Cable outer sheath damage detecting and positioning method and device, computer program product and storage medium

Abstract

The invention discloses a cable outer sheath damage detecting and positioning method and device, a computer program product and a storage medium. The method comprises the steps that a first detection signal of a first detection device and a second detection signal of a second detection device are acquired, the first detection device is arranged at the first end of a target detection section of a cable outer sheath, and the first detection signal at least comprises a first incident signal and a first reflection signal; the second detection device is arranged at the second end of the target detection section, and the second detection signal at least comprises a second incident signal and a second reflected signal; and determining a damage position of the target detection section based on the first detection signal and the second detection signal. The technical problems that a cable outer sheath damage position detection mode is tedious and the detection efficiency is poor are solved.

Description

Technical Field

[0001] The present invention relates to the field of cable detection technology, and in particular to a method, device, computer program product, and storage medium for detecting and locating damage of a cable outer sheath. Background Art

[0002] High-voltage cables are important and widely used power transmission equipment today. In actual laying scenarios, since the internal high-voltage AC high-voltage current generates an induced voltage on the metal outer sheath, a reasonable setting of the grounding box can ensure the safe operation of the cable. However, if the outer sheath of the cable is damaged due to external stress, corrosion or other reasons, it is more complicated and time-consuming to directly inspect and troubleshoot the cable body.

[0003] In the prior art, a method for detecting and locating the outer sheath of a high-voltage cable using time-frequency domain signals is used. This method directly uses the metal outer sheath as the detection signal injection point, injects the signal directly into the metal sheath of the cable, and simultaneously connects a digital oscilloscope to the metal sheath to take the incident and reflected signals. After WVD time-frequency domain decomposition, the normalized curves of the incident and reflected signals are calculated, and the reflected signal is determined by the peak value of the normalized curve. Finally, the damage position is calculated by the time difference and wave velocity between the incident signal and the reflected signal.

[0004] However, the existing methods directly inject the signal into the metal outer sheath. In actual on-site cable laying, the metal outer sheath is not exposed for safety reasons, which results in the inability of the existing detection methods to directly inject the signal into the cable. In addition, the existing methods only consider the one-way transmission of the signal in the cable. In the process of testing the cables actually put into operation, it is cumbersome to strip the cables from the line and then test them, and the detection efficiency is poor.

[0005] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0006] The embodiments of the present invention provide a method, device, computer program product, and storage medium for detecting and locating damage of a cable outer sheath, so as to at least solve the technical problems of cumbersome detection methods and poor detection efficiency of the location of damage to the cable outer sheath.

[0007] According to one aspect of an embodiment of the present invention, a method for detecting and locating damage of a cable outer sheath is provided, comprising: acquiring a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device being arranged at a first end of a target detection segment of the cable outer sheath, the first detection signal comprising at least a first incident signal and a first reflected signal, the first incident signal being an incident signal injected into the cable outer sheath by the first detection device, the first reflected signal being a reflected signal generated by reflection of the first incident signal by the cable, the second detection device being arranged at a second end of the target detection segment, the second detection signal comprising at least a second incident signal and a second reflected signal, the second incident signal being an incident signal injected into the cable outer sheath by the second detection device, the second reflected signal being a reflected signal generated by reflection of the second incident signal by the cable; and determining the damage position of the target detection segment based on the first detection signal and the second detection signal.

[0008] Optionally, before obtaining the second detection signal, the method further includes the following steps: obtaining the first detection signal; judging whether the target detection segment is damaged based on the first detection signal; and obtaining the second detection signal when it is determined that the target detection segment is damaged.

[0009] Optionally, determining a damaged position of the target detection segment based on the first detection signal and the second detection signal includes: judging whether the target detection segment is damaged based on the second detection signal; and when it is determined that the target detection segment is damaged, determining the damaged position of the target detection segment based on the first detection signal and the second detection signal.

[0010] Optionally, during the process of acquiring the first detection signal of the first detection device and the second detection signal of the second detection device, the cable remains in a running state.

[0011] Optionally, the first detection device includes a first signal generator and a first oscilloscope, and obtaining a first detection signal includes the following steps: connecting the first detection device to any two phases of a first grounding box, and the first grounding box is set at the first end of the target detection section; using the first signal generator to generate a first incident signal, and injecting the first incident signal into the first grounding box, the first incident signal enters the outer sheath of the cable along the first grounding box, and is reflected by the cable to generate a first reflected signal; using the first oscilloscope to collect the first incident signal and the first reflected signal.

[0012] Optionally, the second detection device includes a second signal generator and a second oscilloscope, and obtaining a second detection signal includes the following steps: connecting the second detection device to any two phases of a second grounding box, and the second grounding box is arranged at the second end of the target detection section; generating a second incident signal by the second signal generator, and injecting the second incident signal into the second grounding box, and the second incident signal enters the outer sheath of the cable along the second grounding box, and is reflected by the cable to generate a second reflected signal; and collecting the second incident signal and the second reflected signal by the second oscilloscope.

