Transmission conductor fracture risk early warning method and device based on forest fire condition, terminal equipment and storage medium

Abstract

The invention discloses a power transmission conductor fracture risk early warning method and device based on a forest fire condition, terminal equipment and a storage medium. Simulation calculation is performed based on a convective heat transfer model between a power transmission conductor and air, a heat conduction model between an aluminum wire and a steel strand and the surface temperature of the power transmission conductor; evaluating the temperature of each aluminum wire and each steel strand in the inner layer and the outer layer of the transmission conductor; according to the temperature of each aluminum wire and the temperature of each steel strand and the preset tensile strength of each aluminum wire and the preset tensile strength of each steel strand when the mountain fire does not occur, after the tensile strength corresponding to each aluminum wire and each steel strand in the current mountain fire area is obtained, the tensile strength of each aluminum wire and each steel strand in the current mountain fire area is calculated based on the total number of the aluminum wires and the steel strands and the tensile strength of the aluminum wires and the steel strands; according to the method, the third tensile strength corresponding to the power transmission conductor in the current mountain fire area is comprehensively evaluated according to the first tensile strength of the power transmission conductor and the structural parameters and the thermal expansion performance parameters of the power transmission conductor, and accurate early warning of the fracture risk is achieved by simulating the heat exchange process between the conductor and the surrounding environment under the mountain fire condition.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission wire break warning, and particularly to a method, device, terminal device and storage medium for warning the break risk of transmission wires under wildfire conditions. Background Art

[0002] A wildfire refers to a fire phenomenon caused by factors such as climate and terrain in the natural environment. When a wildfire spreads near a transmission line, the high-temperature flame and smoke will have a direct thermal effect on the transmission wire, causing the wire temperature to rise and the mechanical properties to decline. In extreme cases, it may cause the wire to break, resulting in power interruption and property losses. By calculating and judging the breaking force corresponding to the transmission wire in the wildfire area, the break risk of the transmission wire can be warned, and measures can be taken early to avoid or reduce the impact of wildfires on the transmission line.

[0003] However, in the traditional method for calculating the breaking force, when evaluating the breaking force of the transmission wire under wildfire conditions, it does not consider that the heat exchange process between the transmission wire and the surrounding environment under wildfire conditions will cause different temperatures inside and outside the transmission wire. Instead, after the wildfire occurs, it simply assumes that the temperatures and damages inside and outside the wire are uniform, which will lead to a large deviation between the calculation result and the actual situation, and it is impossible to accurately evaluate the breaking force of the transmission wire under wildfire conditions, resulting in a low accuracy of the break risk warning. Summary of the Invention

[0004] Embodiments of the present invention provide a method, device, terminal device and storage medium for warning the break risk of transmission wires under wildfire conditions. Since the convective heat transfer between the wire and the air and the heat conduction between the aluminum wire and the steel strand are considered, the heat exchange process between the wire and the surrounding environment under wildfire conditions can be simulated, so as to accurately evaluate the breaking force of the transmission wire under wildfire conditions and improve the accuracy of the break risk warning.

[0005] An embodiment of the present invention provides a method for warning the break risk of transmission wires under wildfire conditions, including:

[0006] Obtain the surface temperature of the transmission wire in the current wildfire area; wherein, the transmission wire includes: a plurality of aluminum wires and a plurality of steel strands;

[0007] Based on the convective heat transfer model between the transmission wire and the air, the heat conduction model between the aluminum wire and the steel strand, and the simulation calculation of heat transfer based on the surface temperature, generate the temperature simulation results of each aluminum wire and the temperature simulation results of each steel strand;

[0008] Generate the first breaking force corresponding to each aluminum wire in the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when no wildfire occurs; generate the second breaking force corresponding to each steel strand in the current wildfire area according to the temperature simulation result of each steel strand and the second preset breaking force of each steel strand when no wildfire occurs;

[0009] Generate the third breaking force corresponding to the transmission wire in the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters of the transmission wire;

[0010] When it is determined that the third breaking force is less than the preset breaking force threshold corresponding to the transmission wire, generate a warning message indicating that there is a risk of breakage of the transmission wire.

[0011] Preferably, the transmission wire includes: several layers of aluminum wire strands and several layers of steel cores; the surface temperature is the temperature corresponding to the outermost layer of aluminum wire strands of the transmission wire; wherein, each layer of aluminum wire strands contains several aluminum wires, and each layer of steel cores contains several steel strands;

[0012] The simulation calculation of heat transfer based on the convective heat transfer model between the transmission wire and air, the heat conduction model between the aluminum wire and the steel strand, and the surface temperature to generate the temperature simulation result of each aluminum wire and the temperature simulation result of each steel strand includes:

[0013] Perform simulation modeling on the transmission wire according to the total number of layers of aluminum wire strands, the number of aluminum wires in each layer of aluminum wire strands, the total number of layers of steel cores, and the number of steel strands in each layer of steel cores to generate a simulation model corresponding to the transmission wire;

[0014] Construct a convective heat transfer model between the transmission wire and air according to the convective heat transfer coefficient, the surface temperature of the transmission wire, and the air temperature;

[0015] Construct a heat conduction model between the aluminum wire and the steel strand according to the thermal conductivity of the aluminum wire, the thermal conductivity of the steel core, and Fourier's law;

[0016] After using the surface temperature as the boundary temperature of the simulation model, perform simulation calculations of heat transfer on the simulation model, the convective heat transfer model, and the heat conduction model, and output the temperature simulation result of each aluminum wire and the temperature simulation result of each steel strand.

[0017] Preferably, the simulation calculation of heat transfer on the simulation model, the convective heat transfer model, and the heat conduction model to output the temperature simulation result of each aluminum wire and the temperature simulation result of each steel strand includes:

[0018] Repeat the following temperature generation operation until the current iteration count is the same as the preset iteration count. Then, take the highest temperature of each aluminum wire in all simulation calculation operations as the temperature simulation result corresponding to each aluminum wire, and take the highest temperature of each steel strand in all simulation calculation operations as the temperature simulation result corresponding to each steel strand:

[0019] Obtain the current temperature of each aluminum wire and the current temperature of each steel strand;

[0020] When the current iteration count is less than the preset iteration count, perform a simulation calculation operation of heat transfer on the simulation model, convective heat transfer model, and heat conduction model based on the current temperature of each aluminum wire and the current temperature of each steel strand, and output the temperature of each aluminum wire in the current simulation calculation operation and the temperature of each steel strand in the current simulation calculation operation. Initially, generate the current temperature of each aluminum wire and the current temperature of each steel strand according to the surface temperature of the transmission wire and Fourier's law;

[0021] Take the temperature of each aluminum wire in the current simulation calculation operation as the current temperature of each aluminum wire for the next execution of the temperature generation operation, and take the temperature of each steel strand in the current simulation calculation operation as the current temperature of each steel strand for the next execution of the temperature generation operation.

