Insulation damage positioning method for photoelectric composite cable

Abstract

The invention belongs to the related technical field of photoelectric composite cable detection, and particularly relates to a photoelectric composite cable insulation damage positioning method which comprises the following steps: pressurizing a conductive copper pipe of a photoelectric composite cable, and collecting a space-time two-dimensional distribution vibration signal diagram of the composite cable; when a certain sensing channel area on the signal diagram repeatedly generates an impulse abnormal signal group in the time dimension, the impulse abnormal signal group appearing each time shows a bidirectional propagation characteristic occurring along with time in the space dimension, and the voltage on the conductive copper pipe suddenly drops when the impulse abnormal signal group appears each time. If yes, a composite cable space position area corresponding to a certain sensing channel area is taken as an abnormal partial discharge area; in any impulse abnormal signal group appearing at the first time, the space position area corresponding to the sensing channel where the impulse abnormal signal appears at the first time is locked to serve as an abnormal partial discharge signal generation area, and the positioning error is smaller than the length of the sensing channel. According to the invention, long-distance distributed insulation damage positioning of the photoelectric composite cable can be accurately realized.

Description

Technical Field

[0001] The present invention belongs to the technical field related to photoelectric composite cable detection, and more specifically, relates to a method for locating damaged insulation of a photoelectric composite cable. Background Art

[0002] Optical fiber cables are composite cables that integrate optical fibers and copper conductors, used to transmit both optical and electrical signals. With the rapid development of optical communication technology, their application is increasing, particularly in transoceanic submarine communication networks. However, with increasing service life and unreliable construction, the internal insulation of optical fiber cables gradually deteriorates, eventually developing into permanent faults that cause localized abnormal discharges and severely impact the normal operation of conventional services. Therefore, the detection and location of internal insulation problems in optical fiber cables will become a pressing need for future economic development.

[0003] Due to the unique characteristics of long-distance deployment of photovoltaic cables, especially the large-capacity submarine photovoltaic cables currently used for power transmission in offshore wind power, conventional partial discharge detection methods and equipment are relatively difficult to use. Furthermore, the various effects of the extended length of the photovoltaic cables on various electrical measurement signals also significantly reduce the effectiveness of detection. For example, existing traditional electrical detection solutions typically use the traveling wave method to determine the location of partial discharges in cables. However, due to the attenuation of the discharge pulse during cable transmission, positioning errors exist, making it impossible to locate partial discharges in cables over long distances.

[0004] In addition, considering that the spectrum distribution of the optical fiber composite cable is 10~10 7 Hz sound waves, so some current research suggests that detecting the acoustic signals generated by partial discharge can reflect the extent of partial discharge. However, traditional ultrasonic testing is mostly performed using piezoelectric ceramic sensors, making it difficult to achieve distributed testing of long-distance optical fiber composite cables on the seabed. Summary of the Invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a method for locating insulation damage of an optoelectronic composite cable, which aims to accurately achieve long-distance distributed insulation damage positioning of the optoelectronic composite cable.

[0006] To achieve the above object, according to one aspect of the present invention, a method for locating insulation damage in an optoelectronic composite cable is provided, comprising:

[0007] Continuously pressurize the conductive copper tube of the optoelectronic composite cable to be tested, and collect the spatiotemporal two-dimensional distribution vibration signal diagram of the optoelectronic composite cable in real time through optical fiber distributed acoustic wave sensing. If an impulse abnormal signal group repeatedly appears in the time dimension in a certain sensing channel area on the spatiotemporal two-dimensional distribution vibration signal diagram, and each impulse abnormal signal group exhibits a bidirectional propagation characteristic that occurs over time in the spatial dimension, and the voltage on the conductive copper tube suddenly drops each time the impulse abnormal signal group appears, then the impulse abnormal signal group that appears each time is identified as an abnormal partial discharge signal group; the spatial position area of ​​the optoelectronic composite cable corresponding to the certain sensing channel area is the abnormal partial discharge area.

