Method, device and storage medium for detecting temperature of cable conductor

Abstract

The application discloses a kind of temperature detection method, equipment and storage medium of cable conductor, the method includes: cable constructs transient thermal circuit model;Transient thermal circuit model multiple-layer structure includes conductor, insulating layer, inner liner and outer sheath in turn from inside to outside;Under the condition that multiple-layer structure is not coaxial in transient thermal circuit model, the thermal resistance value, heat capacity value of multiple-layer structure in transient thermal circuit model are detected;According to the temperature distribution information of insulating layer before expansion, the thermal resistance value of inner liner is corrected;If correction is completed, according to the temperature value, thermal resistance value and heat capacity value of multiple-layer structure distribution in transient thermal circuit model, target function is constructed;According to target function, the temperature value of conductor is detected.This embodiment considers the expansion of insulating layer to correct the thermal resistance value of inner liner, so as to solve the temperature of conductor, reduce the influence of dynamic load on conductor temperature detection in actual operation, and the accuracy is high.

Description

Technical Field

[0001] This invention relates to the technical field of power grids, and more particularly to a method, device, and storage medium for detecting the temperature of a cable conductor. Background Technology

[0002] Some cables have a gap of a certain thickness between the inner lining and the aluminum sheath to prevent damage to the internal structure of the cable caused by bending during construction or laying.

[0003] During actual cable operation, the cable insulation layer undergoes radial expansion as the cable temperature rises, and the gas gaps in the inner lining change. Therefore, the thermal resistance of the inner lining changes with the conductor temperature.

[0004] To detect conductor temperature and thus assess cable operating status, three main methods are currently used: 1) The first method uses distributed optical fibers to measure cable surface temperature in conjunction with a thermal circuit model to detect conductor temperature; 2) The second method is based on Fourier's heat transfer law and the structural parameters of each layer of the cable, using standard specifications to calculate the thermal resistance of each layer of the cable, establishing a steady-state thermal circuit model of the cable, and using temperature sensors to measure the outer surface temperature of the cable to indirectly measure the conductor temperature; 3) The third method uses infrared probes or infrared thermal imagers and other detection instruments to measure conductor temperature.

[0005] However, the first type of method has high cost and low accuracy of fiber optic temperature measurement, resulting in errors in the parameters of the thermal circuit model and low accuracy of conductor temperature detection; the second type of method uses fixed parameters, which deviate from reality, resulting in large errors in conductor temperature; the third type of method is affected by the detection instrument itself and external infrared radiation, resulting in low measurement accuracy. Summary of the Invention

[0006] In view of this, the present invention provides a method, device and storage medium for detecting the temperature of a cable conductor, so as to improve the accuracy of detecting the temperature of the cable conductor.

[0007] A first aspect of the present invention provides a method for detecting the temperature of a cable conductor, comprising:

[0008] A transient thermal circuit model is constructed for the cable; the multi-layer structure in the transient thermal circuit model includes, from the inside out, a conductor, an insulation layer, an inner liner, and an outer sheath.

[0009] Under the condition that the multilayer structure is non-coaxial in the transient thermal circuit model, the thermal resistance and thermal capacity of the multilayer structure in the transient thermal circuit model are detected.

[0010] The thermal resistance value of the inner liner is corrected based on the temperature distribution information of the insulating layer before expansion;

[0011] If the correction is completed, the objective function is constructed based on the temperature, thermal resistance and heat capacity values ​​of the multilayer structure in the transient thermal circuit model.

[0012] The temperature value of the conductor is detected based on the objective function.

[0013] A second aspect of the present invention provides a temperature detection device for a cable conductor, comprising:

[0014] The cable modeling module is used to construct a transient thermal circuit model for the cable; the transient thermal circuit model has a multi-layer structure from the inside out, including a conductor, an insulation layer, an inner liner, and an outer sheath.

[0015] The thermal parameter calculation module is used to detect the thermal resistance and thermal capacity of the multi-layer structure in the transient thermal circuit model under the condition that the multi-layer structure is non-coaxial.

[0016] The inner liner thermal resistance correction module is used to correct the thermal resistance value of the inner liner based on the temperature distribution information of the insulation layer before expansion.

[0017] The objective function construction module is used to construct an objective function based on the temperature, thermal resistance, and heat capacity values ​​of the multilayer structure distribution in the transient thermal circuit model if the correction is completed.

