C4F7N / CO2 mixed gas 50% lightning impulse voltage prediction method and device, electronic equipment and storage medium

Abstract

The invention discloses a C4F7N / CO2 mixed gas 50% lightning impulse voltage prediction method and device, electronic equipment and a storage medium, and belongs to the field of high-voltage insulation, and the method comprises the steps: obtaining the electron collision cross section, ion transport parameters, electrode gap and electrode type data of mixed gas, and constructing a two-dimensional electrode model; processing the electron impact cross section to obtain electron average energy, mobility, diffusion coefficient and reaction rate; solving a charged particle continuity equation and a Poisson equation by combining the parameters to obtain electric field intensity distribution and a streamer head position; and determining the initial voltage of the stream according to the corresponding externally applied voltage when the electric field intensity is maximum, determining the breakdown voltage of the stream according to the externally applied voltage before the head of the stream reaches the ground electrode, and calculating to obtain a predicted value of the lightning impulse voltage. According to the invention, the problem of lightning impulse voltage prediction failure caused by the fact that the streamer starting voltage and the streamer breakdown voltage cannot be accurately extracted in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of high voltage insulation technology, specifically to a method, apparatus, electronic device, and storage medium for predicting 50% lightning impulse voltage of a C4F7N / CO2 mixed gas. Background Technology

[0002] The 50% lightning impulse voltage of C4F7N / CO2 mixed gas is a core indicator for insulation coordination design of high-voltage equipment. Currently, it mainly relies on costly step-up / step-down tests to obtain this value. Although numerical simulation has been proposed, existing technologies struggle to accurately extract effective characteristic voltage values ​​(i.e., streamer initiation voltage and streamer breakdown voltage) based on fluid models, making accurate prediction impossible.

[0003] The root cause of this problem lies in the fact that existing fluid models typically simplify microscopic parameters to static constants and neglect ion transport, failing to reflect the physical characteristics of electronic parameters dynamically changing with the electric field in real time. This leads to simulation distortion and an inability to accurately define the streamer initiation voltage based on electric field characteristics. More seriously, when simulating the breakdown critical state of the streamer head contacting the ground electrode, abrupt changes in the potential gradient within the computational domain can cause numerical singularities, resulting in non-convergence of the calculation. This makes it impossible for existing technologies to directly extract the effective streamer breakdown voltage from the calculation results. Because these two key characteristic voltage values, which form the basis of prediction, cannot be accurately obtained, the final 50% lightning impulse voltage prediction fails. Summary of the Invention

[0004] This invention provides a method, apparatus, electronic device, and storage medium for predicting 50% lightning impulse voltage of a C4F7N / CO2 mixed gas. It can solve the problem in the prior art where the calculation does not converge due to the distortion of fluid model parameters by simplification and the numerical singularity at the moment of breakdown, making it impossible to accurately extract the initiation voltage and breakdown voltage of the streamer, thus causing the 50% lightning impulse voltage prediction to fail.

[0005] An embodiment of the present invention provides a method for predicting the lightning impulse voltage of a C4F7N / CO2 mixed gas with a concentration of 50%, comprising: Data on electron collision cross-sections, ion transport parameters, electrode gap distances in the experimental chamber, and electrode types of the C4F7N / CO2 mixed gas were obtained; a two-dimensional electrode geometric model was constructed based on the electrode gap distance data and the electrode type data. The electron collision cross-sectional data are processed according to the preset Boltzmann equation to generate the average electron energy, mobility, diffusion coefficient and reaction rate; In the two-dimensional electrode geometric model, under the condition of applying a preset voltage waveform, the preset charged particle continuity equation and preset Poisson equation are solved using the average electron energy, mobility, diffusion coefficient, reaction rate and ion transport parameter data, generating the spatiotemporal distribution data of electric field intensity and the position data of the stream head. Based on the spatiotemporal distribution data of the electric field intensity, the applied voltage corresponding to the moment when the electric field intensity at the needle tip reaches its maximum value is determined as the jet initiation voltage; based on the jet head position data, the applied voltage corresponding to the moment when the jet head reaches the ground electrode minus a preset step size is determined as the jet breakdown voltage; the arithmetic mean of the jet initiation voltage and the jet breakdown voltage is calculated to obtain the 50% lightning impulse voltage prediction value.

[0006] Furthermore, the step of constructing a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data includes: Obtain the inner wall dimension data of the test chamber and the electrode contour dimension data corresponding to the electrode type data; Based on the electrode profile size data, generate the high-voltage electrode profile and the grounding electrode profile. Based on the electrode gap distance data, determine the positioning coordinates of the high-voltage electrode contour line and the grounding electrode contour line in the two-dimensional coordinate system; The inner wall dimension data is processed using a preset scaling ratio to generate model boundary dimension data; Based on the model boundary size data and the positioning coordinates, a computational domain boundary line connecting the high-voltage electrode contour line and the grounding electrode contour line is generated, thus obtaining the two-dimensional electrode geometric model.

[0007] Furthermore, the step of processing the electron collision cross-sectional data according to the preset Boltzmann equation to generate the electron average energy, mobility, diffusion coefficient, and reaction rate includes: Obtain the calculation range data for the reduced electric field; Based on the reduced electric field calculation range data, a reduced electric field sequence data is generated; Based on the electron collision cross-section data and the reduced electric field sequence data, the preset Boltzmann equation is solved to generate electron energy distribution function data corresponding to the reduced electric field sequence data; Based on the electron energy distribution function data and the electron collision cross-section data, the average electron energy, mobility, diffusion coefficient, and reaction rate, which vary with the reduced electric field sequence data, are calculated and generated.

