Bubble defect detecting and positioning system and method based on X-ray enhanced partial discharge

Abstract

The invention discloses a bubble defect detecting and positioning system and method based on X-ray enhanced partial discharge, and belongs to the technical field of nondestructive testing of insulating materials, the system comprises a shielding box slidably mounted on a three-dimensional linear guide rail, an X-ray machine and a red laser are embedded in the shielding box, and double-oblique-angle cameras are mounted on two sides of the three-dimensional linear guide rail; the laser positioning synchronization device is installed on the movable collimation X-ray scanning module, and the movable collimation X-ray scanning module emits an X-ray beam towards the basin-type insulator to be detected; the laser positioning synchronization device emits a laser beam towards the basin-type insulator to be detected; the laser beam is coaxial with the X-ray beam; the double-oblique-angle camera shoots the basin-type insulator to be detected; the pressurization circuit is respectively connected with the pressurization electrode and the partial discharge detection system, and the pressurization electrode is electrically contacted with the basin-type insulator to be detected; the intelligent control platform is connected with the voltage increasing circuit, the movable collimation X-ray scanning module, the laser positioning synchronization device, the double-oblique-angle camera and the partial discharge detection system.

Description

Technical Field

[0001] This invention belongs to the field of non-destructive testing technology for insulating materials, specifically relating to a bubble defect detection and localization system and method based on X-ray enhanced partial discharge. Background Technology

[0002] In fields such as power equipment, aerospace composite materials, and high-end electronic packaging, internal air bubble defects in insulating materials are a key cause of structural failure. Traditional non-destructive testing (NDT) techniques, such as X-ray imaging, are widely used due to their non-contact nature and strong penetrating power. However, they have inherent limitations in detecting small air bubbles in thicker materials. When the material thickness exceeds a certain threshold, the intensity attenuation of X-rays after penetration leads to a significant decrease in the contrast between the defect and the substrate. This is especially true for air bubbles with a diameter less than 1 mm, making it difficult to form identifiable image features and increasing the risk of missed detection.

[0003] To improve defect detection rates, partial discharge detection methods involving direct application of high voltage are commonly used in engineering. Partial discharge refers to the intermittent breakdown of non-penetrating electrodes caused by process defects or structural weaknesses within the insulating medium between electrodes under the influence of a strong electric field. This method relies on the partial discharge signal generated by defects under a strong electric field for detection, but it has significant drawbacks: microbubble defects, due to the lack of free electrons, result in a prolonged statistical time, leading to a high initial discharge voltage, potentially exceeding 80% of the material's withstand limit. This necessitates applying a voltage close to the material's breakdown strength during the detection process. This overvoltage state not only accelerates insulation aging but may also induce irreversible damage, posing a serious threat to precision devices or valuable test samples. Research shows that X-rays have an excitation effect on partial discharge in insulation defects: when high-energy photons penetrate the material, they induce photoionization within the bubbles, generating a large number of initial free electrons, effectively shortening the statistical time delay. Under the influence of an external electric field, these electrons allow micro-defects to trigger stable partial discharges at relatively low applied voltages, significantly reducing electrical stress damage to the material during the detection process.

[0004] Current insulation defect detection systems mostly rely on a single technical approach. While X-ray imaging can provide three-dimensional structural information, its contrast limitations result in insufficient sensitivity to minute defects in thicker materials. Partial discharge localization techniques based on pulsed current methods can identify defects, but cannot obtain their precise three-dimensional coordinates. Furthermore, existing methods generally lack the ability to quantitatively assess defect risk, making it difficult to support tiered maintenance decisions. Therefore, there is an urgent need to develop a non-destructive testing method that integrates X-ray excitation, highly sensitive partial discharge signal capture, and synchronous spatial coordinate locking to achieve precise localization and risk assessment of bubble defects while ensuring material safety. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems by proposing a bubble defect detection and localization system and method based on X-ray enhanced partial discharge.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a bubble defect detection and positioning system based on X-ray enhanced partial discharge, including a pressurization system, a movable collimated X-ray scanning module, a laser positioning synchronization device, a dual oblique angle camera, a partial discharge detection system, and an intelligent control platform; The movable collimated X-ray scanning module includes a three-dimensional linear guide and a shielding box. The shielding box is slidably mounted on the three-dimensional linear guide. An X-ray machine and a red laser are embedded inside the shielding box. Dual angle cameras are installed on both sides of the three-dimensional linear guide. The laser positioning and synchronization device is installed on the movable collimating X-ray scanning module, which emits an X-ray beam toward the pot-shaped insulator under test; the laser positioning and synchronization device emits a laser beam toward the pot-shaped insulator under test; the laser beam and the X-ray beam are coaxial; and the dual oblique angle camera is used to capture images of the pot-shaped insulator under test. The pressurization system includes a pressurization circuit and a pressurization electrode; the pressurization circuit is connected to the pressurization electrode and the partial discharge detection system respectively, and the pressurization electrode is in electrical contact with the basin insulator under test; The intelligent control platform is connected to the pressurization circuit, the movable collimating X-ray scanning module, the laser positioning and synchronization device, the dual oblique angle camera, and the partial discharge detection system. The intelligent control platform captures images of the pot-type insulator under test from multiple angles using dual oblique angle cameras, automatically constructing a three-dimensional digital model of the pot-type insulator under test; it simulates the internal electric field distribution of the pot-type insulator under test based on the three-dimensional digital model; it intelligently calculates the detection voltage, X-ray machine parameters, and optimal scanning path required for bubble defect detection and location of the pot-type insulator under test; the intelligent control platform synchronously acquires signals from the pressurization system, the movable collimating X-ray scanning module, and the partial discharge detection system, automatically analyzes the detection signals and fuses the position information, and locates the internal bubble defects of the pot-type insulator under test in real time to generate a bubble defect location heat map.

[0007] Furthermore, the pressurization circuit includes a withstand voltage test control box, a high-voltage transformer, a protective resistor, and a coupling capacitor; The intelligent control platform is connected to one end of the withstand voltage test control box, the other end of the withstand voltage test control box is connected to one end of the high voltage transformer, the other end of the high voltage transformer is connected to one end of the protective resistor, the other end of the protective resistor is connected to the first end of the coupling capacitor, the second end of the coupling capacitor is connected to the pressurizing electrode, and the third end of the coupling capacitor is connected to the partial discharge detection system. The pressurizing electrode includes a high-voltage electrode and a ground electrode. The high-voltage electrode is connected to the pressurizing circuit via a flexible high-voltage cable. The pressurizing electrode can be a flat plate electrode, a small ball-head electrode, or an adjustable arc-shaped contact.

