X-ray flaw detection system based on high-voltage overhead line maintenance

Abstract

The invention discloses an X-ray flaw detection system based on high-voltage overhead line maintenance, which belongs to the technical field of overhead transmission line detection and comprises a high-voltage pulse power supply module, an X-ray emission module, an X-ray imaging plate module, an image processing module, a positioning compensation module, a wireless communication module, a high-voltage insulation module and a data analysis module. According to the invention, the detection precision can be improved, manual intervention is reduced, and the purpose of safely and efficiently detecting the high-voltage overhead line is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of overhead power transmission line detection, and in particular relates to an X-ray flaw detection system based on high-voltage overhead line maintenance. Background Art

[0002] The connections of the conductors and ground wires of domestic overhead transmission lines are mostly made of crimping-type power fittings - tension clamps and straight joint pipes. They must bear all the tension of the conductors and ground wires, and are also electrical conductors. They will not be disassembled after installation. In the process of materials, processes, production, construction, acceptance, etc., if the conductors and ground wires are not firmly and precisely fitted in the crimping pipes or are not fully penetrated, or the steel core crimping does not meet the requirements, it will bury major hidden dangers for the safe operation of the line. In the power transmission and distribution system, the tension clamp, as the core connection component of the overhead conductor, bears the dual functions of mechanical load transmission and electrical conduction. The quality of its crimping is directly related to the safety of the power grid operation. Once there are defects such as steel core breakage, empty pressure in the aluminum tube or pressure leakage in the anti-skid groove, it may cause major accidents such as line breakage and arc discharge.

[0003] At present, the main method for inspecting crimped tension clamps is for high-altitude workers to climb the pole to install the imaging board and flaw detection host, and then evacuate to a safe area before taking pictures. This inspection method has many disadvantages: ‌1. High safety risk, prominent hidden dangers for personnel and equipment‌: Operators need to climb to the top of the tower to install equipment, which is prone to slipping, falling, and other accidents due to strong winds, rain, snow, or ice on the tower. If the flaw detector host and imaging plate are not firmly fixed during installation, they may fall from a high altitude, endangering personnel and equipment on the ground. The X-ray flaw detector needs to be started in an unsheltered environment, and the operators still need to rely on visual confirmation of the safe distance after evacuation, but radiation leakage is prone to occur in complex terrain, causing potential health damage to surrounding personnel.

[0004] 2. Low detection efficiency and high operation and maintenance costs: From climbing the pole to installing, debugging the equipment to completing the shooting, the detection of a single tension clamp takes a long time. If the shooting angle needs to be adjusted, the time may double. At least two certified high-altitude workers are required to work together, and radiation safety officers are required to supervise the whole process. When repairing in remote areas or at night, human resources are difficult to allocate, resulting in delayed detection.

[0005] 3. Inspection quality is restricted by environmental and human factors: the installation angle of equipment in high-altitude operations relies on manual visual adjustment, which is prone to inclination deviation, resulting in stretching and distortion of X-ray images or blurring of key areas, requiring repeated shooting. In addition, wind speed and temperature changes are likely to affect the inspection results.

[0006] ‌4. Limited coverage and difficult to adapt to complex working conditions: In dense transmission corridors or towers across rivers, it is difficult for operators to carry equipment to specific locations, resulting in blind spots in detection.

[0007] ‌5. Data management is lagging behind and it is difficult to support intelligent decision-making: The inspection data needs to be manually exported by the operators after returning to the ground and then uploaded to the analysis system. The average delay from shooting to generating reports is 2-4 hours, which cannot support rapid response to faults. The image parameters taken by different operators vary greatly, resulting in an increased false alarm rate of the defect recognition model.

[0008] In summary, the existing overhead transmission line detection has significant defects in safety, efficiency, and detection quality. Summary of the invention

[0009] The purpose of the present invention is to provide an X-ray flaw detection system based on high-voltage overhead line maintenance, which can improve detection accuracy, reduce manual intervention, and achieve the purpose of safe and efficient detection of high-voltage overhead lines.

[0010] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows: X-ray flaw detection system based on high voltage overhead line maintenance, including: High-voltage pulse power supply module, used to generate high-voltage pulses to drive the X-ray emission module, charge the energy storage capacitor through the resonant charging circuit, and quickly release energy to achieve high-voltage pulse output; X-ray emission module, which emits electrons through cathode filament heating, accelerates to form electron beam under high voltage electric field, and bombards metal target to generate X-rays; X-ray imaging plate module, which receives X-rays that penetrate the tension clamp, converts the X-rays into visible light through the scintillator layer, and then generates digital image signals through the photoelectric conversion layer; The image processing module performs defect recognition and 3D reconstruction on the original image output by the X-ray imaging plate module and generates a visual inspection report; Positioning compensation module, real-time monitoring of the relative position between the tension clamp and the probe, dynamic correction of scanning path deviation, to ensure detection accuracy; Wireless communication module, encrypts and transmits detection data to the remote terminal and receives control instructions; High-voltage insulation module isolates high-voltage circuits from low-voltage systems to prevent corona discharge or insulation breakdown; Data analysis module, which integrates image data, equipment status and environmental parameters to generate inspection reports and maintenance recommendations; The output voltage of the high-voltage pulse power supply module satisfies: ,in is the critical electric field strength of air medium, is the electrode gap distance, Optimizing coefficients for experiments .

