Lightning current environment simulation arrester testing device, method, medium, and apparatus

Abstract

This invention provides a surge arrester testing apparatus, method, medium, and equipment for simulating lightning current environments. The apparatus includes: a transmission line, an artificial lightning triggering device, a surge arrester, multiple towers, a first impedance matching terminal, and a second impedance matching terminal. The transmission line is installed on the upper ends of the multiple towers. The first and second impedance matching terminals are connected to the two ends of the transmission line, respectively. The artificial lightning triggering device is connected to the transmission line. The surge arrester is connected between one of the towers and the transmission line. The method provided by this invention calculates and configures the impedance matching terminal and grounding system based on the transmission line parameters, enabling the lightning current acquired by the artificial lightning triggering device to propagate on the transmission line in the form of a traveling wave without reflection. This ensures that the voltage and current waveforms experienced by the surge arrester are consistent with the actual waveforms of the traveling lightning current reaching the surge arrester on the actual line, thereby achieving lightning strike action characteristic testing of the surge arrester under near-real operating conditions.

Description

Technical Field

[0001] This invention belongs to the field of lightning protection technology for power transmission lines, specifically relating to a lightning arrester test device, method, medium, and equipment that simulates a lightning current environment. Background Technology

[0002] Surge arresters are key devices for protecting transmission lines from lightning overvoltages. Their operating characteristics, volt-ampere characteristics, energy absorption capacity, and other performance parameters directly affect the safe and stable operation of the power system. Currently, these performance parameters of surge arresters are typically tested in high-voltage laboratories using standard impulse waveforms. For example, a 1.2 / 50μs standard lightning voltage wave is used for discharge voltage testing, and a 4 / 10μs high-current impulse wave is used for current-carrying capacity testing.

[0003] However, the test conditions for surge arresters in existing technologies differ from actual operating conditions. In the laboratory, surge arresters are usually directly connected to the output terminal of the impulse generator or installed on an extremely short lead. The waveform they withstand is determined by the generator's internal resistance and circuit parameters, which is completely different from the traveling wave propagation process in actual circuits. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, in a first aspect, this invention application proposes a surge arrester test device for simulating lightning current environment, comprising: a transmission line, an artificial lightning triggering device, a surge arrester, multiple towers, a first impedance matching terminal and a second impedance matching terminal; The power transmission line is installed on the upper part of the plurality of towers; The first impedance matching terminal and the second impedance matching terminal are respectively connected to both ends of the transmission line; The power transmission line is connected to the artificial lightning triggering device; The surge arrester is connected between one of the towers and the transmission line.

[0005] Preferably, the first impedance matching terminal includes: a plurality of first non-inductive resistors; the plurality of first non-inductive resistors are connected in parallel; The second impedance matching terminal includes: a plurality of second non-inductive resistors; the plurality of second non-inductive resistors are connected in parallel; The energy absorption capacity of the first impedance matching terminal and the second impedance matching terminal is not less than the sum of the initial stage lightning current energy obtained by the artificial lightning triggering device and the lightning current energy flowing into the first impedance matching terminal and the second impedance matching terminal during the operation of the surge arrester.

[0006] Preferably, the surge arrester testing device further includes: a plurality of insulators, the same number as the plurality of towers; Each of the towers is connected to the transmission line by one of the insulators.

[0007] Preferably, the surge arrester testing device further includes: a grounding system; the grounding system includes: an interconnected grounding grid and grounding leads; the grounding leads are connected to the first impedance matching terminal and the second impedance matching terminal; The power frequency grounding resistance of the grounding grid during operation and the lead inductance of the grounding lead during operation shall satisfy the following conditions: | R g +jω L g |<0.02× Z c in, R g The power frequency grounding resistance when the grounding grid is in operation. L g The inductance of the grounding lead during operation, ω is the upper limit angular frequency of the frequency threshold. Z c Let j be the line surge impedance of the transmission line, where j is the imaginary unit.

[0008] Preferably, the resistance values ​​of the first impedance matching terminal and the second impedance matching terminal are the same; The resistance value of the first impedance matching terminal or the second impedance matching terminal is equal to the line wave impedance of the transmission line.

[0009] Preferably, the line surge impedance of the transmission line satisfies the following formula:

[0010] In the above formula, The line surge impedance of the transmission line. m 0 represents the magnetic permeability of air. e 0 is the dielectric constant of air. h The height of the transmission line above the ground. r The radius of the transmission line.

[0011] Preferably, after the surge arrester is activated by lightning, 70-80% of the received lightning current flows to the ground through itself, and 20-30% of the lightning current flows to the ground through the first impedance matching terminal and the second impedance matching terminal.

[0012] Secondly, this invention application also proposes a surge arrester testing method simulating a lightning current environment, comprising: Frequency domain tests were conducted on the first and second impedance matching terminals of the surge arrester test device to induce reflection and refraction of the lightning current waveform. If the frequency domain test results show that the first impedance matching terminal and the second impedance matching terminal will not cause reflection of the lightning current waveform, then a pulse signal with a preset pulse threshold is injected into one end of the transmission line of the surge arrester test device, and the voltage signal on the transmission line is collected; based on the voltage signal, it is determined whether the transmission line will cause reflection of the transmitted signal. If the determination result is that the transmission line will not reflect the transmitted signal, then the artificial lightning triggering device of the surge arrester test device is activated to collect the voltage and current waveforms at each measuring point in the transmission line. The voltage and current waveforms at each measurement point are analyzed; based on the analysis results, the operating characteristics of the surge arrester are evaluated.

[0013] Preferably, the frequency domain test that induces reflection and refraction of the lightning current waveform is performed on the first and second impedance matching terminals of the surge arrester test device, including: After the artificial lightning triggering device is activated, the lightning current turning frequency is calculated using a double exponential model based on the lightning current parameters obtained by the device. The lightning current energy concentration frequency range is then determined based on the lightning current parameters and the turning frequency. If the frequency range of the lightning current energy concentration is within a preset frequency range threshold, then based on the measured resistance of the first impedance matching terminal and the second impedance matching terminal, the terminal mixed impedance formed by the parasitic inductance and stray capacitance to ground generated by the first impedance matching terminal and the second impedance matching terminal is calculated according to the pre-constructed terminal impedance model. Based on the aforementioned terminal mixed impedance, the traveling wave reflection value is calculated using the traveling wave reflection coefficient calculation model; When the traveling wave reflection value is less than a preset coefficient threshold, it is determined that the first impedance matching terminal and the second impedance matching terminal will not cause the reflection of the lightning current waveform. The terminating impedance model is expressed as follows: Z L (ω) =( R main + jω L s ) / / (1 / jω C p )=( R main + jω L s ) / (1-ω 2 L s C p +jω R mainC p ) In the above formula, Z L (ω) represents the terminal mixed impedance. R main The measured resistances of the first and second impedance matching terminals are given. L s The parasitic inductance generated by the first and second impedance matching terminals under the action of lightning current. C p ω represents the stray capacitance to ground generated by the first and second impedance matching terminals under the action of lightning current, ω is the upper limit angular frequency of the frequency threshold, and j is the imaginary unit. The traveling wave reflection coefficient calculation model satisfies the following formula: r =( R Z L (ω)) / ( R + Z L (ω)) In the above formula, r This is the value of the traveling wave reflection. R Let be the theoretical terminating impedances of the first and second impedance matching terminals. Z L (ω) represents the terminal mixed impedance.

[0014] Preferably, after the artificial lightning triggering device is activated, the lightning current transition frequency is calculated using a double exponential lightning current model based on the lightning current parameters obtained by the artificial lightning triggering device, including: After the artificial lightning triggering device is activated, the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning are determined based on the lightning current parameters obtained by the artificial lightning triggering device. The lightning current waveform is constructed based on the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning. Based on the described lightning current waveform, determine the maximum lightning current value and the current peak correction factor; The lightning current turning frequency is calculated using a double exponential model for the maximum lightning current and the peak current correction coefficient. The lightning current double-exponential model satisfies the following formula: , ,

[0015] In the above formula, I0 represents the maximum value of the lightning current. or This is the peak current correction factor. t 1 represents the rise time of the lightning current in the lightning current parameters. t 2 represents the delay time of the lightning current in the lightning current parameters. α The first intermediate quantity ，α =1 / t 2, β As the second intermediate quantity, β =3 / t 1, where t is the time of lightning current occurrence. It is the natural logarithm; This is the first bend frequency of the lightning current. This is the second bend frequency of the lightning current. Pi is the mathematical constant of a circle.

