Variable pitch bearing fillet fatigue damage analysis method and device and medium

Abstract

The invention discloses a variable pitch bearing fillet fatigue damage analysis method and device and a medium. Relates to the field of wind power generation and solves the problem of low accuracy of variable-pitch bearing fatigue damage detection. The maximum fatigue damage value in the fatigue damage values of the four fillets of the target bearing corresponds to a local fillet finite element model of the fillets, and the precision of the local fillet finite element model is higher than that of the overall finite element model; and obtaining a fatigue damage result of the current fillet according to the fillet finite element model. According to the method, the fatigue damage of the four filleted corners of the three-row-column variable-pitch bearing is comprehensively evaluated through the overall finite element model, and the missing of the damage position is avoided; through the establishment of the local fillet finite element model, the fillet with the maximum fatigue damage is further locally analyzed, and the analysis precision of the stress and damage of the bearing fillet area is improved. By predicting the fatigue damage of the bearing, the bearing can be maintained and replaced in advance, the risk of accidental faults is reduced, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of wind power generation, and in particular to a pitch bearing fillet fatigue damage analysis method, device and medium. Background Art

[0002] The three-row column variable pitch bearing is an indispensable and important component in wind turbines and other equipment. It has the advantages of large load-bearing capacity and strong rigidity. The three variable pitch bearings can achieve independent pitch change during operation to improve the power generation rate. The three-row column variable pitch bearing structure adopts the method of setting fillets on the bearing raceway and the cage guide surface to reduce the stress concentration of the structure and facilitate the circulation of grease inside the bearing.

[0003] At present, the industry has seen the failure problem of fillet cracking, which has caused huge economic losses to wind turbines. Therefore, accurate calculation of fillet fatigue damage is of great significance for the safe and stable operation of equipment. Usually, when calculating fatigue damage, only the maximum stress point is extracted as the hotspot to calculate fatigue damage, resulting in low detection accuracy.

[0004] It can be seen that how to solve the problem of low accuracy in pitch bearing fatigue damage detection is a technical problem that needs to be solved urgently by people in this field. Summary of the invention

[0005] The purpose of this application is to provide a pitch bearing fillet fatigue damage analysis method, device and medium to solve the problem of low accuracy in pitch bearing fatigue damage detection.

[0006] In order to solve the above technical problems, the present application provides a pitch bearing fillet fatigue damage analysis method, comprising:

[0007] Obtaining an overall finite element model of a wind turbine including three blades, a hub, bolts, and three pitch bearings and a fatigue SN curve of the wind turbine;

[0008] Applying multiple preset working conditions to the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing;

[0009] Extracting the load component corresponding to the preset working condition according to the blade root time series loads of the three blades of the wind turbine generator set;

[0010] Obtaining fatigue damage values ​​of four fillets of a target bearing according to the load component, the unit stress response, the fatigue SN curve, and a preset number of cycles;

[0011] Establishing a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value, wherein the accuracy of the local fillet finite element model is higher than that of the overall finite element model;

[0012] The fatigue damage result of the current fillet is obtained according to the fillet finite element model.

[0013] As an optional solution, in the above pitch bearing fillet fatigue damage analysis method, the step of obtaining an overall finite element model of a wind turbine including three blades, a hub, bolts, and three pitch bearings includes:

[0014] Acquire a three-dimensional model of the wind turbine generator set;

[0015] An overall finite element model is constructed based on the three-dimensional model, wherein the axial roller of the variable pitch bearing is simulated by at least 7 spring units.

[0016] As an optional solution, in the above pitch bearing fillet fatigue damage analysis method, multiple preset working conditions are applied to the loading points of three blades according to the finite element model to obtain multiple unit stress responses of the target bearing, including:

[0017] Obtaining a unit stress response of a target bearing under a preload condition according to the finite element model;

[0018] According to the finite element model, unit working conditions in four directions of +MX, -MX, +MY, and -MY are applied to the loading points of the three blades in sequence to obtain 12 unit stress responses of the target bearing;

[0019] Among them, the blade root coordinate system is established with the blade corresponding to the target bearing, MX represents the main axis direction, and MY represents the direction perpendicular to the main axis and the blade.