[0018] A conductor temperature detection module is used to detect the temperature value of the conductor according to the objective function.

[0019] A third aspect of the present invention provides an electronic device, the electronic device comprising:

[0020] At least one processor; and

[0021] A memory communicatively connected to the at least one processor; wherein,

[0022] The memory stores a computer program that can be executed by the at least one processor to enable the at least one processor to perform the temperature detection method for the cable conductor as described in the first aspect above.

[0023] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the temperature detection method for a cable conductor as described in the first aspect above.

[0024] A fifth aspect of the present invention provides a computer program product comprising a computer program that, when executed by a processor, implements the temperature detection method for a cable conductor as described in the first aspect above.

[0025] In this embodiment, a transient thermal circuit model is constructed for the cable. The multi-layered structure in the transient thermal circuit model, from the inside out, includes a conductor, an insulation layer, an inner liner, and an outer sheath. Under the condition that the multi-layered structure in the transient thermal circuit model is non-coaxial, the thermal resistance and thermal capacity values ​​of the multi-layered structure are detected. The thermal resistance value of the inner liner is corrected based on the temperature distribution information of the insulation layer before expansion. If the correction is complete, an objective function is constructed based on the temperature, thermal resistance, and thermal capacity values ​​distributed in the multi-layered structure of the transient thermal circuit model. The temperature value of the conductor is detected based on the objective function. This embodiment considers the expansion of the insulation layer to correct the thermal resistance value of the inner liner, thereby solving for the conductor temperature. This reduces the impact of dynamic load on conductor temperature detection during actual operation, resulting in high accuracy. This process mainly relies on basic sensors such as temperature sensors to collect data, resulting in low cost and achieving non-destructive detection of conductor temperature.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart of a method for detecting the temperature of a cable conductor provided in Embodiment 1 of the present invention.

[0029] Figure 2 This is a schematic diagram of a transient thermal circuit model provided in Embodiment 1 of the present invention.

[0030] Figure 3 This is a schematic diagram of a non-coaxial multilayer structure of a transient thermal circuit model provided in Embodiment 1 of the present invention.

[0031] Figure 4 This is a schematic diagram of the structure of a temperature detection device for a cable conductor provided in Embodiment 2 of the present invention.

[0032] Figure 5 This is a schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate so that the embodiments of the invention described herein can cover implementations in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] Example 1

[0036] See Figure 1 The diagram illustrates a flowchart of a cable conductor temperature detection method according to Embodiment 1 of the present invention. This method can be executed by a cable conductor temperature detection device, which can be implemented in hardware and / or software and can be configured in an electronic device. Figure 1 As shown, the method includes:

[0037] Step 101: Construct a transient thermal circuit model for the cable.

[0038] like Figure 2 As shown, considering the change in the air gap size of the inner lining layer with the thermal expansion of the insulation layer, a transient thermal circuit model of the cable considering thermal expansion is established based on Fourier's heat transfer law and the parameters of each layer of the cable structure.

[0039] In the transient thermal circuit model, the multilayer structure, from the inside out, includes a conductor, an insulating layer, an inner liner, and an outer sheath.

[0040] T1 is the thermal resistance of the insulation layer, T2 is the thermal resistance of the inner liner layer, T3 is the thermal resistance of the outer sheath, θ0 is the temperature of the outer surface of the outer sheath, θ1 is the temperature of the conductor, θ2 is the temperature of the outer layer of the insulation layer, θ3 is the temperature of the outer sheath, C1 is the heat capacity of the insulation layer, C2 is the heat capacity of the inner liner layer, C3 is the heat capacity of the outer sheath, and Q1 is the total heat flux.

[0041] Step 102: Under the condition that the multi-layer structure is non-coaxial in the transient thermal circuit model, detect the thermal resistance and thermal capacity of the multi-layer structure in the transient thermal circuit model.

[0042] Due to the presence of air gaps, the multi-layer structure of the cable body in the transient thermal circuit model is non-coaxial, and some structures may be offset by gravity. In this case, the thermal resistance and thermal capacity of the multi-layer structure in the transient thermal circuit model can be detected according to the parameters of the multi-layer structure in the transient thermal circuit model, in accordance with standard specifications. During this process, the calculation of thermal resistance and / or thermal capacity is corrected by considering the non-coaxial factor of some structures.

