A method and system for simulating lightning flashover on the insulating surface of a wind turbine blade

Abstract

The application relates to the technical field of fan blade lightning protection, and discloses a simulation method and system for simulating lightning strike flashover failure of an insulating surface of a fan blade, which comprises the following steps: S1: obtaining insulating material attribute parameters, surface roughness distribution parameters and initial charge distribution parameters of the insulating surface of the fan blade; S2: establishing a multi-physical field coupling simulation environment; S3: inputting lightning strike scene parameters in the multi-physical field coupling simulation environment; S4: calculating an electric field distribution in the multi-physical field coupling simulation environment based on the lightning strike scene parameters; S5: calculating the charge accumulation amount of a subunit of the insulating surface of the fan blade; and S6: comparing the electric field intensity at the subunit in the second electric field distribution with the surface flashover field intensity threshold and the bulk breakdown field intensity threshold based on the surface flashover field intensity threshold and the bulk breakdown field intensity threshold in the insulating material attribute parameters.

Description

Technical Field

[0001] This invention relates to the field of lightning protection technology for wind turbine blades, and in particular to a simulation method and system for simulating lightning strike failure of the insulating surface of wind turbine blades. Background Technology

[0002] With the rapid development of wind power technology, the single-unit capacity of wind turbines is constantly increasing, and the blade length is also continuously increasing. This has significantly increased the probability of wind turbine blades being struck by lightning. Wind turbine blades are usually made of composite materials, and their surfaces have insulating properties. During operation, due to factors such as airflow friction, dust impact, and electrostatic induction, charge can easily accumulate on the insulating surface of the blades. This charge accumulation can cause distortion of the electric field on the blade surface, altering the lightning strike path and potentially triggering surface discharge or insulation breakdown. This can lead to lightning arrester failure, further damaging the internal electrical equipment and structural components of the blades, seriously affecting the safe and stable operation of the wind turbine generator set.

[0003] Current simulation methods for lightning strikes on wind turbine blades mainly focus on conventional electric field distribution calculations and leader development simulations. They do not fully consider the charge accumulation effect on the insulation surface of wind turbine blades, and only simulate based on the initial electric field distribution. This fails to accurately reflect the impact of electric field distortion caused by charge accumulation on the lightning strike process, resulting in a large deviation between the simulation results and the actual situation of the wind turbine blade insulation surface. Furthermore, the simulation of multiple upward leader competition mechanisms is not perfect, failing to consider the impact of charge accumulation and electric field distribution differences on the development speed and priority of each leader, making it difficult to accurately predict the distribution pattern of the lightning strike point. Summary of the Invention

[0004] To overcome at least one of the defects described in the prior art, this invention provides a simulation method and system for simulating lightning strike failure of the insulation surface of wind turbine blades. This invention solves the problems of low simulation accuracy and low realism of wind turbine blade insulation surface simulation, effectively reducing damage to wind turbine blade equipment caused by lightning strikes.

[0005] The technical solution of this invention is implemented as follows: A simulation method for simulating lightning strike failure of the insulating surface of a wind turbine blade includes the following steps: S1: Obtain the insulation material property parameters, surface roughness distribution parameters, and initial charge distribution parameters of the wind turbine blade insulation surface, and divide the wind turbine blade insulation surface into multiple sub-units; S2: Based on the insulating material property parameters, surface roughness distribution parameters, and initial charge distribution parameters, a multiphysics coupling simulation environment is established; S3: Input lightning strike scenario parameters into the multiphysics coupling simulation environment. The lightning strike scenario parameters include the position of the downlink leader head, the velocity of the movement, the initial electric field strength, and the steady-state average field strength. S4: Based on the lightning strike scenario parameters, calculate the electric field distribution in the multiphysics coupling simulation environment to obtain the first electric field distribution of the sub-unit on the insulating surface of the wind turbine blade; S5: Calculate the charge accumulation of the sub-units on the insulating surface of the wind turbine blades, and re-solve the electric field distribution based on the charge accumulation, updating the first electric field distribution to the second electric field distribution; S6: Based on the surface flashover field strength threshold and the bulk breakdown field strength threshold in the insulation material property parameters, compare the electric field strength at the sub-unit in the second electric field distribution with the surface flashover field strength threshold and the bulk breakdown field strength threshold; if the electric field strength at the sub-unit exceeds the surface flashover field strength threshold, it is determined that the surface discharge triggering condition is met; if it exceeds the bulk breakdown field strength threshold, it is determined that the insulation breakdown triggering condition is met. S7: For sub-units that are determined to meet the discharge or breakdown triggering conditions, their conductivity parameters are corrected to a high conductivity state; based on the corrected conductivity distribution, the electric field distribution is re-solved, and the second electric field distribution is updated to the third electric field distribution; S8: Based on the third electric field distribution, determine whether the sub-unit meets the upward leader initiation condition. If the upward leader initiation condition is met, calculate the extension length of the upward leader starting from the sub-unit according to the preset leader development model. The leader development model includes the length judgment rule for the unstable development stage of the leader. If the extension length continues to increase and exceeds the first length threshold, it is determined that a stable upward leader has been formed, and the current head position and path of the stable upward leader are recorded. S9: For each stable uplink leader, determine whether the lightning interception condition is met; the lightning interception condition includes: the spatial distance between the head position of the uplink leader and the head position of the downlink leader is less than a preset distance threshold, or the electric field strength between the head position of the uplink leader and the head position of the downlink leader is greater than a preset connection field strength threshold; when any stable uplink leader meets the lightning interception condition, the lightning interception is determined to be successful, the lightning interception point position is recorded, and the current simulation loop is terminated; S10: Repeat steps S4 to S9 until all sub-units have been traversed, completing the preset simulation range of the lightning strike process; finally output the simulation results, which include the distribution of the lightning strike point, the leader development trajectory, the spatial electric field evolution curve, and the time series data of surface charge accumulation.

