Transmission tower aging detection method and system

Abstract

Embodiments of the present invention disclose a method and system for detecting aging of transmission line towers. The method includes: transmitting a pulsed laser beam to a target area on a transmission line tower via a laser, wherein the pulsed laser beam acts on the target area to generate plasma, wherein the target area is located at any position on the transmission line tower; receiving a plasma radiation beam via a spectrum acquisition device and converting the plasma radiation beam into a spectral signal; acquiring an elemental spectrum of an aging element or an anti-aging element from the spectral signal; determining the content of the aging element or the anti-aging element in the transmission line tower based on the elemental spectrum; and determining whether the transmission line tower is aged based on the content of the aging element or the anti-aging element in the transmission line tower. The technical solution of the embodiments of the present invention implements aging detection of transmission line towers, improving detection efficiency and accuracy.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method and system for detecting aging of transmission line towers. Background Art

[0002] With the increasing demand for electricity, the safety and reliability of transmission lines are becoming increasingly important. Transmission towers are a crucial component of national power transmission. Damage to transmission towers can potentially cause the collapse of the power system. Therefore, regular inspection and maintenance are necessary to check for damage or even breakage of transmission towers. Currently, this requires personnel to conduct on-site inspections of transmission towers one by one, or to collect samples from the towers and then return them to the laboratory for aging testing, which consumes a lot of manpower and time.

[0003] Therefore, a method for detecting transmission line towers is needed to solve the above technical problems. Summary of the Invention

[0004] The embodiments of the present invention provide a method and system for detecting aging of transmission line towers, which realize aging detection of transmission line towers and improve detection efficiency and accuracy.

[0005] In a first aspect, an embodiment of the present invention provides a method for detecting aging of a transmission line tower, characterized by comprising:

[0006] Sending a pulsed laser to a target area on a transmission line tower by a laser, wherein the pulsed laser acts on the target area to generate plasma, and the target area is located at any position on the transmission line tower;

[0007] receiving a plasma radiation beam through a spectrum acquisition device and converting the plasma radiation beam into a spectrum signal; the plasma radiation beam is generated based on the plasma;

[0008] Obtaining element spectra of aging elements or anti-aging elements from spectral signals;

[0009] Obtaining the content of aging elements or anti-aging elements in the transmission line tower according to the element spectrum;

[0010] Based on the content of aging elements or anti-aging elements in the transmission line tower, it is determined whether the transmission line tower is aged.

[0011] In a second aspect, an embodiment of the present invention further provides a transmission line tower aging detection system, characterized by comprising:

[0012] Laser, spectrum acquisition device, element spectrum acquisition module, content determination module and aging judgment module, wherein,

[0013] The laser is used to send pulsed laser light to a target area on a transmission line tower, wherein the pulsed laser light acts on the target area to generate plasma, and the target area is located at any position on the transmission line tower;

[0014] The spectrum acquisition device is used to receive a plasma radiation beam and convert the plasma radiation beam into a spectrum signal; the plasma radiation beam is generated based on the plasma;

[0015] An element spectrum acquisition module, used for acquiring the element spectrum of the aging element or the anti-aging element from the spectrum signal;

[0016] a content determination module, configured to obtain the content of the aging element or the anti-aging element in the transmission line tower according to the element spectrum;

[0017] An aging determination module is used to determine whether the transmission line tower is aged based on the content of aging elements or anti-aging elements in the transmission line tower.

[0018] The technical solution of the embodiments of the present invention uses a laser to transmit pulsed laser light to a target area on a transmission tower. The pulsed laser light acts on the target area to generate plasma. A spectrum acquisition device receives the plasma radiation beam, which is generated based on the plasma. The plasma radiation beam is converted into a spectral signal, from which the content of aging elements or anti-aging elements is obtained. Based on the content of the aging elements or anti-aging elements, the aging of the transmission tower is determined. The technical solution of the embodiments of the present invention can directly perform aging detection on transmission towers without sampling, thereby improving the efficiency of aging detection. Furthermore, the embodiments of the present invention perform aging detection on the transmission tower on-site, converting the plasma radiation beam from the target area to obtain a spectrum. The spectrum of the aging elements or anti-aging elements is then obtained from the spectrum. Based on the spectrum, the content of the aging elements or anti-aging elements in the transmission tower is determined. The aging of the transmission tower is then determined based on the aging elements or anti-aging elements content, rather than visually inspecting the tower. This improves the accuracy of aging detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] in:

[0021] Figure 1Schematic diagram of a flow chart of a method for detecting aging of a transmission line tower in Embodiment 1 of the present invention;

[0022] Figure 2 A schematic diagram of a spectrum intensity in Example 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of an internal standard curve of chromium element in Example 1 of the present invention;

[0024] Figure 4 This is a schematic diagram of an internal standard curve of chlorine in Example 1 of the present invention;

[0025] Figure 5 This is a schematic structural diagram of a fiber-type laser-induced breakdown spectroscopy system in Example 2 of the present invention;

[0026] Figure 6 This is a schematic diagram of the working principle of a laser-fiber coupler in the second embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of a laser focusing optical path structure in the second embodiment of the present invention;

[0028] Figure 8 Schematic diagram of the structure of a single lens probe in embodiment 2 of the present invention;

[0029] Figure 9 This is a schematic diagram of the optical path structure of a single-lens probe in Example 2 of the present invention;

[0030] Figure 10 This is a schematic diagram of the transmission optical path of a pulsed laser and plasma radiation beam in the second embodiment of the present invention;

[0031] Figure 11 This is a structural diagram of a transmission tower aging detection system in Example 3 of the present invention. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] Before describing the technical solution of the embodiment of the present invention, the application scenario of the embodiment of the present invention is exemplarily described:

[0034] In my country, transmission towers are made of two types of materials. The first type is metal, including steel poles and towers. The second type is a mixture of metal and non-metal, including reinforced concrete and prestressed concrete poles. Because transmission towers are exposed to various environmental threats for a long time in the field, they are particularly vulnerable to groundwater containing various chemical components. For example, chloride ions can penetrate into transmission towers. Rebar corrosion caused by chloride ion penetration is the main reason for the shortened lifespan of reinforced concrete transmission towers. For metal transmission towers, a reduction in the chromium content directly affects the corrosion resistance of the metal.

