Three-dimensional contour ultrasonic detection method for oil immersed structure in closed container
Through ultrasonic phased array technology and cubic spline interpolation method, high-resolution three-dimensional image detection of the oil immersion structure in the enclosed container is realized, solving the problem that traditional methods are difficult to detect minor faults, and improving the accuracy and safety of detection. Ensures the stability and safety of the oil-immersed transformer.
Patent Information
- Application Number
- CN202411431816.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-01-07
AI Technical Summary
The prior art is difficult to accurately detect tiny faults and deformation damage in the oil-immersed structure inside the enclosed container. Traditional methods such as visual inspection and infrared temperature measurement are difficult to detect details of the internal structure, which affects the stability and safety of the oil-immersed transformer.
Using ultrasonic phased array technology and cubic spline interpolation method, the ultrasonic detection unit moves along the outer wall of the enclosed container to extract the ultrasonic phased array scan image, convert it into two-dimensional dot matrix data and cubic spline interpolation to form oil immersion inside the enclosed container The three-dimensional surface image of the structure enables non-invasive detection.
It realizes high-resolution three-dimensional image detection of the oil-immersed structure inside the enclosed container, improves the accuracy and visualization of the detection, and can perform non-destructive testing without opening the container, reducing the risk of damage during the detection process, and improving the Safety and adaptability of detection.
Smart Images
Figure CN119268618A_ABST
Abstract
Description
Technical Field
[0001] The present invention mainly relates to the technical field of closed container internal structure detection, and in particular to a three-dimensional contour ultrasonic detection method for an oil-immersed structure inside a closed container. Background Art
[0002] In many engineering projects, when it comes to the inspection of the internal structure of a closed container, an efficient inspection method is needed to monitor the deformation and damage of the internal structure, such as insulation aging, mechanical stress, thermal stress, etc., which lead to deformation, looseness or damage of the internal structure. The stability and reliability of the operating state of the oil-immersed transformer are directly related to the safe operation of the entire power system. The internal winding is its core component. If the winding is damaged and deformed, it may cause serious safety accidents. Accurate and efficient inspection of the internal winding of the transformer is of great practical significance. Although traditional inspection methods such as visual inspection and infrared temperature measurement are simple and easy to use, they are often difficult to detect minor faults inside the closed structure. Summary of the invention
[0003] In view of the technical problems existing in the prior art, the present invention provides a safe, reliable, accurate and efficient three-dimensional contour ultrasonic detection method for the oil-immersed structure inside a closed container.
[0004] In order to solve the above technical problems, the technical solution proposed by the present invention is:
[0005] A method for ultrasonically detecting the three-dimensional profile of an oil-immersed structure inside a closed container, comprising the steps of:
[0006] S1. When the ultrasonic detection unit moves along the outer wall of the closed container, an ultrasonic phased array line scanning image of the oil-immersed structure inside the closed container is extracted at a certain step;
[0007] S2, converting the ultrasonic phased array line scanning image into two-dimensional dot matrix data, calculating the dot matrix data acquisition position coordinates in combination with the scanning motion step length of the ultrasonic detection unit, and forming the contour three-dimensional dot matrix data coordinates;
[0008] S3. Performing cubic spline interpolation on the coordinates of the three-dimensional dot matrix data to amplify the three-dimensional dot matrix data, and converting the amplified three-dimensional dot matrix data into a three-dimensional surface image of the surface contour of the oil-immersed structure inside the closed container.
[0009] Preferably, the specific process of step S2 is:
[0010] S201, binarizing all ultrasonic phased array line scanning images, that is, setting elements of the ultrasonic phased array line scanning images to "0" or "1", where "0" represents background and "1" represents contour;
[0011] S202, extracting the two-dimensional coordinates of element "1" of the ultrasonic phased array line scanning image to form the two-dimensional lattice coordinates (x, y) of the internal oil-immersed structure, and then generating the Z-axis coordinate z corresponding to the extraction position of the ultrasonic phased array line scanning image according to the scanning step;
[0012] S203, combining the two-dimensional dot matrix coordinates (x, y) with the Z-axis coordinate z to form the three-dimensional space coordinates (x, y, z) of the contour three-dimensional dot matrix.
[0013] Preferably, in step S3, a cubic spline interpolation method is used to fit a cubic polynomial to approximate each three-dimensional lattice data, and interpolation is performed between the three-dimensional lattice data to obtain expanded three-dimensional lattice data.
[0014] Preferably, 40-60 data points are interpolated from every two original data points by difference calculation.
