Wind power variable pitch bearing friction torque evaluation and early warning method and device

Abstract

The invention discloses a wind power variable pitch bearing friction torque evaluation and early warning method and device, relates to the technical field of wind power generation, and aims to solve the problem of inaccurate evaluation caused by dependence on an empirical formula in the prior art. Comprising the steps of collecting current of a variable-pitch driving motor in real time, and calculating output torque according to the current; a current wind speed and turbulence intensity are obtained, and a preset database is inquired to obtain a corresponding blade root torque; the output torque of the motor is converted into the total torque acting on the variable-pitch bearing by combining the transmission parameters of the variable-pitch system; the real-time friction torque of the variable-pitch bearing is accurately obtained by calculating the difference value between the total torque and the torque of the root of the blade; the method also compares the friction torque with a preset basic value, and realizes fault early warning according to the degree of exceeding a threshold value; according to the method, online, accurate and dynamic evaluation of the friction torque is realized, and a reliable basis is provided for state monitoring and predictive maintenance of the variable pitch bearing.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, specifically to a method and device for assessing and warning of frictional torque in wind turbine pitch bearings. Background Technology

[0002] The pitch control system is one of the core components of a wind turbine. It adjusts the power captured by the rotor by changing the blade pitch angle, thereby ensuring stable power output above the rated wind speed. As a critical component connecting the blades and the hub, the pitch bearing's operating condition directly affects the safety and lifespan of the entire turbine. The frictional torque of the pitch bearing is an important indicator for assessing its health. An abnormally increased frictional torque is often associated with bearing lubrication failure, raceway damage, abnormal bolt preload, and other faults.

[0003] Currently, the industry's assessment of the frictional torque of pitch bearings often relies on empirical formulas. These empirical formulas are typically based on ideal operating conditions and conservative assumptions, failing to fully consider the complex actual operating conditions of pitch bearings. The frictional torque of pitch bearings is related to various factors such as bearing type, external load, and lubrication conditions. Among these, the external load dynamically changes with wind parameters such as wind speed and turbulence intensity, leading to significant deviations between the calculation results based on empirical formulas and the actual values.

[0004] Therefore, the uncertainties in the existing technology make it difficult to accurately determine the actual friction level of the bearing. This may lead to redundancy in the design of the pitch system's drive torque due to overestimation, or serious failures due to failure to identify the increase in frictional resistance in time. Summary of the Invention

[0005] In view of the above problems, the present invention provides a method and device for evaluating and warning of friction torque of wind turbine pitch bearings, which can evaluate the friction torque of pitch bearings online in real time and dynamically and accurately, effectively reflect its true friction level, and realize reliable fault warning based on this, providing data support for predictive maintenance of wind turbine units.

[0006] In a first aspect, embodiments of the present invention provide a method for assessing and warning of frictional torque in wind turbine pitch bearings, the method comprising: Real-time acquisition of motor operating parameters in the pitch control system; Calculate the output torque of the pitch drive motor based on the aforementioned operating parameters; Obtain the blade root torque under current wind conditions; Based on the output torque and the transmission parameters of the pitch system, calculate the total torque acting on the pitch bearing; The pitch bearing friction torque is calculated based on the difference between the total torque and the blade root torque. The frictional torque is compared with a preset baseline value, and a fault warning is issued based on the comparison result.

[0007] In some embodiments, the real-time acquisition of the operating parameters of the motor in the pitch system includes: acquiring the current of the pitch drive motor; and calculating the output torque of the pitch drive motor based on the operating parameters, which is obtained by the formula T_motor = kI, where k is a preset proportional coefficient.

[0008] In some embodiments, obtaining the blade root torque under the current wind conditions includes: Obtain current wind speed and turbulence intensity data; The pre-established blade root torque database is queried, and the corresponding blade root torque is obtained by matching the current wind speed and turbulence intensity data. The database is established based on the blade root torque calculated under different wind speeds and turbulence intensities using a wind turbine simulation model.

