Nondestructive testing method, system and equipment for insulator defects

Abstract

The invention relates to a nondestructive testing method, a nondestructive testing system and nondestructive testing equipment for insulator defects. The nondestructive testing method comprises the following steps: acquiring first temperature change data of each pixel point after an insulator fitting is heated and second temperature change data after the insulator fitting is heated; determining the maximum temperature value of each piece of first temperature change data, and determining the shortest time of temperature drop in all the first temperature change data; translating the time corresponding to the maximum temperature value to the same time point, and determining reconstruction data according to the shortest time; analyzing the features of the reconstructed data under the fundamental frequency, and detecting the defects of the hardware fitting according to the features of the reconstructed data; analyzing the characteristics of the second temperature change data, and determining the defects of the insulator according to the characteristics of the second temperature change data; the features of the reconstruction data comprise amplitude features and phase features. The method can adapt to detection of different structures of insulators, reduces the misjudgment rate, and is applied to the technical field of power equipment detection.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment detection, and particularly to a non-destructive detection method, system and device for insulator defects. Background Art

[0002] Insulators are vulnerable to temperature changes under extreme climatic conditions. In an environment with large temperature differences, internal or surface cracks and other cracking defects may occur in the insulator due to thermal expansion and contraction. Currently, the existing cracking defect detection methods mainly include visual inspection, electric field measurement, infrared imaging, ultraviolet imaging, etc. In an environment with large temperature differences, temperature changes will interfere with temperature measurement, discharge state, etc., affecting the effect of defect detection and resulting in a relatively high misjudgment rate of the existing detection technology. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a non-destructive detection method, system and device for insulator defects, which can adapt to the detection of different structures of insulators and reduce the misjudgment rate.

[0004] On the one hand, the present invention provides a non-destructive detection method for insulator defects, including the following steps: Obtain the first temperature change data of each pixel point after the insulator fitting is heated and the second temperature change data after the insulator is heated; Determine the maximum temperature value of each first temperature change data, and determine the shortest time for the temperature to drop among all the first temperature change data; Translate the time corresponding to the maximum temperature value to the same time point, and determine the reconstructed data according to the shortest time; Analyze the characteristics of the reconstructed data at the fundamental frequency, and detect the defects of the fitting according to the characteristics of the reconstructed data; analyze the characteristics of the second temperature change data, and determine the defects of the insulator according to the characteristics of the second temperature change data; the characteristics of the reconstructed data include amplitude characteristics and phase characteristics.

[0005] Optionally, the determining the reconstructed data according to the shortest time specifically includes: taking the same time point as the starting point, and intercepting the temperature data after the maximum temperature value and within the shortest time as the reconstructed data.

[0006] Optionally, the analyzing the characteristics of the reconstructed data at the fundamental frequency and detecting the defects of the fitting according to the characteristics of the reconstructed data specifically includes: Perform Fourier transform on the reconstructed data at the fundamental frequency, and determine the amplitude characteristics and phase characteristics of the reconstructed data according to the result of the Fourier transform; Reconstruct the sub-value diagram according to the amplitude characteristics and the phase diagram according to the phase characteristics, determine the defect position based on the sub-value diagram and the phase diagram, and measure the size of the defect according to the peak value at the defect position in the phase diagram.

[0007] On the other hand, the present invention provides a non-destructive testing system for insulator defects. The insulator includes fittings and an insulator body. The non-destructive testing system includes an excitation power supply module, an electromagnetic excitation module, a photo-thermal excitation module, an infrared thermal imaging module, a motion module, and an industrial control computer. The excitation power supply module is used to supply power to the electromagnetic excitation module and the photo-thermal excitation module. The electromagnetic excitation module is used to emit electromagnetic waves, generate electromagnetic induction with the fittings, and heat the fittings. The photo-thermal excitation module is used to emit a light beam to heat the insulator body. The infrared thermal imaging module is used to obtain the first temperature change data after heating the fittings and / or the second temperature change data after heating the insulator body. The motion module is used to move the electromagnetic excitation module, the photo-thermal excitation module, or the infrared thermal imaging module. The industrial control computer is used to implement the above method.

[0008] Optionally, the excitation power supply module is specifically used to supply a first power corresponding to the material and / or shape of the fittings to the electromagnetic excitation module; the first power parameters include the power magnitude, power frequency, and loading time.

