Vertical wind shear calculation method based on impeller azimuth angle and pitch motor current
By calculating vertical wind shear based on impeller azimuth angle and pitch motor current, the problem of deviation in the evaluation of blade flapping moment load and power curve of wind turbine is solved, realizing accurate wind shear evaluation and safety decision-making, and improving the consistency of simulation test and blade safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG MINGYANG WIND POWER IND GRP CO LTD
- Filing Date
- 2026-04-13
- Publication Date
- 2026-06-30
AI Technical Summary
In existing technologies, the measurement error of vertical wind shear is large, which leads to a large deviation in the evaluation of the flapping moment load and power curve of wind turbine blades. Furthermore, it is difficult to accurately evaluate the flapping moment fatigue load of wind turbine blades without blade load sensors.
By obtaining the rotor azimuth angle and pitch motor current of the wind turbine, an array and a relational table are established. The average and maximum values of the pitch motor current for each blade are calculated to determine the vertical wind shear value. The wind shear is then calculated using the relationship between the rotor azimuth angle and the pitch motor current.
It improves the accuracy of simulation testing of blade flapping moment load and power curve, provides a reliable basis for decision-making on safe blade operation, and does not require additional hardware costs.
Smart Images
Figure CN122304943A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of wind turbine simulation testing, and in particular to a method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current. Background Technology
[0002] Vertical wind shear is an important wind resource parameter that has a significant impact on the flapping moment load of wind turbine blades. This parameter is mainly obtained by calculating and fitting the wind speed values measured at different heights by anemometer towers or ground-based lidar. However, the measurement error of vertical wind shear values obtained by this method is large.
[0003] In the type certification test data of wind turbines, there are many instances of low vertical wind shear fitting values. Furthermore, the peak-to-peak value of the frequency component fluctuation of the measured blade root flapping moment load (1P) is significantly higher than the simulated values in the Bladed software under the corresponding wind resource parameters. Simultaneously, the average output power of the measured wind turbines is also significantly higher than the design value at the corresponding wind speed. Additionally, there are instances where the wind speed variation is small below the hub center in the vertical direction, but follows a certain shear exponent above the hub center, or vice versa. The more complex wind speed distribution within the rotor's plane of rotation also cannot be accurately identified, ultimately leading to significant deviations in the assessment of blade flapping moment load and power curves. Moreover, for wind turbines operating in batches, the relationship between the statistical values of vertical wind shear parameters and the design values of vertical wind shear under power generation mode is unknown, making it impossible to assess the blade flapping moment load and operational safety of the wind turbine. For wind turbines without blade load sensors, it is difficult to accurately assess the blade flapping moment fatigue load.
[0004] Therefore, there is an urgent need for a vertical wind shear calculation method to solve the problem of large deviations in simulation test comparisons for type certification, to provide a verification option based on vertical wind shear, to improve the accuracy of simulation test comparisons of blade flapping moment load and power curve, and to further provide a decision-making basis for blade flapping moment fatigue load control. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a method for calculating vertical wind shear based on impeller azimuth and pitch motor current. For type-certified wind turbines, this method provides verification for comparing and evaluating the consistency between simulation and testing of blade flapping moment load and power curves. For wind turbines in batch operation, it enables comparison of the vertical wind shear during each unit's power generation mode with the design vertical wind shear value for the corresponding turbine location, assessing the flapping moment fatigue load of each blade. For wind turbines without blade load sensors, the calculated vertical wind shear is acquired in real time, providing a reliable decision-making basis for safe blade operation.
[0006] The objective of this invention is achieved through the following technical solution: a vertical wind shear calculation method based on impeller azimuth angle and pitch motor current, used to control the blade flapping moment load of wind turbine units, comprising the following steps:
[0007] S1. Obtain the real-time rotor azimuth angle of the wind turbine and the real-time pitch motor current of each blade.
