A cable conductor temperature simulation measurement method and system under a virtual reality platform

Abstract

This invention relates to the field of cable-related technologies and proposes a method and system for simulating and measuring cable conductor temperature under a virtual reality platform. The method includes: establishing an electromagnetic-thermal multiphysics coupled finite element model (EMF) comprising simulation units for electric, magnetic, and temperature fields; constructing multiple simulation scenarios, simulating the temperature field distribution of the cable under different operating conditions based on the EMF, obtaining a temperature simulation dataset, and fitting a model to establish the relationship between the cable conductor temperature and the insulation layer temperature under each simulation scenario; acquiring the measured surface temperature value of the cable insulation layer and the cable current value, and calculating the cable conductor temperature through the relationship model. This innovative approach constructs an EMF and establishes a mapping relationship between conductor temperature and insulation layer surface temperature through virtual simulation scenarios, achieving high-precision, real-time indirect measurement of cable conductor temperature.

Description

Technical Field

[0001] The embodiments of the present invention belong to the field of cable-related technology, specifically, they relate to a method and system for simulating and measuring the temperature of cable conductors under a virtual reality platform. Background Technology

[0002] With the continuous advancement of urban modernization, the demand for electricity in cities is growing rapidly. As a crucial infrastructure of urban power distribution systems, power cables face higher requirements in their construction and maintenance. Overhead transmission lines are gradually being replaced by underground cables due to space constraints, aesthetic concerns, and safety factors. Among these, three-core cables are widely used in urban power distribution networks due to their compact structure and strong adaptability. While cable lines undertake large-scale power supply tasks, their operational stability and safety have become critical issues. In particular, cable operating temperature directly affects the aging rate of conductor insulation and the cable's lifespan; therefore, accurate and real-time monitoring of cable conductor temperature is of great significance.

[0003] Existing power cable temperature monitoring technologies mostly employ distributed fiber optic sensors laid on the insulation surface to acquire temperature data. However, this method only obtains the cable surface temperature, which is difficult to directly reflect the true conductor temperature. It often relies on static empirical formulas for conversion, resulting in insufficient calculation accuracy and poor adaptability, making it difficult to cope with the variable operating conditions in actual laying environments. Furthermore, existing methods lack the ability to integrate with real-time simulation systems, failing to dynamically correct and predict changes in operating conditions, leading to delayed or inaccurate temperature monitoring, and consequently affecting the safe operation of the system. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a method and system for simulating and measuring cable conductor temperature under a virtual reality platform. It innovatively constructs an electromagnetic-thermal multiphysics coupled finite element model and establishes a mapping relationship between conductor temperature and insulation layer surface temperature through a virtual simulation scenario, thereby achieving high-precision, real-time, indirect measurement of cable conductor temperature.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for simulating and measuring the temperature of a cable conductor using a virtual reality platform, comprising the following steps: An electromagnetic-thermal multiphysics coupled finite element model was established, including simulation units for electric field, magnetic field, and temperature field. Based on different laying environments, conductor loads, cable structures and ambient temperature conditions, multiple simulation scenarios were constructed, and the cable temperature field distribution under each simulation scenario was simulated based on the electromagnetic-thermal multiphysics coupled finite element model to obtain the corresponding temperature simulation dataset. By fitting the data in the temperature simulation dataset, a model is established to show the relationship between the cable conductor temperature and the insulation layer temperature under various simulation scenarios. The measured surface temperature of the cable insulation layer and the current value of the cable are obtained, and the temperature of the cable conductor is calculated by matching the relationship model in the scenario.

[0006] A further technical solution involves establishing a method for a coupled electromagnetic-thermal multiphysics finite element model that includes simulation units for electric, magnetic, and temperature fields. This method comprises the following steps: Obtain the geometric model data for cable simulation and generate the geometric model for cable simulation; Based on the geometric model data, electrostatic modules, magnetic field modules, and solid heat transfer modules are loaded at the corresponding positions of the geometric model of the cable simulation to generate virtual electric field, virtual magnetic field, and temperature field, respectively, thus obtaining the electromagnetic-thermal multiphysics module. Obtain boundary condition parameters and initial simulation input parameters, write them into the geometric model data and electromagnetic-thermal multiphysics module, and generate an electromagnetic-thermal multiphysics coupled finite element model.

[0007] Further technical solutions, including the process of constructing simulation scenarios based on different laying environments, cable structures, and ambient temperature conditions, include: Among the laying environment, cable structure, and ambient temperature conditions, physical parameters that affect the temperature of the cable conductor are selected as simulation variables; All simulation variables are combined using Cartesian products to generate a complete list of simulation scenarios. All or some combinations can be selected as simulation scenarios.