[0008] Furthermore, in the two-dimensional electrode geometric model, under the condition of applying a preset voltage waveform, using data on average electron energy, mobility, diffusion coefficient, reaction rate, and ion transport parameters, a preset charged particle continuity equation and a preset Poisson equation are solved to generate spatiotemporal distribution data of electric field intensity and stream head position data, including: Based on the preset initial seed density data, the electron density and ion density in the two-dimensional electrode geometric model are initialized, and the initialized electron density and initialized ion density are generated. Repeat the time-step coupled solution operation until the current simulation time reaches the preset duration, generating spatiotemporal distribution data of electric field intensity and streamer head position data; The time-step coupled solution operation includes: Based on the preset voltage waveform, determine the potential boundary conditions of the high-voltage electrode profile at the current simulation moment; Based on the current electron density, current ion density, and the potential boundary conditions, the preset Poisson equation is solved to calculate the current electric field intensity distribution; wherein, the initial current electron density is the initialized electron density; the initial current ion density is the initialized ion density; The current electric field intensity distribution is recorded as the data at the current simulation moment in the electric field intensity spatiotemporal distribution data. The current stream head position is determined based on the current electron density and the current ion density, and the current stream head position is recorded in the stream head position data. The local reduced electric field is calculated based on the current electric field intensity distribution, and the corresponding local electronic micro-parameters are extracted from the average electron energy, mobility, diffusion coefficient and reaction rate based on the local reduced electric field. Using the local electronic microscopic parameters, the ion transport parameter data, and the current electric field intensity distribution, the preset charged particle continuity equation is solved to calculate the electron density distribution and ion density distribution of the next time step. The electron density distribution and ion density distribution of the next time step are updated to the current electron density and current ion density, and the current simulation time is increased by one time step.

[0009] Furthermore, the step of solving the preset Poisson equation based on the current electron density, current ion density, and the potential boundary conditions to calculate the current electric field intensity distribution includes: Based on the current electron density and the current ion density, determine the space charge density source term used to characterize the net space charge distribution; Using the space charge density source term and the potential boundary conditions, the preset Poisson equation is solved to generate the current potential distribution data; Spatial gradient calculation is performed on the current potential distribution data to generate the current electric field intensity distribution.

[0010] Furthermore, the local electronic microscopic parameters include local mobility, local diffusion coefficient, and local reaction rate; The process of using the local electronic microscopic parameters, the ion transport parameter data, and the current electric field intensity distribution to solve the preset charged particle continuity equation and calculate the electron density distribution and ion density distribution for the next time step includes: Based on the local mobility and local diffusion coefficient in the local electronic micro-parameters, the ion transport parameter data, and the current electric field intensity distribution, the migration and diffusion flux data characterizing the particle drift motion and diffusion motion are calculated. Based on the local reaction rate, current electron density, current ion density, and preset reaction source term formula in the local electronic microscopic parameters, calculate the net reaction source term data characterizing particle generation and loss; Based on the migration and diffusion flux data and the net reaction source term data, the preset charged particle continuity equation is discretized and solved by time integration to generate the electron density distribution and ion density distribution for the next time step.

[0011] Furthermore, the local reaction rate includes the ionization reaction rate, the adhesion reaction rate, and the recombination reaction rate; The step of calculating net reaction source term data characterizing particle generation and loss based on the local reaction rate, current electron density, current ion density, and a preset reaction source term formula in the local electronic microscopic parameters includes: Calculate the electron ionization gain data based on the ionization reaction rate in the local reaction rate and the current electron density; Calculate electron attachment loss data based on the attachment reaction rate in the local reaction rate and the current electron density; Calculate the electron-ion recombination loss data based on the recombination reaction rate, current electron density, and current ion density in the local reaction rate. The electron ionization gain data, the electron attachment loss data, and the electron-ion recombination loss data are subjected to algebraic sum operations to generate net reaction source term data.

[0012] Based on the above method embodiments, the present invention provides corresponding apparatus embodiments.

[0013] One embodiment of the present invention provides a lightning impulse voltage prediction device for a C4F7N / CO2 mixed gas of 50%, comprising: a data acquisition and modeling module, a parameter generation module, a simulation solution module, and a voltage prediction module; The data acquisition and modeling module is used to acquire electron collision cross-sectional data, ion transport parameter data, electrode gap distance data of the test chamber, and electrode type data of the C4F7N / CO2 mixed gas; and to construct a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data. The parameter generation module is used to process the electron collision cross-sectional data according to the preset Boltzmann equation to generate the average electron energy, mobility, diffusion coefficient and reaction rate. The simulation solution module is used to solve the preset charged particle continuity equation and the preset Poisson equation in a two-dimensional electrode geometric model under the condition of applying a preset voltage waveform, using the average electron energy, mobility, diffusion coefficient, reaction rate and ion transport parameter data, and to generate the spatiotemporal distribution data of electric field intensity and the position data of the streamer head. The voltage prediction module is used to determine the applied voltage corresponding to the moment when the electric field strength at the needle tip reaches its maximum value as the streamer initiation voltage based on the spatiotemporal distribution data of the electric field strength; to determine the applied voltage corresponding to the moment when the streamer head reaches the ground electrode minus a preset step size based on the streamer head position data as the streamer breakdown voltage; and to calculate the arithmetic mean of the streamer initiation voltage and the streamer breakdown voltage to obtain the 50% lightning impulse voltage prediction value.

[0014] Based on the above method embodiments, the present invention provides corresponding electronic device embodiments.

[0015] An embodiment of the present invention provides an electronic device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the C4F7N / CO2 mixed gas 50% lightning impulse voltage prediction method described in any of the above-described method embodiments.

[0016] Based on the above method embodiments, the present invention provides corresponding storage medium embodiments.

[0017] One embodiment of the present invention provides a storage medium storing a computer program thereon, wherein, when the computer program is running, it controls the device where the storage medium is located to execute any of the above-described method embodiments of the method for predicting the 50% lightning impulse voltage of a C4F7N / CO2 mixed gas.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method, apparatus, electronic device, and storage medium for predicting the 50% lightning impulse voltage of a C4F7N / CO2 mixed gas. The method acquires data on the electron collision cross-section, ion transport parameters, electrode gap distance, and electrode type of the C4F7N / CO2 mixed gas; a two-dimensional electrode geometric model is constructed based on the electrode gap and electrode type. The Boltzmann equation is used to process the electron collision cross-section to obtain the average electron energy, mobility, diffusion coefficient, and reaction rate. A preset voltage waveform is applied to the two-dimensional model, and the continuity equation and Poisson equation for charged particles are solved by combining the aforementioned electron and ion transport parameters to obtain the spatiotemporal distribution of the electric field intensity and the position of the jet head. The applied voltage corresponding to the first maximum value of the electric field intensity at the needle tip is taken as the jet initiation voltage, and the applied voltage corresponding to the preset step length before the jet head reaches the ground electrode is taken as the jet breakdown voltage. The arithmetic mean of these two values ​​is the predicted 50% lightning impulse voltage.

