A method for calculating residual pollution layer resistance of insulator pollution discharge and related equipment

Abstract

The application provides a method for calculating residual pollution layer resistance of insulator pollution discharge and related equipment, obtains the creepage distance of a target insulator and a profile circle diameter corresponding to the creepage distance, and expands the target insulator into a true-type expansion flat plate with the creepage distance as the horizontal coordinate and the circular half perimeter at the point as the vertical coordinate; performs discrete processing on the surface residual pollution layer of the true-type expansion flat plate to obtain a plurality of micro segments; on the true-type expansion flat plate, the surface current density distribution is solved according to the geometric boundary and the arc root position after arc, and the equivalent conductive width of each micro segment is converted and obtained; each micro segment is decomposed into a plurality of parallel conductive branches according to the pollution components in the longitudinal direction; the branch resistance values corresponding to the conductive branches are obtained from the conductive branch conductivities, and then the micro segment resistance values are obtained, and the pollution layer resistance values of all the micro segments are accumulated and summed, so that the residual pollution layer resistance value on the insulator during the insulator pollution discharge is accurately calculated.

Description

Technical Field

[0001] This invention relates to the field of power equipment monitoring technology, and in particular to a method for calculating the residual pollution layer resistance of insulators during pollution discharge and related equipment. Background Technology

[0002] High-voltage overhead transmission lines are a crucial component of the power system. With the increasing scale of the power system, the number of long-distance high-voltage transmission lines is also growing, leading to a wider impact of high-voltage transmission line faults on the power system, industrial and agricultural production, and people's daily lives. Insulators are an essential component of overhead transmission lines, serving as indispensable external insulation devices that provide mechanical support and electrical isolation. Insulators in transmission lines and substations are required to operate reliably under atmospheric overvoltage, internal overvoltage, and long-term operating voltage. However, insulators are exposed to the atmosphere for extended periods, gradually accumulating industrial emissions, salt, dust, and other contaminants on their surfaces. In humid weather conditions such as fog, dew, or light rain, this contaminant layer absorbs moisture, forming a conductive film. This increases leakage current, potentially triggering surface arcing and developing into pollution flashover, causing large-scale power outages and posing a serious threat to the safe and stable operation of the power system.

[0003] In the physical process of pollution flashover, there is a close coupling relationship between the electric arc and the residual pollution layer resistance. After the local arc ignites, the voltage applied across the insulator is shared by the arc voltage drop and the residual pollution layer resistance voltage drop, which are connected in series to form a circuit loop. The accuracy of the residual pollution layer resistance calculation has a significant impact on predicting whether the arc will continue to develop and whether it will eventually penetrate the entire insulator surface to form a flashover.

[0004] In the circuit model of insulator pollution flashover, the arc is connected in series with the resistance of the remaining pollution layer after arc initiation. To solve for the critical flashover voltage, current and arc length, the key is to accurately calculate the resistance value of the remaining pollution layer on the surface of the insulator.

[0005] For a long time, external insulation design has relied on equivalent salt density and insoluble ash density, based on the conductivity of sodium chloride, as indicators of pollution level. However, the pollution composition in real-world insulator operating scenarios is complex and diverse. Numerous studies have shown that, under the same equivalent salt density, insulators contaminated with different chemical compositions exhibit significant differences in flashover voltage. This indicates that equivalent salt density alone cannot accurately assess insulation hazard, and the chemical composition of the pollution has become one of the key factors affecting discharge characteristics.

[0006] Existing technologies cannot reflect the spatiotemporal dynamic evolution of the resistance and conductivity of the contamination layer as a function of temperature and moisture content during the discharge process of insulators with complex soluble components. They treat the contamination layer as a single medium with uniform composition and statically constant conductivity, without distinguishing the differences in conductivity characteristics of different soluble salt components in the contamination. This results in discrepancies between the calculated and simulated contamination flashover process and the actual situation. Summary of the Invention

[0007] This invention provides a method and related equipment for calculating the resistance of the residual contaminant layer during insulator pollution discharge, with the aim of accurately calculating the resistance value of the residual contaminant layer on the surface of the insulator during pollution discharge.

