Method and processor for lightning strand breakage simulation test of power transmission line conductors

Abstract

The embodiment of the application provides a lightning stroke strand breakage simulation test method and a processor for a power transmission line conductor. The method comprises the following steps: fixing a power transmission conductor to be tested on a wire clamp, setting initial test parameters, starting a test platform, making a gap between an electrode and the power transmission conductor to be tested be broken down by an impulse voltage, triggering a lightning current generator to discharge before an impulse discharge arc is extinguished, applying lightning current on the power transmission conductor to be tested, repeating the step of starting the test platform, and recording test data each time; changing one of the following: conductor tension, conductor operating current, conductor diameter, conductor material, and lightning current of the lightning current generator, repeating the step of starting the test platform, and recording test data each time; and designing lightning protection for the power transmission conductor to be tested according to all the test data. By using the technical scheme, the lightning protection strand breakage power transmission conductor can be designed individually, and the safety of power transmission line operation and the reliability of power supply are improved.

Description

Technical Field

[0001] This application relates to the field of lightning protection technology for power transmission lines, specifically to a method and processor for simulating strand breakage tests of power transmission line conductors caused by lightning strikes. Background Technology

[0002] In recent years, wind power development has been rapid in my country. Wind power lines are mostly located in high-altitude, cold mountainous areas, typically operating at 110kV. Severe icing occurs in winter, and the ground wire, located above the conductor and lacking Joule heating, is more prone to ground wire breakage and conductor-to-ground discharge faults caused by icing. To fundamentally eliminate the impact of ground wire icing on the reliability of 110kV wind power transmission lines, the common practice is to remove the ground wire from wind power lines in heavily iced areas. Furthermore, considering construction costs and economic efficiency, 35kV lines in my country generally do not have ground wires installed along the entire length (only 1-2km at the substation entrances and exits). For 110kV transmission lines without ground wires after this removal, and 35kV lines that lack ground wires altogether, the probability and amplitude of direct lightning strikes on the transmission conductors increase dramatically, potentially causing the outer aluminum strands of the conductors to break under the electric arc generated by the lightning strike energy.

[0003] Existing technologies cannot analyze the voltage and current characteristics of transmission line conductors, the differences in conductor structure and size parameters, nor can they determine the damage area of ​​conductors caused by lightning strikes based on the above differences. They also cannot optimize the design of conductors to prevent lightning strike breakage and cannot protect the safe operation of transmission lines. Summary of the Invention

[0004] The purpose of this application is to provide a method and processor for simulating lightning strike strand breakage tests on power transmission line conductors.

[0005] To achieve the above objectives, the first aspect of this application provides a method for simulating lightning strike strand breakage tests on transmission line conductors, applied to a lightning strike strand breakage simulation test platform for transmission line conductors. The test platform includes post insulators, a lightning current generator, and an impulse voltage generator at both ends. The method includes:

[0006] Step 101: Fix the transmission conductor to be tested on the clamps of the post insulators at both ends of the test platform, and set the initial test parameters. The initial test parameters are: the conductor tension and conductor operating current of the transmission conductor to be tested are preset tension and preset operating current, respectively; and the wavefront and wavetail impedances and charging voltages of the lightning current generator and the impulse voltage generator are preset wavefront impedance, preset wavetail impedance, and preset charging voltage, respectively.

[0007] Step 102: Start the test platform so that the impulse voltage generator generates an impulse voltage to break down the gap between the electrode and the transmission line under test. Before the impulse discharge arc is extinguished, the lightning current generator is triggered to discharge and the lightning current generated by the lightning current generator is applied to the transmission line under test.

[0008] Step 103: Repeat step 102 multiple times and record the test data for each time. The test data includes the transferred charge corresponding to the lightning current generated by the lightning current generator, the lightning damage area of ​​the transmission line under test, and the number of broken strands in the line.

[0009] Step 104: Change one of the following factors: conductor tension, conductor operating current, conductor diameter, conductor material, and lightning current of the lightning current generator. Repeat step 102 multiple times and record the test data for each test.

[0010] Step 105: Based on all the test data, design a lightning strike protection strand breakage protection system for the transmission conductor to be tested.

[0011] In this embodiment of the application, the lightning protection strand breakage design of the transmission conductor to be tested based on all the test data includes: analyzing the transmission conductor to be tested based on all the test data to obtain the optimal conductor parameters of the transmission conductor to be tested, wherein the optimal conductor parameters include the optimal conductor material, optimal conductor diameter, optimal conductor tension, and optimal conductor operating current of the transmission conductor to be tested; and designing the transmission conductor to be tested based on the optimal conductor parameters.

[0012] In this embodiment, the optimal conductor parameters for the transmission line under test are obtained by analyzing all the experimental data, including: determining the functional relationship between the lightning damage area S and the transferred charge corresponding to different lightning currents based on the transferred charge, lightning damage area, and number of broken strands of the transmission line under test under different lightning currents; determining the functional relationship between the lightning damage area S and the conductor tension based on the lightning damage area and number of broken strands of the transmission line under test under different conductor tensions; and determining the optimal parameters for the lightning damage area S and the number of broken strands of the transmission line under test under different conductor operating currents. The functional relationship between the lightning damage area S and the conductor operating current is established. Based on the lightning damage area and the number of broken strands of the transmission line under test for different conductor diameters, the functional relationship between the lightning damage area S and the conductor diameter is determined. Based on the lightning damage area and the number of broken strands of the transmission line under test for different conductor materials, the variation law between the lightning damage area S and the conductor material is determined. The fitting coefficient of each functional relationship is determined. If the difference between the fitting coefficient of the functional relationship and the preset value is less than the preset deviation threshold, the functional relationship is determined as the target relationship. The optimal conductor parameters of the transmission line under test are determined based on the target relationship.

[0013] In this embodiment, the test platform also includes insulators at both ends. Post insulators, conductor clamping devices, insulators, and clamps are connected in sequence to fix the transmission line to be tested at a certain height above the ground. The output end of the power frequency current generator is connected to both ends of the transmission line to be tested via a cable. Fixing the transmission line to be tested on the clamps of the post insulators at both ends of the test platform and setting the initial test parameters includes: adjusting the preload of the conductor clamping device and adding equal weight counterweights to both ends of the transmission line to be tested so that the conductor tension of the transmission line to be tested reaches the preset tension; turning on the power supply of the power frequency current generator and adjusting the voltage regulator built into the power frequency current generator to adjust the output voltage of the power frequency current generator so that the current flowing through the transmission line to be tested reaches the preset operating current.

[0014] In this embodiment of the application, the method further includes: before starting the test platform, setting the mode of the impulse voltage generator to automatic trigger mode, and connecting the signal line of the trigger time relay of the impulse voltage generator to the trigger time relay of the lightning current generator; after setting the lightning current generator and the impulse voltage generator to preset lightning current and preset impulse voltage respectively, charging the capacitors of the lightning current generator and the impulse voltage generator; setting the trigger time of the lightning current generator after the trigger time of the impulse voltage generator to ensure that the lightning current is applied to the transmission line to be tested before the impulse voltage arc is extinguished.

[0015] In this embodiment of the application, recording the test data for each test includes: acquiring the conductor image of the transmission line to be tested after each test; importing the conductor image into a preset image processing platform; and determining the lightning damage area of ​​the transmission line to be tested through the preset image processing platform.

