Cable current-carrying capacity-based cable temperature rise analysis method, medium and equipment

Abstract

The invention relates to a cable temperature rise analysis method based on cable current-carrying capacity, a medium and equipment. Comprises: establishing a geometric model of a cable according to a cable structure; arranging the geometric model according to a preset arrangement mode to construct a three-dimensional laying model, and simplifying the three-dimensional laying model into a two-dimensional laying model; the two-dimensional laying model is laid in soil in a simulated mode, boundary conditions are determined, and a thermodynamic model of the two-dimensional laying model is constructed; and analyzing the thermodynamic models under different current-carrying capacities by adopting a finite element method to obtain a relational expression between the current-carrying capacity and the temperature steady-state value of the cable core and a relational expression between the current-carrying capacity and the temperature steady-state value of the outer sheath. The thermodynamic models under different current-carrying capacities are analyzed by adopting a finite element method, the relationship between the temperature steady-state value of the cable and the load current is disclosed, the temperature steady-state value of the cable can be predicted according to the load current, and a scientific basis is provided for design and operation of the cable.

Description

Background Art

[0002] In the design and operation of power systems, the temperature rise characteristics of cables are one of the key indicators for evaluating their safety and reliability. With the continuous increase in power load, cables often need to carry higher currents during actual operation, which directly leads to changes in cable temperature rise. Excessive temperature rise not only accelerates the aging of cable insulation materials but may also cause serious accidents such as short circuits and fires, threatening the stable operation of the power system. Therefore, in-depth research on the temperature rise characteristics of cables under different current-carrying capacities is of great significance for optimizing cable design, improving operation efficiency, and extending service life.

[0003] Therefore, it is necessary to provide a new technical solution to improve one or more problems existing in the above solution.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present application, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a cable temperature rise analysis method, medium, and device based on cable current-carrying capacity, thereby at least to some extent overcoming one or more problems caused by the limitations and defects of related technologies.

[0006] According to the first aspect of the embodiments of the present application, a cable temperature rise analysis method based on cable current-carrying capacity is provided. The method includes:

[0007] Establish a geometric model of the cable according to the cable structure; wherein, the cable structure includes a cable core, a cable core shielding layer, an insulating layer, a metal shielding layer, and an outer sheath from the inside out;

[0008] Arrange the geometric model according to a preset arrangement method to construct a three-dimensional laying model, and simplify the three-dimensional laying model into a two-dimensional laying model; wherein, the preset arrangement method includes a horizontal laying spacing and a vertical laying spacing, and the two-dimensional laying model includes a geometric model of M×N; wherein, M is the number of arrangements of the geometric model in the horizontal direction, and N is the number of arrangements of the geometric model in the vertical direction;

[0009] Simulate the two-dimensional laying model in the soil, determine the boundary conditions, and construct a thermodynamic model of the two-dimensional laying model;

[0010] Analyze the thermodynamic model under different current-carrying capacities by using the finite element method to obtain the relationship between the current-carrying capacity and the steady-state temperature value of the cable core, and the relationship between the current-carrying capacity and the steady-state temperature value of the outer sheath.

[0011] In the embodiments of the present application, the boundary conditions include:

[0012] It is set that the conditions of the soil, the temperature of the soil, and the laying environment remain unchanged; wherein, the initial temperature of the two-dimensional laying model is equal to the temperature of the soil, and the conditions of the soil include the thermal conductivity of the soil.

[0013] The control equation of the two-dimensional laying model is:

[0014] T(x,y)|Γ=f(x,y)|Γ(1);

[0015] In the formula, Γ represents the region boundary, x and y represent the coordinate positions of the two-dimensional laying model, T represents the temperature at the point (x,y), and f(x,y) represents the temperature function that changes with time and position on the known boundary surface.

[0016] In the embodiments of the present application, the thermodynamic model includes the heat conduction differential equation of the heat source region and the heat conduction differential equation of the non-heat source region; wherein, the heat source region includes the cable core, the insulating layer, and the metal shielding layer, and the non-heat source region includes the cable core shielding layer, the outer sheath, and the soil.

