Fan blade lightning stroke current simulation method and system based on multi-physics field coupling

Abstract

The invention discloses a fan blade lightning stroke current simulation method and system based on multi-physics field coupling, and belongs to the field of wind power generation equipment protection, and the method comprises the steps: building a three-dimensional geometric model of a fan blade; defining a multi-physical field environment including an electromagnetic field, a thermal field and a stress field; setting lightning stroke points on the three-dimensional geometric model according to lightning parameters; calculating electromagnetic distribution, temperature distribution and stress distribution in the blade in the lightning stroke process along the lightning propagation channel by using the electromagnetic field, the thermal field and the stress field based on the lightning stroke point, the lightning stroke basic information and the lightning attenuation rate; and constructing a lightning stroke current simulation result according to the electromagnetic distribution, the temperature distribution and the stress distribution, and performing visual display. The technical problem that the blade lightning protection design is insufficient due to the fact that the influence of lightning stroke on the multi-physical field interaction of the fan blade cannot be comprehensively and accurately simulated and analyzed in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of wind power generation equipment protection, and in particular to a method and system for simulating lightning current of wind turbine blades based on multi-physical field coupling. Background Art

[0002] As a clean and renewable energy source, wind power generation has been widely used around the world in recent years. As the core component of the wind power generation system, the performance and reliability of wind turbine blades directly affect the stable operation of the entire wind power system. In the actual operation of wind turbine blades, due to the high-speed rotation of the blades at high altitudes, they are prone to lightning strikes, which can cause damage to the blade material, electrical system failures, and even major accidents such as fires. Therefore, studying the impact of lightning strikes on wind turbine blades and developing effective protection and evaluation methods are of great significance to ensuring the safe operation of wind power systems.

[0003] At present, the research on lightning strikes on wind turbine blades mainly focuses on the physical mechanism of lightning strikes, material protection, and detection and repair after lightning strikes. However, due to the complex structure of wind turbine blades and the randomness of lightning strikes, the specific impact of lightning strikes on the internal current, temperature, and stress distribution of the blades is difficult to accurately measure and predict through traditional experimental methods. Summary of the invention

[0004] The present application provides a method and system for simulating lightning strike current on wind turbine blades based on multi-physical field coupling, aiming to solve the technical problem that the prior art cannot comprehensively and accurately simulate and analyze the impact of lightning strikes on the multi-physical field interaction of wind turbine blades, thereby leading to insufficient blade lightning protection design.

[0005] In view of the above problems, the present application provides a method and system for simulating lightning current on wind turbine blades based on multi-physical field coupling.

[0006] The first aspect disclosed in the present application provides a method for simulating lightning strike current of a wind turbine blade based on multi-physical field coupling, the method comprising obtaining parameter information of a wind turbine blade motor and establishing a three-dimensional geometric model of the wind turbine blade; defining a multi-physical field environment, including an electromagnetic field, a thermal field and a stress field, wherein the electromagnetic field, the thermal field and the stress field have a mutual coupling relationship; setting a lightning strike point on the three-dimensional geometric model according to lightning parameters, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information; utilizing the electromagnetic field, the thermal field and the stress field, based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate, calculating the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning strike along the lightning propagation channel; constructing a lightning strike current simulation result according to the electromagnetic distribution, the temperature distribution and the stress distribution, and performing a visual display.

[0007] Another aspect disclosed in the present application provides a wind turbine blade lightning current simulation system based on multi-physical field coupling, the system comprising a geometric model establishment module: used to obtain fan blade motor parameter information and establish a three-dimensional geometric model of the fan blade; a multi-physical field environment definition module: used to define a multi-physical field environment, including an electromagnetic field, a thermal field and a stress field, wherein the electromagnetic field, the thermal field and the stress field have a mutual coupling relationship; a lightning strike point setting module: used to set a lightning strike point on the three-dimensional geometric model according to lightning parameters, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information; a multi-dimensional distribution acquisition module: used to calculate the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning propagation channel based on the electromagnetic field, the thermal field and the stress field, the lightning strike point, the basic lightning strike information and the lightning attenuation rate; a visualization display module: used to construct a lightning current simulation result according to the electromagnetic distribution, the temperature distribution and the stress distribution, and perform a visualization display.

[0008] One or more technical solutions provided in this application have at least the following technical effects or advantages: Due to the adoption of a technical solution for simulating wind turbine blade lightning current based on multi-physical field coupling, by acquiring the fan blade motor parameter information and establishing a three-dimensional geometric model, the coupling relationship between the electromagnetic field, thermal field and stress field is defined, and the current, temperature and stress distribution inside the blade during the lightning strike are simulated, which solves the problem that the interaction of multiple physical effects cannot be fully evaluated in traditional lightning strike analysis, and achieves the technical effect of accurately reproducing the complex effects of lightning strikes on blades. This solution not only improves the accuracy of the simulation, but also provides reliable data support for optimizing the lightning protection design of the blades, thereby improving the lightning resistance and safety of the wind turbine blades.

[0009] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A flow chart of a method for simulating lightning current on wind turbine blades based on multi-physics field coupling is provided for an embodiment of the present application.

[0011] Figure 2 A structural schematic diagram of a wind turbine blade lightning current simulation system based on multi-physical field coupling is provided for an embodiment of the present application.

[0012] Explanation of the reference numerals: module for establishing a geometric model 11, module for defining a multi-physical field environment 12, module for setting a lightning strike point 13, module for obtaining a multi-dimensional distribution 14, and module for visualizing and displaying 15. DETAILED DESCRIPTION

[0013] The overall idea of ​​the technical solution provided by this application is as follows:

[0014] The embodiment of the present application provides a method and system for simulating lightning strike current of wind turbine blades based on multi-physics field coupling. By establishing a three-dimensional geometric model of the wind turbine blades and defining a multi-physics field coupling environment of electromagnetic field, thermal field and stress field on this basis, the current, temperature and stress distribution inside the blades during a lightning strike are simulated. Through this coupled simulation analysis, the impact of lightning strikes on blades is comprehensively evaluated, providing a scientific basis for optimizing blade design and improving lightning resistance.

