High-voltage cable conductor temperature dynamic monitoring method and system, electronic equipment and medium

Abstract

The invention discloses a high-voltage cable conductor temperature dynamic monitoring method and system, electronic equipment and a medium, and the method comprises the following steps: S1, pre-installing a temperature sensor in a high-voltage cable sheath layer, and collecting the temperature data of the sheath layer in real time through the temperature sensor; s2, performing RC thermal network equivalence on thermal resistance and thermal capacity of a conductor, an insulating layer and a sheath layer of the high-voltage cable, establishing a dynamic thermal network model of interlayer materials of the high-voltage cable, and constructing an incidence relation between cable core temperature and cable current-carrying capacity; s3, converting the constructed dynamic thermal network model into a high-voltage cable multi-layer heat conduction equation, and performing discretization solution on the equation by adopting a finite difference method to obtain radial distribution of the temperature of the high-voltage cable; according to the method, the sheath temperature real-time monitoring data and the dynamic thermal network model are utilized, the interlayer temperature distribution condition of the high-voltage cable can be represented, and the model is subjected to parameter correction, so that the cable temperature real-time monitoring accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method, system, electronic device, and medium for dynamic monitoring of conductor temperature in high-voltage cables. Background Technology

[0002] Currently, the existing underground pipeline network capacity is nearing saturation, and there is a lack of space to add new cable lines. Limited by underground urban utility tunnels, adding new cable channels is also extremely difficult. Furthermore, cable cross-sectional area selection has reached its manufacturing limits, and line voltage levels cannot be further increased. Therefore, there is an urgent need to improve the current-carrying capacity of existing cable lines to meet the ever-growing urban power supply demands. The temperature of operating high-voltage cables serves as a core parameter characterizing their current-carrying capacity. By monitoring the core temperature of high-voltage cables, their operational status can be assessed. However, due to the complex manufacturing process of high-voltage cables and the high insulation requirements of their applications, temperature monitoring should be conducted without affecting the insulation performance of the high-voltage cables.

[0003] Existing methods mainly rely on the calibration of equivalent or static values ​​of fixed parameters, without considering that boundary heat transfer may change with environmental conditions (wind speed, soil cover, etc.). Furthermore, sensor noise also affects temperature acquisition, leading to increased peak deviation or cross-condition error, and lacking correction under dynamic conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, electronic device, and medium for dynamic monitoring of conductor temperature in high-voltage cables. This invention utilizes real-time monitoring data of sheath temperature and a dynamic thermal network model to characterize the interlayer temperature distribution of high-voltage cables. Furthermore, the model undergoes parameter correction to improve the accuracy of real-time cable temperature monitoring.

[0005] The technical solution of this invention: A method for dynamic monitoring of the conductor temperature of a high-voltage cable, comprising the following steps: Step S1: Pre-install a temperature sensor in the high-voltage cable sheath layer and use the temperature sensor to collect the sheath layer temperature data in real time; Step S2: Equivalently apply the thermal resistance and thermal capacity of the conductor, insulation layer and sheath layer of the high-voltage cable to an RC thermal network, establish a dynamic thermal network model of the interlayer material of the high-voltage cable, and construct the correlation between the cable core temperature and the cable current carrying capacity. Step S3: The constructed dynamic thermal network model is transformed into a multi-layer heat conduction equation for the high-voltage cable. The equation is discretized and solved using the finite difference method to obtain the radial temperature distribution of the high-voltage cable. Step S4: Using the Kalman filter algorithm, combined with the measured temperature data from step S1 and the calculated temperature data from step S3, the parameters of the dynamic thermal network model are corrected to obtain the corrected high-voltage cable temperature distribution.

[0006] In the above-mentioned method for dynamic monitoring of conductor temperature of high-voltage cables, the temperature sensor is a patch-type thermistor with a temperature measurement range of -50℃ to 150℃; the temperature sensors are distributed in the inlet and outlet of cable trench ducts, cable bends, and between the insulation layer and sheath layer of high-voltage cables in horizontally laid cable sections.