[0009] In some embodiments, the total torque acting on the pitch bearing is calculated based on the output torque and the transmission parameters of the pitch system, and its expression is: T_bearing = i T motor η, where i is the gear ratio of the pitch system and η is the transmission efficiency.

[0010] In some embodiments, the pitch bearing friction torque is calculated based on the difference between the total torque and the blade root torque, and its expression is: Tfriction = Tbearing - Troot.

[0011] In some embodiments, a data smoothing step is included before or after the calculation of the pitch bearing friction torque, comprising: processing the output torque of the pitch drive motor, the blade root torque and / or the pitch bearing friction torque using an average value within a predetermined time window.

[0012] In some embodiments, the predetermined time window is 10 minutes.

[0013] In some embodiments, the fault warning based on the comparison result includes: When the frictional torque of the pitch bearing exceeds a first set percentage of the baseline value under the same wind conditions, a minor fault warning is triggered. When the frictional torque of the pitch bearing exceeds a second set percentage of the base value, a fault warning is triggered; wherein the second set percentage is greater than the first set percentage.

[0014] In some embodiments, the wind turbine pitch bearing friction torque assessment and early warning method further includes a system calibration step, including: Perform pitch control in calm or light wind conditions and collect the calculated pitch bearing friction torque as the calibration value. When calculating the friction torque under normal operating conditions, the calibration value is introduced to correct the calculation results.

[0015] Secondly, embodiments of the present invention provide a wind turbine pitch bearing friction torque assessment and early warning device, comprising: The data acquisition module is used to acquire the operating parameters of the motor in the pitch system in real time. The first calculation module is used to calculate the output torque of the pitch drive motor based on the operating parameters; The acquisition module is used to acquire the blade root torque under the current wind conditions; The second calculation module is used to calculate the total torque acting on the pitch bearing based on the output torque and the transmission parameters of the pitch system. The third calculation module is used to calculate the friction torque of the pitch bearing based on the difference between the total torque and the torque at the blade root. The assessment and early warning module is used to compare the friction torque with a preset baseline value and issue a fault warning based on the comparison result.

[0016] Thirdly, embodiments of this application provide an electronic device, including a memory and a processor, wherein the memory stores program code that can run on the processor, and when the program code is executed by the processor, it implements the wind turbine pitch bearing friction torque assessment and early warning method as described in any embodiment of the first aspect.

[0017] Fourthly, embodiments of this application provide a computer storage medium storing one or more programs, which can be executed by an electronic device as described in the third aspect to implement the wind turbine pitch bearing friction torque assessment and early warning method as described in any embodiment of the first aspect.

[0018] This invention provides a method and device for assessing and warning of friction torque in wind turbine pitch bearings. It enables online, real-time dynamic monitoring of the friction torque of pitch bearings, avoiding the conservatism and inaccuracy of traditional empirical formulas, and providing results that better reflect the actual friction state of the bearing. By providing warnings based on the deviation of the friction torque from the baseline value, it can identify potential faults such as poor bearing lubrication and the onset of damage at an early stage, providing a key basis for predictive maintenance and preventing the escalation of faults. Through data smoothing processing, it effectively filters out instantaneous fluctuations caused by dynamic factors such as wind speed and turbulence, making the friction torque trend more stable and the warning more reliable. The calibration process eliminates individual unit differences and systematic errors caused by long-term operation, maintaining assessment accuracy.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0020] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0021] Figure 1 A schematic diagram of an exemplary wind turbine pitch bearing friction torque assessment and early warning method according to an embodiment of the present invention is shown. Figure 2 The illustration shows a schematic diagram of the specific implementation process of an exemplary wind turbine pitch bearing friction torque assessment and early warning method proposed in one embodiment of the present invention; Figure 3 This figure shows a structural block diagram of a wind turbine pitch bearing fault early warning system according to an embodiment of the present invention; Figure 4 A structural block diagram of an electronic device for performing a wind turbine pitch bearing friction torque assessment and early warning method according to an embodiment of this application is shown. Figure 5 An exemplary computer-readable storage medium for storing or carrying a wind turbine pitch bearing friction torque assessment and early warning method according to an embodiment of the present invention is shown. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0023] According to the inventors' research, the frictional torque of traditional wind turbine pitch bearings is often calculated using empirical formulas, which are usually quite conservative and can lead to excessively large driving torque in the pitch system. However, there is no reasonable and accurate calculation method. Since the operating conditions of pitch bearings are quite complex, they are generally related to factors such as bearing type, external load, and lubrication level. Among these factors, the external load varies greatly with the complex operating conditions, resulting in a large deviation between the actual frictional torque of the pitch bearings and the actual value.