[0016] Preferably, the voltage and current waveforms at each measurement point include at least: the voltage and current waveforms at the beginning of the transmission line, the voltage and current waveforms at the surge arrester connection point of the transmission line, and the voltage and current waveforms at the end of the transmission line. The voltage and current waveforms at each measurement point are analyzed; based on the analysis results, the operating characteristics of the surge arrester are evaluated, including: Based on the voltage and current waveforms at the connection points of the surge arresters of the transmission line, it is determined whether the surge arrester has operated. If the voltage and current waveforms show a conduction pulse and are clamped at the residual voltage level, it is determined that the surge arrester has operated. Based on the voltage and current waveforms at the beginning and end of the transmission line, the theoretical terminal impedances of the first and second impedance matching terminals are determined; based on the theoretical terminal impedances and the traveling wave reflection coefficient calculation model, the traveling wave reflection value is determined; if the traveling wave reflection value is less than a preset threshold, the matching of the first and second impedance matching terminals is deemed valid.

[0017] Secondly, this invention application also proposes a surge arrester test system simulating a lightning current environment, comprising: The matching terminal determination module is used to perform frequency domain tests on the first and second impedance matching terminals of the surge arrester test device to induce reflection and refraction of the lightning current waveform. The transmission line determination module is used to inject a pulse signal with a preset pulse threshold into one end of the transmission line of the surge arrester test device if the result of the frequency domain test is that the first impedance matching terminal and the second impedance matching terminal will not cause reflection of the lightning current waveform, and to collect the voltage signal on the transmission line; based on the voltage signal, it determines whether the transmission line will cause reflection of the transmitted signal. The acquisition module is used to start the artificial lightning triggering device of the surge arrester test device and acquire the voltage and current waveforms at each measurement point in the transmission line if the determination result is that the transmission line will not reflect the transmitted signal. The evaluation module is used to analyze the voltage and current waveforms at each measurement point; and to evaluate the operation characteristics of the surge arrester based on the analysis results.

[0018] Preferably, the matching terminal determination module includes: The frequency range determination submodule is used to calculate the lightning current turning frequency based on the lightning current parameters obtained by the artificial lightning triggering device after its activation, using a lightning current double exponential model; and to determine the frequency range of lightning current energy concentration based on the lightning current parameters and the lightning current turning frequency. The terminal mixed impedance calculation submodule is used to calculate the terminal mixed impedance formed by the parasitic inductance and stray capacitance to ground generated by the first impedance matching terminal and the second impedance matching terminal, based on the measured resistance of the first impedance matching terminal and the second impedance matching terminal and according to the pre-built terminal impedance model, if the frequency range of the lightning current energy concentration is within a preset frequency range threshold. The traveling wave reflection value calculation submodule is used to calculate the traveling wave reflection value based on the terminal mixed impedance and using the traveling wave reflection coefficient calculation model. The matching terminal reflection determination submodule is used to determine that the first impedance matching terminal and the second impedance matching terminal will not cause reflection of the lightning current waveform when the traveling wave reflection value is less than a preset coefficient threshold. The terminating impedance model is expressed as follows: Z L (ω) =( R main + jω L s ) / / (1 / jω C p )=( R main + jω L s ) / (1-ω 2 L s C p +jω R main C p ) In the above formula, Z L (ω) represents the terminal mixed impedance. R mainThe measured resistances of the first and second impedance matching terminals are given. L s The parasitic inductance generated by the first and second impedance matching terminals under the action of lightning current. C p ω represents the stray capacitance to ground generated by the first and second impedance matching terminals under the action of lightning current, ω is the upper limit angular frequency of the frequency threshold, and j is the imaginary unit. The traveling wave reflection coefficient calculation model satisfies the following formula: r =( R Z L (ω)) / ( R + Z L (ω)) In the above formula, r This is the value of the traveling wave reflection. R Let be the theoretical terminating impedances of the first and second impedance matching terminals. Z L (ω) represents the terminal mixed impedance.

[0019] Preferably, the frequency range determination submodule is specifically used for: After the artificial lightning triggering device is activated, the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning are determined based on the lightning current parameters obtained by the artificial lightning triggering device. The lightning current waveform is constructed based on the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning. Based on the described lightning current waveform, determine the maximum lightning current value and the current peak correction factor; The lightning current turning frequency is calculated using a double exponential model for the maximum lightning current and the peak current correction coefficient. The lightning current double-exponential model satisfies the following formula: , ,

[0020] In the above formula, I 0 represents the maximum value of the lightning current. or This is the peak current correction factor. t 1 represents the rise time of the lightning current in the lightning current parameters. t 2 represents the delay time of the lightning current in the lightning current parameters. α The first intermediate quantity ，α =1 / t 2,β As the second intermediate quantity, β =3 / t 1, where t is the time of lightning current occurrence. It is the natural logarithm; This is the first bend frequency of the lightning current. This is the second bend frequency of the lightning current. Pi is the mathematical constant of a circle.

[0021] Preferably, the voltage and current waveforms at each measurement point include at least: the voltage and current waveforms at the beginning of the transmission line, the voltage and current waveforms at the surge arrester connection point of the transmission line, and the voltage and current waveforms at the end of the transmission line. The evaluation module is specifically used for: Based on the voltage and current waveforms at the connection points of the surge arresters of the transmission line, it is determined whether the surge arrester has operated. If the voltage and current waveforms show a conduction pulse and are clamped at the residual voltage level, it is determined that the surge arrester has operated. Based on the voltage and current waveforms at the beginning and end of the transmission line, the theoretical terminal impedances of the first and second impedance matching terminals are determined; based on the theoretical terminal impedances and the traveling wave reflection coefficient calculation model, the traveling wave reflection value is determined; if the traveling wave reflection value is less than a preset threshold, the matching of the first and second impedance matching terminals is deemed valid.

[0022] Thirdly, this application also proposes an electronic device, comprising: at least one processor and a memory; wherein the memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the lightning arrester test method simulating a lightning current environment is implemented.

[0023] Fourthly, this application also proposes a readable storage medium having an executable program stored thereon, which, when executed, implements the aforementioned method for testing a surge arrester under a simulated lightning current environment.

[0024] Compared with the closest prior art, the present invention has the following beneficial effects: The present invention provides a surge arrester test device and test method for simulating lightning current environment, comprising: a transmission line, an artificial lightning triggering device, a surge arrester, multiple towers, a first impedance matching terminal, and a second impedance matching terminal; the transmission line is installed on the upper end of the multiple towers; the first impedance matching terminal and the second impedance matching terminal are respectively connected to both ends of the transmission line; the artificial lightning triggering device is connected to the transmission line; and the surge arrester is connected between one of the towers and the transmission line. The method provided by the present invention, by calculating and configuring the impedance matching terminal and grounding system based on the transmission line parameters, enables the lightning current acquired by the artificial lightning triggering device to propagate on the test line in the form of a traveling wave without reflection. This method overcomes the waveform distortion problem caused by directly connecting the surge arrester to the impulse generator in the traditional laboratory, making the voltage and current waveforms borne by the surge arrester highly consistent with the actual waveforms when the traveling wave of lightning current reaches the surge arrester on the actual line, thereby realizing the operation characteristic test of the surge arrester under near-real operating conditions. Attached Figure Description

[0025] Figure 1 A structural diagram of a surge arrester test device simulating a lightning current environment provided in this invention application; Figure 2 A flowchart of a surge arrester test method simulating a lightning current environment provided in this invention application; Figure 3 This is a comparison diagram of the applied lightning current waveform and the waveform propagating to the first impedance matching terminal and the second impedance matching terminal in Embodiment 2 of the present invention; Figure 4 A schematic diagram of a surge arrester test system simulating a lightning current environment provided in this invention application; Figure 5 This is a schematic diagram of the operation of an electronic device provided in this invention application.

[0026] In the diagram, 1 represents a transmission line, 2 represents an artificial lightning arrester, 3 represents a surge arrester, 4 represents a tower, 5 represents the first impedance matching terminal, 6 represents the second impedance matching terminal, 7 represents an insulator, and 8 represents a current-carrying rod. Detailed Implementation

[0027] The specific embodiments of this invention will be further described in detail below with reference to the accompanying drawings.

[0028] Example 1: like Figure 1 As shown, this invention application proposes a surge arrester test device simulating a lightning current environment, comprising: a transmission line 1, an artificial lightning triggering device 2, a surge arrester 3, and multiple towers 4 (example shown). Figure 1Tower No. 1, Tower No. 2, Tower No. 3, Tower No. 4), first impedance matching terminal 5, and second impedance matching terminal 6; The power transmission line 1 is installed on the upper end of the plurality of towers 4; The first impedance matching terminal 5 and the second impedance matching terminal 6 are respectively connected to both ends of the transmission line 1; The power transmission line 1 is connected to the artificial lightning triggering device 2; One of the towers 4 is connected to the surge arrester 3 between the transmission line 1 and the tower 4.

