Joint defect type detection method based on microwave scanning and related equipment

Abstract

The embodiment of the invention discloses a joint defect type detection method based on microwave scanning and related equipment, and relates to the technical field of cable quality detection, 360-degree microwave scanning is carried out on a standard cable terminal joint, and the average voltage amplitude and the average phase of a first microwave reflection signal are obtained as a reference; then the cable terminal joint to be detected is scanned in the same way to obtain a first voltage amplitude and a first phase of a second microwave reflection signal, 360-degree scanning ensures all-directional detection of the cable terminal joint, and any position where a defect possibly exists is not released; by comparing the average voltage amplitude and the average phase with the first voltage amplitude and the first phase, the defect type of the to-be-detected joint can be accurately judged, the method greatly improves the comprehensiveness and accuracy of detection, timely finds potential defects, provides reliable basis for maintenance and replacement of the cable terminal joint, and improves the detection efficiency. The fault occurrence rate is effectively reduced, and safe and stable operation of a power system is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable quality detection, and in particular to a joint defect type detection method based on microwave scanning and related equipment. BACKGROUND

[0002] In the scenario of cable terminal joint quality detection, the traditional detection method has significant defects. In the past, local detection methods have been used, such as detecting only a specific surface or a limited angle area of the cable terminal joint. Due to the different degrees of influence of various factors such as environment and stress on each part of the cable terminal joint in actual operation, defects can occur at any location. Local detection cannot fully obtain the overall information of the joint, and may miss defects hidden in non-detection areas. Once these potential defects are not detected in time, they may gradually worsen in the subsequent use process, eventually leading to joint failure and causing serious accidents such as power outages, affecting the stable operation of the power system and causing great inconvenience to production and life. SUMMARY

[0003] Therefore, the present application provides a joint defect type detection method based on microwave scanning and related equipment.

[0004] The specific technical scheme of the first embodiment of the present application is as follows: a joint defect type detection method based on microwave scanning, the method comprising: performing 360° microwave scanning on a standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflection signal when the standard cable terminal joint is scanned by microwave; the standard cable terminal joint is a defect-free cable terminal joint; performing 360° microwave scanning on a cable terminal joint to be detected to obtain the first voltage amplitude and first phase of the second microwave reflection signal when the cable terminal joint to be detected is scanned by microwave; and performing joint defect type detection on the cable terminal joint to be detected according to the average voltage amplitude, the average phase, the first voltage amplitude and the first phase.

[0005] Preferably, the 360° microwave scanning on the standard cable terminal joint to obtain the average voltage amplitude and average phase of the microwave reflection signal when the standard cable terminal joint is scanned by microwave comprises: using a preset spiral scanning trajectory to perform 360° microwave scanning on the standard cable terminal joint, and collecting a second voltage amplitude and a second phase of a first microwave reflection signal every time a preset angle is rotated; and calculating the average value of all second voltage amplitudes to obtain the average voltage amplitude, and calculating the average value of all second phases to obtain the average phase.

[0006] Preferably, the preset spiral scanning trajectory is obtained using the following formula:

[0007] in, Let be the radial displacement function of the scanning probe in polar coordinates. This is the axial displacement function of the scanning probe in polar coordinates. This represents the initial offset of the scanning probe from the axis of the cable terminal connector. To control the preset growth rate of the helix radius as the angle changes, This is the preset amplitude scaling factor. To adjust the angular frequency of the radial wave density, The number of cycles in the radial plane is the number of the spiral's expansion. The preset exponential attenuation coefficient is used to offset the effects of mechanical backlash. This is the preset sensitivity of the exponential decay term to changes in angle. To establish the reference height for the starting end face of the scan, To control the movement speed of the probe along the axial direction of the cable terminal joint, This represents the number of cycles of the spiral winding along the axial direction of the cable terminal joint. To superimpose the fluctuation amplitude of the axial micro-oscillation, The angular frequency of the axial oscillation. The preset phase adjustment amount is used to eliminate mechanical resonance. The angle is the rotation angle.