[0015] After introducing the basic principles of the present application, various non-limiting implementation methods of the present application will be specifically described below in conjunction with the drawings in the specification.

[0016] Embodiment 1, as Figure 1 As shown, the embodiment of the present application provides a wind turbine blade lightning current simulation method based on multi-physics field coupling, the method comprising:

[0017] Step S100: Obtain fan blade motor parameter information and establish a three-dimensional geometric model of the fan blade.

[0018] Specifically, first, it is necessary to collect and organize the design data related to the wind turbine blades and their drive motors. This data usually includes the size, shape, and material properties of the blades.

[0019] Use computer-aided design (CAD) software, such as SolidWorks, AutoCAD, or CATIA, to build a three-dimensional geometric model of the fan blade based on the acquired fan motor parameter information. First, draw the preliminary geometric shape of the blade based on the basic geometric parameters of the blade. Next, perform geometric trimming, integrate the preliminary geometric shape and the trimmed geometric shape to generate a complete three-dimensional geometric model. Accurately representing the shape and internal structure of the blade becomes the basis for subsequent simulation analysis.

[0020] Through this step, an accurate 3D geometric model is obtained to simulate the physical response of wind turbine blades under extreme conditions such as lightning strikes.

[0021] Step S200: defining a multi-physical field environment, including an electromagnetic field, a thermal field, and a stress field, wherein the electromagnetic field, the thermal field, and the stress field have a mutual coupling relationship.

[0022] Specifically, first, the initial conditions of the electromagnetic field are set based on the material properties of the wind turbine blades and the surrounding environment. The initial temperature conditions and boundary conditions are set based on the thermal physical properties of the blade material, such as thermal conductivity, specific heat capacity, and density. The initial temperature is based on the ambient temperature or the operating temperature of the blade. The initial stress state is set based on the structure and material properties of the blade. This includes the elastic modulus, Poisson's ratio, and prestress conditions of the material. The structural mechanics module is used in the finite element analysis software to build a stress field model.

[0023] The electromagnetic field, thermal field and stress field are integrated through the multi-physics field coupling function of the finite element analysis software. In tools such as ANSYS or COMSOL, set up multi-physics field coupling analysis. Through this multi-physics field coupling analysis, the complex physical phenomena inside the wind turbine blades during the lightning strike can be simulated, such as temperature changes caused by current, stress distribution caused by temperature changes, etc.

[0024] By defining and coupling these physical fields, you can accurately simulate the physical response of wind turbine blades in the event of a lightning strike, providing a scientific basis for understanding and optimizing the design and protection of blades. For example, you can observe how the coupling of thermal and stress fields causes stress concentration and structural damage in the material when lightning strikes the blade.

[0025] Step S300: according to lightning parameters, a lightning strike point is set on the three-dimensional geometric model, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information.

[0026] Specifically, lightning parameters refer to multiple physical parameters that describe lightning characteristics, including lightning current intensity, duration, frequency, attenuation rate, energy distribution, etc. The lightning strike point is the specific location where lightning actually hits the blade, identified in the three-dimensional geometric model. The lightning propagation channel refers to the flow path of the lightning current inside the blade. This path usually propagates along the path of minimum resistance or maximum electric field strength of the material, which is determined by the conductive properties and structure of the blade. The lightning attenuation rate refers to the rate at which the current intensity of the lightning current decreases with distance or time during the propagation process. A higher attenuation rate means that the impact range of lightning is smaller, and conversely, a lower attenuation rate will lead to a wider impact. Basic lightning strike information refers to the basic data of lightning strike events, including lightning intensity, frequency, and the distribution of historical lightning strike events.

[0027] First, by analyzing lightning parameters, the intensity, frequency, attenuation rate and other characteristics of the lightning current are determined. Next, the lightning strike point is selected in the 3D geometric model. After the lightning strike point is selected, the simulation tool will construct a lightning propagation channel based on the material properties (such as conductivity) and geometric structure of the blade. This channel simulates how the lightning current propagates inside the blade, generally along the path with the least resistance or the greatest electric field strength.

[0028] Through this process, the effects of lightning strikes on wind turbine blades can be analyzed in detail, including how the current flows inside the blades, which parts bear greater current shocks, and how these effects weaken over time and distance.

[0029] Step S400: using the electromagnetic field, the thermal field and the stress field, based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate, the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning strike are calculated along the lightning propagation channel.

[0030] Specifically, in the lightning simulation analysis, firstly, according to the geometric model of the wind turbine blade and the electromagnetic field, thermal field and stress field defined by the material properties, the location of the lightning strike point and its related basic information of lightning strike are analyzed to simulate the propagation process of lightning inside the blade. Specifically, the lightning strike point is the initial entry position of the lightning current. The lightning current is applied at this point, and according to the material properties and geometric shape of the blade, the current flow is simulated along the path with the least resistance or the greatest electric field strength, that is, the lightning propagation channel.

[0031] Finite element analysis (FEA) tools, such as ANSYS or COMSOL, are used to simulate how lightning current propagates inside the blade and the electromagnetic effects caused by the current flow. These effects not only affect the electromagnetic environment inside the blade, but also have a direct thermal effect on the blade material, namely the Joule heating effect generated by the current flow.

[0032] Next, based on the electromagnetic distribution data, the temperature distribution during the lightning strike can be calculated using the heat conduction module in the FEA software. These temperature changes directly reflect the heating effect caused by the flow of current and the thermal response of the material. As the temperature changes, corresponding stress will be generated inside the blade material. Using the structural mechanics module of the FEA tool, the stress distribution inside the blade can be further calculated.

[0033] Through this coupled analysis, we can fully understand the electromagnetic, thermal and mechanical responses inside the blades during a lightning strike, thus providing a scientific basis for the design and protection of wind turbine blades.