[0029] Furthermore, the artificial lightning triggering device 2 may include a rocket 21 and a thin steel wire 22. The rocket 21 is connected to one end of the thin steel wire 22, and the other end of the thin steel wire 22 is connected to the power transmission line 1 through a diversion rod 8. The diversion rod 8 can be connected to a preset test point on the power transmission line 1. The power transmission line 1 is a line of finite length, with a length of L. The artificial lightning triggering device 2 is used to inject real lightning impulse current into the transmission line 1; Furthermore, the first impedance matching terminal 5 includes: a plurality of first non-inductive resistors; the plurality of first non-inductive resistors are connected in parallel; The second impedance matching terminal 6 includes: a plurality of second non-inductive resistors; the plurality of second non-inductive resistors are connected in parallel; The energy absorption capacity of the first impedance matching terminal 5 and the second impedance matching terminal 6 is not less than the sum of the initial return stroke energy of the artificial lightning triggering device 2 and the lightning current energy flowing into the first impedance matching terminal 5 and the second impedance matching terminal 6 during the operation of the surge arrester 3.

[0030] As described above, the first impedance matching terminal 5 adopts a parallel connection of multiple first non-inductive resistors to improve the energy absorption capability of the first impedance matching terminal 5; the second impedance matching terminal 6 adopts a parallel connection of multiple second non-inductive resistors to improve the energy absorption capability of the second impedance matching terminal 6; both the first and second non-inductive resistors can be selected as metal film non-inductive resistors or chip resistor arrays, etc.

[0031] Furthermore, the surge arrester testing device also includes: a plurality of insulators 7, the same number as the plurality of towers 4; Each of the towers 4 is connected to an insulator 7 between it and the transmission line 1.

[0032] Furthermore, the surge arrester testing device further includes: a grounding system; the grounding system includes: an interconnected grounding grid and grounding leads; the grounding leads are connected to the first impedance matching terminal 5 and the second impedance matching terminal 6; The power frequency grounding resistance of the grounding grid during operation and the lead inductance of the grounding lead during operation shall satisfy the following conditions: | R g +jω L g |<0.02× Z c in, R g The power frequency grounding resistance when the grounding grid is in operation. L g The inductance of the grounding lead during operation, ω is the upper limit angular frequency of the frequency threshold. Z c Let j be the line surge impedance of the transmission line, where j is the imaginary unit.

[0033] Furthermore, the first impedance matching terminal 5 and the second impedance matching terminal 6 have the same resistance value, so they have the same impedance characteristics. The resistance values ​​of the first impedance matching terminal 5 and the second impedance matching terminal 6 are equal to or close to the line wave impedance of the transmission line. Within the target frequency band, the equivalent impedance of the first impedance matching terminal 5 and the second impedance matching terminal 6 matches the line wave impedance of the transmission line 1. This is used to absorb the traveling wave energy when lightning current propagates from any position in the transmission line 1 to both ends and reaches the endpoints of the transmission line 1, eliminating reflection. Thus, electrically, the transmission line 1 of length L is equivalent to a line extending infinitely to both ends.

[0034] Furthermore, the line surge impedance of the transmission line satisfies the following formula:

[0035] In the above formula, The line surge impedance of the transmission line. m 0 represents the magnetic permeability of air. e 0 is the dielectric constant of air. h The height of the transmission line above the ground. r The radius of the transmission line.

[0036] Furthermore, after the surge arrester 3 is activated by lightning, 70-80% of the received lightning current flows to the ground through itself, and 20-30% of the lightning current flows to the ground through the first impedance matching terminal 5 and the second impedance matching terminal 6.

[0037] Example 2: like Figure 2 As shown, this invention application proposes a test method for surge arresters that simulates lightning current environments, comprising: Step 1: Conduct a frequency domain test on the first impedance matching terminal 5 and the second impedance matching terminal 6 of the surge arrester test device to cause reflection of the lightning current waveform, in order to determine that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause reflection of the lightning current waveform. Step 2: If the result of the frequency domain test is that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause reflection of the lightning current waveform, then inject a pulse signal with a preset pulse threshold to one end of the transmission line 1 of the surge arrester test device, and collect the voltage signal on the transmission line 1; based on the voltage signal, determine whether the transmission line 1 will cause reflection of the transmitted signal. Step 3: If the result of the determination is that the transmission line 1 will not reflect the transmitted signal, then the artificial lightning trigger device 2 of the surge arrester test device is activated to collect the voltage and current waveforms at each measurement point in the transmission line 1. Step 4: Analyze the voltage and current waveforms at each measurement point; evaluate the operating characteristics of surge arrester 3 based on the analysis results; The surge arrester test device is the surge arrester test device described in Example 1.

[0038] Steps 1-4 above constitute a complete closed loop from the parameters of the surge arrester test device to the operating characteristics of surge arrester 3, ensuring the systematic nature of the test method.

[0039] Further, prior to step 1, based on the parameters of the artificial lightning trigger device and the transmission line parameters of the surge arrester test device, and in conjunction with the requirements of the surge arrester test device in Example 1, the first impedance matching terminal 5, the second impedance matching terminal 6, and the grounding system of the surge arrester test device are configured, including: Step 0.1: Determine the line surge impedance of transmission line 1 based on the length of transmission line 1 and the line surge impedance calculation formula of transmission line 1 in the transmission line parameters; Step 0.2: Determine the resistance values ​​of the first impedance matching terminal 5 and the second impedance matching terminal 6 based on the line wave impedance and the parameters of the artificial lightning trigger device; Step 0.3: Determine the location of the grounding system based on the length of the transmission line 1; determine the grounding resistance threshold based on the parameters of the artificial lightning attractor and the obtained lightning current frequency; Step 0.4: Configure the first impedance matching terminal 5 and the second impedance matching terminal 6 according to the resistance value; configure the grounding system according to the arrangement location of the grounding system and the grounding resistance threshold. Among them, the line surge impedance calculation formula for transmission line 1 is as follows:

[0040] In the above formula, Let the line surge impedance be that of transmission line 1. m 0 is the magnetic permeability of air, equal to 4π × 10⁻⁶. -7 H / m; e 0 is the dielectric constant of air, which is equal to 8.85 × 10⁻⁶. -12 F / m; h The height of transmission line 1 above the ground. r Let be the radius of transmission line 1. The formula for calculating the line surge impedance of transmission line 1 can provide accurate reference parameters for the design of the first impedance matching terminal 5 and the second impedance matching terminal 6.

[0041] Steps 0.1-0.4, taking a 110kV transmission line as an example, the height of transmission line 1 above the ground is h=7m, and the radius of transmission line 1 is... r =10.8mm, the line surge impedance of transmission line 1 is calculated using the line surge impedance calculation formula for transmission line 1. =430Ω.

[0042] First, configure the first impedance matching terminal 5 and the second impedance matching terminal 6, specifically including the following steps A1 to A5: A1. Based on the line surge impedance of transmission line 1 Determine the resistance values ​​of the first impedance matching terminal 5 and the second impedance matching terminal 6. R main = =430Ω; Following the principle that the resistance values ​​of the first impedance matching terminal 5 and the second impedance matching terminal 6 are the same, the first impedance matching terminal 5 and the second impedance matching terminal 6 are configured such that their resistance values ​​are both 430Ω. This configuration ensures that the two ends of the transmission line 1 have completely symmetrical boundary conditions, which is beneficial for the uniform absorption of traveling waves at both ends of the transmission line 1.

[0043] A2. Taking a 110kV transmission circuit as an example, the DC reference voltage of surge arrester 3 is... U 1mA ≥148kV, lightning impulse residual voltage ≤296kV, lightning impulse discharge voltage U 50 For voltages ≤525kV, the calculated operating current of surge arrester 3 is: I =4 U 50 / Z c=4×525 / 430=4.88kA, which means that when a lightning current with an amplitude of 4.88kA strikes transmission line 3, the surge arrester 3 installed on transmission line 3 will activate due to the lightning overvoltage. The amplitude of the lightning current obtained by artificial lightning attraction is generally between 10 and 35kA, which is greater than 4.88kA. Therefore, each successful lightning strike can activate the surge arrester 3 installed on transmission line 1. After the surge arrester 3 activates, about 70 to 80% of the lightning current will enter the ground through the surge arrester, and only 20 to 30% of the lightning current will enter the ground through the first impedance matching terminal 5 and the second impedance matching terminal 6 at both ends of the line.

[0044] A3. Considering the initial stage of rocket 21's ascent, an ionizing current, typically several hundred amperes, will form between the rocket 21 tip and the thundercloud, lasting approximately 500 ms. This current will not cause the surge arrester 3 to trip and will instead enter the ground through the first impedance matching terminal 5 and the second impedance matching terminal 6 at both ends of the transmission line. Assuming the maximum lightning current during the initial stage of rocket 21 attracting lightning is 400A, the energy of the lightning current absorbed by the first impedance matching terminal 5 and the second impedance matching terminal 6 during the initial stage is estimated as follows: E =∫ i 2 R Given dt = 5.73 MJ, and assuming that the first impedance matching terminal 5 and the second impedance matching terminal 6 absorb this energy equally, the energy absorbed by either the first impedance matching terminal 5 or the second impedance matching terminal 6 is approximately 3 MJ. This relatively large energy value is a primary consideration in configuring the energy absorption capabilities of the first impedance matching terminal 5 and the second impedance matching terminal 6.

