Pole-mounted circuit breaker energy-taking capacitor internal and external space electric field analysis method

Abstract

The invention discloses a method for analyzing a space electric field with an internal and external energy-taking capacitor of a pole-mounted circuit breaker, and relates to the technical field of pole-mounted circuit breaker analys.The method comprises the steps that a finite element simulation model is constructed based on the structure of the pole-mounted circuit breaker and simulation equipment, and the finite element simulation model is closer to the actual structure; acquiring first electric field distribution data and the position of a target element based on the finite element simulation model, and drawing a first tangent plane electric field based on the position, the first electric field distribution data, the material data of the pole-mounted circuit breaker and the boundary condition of an electrostatic field, obtaining an electric field concentration position and an electric field distortion point based on the first electric field intensity of the tangent plane electric field, constructing a three-dimensional section line based on the electric field concentration position and the electric field distortion point, analyzing the electric field based on the three-dimensional section line, and obtaining an analysis result. And electric field distribution in the pole is influenced, so that electric field distortion is caused.

Description

Technical Field

[0001] The present invention relates to the technical field of pole-mounted circuit breaker analysis, and specifically, to a method and system for analyzing the spatial electric field of an energy-taking capacitor inside and outside a pole-mounted circuit breaker. Background Art

[0002] As a commonly used protection and control device in the power distribution network power system, the performance and reliability of a pole-mounted circuit breaker are directly related to the safe and stable operation of the power grid. With the continuous deepening of the integration of the primary and secondary of the pole-mounted circuit breaker and the continuous increase of high-voltage components inside the pole of the pole-mounted circuit breaker, there are many different schemes for the connection and cooperation mode between the commonly used capacitor power-taking method in the current complete set of pole-mounted circuit breaker equipment and the pole-mounted circuit breaker body, such as the energy-taking capacitor being built inside or outside the pole. However, in the existing complete set of pole-mounted circuit breaker equipment, although the energy-taking capacitor built inside the pole reduces the equipment volume, if its position is set unreasonably, it will affect the electric field distribution inside the pole, especially the mutual influence of the electric fields between multiple high-voltage components, which may lead to electric field distortion, thereby increasing the difficulty and cost of insulation design. Summary of the Invention

[0003] In order to solve the problem that the unreasonable position setting of the energy-taking capacitor in the existing complete set of pole-mounted circuit breaker equipment affects the electric field distribution inside the pole and causes electric field distortion, the present invention provides a method for analyzing the spatial electric field of an energy-taking capacitor inside and outside a pole-mounted circuit breaker, and the method includes:

[0004] Construct a finite element simulation model based on the structure of the pole-mounted circuit breaker and the simulation equipment, which is more in line with the actual structure. Obtain the first electric field distribution data and the position of the target component based on the finite element simulation model. Draw the first cross-sectional electric field based on the position, the first electric field distribution data, the material data of the pole-mounted circuit breaker, and the boundary conditions of the electrostatic field. Obtain the electric field concentration position and the electric field distortion point based on the first electric field intensity of the cross-sectional electric field. Construct a three-dimensional intercept line based on the electric field concentration position and the electric field distortion point. Analyze the electric field based on the three-dimensional intercept line to obtain the analysis result.

[0005] The finite element simulation model of the internal space of the pole-mounted circuit breaker is built. The finite element model is adjusted and arranged according to different design structures of the pole-mounted circuit breaker. According to the material data of the pole-mounted circuit breaker and the boundary conditions of the electrostatic field, the cross-sectional electric field of the target component is established. The materials of each component in the simulation model are set according to the actual materials of the pole-mounted circuit breaker, which is more in line with the reality and the electric field distribution is more accurate. Then, the electric field concentration points and the positions of electric field distortion around it are analyzed, and a three-dimensional intercept line of the spatial electric field distribution of the target component is established to realize the analysis of the variation law of the electric field intensity around the target component with the physical position. Furthermore, the position of the target component is adjusted to reduce the influence of the internal electric field of the pole column and the situation of electric field distortion, so as to more reasonably set the position of the target component and provide theoretical guidance for the design of the pole-mounted circuit breaker.

[0006] In the cross-sectional electric field analysis, the electric field concentration position and the position of electric field distortion represent the places with relatively large electric field intensity in the whole model calculation. In the insulation field, compared with the positions with relatively small electric field intensity, the positions with electric field intensity distortion and relatively large electric field intensity will first generate partial discharge under long-term high-voltage operation, which will cause aging effects on the equipment insulation. Therefore, when analyzing the electric field of the model by finite element, it is necessary to start from the electric field concentration position and the position of electric field distortion. The electric field change at the electric field concentration position and the position of electric field distortion is obvious. Further construct a three-dimensional intercept line at this position to analyze the three-dimensional intercept line data, and the data is more obvious and easier to observe.