[0013] Optionally, determining the damage position of the target detection segment based on the first detection signal and the second detection signal comprises the following steps: determining a first fault distance S based on the first detection signal A , the first fault distance is the distance between the damage point and the first end of the target detection segment; based on the second detection signal, the second fault distance S is determined B , the second fault distance is the distance between the damaged point and the second end of the target detection segment; obtain a preset spacing L, the preset spacing L is the distance between the first grounding box and the second grounding box; based on the preset spacing L, the first fault distance S A and the second fault distance S B , determine the location information of the damage point.

[0014] According to another aspect of an embodiment of the present invention, a cable outer sheath damage detection and positioning device is also provided, including: an acquisition module, the acquisition module is used to acquire a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device is arranged at a first end of a target detection segment of the cable outer sheath, the first detection signal at least includes a first incident signal and a first reflected signal, the first incident signal is an incident signal injected into the cable outer sheath by the first detection device, and the first reflected signal is a reflected signal generated by the reflection of the first incident signal by the cable outer sheath, the second detection device is arranged at a second end of the target detection segment, the second detection signal at least includes a second incident signal and a second reflected signal, the second incident signal is an incident signal injected into the cable outer sheath by the second detection device, and the second reflected signal is a reflected signal generated by the reflection of the second incident signal by the cable outer sheath; a determination module, the determination module is used to determine the damage position of the target detection segment based on the first detection signal and the second detection signal.

[0015] According to another aspect of the embodiments of the present invention, there is further provided a computer program product, including a computer program, which implements the steps of any of the above-mentioned cable outer sheath damage detection and positioning methods when executed by a processor.

[0016] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein when the program is run, the computer-readable storage medium is controlled, and the device where the computer-readable storage medium is located executes any one of the above-mentioned cable outer sheath damage detection and positioning methods.

[0017] In an embodiment of the present invention, a first detection signal of a first detection device and a second detection signal of a second detection device are obtained, the first detection device is arranged at the first end of the target detection section of the cable outer sheath, the first detection signal at least includes a first incident signal and a first reflected signal, the first incident signal is the incident signal injected by the first detection device into the cable outer sheath, the first reflected signal is the reflected signal generated by the first incident signal reflected by the cable, the second detection device is arranged at the second end of the target detection section, the second detection signal at least includes a second incident signal and a second reflected signal, the second incident signal is the incident signal injected by the second detection device into the cable outer sheath, the second reflected signal is the reflected signal generated by the second incident signal reflected by the cable; based on the first detection signal and the second detection signal, the damaged position of the target detection section is determined. The above method can effectively monitor and locate the damaged position of the outer sheath without interrupting the operation of the cable and without stripping the cable from the line for detection, the detection operation process is simple, and the operation safety and maintenance efficiency of the system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 It is a hardware structure block diagram of a computer terminal of a cable outer sheath damage detection and positioning method according to one embodiment of the present invention;

[0020] Figure 2 is a flow chart of a method for detecting and locating damage of a cable outer sheath according to one optional embodiment of the present invention;

[0021] Figure 3 is a structural block diagram of a cable outer sheath damage detection and positioning method according to one embodiment of the present invention;

[0022] Figure 4 It is a schematic flow chart of a method for detecting and locating damage of a cable outer sheath according to one optional embodiment of the present invention;

[0023] Figure 5 is a schematic structural diagram of a cable outer sheath damage detection and positioning device according to one optional embodiment of the present invention;

[0024] Figure 6It is a schematic structural diagram of a detection device according to one optional embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] According to one embodiment of the present invention, an embodiment of a method for detecting and locating damage of a cable outer sheath is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0028] The method embodiment can be executed in a computer terminal or similar computing device including a memory and a processor. For example, if the method is executed on a computer terminal, Figure 1 As shown, the computer terminal may include one or more processors 102 (the processor may include but is not limited to a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microprocessor (MCU), a field programmable logic device (FPGA), a neural network processor (NPU), a tensor processor (TPU), an artificial intelligence (AI) type processor, etc.) and a memory 104 for storing data. Optionally, the above-mentioned computer terminal may also include a transmission device 106 for communication functions, an input and output device 108, and a display 110. It can be understood by those skilled in the art that Figure 1The structure shown is only for illustration and does not limit the structure of the above-mentioned computer terminal. For example, the computer terminal may also include more or fewer components than the above-mentioned structure description, or have a configuration different from the above-mentioned structure description.

