Methods for obtaining parameters in the construction of a charge transport model for polypropylene DC cables

Abstract

This application relates to a method, apparatus, computer equipment, storage medium, and computer program product for obtaining construction parameters of a charge transport model for a polypropylene DC cable. It pertains to the field of electrical cables. The method includes: cutting the cable at different locations within the insulation layer of a polypropylene DC cable with different service times to obtain multiple polypropylene sheets; for each polypropylene sheet, determining a test point based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable; measuring the parameters affecting charge accumulation within the insulation layer at the test point; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth; and obtaining the construction parameters of the charge transport model for the polypropylene DC cable based on the corresponding parameters for each polypropylene sheet. This method improves the accuracy of the obtained construction parameters for establishing the charge transport model of the polypropylene DC cable.

Description

Technical Field

[0001] This application relates to the field of electrical cable technology, and in particular to a method, apparatus, computer equipment, storage medium, and computer program product for obtaining construction parameters of a charge transport model for a polypropylene DC cable. Background Art

[0002] In the field of power cables, polypropylene possesses excellent electrical insulation properties and high heat resistance, as well as high mechanical strength and good chemical corrosion resistance. However, pure polypropylene exhibits poor flexibility at room temperature and is prone to space charge accumulation under high-voltage electric fields. Therefore, studying the accumulation of large amounts of space charge within polypropylene insulation materials under highly polarized electric fields has become an urgent problem to be solved.

[0003] However, current methods for obtaining the charge evolution law of polypropylene insulated high-voltage DC cables involve establishing a bipolar charge carrier transport model by acquiring the construction parameters from an existing charge carrier transport simulation model. However, the experimental objects used to obtain these construction parameters in existing technologies are solid insulating sheet samples. These sheets are typically prepared by hot pressing, and during heating and compression, the material molecules rearrange and recombine, resulting in properties significantly different from the polypropylene insulation material in actual polypropylene DC cables. Therefore, the construction parameters obtained for establishing charge transport models of polypropylene DC cables are currently inaccurate. Summary of the Invention

[0004] Therefore, it is necessary to address the technical problem that the construction parameters obtained above for establishing the charge transport model of polypropylene DC cable are not accurate enough, and to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for obtaining the construction parameters of the charge transport model of polypropylene DC cable.

[0005] In a first aspect, this application provides a method for obtaining the construction parameters of a charge transport model for a polypropylene DC cable, including:

[0006] Multiple polypropylene sheets were obtained by cutting the cable at different locations inside the insulation layer of polypropylene DC cables with different service times.

[0007] For each of the polypropylene sheets, the test point is determined based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable;

[0008] At the test point, the parameters affecting charge accumulation within the insulating layer are measured; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth.

[0009] Based on the influence parameters corresponding to each polypropylene sheet, the construction parameters of the charge transport model for the polypropylene DC cable are obtained.

[0010] In one embodiment, measuring the parameters affecting charge accumulation within the insulating layer at the test point includes: obtaining the electron mobility and hole mobility of the polypropylene sheet based on the time-of-flight method; and obtaining the electron deep trap depth and hole deep trap depth of the polypropylene sheet based on the isothermal surface potential decay method.

[0011] In one embodiment, obtaining the electron mobility and hole mobility of the polypropylene sheet based on the time-of-flight method includes: setting transparent conductive material and non-transparent conductive material on the left and right sides of the polypropylene sheet of a preset thickness, respectively; radiating a single-pulse laser from the transparent conductive material side to the polypropylene sheet to form an external circuit; monitoring the voltage of the external circuit and acquiring the current signal in the external circuit; obtaining the transit time of the charge carriers based on the current signal; and obtaining the electron mobility and hole mobility based on the thickness of the polypropylene sheet, the voltage, and the transit time.

[0012] In one embodiment, obtaining the electron deep trapping depth and the hole deep trapping depth of the polypropylene sheet based on the isothermal surface potential decay method includes: placing the polypropylene sheet of a preset thickness in a needle-plate electrode structure with a gate, and controlling the surface potential value of the polypropylene sheet to a preset value; when the surface potential value of the polypropylene sheet is the preset value, obtaining an expression for the deep trapping depth and an expression for the trappable charge density of the polypropylene sheet; and obtaining the electron deep trapping depth and the hole deep trapping depth according to the expression for the deep trapping depth and the expression for the trappable charge density.

