A method and system for crossarm lightning impulse testing

Abstract

This invention relates to the field of lightning impulse technology, and more particularly to a method and system for testing lightning impulse on a crossarm. The method includes: applying a minimum impulse voltage to discharge the crossarm at any preset position using an impulse voltage generator; acquiring the waveform of this minimum impulse voltage using an oscilloscope; obtaining the actual value of the minimum impulse voltage based on the waveform; calculating the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained; and fitting the lightning impulse insulation strength at all preset positions to obtain a functional relationship characterizing the relationship between the preset position and the lightning impulse insulation strength. This functional relationship can effectively guide the use of crossarms in oil pipeline power supply lines, playing a crucial role in ensuring the reliable and stable operation of oil pipeline stations.

Description

Technical Field

[0001] This invention relates to the field of lightning strike technology, and in particular to a method and system for crossarm lightning strike testing. Background Technology

[0002] The power supply lines at oil pumping stations are more prone to failure during thunderstorms and strong winds. Furthermore, these lines are erected at low heights and operate in complex, unpredictable outdoor environments, resulting in insulation levels far lower than those of the main power grid transmission lines, significantly increasing the probability of failure. If lightning strikes near these power lines, electromagnetic induction can induce overvoltages, leading to wire breaks and insulator explosions. Incomplete statistics indicate that lightning strikes account for over 70% of power line tripping incidents at oil pumping stations annually. Therefore, ensuring the safe operation of oil pumping stations and reducing lightning-induced power line tripping incidents is an urgent issue.

[0003] Crossarms are widely used in power supply lines at oil pipeline stations as insulators and fittings, supporting conductors and lightning protection wires to ensure normal power transmission. Currently, commonly used crossarms in this type of line include iron crossarms and insulated crossarms. Compared to traditional iron crossarms, insulated crossarms can significantly improve the insulation level of the line. Commonly used insulated crossarms are made of ceramic, fiberglass, and composite materials, and their shapes include square and round rods. Insulated crossarms can significantly increase the insulation distance between the conductor and the tower, increase the discharge gap, and reduce the flashover rate of the insulator. However, current research mainly focuses on crossarm structural tests and vibration aging tests, while the effects of crossarm type on enhancing the lightning resistance of towers, reducing line tripping rates, and the impact on personal safety are not systematically studied and lack experimental verification. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for crossarm lightning impulse testing, which addresses the shortcomings of the prior art.

[0005] The technical solution of the present invention for a crossarm lightning impulse test method is as follows:

[0006] A test platform for the power supply line of the oil pumping station was constructed, and the crossarm was fixed to the cement tower of the test platform;

[0007] An impulse voltage generator applies a minimum impulse voltage to discharge the crossarm at any preset position. An oscilloscope acquires the waveform of the minimum impulse voltage and obtains the actual value of the minimum impulse voltage based on the waveform. The processor calculates the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained.

[0008] The processor fits the lightning impulse insulation strength at all preset locations to obtain a functional relationship characterizing the preset location and the lightning impulse insulation strength.

[0009] The beneficial effects of the crossarm lightning impulse test method of the present invention are as follows:

[0010] Utilizing functional relationships can effectively guide the use of crossarms in oil pumping station power supply lines, playing a crucial role in ensuring the reliable and stable operation of these stations. Promoting the application of this invention's technical solution can also enhance the scientific nature of lightning protection for oil pumping station power supply lines, reduce investment in lightning protection upgrades, and thus possess significant economic value.

[0011] The technical solution of the crossarm lightning impulse testing system of the present invention is as follows:

[0012] Includes: an impulse voltage generator, a processor, and a test platform for the power supply lines of the oil pumping station, wherein the test platform is equipped with crossarms on a cement tower;

[0013] An impulse voltage generator applies a minimum impulse voltage to discharge the crossarm at any preset position. An oscilloscope acquires the waveform of the minimum impulse voltage and obtains the actual value of the minimum impulse voltage based on the waveform. The processor calculates the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained.

[0014] The processor fits the lightning impulse insulation strength at all preset locations to obtain a functional relationship characterizing the preset location and the lightning impulse insulation strength.