[0029] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the cable outer sheath damage detection and positioning method in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, the above-mentioned cable outer sheath damage detection and positioning method is realized. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the mobile terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0030] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0031] The display 110 may be, for example, a touch screen liquid crystal display (LCD). The liquid crystal display may enable a user to interact with a user interface of the mobile terminal. In some embodiments, the mobile terminal has a graphical user interface (GUI), and a user may interact with the GUI by finger contact and / or gestures on a touch-sensitive surface, wherein the human-computer interaction functions here may optionally include the following interactions: creating web pages, drawing, word processing, making electronic documents, games, video conferencing, instant messaging, sending and receiving emails, call interfaces, playing digital videos, playing digital music, and / or web browsing, etc. The executable instructions for executing the above human-computer interaction functions are configured / stored in a computer program product or a readable storage medium executable by one or more processors.

[0032] This embodiment provides a method for detecting and locating cable outer sheath damage running on the above-mentioned computer terminal. Figure 2FIG. 1 is a flow chart of a method for detecting and locating cable outer sheath damage according to one embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0033] Step S21: obtaining a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device being arranged at a first end of a target detection section of an outer sheath of a cable, the first detection signal at least comprising a first incident signal and a first reflected signal, the first incident signal being an incident signal injected into the outer sheath of the cable by the first detection device, the first reflected signal being a reflected signal generated by reflection of the first incident signal by the cable, the second detection device being arranged at a second end of the target detection section, the second detection signal at least comprising a second incident signal and a second reflected signal, the second incident signal being an incident signal injected into the outer sheath of the cable by the second detection device, the second reflected signal being a reflected signal generated by reflection of the second incident signal by the cable;

[0034] Specifically, the first detection device and the second detection device use equipment of the same model and function to inject the detection signal to ensure that the first reflection signal and the second reflection signal received from the damaged position of the cable outer sheath correspond to each other (the signal pulse amplitude and pulse frequency are the same). The first incident signal and the second incident signal are signals emitted by the first detection device and the second detection device to the first end and the second end of the target detection segment, and the first reflection signal and the second reflection signal are reflection signals received by the first detection device and the second detection device at the damaged position of the cable outer sheath or the other end. The incident signal and the reflection signal are the incident signal and the reflection signal in the time-frequency domain reflection method (TDR). The time-frequency domain reflection method is a method for testing based on the principle that electromagnetic waves are reflected after encountering an impedance change point when propagating in a cable.

[0035] It should be noted that the first detection device and the second detection device can be the same detection device. The detection device first injects a first detection signal into the first end of the target detection segment, and determines whether to inject a second detection signal into the second end of the target detection end based on the feedback result of the first detection signal. Since the first detection signal and the second detection signal do not need to be injected at the same time, the same detection device can be used to detect and locate cable outer sheath damage.

[0036] Step S22: Determine the damaged position of the target detection segment based on the first detection signal and the second detection signal.

[0037] Specifically, after the first incident signal and the second incident signal are transmitted to the damaged position of the target detection end, the characteristic impedance of the cable changes, causing the incident signal to be reflected at the damaged point of the cable, thereby forming a first reflected signal and a second reflected signal. The first reflected signal and the second reflected signal return to the incident end and can be captured by the detection device. By analyzing and calculating the reflected signals, the damaged position of the target detection end can be determined.

[0038] Through the above steps, the first detection signal of the first detection device and the second detection signal of the second detection device are obtained. The first detection device is set at the first end of the target detection section of the cable outer sheath. The first detection signal at least includes a first incident signal and a first reflected signal. The first incident signal is the incident signal injected by the first detection device into the cable outer sheath, and the first reflected signal is the reflected signal generated by the first incident signal reflected by the cable. The second detection device is set at the second end of the target detection section. The second detection signal at least includes a second incident signal and a second reflected signal. The second incident signal is the incident signal injected by the second detection device into the cable outer sheath, and the second reflected signal is the reflected signal generated by the second incident signal reflected by the cable. Based on the first detection signal and the second detection signal, the damaged position of the target detection section is determined. Through the above method, the damaged position of the outer sheath can be effectively monitored and located without interrupting the operation of the cable and without stripping the cable from the line for detection. The detection operation process is simple, which improves the operation safety and maintenance efficiency of the system.

[0039] In this embodiment, the first detection device and the second detection device perform time-frequency domain analysis on the received first reflected signal and the second reflected signal, and identify the time delay of the reflected signal by using Wigner-Ville distribution and normalized cross-correlation coefficient, that is, the distance between the damaged point and the signal injection point can be calculated by the time difference between the incident and reflected signals of the first detection signal, combined with the propagation speed of electromagnetic waves in the cable. Similarly, if the second detection signal also generates reflection, the distance between the damaged point and the second end of the target detection segment can be calculated.

[0040] Optionally, in step S21, before acquiring the second detection signal, the method further includes the following steps:

[0041] Step S201: Acquire a first detection signal;

[0042] Specifically, a first detection signal is obtained from the first detection device, where the first detection signal is a time-frequency domain signal, and the time-frequency domain signal may be a time-frequency domain signal with time domain characteristics and frequency domain characteristics generated by the first detection device.