[0008] To achieve the above objectives, the present invention provides a method for calculating the residual pollution layer resistance of an insulator during pollution discharge, comprising: Step 1: Obtain the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; Step 2: Calculate the maximum width of the current distribution at each point on the creepage distance using the diameter of the contour circle at each measurement point, and unfold the target insulator into a true unfolded plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate. Step 3: Discretize the surface contaminant layer of the full-size unfolded plate to obtain multiple micro-segments; Step 4: Determine the geometry and boundary conditions of the true-form unfolded plate based on half of the maximum width of the current distribution at any point on the creepage distance. Simulate the surface current density distribution of each micro-segment and calculate the equivalent conductive width of each micro-segment based on the surface current density distribution. Step 5: Decompose each micro-segment longitudinally into multiple parallel conductive branches according to the dirt composition, and obtain the dirt resistance value of each conductive branch by calculating the conductivity of each conductive branch. Step 6: Calculate the contamination resistance value of each micro-segment based on the contamination resistance value of each conductive branch, and sum the contamination resistance values ​​of all micro-segments to obtain the remaining contamination resistance value on the target insulator when it is polluted.

[0009] Furthermore, step 1 includes: Use a ruler or profilometer to fit the surface of the target insulator segment by segment along the marked leakage path, and measure the total path length from the top of the steel foot of the target insulator to the bottom of the iron cap to obtain the creepage distance of the target insulator. Along the leakage path, measurement points are set at equal intervals on the target insulator. At each measurement point, the diameter of the outline circle perpendicular to the central axis of the insulator is measured with a vernier caliper to obtain the outline circle diameter at each measurement point on the target insulator.

[0010] Furthermore, the expression for the equivalent conductive width of each micro-segment, calculated based on the surface current density distribution, is as follows: ; in, Indicates micro-segment The equivalent conductive width, Indicates the current value. micro-segment Surface current density at the axis of symmetry, A / m

[0011] Furthermore, the expression for calculating the conductivity of each conductive branch is: ; in, Indicates a conductive branch conductivity, This represents a coefficient related to the temperature of the contaminated salt solution. , These all represent coefficients related to the concentration of the contaminated salt solution. , , The conductivity was obtained by fitting the experimental conductivity values ​​into the conductivity calculation expression. Indicates micro-segment temperature, Indicates the reference temperature. Indicates a conductive branch The corresponding salt concentration.

[0012] Furthermore, the expression for obtaining the contamination resistance value of each conductive branch by calculating the conductivity of each conductive branch is as follows: ; in, Indicates a conductive branch The resistance value of the contaminant layer, This represents the length of each micro-segment after discretization. This indicates the types of contaminants contained in a micro-segment.

[0013] Furthermore, the expression for calculating the contamination resistance value of each micro-segment based on the contamination resistance value of each conductive branch is as follows: ; in, Indicates micro-segment The resistance value of the contaminant layer, Indicates the number of conductive branches. .

[0014] Furthermore, by summing up the pollution resistance values ​​of all micro-segments, the expression for the remaining pollution resistance value on the target insulator during pollution discharge is as follows: ; in, This indicates the resistance value of the residual contaminant layer on the target insulator during contaminant discharge. This indicates the number of micro-segments.

[0015] This invention also provides a device for calculating the residual contaminant layer resistance of insulators during pollution discharge, and applies a method for calculating the residual contaminant layer resistance of insulators during pollution discharge. The device includes: The acquisition module is used to acquire the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; The unfolding module is used to calculate the maximum width of the current distribution at each point on the creepage distance using the diameter of the contour circle at each measurement point, and unfold the target insulator into a true unfolding plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate. The discretization module is used to discretize the surface contaminant layer of the full-size unfolded plate to obtain multiple micro-segments; The conversion module is used to determine the geometry and boundary conditions of the true-form unfolded plate based on half of the maximum width of the current distribution corresponding to any point on the creepage distance, simulate the surface current density distribution of each micro-segment, and convert the surface current density distribution to obtain the equivalent conductive width of each micro-segment. The decomposition module is used to decompose each micro-segment longitudinally into multiple parallel conductive branches according to the contaminant composition, and to obtain the contaminant resistance value of each conductive branch by calculating the conductivity of each conductive branch. The calculation module is used to calculate the pollution resistance value of each micro-segment based on the pollution resistance value of each conductive branch, and to sum up the pollution resistance values ​​of all micro-segments to obtain the remaining pollution resistance value on the target insulator when it is polluted.

