Optimization method for electric field homogenization of internal insulation components of primary and secondary integrated ring network gas box

Abstract

This invention discloses a method for optimizing the electric field homogenization of internal insulating components in a primary and secondary integrated ring main unit (RMU) gas tank. It relates to the field of electric field optimization technology for high-voltage switchgear. The method involves establishing a three-dimensional model containing all insulating components and independently labeling the surface and internal dielectric properties of each component to accurately characterize the material interface. Then, the actual pressure and composition ratio of the insulating gas are set, and rated voltage and various transient overvoltage excitations are applied to calculate the electric field. Based on the obtained electric field distribution cloud map, high-field-strength regions and their associated specific insulating components and locations can be accurately located, and optimization schemes such as geometric shape adjustment or dielectric constant gradient adjustment can be matched to these locations. This method, through refined modeling of component properties and composite simulation of actual operating conditions, achieves accurate identification and targeted optimization of insulation weaknesses, improving the insulation reliability of the equipment in real-world operating environments.

Description

Technical Field

[0001] This invention belongs to the field of electric field optimization technology for high-voltage switchgear, specifically a method for optimizing the electric field uniformity of internal insulating components of a primary and secondary integrated ring network gas box. Background Technology

[0002] In the design and reliability improvement of gas-insulated ring main units, the simulation analysis and optimization of the internal electric field are crucial. Existing technologies typically use 3D electric field simulation software to establish the geometric model of the equipment and assign a single dielectric constant to the insulating components to simulate their electrical characteristics. This conventional approach, when simplifying the model, often treats the insulating components as a homogeneous whole, equating their surface condition with the internal material. When setting simulation conditions, the rated power frequency voltage is generally used as the primary excitation, and the internal insulating gas is assumed to be an ideal, homogeneous medium with fixed parameters.

[0003] These existing technical solutions have shortcomings. Simplifying insulating components as a homogeneous medium fails to reflect the coatings, contaminant accumulation, micro-roughness, and delamination interfaces that may exist on the actual component surface, as well as within composite materials. This results in simulation calculations failing to accurately capture the initiation and development of surface creepage or interface breakdown, and the identified areas of concentrated electric field may deviate from actual risk points. Furthermore, steady-state analysis based solely on rated voltage ignores the transient overvoltage impacts such as lightning strikes and operational surges that the equipment inevitably experiences during actual operation, and does not consider the nonlinear characteristics of insulation strength caused by changes in the mixing ratio and pressure of the insulating gas. Therefore, optimized designs based on conventional simulations may not guarantee the insulation safety margin of the equipment under complex and harsh real-world operating conditions.

[0004] There is a need for an optimization method that can more accurately simulate the real physical state of insulating components and perform electric field assessments in varied real electrical and gas environments to guide the design of insulating structures with high reliability under all operating conditions. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art;

[0006] Therefore, this invention proposes a method for optimizing the electric field uniformity of internal insulating components of a primary and secondary integrated ring network gas box, including:

[0007] A three-dimensional geometric model of the primary and secondary integrated ring network box gas box and all its internal insulating components is established, and the surface and internal dielectric material properties of each insulating component are labeled in the three-dimensional geometric model;

[0008] The pressure value and composition ratio of the insulating gas inside the gas box are set for the three-dimensional geometric model, and corresponding potential excitations are applied to the high-voltage conductor and the grounding shell. The potential excitations include the rated operating voltage and various transient overvoltage waveforms.

[0009] Based on the three-dimensional geometric model, the dielectric material properties of the insulating components, the pressure value and composition ratio of the insulating gas, and the potential excitation, the initial electric field distribution calculation is performed to obtain the initial electric field intensity spatial distribution cloud map;

[0010] Extract local regions where the electric field intensity is greater than a preset intensity threshold from the initial electric field intensity spatial distribution cloud map, and identify the insulating components associated with the local regions and their specific locations on the insulating components;

[0011] Based on the associated insulating components and their material properties, one or more electric field optimization schemes are matched for the specific location. The electric field optimization schemes include geometric shape adjustment schemes and dielectric constant gradient adjustment schemes.

[0012] Further, the step of extracting local regions with electric field strength greater than a preset intensity threshold from the initial electric field strength spatial distribution cloud map, and identifying the insulating components associated with the local regions and their specific locations on the insulating components, includes:

[0013] A three-dimensional spatial grid is traversed on the initial electric field intensity spatial distribution cloud map to mark all grid nodes whose electric field intensity exceeds the preset intensity threshold;

[0014] The nodes that exceed the preset intensity threshold are clustered according to the three-dimensional spatial connectivity to form several independent electric field intensity exceeding clusters;

[0015] For each cluster of electric field strength exceeding the standard, retrieve which insulating components' surfaces or volumes intersect with its spatial boundary, and determine the intersecting insulating components as the associated insulating components;

[0016] Calculate the geometric center coordinates of the cluster of electric field strength exceeding the standard, and calculate the projected coordinates of the center coordinates in the local coordinate system of the associated insulating component. The projected coordinates are the specific locations of the electric field strength exceeding the standard on the insulating component.

[0017] Record the peak electric field intensity, the associated insulating component identifier, and the specific location of each cluster of electric field intensity exceeding the standard to form a list of electric field optimization targets.