[0007] In the aforementioned method for dynamic monitoring of high-voltage cable conductor temperature, the RC thermal network equivalent process in step S2 is performed as follows: Step S2.1.1: Based on the geometric structure of the high-voltage cable and the material parameters of each dielectric layer, analyze the connection mode of the equivalent circuit between the layers of the high-voltage cable, and convert the thermal resistance and thermal capacity of the conductor, insulation layer and sheath layer of the high-voltage cable into an equivalent RC thermal network. Step S2.1.2: Calculate the interlayer equivalent thermal resistance for a unit length of high-voltage cable. The calculation formula is as follows: ; In the formula, r i , r i+1 The radius of the adjacent dielectric layer of the high-voltage cable and i ≠0; k The thermal conductivity of this cable segment; Step S2.1.3: Calculate the equivalent interlayer heat capacity per unit length of high-voltage cable. The calculation formula is as follows: ; In the formula, ρ For material density, c Specific heat capacity of the material; Step S2.1.4: Calculate the heat exchange branch between the outer surface layer of the high-voltage cable and the environment. The calculation formula is as follows: ; ; Always h rad The thermal emissivity, h conv The convective heat transfer coefficient is... R out The radius of the outer sheath.

[0008] In the aforementioned method for dynamic monitoring of high-voltage cable conductor temperature, the construction process of the high-voltage cable interlayer dynamic thermal network model and the correlation between high-voltage cable core temperature and cable current carrying capacity in step S2 is constructed according to the following steps: Step S2.2.1: Based on the equivalent results of the RC thermal network, and according to the parallel relationship between the circuit voltage drop and the material resistance, construct a dynamic thermal network model between the layers of the high-voltage cable; Step S2.2.2: Perform nodal temperature analysis for each RC thermal network. Each node satisfies the heat balance equation, which is as follows: ; In the formula, Ci For node heat capacity; Ti For node temperature; G i-1,i and G i,i+1 For thermal conductivity between adjacent dielectric layers, C i (t) represents the equivalent volumetric heat source injection for this dielectric layer; Step S2.2.3: According to t The initial condition for heat exchange resulting from temperature changes at any given time is: T i (0)= T ; T Use the initial measured temperature or the steady-state estimate as the initial value; Based on the temperature changes during heat exchange, the boundary conditions for the dynamic thermal network model between high-voltage cable layers are obtained: T i ( t )= A ( t ); T i ( t’ )= B ( t’ ); In the formula, A ( t )and B ( t The values ​​') represent the temperatures measured at different locations on the high-voltage cable within the same time interval.

[0009] In the aforementioned method for dynamic monitoring of high-voltage cable conductor temperature, the radial temperature distribution of the high-voltage cable in step S3 is obtained according to the following steps: Step S3.1: Based on the equivalent results of the RC thermal network, calculate the equivalent thermal conductivity on both sides of the interface, as shown in the following formula: ; In the formula, k eq The equivalent thermal conductivity is T 'andT These represent the temperatures between different layers of the high-voltage cable; Step S3.2: Iterate the time and space terms using the finite difference method. The time term uses forward differencing, and the space term uses backward differencing. The resulting temperature recursive formula is shown below: ; In the formula, n The first equivalent of RC heat network n Nodes, Δ t For time intervals, D It is a symmetric tridiagonal matrix composed of thermal conductivity terms; Step S3.3: Obtain the temperature before correction from the boundary conditions of the high-voltage cable interlayer dynamic thermal network model: Internal boundary conditions: ; External boundary conditions: ; In the formula, r The radius of the dielectric layer of the high-voltage cable. R This refers to the outer insulation radius of the high-voltage cable.

[0010] In the aforementioned method for dynamic monitoring of high-voltage cable conductor temperature, the parameter correction process in step S4 is performed according to the following steps: Step S4.1: Define the thermal resistance R, heat capacity C, and temperature T as an extended state vector, and construct the state vector. x The parameters are then initialized as shown in the following formula: ; Step S4.2: Establish the state equations: ; In the formula, F n Here is the state transition matrix. u n It is the covariance matrix; Step S4.3: Correct and update the state equation and covariance: ; In the formula, It is the first n The number of state updates per node It is the first n Covariance update of each node K n For Kalman gain.