[0016] In this embodiment, determining the lightning damage area of ​​the transmission line under test on a preset image processing platform includes: outlining the closed cross-sectional profile of the lightning damage to the transmission line under test using a curve on the preset image processing platform; dividing the closed cross-sectional profile into m×n square grids; calculating the number of square grids contained in the closed cross-sectional profile, and then the total area of ​​the grids contained in the closed cross-sectional profile is:

[0017] S m×n =×a 2 (1)

[0018] In formula (1), N is the number of square grids contained in the closed cross-sectional profile, and a is the side length of the square grid; set m = m + 1 and n = n + 1, and repeat the above calculation of the closed cross-sectional profile grid division and the total grid area until S m×n With S (-1)×(-1) If the deviation is less than the preset deviation threshold, then S at this time... m×n The area of ​​lightning damage to the transmission line under test.

[0019] The second aspect of this application provides a method for simulating lightning strike strand breakage tests on transmission line conductors, applied to a lightning strike strand breakage simulation test platform for transmission line conductors. The test platform includes post insulators, a lightning current generator, and an impulse voltage generator at both ends. The method includes:

[0020] Obtain the test parameter table, which includes multiple test parameters;

[0021] The initial equipment parameters of the test platform are controlled and adjusted according to the initial test parameters so that the conductor tension and operating current of the transmission line under test are the preset tension and preset operating current, the wavefront impedance and wavetail impedance of the lightning current generator and the impulse voltage generator are the preset wavefront impedance and preset wavetail impedance, and the charging voltage of the lightning current generator and the impulse voltage generator are the preset charging voltage.

[0022] The impulse voltage generator is controlled to enter automatic triggering mode, and the triggering time of the lightning current generator is set after the triggering time of the impulse voltage generator.

[0023] The control test platform is started so that the impulse voltage generator generates an impulse voltage to break down the gap between the electrode and the transmission line under test. Before the impulse discharge arc is extinguished, the lightning current generator is triggered to discharge, and the lightning current generated by the lightning current generator is applied to the transmission line under test.

[0024] For each test parameter in the test parameter table, change the parameter value of the test parameter while keeping the parameter values ​​of other test parameters unchanged to generate a new test parameter table;

[0025] The equipment parameters of the test platform are controlled and adjusted according to the new test parameter table to conduct simulation tests;

[0026] Acquire data from each experiment and send the data to a pre-set analysis platform to obtain the analysis results.

[0027] In this embodiment, the test data includes the transferred charge, lightning damage area, and number of broken strands of the transmission line under test. Data is acquired for each test and sent to a preset analysis platform to obtain the analysis results. These results include: determining the functional relationship between the lightning damage area S and the transferred charge corresponding to different lightning currents based on the transferred charge, lightning damage area, and number of broken strands of the transmission line under test under different lightning currents; determining the functional relationship between the lightning damage area S and the conductor tension based on the lightning damage area and number of broken strands of the transmission line under test under different conductor tensions; and determining the functional relationship between the lightning damage area S and the conductor tension based on the lightning damage area and number of broken strands of the transmission line under test under different conductor operating currents. The functional relationship between the operating current and the conductor diameter is determined. Based on the lightning damage area and the number of broken strands of the transmission line under test for different conductor diameters, the functional relationship between the lightning damage area S and the conductor diameter is determined. Based on the lightning damage area and the number of broken strands of the transmission line under test for different conductor materials, the variation law between the lightning damage area S and the conductor material is determined. The fitting coefficient of each functional relationship is determined. If the difference between the fitting coefficient of the functional relationship and the preset value is less than the preset deviation threshold, the functional relationship is determined as the target relationship. The optimal conductor parameters of the transmission line under test are determined based on the target relationship. The optimal conductor parameters include the optimal conductor material, optimal conductor diameter, optimal conductor tension, and optimal conductor operating current.

[0028] A third aspect of this application provides a processor configured to perform the above-described method for simulating lightning strike strand breakage tests on power transmission line conductors.

[0029] The fourth aspect of this application provides a lightning strike strand breakage simulation test device for transmission line conductors, including the aforementioned processor.

[0030] The fifth aspect of this application provides a machine-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform the above-described method for simulating lightning strike strand breakage tests on transmission line conductors.

[0031] The above technical solution involves fixing the transmission conductor under test to the clamps of the post insulators at both ends of the test platform, setting the initial test parameters, and starting the test platform. This causes the impulse voltage generator to generate an impulse voltage that breaks down the gap between the electrodes and the transmission conductor under test. Before the impulse discharge arc extinguishes, the lightning current generator is triggered to discharge, and the lightning current generated by the lightning current generator is applied to the transmission conductor under test. This process of starting the test platform is repeated, and the test data is recorded each time. The process is repeated by changing one of the following parameters: conductor tension, conductor operating current, conductor diameter, conductor material, and the lightning current generated by the lightning current generator. Based on all the test data, a lightning strike-resistant strand breakage design is performed on the transmission conductor under test. This technical solution effectively analyzes the comprehensive effects of lightning strikes on transmission conductors and provides customized designs for lightning strike-resistant strand breakage transmission conductors, improving the safety of transmission line operation and the reliability of power supply.

[0032] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0034] Figure 1 This schematically illustrates a first process diagram of a lightning strike strand breakage simulation test method for transmission line conductors according to an embodiment of this application;

[0035] Figure 2 A schematic diagram illustrating the area of ​​lightning damage according to an embodiment of this application is provided.

[0036] Figure 3 This illustration schematically shows a structural diagram of a lightning strike strand breakage simulation test platform for transmission line conductors according to an embodiment of this application;

[0037] Figure 4 This schematically illustrates a second process diagram of a lightning strike strand breakage simulation test method for transmission line conductors according to an embodiment of this application;

[0038] Figure 5 The illustration shows a third flowchart of a method for simulating strand breakage during lightning strikes on transmission line conductors according to an embodiment of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] Figure 1 This schematically illustrates a first process flow diagram of a lightning strike strand breakage simulation test method for transmission line conductors according to an embodiment of this application. Figure 1 As shown, in one embodiment of this application, a method for simulating lightning strike strand breakage of transmission line conductors is provided. This method is applied to a lightning strike strand breakage simulation test platform for transmission line conductors. The test platform includes a lightning current generator for post insulators and an impulse voltage generator at both ends. The method includes the following steps:

[0041] Step 101: Fix the transmission conductor to be tested on the clamps of the post insulators at both ends of the test platform, and set the initial test parameters. The initial test parameters are: the conductor tension and conductor operating current of the transmission conductor to be tested are preset tension and preset operating current, respectively; and the wavefront and wavetail impedances and charging voltages of the lightning current generator and the impulse voltage generator are preset wavefront impedance, preset wavetail impedance, and preset charging voltage, respectively.

[0042] Step 102: Start the test platform so that the impulse voltage generator generates an impulse voltage to break down the gap between the electrode and the transmission line under test. Before the impulse discharge arc is extinguished, the lightning current generator is triggered to discharge and the lightning current generated by the lightning current generator is applied to the transmission line under test.

[0043] Step 103: Repeat step 102 multiple times and record the test data for each time. The test data includes the transferred charge corresponding to the lightning current generated by the lightning current generator, the lightning damage area of ​​the transmission line under test, and the number of broken strands of the conductor.

[0044] Step 104: Change one of the following factors: conductor tension, conductor operating current, conductor diameter, conductor material, and lightning current of the lightning current generator. Repeat step 102 multiple times and record the test data for each test.

[0045] Step 105: Based on all the test data, design a lightning strike protection strand breakage protection system for the transmission conductor to be tested.

[0046] A lightning strike strand breakage simulation test platform may include post insulators, pulse current sensors, lightning current generators, and impulse voltage generators. It may also include conductor clamping devices, pulse current sensors, and power frequency current generators. Post insulators are special insulating components used in overhead transmission lines, typically constructed by adhesive bonding or mechanical clamping of insulating parts and metal fittings, used to fix the transmission conductor under test. Conductor clamping devices can apply different conductor tensions to the transmission conductor. Pulse current sensors are detection devices that measure the waveform and amplitude of the impulse current flowing through the transmission conductor. Lightning current generators generate simulated lightning current waveforms and can be used to apply different lightning currents to the transmission conductor. Impulse voltage generators are devices used to perform impulse voltage tests on power equipment and other test objects, including full-wave lightning current impulse voltage, lightning current impulse voltage carrier voltage, and switching impulse voltage waveforms, to verify insulation performance; they can be used to generate different impulse voltages. Power frequency current generators can be used to change the operating current of the transmission conductor.