[0035] Currently, most inspections of transmission line towers require manual on-site sampling of the towers and bringing the samples back to the laboratory for analysis. This approach requires extensive manual labor and is time-consuming and labor-intensive. Furthermore, since it is impossible to collect a large number of samples from each transmission line tower, the sample volume is limited, making it difficult to accurately determine the specific corrosion and aging conditions of the transmission line towers. Therefore, embodiments of the present invention provide a method for on-site aging inspection of transmission line towers, enabling online monitoring of key parts of the towers without affecting the normal operation of the transmission line. Laser 510 transmits a pulsed laser to the transmission line tower. The pulsed laser acts on the tower's surface, generating a plasma. During the cooling process, the plasma generates a radiation beam. A spectrum display device receives the plasma radiation beam, obtaining a spectrum corresponding to the plasma radiation beam. From the spectrum, the elemental spectrum of aging elements and / or anti-aging elements is obtained. Based on the elemental spectrum, the content of the aging elements and / or anti-aging elements in the transmission line tower is determined, thereby determining whether the transmission line tower is aged. The method of embodiments of the present invention can achieve on-site inspection of transmission line towers, improving inspection efficiency and accuracy.

[0036] Example 1

[0037] Figure 1 This is a flow chart of a method for detecting aging of transmission line towers provided by an embodiment of the present invention. This embodiment of the present invention is applicable to detecting aging of transmission line towers. The method can be performed by a transmission line tower detection system, which can be implemented in software and / or hardware.

[0038] like Figure 1 As shown, the method for detecting aging of a transmission line tower according to an embodiment of the present invention specifically includes the following steps:

[0039] S110 , sending a pulse laser to a target area on a transmission line tower through the laser 510 , whereby the pulse laser acts on the target area to generate plasma.

[0040] The target area is located anywhere on the transmission tower. It should be noted that the target area can be a critical part of the transmission tower. Aging in this critical part directly impacts the tower's service life. This critical part can be the junction between the tower and its base, the tower itself, or the base of the tower. Of course, the specific location of the target area is not specifically limited here. Laser 510 refers to a device capable of emitting pulsed laser light.

[0041] Specifically, laser 510 emits a pulsed laser toward a target area on a transmission tower, generating plasma there. The pulsed laser can act on the target area to generate plasma there. For example, plasma can be generated on the tower's surface. Because the plasma radiation beam is generated from the plasma itself, that is, the plasma itself generates the plasma radiation beam. Therefore, the plasma generated in this step can pave the way for subsequent conversion of the plasma radiation beam into a spectral signal.

[0042] Optionally, an embodiment of the present invention can use a laser-induced breakdown spectroscopy (LIBS) method to emit a pulsed laser to a target area so that a plasma corresponding to the pulsed laser is obtained on the target area. LIBS can generate transient plasma based on pulsed laser ablation of the target material, and use characteristic radiation with long duration and high radiation intensity during the plasma cooling process as a light source, that is, a plasma radiation beam. By collecting the spectrum of atoms or ions converted from the plasma radiation beam, qualitative identification or quantitative analysis of the elemental components in the target material can be achieved. LIBS uses long-distance optical fiber to transmit laser energy and return spectral signals, which amplifies the remote working capability of LIBS. It can transmit laser pulses over long distances and return plasma radiation beams, effectively enabling staff and optical instruments to detect the aging of transmission towers in places far away from extreme environments. The target material in the embodiment of the present invention refers to a transmission tower.

[0043] S120 , receiving the plasma radiation beam through the spectrum acquisition device 520 and converting the plasma radiation beam into a spectrum signal.

[0044] The spectrum acquisition device 520 can receive the plasma radiation beam and convert it into a spectrum signal. The spectrum acquisition device 520 can be a spectrometer, or can include a spectrometer and an ICCD detector, or can be a combination of a spectrometer, an ICCD detector, and a display device. The display device can be a computer display screen.

[0045] Specifically, the plasma radiation beam is received by the spectrum acquisition device 520 and converted into a spectrum signal. It should be understood that the spectrum signal here refers to all spectra within the range of the spectrum signal that can be received, for example, all spectra with wavelengths between 380 and 760.

[0046] S130: Obtain an element spectrum of an aging element or an anti-aging element from the spectrum signal.

[0047] Among them, the aging element can be chlorine, etc. The anti-aging element can be chromium, etc. It should be understood that the aging element and the anti-aging element can be selected according to actual conditions. In an embodiment of the present invention, if the target area of ​​the transmission line tower is made of metal, the anti-aging element is chromium. If the target area of ​​the transmission line tower is made of mixed materials, the aging element is chlorine. The mixed material can be reinforced concrete, and the metal material can be carbon structural steel, low-alloy high-strength steel, etc. The selection of the aging element or the anti-aging element is determined by the material of the target area.

[0048] Specifically, the aging element or anti-aging element is extracted from the spectrum signal. Each element has a different wavelength in the spectrum signal, so the corresponding element spectrum can be extracted from the spectrum signal according to the wavelength of the aging element or anti-aging element.

[0049] For example, for the measurement of metal elements, the representative spectrum of Z3CN20-09M steel after 50 sub-pulse laser superposition can be seen in Figure 2. It should be noted that the spectrum is expressed in the form of spectral intensity corresponding to each wavelength, so the horizontal axis is wavelength and the vertical axis is spectral intensity, that is, spectral line intensity. The I after the chemical element symbol in the figure indicates that the element is an atom, for example, Ni I represents nickel atom. The II after the chemical element symbol indicates that the element is an ion, for example, Cr II represents chromium ion. It should be understood that Si represents silicon element, Ni represents nickel element, Cr represents chromium element, Co represents cobalt element, Nb represents niobium element, Mn represents manganese element, Fe represents iron element, and Mo represents molybdenum element. As can be seen from the figure, each element has its own wavelength range, and the element spectrum can be intercepted according to the wavelength of the aging element or anti-aging element. The wavelength of nickel atoms is 378.353, the wavelength of silicon atoms is 390.552, the wavelength of chromium ions is 401.247, the wavelength of cobalt atoms is 412.132, the wavelength of silicon ions is 488.320, the wavelength of niobium atoms is 521.910, the wavelength of molybdenum atoms is 525.903, the wavelength of iron atoms is 438.354, the wavelength of chromium atoms is 425.435, and the wavelength of manganese atoms is 403.307. The spectral line intensity of each element in the figure is the average of 50 spectra for that element. In this embodiment of the present invention, the elemental spectrum of chromium atoms is intercepted. Similarly, the elemental spectrum of chlorine atoms is intercepted for the aged element.