[0015] The beneficial effects of the crossarm lightning impulse testing system of the present invention are as follows:

[0016] Utilizing functional relationships can effectively guide the use of crossarms in oil pumping station power supply lines, playing a crucial role in ensuring the reliable and stable operation of these stations. Promoting the application of this invention's technical solution can also enhance the scientific nature of lightning protection for oil pumping station power supply lines, reduce investment in lightning protection upgrades, and thus possess significant economic value. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a method for conducting a crossarm lightning impulse test according to an embodiment of the present invention.

[0018] Figure 2 This is one of the structural schematic diagrams of a crossarm lightning impulse test system according to an embodiment of the present invention;

[0019] Figure 3This is a second schematic diagram of the structure of a crossarm lightning impulse test system according to an embodiment of the present invention;

[0020] The attached diagram lists the components represented by each number as follows:

[0021] 1. Cement pole; 2. Iron crossarm; 3. Insulated crossarm; 4. Insulator; 5. Impulse voltage generator; 6. Oscilloscope; 7. Voltage divider; 8. High-speed camera; 9. Simulated conductor; 10. High-voltage lead; 11. Rogowski coil; 12. Grounding lead. Detailed Implementation

[0022] like Figure 1 As shown, an embodiment of the present invention provides a method for conducting a crossarm lightning impulse test, comprising the following steps:

[0023] S1. Construct a test platform for the power supply line of the oil pumping station and fix the crossarm to the cement tower 1 of the test platform;

[0024] Among them, the crossarm is either iron crossarm 2 or insulated crossarm 3.

[0025] S2. The impulse voltage generator 5 applies a minimum impulse voltage to discharge the crossarm at any preset position. The oscilloscope 6 acquires the waveform of the minimum impulse voltage and obtains the actual value of the minimum impulse voltage based on the waveform. The processor calculates the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained.

[0026] The process by which the impulse voltage generator 5 applies the minimum impulse voltage to discharge the crossarm at any preset position is as follows:

[0027] Combination Figure 2 and Figure 3 To explain, at any preset position on the crossarm, the insulator 4, the impulse voltage generator 5 applies a minimum impulse voltage to the crossarm through the insulator 4 installed at any preset position on the crossarm.

[0028] The preset position can be understood as follows:

[0029] Any point on the crossarm is used as the base point. The distance between any position where an insulator 4 is installed and the base point is used as the preset position. For example, the base point can be any end of the crossarm or the middle of the crossarm.

[0030] S3. The processor fits the lightning impulse insulation strength at all preset locations to obtain a functional relationship characterizing the preset location and the lightning impulse insulation strength.

[0031] Based on this functional relationship, the lightning impulse insulation strength at any position of the crossarm can be calculated, which can effectively guide the use of crossarms in oil pumping station power supply lines and plays an important role in ensuring the reliable and stable operation of oil pumping stations. Promoting the use of the technical solution of this invention can also enhance the scientific nature of lightning protection for oil pumping station power supply lines, reduce the investment in line lightning protection upgrades, and has high economic value.

[0032] Optionally, in the above technical solution, the process of the impulse voltage generator 5 applying the minimum impulse voltage to the crossarm includes:

[0033] The impulse voltage generator 5 uses a step-up / step-down method to adjust the impulse voltage applied to the crossarm, in order to apply the minimum impulse voltage required to discharge the crossarm. The step-up / step-down method is as follows:

[0034] First, estimate the value U′ of the lightning impulse insulation strength at any predetermined location on the crossarm. 50％ Take 3% of the estimated value as the step size ΔU for reducing pressure, that is, ΔU = 3%U′ 50％ If the initial applied impulse voltage does not trigger a discharge, then U′ 50％ +ΔU is used as the next impulse voltage and applied to the preset position of the crossarm. If the first applied impulse voltage has already caused a discharge, then U′ 50％ -ΔU is used as the next impulse voltage, and so on, to obtain the minimum impulse voltage used to discharge the crossarm.

[0035] Depending on the actual situation, the step size for increasing or decreasing pressure can be set to 1% or 2% of the estimated value.

[0036] In another embodiment, the above process is performed multiple times at the same preset position, with the number of times ranging from 20 to 40 times. It can also be set according to the actual situation to obtain multiple actual values ​​of the minimum impact voltage for the crossarm to discharge. Then, the average value is taken as the final minimum value of the minimum impact voltage for the crossarm to discharge.

[0037] Optionally, the above technical solution further includes: a camera device acquiring discharge photographs of the crossarm discharge, so as to determine the discharge path of the crossarm relative to ground based on the discharge photographs, specifically:

[0038] The discharge path of the crossarm relative to ground is determined manually based on the discharge photographs. The imaging device is a high-speed camera 8.