[0018] Further, based on the associated insulating components and their material properties, one or more sets of electric field optimization schemes are matched for the specific location. These electric field optimization schemes include geometric shape adjustment schemes and dielectric constant gradient adjustment schemes, including:

[0019] Query the type and original geometric parameters of the associated insulating components, including pot insulators, support insulators, bushings, and isolation contact covers;

[0020] If the associated insulating component is of the type that can be curved, the geometry adjustment scheme is triggered; the geometry adjustment scheme includes at least: adding insulating material at the specific location to form a smooth protrusion with an increased radius of curvature, cutting insulating material around the specific location to form a guide groove, and replacing sharp edges with rounded transition surfaces of a specified radius;

[0021] If the associated insulating component allows the use of composite materials or functionally graded materials, the dielectric constant gradient adjustment scheme is triggered; the dielectric constant gradient adjustment scheme includes at least: planning a continuous dielectric constant variation path from the inside to the surface or along a specific direction centered on the specific location, the continuous dielectric constant variation path requiring the dielectric constant of the material to smoothly transition from high to low or from low to high;

[0022] For each item in the list of electric field optimization objectives, combine its feasible geometry adjustment scheme with the dielectric constant gradient adjustment scheme to form one or more sets of electric field optimization schemes for the item.

[0023] Furthermore, it also includes:

[0024] The three-dimensional geometric model is modified by applying each of the electric field optimization schemes to form multiple modified three-dimensional geometric models of the gas box.

[0025] For each of the modified three-dimensional geometric models of the gas box, the electric field distribution calculation is re-executed to generate the corresponding optimized spatial distribution cloud map of the electric field intensity.

[0026] Compare all the optimized electric field intensity spatial distribution cloud maps with the initial electric field intensity spatial distribution cloud map, and calculate the electric field non-uniformity coefficient and the maximum field strength decrease of each optimized model;

[0027] Based on the electric field non-uniformity coefficient and the maximum field strength decrease, and considering the feasibility of fabricating the insulating components, the final design scheme is selected from all the optimization models.

[0028] Based on the final design scheme, generate three-dimensional design drawings and material process specifications to guide the manufacturing of insulating components.

[0029] Furthermore, the modification of the three-dimensional geometric model by applying each set of electric field optimization schemes to form multiple modified three-dimensional geometric models of the gas box includes:

[0030] Read all the electric field optimization schemes for an entry in the electric field optimization target list;

[0031] For the electric field optimization scheme that includes the geometric shape adjustment scheme, the three-dimensional modeling engine is invoked to locate the specific position in the original three-dimensional geometric model. Based on the curvature radius, guide groove size or fillet radius parameters defined in the scheme, the geometric shape of the associated insulating component is directly modified while keeping its assembly relationship with other components in the gas box unchanged.

[0032] For the electric field optimization scheme that includes the dielectric constant gradient adjustment scheme, in the original three-dimensional geometric model, the material property distribution function is redefined for the associated insulating component; the material property distribution function assigns a calculated dielectric constant value to each three-dimensional voxel unit of the insulating component according to the continuous change path of the dielectric constant.

[0033] For electric field optimization schemes that include both schemes, the operations of geometric shape modification and material property distribution function redefinition are performed sequentially.

[0034] After completing the one-time modification of the model for all electric field optimization schemes of the current entry, save it as an independent three-dimensional geometric model of the modified gas box, and establish a mapping relationship between it and the applied electric field optimization scheme;

[0035] Following this process, all items and their combinations in the electric field optimization target list are traversed to generate multiple modified three-dimensional geometric models of the gas box.

[0036] Further, the step of recalculating the electric field distribution for each of the modified three-dimensional geometric models of the gas box to generate a corresponding optimized spatial distribution cloud map of the electric field intensity includes:

[0037] For each of the modified three-dimensional geometric models of the gas box, load the same potential excitation, pressure value of the insulating gas and component ratio parameters as in the initial calculation;

[0038] For insulating components in the model whose geometry has only been modified, their dielectric material properties remain at the initial constant values.

[0039] For insulating components in the model where the material property distribution function has been redefined, the dielectric constant values ​​of each voxel element calculated by the material property distribution function are input into the material parameter library of the electric field solver.

[0040] The electric field numerical solution of the modified three-dimensional geometric model of the gas box is performed using the same finite element or boundary element algorithm and mesh generation strategy as the initial electric field distribution calculation.

[0041] Extract the electric field intensity vector of all nodes or elements in the entire computational domain from the numerical solution results and map it onto the three-dimensional space mesh;

[0042] Based on the mapped data, a visualization image of the electric field intensity distribution across the entire gas box is generated, namely the optimized electric field intensity spatial distribution cloud map.

[0043] Further, the step of comparing all the optimized electric field intensity spatial distribution cloud maps with the initial electric field intensity spatial distribution cloud map, and calculating the electric field non-uniformity coefficient and the maximum field strength decrease of each optimized model, includes:

[0044] Extract the global maximum electric field intensity value from the initial electric field intensity spatial distribution cloud map, and calculate its ratio with the global average electric field intensity value as the reference electric field non-uniformity coefficient;

[0045] From each of the optimized electric field intensity spatial distribution cloud maps, the global maximum electric field intensity value and the global average electric field intensity value are extracted, and their ratio is calculated as the electric field non-uniformity coefficient of the optimized model.

[0046] Calculate the reduction in the global maximum electric field intensity value of the optimized electric field intensity spatial distribution cloud map relative to the global maximum electric field intensity value of the initial electric field intensity spatial distribution cloud map;

[0047] Divide the reduction by the global maximum electric field strength value of the initial electric field strength spatial distribution cloud map to obtain the percentage decrease in the maximum field strength.

[0048] For each modified three-dimensional geometric model of the gas box, record its corresponding electric field non-uniformity coefficient, maximum field strength decrease, and description of the applied electric field optimization scheme.

[0049] Furthermore, it also includes a step of multiphysics coupling verification after selecting the final design scheme:

[0050] Based on the modified three-dimensional geometric model of the air box corresponding to the final design scheme, a coupled simulation calculation model including electric field, thermal field and mechanical stress field is established;

[0051] In the coupled simulation calculation model, a rated current is applied to generate conductor loss heat, while the rated operating voltage in the potential excitation is applied simultaneously;

[0052] Calculate the temperature field distribution inside the insulating component under electrothermal coupling, and update the temperature-dependent dielectric constant and conductivity parameters of the insulating material based on the temperature field distribution;

[0053] Using the updated material parameters, the electric field distribution inside the gas box was recalculated to obtain the steady-state electric field distribution under electrothermal coupling.