[0043] Regarding the insulating layer, on the one hand, the thermal resistance value of the insulating layer is expressed as:

[0044]

[0045] Where T1 is the thermal resistance of the insulating layer, ρ T d is the thermal resistivity of the insulating material (in km / W), t1 is the insulation thickness between the conductor and the metal sheath (in mm), and d is the thermal resistivity of the insulating material. c The diameter of the conductor (in mm).

[0046] On the other hand, the heat capacity of the insulating layer is expressed as:

[0047]

[0048] Where C2 is the heat capacity of the insulating layer, δ pm d1 is the volumetric heat capacity of the insulation layer (in J / (K·m)), d2 is the outer diameter of the insulation layer, and d1 is the inner diameter of the insulation layer.

[0049] For the inner liner, under the condition of non-coaxial multi-layer structure in the transient thermal circuit model, the shape factor of the inner liner can be calculated, where the shape factor represents the state quantity of the inner liner under deformation.

[0050] For example, the shape factor is expressed as:

[0051]

[0052] Among them, such as Figure 3 As shown, S is the shape factor, r1 is the equivalent radius corresponding to the outer surface of the insulation layer, r2 is the equivalent radius corresponding to the inner surface of the outer sheath, e is the eccentricity of the cable under gravity in the presence of non-centrosymmetry, and arcosh is the inverse hyperbolic cosine function.

[0053] The thermal resistance of the lining is obtained by taking the reciprocal of the product between the thermal conductivity and the shape factor of the lining.

[0054] At this point, the thermal resistance value of the lining layer is expressed as:

[0055]

[0056] Where T2 is the thermal resistance of the lining layer, λ2 is the thermal conductivity of the lining layer, and S is the shape factor.

[0057] Regarding the outer sheath, on the one hand, the thermal resistance value of the outer sheath is expressed as:

[0058]

[0059] Where T3 is the thermal resistance of the outer sheath, ρ T D is the thermal resistivity of the insulating material. OC D is the diameter (in mm) of an imaginary concentric cylinder tangent to the outer surface of the corrugated metal sleeve crest. it t3 is the diameter (in mm) of an imaginary concentric cylinder tangent to the inner surface of the trough of the corrugated metal sheath, and t3 is the thickness of the outer sheath. s The thickness is the metal sleeve.

[0060] On the other hand, the heat capacity of the outer sheath is expressed as:

[0061]

[0062] Where C3 is the heat capacity of the outer sheath (in J / K), δ o d4 is the volumetric heat capacity of the outer sheath (in J / (K·m)), d4 is the outer diameter of the outer sheath, and d3 is the inner diameter of the outer sheath.

[0063] Step 103: Correct the thermal resistance value of the inner lining layer based on the temperature distribution information of the insulation layer before expansion.

[0064] In this embodiment, since the cable insulation layer expands radially as the cable temperature rises, the gas gap between the inner liner and the aluminum sheath will change. Therefore, by combining the initial thermal parameters, heat flow values, and cable surface temperature, the Matlab program can be used to calculate the radial temperature distribution information of each layer of the cable structure before the insulation layer expands, thereby correcting the thermal resistance value of the inner liner based on the temperature distribution information before the insulation layer expands.

[0065] In practice, based on the temperature distribution information of the insulation layer before expansion, the expansion amount of the insulation layer is calculated using methods such as integration, and the thermal resistance value of the inner lining layer is corrected based on the expansion amount of the insulation layer.

[0066] For example, the amount of expansion of the insulating layer is expressed as:

[0067]

[0068] Where ΔL is the expansion amount of the insulating layer, r c r is the outer diameter of the conductor. x Let θ be the outer diameter of the insulating layer, a be the coefficient of thermal expansion of the insulating layer, and θ(r) be the temperature distribution information of the insulating layer before expansion.

[0069] Therefore, the corrected thermal resistance value of the inner lining layer is expressed as:

[0070]

[0071] Where T'2 is the corrected thermal resistance of the inner liner, S' is the modified shape factor, ΔL is the expansion of the insulation layer, r1 is the equivalent radius corresponding to the outer surface of the insulation layer, r2 is the equivalent radius corresponding to the inner surface of the outer sheath, λ2 is the thermal conductivity of the inner liner, and arcosh is the inverse hyperbolic cosine function.