[0050] S140. Obtain the content of aging elements or anti-aging elements in the transmission line tower according to the element spectrum.

[0051] The content of aging elements refers to the content of aging elements in the transmission tower. Aging elements can only represent the degree of aging of the target area. In practical applications, it is not necessary to obtain plasma radiation beams in all areas of the transmission tower, which requires a lot of time. Therefore, in an embodiment of the present invention, the aging degree of the target area is set to represent the aging degree of the transmission tower. The content of aging elements can be used as a basis for determining whether the transmission tower is aged. Of course, the selection of the target area is crucial, and the selection of the target area can be set according to actual conditions. For example, in order to improve the accuracy of the aging assessment of the transmission tower, multiple target areas can also be selected to obtain the aging degrees of multiple target areas. Then, if the aging assessment result of any target area is aging, the transmission tower is determined to be aged, or if the aging assessment results of at least two target areas are aging, the transmission tower is determined to be aged. There is no specific limitation on the number of target areas.

[0052] Specifically, the content of aging elements and / or anti-aging elements in the transmission line tower is obtained through elemental spectroscopy, which prepares for the subsequent determination of the aging degree of the transmission line tower based on the aging elements or anti-aging elements.

[0053] Furthermore, in an embodiment of the present invention, obtaining the content of the aging element or anti-aging element in the transmission line tower based on the element spectrum includes: obtaining the content of the aging element or anti-aging element in the transmission line tower based on the ratio of the element spectrum intensity to the internal standard spectrum intensity of a preset internal standard element.

[0054] The content of the element spectrum can be determined using the internal standard method. The internal standard spectrum refers to the spectrum of the internal standard element, and the element spectrum intensity is obtained by converting the element spectrum. The internal standard method is an indirect or relative calibration method. The internal standard element is also called the internal standard substance. When the target area is made of a non-metallic material, the aging element can be chlorine, and the corresponding internal standard element can be calcium. When the target area is made of a metallic material, the anti-aging element can be chromium, and the corresponding internal standard element can be iron.

[0055] Specifically, the element spectrum intensity is divided by the spectrum intensity of the corresponding internal standard element by the internal standard method to obtain a ratio, and the content of the aging element or anti-aging element in the transmission tower is obtained by the ratio.

[0056] For example, in an embodiment of the present invention, an experiment is conducted under laboratory conditions, 40 different positions are uniformly selected on the surface, and 20 pulsed lasers are superimposed at each position to obtain a spectrum. The average value of the 40 spectral intensities is then obtained as the extracted data of the standard sample, and the extracted data is used to establish a calibration curve or calibration model. By the internal calibration method: that is, by the ratio of the analyte to the reference, a calibration curve is constructed relative to the element content. In an embodiment of the present invention, the analyte is the spectral line intensity of the element to be measured, and the reference is the spectral line intensity of the internal standard element. Generally, the internal standard element should be a major element with little variation in content, and a matrix element is usually selected to establish a calibration curve. In the embodiment of the present invention, the matrix element is the internal standard element, which can be iron.

[0057] 1. Select the chromium element spectrum line and the internal standard element spectrum line, and obtain the chromium element internal standard curve according to the intensity ratio of the internal standard element and the element to be measured, see Figure 3 . After experimental verification, the detection limit of chromium is 200ppm. When the chromium content in steel is less than 0.1wt%, the steel will be at risk of corrosion. It should be understood that 0.1wt% means that a certain element accounts for 0.1% of the total weight. The detection limit means that when the content exceeds or falls below the detection limit, the transmission line tower will be at risk of corrosion and aging. In the embodiment of the present invention, the detection limit of the aging element is the preset aging threshold value described below, and the detection limit of the anti-aging element is the preset anti-aging threshold value described below.

[0058] 2. For transmission towers made of a mixture of metal and non-metal elements, for example, reinforced concrete is used as a sample to detect the chlorine content in the sample. Similarly, 40 different positions are evenly selected on the surface of the sample, and 20 pulse laser superpositions are performed at each position to obtain a spectrum. The average value of the 40 spectral intensities is then obtained as the extracted data of the standard sample. The extracted data is used to establish a calibration curve or calibration model. The chlorine atomic spectrum line at 837.6nm is used as the detection spectrum line to obtain a calibration curve, such as Figure 4 Experimental verification shows that the detection limit of chlorine is 1807.2 ppm. When the chlorine content in reinforced concrete exceeds 0.2 wt%, there will be a corrosion risk.

[0059] The above experiments reveal the detection limits of chlorine and chromium. In practical applications, by comparing the chlorine or chromium content in a transmission tower with the respective detection limits, it can be determined whether the tower is at risk of aging. Because aging of transmission towers can cause line damage, resulting in economic losses and even personal safety hazards, in embodiments of the present invention, aging is determined when the content of the aging element exceeds the detection limit, or when the content of the anti-aging element falls below the detection limit. This allows personnel to promptly inspect and repair the tower based on the aging detection results.

[0060] S150. Determine whether the transmission line tower is aged based on the content of aging elements or anti-aging elements in the transmission line tower.

[0061] Specifically, whether the transmission tower is aged is determined based on the content of aging elements or anti-aging elements in the transmission tower. For example, when the content of aging elements in the transmission tower exceeds a preset aging threshold, the transmission tower is determined to be aged. It should be noted that in the embodiment of the present invention, the acquired aging elements and / or anti-aging elements may include multiple elements. However, when the content of any one element does not meet the requirements, the transmission tower is determined to be aged. It should be understood that the requirements here include the content of the aging element exceeding the preset aging threshold or the content of the anti-aging element being less than the preset anti-aging threshold. For example, the aging elements to be detected include chlorine. If the content of chlorine is higher than the preset aging threshold, the detected transmission tower is determined to be aged.

[0062] Furthermore, in an embodiment of the present invention, the determination of whether the transmission tower is aged based on the content of aging elements or anti-aging elements in the transmission tower includes: if the material of the target area is a metal material, and the content of chromium as an anti-aging element in the transmission tower is less than a preset chromium content, then the transmission tower is aged; if the material of the target area is a mixed material, and the content of chlorine as an aging element in the transmission tower is greater than a preset chlorine content, then the transmission tower is aged, and the mixed material includes metal material and non-metal material.