[0008] Preferably, the step of detecting the joint defect type of the cable terminal joint under test based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase includes: determining a first average value, a first maximum value, and a first minimum value of the second voltage amplitude; determining a second average value, a second maximum value, and a second minimum value of the second phase; obtaining a voltage amplitude error based on the first maximum value and the first minimum value; obtaining a phase error value based on the second maximum value and the second minimum value; obtaining a relative value of the voltage amplitude difference for each first voltage amplitude based on the average voltage amplitude, the voltage amplitude error, and the first voltage amplitude; obtaining a relative value of the phase transformation amount for each first phase based on the average phase, the phase error value, and the first phase; and detecting the joint defect type of the cable terminal joint under test based on the relative value of the voltage amplitude difference and the relative value of the phase transformation amount.

[0009] Preferably, the relative value of the voltage amplitude difference is obtained using the following formula:

[0010] in, For the first i The relative value of the voltage amplitude difference at each scan point For the first i The first voltage amplitude at each scan point The average voltage amplitude, The voltage amplitude error, This is the preset temperature correction factor. This is the preset humidity correction factor. This is the preset signal-to-noise ratio correction factor.

[0011] Preferably, the relative value of the phase transformation amount is obtained using the following formula:

[0012] in, For the first i The relative value of the phase transformation at each scan point For the first i The first phase of each scan point This is the second mean. The phase error value is... This is the preset temperature correction factor. This is the preset humidity correction factor. This is the preset signal-to-noise ratio correction factor.

[0013] Preferably, the step of detecting the joint defect type of the cable terminal joint under test based on the relative value of the voltage amplitude difference and the relative value of the phase transformation includes: if the relative value of the voltage amplitude difference is greater than a second threshold and the relative value of the phase transformation is greater than a first threshold, then the defect type of the cable terminal joint under test is a conductive impurity defect; if the relative value of the voltage amplitude difference is greater than a third threshold and less than or equal to the second threshold, and the relative value of the phase transformation is greater than the third threshold and less than or equal to the second threshold, then the defect type of the cable terminal joint under test is a main insulation scratch defect; if the relative value of the voltage amplitude difference is less than 0 and the absolute value of the relative value of the voltage amplitude difference is greater than the third threshold, and the relative value of the phase transformation is greater than the second threshold and less than the first threshold, then the defect type of the cable terminal joint under test is a moisture defect; the first threshold is greater than the second threshold, and the second threshold is greater than the third threshold.

[0014] The specific technical solution of the second embodiment of the present invention is as follows: a joint defect type detection system based on microwave scanning, the system comprising: a first scanning module, a second scanning module, and a detection result output module; the first scanning module is used to perform a 360° microwave scan on a standard cable terminal joint, and obtain the average voltage amplitude and average phase of the first microwave reflection signal when the standard cable terminal joint is microwave scanned; the standard cable terminal joint is a defect-free cable terminal joint; the second scanning module is used to perform a 360° microwave scan on the cable terminal joint to be tested, and obtain the first voltage amplitude and first phase of the second microwave reflection signal when the cable terminal joint to be tested is microwave scanned; the detection result output module is used to detect the joint defect type of the cable terminal joint to be tested based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase.

[0015] The specific technical solution of the third embodiment of the present invention is as follows: a joint defect type detection device based on microwave scanning, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method as described in any one of the first embodiments of this application.

[0016] The specific technical solution of the fourth embodiment of the present invention is as follows: a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor performs the steps of the method as described in any one of the first embodiments of this application.