[0039] The following describes another embodiment of the present invention for a crossarm lightning impulse test method, including:

[0040] S100, Construct a test platform for the power supply line of a 10kV oil transfer station:

[0041] First, the overhead crane erects and fixes the 10kV concrete tower 1 to the ground. A 2m long iron crossarm 2 is then fixed to the top of the tower 1 using clamps. An insulator 4 is fixed to the opening on the crossarm 2. A 2m long steel pipe is used as a simulated bare conductor. The simulated conductor 9 is fixed in the groove at the top of the insulator 4. A high-voltage lead 10 from the impulse voltage generator 5 is added to the simulated conductor 9 and electrically connected to either end of the simulated conductor 9. The iron crossarm 2 is effectively grounded through the grounding lead 12. Figure 2 As shown.

[0042] S101. Constructing the experimental observation platform:

[0043] Oscilloscope 6 is connected to the signal output port of voltage divider 7, which is paired with impulse voltage generator 5, for measuring voltage. A Rogowski coil 11 is threaded onto the grounding lead 12, and the coil's output is connected to another input terminal of oscilloscope 6 for measuring current. A high-speed camera is mounted on a tripod 15m from the concrete tower. The tripod height is adjusted so that the lens is at the same height as the crossarm, and the camera angle is adjusted to ensure the entire crossarm is centered in the lens for observing the discharge process and path. Oscilloscope 6, high-speed camera, and impulse voltage generator 5 output three control signals to the control room. The device operates after commands are issued from the control room, ensuring the safety of high-voltage test personnel. A processor is installed in the control room, such as... Figure 2 As shown.

[0044] S102. Determine the test method:

[0045] Using a negative polarity standard lightning impulse voltage wave with a wavefront time of 1.2 μs (allowable deviation ±30%) and a half-wave peak time of 50 μs (allowable deviation ±20%), the lightning impulse insulation strength U′ of the tower is first estimated. 50％ Take the expected ΔU = 3%U′ 50％ As the step size for increasing and decreasing voltage, if the first applied impulse voltage does not cause a discharge, then the next applied voltage is U′. 50％ If +ΔU causes a discharge, the next applied voltage will be U′. 50％ -ΔU, and so on, following this pattern with each voltage increase, repeating the voltage increase 20-40 times, and statistically analyzing the voltage U at each stage. i Number of pressurizations n i Find the corresponding U. 50％ The formula is as follows:

[0046]

[0047] Conduct 30 lightning impulse discharge tests according to the given rise and fall method. Record the test data and voltage and current waveforms, and take discharge photographs, including the discharge development process and discharge path.

[0048] S103. Test the insulating crossarm 3:

[0049] Replace the iron crossarm 2 with an epoxy resin insulated crossarm 3, 2.4m in length. Drill holes every 20cm at the top of the insulated crossarm 3 to fix insulators 4. The distances from the base of insulator 4 to the fixing bolts are 100cm, 80cm, 60cm, and 40cm respectively. Fix the line insulators 4 at distances of 100cm, 80cm, 60cm, and 40cm from the fixing bolts, which is half the equivalent length of the insulated crossarm 3. Figure 3 As shown, the clamp is effectively grounded through grounding down conductor 12. Thirty lightning impulse discharge tests were conducted using the same rise-fall method, and test data, voltage and current waveforms, and discharge photographs were recorded, including the discharge development process and discharge path.

[0050] S104. Organize the experimental data:

[0051] Based on the captured discharge photographs, the discharge paths to ground under different types of crossarms are classified, including discharge from insulator 4 through breakdown and along the crossarm surface to the grounded clamp, and discharge from the conductor binding point through air gap breakdown directly to the clamp. Next, the influence of the fixed position of insulator 4 on the discharge path is considered, and U is plotted. 50％ Quantitative analysis was performed on the fitted curve of the relationship between insulator 4 and the distance to the clamp. A comprehensive comparative analysis was conducted on the effects of installing iron crossarm 2 and insulated crossarm 3 on enhancing the lightning impulse insulation strength U of the tower. 50％ The study aimed to reduce the impact of line tripping rates and draw reasonable conclusions.

[0052] The control room can be equipped with a processor, such as a computer, to send control signals to the impulse voltage generator 5 and the oscilloscope 6, so that the impulse voltage generator 5 and the oscilloscope 6 can perform their respective functions.

