A method and system for detecting faults in a single-core multi-loop high voltage cable system

Abstract

The application discloses a kind of detection single-core multi-loop high-voltage cable system fault method and system include, every fixed distance to single-core multi-loop high-voltage cable add one auxiliary detection module, auxiliary detection module is used to obtain access loop current parameter, voltage parameter and travelling wave signal parameter;According to the current parameter in loop and voltage parameter, combined with fault judgment criterion, obtain first fault judgment result;According to first fault judgment result, combined with travelling wave signal parameter and fault location criterion, obtain second fault judgment result, according to first fault judgment result and second fault judgment result complete fault detection.Through the identification of online cable fault type, reduce the cost of maintenance inspection, improve cable fault repair efficiency.

Description

Technical Field

[0001] This invention relates to the field of fault detection technology for single-core multi-circuit high-voltage cable systems, and particularly to a method and system for detecting faults in single-core multi-circuit high-voltage cable systems. Background Technology

[0002] With the rapid development of my country's economy, the load density of urban power grids is increasing. Due to the advantages of cables, such as good conductivity and heat resistance, large transmission capacity, lightweight structure, easy bending, simple accessory joints, and convenient installation, they are increasingly widely used in high-voltage distribution networks. Especially in urban power grids, to improve the urban landscape and enhance power supply reliability, there is a demand to increase the proportion of cables and bury main power lines underground, leading to the widespread adoption of cross-linked polyethylene power cables for high-voltage and medium-voltage transmission and distribution lines.

[0003] Currently, most cities in China use a three-tiered power grid structure of 110kV, 10kV, and 380V. A significant number of 110kV cross-linked polyethylene (XLPE) power cable lines are already in operation, and this number is increasing annually. However, because power cables are laid underground in a relatively harsh operating environment, sudden power outages and fire hazards caused by cable faults occur frequently each year. This not only causes huge losses to industrial and agricultural production but also disrupts people's daily lives. Therefore, reducing high-voltage power cable faults is of paramount importance for ensuring the safe and reliable operation of urban power distribution networks. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the aforementioned existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a method and system for detecting faults in a single-core multi-circuit high-voltage cable system, which can solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for detecting faults in a single-core multi-circuit high-voltage cable system, comprising:

[0008] An auxiliary detection module is installed at fixed intervals on the single-core multi-circuit high-voltage cable. The auxiliary detection module is used to acquire the current parameters, voltage parameters and traveling wave signal parameters in the access circuit.

[0009] Based on the current and voltage parameters in the circuit, and combined with the fault judgment criteria, the first fault judgment result is obtained;

[0010] Based on the first fault judgment result, combined with the traveling wave signal parameters and fault location criteria, a second fault judgment result is obtained, and fault detection is completed based on the first fault judgment result and the second fault judgment result.

[0011] As a preferred embodiment of the method for detecting faults in a single-core multi-circuit high-voltage cable system according to the present invention, the step of installing an auxiliary detection module at fixed intervals on the single-core multi-circuit high-voltage cable includes:

[0012] An auxiliary detection module is installed at the beginning and end of each loop. The fixed intervals are determined by the length of the loop and the required accuracy for fault detection after determining the beginning and end positions of each loop, and are expressed by the following formula:

[0013]

[0014] Where, N g The value represents a fixed distance, S represents the distance between the start and end positions of each loop, M represents the number of auxiliary detection modules installed, and J represents the required accuracy value.

[0015] In a preferred embodiment of the method for detecting faults in a single-core multi-circuit high-voltage cable system according to the present invention, the fault judgment criteria include:

[0016] Under normal operating conditions, the polarity and amplitude of the initial transient current in the conductor layer of the line are obtained. If a fault occurs in the line and the polarity of the initial transient current in the conductor layer is reversed, it is initially identified as a main insulation fault. Then, the current amplitude of the conductor layer is obtained.

[0017] If the current amplitude of the conductor layer changes by more than 50% after the fault occurs, it is determined that a main insulation fault has occurred.

[0018] Under normal operating conditions, the polarity of the initial transient current and the voltage amplitude in the armor layer of the line are obtained. If a fault occurs in the line and the polarity of the initial transient current in the armor layer is reversed, it is initially identified as an outer sheath fault. Then, the initial and final transient voltage amplitudes are obtained.