[0043] It should be noted that the time-frequency domain of the first detection signal can be adjusted according to the laying conditions of the high-voltage cable in a specific environment, that is, the first detection signal is adjusted to a suitable frequency to facilitate the detection device to irradiate and receive the detection signal.

[0044] Step S202: Based on the first detection signal, determine whether the target detection segment is damaged;

[0045] Specifically, by calculating the time difference between sending and receiving the first detection signal sent and received by the first detection device, the first detection signal packet sends an incident signal, and also includes the received reflected signal, the position of the damaged section in the cable when the signal is reflected can be calculated; or if the first detection device does not receive the reflected signal in the first detection signal, it proves that there is no damaged point in the target detection section.

[0046] Step S203: When it is determined that the target detection segment is damaged, a second detection signal is acquired.

[0047] Specifically, when the first detection device receives a reflected signal in the first detection signal, in order to determine whether the reflected signal is transmitted from the damaged position of the target detection segment or from the other end of the target detection segment, it is necessary to inject a second detection signal through the second detection device for judgment, and jointly determine the damaged position of the target detection segment by combining the first detection signal and the second detection signal.

[0048] In this embodiment, through preliminary detection, the results fed back by the first detection device can quickly determine whether the target detection section of the cable is damaged, and then determine whether further detailed detection is needed, thereby avoiding unnecessary waste of resources. It is suitable for preliminary screening of large-scale cable networks and improves the targetedness and efficiency of detection.

[0049] Optionally, in step S22, determining a damaged position of the target detection segment based on the first detection signal and the second detection signal includes:

[0050] Step S221: based on the second detection signal, determining whether the target detection segment is damaged;

[0051] Specifically, when the first detection device receives the reflected signal in the first detection signal, it preliminarily determines that the target detection segment is damaged, and injects the second detection signal through the second detection device and the other end of the target detection segment. The second detection signal received by the second detection device is then compared and combined with the first detection signal to determine that the target detection segment is indeed damaged.

[0052] It should be noted that in step S203, the first detection signal is used to preliminarily determine whether the target detection segment is damaged. However, since the detection signal is bidirectionally or multidirectionally propagated in the cable, it is not possible to determine whether the target detection segment is damaged only by the first detection signal, and a comprehensive judgment is required in combination with the second detection signal. At the same time, since the impedance of the two ends of the target detection segment is different from that of the normal cable, the first detection signal will also generate a reflection signal when it reaches the end point of the target detection segment. This reflection signal needs to be filtered out in combination with the second detection signal before it can be determined whether the target detection segment is actually damaged.

[0053] Step S222: When it is determined that the target detection segment is damaged, the damaged position of the target detection segment is determined based on the first detection signal and the second detection signal.

[0054] Specifically, the first detection signal and the second detection signal are periodically input time-frequency domain characteristic signals. The first detection device and the second detection device collect continuous incident signals and reflected signals. Since the characteristics of the two signals are similar, the overall collected signal can be feature extracted to obtain a spectrum diagram or formula containing both time domain characteristics and frequency domain characteristics. Specifically, the time difference between the incident signal and the reflected signal is obtained by calculating the cross-correlation curve between the time-frequency energy of the incident signal and the entire sampling signal, and then the distance between the fault point and the two ends of the target detection section is calculated by the electromagnetic wave velocity of the detection signal (signal propagation speed), and the damaged part of the outer sheath of the high-voltage cable is located. This embodiment adopts a double-end detection method, which can improve the accuracy of detection, and the signal detection at both ends of the target detection section can effectively locate the damaged point.

[0055] Optionally, in the above steps, the cable remains in operation during the process of obtaining the first detection signal of the first detection device and the second detection signal of the second detection device. The cable detection can be performed while the cable is operating normally, without interrupting the power or communication service, thereby ensuring the continuity and stability of the power supply or service.

[0056] Optionally, in step S21, the first detection device includes a first signal generator and a first oscilloscope, and obtaining a first detection signal includes the following steps:

[0057] Step S2111: connecting the first detection device to any two phases of a first grounding box, the first grounding box being arranged at a first end of the target detection section;

[0058] Specifically, Figure 5 , Figure 6As shown, the target detection section adopts the common cross-connected grounding method of three single-core cables. The metal sheaths of the three cables form a cable grounding system by cross-connecting. The first detection device is tested with the first grounding box cable of the grounding system. During the detection process, it is necessary to connect the first signal generator and the first oscilloscope in the first detection device, and lead out two lead wires to the two phases of the first grounding box. Among them, grounding box A is one of the first grounding box and the second grounding box, and grounding box B is the other of the first grounding box and the second grounding box.