[0053] In the above embodiments, although the steps are numbered S1, S2, etc., they are only specific embodiments given in this application. Those skilled in the art can adjust the execution order of S1, S2, etc. according to the actual situation, which is also within the protection scope of this invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0054] like Figure 2 and Figure 3 As shown, an embodiment of the present invention provides a crossarm lightning impulse test system, which includes an impulse voltage generator 5, a processor, and a test platform for the power supply line of an oil pumping station. A crossarm is provided on the cement tower 1 of the test platform.

[0055] The impulse voltage generator 5 applies a minimum impulse voltage to discharge the crossarm at any preset position. The oscilloscope 6 acquires the waveform of the minimum impulse voltage and obtains the actual value of the minimum impulse voltage based on the waveform. The processor calculates the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained.

[0056] The processor fits the lightning impulse insulation strength at all preset locations to obtain a functional relationship characterizing the preset locations and the lightning impulse insulation strength.

[0057] Utilizing functional relationships can effectively guide the use of crossarms in oil pumping station power supply lines, playing a crucial role in ensuring the reliable and stable operation of these stations. Promoting the application of this invention's technical solution can also enhance the scientific nature of lightning protection for oil pumping station power supply lines, reduce investment in lightning protection upgrades, and thus possess significant economic value.

[0058] Optionally, in the above technical solution, the impulse voltage generator 5 applies a minimum impulse voltage to the crossarm through an insulator 4 installed at any preset position on the crossarm.

[0059] Optionally, in the above technical solution, the impulse voltage generator 5 uses a rise-fall method to adjust the impulse voltage applied to the crossarm in order to apply the minimum impulse voltage that causes the crossarm to discharge.

[0060] Optionally, the above technical solution further includes: a camera device acquiring discharge photos of the crossarm discharge, so as to determine the discharge path of the crossarm relative to the ground based on the discharge photos.

[0061] Optionally, in the above technical solution, the crossarm is an iron crossarm 2 or an insulated crossarm 3.

[0062] The parameters and steps for each unit module to achieve their respective functions in the crossarm lightning impulse test system of the present invention described above can be referred to the parameters and steps in the embodiments of the crossarm lightning impulse test method described above, and will not be repeated here.

[0063] Those skilled in the art will know that this invention can be implemented as a system, method, or computer program product.

[0064] Therefore, this disclosure can be implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, the invention can also be implemented as a computer program product in one or more computer-readable media, the computer-readable medium containing computer-readable program code.

[0065] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0066] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for crossarm lightning impulse testing, characterized in that, include: A test platform for the power supply line of the oil pumping station was constructed, and the crossarm was fixed to the cement tower of the test platform; The overhead crane erects the concrete tower and fixes it to the ground. The iron crossarm is fixed 1.5m away from the top of the concrete tower using clamps. The insulator is fixed at the opening position on the iron crossarm. A steel pipe is used as a simulated bare conductor. The middle part of the simulated conductor is fixed in the groove at the top of the insulator. The high-voltage lead from the impulse voltage generator is added to the simulated conductor and electrically connected to either end of the simulated conductor. The iron crossarm is effectively grounded through the grounding lead. An oscilloscope is connected to the signal output port of a voltage divider that is paired with the impulse voltage generator to measure voltage. A Rogowski coil is connected to the grounding lead, and the coil output is connected to another input port of the oscilloscope. A high-speed camera is mounted on a tripod 15m away from the concrete tower. The tripod height is adjusted so that the lens and the crossarm are at the same height. The camera angle is adjusted to ensure that the entire crossarm is centered in the lens. This camera is used to observe the discharge process and discharge path. The oscilloscope, high-speed camera, and impulse voltage generator output control signals to the control room. The device operates after the control room issues a command. A processor is installed in the control room. An impulse voltage generator applies a minimum impulse voltage to discharge the crossarm at any preset position. An oscilloscope acquires the waveform of the minimum impulse voltage and obtains the actual value of the minimum impulse voltage based on the waveform. The processor calculates the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained. The processor fits the lightning impulse insulation strength at all preset locations to obtain a functional relationship characterizing the preset location and the lightning impulse insulation strength. The impulse voltage generator applies a minimum impulse voltage to the crossarm through an insulator installed at any preset position on the crossarm; The process by which the impulse voltage generator applies the minimum impulse voltage to the crossarm includes: The impulse voltage generator uses a rise-fall method to adjust the impulse voltage applied to the crossarm in order to apply the minimum impulse voltage that causes the crossarm to discharge. The specific details of the rising and falling method are as follows: The estimated value U' of the lightning impulse insulation strength at any predetermined position of the crossarm. 50％ Take 3% of the estimated value as the step size ΔU for reducing pressure, that is, ΔU = 3%U′ 50％ If the initial applied impulse voltage does not trigger a discharge, then U′ 50％ +ΔU is used as the next impulse voltage and applied to the preset position of the crossarm. If the first applied impulse voltage has already caused a discharge, then U′ 50％ -ΔU is used as the next impulse voltage until the minimum impulse voltage required to discharge the crossarm is obtained.