[0019] If the initial and final transient voltage amplitudes exhibit voltage distortion after a fault occurs, then an outer sheath fault is considered to have occurred at this time.

[0020] In a preferred embodiment of the method for detecting faults in a single-core multi-circuit high-voltage cable system according to the present invention, the step of obtaining a second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, includes:

[0021] The fault location criteria include obtaining the arrival time of the traveling wave of each auxiliary detection module of the circuit when the fault occurs, determining the three auxiliary detection modules with the shortest time, and the three auxiliary detection modules must be three adjacent auxiliary detection modules, denoted as auxiliary detection modules A, A+1 and A+2, and the time when the first traveling wave arrives at the three auxiliary detection modules is denoted as T1, T2 and T3.

[0022] If T1>T3>T2, then the fault occurs between auxiliary detection modules A+1 and A+2. The specific fault location is indicated as follows:

[0023]

[0024] Where G1 is the distance to the auxiliary detection module A+1;

[0025] If T3 > T1 > T2, then the fault occurs between auxiliary detection modules A and A+1. The specific fault location is indicated as follows:

[0026]

[0027] Where G2 is the distance from the auxiliary detection module A+1;

[0028] If T1 = T3 > T2, then the fault occurs at the auxiliary detection module A+1, and the specific fault location is the location of the auxiliary detection module A+1.

[0029] In a preferred embodiment of the method for detecting faults in a single-core multi-circuit high-voltage cable system according to the present invention, the fault location criteria further include:

[0030] If T1>T3>T2, then the fault occurs between auxiliary detection modules A+1 and A+2. The specific location of the fault in the entire loop is represented as follows:

[0031]

[0032] Among them, T g This is the distance from the starting position of the loop.

[0033] In a preferred embodiment of the method for detecting faults in a single-core multi-circuit high-voltage cable system according to the present invention, the fault location criteria further include:

[0034] If T3 > T1 > T2, then the fault occurs between auxiliary detection modules A and A+1. The specific fault location in the entire loop is represented as follows:

[0035]

[0036] Among them, T g The distance from the starting position of the loop;

[0037] If T1 = T3 > T2, then the fault occurs at the auxiliary detection module A+1. The specific fault location in the entire loop is represented as follows:

[0038] T g = (k-1)·N g

[0039] Where k represents the number of auxiliary detection modules that have been installed in front of auxiliary detection module A+2.

[0040] In a preferred embodiment of the method for detecting faults in a single-core multi-circuit high-voltage cable system according to the present invention, the step of obtaining a second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, further includes:

[0041] If the first fault judgment result is that a main insulation fault has occurred, after determining the specific location of the fault according to the fault location criteria, the coordinates of the specific location of the main insulation fault are sent to the operation and maintenance personnel. The coordinates consist of the specific label of the auxiliary detection module and the specific distance from that label.

[0042] When the fault is to the left of the auxiliary detection module, the distance is negative; when the fault is to the right of the auxiliary detection module, the distance is positive.

[0043] After obtaining the coordinate information, the maintenance personnel rush to the site to confirm whether the fault is a short circuit between the conductor and the metal sheath. If so, they return confirmation information to the server, perform maintenance on the fault, and send a completion message after the maintenance is completed.

[0044] If not, a false alarm message is returned to the server, and the server re-evaluates the fault.

[0045] If the first fault judgment result is that an outer sheath fault has occurred, after determining the specific location of the fault according to the fault location criteria, the coordinates of the specific location of the outer sheath fault are sent to the maintenance personnel. The coordinates consist of the specific label of the auxiliary detection module and the specific distance from that label.

[0046] When the fault is to the left of the auxiliary detection module, the distance is negative; when the fault is to the right of the auxiliary detection module, the distance is positive.

[0047] After obtaining the coordinate information, the maintenance personnel rush to the site to confirm whether the fault is due to damage to the outer sheath insulation, causing the metal sheath to be directly grounded. If so, they return confirmation information to the server, perform maintenance on the fault, and send a completion message after the maintenance is completed.

[0048] If not, a false alarm message is returned to the server, and the server re-evaluates the fault.

[0049] A system for detecting faults in a single-core multi-circuit high-voltage cable system, characterized in that it includes an auxiliary installation module, a first judgment module, and a second judgment module.