[0022] Preferably, generating the first breaking force corresponding to each aluminum wire in the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when there is no wildfire includes:

[0023] For each aluminum wire, calculate the first breaking force corresponding to the aluminum wire in the current wildfire area according to the following formula:

[0024]

[0025] where F 2 is the first breaking force corresponding to the aluminum wire in the current wildfire area, T L is the temperature simulation result of the aluminum wire, and F 1 is the first preset breaking force of the aluminum wire when there is no wildfire.

[0026] Preferably, generating the second breaking force corresponding to each steel strand in the current wildfire area according to the temperature simulation result of each steel strand and the second preset breaking force of each steel strand when there is no wildfire includes:

[0027] For each steel strand, calculate the second breaking force corresponding to the steel strand in the current wildfire area according to the following formula:

[0028]

[0029] Among them, F 4 is the second breaking force corresponding to the steel strand in the current wildfire area, and T G is the temperature simulation result of the steel strand, and F 3 is the second preset breaking force of the steel strand when no wildfire occurs.

[0030] Preferably, the structural parameters of the transmission wire include: the structural parameters of the aluminum wire and the structural parameters of the steel strand; the thermal expansion performance parameters of the transmission wire include: the thermal expansion performance parameters of the aluminum wire and the thermal expansion performance parameters of the steel strand;

[0031] Generating the third breaking force corresponding to the transmission wire in the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters of the transmission wire includes:

[0032] Generating the first comprehensive breaking force of each layer of aluminum wire strands according to the number of aluminum wires in each layer of aluminum wire strands, the structural parameters of the aluminum wire, the thermal expansion performance parameters of the aluminum wire, and the first breaking force corresponding to each aluminum wire in each layer of aluminum wire strands;

[0033] Generating the second comprehensive breaking force of each layer of steel cores according to the number of steel strands in each layer of steel cores, the structural parameters of the steel strand, the thermal expansion performance parameters of the steel strand, and the second breaking force corresponding to each steel strand in each layer of steel cores;

[0034] Generating the third breaking force corresponding to the transmission wire in the current wildfire area according to the first comprehensive breaking force of each layer of aluminum wire strands, the first preset breaking force coefficient corresponding to the aluminum wire strands, the second comprehensive breaking force of each layer of steel cores, and the second preset breaking force coefficient corresponding to the steel cores.

[0035] Preferably, the structural parameters of the aluminum wire include: the number of segments corresponding to the aluminum wire in the current wildfire area, the elastic modulus of the aluminum wire, the cross-sectional area of the aluminum wire, and the length corresponding to the aluminum wire in the current wildfire area; the thermal expansion performance parameters of the aluminum wire include: the linear thermal expansion coefficient of the aluminum wire and the average temperature of each section of the aluminum wire;

[0036] Generating the first comprehensive breaking force of each layer of aluminum wire strands according to the number of aluminum wires in each layer of aluminum wire strands, the structural parameters of the aluminum wire, the thermal expansion performance parameters of the aluminum wire, and the first breaking force corresponding to each aluminum wire in each layer of aluminum wire strands includes:

[0037] Obtaining the regional temperature corresponding to the current wildfire area;

[0038] For each aluminum wire, based on the regional temperature, the linear thermal expansion coefficient of the aluminum wire, the number of segments of the aluminum wire corresponding to the current wildfire area, and the average temperature of each segment of the aluminum wire, generate the length change of the aluminum wire corresponding to the temperature increase;

[0039] For each layer of aluminum wire strands, based on the length change of each aluminum wire corresponding to the temperature increase, the elastic modulus of each aluminum wire, the cross-sectional area of each aluminum wire, the length of the aluminum wire corresponding to the current wildfire area, and the number of aluminum wires in the wire strand, generate the external tensile force of the aluminum wire strand corresponding to the temperature increase;

[0040] For each layer of aluminum wire strands, based on the external tensile force of the aluminum wire strand corresponding to the temperature increase and the first breaking force corresponding to each aluminum wire in the aluminum wire strand, generate the first comprehensive breaking force of the aluminum wire strand.

[0041] Based on the above method embodiments, the present invention correspondingly provides device embodiments.

[0042] An embodiment of the present invention provides a transmission wire break risk warning device based on wildfire conditions, including: a wire surface temperature acquisition module, a temperature simulation result generation module, a first calculation module, a second calculation module, and a warning module;

[0043] The wire surface temperature acquisition module is used to acquire the surface temperature of the transmission wire in the current wildfire area; wherein, the transmission wire includes: a plurality of aluminum wires and a plurality of steel strands;

[0044] The temperature simulation result generation module is used to perform simulation calculations of heat transfer based on the convective heat transfer model between the transmission wire and the air, the heat conduction model between the aluminum wire and the steel strand, and the surface temperature, and generate the temperature simulation results of each aluminum wire and the temperature simulation results of each steel strand;

[0045] The first calculation module is used to generate the first breaking force of each aluminum wire corresponding to the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when there is no wildfire; generate the second breaking force of each steel strand corresponding to the current wildfire area according to the temperature simulation result of each steel strand and the second preset breaking force of each steel strand when there is no wildfire;

[0046] The second calculation module is used to generate the third breaking force of the transmission wire corresponding to the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters of the transmission wire;

[0047] The warning module is used to generate a warning message indicating that there is a risk of breakage of the transmission line when it is determined that the third breaking force is less than the preset breaking force threshold corresponding to the transmission line.

[0048] Based on the above method embodiments, the present invention correspondingly provides embodiments of a terminal device.

[0049] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a method for warning of the risk of breakage of a transmission line under wildfire conditions as described in the above embodiments of the present invention.

[0050] Based on the above method embodiments, the present invention correspondingly provides embodiments of a storage medium.

[0051] Another embodiment of the present invention provides a storage medium. The computer-readable storage medium includes a stored computer program. When the computer program runs, it controls the device where the computer-readable storage medium is located to execute a method for warning of the risk of breakage of a transmission line under wildfire conditions as described in the above embodiments of the present invention.

[0052] By implementing the present invention, the following beneficial effects are achieved:

[0053] The embodiment of the present invention provides a method, a device, a terminal device and a storage medium for early warning of the fracture risk of a transmission wire under wildfire conditions. First, the surface temperature of the transmission wire in the current wildfire area is obtained. Then, based on the surface temperature, the convective heat transfer model between the transmission wire and the air, and the heat conduction model between the aluminum wire and the steel strand, simulation calculations are carried out to accurately evaluate the temperature of each aluminum wire and each steel strand in the inner and outer layers of the transmission wire. Further, according to the temperature simulation results of each aluminum wire and each steel strand, combined with the preset breaking force of each aluminum wire and each steel strand when there is no wildfire, the present invention can further obtain the breaking force corresponding to each aluminum wire and each steel strand in the current wildfire area. Finally, based on the total number of aluminum wires, the total number of steel strands, the breaking force of each aluminum wire and each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters, the third breaking force corresponding to the transmission wire in the current wildfire area is comprehensively evaluated. The present invention also considers the mechanical properties and structural characteristics of the whole wire, making the evaluation result more comprehensive and reliable. Compared with the prior art, the present invention considers the convective heat transfer between the wire and the air and the heat conduction between the aluminum wire and the steel strand, so that the heat exchange process between the wire and the surrounding environment under wildfire conditions can be simulated, and the actual temperature of each aluminum wire and each steel strand can be calculated more accurately, that is, the actual temperatures of different materials in the inner and outer layers of the transmission wire can be obtained. Moreover, the mechanical properties and structural characteristics of the whole wire are also considered, so that the present invention can accurately evaluate the breaking force of the transmission wire under wildfire conditions and improve the accuracy of the fracture risk early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 FIG. is a schematic flowchart of a method for early warning of the fracture risk of a transmission wire under wildfire conditions provided by an embodiment of the present invention.