[0006] Based on the above technical solutions, preferably, the insulating material property parameters include relative permittivity, conductivity, surface flashover field strength threshold, and bulk breakdown field strength threshold; the surface roughness distribution parameters are used to correct the electric field enhancement effect and charge adhesion ability of the wind turbine blades; the initial charge distribution parameters are set based on at least one of the following: wind and sand friction electrification simulation data, raindrop collision electrification simulation data, and environmental electrostatic field induction calculation values ​​of the wind turbine blade operating environment.

[0007] Based on the above technical solutions, preferably, dividing the insulating surface of the wind turbine blade into multiple sub-units includes: dividing the wind turbine blade into an outer peripheral region and an inner peripheral region; in the outer peripheral region, setting the side length of the sub-unit to 0.1mm~1mm; in the inner peripheral region, setting the side length of the sub-unit to 1mm~5mm; each sub-unit corresponds to a unique spatial coordinate index.

[0008] Based on the above technical solutions, preferably, the value range of the surface flashover field strength threshold is 10 kV / cm to 50 kV / cm; and the value range of the volume breakdown field strength threshold is 100 kV / cm to 200 kV / cm.

[0009] Based on the above technical solutions, preferably, determining whether a sub-unit satisfies the upward leader initiation condition based on the third electric field distribution includes: the upward leader initiation condition includes that the electric field strength at the sub-unit is greater than or equal to a leader initiation field strength threshold, and the equivalent surface charge density accumulated at the sub-unit is greater than or equal to a critical charge density threshold, wherein the leader initiation field strength threshold ranges from 1.0 × 10⁻⁶. 6 V / m up to 1.5×10 6 V / m, the critical charge density threshold value ranges from 5 × 10 -7 C / m 2 Up to 1×10 -6 C / m 2 .

[0010] Based on the above technical solutions, preferably, the length judgment rule of the unstable development stage of the leader is that when the extension length of the uplink leader is less than 2m, it is determined to be in an unstable development stage; the value of the first length threshold is 2m; the path recording method of the stable uplink leader is to record the spatial coordinates of the head of the stable uplink leader at time step intervals to form a continuous trajectory curve.

[0011] Based on the above technical solutions, preferably, the preset distance threshold ranges from 0.5m to 1m; and the preset connection field strength threshold ranges from 400kV / m to 600kV / m.

[0012] Secondly, this invention discloses a simulation system for simulating lightning strike failure of the insulation surface of a wind turbine blade, used to execute the aforementioned simulation method for simulating lightning strike failure of the insulation surface of a wind turbine blade, the system comprising: The parameter acquisition module is used to acquire the insulation material property parameters, surface roughness distribution parameters and initial charge distribution parameters of the insulation surface of the wind turbine blade, and to divide the insulation surface of the wind turbine blade into multiple sub-units; The simulation environment construction module is used to establish a multiphysics coupling simulation environment based on the insulating material property parameters, surface roughness distribution parameters, and initial charge distribution parameters. The scene input module is used to input lightning strike scene parameters in the multiphysics coupling simulation environment. The lightning strike scene parameters include the position of the downlink leader, the velocity of the movement, the initial electric field strength, and the steady-state average field strength. The electric field iteration and correction module is used to calculate the first electric field distribution of each sub-unit on the insulating surface of the wind turbine blade based on the input lightning strike scenario parameters in the multi-physics coupled simulation environment; then calculate the charge accumulation of each sub-unit, and resolve the electric field distribution accordingly, updating the first electric field distribution to the second electric field distribution; subsequently, based on the surface flashover field strength threshold and the bulk breakdown field strength threshold in the insulating material property parameters, the electric field strength at each sub-unit in the second electric field distribution is compared with the thresholds: if it exceeds the surface flashover field strength threshold, it is determined that the surface discharge triggering condition is met; if it exceeds the bulk breakdown field strength threshold, it is determined that the insulation breakdown triggering condition is met; for the sub-units determined to meet the discharge or breakdown triggering conditions, their conductivity parameters are corrected to a high conductivity state, and the electric field distribution is resolved again based on the corrected global conductivity distribution, thereby updating the second electric field distribution to the third electric field distribution; The uplink leader development judgment module is used to determine whether the sub-unit meets the uplink leader initiation condition based on the third electric field distribution. If the uplink leader initiation condition is met, the module calculates the extension length of the uplink leader starting from the sub-unit according to a preset leader development model. The leader development model includes length judgment rules for the unstable development stage of the leader. If the extension length continues to increase and exceeds the first length threshold, it is determined that a stable uplink leader has been formed, and the current head position and path of the stable uplink leader are recorded. The lightning interception judgment module is used to determine whether the lightning interception conditions are met for each of the stable uplink leaders. The lightning interception conditions include: the spatial distance between the head position of the uplink leader and the head position of the downlink leader is less than a preset distance threshold, or the electric field strength between the head position of the uplink leader and the head position of the downlink leader is greater than a preset connection field strength threshold. When any of the stable uplink leaders meets the lightning interception conditions, the lightning interception is determined to be successful, the lightning interception point position is recorded, and the current simulation loop is terminated. The result output module is used to repeatedly execute the processing flow from the electric field iteration and correction module to the lightning strike judgment module until all sub-units are traversed and the preset lightning strike process simulation range is completed; finally, the simulation results are output, which include the lightning strike point distribution, the leader development trajectory, the spatial electric field evolution curve, and the surface charge accumulation time series data.