[0008] S2. Establish an array to store the sum of the pitch motor currents. Calculate the sum of the pitch motor currents of each blade within the preset operating cycle and at the corresponding impeller azimuth position. Store the sum of the pitch motor currents in the array. Add the real-time pitch motor currents of each blade obtained in step S1 to the elements of the array at the current impeller azimuth position.
[0009] S3. In each preset operating cycle, calculate the average pitch motor current of each blade within the impeller azimuth interval based on the elements of the array in step S2.
[0010] S4. Based on the average pitch motor current of each blade within the impeller azimuth angle interval, determine the maximum pitch motor current of each blade, and calculate the impeller azimuth angle range corresponding to the maximum pitch motor current of each blade.
[0011] S5. Establish a vertical wind shear vs. impeller azimuth angle relationship table; and based on the impeller azimuth angle range obtained in step S4, query the vertical wind shear vs. impeller azimuth angle relationship table to determine the vertical wind shear value of each blade during the operating cycle, and save it to SCADA data.
[0012] Furthermore, step S1 includes:
[0013] The real-time azimuth angles of blades 1, 2, and 3 on the impeller rotation plane are obtained by an absolute encoder installed inside the hub of the wind turbine and rotating with the main shaft.
[0014] When blade 1 is vertically upward, the impeller azimuth angle is defined as 0°. When the impeller rotates clockwise for one revolution, the impeller azimuth angle increases to a maximum of 360°. After the impeller azimuth angle increases to 360°, it starts to increase again from 0°. Blade 1, blade 2, and blade 3 are arranged clockwise in the impeller rotation plane, and the interval between blade 1 and blade 2, blade 2 and blade 3, and blade 3 and blade 1 is 120°.
[0015] Furthermore, step S1 includes:
[0016] For the pitch electrical system of a wind turbine that drives the blades to rotate and thus adjusts the blade angle, the pitch motor driving torque and the pitch motor current satisfy a linear relationship within the normal operating range, that is: T=K×I.
[0017] Where T represents the driving torque of the pitch motor, I represents the current of the pitch motor, and K represents the torque coefficient;
[0018] The pitch drive electrical systems of blades 1, 2, and 3 exchange data with the wind turbine main control PLC via fieldbus during each task cycle, transmitting the real-time pitch motor current values of blades 1, 2, and 3 to the wind turbine main control PLC.
[0019] Furthermore, step S2 includes:
[0020] Within a 10-millisecond task cycle in the wind turbine main control PLC program, three arrays, each with 180 elements, are created to represent blade 1, blade 2, and blade 3 within a 2° azimuth angle interval during one revolution of the impeller. These arrays are used to store the sum of the pitch motor currents of blade 1, blade 2, and blade 3 at the corresponding impeller azimuth angle positions within a 10-minute operating cycle. The real-time pitch motor currents of blade 1, blade 2, and blade 3 measured in each 10-millisecond task cycle are then superimposed onto the elements of the array at the current impeller azimuth angle position.
[0021] Furthermore, step S3 includes:
[0022] Within each ten-minute operating cycle, the average pitch motor current of blades 1, 2, and 3 within 180 impeller azimuth intervals is calculated based on the elements of the array in step S2.
[0023] Furthermore, step S4 includes:
[0024] When blades 1, 2, and 3 rotate to the impeller azimuth angle range of 240°-330° in the impeller rotation plane, the maximum value of the pitch motor current of blades 1, 2, and 3 and the corresponding impeller azimuth angle range are calculated based on the average value of the pitch motor current of blades 1, 2, and 3 within 180 impeller azimuth angle intervals.
[0025] Furthermore, step S5 includes:
[0026] Establish a table of vertical wind shear vs. impeller azimuth angle relationship under a ten-minute operating cycle based on an interval of 0.05 vertical wind shear; according to the impeller azimuth angle range obtained in step S4, query the table of vertical wind shear vs. impeller azimuth angle relationship, determine the vertical wind shear value of each blade in the ten-minute operating cycle, and save it to SCADA data.