[0024] To address the aforementioned issues, the applicant has proposed a method and device for assessing and warning of frictional torque in wind turbine pitch bearings. This method can accurately identify the frictional torque of pitch bearings, which can be used for the analysis and optimization of wind turbine pitch systems. It also provides real-time online monitoring of dynamic frictional torque levels, providing valuable data for subsequent pitch bearing fault warnings.

[0025] The method for assessing and warning of frictional torque in wind turbine pitch bearings will be described in detail in subsequent embodiments. The application scenarios of the wind turbine pitch bearing frictional torque assessment and warning method provided in this embodiment of the invention are introduced below: Please see Figure 1 , Figure 1 This is a schematic flowchart of a wind turbine pitch bearing friction torque assessment and early warning method provided in an embodiment of the present invention. In this embodiment, the wind turbine pitch bearing friction torque assessment and early warning method can be applied to, for example... Figure 3 The wind turbine pitch bearing fault early warning device 300 shown is neutralizing Figure 4 In the electronic device 200 shown, the following is specifically for... Figure 1 The process shown is described in detail. This wind turbine pitch bearing friction torque assessment and early warning method may include steps S110 to S160.

[0026] S110: Real-time acquisition of motor operating parameters in the pitch system.

[0027] In this embodiment of the application, the operating parameters of the motor in the pitch system are collected in real time, including: collecting the current of the pitch drive motor; wherein, the pitch system generally adopts a permanent magnet synchronous motor, whose output torque has a stable proportional relationship with the current, so by collecting the motor current in real time, basic data can be conveniently provided for subsequent calculations.

[0028] S120: Calculates the output torque of the pitch drive motor based on operating parameters.

[0029] In this embodiment, the output torque of the pitch drive motor is calculated based on the operating parameters and obtained by the formula T_motor = kI, where k is a preset proportional coefficient, which is determined by the motor characteristics.

[0030] S130: Obtain the blade root torque under current wind conditions.

[0031] In this embodiment of the application, steps S131 to S132 are included, wherein: S131: Obtain current wind speed and turbulence intensity data.

[0032] In this step, the current wind speed and turbulence intensity data can be read in real time from the main control system of the wind turbine. These data can be key parameters characterizing the current external aerodynamic load.

[0033] S132: Query the pre-established blade root torque database and match the corresponding blade root torque according to the current wind speed and turbulence intensity data. The database is established based on the blade root torque calculated under different wind speeds and turbulence intensities using a wind turbine simulation model.

[0034] In this step, the blade root torque database is pre-calculated using a high-precision aerodynamic-structural simulation model of the wind turbine, calculating the blade root torque under different wind speeds (e.g., 3m / s, 4m / s, ..., 25m / s) and different turbulence intensities (e.g., 10%, 20%, 30%...), and stored in the form of Table 1 or function mapping as shown below.

[0035]

[0036] Table 1 For example, when the main controller reads that the current wind speed is 8 m / s and the turbulence intensity is 20%, the system can query the database to match the corresponding blade root torque Tblade root = 100,000 Nm. This method overcomes the conservatism and inaccuracy of empirical formulas and can more accurately reflect the current actual aerodynamic load.