[0009] Optionally, the excitation power supply module is specifically used to supply a second power corresponding to the first geometric parameters of the insulator body to the photo-thermal excitation module; the second power parameters include the power and loading time.

[0010] Optionally, the photo-thermal excitation module includes one or more light sources such as a halogen lamp, a downlight, a flash lamp, or an array laser. The industrial control computer is also used to determine the light source for heating according to the type of the insulator body, and turn on the light source for heating in the photo-thermal excitation module to heat the insulator body.

[0011] Optionally, the infrared thermal imaging module includes a number of lenses with different focal lengths; the industrial control computer is also used to select at least one lens according to the second geometric parameters and accuracy of the fittings and / or the insulator body to obtain the first temperature change data after heating the fittings and / or the second temperature change data after heating the insulator body.

[0012] Optionally, the electromagnetic excitation module is specifically used to scan and heat the fittings.

[0013] On the other hand, the present invention provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the above-mentioned method is implemented.

[0014] Implementing the present invention has the following beneficial effects: respectively obtaining the temperature change data after heating the insulator fittings and the insulator part, and according to the characteristics of the insulator, adopting targeted processing methods for specific parts, so that the present invention is adapted to the defect detection of specific parts. At the same time, a defect recognition method based on the phase characteristics and amplitude characteristics at the fundamental frequency is adopted. The depth of thermal wave propagation at this frequency is the deepest, and the signal-to-noise ratio of defect detection is the highest, which can better present the state of the defect. Using the data at the fundamental frequency avoids the influence of invalid data in multi-dimensional data, thereby reducing the misjudgment rate. Description of the Drawings

[0015] 1 - Electromagnetic induction coil; 2 - Photo-thermal excitation source; 3 - Infrared thermal imaging module; 4 - Motion module; 5 - Industrial control computer; 6 - Excitation power supply module; 7 - Porcelain insulator to be detected.

[0016] Figure 1 is a flowchart of the steps of a non-destructive detection method for insulator defects provided by the present invention; Figure 2 is a schematic diagram of the process of reconstructing data provided by the present invention; Figure 3 is a schematic diagram of the module of a non-destructive detection system for insulator defects provided by the present invention; Figure 4 is a schematic diagram of the structure of a non-destructive detection system for insulator defects provided by the present invention; Figure 5 is a schematic diagram of the structure of an electronic device provided by the present invention. Detailed Embodiments

[0017] The following further describes the present invention in detail with reference to the drawings and specific embodiments. For the step numbers in the following embodiments, they are only set for the convenience of explanation and description, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0018] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0019] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0020] In addition, in the description of the present application, unless otherwise specified, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, D and / or E can represent: D exists alone, D and E exist simultaneously, and E exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0021] In some embodiments, as Figure 1 shown, Figure 1 is a step flowchart of a non-destructive detection method for insulator defects. The present invention provides a non-destructive detection method for insulator defects, including the following steps: S1. Obtain the first temperature change data of each pixel point after the insulator fitting is heated and the second temperature change data after the insulator is heated.

[0022] Among them, an insulator includes a fitting and an insulator. The fitting includes several pixel points. The first temperature change data and the second temperature change data can be, but are not limited to, temperature change curves. Each pixel point can be represented by at least one temperature change curve.

[0023] S2. Determine the maximum temperature value of each first temperature change data, and determine the shortest time for the temperature to drop among all the first temperature change data.

[0024] Specifically, as Figure 2 shown, Figure 2 is a schematic flow diagram of reconstructed data. In the figure, F represents the fitting to be detected, 1 represents an electromagnetic induction coil, and 8 represents the reconstructed data. For example, three pixel points A, B, and C on the fitting respectively have three temperature change curves A, B, and C. Determine the maximum temperature value of each temperature change curve and record the time.

[0025] Determine the shortest time for the temperature to drop among all the first temperature change data. For example, in the figure, after the maximum temperature of the temperature change curve C, the time for the temperature to drop is the shortest, and this is taken as the shortest time for the temperature to drop.

[0026] S3. Translate the time corresponding to the maximum temperature value to the same time point, and determine the reconstructed data according to the shortest time; Among them, the same time point can be the time point corresponding to the maximum temperature value of any temperature change curve, or it can be a time point that is not on the temperature change curve.