[0013] In one embodiment, obtaining the construction parameters of the charge transport model for the polypropylene DC cable based on the influence parameters corresponding to each of the polypropylene sheets includes: obtaining an electron diffusion coefficient based on the electron mobility corresponding to each of the polypropylene sheets; obtaining a hole diffusion coefficient based on the hole mobility corresponding to each of the polypropylene sheets; obtaining an electron escape coefficient based on the electron deep trap depth corresponding to each of the polypropylene sheets; obtaining a hole escape coefficient based on the hole deep trap depth corresponding to each of the polypropylene sheets; and determining the electron diffusion coefficient, the hole diffusion coefficient, the electron escape coefficient, and the hole escape coefficient as the construction parameters of the charge transport model for the polypropylene DC cable.

[0014] In one embodiment, obtaining the construction parameters of the charge transport model of the polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet further includes: for each influence parameter, inputting the influence parameter corresponding to each polypropylene sheet into a preset fitting model, and using the fitting result as the target influence parameter; and obtaining the construction parameters of the charge transport model of the polypropylene DC cable based on the target influence parameter corresponding to each influence parameter.

[0015] Secondly, this application also provides a device for obtaining the construction parameters of a charge transport model for a polypropylene DC cable, comprising:

[0016] The polypropylene sheet acquisition module is used to slice polypropylene DC cables at different locations inside the insulation layer for different periods of use, thereby obtaining multiple polypropylene sheets.

[0017] The test point determination module is used to determine the test point for each polypropylene sheet based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable.

[0018] The influence parameter measurement module is used to measure the influence parameters affecting charge accumulation in the insulating layer at the test point; the influence parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth.

[0019] A parameter acquisition module is constructed to acquire the construction parameters of the charge transport model of polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet.

[0020] Thirdly, this application also provides a computer device, the computer device including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0021] Multiple polypropylene sheets were obtained by cutting the cable at different locations inside the insulation layer of polypropylene DC cables with different service times.

[0022] For each of the polypropylene sheets, the test point is determined based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable;

[0023] At the test point, the parameters affecting charge accumulation within the insulating layer are measured; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth.

[0024] Based on the influence parameters corresponding to each polypropylene sheet, the construction parameters of the charge transport model for the polypropylene DC cable are obtained.

[0025] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0026] Multiple polypropylene sheets were obtained by cutting the cable at different locations inside the insulation layer of polypropylene DC cables with different service times.

[0027] For each of the polypropylene sheets, the test point is determined based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable;

[0028] At the test point, the parameters affecting charge accumulation within the insulating layer are measured; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth.

[0029] Based on the influence parameters corresponding to each polypropylene sheet, the construction parameters of the charge transport model for the polypropylene DC cable are obtained.

[0030] Fifthly, this application also provides a computer program product, which includes a computer program that, when executed by a processor, performs the following steps:

[0031] Multiple polypropylene sheets were obtained by cutting the cable at different locations inside the insulation layer of polypropylene DC cables with different service times.

[0032] For each of the polypropylene sheets, the test point is determined based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable;

[0033] At the test point, the parameters affecting charge accumulation within the insulating layer are measured; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth.

[0034] Based on the influence parameters corresponding to each polypropylene sheet, the construction parameters of the charge transport model for the polypropylene DC cable are obtained.

[0035] The method, apparatus, computer equipment, storage medium, and computer program product for obtaining the construction parameters of the charge transport model for polypropylene DC cables described above have the following beneficial effects in the process of obtaining the construction parameters of the charge transport model for polypropylene DC cables: First, cable slices are taken at different locations inside the insulation layer of polypropylene DC cables with different usage times to obtain multiple polypropylene slices; then, for each polypropylene slice, the test point is determined based on the distance between the polypropylene slice and the center of the conductor of the polypropylene DC cable; next, at the test point, the parameters affecting charge accumulation in the insulation layer are measured; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth; finally, based on the corresponding parameters of each polypropylene slice, the construction parameters of the charge transport model for the polypropylene DC cable are obtained. In the above process, by selecting polypropylene DC cables with different usage times and taking cable slices at different locations inside their insulation layers to obtain multiple polypropylene slices, the parameters affecting the charge transport model in the polypropylene DC cable can be obtained more accurately. The construction parameters obtained through multiple sets of parameters are also more accurate. Therefore, the above process effectively improves the accuracy of the obtained construction parameters for establishing the charge transport model of the polypropylene DC cable. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is an application environment diagram illustrating the method for obtaining construction parameters of a charge transport model for a polypropylene DC cable in one embodiment.