[0017] In the embodiments of the present application, the heat conduction differential equation of the heat source region is:

[0018]

[0019] In the formula, q v represents the heat generation rate per unit volume of the heat source, and λ represents the thermal conductivity of the medium.

[0020] In the embodiments of the present application, the heat conduction differential equation of the non-heat source region is:

[0021]

[0022] In the embodiments of the present application, the step of analyzing the thermodynamic model under different current-carrying capacities by using the finite element method to obtain the relationship between the current-carrying capacity and the steady-state temperature value of the cable core, and the relationship between the current-carrying capacity and the steady-state temperature value of the outer sheath includes:

[0023] Applying different load currents to the cable core in the two-dimensional laying model for simulation;

[0024] According to the heat conduction differential equation of the heat source region, obtaining the corresponding steady-state temperature value of the cable core;

[0025] And, according to the heat conduction differential equation of the non-heat source region, obtaining the corresponding steady-state temperature value of the outer sheath.

[0026] In the embodiments of the present application, after the step of obtaining the corresponding temperature steady-state value of the cable core according to the heat conduction differential equation of the heat source region, the following steps are included:

[0027] When the load current is less than or equal to the preset current, according to the load current and the corresponding temperature steady-state value of the cable core, a first relationship between the load current and the temperature steady-state value of the cable core is obtained;

[0028] When the load current is greater than the preset current, according to the load current and the corresponding temperature steady-state value of the cable core, a second relationship between the load current and the temperature steady-state value of the cable core is obtained;

[0029] In the embodiments of the present application, after the step of obtaining the corresponding temperature steady-state value of the outer sheath according to the heat conduction differential equation of the heat source-free region, the following steps are included:

[0030] When the load current is less than or equal to the preset current, according to the load current and the corresponding temperature steady-state value of the outer sheath, a first relationship between the load current and the temperature steady-state value of the outer sheath is obtained;

[0031] When the load current is greater than the preset current, a second relationship between the load current and the corresponding temperature steady-state value of the outer sheath is obtained.

[0032] In the embodiments of the present application, the first relationship between the load current and the temperature steady-state value of the cable core is:

[0033] T 缆芯 = 94.2I 2 - 14.1I + 20.45(4);

[0034] The second relationship between the load current and the temperature steady-state value of the cable core is:

[0035] T 缆芯 = 178 × I - 78.35(5);

[0036] The first relationship between the load current and the temperature steady-state value of the outer sheath is:

[0037] T 外护 = 59.12x 2 - 10.67x + 20.12(6);

[0038] The second relationship between the load current and the temperature steady-state value of the outer sheath is:

[0039] T 外护 = 1.02 × I - 35.15(7);

[0040] In the formula, T缆芯 represents the steady-state temperature value of the cable core, I represents the load current, and T 外护 represents the steady-state temperature value of the outer sheath.

[0041] According to a second aspect of the embodiments of the present application, there is provided a computer-readable storage medium having stored thereon a computer program, which when executed by a processor implements the steps of the method for analyzing the cable temperature rise based on the cable current-carrying capacity described in any one of the above embodiments.

[0042] According to a fourth aspect of the embodiments of the present application, there is provided an electronic device, including:

[0043] a processor; and

[0044] a memory for storing executable instructions of the processor;

[0045] wherein the processor is configured to execute the steps of the method for analyzing the cable temperature rise based on the cable current-carrying capacity described in any one of the above embodiments by executing the executable instructions.

[0046] The technical solutions provided by the embodiments of the present application may include the following beneficial effects:

[0047] In one embodiment of the present application, by the above method, the three-dimensional laying model is simplified to a two-dimensional laying model, reducing the computational complexity in subsequent temperature rise analysis; the boundary conditions are determined, and a thermodynamic model for the two-dimensional laying model is constructed, and the finite element method is used to analyze the thermodynamic model under different current-carrying capacities, revealing the relationship between the steady-state temperature value of the cable and the load current, and the steady-state temperature value of the cable can be predicted according to the load current, providing a scientific basis for the design and operation of the cable.