[0019] This invention utilizes coupled data from electron average energy, mobility, diffusion coefficient, reaction rate, and ion transport parameters, along with data varying with the reduced electric field, to solve the continuity equation for charged particles and a pre-defined Poisson equation within a two-dimensional electrode geometric model. This ensures the authenticity of the generated spatiotemporal distribution data of the electric field intensity, enabling accurate extraction of the streamer initiation voltage based on the moment when the electric field intensity at the needle tip reaches its maximum value. Simultaneously, this invention determines the streamer breakdown voltage using the applied voltage corresponding to the moment the streamer head reaches the ground electrode minus a pre-defined step size. By using time step backsliding, it avoids the numerical singularity problem at the moment of contact, successfully extracting an effective breakdown voltage value. Based on the two precise characteristic voltages obtained through high-fidelity simulation and singularity removal algorithms, this invention calculates their arithmetic mean to achieve accurate prediction of 50% of lightning impulse voltages. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of a method for predicting the lightning impulse voltage of a C4F7N / CO2 mixed gas with a concentration of 50% provided in an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of a C4F7N / CO2 mixed gas 50% lightning impulse voltage prediction device provided in an embodiment of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, to address the problem in existing technologies where simplification of fluid model parameters leads to distortion and numerical singularities at the moment of breakdown, resulting in non-convergence of calculations and thus the inability to accurately extract the initiation voltage and breakdown voltage of the streamer, thereby causing the failure of 50% lightning impulse voltage prediction, an embodiment of the present invention provides a method for predicting the 50% lightning impulse voltage of a C4F7N / CO2 mixed gas, comprising at least the following steps: Step S1: Obtain electron collision cross-section data, ion transport parameter data, electrode gap distance data of the test chamber, and electrode type data of the C4F7N / CO2 mixed gas; construct a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data. In a preferred embodiment, constructing a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data includes: Obtain the inner wall dimension data of the test chamber and the electrode contour dimension data corresponding to the electrode type data; Based on the electrode profile size data, generate the high-voltage electrode profile and the grounding electrode profile. Based on the electrode gap distance data, determine the positioning coordinates of the high-voltage electrode contour line and the grounding electrode contour line in the two-dimensional coordinate system; The inner wall dimension data is processed using a preset scaling ratio to generate model boundary dimension data; Based on the model boundary size data and the positioning coordinates, a computational domain boundary line connecting the high-voltage electrode contour line and the grounding electrode contour line is generated, thus obtaining the two-dimensional electrode geometric model.

[0024] Specifically, the system acquires electron collision cross-sectional data and ion transport parameter data for the C4F7N / CO2 mixed gas. The electron collision cross-sectional data is sourced from publicly available plasma databases or experimental measurements, covering electron scattering cross-sectional information of C4F7N and CO2 molecules at different mixing ratios. The ion transport parameter data includes ion mobility and diffusion coefficient. Simultaneously, the system acquires electrode gap distance data and electrode type data for the experimental chamber. It should be noted that the electrode type data characterizes the degree of inhomogeneity of the electric field in the lightning impact test, specifically including but not limited to: needle-plate electrode type simulating a highly inhomogeneous field, ball-plate electrode type simulating a slightly inhomogeneous field, and plate-plate electrode type simulating a uniform field. Based on the electrode gap distance data and electrode type data, a two-dimensional electrode geometric model is constructed. In this process, to reduce the dimensionality and complexity of subsequent finite element calculations, a two-dimensional axisymmetric approach is typically used to simulate the three-dimensional lightning impact test chamber, i.e., the cross-sectional geometry of the electrodes and gas is constructed in a two-dimensional coordinate system.

[0025] In the specific implementation of constructing the two-dimensional electrode geometric model, the first step is to acquire dimensional data. The system acquires the inner wall dimension data of the test chamber and the electrode profile dimension data corresponding to the electrode type data. The electrode profile dimension data are key geometric parameters that determine the specific shape of the electrode. For example, for a needle-plate electrode, the electrode profile dimension data includes the radius of curvature of the needle tip, the length of the needle body, and the thickness and width of the plate electrode; for a ball-plate electrode, the electrode profile dimension data includes the radius of the sphere. The inner wall dimension data characterizes the physical boundary range of the test chamber shell.

[0026] Next, based on the electrode profile size data, the system uses a geometric drawing algorithm to generate the high-voltage electrode profile and the grounding electrode profile in a two-dimensional coordinate system. The high-voltage electrode profile corresponds to the electrode surface on which a lightning impulse voltage is applied, and the grounding electrode profile corresponds to the electrode surface on which there is zero potential. After generating the profiles, the system determines the positioning coordinates of the high-voltage electrode profile and the grounding electrode profile in the two-dimensional coordinate system based on the electrode gap distance data. Specifically, the system arranges the high-voltage electrode profile and the grounding electrode profile along a preset axis of symmetry and forcibly constrains the vertical distance between the bottom of the high-voltage electrode profile and the top of the grounding electrode profile to be strictly equal to the electrode gap distance data, thereby ensuring that the discharge gap in the model is completely consistent with the actual physical experiment.

[0027] Subsequently, to improve simulation efficiency, the system employs a specific scaling strategy to handle non-critical areas. The system uses a preset scaling ratio to process the inner wall dimension data, generating model boundary dimension data. The processing principle here is: while maintaining the relative position and gap between the high-voltage electrode outline and the grounding electrode outline, the outer shell dimensions of the test chamber far from the discharge core region are proportionally reduced. For example, the radius and height of the test chamber are reduced according to a preset scaling ratio (such as reducing it to 1 / 2 or 1 / 5 of the original size), thereby obtaining the reduced model boundary dimension data.