[0008] A further technical solution, based on an electromagnetic-thermal multiphysics coupled finite element model, simulates the temperature field distribution of cables under different operating conditions, and obtains a temperature simulation dataset containing temperature data, scene data, and cable operation data. This includes: Different simulation scenarios were constructed based on different laying environments, cable structures, and ambient temperature conditions; The simulation transformation parameters are obtained, and the simulation is performed based on the electromagnetic-thermal multiphysics coupled finite element model. All scene combinations are automatically traversed, and the conductor load of the cable is changed in each scene. Each scene is solved independently, and the temperature field distribution results of the corresponding scene are output. The conductor temperature and insulation surface temperature data in each scene are saved, and the temperature data, scene data and cable operation data are constructed into a temperature simulation dataset.

[0009] A further technical solution involves simulation based on an electromagnetic-thermal multiphysics coupled finite element model. This model automatically traverses all scenario combinations, varying the conductor load of the cable in each scenario, and solving each scenario independently. The solution process includes the following: Mesh generation is performed on the electromagnetic-thermal multiphysics coupled finite element model; By selecting the frequency domain-steady-state study type in multiphysics, simulating the operating state of the cable under AC steady load, changing the scenario data and cable load under different scenarios, solving the electromagnetic-thermal multiphysics coupled finite element model, and obtaining the temperature field distribution results; The corresponding values ​​of the conductor center temperature and the insulation layer surface temperature are extracted from the temperature field distribution results to obtain a temperature simulation dataset containing temperature data, scene data, and cable operation data.

[0010] A further technical solution involves fitting the data in the temperature simulation dataset to establish a relationship model between the cable conductor temperature and the insulation layer temperature under various simulation scenarios. The process of constructing the relationship model includes the following: Based on the change in current I of the cable conductor in the cable operation data, the resistance value R of the cable conductor is corrected, and then the conductor loss heat value is calculated. Based on the heat transfer principle of the insulation layer, and according to the heat loss value of the cable conductor and the relationship of heat loss, the temperature difference thermal path relationship inside and outside the insulation layer is constructed. Based on the temperature difference and thermal path relationship inside and outside the insulation layer and the corrected resistance value This yields the final temperature difference thermal path relationship between the inside and outside of the insulation layer; Based on the final temperature difference thermal path relationship between the inside and outside of the insulation layer, the data in the temperature simulation dataset is fitted to obtain the values ​​of each coefficient in the thermal path relationship. The coupling relationship between the conductor temperature and the insulation layer temperature under each scenario is calculated to obtain the relationship model between the cable conductor temperature and the insulation layer temperature under each scenario.

[0011] A further technical solution involves calculating the correction formula for the resistance value R as follows: ; in, The resistivity of the cable conductor at 20℃ For temperature coefficient, Represents the cross-sectional area of ​​the conductor; The final thermal relationship between the inside and outside of the insulation layer is as follows: ; in, For the conductor temperature of the wire core, T is the surface temperature of the insulation layer, and T is the thermal resistance of the insulation layer. Heat is generated due to conductor loss. Heat is generated due to insulation layer loss; The data from the temperature simulation dataset were fitted using the least squares method, and the fitting coefficients obtained included the thermal resistance T of the insulation layer and the heat generation due to insulation layer loss. .

[0012] This invention provides a cable conductor temperature simulation and measurement system under a virtual reality platform, comprising: Cable scene data acquisition device and processor; The cable scene data acquisition device is used to collect data on the cable's operating environment, as well as cable structural parameters and operational data. The processor is configured to execute the steps of the above-described method for simulating and measuring the temperature of a cable conductor under a virtual reality platform.

[0013] This invention provides a cable conductor temperature simulation and measurement system under a virtual reality platform, comprising: The virtual model building module is configured to build an electromagnetic-thermal multiphysics coupled finite element model that includes simulation units for electric, magnetic, and temperature fields; The simulation module is configured to build multiple simulation scenarios based on different laying environments, cable structures and ambient temperature conditions, and simulate the temperature field distribution of the cable under different scenario conditions based on the electromagnetic-thermal multiphysics coupled finite element model, to obtain a corresponding temperature simulation dataset containing temperature data, scenario data and cable operation data. The fitting module is configured to fit the data in the temperature simulation dataset and establish a model of the relationship between the cable conductor temperature and the insulation layer temperature under various simulation scenarios. The calculation module is configured to acquire the measured surface temperature value of the cable insulation layer and the current value of the cable, and calculate the cable conductor temperature by matching the relationship model between the cable conductor temperature and the insulation layer temperature in the scenario.