[0011] Further defined, the working steps of the high voltage pulse power module are: S101, receiving external AC power input, and filtering out high-frequency interference and electromagnetic noise through an inductor-capacitor filter circuit; S102, the rectifier circuit converts the AC power into pulsating DC power, and then outputs a smooth DC voltage through the voltage stabilizing circuit; S103, starting the resonant charging circuit to perform high-frequency resonant charging on the energy storage capacitor through transformer coupling; S104, monitor the capacitor voltage in real time during the charging process, and switch to a constant voltage charging mode when the capacitor voltage reaches a preset threshold; S105, boosting the energy of the energy storage capacitor through a pulse transformer to generate a high-voltage pulse; S106, monitor the output current and voltage in real time, if a load short circuit or overvoltage is detected, immediately turn off the switch group and start the discharge circuit to release the residual energy.

[0012] The high voltage pulse power supply module adopts a cascade Generator topology, the output pulse width calculation formula is: ,in is the cascade number, It is a single-stage energy storage capacitor. is the load equivalent resistance.

[0013] It is further defined that the image processing module has the following working steps: S401, performing histogram equalization on the original image to enhance visibility of details in low-contrast areas; S402, eliminating geometric distortion and correcting image stretching caused by shape or position deviation of the tension clamp; S403, automatically identifying defective areas; S404, classifying and labeling according to the defect morphology distribution characteristics; S405, fusing multi-angle projection data to generate a three-dimensional defect model.

[0014] In the above step S405, the specific steps of generating the three-dimensional defect model are: S4051, the X-ray emission module performs a 360° rotation scan on the tension clamp, collects a penetration image every 10°, and generates 36 sets of two-dimensional projection data in total; S4052. Correct the projection distortion caused by the irregular shape of the tension clamp through feature point matching and regional block adjustment technology to ensure that the multi-angle projection is aligned in a unified coordinate system; S4053, using wavelet transform to filter out metal artifacts and speckle noise and enhance the contrast of defective areas; S4054, back-projecting the 36 sets of two-dimensional projection data into three-dimensional space to generate an initial voxel model; S4055. Use the MLEM algorithm for 8 iterations to correct the grayscale distribution of cracks and pores inside the tension clamp and improve the model resolution. S4056, segment the defect area based on the dynamic threshold method, remove isolated noise points through morphological closing operation, and retain the continuous defect structure; S4057, extract crack length, pore volume and slag inclusion distribution density; S4058, load the pre-trained 3D model, automatically classify the defects according to their morphological features, and annotate the confidence level; S4059. Render the model in pseudo-color: red indicates high-risk cracks, yellow indicates pores, and green indicates slight slag inclusions.

[0015] The image processing module in the present invention plays the role of optimizing the original image, extracting defect features and standardizing data. It solves the shortcomings of image distortion, noise interference and low efficiency of manual interpretation in traditional detection, and has the following advantages: ‌1. Aiming at the problem of sudden changes in X-ray absorption rate caused by the material difference between the steel core and the aluminum tube in the tension clamp, the image processing module can suppress high-frequency noise and improve the grayscale uniformity of the aluminum tube crimping area. After noise suppression, the misjudgment rate of key defects such as steel core breakage and aluminum tube pressure leakage is greatly reduced compared with traditional manual interpretation.

[0016] 2. Based on the structural characteristics of the tension clamp, the image processing module can improve the detail resolution of the loose strands of the aluminum wire and identify smaller defect sizes.

[0017] 3. In view of the image smear caused by wind shaking of the imaging plate during high-altitude operations, the image processing module can restore the clear outline and effectively control the sharpness error of the edge of the anti-skid groove.

[0018] 4. The image processing module can realize automatic stitching of images from different shooting angles, and can completely cover the 1.5-meter-class ultra-long tension clamp, avoiding the problem of missed detection caused by segmented detection. Combining the clamp model with the shooting parameters to correct the perspective distortion, the error of the aluminum tube ovality measurement is greatly reduced.

[0019] 5. The image processing module can reconstruct the defect volume, output quantitative parameters, generate defect heat map and trend analysis report, and guide operation and maintenance personnel to prioritize high-risk wire clamps.

[0020] It is further defined that the positioning compensation module has the following working steps: S501, collect the rotation angle and displacement data of the tension clamp in real time through a high-precision encoder to eliminate the projection offset caused by system vibration; S502, dynamically adjusting the rotation center coordinates based on the geometric features of the multi-angle projection image to ensure that the 360° scanning trajectory is consistent with the theoretical model; S503, extracting the key structure of the tension clamp as a feature point to achieve spatial alignment of multi-angle projection images; S504, correcting the distortion of the projection image by using a radial distortion model to improve the accuracy of three-dimensional reconstruction; S505, mapping the defect area detected in the projection image to a three-dimensional coordinate system, and calculating the spatial coordinates of the defect in the tension clamp by using a back-projection algorithm; S506, performing weighted averaging on the positions of the same defect in projections at different angles to eliminate occlusion errors in single-view detection; S507. Dynamically adjust the X-ray energy and exposure time according to the thickness and density of the tension clamp material to ensure the contrast of the penetration imaging of the defect area; S508, using piecewise linear transformation to standardize the grayscale values ​​of the multi-angle projection images to eliminate the grayscale inconsistency problem of the voxel model caused by X-ray energy fluctuations; S509: Transmit the compensated data to the image processing module in real time, and iteratively update the defect model.