[0017] Implementing the embodiments of the present invention will have the following beneficial effects: This invention employs a 360° microwave scan of a standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflected signal as a benchmark. The same scan is then performed on the cable terminal joint to be inspected to obtain the first voltage amplitude and first phase of the second microwave reflected signal. This 360° scan ensures comprehensive inspection of the cable terminal joint, leaving no potential defect location undetected. By comparing the average voltage amplitude and average phase with the first voltage amplitude and first phase, the defect type of the joint under inspection can be accurately determined. This method significantly improves the comprehensiveness and accuracy of inspection, enabling timely detection of potential defects and providing a reliable basis for the maintenance and replacement of cable terminal joints. It effectively reduces the failure rate and ensures the safe and stable operation of the power system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The flowchart shows the steps of a microwave scanning-based joint defect type detection method. Figure 2 A schematic diagram of the microwave reflected signal voltage amplitude of a defect-free cable terminal sample; Figure 3 A schematic diagram of the microwave reflection signal phase of a defect-free cable terminal sample; Figure 4 A schematic diagram of the microwave reflected signal voltage amplitude of a defective cable terminal joint sample; Figure 5 A schematic diagram of the microwave reflected signal phase of a defective cable terminal joint sample; Figure 6 This is a schematic diagram of a joint defect type detection system based on microwave scanning. Among them, 201 is the first scanning module; 202 is the second scanning module; and 203 is the detection result output module. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] The terms "first," "second," etc., used in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or modules is not limited to the listed steps or modules, but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to such processes, methods, products, or apparatus.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] Please see Figure 1 This is a flowchart illustrating the steps of a microwave scanning-based joint defect type detection method in the first embodiment of this application, aimed at accurately determining the defect type of the joint to be detected. The method includes: Step 101: Perform a 360° microwave scan on the standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflection signal during the microwave scan; the standard cable terminal joint is a defect-free cable terminal joint. Step 102: Perform a 360° microwave scan on the cable terminal joint to be tested, and obtain the first voltage amplitude and first phase of the second microwave reflection signal when the cable terminal joint to be tested is microwave scanned; Step 103: Detect the joint defect type of the cable terminal joint to be tested based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase.

[0024] Specifically, firstly, a 360° omnidirectional microwave scan is performed on the standard cable terminal joint (in a defect-free state) to obtain the average voltage amplitude and average phase of the first microwave reflected signal, establishing a defect-free benchmark and eliminating signal fluctuations caused by differences in joint structure symmetry, material uniformity, and scanning angle. The same scanning operation is then performed on the cable terminal joint to be inspected to obtain the first voltage amplitude and first phase of the second microwave reflected signal. During the scanning process, it is necessary to ensure that the frequency, power, and scanning step size of the microwave excitation signal are consistent with those of the standard cable terminal joint to guarantee data comparability. Based on the average voltage amplitude, average phase, first voltage amplitude, and first phase, the cable terminal joint to be inspected is then used to detect the type of defect.

[0025] The method in this embodiment uses a 360° microwave scan of a standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflected signal as a reference. Then, the same scan is performed on the cable terminal joint to be tested to obtain the first voltage amplitude and first phase of the second microwave reflected signal. The 360° scan ensures comprehensive inspection of the cable terminal joint, leaving no possible defective location undetected. By comparing the average voltage amplitude and average phase with the first voltage amplitude and first phase, the defect type of the joint to be tested can be accurately determined. This method greatly improves the comprehensiveness and accuracy of the inspection, timely detects potential defects, provides a reliable basis for the maintenance and replacement of cable terminal joints, effectively reduces the failure rate, and ensures the safe and stable operation of the power system.

[0026] In a specific embodiment, the step of performing a 360° microwave scan on the standard cable terminal joint to obtain the average voltage amplitude and average phase of the microwave reflected signal during the microwave scan includes: performing a 360° microwave scan on the standard cable terminal joint using a preset spiral scanning trajectory, acquiring the second voltage amplitude and second phase of a first microwave reflected signal for each preset rotation angle; calculating the average voltage amplitude by averaging all the second voltage amplitudes, and calculating the average phase by averaging all the second phases.

[0027] Specifically, the spiral scanning trajectory can cover the axial and radial areas of the cable terminal joint. During the scanning process, the microwave probe moves along the joint axis in fixed steps, and rotates by a preset angle (e.g., 10°) after each step, forming a spiral scanning path. This trajectory design ensures comprehensive acquisition of reflected signals from all locations of the joint, avoiding missed defects due to local scanning omissions. At each scanning point, the second voltage amplitude and second phase of the first microwave reflected signal are acquired. For example, if the axial length of the joint is 100mm, the step distance is 2mm, and the rotation angle is 10°, then a total of (100 / 2)×(360 / 10)=1800 sets of data need to be acquired. Through high-density sampling, signal changes in minute areas of the joint can be captured, providing detailed data support for subsequent analysis. The arithmetic mean of all second voltage amplitudes is taken to obtain the average voltage amplitude; the arithmetic mean of all second phases is taken to obtain the average phase. This averaging process can effectively eliminate random noise and signal fluctuations caused by minor unevenness on the joint surface, establishing a stable defect-free benchmark.