[0007] In actual operation, whether it is the insulation material or the components of the equipment, the parts with relatively large electric field intensity or relatively serious electric field distortion will first generate partial discharge under long-term high-voltage operation or instantaneous lightning strike compared with other positions, which will cause damage to the insulation. The electric field concentration points and the electric field distortion points are prone to insulation breakdown in actual use and need additional insulation design. Analyzing these two positions is more convenient for comparing the difficulty of insulation design of the target component under different setting positions, so as to obtain the advantages and disadvantages of different design methods.

[0008] The finite element model can, through finite element division, transform a large problem that cannot be directly calculated and analyzed in reality into several small problems that can be calculated and analyzed. By calculating several small problems, the calculation result of the large problem is approximately obtained. The mesh generation technology of the finite element technology transforms the large model into several small models through mesh generation, accurately calculates the small models, and finally approximately obtains the calculation result of the large model.

[0009] Furthermore, the specific steps for analyzing the electric field based on the three-dimensional intercept line to obtain the analysis result include: obtaining the second electric field intensity of the three-dimensional intercept line, constructing a longitudinal cross-sectional electric field based on the second electric field intensity and a preset distance, analyzing the electric field distribution law based on the longitudinal cross-sectional electric field and the first cross-sectional electric field, and obtaining the analysis result.

[0010] Considering that the transverse cross-section will pass through the conductive rod and the current transformer coil model in addition to the capacitor, the analysis of the extreme value of the tangent electric field at the corresponding tangent point is likely to be affected by the above factors; and in the process of electric field segmentation of the transverse cross-section, the target component model and the spatial part model corresponding to the target component are not included. Therefore, the present invention constructs the longitudinal cross-section electric field.

[0011] Further, the specific steps for obtaining the first electric field distribution data based on the finite element simulation model include:

[0012] Obtain the number of the target components, set the voltage values of the target components based on the number and the preset limit voltage value, and obtain the first electric field distribution data based on the voltage values.

[0013] Further, the preset limit voltage value is

[0014] By simulating the extreme conditions to analyze the worst-case scenario in practice, and the commonly used withstand voltage test power supply is a 42 kV power frequency voltage. The maximum voltage value that may appear under this condition is the peak value of the sine voltage, that is, Considering that the current energy-taking capacitors are usually fixedly installed at present, but for the capacitors with fixed installation, under different working conditions, such as temperature change, mechanical vibration or the change of the surrounding electromagnetic environment, it will cause the fluctuation of the electric field distortion coefficient, affecting the stability and performance of the equipment. The present invention establishes a dynamic four-dimensional electric field model including the time dimension, real-time collects the spatial electric field distribution through a multi-modal sensor, obtains the optimal position of the energy-taking capacitor according to the dynamic four-dimensional electric field model and the finite element simulation model, adjusts the energy-taking capacitor to the optimal position through an adjustment device, dynamically adjusts the position of the energy-taking capacitor according to different working conditions, reduces the non-uniformity coefficient of the electric field inside the pole column, reduces the fluctuation of the electric field distortion coefficient, and improves the stability and performance of the equipment. Further, the method further includes: obtaining the operation state parameters of the pole column of the pole-mounted circuit breaker and the second electric field distribution data, fusing the operation state parameters and the second electric field distribution data to obtain fusion data; constructing a four-dimensional electric field model of the pole column based on the fusion data and the finite element simulation model; obtaining the optimal position based on the four-dimensional electric field model, obtaining the adjustment amount based on the optimal position, and adjusting the position of the capacitor based on the adjustment amount to adjust the spatial electric field distribution inside the pole column.

[0015] Considering the multi-physical field coupling effect of the dynamic temperature field - mechanical stress field - electromagnetic field during the operation of the equipment, obtaining the three-dimensional space coordinates inside the pole column through the finite element simulation model, constructing the fourth dimension based on the time axis and the operation state parameters, so as to obtain a four-dimensional electric field model, realizing the real-time decoupling of the multi-physical fields, and finding the optimal position of the energy-taking capacitor through the four-dimensional electric field model, so as to improve the uniformity of the electric field distribution inside the pole column and reduce the electric field distortion problem.

[0016] Further, based on the multi-modal sensors, the operating state parameters and the second electric field distribution data are obtained. The operating state parameters include temperature, mechanical stress, and load current. The multi-modal sensors include an electric field sensor, a temperature sensor, and a strain gauge. The electric field sensor is used to collect the spatial electric field distribution, the temperature sensor is used to collect the temperature, and the strain gauge is used to collect the mechanical stress. The electric field sensor is spirally distributed on the inner surface of the pole column, the temperature sensor is built into the pole column, and the strain gauge is installed on the fixing device of the energy-taking capacitor.

[0017] Considering that under temperature cycling, the materials of the internal components of the pole column (such as aluminum alloy, stainless steel, and silicone rubber, etc.) undergo non-linear changes, and the softening or expansion of the materials at high temperatures causes changes in the three-dimensional coordinates inside the pole column, which may lead to conflicts or inaccuracies between the optimal position of the energy-taking capacitor and the components. The present invention establishes a material property database, and at the same time considers the dynamic interaction of the temperature field, mechanical stress field, and electromagnetic field, avoiding the error accumulation of traditional single-field analysis. On the basis of the standard form, the temperature-dependent elastic modulus and thermal expansion coefficient are introduced, that is, the temperature effect and material non-linear characteristics are introduced, to more accurately calculate the influence of thermal stress on the capacitor position, more accurately obtain the three-dimensional spatial coordinates inside the pole column, and further more accurately obtain the optimal position of the energy-taking capacitor.