[0048] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0050] Figure 1 Schematically showing a flowchart of the steps of a method for analyzing the cable temperature rise based on the cable current-carrying capacity in an exemplary embodiment of the present application;

[0051] Figure 2Schematic diagram showing the two-dimensional laying model in an exemplary embodiment of the present application;

[0052] Figure 3 Schematic diagram showing the temperature rise curves of the cable core and the outer sheath in an exemplary embodiment of the present application;

[0053] Figure 4 Schematic diagram showing the operation diagram in the 2×4 type cable laying mode in an exemplary embodiment of the present application;

[0054] Figure 5 Schematic diagram showing a program product in an exemplary embodiment of the present application;

[0055] Figure 6 Schematic diagram showing an electronic device in an exemplary embodiment of the present application. Detailed implementation manners

[0056] Now, example embodiments will be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described can be combined in any suitable manner in one or more embodiments.

[0057] In addition, the accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0058] In this example embodiment, a method for analyzing the temperature rise of a cable based on the current-carrying capacity of the cable is first provided. Referring to Figure 1 as shown, the method may include: step S101 to step S104.

[0059] Among them, step S101: Establish a geometric model of the cable according to the cable structure; wherein, the cable structure includes a cable core, a cable core shielding layer, an insulating layer, a metal shielding layer, and an outer sheath from the inside out.

[0060] Step S102: Arrange the geometric models according to a preset layout method to construct a three-dimensional laying model, and simplify the three-dimensional laying model into a two-dimensional laying model; wherein, the preset layout method includes a horizontal layout spacing and a vertical layout spacing, and the two-dimensional laying model includes a geometric model of M×N; wherein, M is the number of geometric models arranged horizontally, and N is the number of geometric models arranged vertically.

[0061] Step S103: Simulate and lay the two-dimensional laying model in the soil, determine the boundary conditions, and construct a thermodynamic model of the two-dimensional laying model.

[0062] Step S104: Analyze the thermodynamic model under different current-carrying capacities by using the finite element method to obtain the relationship between the current-carrying capacity and the steady-state temperature value of the cable core, and the relationship between the current-carrying capacity and the steady-state temperature value of the outer sheath.

[0063] In an embodiment of the present application, by the above method, the three-dimensional laying model is simplified into a two-dimensional laying model, reducing the computational complexity in subsequent analysis of temperature rise; the boundary conditions are determined, and a thermodynamic model of the two-dimensional laying model is constructed. The finite element method is used to analyze the thermodynamic model under different current-carrying capacities, revealing the relationship between the temperature rise of the cable and the load current. The steady-state temperature value of the cable can be predicted according to the load current, providing a scientific basis for the design and operation of the cable.

[0064] Next, reference will be made to Figures 2 to 4 to describe each step of the above method in the exemplary embodiment in more detail.

[0065] In step S101, a geometric model of the cable is established according to the cable structure; wherein, the cable structure includes a cable core, a cable core shielding layer, an insulating layer, a metal shielding layer, and an outer sheath from the inside out.

[0066] It can be understood that the cable structure includes a cable core, a cable core shielding layer, an insulating layer, a metal shielding layer, and an outer sheath from the inside out. The cable is simulated and modeled according to the cable structure, that is, a geometric model of the cable is built.

[0067] In step S102, arrange the geometric models according to a preset layout method to construct a three-dimensional laying model, and simplify the three-dimensional laying model into a two-dimensional laying model; wherein, the preset layout method includes a horizontal layout spacing and a vertical layout spacing, and the two-dimensional laying model includes a geometric model of M×N; wherein, M is the number of geometric models arranged horizontally, and N is the number of geometric models arranged vertically.

[0068] It can be understood that during the simulation modeling process, the geometric model is arranged according to the lateral layout spacing and the longitudinal layout spacing to build a three-dimensional laying model. Further, in order to reduce the computational complexity when analyzing the temperature rise subsequently, the three-dimensional laying model is simplified to a two-dimensional laying model, and the schematic diagram of the two-dimensional laying model is as shown in Figure 2 shown. Among them, the values of M and N can be set according to the actual situation, and this application will not elaborate on this.

[0069] In step S103, the two-dimensional laying model is simulated and laid in the soil, the boundary conditions are determined, and the thermodynamic model of the two-dimensional laying model is constructed.

[0070] It can be understood that after building the two-dimensional laying model, its situation in the soil is simulated so as to more realistically reflect the relationship between the ampacity and the temperature rise of the cable subsequently.