[0054] Analyze whether the electric field intensity on the surface of the insulating component still meets the preset uniformity design target in the steady-state electric field distribution under the electrothermal coupling effect.

[0055] Simultaneously, the thermal stress caused by the temperature gradient and the Maxwell stress caused by the electric field force are calculated and superimposed to obtain the comprehensive stress distribution within the insulating component;

[0056] Verify whether the comprehensive stress distribution is within the allowable stress range of the insulating material, and complete the multi-physics coupling verification.

[0057] Furthermore, the calculation of the temperature field distribution inside the insulating component under electrothermal coupling, and the updating of the temperature-dependent dielectric constant and conductivity parameters of the insulating material based on the temperature field distribution, includes:

[0058] Based on the formulas for conductor loss and insulating dielectric loss, the power distribution of each heat source in the coupled simulation calculation model is calculated.

[0059] Set the convection heat dissipation boundary conditions for the outer shell of the gas box and the thermal conduction and convection properties of the internal insulating gas;

[0060] By solving the heat conduction and heat convection equations, the temperature field distribution of all insulating components inside the gas box under stable operating conditions is obtained;

[0061] The pre-defined functions of the dielectric constant and conductivity of the insulating material with temperature are given.

[0062] Read the steady-state temperature value of each calculation unit in the insulating component, and calculate the updated dielectric constant and conductivity of each calculation unit according to the functional relationship.

[0063] Replace the original material parameters of the corresponding insulating component unit in the coupled simulation model with the calculated updated dielectric constant and conductivity.

[0064] Furthermore, it also includes a parameter fine-tuning step for the electric field optimization scheme based on process feedback:

[0065] After prototyping the insulating component sample according to the three-dimensional design drawings and material process specifications, the insulating component sample is three-dimensionally scanned to obtain its actual manufacturing geometry.

[0066] By comparing the actual manufacturing geometry with the theoretical geometry of the final design, areas where the dimensional deviation exceeds the tolerance range are identified.

[0067] The geometric data of the area where the dimensional deviation exists is updated in the modified three-dimensional geometric model of the air box corresponding to the final design scheme to form a manufacturing deviation correction model;

[0068] The electric field distribution calculation is re-performed on the manufacturing deviation correction model to evaluate the degree of influence of the dimensional deviation on electric field homogenization.

[0069] If the evaluation results indicate that the electric field strength exceeds the standard again or the uniformity deteriorates significantly, then for the area with the size deviation, the matching electric field optimization scheme is triggered again, and the model is modified and the electric field is calculated to generate a fine-tuning optimization scheme that takes into account the manufacturing process tolerance.

[0070] Compared with the prior art, the beneficial effects of the present invention are:

[0071] This approach distinguishes and independently labels the surface and internal dielectric material properties of insulating components, breaking away from the traditional modeling method that treats components as homogeneous bodies. This technical solution accurately characterizes the differences in dielectric properties between surface coatings, aging layers, contamination layers, and the bulk material, as well as the interface structure within composite materials. In electric field calculations, this model can realistically reproduce the electric field distortion within and at the interfaces of the insulating medium, enabling simulation results to accurately identify localized areas of concentrated electric field caused by poor surface conditions or interface defects. Compared to conventional methods, the identified insulation weaknesses and failure risk sources are more precise, providing a direct and reliable basis for subsequent optimization measures targeting specific locations and materials, thus improving the effectiveness and specificity of the optimization design.

[0072] The simulation model explicitly sets the pressure and specific component ratios of the insulating gas, and applies potential excitations including various transient overvoltage waveforms, extending the simulation environment from ideal steady-state conditions to multi-dimensional actual operating conditions. This technical solution fully considers the nonlinear characteristics of the insulation strength of mixed gases and the excitation differences of different overvoltage waveform spectra. Performing electric field distribution calculations under these combined conditions allows for the evaluation of the electric field response characteristics of the insulation structure under the combined effects of gas parameter fluctuations and transient high-voltage impacts. The high-field-strength regions identified reflect the most severe electrical stress conditions that the equipment may encounter during its lifespan. Optimization based on this enables the design of insulating components to directly address real, dynamic operating environments. The proposed geometric or material optimization schemes have stronger engineering practicality and operating condition adaptability, improving the insulation reliability of the equipment under complex electromagnetic transient processes and different gas states. Attached Figure Description

[0073] Figure 1 This is a step diagram of the method for optimizing the electric field uniformity of internal insulating components of the primary and secondary fusion ring network box gas box according to the present invention;

[0074] Figure 2 A flowchart for identifying areas with excessive electric field strength and the location of associated insulating components;

[0075] Figure 3 This is a flowchart illustrating the simulation iteration and scheme selection process based on the optimization scheme.

[0076] Figure 4 This is a graph showing the quantitative relationship between the relative permittivity and conductivity of insulating materials as a function of temperature.