[0055] Figure 2 FIG. is a schematic diagram of the inner and outer layers of a transmission wire provided by an embodiment of the present invention.

[0056] Figure 3 FIG. is a schematic flowchart of the calculation of the minimum breaking force of a wire and the fracture early warning under wildfire conditions provided by another embodiment of the present invention.

[0057] Figure 4 FIG. is a schematic structural diagram of a device for early warning of the fracture risk of a transmission wire under wildfire conditions provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0059] As Figure 1 shown, it is a schematic flowchart of a method for warning of the risk of transmission line breakage under wildfire conditions provided by an embodiment of the present invention. The method for warning of the risk of transmission line breakage under wildfire conditions includes:

[0060] Step S1: Obtain the surface temperature of the transmission line in the current wildfire area; wherein, the transmission line includes: a plurality of aluminum wires and a plurality of steel stranded wires;

[0061] Step S2: Based on the convective heat transfer model between the transmission line and the air, the heat conduction model between the aluminum wire and the steel stranded wire, and the simulation calculation of heat transfer based on the surface temperature, generate the temperature simulation results of each aluminum wire and the temperature simulation results of each steel stranded wire;

[0062] Step S3: Generate the first breaking force corresponding to each aluminum wire in the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when there is no wildfire; generate the second breaking force corresponding to each steel stranded wire in the current wildfire area according to the temperature simulation result of each steel stranded wire and the second preset breaking force of each steel stranded wire when there is no wildfire;

[0063] Step S4: Generate the third breaking force corresponding to the transmission line in the current wildfire area according to the total number of aluminum wires, the total number of steel stranded wires, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel stranded wire, the structural parameters of the transmission line, and the thermal expansion performance parameters of the transmission line;

[0064] Step S5: When it is determined that the third breaking force is less than the preset breaking force threshold corresponding to the transmission line, generate a warning message indicating that there is a risk of breakage of the transmission line.

[0065] For step S1, in a preferred embodiment, after a wildfire occurs near the transmission line, the surface temperature of the transmission line in the wildfire area, that is, the temperature of the outermost aluminum strands of the wire, can be obtained through infrared image temperature recognition technology.

[0066] Schematically, the transmission line includes: a plurality of layers of aluminum wire strands and a plurality of layers of steel cores; As Figure 2The schematic diagram of the inner and outer layers of the transmission wire shown. The transmission wire of the present invention is a steel-cored aluminum stranded wire, with the inner layer wound by several layers of steel cores and the outer layer wound by several layers of aluminum wire strands. Then, each layer of aluminum wire strands contains several aluminum wires, and each layer of steel cores contains several steel strands;

[0067] Under wildfire conditions, the transmission wire will be affected by thermal radiation and thermal convection, and its surface temperature will rise. Due to the relatively good thermal conductivity of aluminum, the outermost layer of aluminum wire strands will first and significantly reflect this temperature change. Therefore, by measuring the temperature of the outermost aluminum strands, the current heating situation of the wire can be directly obtained.

[0068] Specifically, first, the location of the fire point can be determined. By using infrared thermal imaging technology to convert the infrared radiation signal into a visible image, in the image, objects with different temperatures will present different brightness or colors. Generally, the higher the temperature, the higher the brightness displayed in the image.

[0069] The processing circuit inside the thermal imager will calculate the temperature of the object corresponding to each pixel point in the image according to the received electrical signal and the pre-set algorithm. The calculated temperature information and the optical image are displayed on the display screen of the thermal imager, and then the temperature distribution of the outermost aluminum strands of the wire near the fire point can be visually seen.

[0070] The increase in the temperature of the aluminum wire strands will directly affect their mechanical properties and thermal expansion properties. By measuring the temperature of the outermost aluminum strands, the influence degree of the wildfire on the material properties of the wire can be further evaluated, thus providing key data for subsequent risk assessment.

[0071] For step S2, based on the measured surface temperature, further combined with the convective heat transfer model between the transmission wire and the air and the heat conduction model between the aluminum wire and the steel strand, the present invention can perform more accurate heat transfer simulation calculations, so as to accurately predict the temperature change inside the wire (such as the steel core), and thus more accurately evaluate the fracture risk of the wire.

[0072] In a preferred embodiment, the simulation calculation of heat transfer based on the convective heat transfer model between the transmission wire and the air, the heat conduction model between the aluminum wire and the steel strand, and the surface temperature to generate the temperature simulation results of each aluminum wire and the temperature simulation results of each steel strand includes:

[0073] According to the total number of layers of aluminum wire strands, the number of aluminum wires in each layer of aluminum wire strands, the total number of layers of steel cores, and the number of steel strands in each layer of steel cores, perform simulation modeling on the transmission wire to generate the corresponding simulation model of the transmission wire;

[0074] According to the convective heat transfer coefficient, the surface temperature of the transmission wire, and the air temperature, construct the convective heat transfer model between the transmission wire and the air;

[0075] According to the thermal conductivity of the aluminum wire, the thermal conductivity of the steel core, and Fourier's law, a heat conduction model between the aluminum wire and the steel stranded wire is constructed;

[0076] After using the surface temperature as the boundary temperature of the simulation model, perform a simulation calculation of heat transfer on the simulation model, the convective heat transfer model, and the heat conduction model, and output the temperature simulation results of each aluminum wire and the temperature simulation results of each steel stranded wire.

[0077] Specifically, model the ACSR according to the number of aluminum strands, the number of aluminum wires in each layer, the number of steel core layers, and the number of steel stranded wires in each layer, and set the boundary conditions according to the temperature of the outermost aluminum strands of the conductor. When outputting the temperature simulation results of each aluminum wire and the temperature simulation results of each steel stranded wire, the specific process includes:

[0078] Repeat the following temperature generation operation until the current iteration number is the same as the preset iteration number. Then, take the highest temperature of each aluminum wire in all simulation calculation operations as the temperature simulation result corresponding to each aluminum wire, and take the highest temperature of each steel stranded wire in all simulation calculation operations as the temperature simulation result corresponding to each steel stranded wire:

[0079] Obtain the current temperature of each aluminum wire and the current temperature of each steel stranded wire;

[0080] When the current iteration number is less than the preset iteration number, perform a simulation calculation operation of heat transfer on the simulation model, the convective heat transfer model, and the heat conduction model according to the current temperature of each aluminum wire and the current temperature of each steel stranded wire, and output the temperature of each aluminum wire in the current simulation calculation operation and the temperature of each steel stranded wire in the current simulation calculation operation; among them, initially, generate the current temperature of each aluminum wire and the current temperature of each steel stranded wire according to the surface temperature of the transmission conductor and Fourier's law.

