High-voltage cable buffer layer ablation defect detection device and defect detection method

Abstract

The invention discloses a device and a method for detecting ablation defects of a buffer layer of a high-voltage cable. The device comprises a terahertz wave imaging device, a data processing unit and a display unit, the terahertz wave imaging device is used for carrying out damage-free detection on the buffer layer of the detected cable and obtaining image feature recognition data formed by terahertz wave reflection; the data processing unit is connected with the terahertz wave imaging device, and the data processing unit is used for comparing image feature recognition data formed by terahertz wave reflection with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result; and the display unit is connected with the data processing unit and is used for displaying the defect identification result. Compared with the prior art, the method can detect the ablation defect of the buffer layer without damage during cable production inspection or construction, assess the operation state of the cable, provide a decision basis for whether the cable is qualified or not, and ensure safe and stable operation of electric power.

Description

Technical Field

[0001] The present invention belongs to the technical field of power cable detection, and in particular relates to a device and method for detecting ablation defects of a high-voltage cable buffer layer. Background Art

[0002] High-voltage power cable is an important primary power transmission equipment in the power grid. It plays an important role in the safe and stable operation of power loads. It has the characteristics of small line path width, easy line path selection, concealed burial, not easily affected by the surrounding environment and pollution, and high power transmission reliability. If problems occur in the production, construction, and testing of high-voltage cables, in the later operation, due to the influence of various factors in the complex actual operating environment, the cable operation failure will eventually occur, and the safe, stable, and efficient operation of high-voltage power cables cannot be guaranteed. Because the defects have not developed to the point of causing failures in a short period of time, traditional infrared temperature measurement, partial discharge detection, and ground current detection cannot detect and find cable defects in a timely and effective manner. Cable defect operation is a relatively common phenomenon. Therefore, it is necessary to study a high-voltage cable buffer layer ablation defect detection device to evaluate the operating status of the cable and provide a decision-making basis for whether the cable is qualified.

[0003] In recent years, the problem of cable buffer layer ablation has received widespread attention, and the following related studies have been carried out.

[0004] (1) Partial discharge detection technology: The principle of using partial discharge detection technology to diagnose buffer layer ablation defects is to obtain buffer layer status information by detecting physical phenomena such as light, sound, electric pulses and electromagnetic waves generated when partial discharge occurs in the cable buffer layer, so as to diagnose whether partial discharge has occurred in the buffer layer and the severity of the partial discharge, and then evaluate the severity of the cable buffer layer ablation defects.

[0005] (2) X-ray detection technology: The principle of X-ray detection technology is to use the different thicknesses and densities of the cable materials and white spots, and their different X-ray absorption capabilities, resulting in X-rays of different intensities being left on the DR board after passing through the cable. The internal processor of the DR board converts the X-ray intensity into an electric current signal which is input into the terminal computer, ultimately forming a digital image of the cable, thereby observing the changes in the morphology of each layer inside the cable.

[0006] The deficiency of the prior art is that the ablation defects of the existing cable buffer layer are discovered when the main body is changed or when the cable line has caused a fault and is under repair, and the defect is not discovered by means of detection without changing the main body. That is, the method of the prior art cannot be used to issue warnings for abnormal status information in advance, affecting the normal and stable operation of the cable line.

[0007] Therefore, it is necessary to provide a new high-voltage cable buffer layer ablation defect detection device and defect detection method to solve the above technical problems. Summary of the invention

[0008] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and disclose a high-voltage cable buffer layer ablation defect detection device and a defect detection method to solve the technical problem in the prior art of lacking non-destructive detection means for detecting buffer layer ablation defects during cable production and construction.

[0009] The technical solution adopted by the present invention to solve its technical problem is: the present invention discloses a high-voltage cable buffer layer ablation defect detection device, comprising: a terahertz wave imaging device, a data processing unit and a display unit; the terahertz wave imaging device is used to perform non-destructive detection on the buffer layer of the tested cable, and obtain image feature recognition data formed by terahertz wave reflection; the data processing unit is connected to the terahertz wave imaging device, and the data processing unit is used to compare the image feature recognition data formed by the terahertz wave reflection with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result; the display unit is connected to the data processing unit, and is used to display the defect recognition result.