[0034] Step S500: constructing lightning current simulation results according to the electromagnetic distribution, the temperature distribution and the stress distribution, and performing visual display.

[0035] Specifically, first, a comprehensive lightning response model is formed by combining the electromagnetic distribution, the temperature distribution and the stress distribution. This model includes multiple effects of lightning on the blade, including how the current flows inside the blade, how the temperature in different areas rises, and how the material responds under mechanical stress. Specifically, finite element analysis (FEA) software such as ANSYS or COMSOL is usually used. The electromagnetic, thermal and stress distribution results are integrated into a unified model, so that the electromagnetic, thermal and mechanical effects of lightning on the blade can be displayed simultaneously. Use visualization modules such as MATLAB, Paraview or COMSOL to generate detailed graphical displays.

[0036] Throughout the process, through comprehensive analysis and visual display, the lightning current simulation results not only provide an intuitive display for understanding the impact of lightning strikes on wind turbine blades, but also provide strong data support for optimizing blade design. These display results are helpful for risk assessment in the design stage and for developing effective protective measures, thereby improving the tolerance of wind turbine blades to lightning strikes.

[0037] Furthermore, the method of obtaining fan blade motor parameter information and establishing a three-dimensional geometric model of a fan blade includes: collecting design drawings, manufacturing specifications and material properties of the fan blade based on big data to obtain the fan blade motor parameter information; constructing a preliminary geometric shape of the blade according to the fan blade motor parameter information; performing geometric trimming based on the preliminary geometric shape to obtain a trimmed geometric shape; and obtaining the three-dimensional geometric model according to the preliminary geometric shape and the trimmed geometric shape.

[0038] Specifically, the preliminary geometry refers to the basic three-dimensional structural model of the wind turbine blade that is initially constructed based on the collected parameter information. This is the first step in geometric modeling, which usually includes the basic shape, size and main features of the blade. Geometric finishing refers to further detail adjustment and optimization based on the preliminary geometry to better reflect the actual design and functional requirements of the blade. This includes corrections to the blade surface smoothness, edge curvature and specific details.

[0039] First, collect complete fan blade motor parameter information. Through big data technology, collect information related to fan blades from various data sources such as design drawings, manufacturing specifications, and material property databases. For example, the design drawings provide the basic shape and size of the blades, the manufacturing specifications define the accuracy and tolerance of the materials, and the material property database contains key physical properties such as the density and elastic modulus of the blade material. These information together constitute the fan blade motor parameter information.

[0040] Next, the preliminary geometric shape of the blade is constructed using the fan motor parameter information in computer-aided design (CAD) software such as SolidWorks, AutoCAD or CATIA. This step usually includes defining the basic features of the blade, such as the basic profile, length, width, thickness, etc. For example, a basic blade shape model is initially constructed based on the dimensions provided in the design drawing.

[0041] After the preliminary geometry is established, geometry finishing is performed. This step is to adjust and optimize the preliminary model in detail to make it closer to the actual blade design requirements. Geometry finishing includes smoothing the edges of the blade to improve its aerodynamic performance, or adjusting the curvature of the blade to adapt to the actual manufacturing process and use conditions. For example, certain areas need to be strengthened or specific geometric features added to ensure that the blade has sufficient strength and stability during operation.

[0042] Finally, the preliminary geometry and the trimmed geometry are combined to generate the final 3D geometry model. This model can accurately reflect the real physical form of the blade by comprehensively considering the design requirements, manufacturing process and material properties. For example, this final 3D model can be directly used in subsequent finite element analysis (FEA) or other simulation tools to simulate the behavior of the blade under different operating conditions, such as the distribution of electromagnetic fields, temperature fields and stress fields in the case of lightning strikes.

[0043] Through these steps, an accurate 3D geometric model can be constructed, providing a reliable basis for subsequent analysis and optimization. For example, with this model, different lightning strike scenarios can be tested in simulation tools to evaluate the performance of the blade under extreme conditions, thereby guiding the further optimization of the blade design.

[0044] Furthermore, the multi-physical field environment is defined, including an electromagnetic field, a thermal field and a stress field, wherein the electromagnetic field, the thermal field and the stress field have a mutual coupling relationship, including: in the three-dimensional geometric model, setting initial electromagnetic conditions and electromagnetic boundary conditions to construct the electromagnetic field; in the three-dimensional geometric model, setting initial temperature conditions and thermal boundary conditions to construct the thermal field; based on the fan blade motor parameter information, setting an initial stress state to construct the stress field; configuring the mutual coupling relationship between the electromagnetic field, the thermal field and the stress field, and based on the mutual coupling relationship, fusing the electromagnetic field, the thermal field and the stress field to generate the multi-physical field environment.

[0045] Specifically, electromagnetic conditions refer to the initial parameters that affect the distribution of electromagnetic fields, such as the initial distribution of current intensity, electric field, and magnetic field. Electromagnetic boundary conditions define the behavior of electromagnetic fields on the surface of the blade or other boundaries, such as whether it is a conductive boundary or an insulating boundary. Initial temperature conditions refer to the temperature distribution of the blade material at the beginning of the simulation. Thermal boundary conditions define how heat is transferred or lost on the surface or boundary of the blade. The initial stress state refers to the stress distribution inside the blade material at the beginning of the simulation. Including prestress caused by the manufacturing process or installation conditions. Mutual coupling refers to the interaction between multiple physical fields. For example, the current generated by the electromagnetic field will generate heat (coupling of the electromagnetic field and the thermal field), and the change in heat will cause thermal expansion of the material, thereby generating stress (coupling of the thermal field and the stress field).

[0046] First, in the 3D geometric model of the wind turbine blade, the initial conditions and electromagnetic boundary conditions of the electromagnetic field are set. For example, if the blade edge is a conductive material, the electromagnetic boundary conditions allow current to conduct at this edge, otherwise it is set as an insulating boundary to prevent current from passing.

