Optimization system and optimization method for cable current-carrying capacity calculation model

Abstract

The invention relates to the technical field of numerical simulation, in particular to an optimization system and optimization method for a cable current-carrying capacity calculation model, and the system comprises a test module which carries out an aging test; a monitoring module; the analysis module is used for establishing a relation model of running cable aging and an environment heat dissipation efficiency model according to the test data of the test module; wherein the analysis module is configured to determine an internal temperature variable quantity and a surface temperature variable quantity, input the internal temperature variable quantity and the surface temperature variable quantity into the relation model, determine the current thermal conductivity of an insulating layer of the operating cable, and correct a calculation model of the maximum current-carrying capacity of the operating cable by taking the current thermal conductivity as a correction parameter; according to the method, the relation model is established, and the relation among the surface temperature variable quantity, the internal temperature variable quantity, the boundary condition and the heat conductivity is represented, so that the influence of the aging degree on the calculation result is added in the calculation process of the maximum current-carrying capacity of the cable, and the calculation accuracy of the maximum current-carrying capacity is improved.

Description

Technical Field

[0001] The present invention relates to the field of numerical simulation technology, and in particular to an optimization system and an optimization method for a cable current carrying capacity calculation model. Background Art

[0002] Cables are important carriers of electric energy transmission in power systems. Accurately calculating the rated current carrying capacity of power cables can fully utilize the transmission capacity of cable lines while ensuring the safe and reliable operation of cables. The current carrying capacity of cables is limited by the maximum allowable operating temperature of cables. When the current carrying capacity of cables is too large, the temperature of the cable core will rise sharply due to power loss, which may cause adverse effects such as accelerated aging of cable insulation, reduced service life of cables, and even burning of cables. Therefore, in order to ensure the safe and reliable operation of cables, it is necessary to further improve the accuracy of the current carrying capacity and temperature calculation of cables.

[0003] The prior art discloses a method, device, computer equipment and storage medium for determining the current carrying capacity of a cable. The determination method includes obtaining the core temperature of the conductor core at each area of ​​the cable according to a temperature measuring sensor built into the cable; determining the target area corresponding to the highest core temperature according to the highest core temperature among the core temperatures; inputting the highest core temperature and the ambient temperature corresponding to the target area into a target thermal circuit model to obtain the current calculated temperature of the insulation layer corresponding to the target area, and the target thermal circuit model is used to characterize the heat transfer characteristics of the cable; determining the maximum allowable current value corresponding to the ambient temperature based on the degree of difference between the current calculated temperature and the maximum allowable temperature of the insulation layer, and using the maximum allowable current value as the cable current carrying capacity corresponding to the ambient temperature.

[0004] It can be seen that the cable current-carrying capacity determination method, device, computer equipment and storage medium have the following problems: the maximum current-carrying capacity cannot be adjusted according to the degree of aging during the calculation process, so that when the thermal conductivity of the cable insulation layer is high, the maximum current-carrying capacity is low, or when the thermal conductivity is low, the aging of the cable insulation layer is not sufficient to support the maximum current-carrying capacity, resulting in the calculated maximum current-carrying capacity being inconsistent with the actual situation and having a low accuracy rate. Summary of the invention

[0005] To this end, the present invention provides an optimization system and optimization method for a cable current carrying capacity calculation model, which is used to overcome the problem in the prior art that the maximum current carrying capacity cannot be adjusted according to the aging degree during the calculation process, so that when the thermal conductivity of the cable insulation layer is high, the maximum current carrying capacity is low, or when the thermal conductivity is low, the aging of the cable insulation layer is insufficient to support the maximum current carrying capacity, resulting in the calculated maximum current carrying capacity not being consistent with the actual situation and having a low accuracy.

[0006] To achieve the above object, on the one hand, the present invention provides an optimization system for a cable current carrying capacity calculation model, comprising:

[0007] The test module is used to perform an aging test on the test cable, and during the aging test, detect the thermal conductivity of the insulation layer of the test cable, and detect the surface temperature change and internal temperature change of the test cable corresponding to the current thermal conductivity;

[0008] A monitoring module is arranged on the surface of the cable to monitor the surface temperature of the running cable and the boundary conditions of the running cable in real time;

[0009] An analysis module, which is connected to the test module and the monitoring module respectively, and is used to establish a relationship model of operating cable aging and an environmental heat dissipation efficiency model according to the test data of the test module;

[0010] The analysis module is configured to determine the internal temperature change of the running cable, and obtain the surface temperature change of the running cable according to the monitoring data of the monitoring module.