[0027] A vertical wind shear calculation system based on impeller azimuth angle and pitch motor current is used to implement the aforementioned vertical wind shear calculation method based on impeller azimuth angle and pitch motor current, including:
[0028] The data acquisition module is used to acquire the real-time rotor azimuth angle of the wind turbine and the real-time pitch motor current of each blade.
[0029] An array module is used to store the pitch motor current at each impeller azimuth position;
[0030] The pitch motor current superposition module calculates the sum of the pitch motor current of each blade within a preset operating cycle and at the corresponding impeller azimuth position, stores the sum of the pitch motor current in the array module, and superimposes the real-time pitch motor current of each blade from the data acquisition module into the array module at the current impeller azimuth position.
[0031] The pitch motor current average calculation module calculates the average pitch motor current of each blade within the impeller azimuth angle interval based on the pitch motor current data in the array module within each preset operating cycle.
[0032] The impeller azimuth angle range calculation module determines the maximum value of the pitch motor current for each blade based on the average value of the pitch motor current for each blade within the impeller azimuth angle interval, and calculates the impeller azimuth angle range corresponding to the maximum value of the pitch motor current for each blade.
[0033] The relationship table module includes a built-in vertical wind shear vs. impeller azimuth relationship table.
[0034] The vertical wind shear value determination module, based on the impeller azimuth angle range obtained by the impeller azimuth angle range calculation module, queries the vertical wind shear vs. impeller azimuth angle relationship table in the relationship table module to determine the vertical wind shear value of each blade during the operating cycle and saves it to the SCADA data.
[0035] A non-transitory computer-readable medium storing instructions that, when executed by a processor, perform the steps of the vertical wind shear calculation method based on the impeller azimuth angle and pitch motor current described above.
[0036] A computing device includes a processor and a memory for storing processor-executable programs. When the processor executes the program stored in the memory, it implements the above-described method for calculating vertical wind shear based on impeller azimuth and pitch motor current.
[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0038] 1. For type-certified wind turbines, this invention can obtain accurate vertical wind shear values for testing and verification, significantly improving the accuracy of the simulation and testing consistency comparison evaluation of blade flapping moment load and power curve, which has been a persistent problem in the wind power industry.
[0039] 2. For wind turbine generator sets operating in batches, it is possible to statistically analyze the vertical wind shear of each unit in power generation mode, compare it with the design vertical wind shear value of the corresponding turbine location, and further evaluate the flapping moment fatigue load of each blade.
[0040] 3. For operating conditions where the generator speed is near the rated speed and the vertical wind shear is high, it can provide a reliable basis for decision-making regarding the safe operation of its blades.
[0041] 4. No additional hardware costs are required, making it economical. Attached Figure Description
[0042] Figure 1 This is a flowchart of the vertical wind shear calculation and control based on the impeller azimuth angle and the pitch motor current.
[0043] Figure 2 The scatter plot shows the distribution of the blade root bending moment Mz versus the impeller azimuth angle when the vertical wind shear is 0.2.
[0044] Figure 3 The scatter plot shows the distribution of the blade root bending moment Mz versus the impeller azimuth angle when the vertical wind shear is 0.4.
[0045] Figure 4 Scattered distribution of blade root bending moment Mz versus impeller azimuth angle when vertical wind shear is 0.6.
[0046] Figure 5Scattered distribution of blade root bending moment Mz versus impeller azimuth angle when vertical wind shear is 0.8.
[0047] Figure 6 Scattered distribution of blade root bending moment Mz versus impeller azimuth angle under vertical wind shear of 1.0.
[0048] Figure 7 The scatter plot shows the distribution of the blade root bending moment Mz versus the impeller azimuth angle under a vertical wind shear of 1.2.
[0049] Figure 8 The sequence diagram shows the operation of the fan output power under different vertical wind shears in a steady wind of 8 m / s.