[0047] Next, set the initial conditions and thermal boundary conditions of the thermal field. For example, during a lightning strike, certain areas of the blade surface will experience a significant increase in temperature due to the heating effect caused by the current. These changes need to be accurately simulated by thermal boundary conditions.

[0048] Then, based on the parameter information of the wind blade motor, the initial state of the stress field is set. This step involves determining whether the blade has prestress at the beginning of the simulation, such as due to the manufacturing process or stress accumulation during the operation of the wind turbine. This initial stress state provides a reference baseline for subsequent analysis.

[0049] Furthermore, the mutual coupling relationship between the electromagnetic field, thermal field and stress field is configured. Using finite element analysis (FEA) software, such as ANSYS Multiphysics or COMSOL Multiphysics, these three physical fields can be coupled to each other. For example, when the current generated by lightning strikes flows in the blade material, it will cause a heating effect, which is the coupling of the electromagnetic field and the thermal field; then, the increase in temperature will cause thermal expansion of the material, thereby generating mechanical stress inside the blade, which is the coupling of the thermal field and the stress field. These coupling relationships ensure that the simulation can truly reflect the complex physical phenomena during the lightning strike.

[0050] The whole process can fully understand the impact of lightning strikes on wind turbine blades through multi-physics coupling simulation of electromagnetic fields, thermal fields and stress fields. This simulation method can not only help engineers identify potential problems in blade design, but also provide effective improvement plans to enhance the blade's lightning resistance.

[0051] Furthermore, the configuration of the mutual coupling relationship between the electromagnetic field, the thermal field and the stress field includes: forming a magnetic-thermal coupling relationship based on a magnetic-thermal physical conversion mechanism; forming a thermal-stress coupling relationship based on a thermal-stress physical conversion mechanism; forming a magnetic-stress coupling relationship based on a magnetic-stress physical conversion mechanism; and setting the magnetic-thermal coupling relationship, the thermal-stress coupling relationship and the magnetic-stress coupling relationship as the mutual coupling relationship between the electromagnetic field, the thermal field and the stress field.

[0052] Specifically, the magneto-thermal physical conversion mechanism refers to the coupling relationship between the electromagnetic field and the thermal field. In the case of a lightning strike, the flow of lightning current in the blade will produce a Joule heating effect, which is the process of magneto-thermal physical conversion. The current generates heat when passing through the material, which causes the temperature to rise. The thermal-stress physical conversion mechanism refers to the coupling relationship between the thermal field and the stress field. When the temperature of the blade material rises, the material will undergo thermal expansion, resulting in changes in internal stress. This temperature-induced mechanical stress is the thermal-stress physical conversion. The magneto-stress physical conversion mechanism refers to the coupling relationship between the electromagnetic field and the stress field. In high-intensity electromagnetic fields, especially in conductive materials, the magnetic field will induce stress changes inside the material, and even produce a magnetostrictive effect under certain conditions, that is, the material deforms under the action of the magnetic field.

[0053] First, based on the magneto-thermal physical conversion mechanism, a magneto-thermal coupling relationship is formed. This means that when the lightning current passes through the blade material, heat is generated (Joule heating effect), which leads to an increase in the temperature inside the blade. At this time, the current density in the electromagnetic field directly affects the temperature distribution of the thermal field. For example, in the conductive part of the blade, the stronger the current, the more heat is generated, thus forming a high temperature area.

[0054] Next, based on the heat-stress physical conversion mechanism, a heat-stress coupling relationship is formed. When the temperature of the blade material increases due to the heating effect of the electric current, the material will undergo thermal expansion. This expansion causes mechanical stress inside, especially at the edges or joints of the material, which are subject to greater stress concentration. For example, if a part of the blade expands rapidly due to the thermal effect, this expansion will cause increased stress in the surrounding area, causing micro-cracks or structural deformation of the material.

[0055] At the same time, based on the magneto-stress physical conversion mechanism, a magneto-stress coupling relationship is formed. Under the action of high-intensity electromagnetic fields, especially in magnetic or conductive materials, the magnetic field directly affects the stress distribution inside the material. In some cases, the magnetostrictive effect can cause measurable deformation of the material. For example, if a lightning strike causes a strong magnetic field to be generated inside the blade, this magnetic field causes deformation of certain parts of the blade, thereby increasing local mechanical stress.

[0056] Finally, the three coupling relationships of magnetic-thermal coupling, thermal-stress coupling and magnetic-stress coupling are integrated together to establish a complete multi-physics field mutual coupling relationship. This step is usually achieved by using advanced finite element analysis (FEA) tools, such as ANSYS Multiphysics or COMSOL Multiphysics. It allows multiple physical fields to be simulated simultaneously and their interactions to be analyzed. For example, when performing lightning strike simulations, these coupling relationships ensure that the thermal effects and mechanical stresses caused by current can be accurately predicted and displayed.

[0057] By defining and configuring these coupling relationships, the multiple physical effects of lightning strikes on wind turbine blades can be realistically reproduced, providing key data support for design improvements and safety assessments.

[0058] Furthermore, according to the lightning parameters, a lightning strike point is set on the three-dimensional geometric model, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information, including: determining lightning event information according to historical lightning activities, wherein the lightning event information includes the basic lightning information and multiple potential lightning strike points; selecting the potential lightning strike point on the three-dimensional geometric model; starting from the selected potential lightning strike point, constructing the lightning propagation channel based on the minimum resistance path and / or the maximum electric field strength path; applying the lightning current intensity of the basic lightning information on the lightning propagation channel, and obtaining the lightning attenuation rate according to historical lightning strike data.

[0059] Specifically, lightning event information includes records and data of historical lightning activities, such as the intensity, frequency, and strike location of lightning, etc. It is used to predict the possibility and impact range of future lightning strikes.