[0011] And, inputting the internal temperature change and the surface temperature change of the running cable into the relationship model, determining the current thermal conductivity of the insulation layer of the running cable, and using the current thermal conductivity as a correction parameter to correct the calculation model of the maximum current carrying capacity of the running cable;

[0012] Wherein: the surface temperature change and the internal temperature change of the running cable are respectively the surface temperature change and the internal temperature change of the running cable per unit time when the thermal conductivity is constant and the current carrying capacity changes.

[0013] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the relationship model is: the correspondence between the surface temperature change, the internal temperature change, the heat dissipation efficiency of the environment in which the running cable is located, and the thermal conductivity is constructed as input data; if the surface temperature change, the internal temperature change, and the heat dissipation efficiency of the environment in which the running cable is located are input, the current thermal conductivity of the insulation layer of the running cable is output.

[0014] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, a storage unit is also provided in the analysis module to store the historical data of the thermal conductivity of the operating cable.

[0015] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the analysis module is also used to select the corresponding operation mode according to the historical data of thermal conductivity and thermal conductivity, wherein:

[0016] If the current thermal conductivity is less than the first threshold value and the thermal conductivity in the historical data is in an increasing state, it is determined that the aging condition of the operating cable meets the requirements, and the thermal conductivity is used as a correction parameter to correct the boundary conditions of the operating cable to increase the maximum current carrying capacity of the operating cable;

[0017] If the current thermal conductivity is greater than or equal to the first threshold, or the thermal conductivity in the historical data is in a reduced state, it is determined that the aging condition of the operating cable does not meet the requirements and there is a safety risk.

[0018] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the boundary conditions of the operating cable include: the ambient temperature of the operating cable, the convection heat transfer coefficient and the wind speed.

[0019] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the environmental heat dissipation efficiency model is constructed by taking the corresponding relationship between the ambient temperature, convective heat transfer coefficient and wind speed of the running cable and the heat dissipation efficiency as input data. If the ambient temperature, convective heat transfer coefficient and wind speed of the running cable are input, the environmental heat dissipation efficiency of the running cable is output.

[0020] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the analysis module corrects the thermal balance parameters of the operating cable according to the current thermal conductivity of the operating cable and the environmental heat dissipation efficiency, and substitutes them into the maximum current carrying capacity calculation model for the operating cable.

[0021] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the monitoring module includes a plurality of distributed temperature sensors for collecting surface temperature data of different positions of the running cable in real time.

[0022] As a preferred technical solution for the optimization system of the cable current carrying capacity calculation model, the test cable is a cable sample obtained by randomly sampling the operating cable during the construction of the operating cable.

[0023] On the other hand, the present invention also provides an optimization method for a cable current carrying capacity calculation model, comprising:

[0024] An aging test is performed on the test cable to measure the cable surface temperature change and internal temperature change corresponding to different thermal conductivities of the test cable insulation layer, and a relationship model is established;

[0025] Establish an environmental heat dissipation efficiency model based on the ambient temperature, convection heat transfer coefficient, wind speed and heat dissipation efficiency of the operating cable;

[0026] Calculate the internal temperature change of the running cable based on the thermal circuit model;

[0027] Obtain the surface temperature change of the running cable;

[0028] Inputting the internal temperature variation and the surface temperature variation into the relationship model to obtain the current thermal conductivity of the operating cable;

[0029] The current thermal conductivity is used as a correction parameter to correct the operating parameters in the maximum current carrying capacity calculation model of the operating cable.

[0030] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention characterizes the relationship between the surface temperature change, the internal temperature change, the boundary conditions and the thermal conductivity by establishing a relationship model. On the one hand, the value of the thermal conductivity during the cable operation process can be obtained according to the parameters that are easily obtained during the cable operation process. On the other hand, when the thermal conductivity increases, the speed of cable heat dissipation will be accelerated. At this time, the maximum current carrying capacity can be increased to meet the electricity demand. The specific increased value is obtained by correcting the thermal balance parameters of the operating cable through the current thermal conductivity and the environmental heat dissipation efficiency, and substituting them into the maximum current carrying capacity calculation model for the operating cable for correction, thereby increasing the accuracy of the maximum current carrying capacity calculation during the actual operation of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural block diagram of an optimization system for a cable current carrying capacity calculation model in an embodiment of the present invention;