[0008] Furthermore, it also includes an electromagnetic shielding chamber, which is grounded, and the withstand voltage test control box, ground electrode and partial discharge detection system are connected to the electromagnetic shielding chamber.

[0009] Furthermore, the electromagnetic shielding chamber adopts a composite shielding structure and a deep grounding system. The outer layer of the composite shielding structure protects against X-rays, while the inner layer resists electromagnetic interference.

[0010] Furthermore, the laser positioning synchronization device includes a first plane mirror and a second plane mirror. The reflecting surfaces of both the first plane mirror and the second plane mirror are coated with an X-ray penetrating film. Both the first plane mirror and the second plane mirror are made of aluminum. The laser beam emitted by the red laser is incident on the first plane mirror, and after being reflected by the first plane mirror, it is directed towards the second plane mirror; the second plane mirror reflects the incident laser beam, and the reflected laser beam is directed towards the pot insulator under test.

[0011] Furthermore, the dual-angle camera adopts a high-resolution industrial camera, which includes two angled cameras. The angled cameras are mounted on the turntable of the vertical guide rail of the three-dimensional linear guide. Before bubble defect detection, the angled cameras take pictures from multiple angles. After image acquisition, the images are uploaded to the intelligent control platform for three-dimensional reconstruction. During the X-ray scanning stage, the laser point projected by the laser positioning synchronization device is tracked in real time to assist in locking the defect coordinates.

[0012] Furthermore, the three-dimensional linear guide rail includes a longitudinal base guide rail, a transverse beam guide rail, and a vertical column guide rail. The longitudinal base guide rail and the transverse beam guide rail are connected by a longitudinal slider, and the transverse beam guide rail and the vertical column guide rail are connected by a transverse slider. The longitudinal slider and the transverse slider move linearly through a servo motor and a lead screw. The vertical column guide rail includes a first vertical column guide rail, a second vertical column guide rail, and a third vertical column guide rail. A first slider is installed on the first vertical column guide rail, and a shielding box turntable is installed on the first slider. A second slider is installed on the second vertical column guide rail, and a third slider is installed on the third vertical column guide rail. A first camera turntable is installed on the second slider, and a second camera turntable is installed on the third slider. An angled camera is installed on both the first and second camera turntables. A grating ruler feedback system is set up on the three-dimensional linear guide.

[0013] Furthermore, the shielding box has a collimation hole through which the X-ray beam is output, and the tube voltage of the X-ray machine is continuously adjustable from 50 to 300 kV.

[0014] Furthermore, the partial discharge detection system is built using the MPD800 partial discharge detector with the pulse current method.

[0015] Secondly, the present invention provides a bubble defect detection and localization method based on X-ray enhanced partial discharge (XPD), using an XPD-based bubble defect detection and localization system, comprising the following steps: Images of the tested basin-type insulator are captured multiple times from various angles using dual oblique angle cameras and uploaded to the intelligent control platform. The image data is processed using a 3D reconstruction algorithm to output a 3D model of the tested basin-type insulator. The geometric dimensions of the 3D model are extracted, and the X-ray machine parameters, including the X-ray machine tube voltage and X-ray machine tube current, are calculated based on preset material parameters and the desired detection accuracy. An equally spaced 3D mesh is generated according to the shape of the 3D model, the optimal scanning path of the X-ray machine is planned, and the motion trajectory of the 3D linear guide rail is set to drive the movement of the X-ray machine. By combining the three-dimensional model, the structure and electrical parameters of the pressurizing electrode, finite element simulation calculation of the internal electric field distribution is performed. Based on the simulation results and the database of partial discharge initiation field strength of bubbles with different diameters in X-ray environment, the pressurizing voltage value of the pressurizing system is calculated and set. The electrodes are selected and installed according to the geometry of the insulator under test. The pressure electrode is made into electrical contact with the insulator under test. According to the pressure voltage value, the pressure circuit is gradually increased to the pressure voltage value. Then, the three-dimensional linear guide is started to drive the X-ray machine to emit an X-ray beam for scanning along the optimal scanning path. The red laser emits a laser beam coaxial with the X-ray beam. The laser point of the laser beam indicates the focal position of the X-ray beam. The partial discharge detection system collects signals in real time. Before or during the formal pressure scan, a period of time with no significant discharge signal is selected. The statistical standard deviation of the background noise is automatically calculated and recorded. When the amplitude of a single pulse exceeds a preset threshold, it is determined to be a valid partial discharge event. At the same time as the valid discharge pulse is detected, the spatial three-dimensional coordinates of the laser spot projected onto the surface of the tested basin insulator are determined by the position of the grating ruler of the three-dimensional linear guide and the tracking of the laser point by the dual oblique angle camera. The defect location point is obtained. The discharge signal source is located at the defect location point, and the characteristic parameters of the discharge pulse and the frequency of pulse occurrence at the defect location point within the time window are recorded simultaneously. Based on the characteristic parameters of the defect location and discharge pulse, the detected defect location is mapped onto the three-dimensional model of the tested basin insulator to locate the spatial distribution of bubble defects.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention proposes an X-ray enhanced partial discharge (XPD)-based bubble defect detection and localization system. It utilizes acquired multi-angle images to perform 3D reconstruction, obtaining a 3D model. Based on geometric and material parameters, it automatically calculates the optimal applied voltage, X-ray machine parameters, and scanning path. X-ray excitation of the test sample induces partial discharge in the insulating material, causing bubble defects. Combined with a movable collimated X-ray source and a laser positioning system, it achieves precise bubble defect localization. By real-time correlation between the partial discharge signal and laser position coordinates, it outputs a 3D defect distribution map and a defect detection report, realizing the detection and localization of bubble defects. This system is particularly suitable for locating micro-bubble defects in high-voltage power equipment and can also be extended to bubble detection in semiconductor packaging and aerospace composite materials. The method involves reconstructing a 3D model of the sample using multi-angle imaging, calculating X-ray parameters, planning the scanning path, and determining the applied voltage through electric field simulation. After installing the adapter electrode and applying pressure, the X-ray machine is driven to scan along the path. Simultaneously, a laser coaxial positioning device triggers the partial discharge detection system to synchronously acquire discharge signals. A threshold is dynamically set based on background noise to identify effective partial discharge pulses in real time, lock the corresponding X-ray beam focusing position, and record pulse characteristics. Key parameters are statistically analyzed, and a detection report and 3D distribution map containing defect details, risk assessment, and treatment suggestions are output. The device includes a pressurization system, a movable collimated X-ray scanning module, a laser positioning synchronization device, a dual-angle camera, a partial discharge detection system, and an intelligent control platform. This method and device, through the combination of X-ray excitation, precise laser positioning, and intelligent signal analysis, achieves high-sensitivity, high-precision 3D positioning and visual evaluation of bubble defects, significantly improving detection reliability and efficiency. This method accurately excites defect discharge through X-ray scanning, combined with laser positioning and 3D model mapping, achieving precise positioning of microbubbles, significantly improving the detection rate and positioning accuracy of hidden defects. By integrating 3D reconstruction, electric field simulation, and adaptive X-ray parameters, and intelligently coordinating the scanning path, applied voltage, and high-sensitivity partial discharge acquisition, environmental interference is effectively suppressed, significantly improving the reliability and anti-interference capability of the detection results. The entire process from modeling and parameter calculation to scanning detection is automated, and a structured report containing defect locations and risk assessments is automatically generated. Modular electrode replacement is also supported, significantly improving detection efficiency and adaptability to complex samples. Attached Figure Description

