Device and method for monitoring blade deformation of wind power generation equipment

Abstract

The invention discloses a device and method for monitoring blade deformation of wind power generation equipment, and the device comprises an annular drive track fixed on the outer surface of a tower drum, a fixed frame fixed on one side of the annular drive track, and at least three laser sensor groups which are distributed in the length direction of the fixed frame. The main shaft angle sensor is fixed to one side of a wind power case and monitors the main shaft rotation angle of a wind power hub, the controller is used for triggering the three laser sensor sets to measure the distance between each sensor and a blade according to data of the main shaft angle sensor, the validity of the data is judged, the real-time deformation quantity is calculated when the data is valid, and the real-time deformation quantity is calculated. The invention relates to the technical field of wind power generation. According to the device and method for monitoring the blade deformation of the wind power generation equipment, the problem that the blade structure needs to be damaged during monitoring in the prior art is solved, meanwhile, the data reliability is improved, and preventive maintenance of the blade can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a device and method for monitoring blade deformation of wind power generation equipment. Background Art

[0002] Wind power generation is the process of converting wind kinetic energy into electrical energy. Wind power drives blade rotation, which in turn generates electricity through electromagnetic induction. In the field of wind power generation, blades are core components for capturing wind energy, and their health directly impacts the unit's operational safety and power generation efficiency. Publication No. CN105822508B discloses a system for monitoring blade deformation in wind turbines. A cable is laid axially along the inner surface of the blade, and the cable drives elastic elements to stretch as the blade deforms, obtaining blade deformation. This system can quickly and effectively monitor damage to various blade components in real time. This solution requires installing a cable inside the blade, which involves contact monitoring and can potentially damage the blade's structural integrity. Furthermore, the cable is susceptible to vibration and wear during long-term operation. Publication No. CN114412724B discloses a laser radar ranging system for monitoring the operating status of wind turbine blades. By rotating the laser radar ranging probe at a certain angle, the system measures the swing amplitude of various blade components and determines whether the amplitude is within the normal range for the current wind speed. Although deformation can be monitored in real time, it is not linked to the pitch control system, resulting in measurement deviations. It is also impossible to dynamically adjust the blade stress state according to the deformation, making preventive maintenance difficult. Summary of the Invention

[0003] (1) Technical problems solved

[0004] In response to the shortcomings of the existing technology, the present invention provides a device and method for monitoring the deformation of blades of wind power generation equipment, which solves the problem in the existing technology that monitoring requires destroying the blade structure, while improving the reliability of the data and enabling preventive maintenance of the blades.

[0005] (2) Technical solution

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A device for monitoring blade deformation of wind power generation equipment, comprising:

[0007] annular drive rails, two of which are provided and fixed to the outer surface of the tower;

[0008] a fixing frame, the fixing frame connecting the two annular drive rails and fixed to one side of the annular drive rails, one side of the fixing frame being a vertical plane;

[0009] Three laser sensor groups, wherein at least three laser sensor groups are provided and distributed along the length direction of the fixing frame;

[0010] A main shaft angle sensor is fixed on one side of the wind turbine box and monitors the main shaft rotation angle of the wind turbine hub;

[0011] A data acquisition device is electrically connected to the yaw system, pitch system, anemometer and wind vane of the wind turbine to obtain blade azimuth angle, pitch angle, wind speed and wind direction data, and is communicatively connected to the main shaft angle sensor;

[0012] A database storing standard deformation amounts of blades under different wind speeds and pitch angles, and blade design camber heights corresponding to each set of sensor positions;

[0013] A controller is communicatively connected to the data acquisition instrument and the database, and is used to:

[0014] The annular driving track is controlled according to the azimuth angle to make the fixed frame rotate synchronously;

[0015] The three laser sensors are triggered based on the spindle angle sensor data to measure the distance between each sensor and the blade, and the validity of the data is determined. When the data is valid, the real-time deformation is calculated.

[0016] Retrieve the standard deformation corresponding to the current wind speed and pitch angle, and calculate the real-time deformation;

[0017] The wind farm monitoring center receives controller data through data transmission equipment, and sends a pitch angle adjustment instruction to the pitch control system through the wind power controller when the real-time deformation amount is greater than a preset threshold.