[0010] Preferably, the high-voltage cable buffer layer ablation defect detection device also includes: a USB storage module, a data printing module and an external storage device; the USB storage module is electrically connected to the data processing unit and is used to save the defect identification results; the USB storage module can also be connected to the external storage device; the data printing module is electrically connected to the data processing unit and is used to print the defect identification results.

[0011] Preferably, the high-voltage cable buffer layer ablation defect detection device also includes: a charger, a battery, the charger is electrically connected to the battery for indirect power supply; the battery is respectively connected to the charger, the data processing unit, the display screen, and the terahertz wave imaging device for direct power supply.

[0012] Preferably, the image feature recognition data formed by the reflection of the terahertz wave includes an image signal and an electrical signal formed by the reflection of the terahertz wave.

[0013] Preferably, the battery is a lithium battery.

[0014] Preferably, the display unit is a liquid crystal display screen.

[0015] Preferably, the terahertz wave imaging device comprises: a terahertz transmitter, a silicone lens, a terahertz beam splitter, a terahertz beam splitter, a terahertz receiver and a beam splitter; the femtosecond laser generator is used to generate laser pulses, and the beam splitter is used to split the laser pulses into two beams, wherein: one beam of the laser pulses is transmitted to the terahertz transmitter via the optical fiber and excited into terahertz waves, and the terahertz waves are emitted to the surface of the cable under test through the silicone lens, and the terahertz receiver is used to detect and receive image feature recognition data formed by the terahertz waves reflected by the cable under test, and the host computer is used to detect and store the image feature recognition data.

[0016] Preferably, the defect identification result includes two situations: the defect exists or the defect does not exist.

[0017] Preferably, when there is a defect, the display unit displays that the tested cable is detected normally, and when there is no defect, the display unit displays the defect image and defect location information of the tested cable.

[0018] The present invention also discloses a method for detecting ablation defects of a high-voltage cable buffer layer. The method uses the above-mentioned device for detecting ablation defects of a high-voltage cable buffer layer. The method for detecting ablation defects of a high-voltage cable buffer layer comprises the following steps:

[0019] S1, using the terahertz wave imaging device, relying on terahertz wave imaging technology and image feature recognition technology, to detect the buffer layer of the tested cable; obtaining and analyzing the reflection image of the terahertz wave inside the detection cable;

[0020] S2, using the data processing unit, based on image feature recognition technology, comparing the image feature recognition data formed by the terahertz wave reflection with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result;

[0021] S3, displaying the defect identification result using the display unit;

[0022] S4, the operator evaluates whether the tested cable is qualified based on the defect identification result.

[0023] Preferably, in step S2, before comparison, the image features in the high-voltage cable buffer layer defect image database are classified, and a weight is set according to the probability that if the feature exists, the tested cable must have a defect, and when the comparison is performed, the similarity is related to the weight; when the comparison is performed, when the image feature recognition data formed by the terahertz wave reflection has a similarity with the image in the pre-established high-voltage cable buffer layer defect image database greater than a preset similarity value, the defect recognition result is that a defect exists; otherwise, the defect recognition result is that no defect exists.

[0024] Compared with the prior art, the high-voltage cable buffer layer ablation defect detection device of the present invention is used to detect the ablation defect of the high-voltage cable buffer layer. The device and method of the present invention can detect the ablation defect of the buffer layer without damage during cable production inspection or construction, evaluate the operating status of the cable, and provide a decision basis for whether the cable is qualified. Avoid putting defective cables into use and ensure safe and stable operation of electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the basic principle of terahertz wave imaging detection in the present invention;

[0026] Figure 2 It is a structural schematic diagram of a high-voltage cable buffer layer ablation defect detection device of the present invention;

[0027] Figure 3 It is a schematic flow chart of the method for detecting ablation defects of a high-voltage cable buffer layer of the present invention.