[0013] An electronic device includes a processor, a communication bus, a user interface, a network interface, and a memory. The memory is used to store instructions, the user interface and the network interface are used to communicate with other devices, and the processor is used to execute the instructions stored in the memory to cause the electronic device to perform the method described above.

[0014] A non-transitory computer-readable storage medium, characterized in that the non-transitory computer-readable storage medium stores instructions that, when executed, perform the method described above.

[0015] In summary, the simulation method and system for simulating lightning strike failure of wind turbine blade insulation surface provided by this invention have the following advantages over existing technologies: (1) By acquiring the insulation material property parameters, surface roughness distribution parameters, and initial charge distribution parameters of the wind turbine blade insulation surface, and dividing it into multiple sub-units, the various basic factors affecting lightning strikes are fully considered, providing a detailed data foundation for subsequent accurate simulation; a multi-physics field coupled simulation environment is established, and after calculating the initial electric field distribution based on the lightning strike scenario parameters, the charge accumulation is further calculated and the electric field distribution is updated, which can dynamically reflect the electric field distortion process caused by charge accumulation and more realistically simulate the changes in the electric field under actual lightning strike conditions; based on the surface flashover field strength threshold and volume breakdown field strength threshold in the insulation material property parameters, it is determined whether the sub-unit meets the discharge or breakdown triggering conditions, providing a scientific basis for accurately predicting the damage to the insulation surface of the wind turbine blade; from judging the discharge or breakdown conditions, to correcting the conductivity parameters and updating the electric field distribution, to judging the upward leader initiation conditions, calculating the extension length, and judging the lightning strike conditions, a complete lightning strike process simulation flow is formed, which can comprehensively and systematically simulate various situations of wind turbine blades under lightning strikes; (2) The insulation material properties parameters are clearly defined, including relative permittivity, conductivity, surface flashover field strength threshold and bulk breakdown field strength threshold, so that the simulation process considers the material properties more comprehensively and accurately; the surface roughness distribution parameter is used to correct the electric field enhancement effect and charge adhesion ability, and the influence of actual blade surface roughness on the lightning strike process is considered, which improves the realism of the simulation; the initial charge distribution parameter is set based on a variety of actual operating environment factors, so that the initial conditions are more in line with the actual situation and the reliability of the simulation is enhanced; by setting the range of the surface flashover field strength threshold to 10 kV / cm to 50 kV / cm and the range of the bulk breakdown field strength threshold to 100 kV / cm to 200 kV / cm, specific quantitative standards are provided for judging discharge and breakdown conditions, making the judgment process more accurate; (3) Divide the wind turbine blade into an outer peripheral region and an inner peripheral region, and set up sub-units with different side lengths for each region. This division method takes into account the characteristic differences of different regions of the wind turbine blade, and while ensuring the calculation accuracy, it rationally allocates calculation resources and improves calculation efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating a simulation method for simulating lightning strike failure of the insulating surface of a wind turbine blade, provided in an embodiment of the present invention; Figure 2 A structural block diagram of a simulation system for simulating lightning strike failure of the insulation surface of a wind turbine blade, provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] See Figure 1 As shown, in a first aspect, the present invention discloses a simulation method for simulating lightning strike failure of the insulation surface of a wind turbine blade, comprising the following steps: S1: Obtain the insulation material property parameters, surface roughness distribution parameters, and initial charge distribution parameters of the wind turbine blade insulation surface, and divide the wind turbine blade insulation surface into multiple sub-units; Specifically, the insulating material properties include relative permittivity ε_r, conductivity σ_v, surface flashover field strength threshold E_f, and bulk breakdown field strength threshold E_b. The bulk breakdown field strength threshold E_b represents the minimum field strength required for the material to be electrically broken down, and the surface flashover field strength threshold E_f represents the minimum field strength required for flashover along the material surface. The surface roughness distribution parameter is used to correct the electric field enhancement effect and charge adhesion capability of the wind turbine blades. The surface roughness distribution parameter is measured by a three-dimensional topography instrument or set according to process standards. The initial charge distribution parameter simulates the steady-state surface charge situation of the wind turbine blades after startup and before a lightning strike. It is set based on at least one of the following: wind and sand friction electrification simulation data, raindrop collision electrification simulation data, and environmental electrostatic field induction calculation values. Specifically, it is calculated by computational fluid dynamics to simulate the friction electrification rate of sealing or raindrop collisions, and by electrostatic calculation based on the background field induction under environmental electrostatic fields such as thunderstorm clouds. The typical order of magnitude of the initial charge density ρ_s is 10. -7 ~ 10 -5 C / m².