[0017] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a flowchart of a bubble defect detection and localization method based on X-ray enhanced partial discharge.

[0018] Figure 2 This is a structural diagram of a bubble defect detection and localization system based on X-ray enhanced partial discharge.

[0019] Figure 3 This is a detailed view of the shielding box.

[0020] Figure 4 The mass attenuation coefficient μ of the material m (E) with maximum thickness d max A three-dimensional surface plot showing the change in transmittance T.

[0021] Figure 5 The required tube current I req With maximum thickness d max A three-dimensional surface plot showing the change in transmittance T.

[0022] The components include: 1. Withstand voltage test control box; 2. High voltage transformer; 3. Protective resistor; 4. Coupling capacitor; 5. Three-dimensional linear guide rail; 6. Shielding box; 7. X-ray machine; 8. Red laser; 9. First plane reflector; 91. Second plane reflector; 10. Angled camera; 11. Partial discharge detection system; 12. Intelligent control platform; 13. High voltage electrode; 14. Ground electrode; 15. Test basin insulator; 16. Electromagnetic shielding chamber. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] Example 1 A bubble defect detection and localization system based on X-ray enhanced partial discharge (XPD) includes a pressurization system, a movable collimated X-ray scanning module, a laser positioning and synchronization device, dual-angle cameras, a partial discharge detection system 11, and an intelligent control platform. The movable collimated X-ray scanning module includes a three-dimensional linear guide rail 5 and a shielding box 6. The shielding box 6 is slidably mounted on the three-dimensional linear guide rail 5, and an X-ray machine 7 and a red laser 8 are embedded inside the shielding box 6. Dual-angle cameras are mounted on both sides of the three-dimensional linear guide rail 5. The laser positioning and synchronization device is mounted on the movable collimated X-ray scanning module, which emits an X-ray beam towards the pot-shaped insulator 15 under test. The laser positioning and synchronization device also emits a laser beam towards the pot-shaped insulator 15 under test. The laser beam is coaxial with the X-ray beam. The dual-angle cameras capture images of the pot-shaped insulator 15 under test. The pressurization system includes a pressurization circuit and pressurization electrodes. The pressurization circuit is connected to the pressurization electrodes and the partial discharge detection system 11. The discharge detection system 11 has a pressurized electrode that makes electrical contact with the pot-type insulator 15 under test. The intelligent control platform 12 is connected to the pressurization circuit, the movable collimated X-ray scanning module, the laser positioning synchronization device, the dual-angle camera, and the partial discharge detection system 11. The intelligent control platform 12 captures images of the pot-type insulator 15 under test from multiple angles using the dual-angle camera, and automatically constructs a three-dimensional digital model of the pot-type insulator 15 under test. Based on the three-dimensional digital model, it simulates the internal electric field distribution of the pot-type insulator 15 under test. It intelligently calculates the detection voltage, X-ray machine parameters, and optimal scanning path required for bubble defect detection and positioning of the pot-type insulator 15 under test. The intelligent control platform 12 synchronizes the signal acquisition of the pressurization system, the movable collimated X-ray scanning module, and the partial discharge detection system 11, automatically analyzes the detection signals and fuses the position information, and locates the internal bubble defects of the pot-type insulator 15 under test in real time to generate a bubble defect positioning heat map.

[0028] This embodiment features multi-component collaborative precision operation. A movable collimated X-ray scanning module works in conjunction with a laser positioning synchronization device, ensuring coaxial positioning of the laser and X-ray beams. Dual oblique-angle cameras capture images from multiple angles, and an intelligent control platform constructs a three-dimensional digital model, comprehensively assessing the condition of the tested basin-type insulator. Intelligent calculation optimizes the detection process; the system intelligently calculates the detection voltage, X-ray machine parameters, and optimal scanning path, improving detection efficiency and accuracy. Signal synchronization and intelligent analysis are also achieved. The intelligent control platform synchronizes signal acquisition from the pressurization system, scanning module, and partial discharge detection system, automatically analyzing signals and fusing position information to locate internal bubble defects in real time. An intuitive bubble defect location heatmap is generated, providing clear guidance for subsequent processing. This significantly enhances the automation and intelligence of bubble defect detection and location, ensuring the safe and stable operation of power equipment.