[0050] Figure 9 The figure shows the scatter plots of blade root flapping moment and pitch motor current versus impeller azimuth angle under the operating conditions of an average wind speed of 13.04 m / s and a vertical wind shear of 0.14.
[0051] Figure 10 For an average wind speed of 10.29 m / s and a vertical wind shear of 0.63, the following are scatter plots: blade root flapping moment and blade root flapping moment vs. impeller azimuth angle; and pitch motor current vs. impeller azimuth angle.
[0052] Figure 11 For an average wind speed of 7.63 m / s and a vertical wind shear of 0.98, the following are scatter plots: blade root flapping moment and blade root flapping moment vs. impeller azimuth angle; and pitch motor current vs. impeller azimuth angle.
[0053] Figure 12 For an average wind speed of 3.8 m / s and a measured vertical wind shear of 0.44, the following data are presented: blade root flapping moment, wind turbine output power operation sequence, scatter plots of blade root flapping moment vs. impeller azimuth angle, and scatter plots of pitch motor current vs. impeller azimuth angle.
[0054] Figure 13 The sequence diagram shows the output power of the fan in a Bladed simulation under different vertical wind shears in turbulent wind with an average wind speed of 3.8 m / s.
[0055] Figure 14 The sequence diagram shows the operation of the blade root flapping moment of a wind turbine under different vertical wind shears in a turbulent wind with an average wind speed of 3.8 m / s, as simulated by Bladed.
[0056] Figure 15 For an average wind speed of 6.38 m / s and a measured vertical wind shear of 0.257, the following data are presented: blade root flapping moment, wind turbine output power operation sequence, scatter plots of blade root flapping moment vs. impeller azimuth angle, and scatter plots of pitch motor current vs. impeller azimuth angle.
[0057] Figure 16For an average wind speed of 6.48 m / s and a measured vertical wind shear of 0.35, the following data are collected: blade root flapping moment, wind turbine output power operation sequence, scatter plots of blade root flapping moment vs. impeller azimuth angle, and scatter plots of pitch motor current vs. impeller azimuth angle.
[0058] Figure 17 For an average wind speed of 6.59 m / s and a measured vertical wind shear of 0.749, the following data are presented: blade root flapping moment, wind turbine output power operation sequence, scatter plots of blade root flapping moment vs. impeller azimuth angle, and scatter plots of pitch motor current vs. impeller azimuth angle. Detailed Implementation
[0059] The present invention will be further described below with reference to specific embodiments.
[0060] Example 1
[0061] See Figure 1 As shown, a method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current is used to control the blade flapping moment load of wind turbine units, including the following steps:
[0062] S1. Obtain the real-time rotor azimuth angle of the wind turbine and the real-time pitch motor current of each blade.
[0063] An absolute encoder installed inside the hub of the wind turbine and rotating with the main shaft is used to obtain the real-time azimuth angles of blades 1, 2, and 3 on the rotor rotation plane.
[0064] When blade 1 is vertically upward, the impeller azimuth angle is defined as 0°. When the impeller rotates clockwise for one revolution, the impeller azimuth angle increases to a maximum of 360°. After the impeller azimuth angle increases to 360°, it starts to increase again from 0°. Blade 1, blade 2, and blade 3 are arranged clockwise in the impeller rotation plane, and the interval between blade 1 and blade 2, blade 2 and blade 3, and blade 3 and blade 1 is 120°.
[0065] When the impeller azimuth angle is 90°, blade 1 rotates to the 3 o'clock position; when the impeller azimuth angle is 270°, blade 1 rotates to the 9 o'clock position. When the impeller azimuth angle is 330°, blade 2 rotates to the 3 o'clock position; when the impeller azimuth angle is 150°, blade 2 rotates to the 9 o'clock position. When the impeller azimuth angle is 210°, blade 3 rotates to the 3 o'clock position; when the impeller azimuth angle is 30°, blade 3 rotates to the 9 o'clock position.