[0028] Finally, based on the model boundary dimensions and the positioning coordinates, the system generates a computational domain boundary line connecting the high-voltage electrode contour line and the grounding electrode contour line, thus obtaining the two-dimensional electrode geometric model. The computational domain boundary line, together with the high-voltage electrode contour line and the grounding electrode contour line, forms a closed region. This closed region is the gas computational domain filled with a C4F7N / CO2 mixture, and also serves as the spatial carrier for subsequently solving the continuity equation and Poisson equation for charged particles. Through this construction method, the two-dimensional electrode geometric model retains the core gap physical environment that determines the discharge characteristics while effectively reducing the number of grids in the invalid computational region. This significantly reduces the computational load of the model while ensuring prediction accuracy, thereby improving simulation efficiency.

[0029] Step S2: Process the electron collision cross-sectional data according to the preset Boltzmann equation to generate the average electron energy, mobility, diffusion coefficient and reaction rate; In a preferred embodiment, the step of processing the electron collision cross-sectional data according to a preset Boltzmann equation to generate the electron average energy, mobility, diffusion coefficient, and reaction rate includes: Obtain the calculation range data for the reduced electric field; Based on the reduced electric field calculation range data, a reduced electric field sequence data is generated; Based on the electron collision cross-section data and the reduced electric field sequence data, the preset Boltzmann equation is solved to generate electron energy distribution function data corresponding to the reduced electric field sequence data; Based on the electron energy distribution function data and the electron collision cross-section data, the average electron energy, mobility, diffusion coefficient, and reaction rate, which vary with the reduced electric field sequence data, are calculated and generated.

[0030] Specifically, the core objective of this step is to transform microscopic particle collision probability data into macroscopic transport parameters that can be directly accessed by the fluid model. Specifically, the motion of electrons under an electric field is not a single numerical value but follows a certain statistical distribution. Therefore, it is necessary to solve the Boltzmann equation to obtain the energy distribution of electrons under different electric field intensities, and then obtain the aforementioned macroscopic parameters through statistical integration.

[0031] In a preferred embodiment, the specific process of processing electron collision cross-sectional data according to a preset Boltzmann equation to generate average electron energy, mobility, diffusion coefficient, and reaction rate is as follows: First, the system performs the operation of acquiring the calculation range data of the reduced electric field. Because the electric field strength inside the test chamber changes drastically with time and spatial location during lightning impulse discharge, and the gas particle number density is usually constant or slowly changing, the reduced electric field (i.e., the ratio of electric field strength to gas particle number density, usually expressed in Td), which characterizes the acceleration effect of the electric field on electrons, will fluctuate within a relatively wide numerical range. The system needs to set a range of reduced electric field values ​​(e.g., 0 to 1000 Td) that may occur during the actual discharge process as the domain for parameter calculation. Next, the system generates a sequence of reduced electric field data based on the calculation range data. Within the calculation range, the system discretizes the data according to a preset step size or logarithmic distribution rule, generating a series of discrete reduced electric field numerical points. These numerical points constitute the index sequence for subsequently building the parameter lookup table.

[0032] Subsequently, based on electron collision cross-sectional data and reduced electric field sequence data, the system solves the pre-defined Boltzmann equation to generate electron energy distribution function (EEDF) data corresponding to the reduced electric field sequence data. During this process, the system iterates through each discrete numerical point in the reduced electric field sequence data, substituting the current reduced electric field value and electron collision cross-sectional data from various reactions such as attachment, ionization, elastic collisions, and excitation within the C4F7N / CO2 mixture into the Boltzmann equation. Through numerical solution, the system calculates the electron energy distribution function (EEDF) for each specific reduced electric field value. The electron energy distribution function describes the probability density of electrons with different energies within an electron population under a specific electric field.

[0033] Finally, based on the electron energy distribution function data and electron collision cross-sectional data, the system calculates the average electron energy, mobility, diffusion coefficient, and reaction rate as they vary with the reduced electric field sequence data. Specifically, the system uses the calculated electron energy distribution function to perform a weighted integral on the electron velocity or energy, respectively calculating the average energy, electron mobility, and electron diffusion coefficient of the electron population. Simultaneously, the system convolves the electron energy distribution function with the electron collision cross-sections of specific reaction types (such as ionization reactions and adhesion reactions) to calculate the reaction rate for the corresponding reaction type. The system establishes a one-to-one mapping relationship between the calculated average electron energy, mobility, diffusion coefficient, and reaction rate and the corresponding reduced electric field values, thereby constructing a transport parameter database or lookup table that varies with the reduced electric field. Through these steps, this invention can establish a precise functional relationship between microscopic cross-sectional data and macroscopic transport parameters based on physical mechanisms, ensuring that subsequent fluid simulation models can call accurate physical parameters in real time according to changes in the local electric field, thus guaranteeing the physical realism and prediction accuracy of the simulation results.

[0034] Step S3: In the two-dimensional electrode geometric model, under the condition of applying a preset voltage waveform, the preset charged particle continuity equation and preset Poisson equation are solved using the average electron energy, mobility, diffusion coefficient, reaction rate and ion transport parameter data to generate the spatiotemporal distribution data of electric field intensity and the position data of the stream head. In a preferred embodiment, in the two-dimensional electrode geometric model, under the condition of applying a preset voltage waveform, using data on average electron energy, mobility, diffusion coefficient, reaction rate, and ion transport parameters, a preset charged particle continuity equation and a preset Poisson equation are solved to generate spatiotemporal distribution data of electric field intensity and stream head position data, including: Based on the preset initial seed density data, the electron density and ion density in the two-dimensional electrode geometric model are initialized, and the initialized electron density and initialized ion density are generated. Repeat the time-step coupled solution operation until the current simulation time reaches the preset duration, generating spatiotemporal distribution data of electric field intensity and streamer head position data; The time-step coupled solution operation includes: Based on the preset voltage waveform, determine the potential boundary conditions of the high-voltage electrode profile at the current simulation moment; Based on the current electron density, current ion density, and the potential boundary conditions, the preset Poisson equation is solved to calculate the current electric field intensity distribution; wherein, the initial current electron density is the initialized electron density; the initial current ion density is the initialized ion density; The current electric field intensity distribution is recorded as the data at the current simulation moment in the electric field intensity spatiotemporal distribution data. The current stream head position is determined based on the current electron density and the current ion density, and the current stream head position is recorded in the stream head position data. The local reduced electric field is calculated based on the current electric field intensity distribution, and the corresponding local electronic micro-parameters are extracted from the average electron energy, mobility, diffusion coefficient and reaction rate based on the local reduced electric field. Using the local electronic microscopic parameters, the ion transport parameter data, and the current electric field intensity distribution, the preset charged particle continuity equation is solved to calculate the electron density distribution and ion density distribution of the next time step. The electron density distribution and ion density distribution of the next time step are updated to the current electron density and current ion density, and the current simulation time is increased by one time step.