[0077] Figure 5 This is a diagram illustrating the impact of dimensional deviations on electric field homogenization. Detailed Implementation

[0078] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0079] See Figure 1 A three-dimensional geometric model of the primary and secondary integrated ring network gas box and all its internal insulating components is established. This model must fully reflect the spatial structure and assembly relationship of the gas box shell, high-voltage conductor, grounding components, and each insulating component. The surface and internal dielectric material properties of each insulating component are labeled in the three-dimensional geometric model, specifying its material and corresponding dielectric constant. The pressure value and specific component ratio of the insulating gas inside the gas box are set for the three-dimensional geometric model. Appropriate potential excitations are applied to the high-voltage conductor and grounding shell in the model, including the rated operating voltage of the equipment and various standard transient overvoltage waveforms. Based on this three-dimensional geometric model, the dielectric material properties of the insulating components, the parameters of the insulating gas, and the applied potential excitations, an initial electric field distribution calculation is performed. The electric field is solved using the finite element method or boundary element method to obtain an initial electric field intensity spatial distribution cloud map. Local regions with electric field intensities greater than a preset threshold are extracted from the initial electric field intensity spatial distribution cloud map, and the associated insulating components and their specific locations are identified. Based on the associated insulating components and their material properties, one or more electric field optimization schemes are matched for the specific location. The electric field optimization schemes include geometric shape adjustment schemes for component shape and dielectric constant gradient adjustment schemes for material properties.

[0080] See Figure 2In one embodiment of the present invention, a three-dimensional spatial grid is traversed on the initial electric field intensity spatial distribution cloud map to mark all grid nodes whose electric field intensity exceeds a preset intensity threshold. In some embodiments, the preset intensity threshold is set based on the breakdown field strength and safety margin of the insulating material. Nodes exceeding the preset intensity threshold are clustered according to three-dimensional spatial connectivity to form several independent electric field intensity exceeding clusters. The clustering process is based on the proximity of the node spatial coordinates, grouping interconnected exceeding nodes into the same electric field intensity exceeding cluster.

[0081] In practical implementation, for each cluster of electric field intensity exceeding the standard, the spatial boundary of the cluster intersects with the surfaces or volumes of insulating components. The intersecting insulating components are then identified as associated insulating components. These insulating components include pot insulators, supporting insulators, bushings, and isolating contact covers. The geometric center coordinates of the cluster of electric field intensity exceeding the standard are calculated, and the projected coordinates of these center coordinates in the local coordinate system of the associated insulating components are also calculated. These projected coordinates represent the specific location of the electric field intensity exceeding the standard on the insulating components. The geometric center coordinates are obtained using the formula:

[0082]

[0083] in: This represents the coordinate vector of the geometric center point of the cluster where the electric field intensity exceeds the standard. This represents the total number of nodes in the cluster where the electric field strength exceeds the standard. Indicates the first The three-dimensional coordinate vectors of each node are recorded. The peak electric field intensity, associated insulation component identification, and specific location of each cluster of electric field intensity exceeding the standard are recorded to form a list of electric field optimization targets.

[0084] In practice, the types and original geometric parameters of associated insulating components are queried. These types include basin insulators, support insulators, bushings, and isolating contact covers. In some embodiments, the insulating component type information is stored in a model database. If the associated insulating component is of a type that can be curved, a geometry adjustment scheme is triggered. This scheme includes at least adding insulating material at a specific location to form a smooth protrusion with an increased radius of curvature, cutting insulating material around the specific location to form a channel, and replacing sharp edges with rounded transition surfaces of a specified radius. If the associated insulating component allows the use of composite materials or functionally graded materials, a dielectric constant gradient adjustment scheme is triggered. This scheme includes at least planning a continuously varying dielectric constant path from the interior to the surface or along a specific direction, centered on the specific location. This path requires a smooth transition of the material's dielectric constant from high to low or from low to high. For each item in the electric field optimization target list, feasible geometry adjustment schemes and dielectric constant gradient adjustment schemes are combined to form one or more sets of electric field optimization schemes for each item.

[0085] In practice, the matching process is based on the material properties and geometric characteristics of the insulating components. Optionally, for pot-type insulators, geometric shape adjustment schemes are given priority, while for support insulators, both schemes can be evaluated simultaneously. It is understood that the selection of the electric field optimization scheme depends on the manufacturing process and material science constraints of the insulating components. Optionally, parameters such as the radius of curvature of the geometric shape adjustment scheme are determined based on electric field simulation iterations. In practice, the electric field optimization target list serves as input to drive the optimization process, ensuring that each out-of-target area receives customized treatment.

[0086] See Figure 3 In one embodiment of the present invention, an implementation method for model modification, effect evaluation, and scheme selection using electric field optimization schemes is adopted. Each set of electric field optimization schemes is applied to modify the three-dimensional geometric model, resulting in multiple modified gas box three-dimensional geometric models. In some embodiments, the electric field optimization schemes are derived from the processing results of the electric field optimization target list. For each modified gas box three-dimensional geometric model, the electric field distribution calculation is re-executed to generate a corresponding optimized electric field intensity spatial distribution cloud map. The boundary conditions and solver parameters used in the re-execution of the electric field distribution calculation remain consistent with the initial calculation.

[0087] In practice, all optimized electric field intensity spatial distribution cloud maps are compared with the initial electric field intensity spatial distribution cloud maps to calculate the electric field non-uniformity coefficient and the maximum field strength reduction for each optimized model. The global maximum electric field intensity value is extracted from the initial electric field intensity spatial distribution cloud map, and its ratio to the global average electric field intensity value is calculated as the reference electric field non-uniformity coefficient. The global maximum electric field intensity value is extracted from each optimized electric field intensity spatial distribution cloud map, and its ratio to the global average electric field intensity value is calculated as the electric field non-uniformity coefficient for the optimized model. The reduction in the global maximum electric field intensity value of the optimized electric field intensity spatial distribution cloud map relative to the global maximum electric field intensity value of the initial electric field intensity spatial distribution cloud map is calculated. This reduction is divided by the global maximum electric field intensity value of the initial electric field intensity spatial distribution cloud map to obtain the percentage reduction in maximum field strength. This calculation process is quantified using the following formula:

[0088] in: This indicates the maximum decrease in field strength. This represents the global maximum electric field intensity value in the initial electric field intensity spatial distribution cloud map. This represents the global maximum electric field intensity value of the optimized electric field intensity spatial distribution cloud map. For each modified 3D geometric model of the gas tank, the corresponding electric field non-uniformity coefficient, the maximum field intensity decrease, and a description of the applied electric field optimization scheme are recorded.