[0021] The positioning compensation module in the present invention realizes accurate defect positioning, eliminates environmental interference and ensures detection consistency. Through dynamic space calibration, multi-source error compensation and intelligent path planning, it solves the problem of reduced detection accuracy caused by equipment jitter, posture deviation and environmental disturbance in high-altitude operations, and has the following advantages: 1. Correct the relative position of the X-ray source and detector in three-dimensional space in real time to ensure the stability of the imaging geometry.

[0022] 2. The spatial coordinates of the equipment and the tension clamp are acquired in real time to eliminate the random jitter error caused by wind. In a strong wind environment, the imaging offset caused by equipment jitter can still be controlled to meet the acceptance standards for UHV lines.

[0023] 3. The device posture can be adjusted dynamically so that the center of the beam is always aimed at the target area. It supports non-steady-state working conditions such as shaking of aerial work vehicles and swinging of wires, without the need to repeatedly adjust the device position.

[0024] 4. It can compensate for the impact of equipment mechanical errors, temperature drift and operation deviations on the test results, and avoid the problem of inconsistent winter / summer test standards caused by temperature drift.

[0025] 5. Automatically generate efficient detection paths based on the wire clamp model, spatial obstacle distribution and detection priority.

[0026] It is further defined that the working steps of the data analysis module are: S701. Eliminate shot noise and metal artifacts in X-ray images and improve the contour clarity of the aluminum tube crimping area and steel anchor groove in the tension clamp; S702. Based on the material difference between the aluminum tube wall thickness and the steel core diameter, the image contrast of different detection devices is unified using a segmented grayscale mapping algorithm; S703, based on the reference features of the steel anchor pull ring and aluminum tube port of the tension clamp, the image distortion caused by the shooting angle deviation is eliminated through affine transformation; S704, locating the anti-skid groove contour by edge detection algorithm, and identifying the lack of pressing or pressure leakage defects; S705, based on the gray threshold segmentation of the steel core, detecting defects such as the steel core being broken and not being inserted into the bottom of the steel anchor; S706, using connected domain analysis to determine the proportion of scattered aluminum wires; S707, calculating the average gap between the groove and the contact surface of the aluminum tube, and evaluating the ellipticity of the aluminum tube after crimping by ellipse fitting; S708. Generate a risk distribution map based on defect location, density and historical data to guide operation and maintenance priorities; S709, synchronize defect data to the system in real time, and support query of historical inspection records by line and tower number; S7010, generate a test report, including defect X-ray images, 3D positioning coordinates and processing suggestions.

[0027] The data analysis module in the present invention can realize the functions of deep defect analysis, dynamic risk assessment and operation and maintenance strategy optimization, converting the original detection data into executable operation and maintenance instructions, significantly improving the safety and economy of the power grid. It has the following advantages: 1. Based on X-ray image features and historical database, automatic identification of defect types and dynamic classification of risk levels are achieved.

[0028] 2. Integrate image grayscale distribution, texture features and geometric parameters to construct a high-dimensional feature vector that covers typical defects such as aluminum tube crimping gaps, steel core cracks, and loose strands.

[0029] 3. Based on the defect size, location and line load, through the correlation analysis of multi-cycle detection data, the defect evolution trend is predicted and the maintenance cycle is optimized, and disposal suggestions such as "immediate maintenance" and "continuous monitoring" are automatically triggered.

[0030] It is further defined that the vacuum tube of the X-ray emission module adopts a tantalum-tungsten composite target material, and its emission efficiency satisfies: ,in is the accelerating voltage, is the target atomic number, is the tube temperature, is the cathode-anode distance.

[0031] It is further defined that the working steps of the X-ray emission module are: S201, starting the low voltage power supply to heat the cathode filament to make it emit thermal electrons; S202, receiving a high-voltage electric field applied by a high-voltage pulse power module to accelerate the electron beam, and focusing the electron beam to a tiny focus on the target surface through an electromagnetic lens; S203, high-speed electrons bombard the target material to produce continuous X-ray spectrum and characteristic X-rays; S204, controlling the X-ray energy distribution and penetration capability by adjusting the anode voltage and beam intensity; S205: If the target temperature is detected to be abnormal, a power reduction mode or emergency shutdown protection is triggered.

[0032] The X-ray emission module in the present invention can realize the functions of high-energy ray generation, penetration parameter optimization and safety protection, and has the following advantages: 1. In view of the material differences of the multi-layer composite structure of the tension clamp (steel core, aluminum tube, and crimping area), the X-ray energy and dose are dynamically adjusted to ensure imaging clarity in areas of different thickness.