[0038] Figure 2 This is a flowchart illustrating the method for obtaining the construction parameters of a charge transport model for a polypropylene DC cable in one embodiment.

[0039] Figure 3 This is a schematic diagram illustrating the principle of time-of-flight measurement in one embodiment;

[0040] Figure 4 This is a schematic diagram illustrating the experimental principle of the isothermal surface potential decay method in another embodiment;

[0041] Figure 5 This is an example of the bipolar carrier conduction mechanism principle within the medium.

[0042] Figure 6This is a schematic diagram of the basic system block diagram for obtaining the construction parameters of the charge transport model of a polypropylene DC cable in one embodiment;

[0043] Figure 7 This is a schematic diagram of a polypropylene DC cable slice and sampling points in one embodiment;

[0044] Figure 8 This is a structural block diagram of a device for obtaining the construction parameters of a charge transport model for a polypropylene DC cable in one embodiment.

[0045] Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] In an exemplary embodiment, Figure 1 As shown, a method for obtaining the construction parameters of a charge transport model for a polypropylene DC cable is provided. This embodiment illustrates the application of this method to a terminal. It is understood that this method can also be applied to a server, and to a system including both a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps S102 to S108. Wherein:

[0048] Step S102: Cut the cable into multiple polypropylene sheets at different locations inside the insulation layer of polypropylene DC cables with different usage times.

[0049] Polypropylene is a thermoplastic with excellent electrical insulation properties, chemical resistance, and thermal stability, and is commonly used as an insulation material for DC cables. Cable slicing refers to slicing the insulation layer of a cable to facilitate the analysis of its internal structure and performance.

[0050] Alternatively, a slicer can be used to cut DC polypropylene cables with service lives of 0.5 years, 1 year, and 2 years into segments, and the polypropylene insulation layer of the obtained cable segments can be sliced ​​to cut 100μm and 200μm polypropylene sheets according to different positions of the insulation layer.

[0051] Step S104: For each polypropylene sheet, determine the test point based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable.

[0052] In this context, the test point within the polypropylene sheet refers to a specific location determined by the distance between the polypropylene sheet and the center of the conductor. The number of test points is related to the number and location of the polypropylene sheet slices. This method is typically used to obtain parameters related to the effect of charge accumulation in polypropylene DC cables.

[0053] Step S106: At the test point, measure the parameters that affect charge accumulation in the insulating layer; the parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth.

[0054] Among them, the influencing parameters refer to the parameters that affect the accumulation and transport characteristics of charge within the insulation layer of a DC cable; electron mobility refers to the ability of electrons to migrate under the influence of an electric field; hole mobility refers to the ability of positive charges to migrate in an electric field; a hole is a missing position left by an electron after it jumps from the valence band to the conduction band in the band structure of a material, and the position carries a positive charge; electron deep trap refers to a defect or impurity in the material that can trap an electron and trap it in an energy level lower than the valence band; the deep trap depth refers to the energy depth of the trap, that is, the energy barrier that the electron needs to overcome to be released from the trap to the conduction band (or valence band); hole deep trap refers to a defect or impurity in the material that can trap a hole, and its depth refers to the energy barrier that the hole needs to overcome to be released from the trap to the valence band.

[0055] Specifically, high electron mobility means that electrons can move more freely in an electric field, thus affecting the flow of charge in the electric field; similarly, hole mobility also affects the flow of charge in an electric field; deep traps limit the availability of electrons because electrons in traps cannot participate in conduction, and electron deep traps under the action of a high electric field will lead to the accumulation and uneven distribution of charge; correspondingly, hole deep traps affect the migration ability of positive charges.

[0056] Step S108: Based on the influence parameters corresponding to each polypropylene sheet, obtain the construction parameters of the charge transport model for the polypropylene DC cable.