[0089] In practical implementation, the final design scheme is selected from all optimized models based on the electric field non-uniformity coefficient, the maximum field strength reduction, and the fabrication feasibility of the insulating components. Fabrication feasibility involves the complexity of the geometry and the maturity of the functionally graded material preparation process. Optionally, the selection criterion is the model with the electric field non-uniformity coefficient below a preset threshold and the largest maximum field strength reduction. In some embodiments, a decision analysis weighing multiple indicators is required. Based on the final design scheme, three-dimensional design drawings and material process specifications are generated to guide the manufacturing of the insulating components. The three-dimensional design drawings include the optimized geometric dimensions and tolerances of the insulating components, and the material process specifications include the component gradient distribution requirements of the functionally graded materials.

[0090] In one embodiment of the present invention, a specific implementation method for modifying the model, recalculating the electric field distribution, and quantifying the effect using an electric field optimization scheme is described. This involves reading all electric field optimization schemes for an entry in the electric field optimization target list, which includes peak electric field strength, associated insulating component identifiers, and specific location information. For electric field optimization schemes that include geometric shape adjustment schemes, a 3D modeling engine is invoked to locate the specific position in the original 3D geometric model. Based on the curvature radius, guide channel size, or fillet radius parameters defined in the scheme, the geometric shape of the associated insulating component is directly modified while maintaining its assembly relationship with other components within the gas box.

[0091] In practical implementation, for electric field optimization schemes that include dielectric constant gradient adjustment schemes, the material property distribution function is redefined for the associated insulating components in the original 3D geometric model. The material property distribution function assigns a calculated dielectric constant value to each 3D voxel unit of the insulating component based on the continuous change path of the dielectric constant. For electric field optimization schemes that include both schemes, the geometric shape modification and material property distribution function redefinition operations are performed sequentially. In some embodiments, the geometric shape modification is completed first, followed by the definition of the material property distribution. After completing the one-time modification of the model for all electric field optimization schemes of the current item, it is saved as an independent modified gas box 3D geometric model, and a mapping relationship is established between it and the applied electric field optimization scheme. Following this process, all items and their scheme combinations in the electric field optimization target list are traversed to generate multiple modified gas box 3D geometric models.

[0092] In practice, each modified 3D geometric model of the gas chamber is loaded with the same potential excitation, insulating gas pressure value, and component ratio parameters as the initial calculation. Maintaining consistent boundary conditions is a prerequisite for effective comparison. For insulating components whose geometry has only been modified, their dielectric material properties are kept constant. For insulating components whose material property distribution function has been redefined, the dielectric constant values ​​of each voxel element calculated by the material property distribution function are input into the material parameter library of the electric field solver. The same finite element or boundary element algorithm and mesh generation strategy as the initial electric field distribution calculation are used to numerically solve the electric field of the modified 3D geometric model of the gas chamber. The electric field intensity vectors of all nodes or elements within the entire computational domain are extracted from the numerical solution results and mapped onto a 3D spatial mesh. Based on the mapped data, a visualization image of the electric field intensity distribution across the entire gas chamber is rendered, i.e., the optimized electric field intensity spatial distribution cloud map.

[0093] In practice, all optimized electric field intensity spatial distribution cloud maps are compared with the initial electric field intensity spatial distribution cloud map. The electric field non-uniformity coefficient and the maximum field strength reduction rate are calculated for each optimized model. The global maximum electric field intensity value is extracted from the initial electric field intensity spatial distribution cloud map, and its ratio to the global average electric field intensity value is calculated as the reference electric field non-uniformity coefficient. The global maximum electric field intensity value and the global average electric field intensity value are extracted from each optimized electric field intensity spatial distribution cloud map, and their ratio is calculated as the electric field non-uniformity coefficient of the optimized model. From the formula Definition, in the formula Indicates the coefficient of electric field non-uniformity. This represents the global maximum electric field strength value extracted from the cloud map. This represents the global average electric field strength value extracted from the same cloud map. The reduction in the global maximum electric field strength value of the optimized electric field strength spatial distribution cloud map relative to the global maximum electric field strength value of the initial electric field strength spatial distribution cloud map is calculated. This reduction is divided by the global maximum electric field strength value of the initial electric field strength spatial distribution cloud map to obtain the percentage decrease in maximum field strength. For each modified gas box 3D geometry model, its corresponding electric field non-uniformity coefficient, maximum field strength decrease, and a description of the applied electric field optimization scheme are recorded. In some embodiments, these records are stored in a structured tabular format for subsequent scheme selection.

[0094] In one embodiment of the present invention, for the implementation of multiphysics coupling verification after selecting the final design scheme, a coupled simulation calculation model including electric field, thermal field and mechanical stress field is established based on the modified three-dimensional geometric model of the gas box corresponding to the final design scheme. A rated current is applied in the coupled simulation calculation model to generate conductor loss heat, and a rated operating voltage in the potential excitation is applied simultaneously. In some embodiments, the rated current value is set according to the nameplate parameters of the ring main unit.

[0095] In practical implementation, the temperature field distribution inside the insulating component under electrothermal coupling is calculated, and the temperature-dependent dielectric constant and conductivity parameters of the insulating material are updated based on the temperature field distribution. The power distribution of each heat source in the coupled simulation model is calculated according to the conductor loss and insulating dielectric loss formulas. Convective heat dissipation boundary conditions of the gas box shell and the thermal conduction and convection properties of the internal insulating gas are set. The temperature field distribution of all insulating components in the gas box under stable operating conditions is obtained by solving the thermal conduction and thermal convection equations. The functional relationship between the dielectric constant and the conductivity of the insulating material and the temperature is preset. The steady-state temperature value of each calculation unit in the insulating component is read, and the updated dielectric constant and conductivity of each calculation unit are calculated according to the functional relationship. The original material parameters of the corresponding insulating component unit in the coupled simulation model are replaced with the calculated updated dielectric constant and conductivity. The update process can be carried out according to the parameter relationship shown in the table below. Refer to Table 1, which shows an example relationship of the insulating material parameters changing with temperature.