[0047] The processor can set up a test platform at a preset test location, which is a location that meets the requirements of a lightning strike strand breakage simulation test, such as a high-voltage test hall. The processor can fix the transmission line to be tested onto the clamps of the post insulators at both ends of the test platform and set the initial test parameters. These initial test parameters can include preset conductor tension and operating current for the transmission line under test, and preset wavefront impedance, preset wavetail impedance, and preset charging voltage for the lightning current generator and impulse voltage generator. For example, the transmission line under test can be the LGJ-300 / 40 transmission line used in 110kV transmission lines. The processor can set the initial parameters X for the LGJ-300 / 40 transmission line, where X includes conductor tension X1, conductor operating current X2, wavefront impedance X3, wavetail impedance X4, and charging voltage X5 for the lightning current generator, and wavefront impedance X6, wavetail impedance X7, and charging voltage X8 for the impulse voltage generator. The processor can activate the test platform so that the impulse voltage generated by the impulse voltage generator breaks down the gap between the electrode and the transmission line under test. Before the impulse discharge arc is extinguished, the lightning current generator is triggered, and the lightning current generated by the lightning current generator is applied to the transmission line under test. For example, when the test platform is activated, the 200kV 1.2 / 50μs high-voltage impulse voltage (i.e., a 200kV impulse voltage with a wavefront time of 1.2μs and a half-wave time of 50μs) generated by the impulse voltage generator breaks down the gap between the electrode and the LGJ-300 / 40 transmission line. Before the 1.2 / 50μs impulse discharge arc is extinguished, the lightning current generator can be triggered to discharge, and the 8 / 20μs lightning current generated by the lightning current generator can be applied to the LGJ-300 / 40 transmission line.

[0048] The processor can repeatedly execute the above steps for starting the test platform and record the test data for each test. The test data may include the transferred charge corresponding to the lightning current generated by the lightning current generator, the lightning damage area of ​​the transmission line under test, and the number of broken strands in the line. For example, when starting the test platform, the gap between the 200kV 1.2 / 50μs high-voltage impulse voltage drop electrode generated by the impulse voltage generator and the LGJ-300 / 40 transmission line breaks down. Before the 1.2 / 50μs impulse discharge arc is extinguished, the lightning current generator can be triggered to discharge, and the 8 / 20μs lightning current (i.e., a current of 20KA) generated by the lightning current generator can be applied to the LGJ-300 / 40 transmission line. The first test data was recorded, specifically including a transferred charge Q of 0.33C from the 8 / 20μs lightning current generated by the lightning current generator, a lightning strike damage area S of 42.15 on the LGJ-300 / 40 transmission line, and 0 broken strands. After obtaining the first test data, the processor restarted the test platform, obtaining the second test data: a transferred charge Q of 0.33C from the 8 / 20μs lightning current generated by the lightning current generator, a lightning strike damage area S of 43.28 on the LGJ-300 / 40 transmission line, and 0 broken strands. The processor can change one of the following parameters of the transmission line under test: conductor tension, conductor operating current, conductor diameter, conductor material, and lightning current generated by the lightning current generator; the above steps of starting the test platform are repeated multiple times, recording the test data each time. Based on all the test data, a lightning strike strand breakage protection design is performed on the transmission line under test.

[0049] In one embodiment, recording the test data for each test includes: acquiring conductor images of the transmission line under test after each test; importing the conductor images into a preset image processing platform; and determining the lightning damage area of ​​the transmission line under test using the preset image processing platform. The processor can acquire conductor images of the transmission line under test after each test and import the conductor images into the preset image processing platform, which can employ ACDSee image processing software. The lightning damage area of ​​the transmission line under test can be determined using the ACDSee image processing software.

[0050] In one embodiment, determining the lightning damage area of ​​the transmission line under test on a preset image processing platform includes: outlining the closed cross-sectional profile of the lightning damage to the transmission line under test using a curve on the preset image processing platform; dividing the closed cross-sectional profile into m×n square grids; calculating the number of square grids contained in the closed cross-sectional profile, then the total area of ​​the grids contained in the closed cross-sectional profile is:

[0051] S m×n =×a 2 (1)

[0052] In formula (1), N is the number of square grids contained in the closed cross-sectional profile, and a is the side length of the square grid; set m = m + 1 and n = n + 1, and repeat the above calculation of the closed cross-sectional profile grid division and the total grid area until S m×n With S (-1)×(-1) If the deviation is less than the preset deviation threshold, then S at this time... m×n The area of ​​lightning damage to the transmission line under test.

[0053] For example, such as Figure 2 As shown, the preset image processing platform can use ACDSee image processing software. In ACDSee, the closed cross-sectional profile of the lightning strike damage to the transmission line under test is outlined using curves. The closed cross-sectional profile is divided into 4×15 square grids, with each square grid having a side length of 1. The number of square grids contained in the closed cross-sectional profile is calculated to be 38. Therefore, the total area of ​​the grids contained in the closed cross-sectional profile is: S 4×15 =38 × 1 = 38. Then set m = 5 and n = 16, and we get S. 5×16 =41.75. Calculate S. 4×15 With S 5×16 deviation (S) 5×16 -S 4×15 ) / S 4×15 =0.098, deviation 0.098 ≥ preset deviation value 0.01. Then set m=6, n=17, and obtain S. 6×17 =42.15. Calculate S. 5×16 With S 6×17 deviation (S) 6×17 –S 5×16 ) / S 6×17 =0.0094. Deviation 0.0094 ≤ preset deviation value 0.01. (The last part, "S", appears to be an error and doesn't translate directly.) 6×17 =42.15 is the area of ​​lightning damage to the transmission line under test.

[0054] In one embodiment, before starting the test platform, the impulse voltage generator is set to automatic trigger mode, and the signal line of the trigger time relay of the impulse voltage generator is connected to the trigger time relay of the lightning current generator. After setting the lightning current generator and the impulse voltage generator to preset lightning current and preset impulse voltage respectively, the capacitors of the lightning current generator and the impulse voltage generator are charged. The trigger time of the lightning current generator is set after the trigger time of the impulse voltage generator to ensure that the lightning current is applied to the transmission line under test before the impulse voltage arc is extinguished.

[0055] For example, before starting the test platform, the processor can set the impulse voltage generator to automatic trigger mode and connect the signal line of the impulse voltage generator's trigger time relay to the lightning current generator's trigger time relay. The lightning current generator's current can be set to an 8 / 20μs lightning current, and the impulse voltage generator's impulse voltage can be set to a 200kV 1.2 / 50μs high-voltage impulse voltage. After the lightning current generator and impulse voltage generator are set, they can be charged. The processor can set the trigger time of the lightning current generator 50μs after the trigger time of the impulse voltage generator to ensure that the lightning current is applied to the transmission line under test before the impulse voltage arc is extinguished.