[0060] First, lightning event information is determined based on historical lightning activity data. This information includes basic lightning parameters, such as lightning current intensity, attenuation rate, strike location, and multiple potential lightning strike points. These historical data usually come from meteorological databases or special lightning monitoring systems, which can provide a reliable reference for future lightning strike simulations.

[0061] Next, potential lightning strike points are selected on the 3D geometry model. When selecting potential lightning strike points, exposed locations on the blades are usually considered, such as the tip or edge of the blade, which are more likely to be targets of lightning strikes due to higher electric field strength. Once the lightning strike points are selected, the next step is to construct lightning propagation channels based on the minimum resistance path or the maximum electric field strength path. The minimum resistance path means that the lightning current will propagate along the path with the least resistance in the blade, while the maximum electric field strength path means that the lightning current propagates at the location with the strongest electric field. These two path models help simulate the specific flow of lightning current in the blade.

[0062] After determining the lightning propagation channel, the lightning current intensity in the basic lightning information is applied to this propagation channel during the simulation process. This ensures that the propagation of lightning current inside the blade conforms to the actual physical characteristics. In order to further improve the accuracy of the simulation, the lightning attenuation rate is determined by referring to historical lightning strike data during the simulation process. The lightning attenuation rate reflects the trend that the lightning current gradually weakens inside the blade as the propagation distance or time increases. For example, the lightning current decays faster in the high-resistance area of ​​the material, and propagates farther in the low-resistance area.

[0063] In this way, the constructed lightning current simulation can accurately reflect the propagation and attenuation of lightning current inside the wind turbine blades and its impact on the material. This process provides valuable reference data for blade design, helps to identify weak points, and formulate corresponding protective measures.

[0064] Furthermore, the electromagnetic field, the thermal field and the stress field are used to calculate the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning strike along the lightning propagation channel based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate, including: initializing the electromagnetic field, the thermal field and the stress field through a sensor component to obtain an initial electromagnetic field, an initial thermal field and an initial stress field; dividing the three-dimensional geometric model into a plurality of grid units; based on the initial electromagnetic field, in combination with the lightning strike point, the basic lightning strike information and the lightning attenuation rate, performing finite element simulation analysis on the three-dimensional geometric model along the lightning propagation channel to obtain electromagnetic distributions of a plurality of grid units; based on the magnetic-thermal coupling relationship, in combination with the current of the plurality of grid units Density distribution is subjected to magnetic-thermal conversion in the initial thermal field to obtain temperature distributions of multiple grid cells; based on the thermal-stress coupling relationship, thermal-stress conversion is performed in the initial stress field in combination with the temperature distributions of the multiple grid cells to obtain thermal stress distributions of multiple grid cells; based on the magnetic-stress coupling relationship, magnetic-stress conversion is performed in the initial stress field in combination with the temperature distributions of the multiple grid cells to obtain magnetic stress distributions of multiple grid cells; combined force analysis is performed on the thermal stress distributions of the multiple grid cells and the magnetic stress distributions of the multiple grid cells to obtain stress distributions of multiple grid cells; the electromagnetic density distributions of the multiple grid cells are set to the electromagnetic distribution, the temperature distributions of the multiple grid cells are set to the temperature distribution, and the stress distributions of the multiple grid cells are set to the stress distribution.

[0065] Specifically, first, the electromagnetic field, thermal field and stress field are initialized through sensor components (current sensor, electric field sensor, magnetic field sensor, thermocouple, infrared temperature sensor, strain gauge, fiber Bragg grating sensor). The initial distribution of the electromagnetic field, the initial state of the temperature field and the initial state of the stress field are determined according to the initial conditions of the blade material (such as conductivity, initial temperature and prestress state). This provides a benchmark for subsequent simulation analysis.

[0066] Next, the 3D geometric model is divided into multiple mesh units. Finite element simulation analysis is performed by dividing the complex blade structure into many small mesh units, so that the physical properties of each unit can be calculated step by step, and finally the simulation results of the entire blade can be obtained. The finer the mesh division, the more accurate the simulation results.

[0067] Then, based on the initialized electromagnetic field, combined with the lightning strike point, basic information of lightning strike and lightning attenuation rate, finite element simulation analysis is performed along the lightning propagation channel. Through simulation, the electromagnetic field distribution of each grid unit is calculated, that is, the specific distribution of current density, electric field and magnetic field. These results show the flow path and electromagnetic effect of lightning current inside the blade.

[0068] Based on the coupling relationship between the electromagnetic field and the thermal field, the temperature distribution of each grid unit is calculated by applying the current density distribution to the initial thermal field, performing magnetic-thermal conversion, which means the distribution of heat generated when the current flows through the blade material inside the material, thus revealing which parts of the blade become hotter due to the lightning strike.

[0069] Next, based on the coupling relationship between the thermal field and the stress field, the temperature distribution is applied to the initial stress field, and the thermal-stress conversion is performed to calculate the thermal stress distribution of each grid unit. Temperature changes will cause thermal expansion of the material, which in turn generates stress. These thermal stress distribution results show the distribution of forces generated inside the blade material due to lightning strikes.

[0070] Similarly, based on the coupling relationship between the electromagnetic field and the stress field, the magnetic stress distribution of each grid unit is calculated through magnetic-stress conversion. Under high-intensity electromagnetic fields, the material will be directly affected by electromagnetic forces, which will induce additional stress.

[0071] Finally, these thermal stress and magnetic stress distributions are analyzed together to integrate the stress distribution inside the blade. This means how the total stress inside the blade material is distributed when lightning strikes, and in which areas the stress is most concentrated, which will cause structural damage.

[0072] Finally, these calculation results are set as the electromagnetic distribution, temperature distribution and stress distribution of the blade to form a complete simulation result. Using finite element simulation tools such as ANSYS or COMSOL, three-dimensional graphics and thermal maps can be generated to show the current flow path, temperature rise area and stress concentration point of the blade when struck by lightning.