[0071] Further, the boundary conditions need to be determined.

[0072] The boundary conditions include:

[0073] It is set that the conditions of the soil, the temperature of the soil, and the laying environment remain unchanged; among them, the initial temperature of the two-dimensional laying model is equal to the temperature of the soil.

[0074] The boundary conditions also include the control equation of the two-dimensional laying model. The control equation is as follows:

[0075] T(x,y)|Γ=f(x,y)|Γ(1);

[0076] In the formula, Γ represents the regional boundary, x,y represent the coordinate positions of the two-dimensional laying model, T represents the temperature at the point (x,y), and f(x,y) represents the temperature function that changes with time and position on the known boundary surface.

[0077] It can be understood that the condition of the soil is the thermal conductivity of the soil, the thermal conductivity of the soil is 1.09, the temperature of the soil (i.e., the ambient temperature) is 20 °C, and the laying environment is the planar laying method.

[0078] It should be noted that in this application, when setting the two-dimensional laying model to be laid in the soil, the influence of the temperature on the soil surface on the temperature rise of the cable is not considered.

[0079] After determining the boundary conditions, the thermodynamic model of the two-dimensional laying model is built. According to Fourier's basic law and the law of conservation of energy in heat transfer, the thermodynamic model of the two-dimensional laying model is built.

[0080] Further, the thermodynamic model includes the heat conduction differential equation of the heat source region and the heat conduction differential equation of the region without heat source; wherein, the heat source region includes the cable core, the insulation layer and the metal shielding layer, and the region without heat source includes the cable core shielding layer, the outer sheath and the soil.

[0081] In one embodiment, the heat conduction differential equation of the heat source region is:

[0082]

[0083] In the formula, q v represents the heat generation rate per unit volume of the heat source, and λ represents the thermal conductivity of the medium.

[0084] In one embodiment, the heat conduction differential equation of the region without heat source is:

[0085]

[0086] In one embodiment, in the step of analyzing the thermodynamic model under different current-carrying capacities by using the finite element method to obtain the relationship between the current-carrying capacity and the steady-state temperature value of the cable core, and the relationship between the current-carrying capacity and the steady-state temperature value of the outer sheath, it includes:

[0087] Simulate different load currents applied to the cable core in the two-dimensional laying model;

[0088] According to the heat conduction differential equation of the heat source region, obtain the corresponding steady-state temperature value of the cable core;

[0089] And, according to the heat conduction differential equation of the region without heat source, obtain the corresponding steady-state temperature value of the outer sheath.

[0090] It can be understood that in the simulation process of the present application, the conditions of the soil, the thermal conductivity of the soil, the temperature of the soil and the laying environment remain unchanged, and only the change of the load current (i.e., the current-carrying capacity) is considered. Through simulation, the temperature rise change of the cable under different current-carrying capacities can be intuitively observed.

[0091] It should be noted that after different load currents are simulated and applied to the cable core in the two-dimensional laying model, according to the heat conduction differential equation of the heat source region, the corresponding steady-state temperature value of the cable core can be obtained.

[0092] Further, after the step of obtaining the corresponding steady-state temperature value of the cable core according to the heat conduction differential equation of the heat source region, it includes:

[0093] When the load current is less than or equal to the preset current, according to the load current and the corresponding steady-state temperature value of the cable core, obtain the first relationship between the load current and the steady-state temperature value of the cable core;

[0094] When the load current is greater than the preset current, according to the load current and the corresponding steady-state temperature value of the cable core, a second relationship between the load current and the steady-state temperature value of the cable core is obtained;

[0095] After the step of obtaining the corresponding steady-state temperature value of the outer sheath according to the heat conduction differential equation of the heat source-free region, it includes:

[0096] When the load current is less than or equal to the preset current, according to the load current and the corresponding steady-state temperature value of the outer sheath, a first relationship between the load current and the steady-state temperature value of the outer sheath is obtained;

[0097] When the load current is greater than the preset current, a second relationship between the load current and the corresponding steady-state temperature value of the outer sheath is obtained.

