A method and system for monitoring blade tip torsion of a wind turbine

Abstract

The application discloses a kind of wind generating set blade tip twist monitoring methods, comprising the following steps: S1, sensor, fiber grating and fiber gyroscope are installed at each measuring point of blade tip;S2, after wind generating set is powered on, make fiber gyroscope and sensor record data;S3, data is mediated and filtered;S4, according to the data after processing, construct blade deformation model;S5, based on least square edge model is solved, based on blade stiffness, physical equation is established, and blade deformation data are acquired;S6, according to blade deformation data on different components, the twist amount of blade in the process of rotation can be obtained, and the monitoring of wind generating set blade tip twist is completed;The application can realize the measurement of blade in long-term stability, obtain the twist data of blade tip of super-long blade in the process of operation, solve the problem that original blade root stress monitoring system cannot monitor blade twist.

Description

Technical Field

[0001] This invention relates to the technical field of wind turbine blade tip torsion monitoring, and in particular to a method and system for monitoring wind turbine blade tip torsion. Background Technology

[0002] The tip of a wind turbine blade is relatively small and carries a relatively large load, making load measurement at the blade tip quite challenging. Currently, there is no corresponding measurement equipment; the monitoring range is limited to the area from the blade root to about 30 meters in front of the blade root, resulting in a relatively narrow monitoring range and a lack of comprehensive monitoring of the entire blade. Further improvements are needed to enhance the comprehensive monitoring capabilities for wind turbine blades.

[0003] The existing blade stress monitoring system can only be installed 30m from the blade tip and only monitors the flapping and swaying loads. The actual load deformation at the blade tip differs significantly from the data monitored at the blade root. Furthermore, the blade tip exhibits complex torsional deformation, making data measured at the wind turbine root ineffective for monitoring operational data at the blade tip. The actual blade root data in operation differs considerably from the design requirements. Considering the future development needs of ultra-long wind turbine blades and the functional requirements of blade tip monitoring, it is necessary to collect torsional data at the blade tip. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and propose a method and system for monitoring the tip torsion of wind turbine blades. The sensor is stably installed at the tip of the ultra-long blade of the wind turbine and the blade is measured stably in the medium and long term to obtain the torsion data of the tip of the ultra-long blade during operation.

[0005] The objective of this invention is achieved through the following technical solution: a method for monitoring the tip torsion of wind turbine blades, comprising the following steps:

[0006] S1. Sensors, fiber optic gratings, and fiber optic gyroscopes are installed at various measuring points at the tips of the wind turbine blades, wherein the sensors include fiber optic sensors and temperature sensors.

[0007] S2. After the wind turbine generator is powered on, the fiber optic gyroscope and sensors record data.

[0008] S3. Acquire the data recorded by the sensors at each measuring point, and perform adjustment and filtering on the data;

[0009] S4. Based on the processed data, construct a blade deformation model;

[0010] S5. Based on the blade deformation model and the processed data from step S3, solve the problem using the least squares side division model, establish physical equations based on blade stiffness, and obtain blade deformation data.

[0011] S6. Based on the blade deformation data at different components, the amount of twist of the blade during rotation can be obtained, thus completing the monitoring of the tip twist of the wind turbine blade.

[0012] Furthermore, step S1 includes the following steps:

[0013] Before the wind turbine is assembled, the sensor is installed inside the tip of the wind turbine blade. The demodulator and processor are installed inside the hub of the wind turbine nacelle. The demodulator and processor are wired to the sensor to acquire the data of the sensor's internal operation. At the same time, the fiber optic grating is bonded to the corresponding measuring point inside the blade tip with epoxy resin adhesive. The grating is placed at a distance of 1.5m to 10.5m from the blade tip. Fiber optic gyroscopes are placed at the corresponding positions to monitor the blade position.

[0014] Furthermore, step S2 includes the following steps:

[0015] After the wind turbine generator is powered on, the corresponding working state of the fiber optic gyroscope is recorded, and the working state data is set as the initial state. The state quantities of the fiber optic grating sensor inside the fiber optic sensor and the temperature state quantities of the blade temperature sensor are recorded as the initial state quantities. The fiber optic grating sensor records stress to obtain the measured value of blade strain.