[0016] The present invention also provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements a method for calculating the residual pollution layer resistance of an insulator during pollution discharge.

[0017] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, realizes a method for calculating the residual contamination layer resistance of an insulator during contamination discharge.

[0018] The above-described solution of the present invention has the following beneficial effects: This invention obtains the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; calculates the maximum width of the current distribution at each point along the creepage distance using the contour circle diameter at each measurement point, and unfolds the target insulator into a full-size unfolded plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point along the creepage distance as the ordinate; discretizes the surface contaminant layer of the full-size unfolded plate to obtain multiple micro-segments; determines the geometry and boundary conditions of the full-size unfolded plate based on half of the maximum width of the current distribution at any point along the creepage distance to simulate the surface current density distribution of each micro-segment, and calculates the equivalent conductive width of each micro-segment based on the surface current density distribution; decomposes each micro-segment longitudinally into multiple parallel conductive branches according to the contaminant composition, and obtains the contaminant layer of each conductive branch by calculating the conductivity of each conductive branch. Resistance value; the contamination resistance value of each micro-segment is calculated based on the contamination resistance value of each conductive branch, and the contamination resistance values ​​of all micro-segments are summed to obtain the residual contamination resistance value on the target insulator during contamination discharge; compared with the prior art, the present invention discretizes the insulator surface along the leakage path into multiple series micro-segments, and each micro-segment is further decomposed into multiple parallel conductive branches along the longitudinal direction according to the chemical composition of the contamination. This two-layer architecture of horizontal discretization + vertical decomposition allows the contribution of different contamination components to the macroscopic resistance to be separated and characterized for the first time, solving the key problem in the prior art that different components have different flashover voltages under the same ESDD but cannot be quantitatively distinguished. Using the intrinsic physicochemical parameters of each soluble salt as input, combined with the current local temperature of each micro-segment, the conductivity expression of each parallel branch is directly constructed, thereby accurately calculating the residual contamination resistance value of the insulator.

[0019] Other beneficial effects of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating an embodiment of the present invention; Figure 2 This is a schematic diagram of the discretization of the contamination resistance of a true-type unfolded plate in an embodiment of the present invention; Figure 3 This is a schematic diagram of the equivalent conductive width of a full-size unfolded flat plate in an embodiment of the present invention; Figure 4 This is a schematic diagram of obtaining conductive branches by decomposing micro-segments in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the residual pollution layer resistance calculation device for insulator pollution discharge in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the terminal device in an embodiment of the present invention. Detailed Implementation

[0021] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a locking connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] This invention addresses existing problems by providing a method and related equipment for calculating the residual pollution layer resistance of insulators during pollution discharge.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a method for calculating the residual pollution layer resistance of an insulator during pollution discharge, comprising: Step 1: Obtain the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; Step 2: Calculate the maximum width of the current distribution at each point on the creepage distance using the diameter of the contour circle at each measurement point, and unfold the target insulator into a true-size unfolded plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate. Step 3: Discretize the surface contaminant layer of the full-size unfolded plate to obtain multiple micro-segments; Step 4: Determine the geometry and boundary conditions of the true-form unfolded plate based on half of the maximum width of the current distribution at any point on the creepage distance. Simulate the surface current density distribution of each micro-segment and calculate the equivalent conductive width of each micro-segment based on the surface current density distribution. Step 5: Decompose each micro-segment longitudinally into multiple parallel conductive branches according to the dirt composition, and obtain the dirt resistance value of each conductive branch by calculating the conductivity of each conductive branch. Step 6: Calculate the contamination resistance value of each micro-segment based on the contamination resistance value of each conductive branch, and sum the contamination resistance values ​​of all micro-segments to obtain the remaining contamination resistance value on the target insulator when it is polluted.