[0056] In one embodiment, designing lightning protection strand breakage protection for the transmission line under test based on all experimental data includes: analyzing all experimental data to obtain the optimal conductor parameters; wherein, the optimal conductor parameters include the optimal conductor material, optimal conductor diameter, optimal conductor tension, and optimal conductor operating current. The processor can analyze all experimental data to obtain the optimal parameters of the transmission line under test and design the transmission line under test based on these optimal parameters. For example, the processor starts the test platform for the first time and records experimental data A1; starts the test platform for the second time and records data A2; starts the test platform for the third time and records experimental data A3. The processor changes only the conductor tension of the LGJ-300 / 40 transmission line and records the corresponding test data A4; the processor changes only the conductor operating current of the LGJ-300 / 40 transmission line and records the corresponding test data A5; the processor changes only the conductor diameter of the LGJ-300 / 40 transmission line and records the corresponding test data A6; the processor changes only the conductor material of the LGJ-300 / 40 transmission line and records the corresponding test data A7; the processor changes only the lightning current of the lightning current generator and records the corresponding test data A8. The processor can analyze the LGJ-300 / 40 transmission line based on the test data A1, A2, A3, A4, A5, A6, A7, and A8 to obtain the optimal conductor parameters of the LGJ-300 / 40 transmission line, and design the transmission line to be tested based on the optimal conductor parameters.

[0057] In one embodiment, analyzing all test data to obtain the optimal conductor parameters for the transmission line under test includes: determining the functional relationship between the lightning damage area S and the transferred charge corresponding to different lightning currents based on the transferred charge, lightning damage area, and number of broken strands of the transmission line under test under different lightning currents; determining the functional relationship between the lightning damage area S and the conductor tension based on the lightning damage area and number of broken strands of the transmission line under test under different conductor tensions; and determining the lightning damage... The functional relationship between the lightning damage area S and the conductor operating current is established. Based on the lightning damage area and the number of broken strands of the transmission line under test for different conductor diameters, the functional relationship between the lightning damage area S and the conductor diameter is determined. Based on the lightning damage area and the number of broken strands of the transmission line under test for different conductor materials, the variation law between the lightning damage area S and the conductor material is determined. The fitting coefficient of each functional relationship is determined. If the difference between the fitting coefficient of the functional relationship and the preset value is less than the preset deviation threshold, the functional relationship is determined as the target relationship. The optimal conductor parameters of the transmission line under test are determined based on the target relationship.

[0058] The processor can change the value of the lightning current to determine the functional relationship between the lightning damage area S and the amount of transferred charge corresponding to different lightning currents, based on the amount of transferred charge, the lightning damage area, and the number of broken strands of the transmission line under different lightning currents. For example, as shown in Table 1, under a lightning current of 20kA, the transferred charge of the transmission line under test is 0.327, the lightning damage area is 42.727, and the number of broken strands is 0; under a lightning current of 30kA, the transferred charge is 0.454, the lightning damage area is 54.886, and the number of broken strands is 0; under a lightning current of 40kA, the transferred charge is 0.6465, the lightning damage area is 83.6578, and the number of broken strands is 1; under a lightning current of 50kA, the transferred charge is 0.749, the lightning damage area is 89.831, and the number of broken strands is 3; under a lightning current of 60kA, the transferred charge is 0.866, the lightning damage area is 100.073, and the number of broken strands is 5. The processor can determine the functional relationship between the lightning damage area S and the transferred charge Q0 corresponding to different lightning currents based on the data in Table 1. q =f(Q0) = 110.412Q0 + 7.067.

[0059] <![CDATA[Lightning current amplitude I0 / kA]]> 20 30 40 50 60 Lightning current transfer charge Q0 / C 0.327 0.454 0.6465 0.749 0.866 <![CDATA[Lightning strike damage area S / mm 2 > 42.727 54.886 83.658 89.831 100.073 Number of broken strands / root 0 0 1 3 5

[0060] Table 1. Transferred charge, lightning damage area, and number of broken strands of the transmission line under different lightning currents.

[0061] The processor can change the conductor tension to determine the functional relationship between the lightning damage area S and the conductor tension, based on the lightning damage area and the number of broken strands of the transmission line under test under different conductor tensions. For example, as shown in Table 2, under a conductor tension of 50 MPa, the lightning damage area of ​​the transmission line under test is 42.727 and the number of broken strands is 0; under a conductor tension of 75 MPa, the lightning damage area is 68.372 and the number of broken strands is 0; under a conductor tension of 100 MPa, the lightning damage area is 80.407 and the number of broken strands is 1; under a conductor tension of 125 MPa, the lightning damage area is 94.881 and the number of broken strands is 2; and under a conductor tension of 150 MPa, the lightning damage area is 98.271 and the number of broken strands is 4. The processor can determine the functional relationship between the lightning strike damage area S and the conductor tension T based on the data in Table 2. t =f(T) = -20.178T 2 +1.512T-4.81×10 -3 .

[0062] Conductor tension T / MPa 50 75 100 125 150 <![CDATA[Lightning strike damage area S / mm 2 > 42.727 68.372 80.407 94.881 98.271 Number of broken strands / root 0 0 1 2 4

[0063] Table 2. Lightning damage area and number of broken strands of the tested transmission lines under different conductor tensions.

[0064] The processor changes the conductor operating current to determine the functional relationship between the lightning damage area S and the conductor operating current, based on the lightning damage area and the number of broken strands of the transmission line under test under different conductor operating currents. For example, as shown in Table 3, under a conductor operating current of 150A, the lightning damage area of ​​the transmission line under test is 42.727 and the number of broken strands is 0; under a conductor operating current of 200A, the lightning damage area is 70.758 and the number of broken strands is 0; under a conductor operating current of 250A, the lightning damage area is 107.527 and the number of broken strands is 0; under a conductor operating current of 300A, the lightning damage area is 135.568 and the number of broken strands is 1; and under a conductor operating current of 350A, the lightning damage area is 149.623 and the number of broken strands is 2. The processor can determine the functional relationship between the lightning damage area S and the conductor operating current I based on the data in Table 3.

[0065] Conductor operating current I / A 150 200 250 300 350 <![CDATA[Lightning strike damage area S / mm 2 > 42.727 70.758 107.527 135.568 149.623 Number of broken strands / root 0 0 0 1 2

[0066] Table 3. Lightning damage area and number of broken strands of the transmission lines under test under different conductor operating currents.

[0067] The processor can change the conductor diameter to determine the functional relationship between the lightning damage area S and the conductor diameter, based on the lightning damage area and the number of broken strands of the tested transmission line under different conductor diameters. For example, as shown in Table 4, with a conductor diameter of 2.5 mm, the lightning damage area of ​​the tested transmission line is 65.232 and the number of broken strands is 4; with a conductor diameter of 3.0 mm, the lightning damage area is 57.854 and the number of broken strands is 3; with a conductor diameter of 3.5 mm, the lightning damage area is 50.471 and the number of broken strands is 2; with a conductor diameter of 4 mm, the lightning damage area is 42.727 and the number of broken strands is 1; and with a conductor diameter of 4.5 mm, the lightning damage area is 24.158 and the number of broken strands is 0. The processor can determine the functional relationship between the lightning damage area S and the conductor diameter d based on the data in Table 4. d =f(d) = -6.498d 2 +26.031d+39.829.

[0068] Outer strand aluminum diameter d / mm 2.5 3.0 3.5 4 4.5 <![CDATA[Lightning strike damage area S / mm 2 > 65.232 57.854 50.471 42.727 24.158 Number of broken strands / root 4 3 2 1 0

[0069] Table 4. Lightning damage area and number of broken strands of the tested transmission lines under different conductor diameters.

[0070] The processor sets different conductor materials to determine the relationship between the lightning damage area S and the conductor material, based on the lightning damage area and the number of broken strands of the tested transmission line under different conductor materials. For example, as shown in Table 5, with aluminum conductor material, the lightning damage area of ​​the tested transmission line is 42.727 and the number of broken strands is 1; with aluminum alloy conductor material, the lightning damage area is 21.985 and the number of broken strands is 0; with aluminum-clad steel conductor material, the lightning damage area is 15.366 and the number of broken strands is 0. The processor can determine from the data in Table 5 that the lightning damage area of ​​conductors with aluminum-clad steel outer strand material is smaller than that of aluminum alloy conductors, and the lightning damage area of ​​conductors with aluminum alloy outer strand material is smaller than that of aluminum conductors; and when the outer strand material of the conductor is aluminum alloy or aluminum-clad steel, there is no broken strand phenomenon in the conductor.