[0014] This invention provides an electronic device, including a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When the computer instructions are executed by the processor, they complete the steps in the above-described method for simulating and measuring the temperature of a cable conductor under a virtual reality platform.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention breaks away from the traditional method of calculating conductor temperature based on empirical formulas. It employs a data-driven approach combined with physical simulation to achieve accurate prediction of conductor temperature under different operating conditions. Compared to existing technologies, this method is highly adaptable, dynamically adjusting the model according to the cable laying environment and operating conditions, significantly improving the accuracy and real-time performance of conductor temperature prediction. Simultaneously, it avoids directly deploying sensors inside the conductor, reducing system complexity and maintenance costs, and improving operational safety. Furthermore, this method has good scalability and is applicable to different types of cables and urban power distribution scenarios.

[0016] The advantages of the present invention, as well as its additional advantages, will be described in detail in the following specific embodiments. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute a limitation thereof.

[0018] Figure 1 This is a flowchart of a cable conductor temperature simulation measurement method under a virtual reality platform according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the geometric model of a three-core cable constructed in the experimental example of Embodiment 1 of the present invention; Figure 3 This is an experimental example of the cross-linked polyethylene insulation material's conductivity-field strength-temperature relationship curve from Embodiment 1 of the present invention; Figure 4 This is a mesh generation effect diagram of the geometric model of a three-core cable in the experimental example of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the two-dimensional temperature field distribution of a cable when the conductor load current is 300A and it is laid in the air in the experimental example of Embodiment 1 of the present invention. Figure 6 This is a graph showing the relationship between cable insulation temperature and conductor temperature as a function of conductor load in an experimental example of Embodiment 1 of the present invention. Figure 7 This is a preliminary curve showing the relationship between conductor temperature and insulation external temperature constructed in the experimental example of Embodiment 1 of the present invention; Figure 8 This is an optimized curve showing the relationship between conductor temperature and insulation external temperature in the experimental example of Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of the thermal relationship between the inner and outer temperature differences of the insulation layer in Embodiment 1 of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] It should be noted that the terminology used herein is for describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. It should be noted that, without conflict, the various embodiments and features within those embodiments can be combined with each other. The embodiments will now be described in detail with reference to the accompanying drawings.

[0022] Example 1 In one or more of the technical solutions disclosed in the implementation methods, such as Figure 1 As shown, a method for simulating and measuring the temperature of a cable conductor using a virtual reality platform includes the following steps: Step 1: Establish an electromagnetic-thermal multiphysics coupled finite element model that includes simulation units for electric field, magnetic field, and temperature field; Step 2: Construct different simulation scenarios based on different laying environments, conductor loads, cable structures and ambient temperature conditions. Based on the constructed electromagnetic-thermal multiphysics coupled finite element model, simulate the temperature field distribution of the cable under different scenario conditions and construct the corresponding temperature simulation dataset. Step 3: Fit the data in the temperature simulation dataset to establish a relationship model between conductor temperature and insulation layer temperature under each scenario; Step 4: Obtain the measured surface temperature of the cable insulation layer and the current value of the cable. Calculate the cable conductor temperature by matching the relationship model in the scenario.

[0023] This implementation method, based on finite element analysis (FEM), first constructs a multiphysics coupled model integrating electric, magnetic, and temperature fields. This model is then used to simulate the thermal-electric response of the cable under different environments. Multiple typical scenarios are created by setting different laying methods (e.g., direct burial, conduit, or tunnel laying), conductor load levels (e.g., rated current, overload current), cable structural parameters (e.g., conductor material, insulation thickness), and external ambient temperature within the simulation platform. Then, the electromagnetic-thermal coupled model is run in each simulation scenario to obtain the corresponding data between the internal temperature distribution of the cable conductor and the surface temperature of the insulation layer, constructing a temperature simulation dataset. Next, curve fitting is used to process these data pairs, forming a mathematical expression to describe the functional relationship between conductor temperature and insulation surface temperature. Finally, in practical applications, the cable surface temperature is acquired by sensors and substituted into the fitted expression to quickly calculate the conductor temperature, achieving indirect measurement.