[0027] Specifically, step 1 includes: Use a ruler or profilometer to fit the surface of the target insulator segment by segment along the marked leakage path, and measure the total path length from the top of the steel foot of the target insulator to the bottom of the iron cap to obtain the creepage distance of the target insulator. Along the leakage path, measurement points are set at equal intervals on the target insulator. At each measurement point, the diameter of the outline circle perpendicular to the central axis of the insulator is measured with a vernier caliper to obtain the outline circle diameter at each measurement point on the target insulator.

[0028] In this embodiment of the invention, when the target insulator is an insulator with a skirt, that is, the ruler or profilometer needs to be attached to the upper surface of the skirt, cross the edge of the skirt, and then be attached to the lower surface of the skirt to ensure that the path is continuous and uninterrupted. For the edge of the skirt, the geometric diameter corresponding to the leakage distance point x is equal to the diameter of the skirt circle, and for the root of the skirt, the geometric diameter corresponding to the leakage distance point x is equal to the diameter of the disc.

[0029] Because insulators contain complex groove and ridge structures, the electric field distribution is uneven, making it impossible to directly solve for the surface contamination resistance. This invention, in its embodiment, retains the actual structural features of the insulator and transfers the calculation of the contamination resistance to a unified discretization step, achieving a balance between accuracy and operability. This embodiment calculates the maximum width of the current distribution at each point along the creepage distance using the diameter of the contour circle at each measurement point, as the circumference of the insulator at each point, i.e., the unfolded width of the plate. The calculation expression is: ; in, This represents the circumference of the insulator at various points. This represents half the maximum width of the current distribution at each point along the creepage distance. This represents the geometric diameter corresponding to point x at the leakage distance; Then, starting from the high-voltage end of the target insulator, unfolding along the shortest arc development path, with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate, unfold the target insulator into a two-dimensional plane to obtain the true unfolded plate.

[0030] This invention takes a commonly used suspension insulator as an example, and obtains a true unfolded flat plate as shown in the embodiment of the invention. Figure 2 As shown; after arc initiation, the applied voltage is jointly borne by the arc and the resistance of the residual contaminant layer behind the arc root. At this time, the wet contaminant layer resistance is the same as the residual contaminant layer resistance. However, the thermal effect of the contaminant layer leakage current will cause dynamic changes in the wet contaminant layer resistance. The leakage current distribution on the surface of the true-size unfolded plate is uneven, and the unevenness is aggravated after arc initiation. Therefore, it is not possible to use The overall resistance of the wetted contaminant layer is calculated, where, Indicates volume resistivity. The length representing the direction of the current. This represents the cross-sectional area perpendicular to the current direction. Therefore, this embodiment of the invention transforms a non-uniformly distributed parameter problem that cannot be solved globally into a problem of a large number of independently processable uniform micro-segments. The surface temperature distribution, water content distribution, and conductivity distribution of the fouling layer are all functions of spatial coordinates and are coupled with each other, making it impossible to describe globally by a single analytical expression. However, after dividing the path into micro-segments with sufficiently small step sizes, the state variables inside each micro-segment can be approximated as constants. After solving independently and then accumulating along the path, it can be discretized and approximated as continuous. Figure 2 The middle arrow points to the micro-segment obtained from the discretization process, in which... Indicates distance from steel foot The equivalent water cover thickness at the location, Indicates the equivalent conductive width. This indicates the current value.

[0031] Because the insulator's shed and groove structure makes the geometry of the full-scale unfolded plate irregular, and the shape of the insulator is an important factor affecting the leakage current distribution, the leakage current on the surface of the full-scale unfolded plate is non-uniformly distributed. Especially after the arc is ignited, the current concentration effect generated at the arc root will further aggravate the non-uniformity of the current distribution, which will significantly affect the calculation accuracy of the pollution layer resistance. Therefore, before decomposing the micro-segment, it is necessary to simulate the surface current density distribution and determine the equivalent conductive width at each point on the surface of the full-scale unfolded plate in order to quantify the degree of non-uniformity of the current distribution.