[0098] It should be noted that the value of the load current can be set according to the maximum current I that the cable can safely carry. The load current is proportional to the maximum current I, and the proportionality coefficient is greater than or equal to 10% and less than or equal to 110%. Among them, the preset current = 90%I max .

[0099] It should also be noted that the highest continuous working temperature close to the cable core material is 90°C. At this temperature, the operating state of the cable is close to the thermal stability limit. When 90%I is passed through the cable core max , the steady-state temperature value of the cable core is close to 90°C. Therefore, it can be inferred that the preset current value is 90%I max , which is convenient for studying the relationship between the load current and the steady-state temperature value of the cable core, and studying the relationship between the load current and the steady-state temperature value of the outer sheath.

[0100] Furthermore, the relationship between the load current and the steady-state temperature value of the cable core, and the relationship between the load current and the steady-state temperature value of the outer sheath are specifically as follows.

[0101] In one embodiment, the first relationship between the load current and the steady-state temperature value of the cable core is:

[0102] T 缆芯 = 94.2I 2 - 14.1I + 20.45(4);

[0103] The second relationship between the load current and the steady-state temperature value of the cable core is:

[0104] T 缆芯 = 178×I - 78.35(5);

[0105] The first relationship between the load current and the steady-state temperature value of the outer sheath is:

[0106] T 外护= 59.12x 2 -10.67x + 20.12(6);

[0107] The second relationship between the load current and the steady-state value of the temperature of the outer sheath is:

[0108] T 外护 = 1.02×I - 35.15(7);

[0109] Wherein, T 缆芯 represents the steady-state value of the temperature of the cable core, I represents the load current, and T 外护 represents the steady-state value of the temperature of the outer sheath.

[0110] It can be understood that Equation (4) is the first relationship between the load current and the steady-state value of the temperature of the cable core. When the load current is less than or equal to the preset current, as the load current changes, the corresponding steady-state value of the temperature of the cable core also changes, and the specific change situation is as shown in Equation (4). When the load current changes, the steady-state value of the temperature of the cable core can be predicted through Equation (4).

[0111] Equation (5) is the second relationship between the load current and the steady-state value of the temperature of the cable core. When the load current is greater than the preset current, as the load current changes, the corresponding steady-state value of the temperature of the cable core also changes, and the specific change situation is as shown in Equation (5). When the load current changes, the steady-state value of the temperature of the cable core can be predicted through Equation (5).

[0112] Equation (6) is the first relationship between the load current and the steady-state value of the temperature of the outer sheath. When the load current is less than or equal to the preset current, as the load current changes, the corresponding steady-state value of the temperature of the outer sheath also changes, and the specific change situation is as shown in Equation (6). When the load current changes, the steady-state value of the temperature of the outer sheath can be predicted through Equation (6).

[0113] Equation (7) is the second relationship between the load current and the steady-state value of the temperature of the outer sheath. When the load current is greater than the preset current, as the load current changes, the corresponding steady-state value of the temperature of the outer sheath also changes, and the specific change situation is as shown in Equation (7). When the load current changes, the steady-state value of the temperature of the outer sheath can be predicted through Equation (7).

[0114] The present application will be further described below through simulation experiments.

[0115] The cable laying method of the present application is of the 2×4 type, that is, M is equal to 2 and N is equal to 4. The operation diagram under the 2×4 type cable laying method is as Figure 4 shown.

[0116] Keep the conditions of the soil layer, the temperature of the soil layer, and the laying environment unchanged, apply different load currents to the cable core, and obtain the steady-state simulation values of the outer sheath and the cable core, as well as the time T1 required for the temperature of the cable core to reach the temperature steady-state value and the time T2 required for the temperature steady-state value of the cable core to reach 90°C. The results are as follows:

[0117] Table 1 Temperature steady-state values of the cable core and outer sheath under different load currents

[0118]

[0119] I in Table 1 max represents the maximum current that the cable can safely carry. It can be seen from Table 1 and Figure 3 that as the load current increases, the temperature steady-state value of the cable core rises significantly. When the load current increases from 10% I max to 110% I max , the temperature steady-state value of the cable core rises from 20.8°C to 117.8°C, with a significant increase. Among them, when the load current is in [10% I max , 90% I max , the temperature steady-state value of the cable core rises relatively gently, and there is a first relationship between the load current and the temperature steady-state value of the cable core; when the load current is in (90% I max , 110% I max , the rising speed of the temperature steady-state value of the cable core accelerates, and there is a second relationship between the load current and the temperature steady-state value of the cable core. Overall, it shows a non-linear growth trend. This non-linear relationship conforms to Joule's law, that is, the heat generated by the cable is proportional to the square of the current.