[0045] A4. After successfully attracting lightning during operation, the estimated waveform of the lightning current was 0.43 / 18.94 μs, with an amplitude of 35 kA, and the lightning current energy was ∫ i 2 dt≈( I m 2 × T 2) / 3≈7700A 2 Considering that only 20-30% of the lightning current flows to ground through the first impedance matching terminal 5 and the second impedance matching terminal 6 at both ends of the line when the surge arrester operates during a lightning strike, the calculated lightning current energy of the first impedance matching terminal 5 or the second impedance matching terminal 6 is: E =∫ i 2 dt× R × a=7700×430×(10~15%)=(0.33~0.5)MJ. The lightning current energy is an order of magnitude smaller than the lightning current energy absorbed in the initial stage, but it still needs to be included in the energy absorption capacity design of the first impedance matching terminal 5 and the second impedance matching terminal 6.

[0046] A5. Combining A3-A4, it can be seen that the first impedance matching terminal 5 and the second impedance matching terminal 6 are expected to absorb 3 + (0.33~0.5) = (3.33~3.5) MJ of energy during the entire artificial lightning triggering process. This energy will be entirely converted into heat energy, and no energy will be reflected back into the transmission line. Therefore, in actual configuration, taking a certain margin, the first impedance matching terminal 5 and the second impedance matching terminal 6 can each be designed with a maximum energy absorption capacity of 4 MJ. If 10 4.3kΩ non-inductive resistors are connected in parallel, then each resistor needs to withstand 400J of energy.

[0047] Secondly, configure the grounding system, specifically including the following steps B1 to B3: B1: Determine the location of the grounding system and the grounding resistance threshold. Specifically, the location of the grounding system should be determined based on the length of transmission line 1 and the actual site conditions. It is typically located at both ends of transmission line 1, near the first impedance matching terminal 5 and the second impedance matching terminal 6, to reduce the impact of the grounding system's lead inductance on the grounding effect. The grounding resistance threshold must meet the following condition: the additional reflection introduced by the grounding system is less than 2%, i.e., | R g +jω L g |<0.02× Z c；， in, R g The power frequency grounding resistance when the grounding grid is in operation. L g The inductance of the grounding lead during operation, ω is the upper limit angular frequency of the frequency threshold. Z c Let j be the line surge impedance of the transmission line, where j is the imaginary unit.

[0048] B2: Taking f=2MHz as an example, the lead inductance when the grounding lead is working L g =0.5μH, power frequency grounding resistance when the grounding grid is in operation R g When Ω = 0.5Ω, the calculated value is | R g +jω L g |=|0.5+j6.28|=6.3Ω, and 0.02× Z c=0.02×430=8.6Ω, which satisfies the condition 6.3<8.6, at which point the reflection coefficient is only 0.73%. Even the power frequency grounding resistance during grounding grid operation... R g Increase to 5Ω, | R g +jω L g The power frequency grounding resistance is |=|5+j6.28|=8.03Ω, which still meets the condition of being less than 8.6Ω, and the reflection coefficient is only 0.93%. Therefore, the power frequency grounding resistance when the grounding grid is working is... R g The lead inductance of the grounding lead during operation is not greater than 5Ω. L g When the additional reflection introduced by the grounding system is not greater than 0.5μH, it can be ignored.

[0049] B3: Based on the calculation results of steps B1 and B2, the specific implementation method of the grounding system is as follows: The grounding lead uses copper strips with a width of not less than 10cm or multiple copper wires connected in parallel. The length of the grounding lead does not exceed 5m, and it is laid close to the ground to reduce the inductance of the lead. L g The grounding grid adopts a grid-shaped copper busbar structure with a grid size of 5m×5m and a burial depth of 0.5m. A 2.5m long vertical grounding electrode is installed at the grid intersection. If necessary, a resistance-reducing agent can be used to ensure that the power frequency grounding resistance is not greater than 5Ω.

[0050] Furthermore, the frequency domain test in step 1 on the first impedance matching terminal 5 and the second impedance matching terminal 6 of the surge arrester test device to induce reflection of the lightning current waveform mainly aims to determine that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not induce reflection of the lightning current waveform, and may include the following steps: Step 1.1: After the artificial lightning triggering device 2 is activated, the lightning current turning frequency is calculated using the lightning current double exponential model based on the lightning current parameters obtained by the artificial lightning triggering device 2; the lightning current energy concentration frequency range is determined based on the lightning current parameters and the lightning current turning frequency. Step 1.2: If the frequency range of the lightning current energy concentration is within a preset frequency range threshold, then based on the measured resistance of the first impedance matching terminal 5 and the second impedance matching terminal 6, the terminal mixed impedance formed by the parasitic inductance and stray capacitance to ground generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 is calculated according to the pre-constructed terminal impedance model. Step 1.3: Based on the aforementioned terminal mixed impedance, calculate the traveling wave reflection value using the traveling wave reflection coefficient calculation model; Step 1.4: When the traveling wave reflection value is less than the preset coefficient threshold, it is determined that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause the reflection of the lightning current waveform. The terminating impedance model is expressed as follows: Z L (ω) =( R main + jω L s ) / / (1 / jω C p )=( R main + jω L s ) / (1-ω 2 L s C p +jω R main C p ) In the above formula, Z L (ω) represents the terminal mixed impedance. R main The measured resistances of the first impedance matching terminal 5 and the second impedance matching terminal 6 are shown. L s The parasitic inductance generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current. C p ω represents the stray capacitance to ground generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current, ω is the upper limit angular frequency of the frequency threshold, and j is the imaginary unit. The traveling wave reflection coefficient calculation model satisfies the following formula: r =( R Z L (ω)) / ( R + Z L (ω)) In the above formula, r This is the value of the traveling wave reflection. R Here are the theoretical terminating impedances of the first impedance matching terminal 5 and the second impedance matching terminal 6. Z L (ω) is the terminal mixed impedance, where, R = R main + Rg +jω L g .

[0051] Further, in step 1.1, after the artificial lightning triggering device 2 is activated, the lightning current transition frequency is calculated using a double exponential lightning current model based on the lightning current parameters obtained by the artificial lightning triggering device 2, including the following steps: Step 1.1.1: After the artificial lightning triggering device 2 is activated, determine the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning based on the lightning current parameters obtained by the artificial lightning triggering device 2. Step 1.1.2: Construct the lightning current waveform based on the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning. For example, statistical data shows that 91% of lightning return stroke rise times are between 0 and 0.8 μs, and the average lightning rise time T1 is 0.43 μs; 80% of subsequent return stroke half-amplitude widths are between 0 and 40 μs, and the average lightning half-amplitude width T2 is 18.94 μs. Therefore, the lightning current waveform is designed according to T1 / T2 = 0.43 / 18.94 μs.

[0052] Step 1.1.3: Based on the lightning current waveform, determine the maximum value of the lightning current and the peak current correction coefficient. The maximum value of the lightning current can be determined based on the actual lightning current guided by the artificial lightning trigger device 2, which is usually in the range of 10~35kA. The peak current correction coefficient is used to correct the peak value of the lightning current double exponential model to ensure that the calculated waveform is consistent with the actual waveform at the peak value.

[0053] Step 1.1.4: For the maximum value of the lightning current and the correction coefficient of the peak current, the lightning current double exponential model is used to calculate the lightning current corner frequency; by calculating the corner frequency, the main distribution frequency band of the lightning current energy can be identified, providing a frequency range basis for the wideband design of the first impedance matching terminal 5 and the second impedance matching terminal 6. The lightning current double-exponential model satisfies the following formula: , ,

[0054] In the above formula, I 0 represents the maximum value of the lightning current. or This is the peak current correction factor. t 1 represents the rise time of the lightning current in the lightning current parameters. t 2 represents the delay time of the lightning current in the lightning current parameters. α The first intermediate quantity ，α =1 / t 2, βAs the second intermediate quantity, β =3 / t 1, where t is the time of lightning current occurrence. It is the natural logarithm; This is the first bend frequency of the lightning current. This is the second bend frequency of the lightning current. Let π be the mathematical constant pi. Taking a waveform of 0.43 / 18.94 μs as an example, the following calculation is performed: α =1 / t 2 = 1 / 18.94 × 10 6 =52798, β =3 / t 1 = 3 / 0.43 × 10 6 =6976744. Based on the lightning current double-exponential model, we obtain... =8.4kHz, =1.1MHz, therefore, 90% of the energy of the lightning current with the 0.43 / 18.94μs waveform is mainly concentrated in the range of about 1MHz, so the upper limit of the high-frequency component of the lightning current can be designed to be 2MHz. The determination of this frequency band provides a clear frequency target for the subsequent frequency domain verification of the first impedance matching terminal 5 and the second impedance matching terminal 6.