[0072] Step 104: If the correction is completed, construct the objective function based on the temperature, thermal resistance and heat capacity values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0073] If the thermal resistance of the inner lining is corrected, the objective function can be constructed by modeling the temperature, thermal resistance, and heat capacity of the multilayer structure in the transient thermal circuit model.

[0074] In one embodiment of the present invention, step 104 may include the following steps:

[0075] Step 1041: Differentiate the temperature values ​​of the multilayer structure distribution in the transient thermal circuit model to construct the first temperature matrix.

[0076] In this embodiment, the temperature values ​​of the multilayer structure distribution in the transient thermal circuit model can be differentiated, and a first temperature matrix can be constructed based on the reciprocals of each temperature value.

[0077] It should be noted that the temperature values ​​of the multilayer structure in the transient thermal circuit model include the temperature values ​​of the conductors. The temperature values ​​of the conductors are unknowns that need to be solved. That is, the temperature matrix of the first temperature matrix contains the temperature values ​​of the conductors.

[0078] In practical implementation, the conductor, insulation layer, and outer sheath in the transient thermal circuit model can be selected. The derivatives of the temperature values ​​of the conductor, insulation layer, and outer sheath are calculated to construct a first temperature matrix. At this point, the first temperature matrix... Represented as:

[0079]

[0080] Where θ1 is the temperature of the conductor, θ2 is the temperature of the insulation layer, and θ3 is the temperature of the outer sheath.

[0081] Step 1042: Construct a second temperature matrix from the temperature values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0082] In this embodiment, a second temperature matrix can be constructed from the temperature values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0083] It should be noted that the temperature values ​​of the multilayer structure in the transient thermal circuit model include the temperature values ​​of the conductors. The temperature values ​​of the conductors are unknowns that need to be solved. That is, the temperature matrix of the second temperature matrix contains the temperature values ​​of the conductors.

[0084] Generally, the multi-layer structure of the transient thermal circuit model involved in the first temperature matrix is ​​the same as the multi-layer structure of the transient thermal circuit model involved in the second temperature matrix.

[0085] In practical implementation, the conductor, insulation layer, and outer sheath from the transient thermal circuit model can be selected. A second temperature matrix is ​​constructed using the temperature values ​​of the conductor, insulation layer, and outer sheath. In this case, the second temperature matrix θ is represented as:

[0086] θ = [θ1 θ2 θ3] T

[0087] Where θ1 is the temperature of the conductor, θ2 is the temperature of the insulation layer, and θ3 is the temperature of the outer sheath.

[0088] Step 1043: Construct the first coefficient matrix based on the thermal resistance and thermal capacity values ​​of the multilayer structure in the transient thermal circuit model.

[0089] In this embodiment, a first coefficient matrix can be constructed based on the thermal resistance and thermal capacity values ​​of the multilayer structure in the transient thermal circuit model.

[0090] In practical implementation, the conductor, insulation layer, inner liner, and outer sheath in the transient thermal circuit model can be selected. The thermal resistance values ​​of the insulation layer, inner liner, and outer sheath, as well as the thermal capacitance values ​​of the conductor, insulation layer, and outer sheath, are processed according to standard specifications to construct a first coefficient matrix. Insufficient elements in the first coefficient matrix are filled with 0. Thus, the first coefficient matrix A is represented as:

[0091]

[0092] Where T1 is the thermal resistance of the insulation layer, T2 is the thermal resistance of the inner lining layer, T3 is the thermal resistance of the outer sheath, C1 is the thermal capacity of the conductor, C2 is the thermal capacity of the insulation layer, and C3 is the thermal capacity of the outer sheath.

[0093] Step 1044: Construct the second coefficient matrix based on the heat capacity values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0094] In this embodiment, a second coefficient matrix can be constructed based on the heat capacity values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0095] In practical implementation, the conductor, insulation layer, and outer sheath in the transient thermal circuit model can be selected. The heat capacity values ​​of the conductor, insulation layer, and outer sheath are processed according to standard specifications to construct a second coefficient matrix. Insufficient elements in the second coefficient matrix are filled with 0. At this time, the second coefficient matrix B is represented as:

[0096]

[0097] Where C1 is the heat capacity of the conductor, C2 is the heat capacity of the insulation layer, and C3 is the heat capacity of the outer sheath.