[0057] The construction parameters refer to the parameters used to establish the final charge transport model of the polypropylene DC cable, and are obtained through the influence parameters obtained in the above steps. However, due to the different usage time and slicing positions of the polypropylene DC cable used to form polypropylene sheets, multiple polypropylene sheets will be obtained. Each polypropylene sheet has multiple influence parameters, and multiple polypropylene sheets each have multiple influence parameters. Therefore, it is necessary to perform data fitting on the multiple influence parameters corresponding to the construction parameters to obtain the construction parameters.

[0058] In the above method for obtaining the construction parameters of the charge transport model for polypropylene DC cables, firstly, cable slices are taken at different locations inside the insulation layer of polypropylene DC cables with different usage times, resulting in multiple polypropylene slices. Then, for each polypropylene slice, the test point is determined based on the distance between the polypropylene slice and the center of the conductor of the polypropylene DC cable. Next, at the test point, the parameters affecting charge accumulation within the insulation layer are measured. These parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth. Finally, based on the corresponding parameters for each polypropylene slice, the construction parameters of the charge transport model for the polypropylene DC cable are obtained. In this process, by selecting polypropylene DC cables with different usage times and taking cable slices at different locations inside their insulation layers to obtain multiple polypropylene slices, the parameters affecting the charge transport model in the polypropylene DC cable can be obtained more accurately. The construction parameters obtained through multiple sets of parameters are also more precise. Therefore, the above process effectively improves the accuracy of the obtained construction parameters for establishing the charge transport model of the polypropylene DC cable.

[0059] In an exemplary embodiment, Figure 2 As shown, step S106 involves measuring the parameters affecting charge accumulation within the insulating layer at the test point, including steps S202 to S204. Wherein:

[0060] Step S202: Obtain the electron mobility and hole mobility of the polypropylene sheet based on the time-of-flight method.

[0061] The time-of-flight method is a technique used to measure the mobility of charge carriers in materials. The basic principle is to apply an electric field to accelerate charge carriers through a region of known distance in the material and calculate the mobility by measuring the time required for the charge carriers to pass through the region.

[0062] Step S204: Obtain the electron deep trap depth and hole deep trap depth of the polypropylene sheet based on the isothermal surface potential decay method.

[0063] Among them, the isothermal surface potential decay method is a technique used to measure the deep trap characteristics in materials. By measuring the decay of the potential on the surface of the material over time at a certain temperature, the trap’s trapping and releasing characteristics of charge carriers can be inferred, thereby calculating the depth of the trap.

[0064] In this embodiment, by measuring the electron mobility and hole mobility of polypropylene sheets, their conductivity in electronic devices can be evaluated. The level of mobility directly affects the performance of polypropylene sheets in high-frequency and high-voltage applications. By measuring the depth of deep traps, the influence of defects and impurities in polypropylene sheets can be understood, helping to identify potential problems in the corresponding materials.

[0065] Further, in one embodiment, step S202, which obtains the electron mobility and hole mobility of the polypropylene sheet based on the time-of-flight method, includes: setting transparent conductive materials and non-transparent conductive materials on the left and right sides of a polypropylene sheet of a preset thickness, respectively; radiating a single-pulse laser from the transparent conductive material side to the polypropylene sheet to form an external circuit; monitoring the voltage of the external circuit and acquiring the current signal in the external circuit; obtaining the transit time of the charge carriers based on the current signal; and obtaining the electron mobility and hole mobility based on the thickness value, voltage, and transit time of the polypropylene sheet.

[0066] Among them, transparent conductive materials can be indium tin oxide (ITO), which has good conductivity and light transmittance and is often used in applications such as displays and solar cells; non-transparent conductive materials are usually metallic materials, such as aluminum and copper, which are opaque but have good conductivity; single-pulse laser refers to a laser pulse that releases energy in a short time, which can excite charge carriers in the material and generate current signals; the transit time of charge carriers refers to the time required for charge carriers to move from one side to the other in a polypropylene sheet, reflecting the migration speed of charge carriers.