[0029] The pressurization circuit includes a withstand voltage test control box 1, a high-voltage transformer 2, a protective resistor 3, and a coupling capacitor 4. The intelligent control platform is connected to one end of the withstand voltage test control box 1, the other end of the withstand voltage test control box 1 is connected to one end of the high-voltage transformer 2, the other end of the high-voltage transformer 2 is connected to one end of the protective resistor 3, the other end of the protective resistor 3 is connected to the first end of the coupling capacitor 4, the second end of the coupling capacitor 4 is connected to the pressurization electrode, and the third end of the coupling capacitor 4 is connected to the partial discharge detection system 11. The pressurization electrode includes a high-voltage electrode 13 and a ground electrode 14. The high-voltage electrode 13 is connected to the pressurization circuit through a flexible high-voltage cable. The pressurization electrode adopts a flat electrode, a small ball-head electrode, or an arc-shaped adjustable contact.

[0030] It also includes an electromagnetic shielding chamber 16, which is grounded. The withstand voltage test control box 1, ground electrode 14, and partial discharge detection system 11 are connected to the electromagnetic shielding chamber 16. The electromagnetic shielding chamber 16 adopts a composite shielding structure and a deep grounding system. The outer layer of the composite shielding structure protects against X-rays, and the inner layer of the composite shielding structure resists electromagnetic interference.

[0031] The laser positioning synchronization device includes a first plane mirror 9 and a second plane mirror 91. The reflective surfaces of both the first plane mirror 9 and the second plane mirror 91 are coated with an X-ray penetrating film. Both the first plane mirror 9 and the second plane mirror 91 are made of aluminum. The laser beam emitted by the red laser 8 is incident on the first plane mirror 9. After being reflected by the first plane mirror 9, it is directed towards the second plane mirror 91. The second plane mirror 91 reflects the incident laser beam, and the reflected laser beam is directed towards the basin-type insulator 15 to be tested.

[0032] The dual-angle camera uses a high-resolution industrial camera and includes two angled cameras 10. The angled cameras 10 are mounted on the turntable of the vertical guide rail of the three-dimensional linear guide rail 5. Before bubble defect detection, the angled cameras 10 take pictures from multiple angles and upload the images to the intelligent control platform for three-dimensional reconstruction. During the X-ray scanning stage, the laser point projected by the laser positioning synchronization device is tracked in real time to assist in locking the defect coordinates.

[0033] The three-dimensional linear guide includes a longitudinal base guide, a transverse beam guide, and a vertical column guide. The longitudinal base guide and the transverse beam guide are connected by a longitudinal slider, and the transverse beam guide and the vertical column guide are connected by a transverse slider. The longitudinal slider and the transverse slider move linearly via a servo motor and a lead screw. The vertical column guide includes a first vertical column guide, a second vertical column guide, and a third vertical column guide. A first slider is mounted on the first vertical column guide, and a shielded box turntable is mounted on the first slider. A second slider is mounted on the second vertical column guide, and a third slider is mounted on the third vertical column guide. A first camera turntable is mounted on the second slider, and a second camera turntable is mounted on the third slider. An angled camera 10 is mounted on both the first and second camera turntables. The three-dimensional linear guide is equipped with a grating ruler feedback system.

[0034] The shielding box 6 has a collimation hole through which the X-ray beam is output. The tube voltage of the X-ray machine 7 is continuously adjustable from 50-300kV. The partial discharge detection system 11 is built using the pulse current method with an MPD800 partial discharge detector.

[0035] This embodiment features a rationally designed pressurization circuit structure, with all components working together to ensure stable pressurization. The electromagnetic shielding chamber's composite structure and deep grounding system effectively prevent X-rays and resist electromagnetic interference, ensuring a clean testing environment. The laser positioning synchronization device utilizes a reflector and a penetrating membrane to precisely project a laser beam for accurate positioning. A dual-angle high-resolution industrial camera captures images from multiple angles, providing clear 3D reconstruction and real-time laser point tracking to assist in defect location. A 3D linear guide rail allows for flexible multi-directional movement, and a grating ruler feedback system enhances motion accuracy. The shielding box's collimation hole outputs an X-ray beam, and the X-ray tube voltage is adjustable to meet diverse testing needs. The partial discharge detection system employs the pulse current method and a professional testing instrument, ensuring accurate and reliable detection. All components work closely together, forming a complete and efficient testing process from pressurization, positioning, and imaging to detection. This significantly improves the accuracy, stability, and automation of bubble defect detection and location, providing strong support for the safe operation of the equipment.

[0036] Example 2 A bubble defect detection and localization method based on X-ray enhanced partial discharge (XPD) is used, employing an XPD-based XPD bubble defect detection and localization system, and includes the following steps: Images of the tested basin-type insulator 15 are captured multiple times from various angles using dual oblique angle cameras and uploaded to the intelligent control platform 12. The image data is processed using a 3D reconstruction algorithm to output a 3D model of the tested basin-type insulator 15. The geometric dimensions of the 3D model are extracted, and the X-ray machine parameters, including the X-ray machine tube voltage and X-ray machine tube current, are calculated based on preset material parameters and the desired detection accuracy. An equally spaced 3D mesh is generated according to the shape of the 3D model, the optimal scanning path of the X-ray machine 7 is planned, and the motion trajectory of the 3D linear guide rail 5 is set to drive the X-ray machine 7 to move. By combining the three-dimensional model, the structure and electrical parameters of the pressurizing electrode, finite element simulation calculation of the internal electric field distribution is performed. Based on the simulation results and the database of partial discharge initiation field strength of bubbles with different diameters in X-ray environment, the pressurizing voltage value of the pressurizing system is calculated and set. The electrodes are selected and installed according to the geometric shape of the tested basin insulator 15. The pressure electrode is electrically contacted with the tested basin insulator 15. According to the pressure voltage value, the pressure circuit is gradually increased to the pressure voltage value. Then, the three-dimensional linear guide 5 is started, and the X-ray machine 7 is driven to emit an X-ray beam for scanning along the optimal scanning path. The red laser 8 emits a laser beam coaxial with the X-ray beam. The laser point of the laser beam indicates the focal position of the X-ray beam. The partial discharge detection system 11 collects signals in real time. Before or during the formal pressure scan, a period of time with no significant discharge signal is selected. The statistical standard deviation of the background noise is automatically calculated and recorded. When the amplitude of a single pulse exceeds a preset threshold, it is determined to be a valid partial discharge event. At the same time as the valid discharge pulse is detected, the spatial three-dimensional coordinates of the laser spot projected onto the surface of the tested basin insulator 15 are determined by the position of the grating ruler of the three-dimensional linear guide 5 and the tracking of the laser point by the dual oblique angle camera. The defect location point is obtained. The discharge signal source is located at the defect location point, and the characteristic parameters of the discharge pulse and the frequency of pulse occurrence at the defect location point within the time window are recorded simultaneously. Based on the characteristic parameters of the defect location and discharge pulse, the detected defect location is mapped onto the three-dimensional model of the tested basin insulator 15 to locate the spatial distribution of bubble defects.