[0015] The present invention also discloses an application method of the three-dimensional contour ultrasonic detection method based on the oil-immersed structure inside the closed container as described above to the detection of internal windings in an oil-immersed transformer.
[0016] Preferably, before step S1, a method for arranging an ultrasonic detection unit is also included, specifically including:
[0017] The ultrasonic detection unit is arranged on the outer wall of the container of the oil-immersed transformer. The sensor array is arranged in a direction parallel to the x direction, and the scanning movement direction is along the z direction. The ultrasonic detection unit is attached to the outer surface of the outer wall of the container and acoustically coupled through an acoustic coupling agent.
[0018] Preferably, in step S1, the focusing law of the ultrasonic detection unit is adjusted so that the ultrasonic wave forms a focused sound field on the surface of the oil-immersed component inside the closed container.
[0019] Preferably, in step S1, the position of the ultrasonic detection unit is adjusted so that the line scanning range just covers the internal oil-immersed component in the X direction;
[0020] The ultrasonic detection unit moves along the Z direction and simultaneously extracts the ultrasonic phased array line scanning image of the oil-immersed structure inside the closed container at a certain step.
[0021] The present invention further discloses a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described above are executed.
[0022] The present invention also discloses a computer device, comprising a memory and a processor connected to each other, wherein a computer program is stored in the memory, and when the computer program is run by the processor, the steps of the method described above are executed.
[0023] Compared with the prior art, the advantages of the present invention are:
[0024] The present invention uses ultrasonic phased array technology for nondestructive testing, and improves the accuracy and visualization of the test results through data processing. The ultrasonic detection unit of the present invention can perform detection without contacting the object to be detected, reducing the damage that may be caused to the object during the detection process, and solving the problem that the internal oil-immersed structure in the closed container cannot be entered for detection. Compared with traditional destructive detection methods, ultrasonic testing is non-invasive and can be performed without opening the container, which improves the safety and adaptability of the detection.
[0025] The present invention can obtain high-resolution three-dimensional images of internal oil-immersed structures through data processing methods such as line scanning and spline interpolation, and more accurately reveal the details inside the container; by converting the scanned image into dot matrix data and performing cubic spline interpolation, the surface contour of the oil-immersed structure can be better fitted to provide a more accurate three-dimensional model. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 The present invention is a flow chart of an embodiment of the method for ultrasonic detection of the three-dimensional contour of the oil-immersed structure inside a closed container.
[0027] Figure 2 Schematic diagram of the oil-immersed structure inside the closed container of the present invention; (a) is a side view; (b) is a main view; and (c) is a top view.
[0028] Figure 3 It is a layout diagram of the ultrasonic detection unit of the present invention in a specific application.
[0029] Figure 4 These are ultrasonic phased array line scan images of three characteristic positions of the internal oil-immersed structure of the present invention; wherein (a) is the line scan image of characteristic position 1; (b) is the line scan image of characteristic position 2; and (c) is the line scan image of characteristic position 3.
[0030] Figure 5 The binary images of the surface profiles of three characteristic positions of the internal oil-immersed structure of the present invention; (a) is the binary image of characteristic position 1; (b) is the binary image of characteristic position 2; and (c) is the binary image of characteristic position 3.
[0031] Figure 6 The three-dimensional dot lattice distribution diagram of the three characteristic positions of the internal oil-immersed structure of the present invention; (a) is the three-dimensional dot lattice distribution diagram of characteristic position 1; (b) is the three-dimensional dot lattice distribution diagram of characteristic position 2; (c) is the three-dimensional dot lattice distribution diagram of characteristic position 3.
[0032] Figure 7It is the overall three-dimensional dot lattice distribution and three-dimensional curved surface image of the internal oil-immersed structure contour of the present invention; wherein (a) is the overall three-dimensional dot lattice distribution diagram of the internal oil-immersed structure contour; (b) is the three-dimensional image of the surface contour of the internal oil-immersed structure. DETAILED DESCRIPTION
[0033] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.
[0034] like Figure 1 As shown, the three-dimensional contour ultrasonic detection method of the oil-immersed structure inside the closed container according to the embodiment of the present invention comprises the following steps:
[0035] S1. When an ultrasonic detection unit (such as an ultrasonic sensor) moves along the outer wall of a closed container, an ultrasonic phased array line scanning image of the oil-immersed structure inside the closed container is extracted at a certain step;
[0036] S2, converting the ultrasonic phased array line scanning image into two-dimensional dot matrix data, calculating the dot matrix data acquisition position coordinates in combination with the scanning motion step length of the ultrasonic detection unit, and forming the contour three-dimensional dot matrix data coordinates;
[0037] S3. Performing cubic spline interpolation on the coordinates of the three-dimensional dot matrix data to amplify the three-dimensional dot matrix data, and converting the amplified three-dimensional dot matrix data into a three-dimensional surface image of the surface contour of the oil-immersed structure inside the closed container.