[0081] Take the temperature of each aluminum wire in the current simulation calculation operation as the current temperature of each aluminum wire when performing the temperature generation operation next time, and take the temperature of each steel stranded wire in the current simulation calculation operation as the current temperature of each steel stranded wire when performing the temperature generation operation next time.

[0082] It can be understood that the present invention first constructs a convective heat transfer model between the transmission conductor and the air, and a heat conduction model between the aluminum wire and the steel stranded wire. These two models respectively describe the heat exchange between the conductor and the external environment and the heat conduction process between different materials inside the conductor.

[0083] Then, repeat the temperature generation operation. Initially, the initial temperatures of each aluminum wire and each steel stranded wire can be generated according to the surface temperature of the transmission conductor (i.e., the temperature of the outermost aluminum strands) and Fourier's law.

[0084] In an iterative manner, the simulation calculation of heat transfer is continuously carried out according to the current temperature. In each iteration, the updated temperatures of each aluminum wire and steel strand are calculated based on the simulation model, convective heat transfer model, and heat conduction model. The iterative process continues until the preset number of iterations is reached. In each iteration, the temperatures of each aluminum wire and steel strand are recorded to ensure that the temperature change laws of each aluminum wire and steel strand are captured.

[0085] Finally, after the iteration ends, the highest temperatures of each aluminum wire and steel strand in each simulation calculation operation are output as their temperature simulation results, so as to accurately reflect the temperature distribution of different materials inside the transmission wire under wildfire conditions.

[0086] In a preferred embodiment, due to the existence of heat conduction, the temperature changes of the steel core and aluminum strands are interrelated. Heat conduction transfers heat from the region with a higher temperature (such as the outermost aluminum strands) to the regions with lower temperatures (inside the aluminum wire and the steel core). Then, in the simulation calculation, temperature boundary conditions and related material parameters can be set, such as the thermal conductivity, constant-pressure heat capacity, etc. of the steel core and aluminum strands, and these parameters vary with temperature. The heat conduction of solid heat transfer and the convective heat transfer of solid-fluid heat transfer require continuous iterative calculations to obtain the wire temperature, and the simulation results show the temperature changes of the aluminum strands and the steel core at each time step. Then, the maximum value can be found through the temperature change curve. Assuming the time step is Δt, in the time series t1, t2…, tn, (ti+1 = ti + Δt), the corresponding temperatures of the outermost aluminum strands at each time sequence are Touter-Aluminum(t1),…Touter-Aluminum(tn). Sorting according to the time series and plotting the temperature change law, the highest temperature corresponding to the maximum point of the temperature can be obtained.

[0087] Among them, heat transfer between the steel core and aluminum strands is carried out by means of heat conduction. The basic law of heat conduction is Fourier's law, and its expression can be:

[0088]

[0089] In the formula, the heat flux density J T is the heat transfer rate in the x direction on the unit area perpendicular to the transmission direction. It is proportional to the temperature gradient dT / dx in this direction. The proportionality constant k is a transport property, called the thermal conductivity (also known as the heat conduction coefficient), with the unit of W·m-1·K-1, and it can also be expressed as follows:

[0090]

[0091] Convective heat transfer is considered between the wire and the air. When the wire is in the air, heat is transferred to the surrounding air through convective heat transfer, and this part of the heat loss will affect the temperature distribution inside the wire. When performing the overall temperature calculation, the influence of convective heat transfer needs to be taken into account. The specific convective heat transfer formula is as shown in Equation 3:

[0092] Q = h * A * (T w - T f );

[0093] where Q is the convective heat transfer amount between the transmission wire and the air, h is the convective heat transfer coefficient, A is the heat transfer area, T w is the wall temperature, that is, the surface temperature of the transmission wire of the present invention, and T f is the fluid (air) temperature.

[0094] By continuously iterating the above calculation processes of solid heat transfer and solid-fluid heat transfer, and considering the mutual influence of heat conduction and convective heat transfer, the temperatures of each aluminum wire and each steel strand can be finally obtained. Thus, based on the calculation results, the variation law of the temperatures of each aluminum wire and the steel core with time during the occurrence of the wildfire can be statistically analyzed, and the maximum temperature of each aluminum wire and each steel strand can be extracted as the temperature simulation results of each aluminum wire and each steel strand.

[0095] Then, in the embodiment of the present invention, by continuously iterating the calculation processes of solid heat transfer and solid-fluid heat transfer, and considering the mutual influence of heat conduction and convective heat transfer, the temperature simulation results of each aluminum wire and each steel strand are finally obtained. Then, the temperature variation law of each aluminum wire and steel strand during the wildfire can be captured, including stages such as temperature rise, peak appearance, and temperature drop. Thus, the influence of the wildfire on the temperature distribution of the transmission wire can be more accurately analyzed, as well as the influence of temperature change on the mechanical properties and fracture risk of the wire.

[0096] For step S3, the present invention can consider the influence of the wildfire on the mechanical properties of the transmission wire material, especially the influence of temperature on the breaking force, and further evaluate the breaking forces of each aluminum wire and the steel core under wildfire conditions based on the maximum temperatures of each aluminum wire and the steel core statistically obtained from the simulation results.

[0097] In a preferred embodiment, the generating the first breaking force corresponding to each aluminum wire in the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when no wildfire occurs includes:

[0098] For each aluminum wire, the first breaking force corresponding to the aluminum wire in the current wildfire area is calculated according to the following formula:

[0099]

[0100] Among them, F 2 is the first breaking force corresponding to the aluminum wire in the current wildfire area, and T L is the temperature simulation result of the aluminum wire, and F 1 is the first preset breaking force of the aluminum wire when there is no wildfire.

[0101] In a preferred embodiment, generating the second breaking force corresponding to each strand of steel wire in the current wildfire area according to the temperature simulation result of each strand of steel wire and the second preset breaking force of each strand of steel wire when there is no wildfire includes:

[0102] For each strand of steel wire, calculate the second breaking force corresponding to the strand of steel wire in the current wildfire area according to the following formula:

[0103]

[0104] Among them, F 4 is the second breaking force corresponding to the strand of steel wire in the current wildfire area, T G is the temperature simulation result of the strand of steel wire, and F 3 is the second preset breaking force of the strand of steel wire when there is no wildfire.

[0105] Schematically, the first breaking force corresponding to the aluminum wire in the current wildfire area is the minimum breaking force of the aluminum wire in the current wildfire area. The second breaking force corresponding to the strand of steel wire in the current wildfire area is the minimum breaking force of the strand of steel wire in the current wildfire area.

[0106] Then, based on the minimum breaking forces of each strand of steel wire and aluminum wire calculated above, the minimum breaking force of each layer of aluminum wire strands and the minimum breaking force of each layer of steel cores can be further calculated, that is, the first comprehensive breaking force of each layer of aluminum wire strands and the second comprehensive breaking force of each layer of steel cores.