[0011] The aforementioned system for dynamic monitoring of conductor temperature of a high-voltage cable includes a temperature measurement unit, an equivalent unit of RC thermal network of interlayer medium of high-voltage cable, a dynamic thermal network model acquisition unit of interlayer medium of high-voltage cable, a finite difference method solution unit, and a parameter correction unit. The temperature measurement unit uses a built-in temperature sensor in the high-voltage cable to achieve real-time monitoring of the temperature of the high-voltage cable sheath. The equivalent unit of the high-voltage cable interlayer dielectric RC thermal network is used to analyze the connection mode of the cable interlayer equivalent circuit based on the geometric structure of the high-voltage cable and the material parameters of each dielectric layer, and to establish the equivalent model of the cable interlayer dielectric RC thermal network. The high-voltage cable interlayer medium dynamic thermal network model acquisition unit is connected to the high-voltage cable interlayer medium RC thermal network equivalent unit, and is used to perform node thermal balance equation analysis based on the RC thermal network equivalent results to construct the high-voltage cable interlayer dynamic thermal network model. The finite difference method solution unit is connected to the high-voltage cable interlayer medium dynamic thermal network model acquisition unit, and is used to solve the multilayer heat conduction equation of the high-voltage cable through the finite difference method to obtain the radial distribution of the high-voltage cable temperature. The parameter correction unit is connected to the temperature measurement unit and the finite difference method solution unit. It uses the Kalman filter algorithm to combine temperature data and model calculation data to correct the parameters of the dynamic thermal network model between high-voltage cable layers.

[0012] An electronic device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the dynamic monitoring method for the temperature of a high-voltage cable conductor.

[0013] A computer-readable storage medium storing computer-executable instructions that, when executed, implement the steps of the dynamic temperature monitoring method for high-voltage cable conductors.

[0014] Compared with existing technologies, this invention pre-installs sensors at key locations to collect sheath temperature, providing accurate basic data for subsequent calculations. Then, based on cable structure and material parameters, it constructs an equivalent RC thermal network model, further establishing a dynamic thermal network model of the interlayer materials in the high-voltage cable, and establishing the correlation between cable core temperature and cable current carrying capacity, overcoming the limitations of fixed parameter equivalence. By solving the heat conduction equation using the finite difference method, it accurately obtains the radial temperature distribution, providing reliable input for the model. Finally, it uses the Kalman filter algorithm to fuse measured and calculated data to correct model parameters, effectively suppressing errors caused by environmental changes and sensor noise, reducing peak deviation and cross-condition errors, and achieving dynamic and accurate monitoring of the conductor temperature distribution of high-voltage cables. This provides more reliable support for cable current carrying capacity assessment and safe operation, solving the problems of poor adaptability and large errors in traditional static monitoring methods. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of the high-voltage cable conductor temperature dynamic monitoring method of the present invention; Figure 2 This shows the installation location of the temperature sensor of the present invention in a single high-voltage cable; Figure 3 This indicates the arrangement position of the temperature sensor of the present invention in the pipe arrangement; Figure 4 This is a schematic diagram of the equivalent model of the RC heat network of the present invention; Figure 5 This is a schematic diagram of the temperature measurement experimental circuit according to an embodiment of the present invention; Figure 6 The actual temperature measurement results, calculated temperature results, and errors of this invention are as follows; Figure 7 This is a flowchart illustrating the parameter correction process of the present invention. Figure 8 This is a schematic diagram of the logical structure of the computer device of the present invention. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0017] Example: A method for dynamic monitoring of conductor temperature in high-voltage cables, as shown in the attached figure. Figure 1 As shown, proceed with the following steps: Step S1: The high-voltage cable has an application level of 110kV and is laid in a duct. The high-voltage cable includes a dielectric layer comprising a conductor, an insulation layer, and a sheath layer, as shown in the attached diagram. Figure 2 and attached Figure 3As shown, temperature sensors are pre-installed between the insulation layer and the sheath layer of high-voltage cables at the inlet and outlet of cable trench ducts, cable bends, and horizontally laid cable sections to collect sheath layer temperature data. The temperature sensor is a PTC patch thermistor with a temperature measurement range of -50℃ to +150℃. Step S2: The thermal resistance and thermal capacity of the conductor, insulation layer, and sheath layer of the high-voltage cable are equivalently represented by an RC thermal network. A dynamic thermal network model of the interlayer materials of the high-voltage cable is established, and the correlation between the cable core temperature and the cable current carrying capacity is constructed. Step S2.1.1: Based on the geometric structure of the high-voltage cable and the material parameters of each dielectric layer, analyze the connection method of the equivalent circuit between the high-voltage cable layers. Equip the thermal resistance and thermal capacitance of the conductor, insulation layer, and sheath layer of the high-voltage cable with an equivalent RC thermal network, as shown in the attached diagram. Figure 4 As shown, where, R cd1 C is the equivalent thermal resistance of the conductor. cd1 For the heat capacity of the core-sheath insulation layer, R cd2 For the thermal resistance of the conductor core, C cd2 For the heat capacity of the sheath layer, R cd3 External insulation thermal resistance; Step S2.1.2: Calculate the interlayer equivalent thermal resistance for a unit length of high-voltage cable. The calculation formula is as follows: ; In the formula, r i , r i+1 The radius of the adjacent dielectric layer of the high-voltage cable and i ≠0, the calculation is broken down into the wire core, shielding layer (insulation layer), main insulation (insulation layer), insulation shield (insulation layer), metal sheath (sheath layer) and outer sheath (sheath layer) for independent and accurate calculation; k The thermal conductivity of this cable segment; Step S2.1.3: Calculate the equivalent interlayer heat capacity per unit length of high-voltage cable. The calculation formula is as follows: ; In the formula, ρ For material density, c Specific heat capacity of the material; Step S2.1.4: Calculate the heat exchange branch between the outer surface layer of the high-voltage cable and the environment. The calculation formula is as follows: ; ; Always h radThe thermal emissivity, h conv The convective heat transfer coefficient is... R out The radius of the outer sheath.