[0008] In any impulse abnormal signal group that appears, according to the bidirectional propagation characteristics, the spatial position area of ​​the optoelectronic composite cable corresponding to a sensing channel where the impulse abnormal signal appears first is further locked as the abnormal partial discharge signal occurrence area of ​​the abnormal partial discharge area, that is, the preliminary positioning of the damaged position of the optoelectronic composite cable to be detected, and the positioning error is less than the sensing channel length L S .

[0009] Furthermore, the optical fiber distributed acoustic wave sensing system is connected to any core optical fiber of the optoelectronic composite cable to be detected, and the optical fiber distributed acoustic wave sensing system collects the backscattered light signal of the core optical fiber and demodulates it to obtain the said spatiotemporal two-dimensional distribution vibration signal diagram.

[0010] Furthermore, after the rough positioning, the following steps are also included:

[0011] Extracting an abnormal signal including any abnormal partial discharge signal group from a certain sensing channel region in the spatiotemporal two-dimensional distribution vibration signal graph, wherein the duration of the abnormal signal is greater than the occurrence duration of the abnormal partial discharge signal group and covers the signal before the occurrence of the abnormal partial discharge signal group; using a time sampling window of a preset size and a time sampling interval as a sliding step, performing sliding sampling on the data of each sensing channel in the extracted abnormal signal, performing a short-time Fourier transform on the short-time signal frame obtained by each sampling of the sensing channel, and correspondingly obtaining a frequency domain energy distribution;

[0012] Randomly selecting a sensing channel in the certain sensing channel region, performing Fourier transform on the abnormal partial discharge signal of the sensing channel in any abnormal partial discharge signal group, and using the obtained frequency domain distribution feature as the frequency domain distribution feature of the abnormal partial discharge signal group in the certain sensing channel region; determining a continuous frequency domain range in which power density spectra are superimposed based on the frequency domain distribution feature, and calculating the energy of the frequency domain distribution feature within the continuous frequency domain range;

[0013] Performing power density spectrum superposition on each of the frequency domain energy distributions within a continuous frequency domain to obtain the energy of the short-time signal frame corresponding to the frequency domain energy distribution, and temporally constructing an energy spectrum from the energy of all short-time signal frames corresponding to each sensing channel in the certain sensing channel region; performing time delay calculation on the energy spectrum of a reference sensing channel and the energy spectra of each of the other sensing channels in the certain sensing channel region to obtain a time delay τ of the abnormal local signal of each of the other sensing channels relative to the reference sensing channel; wherein the reference sensing channel is the sensing channel in which the abnormal local discharge signal first appears in the abnormal local discharge signal group selected during the short-time Fourier transform;

[0014] Construct distance and delay data pair (X+(a-1)L S ,τ -a ),……,(X,τ -1 ), (L S -X,τ +1 ),……,(bL S -X,τ +b ), where X represents the distance of the assumed precise discharge position from the starting point of the reference sensing channel; 0≤X≤sensing channel length L S ;X+(a-1)L S bL represents the distance between the ath sensor channel adjacent to the reference sensor channel and the precise discharge position. S -X represents the distance between the bth adjacent sensing channel behind the reference sensing channel and the precise discharge position; τ -a represents the time delay of the abnormal local signal of the ath sensing channel relative to the reference sensing channel; τ +b Indicates the delay of the abnormal local signal of the bth sensing channel relative to the reference sensing channel; in the range of 0 to L S The X is traversed within the range, and at each current X traversed, a linear fit is performed on the distance and delay data pair, and the X corresponding to the minimum fitting error is used as the fine position of the abnormal partial discharge signal on the reference sensing channel.

[0015] Furthermore, a Fourier transform is performed on the abnormal partial discharge signal that appears first in any abnormal partial discharge signal group of the selected sensing channel, and the obtained frequency domain distribution feature is used as the frequency domain distribution feature of the abnormal partial discharge signal group in the certain sensing channel area.

[0016] Furthermore, generalized cross-correlation is used for delay calculation.