[0120] The temperature steady-state value of the outer sheath also rises with the increase of the load current, but the increase amplitude is relatively small compared to the temperature steady-state value of the cable core. When the load current increases from 10% I max to 110% I max , the temperature of the outer sheath rises from 20.5°C to 77.2°C. Among them, when the load current is in [10% I max , 90% I max , the temperature steady-state value of the outer sheath rises relatively gently, and there is a first relationship between the load current and the temperature steady-state value of the outer sheath; when the load current is in (90% I max , 110% I max , the rising speed of the temperature steady-state value of the outer sheath accelerates, and there is a second relationship between the load current and the temperature steady-state value of the outer sheath.

[0121] It should be noted that when the load current is in (90% I max , 110% I maxWhen the temperature of the outer sheath reaches the steady state value, the rising speed is significantly lower than that of the core, indicating that the outer sheath has good heat dissipation effect.

[0122] As the load current increases, the temperature difference between the core and the outer sheath gradually increases. When the load current is in the range of [10%I max , 90%I max , the temperature difference between the core and the outer sheath is relatively small, indicating that the heat generated by the cable is relatively low at this time and the heat can be dissipated through the outer sheath relatively quickly. When the load current is in the range of (90%I max , 110%I max , the temperature difference between the core and the outer sheath is relatively large. For example, when the load current is 99%I max , the temperature difference is 29.2 °C, and when the load current is 110%I max , the temperature difference reaches 40.6 °C. The increase in the temperature difference indicates that as the load current increases, the heat generated by the core increases, while the heat dissipation capacity of the outer sheath gradually reaches its limit, resulting in the accumulation of heat inside the core.

[0123] In addition, by analyzing T1 and T2, it can be found that as the load current increases, the time for the core temperature to reach the steady state value gradually increases. When the load current is 10%I max , T1 is 35 hours; when the load current is 110%I max , T1 increases to 220 hours. This indicates that as the load current increases, the time required for the cable to reach thermal equilibrium significantly extends. The reason is that when the load current is in the range of (90%I max , 110%I max , the heat generation rate of the cable accelerates while the heat dissipation rate is relatively slow. The time T2 for the core temperature steady state value to reach 90 °C significantly shortens as the load current increases. When the load current is 95%I max , T2 is 168 hours. When the load current is 110%I max , T2 shortens to 31.8 hours. This indicates that as the load current increases, the time required for the core temperature steady state value to reach 90 °C significantly decreases.

[0124] It should be noted that although the steps of the method in this application are described in a specific order in the accompanying drawings, this does not require or imply that these steps must be executed in that specific order, or that all the steps shown must be executed to achieve the desired result. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution, etc. Also, it is easily understood that these steps can be executed synchronously or asynchronously, for example, in multiple modules / processes / threads.

[0125] It should be noted that although several modules or units of a device for action execution are mentioned in the above detailed description, such division is not mandatory. In fact, according to the embodiments of the present application, the features and functions of the two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units. The components shown as modules or units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of the present application. A person of ordinary skill in the art can understand and implement it without creative work.

[0126] In an exemplary embodiment of the present application, there is also provided a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method for analyzing cable temperature rise based on cable current-carrying capacity described in any one of the above embodiments can be implemented. In some possible implementation manners, various aspects of the present invention can also be implemented in the form of a program product, which includes program code, and when the program product runs on a terminal device, the program code is used to cause the terminal device to execute the steps according to various exemplary embodiments of the present invention described in the part of the method for analyzing cable temperature rise based on cable current-carrying capacity in this specification.

[0127] Refer to Figure 5 As shown, a program product 300 for implementing the above method according to an embodiment of the present invention is described, which can adopt a portable compact disc read-only memory (CD-ROM) and includes program code, and can run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device.