[0018] Based on the equivalent results of the RC thermal network, the nodal thermal balance equations are analyzed, and a dynamic thermal network model between high-voltage cable layers is constructed according to the following steps: Step S2.2.1: Based on the equivalent results of the RC thermal network, and according to the parallel relationship between the circuit voltage drop and the material resistance, construct a dynamic thermal network model between the layers of the high-voltage cable; Step S2.2.2: Perform nodal temperature analysis for each RC thermal network. Each node satisfies the heat balance equation, which is as follows: ; In the formula, Ci For node heat capacity; Ti For node temperature; G i-1,i and G i,i+1 It is the thermal conductivity between adjacent dielectric layers (the reciprocal of the thermal resistance). C i (t) represents the equivalent volumetric heat source injection of the medium layer (0 when there is no heat source injection); Step S2.2.3: According to t The initial condition for heat exchange resulting from temperature changes at any given time is: T i (0)= T ; T Use the initial measured temperature or the steady-state estimate as the initial value; Based on the temperature changes during heat exchange, the boundary conditions for the dynamic thermal network model between high-voltage cable layers are obtained: T i ( t )= A ( t ); T i ( t’ )= B ( t’ ); In the formula, A ( t )and B ( t The values ​​') represent the temperatures measured at different locations on the high-voltage cable within the same time interval.

[0019] Step S3: Transform the constructed dynamic thermal network model into a multi-layer heat conduction equation for the high-voltage cable. Use the finite difference method to discretize and solve the equation to obtain the radial temperature distribution of the high-voltage cable. Specifically, follow these steps: Step S3.1: Based on the equivalent results of the RC thermal network, calculate the equivalent thermal conductivity on both sides of the interface, as shown in the following formula: ; In the formula, k eq The equivalent thermal conductivity is T 'and T These represent the temperatures between different layers of the high-voltage cable; Step S3.2: Iterate the time and space terms using the finite difference method. The time term uses forward differencing, and the space term uses backward differencing. The resulting temperature recursive formula is shown below: ; In the formula, n The first equivalent of RC heat network n Nodes, Δ t For time intervals, D It is a symmetric tridiagonal matrix composed of thermal conductivity terms; Step S3.3: Obtain the temperature before correction from the boundary conditions of the high-voltage cable interlayer dynamic thermal network model: Internal boundary conditions: ; External boundary conditions: ; In the formula, r The radius of the dielectric layer of the high-voltage cable. R This refers to the outer insulation radius of the high-voltage cable.

[0020] Step S4: Using the Kalman filter algorithm, combined with the measured temperature data from Step S1 and the calculated temperature data from Step S3, the parameters of the dynamic thermal network model are corrected to obtain the corrected high-voltage cable temperature profile, as shown in the attached figure. Figure 7 As shown, the correction process is carried out according to the following steps: Step S4.1: Define the thermal resistance R, heat capacity C, and temperature T as an extended state vector, and construct the state vector. x The parameters are then initialized as shown in the following formula: ; Step S4.2: Establish the state equations: ; In the formula, F n Here is the state transition matrix. u nIt is the covariance matrix; Step S4.3: Correct and update the state equation and covariance: ; In the formula, It is the first n The number of state updates per node It is the first n Covariance update of each node K n For Kalman gain.