[0028] In a specific embodiment, the preset spiral scanning trajectory is obtained using the following formula:

[0029] in, Let be the radial displacement function of the scanning probe in polar coordinates. This is the axial displacement function of the scanning probe in polar coordinates. This represents the initial offset of the scanning probe from the axis of the cable terminal connector. To control the preset growth rate of the helix radius as the angle changes, This is the preset amplitude scaling factor. To adjust the angular frequency of the radial wave density, The number of cycles in the radial plane is the number of the spiral's expansion. The preset exponential attenuation coefficient is used to offset the effects of mechanical backlash. This is the preset sensitivity of the exponential decay term to changes in angle. To establish the reference height for the starting end face of the scan, To control the movement speed of the probe along the axial direction of the cable terminal joint, This represents the number of cycles of the spiral winding along the axial direction of the cable terminal joint. To superimpose the fluctuation amplitude of the axial micro-oscillation, The angular frequency of the axial oscillation. The preset phase adjustment amount is used to eliminate mechanical resonance. The angle is the rotation angle.

[0030] Specifically, by superimposing sinusoidal fluctuations with exponential decay, the risk of mechanical resonance is reduced while ensuring coverage. Automatic compensation for radial offset caused by fixture clearance improves actual measurement positioning accuracy. Axial oscillation term. The three-dimensional interwoven scanning with radial ripples results in a smaller blind area compared to traditional methods.

[0031] In a specific embodiment, the step of detecting the joint defect type of the cable terminal joint under test based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase includes: determining a first average value, a first maximum value, and a first minimum value of the second voltage amplitude; determining a second average value, a second maximum value, and a second minimum value of the second phase; obtaining a voltage amplitude error based on the first maximum value and the first minimum value; obtaining a phase error value based on the second maximum value and the second minimum value; obtaining a relative value of the voltage amplitude difference for each first voltage amplitude based on the average voltage amplitude, the voltage amplitude error, and the first voltage amplitude; obtaining a relative value of the phase transformation amount for each first phase based on the average phase, the phase error value, and the first phase; and detecting the joint defect type of the cable terminal joint under test based on the relative value of the voltage amplitude difference and the relative value of the phase transformation amount.

[0032] Specifically, obtain the first maximum value among the second voltage amplitudes of all scan points. and the first minimum value And calculate the first mean. ; Obtain the second maximum value of the second phase among all scan points. Second minimum value And calculate the second mean. , and The difference is the voltage amplitude error. , and The difference is the phase error value. , take the first mean Second mean Voltage amplitude error and phase error value As a defect-free reference standard, the defect type detection result of the cable terminal joint under test is obtained by comparing the defect-free reference standard with the first voltage amplitude and the first phase.

[0033] In a specific embodiment, the relative value of the voltage amplitude difference is obtained using the following formula:

[0034] in, For the first i The relative value of the voltage amplitude difference at each scan point For the first i The first voltage amplitude at each scan point The average voltage amplitude, The voltage amplitude error, This is the preset temperature correction factor. This is the preset humidity correction factor. This is the preset signal-to-noise ratio correction factor.

[0035] Specifically, this embodiment introduces a temperature correction coefficient. Humidity correction factor and signal-to-noise ratio correction factor This effectively eliminates the influence of environmental interference (such as temperature and humidity changes) and signal noise on the detection results. For example, changes in the dielectric constant of insulating materials at high temperatures may cause a shift in the reflected signal. After correction, environmental interference and actual defects can be accurately distinguished, avoiding misjudgment.

[0036] In a specific embodiment, the relative value of the phase transformation amount is obtained using the following formula:

[0037] in, For the first i The relative value of the phase transformation at each scan point For the first iThe first phase of each scan point This is the second mean. The phase error value is... This is the preset temperature correction factor. This is the preset humidity correction factor. This is the preset signal-to-noise ratio correction factor.