[0027] Specifically, when translating the time corresponding to the maximum temperature value to the same time point, the remaining time points are also translated correspondingly. Starting from this same time point, intercept the temperature data after the maximum temperature value and within the shortest time as the reconstructed data. For example, Figure 2 , intercept the temperature data within time C as the reconstructed data.

[0028] S4. Analyze the characteristics of the reconstructed data at the fundamental frequency, and detect the defects of the fittings according to the characteristics of the reconstructed data; analyze the characteristics of the second temperature change data, and determine the defects of the insulator according to the characteristics of the second temperature change data.

[0029] Among them, the characteristics of the reconstructed data include amplitude characteristics and phase characteristics. The characteristics of the second temperature change data can be, but are not limited to, amplitude characteristics, phase characteristics, maximum temperature, temperature change rate, etc.

[0030] Specifically, perform a Fourier transform on the reconstructed data at the fundamental frequency. As shown in formula (1): (1) Among them, T ( k ) is the reconstructed data, F n represents the n th fast Fourier transform result of the frequency component, L represents the time dimension of the reconstructed data, represents the exponential operation. At the fundamental frequency, n = 1.

[0031] Determine the amplitude characteristics and phase characteristics of the reconstructed data according to the results of the Fourier transform, specifically as shown in formulas (2) and (3): (2) (3) Among them, represents the real part of, represents The imaginary part of represents the arctangent function.

[0032] Reconstruct the sub-value graph according to the amplitude characteristics and the phase graph according to the phase characteristics. Combine the sub-value graph and the phase graph to locate the positions where the data change is greater than the preset value, that is, the defect positions. Measure the size of the defect according to the peak value at the defect position in the phase graph. For example, use the 5 / 12 peak width at the defect position in the phase graph to represent the size of the defect. Compared with the existing measurement results of the full-width at half maximum, it reduces the problem of over-measured size caused by lateral thermal diffusion and improves the measurement accuracy of the defect size.

[0033] On the other hand, as Figure 3 shown, Figure 3 is a schematic diagram of the module of a non-destructive testing system for insulator defects. The present invention provides a non-destructive testing system for insulator defects. The insulator includes fittings and an insulator body. The non-destructive testing system includes an excitation power supply module, an electromagnetic excitation module, a photo-thermal excitation module, an infrared thermal imaging module, a motion module, and an industrial control computer; The excitation power supply module is used to supply power to the electromagnetic excitation module and the photo-thermal excitation module; The electromagnetic excitation module is used to emit electromagnetic waves, generate electromagnetic induction with the fittings, and heat the fittings; The photo-thermal excitation module is used to emit light beams and heat the insulator body; The infrared thermal imaging module is used to obtain the first temperature change data after heating the fittings and / or the second temperature change data after heating the insulator body; The motion module is used to move the electromagnetic excitation module, the photo-thermal excitation module, or the infrared thermal imaging module; The industrial control computer is used to implement the foregoing method.

[0034] Specifically, the modules of the non-destructive testing system can be communicatively connected, or can be connected by wires or mechanically. The overall architecture can be that the motion module drives the excitation power supply module, the electromagnetic excitation module, the photo-thermal excitation module, and the infrared thermal imaging module to move near the insulator. For example, the motion module can be a drone, etc., to realize the on-line detection of the insulator; in addition, the overall architecture can also be as Figure 4 shown, Figure 4 is a schematic structural diagram of a non-destructive testing system for insulator defects.

[0035] The excitation power supply module can include multiple power supplies to supply power to the electromagnetic excitation module and the photo-thermal excitation module respectively, and change the output power, frequency, voltage, and current waveform of the excitation power supply module, so as to provide targeted thermal excitation methods for different detection objects.

[0036] The excitation power supply module is used to provide a first power supply corresponding to the first power supply parameters and the material and / or shape of the fitting. Among them, the first power supply parameters include the power supply size, power supply frequency, and loading time. The materials of the fitting include, but are not limited to, ferromagnetic materials and non-ferromagnetic materials. The shape of the fitting can be represented by, but is not limited to, thickness or area. For ferromagnetic materials, since more heat is generated by electromagnetic induction, the loading time can be within 1 s, the current size can be within 200 A, and the power supply frequency can be 100 - 200 kHz. For non-ferromagnetic materials, the loading time can be 1 - 10 s, the current size can be greater than 200 A, such as 220 A, 300 A. The power supply frequency can be greater than 200 kHz, such as 300 kHz. For the shape of the fitting, on the basis of the corresponding parameters of the fitting material, the thickness and / or area of the material is proportional to the increased loading time, that is, the thicker the material thickness or the larger the area, the longer the loading time. The loading time of the power supply can represent the heating time of a certain area by the electromagnetic excitation module or the photothermal excitation module.