[0035] In a preferred embodiment, the step of solving a preset Poisson equation based on the current electron density, the current ion density, and the potential boundary conditions to calculate the current electric field intensity distribution includes: Based on the current electron density and the current ion density, determine the space charge density source term used to characterize the net space charge distribution; Using the space charge density source term and the potential boundary conditions, the preset Poisson equation is solved to generate the current potential distribution data; Spatial gradient calculation is performed on the current potential distribution data to generate the current electric field intensity distribution.

[0036] In a preferred embodiment, the local electronic microscopic parameters include local mobility, local diffusion coefficient, and local reaction rate; The process of using the local electronic microscopic parameters, the ion transport parameter data, and the current electric field intensity distribution to solve the preset charged particle continuity equation and calculate the electron density distribution and ion density distribution for the next time step includes: Based on the local mobility and local diffusion coefficient in the local electronic micro-parameters, the ion transport parameter data, and the current electric field intensity distribution, the migration and diffusion flux data characterizing the particle drift motion and diffusion motion are calculated. Based on the local reaction rate, current electron density, current ion density, and preset reaction source term formula in the local electronic microscopic parameters, calculate the net reaction source term data characterizing particle generation and loss; Based on the migration and diffusion flux data and the net reaction source term data, the preset charged particle continuity equation is discretized and solved by time integration to generate the electron density distribution and ion density distribution for the next time step.

[0037] In a preferred embodiment, the local reaction rate includes the ionization reaction rate, the adhesion reaction rate, and the recombination reaction rate; The step of calculating net reaction source term data characterizing particle generation and loss based on the local reaction rate, current electron density, current ion density, and a preset reaction source term formula in the local electronic microscopic parameters includes: Calculate the electron ionization gain data based on the ionization reaction rate in the local reaction rate and the current electron density; Calculate electron attachment loss data based on the attachment reaction rate in the local reaction rate and the current electron density; Calculate the electron-ion recombination loss data based on the recombination reaction rate, current electron density, and current ion density in the local reaction rate. The electron ionization gain data, the electron attachment loss data, and the electron-ion recombination loss data are subjected to algebraic sum operations to generate net reaction source term data.

[0038] Specifically, within the constructed two-dimensional electrode geometric model, under the applied preset voltage waveform, the system utilizes data on average electron energy, mobility, diffusion coefficient, reaction rate, and ion transport parameters to couple and solve preset charged particle continuity equations and preset Poisson equations, thereby generating spatiotemporal distribution data of electric field intensity and stream head position data. This process is essentially a time-step-based multiphysics dynamic coupling iterative process.

[0039] In a preferred embodiment, the simulation solution process specifically includes the following steps: First, an initialization operation is performed. The system initializes the electron density and ion density in the two-dimensional electrode geometric model based on preset initial seed density data, generating initial electron density and initial ion density. Typically, a small amount of Gaussian distributed background electrons or ions are set in the high field strength region near the needle tip electrode as the initial seed charge for simulating the discharge process.

[0040] After initialization, the system enters a time-step coupled solution loop, repeatedly executing the following sub-steps until the current simulation time reaches the preset duration: The first step is to determine the potential boundary conditions. The system calculates the instantaneous voltage value corresponding to the current simulation moment based on the preset voltage waveform (e.g., the standard 1.2 / 50μs lightning impulse voltage waveform function), and loads the instantaneous voltage value onto the high-voltage electrode contour line in the two-dimensional electrode geometry model as the potential boundary condition (Dirichlet boundary condition) for the current moment, while the ground electrode contour line remains at zero potential.

[0041] The second step is to solve the Poisson equation to obtain the electric field distribution. The system first determines the space charge density source term, which characterizes the net charge distribution, based on the current electron density and ion density. Specifically, the system sums the densities of all types of positive ions at the current moment and subtracts the current electron density and the densities of all types of negative ions to obtain the net charge number density. This net charge number density is then combined with the elementary charge to calculate the space charge density source term. Subsequently, the system uses the space charge density source term and the potential boundary conditions to solve the pre-defined Poisson equation. The pre-defined Poisson equation describes the distortion effect of space charge on the electric field, and its mathematical expression is as follows: in, Represents the Hamiltonian operator. Represents electric potential, Represents the vacuum permittivity. This represents the relative permittivity of the C4F7N / CO2 gas mixture. Represents the space charge density source term. Represents the amount of elementary charge. This represents the density of positive ions. Represents electron density, This represents the negative ion density. The system solves the above equations using the finite element method to obtain the current potential distribution data across the entire space, and then performs spatial gradient calculation (calculating the negative gradient) on the current potential distribution data to generate the current electric field intensity distribution. At this point, the system records the current electric field intensity distribution as a frame of data in the electric field intensity spatiotemporal distribution data; at the same time, the system determines the current stream head position based on the current electron density and ion density distribution (e.g., selecting the point with the maximum electron density or the point with the strongest electric field distortion), and records the current stream head position in the stream head position data.

[0042] The third step is to extract local microscopic parameters. Based on the calculated current electric field intensity distribution and the gas particle number density, the system calculates the local reduced electric field at each grid node in the two-dimensional electrode geometric model. Subsequently, the system uses the local reduced electric field as an index to extract the corresponding local electronic micro-parameters from the parameter table generated in step S2 through an interpolation algorithm. The aforementioned local electronic micro-parameters specifically include local mobility, local diffusion coefficient, and local reaction rate.