[0018] Further, a material database is constructed. The material database includes several materials, and each material corresponds to the Poisson's ratio, elastic modulus, and thermal expansion coefficient at different temperatures. Based on the temperature, mechanical stress, and the material database, the strain and deformation amount are obtained. Based on the strain and the deformation amount, the four-dimensional electric field model is updated, and based on the updated four-dimensional electric field model, the adjustment amount is obtained.

[0019] The calculation formula for obtaining the strain is:

[0020]

[0021] Among them, σ represents mechanical stress, E represents elastic modulus, v represents Poisson's ratio, ε represents strain tensor, k represents volumetric strain, α represents thermal expansion coefficient, ΔT represents temperature change, and δ represents unit tensor.

[0022] Further, based on the adjustment amount, the adjustment device adjusts the position of the capacitor. The adjustment device includes a base, a piezoelectric ceramic, and a moving platform. The piezoelectric ceramic is installed on the base, the top of the piezoelectric ceramic is connected to the bottom of the moving platform, and the capacitor is installed on the moving platform. Based on the adjustment amount, the driving voltage is obtained, and the driving voltage is input to the piezoelectric ceramic. The piezoelectric ceramic generates a displacement along the axis, pushes the moving platform, and adjusts the position of the capacitor to the optimal position.

[0023] Through the inverse piezoelectric effect of the piezoelectric ceramic, the voltage signal is converted into an accurate displacement. After applying voltage, the lattice structure inside the piezoelectric ceramic deforms, and the piezoelectric ceramic material (such as PZT-8) generates deformation, expands axially, generates mechanical displacement, and pushes the moving platform to move axially, realizing the real-time change of the position of the energy-taking capacitor.

[0024] During the movement process, the piezoelectric ceramic may generate lateral forces or torques, which affect the positioning accuracy. In the present invention, the linear displacement of the piezoelectric ceramic is transmitted to the load without deviation through a guiding mechanism, providing a frictionless and backlash-free guide, while suppressing lateral swing, restricting non-axial degrees of freedom (such as lateral offset or rotation), and reducing the interference of lateral forces.

[0025] Furthermore, the top of the piezoelectric ceramic is connected to the bottom of the moving platform through a stress concentration mechanism, the base and the moving platform are connected through a guiding mechanism, and the piezoelectric ceramic and the base are connected through a pre-tightening force adjustment module.

[0026] Through the pre-tightening force adjustment module, it is ensured that the piezoelectric ceramic is always in a compressed state, avoiding return clearance, applying a controllable static pressure, eliminating mechanical clearance, suppressing mechanical hysteresis, and protecting the piezoelectric ceramic from tensile damage.

[0027] The stress concentration mechanism evenly transmits the concentrated force of the piezoelectric ceramic to the moving platform, reducing the contact stress concentration and avoiding material damage caused by excessive local stress.

[0028] Furthermore, the stress concentration mechanism is a hemispherical ceramic gasket, the guiding mechanism is a flexible hinge, and the pre-tightening force adjustment module is a disc spring. The flexible hinge can provide high-precision guidance and at the same time allow small displacements, avoiding friction and wear.

[0029] While reducing the contact stress concentration, the hemispherical ceramic gasket reduces the friction force and assembly error through spherical contact, improves the displacement transmission efficiency, and the ceramic material has a low coefficient of thermal expansion, reducing the influence of temperature change on the contact interface.

[0030] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0031] 1. The present invention constructs a finite element simulation model for the internal space of a pole-mounted circuit breaker, adjusts and arranges the finite element model according to different design structures of the pole-mounted circuit breaker, establishes a sectional electric field for the target component based on the material data of the pole-mounted circuit breaker and the boundary conditions of the electrostatic field. The materials of each component in the simulation model are set according to the actual materials of the pole-mounted circuit breaker, which is more in line with the actual situation and the electric field distribution is more accurate. Then, the electric field concentration points and the positions of electric field distortion around it are analyzed, and a three-dimensional cross-section is established for the spatial electric field distribution of the target component to realize the analysis of the variation law of the electric field intensity around the target component with the physical position. Furthermore, the position of the target component is adjusted to reduce the influence of the internal electric field of the pole and the situation of electric field distortion, so as to more reasonably set the position of the target component and provide theoretical guidance for the design of the pole-mounted circuit breaker.

[0032] 2. The electric field changes at the electric field concentration position and the position of electric field distortion are obvious. A three-dimensional cross-section is further constructed at this position, and the data of the three-dimensional cross-section is analyzed, making the data more obvious and easier to observe.