[0037] The excitation power supply module is specifically used to provide a second power supply corresponding to the second power supply parameters and the first geometric parameters of the insulator. Among them, the second power supply parameters include the power supply power and the loading time, and the first geometric parameters include the area or thickness of the insulator. Similarly, the area or thickness of the insulator is proportional to the power supply power or the loading time, that is, the thicker the insulator thickness or the larger the area, the greater the required power supply power and the longer the loading time.

[0038] The industrial control computer can determine the power supply parameters according to the materials of the fitting and the insulator, and control the excitation power supply module to implement the power supply parameters.

[0039] The electromagnetic excitation module can include an electromagnetic induction coil. The electromagnetic induction coil can be annular or cylindrical and can scan and heat the fitting. The electromagnetic induction coil generates electromagnetic induction with the fitting to generate Joule heat, and the generation of this Joule heat is not affected by the surface of the fitting. Defects such as cracks in the fitting will affect the heat generation, heating, and cooling processes. Compared with photothermal excitation, there is an additional influence of defects during the heat generation process, providing more information. Generally speaking, heating the fitting part by electromagnetic induction can reduce the influence of the fitting surface, the coupling effect between the electromagnetic wave and the fitting is better, and it can provide information on multiple processes of heat generation, heating, and cooling, and the defect information is more abundant.

[0040] The photothermal excitation module includes one or more light sources such as halogen lamps, downlights, flashlights, or array lasers. The industrial control computer can determine the light source for heating according to the type of insulator, and turn on the light source for heating in the photothermal excitation module to heat the insulator. The types of insulators include, but are not limited to, insulators of different sizes or insulators with or without coating materials. For insulators, the size of the insulator is proportional to the array data volume of the array laser. For example, when the insulator is small, the light source for heating is a row of lasers; when the insulator is large, the light source for heating is all lasers. For coated insulators, if you want to detect the state of the coating layer, the light source for heating is a flashlight excitation source.

[0041] The infrared thermal imaging module includes several thermal imagers with several lenses of different focal lengths; the industrial control computer can select at least one lens according to the second geometric parameters and accuracy of the fitting and / or insulator to obtain the first temperature change data after heating the fitting and / or the second temperature change data after heating the insulator. Here, several means more than one; the second geometric parameters include volume and area; accuracy represents the accuracy of temperature data sampling. The volume or area is inversely proportional to the focal length of the lens, and the accuracy is directly proportional to the focal length of the lens.

[0042] In addition, the industrial control computer can determine the acquisition frequency, pixel size, or acquisition time of the infrared thermal imaging module according to the accuracy.

[0043] The present invention also has the following beneficial effects: In view of the different physical properties of the insulator fittings and insulators, the present invention proposes an adaptive heating method for different objects to be detected. An electromagnetic excitation source is used to detect defects in the fittings, and a photothermal excitation source is used to detect crack defects on the surface of the insulator (such as porcelain parts). According to the properties of the material, different thermal excitation detection methods are selected, which improves the detection accuracy and efficiency.

[0044] The present invention adopts a coil scanning type electromagnetic thermal excitation loading method and combines a method of reconstructing data, which can realize single-shot and large-range detection of fitting defects and improve the detection efficiency of defects.

[0045] In some embodiments, as Figure 5 shown, Figure 5 is a schematic structural diagram of an electronic device provided by the present invention. The present invention also provides an electronic device, which includes a processor 10 and a memory 11. The memory 11 stores a computer program, and when the processor 10 executes the computer program, it implements any one of the methods described in the above method embodiments.

[0046] Among them, the memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. The memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory optionally includes a remote memory remotely disposed relative to the processor, and these remote memories can be connected to the processor through a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0047] In addition, an embodiment of the present application also discloses a computer program product or a computer program, and the computer program product or the computer program is stored in a computer-readable storage medium. The processor of the computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program, so that the computer device executes the above-mentioned method.