[0018] Preferably, the annular drive track includes a fixed ring, which is fixed to the outer surface of the tower by bolts, the top of the fixed ring is fixedly connected to a gear ring, the top of the gear ring is slidably connected to an annular slide, the top of the annular slide is fixedly connected to a protective frame, one side of the inner wall of the protective frame is fixedly connected to a servo motor, and the working end of the servo motor is fixedly connected to a gear meshing with the gear ring.

[0019] Preferably, the fixing bracket is fixed to one side of the protective frame, the cross section of the annular slide is an inverted T-shaped structure, and the top of the gear ring is provided with a sliding groove adapted to the annular slide.

[0020] Preferably, the three-laser sensor group includes a left laser rangefinder, a middle laser rangefinder, a right laser rangefinder and a protective frame, and the left laser rangefinder, the middle laser rangefinder and the right laser rangefinder are located at the same height and within the protective frame.

[0021] Preferably, the distance between the left laser rangefinder and the right laser rangefinder is 50%-80% of the blade width at the corresponding height, and the distance between the left laser rangefinder and the right laser rangefinder is greater than 5%-10% of the blade width from the blade edge, and the three groups of three laser sensors are respectively arranged at 25%, 50% and 85% of the distance from the blade root in the blade length direction.

[0022] Preferably, judging the validity of the measurement data of the three laser sensor groups includes: calculating the theoretical distance difference: D1 = W × tanθ, comparing the actual distance difference: D2 = |D L -D R |, if Determine that the data is valid;

[0023] Calculate real-time deformation

[0024] Where W is the distance between the left laser rangefinder and the right laser rangefinder, D L The distance measured by the left laser rangefinder, D M is the distance measured by the laser rangefinder, D R is the distance measured by the right laser rangefinder, θ is the pitch angle, H is the design arc height of the blade, and the design arc height is measured when there is no wind and θ is 0.

[0025] Preferably, it further comprises a support ring, which is arranged between two annular drive rails. The support ring comprises a ring body, a surface of the ring body is slidably connected to a rotating ring, and one side of the rotating ring is fixedly connected to a fixing frame.

[0026] A blade deformation monitoring method, using the above device, includes the following steps:

[0027] Step 1: Obtain the azimuth angle β and drive the annular drive track to rotate so that the fixed frame rotates synchronously with the azimuth of the blade;

[0028] Step 2: Based on the measurement information of the spindle angle sensor, when one of the blades is vertical, each group of three laser sensors collects data D L 、D M and D R ;

[0029] Step 3: Data validity verification: retrieve the pitch angle θ and the H value corresponding to each layer of the three laser sensor group (3) in the database;

[0030] Calculation: D1 = W × tanθ, D2 = |D L -D R |, if Determine that the data is valid;

[0031] Step 4: Calculate the true shape:

[0032] Step 5: In response to the trigger, when δ is greater than the threshold, perform at least one of the following: send a pitch change instruction; generate a deformation alarm.

[0033] Preferably, if in step 3, the data is determined to be invalid, the set of data is discarded.

[0034] Preferably, the threshold in step 5

[0035] where δ r is the standard deformation variable stored in the database under the current wind speed V and pitch angle θ, V is the real-time wind speed, V r is the rated wind speed of the wind turbine, k is the coefficient, onshore wind turbine: k = 0.025-0.035, offshore wind turbine: k = 0.030-0.045.

[0036] (3) Beneficial effects

[0037] The present invention provides a device and method for monitoring blade deformation of wind power generation equipment. It has the following beneficial effects:

[0038] (1) The sensor and the blade azimuth are rotated synchronously through the annular drive track and the fixed frame, realizing real-time monitoring. At the same time, non-contact monitoring is adopted, which does not require the blade to be modified and avoids affecting the blade structure.

[0039] (2) By setting up multiple three-laser sensor groups, multiple positions of the blades are monitored. At the same time, the validity of the data is verified by combining the pitch angle to ensure the accuracy of the measurement. The false alarm rate is reduced by designing a dynamic threshold.