[0067] Specifically, if Figure 3 As shown, the device structure used in the time-of-flight method measurement is: electrode-polypropylene sheet-electrode. A significant potential barrier exists between the electrode and the polypropylene sheet. Applying a voltage directly between the two electrodes results in a very small current in the circuit. At the start of the test, a single-pulse laser with a pulse width on the nanosecond scale irradiates the sample from one side of the transparent electrode. The polypropylene sheet thickness is 100 μm and 200 μm. The laser cannot penetrate the sample but generates a thin layer of holes and electrons near the electrode. Taking the hole test as an example, the transparent electrode is connected to the positive electrode. Under the influence of the electric field, the electrons generated by the laser radiation quickly enter the positive electrode, while the holes move towards the negative electrode. As the holes move, a current is induced in the external circuit. The voltage across a known resistor connected in series in the external circuit can be recorded using an oscilloscope to obtain the current in the circuit. When the charge carriers completely reach the negative electrode, the current in the external circuit disappears. The resulting transient current signal can be used to determine the time it takes for the charge carriers to travel between the two electrodes; this is called the transit time.

[0068] In this embodiment, by setting different types of conductive materials on both sides of a polypropylene sheet and using a single-pulse laser to excite charge carriers, an external circuit is formed to monitor current and voltage. By analyzing the current signal, the transit time of the charge carriers can be calculated. Combined with the thickness of the polypropylene sheet and the applied voltage, the electron mobility and hole mobility can be obtained, thereby evaluating the electrical performance of the material.

[0069] In one embodiment, step S202, which obtains the electron deep trapping depth and hole deep trapping depth of the polypropylene sheet based on the isothermal surface potential decay method, includes: placing a polypropylene sheet of a preset thickness in a needle-plate electrode structure with a gate, and controlling the surface potential value of the polypropylene sheet to a preset value; obtaining an expression for the deep trapping depth and an expression for the trappable charge density of the polypropylene sheet when the surface potential value of the polypropylene sheet is the preset value; and obtaining the electron deep trapping depth and hole deep trapping depth based on the expressions for the deep trapping depth and the trappable charge density.

[0070] Among them, the gated needle-plate electrode structure is an electrode configuration consisting of a needle-shaped electrode and a planar electrode, with a gate for adjusting the electric field distribution, and is usually used to study the electrical properties of materials; the surface potential value refers to the potential applied to the surface of the polypropylene sheet, which can affect the distribution and behavior of charge carriers within the material; deep traps refer to the energy states existing inside the material, used to trap charge carriers (electrons or holes), usually located at a deeper position between the conduction band and the valence band; the deep trap depth describes the energy difference between the trap energy level and the bottom of the conduction band or the top of the valence band, characterizing the depth of the trap energy level.

[0071] Specifically, if Figure 4 As shown, the positive and negative ions ionized by the needle electrode migrate to the sample surface under the action of the electric field. Under the clamping effect of the grid voltage, the sample surface potential value can be close to the preset value. If the trap charge decays by thermal de-trapping and will not re-enter the trap once de-trapped, and the migration of charge between deep and shallow traps is ignored, the trap distribution characteristic curve is measured. The two trap density peaks represent the centers of deep and shallow traps, respectively, and the trap with the higher energy level is the depth of the deep trap.

[0072] In this embodiment, by placing a polypropylene sheet in a specific needle-plate electrode structure with a gate and controlling its surface potential, the surface potential value can adjust the internal electric field, thereby affecting the carrier behavior inside the material. This reflects the carrier trapping characteristics of the material under the influence of the electric field and helps to obtain the behavior of electrons and holes in deep traps.

[0073] More specifically, in one embodiment, step S108 obtains the construction parameters of the charge transport model for the polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet, including: obtaining the electron diffusion coefficient based on the electron mobility corresponding to each polypropylene sheet; obtaining the hole diffusion coefficient based on the hole mobility corresponding to each polypropylene sheet; obtaining the electron detrapping coefficient based on the electron deep trapping depth corresponding to each polypropylene sheet; obtaining the hole detrapping coefficient based on the hole deep trapping depth corresponding to each polypropylene sheet; and determining the electron diffusion coefficient, hole diffusion coefficient, electron detrapping coefficient, and hole detrapping coefficient as the construction parameters of the charge transport model for the polypropylene DC cable.