[0059] In this embodiment, the first signal generator is used to transmit the first detection signal, and the first oscilloscope is used to collect input and reflected signals; the first detection device also includes a first host computer, which is used to process and store signals and simultaneously connect the two lead wires of the first oscilloscope and the first signal generator.

[0060] Step S2112: using a first signal generator to generate a first incident signal, and injecting the first incident signal into a first grounding box, the first incident signal enters the outer sheath of the cable along the first grounding box, and is reflected by the cable to generate a first reflected signal;

[0061] Specifically, the first signal generator generates a first incident signal, which is injected into the target detection segment through the first grounding box. The damaged part of the cable or the other end of the target detection segment reflects the first incident signal, generating a first reflected signal that returns to the first detection device.

[0062] Step S2113: using a first oscilloscope to collect the first incident signal and the first reflected signal.

[0063] Specifically, the first oscilloscope collects the first incident signal and the first reflected signal in reverse and transmits the signal data to the first host computer, so that the first host computer can analyze and calculate the distance to the cable damage position.

[0064] Optionally, in step S21, the second detection device includes a second signal generator and a second oscilloscope, and obtaining the second detection signal includes the following steps:

[0065] Step S2121: connecting the second detection device to any two phases of a second grounding box, the second grounding box being arranged at the second end of the target detection section;

[0066] Specifically, Figure 5 , Figure 6 As shown, the second detection device is used to detect the second grounding box cable of the grounding system. During the detection process, it is necessary to connect the second signal generator in the second detection device to the second oscilloscope, and lead out two lead wires to connect to the two phases of the second grounding box.

[0067] Step S2122: Generate a second incident signal through a second signal generator, and inject the second incident signal into a second grounding box. The second incident signal enters the outer sheath of the cable along the second grounding box and is reflected by the cable to generate a second reflected signal.

[0068] Specifically, the second signal generator generates a second incident signal, which is injected into the target detection segment through the second grounding box. The damaged part of the cable or the other end of the target detection segment reflects the second incident signal, generating a second reflected signal that returns to the second detection device.

[0069] Step S2123: collecting the second incident signal and the second reflected signal through a second oscilloscope.

[0070] Specifically, the second oscilloscope collects the second incident signal and the second reflected signal in reverse and transmits the signal data to the second host computer, so that the second host computer can analyze and calculate the distance to the cable damage position.

[0071] In one embodiment of the present application, a method of performing position detection on a damaged portion of a cable by specifically arranging a signal generator, an oscilloscope and a host computer in the first detection device and the second detection device, and connecting the first detection device and the second detection device to a grounding box makes the detection process more standardized and automated, which can reduce human operation errors, and the first detection device and the second detection device simultaneously inject and collect frequency domain signals at both ends of the target detection segment, thereby improving the reliability of the detection results.

[0072] Optionally, in step S22, determining the damaged position of the target detection segment based on the first detection signal and the second detection signal comprises the following steps:

[0073] Step S223: Determine the first fault distance S based on the first detection signal A , the first fault distance is the distance between the damage point and the first end of the target detection segment;

[0074] Specifically, based on the first detection signal, the distance S between the fault point and the signal transmission point is calculated according to the electromagnetic wave velocity through the time difference between the first incident signal and the first reflected signal. A , locate the distance between the outer sheath of the high-voltage cable and the first end of the target detection section.

[0075] Step S224: Determine the second fault distance S based on the second detection signal B , the second fault distance is the distance between the damage point and the second end of the target detection segment;

[0076] Specifically, based on the second detection signal, the distance S between the fault point and the signal transmission point is calculated according to the electromagnetic wave velocity through the time difference between the second incident signal and the second reflected signal. B, locate the distance between the outer sheath of the high-voltage cable and the second end of the target detection section.

[0077] Step S225: obtaining a preset distance L, where the preset distance L is the distance between the first grounding box and the second grounding box;

[0078] Specifically, the distance L between the first grounding box and the second grounding box is obtained by a grounding box spacing measurement method, and the grounding box spacing measurement method also uses a time-frequency domain reflection method for measurement, that is, an incident signal is injected at the first grounding box or the second grounding box, and the incident signal is received at the second grounding box or the first grounding box, or a reflected signal is received at the same grounding box, and the distance L between the first grounding box and the second grounding box is measured in combination with the electromagnetic wave velocity.

[0079] Step S226: Based on the preset distance L and the first fault distance S A and the second fault distance S B , determine the location information of the damage point.

[0080] Specifically, if the calculation is accurate, then L = S A +S B However, the relationship between these three factors satisfies the calculation of relative error e, then e=L-(S A +S B ) If the calculation error satisfies e not exceeding 0.1m, the location information of the fault point can be determined, and the error data can be adjusted according to specific indicators. This embodiment is based on the calculation method of the signal reflection distance, which can accurately calculate the absolute position of the damaged point, which helps to optimize the cable maintenance strategy and resource allocation.