[0024] This embodiment breaks away from the traditional method of calculating conductor temperature based on empirical formulas. It employs a data-driven approach combined with physical simulation to achieve accurate prediction of conductor temperature under different operating conditions. Compared to existing technologies, this method is highly adaptable, dynamically adjusting the model according to the cable laying environment and operating conditions, significantly improving the accuracy and real-time performance of conductor temperature prediction. Simultaneously, it avoids directly deploying sensors inside the conductor, reducing system complexity and maintenance costs, and improving operational safety. Furthermore, this method has good scalability and is applicable to different types of cables and urban power distribution scenarios.

[0025] Step 1, the method for establishing an electromagnetic-thermal multiphysics coupled finite element model including simulation units for electric field, magnetic field, and temperature field, includes the following steps: Step 11: Obtain the geometric model data for cable simulation and generate the geometric model for cable simulation; Step 12: Based on the geometric model data, load the electrostatic module, magnetic field module and solid heat transfer module at the corresponding positions to generate virtual electric field, virtual magnetic field and temperature field respectively, and obtain electromagnetic-thermal multiphysics module; Step 13: Obtain the boundary condition parameters and initial simulation input parameters, write them into the geometric model data and the electromagnetic-thermal multiphysics module, and generate an electromagnetic-thermal multiphysics coupled finite element model.

[0026] In step 11, geometric modeling: the geometric model data of the cable simulation, including the distribution, structure, size and performance parameters of each layer of conductor, conductor shield, XLPE insulation layer, insulation shield, metal shield, filler layer, inner lining layer, armor layer and outer sheath layer; Optionally, the processor performing the above steps uses finite element simulation software as a modeling platform to build a geometric model for cable simulation. Step 12 involves physical field modeling, where the coupling settings of electric field, magnetic field, and temperature field can be completed in the multi-physics field node to determine the current-carrying heating and heat dissipation paths of the cable. In step 13, the boundary conditions may include thermal insulation, heat flux, electric potential and current density boundaries, and the initial simulation input parameters include initial temperature, voltage and current values, etc. By using the geometric modeling and physical field settings described above, and selecting frequency domain-steady-state research, the temperature field simulation of the electromagnetic-thermal coupling model can be completed. In step 2, different simulation scenarios are constructed based on different laying environments, conductor loads, cable structures, and ambient temperature conditions. Based on the constructed electromagnetic-thermal multiphysics coupled finite element model, the temperature field distribution of the cable under different scenario conditions is simulated, and the corresponding temperature simulation dataset is constructed. The simulation dataset includes at least the scenario data for simulation, cable operation data such as the current I flowing through the cable, and the obtained temperature data. For a certain simulation scenario, the parameters of the simulation scenario can be kept unchanged, and the current of the cable, i.e., the conductor load, can be changed to obtain temperature field data under different current conditions. The conductor load current can be, for example, 100A, 200A, 300A, 400A, 500A, or 600A; different conductor currents result in different heat generation, which affects the conductor temperature. Furthermore, based on an electromagnetic-thermal multiphysics coupled finite element model, a method is used to simulate the temperature field distribution of cables under different operating conditions, obtaining a temperature simulation dataset containing temperature data, scene data, and cable operation data. This method includes: Step 21: Construct different simulation scenarios based on different laying environments, conductor loads, cable structures, and ambient temperature conditions, including the following steps; Step 211: Use the laying environment, cable structure, and ambient temperature conditions as simulation variables; Optional factors include the laying environment, including laying in air, laying in soil, and laying in enclosed passages. Different laying environments result in different heat dissipation, which in turn affects the temperature of the cable conductor. Cable structure types, including cable structure, insulation thickness and parameters, armored / unarmored structure, etc. Ambient temperature, such as 25°C, 30°C, 35°C, 40°C, etc.

[0027] Step 212: Combine all simulation variables from step 211 into a Cartesian product to generate a complete list of simulation scenarios. Select all combinations or select typical combinations as representative simulation scenarios. For example: Scenario A = Air laying + Standard structure + 30°C; Scenario B = Soil laying + thick insulation structure + 40°C; When simulating the temperature field distribution of a cable under different operating conditions, the processor first obtains the simulation variable parameter types and specific parameter values ​​for each scenario. After executing the simulation program, the temperature field distribution of the cable under different operating conditions is obtained. Further technical solutions involve experimentally testing the thermal conductivity and electrical conductivity of the cable insulation layer to determine the coupling relationship between the electric field and temperature, based on the type of insulation layer. Specifically, in step 211, the parameter setting of the insulation layer in the cable structure includes setting simulation variables for each scenario, including insulation layer parameters. For the cable geometric model, the thermal conductivity and electrical conductivity of the cable insulation layer are set, and the relationship between conductivity and temperature is established as the coupling relationship between the electric field and temperature in the physical field modeling in step 12. This includes the following steps: Step 2131: Test the thermal conductivity of the insulation layer, such as cross-linked polyethylene (XLPE) insulation. Step 2132: Test the change in conductivity of the insulation layer under different temperatures and field strengths, and obtain discrete data of the conductivity of the insulation layer; Step 2133: Interpolate the conductivity of the insulating layer to convert the discrete conductivity into a continuous and smooth function graph, and convert the discrete conductivity into a continuous electric field-temperature function, providing data on the changes of electric field strength and temperature for subsequent material definition, so that the simulation results are closer to the true values.