[0038] Specifically, the specific process of step S2 is:
[0039] S201, binarizing all ultrasonic phased array line scanning images, that is, setting elements of the ultrasonic phased array line scanning images to "0" or "1", where "0" represents background and "1" represents contour;
[0040] S202, extracting the two-dimensional coordinates of element "1" of the ultrasonic phased array line scanning image to form the two-dimensional lattice coordinates (x, y) of the internal oil-immersed structure, and then generating the Z-axis coordinate z corresponding to the extraction position of the ultrasonic phased array line scanning image according to the scanning step;
[0041] S203, combining the two-dimensional dot matrix coordinates (x, y) with the Z-axis coordinate z to form the three-dimensional space coordinates (x, y, z) of the contour three-dimensional dot matrix.
[0042] Specifically, in step S3, a cubic spline interpolation method is used to fit a cubic polynomial to approximate each three-dimensional lattice data, and interpolation is performed between the three-dimensional lattice data to obtain expanded three-dimensional lattice data.
[0043] Since ultrasonic waves can penetrate the oil layer from the traditional outer wall of the outer surface of the closed structure and then be incident on the surface of the internal oil-immersed structure, the present invention can realize imaging detection of the oil-immersed structure inside the closed container through ultrasonic detection; in addition, since the ultrasonic phased array detection technology can flexibly control the focused sound field, it has the advantages of strong penetration ability, high detection sensitivity and fast imaging speed. Therefore, a three-dimensional contour ultrasonic imaging detection method for the surface of the oil-immersed structure inside the closed container is proposed, which effectively improves the accuracy and reliability of non-invasive detection of the state of the oil-immersed internal structure in the closed container.
[0044] The present invention uses ultrasonic phased array technology for nondestructive testing and improves the accuracy and visualization of the test results through data processing. Specific advantages include:
[0045] Non-contact detection: The ultrasonic detection unit can detect without contacting the object being detected, reducing the damage that may be caused to the object during the detection process. Compared with traditional destructive detection methods, ultrasonic detection is non-invasive and can be performed without opening the container, which improves the safety of detection.
[0046] High flexibility: The ultrasonic detection unit can flexibly adjust the scanning angle and step to adapt to closed containers of different shapes and sizes.
[0047] High resolution: Through data processing methods such as line scanning and spline interpolation, high-resolution three-dimensional images of internal oil-immersed structures can be obtained, revealing the details inside the container more accurately. Specifically, line scanning is a method in which the ultrasonic detection unit obtains ultrasonic images of the oil-immersed structure inside a closed container point by point through line scanning; the line scanning sensor moves along the outer wall of the container, emitting and receiving ultrasonic waves point by point, and recording the echo signal of each point. These signals reflect the interface information inside the oil-immersed structure, such as the position, shape, and size of the interface. Spline interpolation is used to interpolate between known data points to generate new data points; in ultrasonic testing, spline interpolation can smoothly connect data points on different scan lines, thereby improving the continuity and resolution of the image; this method can fill the blank areas between scan lines, making the final three-dimensional image more delicate and clear.
[0048] Through the above-mentioned line scanning and spline interpolation processing, a high-resolution three-dimensional image of the oil-immersed structure inside the closed container can be obtained. This image can clearly show the details of the oil-immersed structure, such as tiny cracks, holes, sediments, etc., so that the inspector can accurately evaluate the condition inside the container.
[0049] Data processing capability: By converting the scanned image into dot matrix data and performing cubic spline interpolation, the surface contour of the oil-immersed structure can be better fitted to provide a more accurate three-dimensional model.
[0050] Wide scope of application: This solution is not only suitable for the detection of oil-immersed structures, but can also be used for the detection and analysis of the internal structures of other similar closed containers.
[0051] High degree of automation: The entire detection and data processing process can be automated, reducing human operational errors and improving detection efficiency.
[0052] In summary, the present invention has significant advantages in ensuring safe production, improving detection efficiency and accuracy, and reducing maintenance costs.