[0032] Based on the current continuity equation and the relationship between surface current density and electric potential, the embodiments of the present invention derive the following expression: ; in, K Represents surface current density, A / m. Represents surface charge density, C / m 2 , Electric field strength, expressed in V / m. Indicates the potential distribution. , The operators for gradient and divergence are respectively. The conductivity of the contaminant layer is expressed in S. In the above equation, since the charge distribution no longer changes with time under DC steady-state conditions, therefore , E , V , K All are intermediate variables to be solved—their values ​​are unknown before the solution is obtained, but become known quantities after the solution is obtained and passed to subsequent steps. K For the final output, V and E These are intermediate derivation quantities; The geometry and boundary conditions of the true-form unfolded plate are known input quantities.

[0033] Based on the above set of equations, the potential control equation is obtained as follows: ; The influence of insulator surface salt density and equivalent water thickness on the spatial distribution of leakage current is negligible compared to the insulator geometry; therefore, the conductivity of the contaminant surface is... In space, it can be approximated as a uniform constant, and the above equation degenerates into the Laplace equation: ; The solution to the Laplace equation is uniquely determined by the boundary conditions. After arc initiation, the arc root is the entry point for current injection into the remaining contaminant layer, the grounding terminal is at zero potential, and there is no current crossing the two sides of the plate. Knowing the geometry of the plate and the aforementioned boundary conditions, the global potential distribution V can be solved using half the maximum width of the current distribution at each point along the creepage distance. Furthermore, the surface current density distribution can be obtained from the aforementioned equations. During simulation, the voltage applied to the steel legs of the plate and the resulting leakage current are considered. I The magnitude of the boundary condition only affects the overall amplitude of the solution and does not change the spatial shape of the surface current density distribution. It is a necessary boundary condition for solving the problem.

[0034] like Figure 3 As shown, based on the axisymmetry of the fully-fledged plate, the current density along the leakage path x is taken as the value on the axis of symmetry. After discretization, the center position of each micro-segment of the fully-fledged plate has a definite coordinate. The surface current density value can be directly extracted from the surface current density distribution at this coordinate. Based on the current density distribution, the expression for the equivalent conductive width of each micro-segment is obtained as follows: ; in, Indicates micro-segment The equivalent conductive width, Indicates the leakage current value. micro-segment The surface current density at the axis of symmetry, i.e. , A / m.

[0035] It should be noted that the equivalent conductive width in the embodiments of the present invention... w ( x It only relates to the unfolded shape of the insulator, that is, in the simulation solution w ( x When setting parameters such as voltage (or current), dirt layer thickness, and dirt layer conductivity within any reasonable range, the resulting... w ( x The value is constant.

[0036] Because the moisture adsorbed by the surface contamination layer of a contaminated insulator is unevenly distributed within the contamination layer, this invention introduces the concept of "equivalent water-attached thickness" to quantify this unevenness and further analyze the formation of dry areas and changes in conductivity. This concept is defined as: the moisture content within the contamination layer of the insulator is equivalent to the thickness of a water layer uniformly covering the surface of the contamination layer. The magnitude of the equivalent water-attached thickness depends on the insulator's moisture absorption capacity. When the insulator reaches saturation, the equivalent water-attached thickness represents the maximum moisture content per unit area. The formula for calculating the equivalent water-attached thickness is: ; in, This indicates the weight increase of the insulator due to contamination saturation and moisture absorption. This represents the wet density of the dirt layer. In this embodiment of the invention, the wet density of the dirt layer is equivalent to the density of the water layer, and is taken as 1 g / cm³. 3 , The surface area of ​​an insulator is expressed in cm². 2 .

[0037] It should be noted that the location of the arc root during insulator pollution discharge is directly taken as... , The radius of the arc root.

[0038] Because existing methods, when dealing with the chemical problem of conductivity in mixtures of multiple salts, remain at the level of treating all components as a single homogeneous conductivity, this invention decomposes each micro-segment longitudinally into multiple parallel conductive branches according to the contaminant components, such as... Figure 4 As shown.