[0074] Specifically, the electron mobility of multiple polypropylene sheets is obtained, and the data of multiple electron mobility is processed to obtain the electron diffusion coefficient in the final bonding parameters; correspondingly, the hole mobility, electron deep trapping depth, and hole deep trapping depth of multiple polypropylene sheets are obtained, and the data of multiple hole mobility, electron deep trapping depth, and hole deep trapping depth are processed to obtain the hole diffusion coefficient, electron detrapping coefficient, and hole detrapping coefficient in the final bonding parameters.

[0075] In this embodiment, by processing the data of the influence parameters of multiple polypropylene sheets, the final construction parameters are obtained, which can yield more accurate construction parameters and effectively improve the accuracy of the charge transport model of polypropylene DC cable.

[0076] In one embodiment, step S108, based on the influence parameters corresponding to each polypropylene sheet, obtains the construction parameters of the charge transport model for the polypropylene DC cable, and further includes: for each influence parameter, inputting the influence parameter corresponding to each polypropylene sheet into a preset fitting model, and using the fitting result as the target influence parameter; and obtaining the construction parameters of the charge transport model for the polypropylene DC cable based on the target influence parameter corresponding to each influence parameter.

[0077] Specifically, a fitting model for the influencing parameters is established using multiple sets of historical data. When a new influencing parameter needs to be fitted, the data is first cleaned to remove noise and outliers. The data can be divided into training and testing sets. Then, a fitting model is selected to fit the data. Common models include linear regression, nonlinear regression, multinomial regression, and exponential models, thereby obtaining the final construction parameters, including electron diffusion coefficient, hole diffusion coefficient, electron detrapping coefficient, and hole detrapping coefficient.

[0078] In this embodiment, a fitting model is established using historical data. After processing multiple influencing parameters using the fitting model, the final construction parameters are calculated, which can make the obtained construction parameters more accurate. The charge transport model of polypropylene DC cable established by the construction parameters is more accurate.

[0079] More often, in one embodiment, such as Figure 5 The diagram illustrates the principle of bipolar carrier conduction within a dielectric medium. The conduction process comprises three parts: electrode injection of electrons and holes, trapping and release from traps, and recombination. The model includes four types of charged particles: free electrons, free holes, trapped electrons, and trapped holes. Based on the above steps, the electron diffusion coefficient, hole diffusion coefficient, electron deep trapping coefficient, and hole deep trapping coefficient are obtained. These coefficients allow for comparative analysis of charge transport characteristics changes at different locations within the cable and insulation layer over different service times, thus establishing a charge transport model for polypropylene DC cables.

[0080] Furthermore, this application can use any chip cutter for slicing cable insulation layers to obtain 100μm and 200μm polypropylene sheets; a polymer carrier mobility measurement device to measure the electron mobility and hole mobility inside the medium based on the time-of-flight method; a polymer trap measurement device to measure the deep trap depth and trap charge density of electrons and holes inside the medium based on the isothermal surface potential decay method; and a data processing system for processing experimental data, analyzing and calculating the construction parameters of the charge transport model, and comparing the polypropylene insulation parameters at different usage times and locations.

[0081] Specifically, if Figure 6 As shown, polypropylene cables with different service durations were first obtained, and then slices were taken at different locations in the insulation layer. Experiments were then conducted at the corresponding points on the slices. The depth of electron and hole traps in polypropylene was measured using the Isothermal Surface Profile Decay Method (ISPD), and the electron and hole detrapping coefficients were calculated. The electron and hole mobility of polypropylene was measured using the Time-of-Flight (TOF) method, and the electron and hole diffusion coefficients were calculated. A bipolar carrier charge transport model was then established based on the above four coefficients.

[0082] The implementation of this method includes a slicer and two measuring devices to measure the trap depth, trap density and carrier mobility of the slices of polypropylene DC cable insulation layer. Finally, the parameters for constructing the charge transport model are obtained through data processing, and a bipolar carrier charge transport model for polypropylene DC cable is established.

[0083] In the above embodiments, by measuring the parameters of cable insulation layer slices used for different durations, the authenticity and objectivity of the data are ensured. The study of the charge transport characteristics of insulation materials is of great significance in practical production applications.