[0020] Specifically, dividing the insulating surface of the wind turbine blade into multiple sub-units includes: dividing the wind turbine blade into an outer peripheral region and an inner peripheral region; in the outer peripheral region, the side length of the sub-unit is set to 0.1mm~1mm, the outer peripheral region includes the leading edge, trailing edge, and periphery of the lightning arrester of the wind turbine blade, and a fine grid is used in the outer peripheral region to capture subtle changes in the electric field; in the inner peripheral region, the side length of the sub-unit is set to 1mm~5mm, the remaining inner peripheral region is the central main body area of ​​the wind turbine blade, and a sparse grid is used to balance calculation accuracy and efficiency; each sub-unit corresponds to a unique spatial coordinate index.

[0021] S2: Based on the insulating material property parameters, surface roughness distribution parameters, and initial charge distribution parameters, a multiphysics coupling simulation environment is established.

[0022] Specifically, based on the insulating material property parameters, surface roughness distribution parameters, and initial charge distribution parameters obtained in step S1, a coupled environment including an electric field, a charge transport field, and a flow field is established in commercial software such as COMSOL Multiphysics or a self-developed simulation platform. The electric field is based on the Navier-Stokes equations to set the incoming wind speed and turbulence model, calculating the steady-state or transient airflow distribution around the wind turbine blades. Its velocity vector field V provides the convection term for charge transport. The formula for the convection term is: , It is a velocity vector. It is charge density.

[0023] The governing equations for the charge transport field are a combination of the charge continuity equation and the current density equation: ; ; in t is charge density, measured in C / m³; t is time, measured in seconds. S represents the current density, and S represents the source term such as triboelectricity. It consists of four parts, namely, the electric field-driven migration term. diffusion terms Ohmic conduction term and convection terms in the flow field ,in Where D is the charge mobility and D is the diffusion coefficient. It represents the surface equivalent conductivity.

[0024] The electric field is described by Poisson's equation. ; in, For electric potential, The vacuum permittivity, The relative permittivity, The Laplace operator represents the electric potential, and the curvature of the electric potential reflects the source effect of charge distribution on the electric potential.

[0025] The three physical fields are coupled bidirectionally. The flow field affects charge transport, the charge density ρ generated by the charge transport field acts as a source term to affect the electric field, and the electric field, in turn, acts as a driving force to feed back to the charge transport field.

[0026] S3: Input lightning strike scenario parameters into the multiphysics coupling simulation environment. The lightning strike scenario parameters include the position of the downlink leader, the velocity of motion, the initial electric field strength, and the steady-state average field strength.

[0027] Specifically, the downward pilot head is typically positioned at a certain height directly above the wind turbine blades, for example, between 100 and 300 meters above the blades; the downward pilot's velocity is 1-2 × 10^ 5 m / s, with the direction vertically downward or slightly inclined; the initial electric field strength represents the background electric field of the ground before the lightning strike, typically 10-20 kV / m; the cloud-to-ground average field strength maintained during the approach of the downlink leader, typically 50-500 kV / m. The downlink leader head position, velocity, initial electric field strength, and steady-state average field strength together constitute the dynamic external excitation of the simulation.

[0028] S4: Based on the lightning strike scenario parameters, calculate the electric field distribution in the multiphysics coupling simulation environment to obtain the first electric field distribution of the sub-unit on the wind turbine insulation surface.

[0029] Specifically, the lightning strike scenario parameters in step S3 are input into a multiphysics coupled simulation environment. The downlink leader is simplified into a moving point charge or line charge model, and its initial position is denoted as t0 as a strong field source. The steady-state average field strength is superimposed, and the spatial electric field distribution at time t0, which takes into account the influence of the downlink leader but does not yet consider the self-charge effect of the wind turbine blades, is calculated by solving the Poisson equation. This is the first electric field distribution E1.

[0030] S5: Calculate the charge accumulation of the sub-units on the insulating surface of the wind turbine blades, and re-solve the electric field distribution based on the charge accumulation, updating the first electric field distribution to the second electric field distribution.

[0031] Specifically, the amount of charge accumulation on the insulating surface of the wind turbine blades is calculated using a charge transport field. This involves calculating the migration and redistribution of charges under the influence of electric field force, diffusion, and airflow within an extremely short time step Δt, such as 1 ns, to obtain the new surface and space charge densities. _new; will change the charge density. _new is used as a new source term to resolve the Poisson equation, obtaining an updated electric field distribution. This process marks the beginning of the charge accumulation effect affecting the electric field, updating the first electric field distribution E1 to the second electric field distribution E2. The second electric field distribution E2 is the result of the superposition of the initial downward leading field, the background field, and the initial charge accumulation field.

[0032] S6: Based on the surface flashover field strength threshold and the bulk breakdown field strength threshold in the insulation material property parameters, compare the electric field strength at the sub-unit in the second electric field distribution with the surface flashover field strength threshold and the bulk breakdown field strength threshold; if the electric field strength at the sub-unit exceeds the surface flashover field strength threshold, it is determined that the surface discharge triggering condition is met; if it exceeds the bulk breakdown field strength threshold, it is determined that the insulation breakdown triggering condition is met.

[0033] Specifically, for a typical glass fiber reinforced polymer (GFRP) composite material, the breakdown threshold ranges from 100 kV / cm to 200 kV / cm; the surface flashover field strength threshold E_f represents the minimum field strength required for flashover along the material surface, and is typically 10-50 kV / cm, influenced by surface contamination and humidity; the second electric field distribution E2 is scanned, and a judgment is performed on each sub-unit; the surface discharge criterion is to extract the tangential electric field vector E_tangential at the sub-unit, and if E_tangential is greater than the surface flashover field strength threshold E_f, then the sub-unit is determined to meet the surface discharge triggering condition; the insulation breakdown criterion is to extract the normal electric field component E_normal at the sub-unit, and if E_normal is greater than the bulk breakdown field strength threshold E_b, then the sub-unit is determined to meet the insulation breakdown triggering condition; if a sub-unit meets any of the conditions, it is marked as a potential discharge unit, and this step identifies the first batch of points where insulation failure may occur.