[0063] The preset chromium content can be set differently based on the metal material of the transmission tower and / or the environment in which it is located. For example, if the metal material is steel, the preset minimum chromium content is 200 ppm. Of course, the preset chromium content will also vary for other metals. Similarly, the preset chlorine content can also be set differently based on the mixed material and the environment in which the transmission tower is located. The preset chromium content and the preset chlorine content are not specifically limited here.

[0064] Specifically, if the material of the target area is a metal material, the spectrum of the chromium element is obtained, and then the content of the chromium element is obtained. If the content of the chromium element is less than the preset chromium content, it is determined that the transmission tower is aged. If the material of the target area is a mixed material of metal and non-metal, the spectrum of the chlorine element is obtained, and then the content of the chlorine element is obtained. If the content of the chlorine element is greater than the preset chlorine content, it is determined that the transmission tower is aged. It should be noted that since the transmission tower may include a tower body of a steel frame structure and a base composed of concrete and steel bars, when detecting the aging of the transmission tower, it is necessary to select a target area for detection, and the target area of ​​the transmission tower may be a metal material or a mixed material of non-metal and metal materials. Therefore, before obtaining the aging element or anti-aging element of the target area, the material of the target area is first determined, and then the aging element or anti-aging element related to the material is obtained. In this way, the accuracy of the detection can be improved.

[0065] In the technical solution of the embodiments of the present invention, a laser 510 transmits a pulsed laser to a target area on a transmission tower. The pulsed laser generates a plasma in the target area, and a spectrum acquisition device 520 receives the plasma radiation beam, which is generated based on the plasma. The plasma radiation beam is converted into a spectral signal, from which the content of aging elements or anti-aging elements is obtained. Based on the content of the aging elements or anti-aging elements, the aging of the transmission tower is determined. The technical solution of the embodiments of the present invention allows for direct aging detection of transmission towers without the need for sampling, thereby improving the efficiency of aging detection. Furthermore, the embodiments of the present invention perform aging detection on the transmission tower on-site, converting the plasma radiation beam from the target area to obtain a spectrum. The spectrum of the aging elements or anti-aging elements is then obtained from the spectrum. Based on the spectrum, the content of the aging elements or anti-aging elements in the transmission tower is determined. The aging of the transmission tower is then determined based on the aging elements or anti-aging elements, rather than visually inspecting the tower. This improves the accuracy of aging detection.

[0066] Example 2

[0067] The transmission tower aging detection method provided in the embodiment of the present invention is a preferred embodiment. The technical terms that are the same or similar to those in the above embodiment will not be repeated. The transmission tower aging detection method of the embodiment of the present invention uses a fiber-optic laser-induced breakdown spectroscopy (FO-LIBS) system to perform pulsed laser emission, pulsed laser-fiber coupling, refocusing of the fed pulsed laser beam, and collection and transmission of spectral signals. See Figure 5 It should be noted that the lasers in the embodiments of the present invention all refer to pulsed lasers, and the laser in the following content is the abbreviation of pulsed lasers.

[0068] The fiber-optic laser-induced breakdown spectroscopy system used in the transmission tower aging detection method according to an embodiment of the present invention includes a laser 510, a laser-fiber coupler, a first optical fiber, a second optical fiber, a single-lens probe, a spectrometer and an ICCD detector, a display device, a dichroic mirror, a beam splitter, and an achromatic lens. The single-lens probe refers to the first focusing lens in the following embodiment. The FO-LIBS system according to the embodiment of the present invention is constructed on a precisely controllable motorized displacement platform. In this embodiment of the present invention, the first and second sampling mirrors can be manufactured by Thorlabs, model BSF20-C. The laser energy meter is used to measure the energy of the pulsed laser and display the laser energy for staff to view. The laser energy meter can be model E1000, manufactured by the Institute of Metrology, Chinese Academy of Sciences. The photodetector can be manufactured by Thorlabs, model DET10A. The dichroic mirror can also be a short-pass dichroic mirror, model DMSP805L, manufactured by Thorlabs. The achromatic lens can be manufactured by Thorlabs, model ACN254-040-A. The digital delay generator can be model DG645. It should be understood that the manufacturer and model of the aforementioned laser energy meter, photodetector, and other equipment can be selected based on actual circumstances and are not specifically limited in this embodiment of the present invention.

[0069] To verify the efficiency and accuracy of the FO-LIBS system used in the embodiments of the present invention for detecting transmission tower aging, experiments were conducted under laboratory conditions. Therefore, the area where plasma is generated in the following figures represents the target area on the sample. It should be understood that the lasers used in the following embodiments all refer to pulsed lasers.

[0070] like Figure 5As shown, after emitting a laser beam, it passes through the first sampling mirror, where two laser beams of fixed weights are reflected to a laser energy meter and a photodetector, respectively. Specifically, after passing through the first sampling mirror, a portion of the laser beam is reflected to the laser energy meter, while another portion passes through the first sampling mirror and reaches the second sampling mirror. A portion of this portion passes through the second sampling mirror, forming the main laser beam. The remaining portion of the laser beam passes through the second sampling mirror and is reflected to the photodetector. The laser energy meter monitors the energy of the pulsed laser, while the photodetector records the timing of laser 510. The photodetector is connected to an oscilloscope via a signal line, allowing the operation signals of laser 510 to be displayed on the oscilloscope for easy viewing. Optionally, the first and second sampling mirrors can be beam splitters. Fixed weights mean that a portion of the laser beam is reflected to the laser energy meter or photodetector, while the remaining portion passes through the sampling mirror. The ratio of these two portions of the laser beam is fixed. For example, 20% of the laser beam is reflected to the laser energy meter, while 80% passes through the first sampling mirror. The laser beam that passes through the first and second sampling mirrors is referred to as the main laser beam. After being reflected by a short-pass dichroic mirror, the main laser beam is fed into a first optical fiber via a laser-fiber coupler. The first optical fiber can be a high-power transmission fiber. A fiber connector fixture connects the input and output ends of the first optical fiber. At the output of the first optical fiber, the main laser beam, guided by a single-lens probe, is focused and irradiated onto the sample surface. In a real-world environment, the sample is a transmission line tower. Plasma is generated on the sample surface by the laser focus, generating a plasma radiation beam. This plasma radiation beam is fed into the first optical fiber via a single-lens probe and then back to the laser-fiber coupler. It passes through a short-pass dichroic mirror as a collimated beam. After being focused by an achromatic lens, it is collected by a second optical fiber connected to a spectrometer. The collected plasma radiation beam is transmitted via the second optical fiber to the spectrometer, where it is processed to obtain the spectra of each element in the sample. The spectrometer is connected to two channels of the digital delay generator, each of which can be connected by a cable. The digital delay generator controls the timing of the laser 510, spectrometer, and ICCD detector. The action signals are displayed on an oscilloscope via the gate monitors of the photodetector and ICCD detector, respectively. These signals can indicate the moment a laser is emitted or when an ICCD detector is turned on.