[0043] The fourth step is to solve the charged particle continuity equation. The system uses local electronic microscopic parameters, ion transport parameter data, and the current electric field intensity distribution to solve the pre-defined charged particle continuity equation to calculate the particle density distribution for the next time step. Solving the continuity equation includes calculating the migration-diffusion flux and the net reaction source term.

[0044] When calculating migration and diffusion flux data, the system calculates the flux of electrons and ions based on local electron microscopic parameters such as local mobility and local diffusion coefficient, ion transport parameters, and the current electric field intensity distribution. The flux includes a drift component driven by the electric field and a diffusion component driven by the concentration gradient.

[0045] When calculating net reaction source term data, the system uses local reaction rates, current electron density, current ion density, and preset reaction source term formulas from local electronic microscopic parameters. Considering the electronegativity of the C4F7N / CO2 mixture, local reaction rates include ionization reaction rate, adhesion reaction rate, and recombination reaction rate. The specific calculation logic is as follows: Based on the ionization reaction rate and current electron density in the local reaction rates, electron ionization gain data (characterizing the process of electrons colliding with neutral molecules to generate new electrons) is calculated; based on the adhesion reaction rate and current electron density in the local reaction rates, electron adhesion loss data (characterizing the process of electrons being adsorbed by neutral molecules to form negative ions) is calculated; based on the recombination reaction rate, current electron density, and current ion density in the local reaction rates, electron-ion recombination loss data (characterizing the process of electrons recombinizing and disappearing with positive ions) is calculated; finally, the electron ionization gain data, electron adhesion loss data, and electron-ion recombination loss data are summed algebraically (gain is positive, loss is negative) to generate net reaction source term data.

[0046] Combining the flux and source terms mentioned above, the specific expression of the pre-defined continuity equation for charged particles is as follows: in, Indicates time, This represents electron migration and diffusion flux data. Indicates the first Migration and diffusion flux data of seed ions (positive ions are represented by positive signs, and negative ions by negative signs). Data representing the net reaction source term of electrons, Data representing the net reaction source term of ions; Indicates local electron mobility. Indicates the local electron diffusion coefficient. Indicates ion mobility. Indicates the ion diffusion coefficient; This represents the electron ionization gain data. This represents the data on electron adhesion loss. This represents the data on electron-ion recombination loss.

[0047] The fifth step is time step update. Based on the discretized time integral solution of the continuity equation, the system obtains the electron density distribution and ion density distribution for the next time step, updates them to the new current electron density and ion density, and increments the current simulation time by one time step. Then, it returns to the first step to start the next loop.

[0048] Through the rigorous coupling solution based on the above physical mechanism, this invention can accurately reconstruct the entire spatiotemporal evolution of C4F7N / CO2 mixed gas under lightning impulse voltage. In particular, by accurately calculating the influence of ionization, attachment and recombination reactions on particle number density, and updating the distortion effect of space charge on the electric field in real time, the generated spatiotemporal distribution data of electric field intensity and the position data of the streamer head have extremely high physical authenticity.

[0049] Step S4: Based on the spatiotemporal distribution data of the electric field intensity, determine the applied voltage corresponding to the moment when the electric field intensity at the needle tip reaches its maximum value as the jet initiation voltage; based on the jet head position data, determine the applied voltage corresponding to the moment when the jet head reaches the ground electrode minus a preset step size as the jet breakdown voltage; calculate the arithmetic mean of the jet initiation voltage and the jet breakdown voltage to obtain the 50% lightning impulse voltage prediction value.

[0050] Specifically, in the initial stage of lightning impulse discharge, the electric field strength near the needle tip electrode gradually increases with the increase of the applied voltage. However, once the jetting begins and forms a plasma channel, the space charge accumulated at the jetting head will exert an electrostatic shielding effect on the needle tip electrode, causing a sharp drop in the electric field strength on the needle tip surface. Based on this physical phenomenon, the moment when the electric field strength at the needle tip reaches its maximum value is the critical moment for jetting initiation, which physically corresponds to the critical state where the discharge probability is 0%. The system traverses the spatiotemporal distribution data of the electric field strength, identifies the specific simulation time point when the electric field strength at the needle tip reaches its global maximum value, and searches for the instantaneous voltage value corresponding to this simulation time point from the preset voltage waveform data, determining the instantaneous voltage value as the jetting initiation voltage.

[0051] Next, the system determines the streamer breakdown voltage based on the streamer head position data. The streamer breakdown voltage corresponds to the moment when the streamer completely penetrates the electrode gap, which physically corresponds to the critical state where the discharge probability is 100%. In finite element numerical simulation, when the highly conductive streamer head contacts the ground electrode, the potential gradient at the contact point theoretically tends to infinity, which can generate singularities in the numerical calculation, leading to non-convergence of the calculation results or distortion of the voltage value. To avoid this numerical calculation obstacle, the system monitors the streamer head position data. When the vertical coordinate of the streamer head coincides with the vertical coordinate of the ground electrode, it is marked as the moment when the streamer head arrives at the ground electrode. Subsequently, the system performs a time backtracking operation, subtracting a preset step size (e.g., 0.002 microseconds, which is the empirical minimum time step to ensure the stability of the numerical calculation) from the moment the streamer head arrives at the ground electrode to obtain a corrected moment. The system searches for the instantaneous voltage value corresponding to the corrected moment from the preset voltage waveform data and determines the instantaneous voltage value as the streamer breakdown voltage.

[0052] Finally, the system performs a prediction calculation for the 50% lightning impulse voltage. Based on statistical principles and high-voltage test experience, the 50% lightning impulse voltage (U50%) lies at the statistical center of the 0% breakdown probability voltage and the 100% breakdown probability voltage. The system calculates the arithmetic mean of the streamer initiation voltage and the streamer breakdown voltage using the following formula: in, This represents the 50% predicted value of lightning impulse voltage. Indicates the starting voltage of the streamer. This represents the streamer breakdown voltage. Through the above steps, this invention successfully constructs a quantitative mapping relationship from the deterministic physical simulation boundary (initiation and breakdown) to the statistical median value. This enables accurate prediction of the 50% lightning impulse voltage of the C4F7N / CO2 mixture without the need for extensive statistical experiments, effectively solving the technical problem of large prediction deviations and inability to replace actual measurements caused by the lack of effective mapping algorithms and numerical calculation singularities in existing technologies.