[0039] Because the conductivity of a contaminated salt solution depends only on its concentration at a given temperature, and only on its temperature at a given concentration, temperature and concentration are two independent variables in the conductivity of the contaminated salt solution. Therefore, the conductivity characteristic equation for the contaminated salt solution as a function of temperature and concentration is: ; in, Indicates a conductive branch conductivity, This represents a coefficient related to the temperature of the contaminated salt solution. , These all represent coefficients related to the concentration of the contaminated salt solution. , , The conductivity was obtained by fitting the experimental conductivity values ​​into the conductivity calculation expression. Indicates a conductive branch temperature, Indicates the reference temperature. Indicates a conductive branch The concentration of is calculated using the following expression: ; In the formula, , , They refer to micro segments respectively No. Each conductive branch corresponds to the concentration of the type of pollution and the temperature. The maximum solubility concentration, solute mass and the first The equivalent conductive width of each conductive branch; The equivalent conductive width is primarily affected by the insulator structure, and since each micro-block is uniformly divided, the equivalent conductive width of each micro-block is equal. The expression for obtaining the contaminant resistance value of each conductive branch from its conductivity is as follows: ; in, Indicates a conductive branch The resistance value of the contaminant layer, This represents the length of each micro-segment after discretization. This indicates the types of contaminants contained in a micro-segment.

[0040] Specifically, under the influence of various mixed contaminants, the resistance of each micro-segment after discretization of the wet contaminant layer on the surface of the true-size unfolded plate is the reciprocal of the sum of the resistances of each conductive branch. The expression for calculating the contaminant resistance value of each micro-segment based on the contaminant resistance value of each conductive branch is as follows: ; in, Indicates micro-segment The resistance value of the contaminant layer, Indicates the number of conductive branches. .

[0041] Specifically, by summing up the pollution layer resistance values ​​of all micro-segments, the expression for the remaining pollution layer resistance value on the target insulator during pollution discharge is as follows: ; in, This indicates the resistance value of the residual contaminant layer on the target insulator during contaminant discharge. This indicates the number of micro-segments.

[0042] This invention provides an embodiment for obtaining the creepage distance of a target insulator and the diameter of the contour circle at each measurement point. The maximum width of the current distribution at each point along the creepage distance is calculated using the contour circle diameter at each measurement point. The target insulator is then unfolded into a full-size unfolded plate with the creepage distance as the abscissa and half the maximum width of the current distribution at any point along the creepage distance as the ordinate. The surface contamination layer of the full-size unfolded plate is discretized to obtain multiple micro-segments. The geometry and boundary conditions of the full-size unfolded plate are determined based on half the maximum width of the current distribution at any point along the creepage distance. The surface current density distribution of each micro-segment is simulated, and the equivalent conductive width of each micro-segment is calculated based on the surface current density distribution. Each micro-segment is decomposed longitudinally into multiple parallel conductive branches according to the contamination composition, and the contamination layer of each conductive branch is obtained by calculating the conductivity of each conductive branch. Resistance value; the pollution layer resistance value of each micro-segment is calculated based on the pollution layer resistance value of each conductive branch, and the pollution layer resistance values ​​of all micro-segments are summed to obtain the residual pollution layer resistance value on the target insulator during pollution discharge; compared with the prior art, the embodiment of the present invention discretizes the insulator surface along the leakage path into multiple series micro-segments, and each micro-segment is further decomposed into multiple parallel conductive branches along the longitudinal direction according to the pollution chemical composition. This two-layer architecture of horizontal discretization + vertical decomposition allows the contribution of different pollution components to the macroscopic resistance to be separated and characterized for the first time, solving the key problem in the prior art that different components have different flashover voltages under the same ESDD but cannot be quantitatively distinguished. Using the intrinsic physicochemical parameters of each soluble salt as input, combined with the current local temperature of each micro-segment, the conductivity expression of each parallel branch is directly constructed, thereby accurately calculating the residual pollution layer resistance value of the insulator.