[0107] Schematically, if the breaking force of each layer is directly calculated, large errors may be caused due to factors such as uneven material distribution and temperature difference. In the embodiment of the present invention, the breaking force of each wire is calculated first, and then these results are summarized, which can more effectively control the calculation error of the breaking force, thereby overcoming the problem of different temperature deviations between the inner and outer layers of the transmission wire under wildfire conditions and improving the accuracy of the breaking force evaluation.

[0108] For step S4, by first calculating the first breaking force corresponding to each aluminum wire in the current wildfire area and the second breaking force corresponding to each strand of steel wire in the current wildfire area through step S3, then summarizing to the breaking force of the aluminum wire strands and the breaking force of each layer of steel cores, and then obtaining the breaking force corresponding to the entire transmission wire in the current wildfire area, a more refined evaluation can be achieved.

[0109] In a preferred embodiment, the structural parameters of the transmission wire include: the structural parameters of the aluminum wire and the structural parameters of the steel strand; the thermal expansion performance parameters of the transmission wire include: the thermal expansion performance parameters of the aluminum wire and the thermal expansion performance parameters of the steel strand.

[0110] Then, when generating the third breaking force corresponding to the transmission wire in the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters of the transmission wire, it may specifically include:

[0111] Generate the first comprehensive breaking force of each layer of aluminum wire strands according to the number of aluminum wires in each layer of aluminum wire strands, the structural parameters of the aluminum wire, the thermal expansion performance parameters of the aluminum wire, and the first breaking force corresponding to each aluminum wire in each layer of aluminum wire strands.

[0112] Generate the second comprehensive breaking force of each layer of steel cores according to the number of steel strands in each layer of steel cores, the structural parameters of the steel strand, the thermal expansion performance parameters of the steel strand, and the second breaking force corresponding to each steel strand in each layer of steel cores.

[0113] Generate the third breaking force corresponding to the transmission wire in the current wildfire area according to the first comprehensive breaking force of each layer of aluminum wire strands, the first preset breaking force coefficient corresponding to the aluminum wire strands, the second comprehensive breaking force of each layer of steel cores, and the second preset breaking force coefficient corresponding to the steel cores.

[0114] In a preferred embodiment, the structural parameters of the aluminum wire include: the number of segments corresponding to the aluminum wire in the current wildfire area, the elastic modulus of the aluminum wire, the cross-sectional area of the aluminum wire, and the length corresponding to the aluminum wire in the current wildfire area.

[0115] The thermal expansion performance parameters of the aluminum wire include: the linear thermal expansion coefficient of the aluminum wire and the average temperature of each segment length of the aluminum wire.

[0116] Then, when calculating the first comprehensive breaking force of each layer of aluminum wire strands, specifically:

[0117] Obtain the regional temperature corresponding to the current wildfire area.

[0118] For each aluminum wire, generate the length change amount corresponding to the aluminum wire when the temperature rises according to the regional temperature, the linear thermal expansion coefficient of the aluminum wire, the number of segments corresponding to the aluminum wire in the current wildfire area, and the average temperature of each segment length of the aluminum wire.

[0119] For each layer of aluminum wire strands, generate the external tension corresponding to the aluminum wire strands when the temperature rises according to the length change amount corresponding to each aluminum wire when the temperature rises, the elastic modulus of each aluminum wire, the cross-sectional area of each aluminum wire, the length corresponding to the aluminum wire in the current wildfire area, and the number of aluminum wires in the aluminum wire strands.

[0120] For each layer of aluminum wire strands, according to the external tensile force corresponding to the aluminum wire strands when the temperature rises and the first breaking force corresponding to each aluminum wire in the aluminum wire strands, the first comprehensive breaking force of the aluminum wire strands is generated.

[0121] In a preferred embodiment, the structural parameters of the steel strand include: the number of segments corresponding to the steel strand in the current wildfire area, the elastic modulus of the steel strand, the cross-sectional area of the steel strand, and the length corresponding to the steel strand in the current wildfire area;

[0122] The thermal expansion performance parameters of the steel strand include: the linear thermal expansion coefficient of the steel strand and the average temperature of each segment length of the steel strand;

[0123] Then when calculating the second comprehensive breaking force of each layer of steel cores, specifically:

[0124] Obtain the regional temperature corresponding to the current wildfire area;

[0125] For each steel strand, according to the regional temperature, the linear thermal expansion coefficient of the steel strand, the number of segments corresponding to the steel strand in the current wildfire area, and the average temperature of each segment length of the steel strand, generate the length change amount corresponding to the steel strand when the temperature rises;

[0126] For each layer of steel cores, according to the length change amount corresponding to each steel strand when the temperature rises, the elastic modulus of each steel strand, the cross-sectional area of each steel strand, the length corresponding to each steel strand in the current wildfire area, and the number of steel strands of the steel core, generate the external tensile force corresponding to the steel core when the temperature rises;

[0127] For each layer of steel cores, according to the external tensile force corresponding to the steel core when the temperature rises and the second breaking force corresponding to each steel strand in the steel core, generate the second comprehensive breaking force of the steel core.

[0128] Then, by considering the specific structural parameters (such as the number of segments, elastic modulus, cross-sectional area, and length of aluminum wires and steel strands) and thermal expansion performance parameters (such as linear thermal expansion coefficient and average temperature per unit length) of the transmission line, the embodiments of the present invention can first calculate the first comprehensive breaking force of each layer of aluminum wire strands and the second comprehensive breaking force of each layer of steel cores, and then combine the first preset breaking force coefficient corresponding to the aluminum wire strands and the second preset breaking force coefficient corresponding to the steel cores to obtain the third breaking force corresponding to the transmission line in the current wildfire area.

[0129] Since aluminum wires and steel stranded wires are the main components of transmission conductors, their performance directly affects the performance of the entire transmission conductor. By separately considering the structural parameters and thermal expansion performance parameters of aluminum wires and steel stranded wires, the mechanical properties of transmission conductors under different conditions can be more accurately evaluated, and the stress conditions and fracture risks of transmission conductors under extreme conditions such as wildfires can be predicted more accurately.

[0130] Schematically, the first comprehensive breaking force of each layer of aluminum wire strands is the minimum breaking force of each layer of aluminum wire strands. The second comprehensive breaking force of each layer of steel cores is the minimum breaking force of each layer of steel cores.

[0131] In a preferred embodiment, when calculating the minimum breaking force of each layer of aluminum wire strands based on the first breaking force corresponding to each aluminum wire, it can be calculated according to the following formula:

[0132]

[0133] where ΔL n is the length change amount corresponding to the nth aluminum wire when the temperature rises, which reflects the thermal expansion effect of the aluminum wire due to temperature rise, α is the linear thermal expansion coefficient of the aluminum wire, T i is the average temperature of the ith section length, T ref is the regional temperature corresponding to the current wildfire area, x is the number of sections of the aluminum wire in the current wildfire area, F me is the external tensile force corresponding to the mth layer of aluminum wire strands when the temperature rises, used to evaluate the stress state of the aluminum wire strands, E n is the elastic modulus of the nth aluminum wire, A n is the cross-sectional area of the nth aluminum wire, k is the number of aluminum wires in the mth layer of aluminum wire strands, L is the length of the aluminum wire in the current wildfire area, is the first comprehensive breaking force of the mth layer of aluminum wire strands, F 2 is the first breaking force corresponding to each aluminum wire in the current wildfire area.