[0066] For the pitch electrical system of a wind turbine that drives the blades to rotate and thus adjusts the blade angle, the pitch motor driving torque and the pitch motor current satisfy a linear relationship within the normal operating range, that is: T=K×I.
[0067] Where T represents the driving torque of the pitch motor, I represents the current of the pitch motor, and K represents the torque coefficient.
[0068] The pitch drive electrical systems of blades 1, 2 and 3 exchange data with the wind turbine main control PLC in each task cycle via fieldbus. In this embodiment, the fieldbus adopts Profibus to transmit the real-time pitch motor current values of blades 1, 2 and 3 to the wind turbine main control PLC.
[0069] S2. Within a 10-millisecond task cycle in the wind turbine main control PLC control program, establish three arrays, each with 180 elements, representing blade 1, blade 2, and blade 3 within a 2° azimuth angle interval during one revolution of the impeller. These arrays are used to store the sum of the pitch motor currents of blade 1, blade 2, and blade 3 at the corresponding impeller azimuth angle positions within a 10-minute operating cycle. The real-time pitch motor currents of blade 1, blade 2, and blade 3 measured in each 10-millisecond task cycle are then superimposed onto the elements of the array at the current impeller azimuth angle position.
[0070] S3. Within each ten-minute operating cycle, calculate the average pitch motor current of blades 1, 2, and 3 within 180 impeller azimuth intervals based on the elements of the array in step S2. If the operating condition has not ended after the ten-minute operating cycle, return to step S1.
[0071] S4. Based on the average pitch motor current of each blade within the impeller azimuth angle interval, determine the maximum pitch motor current of each blade, and calculate the impeller azimuth angle range corresponding to the maximum pitch motor current of each blade.
[0072] When blades 1, 2, and 3 rotate to an impeller azimuth angle range of 240°-330° in the impeller rotation plane, i.e., each blade is within the azimuth angle range of 8 o'clock to 11 o'clock, the maximum value of the pitch motor current for blades 1, 2, and 3 and its corresponding impeller azimuth angle range are calculated based on the average value of the pitch motor current for blades 1, 2, and 3 within 180 impeller azimuth angle intervals. In this embodiment, it is preferable to calculate and confirm the impeller azimuth angle range corresponding to the maximum value of the pitch motor current for each blade within an azimuth angle range of approximately 270°, i.e., an azimuth angle range of approximately 9 o'clock.
[0073] S5. Establish a table of vertical wind shear vs. impeller azimuth angle relationship under a ten-minute operating cycle according to the interval of 0.05 vertical wind shear; according to the impeller azimuth angle range obtained in step S4, query the table of vertical wind shear vs. impeller azimuth angle relationship, determine the vertical wind shear value of each blade in the ten-minute operating cycle, and save it to SCADA data.
[0074] S6. When the generator speed of a wind turbine without blade load sensors is running near the rated speed, and the average value of the vertical wind shear of the three blades of the wind turbine exceeds the set threshold, the blade angle is increased to control the maximum value of the blade flapping moment load to remain below the design threshold; otherwise, the operation is terminated.
[0075] Furthermore, the application method of the vertical wind shear value obtained based on the vertical wind shear calculation method described in this embodiment is as follows:
[0076] 1) For type-certified wind turbines, vertical wind shear values are used to verify the consistency between simulation and testing of blade flapping moment load and power curve.
[0077] 2) For wind turbines operating in batches, the vertical wind shear value of each unit in the power generation mode is compared with the design vertical wind shear value of the corresponding turbine location, which is used to evaluate the flapping moment fatigue load of each blade online or offline.
[0078] 3) When the generator speed of a wind turbine without blade load sensors is running near the rated speed, and the average value of the vertical wind shear of the three blades of the wind turbine exceeds the set threshold, the blade angle is increased to control the maximum value of the blade flapping moment load to remain below the design threshold, thus providing a reliable decision-making basis for the safe operation of the blades.