[0020] As an optional solution, in the pitch bearing fillet fatigue damage analysis method, extracting the load component corresponding to the preset working condition according to the blade root time series load of the three blades of the wind turbine generator set includes:

[0021] Obtain blade root time series load files of three blades of the wind turbine generator set and merge them into one time series load file;

[0022] Delete the components in non-MX direction and non-MY direction in the timing load file;

[0023] Separate the remaining time series loads in the time series load file into positive and negative directions to obtain the time series loads of the three blades in four directions of +MX, -MX, +MY, and -MY respectively;

[0024] A column of time series loads with data of 1 is added to the time series load file as the time series load under the preload condition.

[0025] As an optional solution, in the pitch bearing fillet fatigue damage analysis method, the remaining time series loads in the time series load file are separated into positive and negative values, including:

[0026] If the remaining time series load in the time series load file is a positive value, the positive value is retained as the positive component of the current time series load, and the negative component of the current time series load is set to 0;

[0027] If the remaining time series load in the time series load file is a negative value, the positive component of the current time series load is set to 0, and the absolute value of the negative value is taken as the negative component of the current time series load.

[0028] As an optional solution, in the above pitch bearing fillet fatigue damage analysis method, the fatigue damage values ​​of the four fillets of the target bearing are obtained according to the load component, the unit stress response, the fatigue SN curve, and the preset number of cycles, including:

[0029] Corresponding the positive and negative separated load components to the unit stress response one by one;

[0030] The load component, the unit stress response, the fatigue SN curve, and the preset number of cycles are input into the fatigue analysis software to obtain the fatigue damage values ​​of the four fillets of the target bearing.

[0031] As an optional solution, in the pitch bearing fillet fatigue damage analysis method, obtaining the fatigue damage result of the current fillet according to the fillet finite element model includes:

[0032] Acquire the fillet unit stress response of the current fillet according to the fillet finite element model;

[0033] The fatigue damage result of the current fillet is obtained according to the fillet unit stress response, the fatigue SN curve, the load component, and the preset number of cycles.

[0034] In order to solve the above technical problems, the present application also provides a pitch bearing fillet fatigue damage analysis device, comprising:

[0035] An acquisition module is used to acquire an overall finite element model of a wind turbine including three blades, a hub, bolts, and three pitch bearings and a fatigue SN curve of the wind turbine;

[0036] A unit stress analysis module, used for applying a plurality of preset working conditions to the loading points of the three blades according to the finite element model to obtain a plurality of unit stress responses of the target bearing;

[0037] A time series load processing module, used for extracting load components corresponding to the preset working condition according to the blade root time series loads of the three blades of the wind turbine generator set;

[0038] A fatigue damage preliminary determination module, used to obtain fatigue damage values ​​of four fillets of a target bearing according to the load component, the unit stress response, the fatigue SN curve, and a preset number of cycles;

[0039] A local model building module, used to build a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value, wherein the accuracy of the local fillet finite element model is higher than that of the overall finite element model;

[0040] The fatigue damage re-determination module is used to obtain the fatigue damage result of the current fillet according to the fillet finite element model.

[0041] In order to solve the above technical problems, the present application also provides a pitch bearing fillet fatigue damage analysis device, comprising:

[0042] Memory for storing computer programs;

[0043] The processor is used to implement the steps of the above-mentioned pitch bearing fillet fatigue damage analysis method when executing the computer program.

[0044] In order to solve the above technical problems, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned variable pitch bearing fillet fatigue damage analysis method are implemented.

[0045] The pitch bearing fillet fatigue damage analysis method provided in the present application includes: obtaining fatigue damage values ​​of the four fillets of the target bearing according to load components, unit stress response, fatigue SN curve, and preset number of cycles; establishing a local fillet finite element model corresponding to the fillet with the largest fatigue damage value, the accuracy of the local fillet finite element model is higher than that of the overall finite element model; obtaining the fatigue damage result of the current fillet according to the fillet finite element model. The present application firstly realizes a comprehensive evaluation of the fatigue damage of the four fillets of the three-row column pitch bearing through an overall finite element model to avoid missing the damaged location. By establishing a local fillet finite element model, the fillet with the largest fatigue damage is further analyzed locally, thereby improving the analysis accuracy of stress and damage in the fillet area of ​​the bearing. By predicting the fatigue damage of the bearing, maintenance and replacement can be carried out in advance, reducing the risk of unexpected failures and reducing maintenance costs.