[0017] Further, multiple continuous frequency domain ranges Fr where the power density spectrum is superimposed are determined according to the frequency domain distribution characteristics. i ; and calculate each continuous frequency domain range Fr iThe energy Pr of the internal frequency domain distribution characteristics i ;

[0018] In each continuous frequency range Fr i Under the condition of τ, the delay τ of the abnormal local signal of each other sensing channel relative to the reference sensing channel is calculated. i ;

[0019] For each continuous frequency domain range Fr i , build distance and delay data pairs Among them, X i Indicates that in the continuous frequency domain range Fr i The distance between the precise discharge position assumed below and the starting point of the reference sensing channel; 0≤X i ≤ Sensing channel length L S ;X i +(a-1)L S bL represents the distance between the ath sensor channel adjacent to the reference sensor channel and the precise discharge position. S -X i represents the distance between the bth adjacent sensing channel behind the reference sensing channel and the precise discharge position; Indicates that in the continuous frequency domain range Fr i The delay of the abnormal local signal of the a-th sensing channel relative to the reference sensing channel; Indicates that in the continuous frequency domain range Fr i The delay of the abnormal local signal of the bth sensing channel relative to the reference sensing channel; in 0~L S Traverse X in range i , at each current X traversed i Under this condition, a linear fit is made for the distance and delay data pair, and the X corresponding to the minimum fitting error is i As the continuous frequency domain range Fr i The accurately determined location of the abnormal partial discharge signal on the reference sensing channel;

[0020] All continuous frequency domain ranges Fr i The X corresponding to the minimum fitting error i Take the average as the final precise positioning position.

[0021] Furthermore, the above method converts all continuous frequency domain ranges Fr i The X corresponding to the minimum fitting error i The way to take the average is:

[0022]

[0023] Where, Indicates that in the continuous frequency domain range Fr i The X corresponding to the minimum fitting error i .

[0024] According to another aspect of the present invention, an electronic device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0025] According to another aspect of the present invention, a computer-readable storage medium is provided, which includes a stored computer program, wherein when the computer program is executed by a processor, the device where the storage medium is located is controlled to execute the steps of the above-mentioned method.

[0026] According to another aspect of the present invention, a computer program product is provided, comprising a computer program or instructions, which implement the steps of the method described above when executed by a processor.

[0027] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0028] 1. The present invention provides a method for locating insulation damage in an optoelectronic composite cable. This method utilizes fiber-optic distributed acoustic wave sensing to detect the vibrations generated by discharges at the location of insulation damage. When a sensor channel region on a two-dimensional spatiotemporal distribution vibration signal graph repeatedly displays an abnormal impulse signal group in the time dimension, and each occurrence of the abnormal impulse signal group exhibits a bidirectional propagation characteristic over time in the spatial dimension, and each occurrence of the abnormal impulse signal group causes a sudden voltage drop on the conductive copper tube, each occurrence of the abnormal impulse signal group is identified as an abnormal partial discharge signal group. The spatial location of the optoelectronic composite cable corresponding to the sensor channel region is designated as the abnormal partial discharge region. By utilizing the bidirectional propagation characteristics of the discharge vibration signal, the location of insulation damage in the optoelectronic composite cable can be preliminarily located based on the location where the signal first appears. This method can accurately and preliminarily locate the location of insulation damage, providing reliable information for repair and significantly improving repair efficiency. Furthermore, the present invention only requires testing at one end of the submarine optical cable, making it convenient and highly operational.