[0034] S7: For sub-units that are determined to meet the discharge or breakdown triggering conditions, their conductivity parameters are corrected to a high conductivity state; based on the corrected conductivity distribution, the electric field distribution is re-solved, and the second electric field distribution is updated to the third electric field distribution.

[0035] Specifically, for the potential discharge cells marked in step S6, it is assumed that they have already undergone ionization, forming an initial weakly conductive channel. Therefore, in the simulation, their conductivity parameter is changed from an insulator value such as 10. -15 S / m is instantly corrected to a high conductivity value, such as 10. 4 The abrupt change in the local material conductivity (S / m) leads to a drastic redistribution of the electric field. Based on this corrected global conductivity distribution, the first Poisson equation is resolved to obtain the third electric field distribution E3. The third electric field distribution E3 reflects the strong distortion effect of the partial discharge point on the surrounding electric field and is the key electric field environment for inducing the upward leader.

[0036] S8: Based on the third electric field distribution, determine whether the sub-unit meets the upward leader initiation condition. If the upward leader initiation condition is met, calculate the extension length of the upward leader starting from the sub-unit according to the preset leader development model. The leader development model includes the length judgment rule of the unstable development stage of the leader. If the extension length continues to increase and exceeds the first length threshold, it is determined that a stable upward leader is formed, and the current head position and path of the stable upward leader are recorded.

[0037] Specifically, based on the third electric field distribution, determining whether a sub-unit satisfies the upward leader initiation condition includes: the upward leader initiation condition includes an electric field strength at the sub-unit being greater than or equal to a leader initiation field strength threshold, and an equivalent surface charge density accumulated at the sub-unit being greater than or equal to a critical charge density threshold. The leader initiation field strength threshold E_inception is set to a value range of 1.0 × 10⁻⁶. 6 V / m up to 1.5×10 6 V / m, the critical charge density threshold Q_critical ranges from 5 × 10 -7 C / m 2 Up to 1×10 -6 C / m 2 Based on the third electric field distribution E3, an upward leader initiation judgment is made for sub-units with changes in conductivity. First, the electric field criterion is performed: when the electric field strength E_spot at the sub-unit of the third electric field distribution is greater than or equal to the leader initiation field strength threshold E_inception; then the charge criterion is performed: when the charge density σ_spot at the sub-unit of the third electric field distribution is greater than or equal to Q_critical, if both conditions are met, then an unstable upward leader is considered to have been successfully initiated.

[0038] If the uplink leader initiation condition is met, the extension length of the uplink leader starting from the sub-unit is calculated according to a preset leader development model. The leader development model includes a length judgment rule for the unstable development stage of the leader. If the extension length continues to increase and exceeds a first length threshold, a stable uplink leader is determined to be formed, and the current head position and path of the stable uplink leader are recorded. This includes: the length judgment rule for the unstable development stage of the leader is that when the extension length of the uplink leader is less than 2m, it is determined to be in an unstable development stage; the first length threshold is 2m; the path recording method for the stable uplink leader is to record the spatial coordinates of the head of the stable uplink leader at time step intervals to form a continuous trajectory curve.

[0039] Specifically, a pre-defined leader development model is applied. This model is based on charge control theory, meaning that within each time step Δt, the charge increment ΔQ_c(k) injected into the corona region of the leader head is used to extend the leader channel. The formula for calculating the extension length Δl(k) is:

[0040] ; Where ql is the equivalent linear charge density required to form a leader channel per unit length, called the charge constant per unit length, and its value ranges from 1 × 10⁻⁶. -4 -5×10 -4 C / m, ΔQ_c(k) is the charge increment, and the current total length l(k) = l(k-1) + Δl(k).

[0041] The length determination rule is as follows: when the current total length l(k) is less than the first length threshold L_critical, the leader is considered to be in an unstable development stage, and may stagnate or annihilate; when the current total length l(k) is greater than or equal to the first length threshold L_critical, it is determined that it has developed into a stable uplink leader. The system will continuously record the position sequence of each stable uplink leader head to form its three-dimensional development path.

[0042] For multiple potential uplink leader development paths appearing simultaneously during simulation, the system employs preset priority judgment rules for competition and selection to determine the dominant leader development process. The priority judgment rules include at least one of the following: Field strength priority rule: Compare the local electric field strength at the starting point of each potential uplink leader; the leader path corresponding to the point with the highest electric field strength is assigned a higher priority. Geometric position priority rule: Compare the spatial distance between the head of each potential uplink leader and the head of the current downlink leader; the leader path with a closer distance is assigned a higher priority. Development stability priority rule: In the leader development model, the growth rate and persistence of the extension length are evaluated; the leader path with more stable and persistent growth is assigned a higher priority. Finally, if the extension length of a high-priority uplink leader continues to increase and exceeds a first length threshold, it is determined to form a stable uplink leader, and the current head position and path of the stable uplink leader are recorded. Other leader paths with lower priority or that fail to meet the length threshold will be temporarily suppressed or recorded as unsuccessfully developed.