[0098] Step 1045: Detect the total heat flow value based on the temperature and thermal resistance values ​​of the multi-layer structure distribution in the transient thermal circuit model.

[0099] In this embodiment, the heat flow value of the entire line can be detected based on the temperature value and thermal resistance value of the multi-layer structure distribution in the transient thermal circuit model.

[0100] In practical implementation, the temperature value of the outer surface of the transient thermal circuit model, the temperature value of the outer sheath, and the thermal resistance value of the outer sheath can be selected. The difference between the temperature value of the outer surface of the transient thermal circuit model and the temperature value of the outer sheath is divided by the thermal resistance value of the outer sheath to obtain the total heat flux value. At this time, the total heat flux value can be expressed as:

[0101]

[0102] Where θ0 is the temperature value of the outer surface of the transient thermal circuit model, θ3 is the temperature value of the outer sheath, and T3 is the thermal resistance value of the outer sheath.

[0103] Step 1046: Construct a heat flux matrix based on the total heat flux value.

[0104] In this embodiment, a heat flux matrix can be constructed using the total heat flux values, and any missing elements in the heat flux matrix are filled with 0.

[0105] In the specific implementation, the heat flux matrix Φ is represented as:

[0106] Φ=[Q1 0 0]

[0107] Q1 represents the total heat flux.

[0108] Step 1047: Determine the objective function.

[0109] In this embodiment, the objective function can be obtained by modeling based on the first temperature matrix, the second temperature matrix, the first coefficient matrix, the second coefficient matrix, and the heat flux matrix.

[0110] The objective function is expressed as follows: the first temperature matrix is ​​equal to the product of the first coefficient matrix and the second temperature matrix plus the product of the second coefficient matrix and the heat flow matrix. In this case, the objective function represents the thermodynamic relationship of the multilayer structure of the transient thermal circuit model under the conditions of thermal expansion and non-coaxiality.

[0111] In the specific implementation, the objective function is expressed as:

[0112]

[0113] in, Let θ be the first temperature matrix, θ be the second temperature matrix, A be the first coefficient matrix, B be the second coefficient matrix, and Φ be the flow matrix.

[0114] Step 105: Detect the temperature value of the conductor based on the objective function.

[0115] In this embodiment, the objective function contains the temperature value of the conductor. The temperature value, thermal resistance value and thermal capacity value of the multilayer structure distribution in the transient thermal circuit model can be substituted into the objective function, and the objective function can be iteratively solved to obtain the temperature value of the conductor.

[0116] Furthermore, in scenarios such as faults and switching maintenance, the state of the cable fluctuates, causing the temperature values ​​of the multi-layer structure distribution in each transient thermal circuit model to fluctuate. Therefore, the temperature value of the conductor can be continuously monitored until the cable reaches a stable state, and the final temperature value of the conductor can be obtained.

[0117] In this embodiment, a transient thermal circuit model is constructed for the cable. The multi-layered structure in the transient thermal circuit model, from the inside out, includes a conductor, an insulation layer, an inner liner, and an outer sheath. Under the condition that the multi-layered structure in the transient thermal circuit model is non-coaxial, the thermal resistance and thermal capacity values ​​of the multi-layered structure are detected. The thermal resistance value of the inner liner is corrected based on the temperature distribution information of the insulation layer before expansion. If the correction is complete, an objective function is constructed based on the temperature, thermal resistance, and thermal capacity values ​​distributed in the multi-layered structure of the transient thermal circuit model. The temperature value of the conductor is detected based on the objective function. This embodiment considers the expansion of the insulation layer to correct the thermal resistance value of the inner liner, thereby solving for the conductor temperature. This reduces the impact of dynamic load on conductor temperature detection during actual operation, resulting in high accuracy. This process mainly relies on basic sensors such as temperature sensors to collect data, resulting in low cost and achieving non-destructive detection of conductor temperature.

[0118] Example 2

[0119] See Figure 4 The diagram shows a structural schematic of a temperature detection device for a cable conductor provided in Embodiment 2 of the present invention. Figure 4 As shown, the device includes:

[0120] The cable modeling module 401 is used to construct a transient thermal circuit model for the cable; the transient thermal circuit model has a multi-layer structure from the inside out, including a conductor, an insulation layer, an inner liner, and an outer sheath.