[0071] When building a FO-LIBS system, the positions of various components must be precisely determined to prevent issues such as the pulsed laser failing to reach the target area of ​​the sample and / or failing to receive the plasma radiation beam. Optionally, embodiments of the present invention determine the positions of various components as follows.

[0072] 1. Laser-fiber coupling refers to the process of feeding a laser beam into a transmission fiber after it is focused by a lens. Efficient laser-fiber coupling requires the following two conditions: (1) the laser beam's focused spot diameter must be smaller than the fiber's core diameter; and (2) the focused beam's convergence angle must be smaller than the fiber's aperture angle. This is a sufficient condition to ensure total internal reflection of the laser beam during transmission in the fiber:

[0073]

[0074] Where D1 is the focused spot diameter of the incoming laser beam, D2 is the fiber core diameter, θ1 is the convergence half-angle of the focused beam, and NA is the fiber numerical aperture. Therefore, increasing the fiber core diameter and numerical aperture can reduce the difficulty of laser feeding and improve the efficiency of laser coupling. The above formula can be used to select an appropriate fiber core diameter to ensure that the laser is fully fed into the fiber.

[0075] The embodiment of the present invention builds a laser-fiber coupler, and its working principle is as follows: Figure 6 As shown in the figure, the laser focus waist region is located outside the fiber core end face. The laser focus waist refers to the focal point of the laser. D0 represents the diameter of the pulsed laser beam, f is the focal length of the focusing lens, D1 is the diameter of the focused spot of the input laser beam, d2 is the distance from the fiber core to the focal point, and D2 is the fiber core diameter.

[0076] 2. The distance between the fiber core and the focal point is the key to determining the coupling efficiency. Light is a wave and has diffraction phenomena. It cannot be focused into an ideal point at the focal position of the lens. Therefore, ignoring the spherical aberration of the lens, the minimum spot diameter of the input laser beam that can be achieved can be expressed as:

[0077]

[0078] Among them, D 11 is the minimum spot diameter, M 2 is the beam transmission factor, f is the focal length of the focusing lens, λ is the laser wavelength, and D0 represents the diameter of the pulsed laser beam.

[0079] M 2 It can be further expressed as:

[0080]

[0081] Where Θ is the laser beam divergence angle. Optionally, the factory report for laser 510 states Θ as 2 mrad. D4 is the beam diameter at the initial end of laser 510. In this embodiment of the present invention, since the distance between the laser-fiber coupler and the light output port of laser 510 is less than 20 mm, D4 can be approximately considered to be equal to D0.

[0082] The expression for the minimum spot diameter can be expressed as:

[0083] D 11 = fΘ.

[0084] To calculate the safety value d2 of the distance between the fiber core and the focus, a simplified geometric optical path model can be established. The damage mechanisms of laser-fiber coupling are divided into two categories: First, the focused beam waist region with the highest laser irradiance is too close to the fiber core end face, exceeding the damage threshold of the fiber core end face, which may directly cause fiber damage; Second, the focused beam waist region is inside the fiber core, and the irradiance of the incident laser on the inner surface coating is too high, causing ablation of the coating near the fiber core end face. After a small amount of laser coupling, fiber damage occurs. Therefore, the laser focused beam waist region should be located outside the fiber core end face of the optical fiber and maintain an appropriate distance from the fiber core end face to reduce the focused irradiance reaching the fiber core end face. Therefore, it is necessary to calculate the safety value of the distance between the fiber core and the focus. As Figure 7 shown, under the condition of ignoring the spherical aberration of the lens, the actual focused laser beam L1 can be simplified to an ideal beam L2 with a waist diameter of D 33 . Further ignoring laser diffraction and assuming that the beam in the waist region is parallel, a further simplified ideal beam L3 can be established. The safety value d4 in the simplified model can be deduced from the following formula:

[0085]

[0086] where P1 is the highest achievable focused irradiance ignoring the spherical aberration of the lens, and P2 is the fiber damage threshold. Optionally, the spot diameter D4 of the fiber core end face in the simplified model can be expressed as:

[0087]

[0088] It should be noted that the meanings of the letters in Figure 7 are explained as follows: L1 is the actual laser focused beam, L2 is the ideal laser focused beam ignoring the spherical aberration of the lens, L3 is the ideal focused beam of the simplified linear geometric model, where the waist optical path is parallel, D3 is the actual laser focused beam waist diameter, D 33 is the waist diameter of the ideal beam L2, D4 is the diameter of the simplified model L3 irradiating the fiber core end face, D5 is the diameter of the actual L1 irradiating the fiber core end face, d4 is the minimum safety value of the simplified model L3, d2 is the minimum safety value of the actual L1, and L is the length of the parallel waist optical path in L3.

[0089] By calculating, θ l < arcsin(NA). From Figure 7It can be seen that when the distance between the focus and the core end face of the optical fiber is set to d4, the spot diameter D5 at the actual core end face is obviously larger than the simplified model calculated value D4, resulting in the failure of some laser energy to be coupled into the optical fiber in actual conditions, reducing the coupling efficiency, and the laser focusing irradiance at the core end face is less than the damage threshold. Therefore, d4 can be used as the starting point for optimization and adjustment, moving the core end face toward the beam waist area until the coupling efficiency is improved and stabilized. In the embodiment of the present invention, the safe value of d2 is 4.5 mm. It should be understood that the focus refers to the position of the laser focal length beam waist.

[0090] 3. The other end opposite to the end receiving the laser serves as the output end of the laser. The laser beam is in a divergent state after being fed out. In order to achieve the refocusing of the fed laser, a FO-LIBS probe that can work closely on the surface of the target area needs to be set in front of the output end of the optical fiber, which is referred to as a fiber LIBS probe. A focusing lens is required to prevent the diameter of the divergent beam from exceeding the effective collection aperture of the lens. To this end, the embodiment of the present invention designs and builds a single lens probe based on the imaging principle, such as Figure 8 shown.