[0134] Schematically, when calculating the second comprehensive breaking force of each layer of steel cores, the formula and principle for calculating the first comprehensive breaking force of each layer of aluminum wire strands are also adopted, which will not be elaborated here.

[0135] When evaluating the breaking force, the parameters considered cover multiple aspects of the aluminum wire and steel strand, including their structural characteristics (such as elastic modulus, cross-sectional area, length, etc.), thermal expansion properties (such as linear thermal expansion coefficient, average temperature, etc.), and specific stress conditions (such as external tensile force, breaking force, etc.). During the actual process of wildfire impact, the aluminum wire and steel strand may be affected by various factors, such as temperature gradient, material inhomogeneity, complexity of external loads, etc. Then, by comprehensively considering multiple parameters, the present invention can more comprehensively evaluate the influence of these factors on the breaking force, thereby obtaining a more accurate evaluation result.

[0136] Schematically, in the embodiment of the present invention, the average temperature of each meter of the wire is used to simplify the calculation of the expansion length of the wire during the occurrence of wildfire, reducing the calculation complexity while considering the influence of wildfire temperature in different regions on the breaking force of the wire.

[0137] Moreover, by analyzing the breaking force of each aluminum wire and steel strand at high temperature, while considering the expansion stress of the wire, the minimum breaking force of each layer of aluminum wire and steel strand is calculated layer by layer, thereby improving the accuracy of the calculation result of the comprehensive breaking force of the wire under wildfire conditions.

[0138] In a preferred embodiment, the calculation method of the minimum breaking force of the entire ACSR conductor (i.e., the third breaking force corresponding to the transmission wire in the current wildfire area) is as follows:

[0139] F = δF L + βF G ;

[0140] In the formula, F is the third breaking force corresponding to the transmission wire in the current wildfire area, δ is the first preset breaking force coefficient corresponding to the aluminum wire strands, β is the second preset breaking force coefficient corresponding to the steel core, F L is the sum of the breaking forces of each layer of aluminum wire strands, and F G is the sum of the breaking forces of each layer of steel cores.

[0141] Schematically, when the total number of aluminum wires < 37, δ = 0.95, when the number of aluminum wires ≥ 37, δ = 0.9, when the total number of steel strands < 7, β = 0.93, and when the total number of steel strands ≥ 7, β = 0.85.

[0142] For step S5, in a preferred embodiment, the third breaking force corresponding to the power transmission wire in the current wildfire area is compared with the preset breaking force threshold value corresponding to the power transmission wire. Thus, when it is determined that the third breaking force is less than the preset breaking force threshold value corresponding to the power transmission wire, it indicates that the ability of the power transmission wire to withstand tension has fallen below the preset safety threshold, and a warning message for characterizing the risk of wire breakage is generated. Then, the possible risk of wire breakage can be detected in advance, and necessary preventive measures (such as strengthening monitoring, adjusting the operation mode, increasing the maintenance frequency, etc.) can be taken to effectively reduce the probability and consequences of accidents.

[0143] Such as Figure 3 The schematic flow diagram of breaking force calculation and fracture warning shown. The present invention can obtain the line information of the wildfire occurrence location based on the transmission line ledger, control the unmanned aerial vehicle equipped with an infrared thermal imager to obtain the temperature distribution image of the outer layer of the wire, and upload it to the control center. Based on solid heat transfer and fluid-solid heat transfer iterative calculation, the temperature of each aluminum wire and steel strand is calculated, and the minimum breaking force of each steel strand and aluminum wire is calculated based on the maximum temperature of each aluminum wire and steel strand, so as to obtain the minimum breaking force of the comprehensive wire. The minimum breaking force of the wire is compared with the initially set breaking force threshold range to evaluate the risk level of wire breakage, and then corresponding warning and control measures are taken based on the risk level.

[0144] Schematically, after the wildfire occurs, the embodiment of the present invention can monitor the wire through the unmanned aerial vehicle equipped with an infrared thermal imager device to obtain the temperature distribution image of the outermost aluminum strands of the wire. The thermal imager converts the infrared radiation signal into a digital signal and transmits it to the computing system of the ground control center in real time through a wireless communication module.

[0145] Analyze the image transmitted by the thermal imager to identify the contour and temperature information of the wire. Combining the structural information of the wire (number of aluminum wire layers, number of each layer, number of steel strand layers and number of each layer, etc.) in the transmission line ledger or construction record, according to the solid heat transfer and solid-fluid heat transfer calculation methods, through iterative calculation, the real-time temperature, minimum breaking force of each aluminum wire and steel strand, and the comprehensive minimum breaking force F of the power transmission wire are obtained calculate 。

[0146] When F calculate <F min-threshold , it is determined that the wire has a serious fracture risk and is marked as the red warning level;

[0147] When F min-threshold <F calculate <F max-threshold , it is determined that the wire has a moderate fracture risk and is marked as the yellow warning level;

[0148] When F calculate <Fmax-threshold , it is determined as a low risk and marked with a green safety level.

[0149] When it is determined that there is a risk of wire breakage (red or yellow warning), based on the wire identification information (the number obtained from the transmission line ledger), geographical location information (the longitude and latitude coordinates obtained through the GPS positioning system carried by the drone, and the precise location is determined by combining the tower number and the relative position of the wire in the span), risk level, the calculated minimum breaking force value, real-time temperature data, etc., use natural language processing technology to generate detailed warning text information, and convert the warning information into a specific format of data (such as JSON format) for convenient subsequent transmission and processing. And add tags such as timestamp, equipment number, risk type code, etc. to the warning information for the monitoring center to quickly identify and classify.

[0150] The warning information can also be sent to the server of the regional monitoring center through the optical fiber communication network. When the server successfully receives the warning information, it immediately returns a confirmation signal to the sending end. If the sending end does not receive the confirmation signal within the specified time (such as seconds), the warning information will be resent to ensure that the warning information reaches the monitoring center accurately.

[0151] Furthermore, when a red warning occurs, it can also be automatically connected to the intelligent fire extinguishing equipment control system deployed around. Thus, according to the wildfire location and spread direction information transmitted back by the drone, as well as the position coordinates of the wire, calculate the optimal deployment position and spraying angle of the fire extinguishing equipment. And send a flight path planning instruction through the drone fire extinguishing cluster to make it carry fire extinguishing bombs or dry powder fire extinguishing agents and fly accurately to the target area for fire extinguishing operations.