[0028] Description of reference numerals:

[0029] 1. Cable under test; 2. Femtosecond laser generator; 3. Beam splitter; 4. Optical fiber; 5. Silicone lens; 6. Terahertz transmitter. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0031] The following is combined with Figure 1-3 The high-voltage cable buffer layer ablation defect detection device and method of the present invention are further described.

[0032] The present invention discloses a high-voltage cable buffer layer ablation defect detection device, comprising: a terahertz wave imaging device, a data processing unit and a display unit; the terahertz wave imaging device is used to perform non-destructive detection on the buffer layer of a tested cable 1, and obtain image feature recognition data formed by terahertz wave reflection; the data processing unit is connected to the terahertz wave imaging device, and the data processing unit is used to compare the image feature recognition data formed by terahertz wave reflection with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result; the display unit is connected to the data processing unit, and is used to display the defect recognition result.

[0033] The high-voltage cable buffer layer ablation defect detection device of the present invention is designed to address the lack of detection means for detecting buffer layer ablation defects during cable production and construction in the prior art.

[0034] In this embodiment, the terahertz wave imaging device uses terahertz imaging technology for detection. The basic principle is as follows Figure 1 As shown, the laser pulse generated by the femtosecond laser generator 2 is divided into two beams by the beam splitter 3, one of which is transmitted to the terahertz radiation source (terahertz transmitter 6) through the optical fiber 4, so that it is excited into a terahertz wave, which is emitted to the surface of the cable 1 under test through the lens (silicone lens 5), and the reflected echo of the cable is detected and received by the terahertz receiver, and then detected and stored by the host computer.

[0035] The high-voltage cable buffer layer defect image database is a collection of high-voltage cable buffer layer defect images obtained in the laboratory. It is used as the basic data for comparing whether there are defects and needs to be established in advance. For example, when the data processing unit is performing the comparison, it can be set that when the similarity between the image feature recognition data formed by the terahertz wave reflection and the pre-established high-voltage cable buffer layer defect image exceeds a preset percentage, it can be judged that there is a defect.

[0036] The present invention is used to detect the ablation defects of the buffer layer of the high-voltage cable, and finally can detect whether the tested cable 1 has defects, and provide a decision basis for whether the cable is qualified, so as to avoid the use of defective cables and ensure the safe and stable operation of electricity.

[0037] It should be noted that the terahertz wave imaging device may also be an existing device that can be directly purchased from outside.

[0038] According to a specific embodiment of the present invention, the high-voltage cable buffer layer ablation defect detection device also includes: a USB storage module, a data printing module and an external storage device; the USB storage module is electrically connected to the data processing unit and is used to save the defect identification results; the USB storage module can also be connected to the external storage device; the data printing module is electrically connected to the data processing unit and is used to print the defect identification results.

[0039] According to a specific embodiment of the present invention, the high-voltage cable buffer layer ablation defect detection device also includes: a charger, a battery, and the charger is electrically connected to the battery for indirect power supply; the battery is respectively connected to the charger, the data processing unit, the display screen, and the terahertz wave imaging device for direct power supply.

[0040] In the above embodiment, the charger is used for charging, the battery is used for storing electric energy, and the USB storage module is used for storing data. The high-voltage cable buffer layer ablation defect detection device of this embodiment is a more complete structure, which integrates printing, storage, direct power supply and indirect power supply, and has the function of data storage and transfer. The comprehensive performance and convenience of operation of the present invention are greatly improved.

[0041] According to a specific embodiment of the present invention, the image feature recognition data formed by the reflection of the terahertz wave includes an image signal and an electrical signal formed by the reflection of the terahertz wave.

[0042] According to a specific embodiment of the present invention, the storage battery is a lithium battery.

[0043] According to a specific embodiment of the present invention, the display unit is a liquid crystal display screen.