[0029] 2. Furthermore, the present invention proposes a method for precisely locating discharge signals based on propagation delay. This method extracts the distributed discharge signals collected by a fiber-optic distributed acoustic wave sensing system and uses frequency domain energy to accurately estimate the delay. This method solves the problem of large cross-correlation errors when using time domain signals with inconsistent signal waveforms. Furthermore, by segmenting different frequency domains, it reduces errors caused by inconsistent propagation speeds of signals with different frequencies. Finally, the positions obtained from multiple frequency bands are weighted by power to calculate the final position, achieving high accuracy and sub-meter precision. This method can accurately locate faults for subsequent repairs of damaged optical fiber composite cables, improving repair efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A flowchart of a method for locating insulation damage in a photoelectric composite cable provided by an embodiment of the present invention;

[0031] Figure 2 A two-dimensional spatiotemporal distribution vibration signal diagram provided by an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of a device for collecting a spatiotemporal two-dimensional distribution vibration signal graph provided by an embodiment of the present invention;

[0033] Figure 4 A cross-sectional view of an optoelectronic composite cable to be tested provided in an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of linear fitting of all delays of abnormal partial discharge signals provided by an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of two-dimensional spatial positioning of a multi-sensor array provided in an embodiment of the present invention;

[0036] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0037] 1 is the fiber-optic distributed acoustic wave sensing system, 2 is the optoelectronic composite cable to be detected, 2-1 is the conductive copper tube, 2-2 is the optical fiber tube, 3 is the abnormal signal, 3-1 is the abnormal partial discharge area, 4 is the energy spectrum, 5 is the third sensing channel after the reference sensing channel and the delay between it and the reference sensing channel, 6 is the reference sensing channel, 7 is the backward propagation direction of the abnormal partial discharge signal, and 8 is the forward propagation direction of the abnormal partial discharge signal. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0039] Example 1

[0040] A method for locating insulation damage in a photoelectric composite cable, such as Figure 1 Shown, including:

[0041] The conductive copper tube of the optical fiber composite cable to be tested is continuously pressurized, and the time-space two-dimensional distribution vibration signal of the optical fiber composite cable is collected in real time through optical fiber distributed acoustic wave sensing.

[0042] When a certain sensor channel area on the spatio-temporal two-dimensional distribution vibration signal graph (such as Figure 2 As shown in the mark 3-1) shown in the figure, an impulse abnormal signal group repeatedly appears in the time dimension, and each impulse abnormal signal group presents a bidirectional propagation characteristic occurring over time in the spatial dimension, and the voltage on the conductive copper tube suddenly drops each time the impulse abnormal signal group appears, then each impulse abnormal signal group that appears is identified as an abnormal partial discharge signal group; the spatial position area of ​​the optoelectronic composite cable corresponding to the certain sensing channel area is the abnormal partial discharge area;

[0043] In any impulse abnormal signal group that appears, according to the bidirectional propagation characteristics, the spatial position area of ​​the optoelectronic composite cable corresponding to a sensing channel where the impulse abnormal signal appears first is further locked as the abnormal partial discharge signal occurrence area of ​​the abnormal partial discharge area, that is, the rough positioning of the damaged position of the optoelectronic composite cable to be detected, and the positioning error is less than the sensing channel length L S .

[0044] The method of this embodiment uses optical fiber distributed acoustic wave sensing to detect the vibration generated by discharge at the insulation damaged location to achieve rough positioning of the insulation damaged location. Testing only needs to be performed at one end of the submarine optical cable.

[0045] Preferably, the optical fiber distributed acoustic wave sensing system is connected to any core optical fiber of the optoelectronic composite cable to be detected, and the optical fiber distributed acoustic wave sensing system collects the backscattered light signal of the core optical fiber and demodulates it to obtain the said spatiotemporal two-dimensional distribution vibration signal diagram.

[0046] For example, Figure 3 and Figure 4As shown, a phase-sensitive optical time domain reflectometer 1 of an optical fiber distributed acoustic wave sensing system is connected to any core optical fiber in the optical fiber tube 2-2 of the optoelectronic composite cable 2 to be detected; the conductive copper tube 2-1 of the optoelectronic composite cable to be detected is pressurized until partial discharge occurs; the phase-sensitive optical time domain reflectometer 1 monitors the distributed vibration signal of the optoelectronic composite cable in real time during the pressurization process with a spatial resolution of 10m and a sampling rate of 2000Hz (for example, the length of the composite cable is set according to specific circumstances).