[0121] The thermal parameter calculation module 402 is used to detect the thermal resistance and thermal capacity of the multi-layer structure in the transient thermal circuit model under the condition that the multi-layer structure is non-coaxial in the transient thermal circuit model.

[0122] The inner liner thermal resistance correction module 403 is used to correct the thermal resistance value of the inner liner based on the temperature distribution information of the insulating layer before expansion.

[0123] The objective function construction module 404 is used to construct an objective function based on the temperature, thermal resistance and heat capacity values ​​of the multilayer structure distribution in the transient thermal circuit model if the correction is completed.

[0124] The conductor temperature detection module 405 is used to detect the temperature value of the conductor according to the objective function.

[0125] In one embodiment of the present invention, the thermal resistance value of the insulating layer is expressed as:

[0126]

[0127] Where T1 is the thermal resistance of the insulating layer, ρ T d is the thermal resistance coefficient of the insulating material, t1 is the insulation thickness between the conductor and the metal sleeve, and d is the insulation thickness between the conductor and the metal sleeve. c The diameter of the conductor;

[0128] The thermal resistance value of the outer sheath is expressed as:

[0129]

[0130] Where T3 is the thermal resistance of the outer sheath, ρ T D is the thermal resistivity of the insulating material. OC D is the diameter of an imaginary concentric cylinder tangent to the outer surface of the corrugated metal sleeve crest. it t3 is the diameter of an imaginary concentric cylinder tangent to the inner surface of the trough of the corrugated metal sheath, and t is the thickness of the outer sheath. s The thickness of the metal sleeve;

[0131] The heat capacity of the insulating layer is expressed as follows:

[0132]

[0133] Where C2 is the heat capacity of the insulating layer, δ pmd1 is the volumetric heat capacity of the insulating layer, d2 is the outer diameter of the insulating layer, and d1 is the inner diameter of the insulating layer.

[0134] The heat capacity of the outer sheath is expressed as:

[0135]

[0136] Wherein, C3 is the heat capacity of the outer sheath, δ o d4 is the volumetric heat capacity of the outer sheath, d3 is the outer diameter of the outer sheath, and d4 is the inner diameter of the outer sheath.

[0137] In one embodiment of the present invention, the thermal parameter calculation module 402 includes:

[0138] A shape factor calculation module is used to calculate the shape factor of the inner liner under the condition that the multilayer structure is non-coaxial in the transient thermal circuit model.

[0139] The inner lining thermal resistance calculation module is used to take the reciprocal of the product between the thermal conductivity of the inner lining and the shape factor to obtain the thermal resistance value of the inner lining.

[0140] In one embodiment of the present invention, the shape factor is represented as:

[0141]

[0142] Wherein, S is the shape factor, r1 is the equivalent radius corresponding to the outer surface of the insulation layer, r2 is the equivalent radius corresponding to the inner surface of the outer sheath, and e is the eccentricity of the cable under gravity when there is non-centrosymmetry.

[0143] In one embodiment of the present invention, the lining thermal resistance correction module includes:

[0144] An expansion calculation module is used to calculate the expansion amount of the insulating layer based on the temperature distribution information of the insulating layer before expansion.

[0145] An expansion correction module is used to correct the thermal resistance value of the inner liner based on the expansion amount of the insulating layer.

[0146] In one embodiment of the present invention, the expansion amount of the insulating layer is expressed as:

[0147]

[0148] Where ΔL is the expansion amount of the insulating layer, r c r is the outer diameter of the conductor. x Let be the outer diameter of the insulating layer, a be the coefficient of thermal expansion of the insulating layer, and θ(r) be the temperature distribution information of the insulating layer before expansion.

[0149] The corrected thermal resistance value of the inner liner is expressed as follows:

[0150]

[0151] Where T'2 is the corrected thermal resistance of the inner liner, ΔL is the expansion of the insulation layer, r1 is the equivalent radius corresponding to the outer surface of the insulation layer, r2 is the equivalent radius corresponding to the inner surface of the outer sheath, and λ2 is the thermal conductivity of the inner liner.

[0152] In one embodiment of the present invention, the objective function construction module 404 includes:

[0153] The first temperature matrix construction module is used to differentiate the temperature values ​​of the multilayer structure distribution in the transient thermal circuit model in order to construct the first temperature matrix.