[0053] Based on the above method embodiments, the present invention provides corresponding apparatus embodiments.

[0054] like Figure 2 As shown, an embodiment of the present invention provides a 50% lightning impulse voltage prediction device for a C4F7N / CO2 mixed gas, including: a data acquisition and modeling module, a parameter generation module, a simulation solution module, and a voltage prediction module; The data acquisition and modeling module is used to acquire electron collision cross-sectional data, ion transport parameter data, electrode gap distance data of the test chamber, and electrode type data of the C4F7N / CO2 mixed gas; and to construct a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data. The parameter generation module is used to process the electron collision cross-sectional data according to the preset Boltzmann equation to generate the average electron energy, mobility, diffusion coefficient and reaction rate. The simulation solution module is used to solve the preset charged particle continuity equation and the preset Poisson equation in a two-dimensional electrode geometric model under the condition of applying a preset voltage waveform, using the average electron energy, mobility, diffusion coefficient, reaction rate and ion transport parameter data, and to generate the spatiotemporal distribution data of electric field intensity and the position data of the streamer head. The voltage prediction module is used to determine the applied voltage corresponding to the moment when the electric field strength at the needle tip reaches its maximum value as the streamer initiation voltage based on the spatiotemporal distribution data of the electric field strength; to determine the applied voltage corresponding to the moment when the streamer head reaches the ground electrode minus a preset step size based on the streamer head position data as the streamer breakdown voltage; and to calculate the arithmetic mean of the streamer initiation voltage and the streamer breakdown voltage to obtain the 50% lightning impulse voltage prediction value.

[0055] It should be noted that the embodiments of the device described above correspond to the embodiments of the present invention described above, and can realize the 50% lightning impulse voltage prediction method for C4F7N / CO2 mixed gas described in any one of the above embodiments of the present invention. Furthermore, the embodiments of the device described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without creative effort.

[0056] Based on the above-described method embodiments of the present invention, a corresponding embodiment of an electronic device is provided.

[0057] An embodiment of the present invention provides an electronic device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the method for predicting the 50% lightning impulse voltage of the C4F7N / CO2 mixed gas according to any one of the present invention, or, when the processor executes the computer program, it implements the functions of each module in the above-described device embodiments.

[0058] For example, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the terminal device.

[0059] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0060] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0061] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, applications required for at least one function, etc.; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital card (SD card), flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0062] Based on the above method embodiments, the present invention provides corresponding storage medium embodiments; Another embodiment of the present invention provides a storage medium comprising a stored computer program, wherein, when the computer program is executed, the device containing the storage medium is controlled to execute any of the above-described C4F7N / CO2 mixed gas 50% lightning impulse voltage prediction methods of the present invention.

[0063] The aforementioned storage medium is a computer-readable storage medium, and the computer program includes computer program code, which may be in the form of source code, object code, executable file, or certain intermediate forms. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0065] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for predicting the lightning impulse voltage of a 50% C4F7N / CO2 mixed gas, characterized in that, include: Data on electron collision cross-sections, ion transport parameters, electrode gap distances in the experimental chamber, and electrode types of the C4F7N / CO2 mixed gas were obtained; a two-dimensional electrode geometric model was constructed based on the electrode gap distance data and the electrode type data. The electron collision cross-sectional data are processed according to the preset Boltzmann equation to generate the average electron energy, mobility, diffusion coefficient and reaction rate; In the two-dimensional electrode geometric model, under the condition of applying a preset voltage waveform, the preset charged particle continuity equation and preset Poisson equation are solved using the average electron energy, mobility, diffusion coefficient, reaction rate and ion transport parameter data, generating the spatiotemporal distribution data of electric field intensity and the position data of the stream head. Based on the spatiotemporal distribution data of the electric field intensity, the applied voltage corresponding to the moment when the electric field intensity at the needle tip reaches its maximum value is determined as the jet initiation voltage; Based on the jet head position data, the applied voltage corresponding to the time when the jet head reaches the ground electrode minus the preset step size is determined as the jet breakdown voltage. The arithmetic mean of the streamer initiation voltage and the streamer breakdown voltage is calculated to obtain the 50% lightning impulse voltage prediction value.

2. The method for predicting the lightning impulse voltage of a C4F7N / CO2 mixed gas with a concentration of 50% as described in claim 1, characterized in that, The step of constructing a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data includes: Obtain the inner wall dimension data of the test chamber and the electrode contour dimension data corresponding to the electrode type data; Based on the electrode profile size data, generate the high-voltage electrode profile and the grounding electrode profile. Based on the electrode gap distance data, determine the positioning coordinates of the high-voltage electrode contour line and the grounding electrode contour line in the two-dimensional coordinate system; The inner wall dimension data is processed using a preset scaling ratio to generate model boundary dimension data; Based on the model boundary size data and the positioning coordinates, a computational domain boundary line connecting the high-voltage electrode contour line and the grounding electrode contour line is generated, thus obtaining the two-dimensional electrode geometric model.

3. The method for predicting the lightning impulse voltage of a C4F7N / CO2 mixed gas with a concentration of 50% as described in claim 2, characterized in that, The process of processing the electron collision cross-sectional data according to the preset Boltzmann equation to generate the electron average energy, mobility, diffusion coefficient, and reaction rate includes: Obtain the calculation range data for the reduced electric field; Based on the reduced electric field calculation range data, a reduced electric field sequence data is generated; Based on the electron collision cross-section data and the reduced electric field sequence data, the preset Boltzmann equation is solved to generate electron energy distribution function data corresponding to the reduced electric field sequence data; Based on the electron energy distribution function data and the electron collision cross-section data, the average electron energy, mobility, diffusion coefficient, and reaction rate, which vary with the reduced electric field sequence data, are calculated and generated.

