Method for simulating influence of compaction coefficient on electric field of polypropylene coarsened film capacitor

Abstract

The invention discloses a method for simulating the influence of a compaction coefficient on an electric field of a polypropylene coarsened film capacitor. Comprising the following steps: constructing a three-dimensional simulation model of a target polypropylene coarsened film capacitor winding structure; adding a current physical field into the three-dimensional simulation model, and respectively setting relative dielectric constants, conductivity and global parameters for the polypropylene film, the benzyl toluene insulating oil and the aluminum foil electrode in the three-dimensional simulation model; setting a potential boundary condition for the set three-dimensional simulation model, and determining an electric field influence simulation function; based on the electric field influence simulation function and the potential boundary condition, determining the maximum electric field intensity value of the electric field of the target polypropylene coarsened film capacitor under each to-be-evaluated compaction coefficient and the corresponding position information of the maximum electric field intensity value; and based on the maximum electric field intensity value under each compaction coefficient and the corresponding position information, analyzing the influence of the compaction coefficient on the electric field of the target polypropylene coarsened film capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment insulation, and in particular to a simulation method for the influence of the compaction coefficient on the electric field of a polypropylene roughened film capacitor. Background Art

[0002] Polypropylene film is the core dielectric material of power capacitors. The composite dielectric composed of it and benzyltoluene insulating oil determines the energy storage performance of the capacitors. However, under the condition of power frequency alternating current, the electric field distortion at the folded edge of the aluminum foil electrode is likely to cause partial discharge, resulting in dielectric aging and even breakdown. Existing research mostly focuses on the performance of the material itself and ignores the influence of the compaction coefficient (i.e., the tightness of the dielectric) on the electric field distribution.

[0003] Currently, usually, physical samples of polypropylene roughened film capacitors are repeatedly manufactured for experiments, and the influence of the compaction coefficient on the electric field distribution is determined according to the experimental results. However, this way of repeatedly manufacturing physical samples is time-consuming, laborious, and costly. Summary of the Invention

[0004] The present invention provides a simulation method for the influence of the compaction coefficient on the electric field of a polypropylene roughened film capacitor, mainly aiming at improving the analysis efficiency of the influence of the compaction coefficient on the electric field of the polypropylene roughened film capacitor and saving the analysis cost.

[0005] According to the first aspect of the present invention, a simulation method for the influence of the compaction coefficient on the electric field of a polypropylene roughened film capacitor is provided, including:

[0006] Constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor by using a preset simulation software, wherein the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyltoluene insulating oil, and aluminum foil electrode layers arranged at both ends of the polypropylene film layers;

[0007] Adding a current physical field to the three-dimensional simulation model, and respectively setting relative permittivity and conductivity for the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and setting global parameters in the three-dimensional simulation model, wherein the global parameters include the film thickness, roughness, and initial compaction coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyltoluene insulating oil;

[0008] Setting potential boundary conditions for the set three-dimensional simulation model and determining an electric field influence simulation function;

[0009] Determine a plurality of pressing coefficients to be evaluated in units of a preset step within a preset pressing coefficient range, and based on the electric field influence simulation function and the electric potential boundary conditions, determine the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each pressing coefficient to be evaluated, and the position information corresponding to the maximum electric field strength value;

[0010] Based on the maximum electric field strength value and its corresponding position information under each working condition, analyze the influence of the pressing coefficient on the electric field of the target polypropylene roughened film capacitor.

[0011] Optionally, the method further includes:

[0012] Determine the hemming length, hemming chamfer radius, and total electrode length of the aluminum foil electrode, and perform hemming treatment on the aluminum foil electrode based on the hemming length, the hemming chamfer radius, and the total electrode length.

[0013] Optionally, setting the relative permittivity and conductivity for the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model respectively includes:

[0014] Set a relative permittivity with a first preset dielectric value and a conductivity with a first conductivity value for the polypropylene film;

[0015] Set a relative permittivity with a second preset dielectric value and a conductivity with a second conductivity value for the benzyltoluene insulating oil;

[0016] Set a relative permittivity with a third preset dielectric value and a conductivity with a third conductivity value for the aluminum foil electrode.

[0017] Optionally, the electric field influence simulation function is: J c =σE, D=ε o ε r E, where J c is the current density of the electric field of the target polypropylene roughened film capacitor, σ is the conductivity of the composite medium in the electric field of the target polypropylene roughened film capacitor, E is the electric field strength of the electric field of the target polypropylene roughened film capacitor, D is the electric displacement vector of the electric field of the target polypropylene roughened film capacitor, ε o is the vacuum permittivity, and ε r is the relative permittivity of the composite medium.

[0018] Optionally, the determining the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each pressing coefficient to be evaluated, and the position information corresponding to the maximum electric field strength value based on the electric field influence simulation function and the electric potential boundary conditions includes:

[0019] Dividing the three-dimensional simulation model into a plurality of discrete grid units, and based on Gauss's law, converting the electric field influence simulation function corresponding to the three-dimensional simulation model into a continuous partial differential simulation function, and discretizing the continuous partial differential simulation function into a unit function corresponding to each of the grid units based on a preset finite element algorithm;

[0020] Determine the relative dielectric constant of the composite medium based on the relative dielectric constants corresponding to the polypropylene film, the benzyl toluene insulating oil, and the aluminum foil electrode, and determine the electrical conductivity of the composite medium based on the electrical conductivities corresponding to the polypropylene film, the benzyl toluene insulating oil, and the aluminum foil electrode, respectively;

[0021] Based on the potential boundary conditions, the current density under the working conditions corresponding to each of the compaction coefficients to be evaluated is determined, and each of the current density, the electrical conductivity of the composite medium, and the relative dielectric constant of the composite medium are respectively substituted into the function group composed of each of the unit functions to perform electric field strength calculation, so as to obtain the electric field strength value on each of the grid units under each of the working conditions, and the maximum electric field strength value among the electric field strength values on each of the grid units is determined as the maximum electric field strength value under each of the working conditions, and the position of the grid unit corresponding to the maximum electric field strength value is determined as the position information corresponding to the maximum electric field strength value.