[0047] The phase-sensitive optical time-domain reflectometer 1 monitors the distributed vibration signals of the optical fiber composite cable during the pressurization process in real time. Specifically, the voltage applied to the conductive copper tube 2-1 of the optical fiber composite cable to be tested is continuously increased, while the phase-sensitive optical time-domain reflectometer 1 monitors the two-dimensional time-space distribution signal (i.e., the distributed vibration signal) output by the phase-sensitive optical time-domain reflectometer 1 in real time until, at a certain position on the two-dimensional time-space distribution signal, an impulse abnormality signal group recurs in the time domain, similar to an impulse signal, and exhibits bidirectional propagation characteristics in space. Each time this impulse abnormality signal group appears, the voltage on the conductive copper tube 2-1 of the optical fiber composite cable to be tested suddenly drops. When both of these conditions are met simultaneously, the impulse abnormality signal group is identified as an abnormal partial discharge signal group.

[0048] The spatial position area of ​​the optoelectronic composite cable corresponding to the sensing channel area where the abnormal partial discharge signal group is detected is the abnormal partial discharge area. According to the propagation characteristics, the spatial position of the optoelectronic composite cable corresponding to the sensing channel where the abnormal partial discharge signal first appears is the approximate location of the occurrence of the abnormal partial discharge signal (i.e., preliminary positioning), which is the preliminary positioning of the damaged position of the optoelectronic composite cable to be detected. The positioning error is less than the sensing channel length L S .

[0049] In this embodiment, the optical fiber of the phase-sensitive optical time domain reflectometer 1 connected to the optoelectronic composite cable is arranged linearly in the optical fiber tube 2 - 2 inside the optoelectronic composite cable 2 .

[0050] As a preferred implementation method, after the rough positioning, the method further includes:

[0051] Extract the abnormal signals (such as any abnormal partial discharge signal group) in the certain sensing channel area in the spatiotemporal two-dimensional distribution vibration signal diagram Figure 2 3), the duration of the abnormal signal is greater than the duration of the occurrence of the abnormal partial discharge signal group and covers the signal before the occurrence of the abnormal partial discharge signal group; a time sampling window of a preset size is used, with 1 time sampling interval as a sliding step, the data of each sensing channel in the extracted abnormal signal is slidingly sampled, and a short-time Fourier transform is performed on the short-time signal frame obtained by each sampling of the sensing channel to obtain a corresponding frequency domain energy distribution;

[0052] Randomly selecting a sensing channel in the certain sensing channel region, performing Fourier transform on the abnormal partial discharge signal of the sensing channel in any abnormal partial discharge signal group, and using the obtained frequency domain distribution feature as the frequency domain distribution feature of the abnormal partial discharge signal group in the certain sensing channel region; determining a continuous frequency domain range in which power density spectra are superimposed based on the frequency domain distribution feature, and calculating the energy of the frequency domain distribution feature within the continuous frequency domain range;

[0053] The power density spectrum of each frequency domain energy distribution is superimposed in the continuous frequency domain to obtain the energy of the short-time signal frame corresponding to the frequency domain energy distribution, and the energy of all short-time signal frames corresponding to each sensing channel in the certain sensing channel area is formed into an energy spectrum in time; the energy spectrum of the reference sensing channel and the energy spectrum of each other sensing channel in the certain sensing channel area are respectively delayed to obtain the delay τ of the abnormal local signal of each other sensing channel relative to the reference sensing channel (such as Figure 5 The reference sensing channel is the sensing channel in which the abnormal partial discharge signal first appears in the abnormal partial discharge signal group selected when performing short-time Fourier transform;