[0032] Figure 2 is a flow chart of determination according to historical data of thermal conductivity and thermal conductivity in an embodiment of the present invention;

[0033] Figure 3 The present invention is a flowchart of the steps of an optimization system for a cable current carrying capacity calculation model in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0036] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0037] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] See also Figure 1 As shown, it is a structural block diagram of an optimization system for a cable current carrying capacity calculation model according to the present invention, comprising:

[0039] The test module is used to perform an aging test on the test cable, and during the aging test, detect the thermal conductivity of the insulation layer of the test cable, and detect the surface temperature change and internal temperature change of the test cable corresponding to the current thermal conductivity;

[0040] A monitoring module is arranged on the surface of the cable to monitor the surface temperature of the running cable and the boundary conditions of the running cable in real time;

[0041] An analysis module, which is connected to the test module and the monitoring module respectively, and is used to establish a relationship model of operating cable aging and an environmental heat dissipation efficiency model according to the test data of the test module;

[0042] The analysis module is configured to determine the internal temperature change of the running cable, and obtain the surface temperature change of the running cable according to the monitoring data of the monitoring module.

[0043] and inputting the internal temperature variation and the surface temperature variation of the operating cable into the relationship model, determining the current thermal conductivity of the insulation layer of the operating cable, and using the current thermal conductivity as a correction parameter to correct the calculation model of the maximum current carrying capacity of the operating cable;

[0044] Wherein: the surface temperature change and internal temperature change of the running cable are the surface temperature change and internal temperature change of the running cable per unit time when the thermal conductivity is constant and the current carrying capacity changes.

[0045] In detail, the internal temperature variation of the running cable can be determined by a model, calculation or direct detection method, such as ultrasonic wave which can detect the continuous temperature field of the cable cross section.

[0046] Specifically, an aging test detection method is provided in an embodiment of the present invention, wherein: temperature sensors are installed at different positions of the test cable (such as the surface and the insulation layer), and it is ensured that the sensors can accurately reflect the changes in the internal and surface temperatures of the cable, and the operating cable is aged by adjusting the ambient temperature, humidity and current load.

[0047] Furthermore, during the experiment, the temperature changes at different locations on the cable surface and the temperature changes inside the cable are recorded, and the thermal conductivity of the cable is tested in each time period. The thermal conductivity can be directly measured on the cable by special equipment, or indirectly calculated by the principle of thermal balance. The method used in the embodiment of the present invention is the laser flash method to directly detect the thermal conductivity.

[0048] Specifically, the relationship model is: the correspondence between the surface temperature change, the internal temperature change, the heat dissipation efficiency of the environment in which the running cable is located, and the thermal conductivity is constructed as input data. If the surface temperature change, the internal temperature change, and the heat dissipation efficiency of the environment in which the running cable is located are input, the current thermal conductivity of the insulation layer of the running cable is output.

[0049] Specifically, in actual use, due to the use environment of the cable, the thermal conductivity of the cable is usually difficult to detect. During the operation of the cable, the current carrying capacity per unit time changes, and the change in heat generated can be calculated according to the thermal circuit model. If the internal temperature increases by five degrees and the insulation layer has not aged, the surface temperature should increase by three degrees per unit time. However, due to the aging of the insulation layer, the thermal conductivity increases, and the external temperature increases by four degrees, that is, the amplitude of the internal and surface temperature changes per unit time is related to the aging of the cable. The present invention establishes a relationship model to link the surface temperature change, the internal temperature change, the boundary conditions and the thermal conductivity. On the one hand, the value of the thermal conductivity during the operation of the cable can be obtained according to the parameters that are easily obtained during the operation of the cable. On the other hand, when the thermal conductivity increases, the speed of the cable heat dissipation will be accelerated. At this time, the maximum current carrying capacity can be increased to meet the power demand. The specific increased value is corrected by the current thermal conductivity and the environmental heat dissipation efficiency to correct the thermal balance parameters of the running cable, and is substituted into the maximum current carrying capacity calculation model for the running cable for correction, thereby increasing the accuracy of the maximum current carrying capacity calculation during the actual operation of the cable.