[0022] Optionally, before determining the maximum electric field strength value of the target polypropylene roughened film capacitor electric field under the operating conditions corresponding to each of the compression coefficients to be evaluated, the method further includes:

[0023] determining an initial gap and a contact area between the polypropylene film layer and the aluminum foil electrode layer, and obtaining film material properties of the polypropylene film and electrode material properties of the aluminum foil electrode;

[0024] Determining the interlayer gap to be adjusted between the polypropylene film layer and the aluminum foil electrode layer corresponding to each compression coefficient to be evaluated based on each compression coefficient to be evaluated, the initial gap, the contact area, the film material properties, and the electrode material properties;

[0025] Based on each interlayer gap to be adjusted, the interlayer gap between the polypropylene film layer and the aluminum foil electrode layer is adjusted in sequence to obtain the working condition corresponding to each compression coefficient to be evaluated.

[0026] Optionally, the analyzing the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field strength value under each of the operating conditions and its corresponding position information includes:

[0027] Construct an electric field strength sequence based on the maximum electric field strength value under each of the working condition conditions, and construct a position sequence based on the position information corresponding to the maximum electric field strength value under each of the working condition conditions;

[0028] Perform region prediction based on the three-dimensional simulation model, the electric field strength sequence, the position sequence, and a preset electric field strength threshold to obtain the electric field safety region in the three-dimensional simulation model;

[0029] Determine the electric field distortion coefficient corresponding to the electric field safety region, and analyze the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor based on the electric field safety region and its corresponding electric field distortion coefficient.

[0030] According to a second aspect of the present invention, there is provided a simulation device for the influence of the compaction coefficient on the electric field of a polypropylene roughened film capacitor, including:

[0031] A construction unit for constructing a three-dimensional simulation model of the winding structure of a target polypropylene roughened film capacitor by using a preset simulation software, wherein the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyl toluene insulating oil, and aluminum foil electrode layers provided at both ends of the polypropylene film layers;

[0032] A setting unit for adding a current physical field to the three-dimensional simulation model, and respectively setting relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and setting global parameters in the three-dimensional simulation model, wherein the global parameters include the film thickness, roughness, and initial compaction coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyl toluene insulating oil;

[0033] A first determination unit for setting a potential boundary condition for the set three-dimensional simulation model and determining an electric field influence simulation function;

[0034] A second determination unit for determining a plurality of compaction coefficients to be evaluated at a preset step length within a preset compaction coefficient range, and determining the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working condition corresponding to each of the compaction coefficients to be evaluated, and the position information corresponding to the maximum electric field strength value, based on the electric field influence simulation function and the potential boundary condition;

[0035] An analysis unit for analyzing the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field strength value under each of the working condition conditions and its corresponding position information.

[0036] According to a third aspect of the present invention, there is provided a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the above-described simulation device for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor.

[0037] According to a fourth aspect of the present invention, there is provided a computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the program, it implements the above-described simulation device for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor.

[0038] A simulation method for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor provided by the present invention, compared with the current method of repeatedly making physical samples of polypropylene roughened film capacitors for testing and determining the influence of the pressing coefficient on the electric field distribution according to the test results, the present invention constructs a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor, sets parameters such as relative permittivity, conductivity, film thickness, roughness, etc. for the three-dimensional simulation model, sets the electric potential boundary conditions for the set three-dimensional simulation model, and under the electric potential boundary conditions, based on the electric field influence simulation function, determines the maximum electric field strength value and its corresponding position of the electric field of the target polypropylene roughened film capacitor under different pressing coefficients, and based on the maximum electric field strength value and its corresponding position, analyzes the influence of the pressing coefficient on the electric field of the target polypropylene roughened film capacitor. Thus, by constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor and performing simulation analysis on the working conditions corresponding to different pressing coefficients, and determining the influence of the pressing coefficient on the electric field according to the simulation analysis results, it is possible to reduce the cost and time required for making physical samples, so that the present invention can improve the analysis efficiency of the influence of the pressing coefficient on the electric field and save the analysis cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 Shows a flowchart of a simulation method for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor provided by an embodiment of the present invention;

[0041] Figure 2 Shows a schematic diagram of a three-dimensional simulation model of the winding structure of a target polypropylene roughened film capacitor provided by an embodiment of the present invention;

[0042] Figure 3 Shows a distribution diagram of the electric potential of the winding structure of a target polypropylene roughened film capacitor with a pressing coefficient of 0.7 provided by an embodiment of the present invention;

[0043] Figure 4 Shows the electric field distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.7 provided by an embodiment of the present invention;

[0044] Figure 5 Shows the current density distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.7 provided by an embodiment of the present invention;

[0045] Figure 6 Shows the electric potential distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.75 provided by an embodiment of the present invention;

[0046] Figure 7 Shows the electric field distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.75 provided by an embodiment of the present invention;

[0047] Figure 8 Shows the current density distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.75 provided by an embodiment of the present invention;

[0048] Figure 9 Shows the electric potential distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.8 provided by an embodiment of the present invention;

[0049] Figure 10 Shows the electric field distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.8 provided by an embodiment of the present invention;

[0050] Figure 11 Shows the current density distribution diagram of a target polypropylene roughened film capacitor winding structure with a pressing coefficient of 0.8 provided by an embodiment of the present invention;

[0051] Figure 12 Shows the flowchart of a simulation method for the influence of another pressing coefficient on the electric field of a polypropylene roughened film capacitor provided by an embodiment of the present invention;

[0052] Figure 13 Shows the structural schematic diagram of a simulation device for the influence of a pressing coefficient on the electric field of a polypropylene roughened film capacitor provided by an embodiment of the present invention;

[0053] Figure 14 Shows the structural schematic diagram of an entity of a computer device provided by an embodiment of the present invention. Detailed implementation manners

[0054] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0055] Currently, the method of repeatedly making physical samples of polypropylene roughened film capacitors for experiments and determining the influence of the pressing coefficient on the electric field distribution based on the experimental results is time-consuming, laborious and costly.

[0056] To solve the above problems, an embodiment of the present invention provides a simulation method for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor, as Figure 1 shown, the method includes:

[0057] 101. Use a preset simulation software to construct a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor. Among them, the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyl toluene insulating oil, and aluminum foil electrode layers provided at both ends of the polypropylene film layers.

[0058] Among them, the preset simulation software includes COMSOL, ANSYS, etc.

[0059] For the embodiment of the present invention, as Figure 2 shown, a constructed three-dimensional simulation model is shown. The three-dimensional simulation model mainly includes two parts: an aluminum foil electrode and a polypropylene film. The gap between the aluminum foil electrode and the polypropylene film is uniformly filled with benzyl toluene insulating oil. When constructing the three-dimensional simulation model, it is also necessary to set a hem for the aluminum foil electrode. Based on this, the method includes: determining the hem length, hem chamfer radius, and total electrode length of the aluminum foil electrode, and performing a hem treatment on the aluminum foil electrode based on the hem length, the hem chamfer radius, and the total electrode length.