[0054] Construct distance and delay data pair (X+(a-1)L S ,τ -a ),……,(X,τ -1 ), (L S -X,τ +1 ),……,(bL S -X,τ +b ), where X represents the distance of the assumed precise discharge position from the starting point of the reference sensing channel; 0≤X≤sensing channel length L S ;X+(a-1)L S bL represents the distance between the ath sensor channel adjacent to the reference sensor channel and the precise discharge position. S -X represents the distance between the bth adjacent sensing channel behind the reference sensing channel and the precise discharge position; τ -a represents the time delay of the abnormal local signal of the ath sensing channel relative to the reference sensing channel; τ +b Indicates the delay of the abnormal local signal of the bth sensing channel relative to the reference sensing channel; in the range of 0 to L S The X is traversed within the range, and at each current X traversed, a linear fit is performed on the distance and delay data pair, and the X corresponding to the minimum fitting error is used as the fine position of the abnormal partial discharge signal on the reference sensing channel.

[0055] like Figure 6As shown in the figure, the red star represents the precise discharge position X, which traverses the vertical direction between the two red dashed lines. 6 represents the reference sensing channel, 5 represents the third sensing channel after the reference sensing channel and its delay with the reference sensing channel, 7 represents the backward propagation direction of the abnormal partial discharge signal, and 8 represents the forward propagation direction of the abnormal partial discharge signal.

[0056] In this embodiment, the short-time Fourier transform step of the local area discharge signal is as follows: the data of all sensing channels of the abnormal signal including the abnormal local discharge signal group are subjected to short-time Fourier transform with 100 time sampling data, and a corresponding frequency domain energy distribution is obtained (for the same time window, each sensing channel corresponds to a frequency domain energy distribution), and the short-time signal frame of the 100 time sampling data is moved only by one time sampling interval each time.

[0057] In addition, for example, if a broadband distribution is present within 1000 Hz, the power density spectrum superposition frequency domain range can be determined to be 0 to 1000 Hz.

[0058] In this preferred embodiment, the final accurate positioning result of the abnormal discharge signal is the position X corresponding to the minimum fitting error, with an accuracy of sub-meter level, and the positioning error is much smaller than the spatial resolution of the phase-sensitive optical time domain reflectometer.

[0059] Preferably, a Fourier transform is performed on the abnormal partial discharge signal that appears first in any abnormal partial discharge signal group of the selected sensing channel, and the obtained frequency domain distribution characteristics are used as the frequency domain distribution characteristics of the abnormal partial discharge signal group in the certain sensing channel area.

[0060] Preferably, generalized cross-correlation is used for delay calculation.

[0061] As an example, multiple continuous frequency domain ranges Fr of power density spectrum superposition can be determined according to the frequency domain distribution characteristics. i ; and calculate each continuous frequency domain range Fr i The energy Pr of the internal frequency domain distribution characteristics i ;

[0062] In each continuous frequency range Fr i Under the condition of τ, the delay τ of the abnormal local signal of each other sensing channel relative to the reference sensing channel is calculated. i ;

[0063] For each continuous frequency domain range Fr i , build distance and delay data pairs Among them, X i Indicates that in the continuous frequency domain range Fr iThe distance between the precise discharge position assumed below and the starting point of the reference sensing channel; 0≤X i ≤ Sensing channel length L S ;X i +(a-1)L S bL represents the distance between the ath sensor channel adjacent to the reference sensor channel and the precise discharge position. S -X i represents the distance between the bth adjacent sensing channel behind the reference sensing channel and the precise discharge position; Indicates that in the continuous frequency domain range Fr i The delay of the abnormal local signal of the a-th sensing channel relative to the reference sensing channel; Indicates that in the continuous frequency domain range Fr i The delay of the abnormal local signal of the bth sensing channel relative to the reference sensing channel; in 0~L S Traverse X in range i , at each current X traversed i Under this condition, a linear fit is made for the distance and delay data pair, and the X corresponding to the minimum fitting error is i As the continuous frequency domain range Fr i The accurately determined location of the abnormal partial discharge signal on the reference sensing channel;

[0064] All continuous frequency domain ranges Fr i The X corresponding to the minimum fitting error i Take the average as the final precise positioning position.