[0055] Furthermore, steps 1.2 to 1.4 are specifically calculated using the example of the resistance value of the first impedance matching terminal 5 being 430Ω and the resistance value of the second impedance matching terminal 6 being 430Ω: When the frequency range threshold f = 0-2MHz, the parasitic inductance generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current is taken. L s =0.4μH, stray capacitance to ground generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current. C p =20pF, and substitute them into the terminal impedance model for calculation. Then, through the traveling wave reflection coefficient calculation model, the traveling wave reflection value can be obtained as 4.8%, and the preset coefficient threshold is set to 5%, 4.8% < 5%; Furthermore, it can also calculate the parasitic inductance and stray capacitance of the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current. C p resonant frequency between :

[0056] The resonant frequency of 56MHz far exceeds the main energy frequency band of lightning current (around 1MHz), therefore, the lightning current will not resonate during propagation. Thus, the reflections caused by parasitic inductance and stray capacitance to ground of the first impedance matching terminal 5 and the second impedance matching terminal 6 under the high-frequency action of lightning current are negligible, fully meeting the test requirements.

[0057] Therefore, it can be determined that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause reflection of the lightning current waveform.

[0058] Further, in step 2, if the result of the frequency domain test is that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause reflection of the lightning current waveform, then a pulse signal with a preset pulse threshold is injected into one end of the transmission line 1 of the surge arrester test device, and the voltage signal on the transmission line 1 is collected to confirm that the transmission line 1 will not cause reflection of the transmitted signal. Examples include the following steps: Step 2.1: A low-voltage pulse signal with a rise time of less than 1 μs and an amplitude of less than 1 kV is injected at the beginning of transmission line 1. The rise time of this pulse signal is comparable to the wavefront steepness of the lightning current, which can effectively verify the transmission characteristics of transmission line 1 under high-frequency conditions. An amplitude of less than 1 kV is chosen to ensure experimental safety and avoid damage to transmission line 1. Then, the midpoint voltage signal and terminal voltage signal of transmission line 1 are simultaneously acquired, and the acquired waveforms are compared and analyzed with the incident wave.

[0059] Step 2.2: According to transmission line theory, when the two ends of transmission line 1 are well matched, the midpoint voltage should be half of the incident wave voltage. This is because the traveling wave has not yet encountered boundary reflection when it reaches the midpoint, and the voltage amplitude is dominated by the incident wave. The terminal voltage should be the waveform of the incident wave after a delay of τ, with no obvious reflection phenomenon, where the delay time is... t = L / v L is the length of transmission line 1. v The speed of wave propagation (approximately equal to the speed of light 3 × 10⁻⁶) 8 (m / s). For example, when the length of transmission line 1 is 2km, the delay time of the terminal voltage relative to the incident wave is approximately 6.67μs.

[0060] Step 2.3: If the measurement results show that the midpoint voltage amplitude is approximately 50% of the incident wave amplitude, and the terminal voltage waveform is consistent with the incident wave waveform and has a similar amplitude, without obvious oscillations or step-like distortion, then it indicates that the first impedance matching terminal 5 and the second impedance matching terminal 6 can effectively absorb traveling wave energy under low-voltage pulse conditions and will not produce obvious reflections. This low-voltage pulse verification is an important preliminary step before the high-voltage impulse test, which can effectively reduce the risks and costs of the high-voltage test, and also ensure the accuracy of waveform data acquired in subsequent high-voltage tests.

[0061] Furthermore, if the determination result in step 3 is that the transmission line 1 will not reflect the transmitted signal, then the artificial lightning triggering device 2 is activated to collect the voltage and current waveforms at each measurement point in the transmission line 1, specifically including the following example steps: Step 3.1: Activate the artificial lightning triggering device 2. The artificial lightning triggering device 2 uses a rocket 21 to drag a thin steel wire 22. When the rocket 21 ascends to the bottom of the thundercloud, the electric field strength between the thin steel wire 22 and the thundercloud exceeds the air breakdown threshold, thereby triggering a natural lightning discharge. The real lightning current is guided to the preset lightning strike point through the thin steel wire 22 and the guide rod 8. The lightning current waveform obtained in this way has the advantages of being realistic and irreplaceable.

[0062] In this design, the lightning strike point of the artificial lightning trigger device 2 is located between the line arrester 3 and the first impedance matching terminal 5 or the second impedance matching terminal 6, and the distance between the lightning strike point and the line arrester 3 is not less than 100m, and the distance between the lightning strike point and the first impedance matching terminal 5 or the second impedance matching terminal 6 is not less than 100m. The purpose of setting this distance constraint is to ensure that the incident lightning current wave has sufficient propagation distance to form a stable traveling wave waveform before reaching the arrester 3; at the same time, it ensures that the unloading wave generated by the operation of the arrester 3 and the absorption process of the first impedance matching terminal 5 and the second impedance matching terminal 6 can be clearly observed and distinguished, avoiding the overlap of waveforms in time.

[0063] Step 3.2: Synchronously acquire the voltage and current waveforms at the beginning of transmission line 1, the voltage and current waveforms at the connection point of surge arrester 3 (surge arrester 3 is usually installed at the crossarm of the tower), and the voltage and current waveforms at the end of transmission line 1. The sampling rate should be no less than 100MHz to meet the Nyquist sampling requirements for the high-frequency component of lightning current (up to about 2MHz); the recording duration should be no less than 1s to completely capture the entire process of lightning current incidence (μs level), surge arrester 3 operation (μs level), unloading wave propagation, and absorption by the first impedance matching terminal 5 and the second impedance matching terminal 6, while simultaneously recording the continuous current during the initial stage of artificial lightning triggering (about 500ms). All measurement channels should be synchronously triggered using the same clock source to ensure accurate time correspondence between waveforms, facilitating subsequent traveling wave analysis and energy calculation.

[0064] For steps 3.1-3.2, such as Figure 3 As shown, a lightning current with an amplitude of 50kA and a waveform of 0.5 / 20μs struck tower No. 3, with a span of 200m. The red curve in the figure represents the original waveform of the applied lightning current, and the green curve represents the lightning current waveform monitored when it propagates to tower No. 1. It can be seen that the lightning current propagated to the end of transmission line 1 without reflection. The green waveform is highly consistent with the red waveform (both 0.5 / 20μs), and its amplitude is half of the applied amplitude (25kA). This conforms to the natural current shunting characteristics of traveling waves propagating in a non-reflective line, proving that the lightning current, transmitted through transmission line 1 to the first impedance matching terminal 5 and the second impedance matching terminal 6 at both ends, effectively absorbed the traveling wave energy, eliminating end reflection. This allowed the surge arrester 3 to withstand a single lightning current action completely identical to that in an infinitely long line, avoiding false responses of the surge arrester 3 caused by back-and-forth reflections of the lightning current.

[0065] Furthermore, the voltage and current waveforms at each measurement point include at least: the voltage and current waveforms at the beginning of the transmission line 1, the voltage and current waveforms at the connection point of the surge arrester 3 of the transmission line 1, and the voltage and current waveforms at the end of the transmission line 1. Step 4 involves analyzing the voltage and current waveforms at each measurement point; based on the analysis results, evaluating the operating characteristics of the surge arrester 3, including the following steps: Step 4.1: Based on the voltage and current waveforms at the connection point of the surge arrester 3 of the transmission line 1, determine whether the surge arrester 3 has operated. If the voltage and current waveforms show a conduction pulse and are clamped at the residual voltage level, then the surge arrester 3 is determined to have operated. Step 4.2: Based on the voltage and current waveforms at the beginning and end of the transmission line 1, determine the theoretical terminal impedances of the first impedance matching terminal 5 and the second impedance matching terminal 6; based on the theoretical terminal impedances and the traveling wave reflection coefficient calculation model, determine the traveling wave reflection value; if the traveling wave reflection value is less than a preset threshold (5% in the example), then the matching of the first impedance matching terminal 5 and the second impedance matching terminal 6 is deemed valid.

[0066] In step 4.1 above, the voltage and current waveforms collected at the connection point of surge arrester 3 are used to determine whether surge arrester 3 has operated. The judgment is based on observing the current waveform. i arrester(t) Does a noticeable conduction pulse occur (current suddenly jumps from near zero to the kA level), along with the voltage waveform? u arrester(t) Whether it is quickly clamped at the residual voltage level of surge arrester 3 (for 110kV line surge arresters, DC reference voltage) U 1mA ≥148kV, lightning impulse residual voltage ≤296kV, lightning impulse discharge voltage U 50≤525kV). If both conditions are met simultaneously, then surge arrester 3 is determined to have operated normally. Then, the theoretical calculation can be verified based on the operating current amplitude of surge arrester 3: the operating current of surge arrester 3. I =4 U 50 / Z c =4×525 / 430=4.88kA, while the amplitude of the lightning current obtained by the artificial lightning triggering device 2 is generally between 10 and 35kA, which is greater than 4.88kA. Therefore, each successful lightning strike can cause the surge arrester 3 installed on the transmission line 1 to operate.