[0016] Furthermore, step S3 includes the following steps:

[0017] The optical signal data at the corresponding measurement point is acquired, demodulated, and filtered. The temperature data at the measurement point is then recorded, the temperature drift is adjusted, and the data from the fiber Bragg grating sensor is processed to reduce the interference of temperature on the signal.

[0018] Furthermore, step S4 includes the following steps:

[0019] After parametric modeling using the inverse finite element method, a shape function matrix is ​​established using 24-DOF four-node surface elements based on the processed blade data. The matrix is ​​then calculated based on strain theory to construct the blade deformation model, as shown in the following formula:

[0020]

[0021] Where T represents the amount of deformation of the corresponding sheet metal, u i v i w i Let θ be the displacement corresponding to the blade. xiLet θ be the angle of twist on the X-axis. yi Let θ be the angle of twist on the Y-axis. zi Let be the torsion angle on the Z-axis.

[0022] Furthermore, step S5 includes the following steps:

[0023] Based on the calculation parameters of the corresponding blade deformation model and the measured blade strain values ​​obtained in step S3, the solution is performed using the least squares side-part model. Simultaneously, a physical equation is established based on the blade stiffness to obtain blade deformation data. The physical equation established based on the blade stiffness is as follows:

[0024]

[0025]

[0026] Where K1 is the blade elongation displacement, K2 is the blade bending displacement, K3 is the blade torsional displacement, and U R For the displacement at the corresponding point, F R For stress.

[0027] Furthermore, step S6 includes the following steps:

[0028] Based on the data from the fiber optic gyroscope and the corresponding rotation state of the blade, after obtaining the corresponding rotation state and relative position data, the blade deformation data is analyzed. By obtaining the deformation data in different components, the amount of twist of the blade during the rotation process can be obtained, thus completing the monitoring of the tip twist of the wind turbine blade.

[0029] A monitoring system for the tip torsion of wind turbine blades, used to implement the aforementioned method for monitoring the tip torsion of wind turbine blades, comprising:

[0030] The data acquisition module is used to acquire data from the fiber optic gyroscope and sensors;

[0031] The data processing module is used to adjust and filter the acquired data;

[0032] The blade deformation model construction module constructs a blade deformation model based on the processed data.

[0033] The blade tip torsion calculation module calculates the amount of torsion of the blade during rotation based on the blade deformation data at different components.

[0034] A non-transitory computer-readable medium storing instructions that, when executed by a processor, perform the steps of the wind turbine blade tip torsion monitoring method described above.

[0035] A computing device includes a processor and a memory for storing processor-executable programs, wherein when the processor executes the programs stored in the memory, it implements the above-described method for monitoring the tip torsion of wind turbine blades.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] 1. Improve the monitoring performance of the existing blade root stress monitoring system to monitor the blade tip and avoid misjudgment of blade data caused by the large difference between the operating data at the blade root and the operating data at the blade tip.

[0038] 2. Monitor the torsional deformation of the blade during its rotation process, solving the previous problem of not being able to monitor the blade at its full size, and also solving the problem that the original blade root stress monitoring system could not monitor blade torsion.

[0039] 3. Solve the problem of installing the sensor at the blade tip, realize the installation of the sensor at the blade tip and achieve medium- and long-term use. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the isometric structure of a wind turbine blade tip.

[0041] Figure 2 This is a flowchart of the algorithm for monitoring the tip torsion of wind turbine blades. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments.

[0043] Example 1

[0044] See Figures 1 to 2 As shown, this embodiment provides a method for monitoring the tip torsion of wind turbine blades, including the following steps:

[0045] S1. Install sensors, fiber optic gratings, and fiber optic gyroscopes at various measuring points on the tips of wind turbine blades, wherein the sensors include fiber optic sensors and temperature sensors, and include the following steps:

[0046] Before the wind turbine is assembled, the sensor is installed inside the tip of the wind turbine blade. The demodulator and processor are installed inside the hub of the wind turbine nacelle. The demodulator and processor are wired to the sensor to acquire the data of the sensor's internal operation. At the same time, the fiber optic grating is bonded to the corresponding measuring point inside the blade tip with epoxy resin adhesive. The grating is placed at a distance of 1.5m to 10.5m from the blade tip. Fiber optic gyroscopes are placed at the corresponding positions to monitor the blade position.