[0033] 2. Suppress the interference of wind vibration, temperature drift and power supply fluctuation on the quality of radiation during high-altitude operations to ensure imaging consistency.

[0034] 3. Through precise energy control, dynamic stability compensation and multi-scenario adaptation design, the problems of insufficient penetration of traditional X-ray equipment, high imaging noise and poor adaptability to high-altitude operations have been solved.

[0035] It is further defined that the X-ray imaging plate module has the following working steps: S301, the X-rays penetrating the tension clamp irradiate the scintillator layer, and stimulate the scintillator to emit visible light photons; S302, converting visible light into analog electrical signals; S303, digitizing the analog electrical signal to generate an original grayscale image matrix; S304: Pack the pre-processed image data into a standardized format and transmit it to the image processing module.

[0036] The X-ray imaging plate module in the present invention realizes the functions of receiving ray signals, digitalizing images and enhancing defect features, and has the following advantages: 1. Accurately capture X-ray signals and achieve wide dynamic range imaging, ensuring that details of materials with different densities such as steel core and aluminum tube are clearly visible at the same time.

[0037] 2. Through algorithm optimization and hardware collaboration, high-altitude environmental vibration, scattered noise and equipment background interference are eliminated to improve image availability.

[0038] 3. Through high-sensitivity detection, dynamic noise reduction and intelligent image optimization technology, the misjudgment problems caused by image blur, insufficient contrast and environmental interference in high-altitude detection are solved.

[0039] It is further defined that the working steps of the high voltage insulation module are: S601, arranging an annular voltage-equalizing cover around the high-voltage electrode, controlling the electric field distribution through gradient resistance, and suppressing local discharge; S602, real-time monitoring of leakage current, if the leakage current exceeds the safety threshold, triggering an audible and visual alarm and cutting off the high voltage output; S603. Conduct insulation resistance tests regularly and record historical data to predict aging trends; S604: When the insulation resistance value drops to a critical point, the maintenance personnel are prompted to replace system components.

[0040] In view of the problems of low efficiency, high risk and insufficient precision in traditional manual pole climbing detection, the X-ray flaw detection system based on high-voltage overhead line maintenance of the present invention is carried on a drone for use. Through intelligent, lightweight and full-scenario adaptation design, it realizes efficient identification and safe operation and maintenance of hidden defects of high-voltage overhead lines. The advantages are mainly reflected in the following aspects: 1. There is no need for operators to climb the tower or operate at close range. The whole process can be remotely controlled through drone collaboration, which improves detection efficiency and safety, reduces operation and maintenance costs and improves power grid reliability.

[0041] 2. Real-time flaw detection of tension clamps and joint pipes can be completed without power outage, and the inspection time of single-base towers is greatly reduced compared with the traditional power outage mode.

[0042] 3. Adapt to complex terrains such as across canyons and rivers, and adapt to complex working conditions.

[0043] 4. Through multi-level ray penetration and intelligent image processing technology, accurate positioning of hidden defects such as steel core fracture and crimping gap can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings; Figure 1 It is a schematic diagram of a module of the present invention; Figure 2 This is a working diagram of the high voltage pulse power supply module of the present invention; Figure 3 is a working flow chart of the X-ray emission module in the present invention; Figure 4 This is a working flow chart of the X-ray imaging plate module in the present invention; Figure 5 is a workflow diagram of the image processing module in the present invention; Figure 6 This is a working diagram of the positioning compensation module in the present invention; Figure 7 This is a working diagram of the high voltage insulation module of the present invention; Figure 8 It is a workflow diagram of the data analysis module in the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0046] At present, the main method for inspecting crimped tension clamps is for high-altitude workers to climb the pole to install the imaging board and flaw detection host, and then evacuate to a safe area before taking pictures. This inspection method has significant defects in terms of safety, efficiency, and inspection quality.

[0047] At present, the research direction is mainly from the following contents. First, for the design and optimization of the integrated body structure of UAVs, for the complex operating environment of high-altitude power transmission lines, the integrated body structure design of UAVs is carried out, and the selection and optimization of lightweight and high-strength body materials are studied to ensure the flight stability and wind resistance of UAVs in complex high-altitude environments. Second, research on X-ray imaging and intelligent recognition technology. Develop an X-ray image defect recognition algorithm based on deep learning, and study the automatic recognition and classification methods of defective images, including the accurate recognition of defects such as leakage, undervoltage, burrs, and deformation. Study image enhancement and denoising technology to improve the resolution and detection accuracy of X-ray images, and provide support for high-quality intelligent analysis. Third, demonstration application verification. System application verification is carried out in the actual operating environment of high-voltage transmission lines to analyze the detection accuracy, operation efficiency and stability of the system.

[0048] Among them, focusing on the research on X-ray imaging and intelligent recognition technology, an X-ray flaw detection system based on high-voltage overhead line maintenance has been developed. This system, when used in conjunction with drones, can improve detection accuracy, reduce manual intervention, and achieve the goal of safe and efficient detection of high-voltage overhead lines.