[0067] In step 4.2: First, based on the voltage and current waveforms at the beginning and end of transmission line 1, the matching effect of the first impedance matching terminal 5 and the second impedance matching terminal 6 is verified, and the energy matching characteristics of the surge arrester 3 with the first impedance matching terminal 5 and the second impedance matching terminal 6 are evaluated. Specifically, the terminal voltage waveform is compared with the beginning voltage waveform, and the actual reflection coefficient is calculated. If the calculated traveling wave reflection coefficient is less than 5%, the matching is effective. Simultaneously, the consistency between the terminal current waveform and the beginning current waveform is observed for further verification; based on this, the energy absorbed by the surge arrester 3 is calculated. E The calculation formula is: E = ∫ u arrester(t) × i arrester(t) dt, where t is the running time, and the integration interval is the entire process from the start of arrester 3's operation until the current returns to zero; simultaneously, the energy absorbed by the first impedance matching terminal 5 and the second impedance matching terminal 6 is calculated. E2 Its formula is E2 = ∫ i L(t) 2 × R dt, i L(t) For the current of transmission line 1 ， Based on the energy distribution ratio (surge arrester 3 absorbs about 70-80%, and matching terminal absorbs about 20-30%) and the initial stage lightning current energy, verify the energy margin of the matching terminal (e.g., take 8MJ); if the above traveling wave reflection conditions are met and the energy matching is as expected, then the matching of the first impedance matching terminal 5 and the second impedance matching terminal 6 is determined to be effective.

[0068] Following step 4.2, the performance of surge arrester 3 needs to be retested. Macroscopic performance parameters such as the power frequency reference voltage, leakage current, and lightning impulse residual voltage before and after the lightning strike are compared, along with microstructural changes such as the lattice size of the zinc oxide varistor inside surge arrester 3 observed using scanning electron microscopy. This comprehensive assessment evaluates the degree of performance degradation of surge arrester 3 under actual lightning current. If the power frequency reference voltage change of surge arrester 3 does not exceed 10%, the leakage current does not increase significantly and is below 50 μA, the residual voltage change does not exceed -2% to 5%, and no obvious grain boundary slip or thermal damage is observed in the microstructure, then surge arrester 3 is deemed to have passed the performance test under actual lightning current. This complete evaluation system provides comprehensive data support for the reliability assessment and lifespan prediction of surge arrester 3 for transmission line 1.

[0069] In summary, the surge arrester testing method simulating a lightning current environment proposed in this invention effectively absorbs the traveling wave energy reaching the endpoints of the transmission line 1 by configuring a broadband first impedance matching terminal 5 and a second impedance matching terminal 6 at both ends of the finite-length transmission line 1, completely eliminating reflection. Simultaneously, a real lightning current is injected using an artificial lightning-attracting device 2, making the transmission line 1 electrically equivalent to an infinitely extending transmission line from the installation point of the surge arrester 3 to both sides, thus providing a pure and realistic single-event lightning current environment for the surge arrester 3. This method significantly improves the realism and accuracy of the test, providing an ideal platform for studying the performance of the surge arrester 3 using real lightning parameters and simulating real operating conditions.

[0070] Furthermore, existing laboratory testing methods have the following inherent limitations: First, the test waveform differs from the actual lightning waveform. The standard waveforms used in the laboratory (such as 1.2 / 50μs, 4 / 10μs) are simplified simulations based on the statistical average of millions of lightning strikes in nature, and differ significantly from the real lightning waveform in terms of wavefront steepness, wave tail duration, energy distribution, and multiple return strokes. Second, the test conditions for surge arrester 3 differ from actual operating conditions. On a real line, surge arrester 3 withstands the traveling wave of lightning propagating along the line, and its voltage and current waveforms are determined by the incident wave and the line boundary conditions. In the laboratory, however, surge arrester 3 is usually directly connected to the output of the impulse generator or installed on an extremely short lead, and the waveform it withstands is determined by the generator's internal resistance and loop parameters, which is completely different from the traveling wave propagation process in an actual line. Third, the reflection and refraction effects of the finite-length test line cause waveform distortion. Due to the limitations of laboratory space, the length of the test line is usually only a few hundred meters to several kilometers, much shorter than that of actual transmission lines (tens to hundreds of kilometers). When lightning current is injected into a short line, it will cause strong reflections at both ends of the line, resulting in complex superposition of traveling waves on the line. This means that the voltage and current waveforms that the surge arrester 3 installed on the line will not be the actual single lightning incident wave, but a distorted waveform mixed with multiple reflected waves. This condition is seriously inconsistent with the single action process of lightning current propagating far away and gradually attenuating and disappearing in actual long lines.

[0071] The aforementioned limitations lead to the following technical defects in existing testing methods: Distorted testing conditions: The reflected wave causes the surge arrester 3 to experience additional current surges and voltage stress, potentially overestimating its energy absorption and making the operating load test conditions too stringent, failing to accurately reflect the actual operating performance of the surge arrester 3 in real-world circuits. Difficulty in mechanism research: The interference from the reflected wave prevents the pure reproduction and study of the fundamental physical process of "lightning current incidence - surge arrester 3 operation - generation of unloading wave" in the laboratory, hindering a deeper understanding of the dynamic response characteristics of the surge arrester 3. Limited application of artificial lightning induction technology: Although artificial lightning induction can obtain a true lightning waveform, if there are no matching absorption measures at the end of the line, residual energy will still reflect back and forth in the short circuit, interfering with subsequent measurements and failing to fully utilize its waveform authenticity advantage.

[0072] This invention, through experimental line parameter determination, impedance matching terminal design, lightning current frequency domain verification, low-voltage pulse verification, and high-voltage impulse testing, achieves impedance matching between the impedance matching terminal and the line wave impedance across a wide frequency band of the main energy of the lightning current, completely absorbing the traveling wave energy reaching the line endpoints. This invention creates a "reflection-free boundary" on a finite-length line, simulating the physical process of lightning current freely propagating on an infinitely long line. It eliminates the reflection effect of wave propagation along a short line to the end, allowing the surge arrester 3 to withstand the same single lightning current action as in an infinitely long line. This significantly improves the realism and accuracy of the test, effectively avoiding the technical defects caused by the aforementioned limitations, and enabling the study of the surge arrester 3's performance using real lightning parameters and simulating real operating conditions.

[0073] The method of this invention eliminates the need for constructing long lines of tens of kilometers. By using wideband impedance matching at both ends, it can simulate the environment of an infinitely long line using existing laboratory space and a relatively short line, completely eliminating reflections at the short line end. This ensures that the voltage and current waveforms experienced by the surge arrester are highly consistent with those experienced when struck by lightning on an actual infinitely long line. The test results are authentic and reliable, and the test conditions are controllable with good repeatability, significantly reducing research and development and testing costs. This method is not only applicable to line surge arresters 3, but can also be extended to lightning impulse tests on high-voltage equipment (such as insulator strings, cable terminals, etc.) of different voltage levels and types by adjusting line parameters and matching terminal design.

[0074] Example 3: like Figure 4 As shown, this invention application proposes a surge arrester test system simulating a lightning current environment, comprising: The matching terminal determination module is used to perform frequency domain tests on the first impedance matching terminal 5 and the second impedance matching terminal 6 of the surge arrester test device to induce the reflection and refraction of the lightning current waveform. The transmission line determination module is used to inject a pulse signal with a preset pulse threshold into one end of the transmission line 1 of the surge arrester test device if the result of the frequency domain test is that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause reflection of the lightning current waveform, and to collect the voltage signal on the transmission line 1; based on the voltage signal, determine whether the transmission line 1 will cause reflection of the transmitted signal. The acquisition module is used to start the artificial lightning trigger device 2 of the surge arrester test device and acquire the voltage and current waveforms at each measurement point in the transmission line 1 if the determination result is that the transmission line 1 will not reflect the transmitted signal. The evaluation module is used to analyze the voltage and current waveforms at each measurement point; and to evaluate the operating characteristics of the surge arrester 3 based on the analysis results. The surge arrester testing device is the surge arrester testing device described in Embodiment 1 above.

[0075] Furthermore, the matching terminal determination module includes: The frequency range determination submodule is used to calculate the lightning current turning frequency based on the lightning current parameters obtained by the artificial lightning triggering device 2 after its activation, using a lightning current double exponential model; and to determine the frequency range of lightning current energy concentration based on the lightning current parameters and the lightning current turning frequency. The terminal mixed impedance calculation submodule is used to calculate the terminal mixed impedance formed by the parasitic inductance and stray capacitance to ground generated by the first impedance matching terminal 5 and the second impedance matching terminal 6, based on the measured resistance of the first impedance matching terminal 5 and the second impedance matching terminal 6, according to the pre-built terminal impedance model, if the frequency range of the lightning current energy concentration is within a preset frequency range threshold. The traveling wave reflection value calculation submodule is used to calculate the traveling wave reflection value based on the terminal mixed impedance and using the traveling wave reflection coefficient calculation model. The matching terminal reflection determination submodule is used to determine that the first impedance matching terminal 5 and the second impedance matching terminal 6 will not cause reflection of the lightning current waveform when the traveling wave reflection value is less than a preset coefficient threshold. The terminating impedance model is expressed as follows: Z L (ω) =( R main + jω L s ) / / (1 / jω C p )=( R main + jω L s ) / (1-ω 2 L s C p +jω R main C p ) In the above formula, Z L (ω) represents the terminal mixed impedance. R main The measured resistances of the first impedance matching terminal 5 and the second impedance matching terminal 6 are shown. L s The parasitic inductance generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current. C pω represents the stray capacitance to ground generated by the first impedance matching terminal 5 and the second impedance matching terminal 6 under the action of lightning current, ω is the upper limit angular frequency of the frequency threshold, and j is the imaginary unit. The traveling wave reflection coefficient calculation model satisfies the following formula: r =( R Z L (ω)) / ( R + Z L (ω)) In the above formula, r This is the value of the traveling wave reflection. R Here are the theoretical terminating impedances of the first impedance matching terminal 5 and the second impedance matching terminal 6. Z L (ω) represents the terminal mixed impedance.