[0046] In addition, the present application also provides a device and a medium, which correspond to the above-mentioned pitch bearing fillet fatigue damage analysis method and have the same effect as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1A flow chart of a pitch bearing fillet fatigue damage analysis method provided in an embodiment of the present application;

[0049] Figure 2 A partial schematic diagram of a wind turbine generator system provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of the fillet position of a three-row column pitch bearing provided in an embodiment of the present application;

[0051] Figure 4 A schematic cross-sectional view of a pitch bearing provided in an embodiment of the present application;

[0052] Figure 5 A schematic diagram of a blade root coordinate system provided in an embodiment of the present application;

[0053] Figure 6 A structural diagram of a pitch bearing fillet fatigue damage analysis device provided in an embodiment of the present application;

[0054] Figure 7 A structural diagram of another pitch bearing fillet fatigue damage analysis device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] The core of this application is to provide a pitch bearing fillet fatigue damage analysis method, device and medium.

[0057] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0058] To solve the above problems, the present application provides a pitch bearing fillet fatigue damage analysis method, such as Figure 1 As shown, including:

[0059] S11: Obtain the overall finite element model of the wind turbine including three blades, a hub, bolts, and three pitch bearings and the fatigue SN curve of the wind turbine;

[0060] S12: applying multiple preset working conditions to the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing;

[0061] S13: extracting load components corresponding to a preset working condition according to the blade root time series loads of the three blades of the wind turbine generator set;

[0062] S14: Obtain fatigue damage values ​​of four fillets of the target bearing according to the load component, the unit stress response, the fatigue SN curve, and the preset number of cycles;

[0063] S15: Establish a local fillet finite element model corresponding to the fillet with the maximum fatigue damage value. The accuracy of the local fillet finite element model is higher than that of the overall finite element model.

[0064] S16: Obtain fatigue damage results of the current fillet according to the fillet finite element model.

[0065] In order to obtain the stress response of the target bearing under different working conditions and then evaluate its fatigue damage, step S11 establishes a finite element model containing all key components of the wind turbine, including three blades, a hub, bolts, and three pitch bearings. The model is used to simulate the mechanical behavior of the actual wind turbine in operation, including stress, strain, etc. This can be achieved by establishing and solving the finite element model through computer-aided engineering software. Figure 2 A partial schematic diagram of a wind turbine generator system provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, an overall finite element model including three blades, a hub, bolts, and three pitch bearings is established. Due to the symmetry relationship of the pitch bearings, only one of the pitch bearings is analyzed.

[0066] The fatigue SN curve refers to the relationship curve between the fatigue life and stress of a material under cyclic load. This is achieved by obtaining the SN curve through experimental data or material database (the SN curve is a curve that uses the fatigue strength of a standard specimen of a material as the ordinate and the logarithm of the fatigue life lg N as the abscissa to represent the relationship between the fatigue strength and fatigue life of a standard specimen under certain cyclic characteristics, also known as a stress-life curve). According to industry standards, input materials: ultimate tensile strength (MPa), yield strength (MPa), input correction information including: whether it is a test value, stress concentration, loading form, surface roughness, quality grade, detection method, size thickness, material safety factor, etc., to obtain the fatigue SN curve.

[0067] Step S12: In order to simulate and analyze the stress response of the bearing under different working conditions and provide data for subsequent fatigue damage analysis, multiple preset working conditions are applied to the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing. The preset working conditions refer to various load conditions that may be encountered by the simulated wind turbine in actual operation, which can be specifically simulated wind turbine operation under different environmental conditions to evaluate the response of the bearing. This is achieved by applying different load conditions in the finite element model.

[0068] It should be noted that the loading point is usually located at the center of the contact surface between the pitch bearing and the blade.

[0069] In order to match the load in actual operation with the model analysis results to improve the accuracy of the analysis, step S13 extracts the load components corresponding to the preset working conditions based on the blade root sequential loads of the three blades of the wind turbine. The blade root sequential load refers to the load of the wind turbine that changes over time under different working conditions. Through the calculation of sequential loads, the fatigue life of the wind turbine can be more accurately evaluated to ensure its safe and reliable operation.