[0073] Through this comprehensive simulation of multi-physics fields, we can better understand the impact of lightning strikes on wind turbine blades and provide a scientific basis for blade design and lightning protection measures.

[0074] Furthermore, the method also includes: executing several lightning current simulation results to obtain the ultimate lightning basic information, ultimate electromagnetic distribution, ultimate temperature distribution and ultimate stress distribution of the wind turbine blade extreme state; constructing graphical display information in the three-dimensional geometric model according to the ultimate electromagnetic distribution, the ultimate temperature distribution and the ultimate stress distribution; generating the lightning current simulation results for visual display according to the ultimate lightning basic information and the graphical display information.

[0075] Specifically, the extreme electromagnetic distribution is the maximum distribution of the current inside the blade under extreme lightning strike conditions, showing the strongest path and area of ​​lightning current flowing in the blade. The extreme temperature distribution is the highest distribution of the temperature inside the blade under extreme lightning strike conditions, showing the highest temperature reached by the blade under the most severe lightning strike conditions. The extreme stress distribution is the maximum distribution of stress inside the blade under extreme lightning strike conditions, revealing the maximum mechanical stress borne by the blade under extreme conditions. Among them, the extreme lightning strike is the most severe lightning strike event borne by wind turbine blades.

[0076] First, by applying different lightning strike conditions and performing multiple simulation analyses, we gradually approached the most severe lightning strike conditions that the blades would withstand. These simulation results can help determine basic information about the extreme lightning strike, such as the maximum current intensity and the most severe attenuation rate.

[0077] After obtaining the data under these extreme conditions, the next step is to calculate the extreme electromagnetic distribution, extreme temperature distribution, and extreme stress distribution of the blade. These distribution results show the maximum current, maximum temperature, and maximum stress that each internal area of ​​the blade bears when the lightning strike is the most severe. For example, through simulation tools such as ANSYS or COMSOL, it is possible to calculate which parts of the blade have the most concentrated current density under the maximum current condition, and how these high current areas lead to temperature increases and stress concentrations.

[0078] After obtaining these extreme distribution data, engineers need to convert these complex physical data into intuitive graphical display information. By using the built-in visualization function of 3D modeling software or simulation tools, the extreme electromagnetic distribution, temperature distribution and stress distribution can be displayed in the form of a three-dimensional model, thermal map or stress map. For example, a part of the blade receives the strongest current when struck by lightning. Through visualization, this area can be highlighted in the 3D model, and the corresponding temperature and stress distribution can be displayed at the same time.

[0079] Finally, based on these graphical display information, the complete lightning current simulation results are generated and visualized. This visualization not only includes the distribution of all key physical fields under the limit state, but also can simulate the entire process of lightning strike from start to finish through animation or dynamic display. For example, a dynamic video can be generated to show how lightning propagates along the blade, which areas have the most concentrated current, how the temperature rises, and how stress accumulates inside the blade. Such visualization results can help engineers intuitively understand the impact of lightning strikes on blades, identify potential weaknesses in the design, and develop improvement plans.

[0080] Through multiple simulations and visualization displays, engineers can better evaluate the ultimate performance of wind turbine blades, ensure that the blades can still operate safely under the worst lightning strike conditions, and provide reliable data support for further design optimization.

[0081] In summary, the wind turbine blade lightning current simulation method based on multi-physics field coupling provided in the embodiment of the present application has the following technical effects:

[0082] 1. Through multi-physics coupling simulation, the current, temperature and stress distribution inside the blade during a lightning strike can be simulated, which can comprehensively evaluate the various effects of lightning strikes on wind turbine blades. This coupling analysis improves the accuracy of the simulation, helps engineers identify weak points during the design phase, and then optimizes the lightning protection design of the blade, improving the blade's lightning resistance and overall reliability.

[0083] 2. By defining the electromagnetic field, thermal field and stress field and configuring the mutual coupling relationship between them, the simulation can simulate the interaction of various physical fields during the lightning strike. This multi-physics field coupling analysis method can fully capture the multiple effects of lightning strikes on blades, provide more accurate results, and help engineers conduct comprehensive structural analysis and design optimization to improve the lightning resistance of wind turbine blades.

[0084] 3. Through finite element simulation analysis, combined with the coupling relationship between electromagnetic field, thermal field and stress field, the electromagnetic, temperature and stress distribution inside the blade during the lightning strike is accurately calculated. This method ensures the accuracy of the simulation results and provides detailed information such as stress concentration and temperature hot spots, which helps engineers evaluate the lightning resistance of the blade and make effective design improvements.

[0085] 4. Through multiple lightning strike simulations, the current, temperature and stress distribution of the blade under extreme conditions are obtained and visualized. This technology can comprehensively evaluate the performance of the blade under the most severe lightning strike conditions, help engineers identify potential risks in the design, and improve the scientificity and reliability of design decisions through intuitive visualization.

[0086] Embodiment 2 is based on the same inventive concept as the wind turbine blade lightning current simulation method based on multi-physical field coupling in the above embodiment. Figure 2 As shown, the embodiment of the present application provides a wind turbine blade lightning current simulation system based on multi-physics field coupling, the system comprising:

[0087] A geometric model building module 11 is used to obtain the fan blade motor parameter information and build a three-dimensional geometric model of the fan blade;

[0088] A multi-physics field environment definition module 12 is used to define a multi-physics field environment, including an electromagnetic field, a thermal field, and a stress field, wherein the electromagnetic field, the thermal field, and the stress field have a mutual coupling relationship;

[0089] A lightning strike point setting module 13 is used to set a lightning strike point on the three-dimensional geometric model according to lightning parameters, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information;

[0090] Obtaining a multi-dimensional distribution module 14: used to calculate the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning strike along the lightning propagation channel based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate by using the electromagnetic field, the thermal field and the stress field;

[0091] Visualization display module 15: used to construct lightning current simulation results according to the electromagnetic distribution, the temperature distribution and the stress distribution, and perform visualization display.

