records in real time the distances of blades 1, 2 and 3 relative to point O when they rotate to the vertical 6 o'clock position: a, b and c respectively.

[0056] Step S104 : calculating the blade imbalance of the wind turbine generator set based on the horizontal distances corresponding to all blades in the wind turbine generator set.

[0057] Specifically, the horizontal distances corresponding to all the blades in the wind turbine obtained in the previous step are combined, and the blade imbalance of the wind turbine is calculated using the corresponding blade rotation imbalance calculation method. The blade imbalance value is compared with the safety threshold to determine whether the current blade imbalance is within an acceptable range, so as to identify whether the wind turbine has blade imbalance.

[0058] In one embodiment of the present application, the blade imbalance of the wind turbine is calculated based on the horizontal distances corresponding to all the blades in the wind turbine, including the following steps: first, calculating the average value of the horizontal distances corresponding to all the blades in the wind turbine; then subtracting the minimum distance from the maximum distance among the horizontal distances corresponding to all the blades to obtain a target difference; finally, comparing the target difference with the average value to obtain the blade imbalance of the wind turbine.

[0059] Continuing with the example in step S103, for the three blade A / D distances a, b, and c measured in real time, the average d of these three values ​​is calculated: d = (a + b + c) / 3. Next, the minimum value of a, b, and c is subtracted from the maximum value to obtain e, the target difference. Consequently, the degree of imbalance is equal to e / d * 100%.

[0060] Furthermore, the calculated imbalance degree is compared with a set threshold value to determine whether relevant safety measures need to be implemented on the unit.

[0061] That is, in one embodiment of the present application, after calculating the blade imbalance of the wind turbine, it also includes: comparing the blade imbalance with a preset safety threshold; when the blade imbalance is greater than the safety threshold, controlling the propeller system of the wind turbine to retract to 90 degrees and controlling the blade speed to decrease.

[0062] Continuing with the above example, after calculating the imbalance degree e / d*100%, the controller module transmits the calculated real-time imbalance value to the wind turbine's main control programmable logic controller (PLC). The PLC compares the imbalance value with a pre-stored safety threshold, which can be determined based on historical operating experience, expert knowledge, and extensive experimental data. If the PLC determines in real time that the imbalance degree exceeds the preset safety threshold, it controls the wind turbine's pitch control system to retract the pitch to 90 degrees, reducing the turbine's absorption of wind energy and lowering the turbine's speed to ensure turbine safety.

[0063] Therefore, the present application can monitor the imbalance of the blades in real time, and when it is identified in real time that the imbalance of the unit exceeds the safety threshold, the variable pitch and return pitch mechanism is activated to ensure the safety of the unit.

[0064] In one embodiment of the present application, after calculating the three-dimensional coordinates of the point cloud corresponding to each blade, the real-time distance between the tip of each blade and the outer wall of the tower of the wind turbine can also be calculated based on the three-dimensional coordinates of the point cloud corresponding to each blade. It can be understood that since the position of the wind turbine tower is fixed, the position of each point on the outer wall of the tower is known information. After determining the corresponding point of the blade tip on the outer wall of the tower, the real-time distance between the blade tip and the outer wall of the tower of the wind turbine can be calculated. The specific calculation method can refer to the calculation method of the horizontal distance mentioned above. Therefore, this embodiment can determine whether the distance between the blade and the tower in actual operation is equal to the designed distance based on the real-time distance between the blade tip and the outer wall of the tower and other components, so as to facilitate timely adjustment of the operating status of the component.

[0065] It should be noted that in some embodiments of the present application, when the accuracy of blade imbalance recognition is not required to be high, an ultrasonic ranging device or an infrared ranging device, etc. can be set at the front of the cabin, and the ranging device can be controlled to work intermittently, and blade imbalance recognition is performed every few preset cycles to reduce the amount of calculation, reduce the hardware cost of imbalance recognition and the computing resources occupied.

[0066] In summary, the method for identifying imbalance in the blades of a wind turbine according to an embodiment of the present application is to set a laser rangefinder to measure the three-dimensional coordinates of the blade tip when each blade rotates to the 6 o'clock position, and then calculate the distance between the blade tip and the perpendicular line of the laser rangefinder based on the measured three-dimensional coordinates, and detect the blade imbalance according to the distance of each blade. Thus, the method can accurately calculate the imbalance between each blade during the rotation of the wind turbine blades by monitoring the real-time distance from the blade tip to the rangefinder in real time within one cycle. The recognition result is consistent with the actual situation, the recognition time is short, and the recognition result within the current rotation cycle can be obtained, thereby improving the accuracy, reliability and real-time performance of the wind turbine blade imbalance recognition. In addition, the recognition process of this method does not require other historical data, which reduces the amount of calculation and complexity in the recognition process. The present application can control the unit accordingly based on the recognition result, which is conducive to reducing the load of the unit and ensuring the normal and safe operation of the wind turbine.