[0033] 3. The electric field concentration point and the electric field distortion point are prone to insulation breakdown during actual use, and additional insulation design is required. Analyzing these two positions is more convenient for comparing the difficulty of insulation design of the target component at different setting positions, so as to obtain the advantages and disadvantages of different design methods.

[0034] 4. The optimal position of the energy-taking capacitor is obtained according to the four-dimensional electric field model and the finite element simulation model. The energy-taking capacitor is adjusted to the optimal position through an adjustment device, and the position of the energy-taking capacitor is dynamically adjusted according to different working conditions to reduce the uneven coefficient of the internal electric field of the pole and the fluctuation of the electric field distortion coefficient, and improve the stability and performance of the equipment. Description of the Drawings

[0035] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of the present invention, and do not limit the embodiments of the present invention;

[0036] Figure 1 is a schematic flow chart of a method for analyzing the spatial electric field of an internal and external energy-taking capacitor of a pole-mounted circuit breaker in the present invention;

[0037] Figure 2 is a structural diagram of a finite element simulation model of an energy-taking capacitor built-in pole;

[0038] Figure 3 is a structural diagram of a finite element simulation model of an energy-taking capacitor external to the pole;

[0039] Figure 4 is a top view of a finite element simulation model of an energy-taking capacitor built-in pole;

[0040] Figure 5It is the top view of the finite element simulation model of the external pole of the energy-taking capacitor;

[0041] Figure 6 It is a schematic diagram of a three-dimensional cross-section line;

[0042] Figure 7 It is a schematic diagram of the distribution of the electric field along the longitudinal physical distance at position a of the stacked sampling capacitor on the three-dimensional cross-section line;

[0043] Figure 8 It is a schematic diagram of the distribution of the electric field along the longitudinal physical distance at position b of the stacked sampling capacitor on the three-dimensional cross-section line;

[0044] Figure 9 It is a schematic diagram of the distribution of the electric field along the longitudinal physical distance at position c of the stacked sampling capacitor on the three-dimensional cross-section line;

[0045] Figure 10 It is a schematic diagram of the distribution of the electric field along the longitudinal physical distance at position d of the stacked sampling capacitor on the three-dimensional cross-section line;

[0046] Among them, 1 - stacked sampling capacitor, 2 - wound energy-taking capacitor, 3 - current transformer coil winding, 4 - conductive rod on the pole outlet side of the pole-mounted circuit breaker, 5 - grounding rod, and a, b, c, and d represent 4 corner points of the stacked sampling capacitor. Specific implementation manner

[0047] In order to be able to more clearly understand the above-mentioned objects, features, and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0048] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described within the scope here. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0049] Embodiment 1

[0050] Reference Figures 1 - 10 , this embodiment provides a method for analyzing the spatial electric field of the internal and external energy-taking capacitors of a pole-mounted circuit breaker, and the method includes:

[0051] Construct a finite element simulation model based on the structure of the pole-mounted circuit breaker and the simulation equipment. In this embodiment, the simulation equipment can be the AC / DC module of COMSOL Multiphysics.

[0052] Obtain the first electric field distribution data and the position of the target component based on the finite element simulation model; the specific steps for obtaining the first electric field distribution data based on the finite element simulation model include: obtaining the number of the target components, setting the voltage values of the target components based on the number and a preset limit voltage value, such as assigning voltage values to each target component proportionally according to the number and the limit voltage value. For example, if the voltage value is 20 and the number is 5, the voltage values are 20, 15, 10, and 5 respectively. Based on the voltage values, obtain the first electric field distribution data in the simulation calculation of the simulation device.

[0053] Based on the position, the first electric field distribution data, the material data of the pole-mounted circuit breaker, and the boundary conditions of the electrostatic field, draw the first cross-sectional electric field.

[0054] Obtain the electric field concentration position and the electric field distortion points based on the first electric field strength of the cross-sectional electric field. For example, in the AC / DC module of COMSOL Multiphysics, obtain the electric field strength from the electric field numerical legend, obtain the point with the maximum electric field strength or the point at the highlighted position (in the cross-sectional electric field, the red highlighted points represent the positions with large electric field strength), so as to obtain the electric field concentration position; through the numerical change of the electric field, such as the numerical change being greater than a preset value, it is an electric field distortion point.

[0055] Construct a three-dimensional intercept line based on the electric field concentration position and the electric field distortion points;

[0056] Analyze the electric field based on the three-dimensional intercept line to obtain the analysis result. The specific steps include: obtaining the second electric field strength of the three-dimensional intercept line, constructing a longitudinal cross-sectional electric field based on the second electric field strength and a preset distance, and analyzing the electric field distribution law based on the longitudinal cross-sectional electric field and the first cross-sectional electric field to obtain the analysis result. For example, extract the electric field strength on the three-dimensional intercept line, establish the electric field distribution along the longitudinal physical distance, and combine it with the first cross-sectional electric field to analyze the electric field distribution law.