[0079] See Figures 2 to 7 As shown, the software simulation of the blade root Mz bending moment vs. impeller azimuth angle under a steady wind of 8 m / s with vertical wind shear of 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 shows that as the vertical wind shear increases, near 9 o'clock, i.e., when the blade azimuth angle is around 270°, the impeller azimuth angle corresponding to the peak value of the blade root Mz bending moment (pitch motor current) continuously increases from 285° to 325°.
[0080] See Figure 8 As shown, the software simulation of wind turbine output power operation under different vertical wind shears at 8 m / s steady wind shows that as the vertical wind shear increases, the wind turbine output power continuously increases without stalling when the blades rotate to a height above the hub center.
[0081] See Figure 9 The figure shows the operating conditions with a measured average wind speed of 13.04 m / s and a vertical wind shear of 0.14. It also shows the sequence of blade root flapping moment and the scatter plot of pitch motor current vs. impeller azimuth angle. The measured value of vertical wind shear is consistent with the theoretical value.
[0082] See Figure 10As shown, under the condition of an average wind speed of 10.29 m / s and a vertical wind shear of 0.63, the blade root flapping moment operation sequence and the scatter plot of blade root flapping moment VS impeller azimuth angle (without blade stall), and the scatter plot of pitch motor current VS impeller azimuth angle are shown. The measured value of vertical wind shear is consistent with the theoretical value.
[0083] See Figure 11 As shown, under the condition of an average wind speed of 7.63 m / s and a vertical wind shear of 0.98, the blade root flapping moment operation sequence and the scatter plot of blade root flapping moment VS impeller azimuth angle (without blade stall), and the scatter plot of pitch motor current VS impeller azimuth angle are shown. The measured value of vertical wind shear is consistent with the theoretical value.
[0084] See Figure 12 As shown, the measured wind speed and vertical wind shear values are relatively low, while the peak-to-peak value of the blade root flapping moment fluctuation and the wind turbine output power are relatively high; compared with Figure 12 Under the condition that average wind speed and other wind resource parameters are the same. Figure 13 as well as Figure 14 The software simulation results show the operating sequence of turbine output power and blade root flapping moment under different vertical wind shear conditions. Only by significantly increasing the vertical wind shear value can the peak-to-peak value of the corresponding blade root flapping moment fluctuation and the turbine output power match the measured values. In the measured pitch motor current vs. impeller azimuth scatter plot, the peak value of the pitch motor current near 9 o'clock corresponds to a high impeller azimuth angle, indicating a vertical wind shear above 1.5. Therefore, using the pitch motor current vs. impeller azimuth scatter plot to determine the vertical wind shear method is relatively accurate.
[0085] Figures 15 to 17 and Figure 12 The operating characteristics are similar, namely, the measured wind speed and vertical wind shear values are relatively low, while the peak-to-peak value of the blade root flapping moment fluctuation and the wind turbine output power are relatively high, which is also the problem of low vertical wind shear measurement value; while the measured pitch motor current peaks around 9 o'clock, corresponding to a high impeller azimuth angle, which corresponds to a higher vertical wind shear measurement value.
[0086] See Figures 9 to 17 Test data and software simulation results show that the accuracy of vertical wind shear values obtained by wind measurement towers or ground-based lidar is relatively low, while the accuracy of vertical wind shear determined by the pitch motor current vs. impeller azimuth method is significantly improved.
[0087] Example 2
[0088] This embodiment provides a vertical wind shear calculation system based on impeller azimuth angle and pitch motor current, used to implement the vertical wind shear calculation method based on impeller azimuth angle and pitch motor current described in Embodiment 1, including:
[0089] The data acquisition module is used to acquire the real-time rotor azimuth angle of the wind turbine and the real-time pitch motor current of each blade.