[0043] S9: For each stable uplink leader, determine whether the lightning connection condition is met; the lightning connection condition includes: the spatial distance between the head position of the uplink leader and the head position of the downlink leader is less than a preset distance threshold, or the electric field strength between the head position of the uplink leader and the head position of the downlink leader is greater than a preset connection field strength threshold; when any stable uplink leader meets the lightning connection condition, the lightning connection is determined to be successful, the lightning connection point position is recorded, and the current simulation loop is terminated.

[0044] Specifically, the preset distance threshold ranges from 0.5m to 1m; the preset connection field strength threshold ranges from 400kV / m to 600kV / m. For all stable uplink leaders, it is determined whether they are connected to the downlink leader. The Euclidean distance d between the heads of the uplink and downlink leaders must be less than or equal to the preset distance threshold d_threshold, or the electric field strength E_avg between the head positions of the uplink and downlink leaders must be greater than the preset connection field strength threshold E_connect. If either condition is met, the lightning strike is considered successfully connected, and the coordinates of the starting sub-unit of the uplink leader causing the connection are immediately recorded as the connection point location. Subsequently, the subsequent calculation loop for the current time step is terminated, and the process jumps to the result output or begins the next simulation.

[0045] S10: Repeat steps S4 to S9 until all sub-units have been traversed, completing the preset simulation range of the lightning strike process; finally output the simulation results, which include the distribution of the lightning strike point, the leader development trajectory, the spatial electric field evolution curve, and the time series data of surface charge accumulation.

[0046] Specifically, if no lightning strike is detected in step S9, the simulation time is advanced by one time step Δt. Based on the downlink leader velocity v_leader, the downlink leader head position P_leader(t+Δt) = P_leader(t) - v_leader * Δt is updated. Then the process returns to step S5, using the new leader position and updated charge distribution as initial conditions, and begins the next time step's charge transport, electric field update, criterion judgment, and leader development loop until a lightning strike occurs or the accumulated simulation time reaches a preset range T_max, such as 100μs to 1ms. After the loop ends, the data from all time steps are integrated, and comprehensive simulation results are output, including: a distribution map of all lightning strike attempts, three-dimensional trajectory animations of the uplink and downlink leaders, curves of electric field intensity changes over time at key locations, and spatiotemporal cloud maps of the evolution of charge density on the blade surface.

[0047] See Figure 2 As shown, in a second aspect, the present invention also discloses a simulation system for simulating lightning strike failure of the insulation surface of wind turbine blades. This system employs the aforementioned simulation method for simulating lightning strike failure of the insulation surface of wind turbine blades. The system includes a parameter acquisition module 101, a simulation environment construction module 102, a scene input module 103, an electric field iteration and correction module 104, an uplink leader development judgment module 105, a lightning strike judgment module 106, and a result output module 107. The parameter acquisition module 101 is used to acquire the insulation material property parameters, surface roughness distribution parameters and initial charge distribution parameters of the wind turbine blade insulation surface, and divide the wind turbine blade insulation surface into multiple sub-units; The simulation environment construction module 102 is used to establish a multi-physics field coupled simulation environment based on the insulating material property parameters, surface roughness distribution parameters and initial charge distribution parameters. The scene input module 103 is used to input lightning strike scene parameters in the multiphysics coupling simulation environment. The lightning strike scene parameters include the position of the downlink leader head, the velocity of the movement, the initial electric field strength, and the steady-state average field strength. The electric field iteration and correction module 104 is used to calculate the first electric field distribution of each sub-unit on the insulating surface of the wind turbine blade based on the input lightning strike scenario parameters in the multi-physics coupled simulation environment; then calculate the charge accumulation of each sub-unit, and resolve the electric field distribution accordingly, updating the first electric field distribution to the second electric field distribution; subsequently, based on the surface flashover field strength threshold and the bulk breakdown field strength threshold in the insulating material property parameters, the electric field strength at each sub-unit in the second electric field distribution is compared with the threshold: if it exceeds the surface flashover field strength threshold, it is determined that the surface discharge triggering condition is met; if it exceeds the bulk breakdown field strength threshold, it is determined that the insulation breakdown triggering condition is met; for the sub-units that are determined to meet the discharge or breakdown triggering conditions, their conductivity parameters are corrected to a high conductivity state, and the electric field distribution is resolved again based on the corrected global conductivity distribution, thereby updating the second electric field distribution to the third electric field distribution; The uplink leader development judgment module 105 is used to determine whether the sub-unit meets the uplink leader initiation condition based on the third electric field distribution. If the uplink leader initiation condition is met, the extension length of the uplink leader starting from the sub-unit is calculated according to the preset leader development model. The leader development model includes the length judgment rule of the leader unstable development stage. If the extension length continues to increase and exceeds the first length threshold, it is determined that a stable uplink leader has been formed, and the current head position and path of the stable uplink leader are recorded. The lightning interception judgment module 106 is used to determine whether the lightning interception conditions are met for each of the stable uplink leaders. The lightning interception conditions include: the spatial distance between the head position of the uplink leader and the head position of the downlink leader is less than a preset distance threshold, or the electric field strength between the head position of the uplink leader and the head position of the downlink leader is greater than a preset connection field strength threshold. When any of the stable uplink leaders meets the lightning interception conditions, the lightning interception is determined to be successful, the lightning interception point position is recorded, and the current simulation loop is terminated. The result output module 107 is used to repeatedly execute the processing flow from the electric field iteration and correction module to the lightning strike judgment module until all sub-units are traversed and the preset lightning strike process simulation range is completed; finally, the simulation results are output, including the lightning strike point distribution, the leader development trajectory, the spatial electric field evolution curve, and the surface charge accumulation time series data.