[0049] like Figure 1-Figure 8 As shown, the X-ray flaw detection system based on high-voltage overhead line maintenance of the present invention includes: High-voltage pulse power supply module, used to generate high-voltage pulses to drive the X-ray emission module, charge the energy storage capacitor through the resonant charging circuit, and quickly release energy to achieve high-voltage pulse output; X-ray emission module, which emits electrons through cathode filament heating, accelerates to form electron beam under high voltage electric field, and bombards metal target to generate X-rays; X-ray imaging plate module, which receives X-rays that penetrate the tension clamp, converts the X-rays into visible light through the scintillator layer, and then generates digital image signals through the photoelectric conversion layer; The image processing module performs defect recognition and 3D reconstruction on the original image output by the X-ray imaging plate module and generates a visual inspection report; Positioning compensation module, real-time monitoring of the relative position between the tension clamp and the probe, dynamic correction of scanning path deviation, to ensure detection accuracy; Wireless communication module, encrypts and transmits detection data to the remote terminal and receives control instructions; High-voltage insulation module isolates high-voltage circuits from low-voltage systems to prevent corona discharge or insulation breakdown; Data analysis module, which integrates image data, equipment status and environmental parameters to generate inspection reports and maintenance recommendations; The high-voltage pulse power supply module is connected to the X-ray emission module through the voltage-resistant shielded wire of the high-voltage insulation module, the X-ray imaging board module is connected to the image processing module through a multi-channel data bus, and each module forms a distributed architecture with the central controller through the CAN bus.

[0050] The output voltage of the high-voltage pulse power supply module meets the following requirements: ,in is the critical electric field strength of air medium, is the electrode gap distance, Optimizing coefficients for experiments , The calculation formula is in is the environmental interference weight, is the temperature gradient, For humidity, is the material deformation weight, is the thermal expansion coefficient of the target material, is the system running time, is the sensor drift weight, when When the system defaults to the minimum safety threshold ;when When the system self-check protocol is triggered, the sensor and environmental parameters are recalibrated.

[0051] For example: , , wind speed disturbance = 8m / s (reflected by IMU drift), , sensor drift , The weight distribution is: , , Substitute into the dynamic correction equation: When the calculation result ‌Out of preset range When the system triggers the following actions: ‌Force lock ; Recollect temperature, humidity and wind speed data. If the wind speed disturbance continues to exceed the standard, reduce the environmental weight. To 0.5, increase the sensor weight To 0.2, recalculate value, , it is necessary to further optimize the sensor calibration algorithm or limit the system operating parameters under extreme working conditions.

[0052] The working steps of the high-voltage pulse power supply module in the present invention are: S101, receiving external AC power input, and filtering out high-frequency interference and electromagnetic noise through an inductor-capacitor filter circuit; S102, the rectifier circuit converts the AC power into pulsating DC power, and then outputs a smooth DC voltage through the voltage stabilizing circuit; S103, starting the resonant charging circuit to perform high-frequency resonant charging on the energy storage capacitor through transformer coupling; S104, monitor the capacitor voltage in real time during the charging process, and switch to a constant voltage charging mode when the capacitor voltage reaches a preset threshold; S105, boosting the energy of the energy storage capacitor through a pulse transformer to generate a high-voltage pulse; S106, monitor the output current and voltage in real time, if a load short circuit or overvoltage is detected, immediately turn off the switch group and start the discharge circuit to release the residual energy.

[0053] The high-voltage pulse power supply module adopts a cascaded Marx generator topology, and its output pulse width calculation formula is: in, is the cascade number, The value of refers to the IEC 61000-4-30 electromagnetic compatibility standard. Can meet the anti-interference requirements in industrial environments; Avoid harmonic interference with the communication frequency band, Single-stage energy storage capacitor , is the load equivalent resistance .

[0054] The vacuum tube of the X-ray emission module uses a tantalum-tungsten composite target material, and its emission efficiency meets the following requirements: in, is the accelerating voltage (kV), is the target atomic number, is the tube temperature, is the cathode-anode distance.

[0055] The working steps of the X-ray emission module in the present invention are: S201, starting the low voltage power supply to heat the cathode filament to make it emit thermal electrons; S202, receiving a high-voltage electric field applied by a high-voltage pulse power module to accelerate the electron beam, and focusing the electron beam to a tiny focus on the target surface through an electromagnetic lens; S203, high-speed electrons bombard the target material to produce continuous X-ray spectrum and characteristic X-rays; S204, controlling the X-ray energy distribution and penetration capability by adjusting the anode voltage and beam intensity; S205: If the target temperature is detected to be abnormal, a power reduction mode or emergency shutdown protection is triggered.

[0056] The X-ray imaging plate module of the present invention has the following working steps: S301. The X-rays penetrating the tension clamp irradiate the scintillator layer, thereby exciting the scintillator to emit visible light photons.

[0057] S302, converting visible light into analog electrical signals.

[0058] S303, digitizing the analog electrical signal to generate an original grayscale image matrix.

[0059] S304: Pack the pre-processed image data into a standardized format and transmit it to the image processing module.

[0060] The image processing module in the present invention works as follows: S401, performing histogram equalization on the original image to enhance visibility of details in low-contrast areas; S402, eliminating geometric distortion and correcting image stretching caused by shape or position deviation of the tension clamp; S403, automatically identifying defective areas; S404, classifying and labeling according to the defect morphology distribution characteristics; S405, fusing multi-angle projection data to generate a three-dimensional defect model.