[0050] An auxiliary installation module is provided, which is used to install an auxiliary detection module at fixed intervals on a single-core multi-circuit high-voltage cable. The auxiliary detection module is used to acquire the current parameters, voltage parameters, and traveling wave signal parameters in the access circuit.

[0051] The first judgment module is used to obtain a first fault judgment result based on the current parameters and voltage parameters in the circuit and the fault judgment criteria.

[0052] The second judgment module is used to obtain a second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, and to complete fault detection based on the first fault judgment result and the second fault judgment result.

[0053] A computer device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the method described above.

[0054] A computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of the method described above.

[0055] The beneficial effects of this invention are as follows: This invention proposes a method and system for detecting faults in a single-core multi-circuit high-voltage cable system. An auxiliary detection module is installed at fixed intervals on the single-core multi-circuit high-voltage cable. The auxiliary detection module acquires current parameters, voltage parameters, and traveling wave signal parameters in the connected circuit. Based on the current and voltage parameters in the circuit, and combined with fault judgment criteria, a first fault judgment result is obtained. Based on the first fault judgment result, and combined with the traveling wave signal parameters and fault location criteria, a second fault judgment result is obtained. Fault detection is completed based on the first and second fault judgment results. By identifying the types of online cable faults, the cost of maintenance and inspection is reduced, and the efficiency of cable fault repair is improved. Attached Figure Description

[0056] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0057] Figure 1 A method and system flowchart for detecting faults in a single-core multi-circuit high-voltage cable system, as provided in one embodiment of the present invention;

[0058] Figure 2 This invention provides a method for detecting faults in a single-core multi-circuit high-voltage cable system and the fault current in each layer of the fault phase of the system, as an embodiment of the present invention.

[0059] Figure 3 This invention provides a method for detecting faults in a single-core multi-circuit high-voltage cable system and the current waveform of the three-phase circuit conductor layer of the system, as an embodiment of the present invention.

[0060] Figure 4 This invention provides a method for detecting faults in a single-core multi-circuit high-voltage cable system and the fault current in each layer of the fault phase of the system, as an embodiment of the present invention.

[0061] Figure 5 This invention provides a method for detecting faults in a single-core multi-circuit high-voltage cable system and the three-phase circuit armor layer current waveform of the system, as an embodiment of the present invention.

[0062] Figure 6 This invention provides a method for detecting faults in a single-core multi-circuit high-voltage cable system and an internal structural diagram of the computer equipment used in the system. Detailed Implementation

[0063] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0064] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0065] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0066] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0067] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0068] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] Example 1

[0070] Reference Figure 1-6 This is the first embodiment of the present invention, which provides a method and system for detecting faults in a single-core multi-circuit high-voltage cable system, comprising:

[0071] An auxiliary detection module is installed at fixed intervals on the single-core multi-circuit high-voltage cable. The auxiliary detection module is used to obtain the current parameters, voltage parameters and traveling wave signal parameters in the access circuit.

[0072] The installation of an auxiliary detection module at fixed intervals for single-core multi-circuit high-voltage cables includes installing one auxiliary detection module at the beginning and end of each circuit. The fixed intervals are determined by the circuit length and the required accuracy for fault detection, after determining the beginning and end positions of each circuit, and are expressed by the following formula:

[0073]

[0074] Where, N g The value represents a fixed distance, S represents the distance between the start and end positions of each loop, M represents the number of auxiliary detection modules installed, and J represents the required accuracy value.

[0075] Furthermore, based on the current and voltage parameters in the circuit, combined with the fault judgment criteria, the first fault judgment result is obtained;

[0076] The fault judgment criteria include obtaining the polarity and amplitude of the initial transient current in the conductor layer of the line under normal operating conditions. If a fault occurs in the line and the polarity of the initial transient current in the conductor layer is opposite, it is initially identified as a main insulation fault, and then the current amplitude of the conductor layer is obtained.

[0077] It should be noted that if the current amplitude of the conductor layer changes by more than 50% after the fault occurs, it is considered that a main insulation fault has occurred.