[0076] Furthermore, the frequency range determination submodule is specifically used for: After the artificial lightning triggering device 2 is activated, the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning are determined based on the lightning current parameters obtained by the artificial lightning triggering device 2. The lightning current waveform is constructed based on the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning. Based on the lightning current waveform, determine the maximum lightning current and the current peak correction factor; The lightning current turning frequency is calculated using a double exponential model for the maximum lightning current and the peak current correction coefficient. The lightning current double-exponential model satisfies the following formula: , ,

[0077] In the above formula, I 0 represents the maximum value of the lightning current. or This is the peak current correction factor. t 1 represents the rise time of the lightning current in the lightning current parameters. t 2 represents the delay time of the lightning current in the lightning current parameters. α The first intermediate quantity ，α =1 / t 2, β As the second intermediate quantity, β =3 / t 1, where t is the time of lightning current occurrence. It is the natural logarithm; This is the first bend frequency of the lightning current. This is the second bend frequency of the lightning current. Pi is the mathematical constant of a circle.

[0078] Furthermore, the voltage and current waveforms at each measurement point include at least: the voltage and current waveforms at the beginning of the transmission line 1, the voltage and current waveforms at the connection point of the surge arrester 3 of the transmission line 1, and the voltage and current waveforms at the end of the transmission line 1. The evaluation module is specifically used for: Based on the voltage and current waveforms at the connection point of the surge arrester 3 of the transmission line 1, determine whether the surge arrester 3 has operated. If the voltage and current waveforms show a conduction pulse and are clamped at the residual voltage level, then the surge arrester 3 is determined to have operated. Based on the voltage and current waveforms at the beginning and end of the transmission line 1, the theoretical terminal impedances of the first impedance matching terminal 5 and the second impedance matching terminal 6 are determined; based on the theoretical terminal impedances and the traveling wave reflection coefficient calculation model, the traveling wave reflection value is determined; if the traveling wave reflection value is less than a preset threshold, the matching of the first impedance matching terminal 5 and the second impedance matching terminal 6 is deemed valid.

[0079] Example 4: like Figure 5 As shown, the present invention also provides an electronic device, which may be a computer device, a microcontroller device, a smart mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, processor, and transceiver component are connected via a bus; the memory can be used to store executable programs, and an exemplary executable program may include instructions; the processor is used to execute the instructions stored in the memory. The memory can also be used to store data, which can be accessed and / or modified when instructions are executed.

[0080] The processor may be a Central Processing Unit (CPU), or it may 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. It is the computing core and control core of the terminal, and it is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the storage medium to realize the corresponding method flow or corresponding function, so as to realize the steps of the surge arrester test method simulating lightning current environment in the above embodiments.

[0081] Example 5: Based on the same inventive concept, this invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory). This readable storage medium is a memory device within an electronic device used to store programs and data. It is understood that the storage medium here can include both built-in storage media within the electronic device and extended storage media supported by the electronic device. The storage medium provides storage space, which stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more executable programs (including program code). It should be noted that the storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. Loading and executing one or more instructions stored in the storage medium by the processor can implement the steps of a surge arrester test method simulating a lightning current environment as described in the above embodiments.

[0082] Those skilled in the art will understand that embodiments of this invention can be provided as methods, systems, or computer program products. Therefore, this invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this invention 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.

[0083] This invention application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. 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, generate instructions for implementing the flowchart... Figure one One or more processes and / or boxes Figure one A device that provides the functions specified in one or more boxes.

[0084] 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 one One or more processes and / or boxes Figure one The function specified in one or more boxes.

[0085] 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 one One or more processes and / or boxes Figure one The steps of the function specified in one or more boxes.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the application, but these changes, modifications or equivalent substitutions are all within the protection scope of the claims pending approval.

Claims

1. A surge arrester testing device simulating a lightning current environment, characterized in that, include: Transmission lines, artificial lightning arresters, surge arresters, multiple towers, first impedance matching terminal and second impedance matching terminal; The power transmission line is installed on the upper part of the plurality of towers; The first impedance matching terminal and the second impedance matching terminal are respectively connected to both ends of the transmission line; The power transmission line is connected to the artificial lightning triggering device; The surge arrester is connected between one of the towers and the transmission line.

2. The surge arrester testing apparatus according to claim 1, characterized in that, The first impedance matching terminal includes: a plurality of first non-inductive resistors; the plurality of first non-inductive resistors are connected in parallel. The second impedance matching terminal includes: a plurality of second non-inductive resistors; the plurality of second non-inductive resistors are connected in parallel; The energy absorption capacity of the first impedance matching terminal and the second impedance matching terminal is not less than the sum of the initial stage lightning current energy obtained by the artificial lightning triggering device and the lightning current energy flowing into the first impedance matching terminal and the second impedance matching terminal during the operation of the surge arrester.

3. The surge arrester testing apparatus according to claim 1, characterized in that, Also includes: The same number of insulators as the plurality of towers; Each of the towers is connected to the transmission line by one of the insulators.

4. The surge arrester testing apparatus according to claim 1, characterized in that, Also includes: Grounding system; The grounding system includes: an interconnected grounding grid and grounding leads; the grounding leads are connected to the first impedance matching terminal and the second impedance matching terminal; The power frequency grounding resistance of the grounding grid during operation and the lead inductance of the grounding lead during operation shall satisfy the following conditions: ∣ R g +jω L g ∣<0.02× Z c in, R g The power frequency grounding resistance when the grounding grid is in operation. L g The inductance of the grounding lead during operation, ω is the upper limit angular frequency of the frequency threshold. Z c Let j be the line surge impedance of the transmission line, where j is the imaginary unit.

5. The surge arrester testing apparatus according to claim 2, characterized in that, The resistance values ​​of the first impedance matching terminal and the second impedance matching terminal are the same; The resistance value of the first impedance matching terminal or the second impedance matching terminal is equal to the line wave impedance of the transmission line.

6. The surge arrester testing apparatus according to claim 5, characterized in that, The line surge impedance of the transmission line satisfies the following formula: In the above formula, The line surge impedance of the transmission line. μ 0 represents the magnetic permeability of air. ε 0 is the dielectric constant of air. h The height of the transmission line above the ground. r The radius of the transmission line.

7. The surge arrester testing apparatus according to claim 2, characterized in that, After the surge arrester is activated by lightning, 70-80% of the received lightning current flows to the ground through itself, and 20-30% of the lightning current flows to the ground through the first impedance matching terminal and the second impedance matching terminal.

8. A test method for surge arresters simulating lightning current environments, characterized in that, include: Frequency domain tests were conducted on the first and second impedance matching terminals of the surge arrester test device to induce reflection and refraction of the lightning current waveform. If the result of the frequency domain test is that the first impedance matching terminal and the second impedance matching terminal will not cause reflection of the lightning current waveform, then a pulse signal with a preset pulse threshold is injected into one end of the transmission line of the surge arrester test device, and the voltage signal on the transmission line is collected. Based on the voltage signal, it is determined whether the transmission line will reflect or refract the transmitted signal; If the determination result is that the transmission line will not reflect the transmitted signal, then the artificial lightning triggering device of the surge arrester test device is activated to collect the voltage and current waveforms at each measuring point in the transmission line. The voltage and current waveforms at each measurement point are analyzed; based on the analysis results, the operating characteristics of the surge arrester are evaluated. The surge arrester testing device is the surge arrester testing device according to any one of claims 1-7.