[0070] Step S14 obtains the fatigue damage values ​​of the four fillets of the target bearing according to the load components, unit stress response, fatigue SN curve, and preset number of cycles. The fatigue damage value refers to the fatigue damage degree of the bearing fillet calculated based on the load components, stress response, SN curve, and number of cycles. Evaluate the reliability and life of the bearing in long-term operation. This can be achieved through fatigue analysis software (Ncode) or a custom algorithm. For example, the unit stress response, time series load, 20-year cycle number for each working condition, and fatigue SN curve are imported into the fatigue calculation software to obtain the fatigue damage value. The preset number of cycles can be set according to actual needs, such as counting the number of occurrences of each working condition within 20 years. In addition, the fatigue damage values ​​of the four fillets can also be obtained by using classic fatigue analysis methods such as the rain flow counting method.

[0071] Figure 3 A schematic diagram of the fillet position of a three-row column pitch bearing provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, it includes outer upper fillet, outer lower fillet, inner upper fillet and inner lower fillet.

[0072] In order to improve the analysis accuracy of stress and damage in the fillet area of ​​the bearing, step S14 establishes a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value. The accuracy of the local fillet finite element model is higher than that of the overall finite element model. The local fillet finite element model only contains a detailed finite element model of the fillet area of ​​the bearing, and its mesh division is finer to obtain a more accurate stress distribution. This is achieved by creating a finer mesh in the finite element analysis software.

[0073] Step S16 obtains the fatigue damage result of the current fillet according to the fillet finite element model, which refers to the fatigue damage data of the fillet area calculated based on the local fillet finite element model. Specifically, the unit stress response of the fillet is obtained through the local fillet finite element model, and the fatigue damage result of the current fillet is obtained by combining the time series load, the number of cycles, and the fatigue SN curve.

[0074] The pitch bearing fillet fatigue damage analysis method provided by the embodiment of the present application includes: obtaining the overall finite element model of the wind turbine including three blades, a hub, bolts, and three pitch bearings and the fatigue SN curve of the wind turbine; applying multiple preset working conditions on the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing; extracting the load components corresponding to the preset working conditions according to the root time series loads of the three blades of the wind turbine; obtaining the fatigue damage values ​​of the four fillets of the target bearing according to the load components, unit stress responses, fatigue SN curves, and preset number of cycles; establishing a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value, the accuracy of the local fillet finite element model is higher than that of the overall finite element model; obtaining the fatigue damage results of the current fillet according to the fillet finite element model. The present application firstly realizes a comprehensive evaluation of the fatigue damage of the four fillets of the three-row column pitch bearing through the overall finite element model to avoid missing the damage position. Through the establishment of the local fillet finite element model, the fillet with the largest fatigue damage is further analyzed locally, which improves the analysis accuracy of the stress and damage in the bearing fillet area. By predicting bearing fatigue damage, maintenance and replacement can be carried out in advance, reducing the risk of unexpected failures and lowering maintenance costs.

[0075] Specifically, the overall finite element model of the wind turbine including three blades, a hub, bolts, and three pitch bearings is obtained, including:

[0076] Obtain a three-dimensional model of a wind turbine;

[0077] An overall finite element model is constructed based on the three-dimensional model, in which the axial roller of the pitch bearing is simulated by at least 7 spring units.

[0078] The 3D model refers to the geometric representation of the wind turbine, including the detailed geometry and dimensions of the blades, hubs, bolts, pitch bearings, etc. The detailed geometric design of the wind turbine is created or imported using Computer Aided Design (CAD) software to achieve an accurate 3D representation of the wind turbine structure.

[0079] Convert the 3D model into a format that can be processed by the finite element analysis software, including defining material properties, boundary conditions, loads, etc. In this step, the overall finite element modeling of the wind turbine is achieved by importing the 3D model into the finite element analysis software, defining the material properties of each component (such as elastic modulus, Poisson's ratio, yield strength, etc.), and setting the boundary conditions and loads for the analysis.

[0080] Spring unit simulation refers to the use of spring units to simulate the behavior of axial rollers in pitch bearings. This is a simplified modeling method used to capture the force and motion characteristics of rollers without the need to simulate the geometry of the rollers in detail. In this step, a simplified and effective modeling of the pitch bearing is achieved by using at least 7 spring units in the finite element model to simulate the behavior of each axial roller.

[0081] Figure 4 A cross-sectional schematic diagram of a pitch bearing provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, 7 spring elements (comb39) are used to simulate the axial rollers.