[0152] When a yellow warning or above level is triggered, it can also interact with the intelligent power grid control system of the power grid dispatching center to obtain the real-time operation data of the current transmission network, including parameters such as load current, voltage, power factor of each line, as well as the output power of the power source point and the available capacity of the standby line, etc. On the premise of meeting the constraints of the safe operation of the power grid, calculate the optimal line reconfiguration plan to gradually transfer the load of the line where the risky wire is located to the safe standby line.

[0153] Schematically, after the wildfire ends, all the data of the wire during the wildfire can also be collected and sorted out, including the minimum breaking force change curve, temperature change curve, execution records of control measures (such as operation logs of fire extinguishing equipment, line switching time and sequence, lifting records of support towers, etc.), wildfire development trajectory (data of flame position and intensity changing with time), etc., and replace the broken-strand and loose-strand wires in the wildfire environment.

[0154] Therefore, by monitoring and calculating the breaking force of the transmission line in real time and comparing it with a preset safety threshold, the present invention can timely detect potential fracture risks, and thus take preventive measures, such as strengthening monitoring, adjusting the operation mode or increasing the maintenance frequency, to effectively avoid the occurrence of accidents.

[0155] As Figure 4 shown, based on the above embodiments of various warning methods for the fracture risk of transmission lines under wildfire conditions, the present invention correspondingly provides an apparatus embodiment;

[0156] An embodiment of the present invention provides a warning device for the fracture risk of transmission lines under wildfire conditions, including: a wire surface temperature acquisition module, a temperature simulation result generation module, a first calculation module, a second calculation module, and a warning module;

[0157] The wire surface temperature acquisition module is used to acquire the surface temperature of the transmission line in the current wildfire area; wherein, the transmission line includes: a plurality of aluminum wires and a plurality of steel stranded wires;

[0158] The temperature simulation result generation module is used to perform simulation calculations of heat transfer based on the convective heat transfer model between the transmission line and the air, the heat conduction model between the aluminum wire and the steel stranded wire, and the surface temperature, and generate the temperature simulation results of each aluminum wire and the temperature simulation results of each steel stranded wire;

[0159] The first calculation module is used to generate the first breaking force corresponding to each aluminum wire in the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when there is no wildfire; generate the second breaking force corresponding to each steel stranded wire in the current wildfire area according to the temperature simulation result of each steel stranded wire and the second preset breaking force of each steel stranded wire when there is no wildfire;

[0160] The second calculation module is used to generate the third breaking force corresponding to the transmission line in the current wildfire area according to the total number of aluminum wires, the total number of steel stranded wires, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel stranded wire, the structural parameters of the transmission line, and the thermal expansion performance parameters of the transmission line;

[0161] The warning module is used to generate a warning information indicating that there is a fracture risk of the transmission line when it is determined that the third breaking force is less than the preset breaking force threshold corresponding to the transmission line.

[0162] It should be noted that the device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the attached drawings of the device embodiments provided by the present invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement this without creative efforts.

[0163] Those skilled in the art can clearly understand that for the convenience and conciseness, the specific working process of the device described above can refer to the corresponding process in the foregoing method embodiment and will not be elaborated herein.

[0164] Based on the above embodiments of various methods for early warning of the risk of transmission line breakage under wildfire conditions, the present invention correspondingly provides embodiments of a terminal device.

[0165] An embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a method for early warning of the risk of transmission line breakage under wildfire conditions according to any method embodiment of the present invention.

[0166] The terminal device can be a computing terminal device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory.

[0167] The so-called processor may be a central processing unit (CPU), or may also be 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. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the terminal device, connecting various parts of the entire terminal device through various interfaces and lines.

[0168] The memory can be used to store the computer program. By running or executing the computer program stored in the memory and calling the data stored in the memory, the processor realizes various functions of the terminal device. The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include high-speed random access memory, and can also include non-volatile memory, such as a hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one magnetic disk storage device, flash device or other volatile solid-state storage devices.

[0169] Based on the above embodiments of various methods for warning of the risk of transmission line breakage under wildfire conditions, the present invention correspondingly provides an embodiment of a storage medium.

[0170] An embodiment of the present invention provides a storage medium, which includes a stored computer program. When the computer program runs, it controls the device where the computer-readable storage medium is located to execute a method for warning of the risk of transmission line breakage under wildfire conditions according to any embodiment of the method items of the present invention.

[0171] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the above various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0172] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A method for early warning of power transmission line fracture risk under wildfire conditions, characterized in that: include: Obtaining the surface temperature of the power transmission wire in the current wildfire area; wherein the power transmission wire includes: a plurality of aluminum wires and a plurality of steel strands; Based on the convection heat transfer model between the transmission wire and the air, the heat conduction model between the aluminum wire and the steel strand, and the surface temperature, a simulation calculation of heat transfer is performed to generate a temperature simulation result of each aluminum wire and a temperature simulation result of each steel strand; According to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when no wildfire occurs, the first breaking force corresponding to each aluminum wire in the current wildfire area is generated; according to the temperature simulation result of each steel strand and the second preset breaking force of each steel strand when no wildfire occurs, the second breaking force corresponding to each steel strand in the current wildfire area is generated; Generate a third breaking force corresponding to the transmission wire in the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters of the transmission wire; When it is determined that the third breaking force is less than the preset breaking force threshold corresponding to the transmission wire, early warning information is generated to indicate that there is a risk of breaking of the transmission wire.

2. A method for early warning of power transmission line fracture risk under wildfire conditions according to claim 1, characterized in that: The transmission wire comprises: a plurality of layers of aluminum strands and a plurality of layers of steel core; the surface temperature is the temperature corresponding to the outermost layer of aluminum strands of the transmission wire; wherein each layer of aluminum strands comprises a plurality of aluminum wires, and each layer of steel core comprises a plurality of steel strands; The heat transfer simulation calculation based on the convection heat transfer model between the transmission wire and the air, the heat conduction model between the aluminum wire and the steel strand, and the surface temperature generates the temperature simulation result of each aluminum wire and the temperature simulation result of each steel strand, including: According to the total number of layers of aluminum wire strands, the number of aluminum wires in each layer of aluminum wire strands, the total number of layers of steel cores, and the number of steel strands in each layer of steel cores, simulation modeling is performed on the transmission wire to generate a simulation model corresponding to the transmission wire; According to the convection heat transfer coefficient, the surface temperature of the transmission line and the air temperature, a convection heat transfer model between the transmission line and the air is constructed; According to the thermal conductivity of aluminum wire, the thermal conductivity of steel core and Fourier's law, a heat conduction model between aluminum wire and steel strand is constructed; After the surface temperature is used as the boundary temperature of the simulation model, the simulation model, the convection heat transfer model and the heat conduction model are simulated and calculated for heat transfer, and the temperature simulation results of each aluminum wire and each steel strand are output.