[0037] This embodiment utilizes a dual-angle camera for multi-angle shooting and a 3D reconstruction algorithm to accurately construct a 3D model of the tested basin-type insulator, providing a solid foundation for subsequent parameter calculation and path planning. By extracting geometric dimensions to calculate X-ray machine parameters and combining the 3D model to plan the optimal scanning path, the insulator can be inspected efficiently and comprehensively, avoiding missed detections. The voltage value is set scientifically and reasonably using finite element simulation calculations, ensuring the safety of the inspection process and effectively stimulating the partial discharge signal of bubble defects. During the inspection process, the background noise standard deviation is automatically calculated to accurately determine valid partial discharge events. The location of defects is determined by tracking laser points using a grating ruler and camera, ensuring precise positioning. The defect location is mapped onto the 3D model, intuitively presenting the spatial distribution of bubble defects. This provides detailed and accurate basis for subsequent insulator quality assessment, repair, or replacement, greatly improving the reliability and practicality of the inspection.

[0038] Example 3 A bubble defect detection and localization system based on X-ray enhanced partial discharge, such as Figure 1 As shown, the construction method includes the following steps: 1. The system first configures two movable and rotating angle cameras 10. Through a synchronous triggering device, it captures multiple images of the tested basin-type insulator 15 from various angles. After multiple image acquisitions, the images are uploaded to the intelligent control platform 12 to achieve 3D reconstruction and output a 3D model of the tested object. Proceed to step 2; The core of the system consists of a pressurization system, a movable collimated X-ray scanning module, a laser positioning and synchronization device, dual-angle cameras, a partial discharge detection system, and an intelligent control platform. Before testing, a safety environment check and equipment self-test are performed, and the X-ray dose, partial discharge level, and laser positioning are calibrated. Two high-resolution industrial cameras, mounted on a vertical guide rail turntable of a three-dimensional linear guide, are used to capture multiple images of the test object from different angles under the control of a synchronous triggering device. The acquired images are uploaded to the intelligent control platform, which processes the image data using a 3D reconstruction algorithm and outputs a precise 3D model of the test object.

[0039] 2. Extract key geometric parameters of the test specimen from its 3D model, select material parameters and detection accuracy, and calculate the required parameters for the X-ray machine 7. Simultaneously, generate an equally spaced grid based on the 3D model of the test specimen, plan the X-ray scanning path, and set the 3D linear guide rail 5 of the movable X-ray machine 7. Perform electric field distribution simulation calculations based on the 3D model of the test specimen, electrode structure, and electrical characteristic parameters to ensure that the smallest diameter bubble defect at the weakest electric field intensity can be effectively detected. Calculate the required voltage for detection based on the partial discharge initiation field strength of bubble defects of different diameters under X-ray excitation. Verify through finite element simulation that, under the set voltage, the field strength of the smallest target bubble defect in the region of lowest electric field intensity inside the material exceeds its partial discharge initiation field strength under X-ray excitation. Proceed to step 3; Based on the generated 3D model, the intelligent control platform performs key parameter calculations. The platform extracts the model's geometric dimensions and, combined with user-defined material parameters such as mass attenuation coefficient, density, thickness, and desired detection accuracy such as the minimum detectable bubble diameter, automatically calculates the X-ray machine parameters. Simultaneously, the platform generates an evenly spaced 3D mesh based on the model's shape, plans the optimal scanning path for the X-ray machine, and sets up a 3D linear guide rail to drive its movement. This 3D linear guide rail includes a longitudinal base rail, a column with vertical guide rails, and a beam with transverse guide rails. All directions are driven by servo motors and precision lead screws, and equipped with a grating ruler feedback system, achieving an absolute positioning accuracy of ±0.1mm. Furthermore, the platform combines the 3D model, the applied electrode structure, and electrical parameters such as material dielectric constant and conductivity to perform finite element simulation calculations of the internal electric field distribution. The core objective of the simulation is to ensure that, under the planned X-ray excitation, even the smallest target diameter bubble defect in the region with the weakest electric field intensity can reach the partial discharge initiation field strength and be effectively excited to discharge. Based on simulation results and a database of partial discharge initiation field strengths of bubbles of different diameters under X-ray conditions, the platform ultimately calculates and sets the required pressurization voltage value for detection.

[0040] 3. Based on the geometry of the test sample, select a suitable high-voltage electrode 13 and a grounding electrode 14 to achieve reliable electrical contact with the test sample, and gradually increase the voltage to the applied voltage. Start the three-dimensional linear guide 5 to drive the X-ray machine 7 to scan along the planned path, output the X-ray beam through the collimation aperture, and use the laser positioning and synchronization device to make the laser beam coaxial with the X-ray beam, synchronously triggering the partial discharge detection system to collect partial discharge signals in real time; proceed to step 4; Based on the specific geometry of the test specimen, such as planar, curved, or point-contact surfaces, appropriate replaceable electrode modules, such as flat electrodes, small ball-head electrodes, and adjustable arc-shaped contacts, are selected and installed. The high-voltage electrode is connected to the pressurization circuit via a flexible high-voltage cable. This circuit consists of a withstand voltage test control box, an AC 150kV withstand voltage transformer, protective resistors, and coupling capacitors, ensuring reliable electrical contact with the test specimen. Subsequently, the system gradually increases the voltage to the target value according to the pressure value set by the intelligent platform through the withstand voltage test control box. After the voltage increase is complete, the three-dimensional linear guide system is activated, driving the X-ray machine within the shielding box, which uses 12mm lead equivalent composite shielding material and has a precision collimation hole with a diameter of Φ1.5±0.1mm, to scan along the planned path. The red laser embedded in the shielding box has a wavelength of 650nm and an output power of <5mW. It achieves strict coaxiality with the X-ray beam through two aluminum plane mirrors with special X-ray penetrating films, such as ultra-thin aluminum or beryllium films. The laser calibration mechanism is equipped with a fine-tuning knob, achieving a calibration accuracy of ±0.1°, ensuring the laser point precisely indicates the focal position of the X-ray beam. During scanning, the intelligent control platform strictly and synchronously triggers the partial discharge detection system to acquire signals in real time. The partial discharge detection system employs the pulsed current method, using an Omicron MPD 800 partial discharge detector with a measurement bandwidth set to 300kHz, a center frequency of 250kHz, and detection impedance and coupling capacitance conforming to IEC 60270 standards, achieving a detection sensitivity of 10fC.