[0048] The present invention also provides a computer-readable storage medium, in which a program executable by a processor is stored, and the program executable by the processor is used to execute any one of the methods described in the above method embodiments when executed by the processor.

[0049] Similarly, the content in the above method embodiments is applicable to the present storage medium embodiment. The function specifically implemented by the present storage medium embodiment is the same as that of the above method embodiment, and the beneficial effects achieved are also the same as those of the above method embodiment.

[0050] It will be understood that all or some of the steps and systems disclosed in the above methods may be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and may include any information delivery media.

[0051] The above is a specific description of the preferred embodiment of the present invention, but the present invention is not limited to the described embodiment. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A non-destructive testing method for insulator defects, characterized in that, The method includes the following steps: Obtain the first temperature change data of each pixel point after the insulator fitting is heated and the second temperature change data after the insulator is heated; Determine the maximum temperature value of each first temperature change data, and determine the shortest time for the temperature to drop among all the first temperature change data; Translate the time corresponding to the maximum temperature value to the same time point, and determine the reconstructed data according to the shortest time; Analyze the characteristics of the reconstructed data at the fundamental frequency, and detect the defects of the fitting according to the characteristics of the reconstructed data; analyze the characteristics of the second temperature change data, and determine the defects of the insulator according to the characteristics of the second temperature change data; the characteristics of the reconstructed data include amplitude characteristics and phase characteristics.

2. The method according to claim 1, wherein The determining the reconstructed data according to the shortest time specifically includes: starting from the same time point, intercepting the temperature data after the maximum temperature value and within the shortest time as the reconstructed data.

3. The method according to claim 1, characterized in that, The analyzing the characteristics of the reconstructed data at the fundamental frequency and detecting the defects of the fitting according to the characteristics of the reconstructed data specifically includes: Performing Fourier transform on the reconstructed data at the fundamental frequency, and determining the amplitude characteristics and phase characteristics of the reconstructed data according to the results of the Fourier transform; Reconstructing an amplitude map according to the amplitude characteristics and a phase map according to the phase characteristics, determining the defect position according to the amplitude map and the phase map, and measuring the size of the defect according to the peak value at the defect position in the phase map.

4. A non-destructive testing system for insulator defects, characterized in that, The insulator includes a fitting and an insulator, and the non-destructive testing system includes an excitation power supply module, an electromagnetic excitation module, a photo-thermal excitation module, an infrared thermal imaging module, a motion module, and an industrial control computer; The excitation power supply module is used to provide power to the electromagnetic excitation module and the photo-thermal excitation module; The electromagnetic excitation module is used to emit electromagnetic waves, generate electromagnetic induction with the fitting, and heat the fitting; The photo-thermal excitation module is used to emit a light beam to heat the insulator; The infrared thermal imaging module is used to obtain the first temperature change data after the fitting is heated and / or the second temperature change data after the insulator is heated; The motion module is used to move the electromagnetic excitation module, the photo-thermal excitation module, or the infrared thermal imaging module; The industrial control computer is used to implement the method according to any one of claims 1-3.

5. The system according to claim 4, wherein The excitation power supply module is specifically used to provide a first power supply corresponding to the material and / or shape of the fitting with a first power parameter to the electromagnetic excitation module; the first power parameter includes the power size, power frequency, and loading time.

6. The system according to claim 4, wherein The excitation power supply module is specifically used to provide a second power supply corresponding to the first geometric parameter of the insulator with a second power parameter to the photo-thermal excitation module; the second power parameter includes the power and loading time.

7. The system according to claim 4, wherein The photo-thermal excitation module includes one or more light sources such as a halogen lamp, a downlight, a flash lamp, or an array laser, and the industrial control computer is further used to determine the light source for heating according to the type of the insulator, and turn on the light source for heating in the photo-thermal excitation module to heat the insulator.

8. The system according to claim 4, characterized in that, The infrared thermal imaging module includes a number of lenses with different focal lengths; the industrial control computer is further configured to select at least one lens according to the second geometric parameters and accuracy of the fitting and / or the insulator to obtain the first temperature change data after heating of the fitting and / or the second temperature change data after heating of the insulator.

9. The system according to claim 4, characterized in that, The electromagnetic excitation module is specifically configured to perform scanning heating on the fitting.

10. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1-3 is implemented.

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