[0050] In detail, the relationship model is established as follows:

[0051] First, data is collected in real time using sensors installed on, inside, and around the cable. Data collection includes:

[0052] Temperature variation (ΔT_surface and ΔT_internal): The sensor records the temperature variation on the cable surface and inside during a specific period of time.

[0053] Environmental heat dissipation efficiency (η_environment): includes the measurement of air temperature, air thermal conductivity and wind speed environmental factors. The environmental conditions around the cable are obtained through wind speed sensors and temperature and humidity sensors, and the environmental heat dissipation efficiency of the cable is calculated.

[0054] Secondly, data preprocessing is performed: denoising, data smoothing and time synchronization are performed on the collected data to ensure its accuracy and consistency.

[0055] Finally, perform model training:

[0056] Establishing a mathematical model: using regression analysis or machine learning algorithms (such as support vector machines, neural networks) to train the data. Selecting the best fitting relationship between the temperature change, the environmental heat dissipation efficiency and the cable thermal conductivity as the relationship model in the embodiment of the present invention.

[0057] Furthermore, a storage unit is provided in the analysis module for storing historical data of the thermal conductivity of the operating cable.

[0058] See also Figure 2 As shown, it is a determination flow chart for determining according to the historical data of thermal conductivity and thermal conductivity in an embodiment of the present invention, and the corresponding operation mode is selected according to the determination result, wherein:

[0059] If the current thermal conductivity is less than the first threshold value and the thermal conductivity in the historical data is in an increasing state, it is determined that the aging condition of the operating cable meets the requirements, and the thermal conductivity is used as a correction parameter to correct the boundary conditions of the operating cable to increase the maximum current carrying capacity of the operating cable;

[0060] If the current thermal conductivity is greater than or equal to the first threshold, or the thermal conductivity in the historical data is in a reduced state, it is determined that the aging condition of the operating cable does not meet the requirements and there is a safety risk.

[0061] In detail, the selection of the first threshold is determined according to the actual variation range of the thermal conductivity of the operating cable, and the value within the interval where the thermal conductivity increases is selected as the first threshold. It is known that the thermal conductivity of the operating cable meets the actual use conditions in the interval between 0.2W / m·K and 0.5W / m·K. In the embodiment of the present invention, the initial value of the thermal conductivity of the test cable is 0.2W / m·K. During the aging test, the thermal conductivity first increases to 0.46W / m·K, and then decreases to 0.2W / m·K, which does not meet the actual use conditions. That is, during the aging process, the thermal conductivity increases in the interval between 0.40W / m·K and 0.46W / m·K. The aging degree in this interval is light and the thermal conductivity is high, that is, the selection range of the first threshold is between 0.40W / m·K and 0.46W / m·K. In the embodiment of the present invention, the value of the first threshold is 0.40W / m·K.

[0062] Specifically, in the early stages of cable aging, as some low thermal conductivity components in the insulation layer material (such as organic compounds, low molecular substances in the polymer matrix) are decomposed or chemically reacted, the thermal conductivity will increase. As aging continues, the molecular chain breakage, dehydration or oxidation reaction of the insulation layer material intensifies, so the structure of the material becomes loose, the heat conduction path may become discontinuous, the heat transfer efficiency decreases, and the thermal conductivity decreases. Therefore, combining the first threshold value of thermal conductivity with historical data, the aging of the cable can be accurately judged, avoiding the phenomenon of qualified thermal conductivity but high degree of aging, and avoiding safety risks caused by adjusting the maximum current carrying capacity, thereby increasing the accuracy of calculations for the maximum current carrying capacity.

[0063] Furthermore, the boundary conditions of the operating cable include: the ambient temperature of the operating cable, the convection heat transfer coefficient and the wind speed.

[0064] Furthermore, the environmental heat dissipation efficiency model is constructed by taking the ambient temperature of the running cable, the convection heat transfer coefficient, and the correspondence between the wind speed and the heat dissipation efficiency as input data. If the ambient temperature, the convection heat transfer coefficient, and the wind speed of the running cable are input, the environmental heat dissipation efficiency of the running cable is output.

[0065] Specifically, during actual operation, the environment will also have a certain impact on the surface temperature of the cable. If the environment has good heat dissipation and the surface temperature drops significantly, it will have a greater impact on the calculation result of the thermal conductivity. The present invention establishes an environmental heat dissipation efficiency model, thereby taking the efficiency of the environmental heat dissipation efficiency model into account in the relationship model of thermal conductivity, so that the obtained thermal conductivity is more accurate, thereby increasing the accuracy of subsequent calculation results for the maximum current carrying capacity.