[0084] More, such as Figure 7 The diagram shows a cross-section and sampling point of a polypropylene DC cable. 1 is the conductor part, and the center of conductor 1 is the conductor center 2. 3 is the insulation layer part. 4 indicates the cutting position of the three polypropylene sheets. 5 is the copper strip and 6 is the sheath.

[0085] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0086] Based on the same inventive concept, this application also provides an apparatus for obtaining the construction parameters of a polypropylene DC cable charge transport model, used to implement the method for obtaining construction parameters of the polypropylene DC cable charge transport model described above. The solution provided by this apparatus is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the apparatus for obtaining construction parameters of a polypropylene DC cable charge transport model provided below can be found in the limitations of the method for obtaining construction parameters of a polypropylene DC cable charge transport model described above, and will not be repeated here.

[0087] In an exemplary embodiment, Figure 8 As shown, a device for obtaining construction parameters for a charge transport model of a polypropylene DC cable is provided, comprising: a polypropylene sheet acquisition module 801, a test point determination module 802, an influence parameter measurement module 803, and a construction parameter acquisition module 804, wherein:

[0088] The polypropylene sheet acquisition module 801 is used to slice the cable at different locations inside the insulation layer of polypropylene DC cables with different service times, thereby obtaining multiple polypropylene sheets.

[0089] The test point determination module 802 is used to determine the test point for each polypropylene sheet based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable.

[0090] The influence parameter measurement module 803 is used to measure the influence parameters affecting charge accumulation in the insulating layer at the test point; the influence parameters include electron mobility, hole mobility, electron deep trap depth and hole deep trap depth.

[0091] The parameter acquisition module 804 is used to acquire the construction parameters of the charge transport model of polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet.

[0092] Furthermore, in one embodiment, the influence parameter measurement module 803 is also used to obtain the electron mobility and hole mobility of the polypropylene sheet based on the time-of-flight method; and to obtain the electron deep trap depth and hole deep trap depth of the polypropylene sheet based on the isothermal surface potential decay method.

[0093] Furthermore, in one embodiment, the influence parameter measurement module 803 is also used to set transparent conductive materials and non-transparent conductive materials on the left and right sides of a polypropylene sheet of a preset thickness, respectively; to radiate a single-pulse laser from the transparent conductive material side to the polypropylene sheet to form an external circuit, monitor the voltage of the external circuit and acquire the current signal in the external circuit; to obtain the transit time of charge carriers based on the current signal; and to acquire electron mobility and hole mobility based on the thickness value, voltage and transit time of the polypropylene sheet.

[0094] Furthermore, in one embodiment, the influence parameter measurement module 803 is also used to place a polypropylene sheet of a preset thickness in a needle-plate electrode structure with a gate, and control the surface potential value of the polypropylene sheet to a preset value; when the surface potential value of the polypropylene sheet is the preset value, obtain the expression for the deep trapping depth and the expression for the trappable charge density of the polypropylene sheet; and obtain the electron deep trapping depth and the hole deep trapping depth according to the expression for the deep trapping depth and the expression for the trappable charge density.

[0095] Furthermore, in one embodiment, the parameter acquisition module 804 is also used to acquire an electron diffusion coefficient based on the electron mobility corresponding to each polypropylene sheet; acquire a hole diffusion coefficient based on the hole mobility corresponding to each polypropylene sheet; acquire an electron detrapping coefficient based on the electron deep trap depth corresponding to each polypropylene sheet; acquire a hole detrapping coefficient based on the hole deep trap depth corresponding to each polypropylene sheet; and determine the electron diffusion coefficient, hole diffusion coefficient, electron detrapping coefficient, and hole detrapping coefficient as the construction parameters of the charge transport model of the polypropylene DC cable.

[0096] Furthermore, in one embodiment, the parameter acquisition module 804 is also used to establish a fitting model for the influence parameters corresponding to multiple polypropylene sheets; input the influence parameters corresponding to each polypropylene sheet into the fitting model respectively, and use the fitting result as the target influence parameter for acquiring the construction parameters; based on the target influence parameter, acquire the construction parameters of the charge transport model of the polypropylene DC cable.

[0097] The modules in the device for acquiring the construction parameters of the aforementioned polypropylene DC cable charge transport model can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0098] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 9 As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data about polypropylene sheets. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When executed by the processor, the computer program implements a method for obtaining construction parameters for a charge transport model of a polypropylene DC cable.