[0060] Specifically, determine the hem length, hem chamfer radius, and total electrode length of the aluminum foil electrode according to actual needs, and then perform a hem treatment on the aluminum foil electrode according to the hem length, the hem chamfer radius, and the total electrode length. Among them, the total electrode length should exceed the length of the polypropylene film. By performing a hem treatment on the aluminum foil electrode, the electric field uniformity can be improved, the influence of uneven electric field on the analysis result can be avoided, and thus the analysis accuracy of the influence of the pressing coefficient on the electric field of the target polypropylene roughened film capacitor can be improved.

[0061] 102. Add a current physical field to the three-dimensional simulation model, and set relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model respectively. Set global parameters in the three-dimensional simulation model. Among them, the global parameters include the film thickness, roughness, and initial pressing coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyl toluene insulating oil.

[0062] For the embodiments of the present invention, in order to perform electric field simulation on the winding structure of the target polypropylene roughened film capacitor, it is first necessary to add a current physical field to the three-dimensional simulation model, and the value of the current can be set according to actual needs. At the same time, it is also necessary to set the relative permittivity and conductivity for the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model respectively. Based on this, step 102 specifically includes: setting the relative permittivity with a first preset dielectric value and the conductivity with a first conductance value for the polypropylene film; setting the relative permittivity with a second preset dielectric value and the conductivity with a second conductance value for the benzyltoluene insulating oil; setting the relative permittivity with a third preset dielectric value and the conductivity with a third conductance value for the aluminum foil electrode.

[0063] Among them, the first preset dielectric value, the conductivity with the first conductance value, the second preset dielectric value, the conductivity with the second conductance value, the third preset dielectric value, and the conductivity with the third conductance value can be set according to actual needs. For example, set the relative permittivity of the polypropylene film to 2.2 and the conductivity to 9.43×10 -14 s / m; set the relative permittivity of the benzyltoluene insulating oil to 2.65 and the conductivity to 4.8×10 -12 s / m; set the relative permittivity of the aluminum foil electrode to 1 and the conductivity to 3.8×10 7 s / m. In the embodiments of the present invention, set the film thickness and roughness for the polypropylene film in the three-dimensional simulation model, set the initial pressing coefficient between the polypropylene film and the aluminum foil electrode, and define the composite dielectric structure of the polypropylene film and the benzyltoluene insulating oil according to actual needs, such as parameters of materials.

[0064] 103. Set the potential boundary conditions for the set three-dimensional simulation model and determine the electric field influence simulation function.

[0065] For the embodiments of the present invention, apply a power frequency alternating voltage to the high voltage side of the set three-dimensional simulation model, and ground the low voltage side and the outer shell to obtain the potential boundary conditions. At the same time, determine the current constitutive equation as the electric field influence simulation function. Among them, the electric field influence simulation function is: J c =σE, D = ε o ε r E, where J c is the current density of the electric field of the target polypropylene roughened film capacitor, σ is the conductivity of the composite dielectric in the electric field of the target polypropylene roughened film capacitor, E is the electric field strength of the electric field of the target polypropylene roughened film capacitor, D is the electric displacement vector of the electric field of the target polypropylene roughened film capacitor, ε o is the vacuum permittivity, and ε r is the relative permittivity of the composite dielectric.

[0066] In the embodiment of the present invention, by constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor and setting various parameters and boundary conditions for the three-dimensional simulation model, the simulation effect can be ensured, thereby improving the simulation accuracy of the influence of the compression coefficient on the electric field of the polypropylene roughened film capacitor.

[0067] 104. Determine a plurality of compression coefficients to be evaluated in units of a preset step size within a preset compression coefficient range, and based on the electric field influence simulation function and the potential boundary condition, determine the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working condition corresponding to each compression coefficient to be evaluated, and the position information corresponding to the maximum electric field strength value.

[0068] Among them, the preset compression coefficient range is set according to actual needs, such as 0.7 - 0.8; the preset step size is determined according to actual needs, such as 0.01.

[0069] For the embodiment of the present invention, for example, if the initial compression coefficient is 0.7 and the preset step size is 0.1, the plurality of compression coefficients to be evaluated can be: 0.71, 0.72, 0.73, 0.74, 0.75, etc. Each compression coefficient to be evaluated corresponds to a working condition. Under the constraints of the potential boundary condition and the electric field influence simulation function, solve the electric field distribution of the target polypropylene roughened film capacitor, and according to the electric field distribution, determine the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under each working condition, and the position information corresponding to the maximum electric field strength value. When solving the electric field distribution in the embodiment of the present invention, the electric field influence simulation function and the potential boundary condition are used as constraint conditions. Since the potential boundary condition can set the potential value on the boundary of the solution domain, it helps to limit the solution space and makes the numerical solution more stable and efficient. The electric field influence simulation function describes the relationship between the current density and the electric field strength and can quickly and accurately solve the electric field distribution.

[0070] 105. Analyze the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field strength value under each working condition and its corresponding position information.

[0071] For the embodiments of the present invention, a scatter plot is established with the compaction coefficient as the horizontal axis and the maximum electric field strength value as the vertical axis, and a curve is fitted. If the maximum electric field strength value increases monotonically with the increase of the compaction coefficient, it indicates that compaction leads to an intensification of local electric field concentration (such as enhanced edge effect). If the maximum electric field strength value first decreases and then increases with the increase of the compaction coefficient, there may be a critical compaction coefficient K, at which time the electric field distribution is the most uniform. At the same time, determine the position coordinates where the maximum electric field strength value appears under different compaction coefficients, such as the distance from the electrode edge. According to the position coordinates, determine the influence of the compaction coefficient on the electric field. For example, at a low compaction coefficient, the maximum electric field strength value (hot spot) may be located at the electrode edge or film defects (such as the tip of roughened particles). At a high compaction coefficient, the maximum electric field strength value (hot spot) may migrate towards the winding center because compaction increases the edge curvature, but the interlayer contact pressure at the center is higher. Finally, according to the variation relationship between the compaction coefficient and the maximum electric field length and its corresponding position information, the optimal compaction coefficient can be selected, and the winding structure of the polypropylene roughened film capacitor can be adjusted according to the optimal compaction coefficient, thereby avoiding partial discharge caused by electric field distortion and preventing damage to the winding structure of the polypropylene roughened film capacitor.