[0071] Outer strand material aluminum aluminum alloy Aluminum-clad steel <![CDATA[Lightning strike damage area S / mm 2 > 42.727 21.985 15.366 Number of broken strands / root 1 0 0

[0072] Table 5. Lightning damage area and number of broken strands of the tested transmission lines under different conductor materials.

[0073] The processor can determine the functional relationship between the lightning strike damage area S and the transferred charge Q0 corresponding to different lightning currents. q Fit coefficient The functional relationship between the lightning strike damage area S and the conductor tension T is S t Fit coefficient The functional relationship between the lightning strike damage area S and the conductor operating current I is S i Fit coefficient And the functional relationship between the lightning strike damage area S and the conductor diameter d. d Fit coefficient Determine the fitting coefficients respectively The difference between the value and the preset value, if the difference is less than the preset deviation threshold, will be used to modify the functional relationship S. q S t S i S d The target relation is determined, and the optimal conductor parameters of the transmission line to be tested are determined based on the target relation. When the difference is greater than or equal to a preset deviation threshold, the functional relation S is adjusted accordingly. q S t S i S d Determine the adjusted functional relationship S q S t S i S d Fit coefficient Until the adjusted functional relationship S q S t S i S d Fit coefficient The difference between the value and the preset value is less than the preset deviation threshold.

[0074] In one embodiment, the test platform further includes insulators at both ends, with post insulators, conductor clamping devices, and insulators and clamps connected in sequence to fix the transmission line under test at a certain height above the ground. The output end of the power frequency current generator is connected to both ends of the transmission line under test via a cable. Fixing the transmission line under test onto the clamps of the post insulators at both ends of the test platform and setting the initial test parameters includes: adjusting the preload of the conductor clamping device and adding equal weight counterweights to both ends of the transmission line under test to achieve a preset tension; connecting the power frequency current generator and adjusting the voltage regulator to adjust the output voltage of the power frequency current generator so that the current flowing through the transmission line under test reaches a preset operating current. The preload refers to the force applied before the connection is subjected to a working load to enhance the reliability and tightness of the connection and prevent gaps or relative slippage between the connecting parts after being subjected to a load.

[0075] For example, such as Figure 3 As shown, the lightning strike strand breakage simulation test platform may include a post insulator 1, a transmission conductor under test 2, a cable 3, a power frequency current generator 4, a conductor clamping device 5, an insulator 6, a wire clamp 7, a lightning current generator 8, an impulse voltage generator 9, a pulse current sensor 10, and a discharge electrode 11. The post insulator 1, conductor clamping device 5, insulator 6, and wire clamp 7 are connected sequentially to fix the transmission conductor under test 2 at a certain height above the ground. The output terminal of the power frequency current generator 4 is connected to both ends of the transmission conductor under test 2 via the cable 3. The processor can fix the transmission conductor under test 2 onto the wire clamps 7 of the post insulators 1 at both ends of the test platform and set the initial test parameters. Specifically, the preload of the conductor clamping device 5 can be adjusted, and equal weights can be added to both ends of the transmission conductor under test 2 to achieve the preset tension. Turn on the power supply of the power frequency current generator 4, and adjust the voltage regulator built into the power frequency current generator 4 to adjust the output voltage of the power frequency current generator 4 so that the current flowing through the transmission line 2 under test reaches the preset operating current.

[0076] Figure 4 This schematically illustrates a second process diagram of a lightning strike strand breakage simulation test method for transmission line conductors according to an embodiment of this application. (See diagram below.) Figure 4 As shown in one embodiment of this application, a method for simulating lightning strike strand breakage tests on transmission line conductors is provided. The method is applied to a lightning strike strand breakage simulation test platform for transmission line conductors. The test platform includes post insulators, a lightning current generator, and an impulse voltage generator at both ends. The method includes:

[0077] Step 401: Obtain the test parameter table, which includes multiple test parameters.

[0078] Step 402: Control and adjust the initial equipment parameters of the test platform according to the initial test parameters so that the conductor tension and operating current of the transmission line to be tested are preset tension and preset operating current, the wavefront impedance and wavetail impedance of the lightning current generator and the impulse voltage generator are preset wavefront impedance and preset wavetail impedance, and the charging voltage of the lightning current generator and the impulse voltage generator is preset charging voltage.

[0079] Step 403: Control the impulse voltage generator to enter the automatic triggering mode, and set the triggering time of the lightning current generator after the triggering time of the impulse voltage generator.

[0080] Step 404: Control the test platform to start so that the impulse voltage generator generates an impulse voltage to break down the gap between the electrode and the transmission line under test. Before the impulse discharge arc is extinguished, the lightning current generator is triggered to discharge and the lightning current generated by the lightning current generator is applied to the transmission line under test.

[0081] Step 405: For each test parameter in the test parameter table, change the parameter value of the test parameter, while keeping the parameter values ​​of other test parameters unchanged, to generate a new test parameter table.

[0082] Step 406: Control and adjust the equipment parameters of the test platform according to the new test parameter table to conduct a simulation test.

[0083] Step 407: Obtain the experimental data for each test and send the experimental data to the preset analysis platform to obtain the analysis results of the experimental data.

[0084] A lightning strike strand breakage simulation test platform may include post insulators, pulse current sensors, lightning current generators, and impulse voltage generators. It may also include conductor clamping devices, pulse current sensors, and power frequency current generators. Post insulators are special insulating components used in overhead transmission lines, typically constructed by adhesive bonding or mechanical clamping of insulating parts and metal fittings, used to fix the transmission conductor under test. Conductor clamping devices can apply different conductor tensions to the transmission conductor. Pulse current sensors are detection devices that measure the waveform and amplitude of the impulse current flowing through the transmission conductor. Lightning current generators generate simulated lightning current waveforms and can be used to apply different lightning currents to the transmission conductor. Impulse voltage generators are devices used to perform impulse voltage tests on power equipment and other test objects, including full-wave lightning current impulse voltage, lightning current impulse voltage carrier voltage, and switching impulse voltage waveforms, to verify insulation performance; they can be used to generate different impulse voltages. Power frequency current generators can be used to change the operating current of the transmission conductor.

[0085] The processor can include a test parameter table containing multiple test parameters. The processor can control and adjust the initial equipment parameters of the test platform based on the initial test parameters, such that the conductor tension applied to the transmission line under test by the wire clamping device is X1, the operating current output by the power frequency current generator is X2, the wavefront impedance of the lightning current generator is X3, the wavetail impedance is X4, the charging voltage is X5, and the wavefront impedance is X6, the wavetail impedance is X7, the charging voltage is X8, and the charging voltage of the respective lightning current generator and impulse voltage generator is V1. The processor can control the impulse voltage generator to enter automatic trigger mode and set the trigger time of the lightning current generator 50μs after the trigger time of the impulse voltage generator.

[0086] The processor can activate the test platform, causing the impulse voltage generated by the impulse voltage generator to break down the gap between the electrode and the transmission line under test. Before the impulse discharge arc extinguishes, the lightning current generator is triggered to discharge, applying the lightning current generated by the lightning current generator to the transmission line under test. For example, when the test platform is activated, the 200kV 1.2 / 50μs high-voltage impulse voltage (i.e., a 200kV impulse voltage with a wavefront time of 1.2μs and a half-wave time of 50μs) generated by the impulse voltage generator breaks down the gap between the electrode and the LGJ-300 / 40 transmission line. Before the 1.2 / 50μs impulse discharge arc extinguishes, the lightning current generator can be triggered to discharge, applying the 8 / 20μs lightning current generated by the lightning current generator to the LGJ-300 / 40 transmission line. For each test parameter in the test parameter table, the processor can change the parameter value of the test parameter while keeping the parameter values ​​of other test parameters unchanged to generate a new test parameter table. The equipment parameters of the test platform are controlled and adjusted according to the new test parameter table to conduct simulation tests; test data for each test are acquired and sent to the preset analysis platform to obtain the analysis results of the test data.