[0082] In this embodiment, by using spring units to simulate axial rollers, the complexity of the model and the demand for computing resources can be significantly reduced without sacrificing too much accuracy, thereby improving the efficiency of the analysis.

[0083] In a specific embodiment, the purpose of the pitch bearing fillet fatigue damage analysis method is to accurately evaluate the stress response of the pitch bearing under different working conditions by simulating multiple load conditions under actual working conditions, so as to predict its fatigue damage. Specifically, multiple preset working conditions are applied to the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing, including:

[0084] The unit stress response of the target bearing under the preload condition is obtained according to the finite element model;

[0085] According to the finite element model, unit working conditions in four directions of +MX, -MX, +MY, and -MY are applied to the loading points of the three blades in sequence, and 12 unit stress responses of the target bearing are obtained;

[0086] Among them, the blade root coordinate system is established with the blade corresponding to the target bearing, MX represents the main axis direction, MZ represents the blade direction, and MY represents the direction perpendicular to the main axis and the blade.

[0087] This embodiment accurately evaluates the stress response of the variable pitch bearing under different working conditions by simulating various load conditions under actual working conditions. The preload condition refers to the force applied during the installation or preload process of the variable pitch bearing, which will affect the initial stress state of the bearing. In this step, the unit stress response of the target bearing under this specific condition is obtained by simulating the preload condition in the finite element model. The unit stress response obtained by simulating the preload condition is equivalent to the initial stress state of the bearing when there is no external load.

[0088] Figure 5 A schematic diagram of a blade root coordinate system provided in an embodiment of the present application is shown in FIG. Figure 5As shown in the figure, +MX, -MX, +MY, and -MY represent the positive loads in the main axis direction and perpendicular to the main axis and blade direction, respectively. The loads in these directions simulate the forces in different directions that the wind turbine may encounter in actual operation. The unit operating condition refers to the load in a single direction. By simulating these unit operating conditions, the stress response of the variable pitch bearing under the action of a single direction load can be obtained.

[0089] In this step, by applying these unit working conditions on the loading points of the three blades in sequence, the stress response of the variable pitch bearing under loads in different directions can be obtained, providing data support for subsequent fatigue damage analysis.

[0090] This embodiment can comprehensively evaluate the stress response of the variable pitch bearing under various load conditions by simulating the preload conditions and unit conditions in different directions. By accurately simulating loads in different directions, the fatigue damage of the variable pitch bearing can be more accurately predicted.

[0091] In order to accurately simulate and analyze the complex load conditions experienced by the wind turbine in actual operation, so as to more accurately predict the fatigue damage of the pitch bearing, this embodiment provides a specific embodiment, which extracts the load components corresponding to the preset working conditions according to the root time series loads of the three blades of the wind turbine, including:

[0092] Obtain the blade root time series load files of the three blades of the wind turbine and merge them into one time series load file;

[0093] Delete the components in non-MX and non-MY directions in the time series load file;

[0094] Separate the remaining time series loads in the time series load file into positive and negative directions, and obtain the time series loads of the three blades in the four directions of +MX, -MX, +MY, and -MY respectively;

[0095] Add a column of time series loads with data 1 in the time series load file as the time series load under the preload condition.

[0096] The blade root time series load files of the three blades of the wind turbine are obtained and merged into one time series load file. The blade root time series load data of the three blades are merged to provide a unified data set for subsequent processing.

[0097] Remove load components that are not relevant to the analysis, such as Figure 5 The components in the directions of MZ, Fx, Fy, Fz, etc. are shown, and the loads in the directions of MX and MY, which have the greatest impact on the fatigue damage of the pitch bearing, are retained. This reduces the complexity of the data and focuses on the load components that are most critical to fatigue damage analysis.

[0098] The time series load data are divided into positive and negative parts to simulate the loads in both positive and negative directions that the blades may encounter in actual operation.

[0099] The load effect under the simulated preload condition is added, which is the internal stress state of the variable pitch bearing without external load. The purpose of adding a column of time series loads with data of 1 is to simulate this internal stress state and ensure that all factors that may affect the fatigue damage of the variable pitch bearing are taken into account in the analysis.

[0100] This embodiment can more accurately simulate the load conditions experienced by the wind turbine in actual operation by extracting the load components corresponding to the preset working conditions. The processed time series load data can correspond one-to-one with the unit stress response data, thereby improving the accuracy of pitch bearing fatigue damage analysis.