3. A method for early warning of power transmission line fracture risk under wildfire conditions as claimed in claim 2, characterized in that: The simulation calculation of heat transfer is performed on the simulation model, the convection heat transfer model and the heat conduction model, and the temperature simulation result of each aluminum wire and the temperature simulation result of each steel strand are output, including: Repeat the following temperature generation operation until the current number of iterations is the same as the preset number of iterations, and take the highest temperature of each aluminum wire in all simulation calculation operations as the temperature simulation result corresponding to each aluminum wire, and take the highest temperature of each steel strand in all simulation calculation operations as the temperature simulation result corresponding to each steel strand: Get the current temperature of each aluminum wire and the current temperature of each steel strand; When the current number of iterations is less than the preset number of iterations, the simulation model, the convection heat transfer model and the heat conduction model are subjected to a simulation calculation operation of heat transfer according to the current temperature of each aluminum wire and the current temperature of each steel strand, and the temperature of each aluminum wire in the current simulation calculation operation and the temperature of each steel strand in the current simulation calculation operation are output; wherein, initially, the current temperature of each aluminum wire and the current temperature of each steel strand are generated according to the surface temperature of the transmission wire and Fourier's law; The temperature of each aluminum wire in the current simulation calculation operation is used as the current temperature of each aluminum wire when the temperature generation operation is performed next time, and the temperature of each steel strand in the current simulation calculation operation is used as the current temperature of each steel strand when the temperature generation operation is performed next time.

4. A method for early warning of power transmission line fracture risk under wildfire conditions as claimed in claim 3, characterized in that: The generating, according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when no wildfire occurs, the first breaking force corresponding to each aluminum wire in the current wildfire area includes: For each aluminum wire, the first breaking force corresponding to the aluminum wire in the current wildfire area is calculated according to the following formula: Among them, F2 is the first tensile force corresponding to the aluminum wire in the current wildfire area, T L is the temperature simulation result of the aluminum wire, and F1 is the first preset breaking force of the aluminum wire when no wildfire occurs.

5. A method for early warning of power transmission line fracture risk under wildfire conditions as claimed in claim 4, characterized in that: The generating of the second breaking force corresponding to each steel strand in the current wildfire area according to the temperature simulation result of each steel strand and the second preset breaking force of each steel strand when no wildfire occurs comprises: For each steel strand, the second breaking force corresponding to the steel strand in the current wildfire area is calculated according to the following formula: Among them, F4 is the second tensile force corresponding to the steel strand in the current wildfire area, T G is the temperature simulation result of the steel strand, and F3 is the second preset breaking force of the steel strand when no wildfire occurs.

6. A method for early warning of power transmission line fracture risk under wildfire conditions as claimed in claim 5, characterized in that: The structural parameters of the transmission wire include: the structural parameters of the aluminum wire and the structural parameters of the steel strand; the thermal expansion performance parameters of the transmission wire include: the thermal expansion performance parameters of the aluminum wire and the thermal expansion performance parameters of the steel strand; The method of generating a third breaking force corresponding to the transmission line in the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission line, and the thermal expansion performance parameters of the transmission line includes: Generate a first comprehensive breaking force of each layer of aluminum wire strands according to the number of aluminum wires in each layer of aluminum wire strands, structural parameters of the aluminum wires, thermal expansion performance parameters of the aluminum wires, and a first breaking force corresponding to each aluminum wire in each layer of aluminum wire strands; According to the number of steel strands in each layer of steel core, the structural parameters of the steel strands, the thermal expansion performance parameters of the steel strands, and the second breaking force corresponding to each steel strand in each layer of steel core, the second comprehensive breaking force of each layer of steel core is generated; According to the first comprehensive breaking force of each layer of aluminum wire strands, the first preset breaking force coefficient corresponding to the aluminum wire strands, the second comprehensive breaking force of each layer of steel core and the second preset breaking force coefficient corresponding to the steel core, the third breaking force corresponding to the transmission line in the current wildfire area is generated.

7. A method for early warning of power transmission line rupture risk under wildfire conditions according to claim 6, characterized in that: The structural parameters of the aluminum wire include: the number of segments of the aluminum wire in the current wildfire area, the elastic modulus of the aluminum wire, the cross-sectional area of ​​the aluminum wire, and the length of the aluminum wire in the current wildfire area; the thermal expansion performance parameters of the aluminum wire include: the linear thermal expansion coefficient of the aluminum wire and the average temperature of each segment of the aluminum wire; The method of generating the first comprehensive breaking force of each layer of aluminum wire strands according to the number of aluminum wires in each layer of aluminum wire strands, the structural parameters of the aluminum wires, the thermal expansion performance parameters of the aluminum wires, and the first breaking force corresponding to each aluminum wire in each layer of aluminum wire strands comprises: Get the regional temperature corresponding to the current wildfire area; For each aluminum wire, a length change corresponding to the increase in temperature of the aluminum wire is generated according to the regional temperature, the linear thermal expansion coefficient of the aluminum wire, the number of sections of the aluminum wire corresponding to the current wildfire area, and the average temperature of each section of the aluminum wire; For each layer of aluminum wire strands, the external tension corresponding to the aluminum wire strands when the temperature rises is generated according to the length change corresponding to each aluminum wire when the temperature rises, the elastic modulus of each aluminum wire, the cross-sectional area of ​​each aluminum wire, the length of the aluminum wire in the current wildfire area, and the number of aluminum wires in the aluminum wire strands; For each layer of aluminum wire strands, a first comprehensive breaking force of the aluminum wire strands is generated according to the external tensile force corresponding to the aluminum wire strands when the temperature increases and the first breaking force corresponding to each aluminum wire in the aluminum wire strands.

8. A transmission line break risk warning device based on wildfire conditions, characterized in that: include: A conductor surface temperature acquisition module, a temperature simulation result generation module, a first calculation module, a second calculation module and an early warning module; The conductor surface temperature acquisition module is used to acquire the surface temperature of the power transmission conductor in the current wildfire area; wherein the power transmission conductor includes: a plurality of aluminum wires and a plurality of steel strands; The temperature simulation result generating module is used to perform a simulation calculation of heat transfer based on a convection heat transfer model between the transmission wire and the air, a heat conduction model between the aluminum wire and the steel strand, and the surface temperature, to generate a temperature simulation result of each aluminum wire and a temperature simulation result of each steel strand; The first calculation module is used to generate a first breaking force corresponding to each aluminum wire in the current wildfire area according to the temperature simulation result of each aluminum wire and the first preset breaking force of each aluminum wire when no wildfire occurs; and to generate a second breaking force corresponding to each steel strand in the current wildfire area according to the temperature simulation result of each steel strand and the second preset breaking force of each steel strand when no wildfire occurs; The second calculation module is used to generate a third breaking force corresponding to the transmission wire in the current wildfire area according to the total number of aluminum wires, the total number of steel strands, the first breaking force corresponding to each aluminum wire, the second breaking force corresponding to each steel strand, the structural parameters of the transmission wire, and the thermal expansion performance parameters of the transmission wire; The early warning module is used to generate early warning information for indicating that there is a risk of fracture of the transmission line when it is determined that the third breaking force is less than a preset breaking force threshold corresponding to the transmission line.

9. A terminal device, characterized in that: It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a transmission line rupture risk warning method based on wildfire conditions as described in any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the transmission line rupture risk warning method based on wildfire conditions as described in any one of claims 1 to 7.

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