[0021] As attached Figure 5 As shown, an experimental circuit including cables was constructed under laboratory conditions. To simulate conduit installation, the cables were laid through PVC pipes. Figure 6 To compare the measured core temperature obtained using this temperature measurement circuit with the calculated temperature using the method proposed in this embodiment, the appendix... Figure 6 It can be seen that the error in the calculation result of the wire core temperature by this method is within 5%, and the accuracy is relatively high.

[0022] In summary, the dynamic monitoring method for high-voltage cable conductor temperature proposed in this invention addresses the core need for accurate monitoring of high-voltage cable temperature by constructing a complete technical chain encompassing data acquisition, model building, numerical solution, and parameter correction. This effectively overcomes the limitations of existing technologies that primarily rely on fixed parameter equivalence or static numerical calibration. This method first pre-installs temperature sensors between the insulation and sheath layers at key locations such as the inlet and outlet of cable trench ducts and bends to ensure the targeted and reliable acquisition of sheath layer temperature data, providing high-quality basic data for subsequent calculations. Then, based on the cable geometry, dielectric material parameters, and equivalent circuit connection methods, it achieves accurate quantification of thermal resistance and heat capacity through an RC thermal network. Combined with the nodal thermal balance equations, it constructs a dynamic interlayer thermal network model, overcoming the bottleneck of traditional static models' inability to adapt to environmental changes. Subsequently, it uses the finite difference method to solve the multilayer heat conduction equations, accurately obtaining the radial temperature distribution and inner and outer boundary temperatures, providing the model with input conditions consistent with actual heat transfer laws. Finally, it introduces a Kalman filter algorithm, fusing measured temperature data with model calculation data to dynamically correct the thermal network model parameters, effectively suppressing interference from environmental factors such as wind speed and soil cover, as well as sensor noise, significantly reducing peak deviation and cross-condition errors. This method enables dynamic and accurate monitoring of the conductor temperature of high-voltage cables, providing reliable temperature data support for improving the current-carrying capacity of existing cable lines. It meets the practical needs for cable operation status assessment in the context of increasing urban power supply demand, combining technological innovation with engineering practicality.

[0023] Example 2: High-voltage cable conductor temperature dynamic monitoring system, used for high-voltage cable conductor temperature dynamic monitoring method, including temperature measurement unit, high-voltage cable interlayer dielectric RC thermal network equivalent unit, high-voltage cable interlayer dielectric dynamic thermal network model acquisition unit, finite difference method solution unit and parameter correction unit; The temperature measurement unit uses a built-in temperature sensor in the high-voltage cable to monitor the temperature of the high-voltage cable sheath in real time. The temperature measurement unit consists of a data acquisition device, a signal conditioning circuit, and a microcontroller. The data acquisition device includes, but is not limited to, a PLC and a microcontroller, which convert the acquired signal into a digital signal that can be processed by the microcontroller. The signal conditioning circuit performs amplification (gain adjustment), filtering (noise removal), isolation (interference suppression), linearization (compensation for nonlinear errors), and analog-to-digital conversion (ADC) on the acquired signal. The controller can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0024] The equivalent unit of the RC thermal network of the interlayer dielectric of the high-voltage cable is an embedded processing system based on digital signal processing, or it can be an embedded processing system based on field-programmable gate array. It is used to analyze the connection mode of the equivalent circuit between the interlayer dielectric of the high-voltage cable and the material parameters of each dielectric layer, and to establish an equivalent model of the RC thermal network of the interlayer dielectric of the cable. The high-voltage cable interlayer medium dynamic thermal network model acquisition unit is connected to the high-voltage cable interlayer medium RC thermal network equivalent unit. It is an embedded processing system based on digital signal processing, or it can be an embedded processing system based on field-programmable gate array. It is used to perform node thermal balance equation analysis based on RC thermal network equivalent results and construct a high-voltage cable interlayer dynamic thermal network model. The finite difference method solution unit is connected to the high-voltage cable interlayer medium dynamic thermal network model acquisition unit. It is an embedded processing system based on digital signal processing, or it can be an embedded processing system based on field programmable gate array. It is used to solve the multilayer heat conduction equation of high-voltage cable through the finite difference method to obtain the radial distribution of high-voltage cable temperature. The parameter correction unit connects the temperature measurement unit and the finite difference method solution unit. It is an embedded processing system based on digital signal processing, or it can be an embedded processing system based on field-programmable gate array. It corrects the parameters of the dynamic thermal network model between high-voltage cable layers by combining temperature data and model calculation data with the Kalman filter algorithm.