[0072] For example, take the compaction coefficient K = 0.7 as an example. The potential distribution of the target winding structure of the polypropylene roughened film capacitor is as Figure 3 shown. The electric field distribution calculated based on the initial electric field and initial charge is as Figure 4 shown; it can be seen from the figure that the maximum electric field strength appears in the impregnating agent near the hem head of the target winding structure of the polypropylene roughened film capacitor, which is 172.41 MV / m, and the electric field strength at the uniform position in the impregnating agent is 45.99 MV / m. The calculated current density distribution is as Figure 5 shown, and the maximum current density appears at the hem head position, which is 1.28 A / m2. The direction points to the axial direction after winding. Through further calculation, the electric field distortion coefficient is approximately 3.75.

[0073] Take the compaction coefficient K = 0.75 as an example. The potential distribution of the target winding structure of the polypropylene roughened film capacitor is as Figure 6 shown. The electric field distribution calculated based on the initial electric field and initial charge is as Figure 7 shown; it can be seen from the figure that the maximum electric field strength appears in the impregnating agent near the hem head of the composite structure of the target winding structure of the polypropylene roughened film capacitor, which is 177.76 MV / m, and the electric field strength at the uniform position in the impregnating agent is 50.54 MV / m. The calculated current density distribution is as Figure 8 shown, and the maximum current density appears at the hem head position, which is 1.35 A / m2. The direction points to the axial direction after winding. Through further calculation, the electric field distortion coefficient is approximately 3.51.

[0074] Taking the compression coefficient K = 0.8 as an example. The potential distribution of the winding structure of the target polypropylene roughened film capacitor is as Figure 9 shown. The electric field distribution calculated based on the initial electric field and initial charge is as Figure 10 shown; it can be seen from the figure that the maximum electric field intensity appears in the impregnating agent near the folded edge head of the composite structure of the winding structure of the target polypropylene roughened film capacitor, which is 183.40 MV / m, and the electric field intensity at the uniform position in the impregnating agent is 53.75 MV / m. The calculated current density distribution is as Figure 11 shown, and the maximum current density appears at the folded edge head position, which is 1.35 A / m2. The direction points to the axial direction after winding. Through further calculation, the electric field distortion coefficient is approximately 3.41. The calculation formula of the electric field distortion coefficient is where K qh is the electric field distortion coefficient, E max is the maximum electric field intensity value, and E ave is the standard electric field intensity value.

[0075] The embodiments of the present invention show that increasing the compression coefficient can reduce the electric field distortion coefficient, but will increase the local maximum electric field intensity. The relationship between the two can be weighed through simulation, and preferably K = 0.75 is used as the balance point to provide a quantitative basis for capacitor design.

[0076] According to a simulation method for the influence of the compression coefficient on the electric field of a polypropylene roughened film capacitor provided by the present invention, compared with the current method of repeatedly making physical samples of polypropylene roughened film capacitors for experiments and determining the influence of the compression coefficient on the electric field distribution according to the experimental results, the present invention constructs a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor, sets parameters such as relative permittivity, conductivity, film thickness, and roughness for the three-dimensional simulation model, sets the potential boundary conditions for the set three-dimensional simulation model, and based on the electric field influence simulation function under the potential boundary conditions, determines the maximum electric field intensity value and its corresponding position of the electric field of the target polypropylene roughened film capacitor under different compression coefficients, and based on the maximum electric field intensity value and its corresponding position, analyzes the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor. Thus, by constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor and performing simulation analysis on the working conditions corresponding to different compression coefficients, and determining the influence of the compression coefficient on the electric field according to the simulation analysis results, it is possible to reduce the cost and time required for making physical samples, so that the present invention can improve the analysis efficiency of the influence of the compression coefficient on the electric field and save the analysis cost.

[0077] Furthermore, in order to better illustrate the above process of classifying data, as a refinement and extension of the above embodiments, the embodiments of the present invention provide another simulation method for the influence of the compression coefficient on the electric field of a polypropylene roughened film capacitor, as Figure 12As shown, the method includes:

[0078] 201. Use a preset simulation software to construct a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor. Among them, the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyltoluene insulating oil, and aluminum foil electrode layers arranged at both ends of the polypropylene film layers.

[0079] Specifically, use software such as COMSOL to construct a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor.

[0080] 202. Add a current physical field to the three-dimensional simulation model, and respectively set the relative permittivity and conductivity for the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model. Set global parameters in the three-dimensional simulation model. Among them, the global parameters include the film thickness, roughness, and initial compaction coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyltoluene insulating oil.

[0081] Specifically, set the relative permittivity and conductivity of the materials of the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and set the compaction coefficient K, film thickness d, and roughness Ra of the polypropylene film in the global parameters, and define the composite dielectric structure of the polypropylene film and benzyltoluene insulating oil.

[0082] 203. Set the electric potential boundary conditions for the set three-dimensional simulation model and determine the electric field influence simulation function.

[0083] Specifically, based on actual requirements, set the electric potential boundary conditions for the three-dimensional simulation model, and construct an electric field influence simulation function among parameters such as the electric field strength value, relative permittivity, and composite dielectric conductivity. Among them, the electric field influence simulation function can be constructed according to the historical electric field distribution data of the winding structure of the polypropylene roughened film capacitor. Through the historical electric field distribution data, determine the electric field function relationship between the composite dielectric conductivity, electric field strength value, and current density, and through the historical electric field distribution data, determine the electric displacement function relationship between the relative permittivity, electric field strength value, and electric displacement vector. Thus, construct the electric field influence simulation function according to the electric field function relationship and the electric displacement function relationship.

[0084] 204. Determine a plurality of to-be-evaluated compaction coefficients in units of a preset step size within a preset compaction coefficient range, and based on the electric field influence simulation function and the electric potential boundary conditions, determine the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each to-be-evaluated compaction coefficient, and the position information corresponding to the maximum electric field strength value.

[0085] For the embodiments of the present invention, a plurality of pressing coefficients to be evaluated are selected within a preset pressing coefficient range. After that, based on the plurality of pressing coefficients to be evaluated, different working conditions need to be determined. Based on this, the method includes: determining the initial gap and contact area between the polypropylene film layer and the aluminum foil electrode layer, and obtaining the film material properties of the polypropylene film and the electrode material properties of the aluminum foil electrode; based on each of the pressing coefficients to be evaluated, the initial gap, the contact area, the film material properties, and the electrode material properties, determining the interlayer gap to be adjusted between the polypropylene film layer and the aluminum foil electrode layer corresponding to each of the pressing coefficients to be evaluated; based on each of the interlayer gaps to be adjusted, sequentially adjusting the interlayer gap between the polypropylene film layer and the aluminum foil electrode layer to obtain the working conditions corresponding to each of the pressing coefficients to be evaluated.