[0081] The present invention also provides a preferred embodiment of a cable outer sheath damage detection and positioning method, which mainly solves the problem that when the signal is injected, if there is a reflected signal in the sampled waveform after the signal propagates in both directions, it is impossible to determine which section of the cable is damaged. Figure 4 As shown, the method comprises the following steps:

[0082] Step 1: determine the target cable segment to be tested, and select the first grounding box at the first end of the target detection segment for testing;

[0083] Among them, the detection work mainly includes connecting the first detection device to any two phases of the first grounding box, and then using the first signal generator to generate time-frequency domain signals and injecting the signals into the first grounding box. The signals will enter the metal sheaths of the two phases from the first grounding box. At this time, the signals are bidirectionally propagated.

[0084] Step 2: The first oscilloscope collects the first incident signal and the first reflected signal, transmits the signal to the first host computer for calculation and processing to obtain the time difference between the first incident signal and the first reflected signal, calculates the damaged position of the cable outer sheath, and detects the signal to obtain the fault distance S A ;

[0085] Among them, when the signal is reflected by the damaged section of the cable, the first incident signal and the first reflected signal can be collected by the first oscilloscope, and the first oscilloscope transmits the sampling information to the first host computer. The first host computer can process the signal through time-frequency domain decomposition methods such as Wigner-Ville distribution and normalized cross-correlation coefficient methods to obtain the time difference between the first incident signal and the first reflected signal, and obtain the damaged position of the cable outer sheath through the wave velocity and the time difference.

[0086] Step 3: After the first host computer obtains the information and stores it, check whether there is a first reflection signal generated by the cable outer sheath. If no damaged signal is returned, replace the other two phases of the first grounding box and jump to step 1; if there is no fault signal in any two phases of the first grounding box, it can be determined that the target detection section has no outer sheath damage; if a damaged signal is detected, move to the second end of the target detection section to detect the second grounding box;

[0087] Step 4: Select the second grounding box at the second end of the target detection section for detection;

[0088] Step 5: The second oscilloscope collects the second incident signal and the second reflected signal, transmits the signal to the second host computer for calculation and processing to obtain the time difference between the second incident signal and the second reflected signal, calculates the damaged position of the cable outer sheath, and detects the signal to obtain the fault distance S B ;

[0089] Step 6: Measure the distance L between the first grounding box and the second grounding box and calculate the fault distance S A , Fault distance S B , and the relative error between L.

[0090] The processing method after the above signal collection and the principle of determining the damaged position of the cable outer sheath are as follows:

[0091] By periodically inputting the time-frequency domain characteristic signal, the oscilloscope can collect continuous incident signals and reflected signals. Since the characteristics of the two signals are similar, the overall collected signal can be extracted. Through the Wigner-Ville distribution extraction scheme, the time-domain characteristics and frequency-domain characteristics of the signal are expressed in the form of a matrix. The time-frequency domain matrix W of the incident signal is r (t,ω), the time-frequency matrix W of the reflected signal s(t,ω), a spectrum diagram containing both time domain features and frequency domain features is obtained, using the following mutual correlation coefficient C sr The calculation formula is:

[0092]

[0093] Among them, E r =∫∫W r (t,ω)dωdτ;E s =∫∫W s (t,ω)dωdτ.

[0094] In the above formula, E r and E s are the energy of the incident signal and the reflected signal, respectively, for the entire C sr Normalization of the curve is specifically achieved by calculating the cross-correlation curve between the time-frequency energy of the incident signal and the entire sampling signal, where the normalized cross-correlation coefficient is 1 for the time center of the incident signal, and the second peak for the time center of the first reflected signal. Thus, the time difference Δt between the incident and reflected signals can be obtained, using the formula:

[0095]

[0096] The distance S between the fault point and the signal emission point can be calculated according to the electromagnetic wave velocity, and the damaged part of the outer sheath of the high-voltage cable can be located.

[0097] After obtaining the sampling waveforms of the incident signal and the reflected signal, it is necessary to determine the terminal reflected signal according to the distance between the ground boxes at both ends of the target detection section and filter it out. Since the sampling signal will contain the incident signal, the reflected signal at the fault location, and the reflected signal at the other ground box, for cables with a known distance between the two ground boxes, the reflected signal at the ground box can be directly taken out; but for cables with unknown spacing, it is necessary to compare the two ground boxes at the same time to determine the reflected signals with the same amplitude and the same position. If there are two signals that meet the above conditions, the second signal is removed. At this time, the cable outer sheath damage is very likely to occur in the middle of the two ground boxes.

[0098] Except for the above-mentioned case where the cable outer sheath is damaged in the middle of the two grounding boxes, most of the other cases require the fault distance S to be obtained by testing the two grounding boxes. A and S B At the same time, the distance L between the two grounding boxes is determined by the above grounding box distance measurement method. The above three relationships satisfy the calculation of the relative error e:

[0099] e=L-(S A +S B );

[0100] If the calculation error satisfies e≤0.1m, the location information of the fault point can be determined, and the error value can be adjusted according to specific indicators.