[0065] As a preference, the above method can be used to convert all continuous frequency domain ranges Fr i The X corresponding to the minimum fitting error i The way to take the average is:

[0066]

[0067] Where, Indicates that in the continuous frequency domain range Fr i The X corresponding to the minimum fitting error i .

[0068] Example 2

[0069] The present application also relates to an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0070] The electronic device may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The processor may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The memory may be used to store computer programs and / or modules, and the processor may perform various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory, and calling the data stored in the memory.

[0071] The relevant technical solutions are the same as above and will not be repeated here.

[0072] Example 3

[0073] The present application also relates to a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when the computer program is executed by a processor.

[0074] Specifically, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0075] The relevant technical solutions are the same as above and will not be repeated here.

[0076] Example 4

[0077] The present invention provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of the method of the above-described embodiment of the present invention.

[0078] The relevant technical solutions are the same as above and will not be repeated here.

[0079] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for locating insulation damage in a photoelectric composite cable, characterized in that: include: Continuously pressurize the conductive copper tube of the optoelectronic composite cable to be tested, and collect the spatiotemporal two-dimensional distribution vibration signal diagram of the optoelectronic composite cable in real time through optical fiber distributed acoustic wave sensing. If an impulse abnormal signal group repeatedly appears in the time dimension in a certain sensing channel area on the spatiotemporal two-dimensional distribution vibration signal diagram, and each impulse abnormal signal group exhibits a bidirectional propagation characteristic that occurs over time in the spatial dimension, and the voltage on the conductive copper tube suddenly drops each time the impulse abnormal signal group appears, then the impulse abnormal signal group that appears each time is identified as an abnormal partial discharge signal group; the spatial position area of ​​the optoelectronic composite cable corresponding to the certain sensing channel area is the abnormal partial discharge area. In any impulse abnormal signal group that appears, according to the bidirectional propagation characteristics, the spatial position area of ​​the optoelectronic composite cable corresponding to a sensing channel where the impulse abnormal signal appears first is further locked as the abnormal partial discharge signal occurrence area of ​​the abnormal partial discharge area, that is, the preliminary positioning of the damaged position of the optoelectronic composite cable to be detected, and the positioning error is less than the sensing channel length L S .

2. A method for locating insulation damage in a photoelectric composite cable according to claim 1, characterized in that: The optical fiber distributed acoustic wave sensing system is connected to any core optical fiber of the optoelectronic composite cable to be detected, and the optical fiber distributed acoustic wave sensing system collects the backscattered light signal of the core optical fiber and demodulates it to obtain the said spatiotemporal two-dimensional distribution vibration signal diagram.