[0044] According to a specific embodiment of the present invention, a terahertz wave imaging device includes: a terahertz transmitter 6, a silicone lens 5, a terahertz beam splitter, a terahertz beam splitter, a terahertz receiver and a beam splitter 3; a femtosecond laser generator 2 is used to generate laser pulses, and the beam splitter 3 is used to divide the laser pulses into two beams, wherein: a beam of laser pulses is transmitted to the terahertz transmitter 6 via an optical fiber 4 and excited into a terahertz wave, and the terahertz wave is emitted to the surface of the cable 1 under test through the silicone lens 5, and the terahertz receiver is used to detect and receive image feature recognition data formed by the reflection of the terahertz wave reflected by the cable 1 under test, and the host computer is used to detect and store the image feature recognition data.

[0045] According to a specific embodiment of the present invention, the defect identification result includes two situations: the defect exists or the defect does not exist.

[0046] According to a specific embodiment of the present invention, when there is a defect, the display unit displays that the tested cable 1 is detected normally, and when there is no defect, the display unit displays the defect image and defect position information of the tested cable 1.

[0047] The present invention also discloses a method for detecting ablation defects of a high-voltage cable buffer layer. The method for detecting ablation defects of a high-voltage cable buffer layer uses the high-voltage cable buffer layer ablation defect detection device in the above embodiment. The method for detecting ablation defects of a high-voltage cable buffer layer comprises the following steps:

[0048] S1, using a terahertz wave imaging device, relying on terahertz wave imaging technology and image feature recognition technology, to detect the buffer layer of the tested cable 1; obtaining and analyzing the reflection image of the terahertz wave inside the tested cable.

[0049] S2, using a data processing unit, based on image feature recognition technology, compares the image feature recognition data formed by the terahertz wave reflection with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result.

[0050] S3, using a display unit to display the defect recognition result.

[0051] S4, the operator evaluates whether the tested cable 1 is qualified based on the defect identification result.

[0052] In this embodiment, a method for detecting ablation defects of a high-voltage cable buffer layer is provided. This method relies on terahertz wave imaging technology and image feature recognition technology to detect the buffer layer of the cable 1 under test; obtain and analyze the reflection image of the terahertz wave inside the detection cable, and based on the image feature recognition technology, obtain a high-voltage cable buffer layer defect image database in combination with the laboratory, and compare and identify the internal defects of the cable 1 under test. And intuitively display it through a display unit. By adopting the method of the present invention, the ablation defects of the buffer layer can be non-destructively detected during cable production inspection or construction, and the operating status of the cable can be evaluated.

[0053] According to a specific implementation of the present invention, in step S2, before comparison, the image features in the high-voltage cable buffer layer defect image database are classified, and a weight is set according to the probability that if the feature exists, the tested cable 1 must have a defect, and when the comparison is performed, the similarity is related to the weight; when the comparison is performed, when the image feature recognition data formed by the terahertz wave reflection has a similarity with the image in the pre-established high-voltage cable buffer layer defect image database greater than a preset similarity value, the defect recognition result is that a defect exists; otherwise, the defect recognition result is that no defect exists.

[0054] In this embodiment, the possibility and necessity of the image features and whether the tested cable 1 has defects are graded and assigned different weights. For example, if a certain feature exists, the tested cable 1 must have defects, so a high weight is assigned. If a certain feature exists, the tested cable 1 may have defects, so a relatively low weight can be assigned. When making a comparison, a similarity comparison is performed on each small feature, and the similarity of each feature is multiplied by the weight to obtain the final similarity of the feature. The final similarities of all the features are then summed and compared with the preset similarity value to obtain the defect identification result. The method of this embodiment can greatly improve the accuracy of the defect identification result.

[0055] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0056] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A high voltage cable buffer layer ablation defect detection device, characterized in that: include: A terahertz wave imaging device, a data processing unit and a display unit; the terahertz wave imaging device is used to perform non-destructive detection on the buffer layer of the tested cable and obtain image feature recognition data formed by the reflection of the terahertz wave; the data processing unit is connected to the terahertz wave imaging device, and the data processing unit is used to compare the image feature recognition data formed by the reflection of the terahertz wave with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result; the display unit is connected to the data processing unit and is used to display the defect recognition result.