[0090] An array module is used to store the pitch motor current at each impeller azimuth position;
[0091] The pitch motor current superposition module calculates the sum of the pitch motor current of each blade within a preset operating cycle and at the corresponding impeller azimuth position, stores the sum of the pitch motor current in the array module, and superimposes the real-time pitch motor current of each blade from the data acquisition module into the array module at the current impeller azimuth position.
[0092] The pitch motor current average calculation module calculates the average pitch motor current of each blade within the impeller azimuth angle interval based on the pitch motor current data in the array module within each preset operating cycle.
[0093] The impeller azimuth angle range calculation module determines the maximum value of the pitch motor current for each blade based on the average value of the pitch motor current for each blade within the impeller azimuth angle interval, and calculates the impeller azimuth angle range corresponding to the maximum value of the pitch motor current for each blade.
[0094] The relationship table module includes a built-in vertical wind shear vs. impeller azimuth relationship table.
[0095] The vertical wind shear value determination module, based on the impeller azimuth angle range obtained by the impeller azimuth angle range calculation module, queries the vertical wind shear vs. impeller azimuth angle relationship table in the relationship table module to determine the vertical wind shear value of each blade during the operating cycle and saves it to the SCADA data.
[0096] Example 3
[0097] This embodiment discloses a non-transitory computer-readable medium storing instructions that, when executed by a processor, perform the steps of the vertical wind shear calculation method based on impeller azimuth and pitch motor current as described in Embodiment 1.
[0098] 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.
[0099] Example 4
[0100] 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 vertical wind shear calculation method based on impeller azimuth angle and pitch motor current described in Embodiment 1.
[0101] 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.
[0102] 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 calculating the vertical wind shear based on the azimuth angle of the rotor and the current of the pitch motor for controlling the flap bending moment load of the blades of a wind turbine, characterized in that, Includes the following steps: S1. Obtain the real-time rotor azimuth angle of the wind turbine and the real-time pitch motor current of each blade. S2. Establish an array to store the sum of the pitch motor currents. Calculate the sum of the pitch motor currents of each blade within the preset operating cycle and at the corresponding impeller azimuth position. Store the sum of the pitch motor currents in the array. Add the real-time pitch motor currents of each blade obtained in step S1 to the elements of the array at the current impeller azimuth position. S3. In each preset operating cycle, calculate the average pitch motor current of each blade within the impeller azimuth interval based on the elements of the array in step S2. S4. Based on the average pitch motor current of each blade within the impeller azimuth angle interval, determine the maximum pitch motor current of each blade, and calculate the impeller azimuth angle range corresponding to the maximum pitch motor current of each blade. S5. Establish a vertical wind shear vs. impeller azimuth angle relationship table; and based on the impeller azimuth angle range obtained in step S4, query the vertical wind shear vs. impeller azimuth angle relationship table to determine the vertical wind shear value of each blade during the operating cycle, and save it to SCADA data.
2. The method for calculating the vertical wind shear based on the azimuth angle of the blade and the current of the pitch motor according to claim 1, characterized in that, Step S1 includes: The real-time azimuth angles of blades 1, 2, and 3 on the impeller rotation plane are obtained by an absolute encoder installed inside the hub of the wind turbine and rotating with the main shaft. When blade 1 is vertically upward, the impeller azimuth angle is defined as 0°. When the impeller rotates clockwise for one revolution, the impeller azimuth angle increases to a maximum of 360°. After the impeller azimuth angle increases to 360°, it starts to increase again from 0°. Blade 1, blade 2, and blade 3 are arranged clockwise in the impeller rotation plane, and the interval between blade 1 and blade 2, blade 2 and blade 3, and blade 3 and blade 1 is 120°.
3. The method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current according to claim 2, characterized in that, Step S1 includes: For the pitch electrical system of a wind turbine that drives the blades to rotate and thus adjusts the blade angle, the pitch motor driving torque and the pitch motor current satisfy a linear relationship within the normal operating range, that is: T=K×I. Where T represents the driving torque of the pitch motor, I represents the current of the pitch motor, and K represents the torque coefficient; The pitch drive electrical systems of blades 1, 2, and 3 exchange data with the wind turbine main control PLC via fieldbus during each task cycle, transmitting the real-time pitch motor current values of blades 1, 2, and 3 to the wind turbine main control PLC.