[0066] In detail, the present invention provides an environmental heat dissipation efficiency model, setting Q = h × A × ΔT. Where:

[0067] Q is the heat dissipated by the running cable (unit: Watt, W).

[0068] h is the convection heat transfer coefficient (unit: W / m 2 K), which is the ability of heat exchange between air flow and cable surface, affected by wind speed and temperature difference.

[0069] A is the cable surface area (unit: m 2 ), the larger the surface of the cable, the greater the heat dissipation capacity.

[0070] ΔT is the temperature difference between the cable surface temperature and the ambient temperature (unit: K).

[0071] Set the convection heat transfer coefficient h = α × (v / L) β ,in:

[0072] α and β are empirical constants obtained through experiments.

[0073] v is the wind speed of air (unit: m / s).

[0074] L is the characteristic length of the cable, usually the diameter of the cable (unit: m).

[0075] Substituting the above data into the heat dissipation efficiency η environment The calculation formula is:

[0076] Determine the heat dissipation efficiency;

[0077] Where: h max is the convective heat transfer coefficient A under optimal environmental conditions max is the surface area under optimal environmental conditions, ΔT max is the temperature difference at the maximum ambient temperature difference.

[0078] Furthermore, the analysis module corrects the thermal balance parameters of the operating cable according to the current thermal conductivity of the operating cable and the ambient heat dissipation efficiency, and substitutes the parameters into a maximum current carrying capacity calculation model for the operating cable.

[0079] Specifically, the monitoring module includes a plurality of distributed temperature sensors for collecting surface temperature data of different positions of the running cable in real time.

[0080] In detail, the test cable is a cable sample obtained by randomly sampling the operating cable during the construction of the operating cable.

[0081] Specifically, randomly selecting samples from actual operating cables can ensure that the test cables are representative, thereby increasing the accuracy of the thermal conductivity output by the relationship model. The length and cross-sectional area of ​​the cable should be selected according to the standard to ensure that the simulated load conditions and current density are reasonable.

[0082] See also Figure 3 As shown, it is a flowchart of the steps of an optimization method for a cable current carrying capacity calculation model in an embodiment of the present invention, including:

[0083] Step S1, performing an aging test on the test cable, measuring the cable surface temperature change and the internal temperature change corresponding to different thermal conductivities of the test cable insulation layer, and establishing a relationship model;

[0084] Step S2, establishing an environmental heat dissipation efficiency model according to the ambient temperature, convection heat transfer coefficient, wind speed and heat dissipation efficiency of the operating cable;

[0085] Step S3, calculating the internal temperature change of the running cable according to the thermal circuit model;

[0086] Step S4, obtaining the surface temperature change of the running cable;

[0087] Step S5, inputting the internal temperature change and the surface temperature change into the relationship model to obtain the current thermal conductivity of the operating cable;

[0088] Step S6: Using the current thermal conductivity as a correction parameter, the operating parameters in the maximum current carrying capacity calculation model of the operating cable are corrected.

[0089] Specifically, the international standard IEC 60287-1-1 gives the calculation for the allowable rated current of the cable, involving parameters: the thermal resistance per unit length between the cable surface and the surrounding environment, which is obtained by calculating the convection thermal resistance and the radiation thermal resistance, and the temperature of the cable surface directly affects the efficiency of the convection heat transfer. If the thermal conductivity of the insulation layer is high, the heat inside the cable can be transferred to the surface more quickly, thereby affecting the surface temperature of the cable. When the surface temperature is high, the convection heat transfer coefficient usually increases, thereby improving the heat dissipation capacity of the cable, thereby correcting the convection thermal resistance, and thus correcting the calculation result of the allowable rated current of the cable. The specific calculation process is all existing technology and will not be repeated here.