[0041] 4. Before or during the formal pressurized scan, a period without significant discharge is selected. The system automatically calculates and records the standard deviation σ of the background noise, and analyzes the acquired partial discharge pulse signals in real time. When the amplitude Q of a single pulse exceeds a preset threshold, such as 2σ, or a threshold dynamically adjusted according to the signal-to-noise ratio, it is determined to be a valid partial discharge event. At the same moment a valid discharge pulse is detected, the system immediately captures and locks the spatial three-dimensional coordinates indicated by the current laser positioning device. These coordinates precisely correspond to the position where the X-ray beam is focused at this time. The system synchronously records the key characteristic parameters of the discharge pulse, including the pulse amplitude Q, pulse phase angle φ, pulse waveform characteristics such as rise time, fall time, pulse width, and pulse occurrence frequency. When no single pulse amplitude Q exceeds the preset threshold is detected, the test sample is determined to meet the detection requirements. Proceed to step 5; Before or during the formal pressurized scan, a period is selected where no significant discharge is detected. The background noise threshold is determined based on the detection accuracy. The system automatically calculates and records the statistical standard deviation σ of the background noise when the background noise is less than the threshold signal. The system analyzes the acquired partial discharge pulse signals in real time. When the amplitude Q of a single pulse exceeds a preset threshold (usually set to 2σ, or dynamically adjusted by the intelligent platform based on the real-time signal-to-noise ratio), the system determines the event as a valid partial discharge event. At the same precise moment a valid discharge pulse is detected, the system immediately captures and locks the spatial three-dimensional coordinates corresponding to the spot projected onto the surface of the test object by the current laser positioning device. These coordinates are determined with the aid of the grating ruler position of the three-dimensional guide rail and the camera tracking the laser point. These coordinates precisely correspond to the position where the X-ray beam is focused, thus locating the discharge signal source to that spatial point. The system simultaneously records the key characteristic parameters of the discharge pulse, including the pulse amplitude Q, the phase angle φ of the pulse relative to the power supply cycle, and pulse waveform characteristics such as rise time t. r descent time t f Pulse width t w And the frequency N of pulse occurrence at that location within a certain time window. If no valid discharge pulse with an amplitude exceeding the preset threshold is detected during the entire scan, the tested object is determined to meet the detection requirements.

[0042] 5. Generate a 3D defect distribution map and output an inspection report. Based on the defect features recorded in step 4, map the defect coordinates onto the 3D model of the test sample to accurately locate the bubble defect. Statistically analyze key parameters for the located defects and generate an inspection report containing information about the test sample and inspection parameters. Defect details include the precise location coordinates of the defect, Qmax, Qavg, and preliminary risk assessment level, as well as the final conclusion and handling recommendations: qualified / rework / highlighted.

[0043] Based on the spatial coordinates and characteristic parameters Q, φ, t of the effective discharge events recorded in step 4. r , t f , t w The system maps the detected defect coordinates onto the 3D digital model of the test object, accurately locating the spatial distribution of bubble defects. The intelligent control platform statistically analyzes key parameters of the located defects, such as the maximum discharge quantity Q at the defect location. max Average discharge quantity Q avg The platform assigns a preliminary risk assessment level to defects based on factors such as discharge frequency and other parameters, in accordance with pre-defined risk assessment rules. Finally, the platform generates a comprehensive test report containing basic information about the tested item, test parameters, precise defect location coordinates, defect characteristic statistics, and risk assessment level, along with a clear final conclusion and specific handling recommendations.

[0044] The method for calculating the X-ray tube voltage is to extract the maximum thickness dmax (cm) and material density ρ (g / cm³) of the test sample from the three-dimensional model. 3 Based on the set target transmittance T, the minimum required X-ray tube voltage V is estimated using the following empirical relationship. min :

[0045] Where μ m (E) is the mass decay coefficient of the material at an energy E (keV), in cm. 2 / g, the target transmittance T is determined based on the radiation required to induce partial discharge in bubble defects under experimentally calibrated X-ray excitation. According to this equation, the minimum X-ray photon energy Emin satisfying the above conditions is determined by looking up a table or modeling, and the required tube voltage V is thus determined. min ,have: Unit kV The X-ray tube current setting is based on the radiation dose rate D required to induce partial discharge in bubble defects under X-ray excitation, as determined by experimental calibration. req Calculation determined:

[0046] Where k is the X-ray machine radiation constant, provided by the equipment calibration.

[0047] The pressurization system consists of a withstand voltage test control box, a high-voltage transformer, protective resistors, coupling capacitors, high-voltage electrodes, and ground electrodes. The high-voltage electrodes are connected to the pressurization circuit via flexible high-voltage cables, with a withstand voltage rating of AC 150kV. The pressurization electrodes consist of replaceable ground electrode modules and replaceable high-voltage electrode modules, including flat electrode modules suitable for planar samples, small ball-head electrode modules suitable for point contacts, and curved adjustable contacts suitable for curved surfaces.

[0048] The movable collimated X-ray scanning module consists of a three-dimensional linear guide and a shielding box. The three-dimensional linear guide includes a longitudinal base rail, a column containing vertical guide rails, a beam containing transverse guide rails, and three vertical guide rails. These guide rails are connected by sliders and linear motion is achieved via servo motors and lead screws. Turntables are mounted on the sliders of the three vertical guide rails, which can rotate the shielding box and the dual-angle camera. The three-dimensional linear guide is equipped with a grating ruler feedback system and has an absolute positioning accuracy of ±0.1mm. The shielding box uses 12mm lead equivalent composite shielding and has collimation holes with a diameter of Φ1.5±0.1mm. Figure 3 X-ray machine and red laser with continuously adjustable embedded tube voltage of 50-300kV.