[0028] Step 22: Simulate the cable geometry model with set parameters, automatically traverse all scene combinations, change the conductor load of the cable in each scene, solve each scene independently, output the corresponding temperature field distribution results, save the conductor temperature and insulation surface temperature data in each scene, and construct a temperature simulation dataset by combining the temperature data, scene data and cable operation data; optional, scene parameter labels can also be added to the temperature simulation dataset. It is feasible to perform simulations based on an electromagnetic-thermal multiphysics coupled finite element model, automatically traversing all scene combinations, with each scene solved independently. The solution process includes the following: Step 221: Mesh the electromagnetic-thermal multiphysics coupled finite element model; Optionally, the mesh type is a triangular mesh, and the material interfaces (such as between the shielding layer and the insulation layer) are refined; Mesh generation has a decisive impact on the accuracy and reliability of simulation results. By reasonably setting the mesh size and distribution, the solution accuracy in key areas can be significantly improved while ensuring computational efficiency. In this embodiment, a triangular mesh is used. At the junctions of different parts of the cable, due to the different materials, the mesh needs to be more finely divided. At the same time, the conductor shield and insulation shield are thin, and their corresponding areas are very small, so the divided areas are even finer. Reasonable temperature field mesh generation ensures the accuracy of simulation results while improving computational efficiency.

[0029] Step 222: Select the frequency domain-steady-state study type in the multiphysics field, simulate the operating state of the cable under AC stable load, change the scene data and cable load under different scenarios, solve the electromagnetic-thermal multiphysics coupled finite element model, and obtain the temperature field distribution results; the scene data is the simulation variable parameter data under different scenarios. Specifically, the operating conditions in different scenarios can include: different laying conditions (such as air, soil, closed tunnel), different conductor loads (such as 100A~600A), and different ambient temperatures. Simulations are performed under different operating conditions in different scenarios to obtain the temperature field distribution results in each scenario, including thermal field information such as conductor internal temperature and insulation layer surface temperature.

[0030] Frequency domain-steady-state study type is a type of study in simulation. The frequency domain is used to consider electromagnetic fluctuations in AC systems. In this embodiment, it is used to simulate the electromagnetic behavior of a three-core cable at power frequency (e.g., 50Hz). Steady state refers to the system entering a stable operating state. Transient responses that change with time are not considered. Only the temperature distribution under the final thermal equilibrium state is calculated.

[0031] Step 223: Extract the corresponding values ​​of conductor center temperature and insulation layer surface temperature from the temperature field distribution results to obtain a temperature simulation dataset containing temperature data, scene data and cable operation data; finally, obtain a multi-scene temperature simulation dataset under multiple operating conditions to provide a foundation for subsequent temperature fitting modeling.

[0032] In step 3, the data in the temperature simulation dataset are fitted to establish a relationship model between conductor temperature and insulation layer temperature under each scenario, including the following steps: Step 31: Based on the change in current I of the cable conductor in the cable operation data, correct the resistance value R of the cable conductor, and then calculate the conductor loss heat value. The resistance of a conductor changes with the current flowing through it. The formula for correcting the resistance value R is as follows: ; in, The resistivity of the conductor at 20℃ is 1.7241. 10 -8 Ω.m, The temperature coefficient is 0.003931 / ℃ when the wire core is a copper conductor. This represents the cross-sectional area of ​​the conductor.