[0053] The embodiment of the present invention further provides an application method of the three-dimensional contour ultrasonic detection method based on the oil-immersed structure inside the closed container in detecting the internal winding of the oil-immersed transformer, which specifically includes the following steps:
[0054] (1) The ultrasonic detection unit is arranged on the outer wall of the closed container, and the movement scanning direction of the ultrasonic detection unit is perpendicular to the array arrangement direction; wherein the ultrasonic detection unit arrangement method specifically includes:
[0055] The internal oil-immersed structure is shaped like Figure 2 As shown, the internal oil-immersed structure is placed at the center of the bottom of the container.
[0056] The ultrasonic detection unit is arranged on the outer wall of the closed container, the array arrangement direction is parallel to the x direction, the scanning movement direction is along the y direction, the ultrasonic detection unit is attached to the outer surface of the outer wall of the container, and acoustic coupling is performed through an acoustic coupling agent.
[0057] (2) Figure 3 As shown, the motion unit carries the ultrasonic detection unit to perform one-dimensional scanning motion, and at the same time extracts the ultrasonic phased array line scanning image of the oil-immersed structure inside the closed container at a certain step; specifically, the focusing rule of the phased array sensor is adjusted so that the ultrasonic wave forms a focused sound field on the surface of the internal oil-immersed component, with a focusing depth of 290 mm; the line scanning aperture is set to 32 and the line scanning imaging width is 48 mm; the position of the ultrasonic detection unit is adjusted so that the line scanning range just covers the internal oil-immersed component with a width (X direction) of 48 mm;
[0058] The motion unit is equipped with an ultrasonic detection unit to perform scanning motion along the Z direction, and at the same time, the ultrasonic phased array line scanning image of the internal oil-immersed structure is extracted at a certain step (3 mm). The line scanning images corresponding to the three characteristic positions 1 to 3 (components A+B, A, and C) in the Z direction of the internal oil-immersed component are as follows: Figure 4 As shown in (a), (b) and (c).
[0059] (3) Convert the contour ultrasonic phased array line scanning image into two-dimensional dot matrix data, calculate the dot matrix data acquisition position coordinates in combination with the scanning motion step length, and form the coordinates of the contour three-dimensional dot matrix data; specifically:
[0060] All acquired ultrasonic phased array line scan images are binarized, that is, the elements of the line scan images are set to "0" or "1", "0" for background and "1" for contour;
[0061] The binary images of the internal oil-immersed component A+B, component A, and component C collected by the ultrasonic testing unit at positions 1 to 3 are shown in FIG. Figure 5 As shown in (a), (b) and (c).
[0062] The two-dimensional coordinates of "1" are extracted to form the two-dimensional lattice coordinates (x, y) of the internal oil-immersed component. The Z-axis coordinates corresponding to the extraction position of the phased array line scan image are generated according to the scanning step, and combined with (x, y) to form the three-dimensional spatial coordinates (x, y, z) of the contour lattice. The lattice three-dimensional spatial position diagram of the internal oil-immersed component (components A, B, C) collected at the three characteristic positions 1-3 is shown in Figure 6 As shown in (a), (b) and (c).
[0063] (4) The three-dimensional dot matrix data is amplified by performing cubic spline interpolation on the coordinates of the three-dimensional dot matrix data, and the amplified three-dimensional dot matrix is converted into a three-dimensional surface image of the surface contour of the internal oil-immersed structure.
[0064] The cubic spline interpolation of the three-dimensional lattice is as follows: a cubic polynomial is fitted using the cubic interpolation method to approximate each data point, and interpolation is performed between the data points to obtain an expanded three-dimensional lattice, and 50 data points are inserted into every two original data points through difference operation.
[0065] The specific process of cubic spline interpolation is as follows: first search the original data point set to find the data points closest to the query point; these neighboring data points will be used to construct a local cubic spline interpolation function;
[0066] Based on the neighboring data points of the query point, a piecewise cubic spline interpolation function is constructed; then, this cubic spline interpolation function is used to estimate the function value at the query point.
[0067] The three-dimensional spatial distribution of the dot matrix of the surface contour of the internal oil-immersed structure after amplification is shown in Figure 2. Figure 7 As shown in (a).
[0068] The data points in the augmented three-dimensional lattice are denser than those in the original three-dimensional lattice, so that a smoother three-dimensional surface can be generated;
[0069] Finally, the three-dimensional surface of the internal oil-immersed structure is generated based on the three-dimensional spatial coordinates of the surface contour lattice of the internal oil-immersed structure, that is, the three-dimensional image of the surface contour of the internal oil-immersed structure, such as Figure 7 As shown in (b).