[0057] Among them, the preset limit voltage value is

[0058] The cross-sectional electric field refers to the electric field generated on the cutting surface due to the redistribution of charges after an object is cut. This electric field phenomenon can be explained by the principles of electrostatics, that is, the charges are redistributed on the surface of the object, resulting in a specific electric field distribution on the cutting surface.

[0059] The three-dimensional intercept line refers to a line segment determined by a specific direction and endpoints in three-dimensional space, used to intercept or divide a specific part of a three-dimensional model.

[0060] The AC / DC module of COMSOL Multiphysics is a professional tool for analyzing static and low-frequency electromagnetic problems, providing rich modeling functions and numerical methods to help users deeply study electromagnetic fields and EMI / EMC problems by solving Maxwell's equations.

[0061] The boundary conditions of the electrostatic field refer to some conditions that need to be satisfied between different media or between different regions in the same medium during the analysis of the electrostatic field. These conditions are used to solve problems such as potential differences and electric field intensities generated between different media or regions.

[0062] A finite element model is a model established when using the finite element analysis method, which is a combination of elements that are only connected at nodes, only transfer forces through nodes, and are only constrained at nodes.

[0063] An electric field distortion point refers to a position in the electric field where the electric field distribution changes significantly due to certain factors. An electric field concentration position refers to a position in the electric field where the electric field intensity is the largest.

[0064] Example Two

[0065] Reference Figures 1 - 10 , on the basis of the above embodiments, in this embodiment, an example is given to illustrate the position selection of the energy-taking capacitor:

[0066] 1. Select two cases of the internal and external poles of the energy-taking capacitor, and respectively obtain the three-dimensional simplified model inside the pole of the pole-mounted circuit breaker;

[0067] Reference Figure 2 , the model of the internal pole of the energy-taking capacitor includes a stacked sampling capacitor, a wound energy-taking capacitor, a current transformer coil winding, a conductive rod on the outgoing side of the pole of the pole-mounted circuit breaker, and a grounding rod;

[0068] When the energy-taking capacitor is on the external pole, since there is a sufficient electrical insulation distance between the energy-taking capacitor and the pole, and the energy-taking capacitor has an independent insulation structure under the condition of the external energy-taking capacitor, and there is a composite insulation of epoxy resin and silicone rubber between the energy-taking capacitor and the internal components of the pole, it can be considered that there is no impact on the inside of the pole. In this embodiment, a simulation model without an energy-taking capacitor is directly used. Reference Figure 3 , the model of the external pole of the energy-taking capacitor includes a stacked sampling capacitor, a current transformer coil winding, a conductive rod on the outgoing side of the pole of the pole-mounted circuit breaker, and a grounding rod;

[0069] Construct finite element simulation models of the two models in the AC / DC module of COMSOL Multiphysics respectively;

[0070] 2. Set the research type to steady-state research, the materials of each component, and the electrostatic boundary conditions. The pole conductive rod is at a high potential. Considering the extreme case of model simulation calculation, use the extreme voltage value. The current transformer coil winding and the grounding rod are set to zero potential. The sampling capacitor and the energy-taking capacitor are assigned proportionally according to the extreme voltage value from top to bottom according to the number of capacitor models. Assign values in equal proportion according to the extreme voltage value;

[0071] Use the electrostatic field of the AC / DC module of COMSOL Multiphysics 5.5 to solve, perform extreme ideal assignment, use the steady-state Maxwell's equations as the theoretical calculation formula, perform finite element splitting and simulation calculation on the model, and take the electric field distribution between the sampling capacitor and the energy-taking capacitor itself and the two as the main research object to obtain the simulation results. The steady-state Maxwell's equations can be:

[0072]

[0073] Among them, represents the operator of the vector, H represents the magnetic field intensity, represents the displacement current density, J represents the conduction current density, E represents the electric field intensity, D represents the electric flux density, ρ represents the charge density, and B represents the magnetic induction intensity.

[0074] 3. Refer to Figures 4 - 5 , use the ab and cd planes to draw the cross-sectional electric field of the simulation results, analyze the electric field distribution of the model cross-section, and show the electric field distortion points and the electric field concentration positions in the cross-sectional electric field distribution diagram according to the legend of the electric field value and the color table, that is, the positions with larger electric field intensity values;

[0075] According to the maximum electric field intensity, it can be concluded that compared with the external energy-taking capacitor, due to the shorter electrical distance between the internal energy-taking capacitor and the sampling capacitor, there are more distortion points in its electric field distribution, mainly reflected in:

[0076] (1) Around the top capacitor and the bottom part of the left side of the sampling capacitor;

[0077] (2) The top capacitor and the bottom capacitor on the right side of the sampling capacitor;

[0078] (3) Both sides of the energy-taking capacitor and the connection between the components of the energy-taking capacitor;

[0079] 4. According to Gauss's law, a conductor in electrostatic equilibrium is an equipotential body, the surface is an equipotential surface, charges can only be distributed on the surface, and the surface charge density everywhere is proportional to the magnitude of the electric field intensity in the immediate vicinity of the local surface, that is, the magnitude of the gradient of the electric potential. And the electric potential gradient is larger and the electric field is stronger where the surface curvature is large.