[0154] The second temperature matrix construction module is used to construct a second temperature matrix from the temperature values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0155] The first coefficient matrix construction module is used to construct the first coefficient matrix based on the thermal resistance and thermal capacity values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0156] The second coefficient matrix construction module is used to construct a second coefficient matrix based on the heat capacity values ​​of the multilayer structure distribution in the transient thermal circuit model.

[0157] The overall heat flux calculation module is used to detect the overall heat flux value based on the temperature value and thermal resistance value of the multi-layer structure distribution in the transient thermal circuit model.

[0158] A heat flux matrix construction module is used to construct a heat flux matrix based on the total heat flux value.

[0159] The objective function determination module is used to determine the objective function; the objective function is expressed as the first temperature matrix being equal to the product of the first coefficient matrix and the second temperature matrix plus the product of the second coefficient matrix and the heat flux matrix.

[0160] In one embodiment of the present invention, the objective function is expressed as:

[0161]

[0162] in, Let θ be the first temperature matrix, θ be the second temperature matrix, A be the first coefficient matrix, B be the second coefficient matrix, and Φ be the heat flux matrix;

[0163] First temperature matrix Represented as:

[0164]

[0165] The second temperature matrix θ is represented as:

[0166] θ = [θ1 θ2 θ3] T

[0167] The first coefficient matrix A is represented as:

[0168]

[0169] The second coefficient matrix B is represented as follows:

[0170]

[0171] The heat flux matrix Φ is represented as:

[0172] Φ=[Q1 0 0

[0173]

[0174] Wherein, θ0 is the temperature value of the outer surface of the transient thermal circuit model, θ1 is the temperature value of the conductor, θ2 is the temperature value of the insulation layer, θ3 is the temperature value of the outer sheath, T1 is the thermal resistance value of the insulation layer, T2 is the thermal resistance value of the inner lining layer, T3 is the thermal resistance value of the outer sheath, C1 is the thermal capacity value of the conductor, C2 is the thermal capacity value of the insulation layer, C3 is the thermal capacity value of the outer sheath, and Q1 is the total heat flux value.

[0175] The temperature detection device for cable conductors provided in this embodiment of the invention can execute the temperature detection method for cable conductors provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the temperature detection method for cable conductors.

[0176] Example 3

[0177] See Figure 5 This diagram illustrates a structural schematic of an electronic device according to an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0178] like Figure 5As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0179] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0180] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the temperature detection method for cable conductors.

[0181] In some embodiments, the cable conductor temperature detection method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the cable conductor temperature detection method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the cable conductor temperature detection method by any other suitable means (e.g., by means of firmware).

[0182] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0183] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0184] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0185] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0186] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0187] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0188] Example 4

[0189] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the temperature detection method for cable conductors as provided in any embodiment of this invention.

[0190] In implementing the computer program product, computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0191] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0192] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for detecting the temperature of a cable conductor, characterized in that, include: Construct a transient thermal circuit model for the cable; The transient thermal circuit model consists of a multilayer structure from the inside out, including a conductor, an insulating layer, an inner liner, and an outer sheath; wherein, a gas gap exists between the inner liner and the outer sheath. Under the condition that the multilayer structure is non-coaxial in the transient thermal circuit model, the thermal resistance and thermal capacity of the multilayer structure in the transient thermal circuit model are detected. The thermal resistance value of the inner liner is corrected based on the temperature distribution information of the insulation layer before expansion; wherein, the insulation layer undergoes radial expansion as the temperature of the cable increases; If the correction is completed, the objective function is constructed based on the temperature, thermal resistance and heat capacity values ​​of the multilayer structure in the transient thermal circuit model. The temperature value of the conductor is detected based on the objective function. The step of correcting the thermal resistance value of the inner liner based on the temperature distribution information of the insulating layer before expansion includes: The expansion amount of the insulating layer is calculated based on the temperature distribution information of the insulating layer before expansion; The thermal resistance value of the inner liner is corrected based on the expansion amount of the insulating layer; The expansion amount of the insulating layer is expressed as: in, This refers to the amount of expansion of the insulating layer. The outer diameter of the conductor. The outer diameter of the insulating layer is... The coefficient of thermal expansion of the insulating layer is _____. This refers to the temperature distribution information of the insulating layer before expansion; The corrected thermal resistance value of the inner liner is expressed as follows: in, The corrected thermal resistance value of the inner liner. This refers to the amount of expansion of the insulating layer. The equivalent radius corresponding to the outer surface of the insulating layer. The equivalent radius corresponding to the inner surface of the outer sheath. The thermal conductivity of the inner lining layer is given.