[0067] In order to more clearly illustrate the implementation process of the method for identifying imbalance of wind turbine blades according to the embodiment of the present application, a specific method embodiment is described in detail below. Figure 4 This is a flow chart of a specific method for identifying imbalance of wind turbine blades proposed in an embodiment of the present application, as shown in FIG. Figure 4 As shown, the fault diagnosis method of this embodiment includes the following steps:

[0068] Step S401: collect the three-dimensional point cloud coordinates corresponding to the blade tip at the 6 o'clock position of the blade using a laser radar rangefinder.

[0069] Step S402 : Processing the measured three-dimensional point cloud coordinates of the blade tip by the controller processing module.

[0070] Step S403: Identify the horizontal distance of the blade at the vertical 6 o'clock position relative to the Z-axis point O of the laser radar rangefinder.

[0071] Step S404: When the blade rotates one circle, the horizontal distance of each blade relative to point O when the blade rotates to the vertical 6 o'clock position is recorded in real time.

[0072] Step S405 , obtaining the balance of the blade rotation by calculating the percentage of the maximum real-time fluctuation distance of the three blades relative to the average value.

[0073] It should be noted that the specific implementation of each step in this embodiment can refer to the relevant description in the above embodiment and will not be repeated here.

[0074] In order to implement the above embodiment, the present application also proposes a wind turbine blade imbalance identification system. Figure 5This is a structural diagram of a wind turbine blade imbalance identification system proposed in an embodiment of the present application, as shown in FIG. Figure 5 As shown, the system includes a setting module 100 , a measurement module 200 , a first calculation module 300 and a second calculation module 400 .

[0075] The setting module 100 is used to set a laser rangefinder at the front of the nacelle of the wind turbine generator, wherein the laser light source of the laser rangefinder is perpendicular to the ground plane.

[0076] The measurement module 200 is used to measure the three-dimensional coordinates of the tip of each blade of the wind turbine when each blade rotates to a position perpendicular to the ground plane through a laser rangefinder during one rotation of the wind turbine blade.

[0077] The first calculation module 300 is used to calculate the horizontal distance between the tip of each blade and the perpendicular bisector of the laser rangefinder according to the corresponding three-dimensional coordinates of the point cloud.

[0078] The second calculation module 400 is configured to calculate the blade imbalance of the wind turbine generator set based on the horizontal distances corresponding to all blades in the wind turbine generator set.

[0079] Optionally, in one embodiment of the present application, the second calculation module 400 is specifically used to: calculate the average value of the horizontal distances corresponding to all blades in the wind turbine; subtract the minimum distance from the maximum distance among the horizontal distances corresponding to all blades to obtain a target difference; and compare the target difference with the average value to obtain the blade imbalance of the wind turbine.

[0080] Optionally, in one embodiment of the present application, the system also includes a control module, which is specifically used to: compare the blade imbalance with a preset safety threshold; when the blade imbalance is greater than the safety threshold, control the wind turbine's propeller system to retract to 90 degrees and control the blade's rotation speed to decrease.

[0081] Optionally, in one embodiment of the present application, a module 100 is provided, specifically for: setting a laser rangefinder on the bottom outer wall of the front part of the nacelle of the wind turbine, wherein the Z axis in the three-dimensional coordinate system constructed for the laser rangefinder is perpendicular to the ground plane; adjusting the horizontal position of the laser rangefinder so that the position of each blade when it is rotated to be perpendicular to the ground plane is within the detection range of the laser rangefinder.

[0082] Optionally, in one embodiment of the present application, the laser rangefinder is a laser radar with a detection distance of 500 meters, the detection range of the laser rangefinder is a 60-degree cone, and the laser rangefinder distributes 240,000 points of point cloud data within the detection range per second.

[0083] Optionally, in one embodiment of the present application, the second calculation module 400 is further used to calculate the real-time distance between the tip of each blade and the outer wall of the tower of the wind turbine generator system according to the three-dimensional coordinates of the point cloud corresponding to each blade.

[0084] It should be noted that the above explanation of the embodiment of the method for identifying imbalance of wind turbine blades is also applicable to the system of this embodiment and will not be repeated here.

[0085] In summary, the wind turbine blade imbalance identification system of the embodiment of the present application sets a laser rangefinder to measure the three-dimensional coordinates of the blade tip when each blade rotates to the 6 o'clock position, and then calculates the distance between the blade tip and the perpendicular line of the laser rangefinder based on the measured three-dimensional coordinates, and detects the blade imbalance according to the distance of each blade. Thus, the system can accurately calculate the imbalance between each blade during the rotation of the wind turbine blade by monitoring the real-time distance from the blade tip to the rangefinder in real time within one cycle. The identification result is consistent with the actual situation, the identification time is short, and the identification result within the current rotation cycle can be obtained, thereby improving the accuracy, reliability and real-time performance of the wind turbine blade imbalance identification. In addition, the identification process of the system does not require other historical data, which reduces the amount of calculation and complexity in the identification process. The present application can control the unit accordingly based on the identification result, which is conducive to reducing the unit load and ensuring the normal and safe operation of the wind turbine.