[0091] In a single-lens probe, the imaging principle is used to focus the outgoing laser beam: essentially, the end face of the optical fiber output end can have a high-energy-density laser spot, which is placed on the sample surface through the focusing lens. The center height of the sample is the same as the center height of the focusing lens. Conversely, the plasma radiation beam is also sent to the end face of the optical fiber output end through the focusing lens, such as Figure 9 For ease of understanding, the laser spot may refer to the spot image, and the plasma may refer to the plasma image. In this way, the diameter of the laser spot can be determined based on the imaging principle.

[0092] According to the imaging principle, for a given object distance, the corresponding image distance and conjugate position are uniquely determined and should satisfy

[0093]

[0094] Where: u is the object distance, which represents the distance from the end face of the optical fiber output end to the lens; v is the image distance, which represents the distance between the focusing lens and the sample; and f is the focal length of the focusing lens. The object distance must be greater than the focal length of the focusing lens. The spot diameter D7 focused on the sample surface can be expressed as

[0095]

[0096] Where: D6 refers to the spot diameter of the fed laser beam at the fiber end face at the fiber output end, and D6 can be approximately equal to the fiber core diameter.

[0097] Therefore, the laser spot diameter can be controlled by measuring the object distance and image distance. In experiments, a CCD camera can be used to capture an image of the spot on the fiber end face and measure the spot diameter. An ICCD camera can then be used to capture an image of the plasma on the sample surface. The spot diameter can then be adjusted based on the desired plasma image size. Alternatively, the laser spot diameter can be adjusted based on the plasma image during the initial period. The initial period can be the time when the plasma radiation beam is initially received. By determining the spot diameter during this initial period, the positions of the sample, lens, and fiber can be maintained, improving the accuracy and efficiency of plasma generation.

[0098] In the constructed single-lens probe, based on the principle of optical path reversibility, the divergent plasma radiation beam can be collected in reverse by the single-lens probe, and coupled at the end face of the laser beam output end of the first optical fiber, and transmitted back to the laser-fiber coupling end face. The plasma radiation beam is gathered by the single-lens probe to form a collimated beam, which propagates in reverse along the laser optical path. At this time, a dichroic beam splitter can be placed in the front optical path of the laser-fiber coupling to separate the plasma radiation beam from the laser transmission optical path, and the plasma radiation beam is transmitted to the second optical fiber through an achromatic lens. Figure 10 shown.

[0099] Changing the image distance in a single-lens probe affects not only the focused spot size but also the efficiency of the plasma radiation beam's return. The optimal image distance should be determined by analyzing the initial plasma image and seeking the plasma with the highest radiation intensity or the desired size.

[0100] For example, in an embodiment of the present invention, the laser 510 and the laser-fiber coupler are used as an integrated device, which can simultaneously realize functions such as the generation of fiber-transmitted laser, the reception of plasma radiation beams, and laser action. The integrated device may also include a spectrometer and a photodetector. The functions of the photodetector and the spectrometer have been explained in the above embodiments and will not be repeated here. The integrated device and equipment such as the laser energy meter, oscilloscope, and computer can be located in an area far away from the transmission tower, and the integrated device is connected to a single-lens probe operating in an extreme environment through a long-distance high-power optical fiber. By setting it up in this way, the integrated device and equipment such as the spectrometer, oscilloscope, and computer will not be affected by the extreme environment, thereby avoiding errors in the aging detection of transmission towers caused by equipment failure.

[0101] The technical solution of the present invention utilizes a fiber-based laser-induced breakdown spectroscopy system to detect aging of transmission line towers, enabling remote, real-time, nondestructive testing of aging and corrosion of transmission lines. The system primarily detects the chlorine content in reinforced concrete and the chromium content in steel, both of which are important factors affecting transmission tower corrosion. By manipulating the beam waist region of the pulsed laser before entering the fiber, laser-fiber coupling with high transmission efficiency and highly stable energy input is achieved using a quartz fiber with a numerical aperture of 0.37 and a core diameter of 0.8 mm. A single-lens probe is installed at the output end of the fiber, and by adjusting the object and image distances, focusing is achieved down to a minimum diameter of 530 μm. The transmission efficiency of this embodiment of the invention can reach over 80%, and the energy input can reach over 55 mJ. By utilizing fiber-based laser-induced breakdown spectroscopy, this technical solution effectively addresses the problem of rapid, online, and real-time monitoring of aging and corrosion of transmission lines. Furthermore, the optical fiber effectively enables monitoring under conditions that do not affect the normal operation of the transmission line and in extreme environments.

[0102] Example 3

[0103] Figure 11 This is a schematic diagram of the structure of a transmission tower aging detection system provided by an embodiment of the present invention. The transmission tower aging detection system provided by an embodiment of the present invention can execute the transmission tower aging detection method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. The system includes: a laser 510, a spectrum acquisition device 520, an element spectrum acquisition module 530, a content determination module 540, and an aging determination module 550, wherein:

[0104] The laser 510 is used to send a pulsed laser to a target area on a transmission tower. The pulsed laser acts on the target area to generate plasma. The target area is located at any position on the transmission tower. The spectrum acquisition device 520 is used to receive a plasma radiation beam and convert the plasma radiation beam into a spectrum signal. The plasma radiation beam is generated based on the plasma. The element spectrum acquisition module 530 is used to obtain the element spectrum of the aging element or the anti-aging element from the spectrum signal. The content determination module 540 is used to obtain the content of the aging element or the anti-aging element in the transmission tower based on the element spectrum. The aging judgment module 550 is used to determine whether the transmission tower is aged based on the content of the aging element or the anti-aging element in the transmission tower.

[0105] Furthermore, in an embodiment of the present invention, the content determination module 540 further includes:

[0106] The content acquisition submodule is used to obtain the content of the aging element or anti-aging element in the transmission line tower based on the ratio of the element spectrum intensity to the internal standard spectrum intensity of a preset internal standard element, wherein the internal standard spectrum refers to the spectrum of the internal standard element, and the element spectrum intensity is obtained by converting the element spectrum.

[0107] Furthermore, in this embodiment of the present invention, the aging determination module 550 further includes:

[0108] The first judgment submodule is used to determine that if the material of the target area is a metal material and the content of chromium as an anti-aging element in the transmission tower is less than a preset chromium content, the transmission tower is aged; the second judgment submodule is used to determine that if the material of the target area is a mixed material and the content of chlorine as an aging element in the transmission tower is greater than a preset chlorine content, the transmission tower is aged, and the mixed material includes metal material and non-metal material.