[0038] In a specific embodiment, the step of detecting the defect type of the cable terminal joint under test based on the relative value of the voltage amplitude difference and the relative value of the phase transformation includes: if the relative value of the voltage amplitude difference is greater than a second threshold and the relative value of the phase transformation is greater than a first threshold, then the defect type of the cable terminal joint under test is a conductive impurity defect; if the relative value of the voltage amplitude difference is greater than a third threshold and less than or equal to the second threshold, and the relative value of the phase transformation is greater than the third threshold and less than or equal to the second threshold, then the defect type of the cable terminal joint under test is a main insulation scratch defect; if the relative value of the voltage amplitude difference is less than 0 and the absolute value of the relative value of the voltage amplitude difference is greater than the third threshold, and the relative value of the phase transformation is greater than the second threshold and less than the first threshold, then the defect type of the cable terminal joint under test is a moisture defect; the first threshold is greater than the second threshold, and the second threshold is greater than the third threshold.

[0039] Specifically, if the relative value of the voltage amplitude difference is greater than 200% and the phase is reversed, and the relative value of the phase change is greater than 500%, it is determined to be a conductive impurity defect; if the relative value of the voltage amplitude difference is less than 200% but greater than 100%, the phase is lagging, and the relative value of the phase change is less than 200% but greater than 100%, it is determined to be a main insulation scratch defect; if the relative value of the voltage amplitude difference is negative and the absolute value is greater than 100%, the phase is leading, and the relative value of the phase change is greater than 200%, it is determined to be a moisture defect.

[0040] In a specific embodiment, defect-free 10kV cable terminal joint samples are prepared. The surface of the XLPE cable is cleaned to remove foreign objects and impurities that may affect the test results and avoid interference in subsequent tests. A total of five defect-free cable terminal joint samples are made. The defect-free cable terminal joint samples are placed in a suitable position. For each sample, a waveguide is positioned radially along the sample surface, close to the sample surface. A waveguide probe is used to perform a 360° scan around the sample using a preset helical scanning trajectory to obtain the reflected voltage at each scan point. and phase The test results of a defect-free cable terminal sample are as follows: Figure 2 and Figure 3 As shown, the average reflected voltage of the five defect-free cable termination joint samples can be calculated. and phase mean and error value and .

[0041] Prepare a defective cable termination sample. Clean the XLPE surface to remove foreign objects and impurities that may affect the test results and interfere with subsequent tests. Place a copper foil on the XLPE surface of the sample to simulate the presence of conductive impurities. Pre-fabricate a rectangular groove 10 mm horizontally from the copper foil to simulate scratches on the main insulation. Add absorbent paper 20 mm horizontally from the copper foil and saturate it to simulate moisture absorption. Place the cable termination sample B in a suitable position, with the waveguide tightly attached to and perpendicular to the upper surface of the silicone rubber layer of the sample. The waveguide displacement range is 0-30 mm, with a displacement step of 5 mm. Analyze the obtained microwave reflection signal characteristic parameters (…). , The mean value of the characteristic parameters of the microwave reflection signal of the defect-free sample () , The difference is recorded as the reflected voltage difference. Phase transformation quantity Then compare the error value with that of the defect-free sample. and Find the ratio, denoted as the relative value of the voltage amplitude difference of the microwave reflected signal. Relative value of phase transformation quantity The relationship is as follows: , If the relative value exceeds 100%, it means that the error is more than double the systematic error, and it will show a more obvious change in the detection curve, which can effectively determine the existence of defects.

[0042] Relative values ​​of microwave reflection characteristic parameters for three different types of defects and There are obvious differences, such as Figure 4 and Figure 5 As shown, the voltage amplitude difference of the microwave reflected signal indicates that the reflected voltage at defects containing conductive impurities and scratches on the main insulation is greater than that at defects without defects, while the reflected voltage at moisture-affected defects is less than that at defects without defects. The order of reflected voltage magnitude is: defects containing conductive impurities > scratches on the main insulation > moisture-affected defects. The relative value of the voltage amplitude difference at defects containing conductive impurities... The relative value of voltage amplitude difference is approximately 250%, while the main insulation scratch defect is approximately 120%, and the moisture defect is approximately -240%. The absolute values ​​of all of them are greater than 100%.