[0037] S140: Calculate the total torque acting on the pitch bearing based on the output torque and the transmission parameters of the pitch system.

[0038] In this embodiment, the total torque acting on the pitch bearing is calculated based on the output torque and the transmission parameters of the pitch system. Its expression is: Tbearing = i T motor η, where i is the gear ratio of the pitch system and η is the transmission efficiency.

[0039] For example, if the transmission ratio i = 3000, the transmission efficiency η = 0.91, and the motor output torque Tmotor = 50 Nm, then the calculated total torque acting on the pitch bearing Tbearing = 3000 Nm. 50 0.91 = 136,500 Nm. This total torque is the total driving force that drives the blades to rotate to overcome aerodynamic loads and bearing friction.

[0040] S150: Calculate the friction torque of the pitch bearing based on the difference between the total torque and the torque at the blade root.

[0041] In this embodiment, the friction torque of the pitch bearing is calculated based on the difference between the total torque and the torque at the blade root, and its expression is: Tfriction = Tbearing - Troot.

[0042] According to the principle of torque balance, the total torque on the pitch bearing (Tbearing) is equal to the sum of the torque used to overcome aerodynamic loads (Troot) and the torque used to overcome the bearing's own friction (Tfriction). Therefore, the friction torque Tfriction = 136,500 Nm - 100,000 Nm = 36,500 Nm. This calculation enables accurate online real-time evaluation of the friction torque of the pitch bearing.

[0043] In some implementations, a data smoothing step is included before or after calculating the pitch bearing friction torque, including: The output torque of the pitch drive motor, the blade root torque, and / or the pitch bearing friction torque are processed using the average value within a predetermined time window.

[0044] In this embodiment, the data smoothing step is crucial. Due to the dynamic changes in parameters such as wind speed and turbulence, instantaneous calculated values ​​may fluctuate and contain noise. By averaging the continuously collected and calculated data (Tmotor, Tblade root) or the finally calculated Tfriction, the data curve can be smoothed, short-term interference can be filtered out, and the trend of friction torque can be made more stable, thereby improving the accuracy and reliability of fault warning. Moving average or arithmetic average methods are typically used.

[0045] In some implementations, the predetermined time window is 10 minutes.

[0046] S160: Compare the friction torque with the preset baseline value and provide a fault warning based on the comparison result.

[0047] Among them, S160 includes S161 to S162 for fault warning based on comparison results, wherein: S161: When the frictional torque of the pitch bearing exceeds the first set percentage of the base value under the same wind conditions, a minor fault warning is triggered.

[0048] S162: When the frictional torque of the pitch bearing exceeds the second set percentage of the base value, a fault warning is triggered; wherein, the second set percentage is greater than the first set percentage.

[0049] In this embodiment, the baseline value, Tbase, is a benchmark representing the normal friction level, determined by statistical analysis, such as taking the 10-minute average value, after monitoring and calculating a series of pitch bearing friction torques under various typical wind conditions during the initial normal operation of the wind turbine. The warning threshold can be specifically set as follows: when the real-time friction torque exceeds the baseline value by 10% under the same wind conditions, the system triggers a minor fault warning, indicating an increase in friction level requiring attention; when it exceeds the baseline value by 20%, a fault warning is triggered, indicating a significant increase in frictional resistance, potentially indicating lubrication failure or damage, requiring immediate inspection and maintenance. This tiered warning mechanism helps achieve predictive maintenance.

[0050] In some implementations, the wind turbine pitch bearing friction torque assessment and early warning method further includes: a system calibration step, including: Perform pitch control in calm or light wind conditions and collect the calculated pitch bearing friction torque as the calibration value. When calculating friction torque under normal operating conditions, a calibration value is introduced to correct the calculation results.