[0047] S2. After the wind turbine generator is powered on, the fiber optic gyroscope and sensors record data, including the following steps:

[0048] After the wind turbine generator is powered on, the corresponding working state of the fiber optic gyroscope is recorded, and the working state data is set as the initial state. The state quantities of the fiber optic grating sensor inside the fiber optic sensor and the temperature state quantities of the blade temperature sensor are recorded as the initial state quantities. The fiber optic grating sensor records stress to obtain the measured value of blade strain.

[0049] S3. Acquire the data recorded by the sensors at each measuring point, and perform data adjustment and filtering processing, including the following steps:

[0050] The optical signal data at the corresponding measurement point is acquired, demodulated, and filtered. The temperature data at the measurement point is then recorded, the temperature drift is adjusted, and the data from the fiber Bragg grating sensor is processed to reduce the interference of temperature on the signal.

[0051] S4. Based on the processed data, construct a blade deformation model, including the following steps:

[0052] After parametric modeling using the inverse finite element method, a shape function matrix is ​​established using 24-DOF four-node surface elements based on the processed blade data. The matrix is ​​then calculated based on strain theory to construct the blade deformation model, as shown in the following formula:

[0053]

[0054] Where T represents the amount of deformation of the corresponding sheet metal, u i v i w i Let θ be the displacement corresponding to the blade. xi Let θ be the angle of twist on the X-axis. yi Let θ be the angle of twist on the Y-axis. zt Let be the torsion angle on the Z-axis.

[0055] S5. Based on the blade deformation model and the processed data from step S3, solve the problem using the least squares side-part model, establish physical equations based on blade stiffness, and obtain blade deformation data, including the following steps:

[0056] Based on the calculation parameters of the corresponding blade deformation model and the measured blade strain values ​​obtained in step S3, the solution is performed using the least squares side-part model. Simultaneously, a physical equation is established based on the blade stiffness to obtain blade deformation data. The physical equation established based on the blade stiffness is as follows:

[0057]

[0058]

[0059] Where K1 is the blade elongation displacement, K2 is the blade bending displacement, K3 is the blade torsional displacement, and U R For the displacement at the corresponding point, F R For stress.

[0060] S6. Based on the blade deformation data at different components, the amount of twist of the blade during rotation can be obtained, thus completing the monitoring of the tip twist of the wind turbine blade. This includes the following steps:

[0061] Based on the data from the fiber optic gyroscope and the corresponding rotation state of the blade, after obtaining the corresponding rotation state and relative position data, the blade deformation data is analyzed. By obtaining the deformation data in different components, the amount of twist of the blade during the rotation process can be obtained, thus completing the monitoring of the tip twist of the wind turbine blade.

[0062] See Figure 2 As shown, the algorithm construction process used in this invention is as follows:

[0063] 1) A shape function matrix is ​​established using 24-DOF four-node surface elements to obtain monitoring data from distributed strain sensors;

[0064] 2) Optimize the configuration of the strain sensor monitoring data after dimensionality reduction, establish the strain theory calculation matrix, and obtain the blade elongation-bending-torsional strain field;

[0065] 3) Solve for the stiffness matrix and establish the physical equations. Calculate the actual measured strain values ​​using the least squares functional method.

[0066] Example 2

[0067] This embodiment provides a monitoring system for the tip torsion of wind turbine blades, characterized in that it is used in the monitoring method for the tip torsion of wind turbine blades described in Embodiment 1, comprising:

[0068] The data acquisition module is used to acquire data from the fiber optic gyroscope and sensors;

[0069] The data processing module is used to adjust and filter the acquired data;

[0070] The blade deformation model construction module constructs a blade deformation model based on the processed data.

[0071] The blade tip torsion calculation module calculates the amount of torsion of the blade during rotation based on the blade deformation data at different components.

[0072] Example 3

[0073] This embodiment discloses a non-transitory computer-readable medium storing instructions that, when executed by a processor, perform the steps of the monitoring method for wind turbine blade tip torsion according to Embodiment 1.

[0074] In this embodiment, the non-transitory computer-readable medium can be a disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), USB flash drive, portable hard drive, etc.