[0033] Conductor loss heat value The calculation formula is: ; Step 32: Based on the heat transfer principle of the insulation layer, and according to the conductor loss heating value and the heat loss relationship, the temperature difference thermal path relationship inside and outside the insulation layer is obtained, such as... Figure 9 As shown; The thermal relationship between the inside and outside of the insulation layer is as follows: ; in, For the conductor temperature of the wire core, T is the surface temperature of the insulation layer, and T is the thermal resistance of the insulation layer. Heat is generated due to conductor loss. Heat is generated due to insulation layer loss; The internal temperature of the insulation layer is the same as the temperature of the cable conductor, and the internal temperature of the insulation layer is the same as the temperature of the outer wall of the cable insulation layer; the thermal relationship of the temperature difference between the inside and outside of the insulation layer is as follows: ; Based on the relationship between conductor temperature and outer wall temperature of insulation layer, and the corrected resistance value The formula yields the final thermal path relationship: ; Step 33: Based on the obtained thermal circuit relationship of the temperature difference inside and outside the insulation layer, fit the data in the temperature simulation dataset to obtain the values ​​of each coefficient in the thermal circuit relationship, calculate the coupling relationship between conductor temperature and insulation layer temperature for each scenario, and obtain the relationship model between cable conductor temperature and insulation layer temperature for each scenario. Specifically, the data in the temperature simulation dataset is fitted using the least squares method to obtain fitting coefficients, including the thermal resistance T of the insulation layer and the heat generated by insulation layer loss. Temperature coefficient Since the current I is a fixed value, all other parameters in the final thermal relationship formula are known quantities. Changing the current I changes both the core temperature and the insulation surface temperature. In each scenario, by fitting the temperature measurements under different currents, the coupling relationship between the conductor temperature and the insulation temperature can be obtained.

[0034] In this embodiment, the surface temperature of the insulation layer measured by the fiber optic temperature measurement system is extracted, and combined with the thermal path relationship of the temperature difference between the inside and outside of the insulation layer derived based on the cable physical model, the conductor temperature ( ) and the surface temperature of the insulation layer ( By establishing a formula for calculating conductor temperature through a fitting method, an indirect and accurate calculation of conductor temperature is achieved. Simultaneously, the fitting process considers the dynamic changes in conductor temperature and resistance (R) caused by variations in core current. Linear fitting effectively balances calculation sensitivity and accuracy, solving the problem that optical fibers cannot directly measure conductor temperature, and providing an efficient and reliable technical path for real-time cable monitoring.

[0035] After the above fitting process is completed, the measured surface temperature value of the cable insulation layer is obtained, and the cable conductor temperature is calculated by matching the fitting expression under the scenario.

[0036] To illustrate the implementation process of this embodiment, specific examples are provided. Taking a 10kV three-core cross-linked polyethylene insulated cable as the research object, its geometric model schematic diagram is as follows: Figure 2 As shown, from the inside out, the components are: copper conductor, conductor shield, cross-linked polyethylene insulation, insulation shield, metal shield, polypropylene rope filler, polyvinyl chloride inner lining, double steel tape armor, and polyvinyl chloride outer sheath.

[0037] The dimensions and material parameters of each layer of the example cable are shown in Tables 1 and 2.

[0038] Table 1 Example cable structure dimensions;

[0039] Table 2. Specific parameters of materials used in the simulation;

[0040] The thermal conductivity of the insulation layer and sheath layer was determined experimentally, and the data are shown in Table 3. The curves showing the relationship between the electrical conductivity of cross-linked polyethylene insulation and temperature and electric field strength are shown below. Figure 3 As shown.

[0041] Table 3 Thermal conductivity parameters of various materials;

[0042] A finite element model of a three-core cable was established to simulate the temperature field distribution under different laying conditions and conductor loads. The selected meshing primarily consisted of triangular meshes at the boundaries between different parts of the cable. Because the materials at these boundaries differ, a finer mesh was necessary. Furthermore, since the conductor shield and insulation shield are thin and their corresponding regions are small, the meshed areas were also finer. A reasonable temperature field meshing ensured the accuracy of the simulation results while also improving computational efficiency. After determining the meshing form and size, a meshing contribution term was added to mesh the cable. The meshing of the three-core cable is shown below. Figure 4 As shown.

[0043] After selecting an air-laying scenario, setting boundary conditions and meshing, and then selecting the frequency domain-steady-state study for the research section, a temperature plot was added to the results. The legend and units for the temperature display were then configured. After completing the research setup, the external ambient temperature of the cable was set to 30°C, and the conductor load to 300A. The temperature field of the three-core cable was calculated. Figure 5 To simulate the two-dimensional temperature field distribution, the conductor load was varied from 100A to 600A. The temperature field of a three-core cable was analyzed, and the conductor temperature and the outer temperature of the insulation layer were extracted. The temperature-load variation curve was then plotted. Figure 6 As shown.

[0044] Will Figure 6The temperature difference between the outer surface of the middle insulation layer and the conductor was fitted, and the results are as follows: Figure 7 As shown, the fitted equation is obtained; the least squares optimization algorithm is used to adjust the slope and bias to minimize the residuals. The fitting results are as follows. Figure 8 As shown, the least squares optimization method results in higher fitting accuracy and smaller residuals.