[0086] Among them, the film material properties include the film thickness and elastic modulus of the polypropylene film; the electrode material properties include the electrode thickness and elastic modulus of the aluminum foil electrode. Specifically, the interlayer gap d to be adjusted is determined according to the following formula:

[0087]

[0088] Among them, d0 is the initial gap, K is the pressing coefficient, t p is the film thickness of the polypropylene film, t a is the electrode thickness of the aluminum foil electrode, E p is the elastic modulus of the polypropylene film, E a is the elastic modulus of the aluminum foil electrode, and A is the contact area. Thus, according to the above formula, the interlayer gap d to be adjusted under different pressing coefficients can be calculated. After that, based on each interlayer gap to be adjusted, the interlayer gap between the polypropylene film layer and the aluminum foil electrode layer is adjusted to obtain the working conditions corresponding to each pressing coefficient to be evaluated.

[0089] Furthermore, it is necessary to determine the maximum electric field strength value and its corresponding position information of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each compression coefficient to be evaluated. Based on this, step 204 specifically includes: dividing the three-dimensional simulation model into multiple discrete grid cells, and based on Gauss's law, transforming the electric field influence simulation function corresponding to the three-dimensional simulation model into a continuous partial differential simulation function, and discretizing the continuous partial differential simulation function into a unit function corresponding to each grid cell based on a preset finite element algorithm; determining the relative permittivity of the composite dielectric based on the relative permittivities of the polypropylene film, the benzyltoluene insulating oil, and the aluminum foil electrode respectively, and determining the conductivity of the composite dielectric based on the conductivities of the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode respectively; determining the current density under the working conditions corresponding to each compression coefficient to be evaluated based on the potential boundary conditions, and substituting each current density, the conductivity of the composite dielectric, and the relative permittivity of the composite dielectric into the function group composed of each unit function for electric field strength calculation, obtaining the electric field strength values on each grid cell under each working condition, determining the maximum electric field strength value among the electric field strength values on each grid cell as the maximum electric field strength value under each working condition, and determining the position where the grid cell corresponding to the maximum electric field strength value is located as the position information corresponding to the maximum electric field strength value.

[0090] Specifically, the three-dimensional simulation model is divided into multiple discrete grid cells in the form of hexahedrons or tetrahedrons, etc. Then, the electric field influence simulation function: J c =σE, D = ε o ε r E is transformed into a continuous partial differential simulation function (where J c is the current density, σ is the conductivity of the composite dielectric, E is the electric field strength, D is the electric displacement vector, ε o is the vacuum permittivity, ε r is the relative permittivity of the composite dielectric). First, J c =σE is transformed. The differential form of the corresponding charge conservation law is as follows:

[0091]

[0092] where ρ is the charge density and t is the time. In the analysis of the electrostatic field, it is usually assumed that the charge distribution does not change with time. Therefore Therefore, there is the following formula:

[0093]

[0094] Substituting J c =σE into the above formula gives

[0095] Meanwhile, for D = ε o ε r E, a conversion of the partial differential simulation function is performed. Specifically, first, the definition formula of the electric displacement vector D is combined with Gauss's law. The differential form of Gauss's law is as follows:

[0096]

[0097] Substitute D = ε o ε r E into the above formula to obtain In summary, the partial differential simulation function is as follows:

[0098]

[0099] Furthermore, using the weighted residual method, the partial differential simulation function is converted into the weak form as follows:

[0100]

[0101] where ω is the weight function, φ is the electric potential, σ is the conductivity of the composite medium in the electric field of the target polypropylene roughened film capacitor, V is the voltage, ε o is the vacuum permittivity, ε r is the relative permittivity of the composite medium. Then, the linear basis function N i of the i-th grid cell is selected, and the electric potential is discretized in the following form:

[0102]

[0103] where i represents the i-th grid cell, n is the total number of grid cells, and φ i is the electric potential of the i-th grid cell. The above formula is converted into the following unit function group:

[0104] [K σ +K ε φ i =F ρ

[0105] where F ρ =∫ Ω N i ρ f dV, and N j is the linear basis function of the j-th grid cell. Then, through the current density, the voltage can be obtained. Substitute the voltage, the conductivity of the composite medium, the relative permittivity of the composite medium, and the vacuum permittivity into the above unit function group, and the electric potential φ i can be solved. Then, the electric field strength value E of each grid cell i is determined according to the following formulai :

[0106]

[0107] Among them, the linear basis function N i has a value of 1 at node i and a value of 0 at other nodes. Thus, the electric field intensity values on each grid cell i under each compression coefficient can be obtained in the above manner. For a certain compression coefficient, the maximum electric field intensity value among its corresponding electric field intensity values is determined, and the position where the grid cell corresponding to the maximum electric field intensity value is located is determined as the position information corresponding to the maximum electric field intensity value.

[0108] 205. Based on the maximum electric field intensity values under each working condition, an electric field intensity sequence is constructed, and based on the position information corresponding to the maximum electric field intensity values under each working condition, a position sequence is constructed.

[0109] Specifically, the maximum electric field intensity values and the position information are sorted in ascending order of the compression coefficient to obtain the electric field intensity sequence and the position sequence respectively.

[0110] 206. Based on the three-dimensional simulation model, the electric field intensity sequence, the position sequence, and the preset electric field intensity threshold, regional prediction is performed to obtain the electric field intensity safety region in the three-dimensional simulation model.

[0111] Among them, the preset electric field intensity threshold is a value set according to actual requirements, and the electric field intensity exceeding the preset electric field intensity threshold is the risk electric field intensity.

[0112] 207. Determine the electric field distortion coefficient corresponding to the electric field intensity safety region, and based on the electric field intensity safety region and its corresponding electric field distortion coefficient, analyze the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor.