[0101] Through the description of the above embodiments, it can be seen that the embodiments of the present application have the following beneficial effects:

[0102] 1) By considering the problem that the metal outer sheath of the high-voltage cable cannot be directly connected during the actual operation process, the grounding box is used as the medium for signal input and sampling to realize the outer sheath detection of the commissioned cable.

[0103] 2) By considering the problem of bidirectional signal transmission, a detection method using two grounding boxes to determine the faulty section of the cable at one end is adopted to avoid the problem of being unable to determine the damaged section and unable to accurately locate it after the reflected signals are superimposed.

[0104] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0105] In this embodiment, a cable outer sheath damage detection and positioning device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0106] Figure 3 is a structural block diagram of a cable outer sheath damage detection and positioning device according to one embodiment of the present invention, such as Figure 3As shown, the device includes: an acquisition module 42, the acquisition module 42 is used to acquire a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device is arranged at a first end of a target detection section of the cable outer sheath, the first detection signal at least includes a first incident signal and a first reflected signal, the first incident signal is an incident signal injected into the cable outer sheath by the first detection device, and the first reflected signal is a reflected signal generated by the first incident signal reflected by the cable outer sheath, the second detection device is arranged at a second end of the target detection section, the second detection signal at least includes a second incident signal and a second reflected signal, the second incident signal is an incident signal injected into the cable outer sheath by the second detection device, and the second reflected signal is a reflected signal generated by the second incident signal reflected by the cable outer sheath; a determination module 44, the determination module 44 is used to determine the damaged position of the target detection section based on the first detection signal and the second detection signal.

[0107] Through the above device, the acquisition module 42 is used to acquire the first detection signal of the first detection device and the second detection signal of the second detection device. The first detection device is set at the first end of the target detection section of the cable outer sheath. The first detection signal at least includes a first incident signal and a first reflection signal. The first incident signal is the incident signal injected by the first detection device into the cable outer sheath, and the first reflection signal is the reflection signal generated by the first incident signal reflected by the cable outer sheath. The second detection device is set at the second end of the target detection section. The second detection signal at least includes a second incident signal and a second reflection signal. The second incident signal is the incident signal injected by the second detection device into the cable outer sheath, and the second reflection signal is the reflection signal generated by the second incident signal reflected by the cable outer sheath. Based on the first detection signal and the second detection signal, the damaged position of the target detection section is determined. This device can effectively monitor and locate the damaged position of the outer sheath without interrupting the operation of the cable and without stripping the cable from the line for detection. The detection operation process is simple, which improves the operation safety and maintenance efficiency of the system.

[0108] It should be noted that the above modules can be implemented by software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all located in the same processor; or the above modules are located in different processors in any combination.

[0109] Optionally, in addition to the above-mentioned acquisition module 42 and determination module 44, other modules may also be included. For example, the cable outer sheath damage detection and positioning device also includes a filtering module, which is used to automatically eliminate the reflected signals generated at both ends of the target detection segment; a communication module, which is used to transmit the signal data in real-time through wired or wireless means. The detection results and information are transmitted to a remote monitoring center or the cloud, etc.

[0110] According to an embodiment of the present invention, a computer program product is also provided, including a computer program. When the computer program is executed by a processor, the steps in any one of the above-mentioned embodiments of the method for detecting and locating damage of a cable outer sheath are implemented.

[0111] An embodiment of the present invention further provides a computer program product, which is configured to execute the steps in any of the above-mentioned cable outer sheath damage detection and positioning method embodiments.

[0112] Optionally, in this embodiment, the computer program is configured to perform the following steps:

[0113] Step S1, obtaining a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device being arranged at a first end of a target detection section of an outer sheath of a cable, the first detection signal at least comprising a first incident signal and a first reflected signal, the first incident signal being an incident signal injected into the outer sheath of the cable by the first detection device, the first reflected signal being a reflected signal generated by reflection of the first incident signal by the cable, the second detection device being arranged at a second end of the target detection section, the second detection signal at least comprising a second incident signal and a second reflected signal, the second incident signal being an incident signal injected into the outer sheath of the cable by the second detection device, the second reflected signal being a reflected signal generated by reflection of the second incident signal by the cable;

[0114] Step S2: determining a damaged position of the target detection segment based on the first detection signal and the second detection signal.

[0115] An embodiment of the present invention further provides a storage medium, in which a computer program is stored, wherein the computer program is configured to execute the steps of any of the above method embodiments when running.