[0040] (3) By linking with the variable pitch system, the pitch angle is dynamically adjusted according to the deformation, reducing the force on the blades and extending their service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the structural installation of the present invention;

[0042] Figure 2 This is a schematic structural diagram of the annular drive track and the fixing frame of the present invention;

[0043] Figure 3 For the present invention Figure 1 Enlarged view of point A in the middle;

[0044] Figure 4 is a system block diagram of the present invention;

[0045] Figure 5 This is a measurement schematic diagram of the present invention when the pitch angle is 0;

[0046] Figure 6 Schematic diagram of measurement of a pitch angle θ according to the present invention;

[0047] Figure 7 For the present invention Figure 6 Enlarged view of point B in the middle.

[0048] In the figure: 1-annular drive track, 101-fixed ring, 102-gear ring, 103-annular slide, 104-protective frame, 105-servo motor, 106-gear, 2-fixed frame, 3-three-laser sensor group, 301-left laser rangefinder, 302-center laser rangefinder, 303-right laser rangefinder, 304-protective frame, 4-spindle angle sensor, 5-support ring, 51-ring body, 52-rotating ring. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] See also Figure 1-7 The present invention provides a technical solution: a device for monitoring blade deformation of a wind power generation device, comprising:

[0051] The annular drive track 1 is provided with two annular drive tracks 1 and is fixed to the outer surface of the tower, wherein the annular drive track 1 includes a fixed ring 101, the fixed ring 101 is fixed to the outer surface of the tower by bolts, the top of the fixed ring 101 is fixedly connected with a gear ring 102, the top of the gear ring 102 is slidably connected with an annular slide 103, the cross section of the annular slide 103 is an inverted T-shaped structure, the top of the gear ring 102 is provided with a slide groove adapted to the annular slide 103, the top of the annular slide 103 is fixedly connected with a protective frame 104, the protective frame A servo motor 105 is fixedly connected to one side of the inner wall of the frame 104, and a working end of the servo motor 105 is fixedly connected to a gear 106 meshing with the gear ring 102. The fixed ring 101, the gear ring 102, the annular slide 103 and the protective frame 104 are divided into three or four equal parts, which is convenient for installation on the surface of the tower. The servo motor 105 is started to drive the rotation of the protective frame 104 through the gear meshing transmission. A sealing ring can also be set between one side of the protective frame 104 and the tower surface to reduce rainwater and wind and sand from entering the protective frame 104.

[0052] The fixing frame 2 is connected to the two annular drive rails 1 and fixed to one side of the annular drive rail 1, and one side of the fixing frame 2 is a vertical plane; the fixing frame 2 is fixed to one side of the protective frame 104 and is fixed by bolts.

[0053] Three laser sensor groups 3, at least three groups of three laser sensor groups 3 are provided and distributed along the length direction of the fixed frame 2, and the three groups of three laser sensor groups 3 are respectively arranged at 10-30%, 35-65% and 75-90% of the distance from the blade root in the blade length direction, such as 25%, 50% and 85%, which can be adjusted according to actual needs.

[0054] The three-laser sensor group 3 includes a left laser rangefinder 301, a middle laser rangefinder 302, a right laser rangefinder 303 and a protective frame 304. The left laser rangefinder 301, the middle laser rangefinder 302 and the right laser rangefinder 303 are located at the same height and within the protective frame 304. The protective frame 304 provides a certain degree of protection for the laser rangefinders.

[0055] The distance between the left laser rangefinder 301 and the right laser rangefinder 303 is 50%-80% of the blade width at the corresponding height, and the distance between the left laser rangefinder 301 and the right laser rangefinder 303 and the blade edge is greater than 5%-10% of the blade width. The middle laser rangefinder 302 is aligned with the middle of the blade when it is in a vertical state.

[0056] The main shaft angle sensor 4 is fixed on one side of the wind turbine box. The main shaft angle sensor 4 monitors the main shaft rotation angle of the wind turbine hub to ensure that the three laser sensor groups 3 work and measure when the blades are located on one side of the tower.