[0128] The program product can adopt any combination of one or more readable media. The readable media can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0129] The computer-readable storage medium may include a data signal propagated in a baseband or as part of a carrier wave, in which the readable program code is carried. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. The readable storage medium may also be any readable medium other than the readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0130] The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, executed as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., by using an Internet service provider to connect through the Internet).

[0131] In an exemplary embodiment of the present application, an electronic device is further provided. The electronic device may include a processor and a memory for storing executable instructions of the processor. Wherein, the processor is configured to execute the steps of the cable temperature rise analysis method based on cable current-carrying capacity described in any one of the foregoing embodiments by executing the executable instructions.

[0132] Those skilled in the art can understand that various aspects of the present invention can be implemented as a system, method, or program product. Therefore, various aspects of the present invention can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software aspects, which can be collectively referred to as "circuitry", "module", or "system" here.

[0133] The following refers to Figure 6 to describe the electronic device 600 according to this embodiment of the present invention. Figure 6 The displayed electronic device 600 is only an example and should not impose any limitations on the functions and usage scope of the embodiments of the present invention.

[0134] AsFigure 6 As shown, the electronic device 600 is presented in the form of a general-purpose computing device. The components of the electronic device 600 may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different system components (including the storage unit 620 and the processing unit 610), a display unit 640, etc.

[0135] Among them, the storage unit stores program code, and the program code can be executed by the processing unit 610, so that the processing unit 610 executes the steps according to various exemplary embodiments of the present invention described in the above-mentioned part of the cable temperature rise analysis method based on cable current-carrying capacity in this specification. For example, the processing unit 610 can execute steps as Figure 1 shown in.

[0136] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 6201 and / or a cache storage unit 6202, and may further include a read-only storage unit (ROM) 6203.

[0137] The storage unit 620 may further include a program / utility 6204 having a set (at least one) of program modules 6205. Such program modules 6205 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment.

[0138] The bus 630 may represent one or more of several types of bus structures, including a storage unit bus or a storage unit controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any bus structure in a variety of bus structures.

[0139] The electronic device 600 can also communicate with one or more external devices 700 (such as a keyboard, a pointing device, a Bluetooth device, etc.), and can also communicate with one or more devices that enable a user to interact with the electronic device 600, and / or communicate with any device that enables the electronic device 600 to communicate with one or more other computing devices (such as a router, a modem, etc.). Such communication can be carried out through the input / output (I / O) interface 650. Moreover, the electronic device 600 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through the network adapter 660. The network adapter 660 can communicate with other modules of the electronic device 600 through the bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in combination with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0140] Through the description of the above embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software, or can be implemented by the way of software in combination with necessary hardware. Therefore, the technical solution according to the embodiments of the present application can be embodied in the form of a software product, and the software product can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to execute the above-mentioned cable temperature rise analysis method based on cable current-carrying capacity according to the embodiments of the present application.

[0141] After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily conceive of other embodiments of the present application. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include common general knowledge or conventional technical means in the technical field not disclosed in the present application.

Claims

1. A cable temperature rise analysis method based on cable current carrying capacity, characterized in that: include: A geometric model of the cable is established according to the cable structure; wherein the cable structure includes, from inside to outside, a cable core, a cable core shielding layer, an insulating layer, a metal shielding layer and an outer sheath; Arrange the geometric models according to a preset arrangement mode to construct a three-dimensional laying model, and simplify the three-dimensional laying model into a two-dimensional laying model; wherein the preset arrangement mode includes a horizontal laying spacing and a vertical laying spacing, and the two-dimensional laying model includes M×N geometric models; wherein M is the number of arrangements of the geometric models in the horizontal direction, and N is the number of arrangements of the geometric models in the vertical direction; Simulating the deployment of the two-dimensional deployment model in soil, determining boundary conditions, and constructing a thermodynamic model of the two-dimensional deployment model; The thermodynamic model under different current carrying capacities is analyzed by using the finite element method to obtain a relationship between the current carrying capacity and the steady-state temperature value of the cable core, and a relationship between the current carrying capacity and the steady-state temperature value of the outer sheath.