[0099] Those skilled in the art will understand that Figure 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0100] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0101] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0102] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0103] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0104] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0105] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for obtaining the construction parameters of a charge transport model for a polypropylene DC cable, characterized in that, The method includes: Multiple polypropylene sheets were obtained by cutting the cable at different locations inside the insulation layer of polypropylene DC cables with different service times. For each of the polypropylene sheets, the test point is determined based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable; At the test point, the parameters affecting charge accumulation within the insulating layer are measured; these parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth. Based on the influence parameters corresponding to each polypropylene sheet, the construction parameters of the charge transport model for the polypropylene DC cable are obtained.

2. The method according to claim 1, characterized in that, The measurement of parameters affecting charge accumulation within the insulating layer at the test point includes: The electron mobility and hole mobility of the polypropylene sheet were obtained based on the time-of-flight method. The electron deep trap depth and hole deep trap depth of the polypropylene sheet were obtained based on the isothermal surface potential decay method.

3. The method according to claim 2, characterized in that, The method of obtaining the electron mobility and hole mobility of the polypropylene sheet based on the time-of-flight method includes: Transparent conductive material and non-transparent conductive material are respectively disposed on the left and right sides of the polypropylene sheet of a preset thickness; A single-pulse laser is radiated from the transparent conductive material side to the polypropylene sheet to form an external circuit, and the voltage of the external circuit is monitored and the current signal in the external circuit is acquired. The transit time of the charge carriers is obtained from the current signal. The electron mobility and hole mobility are obtained based on the thickness of the polypropylene sheet, the voltage, and the transit time.

4. The method according to claim 2, characterized in that, The method of obtaining the electron deep trap depth and hole deep trap depth of the polypropylene sheet based on the isothermal surface potential decay method includes: A polypropylene sheet of a preset thickness is placed in a needle-plate electrode structure with a gate, and the surface potential value of the polypropylene sheet is controlled to a preset value. Given a preset surface potential value for the polypropylene sheet, obtain expressions for the deep trapping depth and the trappable charge density of the polypropylene sheet. The electron deep trap depth and the hole deep trap depth are obtained based on the expressions for the deep trap depth and the trappable charge density.

5. The method according to claim 1, characterized in that, The process of obtaining the construction parameters for the charge transport model of the polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet includes: The electron diffusion coefficient is obtained based on the electron mobility corresponding to each polypropylene sheet. Based on the hole mobility corresponding to each polypropylene sheet, the hole diffusion coefficient is obtained; The electron detrapping coefficient is obtained based on the electron deep trapping depth corresponding to each of the polypropylene sheets; Based on the cavity deep trap depth corresponding to each of the polypropylene sheets, the cavity detrapping coefficient is obtained; The electron diffusion coefficient, hole diffusion coefficient, electron detrapping coefficient, and hole detrapping coefficient are determined as the construction parameters for the charge transport model of polypropylene DC cable.

6. The method according to claim 1, characterized in that, The step of obtaining the construction parameters for the charge transport model of the polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet further includes: For each influencing parameter, the influencing parameter corresponding to each polypropylene sheet is input into a preset fitting model, and the fitting result is used as the target influencing parameter. Based on the target influence parameter corresponding to each influence parameter, the construction parameters of the charge transport model of polypropylene DC cable are obtained.

7. A device for obtaining construction parameters of a charge transport model for a polypropylene DC cable, characterized in that, The device includes: The polypropylene sheet acquisition module is used to slice polypropylene DC cables at different locations inside the insulation layer for different periods of use, thereby obtaining multiple polypropylene sheets. The test point determination module is used to determine the test point for each polypropylene sheet based on the distance between the polypropylene sheet and the center of the conductor of the polypropylene DC cable. The influence parameter measurement module is used to measure the influence parameters affecting charge accumulation in the insulating layer at the test point; the influence parameters include electron mobility, hole mobility, electron deep trap depth, and hole deep trap depth. A parameter acquisition module is constructed to acquire the construction parameters of the charge transport model of polypropylene DC cable based on the influence parameters corresponding to each polypropylene sheet.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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