[0043] The phase shift of the microwave reflected signal shows that the main insulation scratch defect lags in phase, while the moisture defect leads in phase; both have negative phase values. However, the phase of the defect containing conductive impurities is reversed. The relative value of the phase shift of the defect containing conductive impurities... The relative value of the reflected voltage difference is approximately -900%, with main insulation scratch defects at 191% and moisture defects at approximately -251%. The absolute values ​​of all of them are greater than 100%.

[0044] if When it exceeds 200%, and the phase is reversed, If the absolute value is greater than 500%, it is determined to be a conductive impurity defect; if When the percentage is less than 200% or greater than 100%, there is phase lag. If the absolute value is less than 200% and greater than 100%, it is determined to be a primary insulation scratch defect; if When the value is negative and its absolute value is greater than 100%, the phase is leading. If the percentage is greater than 200%, it is determined to be a moisture defect.

[0045] In a specific embodiment, please refer to Figure 6 This is a schematic diagram of a joint defect type detection system based on microwave scanning according to a second embodiment of this application. The system includes: a first scanning module 201, a second scanning module 202, and a detection result output module 203. The first scanning module 201 is used to perform a 360° microwave scan on a standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflection signal when the standard cable terminal joint is scanned. The standard cable terminal joint is a defect-free cable terminal joint. The second scanning module 202 is used to perform a 360° microwave scan on the cable terminal joint to be tested to obtain the first voltage amplitude and first phase of the second microwave reflection signal when the cable terminal joint to be tested is scanned. The detection result output module 203 is used to detect the joint defect type of the cable terminal joint to be tested based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase.

[0046] The system in this embodiment performs a 360° microwave scan on a standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflected signal as a reference. Then, the same scan is performed on the cable terminal joint to be tested to obtain the first voltage amplitude and first phase of the second microwave reflected signal. The 360° scan ensures comprehensive inspection of the cable terminal joint, leaving no possible defective location undetected. By comparing the average voltage amplitude and average phase with the first voltage amplitude and first phase, the defect type of the joint to be tested can be accurately determined. This method greatly improves the comprehensiveness and accuracy of the inspection, timely detects potential defects, provides a reliable basis for the maintenance and replacement of cable terminal joints, effectively reduces the failure rate, and ensures the safe and stable operation of the power system.

[0047] In a specific embodiment, the third embodiment of this application provides a joint defect type detection device based on microwave scanning, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method as described in any one of the first embodiments of this application.

[0048] In a specific embodiment, the fourth embodiment of this application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method as described in any one of the first embodiments of this application.

[0049] The above embodiments merely illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for detecting joint defect types based on microwave scanning, characterized in that, The method includes: A standard cable terminal joint is subjected to a 360° microwave scan to obtain the average voltage amplitude and average phase of the first microwave reflection signal during the microwave scan; the standard cable terminal joint is a defect-free cable terminal joint. A 360° microwave scan is performed on the cable terminal joint to be tested to obtain the first voltage amplitude and first phase of the second microwave reflection signal when the cable terminal joint to be tested is microwave scanned. The defect type of the cable terminal joint to be tested is detected based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase.

2. The method for detecting joint defect types based on microwave scanning as described in claim 1, characterized in that, The step of performing a 360° microwave scan on a standard cable terminal joint to obtain the average voltage amplitude and average phase of the microwave reflected signal during the microwave scan includes: The standard cable terminal joint is subjected to a 360° microwave scan using a preset spiral scanning trajectory. The second voltage amplitude and second phase of a first microwave reflection signal are collected for each preset rotation angle. The average voltage amplitude is obtained by averaging all the second voltage amplitudes, and the average phase is obtained by averaging all the second phases.