3. The method for locating insulation damage of a photoelectric composite cable according to claim 1, characterized in that: After the initial positioning, it also includes: Extracting an abnormal signal including any abnormal partial discharge signal group from a certain sensing channel region in the spatiotemporal two-dimensional distribution vibration signal graph, wherein the duration of the abnormal signal is greater than the occurrence duration of the abnormal partial discharge signal group and covers the signal before the occurrence of the abnormal partial discharge signal group; using a time sampling window of a preset size and a time sampling interval as a sliding step, performing sliding sampling on the data of each sensing channel in the extracted abnormal signal, performing a short-time Fourier transform on the short-time signal frame obtained by each sampling of the sensing channel, and correspondingly obtaining a frequency domain energy distribution; Randomly selecting a sensing channel in the certain sensing channel region, performing Fourier transform on the abnormal partial discharge signal of the sensing channel in any abnormal partial discharge signal group, and using the obtained frequency domain distribution feature as the frequency domain distribution feature of the abnormal partial discharge signal group in the certain sensing channel region; determining a continuous frequency domain range in which power density spectra are superimposed based on the frequency domain distribution feature, and calculating the energy of the frequency domain distribution feature within the continuous frequency domain range; Performing power density spectrum superposition on each of the frequency domain energy distributions within a continuous frequency domain to obtain the energy of the short-time signal frame corresponding to the frequency domain energy distribution, and temporally constructing an energy spectrum from the energy of all short-time signal frames corresponding to each sensing channel in the certain sensing channel region; performing time delay calculation on the energy spectrum of a reference sensing channel and the energy spectra of each of the other sensing channels in the certain sensing channel region to obtain a time delay τ of the abnormal local signal of each of the other sensing channels relative to the reference sensing channel; wherein the reference sensing channel is the sensing channel in which the abnormal local discharge signal first appears in the abnormal local discharge signal group selected during the short-time Fourier transform; Construct distance and delay data pair (X+(a-1)L S ,τ -a ),……,(X,τ -1 ), (L S -X,τ +1 ),……,(bL S -X,τ +b ), where X represents the distance of the assumed precise discharge position from the starting point of the reference sensing channel; 0≤X≤sensing channel length L S ;X+(a-1)L S bL represents the distance between the ath sensor channel adjacent to the reference sensor channel and the precise discharge position. S -X represents the distance between the bth adjacent sensing channel behind the reference sensing channel and the precise discharge position; τ -a represents the time delay of the abnormal local signal of the ath sensing channel relative to the reference sensing channel; τ +b Indicates the delay of the abnormal local signal of the bth sensing channel relative to the reference sensing channel; in the range of 0 to L S The X is traversed within the range, and at each current X traversed, a linear fit is performed on the distance and delay data pair, and the X corresponding to the minimum fitting error is used as the fine position of the abnormal partial discharge signal on the reference sensing channel.

4. A method for locating insulation damage in a photoelectric composite cable according to claim 3, characterized in that: A Fourier transform is performed on the abnormal partial discharge signal that appears first in any abnormal partial discharge signal group of the selected sensing channel, and the obtained frequency domain distribution feature is used as the frequency domain distribution feature of the abnormal partial discharge signal group in the certain sensing channel area.

5. The method for locating insulation damage of a photoelectric composite cable according to claim 3, wherein: Generalized cross-correlation is used for delay calculation.

6. A method for locating insulation damage in a photoelectric composite cable according to claim 3, characterized in that: According to the frequency domain distribution characteristics, multiple continuous frequency domain ranges Fr of power density spectrum superposition are determined. i ; and calculate each continuous frequency domain range Fr i The energy Pr of the internal frequency domain distribution characteristics i ; In each continuous frequency range Fr i Under the condition of τ, the delay τ of the abnormal local signal of each other sensing channel relative to the reference sensing channel is calculated. i ; For each continuous frequency domain range Fr i , build distance and delay data pairs Among them, X i Indicates that in the continuous frequency domain range Fr i The distance between the precise discharge position assumed below and the starting point of the reference sensing channel; 0≤X i ≤ Sensing channel length L S ;X i +(a-1)L S bL represents the distance between the ath sensor channel adjacent to the reference sensor channel and the precise discharge position. S -X i represents the distance between the bth adjacent sensing channel behind the reference sensing channel and the precise discharge position; Indicates that in the continuous frequency domain range Fr i The delay of the abnormal local signal of the a-th sensing channel relative to the reference sensing channel; Indicates that in the continuous frequency domain range Fr i The delay of the abnormal local signal of the bth sensing channel relative to the reference sensing channel; in 0~L S Traverse X in range i , at each current X traversed i Under this condition, a linear fit is made for the distance and delay data pair, and the X corresponding to the minimum fitting error is i As the continuous frequency range Fr i The accurately determined location of the abnormal partial discharge signal on the reference sensing channel; All continuous frequency domain ranges Fr i The X corresponding to the minimum fitting error i Take the average as the final precise positioning position.

7. A method for locating insulation damage in a photoelectric composite cable according to claim 6, characterized in that: The continuous frequency domain range Fr i The X corresponding to the minimum fitting error i The way to take the average is: Where, Indicates that in the continuous frequency domain range Fr i The X corresponding to the minimum fitting error i .

8. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed by a processor, the device where the storage medium is located is controlled to perform the steps of the method according to any one of claims 1 to 7.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images