[0080] According to the cross-sectional electric field distribution obtained from simulation calculations, it can be seen from the electric field numerical legend in the cross-sectional electric field distribution diagram that the electric field distortion is the most severe at the edges of the sampling capacitor, which also conforms to the characteristic in the high-voltage field that the electric field is more concentrated at the tips or burrs of components. Therefore, a three-dimensional intercept line is constructed at the position where the electric field is concentrated, that is, a three-dimensional intercept line is established at the edges around the sampling capacitor. Refer to Figure 6 , construct a three-dimensional intercept line to determine the specific distribution of the electric field at the position where the electric field is concentrated. The simulation software calibrates the position of the three-dimensional intercept line, and the number of specific calibration points can be controlled. The software extracts the horizontal and vertical coordinates of the calibration points and the corresponding electric field strength as parameters, forming multiple data composed of (horizontal coordinate, vertical coordinate, electric field strength value). Based on the data in the array, draw and establish the electric field distribution along the longitudinal physical distance in the surrounding space of the model, that is Figure 2 and Figure 3 the electric fields at the longitudinal physical distances corresponding to positions a, b, c, and d in

[0081] 5. Refer to Figures 7 - 10 , evaluate and compare the advantages and disadvantages of the two design methods according to the results of cross-sectional electric field analysis and three-dimensional intercept line analysis.

[0082] For positions a and c, at the edge of the sampling capacitor, the electric field strength of the energy-taking capacitor built-in model is significantly greater than that of the external model, and it increases as the longitudinal physical position rises;

[0083] For position b, at the edge of the sampling capacitor, the electric field strength of the energy-taking capacitor built-in model is less than that of the external model, but the numerical difference between the two is not large; while near the top capacitor of the sampling capacitor, the electric field strength of the energy-taking capacitor built-in model is greater than that of the external model;

[0084] For position d, the electric field strength of the energy-taking capacitor built-in model is less than that of the external model, but the numerical difference is also small, and the electric field strengths of the two are relatively close near the top capacitor of the sampling capacitor;

[0085] In summary, based on the above simulation, the following conclusions can be obtained:

[0086] (1) In terms of the cross-sectional electric field, compared with the external model, the energy-taking capacitor built-in model has more electric field distortion points under the same applied voltage, and the maximum field strength value of its corresponding cross-sectional electric field distribution is also larger. Therefore, in long-term operation, the energy-taking capacitor built-in design has a greater risk in insulation design.

[0087] (2) In the energy-taking capacitor built-in design, the electrical distance between the sampling capacitor and the energy-taking capacitor is relatively short. Therefore, the electric fields of the two will interact with each other, which may have a certain impact on the use accuracy and service life of the two types of capacitors.

[0088] (3) When the energy-taking capacitor is externally placed, the surrounding space electric field distribution at the edge of the sampling capacitor is significantly better than the internal design,

[0089] and the maximum electric field strength at the edge of the sampling capacitor is also relatively small.

[0090] Therefore, in maintaining the uniform distribution of the internal space electric field of the pole column and the optimization design, the design method of externally placing the energy-taking capacitor has obvious advantages in the design of uniform electric field distribution compared with the design of placing the energy-taking capacitor inside the pole column.

[0091] Embodiment Three

[0092] Based on the above embodiments, in this embodiment, the method further includes:

[0093] Obtain the operating state parameters and the second electric field distribution data of the pole column of the column-mounted circuit breaker, fuse the operating state parameters and the second electric field distribution data to obtain fused data;

[0094] Based on the fused data and the finite element simulation model, construct a four-dimensional electric field model of the pole column;

[0095] Obtain the optimal position based on the four-dimensional electric field model; in this embodiment, the optimal position can be obtained by using existing algorithms (such as starting the quantum genetic algorithm for multi-objective optimization, generating a Pareto front solution set, and selecting the optimal solution) and historical electric field data to train the model, and finding the optimal position through the model.

[0096] Obtain the adjustment amount based on the optimal position, such as obtaining the adjustment amount according to the initial position and the optimal position of the energy-taking capacitor;

[0097] Adjust the position of the capacitor based on the adjustment amount to adjust the internal space electric field distribution of the pole column.

[0098] Among them, in this embodiment, the operating state parameters and the second electric field distribution data are obtained based on a multi-modal sensor, and the operating state parameters include temperature, mechanical stress, and load current;

[0099] The multi-modal sensor includes an electric field sensor, a temperature sensor, and a strain gauge. The electric field sensor is used to collect the spatial electric field distribution, the temperature sensor is used to collect the temperature, and the strain gauge is used to collect the mechanical stress;

[0100] The electric field sensor is spirally distributed on the inner surface of the pole column, the temperature sensor is placed inside the pole column, and the strain gauge is installed on the fixing device of the energy-taking capacitor.