[0096] Table 1: Temperature Dependence of Insulation Material Parameters

[0097]

[0098] In practical implementation, the electric field distribution inside the gas box is recalculated using updated material parameters to obtain the steady-state electric field distribution under electrothermal coupling. Analysis is then conducted to determine whether the electric field intensity on the surface of the insulating component still meets the preset homogenization design target in the steady-state electric field distribution under electrothermal coupling. It can be understood that the preset homogenization design target is typically that the electric field intensity in all critical areas is lower than a certain percentage of the material's allowable field strength. Simultaneously, the thermal stress caused by the temperature gradient and the Maxwell stress caused by the electric field force are calculated and superimposed to obtain the comprehensive stress distribution within the insulating component. The calculation of the comprehensive stress distribution can be expressed as:

[0099]

[0100] in: Represents the combined stress tensor. This represents the thermal stress tensor caused by the temperature gradient. This represents the Maxwell stress tensor induced by the electric field. Verification of the combined stress distribution within the allowable stress range of the insulating material completes the multiphysics coupling verification. In some embodiments, the allowable stress range is given by the mechanical property data sheet of the insulating material.

[0101] See Figure 4 This is a quantitative graph showing the relationship between the relative permittivity and conductivity of an insulating material as a function of temperature. For every 20°C increase in temperature, the relative permittivity decreases by approximately 0.1, a drop of about 7.1%. This characteristic causes a shift in the electric field distribution of the insulating component with increasing temperature, and is a core parameter that must be corrected in electrothermal coupling simulations. The conductivity exhibits an exponential growth characteristic: from 20°C to 80°C, the conductivity increases from 10¹⁰... 5 The leakage current loss of the insulating material increases from the S / m level to the 10¹²S / m level, a 1000-fold increase. This means that the leakage current loss of the insulating material will increase dramatically at high temperatures, further exacerbating the temperature rise and forming a positive feedback loop of "temperature rise - increased conductivity - increased loss". At approximately 50℃, the trends of the dielectric constant fitting value and the conductivity fitting value intersect, which is a critical temperature node for the transition of the insulating material from "low-temperature insulation dominance" to "high-temperature loss dominance", and also an important threshold for the thermal design of the ring main unit.

[0102] In one embodiment of the present invention, after prototyping an insulating component sample based on 3D design drawings and material process specifications, the sample is 3D scanned to obtain its actual manufacturing geometry. The actual manufacturing geometry is compared with the theoretical geometry of the final design to identify areas where dimensional deviations exceed the tolerance range. In some embodiments, the tolerance range is explicitly defined by the part's engineering drawings.

[0103] In practice, the geometric data of areas with dimensional deviations are updated into the modified 3D geometric model of the air box corresponding to the final design, forming a manufacturing deviation correction model. This update operation involves replacing or adjusting local surfaces or voxels with dimensional deviations on the original digital geometric model. The electric field distribution calculation is then re-performed on the manufacturing deviation correction model to assess the impact of dimensional deviations on electric field homogenization. This assessment includes calculating the global maximum electric field strength of the manufacturing deviation correction model and comparing it with the expected value of the final design. If the assessment results indicate that the electric field strength exceeds the limit again or the homogenization significantly deteriorates, the matching electric field optimization scheme is re-triggered for the dimensional deviation area, and the model is modified and the electric field calculation is performed again. The re-triggered process is consistent with the initial optimization process, but the target area for optimization is limited to the identified dimensional deviation areas. A fine-tuned optimization scheme, considering manufacturing process tolerances, is generated. This fine-tuned optimization scheme serves as a supplement or correction to the original final design, guiding subsequent mass production.

[0104] In practical implementation, the impact of dimensional deviations on electric field homogenization can be evaluated using quantitative indicators, such as the degree of impact. From the formula:

[0105] in: This represents the factor that influences the maximum electric field strength due to dimensional deviation. This represents the global maximum electric field strength value calculated by the manufacturing deviation correction model. This represents the expected global maximum electric field strength calculated from the modified three-dimensional geometric model of the gas chamber corresponding to the final design scheme. In some embodiments, when the influence factor... When the threshold is exceeded, it is determined that the uniformity has significantly deteriorated and the fine-tuning optimization process needs to be initiated. When the matching electric field optimization scheme is retried, a matching geometry adjustment scheme or a dielectric constant gradient adjustment scheme is used for the new local high field strength region. It is understandable that, since manufacturing deviations are usually specific, the fine-tuning scheme may focus more on local geometric compensation.

[0106] In practice, the point cloud data acquired by 3D scanning needs to be processed and accurately compared with the theoretical CAD model. Optionally, the comparison software can automatically generate a dimensional deviation chromatogram to visually display the location and magnitude of the deviation. After the fine-tuning and optimization scheme is generated, its effectiveness also needs to be verified by electric field distribution calculation, and the 3D design drawings and material process specifications need to be updated. This step ensures the robustness of the design to manufacturing process fluctuations. Fine-tuning based on process feedback is a closed-loop process that feeds actual production data back to the design stage to iteratively improve the manufacturability and electrical reliability of the product.