[0113] Specifically, high electric field intensity values greater than a preset electric field intensity threshold are determined in the electric field intensity sequence, and high position information corresponding to the high electric field intensity values is determined in the position sequence. The region composed of the high position information is determined as the electric field intensity risk region. At the same time, low electric field intensity values less than or equal to the preset electric field intensity threshold are determined in the electric field intensity sequence, and low position information corresponding to the low electric field intensity values is determined in the position sequence. The region composed of the low position information is determined as the electric field intensity safe region. Since the electric field intensity safe region corresponds to electric field intensity values under multiple compaction factors, in order to select the optimal compaction factor under multiple compaction factors, it is also necessary to determine the electric field distortion coefficient corresponding to the electric field intensity safe region. Specifically, the maximum electric field intensity value in the grid cells of the electric field intensity safe region can be divided by the mean value of the electric field intensity values of each grid cell to obtain the electric field distortion coefficient corresponding to the grid cell, and thus the electric field intensity values and electric field distortion coefficients corresponding to each compaction factor can be obtained. From the simulation process of the influence of the compaction factor on the electric field of the polypropylene roughened film capacitor, it can be seen that the electric field intensity value increases with the increase of the compaction factor, but the electric field distortion coefficient decreases with the increase of the compaction factor. Through simulation, the relationship between the electric field distortion coefficient and the electric field intensity can be balanced, so as to select the optimal compaction factor and provide a quantitative basis for capacitor design. For example, when the compaction factor is 0.7, the maximum electric field intensity value is 172.41 MV / m, and the electric field distortion coefficient is 3.75; when the compaction factor is 0.75, the maximum electric field intensity value is 177.76 MV / m, and the electric field distortion coefficient is 3.51; when the compaction factor is 0.8, the maximum electric field intensity value is 173.40 MV / m, and the electric field distortion coefficient is 3.41. Through simulation, the relationship between the two can be balanced, and the compaction factor 0.75 is preferably selected as the balance point to provide a quantitative basis for capacitor design. It can be seen from the embodiments of the present invention that the electric field intensity value will cause defects such as electric field breakdown phenomenon and enhanced radiation, the electric field distortion coefficient will affect the aging of the electric field and the performance of the equipment, and the compaction factor affects the electric field intensity and the electric field distortion coefficient. In summary, the influence of the compaction factor on the electric field can be known, that is, too large or too small compaction factor will have an adverse impact on the electric field. It is necessary to balance the electric field intensity value and the electric field distortion coefficient and select the compaction factor preferably.

[0114] Another simulation method for the influence of the compaction factor on the electric field of a polypropylene roughened film capacitor provided by the present invention. Compared with the current method of repeatedly manufacturing physical samples of polypropylene roughened film capacitors for experiments and determining the influence of the compaction factor on the electric field distribution according to the experimental results, the present invention constructs a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor, sets parameters such as relative permittivity, conductivity, film thickness, and roughness for the three-dimensional simulation model, sets the electric potential boundary conditions for the set three-dimensional simulation model, and under the electric potential boundary conditions, based on the electric field influence simulation function, determines the maximum electric field strength value and its corresponding position of the electric field of the target polypropylene roughened film capacitor under different compaction factors, and analyzes the influence of the compaction factor on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field strength value and its corresponding position. Thus, by constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor and performing simulation analysis on the working conditions corresponding to different compaction factors, and determining the influence of the compaction factor on the electric field according to the simulation analysis results, it is possible to reduce the cost and time required for manufacturing physical samples, so that the present invention can improve the analysis efficiency of the influence of the compaction factor on the electric field and save the analysis cost.

[0115] Further, as Figure 1 a specific implementation of Figure 13 shown, the device includes: a construction unit 31, a setting unit 32, a first determination unit 33, a second determination unit 34, and an analysis unit 35.

[0116] The construction unit 31 can be used to construct a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor by using a preset simulation software, wherein the three-dimensional simulation model includes alternately stacked polypropylene film layers, a dielectric layer of benzyl toluene insulating oil, and aluminum foil electrode layers provided at both ends of the polypropylene film layers.

[0117] The setting unit 32 can be used to add a current physical field to the three-dimensional simulation model, and respectively set the relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and set global parameters in the three-dimensional simulation model, wherein the global parameters include the film thickness, roughness, and initial compaction factor of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyl toluene insulating oil.

[0118] The first determination unit 33 can be used to set the electric potential boundary conditions for the set three-dimensional simulation model and determine the electric field influence simulation function.

[0119] The second determination unit 34 can be used to determine multiple to-be-evaluated compression coefficients in units of a preset step within a preset compression coefficient range, and based on the electric field influence simulation function and the electric potential boundary condition, determine the maximum electric field intensity value of the electric field of the target polypropylene roughened film capacitor under the working condition corresponding to each to-be-evaluated compression coefficient, and the position information corresponding to the maximum electric field intensity value.

[0120] The analysis unit 35 can be used to analyze the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field intensity value under each working condition and its corresponding position information.

[0121] In a specific application scenario, in order to perform hemming treatment on the aluminum foil electrode, the device further includes a hemming unit 36.

[0122] The hemming unit 36 can be used to determine the hemming length, hemming chamfer radius, and total electrode length of the aluminum foil electrode, and perform hemming treatment on the aluminum foil electrode based on the hemming length, the hemming chamfer radius, and the total electrode length.

[0123] In a specific application scenario, in order to set the relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model respectively, the setting unit 32 can specifically be used to set the relative permittivity with a first preset dielectric value and the conductivity with a first conductivity value for the polypropylene film; set the relative permittivity with a second preset dielectric value and the conductivity with a second conductivity value for the benzyl toluene insulating oil; set the relative permittivity with a third preset dielectric value and the conductivity with a third conductivity value for the aluminum foil electrode.

[0124] In a specific application scenario, the electric field influence simulation function is: J c = σE, D = ε o ε r εE, where J c is the current density of the electric field of the target polypropylene roughened film capacitor, σ is the conductivity of the composite medium in the electric field of the target polypropylene roughened film capacitor, E is the electric field intensity of the electric field of the target polypropylene roughened film capacitor, D is the electric displacement vector of the electric field of the target polypropylene roughened film capacitor, ε o is the vacuum permittivity, and ε r is the relative permittivity of the composite medium.

[0125] In a specific application scenario, in order to determine the maximum electric field intensity value and its corresponding position information, the second determination unit 34 includes a division module 341 and a determination module 342.

[0126] The partitioning module 341 can be used to partition the three-dimensional simulation model into multiple discrete grid cells, and based on Gauss's law, transform the electric field influence simulation function corresponding to the three-dimensional simulation model into a continuous partial differential simulation function, and discretize the continuous partial differential simulation function into a cell function corresponding to each grid cell based on a preset finite element algorithm.

[0127] The determination module 342 can be used to determine the relative permittivity of the composite dielectric based on the relative permittivities of the polypropylene film, the benzyltoluene insulating oil, and the aluminum foil electrode respectively, and determine the conductivity of the composite dielectric based on the conductivities of the polypropylene film, the benzyltoluene insulating oil, and the aluminum foil electrode respectively.