[0101] In this embodiment, the electric field sensor can be a graphene film electric field sensor, the temperature sensor can be a fiber Bragg grating temperature sensor, and the strain gauge can be a MEMS micro-strain gauge.

[0102] Among them, in this embodiment, a material database is constructed. The material database includes a number of materials, and each material corresponds to the Poisson's ratio, elastic modulus, and coefficient of thermal expansion at different temperatures.

[0103] Based on the temperature, mechanical stress, and the material database, strain and deformation are obtained. Based on the strain and the deformation, the four-dimensional electric field model is updated. Based on the updated four-dimensional electric field model, the adjustment amount is obtained. For example, the degree of deformation of the material is obtained according to the strain and deformation, and the three-dimensional coordinates inside the pole column are updated in real time, thereby updating the four-dimensional electric field model.

[0104] The calculation formula for obtaining the strain is:

[0105]

[0106] The calculation formula for obtaining the deformation is:

[0107] L = α·L0·ΔT;

[0108] Among them, σ represents mechanical stress, E represents elastic modulus, v represents Poisson's ratio, ε represents strain tensor, k represents volume strain, α represents coefficient of thermal expansion, ΔT represents temperature change, δ represents unit tensor, L represents deformation, and L0 represents initial length.

[0109] Among them, in this embodiment, based on the adjustment amount, the adjustment device adjusts the position of the capacitor. The adjustment device includes a base, a piezoelectric ceramic, and a moving platform. The piezoelectric ceramic is installed on the base, the top of the piezoelectric ceramic is connected to the bottom of the moving platform, and the capacitor is installed on the moving platform.

[0110] Based on the adjustment amount, a driving voltage is obtained, and the driving voltage is input to the piezoelectric ceramic. The piezoelectric ceramic generates a displacement along the axis, pushes the moving platform, and adjusts the position of the capacitor to the optimal position.

[0111] In this embodiment, the piezoelectric ceramic can be a stacked piezoelectric actuator or composed of multiple layers of PZT sheets connected in series to achieve large displacement output. The piezoelectric ceramic is electrically connected to the pole-mounted circuit breaker to realize inputting the driving voltage to the piezoelectric ceramic.

[0112] Piezoelectric ceramic materials (such as PZT-8) directly generate mechanical deformation under the action of voltage. The displacement resolution can reach 0.1 nm, and the response time is in the microsecond level, meeting the requirements of real-time dynamic adjustment. Moreover, due to its high stiffness, it can withstand the electromagnetic force impact under high voltage electric fields, avoid displacement drift, and has strong anti-interference ability, ensuring stability in extreme environments; and the piezoelectric ceramic stack is driven by material deformation, without mechanical contact components, greatly improving the service life.

[0113] The calculation formula for obtaining the driving voltage is:

[0114] ΔL = d 33 ·V·n;

[0115] Where, ΔL represents the adjustment amount, d 33 represents the piezoelectric strain constant, V represents the driving voltage, and n represents the number of piezoelectric ceramic sheets

[0116] Where, in this embodiment, the top of the piezoelectric ceramic is connected to the bottom of the moving platform through a stress concentration mechanism, and the base and the moving platform are connected through a guiding mechanism, such as connecting to the bottom of the moving platform and the top of the base. The piezoelectric ceramic and the base are connected through a pre-tightening force adjustment module.

[0117] Where, the stress concentration mechanism can be an elastomeric pad, which disperses the contact stress through the compression deformation of an elastic material (such as silicone rubber) to avoid local stress concentration. In this embodiment, it is preferably a hemispherical ceramic pad. The circular plane of the hemispherical ceramic pad is connected to the bottom of the moving platform, and the arc top of the semi-circular surface is fixedly connected to the center point of the piezoelectric ceramic; while reducing the contact stress concentration, the hemispherical ceramic pad reduces the friction force and assembly error through spherical contact, improves the displacement transfer efficiency, and the ceramic material has a low coefficient of thermal expansion, reducing the influence of temperature changes on the contact interface.

[0118] The guiding mechanism can be a leaf spring flexure (using the bending deformation of an elastic thin plate to achieve single-degree-of-freedom guiding) or a flexible hinge, preferably a double parallelogram flexure, which is symmetrically distributed to offset non-axial forces, can provide high-precision guiding, and at the same time allows small displacements to avoid friction and wear.

[0119] The pre-tightening force adjustment module can be an elastic element, such as a spring, preferably a disc spring. The spring stiffness coefficient matches the output characteristics of the piezoelectric ceramic. The spring can be compressed by an adjusting screw, and the pressure is applied to the platform through the adjusting screw to ensure that the piezoelectric stack is always in a compressed state.