[0090] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the device, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based device that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0091] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An optimization system for a cable current carrying capacity calculation model, characterized in that: include: The test module is used to perform an aging test on the test cable, and during the aging test, detect the thermal conductivity of the insulation layer of the test cable, and detect the surface temperature change and internal temperature change of the test cable corresponding to the current thermal conductivity; A monitoring module is arranged on the surface of the cable to monitor the surface temperature of the running cable and the boundary conditions of the running cable in real time; An analysis module, which is connected to the test module and the monitoring module respectively, and is used to establish a relationship model of operating cable aging and an environmental heat dissipation efficiency model according to the test data of the test module; The analysis module is configured to determine the internal temperature change of the running cable, and obtain the surface temperature change of the running cable according to the monitoring data of the monitoring module. And, inputting the internal temperature change and the surface temperature change of the running cable into the relationship model, determining the current thermal conductivity of the insulation layer of the running cable, and using the current thermal conductivity as a correction parameter to correct the calculation model of the maximum current carrying capacity of the running cable; Wherein: the surface temperature change and the internal temperature change of the running cable are respectively the surface temperature change and the internal temperature change of the running cable per unit time when the thermal conductivity is constant and the current carrying capacity changes.

2. The optimization system for the cable current carrying capacity calculation model according to claim 1, characterized in that: The relationship model is constructed by taking the correspondence between the surface temperature change, the internal temperature change, the heat dissipation efficiency of the environment in which the running cable is located and the thermal conductivity as input data. If the surface temperature change, the internal temperature change and the heat dissipation efficiency of the environment in which the running cable is located are input, the current thermal conductivity of the insulation layer of the running cable is output.

3. The optimization system for the cable current carrying capacity calculation model according to claim 2, characterized in that: The analysis module is also provided with a storage unit for storing historical data of the thermal conductivity of the operating cable.

4. The optimization system for the cable current carrying capacity calculation model according to claim 3, characterized in that: The analysis module is also used to select a corresponding operation mode according to the historical data of thermal conductivity and thermal conductivity, wherein: If the current thermal conductivity is less than the first threshold value and the thermal conductivity in the historical data is in an increasing state, it is determined that the aging condition of the operating cable meets the requirements, and the thermal conductivity is used as a correction parameter to correct the boundary conditions of the operating cable to increase the maximum current carrying capacity of the operating cable; If the current thermal conductivity is greater than or equal to the first threshold, or the thermal conductivity in the historical data is in a reduced state, it is determined that the aging condition of the operating cable does not meet the requirements and there is a safety risk.

5. The optimization system for the cable current carrying capacity calculation model according to claim 1, characterized in that: The boundary conditions for the running cable include: the ambient temperature of the running cable, the convection heat transfer coefficient and the wind speed.

6. The optimization system for the cable current carrying capacity calculation model according to claim 5, characterized in that: The environmental heat dissipation efficiency model is constructed by taking the corresponding relationship between the ambient temperature of the running cable, the convection heat transfer coefficient, and the wind speed and the heat dissipation efficiency as input data. If the ambient temperature of the running cable, the convection heat transfer coefficient, and the wind speed are input, the environmental heat dissipation efficiency of the running cable is output.

7. The optimization system for the cable current carrying capacity calculation model according to claim 6, characterized in that: The analysis module corrects the thermal balance parameters of the operating cable according to the current thermal conductivity of the operating cable and the environmental heat dissipation efficiency, and substitutes the parameters into the maximum current carrying capacity calculation model for the operating cable.

8. The optimization system for the cable current carrying capacity calculation model according to claim 1, characterized in that: The monitoring module includes a plurality of distributed temperature sensors for collecting surface temperature data of different positions of the running cable in real time.

9. The optimization system for the cable current carrying capacity calculation model according to claim 1, characterized in that: The test cable is a cable sample obtained by randomly sampling the operating cable during the construction of the operating cable.

10. An optimization method for a cable current carrying capacity calculation model, characterized in that: The optimization system for the cable current carrying capacity calculation model as described in any one of claims 1 to 9 is characterized by comprising: An aging test is performed on the test cable to measure the cable surface temperature change and internal temperature change corresponding to different thermal conductivities of the test cable insulation layer, and a relationship model is established; Establish an environmental heat dissipation efficiency model based on the ambient temperature, convection heat transfer coefficient, wind speed and heat dissipation efficiency of the operating cable; Calculate the internal temperature change of the running cable based on the thermal circuit model; Obtain the surface temperature change of the running cable; Inputting the internal temperature variation and the surface temperature variation into the relationship model to obtain the current thermal conductivity of the operating cable; The current thermal conductivity is used as a correction parameter to correct the operating parameters in the maximum current carrying capacity calculation model of the operating cable.

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