[0116] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0117] Step S1, obtaining a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device being arranged at a first end of a target detection section of an outer sheath of a cable, the first detection signal at least comprising a first incident signal and a first reflected signal, the first incident signal being an incident signal injected into the outer sheath of the cable by the first detection device, the first reflected signal being a reflected signal generated by reflection of the first incident signal by the cable, the second detection device being arranged at a second end of the target detection section, the second detection signal at least comprising a second incident signal and a second reflected signal, the second incident signal being an incident signal injected into the outer sheath of the cable by the second detection device, the second reflected signal being a reflected signal generated by reflection of the second incident signal by the cable;

[0118] Step S2: determining a damaged position of the target detection segment based on the first detection signal and the second detection signal.

[0119] Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0120] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0121] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0122] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0123] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0124] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0125] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for detecting and locating damage of a cable outer sheath, characterized in that: The method comprises the following steps: Acquire a first detection signal of a first detection device and a second detection signal of a second detection device, wherein the first detection device is disposed at a first end of a target detection section of the cable outer sheath, the first detection signal at least includes a first incident signal and a first reflected signal, the first incident signal is an incident signal injected into the cable outer sheath by the first detection device, and the first reflected signal is a reflected signal generated by the reflection of the first incident signal by the cable, the second detection device is disposed at a second end of the target detection section, the second detection signal at least includes a second incident signal and a second reflected signal, the second incident signal is an incident signal injected into the cable outer sheath by the second detection device, and the second reflected signal is a reflected signal generated by the reflection of the second incident signal by the cable; Based on the first detection signal and the second detection signal, a damaged position of the target detection segment is determined.

2. The method according to claim 1, characterized in that: Before acquiring the second detection signal, the method further includes the following steps: Acquire the first detection signal; Based on the first detection signal, determining whether the target detection segment is damaged; When it is determined that the target detection segment is damaged, the second detection signal is acquired.

3. The method according to claim 2, characterized in that Determining a damaged position of the target detection segment based on the first detection signal and the second detection signal includes: Based on the second detection signal, determining whether the target detection segment is damaged; When it is determined that the target detection segment is damaged, a damaged position of the target detection segment is determined based on the first detection signal and the second detection signal.

4. The method according to claim 1, characterized in that During the process of acquiring the first detection signal of the first detection device and the second detection signal of the second detection device, the cable remains in a running state.

5. The method according to claim 2, characterized in that: The first detection device includes a first signal generator and a first oscilloscope, and obtaining the first detection signal includes the following steps: Connecting the first detection device to any two phases of a first grounding box, wherein the first grounding box is disposed at a first end of the target detection section; The first signal generator is used to generate a first incident signal, and the first incident signal is injected into the first grounding box, so that the first incident signal enters the outer sheath of the cable along the first grounding box and is reflected by the cable to generate a first reflected signal; The first incident signal and the first reflected signal are collected using the first oscilloscope.

6. The method according to claim 5, characterized in that The second detection device includes a second signal generator and a second oscilloscope, and obtaining the second detection signal includes the following steps: Connecting the second detection device to any two phases of a second grounding box, the second grounding box being disposed at a second end of the target detection section; Generate a second incident signal by the second signal generator, and inject the second incident signal into the second grounding box, so that the second incident signal enters the outer sheath of the cable along the second grounding box and is reflected by the cable to generate a second reflected signal; The second incident signal and the second reflected signal are collected by the second oscilloscope.

7. The method according to claim 6, characterized in that Determining a damaged position of the target detection segment based on the first detection signal and the second detection signal comprises the following steps: Based on the first detection signal, a first fault distance S is determined A , the first fault distance is the distance between the damage point and the first end of the target detection segment; Based on the second detection signal, determine the second fault distance S B , the second fault distance is the distance between the damaged point and the second end of the target detection segment; Obtaining a preset distance L, where the preset distance L is the distance between the first grounding box and the second grounding box; Based on the preset distance L, the first fault distance S A and the second fault distance S B , determine the location information of the damaged point.

8. A cable outer sheath damage detection and positioning device, characterized in that: include: an acquisition module, the acquisition module being used to acquire a first detection signal of a first detection device and a second detection signal of a second detection device, the first detection device being arranged at a first end of a target detection section of the cable outer sheath, the first detection signal comprising at least a first incident signal and a first reflected signal, the first incident signal being an incident signal injected into the cable outer sheath by the first detection device, the first reflected signal being a reflected signal generated by the reflection of the first incident signal by the cable outer sheath, the second detection device being arranged at a second end of the target detection section, the second detection signal comprising at least a second incident signal and a second reflected signal, the second incident signal being an incident signal injected into the cable outer sheath by the second detection device, the second reflected signal being a reflected signal generated by the reflection of the second incident signal by the cable outer sheath; A determination module is used to determine a damaged position of the target detection segment based on the first detection signal and the second detection signal.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the cable outer sheath damage detection and positioning method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the computer-readable storage medium is controlled, and the device in which the program is located executes the cable outer sheath damage detection and positioning method as claimed in any one of claims 1 to 7.

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