9. The surge arrester test method according to claim 8, characterized in that, The frequency domain test that induces reflection and refraction of the lightning current waveform is performed on the first and second impedance matching terminals of the surge arrester test device, including: After the artificial lightning triggering device is activated, the lightning current turning frequency is calculated using a double exponential model based on the lightning current parameters obtained by the device. The lightning current energy concentration frequency range is then determined based on the lightning current parameters and the turning frequency. If the frequency range of the lightning current energy concentration is within a preset frequency range threshold, then based on the measured resistance of the first impedance matching terminal and the second impedance matching terminal, the terminal mixed impedance formed by the parasitic inductance and stray capacitance to ground generated by the first impedance matching terminal and the second impedance matching terminal is calculated according to the pre-constructed terminal impedance model. Based on the aforementioned terminal mixed impedance, the traveling wave reflection value is calculated using the traveling wave reflection coefficient calculation model; When the traveling wave reflection value is less than a preset coefficient threshold, it is determined that the first impedance matching terminal and the second impedance matching terminal will not cause the reflection of the lightning current waveform. The terminating impedance model is expressed as follows: Z L (ω) =( R main + jω L s ) / / (1 / jω C p )=( R main + jω L s ) / (1-ω 2 L s C p +jω R main C p ) In the above formula, Z L (ω) represents the terminal mixed impedance. R main The measured resistances of the first and second impedance matching terminals are given. L s The parasitic inductance generated by the first and second impedance matching terminals under the action of lightning current. C p ω represents the stray capacitance to ground generated by the first and second impedance matching terminals under the action of lightning current, ω is the upper limit angular frequency of the frequency threshold, and j is the imaginary unit. The traveling wave reflection coefficient calculation model satisfies the following formula: ρ =( R Z L (ω)) / ( R + Z L (oh)) In the above formula, ρ This is the value of the traveling wave reflection. R Let be the theoretical terminating impedance of the first impedance matching terminal and the second impedance matching terminal. Z L (ω) represents the terminal mixed impedance.

10. The surge arrester test method according to claim 9, characterized in that, After the artificial lightning triggering device is activated, based on the lightning current parameters obtained by the device, the lightning current transition frequency is calculated using a double exponential lightning current model, including: After the artificial lightning triggering device is activated, the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning are determined based on the lightning current parameters obtained by the artificial lightning triggering device. The lightning current waveform is constructed based on the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning. Based on the described lightning current waveform, determine the maximum lightning current value and the current peak correction factor; The lightning current turning frequency is calculated using a double exponential model for the maximum lightning current and the peak current correction coefficient. The lightning current double-exponential model satisfies the following formula: ， ， In the above formula, I 0 represents the maximum value of the lightning current. η This is the peak current correction factor. τ 1 represents the rise time of the lightning current in the lightning current parameters. τ 2 represents the delay time of the lightning current in the lightning current parameters. α The first intermediate quantity ，α =1 / τ 2, β As the second intermediate quantity, β =3 / τ 1, where t is the time of lightning current occurrence. It is the natural logarithm; This is the first bend frequency of the lightning current. This is the second bend frequency of the lightning current. Pi is the mathematical constant of a circle.

11. The surge arrester test method according to claim 8, characterized in that, The voltage and current waveforms at each measurement point include at least: the voltage and current waveforms at the beginning of the transmission line, the voltage and current waveforms at the surge arrester connection point of the transmission line, and the voltage and current waveforms at the end of the transmission line. The voltage and current waveforms at each measurement point are analyzed; based on the analysis results, the operating characteristics of the surge arrester are evaluated, including: Based on the voltage and current waveforms at the connection points of the surge arresters of the transmission line, it is determined whether the surge arrester has operated. If the voltage and current waveforms show a conduction pulse and are clamped at the residual voltage level, it is determined that the surge arrester has operated. Based on the voltage and current waveforms at the beginning and end of the transmission line, the theoretical terminal impedances of the first and second impedance matching terminals are determined; based on the theoretical terminal impedances and the traveling wave reflection coefficient calculation model, the traveling wave reflection value is determined; if the traveling wave reflection value is less than a preset threshold, the matching of the first and second impedance matching terminals is deemed valid.

12. A surge arrester test system simulating a lightning current environment, characterized in that, include: The matching terminal determination module is used to perform frequency domain tests on the first and second impedance matching terminals of the surge arrester test device to induce reflection and refraction of the lightning current waveform. The transmission line determination module is used to inject a pulse signal with a preset pulse threshold into one end of the transmission line of the surge arrester test device and collect the voltage signal on the transmission line if the result of the frequency domain test is that the first impedance matching terminal and the second impedance matching terminal will not cause reflection of the lightning current waveform. Based on the voltage signal, it is determined whether the transmission line will reflect or refract the transmitted signal; The acquisition module is used to start the artificial lightning triggering device of the surge arrester test device and acquire the voltage and current waveforms at each measurement point in the transmission line if the determination result is that the transmission line will not reflect the transmitted signal. The evaluation module is used to analyze the voltage and current waveforms at each measurement point; and to evaluate the operation characteristics of the surge arrester based on the analysis results. The surge arrester testing device is the surge arrester testing device according to any one of claims 1-7.

13. The surge arrester testing system according to claim 12, characterized in that, The matching terminal determination module includes: The frequency range determination submodule is used to calculate the lightning current turning frequency based on the lightning current parameters obtained by the artificial lightning triggering device after its activation, using a lightning current double exponential model; and to determine the frequency range of lightning current energy concentration based on the lightning current parameters and the lightning current turning frequency. The terminal mixed impedance calculation submodule is used to calculate the terminal mixed impedance formed by the parasitic inductance and stray capacitance to ground generated by the first impedance matching terminal and the second impedance matching terminal, based on the measured resistance of the first impedance matching terminal and the second impedance matching terminal and according to the pre-built terminal impedance model, if the frequency range of the lightning current energy concentration is within a preset frequency range threshold. The traveling wave reflection value calculation submodule is used to calculate the traveling wave reflection value based on the terminal mixed impedance and using the traveling wave reflection coefficient calculation model. The matching terminal reflection determination submodule is used to determine that the first impedance matching terminal and the second impedance matching terminal will not cause reflection of the lightning current waveform when the traveling wave reflection value is less than a preset coefficient threshold. The terminating impedance model is expressed as follows: Z L (ω) =( R main + jω L s ) / / (1 / jω C p )=( R main + jω L s ) / (1-ω 2 L s C p +jω R main C p ) In the above formula, Z L (ω) represents the terminal mixed impedance. R main The measured resistances of the first and second impedance matching terminals are given. L s The parasitic inductance generated by the first and second impedance matching terminals under the action of lightning current. C p ω represents the stray capacitance to ground generated by the first and second impedance matching terminals under the action of lightning current, ω is the upper limit angular frequency of the frequency threshold, and j is the imaginary unit. The traveling wave reflection coefficient calculation model satisfies the following formula: ρ =( R Z L (ω)) / ( R + Z L (oh)) In the above formula, ρ This is the value of the traveling wave reflection. R Let be the theoretical terminating impedance of the first impedance matching terminal and the second impedance matching terminal. Z L (ω) represents the terminal mixed impedance.

14. The surge arrester testing system according to claim 13, characterized in that, The frequency range determination submodule is specifically used for: After the artificial lightning triggering device is activated, the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning are determined based on the lightning current parameters obtained by the artificial lightning triggering device. The lightning current waveform is constructed based on the lightning return stroke rise time, the average lightning rise time, and the average half-amplitude width of the lightning. Based on the lightning current waveform, determine the maximum lightning current and the current peak correction factor; The lightning current turning frequency is calculated using a double exponential model for the maximum lightning current and the peak current correction coefficient. The lightning current double-exponential model satisfies the following formula: ， ， In the above formula, I 0 represents the maximum value of the lightning current. η This is the peak current correction factor. τ 1 represents the rise time of the lightning current in the lightning current parameters. τ 2 represents the delay time of the lightning current in the lightning current parameters. α The first intermediate quantity ，α =1 / τ 2, β As the second intermediate quantity, β =3 / τ 1, where t is the time of lightning current occurrence. It is the natural logarithm; This is the first bend frequency of the lightning current. This is the second bend frequency of the lightning current. Pi is the mathematical constant of a circle.

15. The surge arrester testing system according to claim 12, characterized in that, The voltage and current waveforms at each measurement point include at least: the voltage and current waveforms at the beginning of the transmission line, the voltage and current waveforms at the surge arrester connection point of the transmission line, and the voltage and current waveforms at the end of the transmission line. The evaluation module is specifically used for: Based on the voltage and current waveforms at the connection points of the surge arresters of the transmission line, it is determined whether the surge arrester has operated. If the voltage and current waveforms show a conduction pulse and are clamped at the residual voltage level, it is determined that the surge arrester has operated. Based on the voltage and current waveforms at the beginning and end of the transmission line, the theoretical terminal impedances of the first and second impedance matching terminals are determined; based on the theoretical terminal impedances and the traveling wave reflection coefficient calculation model, the traveling wave reflection value is determined; if the traveling wave reflection value is less than a preset threshold, the matching of the first and second impedance matching terminals is deemed valid.

16. An electronic device, characterized in that, include: At least one processor and memory; The memory and processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, a surge arrester test method simulating a lightning current environment as described in any one of claims 8 to 11 is implemented.

17. A readable storage medium, characterized in that, It contains an execution program, which, when executed, implements a surge arrester test method simulating a lightning current environment as described in any one of claims 8 to 11.

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