2. The method for crossarm lightning impulse testing according to claim 1, characterized in that, Also includes: The camera device captures discharge photos of the crossarm to determine the discharge path of the crossarm relative to ground based on the discharge photos.

3. The method for crossarm lightning impulse testing according to claim 1, characterized in that, The crossarm is either an iron crossarm or an insulated crossarm.

4. A crossarm lightning impulse testing system, characterized in that, include: A test platform for an impulse voltage generator, oscilloscope, processor, and power supply lines for an oil pumping station, wherein the test platform is equipped with crossarms on a cement tower; The impulse voltage generator applies a minimum impulse voltage to discharge the crossarm at any preset position. The oscilloscope acquires the waveform of the minimum impulse voltage and obtains the actual value of the minimum impulse voltage based on the waveform. The processor calculates the lightning impulse insulation strength at the preset position of the crossarm based on the discharge path of the crossarm relative to ground and the actual value of the minimum impulse voltage, until the lightning impulse insulation strength at each preset position of the crossarm is obtained. The processor fits the lightning impulse insulation strength at all preset positions to obtain a function relationship characterizing the relationship between the preset position and the lightning impulse insulation strength; The gantry crane erects the cement pole tower and fixes it on the ground. The iron cross arm is fixed at a position 1.5 m away from the top of the cement pole tower through the hoop fitting. The insulator is fixed at the opening position on the iron cross arm. A steel pipe is taken as the simulated bare conductor. The middle of the simulated conductor is fixed in the groove at the top of the insulator. The high-voltage lead wire led out by the impulse voltage generator is applied to the simulated conductor and is electrically connected to any one end of the simulated conductor. The iron cross arm is effectively grounded through the grounding lead wire; The oscilloscope is connected to the signal output port of the voltage divider supporting the impulse voltage generator for measuring the voltage. A Rogowski coil is sleeved on the grounding lead wire, and the output end of the coil is connected to another input end of the oscilloscope. The high-speed camera is installed on a tripod 15 m away from the cement pole tower. The height of the tripod is adjusted until the lens is at the same height as the cross arm position. The camera angle is adjusted to ensure that the entire cross arm is located in the center of the lens for observing the discharge process and the discharge path. The oscilloscope, the high-speed camera, and the impulse voltage generator lead out control signals to the control room, and the device operates after receiving instructions from the control room. Among them, a processor is set in the control room; the impulse voltage generator applies the minimum impulse voltage to the cross arm through the insulator at any preset position installed on the cross arm; The impulse voltage generator adjusts the impulse voltage applied to the cross arm by the lift method to apply the minimum impulse voltage that causes the cross arm to discharge; The specific lift method is as follows: The estimated value U' of the lightning impulse insulation strength at any predetermined position of the crossarm. 50％ Take 3% of the estimated value as the step size ΔU for reducing pressure, that is, ΔU = 3%U′ 50％ If the initial applied impulse voltage does not trigger a discharge, then U′ 50％ +ΔU is used as the next impulse voltage and applied to the preset position of the crossarm. If the first applied impulse voltage has already caused a discharge, then U′ 50％ -ΔU is used as the next impulse voltage until the minimum impulse voltage required to discharge the crossarm is obtained.

5. The crossarm lightning impulse testing system according to claim 4, characterized in that, It also includes: The imaging device collects the discharge photos of the cross arm discharging to determine the discharge path of the cross arm relative to the ground according to the discharge photos.

6. The crossarm lightning impulse testing system according to claim 4, characterized in that, The cross arm is an iron cross arm or an insulating cross arm.

Images