[0057] A data acquisition device is electrically connected to the yaw system, pitch system, anemometer and wind vane of the wind turbine to obtain blade azimuth, pitch angle, wind speed and wind direction data, and is in communication with the main shaft angle sensor 4;

[0058] Database, the database stores the standard deformation of the blade under different wind speeds and pitch angles, and the blade design arc height H corresponding to each set of sensor positions;

[0059] The controller is connected to the data acquisition instrument and the database. The controller is used to:

[0060] Control the annular driving track 1 according to the azimuth angle to make the fixed frame 2 rotate synchronously;

[0061] According to the data from the spindle angle sensor 4, the three laser sensor group 3 is triggered to measure the distance between each sensor and the blade, and the validity of the data is judged. When the data is valid, the real-time deformation amount is calculated;

[0062] Judging the validity of the measurement data of the three laser sensor group 3 includes: calculating the theoretical distance difference: D1 = W × tanθ, comparing the measured distance difference: D2 = |D L -D R |, if Determine that the data is valid;

[0063] Retrieve the standard deformation corresponding to the current wind speed and pitch angle, and calculate the real-time deformation:

[0064]

[0065] Where W is the distance between the left laser rangefinder 301 and the right laser rangefinder 303, D L is the distance measured by the left laser rangefinder 301, D M is the distance measured by the laser rangefinder 302, D R is the distance measured by the right laser rangefinder 301, θ is the pitch angle, H is the design arc height of the blade, and the design arc height is measured when there is no wind and the blade is stationary.

[0066] The wind farm monitoring center receives controller data through data transmission equipment. When the real-time deformation is greater than the preset threshold, the wind power controller sends a pitch angle adjustment instruction to the pitch system.

[0067] The threshold

[0068] Where δ r is the standard deformation variable stored in the database under the current wind speed V and pitch angle θ, V is the real-time wind speed, V r is the rated wind speed of the wind turbine, k is the coefficient, onshore wind turbine: k = 0.025-0.035, offshore wind turbine: k = 0.030-0.045.

[0069] The data transmission equipment, controller, wind turbine controller, database and data acquisition instrument are all installed in the wind turbine chassis.

[0070] It also includes a support ring 5, which is arranged between the two annular drive rails 1. The support ring 5 includes a ring body 51. The surface of the ring body 51 is slidably connected to a rotating ring 52. One side of the rotating ring 52 is fixedly connected to the fixed frame 2. The support ring 5 provides lateral support to the fixed frame 2 to improve the stability of the fixed frame 2.

[0071] A blade deformation monitoring method, using the above-mentioned device, comprises the following steps:

[0072] Step 1: Obtain the azimuth angle β and drive the annular drive track 1 to rotate, so that the fixing frame 2 rotates synchronously with the azimuth of the blade;

[0073] Step 2: According to the measurement information of the main shaft angle sensor 4, when one of the blades is vertical, each group of three laser sensors 3 collects data D L 、D M and D R ;

[0074] Step 3: Data validity verification: retrieve the pitch angle θ and the H value corresponding to each layer of three laser sensor group 3 in the database;

[0075] Calculation: D1 = W × tanθ, D2 = |D L -D R |, if Determine that the data is valid;

[0076] Step 4: Calculate the true shape:

[0077] Step 5: In response to the trigger, when δ is greater than the threshold, perform at least one of the following: send a pitch change instruction; generate a deformation alarm.

[0078] If in step 3, the data is determined to be invalid, the set of data is discarded.

[0079] The threshold in step 5

[0080] where δ r is the standard deformation variable stored in the database under the current wind speed V and pitch angle θ, V is the real-time wind speed, V r is the rated wind speed of the wind turbine, k is the coefficient, onshore wind turbine: k = 0.025-0.035, offshore wind turbine: k = 0.030-0.045.

[0081] When the wind speed V is 0.5 times the rated wind speed, δ1=δ r *[1+k*(0.5-0.5)]=δ r ,

[0082] That is, the threshold is equal to the standard deformation. When the wind speed is higher than 0.5 times the rated wind speed, When the value is positive, the threshold value increases. When the wind speed is lower than 0.5 times the rated wind speed, When it is negative, the threshold value decreases. This is because when the wind speed increases, the normal deformation of the blade will increase, so the threshold value needs to be relaxed to avoid false alarms. When the wind speed is low, the normal deformation of the blade should be small, so the threshold value needs to be tightened to improve the detection sensitivity.