[0025] Example 3: An electronic device includes at least one processor and a memory communicatively connected to the at least one processor; the memory stores a computer program executable by the at least one processor, which, when executed by the at least one processor, causes the electronic device to perform the steps of the high-voltage cable conductor temperature dynamic monitoring method according to Example 1 of the present invention.

[0026] Example 4: A computer-readable storage medium, as shown in the attached document. Figure 8 As shown, the computer-readable storage medium stores computer-executable instructions, which, when executed, implement the steps of the high-voltage cable conductor temperature dynamic monitoring method of Embodiment 1.

[0027] In this embodiment, it should be understood that the disclosed system can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical or other forms.

[0028] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0029] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0030] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

Claims

1. A method for dynamic monitoring of conductor temperature in high-voltage cables, characterized in that: Follow these steps: Step S1: Pre-install a temperature sensor in the high-voltage cable sheath layer and use the temperature sensor to collect the sheath layer temperature data in real time; Step S2: Equivalently apply the thermal resistance and thermal capacity of the conductor, insulation layer and sheath layer of the high-voltage cable to an RC thermal network, establish a dynamic thermal network model of the interlayer material of the high-voltage cable, and construct the correlation between the cable core temperature and the cable current carrying capacity. Step S3: The constructed dynamic thermal network model is transformed into a multi-layer heat conduction equation for the high-voltage cable. The equation is discretized and solved using the finite difference method to obtain the radial temperature distribution of the high-voltage cable. Step S4: Using the Kalman filter algorithm, combined with the measured temperature data from step S1 and the calculated temperature data from step S3, the parameters of the dynamic thermal network model are corrected to obtain the corrected high-voltage cable temperature distribution.

2. The method for dynamic monitoring of high-voltage cable conductor temperature according to claim 1, characterized in that: The temperature sensor is a patch-type thermistor with a temperature measurement range of -50℃ to 150℃. The temperature sensors are distributed in the inlet and outlet of the cable trench duct, at cable bends, and between the insulation and sheath layers of the high-voltage cable in horizontally laid cable sections.

3. The method for dynamic monitoring of high-voltage cable conductor temperature according to claim 1, characterized in that: The RC thermal network equivalent process in step S2 is performed as follows: Step S2.1.1: Based on the geometric structure of the high-voltage cable and the material parameters of each dielectric layer, analyze the connection mode of the equivalent circuit between the layers of the high-voltage cable, and convert the thermal resistance and thermal capacity of the conductor, insulation layer and sheath layer of the high-voltage cable into an equivalent RC thermal network. Step S2.1.2: Calculate the interlayer equivalent thermal resistance for a unit length of high-voltage cable. The calculation formula is as follows: ； In the formula, r i , r i+1 The radius of the adjacent dielectric layer of the high-voltage cable and i ≠0; k The thermal conductivity of this cable segment; Step S2.1.3: Calculate the equivalent interlayer heat capacity per unit length of high-voltage cable. The calculation formula is as follows: ； In the formula, ρ For material density, c Specific heat capacity of the material; Step S2.1.4: Calculate the heat exchange branch between the outer surface layer of the high-voltage cable and the environment. The calculation formula is as follows: ； ； Always h rad The thermal emissivity, h conv The convective heat transfer coefficient is... R out The radius of the outer sheath.