[0087] In one embodiment, the processor can control the impulse voltage generator to enter automatic triggering mode and connect the signal line of the impulse voltage generator's trigger time relay to the trigger time relay of the lightning current generator. The current of the lightning current generator can be set to an 8 / 20μs lightning current, and the impulse voltage of the impulse voltage generator can be set to a 200kV 1.2 / 50μs high-voltage impulse voltage. After the lightning current generator and impulse voltage generator are set, they can be charged. The processor can set the trigger time of the lightning current generator 50μs after the trigger time of the impulse voltage generator to ensure that the lightning current is applied to the transmission line under test before the impulse voltage arc is extinguished.

[0088] In one embodiment, the test data includes the transferred charge, lightning damage area, and number of broken strands of the transmission line under test. Data is acquired for each test and sent to a pre-set analysis platform to obtain the analysis results. These results include: determining the functional relationship between the lightning damage area S and the transferred charge corresponding to different lightning currents, based on the transferred charge, lightning damage area, and number of broken strands of the transmission line under test under different lightning currents; determining the functional relationship between the lightning damage area S and the conductor tension, based on the lightning damage area and number of broken strands of the transmission line under test under different conductor tensions; and determining the functional relationship between the lightning damage area S and the conductor tension, based on the lightning damage area and number of broken strands of the transmission line under test under different conductor operating currents. The functional relationship between the lightning strike damage area S and the conductor diameter is determined based on the lightning strike damage area and the number of broken strands of the transmission line under test for different conductor diameters. The variation law between the lightning strike damage area S and the conductor material is determined based on the lightning strike damage area and the number of broken strands of the transmission line under test for different conductor materials. The fitting coefficient of each functional relationship is determined. If the difference between the fitting coefficient of the functional relationship and the preset value is less than the preset deviation threshold, the functional relationship is determined as the target relationship. The optimal conductor parameters of the transmission line under test are determined based on the target relationship. The optimal conductor parameters include the optimal conductor material, optimal conductor diameter, optimal conductor tension, and optimal conductor operating current.

[0089] For example, under a lightning current of 20kA, the transferred charge of the transmission line under test is 0.327, the lightning damage area is 42.727, and the number of broken conductor strands is 0; under a lightning current of 30kA, the transferred charge of the transmission line under test is 0.454, the lightning damage area is 54.886, and the number of broken conductor strands is 0; the processor can determine the functional relationship between the lightning damage area S and the transferred charge Q0 corresponding to different lightning currents as S q Under a conductor tension of 50 MPa, the lightning strike damage area of ​​the tested transmission line is 42.727 mm², and the number of broken strands is 0. Under a conductor tension of 75 MPa, the lightning strike damage area of ​​the tested transmission line is 68.372 mm², and the number of broken strands is 0. The processor can determine the functional relationship between the lightning strike damage area S and the conductor tension T as S = ... t Under a conductor operating current of 150A, the lightning damage area of ​​the tested transmission line is 42.727 mm², and the number of broken conductor strands is 0. Under a conductor operating current of 200A, the lightning damage area of ​​the tested transmission line is 70.758 mm², and the number of broken conductor strands is 0. The processor can determine the functional relationship between the lightning damage area S and the conductor operating current I as S = ... iWith a conductor diameter of 2.5 mm, the lightning damage area of ​​the tested transmission line is 65.232 mm², and the number of broken strands is 4. With a conductor diameter of 3.0 mm, the lightning damage area is 57.854 mm², and the number of broken strands is 3. The processor can determine the functional relationship between the lightning damage area S and the conductor diameter d as S = ... d With aluminum conductors, the lightning damage area of ​​the tested transmission line was 42.727 mm², and the number of broken strands was 1. With aluminum alloy conductors, the lightning damage area was 21.985 mm², and the number of broken strands was 0. With aluminum-clad steel conductors, the lightning damage area was 15.366 mm², and the number of broken strands was 0. The processor can determine the variation between the lightning damage area S and the conductor material.

[0090] The processor can determine the functional relation S q Fit coefficient The functional relationship is S t Fit coefficient Functional relation S i Fit coefficient and the functional relationship S d Fit coefficient Determine the fitting coefficients respectively The difference between the value and the preset value, if the difference is less than the preset deviation threshold, will be used to modify the functional relationship S. q S t S i S d The target relation is determined, and the optimal conductor parameters of the transmission line to be tested are determined based on the target relation. When the difference is greater than or equal to a preset deviation threshold, the functional relation S is adjusted accordingly. q S t S i S d Determine the adjusted functional relationship S q S t S i S d Fit coefficient Until the adjusted functional relationship S q S t S i S d Fit coefficient The difference between the value and the preset value is less than the preset deviation threshold.

[0091] In one embodiment, designing lightning protection strand breakage protection for the transmission line under test based on all test data includes: analyzing all test data to obtain the optimal conductor parameters, wherein the optimal conductor parameters include the optimal conductor material, optimal conductor diameter, optimal conductor tension, and optimal conductor operating current; and designing the transmission line under test based on the optimal conductor parameters. The processor can analyze all test data to obtain the optimal parameters of the transmission line under test. For example, the processor can start the test platform for the first time and record experimental data A1; start the test platform for the second time and record data A2; and start the test platform for the third time and record experimental data A3. The processor changes only the conductor tension of the LGJ-300 / 40 transmission line and records the corresponding test data A4; the processor changes only the conductor operating current of the LGJ-300 / 40 transmission line and records the corresponding test data A5; the processor changes only the conductor diameter of the LGJ-300 / 40 transmission line and records the corresponding test data A6; the processor changes only the conductor material of the LGJ-300 / 40 transmission line and records the corresponding test data A7; the processor changes only the lightning current of the lightning current generator and records the corresponding test data A8. The processor can analyze the LGJ-300 / 40 transmission line based on the test data A1, A2, A3, A4, A5, A6, A7, and A8 to obtain the optimal conductor parameters of the LGJ-300 / 40 transmission line, and design the transmission line to be tested based on the optimal conductor parameters.

[0092] In one embodiment, recording the test data for each test includes: acquiring conductor images of the transmission line under test after each test; importing the conductor images into a preset image processing platform; and determining the lightning damage area of ​​the transmission line under test using the preset image processing platform. The processor can acquire conductor images of the transmission line under test after each test and import the conductor images into the preset image processing platform, which can employ ACDSee image processing software. The lightning damage area of ​​the transmission line under test can be determined using the ACDSee image processing software.

[0093] In one embodiment, determining the lightning damage area of ​​the transmission line under test on a preset image processing platform includes: outlining the closed cross-sectional profile of the lightning damage to the transmission line under test using a curve on the preset image processing platform; dividing the closed cross-sectional profile into m×n square grids; calculating the number of square grids contained in the closed cross-sectional profile, then the total area of ​​the grids contained in the closed cross-sectional profile is:

[0094] S m×n =×a 2 (1)

[0095] In formula (1), N is the number of square grids contained in the closed cross-sectional profile, and a is the side length of the square grid; set m = m + 1 and n = n + 1, and repeat the above calculation of the closed cross-sectional profile grid division and the total grid area until S m×n With S (-1)×(-1) If the deviation is less than the preset deviation threshold, then S at this time... m×n The area of ​​lightning damage to the transmission line under test.