[0109] Furthermore, in an embodiment of the present invention, the system further includes:

[0110] a first optical fiber, configured to receive the pulsed laser through the first end of the first optical fiber and transmit the pulsed laser to the target area of ​​the transmission tower through the second end of the first optical fiber; a laser-fiber coupler, connected to the first end of the first optical fiber, configured to focus the pulsed laser onto the first end of the first optical fiber; and a first focusing lens, configured to focus the pulsed laser outputted from the second end of the first optical fiber onto the target area of ​​the transmission tower.

[0111] Specifically, in this embodiment of the present invention, the pulsed laser light emitted by laser 510 is focused onto the first end of a first optical fiber via a laser-fiber coupler. The second end then emits pulsed laser light, which is then focused onto the target area of ​​the transmission tower via a first focusing lens, completing the transmission of the pulsed laser light onto the target area of ​​the transmission tower. Because the pulsed laser light emitted by laser 510 has a relatively large diameter and needs to be focused within the optical fiber, a laser-fiber coupler is used. Since the laser light emitted from the optical fiber is divergent, a first focusing lens is used to focus the pulsed laser light onto the target area.

[0112] Optionally, the pulsed laser emitted by laser 510 first passes through a first sampling mirror, which reflects a portion of the pulsed laser to a laser energy meter for measuring the energy of the pulsed laser, making it easier for staff to view the information. The energy of the pulsed laser is then adjusted based on the energy of the pulsed laser recorded by the laser energy meter. The main beam of the pulsed laser that passes through the first sampling mirror passes through a second sampling mirror, which reflects a portion of the pulsed laser to a photodetector, which records the timing of the pulsed laser transmission. The photodetector is connected to an oscilloscope, which sends the recorded timing to the oscilloscope, which displays the timing of the pulsed laser on the oscilloscope for easier viewing by staff. After being reflected by a short-pass dichroic mirror, the main laser beam is fed into the first end of the first optical fiber through a laser-fiber coupler.

[0113] Furthermore, in an embodiment of the present invention, the first focusing lens is also used to focus the plasma radiation beam generated in the target area to the second end of the first optical fiber, and the system also includes a second optical fiber and a dichroic mirror; the laser fiber coupler is also used to transmit the plasma radiation beam emitted from the first end of the first optical fiber to the second optical fiber, and the second optical fiber is used to receive the plasma radiation beam and send the plasma radiation beam to the spectrum acquisition device 520; the dichroic mirror is used to change the direction of the pulsed laser so that an angle exists between the pulsed laser and the plasma radiation beam.

[0114] Specifically, the pulsed laser acts on the target area to generate plasma, and the first optical fiber receives the plasma radiation beam and transmits the plasma radiation beam to one end of the second optical fiber. The other end of the second optical fiber is connected to the spectrum acquisition device 520. Therefore, the second optical fiber can transmit the plasma radiation beam to the spectrum acquisition device 520. The spectrum acquisition device 520 can be an ICCD detector and a spectrometer. The ICCD detector and the spectrometer cooperate with each other to receive the plasma radiation beam. The dichroic mirror can be a short-pass dichroic mirror, which is used to change the direction of the pulsed laser. In this way, the plasma radiation beam can be prevented from being sent to the laser 510. The plasma radiation beam can pass through the dichroic mirror and be transmitted to the second optical fiber. The dichroic mirror does not affect the transmission of the plasma radiation beam, but affects the transmission of the laser beam, that is, the dichroic mirror can reflect the pulsed laser onto the laser fiber coupler. See. Figure 5 Optionally, the ICCD detector can be an Andor scientific-grade ICCD camera-DH334, and the spectrometer can be an SR750 ultra-high-resolution spectrometer. The SR-750, combined with the Andor scientific-grade ICCD camera-DH334, facilitates simultaneous acquisition and measurement of multi-point spectra.

[0115] Furthermore, in an embodiment of the present invention, the spectrum acquisition device 520 includes a spectrum receiving module and a display module, and the display module includes a spectrometer and an ICCD detector; the spectrum receiving module is used to receive the plasma radiation beam, convert the plasma radiation beam into a spectrum signal, and send the spectrum signal to the display module; the display module is used to receive the spectrum signal sent by the spectrum receiving module and display the spectrum signal.

[0116] Specifically, the plasma radiation beam is received by a spectrometer and an ICCD detector and converted into a spectrum. Optionally, the display module can be a computer monitor, which transmits the spectrum to the computer for display on the computer screen. Optionally, the element spectrum acquisition module 530, the content determination module 540, and the aging determination module 550 can refer to functional modules within the computer. The computer has received the spectral signal and processes the spectral signal through the element spectrum acquisition module 530, the content determination module 540, and the aging determination module 550.

[0117] Furthermore, in an embodiment of the present invention, the system further includes: a digital delay generator for controlling the timing of the laser 510 emitting pulsed laser light and the timing of the spectrum receiving module receiving the plasma radiation beam.

[0118] Optionally, the system further includes an oscilloscope, and the digital delay generator is connected to the oscilloscope to display the timing.

[0119] The technical solution of the embodiment of the present invention includes a laser 510 that sends a pulsed laser to a target area on a transmission line tower. The pulsed laser acts on the target area to generate plasma. The target area is located at any position on the transmission line tower. It also includes a spectrum acquisition device 520 for receiving a plasma radiation beam and converting the plasma radiation beam into a spectrum signal. The plasma radiation beam is generated based on the plasma. An element spectrum acquisition module 530 is used to obtain the element spectrum of the aging element or the anti-aging element from the spectrum signal. A content determination module 540 is used to obtain the content of the aging element or the anti-aging element in the transmission line tower based on the element spectrum. An aging judgment module 550 is used to judge whether the transmission line tower is aged based on the content of the aging element or the anti-aging element in the transmission line tower. The technical solution of the embodiment of the present invention can directly perform aging detection on the transmission line tower without the need for sampling, thereby improving the efficiency of aging detection. Furthermore, the embodiment of the present invention performs on-site aging detection on the transmission line tower, obtains a spectrum by converting the plasma radiation beam generated in the target area, and obtains the spectrum of the aging element or the anti-aging element from the spectrum. Based on the spectrum, the content of the aging element or the anti-aging element in the transmission line tower is obtained, and then whether the transmission line tower is aged is determined based on the content of the aging element or the anti-aging element, rather than observing whether the transmission line tower is aged with the naked eye, thereby improving the accuracy of aging detection of the transmission line tower.