[0070] The present invention also discloses a computer-readable storage medium, on which a computer program is stored, and the computer program executes the steps of the above method when it is run by a processor. The present invention further discloses a computer device, including a memory and a processor connected to each other, and a computer program is stored on the memory, and the computer program executes the steps of the above method when it is run by the processor. The present invention implements all or part of the process in the above embodiment method, and can also be completed by hardware related to computer program instructions. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above method embodiment when it is executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable storage media include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-On lyMemory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. The memory is used to store computer programs and / or modules. The processor implements various functions by running or executing the computer programs and / or modules stored in the memory, and calling the data stored in the memory. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Med ia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (FlashCard), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices, etc.
[0071] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0072] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0073] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0074] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.
Claims
1. A three-dimensional contour ultrasonic detection method for an oil-immersed structure inside a closed container, characterized in that: Includes steps: S1. When the ultrasonic detection unit moves along the outer wall of the closed container, an ultrasonic phased array line scanning image of the oil-immersed structure inside the closed container is extracted at a certain step; S2, converting the ultrasonic phased array line scanning image into two-dimensional dot matrix data, calculating the dot matrix data acquisition position coordinates in combination with the scanning motion step length of the ultrasonic detection unit, and forming the contour three-dimensional dot matrix data coordinates; S3. Performing cubic spline interpolation on the coordinates of the three-dimensional dot matrix data to amplify the three-dimensional dot matrix data, and converting the amplified three-dimensional dot matrix data into a three-dimensional surface image of the surface contour of the oil-immersed structure inside the closed container.
2. The three-dimensional contour ultrasonic detection method of the oil-immersed structure inside a closed container according to claim 1 is characterized in that: The specific process of step S2 is: S201, binarizing all ultrasonic phased array line scanning images, that is, setting elements of the ultrasonic phased array line scanning images to "0" or "1", where "0" represents background and "1" represents contour; S202, extracting the two-dimensional coordinates of the element "1" of the ultrasonic phased array line scanning image to form the two-dimensional lattice coordinates (x, y) of the internal oil-immersed structure, and then generating the Z-axis coordinate z corresponding to the extraction position of the ultrasonic phased array line scanning image according to the scanning step; S203, combining the two-dimensional dot matrix coordinates (x, y) with the Z-axis coordinate z to form the three-dimensional space coordinates (x, y, z) of the contour three-dimensional dot matrix.
3. The three-dimensional contour ultrasonic detection method of the oil-immersed structure inside a closed container according to claim 2 is characterized in that: In step S3, a cubic spline interpolation method is used to fit a cubic polynomial to approximate each three-dimensional lattice data, and interpolation is performed between the three-dimensional lattice data to obtain expanded three-dimensional lattice data.
4. The three-dimensional contour ultrasonic detection method of the oil-immersed structure inside a closed container according to claim 3, characterized in that: Every two original data points are interpolated into 40-60 data points by interpolation operation.
5. An application method of the three-dimensional contour ultrasonic detection method of the oil-immersed structure inside a closed container according to any one of claims 1 to 4 in detecting internal windings in an oil-immersed transformer.
6. The application method according to claim 5, characterized in that: Before step S1, a method for arranging the ultrasonic detection unit is also included, which specifically includes: The ultrasonic detection unit is arranged on the outer wall of the container of the oil-immersed transformer. The sensor array is arranged in a direction parallel to the x direction, and the scanning movement direction is along the z direction. The ultrasonic detection unit is attached to the outer surface of the outer wall of the container and acoustically coupled through an acoustic coupling agent.
7. The application method according to claim 6, characterized in that: In step S1, the focusing law of the ultrasonic detection unit is adjusted so that the ultrasonic wave forms a focused sound field on the surface of the oil-immersed component inside the closed container.
8. The application method according to claim 7, characterized in that: In step S1, the position of the ultrasonic detection unit is adjusted so that the line scanning range just covers the internal oil-immersed component in the X direction; The ultrasonic detection unit moves along the Z direction and simultaneously extracts the ultrasonic phased array line scanning image of the oil-immersed structure inside the closed container at a certain step.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program executes the steps of the method according to any one of claims 1 to 4 when executed by a processor.
10. A computer device comprising a memory and a processor connected to each other, wherein a computer program is stored in the memory, characterized in that: The computer program executes the steps of the method according to any one of claims 1 to 4 when executed by a processor.