2. The high-voltage cable buffer layer ablation defect detection device according to claim 1 is characterized in that: The high-voltage cable buffer layer ablation defect detection device also includes: a USB storage module, a data printing module and an external storage device; the USB storage module is electrically connected to the data processing unit and is used to save the defect identification result; the USB storage module can also be connected to the external storage device; the data printing module is electrically connected to the data processing unit and is used to print the defect identification result.

3. The high-voltage cable buffer layer ablation defect detection device according to claim 2 is characterized in that: The high-voltage cable buffer layer ablation defect detection device also includes: a charger, a battery, the charger is electrically connected to the battery for indirect power supply; the battery is respectively connected to the charger, the data processing unit, the display screen, and the terahertz wave imaging device for direct power supply.

4. The high-voltage cable buffer layer ablation defect detection device according to claim 3 is characterized in that: The image feature recognition data formed by the terahertz wave reflection includes an image signal and an electrical signal formed by the terahertz wave reflection.

5. The high-voltage cable buffer layer ablation defect detection device according to claim 4, characterized in that: The storage battery is a lithium battery; the display unit is a liquid crystal display screen.

6. The high-voltage cable buffer layer ablation defect detection device according to claim 5, characterized in that: The terahertz wave imaging device includes: a terahertz transmitter, a silicone lens, a terahertz beam splitter, a terahertz beam splitter, a terahertz receiver and a beam splitter; the femtosecond laser generator is used to generate laser pulses, and the beam splitter is used to split the laser pulses into two beams, wherein: one beam of the laser pulses is transmitted to the terahertz transmitter through the optical fiber and excited into terahertz waves, and the terahertz waves are emitted to the surface of the measured cable through the silicone lens, and the terahertz receiver is used to detect and receive image feature recognition data formed by the reflection of the terahertz waves by the measured cable, and the host computer is used to detect and store the image feature recognition data.

7. The high-voltage cable buffer layer ablation defect detection device according to claim 6, characterized in that: The defect identification result includes two situations: the defect exists or the defect does not exist.

8. The high-voltage cable buffer layer ablation defect detection device according to claim 7, characterized in that: When there is a defect, the display unit displays that the tested cable is detected normally. When there is no defect, the display unit displays the defect image and defect position information of the tested cable.

9. A method for detecting ablation defects of a high-voltage cable buffer layer, characterized in that: The high-voltage cable buffer layer ablation defect detection method uses the high-voltage cable buffer layer ablation defect detection device according to any one of claims 1 to 8, and the high-voltage cable buffer layer ablation defect detection method comprises the following steps: S1, using the terahertz wave imaging device, relying on terahertz wave imaging technology and image feature recognition technology, to detect the buffer layer of the tested cable; obtaining and analyzing the reflection image of the terahertz wave inside the detection cable; S2, using the data processing unit, based on image feature recognition technology, comparing the image feature recognition data formed by the terahertz wave reflection with a pre-established high-voltage cable buffer layer defect image database to obtain a defect recognition result; S3, displaying the defect identification result using the display unit; S4, the operator evaluates whether the tested cable is qualified based on the defect identification result.

10. The method for detecting ablation defects of a high-voltage cable buffer layer according to claim 9, characterized in that: In step S2, before comparison, the image features in the high-voltage cable buffer layer defect image database are classified, and weights are set according to the probability that if the feature exists, the tested cable must have defects. When the comparison is performed, the similarity is related to the weight; when the comparison is performed, when the similarity between the image feature recognition data formed by the terahertz wave reflection and the image in the pre-established high-voltage cable buffer layer defect image database is greater than a preset similarity value, the defect recognition result is that there is a defect; otherwise, the defect recognition result is that there is no defect.

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