[0128] The determination module 342 can specifically be used to determine the current density under the working conditions corresponding to each to-be-evaluated compression coefficient based on the potential boundary conditions, and substitute each current density, the conductivity of the composite dielectric, and the relative permittivity of the composite dielectric into the function group composed of each cell function for calculating the electric field strength, so as to obtain the electric field strength values on each grid cell under each working condition, determine the maximum electric field strength value among the electric field strength values on each grid cell as the maximum electric field strength value under each working condition, and determine the position where the grid cell corresponding to the maximum electric field strength value is located as the position information corresponding to the maximum electric field strength value.

[0129] In a specific application scenario, in order to determine the working conditions corresponding to each to-be-evaluated compression coefficient, the first determination unit 33 can also be used to determine the initial gap and contact area between the polypropylene film layer and the aluminum foil electrode layer, and obtain the film material properties of the polypropylene film and the electrode material properties of the aluminum foil electrode; based on each to-be-evaluated compression coefficient, the initial gap, the contact area, the film material properties, and the electrode material properties, determine the to-be-adjusted interlayer gap between the polypropylene film layer and the aluminum foil electrode layer corresponding to each to-be-evaluated compression coefficient; based on each to-be-adjusted interlayer gap, sequentially adjust the interlayer gap between the polypropylene film layer and the aluminum foil electrode layer to obtain the working conditions corresponding to each to-be-evaluated compression coefficient.

[0130] In a specific application scenario, in order to analyze the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor, the analysis unit 35 includes a construction module 351, a prediction module 352, and an analysis module 353.

[0131] The construction module 351 can be used to construct an electric field strength sequence based on the maximum electric field strength value under each working condition, and construct a position sequence based on the position information corresponding to the maximum electric field strength value under each working condition.

[0132] The prediction module 352 can be used to perform area prediction based on the three-dimensional simulation model, the electric field intensity sequence, the position sequence, and a preset electric field intensity threshold to obtain an electric field intensity safe area in the three-dimensional simulation model.

[0133] The analysis module 353 can be used to determine an electric field distortion coefficient corresponding to the electric field intensity safe area, and analyze the influence of the pressing coefficient on the electric field of the target polypropylene roughened film capacitor based on the electric field intensity safe area and its corresponding electric field distortion coefficient.

[0134] It should be noted that for other corresponding descriptions of each functional module involved in the simulation device for the influence of the pressing coefficient on the electric field of the polypropylene roughened film capacitor provided in the embodiments of the present invention, reference can be made to Figure 1 the corresponding description of the method shown, which will not be elaborated here.

[0135] Based on the above as Figure 1 shown in the method, correspondingly, the embodiments of the present invention further provide a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the following steps are implemented: constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor by using a preset simulation software, where the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyltoluene insulating oil, and aluminum foil electrode layers provided at both ends of the polypropylene film layers; adding a current physical field to the three-dimensional simulation model, and respectively setting relative permittivity and conductivity for the polypropylene film, benzyltoluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and setting global parameters in the three-dimensional simulation model, where the global parameters include the film thickness, roughness, and initial pressing coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyltoluene insulating oil; setting a potential boundary condition for the set three-dimensional simulation model, and determining an electric field influence simulation function; determining a plurality of pressing coefficients to be evaluated in units of a preset step size within a preset pressing coefficient range, and based on the electric field influence simulation function and the potential boundary condition, determining the maximum electric field intensity value of the electric field of the target polypropylene roughened film capacitor under the working condition corresponding to each pressing coefficient to be evaluated, and the position information corresponding to the maximum electric field intensity value; analyzing the influence of the pressing coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field intensity value under each working condition and its corresponding position information.

[0136] Based on the above as Figure 1 shown in the method and as Figure 13 shown in the embodiment of the device, the embodiments of the present invention further provide an entity structure diagram of a computer device, as Figure 14As shown in the figure, the computer device includes: a processor 41, a memory 42, and a computer program stored on the memory 42 and executable on the processor. Both the memory 42 and the processor 41 are arranged on a bus 43. When the processor 41 executes the program, the following steps are implemented: constructing a three-dimensional simulation model of the winding structure of a target polypropylene roughened film capacitor by using a preset simulation software, where the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyl toluene insulating oil, and aluminum foil electrode layers arranged at both ends of the polypropylene film layers; adding a current physical field to the three-dimensional simulation model, and respectively setting relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrodes in the three-dimensional simulation model, and setting global parameters in the three-dimensional simulation model, where the global parameters include the film thickness, roughness, and initial compaction coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyl toluene insulating oil; setting potential boundary conditions for the set three-dimensional simulation model, and determining an electric field influence simulation function; determining a plurality of compaction coefficients to be evaluated in units of a preset step size within a preset compaction coefficient range, and based on the electric field influence simulation function and the potential boundary conditions, determining the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each compaction coefficient to be evaluated, and the position information corresponding to the maximum electric field strength value; based on the maximum electric field strength value and its corresponding position information under each working condition, analyzing the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor.

[0137] Through the technical solution of the present invention, compared with the way of repeatedly making physical samples of polypropylene roughened film capacitors for experiments and determining the influence of the compaction coefficient on the electric field distribution according to the experimental results, the present invention constructs a three-dimensional simulation model of the winding structure of a target polypropylene roughened film capacitor, sets parameters such as relative permittivity, conductivity, film thickness, and roughness for the three-dimensional simulation model, sets potential boundary conditions for the set three-dimensional simulation model, and under the potential boundary conditions, based on the electric field influence simulation function, determines the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor and its corresponding position under different compaction coefficients, and based on the maximum electric field strength value and its corresponding position, analyzes the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor. Thus, by constructing a three-dimensional simulation model of the winding structure of a target polypropylene roughened film capacitor and performing simulation analysis on the working conditions corresponding to different compaction coefficients, and determining the influence of the compaction coefficient on the electric field according to the simulation analysis results, it is possible to reduce the cost and time required for making physical samples, so that the present invention can improve the analysis efficiency of the influence of the compaction coefficient on the electric field and save the analysis cost.

[0138] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a sequence different from here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. In this way, the present invention is not limited to any specific combination of hardware and software.