[0096] For example, the preset image processing platform can use ACDSee image processing software. In ACDSee, a curve is used to outline the closed cross-sectional profile of the lightning strike damage to the transmission line under test. The closed cross-sectional profile is divided into 4×15 square grids, with each square grid having a side length of 1. The number of square grids contained in the closed cross-sectional profile is calculated to be 38. Therefore, the total area of ​​the grids contained in the closed cross-sectional profile is: S 4×15 =38 × 1 = 38. Then set m = 5 and n = 16, and we get S. 5×16 =41.75. Calculate S. 4×15 With S 5×16 deviation (S) 5×16 -S 4×15 ) / S 4×15 =0.098, deviation 0.098 ≥ preset deviation value 0.01. Then set m=6, n=17, and obtain S. 6×17 =42.15. Calculate S. 5×16 With S 6×17 deviation (S) 6×17 –S 5×16 ) / S 6×17 =0.0094. Deviation 0.0094 ≤ preset deviation value 0.01. (The last part, "S", appears to be an error and doesn't translate directly.) 6×17 =42.15 is the area of ​​lightning damage to the transmission line under test.

[0097] In one embodiment, the test platform further includes insulators at both ends, with post insulators, conductor clamping devices, and insulators and clamps connected in sequence to fix the transmission line under test at a certain height above the ground. The output end of the power frequency current generator is connected to both ends of the transmission line under test via a cable. Fixing the transmission line under test onto the clamps of the post insulators at both ends of the test platform and setting the initial test parameters includes: adjusting the preload of the conductor clamping device and adding equal weight counterweights to both ends of the transmission line under test to achieve a preset tension; connecting the power frequency current generator and adjusting the voltage regulator to adjust the output voltage of the power frequency current generator so that the current flowing through the transmission line under test reaches a preset operating current. The preload refers to the force applied before the connection is subjected to a working load to enhance the reliability and tightness of the connection and prevent gaps or relative slippage between the connecting parts after being subjected to a load.

[0098] In one embodiment, such as Figure 5 As shown, a simulated lightning strike strand breakage test platform for transmission line conductors was constructed in the high-voltage test hall. The transmission conductor to be tested was fixed on the test platform, and the conductor tension, operating current, and wavefront and tail impedances of the lightning current generator and impulse voltage generator were set. A set lightning current I0 was applied to the transmission conductor, and the transferred charge Q and the number of broken strands (i.e., the first test data) corresponding to the lightning current I0 were recorded. The lightning strike damage area S of the transmission conductor was calculated using image recognition (i.e., a preset image processing platform). i Determine whether the number of tests N reaches the preset value. If N reaches the preset value, determine the area of ​​damage to the transmission line caused by lightning strikes due to the lightning current I0 as the area of ​​damage S caused by N lightning strikes. iThe average value is calculated. If N does not reach the preset value, the step of applying the set lightning current I0 to the transmission line is repeated until N reaches the preset value. Given all the lightning current, conductor tension, conductor operating current, aluminum strand diameter, and material conditions, the lightning damage area S of the transmission line is obtained through curve fitting, relating it to the lightning current transfer charge Q, conductor tension T, conductor operating current I, and aluminum strand diameter d, respectively denoted as S = f(Q0), S = f(T), S = f(I), and S = f(d). Based on the lightning damage area and the number of broken strands of the transmission line conductor, the diameter, material, conductor tension, and other parameters of the lightning-resistant broken strand transmission line are designed. Without obtaining all the lightning current, conductor tension, conductor operating current, aluminum strand diameter, and material-specific lightning damage area of ​​the conductor under test, the values ​​of lightning current, conductor tension, operating current, and aluminum strand diameter of the conductor under test are changed respectively. The process is then repeated by fixing the transmission conductor under test on the test platform and setting the conductor tension, operating current, and wavefront and wavetail impedances of the lightning current generator and impulse voltage generator until all the lightning current, conductor tension, conductor operating current, aluminum strand diameter, and material-specific lightning damage area of ​​the conductor are obtained.

[0099] The above technical solution involves fixing the transmission conductor under test to the clamps of the post insulators at both ends of the test platform, setting the initial test parameters, and starting the test platform. This causes the impulse voltage generator to generate an impulse voltage that breaks down the gap between the electrodes and the transmission conductor under test. Before the impulse discharge arc extinguishes, the lightning current generator is triggered to discharge, and the lightning current generated by the lightning current generator is applied to the transmission conductor under test. This process of starting the test platform is repeated, and the test data is recorded each time. The process is repeated by changing one of the following parameters: conductor tension, conductor operating current, conductor diameter, conductor material, and the lightning current generated by the lightning current generator. Based on all the test data, a lightning strike-resistant strand breakage design is performed on the transmission conductor under test. This technical solution effectively analyzes the comprehensive effects of lightning strikes on transmission conductors and provides customized designs for lightning strike-resistant strand breakage transmission conductors, improving the safety of transmission line operation and the reliability of power supply.

[0100] Figure 1 , 4 Figure 5 is a flowchart illustrating a lightning strike strand breakage simulation test method for transmission line conductors in one embodiment. It should be understood that, although... Figure 1 , 4The steps in flowchart 5 are shown sequentially as indicated by the arrows; however, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise explicitly stated herein, there is no strict order in which these steps are performed, and they can be executed in other orders. Furthermore, Figure 1 , 4 At least some of the steps in 5 may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0101] This application provides a processor for running a program, wherein the program executes the above-described method for simulating lightning strike strand breakage tests on power transmission line conductors.

[0102] This application provides a lightning strike strand breakage simulation test device for power transmission line conductors, including the aforementioned processor.

[0103] This application provides a machine-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform the above-described method for simulating lightning strike strand breakage tests on power transmission line conductors.

[0104] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, systems, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0105] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure and not to limit its protection scope. Although this disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this disclosure, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims.

[0109] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0110] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for simulating a lightning strand breakage test of a power transmission line conductor, characterized by, The application relates to a lightning stroke strand breakage simulation test platform applied to a power transmission line conductor, both ends of the test platform comprising a post insulator, a lightning current generator and an impulse voltage generator, and the method comprises the following steps: In step 101, the power transmission conductor to be tested is fixed on the wire clamp of the post insulator at both ends of the test platform, and initial test parameters are set, wherein the initial test parameters refer to that the conductor tension and the conductor operating current of the power transmission conductor to be tested are preset tension and preset operating current, and the wave head and wave tail impedance of the lightning current generator, the charging voltage are preset wave head impedance and preset wave tail impedance, preset charging voltage, and the wave head and wave tail impedance of the impulse voltage generator, the charging voltage are preset wave head impedance and preset wave tail impedance, preset charging voltage; In step 102, the test platform is started to make the impulse voltage generator generate impulse voltage to break down the gap between the electrode and the power transmission conductor to be tested, and the lightning current generator is triggered to discharge before the impulse discharge arc is extinguished, so that the lightning current generated by the lightning current generator is applied to the power transmission conductor to be tested; In step 103, step 102 is repeatedly executed for multiple times, and test data of each time are recorded, wherein the test data include the transferred charge corresponding to the lightning current generated by the lightning current generator, the lightning stroke damage area of the power transmission conductor to be tested and the number of conductor strand breaks; In step 104, one of the conductor tension, the conductor operating current, the conductor diameter, the conductor material and the lightning current of the power transmission conductor to be tested is changed, and step 102 is repeatedly executed for multiple times again, and test data of each time are recorded; In step 105, lightning stroke strand breakage design of the power transmission conductor to be tested is carried out according to all the test data.