[0061] In the above step S405, the specific steps of generating the three-dimensional defect model are: S4051, X-ray emission module performs 360° rotation scanning on the tension clamp, collects a penetration image every 10°, and generates 36 sets of two-dimensional projection data; detector resolution: 1024×1024 pixels, X-ray energy 160kV, exposure time 300ms; S4052. Correct the projection distortion caused by the irregular shape of the tension clamp through feature point matching and regional block adjustment technology to ensure that the multi-angle projection is aligned in a unified coordinate system; S4053, using wavelet transform to filter out metal artifacts and speckle noise and enhance the contrast of defective areas; S4054, back-projecting the 36 sets of two-dimensional projection data into three-dimensional space to generate an initial voxel model; S4055. Use the MLEM algorithm for 8 iterations to correct the grayscale distribution of cracks and pores inside the tension clamp and improve the model resolution to 0.05 mm³.

[0062] S4056, segment the defect area based on the dynamic threshold method, remove isolated noise points through morphological closing operation, and retain the continuous defect structure; S4057, extract crack length, pore volume and slag inclusion distribution density; S4058, load the pre-trained 3D model, automatically classify the defects according to their morphological features, and annotate the confidence level; S4059. Pseudo-color rendering of the model: red indicates high-risk cracks (depth > 1 mm), yellow indicates pores (volume < 0.1 mm³), and green indicates slight slag inclusions.

[0063] The working steps of the positioning compensation module in the present invention are as follows: S501, collect the rotation angle and displacement data of the tension clamp in real time through a high-precision encoder to eliminate the projection offset caused by system vibration; S502, dynamically adjusting the rotation center coordinates based on the geometric features of the multi-angle projection image to ensure that the 360° scanning trajectory is consistent with the theoretical model; S503, extracting key structures of the tension clamp (such as steel anchor grooves and aluminum tube crimping areas) as feature points to achieve spatial alignment of multi-angle projection images; S504, correcting the distortion of the projection image by using a radial distortion model to improve the accuracy of three-dimensional reconstruction; S505, mapping the defective area (such as cracks and pores) detected in the projection image to a three-dimensional coordinate system, and calculating the spatial coordinates of the defect in the tension clamp by combining a back-projection algorithm; S506, performing weighted averaging on the positions of the same defect in projections at different angles to eliminate occlusion errors in single-view detection; S507. Dynamically adjust the X-ray energy and exposure time according to the thickness and density of the tension clamp material to ensure the contrast of the penetration imaging of the defect area; S508, using piecewise linear transformation to standardize the grayscale values ​​of the multi-angle projection images to eliminate the grayscale inconsistency problem of the voxel model caused by X-ray energy fluctuations; S509: Transmit the compensated data to the image processing module in real time, and iteratively update the defect model.

[0064] In the above step S506, the method of weighted averaging the positions of the same defect in different angle projections is illustrated by taking the detection of the pores (diameter 0.2 mm) inside the tension clamp as an example. Assuming that the coordinates of the pores are detected by projection at three different viewing angles (0°, 120°, 240°) (as shown in Table 1), the precise three-dimensional position is calculated by weighted averaging:

[0065] According to the formula , substitute the data, the final coordinates The Euclidean distance between the coordinates of view 3 (2.8, 3.9, 2.2) and the mean (2.25, 3.48, 1.78) is , set the threshold to 0.5mm, determine that the angle 3 is an abnormal value, remove it and recalculate , the actual coordinates of the pores verified by CT scanning are (2.20, 3.45, 1.75) mm, and the initial weighted average error is: , Error after optimization: , The positioning error is optimized from 0.06mm to 0.04mm, meeting the defect detection standards for power equipment.

[0066] The working steps of the high voltage insulation module in the present invention are: S601. Arrange an annular voltage-equalizing cover around the high-voltage electrode, control the electric field distribution through gradient resistance, and suppress local discharge.

[0067] S602, real-time monitoring of leakage current, if the leakage current exceeds the safety threshold, triggering an audible and visual alarm and cutting off the high voltage output.

[0068] S603. Perform insulation resistance tests regularly and record historical data to predict aging trends.

[0069] S604: When the insulation resistance value drops to a critical point, the maintenance personnel are prompted to replace system components.

[0070] The creepage distance of the high voltage insulation module meets the following requirements: in, is the rated voltage (kV), is the material correction factor , Environmental factors .

[0071] in The value of is obtained by the following method: ‌Low resistance segment ‌: Assuming instrument error ±5%, temperature drift: ±8%, capacitive error: ±5%, total error: ; ‌High resistance segment ‌: Assuming instrument error: ±1%, temperature drift: ±3%, capacitive error: ±2%. Total error: ; Actual resistance With measured value relation: ; When the deviation is extremely negative: ; When the deviation is extremely positive: ; ‌Low resistance segment: Theory , but need to be superimposed, long-term stability attenuation (2%): ; Electromagnetic interference (+5%): .

[0072] High resistance section: theory , but need to be superimposed, long-term stability attenuation (2%): ; Electromagnetic interference (+5%): .