[0107] See Figure 5 This is a graph analyzing the impact of dimensional deviations on electric field homogenization. When the dimensional deviation increases from 0% to 3.0%, the electric field strength influence factor rises from 1.00 to 1.54, an increase of 54%; the electric field non-uniformity coefficient changes from 1.00 to 1.52, an increase of 52%. This indicates that the manufacturing precision of insulating components is extremely sensitive to the electric field distribution; even small dimensional deviations can lead to a significant deterioration in electric field performance. The two curves almost completely overlap, indicating a high positive correlation between the electric field strength influence factor and the change in the electric field non-uniformity coefficient. This means that while dimensional deviations exacerbate local field strength, they also disrupt the uniformity of the electric field distribution; these are different manifestations of the same physical process. By quantifying the impact of dimensional deviations on electric field performance, process tolerances in some non-critical areas can be reasonably relaxed while ensuring insulation reliability, thereby reducing manufacturing costs and achieving an optimal balance between performance and cost.

[0108] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for optimizing the electric field homogenization of the internal insulation components of a secondary fuse ring network box gas tank, characterized in that, The method includes: A three-dimensional geometric model of the primary and secondary integrated ring network box gas box and all its internal insulating components is established, and the surface and internal dielectric material properties of each insulating component are labeled in the three-dimensional geometric model; The pressure value and composition ratio of the insulating gas inside the gas box are set for the three-dimensional geometric model, and corresponding potential excitations are applied to the high-voltage conductor and the grounding shell. The potential excitations include the rated operating voltage and various transient overvoltage waveforms. Based on the three-dimensional geometric model, the dielectric material properties of the insulating components, the pressure value and composition ratio of the insulating gas, and the potential excitation, the initial electric field distribution calculation is performed to obtain the initial electric field intensity spatial distribution cloud map; Extracting local regions with electric field intensities greater than a preset threshold from the initial electric field intensity spatial distribution cloud map, identifying the insulating components associated with these local regions and their specific locations on the insulating components, including: A three-dimensional spatial grid is traversed on the initial electric field intensity spatial distribution cloud map to mark all grid nodes whose electric field intensity exceeds the preset intensity threshold; Nodes exceeding the preset intensity threshold are clustered based on three-dimensional spatial connectivity to form several independent clusters with excessive electric field intensity. For each cluster of electric field strength exceeding the standard, retrieve which insulating components' surfaces or volumes intersect with its spatial boundary, and determine the intersecting insulating components as the associated insulating components; Calculate the geometric center coordinates of the cluster of electric field strength exceeding the standard, and calculate the projected coordinates of the center coordinates in the local coordinate system of the associated insulating component. The projected coordinates are the specific locations of the electric field strength exceeding the standard on the insulating component. Record the peak electric field intensity, the associated insulating component identifier, and the specific location of each cluster of electric field intensity exceeding the standard to form a list of electric field optimization targets; Based on the associated insulating components and their material properties, one or more electric field optimization schemes are matched for the specific location. The electric field optimization schemes include geometric shape adjustment schemes and dielectric constant gradient adjustment schemes.

2. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 1, characterized in that, The step involves matching one or more electric field optimization schemes to the specific location based on the associated insulating components and their material properties. These electric field optimization schemes include geometric shape adjustment schemes and dielectric constant gradient adjustment schemes. Query the type and original geometric parameters of the associated insulating components, including pot insulators, support insulators, bushings, and isolation contact covers; If the associated insulating component is of the type that can be curved, the geometry adjustment scheme is triggered; the geometry adjustment scheme includes at least: adding insulating material at the specific location to form a smooth protrusion with an increased radius of curvature, cutting insulating material around the specific location to form a guide groove, and replacing sharp edges with rounded transition surfaces of a specified radius; If the associated insulating component allows the use of composite materials or functionally graded materials, the dielectric constant gradient adjustment scheme is triggered; the dielectric constant gradient adjustment scheme includes at least: planning a continuous dielectric constant variation path from the inside to the surface or along a specific direction centered on the specific location, the continuous dielectric constant variation path requiring the dielectric constant of the material to smoothly transition from high to low or from low to high; For each item in the list of electric field optimization objectives, combine its feasible geometry adjustment scheme with the dielectric constant gradient adjustment scheme to form one or more sets of electric field optimization schemes for the item.

3. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary integrated ring network gas box according to claim 2, characterized in that, Also includes: The three-dimensional geometric model is modified by applying each of the electric field optimization schemes to form multiple modified three-dimensional geometric models of the gas box. For each of the modified three-dimensional geometric models of the gas box, the electric field distribution calculation is re-executed to generate the corresponding optimized spatial distribution cloud map of the electric field intensity. Compare all the optimized electric field intensity spatial distribution cloud maps with the initial electric field intensity spatial distribution cloud map, and calculate the electric field non-uniformity coefficient and the maximum field strength decrease of each optimized model; Based on the electric field non-uniformity coefficient and the maximum field strength decrease, and considering the feasibility of fabricating the insulating components, the final design scheme is selected from all the optimization models. Based on the final design scheme, generate three-dimensional design drawings and material process specifications to guide the manufacturing of insulating components.

4. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 3, characterized in that, The process involves applying each of the electric field optimization schemes to modify the three-dimensional geometric model, resulting in multiple modified three-dimensional geometric models of the gas box, including: Read all the electric field optimization schemes for an entry in the electric field optimization target list; For the electric field optimization scheme that includes the geometric shape adjustment scheme, the three-dimensional modeling engine is invoked to locate the specific position in the original three-dimensional geometric model. Based on the curvature radius, guide groove size or fillet radius parameters defined in the scheme, the geometric shape of the associated insulating component is directly modified while keeping its assembly relationship with other components in the gas box unchanged. For the electric field optimization scheme that includes the dielectric constant gradient adjustment scheme, in the original three-dimensional geometric model, the material property distribution function is redefined for the associated insulating component; the material property distribution function assigns a calculated dielectric constant value to each three-dimensional voxel unit of the insulating component according to the continuous change path of the dielectric constant. For electric field optimization schemes that include both schemes, the operations of geometric shape modification and material property distribution function redefinition are performed sequentially. After completing the one-time modification of the model for all electric field optimization schemes of the current entry, save it as an independent three-dimensional geometric model of the modified gas box, and establish a mapping relationship between it and the applied electric field optimization scheme; Following this process, all items and their combinations in the electric field optimization target list are traversed to generate multiple modified three-dimensional geometric models of the gas box.

5. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 4, characterized in that, The step of recalculating the electric field distribution for each of the modified three-dimensional geometric models of the gas box to generate a corresponding optimized spatial distribution cloud map of the electric field intensity includes: For each of the modified three-dimensional geometric models of the gas box, load the same potential excitation, pressure value of the insulating gas and component ratio parameters as in the initial calculation; For insulating components in the model whose geometry has only been modified, their dielectric material properties remain at the initial constant values. For insulating components in the model where the material property distribution function has been redefined, the dielectric constant values ​​of each voxel element calculated by the material property distribution function are input into the material parameter library of the electric field solver. The electric field numerical solution of the modified three-dimensional geometric model of the gas box is performed using the same finite element or boundary element algorithm and mesh generation strategy as the initial electric field distribution calculation. Extract the electric field intensity vector of all nodes or elements in the entire computational domain from the numerical solution results and map it onto the three-dimensional space mesh; Based on the mapped data, a visualization image of the electric field intensity distribution across the entire gas box is generated, namely the optimized electric field intensity spatial distribution cloud map.

6. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 5, characterized in that, The step of comparing all the optimized electric field intensity spatial distribution cloud maps with the initial electric field intensity spatial distribution cloud map, and calculating the electric field non-uniformity coefficient and the maximum field strength decrease of each optimized model, includes: Extract the global maximum electric field intensity value from the initial electric field intensity spatial distribution cloud map, and calculate its ratio with the global average electric field intensity value as the reference electric field non-uniformity coefficient; From each of the optimized electric field intensity spatial distribution cloud maps, the global maximum electric field intensity value and the global average electric field intensity value are extracted, and their ratio is calculated as the electric field non-uniformity coefficient of the optimized model. Calculate the reduction in the global maximum electric field intensity value of the optimized electric field intensity spatial distribution cloud map relative to the global maximum electric field intensity value of the initial electric field intensity spatial distribution cloud map; Divide the reduction by the global maximum electric field strength value of the initial electric field strength spatial distribution cloud map to obtain the percentage decrease in the maximum field strength. For each modified three-dimensional geometric model of the gas box, record its corresponding electric field non-uniformity coefficient, maximum field strength decrease, and description of the applied electric field optimization scheme.

7. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 6, characterized in that, It also includes a step of multiphysics coupling verification after selecting the final design scheme: Based on the modified three-dimensional geometric model of the air box corresponding to the final design scheme, a coupled simulation calculation model including electric field, thermal field and mechanical stress field is established; In the coupled simulation calculation model, a rated current is applied to generate conductor loss heat, while the rated operating voltage in the potential excitation is applied simultaneously; Calculate the temperature field distribution inside the insulating component under electrothermal coupling, and update the temperature-dependent dielectric constant and conductivity parameters of the insulating material based on the temperature field distribution; Using the updated material parameters, the electric field distribution inside the gas box was recalculated to obtain the steady-state electric field distribution under electrothermal coupling. Analyze whether the electric field intensity on the surface of the insulating component still meets the preset uniformity design target in the steady-state electric field distribution under the electrothermal coupling effect. Simultaneously, the thermal stress caused by the temperature gradient and the Maxwell stress caused by the electric field force are calculated and superimposed to obtain the comprehensive stress distribution within the insulating component; Verify whether the comprehensive stress distribution is within the allowable stress range of the insulating material, and complete the multi-physics coupling verification.

8. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 7, characterized in that, The calculation of the temperature field distribution inside the insulating component under electrothermal coupling, and the updating of the temperature-dependent dielectric constant and conductivity parameters of the insulating material based on the temperature field distribution, includes: Based on the formulas for conductor loss and insulating dielectric loss, the power distribution of each heat source in the coupled simulation calculation model is calculated. Set the convection heat dissipation boundary conditions for the outer shell of the gas box and the thermal conduction and convection properties of the internal insulating gas; By solving the heat conduction and heat convection equations, the temperature field distribution of all insulating components inside the gas box under stable operating conditions is obtained; The pre-defined functions of the dielectric constant and conductivity of the insulating material with temperature are given. Read the steady-state temperature value of each calculation unit in the insulating component, and calculate the updated dielectric constant and conductivity of each calculation unit according to the functional relationship. Replace the original material parameters of the corresponding insulating component unit in the coupled simulation model with the calculated updated dielectric constant and conductivity.

9. The method for optimizing the electric field uniformity of internal insulating components of a primary and secondary fusion ring network gas box according to claim 8, characterized in that, It also includes a parameter fine-tuning step for the electric field optimization scheme based on process feedback: After prototyping the insulating component sample according to the three-dimensional design drawings and material process specifications, the insulating component sample is three-dimensionally scanned to obtain its actual manufacturing geometry. By comparing the actual manufacturing geometry with the theoretical geometry of the final design, areas where the dimensional deviation exceeds the tolerance range are identified. The geometric data of the area where the dimensional deviation exists is updated in the modified three-dimensional geometric model of the air box corresponding to the final design scheme to form a manufacturing deviation correction model; The electric field distribution calculation is re-performed on the manufacturing deviation correction model to evaluate the degree of influence of the dimensional deviation on electric field homogenization. If the evaluation results indicate that the electric field strength exceeds the standard again or the uniformity deteriorates significantly, then for the area with the size deviation, the matching electric field optimization scheme is triggered again and the process of model modification and electric field calculation is performed to generate a fine-tuning optimization scheme that takes into account the manufacturing process tolerance.

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