[0092] Furthermore, the system is also used to perform the following steps:

[0093] Based on big data, design drawings, manufacturing specifications and material properties of fan blades are collected to obtain parameter information of the fan blade motor;

[0094] Constructing a preliminary geometric shape of the blade according to the fan motor parameter information;

[0095] Performing geometric trimming processing based on the preliminary geometric shape to obtain a trimmed geometric shape;

[0096] The three-dimensional geometric model is obtained according to the preliminary geometric shape and the trimmed geometric shape.

[0097] Furthermore, the system is also used to perform the following steps:

[0098] In the three-dimensional geometric model, initial electromagnetic conditions and electromagnetic boundary conditions are set to construct the electromagnetic field;

[0099] In the three-dimensional geometric model, initial temperature conditions and thermal boundary conditions are set to construct the thermal field;

[0100] Based on the fan blade motor parameter information, an initial stress state is set to construct the stress field;

[0101] The mutual coupling relationship among the electromagnetic field, the thermal field and the stress field is configured, and based on the mutual coupling relationship, the electromagnetic field, the thermal field and the stress field are integrated to generate the multi-physical field environment.

[0102] Furthermore, the system is also used to perform the following steps:

[0103] Based on the magneto-thermal physical conversion mechanism, a magneto-thermal coupling relationship is formed;

[0104] Based on the heat-stress physical conversion mechanism, a heat-stress coupling relationship is formed;

[0105] Based on the magneto-stress physical conversion mechanism, a magneto-stress coupling relationship is formed;

[0106] The magnetic-thermal coupling relationship, the thermal-stress coupling relationship and the magnetic-stress coupling relationship are set as mutual coupling relationships between the electromagnetic field, the thermal field and the stress field.

[0107] Furthermore, the system is also used to perform the following steps:

[0108] Determine lightning event information based on historical lightning activities, wherein the lightning event information includes the basic lightning information and multiple potential lightning strike points;

[0109] Selecting the potential lightning strike point on the three-dimensional geometric model;

[0110] Starting from the selected potential lightning strike point, the lightning propagation channel is constructed based on the minimum resistance path and / or the maximum electric field strength path;

[0111] The lightning current intensity of the basic lightning information is applied to the lightning propagation channel, and the lightning attenuation rate is obtained according to historical lightning strike data.

[0112] Furthermore, the system is also used to perform the following steps:

[0113] Initializing the electromagnetic field, the thermal field and the stress field through the sensor assembly to obtain an initial electromagnetic field, an initial thermal field and an initial stress field;

[0114] Dividing the three-dimensional geometric model into a plurality of grid units;

[0115] Based on the initial electromagnetic field, in combination with the lightning strike point, the basic lightning strike information and the lightning attenuation rate, a finite element simulation analysis is performed on the three-dimensional geometric model along the lightning propagation channel to obtain electromagnetic distributions of multiple grid units;

[0116] Based on the magnetic-thermal coupling relationship, combining the current density distribution of the multiple grid units, magnetic-thermal conversion is performed in the initial thermal field to obtain temperature distribution of multiple grid units;

[0117] Based on the thermal-stress coupling relationship, thermal-stress conversion is performed in the initial stress field in combination with the temperature distributions of the multiple grid units to obtain thermal stress distributions of the multiple grid units;

[0118] Based on the magnetic-stress coupling relationship, magnetic-stress conversion is performed in the initial stress field in combination with the temperature distributions of the multiple grid units to obtain magnetic stress distributions of multiple grid units;

[0119] Performing a combined force analysis on the thermal stress distributions of the plurality of grid cells and the magnetic stress distributions of the plurality of grid cells to obtain stress distributions of the plurality of grid cells;

[0120] The electromagnetic density distribution of the plurality of grid cells is set as the electromagnetic distribution, the temperature distribution of the plurality of grid cells is set as the temperature distribution, and the stress distribution of the plurality of grid cells is set as the stress distribution.

[0121] Furthermore, the system is also used to perform the following steps:

[0122] Execute several lightning current simulation results to obtain the ultimate lightning basic information, ultimate electromagnetic distribution, ultimate temperature distribution and ultimate stress distribution of the wind turbine blade limit state;

[0123] Constructing graphical display information in the three-dimensional geometric model according to the limit electromagnetic distribution, the limit temperature distribution and the limit stress distribution;

[0124] The lightning strike current simulation result is generated according to the extreme lightning strike basic information and the graphical display information for visual display.

[0125] Any step of the method described above can be stored as a computer instruction or program in an unlimited computer memory, and can be called and recognized by an unlimited computer processor to implement any method in the embodiments of the present application, without any unnecessary restrictions.

[0126] Furthermore, the first or second mentioned above may not only represent an order relationship, but may also represent a specific concept, and / or refer to multiple elements that can be selected individually or in full. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalents, the present application intends to include these modifications and variations.

Claims

1. A wind turbine blade lightning current simulation method based on multi-physics field coupling, characterized in that: The method comprises: Obtain the fan blade motor parameter information and establish a three-dimensional geometric model of the fan blade; Defining a multi-physics field environment, including an electromagnetic field, a thermal field, and a stress field, wherein the electromagnetic field, the thermal field, and the stress field have a mutual coupling relationship; According to lightning parameters, a lightning strike point is set on the three-dimensional geometric model, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information; Utilizing the electromagnetic field, the thermal field and the stress field, based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate, the electromagnetic distribution, the temperature distribution and the stress distribution inside the blade during the lightning strike are calculated along the lightning propagation channel; According to the electromagnetic distribution, the temperature distribution and the stress distribution, a lightning current simulation result is constructed and displayed visually.