[0073] ‌Final range‌: Take the expanded result of the most severe working condition (low resistance section) and round it to ‌1.2~1.8. ‌ The value of is obtained by the following method: Assume standard environment: 25℃, , at this time ; For every deviation of temperature from ±10℃, the correction value is ±0.1; for every deviation of humidity from ±20%, the correction value is ±0.1; the correction formula is: ,in is the actual ambient temperature, is the actual humidity of the environment. If the calculated result exceeds 0.8~1.2, directly take the boundary value.

[0074] The working steps of the data analysis module in the present invention are: S701. Eliminate shot noise and metal artifacts in X-ray images and improve the contour clarity of the aluminum tube crimping area and steel anchor groove in the tension clamp; S702. Based on the material difference between the aluminum tube wall thickness and the steel core diameter, the image contrast of different detection devices is unified using a segmented grayscale mapping algorithm; S703, based on the reference features of the steel anchor pull ring and aluminum tube port of the tension clamp, the image distortion caused by the shooting angle deviation is eliminated through affine transformation; S704, locating the anti-skid groove contour by edge detection algorithm, and identifying the lack of pressing or pressure leakage defects; S705, based on the gray threshold segmentation of the steel core, detecting defects such as the steel core being broken and not being inserted into the bottom of the steel anchor; S706, using connected domain analysis to determine the proportion of scattered aluminum wires; S707, calculating the average gap between the groove and the contact surface of the aluminum tube, and evaluating the ellipticity of the aluminum tube after crimping by ellipse fitting; S708. Generate a risk distribution map based on defect location, density and historical data to guide operation and maintenance priorities; S709, synchronize defect data to the system in real time, and support query of historical inspection records by line and tower number; S7010, generate a test report, including defect X-ray images, 3D positioning coordinates and processing suggestions.

[0075] The workflow of the system of the present invention is: ‌Start-up phase‌: The high-voltage pulse power supply module starts according to the partition voltage climbing strategy, driving the X-ray emission module to generate X-rays.

[0076] ‌Scanning phase‌: The X-ray imaging module captures the penetration signal, and the positioning compensation module synchronously corrects the probe position deviation.

[0077] Result output: After the image processing module identifies the defect, the wireless communication module encrypts and uploads the report to the cloud platform.

[0078] ‌Safety protection‌: The high-voltage insulation module monitors leakage current in real time, cuts off high-voltage output and triggers an alarm in case of abnormality‌.

[0079] The above is a detailed introduction to the X-ray flaw detection system based on high-voltage overhead line maintenance provided by the present invention. The description of the specific embodiment is only used to help understand the method and its core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. X-ray flaw detection system based on high voltage overhead line maintenance, characterized by: include High-voltage pulse power supply module, used to generate high-voltage pulses to drive the X-ray emission module, charge the energy storage capacitor through the resonant charging circuit, and quickly release energy to achieve high-voltage pulse output; ‌ The X-ray emission module emits electrons through heating of the cathode filament, which are accelerated under a high-voltage electric field to form an electron beam, bombarding the metal target to generate X-rays; ‌ The X-ray imaging plate module receives the X-rays that penetrate the tension clamp, converts the X-rays into visible light through the scintillator layer, and then generates digital image signals through the photoelectric conversion layer; ‌ The image processing module performs defect recognition and 3D reconstruction on the original image output by the X-ray imaging plate module and generates a visual inspection report; Positioning compensation module monitors the relative position of the tension clamp and the probe in real time, dynamically corrects the scanning path deviation, and ensures detection accuracy; ‌ Wireless communication module, encrypts and transmits detection data to the remote terminal and receives control instructions; High-voltage insulation module isolates high-voltage circuits from low-voltage systems to prevent corona discharge or insulation breakdown; Data analysis module, which integrates image data, equipment status and environmental parameters to generate inspection reports and maintenance recommendations; The output voltage of the high-voltage pulse power supply module satisfies: ,in is the critical electric field strength of air medium, is the electrode gap distance, Optimizing coefficients for experiments .

2. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The high voltage pulse power supply module adopts a cascade Generator topology, the output pulse width calculation formula is: in is the cascade level, It is a single-stage energy storage capacitor. is the load equivalent resistance.

3. According to claim 1, the X-ray flaw detection system based on high-voltage overhead line maintenance is characterized in that: The image processing module works as follows: S401, performing histogram equalization on the original image to enhance visibility of details in low-contrast areas; S402, eliminating geometric distortion and correcting image stretching caused by shape or position deviation of the tension clamp; S403, automatically identifying defective areas; S404, classifying and labeling according to the defect morphology distribution characteristics; S405, fusing multi-angle projection data to generate a three-dimensional defect model.

4. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 3 is characterized in that: In the above step S405, the specific steps of generating the three-dimensional defect model are: S4051, the X-ray emission module performs a 360° rotation scan on the tension clamp, collects a penetration image every 10°, and generates 36 sets of two-dimensional projection data in total; S4052. Correct the projection distortion caused by the irregular shape of the tension clamp through feature point matching and regional block adjustment technology to ensure that the multi-angle projection is aligned in a unified coordinate system; S4053, using wavelet transform to filter out metal artifacts and speckle noise and enhance the contrast of defective areas; S4054, back-projecting the 36 sets of two-dimensional projection data into three-dimensional space to generate an initial voxel model; S4055. Use the MLEM algorithm for 8 iterations to correct the grayscale distribution of cracks and pores inside the tension clamp and improve the model resolution. S4056, segment the defect area based on the dynamic threshold method, remove isolated noise points through morphological closing operation, and retain the continuous defect structure; S4057, extract crack length, pore volume and slag inclusion distribution density; S4058, load the pre-trained 3D model, automatically classify the defects according to their morphological features, and annotate the confidence level; S4059. Render the model in pseudo-color: red indicates high-risk cracks, yellow indicates pores, and green indicates slight slag inclusions.

5. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The positioning compensation module works as follows: S501, collect the rotation angle and displacement data of the tension clamp in real time through a high-precision encoder to eliminate the projection offset caused by system vibration; S502, dynamically adjusting the rotation center coordinates based on the geometric features of the multi-angle projection image to ensure that the 360° scanning trajectory is consistent with the theoretical model; S503, extracting the key structure of the tension clamp as a feature point to achieve spatial alignment of multi-angle projection images; S504, correcting the distortion of the projection image by using a radial distortion model to improve the accuracy of three-dimensional reconstruction; S505, mapping the defect area detected in the projection image to a three-dimensional coordinate system, and calculating the spatial coordinates of the defect in the tension clamp by using a back-projection algorithm; S506, performing weighted averaging on the positions of the same defect in projections at different angles to eliminate occlusion errors in single-view detection; S507. Dynamically adjust the X-ray energy and exposure time according to the thickness and density of the tension clamp material to ensure the contrast of the penetration imaging of the defect area; S508, using piecewise linear transformation to standardize the grayscale values ​​of the multi-angle projection images to eliminate the grayscale inconsistency problem of the voxel model caused by X-ray energy fluctuations; S509: Transmit the compensated data to the image processing module in real time, and iteratively update the defect model.

6. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The working steps of the data analysis module are: S701. Eliminate shot noise and metal artifacts in X-ray images and improve the contour clarity of the aluminum tube crimping area and steel anchor groove in the tension clamp; S702. Based on the material difference between the aluminum tube wall thickness and the steel core diameter, the image contrast of different detection devices is unified using a segmented grayscale mapping algorithm; S703, based on the reference features of the steel anchor pull ring and aluminum tube port of the tension clamp, the image distortion caused by the shooting angle deviation is eliminated through affine transformation; S704, locating the anti-skid groove contour by edge detection algorithm, and identifying the lack of pressing or pressure leakage defects; S705, based on the gray threshold segmentation of the steel core, detecting defects such as the steel core being broken and not being inserted into the bottom of the steel anchor; S706, using connected domain analysis to determine the proportion of scattered aluminum wires; S707, calculating the average gap between the groove and the contact surface of the aluminum tube, and evaluating the ellipticity of the aluminum tube after crimping by ellipse fitting; S708. Generate a risk distribution map based on defect location, density and historical data to guide operation and maintenance priorities; S709, synchronize defect data to the system in real time, and support query of historical inspection records by line and tower number; S7010, generate a test report, including defect X-ray images, 3D positioning coordinates and processing suggestions.

7. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The vacuum tube of the X-ray emission module adopts a tantalum-tungsten composite target material, and its emission efficiency satisfies: ,in is the accelerating voltage, is the target atomic number, is the tube temperature, is the cathode-anode distance.

8. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The working steps of the X-ray emission module are: S201, starting the low voltage power supply to heat the cathode filament to make it emit thermal electrons; S202, receiving a high-voltage electric field applied by a high-voltage pulse power module to accelerate the electron beam, and focusing the electron beam to a tiny focus on the target surface through an electromagnetic lens; S203, high-speed electrons bombard the target material to produce continuous X-ray spectrum and characteristic X-rays; S204, controlling the X-ray energy distribution and penetration capability by adjusting the anode voltage and beam intensity; S205: If the target temperature is detected to be abnormal, a power reduction mode or emergency shutdown protection is triggered.

9. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The X-ray imaging plate module works as follows: S301, the X-rays penetrating the tension clamp irradiate the scintillator layer, and stimulate the scintillator to emit visible light photons; S302, converting visible light into analog electrical signals; S303, digitizing the analog electrical signal to generate an original grayscale image matrix; S304: Pack the pre-processed image data into a standardized format and transmit it to the image processing module.

10. The X-ray flaw detection system based on high-voltage overhead line maintenance according to claim 1 is characterized in that: The working steps of the high voltage insulation module are: S601, arranging an annular voltage-equalizing cover around the high-voltage electrode, controlling the electric field distribution through gradient resistance, and suppressing local discharge; S602, real-time monitoring of leakage current, if the leakage current exceeds the safety threshold, triggering an audible and visual alarm and cutting off the high voltage output; S603. Conduct insulation resistance tests regularly and record historical data to predict aging trends; S604: When the insulation resistance value drops to a critical point, the maintenance personnel are prompted to replace system components.

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