[0120] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn of the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0121] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for analyzing the spatial electric field of an energy-taking capacitor with internal and external placement on a pole-mounted circuit breaker, characterized in that, The method includes: Constructing a finite element simulation model based on the structure of the pole-mounted circuit breaker and the simulation equipment, obtaining first electric field distribution data and the position of the target component based on the finite element simulation model, drawing a first cross-sectional electric field based on the position, the first electric field distribution data, the material data of the pole-mounted circuit breaker, and the boundary conditions of the electrostatic field, obtaining the electric field concentration position and the electric field distortion point based on the first electric field intensity of the cross-sectional electric field, constructing a three-dimensional intercept line based on the electric field concentration position and the electric field distortion point, and analyzing the electric field based on the three-dimensional intercept line to obtain an analysis result.

2. The method for analyzing the internal and external space electric fields of the energy-taking capacitor of the pole-mounted circuit breaker according to claim 1, wherein, The specific steps of analyzing the electric field based on the three-dimensional intercept line to obtain an analysis result include: Obtaining the second electric field intensity of the three-dimensional intercept line, constructing a longitudinal cross-sectional electric field based on the second electric field intensity and a preset distance, and analyzing the electric field distribution law based on the longitudinal cross-sectional electric field and the first cross-sectional electric field to obtain the analysis result.

3. The method for analyzing the internal and external space electric fields of the energy-taking capacitor of the pole-mounted circuit breaker according to claim 1, characterized in that The specific steps of obtaining the first electric field distribution data based on the finite element simulation model include: Obtaining the number of the target components, setting the voltage values of the target components based on the number and a preset limit voltage value, and obtaining the first electric field distribution data based on the voltage values.

4. A method for analyzing the internal and external space electric fields of an energy-taking capacitor of a pole-mounted circuit breaker according to claim 3, characterized in that, The preset limit voltage value is 5. A method for analyzing the internal and external space electric field of the energy-taking capacitor of a pole-mounted circuit breaker according to claim 1, characterized in that, The method further includes: Obtaining the operating state parameters and the second electric field distribution data of the pole of the pole-mounted circuit breaker, and fusing the operating state parameters and the second electric field distribution data to obtain fusion data; Constructing a four-dimensional electric field model of the pole based on the fusion data and the finite element simulation model; Obtaining an optimal position based on the four-dimensional electric field model, obtaining an adjustment amount based on the optimal position, and adjusting the position of the capacitor based on the adjustment amount to adjust the electric field distribution in the internal space of the pole.

6. A method for analyzing the internal and external space electric fields of an energy-taking capacitor of a pole-mounted circuit breaker according to claim 5, characterized in that, Obtaining the operating state parameters and the second electric field distribution data based on a multi-modal sensor, where the operating state parameters include temperature, mechanical stress, and load current; The multi-modal sensor includes an electric field sensor, a temperature sensor, and a strain gauge. The electric field sensor is used to collect the spatial electric field distribution, the temperature sensor is used to collect the temperature, and the strain gauge is used to collect the mechanical stress; The electric field sensors are spirally distributed on the inner surface of the pole, the temperature sensor is built into the pole, and the strain gauge is installed on the fixing device of the energy-taking capacitor.

7. A method for analyzing the spatial electric field of an energy-taking capacitor with internal and external placement on a pole-mounted circuit breaker according to claim 6, characterized in that, Constructing a material database, where the material database includes several materials, and each material corresponds to the Poisson's ratio, elastic modulus, and coefficient of thermal expansion at different temperatures; Obtaining the strain and deformation amount based on the temperature, mechanical stress, and the material database, updating the four-dimensional electric field model based on the strain and the deformation amount, and obtaining the adjustment amount based on the updated four-dimensional electric field model; The calculation formula for obtaining the strain is: where σ represents the mechanical stress, E represents the elastic modulus, v represents the Poisson's ratio, ε represents the strain tensor, k represents the volumetric strain, α represents the coefficient of thermal expansion, ΔT represents the temperature change, and δ represents the unit tensor.

8. A method for analyzing the internal and external space electric fields of an energy-taking capacitor of a pole-mounted circuit breaker according to claim 5, characterized in that Based on the adjustment amount, an adjustment device adjusts the position of the capacitor. The adjustment device includes a base, a piezoelectric ceramic, and a moving platform. The piezoelectric ceramic is installed on the base, the top of the piezoelectric ceramic is connected to the bottom of the moving platform, and the capacitor is installed on the moving platform. Obtain a driving voltage based on the adjustment amount, input the driving voltage to the piezoelectric ceramic, the piezoelectric ceramic generates a displacement along the axial direction, pushes the moving platform, and adjusts the position of the capacitor to the optimal position.

9. The method for analyzing the internal and external space electric field of the energy-taking capacitor of the pole-mounted circuit breaker according to claim 8, characterized in that, The top of the piezoelectric ceramic is connected to the bottom of the moving platform through a stress concentration mechanism, the base and the moving platform are connected through a guiding mechanism, and the piezoelectric ceramic and the base are connected through a pre-tightening force adjustment module.

10. A method for analyzing the spatial electric field of an on-column circuit breaker energy-taking capacitor with internal and external placement, characterized in that, The stress concentration mechanism is a hemispherical ceramic gasket, the guiding mechanism is a flexible hinge, and the pre-tightening force adjustment module is a disc spring.

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