[0051] In this embodiment, the system calibration step is used to correct system errors. Due to factors such as blade manufacturing errors, slight differences in aerodynamic characteristics, and assembly, there may be a slight deviation between the Tblade root value retrieved from a general database and the actual torque of the blades in a specific unit. By performing pitch control under calm or light wind conditions, the calculated Tfriction is approximately equal to Tbearing, mainly reflecting the bearing's own friction and transmission chain losses. This value can be used as the calibration value. In subsequent normal calculations, subtracting this calibration value from the calculation result (Tfriction = Tbearing - Tblade root - calibration value) effectively eliminates inherent system errors, making the evaluation results closer to the actual friction state of the bearing. This calibration can be performed periodically to track changes that may occur in the system over time.

[0052] See Figure 2 In a specific implementation, the following steps may be included: Assuming a wind turbine's pitch control system is in operation, it is necessary to assess the frictional torque of its pitch bearings and provide early warning of potential faults. S1. Obtain the motor output torque. The permanent magnet synchronous motor in the pitch system has its operating current collected in real time. For example, the motor current collected at the current moment is I=10A. Based on the known proportional coefficient k=5 for this motor, the output torque Tmotor=50Nm is calculated.

[0053] S2. Obtaining Blade Root Torque: Simultaneously, the wind turbine's main control system reads the current wind speed and turbulence data. Assuming the current wind speed and turbulence intensity, the system queries a pre-established blade root torque database (this database is calculated based on a wind turbine simulation model for different wind speeds and turbulence conditions), finding that under the conditions of a wind speed of 8 m / s and turbulence intensity of 20%, the blade root torque Tblade root = 100,000 Nm.

[0054] S3. Calculate the total torque of the pitch bearing: Assume the transmission ratio of the pitch system is i = 3000 and the transmission efficiency is η = 0.91. The total torque acting on the pitch bearing is Tbearing = iTmotor η=3000 50 0.91 = 136500 Nm.

[0055] S4. Calculate the friction torque of the pitch bearing: According to the formula T_friction = T_bearing The actual frictional torque of the pitch bearing at the T-blade root is 136500-100000=36500Nm.

[0056] S5. Establishing baseline values ​​and fault early warning: In the initial stage of normal operation of the wind turbine, under similar wind conditions, such as a wind speed of 8 m / s and 20% turbulence, after a period of monitoring and data processing, such as averaging over 10 minutes, the average baseline value of the pitch bearing friction torque Tbase = 36500 Nm is recorded and calculated. It should be noted that the average baseline value will vary under different wind speeds.

[0057] During subsequent operation, the system continuously monitors and calculates the 10-minute average value of the real-time friction torque. Assume that within a certain monitoring period, the calculated 10-minute average friction torque is 45000 Nm.

[0058] The system compares this value with the base value: The percentage increase in frictional torque is Tfriction - Tbase / Tbase 100%; The percentage increase = (45000-36500) / 36500 = 0.233 (23.3%).

[0059] According to the early warning standard: if the friction torque of the pitch bearing exceeds the baseline value by 10% under the same wind conditions during the later operation of the wind turbine, it indicates a minor fault; if it exceeds 20%, a fault warning will be issued.

[0060] If the calculated increase exceeds the 20% threshold, the system will immediately issue a fault warning, indicating that the pitch bearing may have a serious problem of increased frictional resistance, requiring immediate inspection or maintenance to avoid potential failures.

[0061] The 10-minute average processing of torque and torque data involves averaging all calculated torques and torques, including motor output torque, pitch bearing total torque, pitch bearing friction torque, and blade root torque, over a 10-minute period.

[0062] In actual operation, wind turbines experience dynamic changes in various parameters (such as wind speed, turbulence, and motor current), which can lead to noise and short-term fluctuations in the instantaneously calculated torque and moment data. Averaging these data effectively smooths the data curves, filters out transient interference, and makes the calculated frictional torque more stable. This significantly improves the accuracy and reliability of fault warnings.