[0120] It is worth noting that the various modules included in the above system are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the embodiments of the present invention.

[0121] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A transmission line tower aging detection method, applied to a transmission line tower aging detection system, characterized in that: include: Sending a pulsed laser to a target area on a transmission line tower by a laser, wherein the pulsed laser acts on the target area to generate plasma, and the target area is located at any position on the transmission line tower; receiving a plasma radiation beam through a spectrum acquisition device and converting the plasma radiation beam into a spectrum signal; the plasma radiation beam is generated based on the plasma; Obtaining element spectra of aging elements or anti-aging elements from spectral signals; Obtaining the content of aging elements or anti-aging elements in the transmission line tower according to the element spectrum; Determining whether the transmission line tower is aged based on the content of aging elements or anti-aging elements in the transmission line tower; The method of obtaining the content of the aging element or the anti-aging element in the transmission line tower according to the element spectrum includes: Obtaining the content of the aging element or anti-aging element in the transmission line tower according to the ratio of the element spectrum intensity to the internal standard spectrum intensity of a preset internal standard element, wherein the internal standard spectrum refers to the spectrum of the internal standard element, and the element spectrum intensity is obtained by conversion of the element spectrum; The transmission line tower aging detection system includes: a first optical fiber, configured to receive the pulsed laser light through a first end of the first optical fiber and transmit the pulsed laser light to a target area of ​​the transmission tower through a second end of the first optical fiber; a laser-fiber coupler connected to the first end of the first optical fiber, and configured to focus the pulsed laser onto the first end of the first optical fiber; a first focusing lens, configured to focus the pulsed laser outputted from the second end of the first optical fiber onto a target area of ​​the transmission line tower; The method further includes: setting a preset condition in the laser-fiber coupler, wherein the preset condition includes: in, D 1 is the focal spot diameter of the input laser beam, D 2 is the fiber core diameter, θ 1 is the convergence half angle of the focused beam, NA is the numerical aperture of the optical fiber, and the laser beam is the pulsed laser; The minimum spot diameter of the focused laser beam is: in, D 11 is the minimum spot diameter, M 2 is the beam transmission factor, f is the focal length of the first focusing lens, λ is the laser wavelength, D 0 is the diameter of the pulsed laser beam; The diameter of the light spot focused on the sample surface is: in, D 7 is the spot diameter focused on the sample surface, D 6 is the spot diameter of the fed laser beam at the fiber end face at the output end of the fiber, u is the object distance, which indicates the distance from the end face of the optical fiber output end to the lens; v is the image distance, which represents the distance between the focusing lens and the sample, wherein the sample is a sample of the target area on the transmission line tower; The determining whether the transmission line tower is aged based on the content of the aging element or the anti-aging element in the transmission line tower includes: If the target area is made of metal and the content of chromium as an anti-aging element in the transmission tower is less than a preset chromium content, the transmission tower is aged. If the material of the target area is a mixed material, and the content of chlorine as an aging element in the transmission tower is greater than a preset chlorine content, the transmission tower is aged, and the mixed material includes metal material and non-metal material.

2. The method for detecting aging of a transmission line tower according to claim 1, wherein: The transmission line tower aging detection system also includes: Laser, spectrum acquisition device, element spectrum acquisition module, content determination module and aging judgment module, wherein, The laser is used to send pulsed laser light to a target area on a transmission line tower, wherein the pulsed laser light acts on the target area to generate plasma, and the target area is located at any position on the transmission line tower; The spectrum acquisition device is used to receive a plasma radiation beam and convert the plasma radiation beam into a spectrum signal; the plasma radiation beam is generated based on the plasma; An element spectrum acquisition module, used for acquiring the element spectrum of the aging element or the anti-aging element from the spectrum signal; a content determination module, configured to obtain the content of the aging element or the anti-aging element in the transmission line tower according to the element spectrum; An aging determination module is used to determine whether the transmission line tower is aged based on the content of aging elements or anti-aging elements in the transmission line tower.

3. The method for detecting aging of transmission line towers according to claim 2, characterized in that: The content determination module also includes: The content acquisition submodule is used to obtain the content of the aging element or anti-aging element in the transmission line tower based on the ratio of the element spectrum intensity to the internal standard spectrum intensity of a preset internal standard element, wherein the internal standard spectrum refers to the spectrum of the internal standard element, and the element spectrum intensity is obtained by converting the element spectrum.

4. The method for detecting aging of transmission line towers according to claim 3, characterized in that: The aging determination module further includes: A first judgment submodule is configured to determine that if the material of the target area is metal and the content of chromium as an anti-aging element in the transmission line tower is less than a preset chromium content, the transmission line tower is aged; The second judgment submodule is configured to determine that if the material of the target area is a mixed material and the content of chlorine as an aging element in the transmission tower is greater than a preset chlorine content, the transmission tower is aged, and the mixed material includes metal material and non-metal material.

5. The method for detecting aging of transmission line towers according to claim 1, characterized in that: The first focusing lens is also used to focus the plasma radiation beam generated in the target area to the second end of the first optical fiber. The system also includes a second optical fiber and a dichroic mirror; The laser-fiber coupler is also used to transmit the plasma radiation beam emitted from the first end of the first optical fiber to the second optical fiber. The second optical fiber is used to receive the plasma radiation beam and send the plasma radiation beam to the spectrum acquisition device; The dichroic mirror is used to change the direction of the pulsed laser so that an angle exists between the pulsed laser and the plasma radiation beam. The plasma radiation beam passes through the dichroic mirror and is transmitted to the second optical fiber.

6. The method for detecting aging of transmission line towers according to claim 2, characterized in that: The spectrum acquisition device includes a spectrum receiving module and a display module, and the display module includes a spectrometer and an ICCD detector; The spectrum receiving module is used to receive the plasma radiation beam, convert the plasma radiation beam into a spectrum signal, and send the spectrum signal to the display module; The display module is used to receive the spectrum signal sent by the spectrum receiving module and display the spectrum signal.

7. The method for detecting aging of transmission line towers according to claim 6, characterized in that: The transmission line tower aging detection system also includes: The digital delay generator is used to control the timing of the laser emitting pulsed lasers and the timing of the spectrum receiving module receiving the plasma radiation beam.

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