3. The method for detecting joint defect types based on microwave scanning as described in claim 2, characterized in that, The preset spiral scanning trajectory is obtained using the following formula: in, Let be the radial displacement function of the scanning probe in polar coordinates. This is the axial displacement function of the scanning probe in polar coordinates. This represents the initial offset of the scanning probe from the axis of the cable terminal connector. To control the preset growth rate of the helix radius as the angle changes, This is the preset amplitude scaling factor. To adjust the angular frequency of the radial wave density, The number of cycles in the radial plane is the number of the spiral's expansion. The preset exponential attenuation coefficient is used to offset the effects of mechanical backlash. This is the preset sensitivity of the exponential decay term to changes in angle. To establish the reference height for the starting end face of the scan, To control the movement speed of the probe along the axial direction of the cable terminal joint, This represents the number of cycles of the spiral winding along the axial direction of the cable terminal joint. To superimpose the fluctuation amplitude of the axial micro-oscillation, The angular frequency of the axial oscillation. The preset phase adjustment amount is used to eliminate mechanical resonance. The angle is the rotation angle.

4. The method for detecting joint defect types based on microwave scanning as described in claim 2, characterized in that, The method of detecting the defect type of the cable terminal joint under test based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase includes: Determine the first average, first maximum, and first minimum values ​​of the second voltage amplitude; Determine the second mean, second maximum, and second minimum value of the second phase; The voltage amplitude error is obtained based on the first maximum value and the first minimum value; The phase error value is obtained based on the second maximum value and the second minimum value; Based on the average voltage amplitude, the voltage amplitude error, and the first voltage amplitude, obtain the relative value of the voltage amplitude difference for each first voltage amplitude; Based on the average phase, the phase error value, and the first phase, the relative value of the phase transformation amount for each first phase is obtained; The defect type of the cable terminal joint to be tested is detected based on the relative value of the voltage amplitude difference and the relative value of the phase transformation.

5. The method for detecting joint defect types based on microwave scanning as described in claim 4, characterized in that, The relative value of the voltage amplitude difference is obtained using the following formula: in, For the first i The relative value of the voltage amplitude difference at each scan point For the first i The first voltage amplitude at each scan point The average voltage amplitude, The voltage amplitude error, This is the preset temperature correction factor. This is the preset humidity correction factor. This is the preset signal-to-noise ratio correction factor.

6. The method for detecting joint defect types based on microwave scanning as described in claim 4, characterized in that, The relative value of the phase transformation amount is obtained using the following formula: in, For the first i The relative value of the phase transformation at each scan point For the first i The first phase of each scan point This is the second mean. The phase error value is... This is the preset temperature correction factor. This is the preset humidity correction factor. This is the preset signal-to-noise ratio correction factor.

7. The method for detecting joint defect types based on microwave scanning as described in claim 4, characterized in that, The step of detecting the joint defect type of the cable terminal joint under test based on the relative value of the voltage amplitude difference and the relative value of the phase transformation includes: If the relative value of the voltage amplitude difference is greater than the second threshold and the relative value of the phase transformation is greater than the first threshold, then the defect type of the cable terminal joint to be tested is a conductive impurity defect. If the relative value of the voltage amplitude difference is greater than the third threshold and less than or equal to the second threshold, and the relative value of the phase transformation is greater than the third threshold and less than or equal to the second threshold, then the defect type of the cable terminal joint to be tested is a main insulation scratch defect. If the relative value of the voltage amplitude difference is less than 0 and the absolute value of the relative value of the voltage amplitude difference is greater than the third threshold, and the relative value of the phase transformation is greater than the second threshold and less than the first threshold, then the defect type of the cable terminal joint to be tested is a moisture defect; the first threshold is greater than the second threshold, and the second threshold is greater than the third threshold.

8. A joint defect type detection system based on microwave scanning, characterized in that, The system includes: a first scanning module, a second scanning module, and a detection result output module; The first scanning module is used to perform a 360° microwave scan on a standard cable terminal joint to obtain the average voltage amplitude and average phase of the first microwave reflection signal when the standard cable terminal joint is microwave scanned; the standard cable terminal joint is a defect-free cable terminal joint. The second scanning module is used to perform a 360° microwave scan on the cable terminal joint to be tested, and to obtain the first voltage amplitude and first phase of the second microwave reflection signal when the cable terminal joint to be tested is microwave scanned. The detection result output module is used to detect the joint defect type of the cable terminal joint to be tested based on the average voltage amplitude, the average phase, the first voltage amplitude, and the first phase.

9. A joint defect type detection device based on microwave scanning, comprising a memory and a processor, characterized in that, The memory stores a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

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