[0101] Specifically, the remaining time series loads in the time series load file are separated into positive and negative parts, including:

[0102] If the remaining time series load in the time series load file is positive, the positive value is retained as the positive component of the current time series load, and the negative component of the current time series load is set to 0;

[0103] If the remaining time series load in the time series load file is a negative value, the positive component of the current time series load is set to 0, and the absolute value of the negative value is taken as the negative component of the current time series load.

[0104] In the timing load file, each timing load has a specific value, which may be positive or negative. If the remaining timing loads in the timing load file are positive, then this positive value is directly retained as the positive component of the current timing load, and at the same time, the negative component of the current timing load is set to 0, because at this specific timing point, the negative load does not act.

[0105] If the remaining time series loads in the time series load file are negative, the positive component of the current time series load is set to 0, because at this particular time series point, the positive load does not act. The negative load is taken as the negative component of the current time series load after taking the absolute value to ensure that the magnitude of the load is used in the analysis.

[0106] By separating the positive and negative, the actual working conditions can be simulated more accurately, thus improving the accuracy of fatigue damage analysis of variable pitch bearings.

[0107] Specifically, the fatigue time series load is input as three time series files, namely blade1 fatigue.txt, blade2 fatigue.txt and blade3 fatigue.txt. First, the three blade root time series loads are deleted, and then merged into one document; secondly, the time series loads need to be separated into positive and negative. That is, the six columns of time series loads of blade 1 in Mx direction, blade 1 in My direction, blade 2 in Mx direction, blade 2 in My direction, blade 3 in Mx direction, and blade 3 in My direction are processed into 12 columns of time series loads of blade 1 in +Mx direction, blade 1 in -Mx direction, blade 1 in +My direction, blade 1 in -My direction, blade 2 in +Mx direction, blade 2 in -Mx direction, blade 2 in +My direction, blade 2 in -My direction, blade 3 in +Mx direction, blade 3 in -Mx direction, blade 3 in +My direction, and blade 3 in -My direction. Among them, if the original load is positive, the positive value of the original data is retained and the negative value of the original data is set to 0; if the original load is negative, the positive value of the original data is set to 0, and the negative value is retained after taking the absolute value. Then add the preload condition load, and set all the first columns to 1. In this way, the load can correspond one by one to the 12 unit stress responses of the single condition calculated by the finite element.

[0108] Furthermore, the fatigue damage values ​​of the four fillets of the target bearing are obtained according to the load component, the unit stress response, the fatigue SN curve, and the preset number of cycles, including:

[0109] Match the positive and negative separated load components to the unit stress response one by one;

[0110] The fatigue analysis software inputs the load component, unit stress response, fatigue SN curve, and preset number of cycles to obtain the fatigue damage values ​​of the four fillets of the target bearing. The load components separated by positive and negative are matched with the unit stress response obtained previously. This means that each load component (including +MX, -MX, +MY, -MY) will be associated with its corresponding unit stress response. Through this correspondence, the load data and stress response data can be integrated to provide complete input data for subsequent fatigue damage calculations.

[0111] Fatigue analysis software (Ncode) is a software specially used to calculate structural fatigue damage. It can perform fatigue damage analysis based on input data. Based on these input data, the fatigue damage values ​​of the four fillets of the target bearing are calculated to evaluate the expected life and maintenance requirements of the variable pitch bearing.

[0112] In a specific embodiment, the fatigue damage result of the current fillet is obtained according to the fillet finite element model, including:

[0113] Obtain the fillet unit stress response of the current fillet according to the fillet finite element model;

[0114] The fatigue damage result of the current fillet is obtained according to the fillet unit stress response, fatigue SN curve, load component, and preset number of cycles.

[0115] The fillet finite element model is a high-precision local model specifically designed for the fillet area of ​​the pitch bearing to capture the detailed stress distribution in the area. The fillet unit stress response is the stress response of the fillet area under a specific load. This step is to obtain stress data of the fillet area under different load conditions. By combining the stress response, fatigue SN curve and number of cycles, the fatigue damage results of the fillet area are predicted.

[0116] The local fillet finite element model is used to refine the mesh of the area of ​​concern and recalculate the fatigue damage. The fatigue damage calculation steps are the same as the overall model, so as to achieve a high-precision assessment of the fatigue damage in the fillet area of ​​the variable pitch bearing.