2. The wind turbine blade lightning current simulation method based on multi-physics field coupling according to claim 1, characterized in that: The step of obtaining the fan blade motor parameter information and establishing the three-dimensional geometric model of the fan blade includes: Based on big data, design drawings, manufacturing specifications and material properties of fan blades are collected to obtain parameter information of the fan blade motor; Constructing a preliminary geometric shape of the blade according to the fan motor parameter information; Performing geometric trimming processing based on the preliminary geometric shape to obtain a trimmed geometric shape; The three-dimensional geometric model is obtained according to the preliminary geometric shape and the trimmed geometric shape.

3. The wind turbine blade lightning current simulation method based on multi-physics field coupling according to claim 1, characterized in that: The multi-physical field environment is defined, including an electromagnetic field, a thermal field and a stress field, wherein the electromagnetic field, the thermal field and the stress field have a mutual coupling relationship, including: In the three-dimensional geometric model, initial electromagnetic conditions and electromagnetic boundary conditions are set to construct the electromagnetic field; In the three-dimensional geometric model, initial temperature conditions and thermal boundary conditions are set to construct the thermal field; Based on the fan blade motor parameter information, an initial stress state is set to construct the stress field; The mutual coupling relationship among the electromagnetic field, the thermal field and the stress field is configured, and based on the mutual coupling relationship, the electromagnetic field, the thermal field and the stress field are integrated to generate the multi-physical field environment.

4. The wind turbine blade lightning current simulation method based on multi-physics field coupling according to claim 3 is characterized in that: The configuring the mutual coupling relationship among the electromagnetic field, the thermal field and the stress field comprises: Based on the magneto-thermal physical conversion mechanism, a magneto-thermal coupling relationship is formed; Based on the heat-stress physical conversion mechanism, a heat-stress coupling relationship is formed; Based on the magneto-stress physical conversion mechanism, a magneto-stress coupling relationship is formed; The magnetic-thermal coupling relationship, the thermal-stress coupling relationship and the magnetic-stress coupling relationship are set as mutual coupling relationships between the electromagnetic field, the thermal field and the stress field.

5. The wind turbine blade lightning current simulation method based on multi-physics field coupling according to claim 1, characterized in that: The step of setting a lightning strike point on the three-dimensional geometric model according to the lightning parameters, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate, and basic lightning strike information, including: Determine lightning event information based on historical lightning activities, wherein the lightning event information includes the basic lightning information and multiple potential lightning strike points; Selecting the potential lightning strike point on the three-dimensional geometric model; Starting from the selected potential lightning strike point, the lightning propagation channel is constructed based on the minimum resistance path and / or the maximum electric field strength path; The lightning current intensity of the basic lightning information is applied to the lightning propagation channel, and the lightning attenuation rate is obtained according to historical lightning strike data.

6. The wind turbine blade lightning current simulation method based on multi-physics field coupling according to claim 4, characterized in that: The method of calculating the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning strike along the lightning propagation channel by using the electromagnetic field, the thermal field and the stress field based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate includes: Initializing the electromagnetic field, the thermal field and the stress field through the sensor assembly to obtain an initial electromagnetic field, an initial thermal field and an initial stress field; Dividing the three-dimensional geometric model into a plurality of grid units; Based on the initial electromagnetic field, in combination with the lightning strike point, the basic lightning strike information and the lightning attenuation rate, a finite element simulation analysis is performed on the three-dimensional geometric model along the lightning propagation channel to obtain electromagnetic distributions of multiple grid units; Based on the magnetic-thermal coupling relationship, combining the current density distribution of the multiple grid units, magnetic-thermal conversion is performed in the initial thermal field to obtain temperature distribution of multiple grid units; Based on the thermal-stress coupling relationship, thermal-stress conversion is performed in the initial stress field in combination with the temperature distributions of the multiple grid units to obtain thermal stress distributions of the multiple grid units; Based on the magnetic-stress coupling relationship, magnetic-stress conversion is performed in the initial stress field in combination with the temperature distributions of the multiple grid units to obtain magnetic stress distributions of multiple grid units; Performing a combined force analysis on the thermal stress distributions of the plurality of grid cells and the magnetic stress distributions of the plurality of grid cells to obtain stress distributions of the plurality of grid cells; The electromagnetic density distribution of the plurality of grid cells is set as the electromagnetic distribution, the temperature distribution of the plurality of grid cells is set as the temperature distribution, and the stress distribution of the plurality of grid cells is set as the stress distribution.

7. The wind turbine blade lightning current simulation method based on multi-physics field coupling according to claim 1, characterized in that: The method further comprises: Execute several lightning current simulation results to obtain the ultimate lightning basic information, ultimate electromagnetic distribution, ultimate temperature distribution and ultimate stress distribution of the wind turbine blade limit state; Constructing graphical display information in the three-dimensional geometric model according to the extreme electromagnetic distribution, the extreme temperature distribution and the extreme stress distribution; The lightning strike current simulation result is generated according to the extreme lightning strike basic information and the graphical display information for visual display.

8. A wind turbine blade lightning current simulation system based on multi-physics field coupling, characterized in that: For executing the method according to any one of claims 1 to 7, the system comprises: Establishing geometric model module: used to obtain fan blade motor parameter information and establish a three-dimensional geometric model of the fan blade; A multi-physics field environment definition module is used to define a multi-physics field environment, including an electromagnetic field, a thermal field, and a stress field, wherein the electromagnetic field, the thermal field, and the stress field have a mutual coupling relationship; A lightning strike point setting module is used to set a lightning strike point on the three-dimensional geometric model according to lightning parameters, wherein the lightning strike point has a lightning propagation channel, a lightning attenuation rate and basic lightning strike information; Obtaining a multi-dimensional distribution module: for calculating the electromagnetic distribution, temperature distribution and stress distribution inside the blade during the lightning strike along the lightning propagation channel based on the lightning strike point, the basic lightning strike information and the lightning attenuation rate by using the electromagnetic field, the thermal field and the stress field; Visualization display module: used to construct lightning current simulation results according to the electromagnetic distribution, the temperature distribution and the stress distribution, and perform visual display.

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