2. The method according to claim 1, characterized in that, The thermal resistance value of the insulating layer is expressed as: in, The thermal resistance value of the insulating layer is... The thermal resistivity of the insulating material. The insulation thickness between the conductor and the metal sleeve. The diameter of the conductor; The thermal resistance value of the outer sheath is expressed as: in, The thermal resistance value of the outer sheath. The thermal resistivity of the insulating material. The diameter of an imaginary concentric cylinder tangent to the outer surface of the corrugated metal sleeve crest. The diameter of an imaginary concentric cylinder tangent to the inner surface of the trough of the wrinkled metal sheath. The thickness of the outer sheath. The thickness of the metal sleeve; The heat capacity of the insulating layer is expressed as follows: in, The value of the heat capacity of the insulating layer. The volumetric heat capacity of the insulating layer is [value missing]. The outer diameter of the insulating layer is... The inner diameter of the insulating layer; The heat capacity of the outer sheath is expressed as: in, The heat capacity of the outer sheath is [value missing]. The volumetric heat capacity of the outer sheath is [value missing]. The outer diameter of the outer sheath is [missing information]. The inner diameter of the outer sheath is given.

3. The method according to claim 1, characterized in that, Under the condition that the multilayer structure in the transient thermal circuit model is non-coaxial, the thermal resistance and thermal capacity of the multilayer structure in the transient thermal circuit model are detected, including: Under the condition of non-coaxial multilayer structure in the transient thermal circuit model, the shape factor of the inner liner is calculated; The thermal resistance of the inner lining is obtained by taking the reciprocal of the product between the thermal conductivity of the inner lining and the shape factor.

4. The method according to claim 3, characterized in that, The shape factor is expressed as: in, For the shape factor, The equivalent radius corresponding to the outer surface of the insulating layer. The equivalent radius corresponding to the inner surface of the outer sheath. The eccentricity of the cable under gravity in the presence of non-central symmetry is defined as the eccentricity of the cable.

5. The method according to any one of claims 1-4, characterized in that, The objective function constructed based on the temperature, thermal resistance, and heat capacity values ​​distributed across the multilayer structure in the transient thermal circuit model includes: The temperature values ​​of the multilayer structure distribution in the transient thermal circuit model are differentiated to construct the first temperature matrix; A second temperature matrix is ​​constructed using the temperature values ​​distributed across the multilayer structure in the transient thermal circuit model. A first coefficient matrix is ​​constructed based on the thermal resistance and thermal capacity values ​​distributed in the multilayer structure in the transient thermal circuit model. A second coefficient matrix is ​​constructed based on the heat capacity values ​​distributed across the multilayer structure in the transient thermal circuit model. The total heat flow value is detected based on the temperature and thermal resistance values ​​of the multilayer structure in the transient thermal circuit model. Construct a heat flux matrix based on the total heat flux values; Determine the objective function; the objective function is expressed as the first temperature matrix being equal to the product of the first coefficient matrix and the second temperature matrix plus the product of the second coefficient matrix and the heat flux matrix.

6. The method according to claim 5, characterized in that, The objective function is expressed as: in, This is the first temperature matrix. This is the second temperature matrix. Let be the first coefficient matrix. This is the second coefficient matrix. The heat flux matrix; First temperature matrix Represented as: The second temperature matrix Represented as: The first coefficient matrix Represented as: Second coefficient matrix Represented as: The heat flow matrix Represented as: in, The temperature value of the outer surface of the transient thermal circuit model. The temperature value of the conductor. The temperature value of the insulating layer. The temperature value of the outer sheath. The thermal resistance value of the insulating layer is... The thermal resistance value of the inner lining layer. The thermal resistance value of the outer sheath. The value of the conductor's heat capacity. The value of the heat capacity of the insulating layer. The heat capacity of the outer sheath is [value missing]. The total heat flux value is denoted as .

7. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the temperature detection method for a cable conductor as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the temperature detection method for a cable conductor as described in any one of claims 1-6.

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