4. The method for predicting the lightning impulse voltage of a C4F7N / CO2 mixed gas with a concentration of 50% as described in claim 3, characterized in that, In the two-dimensional electrode geometric model, under the condition of applying a preset voltage waveform, using data on average electron energy, mobility, diffusion coefficient, reaction rate, and ion transport parameters, a preset charged particle continuity equation and a preset Poisson equation are solved to generate spatiotemporal distribution data of electric field intensity and stream head position data, including: Based on the preset initial seed density data, the electron density and ion density in the two-dimensional electrode geometric model are initialized, and the initialized electron density and initialized ion density are generated. Repeat the time-step coupled solution operation until the current simulation time reaches the preset duration, generating spatiotemporal distribution data of electric field intensity and streamer head position data; The time-step coupled solution operation includes: Based on the preset voltage waveform, determine the potential boundary conditions of the high-voltage electrode profile at the current simulation moment; Based on the current electron density, current ion density, and the potential boundary conditions, the preset Poisson equation is solved to calculate the current electric field intensity distribution; wherein, the initial current electron density is the initialized electron density; the initial current ion density is the initialized ion density; The current electric field intensity distribution is recorded as the data at the current simulation moment in the electric field intensity spatiotemporal distribution data. The current stream head position is determined based on the current electron density and the current ion density, and the current stream head position is recorded in the stream head position data. The local reduced electric field is calculated based on the current electric field intensity distribution, and the corresponding local electronic micro-parameters are extracted from the average electron energy, mobility, diffusion coefficient and reaction rate based on the local reduced electric field. Using the local electronic microscopic parameters, the ion transport parameter data, and the current electric field intensity distribution, the preset charged particle continuity equation is solved to calculate the electron density distribution and ion density distribution of the next time step. The electron density distribution and ion density distribution of the next time step are updated to the current electron density and current ion density, and the current simulation time is increased by one time step.

5. The method for predicting the 50% lightning impulse voltage of a C4F7N / CO2 mixed gas as described in claim 4, characterized in that, The step of solving a preset Poisson equation based on the current electron density, current ion density, and the potential boundary conditions to calculate the current electric field intensity distribution includes: Based on the current electron density and the current ion density, determine the space charge density source term used to characterize the net space charge distribution; Using the space charge density source term and the potential boundary conditions, the preset Poisson equation is solved to generate the current potential distribution data; Spatial gradient calculation is performed on the current potential distribution data to generate the current electric field intensity distribution.

6. The method for predicting the 50% lightning impulse voltage of a C4F7N / CO2 mixed gas as described in claim 5, characterized in that, The local electronic microscopic parameters include local mobility, local diffusion coefficient, and local reaction rate; The process of using the local electronic microscopic parameters, the ion transport parameter data, and the current electric field intensity distribution to solve the preset charged particle continuity equation and calculate the electron density distribution and ion density distribution for the next time step includes: Based on the local mobility and local diffusion coefficient in the local electronic micro-parameters, the ion transport parameter data, and the current electric field intensity distribution, the migration and diffusion flux data characterizing the particle drift motion and diffusion motion are calculated. Based on the local reaction rate, current electron density, current ion density, and preset reaction source term formula in the local electronic microscopic parameters, calculate the net reaction source term data characterizing particle generation and loss; Based on the migration and diffusion flux data and the net reaction source term data, the preset charged particle continuity equation is discretized and solved by time integration to generate the electron density distribution and ion density distribution for the next time step.

7. The method for predicting the 50% lightning impulse voltage of a C4F7N / CO2 mixed gas as described in claim 6, characterized in that, The local reaction rate includes the ionization reaction rate, the adhesion reaction rate, and the recombination reaction rate; The step of calculating net reaction source term data characterizing particle generation and loss based on the local reaction rate, current electron density, current ion density, and a preset reaction source term formula in the local electronic microscopic parameters includes: Calculate the electron ionization gain data based on the ionization reaction rate in the local reaction rate and the current electron density; Calculate electron attachment loss data based on the attachment reaction rate in the local reaction rate and the current electron density; Calculate the electron-ion recombination loss data based on the recombination reaction rate, current electron density, and current ion density in the local reaction rate. The electron ionization gain data, the electron attachment loss data, and the electron-ion recombination loss data are subjected to algebraic sum operations to generate net reaction source term data.

8. A lightning impulse voltage prediction device for a C4F7N / CO2 mixed gas of 50%, characterized in that, include: The module includes a data acquisition and modeling module, a parameter generation module, a simulation solution module, and a voltage prediction module. The data acquisition and modeling module is used to acquire electron collision cross-sectional data, ion transport parameter data, electrode gap distance data of the test chamber, and electrode type data of the C4F7N / CO2 mixed gas; and to construct a two-dimensional electrode geometric model based on the electrode gap distance data and the electrode type data. The parameter generation module is used to process the electron collision cross-sectional data according to the preset Boltzmann equation to generate the average electron energy, mobility, diffusion coefficient and reaction rate. The simulation solution module is used to solve the preset charged particle continuity equation and the preset Poisson equation in a two-dimensional electrode geometric model under the condition of applying a preset voltage waveform, using the average electron energy, mobility, diffusion coefficient, reaction rate and ion transport parameter data, and to generate the spatiotemporal distribution data of electric field intensity and the position data of the streamer head. The voltage prediction module is used to determine the applied voltage corresponding to the moment when the electric field strength at the needle tip reaches its maximum value as the streamer initiation voltage based on the spatiotemporal distribution data of the electric field strength. Based on the jet head position data, the applied voltage corresponding to the time when the jet head reaches the ground electrode minus the preset step size is determined as the jet breakdown voltage. The arithmetic mean of the streamer initiation voltage and the streamer breakdown voltage is calculated to obtain the 50% lightning impulse voltage prediction value.

9. An electronic device, characterized in that, The method includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the method for predicting 50% lightning impulse voltage of a C4F7N / CO2 mixed gas as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device containing the storage medium to perform the 50% lightning impulse voltage prediction method for C4F7N / CO2 mixed gas as described in any one of claims 1 to 7.

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