[0043] like Figure 5 As shown, this embodiment of the invention also provides a device 100 for calculating the residual contaminant layer resistance of an insulator during pollution discharge. Applying the above-described method for calculating the residual contaminant layer resistance of an insulator during pollution discharge, the device 100 includes: The acquisition module 101 is used to acquire the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; The unfolding module 102 is used to calculate the maximum width of the current distribution at each point on the creepage distance by using the diameter of the contour circle at each measurement point, and unfold the target insulator into a true unfolding plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate. Discretization module 103 is used to discretize the surface contaminant layer of the full-size unfolded plate to obtain multiple micro-segments; The conversion module 104 is used to determine the geometry and boundary conditions of the true-form unfolded plate based on half of the maximum width of the current distribution corresponding to any point on the creepage distance, simulate the surface current density distribution of each micro-segment, and convert the surface current density distribution to obtain the equivalent conductive width of each micro-segment. The decomposition module 105 is used to decompose each micro-segment longitudinally into multiple parallel conductive branches according to the contaminant composition, and to obtain the contaminant resistance value of each conductive branch by calculating the conductivity of each conductive branch. The calculation module 106 is used to calculate the pollution resistance value of each micro-segment based on the pollution resistance value of each conductive branch, and to sum up the pollution resistance values ​​of all micro-segments to obtain the remaining pollution resistance value on the target insulator when it is polluted.

[0044] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0045] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0046] This invention also provides a terminal device, such as... Figure 6 As shown, the terminal device D10 of this embodiment includes: at least one processor D100 ( Figure 6The diagram shows only one processor, a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100. When the processor D100 executes the computer program D102, it implements the above-described method for calculating the residual pollution layer resistance of insulator pollution discharge.

[0047] The terminal device D10 can be a desktop computer, laptop, handheld computer, server, server cluster, or cloud server, etc. This terminal device may include, but is not limited to, a processor D100 and a memory D101. Those skilled in the art will understand that... Figure 6 This is merely an example of terminal device D10 and does not constitute a limitation on terminal device D10. It may include more or fewer components than shown in the figure, or combine certain components, or different components, such as input / output devices, network access devices, etc.

[0048] The processor D100 can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0049] In some embodiments, the memory D101 may be an internal storage unit of the terminal device D10, such as a hard disk or memory of the terminal device D10. In other embodiments, the memory D101 may be an external storage device of the terminal device D10, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the terminal device D10. Furthermore, the memory D101 may include both internal and external storage units of the terminal device D10. The memory D101 is used to store the operating system, applications, boot loader, data, and other programs, such as the program code of the computer program. The memory D101 can also be used to temporarily store data that has been output or will be output.

[0050] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0051] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0052] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements a method for calculating the residual contamination layer resistance of an insulator during contamination discharge.

[0053] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to a building device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0054] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for calculating the residual pollution layer resistance of an insulator during pollution discharge, characterized in that, include: Step 1: Obtain the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; Step 2: Calculate the maximum width of the current distribution at each point on the creepage distance using the diameter of the contour circle at each measurement point, and unfold the target insulator into a full-size unfolded plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate. Step 3: Discretize the surface contaminant layer of the true-shape unfolded plate to obtain multiple micro-segments; Step 4: Determine the geometry and boundary conditions of the true-size unfolded plate based on half of the maximum width of the current distribution corresponding to any point on the creepage distance. Simulate the surface current density distribution of each micro-segment and calculate the equivalent conductive width of each micro-segment based on the surface current density distribution. Step 5: Decompose each micro-segment longitudinally into multiple parallel conductive branches according to the dirt composition, and obtain the dirt layer resistance value of each conductive branch by calculating the conductivity of each conductive branch. Step 6: Calculate the contamination resistance value of each micro-segment based on the contamination resistance value of each conductive branch, and sum the contamination resistance values ​​of all micro-segments to obtain the remaining contamination resistance value on the target insulator when it is polluted.