[0063] It should be noted that the database of blade root torque is based on a general or idealized wind turbine simulation model, which considers different wind speeds and turbulence conditions. In actual operating environments, the blades of each wind turbine may exhibit subtle individual differences and dynamic changes. These differences may stem from: There are many factors that affect error, such as production error, blade aerodynamic error, and pitch bearing assembly error, but these effects are relatively small and can be ignored.

[0064] This application employs a calibration method to further reduce errors. It directly calibrates the pitch bearing friction torque by performing pitch control under calm (light) conditions to eliminate aerodynamic influences and reading the pitch drive motor torque as the initial value for the pitch bearing friction torque. For example, calibration can be performed every 3 or 6 months to update the initial value, ultimately resulting in Tfriction = Tbearing. T leaf root The calibration value is used to eliminate errors.

[0065] Please see Figure 3 , Figure 3 A structural block diagram of a wind turbine pitch bearing fault early warning system provided by the present invention includes: a data acquisition module 310, a first calculation module 320, an acquisition module 330, a second calculation module 340, a third calculation module 350, and an evaluation and early warning module 360, wherein: The acquisition module 310 is used to acquire the operating parameters of the motor in the pitch system in real time; The first calculation module 320 is used to calculate the output torque of the pitch drive motor based on the operating parameters; The acquisition module 330 is used to acquire the blade root torque under the current wind conditions; The second calculation module 340 is used to calculate the total torque acting on the pitch bearing based on the output torque and the transmission parameters of the pitch system. The third calculation module 350 is used to calculate the friction torque of the pitch bearing based on the difference between the total torque and the torque at the blade root. The evaluation and early warning module 360 ​​is used to compare the friction torque with a preset baseline value and to issue a fault warning based on the comparison result.

[0066] It should be noted that the device embodiments in this invention correspond to the aforementioned method embodiments. The specific principles in the device embodiments can be found in the content of the aforementioned method embodiments, and will not be repeated here.

[0067] In the several embodiments provided in this example, the coupling between modules can be electrical, mechanical, or other forms of coupling.

[0068] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0069] Please see Figure 4 , Figure 4 The present application provides a structural block diagram of an electronic device 200 that can perform the above-described wind turbine pitch bearing friction torque assessment and early warning method. The electronic device 200 may be a smartphone, tablet computer, computer, or portable computer.

[0070] The electronic device 200 also includes a processor 202 and a memory 204. The memory 204 stores programs that can execute the contents of the foregoing embodiments, and the processor 202 can execute the programs stored in the memory 204.

[0071] The processor 202 may include one or more cores for data processing and message matrix units. The processor 202 connects to various parts within the electronic device 200 using various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 204, and by calling data stored in the memory 204. Optionally, the processor 202 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 202 may integrate one or more of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem / decoder. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem / decoder handles wireless communication. It is understood that the modem / decoder may also be implemented separately as a communication chip, without being integrated into the processor.

[0072] Memory 204 may include random access memory (RAM) or read-only memory (ROM). Memory 204 can be used to store instructions, programs, code, code sets, or instruction sets. Memory 204 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (e.g., instructions for a user to obtain random numbers), instructions for implementing the various method embodiments described below, etc. The data storage area may also store data (e.g., random numbers) created by the terminal during use.

[0073] Electronic device 200 may also include a network module and a screen. The network module is used to receive and transmit electromagnetic waves, converting electromagnetic waves into electrical signals, thereby enabling communication with communication networks or other devices, such as audio playback devices. The network module may include various existing circuit elements used to perform these functions, such as antennas, radio frequency transceivers, digital signal processors, encryption / decryption chips, SIM cards, memory, etc. The network module can communicate with various networks such as the Internet, corporate intranets, and wireless networks, or communicate with other devices via wireless networks. The aforementioned wireless networks may include cellular telephone networks, wireless local area networks, or metropolitan area networks. The screen can display interface content and facilitate data interaction.