[0048] It should be noted that this system corresponds to the above-mentioned simulation method for lightning strike failure of the insulation surface of wind turbine blades. All implementation methods in the above-mentioned method embodiments are applicable to the embodiments of this system and can achieve the same technical effect.

[0049] Thirdly, please refer to Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device 200 provided in this embodiment includes a processor 210 and a memory 220; the memory 220 stores a computer program, wherein the computer program, when executed by the processor, implements the aforementioned simulation method for simulating lightning strike failure of the insulation surface of a wind turbine blade.

[0050] Specifically, processor 210 may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. Processor 210 may also include onboard memory for caching purposes. Processor 210 may be a single processing unit or multiple processing units for performing different actions of the method flow according to embodiments of this application.

[0051] Memory 220 may be any medium capable of containing, storing, transmitting, propagating, or transmitting instructions. For example, memory 220 may include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, instruments, or propagation media. Specific examples of memory 220 include: magnetic storage devices such as magnetic tape or hard disk drives (HDDs); optical storage devices such as optical discs (CD-ROMs); and may also be random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0052] This application also provides a non-transitory computer-readable medium storing a computer program thereon, which, when executed by a processor, implements the method described above. This non-transitory computer-readable medium may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into that device / apparatus / system. The aforementioned computer-readable medium carries one or more programs, which, when executed, implement the method according to the embodiments of this application.

[0053] According to embodiments of this application, a computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wired, optical fiber, radio frequency signals, etc., or any suitable combination thereof.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A simulation method for simulating lightning strike failure of the insulating surface of a wind turbine blade, characterized in that, Includes the following steps: S1: Obtain the insulation material property parameters, surface roughness distribution parameters, and initial charge distribution parameters of the wind turbine blade insulation surface, and divide the wind turbine blade insulation surface into multiple sub-units; S2: Based on the insulating material property parameters, surface roughness distribution parameters, and initial charge distribution parameters, a multiphysics coupling simulation environment is established; S3: Input lightning strike scenario parameters into the multiphysics coupling simulation environment. The lightning strike scenario parameters include the position of the downlink leader head, the velocity of the movement, the initial electric field strength, and the steady-state average field strength. S4: Based on the lightning strike scenario parameters, calculate the electric field distribution in the multiphysics coupling simulation environment to obtain the first electric field distribution of the sub-unit on the insulating surface of the wind turbine blade; S5: Calculate the charge accumulation of the sub-units on the insulating surface of the wind turbine blades, and re-solve the electric field distribution based on the charge accumulation, updating the first electric field distribution to the second electric field distribution; S6: Based on the surface flashover field strength threshold and the bulk breakdown field strength threshold in the insulating material property parameters, compare the electric field strength at the sub-unit in the second electric field distribution with the surface flashover field strength threshold and the bulk breakdown field strength threshold; if the electric field strength at the sub-unit exceeds the surface flashover field strength threshold, it is determined that the surface discharge triggering condition is met. If the bulk breakdown field strength threshold is exceeded, the insulation breakdown triggering condition is determined to be met. S7: For sub-units that are determined to meet the discharge or breakdown triggering conditions, their conductivity parameters are corrected to a high conductivity state; based on the corrected conductivity distribution, the electric field distribution is re-solved, and the second electric field distribution is updated to the third electric field distribution; S8: Based on the third electric field distribution, determine whether the sub-unit meets the upward leader initiation condition. If the upward leader initiation condition is met, calculate the extension length of the upward leader starting from the sub-unit according to the preset leader development model. The leader development model includes the length judgment rule for the unstable development stage of the leader. If the extension length continues to increase and exceeds the first length threshold, it is determined that a stable upward leader has been formed, and the current head position and path of the stable upward leader are recorded. S9: For each of the stable uplink leaders, determine whether the flash connection conditions are met; The lightning interception conditions include: the spatial distance between the head position of the uplink leader and the head position of the downlink leader is less than a preset distance threshold, or the electric field strength between the head position of the uplink leader and the head position of the downlink leader is greater than a preset connection field strength threshold; when any of the stable uplink leaders meets the lightning interception conditions, the lightning interception is determined to be successful, the lightning interception point position is recorded, and the current simulation loop is terminated. S10: Repeat steps S4 to S9 until all sub-units have been traversed, completing the preset simulation range of the lightning strike process; finally output the simulation results, which include the distribution of the lightning strike point, the leader development trajectory, the spatial electric field evolution curve, and the time series data of surface charge accumulation.

2. The simulation method for lightning strike failure of the insulation surface of a wind turbine blade according to claim 1, characterized in that, The insulating material properties include relative permittivity, conductivity, surface flashover field strength threshold, and bulk breakdown field strength threshold. The surface roughness distribution parameters are used to correct the electric field enhancement effect and charge adhesion ability of the wind turbine blades; The initial charge distribution parameters are set based on at least one of the following: wind and sand friction electrification simulation data, raindrop collision electrification simulation data, and environmental electrostatic field induction calculation values ​​of the wind turbine blade operating environment.