[0049] A laser positioning and synchronization device was constructed to achieve coaxial alignment of a 650nm red laser with an output power of <5mW and an X-ray beam using two plane mirrors with X-ray penetration coatings on their reflective surfaces. The laser calibration mechanism includes a fine-tuning knob with an accuracy of ±0.1°. The plane mirrors are made of aluminum.

[0050] A dual-angle camera system employs high-resolution industrial cameras, mounted on a turntable with a vertical guide rail of a 3D linear guide. Before inspection, the angled cameras capture images from multiple angles, which are then uploaded to the intelligent control system for 3D reconstruction. During the X-ray scanning phase, the system tracks the laser point projected by the laser positioning and synchronization device in real time, assisting in locking the defect coordinates.

[0051] An intelligent control platform is established to automatically construct a 3D digital model of the test object from captured images. Based on this model, the platform simulates the internal electric field distribution and intelligently calculates the required detection voltage, X-ray machine parameters, and optimal scanning path. The platform then precisely coordinates the operation of the pressurization system, the movable collimating X-ray scanning module, and the partial discharge detection system, strictly synchronizing signal acquisition timing, automatically analyzing detection signals and fusing location information, locating internal bubble defects in real time, and finally generating a structured inspection report containing a thermal map of the defect location.

[0052] The testing is conducted in a dedicated electromagnetic shielding chamber. This chamber employs a composite shielding structure with an outer layer to protect against X-rays, an inner layer to resist electromagnetic interference, and a deep grounding system. This ensures that the background noise is ≤300 fC (IEC 60270 test standard) and the external radiation dose rate is ≤2.5 μSv / h (GBZ 117-2015 standard). It effectively isolates external light, wireless signals, and electromagnetic interference, guaranteeing the sensitivity and reliability of the testing.

[0053] The invention describes a method for detecting and locating bubble defects in practical large basin-type insulators, as follows: Figure 1 , 2 Figures 3, 4, and 5 illustrate the construction process of the method for detecting and locating bubble defects in large basin insulators according to the present invention.

[0054] like Figure 2 As shown, the insulator under test is photographed from multiple angles using a dual-angle camera, and the images are uploaded to an intelligent control platform to reconstruct its three-dimensional surface model. The platform automatically calculates the X-ray tube voltage based on the model's thickness distribution and material parameters, and plans a three-dimensional scanning path covering the insulator surface. After installing the appropriate curved electrode, the voltage is increased to the set value, and the X-ray machine is started to scan along the path, with the laser beam precisely pointing to the irradiation point. The partial discharge detection system captures discharge pulses in real time, and immediately locks the spatial coordinates of the laser point when the pulse amplitude exceeds the dynamic threshold. All detected defect coordinates are mapped to the three-dimensional model to generate a location heatmap, and a test report containing the risk level and repair coordinates is output.

[0055] The intelligent control platform automatically calculates X-ray inspection parameters based on a 3D model of the insulator under test. This is achieved by extracting the maximum thickness d from the key geometric dimensions of the model. max Based on the material properties of epoxy resin, including density ρ, and the preset detection accuracy requirement of target transmittance T, the required radiation dose rate D for inducing partial discharge in bubble defects under X-ray excitation was experimentally calibrated. req Calculate the optimal operating parameters of the X-ray machine in real time. Figure 4 Display material mass attenuation coefficient μ m (E) with maximum thickness d max The three-dimensional surface relationship between the transmittance T and the change in transmittance; Figure 5 Display tube current requirement value I req With maximum thickness d max The relationship between the three-dimensional surface and the change in transmittance T.

[0056] Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Therefore, the scope of this teaching should not be determined by reference to the foregoing description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

[0057] The above content provides a further detailed description of the present invention. It should not be construed that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the defined protection scope of the present invention.

Claims

1. A bubble defect detection and localization system based on X-ray enhanced partial discharge, characterized in that, It includes a pressurization system, a movable collimated X-ray scanning module, a laser positioning and synchronization device, a dual oblique angle camera, a partial discharge detection system (11), and an intelligent control platform; The movable collimated X-ray scanning module includes a three-dimensional linear guide (5) and a shielding box (6). The shielding box (6) is slidably mounted on the three-dimensional linear guide (5). An X-ray machine (7) and a red laser (8) are embedded inside the shielding box (6). Dual angle cameras are installed on both sides of the three-dimensional linear guide (5). The laser positioning and synchronization device is installed on the movable collimating X-ray scanning module, which emits an X-ray beam toward the pot insulator (15) to be tested; the laser positioning and synchronization device emits a laser beam toward the pot insulator (15) to be tested; the laser beam is coaxial with the X-ray beam; the dual oblique angle camera takes pictures toward the pot insulator (15) to be tested; The pressurization system includes a pressurization circuit and a pressurization electrode; the pressurization circuit is connected to the pressurization electrode and the partial discharge detection system (11) respectively, and the pressurization electrode is in electrical contact with the basin insulator (15) under test; The intelligent control platform (12) is connected to the pressurization circuit, the movable collimated X-ray scanning module, the laser positioning synchronization device, the dual oblique angle camera and the partial discharge detection system (11). The intelligent control platform (12) captures images of the pot insulator (15) under test from multiple angles using a dual oblique angle camera, automatically constructs a three-dimensional digital model of the pot insulator (15) under test, simulates the internal electric field distribution of the pot insulator (15) under test based on the three-dimensional digital model, intelligently calculates the detection voltage, X-ray machine parameters and optimal scanning path required for bubble defect detection and positioning of the pot insulator (15) under test, and automatically analyzes the detection signals and fuses the position information to locate the internal bubble defects of the pot insulator (15) under test in real time and generates a bubble defect positioning heat map.

2. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 1, characterized in that, The pressurization circuit includes a withstand voltage test control box (1), a high voltage transformer (2), a protective resistor (3), and a coupling capacitor (4); The intelligent control platform is connected to one end of the withstand voltage test control box (1), the other end of the withstand voltage test control box (1) is connected to one end of the high voltage transformer (2), the other end of the high voltage transformer (2) is connected to one end of the protection resistor (3), the other end of the protection resistor (3) is connected to the first end of the coupling capacitor (4), the second end of the coupling capacitor (4) is connected to the pressurizing electrode, and the third end of the coupling capacitor (4) is connected to the partial discharge detection system (11). The pressurizing electrode includes a high-voltage electrode (13) and a ground electrode (14). The high-voltage electrode (13) is connected to the pressurizing circuit via a flexible high-voltage cable. The pressurizing electrode is a flat plate electrode, a small ball-head electrode, or an adjustable arc-shaped contact.

3. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 2, characterized in that, It also includes an electromagnetic shielding chamber (16), which is grounded, and the withstand voltage test control box (1), ground electrode (14) and partial discharge detection system (11) are connected to the electromagnetic shielding chamber (16).

4. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 3, characterized in that, The electromagnetic shielding chamber (16) adopts a composite shielding structure and a deep grounding system. The outer layer of the composite shielding structure is protected against X-rays, and the inner layer of the composite shielding structure is resistant to electromagnetic interference.

5. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 1, characterized in that, The laser positioning synchronization device includes a first plane mirror (9) and a second plane mirror (91). The reflective surfaces of the first plane mirror (9) and the second plane mirror (91) are coated with an X-ray penetrating film. The first plane mirror (9) and the second plane mirror (91) are both made of aluminum. The laser beam emitted by the red laser (8) is incident on the first plane mirror (9), and after being reflected by the first plane mirror (9), it is directed towards the second plane mirror (91); the second plane mirror (91) reflects the incident laser beam, and the reflected laser beam is directed towards the basin insulator (15) to be tested.

6. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 1, characterized in that, The dual-angle camera is a high-resolution industrial camera. The dual-angle camera includes two angle cameras (10). The angle cameras (10) are mounted on the turntable of the vertical guide rail of the three-dimensional linear guide rail (5). Before the bubble defect detection, the angle cameras (10) take pictures from multiple angles. After the image acquisition is completed, the images are uploaded to the intelligent control platform for three-dimensional reconstruction. During the X-ray scanning stage, the laser point projected by the laser positioning synchronization device is tracked in real time to assist in locking the defect coordinates.

7. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 1, characterized in that, The three-dimensional linear guide rail includes a longitudinal base guide rail, a transverse beam guide rail, and a vertical column guide rail. The longitudinal base guide rail and the transverse beam guide rail are connected by a longitudinal slider, and the transverse beam guide rail and the vertical column guide rail are connected by a transverse slider. The longitudinal slider and the transverse slider move linearly via a servo motor and a lead screw. The vertical column guide rail includes a first vertical column guide rail, a second vertical column guide rail and a third vertical column guide rail. A first slider is installed on the first vertical column guide rail, and a shielding box turntable is installed on the first slider. A second slider is installed on the second vertical column guide rail, and a third slider is installed on the third vertical column guide rail. A first camera turntable is installed on the second slider, and a second camera turntable is installed on the third slider. An angled camera (10) is installed on both the first camera turntable and the second camera turntable. The three-dimensional linear guide is equipped with a grating ruler feedback system.

8. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 1, characterized in that, The shielding box (6) has a collimation hole, through which the X-ray beam is output. The tube voltage of the X-ray machine (7) is continuously adjustable from 50 to 300 kV.

9. The bubble defect detection and positioning system based on X-ray enhanced partial discharge according to claim 1, characterized in that, The partial discharge detection system (11) is built using the pulse current method with an MPD800 partial discharge detector.

10. A method for detecting and locating bubble defects based on X-ray enhanced partial discharge, characterized in that, The bubble defect detection and localization system based on X-ray enhanced partial discharge as described in any one of claims 1-9 includes the following steps: Images of the tested basin insulator (15) are captured multiple times from multiple angles using a dual oblique angle camera and uploaded to the intelligent control platform (12). The image data is processed using a three-dimensional reconstruction algorithm to output a three-dimensional model of the tested basin insulator (15). The geometric dimensions of the three-dimensional model are extracted, and the X-ray machine parameters, including the X-ray machine tube voltage and X-ray machine tube current, are calculated based on the preset material parameters and the expected detection accuracy. An equally spaced three-dimensional grid is generated according to the shape of the three-dimensional model, the optimal scanning path of the X-ray machine (7) is planned, and the motion trajectory of the three-dimensional linear guide rail (5) is set to drive the X-ray machine (7) to move. By combining the three-dimensional model, the structure and electrical parameters of the pressurizing electrode, finite element simulation calculation of the internal electric field distribution is performed. Based on the simulation results and the database of partial discharge initiation field strength of bubbles with different diameters in X-ray environment, the pressurizing voltage value of the pressurizing system is calculated and set. The electrodes are selected and installed according to the geometric shape of the tested basin insulator (15). The pressure electrode is electrically contacted with the tested basin insulator (15). According to the pressure voltage value, the pressure circuit is gradually increased to the pressure voltage value. Then, the three-dimensional linear guide (5) is started, and the X-ray machine (7) is driven to emit an X-ray beam for scanning according to the optimal scanning path. The red laser (8) emits a laser beam coaxial with the X-ray beam. The laser point of the laser beam indicates the focal position of the X-ray beam. The partial discharge detection system (11) collects the signal in real time. Before the formal pressure scan begins or during the scan, a period of time is selected to confirm that there is no significant discharge signal. The statistical standard deviation of the background noise is automatically calculated and recorded. When the amplitude of a single pulse exceeds the preset threshold, it is determined to be a valid partial discharge event. At the same time as the valid discharge pulse is detected, the spatial three-dimensional coordinates of the laser spot projected onto the surface of the tested basin insulator (15) are determined by the position of the grating ruler of the three-dimensional linear guide (5) and the tracking laser point of the dual oblique angle camera. The defect location point is obtained. The discharge signal source is located at the defect location point, and the characteristic parameters of the discharge pulse and the frequency of pulse occurrence at the defect location point within the time window are recorded simultaneously. Based on the characteristic parameters of the defect location and discharge pulse, the detected defect location is mapped onto the three-dimensional model of the tested basin insulator (15) to locate the spatial distribution of bubble defects.

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