2. The method for calculating the residual pollution layer resistance of an insulator during pollution discharge according to claim 1, characterized in that, Step 1 includes: Using a ruler or profilometer, the target insulator is attached to the surface segment by segment along the marked leakage path. The total path length from the top of the steel foot of the target insulator to the bottom of the iron cap is measured to obtain the creepage distance of the target insulator. Measurement points are set at equal intervals on the target insulator along the leakage path. At each measurement point, the diameter of the outline circle perpendicular to the central axis of the insulator is measured with a vernier caliper to obtain the outline circle diameter at each measurement point on the target insulator.

3. The method for calculating the residual pollution layer resistance of an insulator during pollution discharge according to claim 1, characterized in that, The expression for the equivalent conductive width of each micro-segment, calculated based on the surface current density distribution, is as follows: ； in, Indicates micro-segment The equivalent conductive width, Indicates the current value. micro-segment Surface current density at the axis of symmetry, A / m.

4. The method for calculating the residual pollution layer resistance of an insulator during pollution discharge according to claim 1, characterized in that, The expression for calculating the conductivity of each conductive branch is: ； in, Indicates a conductive branch conductivity, This represents a coefficient related to the temperature of the contaminated salt solution. , These all represent coefficients related to the concentration of the contaminated salt solution. , , The conductivity was obtained by fitting the experimental conductivity values ​​into the conductivity calculation expression. Indicates micro-segment dx temperature, Indicates the reference temperature. Indicates a conductive branch The corresponding salt concentration.

5. The method for calculating the residual pollution layer resistance of an insulator during pollution discharge according to claim 4, characterized in that, The expression for the contaminant resistance value of each conductive branch, obtained by calculating the conductivity of each conductive branch, is as follows: ； in, Indicates a conductive branch The resistance value of the contaminant layer, This represents the length of each micro-segment after discretization. This indicates the types of contaminants contained in a micro-segment.

6. The method for calculating the residual pollution layer resistance of an insulator during pollution discharge according to claim 5, characterized in that, The expression for calculating the contamination resistance value of each micro-segment based on the contamination resistance value of each conductive branch is as follows: ； in, Indicates micro-segment The resistance value of the contaminant layer, Indicates the number of conductive branches. .

7. The method for calculating the residual pollution layer resistance of an insulator during pollution discharge according to claim 6, characterized in that, The summation of the pollution layer resistance values ​​of all micro-segments yields the expression for the residual pollution layer resistance value on the target insulator during pollution discharge: ； in, This indicates the resistance value of the residual contaminant layer on the target insulator during contaminant discharge. This indicates the number of micro-segments.

8. A device for calculating the residual pollution layer resistance of an insulator during pollution discharge, characterized in that, The method for calculating the residual contamination layer resistance of an insulator as described in any one of claims 1-7, the calculation apparatus comprising: The acquisition module is used to acquire the creepage distance of the target insulator and the diameter of the contour circle at each measurement point; The unfolding module is used to calculate the maximum width of the current distribution at each point on the creepage distance by using the diameter of the contour circle at each measurement point, and unfold the target insulator into a true unfolding plate with the creepage distance as the abscissa and half of the maximum width of the current distribution at any point on the creepage distance as the ordinate. The discretization module is used to discretize the surface contaminant layer of the true-type unfolded plate to obtain multiple micro-segments; The conversion module is used to determine the geometry and boundary conditions of the true-size unfolded plate based on half of the maximum width of the current distribution corresponding to any point on the creepage distance, simulate the surface current density distribution of each micro-segment, and convert the surface current density distribution to obtain the equivalent conductive width of each micro-segment. The decomposition module is used to decompose each micro-segment longitudinally into multiple parallel conductive branches according to the contaminant composition, and to obtain the contaminant resistance value of each conductive branch by calculating the conductivity of each conductive branch. The calculation module is used to calculate the pollution resistance value of each micro-segment based on the pollution resistance value of each conductive branch, and to sum up the pollution resistance values ​​of all micro-segments to obtain the remaining pollution resistance value on the target insulator when it is polluted.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for calculating the residual pollution layer resistance of insulator pollution discharge as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the residual pollution layer resistance of insulator pollution discharge as described in any one of claims 1 to 7.

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