[0083] The coefficient k is set based on the aerodynamic characteristics of the wind turbine blades. The relationship between the deformation and wind speed is approximately linear. Usually for onshore wind turbines: k = 0.025-0.035, offshore wind turbines: k = 0.030-0.045. Here, k = 0.03 can be taken.

[0084] During installation, two height positions are selected on the tower's outer surface. A retaining ring 101 is bolted in place, ensuring its plane is parallel to the chassis' rotational plane. A gear ring 102 is installed atop the retaining ring. An annular slide 103 slots into the ring's top slot, forming an inverted T-shaped cross-section to prevent it from falling off. A protective frame 104 is secured to the top of the slide, housing a servo motor 105, whose output gear 106 meshes with the gear ring. A retaining bracket 2 is fixed perpendicularly to the side of the retaining bracket, forming a vertical measurement plane. Three laser sensor groups 3 are mounted on the bracket at 25%, 50%, and 85% of the blade root's length, respectively. The spacing between the left and right laser rangefinders 301 and 303 in each group is set to 70% of the blade width at the corresponding height, and 8% of the blade width from the edge, ensuring coverage of the effective blade measurement area.

[0085] In the absence of wind and with the pitch angle at 0, place the blades in a vertical position, measure the initial distance of each group of three laser sensors, and calculate the design arc height. Store in database.

[0086] During monitoring, when the wind speed sensor detects a wind speed of V = 12 m / s, the data acquisition instrument obtains the current pitch angle θ = 20°, the main shaft angle sensor feedback shows that the hub rotates to the vertical position of the blade, and the three laser sensor groups collect data: DL = 5.23 m, DM = 5.01 m, DR = 5.25 m.

[0087] Given that the blade width W of this set of sensors is 4 m, the theoretical distance difference D1 is calculated as 4 × tan20° ≈ 1.46 m, D2 = |5.23-5.25| = 0.02 m, and |D2-D1| / D1 = (1.46-0.02) / 1.46 ≈ 0.986 ≤ 0.1. The data is valid.

[0088] Retrieve the standard deformation variable δ under this working condition r =0.08m, H=0.1m, rated wind speed V r =12m / s, onshore wind turbine k=0.03.

[0089] The calculated threshold value δ1=0.08×[1+0.03×(12 / 12-0.5)]=0.08×1.015=0.0812m.

[0090] The calculated true deformation δ = |(5.23+5.25) / 2-5.01-0.1×cos20°| = |5.24-5.01-0.094| = 0.136m>0.0812m.

[0091] The wind farm monitoring center sends instructions to the pitch control system to increase the pitch angle, reduce the windward area of the blades, and reduce deformation stress.

[0092] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0093] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for monitoring blade deformation of a wind power generation device, characterized in that: include: An annular drive track (1), wherein two annular drive tracks (1) are provided and fixed to the outer surface of the tower; A fixing frame (2), the fixing frame (2) being connected to the two annular drive rails (1) and fixed on one side of the annular drive rails (1), one side of the fixing frame (2) being a vertical plane; Three laser sensor groups (3), wherein at least three of the three laser sensor groups (3) are provided and distributed along the length direction of the fixing frame (2); A main shaft angle sensor (4), the main shaft angle sensor (4) is fixed on one side of the wind turbine box, and the main shaft angle sensor (4) monitors the main shaft rotation angle of the wind turbine hub; A data acquisition device, the data acquisition device is electrically connected to the yaw system, pitch system, anemometer and wind vane of the wind turbine generator set, acquires blade azimuth angle, pitch angle, wind speed and wind direction data, and is communicatively connected to the main shaft angle sensor (4); A database storing standard deformation amounts of blades under different wind speeds and pitch angles, and blade design camber heights corresponding to each set of sensor positions; A controller is communicatively connected to the data acquisition instrument and the database, and is used to: Controlling the annular driving track (1) according to the azimuth angle causes the fixing frame (2) to rotate synchronously; According to the data of the main shaft angle sensor (4), the three laser sensor groups (3) are triggered to measure the distance between each sensor and the blade, and the validity of the data is judged. When the data is valid, the real-time deformation amount is calculated; Retrieve the standard deformation corresponding to the current wind speed and pitch angle, and calculate the real-time deformation; The wind farm monitoring center receives controller data through data transmission equipment, and sends a pitch angle adjustment instruction to the pitch control system through the wind power controller when the real-time deformation amount is greater than a preset threshold.