[0074] Please refer to Figure 5 , Figure 5 This diagram illustrates a structural block diagram of a computer-readable storage medium according to an embodiment of this application. The computer-readable storage medium 400 stores program code 410, which can be called by a processor to execute the methods described in the above method embodiments.

[0075] The computer-readable storage medium 400 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium includes a non-transitory computer-readable storage medium. The computer-readable storage medium 400 has storage space for program code 410 that performs any of the method steps described above. This program code 410 can be read from or written to one or more computer program products. The program code 410 may be compressed, for example, in a suitable form.

[0076] This application also provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform a method for intelligent collection and deduplication of network data as described in the various optional implementations above.

Claims

1. A method for assessing and warning of frictional torque in wind turbine pitch bearings, characterized in that, The method includes: Real-time acquisition of motor operating parameters in the pitch control system; Calculate the output torque of the pitch drive motor based on the aforementioned operating parameters; Obtain the blade root torque under current wind conditions; Based on the output torque and the transmission parameters of the pitch system, calculate the total torque acting on the pitch bearing; The pitch bearing friction torque is calculated based on the difference between the total torque and the blade root torque. The frictional torque is compared with a preset baseline value, and a fault warning is issued based on the comparison result.

2. The wind turbine pitch bearing friction torque assessment and early warning method according to claim 1, characterized in that, The real-time acquisition of motor operating parameters in the pitch system includes: acquiring the current of the pitch drive motor; and calculating the output torque of the pitch drive motor based on the operating parameters, which is obtained by the formula T_motor = kI, where k is a preset proportional coefficient.

3. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 1, characterized in that, The process of obtaining the blade root torque under the current wind conditions includes: Obtain current wind speed and turbulence intensity data; The pre-established blade root torque database is queried, and the corresponding blade root torque is obtained by matching the current wind speed and turbulence intensity data. The database is established based on the blade root torque calculated under different wind speeds and turbulence intensities using a wind turbine simulation model.

4. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 1, characterized in that, The total torque acting on the pitch bearing is calculated based on the output torque and the transmission parameters of the pitch system. Its expression is: Tbearing = i T motor η, where i is the gear ratio of the pitch system and η is the transmission efficiency.

5. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 1, characterized in that, The pitch bearing friction torque is calculated based on the difference between the total torque and the blade root torque, and its expression is: Tfriction = Tbearing - Troot.

6. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 1, characterized in that, Before or after calculating the pitch bearing friction torque, a data smoothing step is also included, which includes processing the output torque of the pitch drive motor, the blade root torque and / or the pitch bearing friction torque using the average value within a predetermined time window.

7. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 6, characterized in that, The predetermined time window is 10 minutes.

8. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 1, characterized in that, The fault warning based on the comparison results includes: When the frictional torque of the pitch bearing exceeds a first set percentage of the baseline value under the same wind conditions, a minor fault warning is triggered. When the frictional torque of the pitch bearing exceeds a second set percentage of the base value, a fault warning is triggered; wherein the second set percentage is greater than the first set percentage.

9. The method for assessing and warning of frictional torque in wind turbine pitch bearings according to claim 1, characterized in that, It also includes system calibration steps, including: Perform pitch control in calm or light wind conditions and collect the calculated pitch bearing friction torque as the calibration value. When calculating the friction torque under normal operating conditions, the calibration value is introduced to correct the calculation results.

10. A wind turbine pitch bearing friction torque assessment and early warning device, characterized in that, The device includes: The data acquisition module is used to acquire the operating parameters of the motor in the pitch system in real time. The first calculation module is used to calculate the output torque of the pitch drive motor based on the operating parameters; The acquisition module is used to acquire the blade root torque under the current wind conditions; The second calculation module is used to calculate the total torque acting on the pitch bearing based on the output torque and the transmission parameters of the pitch system. The third calculation module is used to calculate the friction torque of the pitch bearing based on the difference between the total torque and the torque at the blade root. The assessment and early warning module is used to compare the friction torque with a preset baseline value and issue a fault warning based on the comparison result.

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