4. The method for dynamic monitoring of high-voltage cable conductor temperature according to claim 1, characterized in that: The process of constructing the high-voltage cable interlayer dynamic thermal network model and the correlation between high-voltage cable core temperature and cable current carrying capacity in step S2 is as follows: Step S2.2.1: Based on the equivalent results of the RC thermal network, and according to the parallel relationship between the circuit voltage drop and the material resistance, construct a dynamic thermal network model between the layers of the high-voltage cable; Step S2.2.2: Perform nodal temperature analysis for each RC thermal network. Each node satisfies the heat balance equation, which is as follows: ； In the formula, Ci For node heat capacity; Ti For node temperature; G i-1,i and G i,i+1 For thermal conductivity between adjacent dielectric layers, C i (t) represents the equivalent volumetric heat source injection for this dielectric layer; Step S2.2.3: According to t The initial condition for heat exchange resulting from temperature changes at any given time is: T i (0)= T ； T Use the initial measured temperature or the steady-state estimate as the initial value; Based on the temperature changes during heat exchange, the boundary conditions for the dynamic thermal network model between high-voltage cable layers are obtained: T i ( t )= A ( t )； T i ( t’ )= B ( t’ )； In the formula, A ( t )and B ( t The values ​​') represent the temperatures measured at different locations on the high-voltage cable within the same time interval.

5. The method for dynamic monitoring of high-voltage cable conductor temperature according to claim 4, characterized in that: The radial temperature distribution of the high-voltage cable in step S3 is obtained by the following steps: Step S3.1: Based on the equivalent results of the RC thermal network, calculate the equivalent thermal conductivity on both sides of the interface, as shown in the following formula: ； In the formula, k eq The equivalent thermal conductivity is T 'and T These represent the temperatures between different layers of the high-voltage cable; Step S3.2: Iterate the time and space terms using the finite difference method. The time term uses forward differencing, and the space term uses backward differencing. The resulting temperature recursive formula is shown below: ； In the formula, n The first equivalent of RC heat network n Nodes, Δ t For time intervals, D It is a symmetric tridiagonal matrix composed of thermal conductivity terms; Step S3.3: Obtain the temperature before correction from the boundary conditions of the high-voltage cable interlayer dynamic thermal network model: Internal boundary conditions: ; External boundary conditions: ; In the formula, r The radius of the dielectric layer of the high-voltage cable. R This refers to the outer insulation radius of the high-voltage cable.

6. The method for dynamic monitoring of high-voltage cable conductor temperature according to claim 1, characterized in that: The parameter correction process in step S4 is performed according to the following steps: Step S4.1: Define the thermal resistance R, heat capacity C, and temperature T as an extended state vector, and construct the state vector. x The parameters are then initialized as shown in the following formula: ； Step S4.2: Establish the state equations: ； In the formula, F n Here is the state transition matrix. u n It is the covariance matrix; Step S4.3: Correct and update the state equation and covariance: ； In the formula, It is the first n The number of state updates per node It is the first n Covariance update of each node K n For Kalman gain.

7. The system for dynamic monitoring of high-voltage cable conductor temperature according to any one of claims 1-6, characterized in that: The system includes a temperature measurement unit, an equivalent unit of the RC thermal network of the interlayer medium of the high-voltage cable, a dynamic thermal network model acquisition unit of the interlayer medium of the high-voltage cable, a finite difference method solution unit, and a parameter correction unit. The temperature measurement unit uses a built-in temperature sensor in the high-voltage cable to achieve real-time monitoring of the temperature of the high-voltage cable sheath. The equivalent unit of the high-voltage cable interlayer dielectric RC thermal network is used to analyze the connection mode of the cable interlayer equivalent circuit based on the geometric structure of the high-voltage cable and the material parameters of each dielectric layer, and to establish the equivalent model of the cable interlayer dielectric RC thermal network. The high-voltage cable interlayer medium dynamic thermal network model acquisition unit is connected to the high-voltage cable interlayer medium RC thermal network equivalent unit, and is used to perform node thermal balance equation analysis based on the RC thermal network equivalent results to construct the high-voltage cable interlayer dynamic thermal network model. The finite difference method solution unit is connected to the high-voltage cable interlayer medium dynamic thermal network model acquisition unit, and is used to solve the multilayer heat conduction equation of the high-voltage cable through the finite difference method to obtain the radial distribution of the high-voltage cable temperature. The parameter correction unit is connected to the temperature measurement unit and the finite difference method solution unit. It uses the Kalman filter algorithm to combine temperature data and model calculation data to correct the parameters of the dynamic thermal network model between high-voltage cable layers.

8. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform the steps of the dynamic monitoring method for high-voltage cable conductor temperature as described in any one of claims 1-6.

9. A computer-readable storage medium storing computer-executable instructions that, when executed, implement the steps of the dynamic temperature monitoring method for high-voltage cable conductors according to any one of claims 1-6.

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