[0045] Example 2 Based on Embodiment 1, this embodiment provides a cable conductor temperature simulation and measurement system under a virtual reality platform, including: Cable scene data acquisition device and processor; A cable scene data acquisition device is used to collect data on the cable operating environment, as well as cable structural parameters and operating data. The processor is configured to execute the steps of the cable conductor temperature simulation measurement method under a virtual reality platform as described in Example 1.

[0046] Example 3 Based on Embodiment 1, this embodiment provides a cable conductor temperature simulation and measurement system under a virtual reality platform, including: The virtual model building module is configured to build an electromagnetic-thermal multiphysics coupled finite element model that includes simulation units for electric, magnetic, and temperature fields; The simulation module is configured to build multiple simulation scenarios based on different laying environments, cable structures and ambient temperature conditions, and simulate the temperature field distribution of the cable under different scenario conditions based on the electromagnetic-thermal multiphysics coupled finite element model, to obtain a corresponding temperature simulation dataset containing temperature data, scenario data and cable operation data. The fitting module is configured to fit the data in the temperature simulation dataset and establish a model of the relationship between the cable conductor temperature and the insulation layer temperature under various simulation scenarios. The calculation module is configured to acquire the measured surface temperature value of the cable insulation layer and the current value of the cable, and calculate the cable conductor temperature by matching the relationship model between the cable conductor temperature and the insulation layer temperature in the scenario.

[0047] It should be noted that each module in this embodiment corresponds one-to-one with each step in embodiment 1, and their specific implementation process is the same, so it will not be repeated here.

[0048] Example 4 Based on Embodiment 1, this embodiment provides an electronic device, including a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When the computer instructions are executed by the processor, they complete the steps in the cable conductor temperature simulation measurement method under a virtual reality platform described in Embodiment 1.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0050] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for simulating and measuring the temperature of a cable conductor using a virtual reality platform, characterized in that, Includes the following steps: An electromagnetic-thermal multiphysics coupled finite element model was established, including simulation units for electric field, magnetic field, and temperature field. Based on different laying environments, cable structures and ambient temperature conditions, multiple simulation scenarios are constructed, and based on the electromagnetic-thermal multiphysics coupled finite element model, the temperature field distribution of the cable under different scenario conditions is simulated to obtain a corresponding temperature simulation dataset containing temperature data, scenario data and cable operation data. The data in the temperature simulation dataset are fitted to establish a relationship model between the cable conductor temperature and the insulation layer temperature under each simulation scenario. The measured surface temperature of the cable insulation layer and the current value of the cable are obtained. The cable conductor temperature is calculated by matching the relationship model between the cable conductor temperature and the insulation layer temperature in the scenario.

2. The method for simulating and measuring cable conductor temperature under a virtual reality platform as described in claim 1, characterized in that: The method for establishing an electromagnetic-thermal multiphysics coupled finite element model that includes simulation elements for electric, magnetic, and temperature fields includes the following steps: Obtain the geometric model data for cable simulation and generate the geometric model for cable simulation; Based on the geometric model data, an electrostatic module, a magnetic field module, and a solid heat transfer module are loaded at the corresponding positions of the geometric model of the cable simulation to generate a virtual electric field, a virtual magnetic field, and a temperature field, respectively, thus obtaining an electromagnetic-thermal multiphysics module. Obtain the boundary condition parameters and initial simulation input parameters, and write them into the geometric model data and the electromagnetic-thermal multiphysics module to generate an electromagnetic-thermal multiphysics coupled finite element model.

3. The method for simulating and measuring cable conductor temperature under a virtual reality platform as described in claim 1, characterized in that: The process of constructing simulation scenarios based on different laying environments, cable structures, and ambient temperature conditions includes: Among the laying environment, cable structure, and ambient temperature conditions, physical parameters that affect the temperature of the cable conductor are selected as simulation variables; All simulation variables are combined using Cartesian products to generate a complete list of simulation scenarios. All or some combinations can be selected as simulation scenarios.

4. The method for simulating and measuring cable conductor temperature under a virtual reality platform as described in claim 1, characterized in that: Based on the aforementioned electromagnetic-thermal multiphysics coupled finite element model, a method is used to simulate the temperature field distribution of cables under different operating conditions and obtain a corresponding temperature simulation dataset containing temperature data, scene data, and cable operation data, including: Different simulation scenarios were constructed based on different laying environments, cable structures, and ambient temperature conditions; The simulation transformation parameters are obtained, and the simulation is performed based on the electromagnetic-thermal multiphysics coupled finite element model. All scene combinations are automatically traversed, and the conductor load of the cable is changed in each scene. Each scene is solved independently, and the temperature field distribution results of the corresponding scene are output. The conductor temperature and insulation surface temperature data in each scene are saved, and the temperature data, scene data and cable operation data are constructed into a temperature simulation dataset.