[0117] In the above embodiments, the pitch bearing fillet fatigue damage analysis method is described in detail, and the present application also provides a corresponding embodiment of the pitch bearing fillet fatigue damage analysis device. It should be noted that the present application describes the embodiments of the device part from two perspectives, one is based on the functional module perspective, and the other is based on the hardware perspective.

[0118] From the perspective of functional modules, Figure 6 A structural diagram of a pitch bearing fillet fatigue damage analysis device provided in an embodiment of the present application, such as Figure 6 As shown, a pitch bearing fillet fatigue damage analysis device comprises:

[0119] An acquisition module 21 is used to acquire an overall finite element model of the wind turbine including three blades, a hub, bolts, and three pitch bearings and a fatigue SN curve of the wind turbine;

[0120] The unit stress analysis module 22 is used to apply multiple preset working conditions to the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing;

[0121] A time series load processing module 23 is used to extract load components corresponding to a preset working condition according to the time series loads of the blade roots of the three blades of the wind turbine generator set;

[0122] A fatigue damage preliminary determination module 24 is used to obtain fatigue damage values ​​of four fillets of the target bearing according to load components, unit stress response, fatigue SN curve, and preset number of cycles;

[0123] A local model building module 25 is used to build a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value, and the accuracy of the local fillet finite element model is higher than that of the overall finite element model;

[0124] The fatigue damage re-determination module 26 is used to obtain the fatigue damage result of the current fillet according to the fillet finite element model.

[0125] Since the embodiments of the apparatus part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the apparatus part, which will not be repeated here.

[0126] Figure 7 A structural diagram of another pitch bearing fillet fatigue damage analysis device provided in an embodiment of the present application, such as Figure 7 As shown, the pitch bearing fillet fatigue damage analysis device comprises: a memory 30, for storing a computer program;

[0127] The processor 31 is used to implement the steps of the method for obtaining user operation habit information in the above embodiment (pitch bearing fillet fatigue damage analysis method) when executing the computer program.

[0128] The pitch bearing fillet fatigue damage analysis device provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer, or a desktop computer.

[0129] Among them, the processor 31 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 31 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 31 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 31 may be integrated with a graphics processing unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 31 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0130] The memory 30 may include one or more computer-readable storage media, which may be non-transitory. The memory 30 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 30 is at least used to store the following computer program 301, wherein, after the computer program is loaded and executed by the processor 31, it can implement the relevant steps of the variable pitch bearing fillet fatigue damage analysis method disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 30 may also include an operating system 302 and data 303, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 302 may include Windows, Unix, Linux, etc. Data 303 may include but is not limited to data involved in implementing the variable pitch bearing fillet fatigue damage analysis method, etc.

[0131] In some embodiments, the pitch bearing fillet fatigue damage analysis device may further include a display screen 32 , an input / output interface 33 , a communication interface 34 , a power supply 35 , and a communication bus 36 .

[0132] Those skilled in the art will understand that Figure 7 The structure shown in the figure does not constitute a limitation on the pitch bearing fillet fatigue damage analysis device, and may include more or fewer components than those shown in the figure.

[0133] The pitch bearing fillet fatigue damage analysis device provided in the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: pitch bearing fillet fatigue damage analysis method.

[0134] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps described in the embodiment of the pitch bearing fillet fatigue damage analysis method are implemented.

[0135] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the methods of each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0136] The computer-readable storage medium provided in this embodiment stores a computer program, and when a processor executes the program, the following method can be implemented: a pitch bearing fillet fatigue damage analysis method.

[0137] The pitch bearing fillet fatigue damage analysis method, device and medium provided by the present application are introduced in detail above. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0138] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A pitch bearing fillet fatigue damage analysis method, characterized in that: include: Obtaining an overall finite element model of a wind turbine including three blades, a hub, bolts, and three pitch bearings and a fatigue SN curve of the wind turbine; Applying multiple preset working conditions to the loading points of the three blades according to the finite element model to obtain multiple unit stress responses of the target bearing; Extracting the load component corresponding to the preset working condition according to the blade root time series loads of the three blades of the wind turbine generator set; Obtaining fatigue damage values ​​of four fillets of a target bearing according to the load component, the unit stress response, the fatigue SN curve, and a preset number of cycles; Establishing a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value, wherein the accuracy of the local fillet finite element model is higher than that of the overall finite element model; The fatigue damage result of the current fillet is obtained according to the fillet finite element model.