[0086] In order to implement the above embodiments, the present application also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for identifying wind turbine blade imbalance as described in any of the above embodiments is implemented.

[0087] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0088] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0089] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0090] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0091] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0092] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0093] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0094] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for identifying imbalance of wind turbine blades, characterized in that: The following steps are involved: A laser rangefinder is arranged at the front of the nacelle of the wind turbine, wherein the laser light source of the laser rangefinder is perpendicular to the ground plane; During one rotation of the wind turbine blade, the laser rangefinder measures the three-dimensional coordinates of the tip of each blade of the wind turbine when the blade rotates to a position perpendicular to the ground plane; Calculate the horizontal distance between the tip of each blade and the perpendicular bisector of the laser rangefinder according to the corresponding three-dimensional coordinates of the point cloud; The blade imbalance of the wind turbine generator set is calculated based on the horizontal distances corresponding to all blades in the wind turbine generator set.

2. The method for identifying imbalance of wind turbine blades according to claim 1, characterized in that: The calculating the blade imbalance of the wind turbine generator set based on the horizontal distances corresponding to all blades in the wind turbine generator set includes: Calculating an average value of the horizontal distances corresponding to all blades in the wind turbine generator set; Subtracting the minimum distance from the maximum distance among the horizontal distances corresponding to all the blades to obtain a target difference; The target difference is compared with the average value to obtain the blade imbalance of the wind turbine generator set.

3. The method for identifying imbalance of wind turbine blades according to claim 1 or 2, characterized in that: After calculating the blade imbalance of the wind turbine generator set, the method further includes: comparing the blade imbalance with a preset safety threshold; When the blade imbalance is greater than the safety threshold, the propeller system of the wind turbine generator set is controlled to retract the propeller to 90 degrees and the rotation speed of the blade is controlled to decrease.

4. The method for identifying imbalance of wind turbine blades according to claim 1, characterized in that: The laser rangefinder is arranged at the front of the nacelle of the wind turbine generator, including: The laser rangefinder is arranged on the outer wall of the bottom end of the front part of the nacelle of the wind turbine generator, wherein the Z axis in the three-dimensional coordinate system constructed for the laser rangefinder is perpendicular to the earth plane; The horizontal position of the laser rangefinder is adjusted so that the position of each blade when it rotates to be perpendicular to the ground plane is within the detection range of the laser rangefinder.

5. The method for identifying imbalance of wind turbine blades according to claim 4, characterized in that: The laser rangefinder is a laser radar with a detection distance of 500 meters. The detection range of the laser rangefinder is a 60-degree cone. The laser rangefinder distributes 240,000 points of point cloud data within the detection range per second.

6. The method for identifying imbalance of wind turbine blades according to claim 1, characterized in that: Also includes: The real-time distance between the tip of each blade and the outer wall of the tower of the wind turbine generator set is calculated according to the three-dimensional coordinates of the point cloud corresponding to each blade.

7. A wind turbine blade imbalance identification system, characterized in that: Includes the following modules: A setting module is used to set a laser rangefinder at the front of the nacelle of the wind turbine generator, wherein the laser light source of the laser rangefinder is perpendicular to the ground plane; a measurement module, configured to measure, by means of the laser rangefinder, the three-dimensional coordinates of the point cloud of the tip of each blade of the wind turbine when each blade rotates to a position perpendicular to the ground plane during one rotation of the wind turbine blade; A first calculation module is used to calculate the horizontal distance between the tip of each blade and the perpendicular bisector of the laser rangefinder according to the corresponding three-dimensional coordinates of the point cloud; The second calculation module is configured to calculate the blade imbalance of the wind turbine generator set based on the horizontal distances corresponding to all blades in the wind turbine generator set.

8. The wind turbine blade imbalance identification system according to claim 7, characterized in that: The second calculation module is specifically configured to: Calculating an average value of the horizontal distances corresponding to all blades in the wind turbine generator set; Subtracting the minimum distance from the maximum distance among the horizontal distances corresponding to all the blades to obtain a target difference; The target difference is compared with the average value to obtain the blade imbalance of the wind turbine generator set.

9. The wind turbine blade imbalance identification system according to claim 7 or 8, characterized in that: It also includes a control module, which is specifically used to: comparing the blade imbalance with a preset safety threshold; When the blade imbalance is greater than the safety threshold, the propeller system of the wind turbine generator set is controlled to retract the propeller to 90 degrees and the rotation speed of the blade is controlled to decrease.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for identifying imbalance of wind turbine blades according to any one of claims 1 to 6 is implemented.

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