4. The method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current according to claim 3, characterized in that, Step S2 includes: Within a 10-millisecond task cycle in the wind turbine main control PLC program, three arrays, each with 180 elements, are created to represent blade 1, blade 2, and blade 3 within a 2° azimuth angle interval during one revolution of the impeller. These arrays are used to store the sum of the pitch motor currents of blade 1, blade 2, and blade 3 at the corresponding impeller azimuth angle positions within a 10-minute operating cycle. The real-time pitch motor currents of blade 1, blade 2, and blade 3 measured in each 10-millisecond task cycle are then superimposed onto the elements of the array at the current impeller azimuth angle position.
5. The method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current according to claim 4, characterized in that, Step S3 includes: Within each ten-minute operating cycle, the average pitch motor current of blades 1, 2, and 3 within 180 impeller azimuth intervals is calculated based on the elements of the array in step S2.
6. The method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current according to claim 5, characterized in that, Step S4 includes: When blades 1, 2, and 3 rotate to the impeller azimuth angle range of 240°-330° in the impeller rotation plane, the maximum value of the pitch motor current of blades 1, 2, and 3 and the corresponding impeller azimuth angle range are calculated based on the average value of the pitch motor current of blades 1, 2, and 3 within 180 impeller azimuth angle intervals.
7. The method for calculating vertical wind shear based on impeller azimuth angle and pitch motor current according to claim 6, characterized in that, Step S5 includes: Establish a table of vertical wind shear vs. impeller azimuth angle relationship under a ten-minute operating cycle based on an interval of 0.05 vertical wind shear; based on the impeller azimuth angle range obtained in step S4, query the table of vertical wind shear vs. impeller azimuth angle relationship, determine the vertical wind shear value of each blade within the ten-minute operating cycle, and save it to SCADA data.
8. A vertical wind shear calculation system based on impeller azimuth angle and pitch motor current, characterized in that, The method for calculating vertical wind shear based on impeller azimuth and pitch motor current as described in any one of claims 1-7 includes: The data acquisition module is used to acquire the real-time rotor azimuth angle of the wind turbine and the real-time pitch motor current of each blade. An array module is used to store the pitch motor current at each impeller azimuth position; The pitch motor current superposition module calculates the sum of the pitch motor current of each blade within a preset operating cycle and at the corresponding impeller azimuth position, stores the sum of the pitch motor current in the array module, and superimposes the real-time pitch motor current of each blade from the data acquisition module into the array module at the current impeller azimuth position. The pitch motor current average calculation module calculates the average pitch motor current of each blade within the impeller azimuth angle interval based on the pitch motor current data in the array module within each preset operating cycle. The impeller azimuth angle range calculation module determines the maximum value of the pitch motor current for each blade based on the average value of the pitch motor current for each blade within the impeller azimuth angle interval, and calculates the impeller azimuth angle range corresponding to the maximum value of the pitch motor current for each blade. The relationship table module includes a built-in vertical wind shear vs. impeller azimuth relationship table. The vertical wind shear value determination module, based on the impeller azimuth angle range obtained by the impeller azimuth angle range calculation module, queries the vertical wind shear vs. impeller azimuth angle relationship table in the relationship table module to determine the vertical wind shear value of each blade during the operating cycle and saves it to the SCADA data.
9. A non-transitory computer-readable medium storing instructions, characterized in that, When the instruction is executed by the processor, the steps of the vertical wind shear calculation method based on impeller azimuth and pitch motor current as described in any one of claims 1-7 are performed.
10. 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 vertical wind shear calculation method based on the impeller azimuth angle and the pitch motor current as described in any one of claims 1-7.