[0075] Example 4

[0076] This embodiment discloses a computing device, including a processor and a memory for storing processor-executable programs. When the processor executes the program stored in the memory, it implements the method for monitoring the tip torsion of wind turbine blades as described in Embodiment 1.

[0077] The computing device described in this embodiment may be a desktop computer, laptop computer, smartphone, PDA handheld terminal, tablet computer, programmable logic controller (PLC), or other terminal device with processor function.

[0078] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any changes made in accordance with the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for monitoring tip torsion of wind turbine blades, characterized in that, Includes the following steps: S1. Install sensors and fiber optic gyroscopes at various measuring points on the blade tip of the wind turbine generator set. The sensors include fiber optic grating sensors and temperature sensors. The installation process includes the following steps: Before the wind turbine generator set is molded, the sensors are installed inside the blade tip. The demodulator and processor are installed inside the nacelle hub of the wind turbine generator set. The demodulator and processor are wired to the sensors to acquire data on the operation inside the sensors. At the same time, the fiber optic grating sensors are glued to the corresponding measuring points inside the blade tip using epoxy resin adhesive. The arrangement positions are 1.5m to 10.5m away from the blade tip, and fiber optic gyroscopes are arranged at the corresponding positions to monitor the blade position. S2. After the wind turbine generator is powered on, the fiber optic gyroscope and sensor record data, including the following steps: After the wind turbine generator is powered on, the corresponding working state of the fiber optic gyroscope is recorded and the working state is set as the initial state. The state quantity of the fiber optic grating inside the fiber optic grating sensor and the temperature state quantity of the blade temperature sensor are recorded as the initial state quantity. The fiber optic grating sensor records stress to obtain the measured value of blade strain. S3. Acquire the data recorded by the sensors at each measuring point, and perform adjustment and filtering on the data; S4. Based on the processed data, construct a blade deformation model, including the following steps: After parametric modeling using the inverse finite element method, a shape function matrix is ​​established using 24-DOF four-node surface elements based on the processed blade data. The matrix is ​​then calculated based on strain theory to construct the blade deformation model, as shown in the following formula: ； Where T represents the amount of deformation of the corresponding sheet metal. This represents the displacement corresponding to the blade. Let be the angle of twist on the X-axis. Let be the angle of twist on the Y-axis. The angle of twist on the Z-axis; S5. Based on the blade deformation model and the processed data from step S3, solve the problem using the least squares side division model, establish physical equations based on blade stiffness, and obtain blade deformation data. S6. Based on the blade deformation data at different components, the amount of twist of the blade during rotation can be obtained, thus completing the monitoring of the tip twist of the wind turbine blade.

2. The method for monitoring tip torsion of wind turbine blades according to claim 1, characterized in that, Step S3 includes the following steps: The optical signal data at the corresponding measurement point is acquired, demodulated, and filtered. The temperature data at the measurement point is then recorded, the temperature drift is adjusted, and the data from the fiber optic grating sensor is filtered to reduce the interference of temperature on the signal.

3. The method for monitoring tip torsion of wind turbine blades according to claim 1, characterized in that, Step S6 includes the following steps: Based on the data from the fiber optic gyroscope and the corresponding rotation state of the blade, after obtaining the corresponding rotation state and relative position data, the blade deformation data is analyzed. By obtaining the deformation data in different components, the amount of twist of the blade during the rotation process can be obtained, thus completing the monitoring of the tip twist of the wind turbine blade.

4. A monitoring system for tip torsion of wind turbine blades, characterized in that, The method for monitoring the tip torsion of wind turbine blades according to any one of claims 1-3 includes: The data acquisition module is used to acquire data from the fiber optic gyroscope and sensors; The data processing module is used to adjust and filter the acquired data; The blade deformation model construction module constructs a blade deformation model based on the processed data. The blade tip torsion calculation module calculates the amount of torsion of the blade during rotation based on the blade deformation data at different components.

5. A non-transitory computer-readable medium storing instructions, characterized in that, When the instruction is executed by the processor, the steps of the method for monitoring the tip torsion of wind turbine blades according to any one of claims 1-3 are performed.

6. A computing device, comprising a processor and a memory for storing a processor-executable program, characterized in that, When the processor executes the program stored in the memory, it implements the method for monitoring the tip torsion of wind turbine blades as described in any one of claims 1-3.

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