2. The method of claim 1, wherein, The lightning stroke strand breakage design of the power transmission conductor to be tested according to all the test data comprises the following steps: The power transmission conductor to be tested is analyzed according to all the test data to obtain optimal conductor parameters of the power transmission conductor to be tested, wherein the optimal conductor parameters include optimal conductor material, optimal conductor diameter, optimal conductor tension and optimal conductor operating current of the power transmission conductor to be tested; The power transmission conductor to be tested is designed according to the optimal conductor parameters.

3. The method of claim 2, wherein, The analysis of the power transmission conductor to be tested according to all the test data to obtain optimal conductor parameters of the power transmission conductor to be tested comprises the following steps: A function relationship formula between the lightning stroke damage area S and the transferred charge corresponding to different lightning currents is determined according to the transferred charge, the lightning stroke damage area and the number of conductor strand breaks of the power transmission conductor to be tested under different lightning currents; A function relationship formula between the lightning stroke damage area S and the conductor tension is determined according to the lightning stroke damage area and the number of conductor strand breaks of the power transmission conductor to be tested under different conductor tensions; A function relationship formula between the lightning stroke damage area S and the conductor operating current is determined according to the lightning stroke damage area and the number of conductor strand breaks of the power transmission conductor to be tested under different conductor operating currents; determining a function relationship between the lightning damage area S and the conductor diameter according to the lightning damage area and the number of broken strands of the conductor to be tested under different conductor diameters; determining a variation law between the lightning damage area S and the conductor material according to the lightning damage area and the number of broken strands of the conductor to be tested under different conductor materials; determining a fitting coefficient of each function relationship; determining the function relationship as a target relationship in a case that a difference between the fitting coefficient of the function relationship and a preset value is less than a preset deviation threshold; determining an optimal conductor parameter of the conductor to be tested according to the target relationship.

4. The method of claim 1, wherein, The test platform further comprises insulators at two ends thereof, the post insulators, the conductor clamping device, the insulators and the wire clamps are sequentially connected, and are used for fixing the conductor to be tested at a certain height from the ground, and an output end of the power frequency current generator is connected to two ends of the conductor to be tested through a cable; The conductor to be tested is fixed on the wire clamp of the post insulator at two ends of the test platform, and initial test parameters are set, which comprises: adjusting the pre-tightening force of the conductor clamping device, and adding equal weights of counterweights at two ends of the conductor to be tested to make the conductor tension of the conductor to be tested reach the preset tension; turning on the power supply of the power frequency current generator, adjusting the voltage regulator of the power frequency current generator to adjust the output voltage of the power frequency current generator, so that the current flowing through the conductor to be tested reaches the preset operating current.

5. The method of claim 1, wherein, The method further comprises: setting the mode of the impulse voltage generator as an automatic triggering mode before starting the test platform, and connecting the signal line of the triggering time relay of the impulse voltage generator to the triggering time relay of the lightning current generator; after setting the lightning current generator and the impulse voltage generator as the preset lightning current and the preset impulse voltage respectively, charging the capacitors of the lightning current generator and the impulse voltage generator; setting the triggering time of the lightning current generator after the triggering time of the impulse voltage generator to ensure that the lightning current is loaded on the conductor to be tested before the impulse voltage arc is extinguished.

6. The method of claim 1, wherein, Recording test data each time comprises: collecting the conductor image of the conductor to be tested after each test; importing the conductor image into a preset image processing platform; determining the lightning damage area of the conductor to be tested through the preset image processing platform.

7. The method of claim 6, wherein, The determination of the lightning damage area of the conductor to be tested through the preset image processing platform comprises: using a curve to outline the closed cross-sectional profile of the lightning damage of the conductor to be tested in the preset image processing platform; dividing the closed cross-sectional profile by using mxn square grids; calculating the number of square grids contained in the closed cross-sectional profile, and the total area of the grids contained in the closed cross-sectional profile is: （1） In formula (1), is the number of square grids contained by the closed cross-sectional profile, is the side length of the square grid, is the total area of the grid, is the number of square grids of the wide side of the closed cross-sectional profile, is the number of square grids of the long side of the closed cross-sectional profile; Set m=m+1 and n=n+1, and repeat the above calculation of closed section contour meshing and total mesh area until... and If the deviation is less than the preset deviation threshold, then at this time... The lightning strike damage area of ​​the transmission line under test is defined as follows: To set the total area of ​​the grid after m=m+1 and n=n+1, This is the total area of ​​the grid before setting m=m+1 and n=n+1.

8. A method for simulating lightning strand breakage of a power line conductor, characterized by, The lightning broken strand simulation test platform applied to the conductor of a power transmission line, two ends of the test platform comprise post insulators, a lightning current generator and an impulse voltage generator, and the method comprises: obtain a test parameter table, wherein the test parameter table comprises a plurality of test parameters; control and adjust initial device parameters of the test platform according to the test parameters, so that conductor tension and operating current of the to-be-tested power transmission conductor are preset tension and preset operating current respectively, wave head impedance and wave tail impedance of the lightning current generator are preset wave head impedance and preset wave tail impedance respectively, wave head impedance and wave tail impedance of the impulse voltage generator are preset wave head impedance and preset wave tail impedance respectively, and charging voltage of the lightning current generator and the impulse voltage generator is preset charging voltage; control the impulse voltage generator to enter an automatic triggering mode, and set a triggering time of the lightning current generator to be after a triggering time of the impulse voltage generator; control the test platform to start, so that the impulse voltage generator generates impulse voltage to break down a gap between an electrode and the to-be-tested power transmission conductor, and the lightning current generator is triggered to discharge before an impulse discharge arc is extinguished, and lightning current generated by the lightning current generator is applied to the to-be-tested power transmission conductor; for each test parameter in the test parameter table, change a parameter value of the test parameter, and keep parameter values of other test parameters unchanged, to generate a new test parameter table; control and adjust device parameters of the test platform according to the new test parameter table, to perform a simulation test; obtain test data each time, and send the test data to a preset analysis platform to obtain an analysis result of the test data.

9. The method of claim 8, wherein, The test data comprises transferred charge quantity, lightning damage area and conductor broken strand number of the to-be-tested power transmission conductor, and the obtaining of the test data each time and the sending of the test data to the preset analysis platform to obtain the analysis result of the test data comprises: determining a functional relationship between the lightning damage area S and the transferred charge quantity corresponding to different lightning currents according to the transferred charge quantity, the lightning damage area and the conductor broken strand number of the to-be-tested power transmission conductor under different lightning currents; determining a functional relationship between the lightning damage area S and the conductor tension according to the lightning damage area and the conductor broken strand number of the to-be-tested power transmission conductor under different conductor tensions; determining a functional relationship between the lightning damage area S and the conductor operating current according to the lightning damage area and the conductor broken strand number of the to-be-tested power transmission conductor under different conductor operating currents; determining a functional relationship between the lightning damage area S and the conductor diameter according to the lightning damage area and the conductor broken strand number of the to-be-tested power transmission conductor under different conductor diameters; determining a variation law between the lightning damage area S and the conductor material according to the lightning damage area and the conductor broken strand number of the to-be-tested power transmission conductor under different conductor materials; determining a fitting coefficient of each functional relationship; determining a target relationship as the functional relationship in a case where a difference between the fitting coefficient of the functional relationship and a preset value is less than a preset deviation threshold; determining an optimal conductor parameter of the to-be-tested power transmission conductor according to the target relationship. The optimal conductor parameters include optimal conductor material, optimal conductor diameter, optimal conductor tension, and optimal conductor operating current of the power transmission conductor to be tested.

10. A processor, comprising: configured to perform the lightning-induced strand breakage simulation test method for a power transmission line conductor according to any one of claims 8 or 9. configured to perform the lightning-induced strand breakage simulation test method for a power transmission line conductor according to any one of claims 8 or 9.

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