2. The device for monitoring blade deformation of a wind power generation device according to claim 1, characterized in that: The annular drive track (1) comprises a fixing ring (101), the fixing ring (101) being fixed to the outer surface of the tower by bolts, the top of the fixing ring (101) being fixedly connected to a gear ring (102), the top of the gear ring (102) being slidably connected to an annular slide (103), the top of the annular slide (103) being fixedly connected to a protective frame (104), one side of the inner wall of the protective frame (104) being fixedly connected to a servo motor (105), and the working end of the servo motor (105) being fixedly connected to a gear (106) meshing with the gear ring (102).

3. The device for monitoring blade deformation of a wind power generation device according to claim 2, characterized in that: The fixing frame (2) is fixed to one side of the protective frame (104); the cross section of the annular slide (103) is an inverted T-shaped structure; and a sliding groove adapted to the annular slide (103) is provided on the top of the gear ring (102).

4. The device for monitoring blade deformation of a wind power generation device according to claim 1, characterized in that: The three-laser sensor group (3) comprises a left laser rangefinder (301), a middle laser rangefinder (302), a right laser rangefinder (303) and a protective frame (304); the left laser rangefinder (301), the middle laser rangefinder (302) and the right laser rangefinder (303) are located at the same height and within the protective frame (304).

5. The device for monitoring blade deformation of wind power generation equipment according to claim 4, characterized in that: The distance between the left laser rangefinder (301) and the right laser rangefinder (303) is 50%-80% of the blade width at the corresponding height, and the distance between the left laser rangefinder (301) and the right laser rangefinder (303) and the blade edge is greater than 5%-10% of the blade width. The three groups of three laser sensor groups (3) are respectively arranged at 25%, 50% and 85% of the distance from the blade root in the blade length direction.

6. The device for monitoring blade deformation of a wind power generation device according to claim 4, characterized in that: The validity of the measurement data of the three laser sensor groups (3) is determined by: calculating the theoretical distance difference: D1 = W × tanθ, comparing the measured distance difference: D2 = |D L -D R |, if Determine that the data is valid; Calculate real-time deformation Where W is the distance between the left laser rangefinder (301) and the right laser rangefinder (303), D L is the distance measured by the left laser rangefinder (301), D M is the distance measured by the laser rangefinder (302), D R is the distance measured by the right laser rangefinder (301), θ is the pitch angle, H is the design arc height of the blade, and the design arc height is measured when there is no wind and θ is 0.

7. The device for monitoring blade deformation of a wind power generation device according to claim 1, characterized in that: The invention also comprises a support ring (5), wherein the support ring (5) is arranged between two annular drive rails (1), and the support ring (5) comprises a ring body (51), a surface of the ring body (51) is slidably connected to a rotating ring (52), and one side of the rotating ring (52) is fixedly connected to the fixed frame (2).

8. A blade deformation monitoring method, using the device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Obtain the azimuth angle β, drive the annular driving track (1) to rotate, so that the fixing frame (2) rotates synchronously with the azimuth of the blade; Step 2: According to the measurement information of the main shaft angle sensor (4), when one of the blades is vertical, each group of three laser sensors (3) collects data D L 、D M and D R ; Step 3: Data validity verification: retrieve the pitch angle θ and the H value corresponding to each layer of the three laser sensor group (3) in the database; Calculation: D1 = W × tanθ, D2 = |D L -D R |, if Determine that the data is valid; Step 4: Calculate the true shape: Step 5: In response to the trigger, when δ is greater than the threshold, perform at least one of the following: send a pitch change instruction; generate a deformation alarm.

9. The blade deformation monitoring method according to claim 8, characterized in that: If in step 3, the data is determined to be invalid, the set of data is discarded.

10. The blade deformation monitoring method according to claim 8, characterized in that: The threshold in step 5 where δ r is the standard deformation variable stored in the database under the current wind speed V and pitch angle θ, V is the real-time wind speed, V r is the rated wind speed of the wind turbine, k is the coefficient, onshore wind turbine: k = 0.025-0.035, offshore wind turbine: k = 0.030-0.045.

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