5. The method for simulating and measuring cable conductor temperature under a virtual reality platform as described in claim 4, characterized in that: Simulations were performed based on the electromagnetic-thermal multiphysics coupled finite element model. All scenario combinations were automatically traversed, and the conductor load of the cable was varied in each scenario. Each scenario was solved independently, and the solution process included the following: Mesh generation is performed on the electromagnetic-thermal multiphysics coupled finite element model; By selecting the frequency domain-steady-state study type in multiphysics, simulating the operating state of the cable under AC steady load, changing the scenario data and cable load under different scenarios, solving the electromagnetic-thermal multiphysics coupled finite element model, and obtaining the temperature field distribution results; The corresponding values ​​of the conductor center temperature and the insulation layer surface temperature are extracted from the temperature field distribution results to obtain a temperature simulation dataset containing temperature data, scene data, and cable operation data.

6. The method for simulating and measuring the temperature of a cable conductor under a virtual reality platform as described in claim 1, characterized in that: The data in the temperature simulation dataset are fitted to establish a relationship model between the cable conductor temperature and the insulation layer temperature under each simulation scenario. The process of constructing the relationship model includes the following: Based on the change in current I of the cable conductor in the cable operation data, the resistance value R of the cable conductor is corrected, and then the conductor loss heat value is calculated. Based on the heat transfer principle of the insulation layer, and according to the heat loss value of the cable conductor and the relationship of heat loss, the temperature difference thermal path relationship inside and outside the insulation layer is constructed. Based on the temperature difference and thermal path relationship inside and outside the insulation layer and the corrected resistance value This yields the final temperature difference thermal path relationship between the inside and outside of the insulation layer; Based on the final temperature difference thermal path relationship between the inside and outside of the insulation layer, the data in the temperature simulation dataset is fitted to obtain the values ​​of each coefficient in the thermal path relationship. The coupling relationship between the conductor temperature and the insulation layer temperature under each scenario is calculated to obtain the relationship model between the cable conductor temperature and the insulation layer temperature under each scenario.

7. The method for simulating and measuring the temperature of a cable conductor under a virtual reality platform as described in claim 6, characterized in that: The formula for correcting the resistance value R is as follows: ； in, The resistivity of the cable conductor at 20℃ For temperature coefficient, Represents the cross-sectional area of ​​the conductor; The final thermal relationship between the inside and outside of the insulation layer is as follows: ； in, For the conductor temperature of the wire core, T is the surface temperature of the insulation layer, and T is the thermal resistance of the insulation layer. Heat is generated due to conductor loss. Heat is generated due to insulation layer loss; The data from the temperature simulation dataset were fitted using the least squares method, and the fitting coefficients obtained included the thermal resistance T of the insulation layer and the heat generation due to insulation layer loss. .

8. A cable conductor temperature simulation and measurement system under a virtual reality platform, characterized in that, include: Cable scene data acquisition device and processor; A cable scene data acquisition device is used to collect data on the cable operating environment, as well as cable structural parameters and operating data. The processor is configured to perform the steps of a method for simulating and measuring the temperature of a cable conductor under a virtual reality platform as described in any one of claims 1-7.

9. A cable conductor temperature simulation and measurement system under a virtual reality platform, characterized in that, include: The virtual model building module is configured to build an electromagnetic-thermal multiphysics coupled finite element model that includes simulation units for electric, magnetic, and temperature fields; The simulation module is configured to construct multiple simulation scenarios based on different laying environments, conductor loads, cable structures and ambient temperature conditions, and to simulate the cable temperature field distribution under each simulation scenario based on the electromagnetic-thermal multiphysics coupled finite element model to obtain the corresponding temperature simulation dataset. The fitting module is configured to fit the data in the temperature simulation dataset and establish a relationship model between the cable conductor temperature and the insulation layer temperature under each simulation scenario. The calculation module is configured to acquire the measured surface temperature and current values ​​of the cable insulation layer, and calculate the cable conductor temperature by matching the relationship model in the scenario.

10. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, complete the steps in the cable conductor temperature simulation measurement method under a virtual reality platform as described in any one of claims 1-7.

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