2. The pitch bearing fillet fatigue damage analysis method according to claim 1, characterized in that: The obtaining of the overall finite element model of the wind turbine generator set including three blades, a hub, bolts, and three pitch bearings includes: Acquire a three-dimensional model of the wind turbine generator set; An overall finite element model is constructed based on the three-dimensional model, wherein the axial roller of the variable pitch bearing is simulated by at least 7 spring units.

3. The pitch bearing fillet fatigue damage analysis method according to claim 1, characterized in that: According to the finite element model, multiple preset working conditions are applied to the loading points of the three blades to obtain multiple unit stress responses of the target bearing, including: Obtaining a unit stress response of a target bearing under a preload condition according to the finite element model; According to the finite element model, unit working conditions in four directions of +MX, -MX, +MY, and -MY are applied to the loading points of the three blades in sequence to obtain 12 unit stress responses of the target bearing; Among them, the blade root coordinate system is established with the blade corresponding to the target bearing, MX represents the main axis direction, and MY represents the direction perpendicular to the main axis and the blade.

4. The pitch bearing fillet fatigue damage analysis method according to claim 3 is characterized in that: Extracting load components corresponding to the preset working condition according to the blade root time series loads of the three blades of the wind turbine generator system includes: Obtain blade root time series load files of three blades of the wind turbine generator set and merge them into one time series load file; Delete the components in non-MX direction and non-MY direction in the timing load file; Separate the remaining time series loads in the time series load file into positive and negative directions to obtain the time series loads of the three blades in four directions of +MX, -MX, +MY, and -MY respectively; A column of time series loads with data of 1 is added to the time series load file as the time series load under the preload condition.

5. The pitch bearing fillet fatigue damage analysis method according to claim 4, characterized in that: Separate the remaining time series loads in the time series load file into positive and negative states, including: If the remaining time series load in the time series load file is a positive value, the positive value is retained as the positive component of the current time series load, and the negative component of the current time series load is set to 0; If the remaining time series load in the time series load file is a negative value, the positive component of the current time series load is set to 0, and the absolute value of the negative value is taken as the negative component of the current time series load.

6. The pitch bearing fillet fatigue damage analysis method according to claim 5, characterized in that: Obtaining fatigue damage values ​​of four fillets of a target bearing according to the load component, the unit stress response, the fatigue SN curve, and a preset number of cycles includes: One-to-one correspondence between the positive and negative separated load components and the unit stress response; The load component, the unit stress response, the fatigue SN curve, and the preset number of cycles are input into the fatigue analysis software to obtain the fatigue damage values ​​of the four fillets of the target bearing.

7. The pitch bearing fillet fatigue damage analysis method according to claim 6, characterized in that: The fatigue damage result of the current fillet is obtained according to the fillet finite element model, including: Acquire the fillet unit stress response of the current fillet according to the fillet finite element model; The fatigue damage result of the current fillet is obtained according to the fillet unit stress response, the fatigue SN curve, the load component, and the preset number of cycles.

8. A pitch bearing fillet fatigue damage analysis device, characterized in that: include: An acquisition module is used to acquire an overall finite element model of a wind turbine including three blades, a hub, bolts, and three pitch bearings and a fatigue SN curve of the wind turbine; A unit stress analysis module, used to apply a plurality of preset working conditions to the loading points of the three blades according to the finite element model to obtain a plurality of unit stress responses of the target bearing; A time series load processing module, used for extracting load components corresponding to the preset working condition according to the blade root time series loads of the three blades of the wind turbine generator set; A fatigue damage preliminary determination module is used to obtain fatigue damage values ​​of four fillets of a target bearing according to the load component, the unit stress response, the fatigue SN curve, and a preset number of cycles; A local model building module, used to build a local fillet finite element model of the fillet corresponding to the maximum fatigue damage value, wherein the accuracy of the local fillet finite element model is higher than that of the overall finite element model; The fatigue damage re-determination module is used to obtain the fatigue damage result of the current fillet according to the fillet finite element model.

9. A pitch bearing fillet fatigue damage analysis device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the pitch bearing fillet fatigue damage analysis method as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the pitch bearing fillet fatigue damage analysis method according to any one of claims 1 to 7 are implemented.

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