2. The cable temperature rise analysis method based on cable current carrying capacity according to claim 1 is characterized in that: The boundary conditions include: The soil conditions, soil temperature and laying environment are set to remain unchanged; wherein the initial temperature of the two-dimensional laying model is equal to the temperature of the soil, and the soil conditions include the thermal conductivity of the soil; The governing equation of the two-dimensional laying model is: T(x,y)|Γ=f(x,y)|Γ(1); Where Γ represents the region boundary, x, y represent the coordinate position of the two-dimensional laying model, T represents the temperature at the point (x, y), and f(x, y) represents the temperature function of the known boundary surface that changes with time and position.

3. The cable temperature rise analysis method based on cable current carrying capacity according to claim 2 is characterized in that: The thermodynamic model includes a heat conduction differential equation of a heat source region and a heat conduction differential equation of a non-heat source region; wherein the heat source region includes a cable core, an insulating layer and a metal shielding layer, and the non-heat source region includes a cable core shielding layer, an outer sheath and soil.

4. The cable temperature rise analysis method based on cable current carrying capacity according to claim 3 is characterized in that: The heat conduction differential equation of the heat source area is: In the formula, q v represents the heat generation rate per unit volume of the heat source, and λ represents the thermal conductivity of the medium.

5. The cable temperature rise analysis method based on cable current carrying capacity according to claim 4 is characterized in that: The heat conduction differential equation of the heat source-free area is:

6. The cable temperature rise analysis method based on cable current carrying capacity according to claim 5 is characterized in that: The step of analyzing the thermodynamic model under different current carrying capacity by using the finite element method to obtain the relationship between the current carrying capacity and the steady-state temperature value of the cable core, and the relationship between the current carrying capacity and the steady-state temperature value of the outer sheath, comprises: Applying different load currents to the cable core simulation in the two-dimensional laying model; According to the heat conduction differential equation of the heat source area, the corresponding steady-state temperature value of the cable core is obtained; And, according to the heat conduction differential equation of the heat source-free area, the corresponding steady-state temperature value of the outer sheath is obtained.

7. The cable temperature rise analysis method based on cable current carrying capacity according to claim 6 is characterized in that: After the step of obtaining the corresponding steady-state temperature value of the cable core according to the heat conduction differential equation of the heat source region, the method further comprises: When the load current is less than or equal to a preset current, a first relationship between the load current and the steady-state temperature value of the cable core is obtained according to the load current and the corresponding steady-state temperature value of the cable core; When the load current is greater than a preset current, a second relationship between the load current and the steady-state temperature value of the cable core is obtained according to the load current and the corresponding steady-state temperature value of the cable core; After the step of obtaining the corresponding steady-state temperature value of the outer sheath according to the heat conduction differential equation of the heat source-free region, the method further comprises: When the load current is less than or equal to a preset current, a first relationship between the load current and the steady-state temperature value of the outer sheath is obtained according to the load current and the corresponding steady-state temperature value of the outer sheath; When the load current is greater than the preset current, a second relationship between the load current and the corresponding steady-state temperature value of the outer sheath is obtained.

8. The cable temperature rise analysis method based on cable current carrying capacity according to claim 7 is characterized in that: The first relationship between the load current and the steady-state temperature value of the cable core is: T 缆芯 =94.2I 2 -14.1I+20.45(4); The second relationship between the load current and the steady-state temperature value of the cable core is: T 缆芯 =178×I-78.35(5); The first relationship between the load current and the steady-state value of the temperature of the outer sheath is: T 外护 =59.12x 2 -10.67x+20.12(6); The second relationship between the load current and the steady-state value of the temperature of the outer sheath is: T 外护 =1.02×I-35.15(7); Where, T 缆芯 represents the steady-state temperature value of the cable core, I represents the load current, T 外护 Indicates the steady-state value of the outer protection temperature.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the cable temperature rise analysis method based on the cable current carrying capacity described in any one of claims 1 to 8 are implemented.

10. An electronic device, characterized in that: include: processor; as well as A memory, configured to store executable instructions of the processor; The processor is configured to execute the steps of the cable temperature rise analysis method based on the cable current carrying capacity according to any one of claims 1 to 8 by executing the executable instructions.

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