3. The simulation method for lightning strike failure of the insulating surface of a wind turbine blade according to claim 2, characterized in that, The process of dividing the insulating surface of the wind turbine blades into multiple sub-units includes: The wind turbine blades are divided into an outer peripheral region and an inner peripheral region; In the outer peripheral region, the side length of the sub-unit is set to 0.1mm~1mm; in the inner peripheral region, the side length of the sub-unit is set to 1mm~5mm; each sub-unit corresponds to a unique spatial coordinate index.

4. The simulation method for lightning strike failure of the insulation surface of a wind turbine blade according to claim 1, characterized in that, The range of the surface flashover field strength threshold is 10 kV / cm to 50 kV / cm; the range of the volume breakdown field strength threshold is 100 kV / cm to 200 kV / cm.

5. The simulation method for lightning strike failure of the insulating surface of a wind turbine blade according to claim 1, characterized in that, Based on the third electric field distribution, determine whether the sub-unit satisfies the uplink leader initiation condition, including: The upward leader initiation condition includes that the electric field strength at the sub-unit is greater than or equal to the leader initiation field strength threshold, and the equivalent surface charge density accumulated at the sub-unit is greater than or equal to the critical charge density threshold. The leader initiation field strength threshold ranges from 1.0 × 10⁻⁶. 6 V / m up to 1.5×10 6 V / m, the critical charge density threshold value ranges from 5 × 10 -7 C / m 2 Up to 1×10 -6 C / m 2 .

6. The simulation method for lightning strike failure of the insulation surface of a wind turbine blade according to claim 1, characterized in that, The rule for determining the length of the unstable development stage of the leader is that when the extension length of the uplink leader is less than 2m, it is determined to be in an unstable development stage; the first length threshold is 2m; the path recording method of the stable uplink leader is to record the spatial coordinates of the head of the stable uplink leader at time step intervals to form a continuous trajectory curve.

7. The simulation method for lightning strike failure of the insulating surface of a wind turbine blade according to claim 6, characterized in that, The preset distance threshold ranges from 0.5m to 1m; the preset connection field strength threshold ranges from 400kV / m to 600kV / m.

8. A simulation system for simulating lightning strike failure of the insulating surface of a wind turbine blade, characterized in that, A system for performing a simulation method for lightning strike failure of the insulation surface of a wind turbine blade as described in any one of claims 1 to 7, the system comprising: The parameter acquisition module is used to acquire the insulation material property parameters, surface roughness distribution parameters and initial charge distribution parameters of the insulation surface of the wind turbine blade, and to divide the insulation surface of the wind turbine blade into multiple sub-units; The simulation environment construction module is used to establish a multiphysics coupling simulation environment based on the insulating material property parameters, surface roughness distribution parameters, and initial charge distribution parameters. The scene input module is used to input lightning strike scene parameters in the multiphysics coupling simulation environment. The lightning strike scene parameters include the position of the downlink leader, the velocity of the movement, the initial electric field strength, and the steady-state average field strength. The electric field iteration and correction module is used to calculate the first electric field distribution of each sub-unit on the insulating surface of the wind turbine blade based on the input lightning strike scenario parameters in the multi-physics coupled simulation environment; then calculate the charge accumulation of each sub-unit, and resolve the electric field distribution accordingly, updating the first electric field distribution to the second electric field distribution; subsequently, based on the surface flashover field strength threshold and the bulk breakdown field strength threshold in the insulating material property parameters, the electric field strength at each sub-unit in the second electric field distribution is compared with the thresholds: if it exceeds the surface flashover field strength threshold, it is determined that the surface discharge triggering condition is met; if it exceeds the bulk breakdown field strength threshold, it is determined that the insulation breakdown triggering condition is met; for the sub-units determined to meet the discharge or breakdown triggering conditions, their conductivity parameters are corrected to a high conductivity state, and the electric field distribution is resolved again based on the corrected global conductivity distribution, thereby updating the second electric field distribution to the third electric field distribution; The uplink leader development judgment module is used to determine whether the sub-unit meets the uplink leader initiation condition based on the third electric field distribution. If the uplink leader initiation condition is met, the module calculates the extension length of the uplink leader starting from the sub-unit according to a preset leader development model. The leader development model includes length judgment rules for the unstable development stage of the leader. If the extension length continues to increase and exceeds the first length threshold, it is determined that a stable uplink leader has been formed, and the current head position and path of the stable uplink leader are recorded. The lightning interception judgment module is used to determine whether the lightning interception conditions are met for each of the stable uplink leaders. The lightning interception conditions include: the spatial distance between the head position of the uplink leader and the head position of the downlink leader is less than a preset distance threshold, or the electric field strength between the head position of the uplink leader and the head position of the downlink leader is greater than a preset connection field strength threshold. When any of the stable uplink leaders meets the lightning interception conditions, the lightning interception is determined to be successful, the lightning interception point position is recorded, and the current simulation loop is terminated. The result output module is used to repeatedly execute the processing flow from the electric field iteration and correction module to the lightning strike judgment module until all sub-units are traversed and the preset lightning strike process simulation range is completed; finally, the simulation results are output, which include the lightning strike point distribution, the leader development trajectory, the spatial electric field evolution curve, and the surface charge accumulation time series data.

9. An electronic device, characterized in that, The device includes a processor, a communication bus, a user interface, a network interface, and a memory. The memory is used to store instructions. The user interface and the network interface are used to communicate with other devices. The processor is used to execute the instructions stored in the memory to cause the electronic device to perform the method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores instructions that, when executed, perform the method as described in any one of claims 1 to 7.

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