[0139] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A simulation method for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor, characterized in that, Including: Construct a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor by using a preset simulation software, wherein the three-dimensional simulation model includes alternately stacked polypropylene film layers, dielectric layers of benzyl toluene insulating oil, and aluminum foil electrode layers arranged at both ends of the polypropylene film layers; Add a current physical field to the three-dimensional simulation model, and respectively set relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and set global parameters in the three-dimensional simulation model, wherein the global parameters include the film thickness, roughness, and initial compaction coefficient of the polypropylene film, and the composite dielectric structure parameters of the polypropylene film and benzyl toluene insulating oil; Set the electric potential boundary conditions for the set three-dimensional simulation model, and determine the electric field influence simulation function; Determine a plurality of to-be-evaluated compaction coefficients in units of a preset step within a preset compaction coefficient range, and based on the electric field influence simulation function and the electric potential boundary conditions, determine the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each to-be-evaluated compaction coefficient, and the position information corresponding to the maximum electric field strength value; Analyze the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field strength value and its corresponding position information under each working condition.

2. The method according to claim 1, wherein The method further includes: Determine the hemming length, hemming chamfer radius, and total electrode length of the aluminum foil electrode, and perform hemming treatment on the aluminum foil electrode based on the hemming length, the hemming chamfer radius, and the total electrode length.

3. The method according to claim 1, wherein The step of respectively setting relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model includes: Set a relative permittivity with a first preset dielectric value and a conductivity with a first conductivity value for the polypropylene film; Set a relative permittivity with a second preset dielectric value and a conductivity with a second conductivity value for the benzyl toluene insulating oil; Set a relative permittivity with a third preset dielectric value and a conductivity with a third conductivity value for the aluminum foil electrode.

4. The method according to claim 1, characterized in that, The electric field influence simulation function is: J c = σE, D = ε o ε r E, where J c is the current density of the electric field of the target polypropylene roughened film capacitor, σ is the conductivity of the composite medium in the electric field of the target polypropylene roughened film capacitor, E is the electric field strength of the electric field of the target polypropylene roughened film capacitor, D is the electric displacement vector of the electric field of the target polypropylene roughened film capacitor, and ε o is the vacuum permittivity, and ε r is the relative permittivity of the composite medium.

5. The method according to claim 4, wherein The step of determining the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each to-be-evaluated compaction coefficient and the position information corresponding to the maximum electric field strength value based on the electric field influence simulation function and the electric potential boundary conditions includes: Divide the three-dimensional simulation model into a plurality of discrete grid cells, and based on Gauss's law, transform the electric field influence simulation function corresponding to the three-dimensional simulation model into a continuous partial differential simulation function, and discretize the continuous partial differential simulation function into a unit function corresponding to each grid cell based on a preset finite element algorithm; Determine the relative permittivity of the composite dielectric based on the relative permittivities corresponding to the polypropylene film, the benzyl toluene insulating oil, and the aluminum foil electrode respectively, and determine the conductivity of the composite dielectric based on the conductivities corresponding to the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode respectively; Based on the potential boundary conditions, determine the current density under the working conditions corresponding to each of the to-be-evaluated compaction coefficients, and respectively substitute each of the current densities, the composite medium conductivity, and the relative permittivity of the composite medium into the function group composed of each of the unit functions to calculate the electric field strength, so as to obtain the electric field strength values on each of the grid cells under each of the working conditions. Determine the maximum electric field strength value under each of the working conditions as the maximum electric field strength value under each of the working conditions, and determine the position where the grid cell corresponding to the maximum electric field strength value is located as the position information corresponding to the maximum electric field strength value.

6. The method according to claim 1, characterized in that Before determining the maximum electric field strength value of the electric field of the target polypropylene roughened film capacitor under the working conditions corresponding to each of the to-be-evaluated compaction coefficients, the method further includes: Determine the initial gap and contact area between the polypropylene film layer and the aluminum foil electrode layer, and obtain the film material properties of the polypropylene film and the electrode material properties of the aluminum foil electrode; Based on each of the to-be-evaluated compaction coefficients, the initial gap, the contact area, the film material properties, and the electrode material properties, determine the to-be-adjusted interlayer gap between the polypropylene film layer and the aluminum foil electrode layer corresponding to each of the to-be-evaluated compaction coefficients; Based on each of the to-be-adjusted interlayer gaps, sequentially adjust the interlayer gap between the polypropylene film layer and the aluminum foil electrode layer to obtain the working conditions corresponding to each of the to-be-evaluated compaction coefficients.

7. The method according to claim 1, wherein The analyzing the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field strength value under each of the working conditions and its corresponding position information includes: Based on the maximum electric field strength value under each of the working conditions, construct an electric field strength sequence, and based on the position information corresponding to the maximum electric field strength value under each of the working conditions, construct a position sequence; Based on the three-dimensional simulation model, the electric field strength sequence, the position sequence, and a preset electric field strength threshold, perform region prediction to obtain the electric field strength safe region in the three-dimensional simulation model; Determine the electric field distortion coefficient corresponding to the electric field strength safe region, and based on the electric field strength safe region and its corresponding electric field distortion coefficient, analyze the influence of the compaction coefficient on the electric field of the target polypropylene roughened film capacitor.

8. A simulation device for the influence of the pressing coefficient on the electric field of a polypropylene roughened film capacitor, characterized in that, including: A construction unit for constructing a three-dimensional simulation model of the winding structure of the target polypropylene roughened film capacitor by using a preset simulation software, wherein the three-dimensional simulation model includes an alternately stacked polypropylene film layer, a dielectric layer of benzyl toluene insulating oil, and aluminum foil electrode layers provided at both ends of the polypropylene film layer; A setting unit for adding a current physical field to the three-dimensional simulation model, and respectively setting the relative permittivity and conductivity for the polypropylene film, benzyl toluene insulating oil, and aluminum foil electrode in the three-dimensional simulation model, and setting global parameters in the three-dimensional simulation model, wherein the global parameters include the film thickness, roughness, and initial compaction coefficient of the polypropylene film, and the composite medium structure parameters of the polypropylene film and benzyl toluene insulating oil; The first determination unit is configured to set an electric potential boundary condition for the set three-dimensional simulation model and determine an electric field influence simulation function; The second determination unit is configured to determine a plurality of compression coefficients to be evaluated in units of a preset step within a preset compression coefficient range, and based on the electric field influence simulation function and the electric potential boundary condition, determine the maximum electric field intensity value of the electric field of the target polypropylene roughened film capacitor under the working condition corresponding to each compression coefficient to be evaluated, and the position information corresponding to the maximum electric field intensity value; The analysis unit is configured to analyze the influence of the compression coefficient on the electric field of the target polypropylene roughened film capacitor based on the maximum electric field intensity value under each working condition and its corresponding position information.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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