[0078] Furthermore, the polarity of the initial transient current and the voltage amplitude in the armor layer of the line under normal operating conditions are obtained. If a fault occurs in the line and the polarity of the initial transient current in the armor layer is reversed, it is initially identified as an outer sheath fault. Then, the initial transient and final transient voltage amplitudes are obtained.

[0079] It should be noted that if the initial transient and final transient voltage amplitudes show voltage distortion after the fault occurs, then the outer sheath fault is considered to have occurred at this time.

[0080] Furthermore, based on the first fault judgment result, combined with the traveling wave signal parameters and fault location criteria, a second fault judgment result is obtained, and fault detection is completed based on the first fault judgment result and the second fault judgment result.

[0081] The second fault judgment result, obtained based on the first fault judgment result, combined with the traveling wave signal parameters and fault location criteria, includes:

[0082] Furthermore, the fault location criteria include obtaining the arrival time of the traveling wave of each auxiliary detection module in the circuit when the fault occurs, determining the three auxiliary detection modules with the shortest time, and the three auxiliary detection modules must be three adjacent auxiliary detection modules, denoted as auxiliary detection modules A, A+1 and A+2, and the time when the first traveling wave arrives at the three auxiliary detection modules is denoted as T1, T2 and T3.

[0083] It should be noted that if T1>T3>T2, the fault occurs between auxiliary detection modules A+1 and A+2, and the specific fault location is indicated as follows:

[0084]

[0085] Where G1 is the distance to the auxiliary detection module A+1;

[0086] It should be noted that if T3 > T1 > T2, the fault occurs between auxiliary detection modules A and A+1, and the specific fault location is indicated as follows:

[0087]

[0088] Where G2 is the distance from the auxiliary detection module A+1;

[0089] It should be noted that if T1 = T3 > T2, then the fault occurs at the auxiliary detection module A+1, and the specific fault location is the location of the auxiliary detection module A+1.

[0090] It should be noted that if T1>T3>T2, the fault occurs between auxiliary detection modules A+1 and A+2. The specific location of the fault in the entire loop is represented as follows:

[0091]

[0092] Among them, T g This is the distance from the starting position of the loop.

[0093] It should be noted that if T3>T1>T2, the fault occurs between auxiliary detection modules A and A+1. The specific fault location in the entire loop is represented as follows:

[0094]

[0095] Among them, T g The distance from the starting position of the loop;

[0096] It should be noted that if T1 = T3 > T2, the fault occurs at the auxiliary detection module A+1. The specific fault location in the entire loop is represented as follows:

[0097] T g = (k-1)·N g

[0098] Where k represents the number of auxiliary detection modules that have been installed in front of auxiliary detection module A+2.

[0099] Furthermore, based on the first fault diagnosis result, combined with the traveling wave signal parameters and fault location criteria, the second fault diagnosis result also includes:

[0100] It should be noted that if the first fault judgment result is that a main insulation fault has occurred, after determining the specific location of the fault according to the fault location criteria, the coordinates of the specific location of the main insulation fault are sent to the operation and maintenance personnel. The coordinates consist of the specific label of the auxiliary detection module and the specific distance from that label.

[0101] It should be noted that when the fault is to the left of the auxiliary detection module, the distance is negative; when the fault is to the right of the auxiliary detection module, the distance is positive.

[0102] It should be noted that after obtaining the coordinate information, the maintenance personnel will go to the site to confirm whether the fault is a short circuit between the conductor and the metal sheath. If so, they will return confirmation information to the server, perform maintenance on the fault, and send a completion message after the maintenance is completed.

[0103] It should be noted that if not, a misjudgment information will be returned to the server, and the server will re-evaluate the fault.

[0104] Furthermore, if the first fault judgment result is that the outer sheath has failed, after determining the specific location of the fault according to the fault location criteria, the coordinates of the specific location of the outer sheath fault are sent to the maintenance personnel. The coordinates consist of the specific label of the auxiliary detection module and the specific distance from that label.

[0105] It should be noted that when the fault is to the left of the auxiliary detection module, the distance is negative; when the fault is to the right of the auxiliary detection module, the distance is positive.

[0106] It should be noted that after obtaining the coordinate information, the maintenance personnel will rush to the site to confirm whether the fault is due to the damage to the outer sheath insulation, causing the metal sheath to be directly grounded. If so, they will return confirmation information to the server, perform maintenance on the fault, and send a completion message after the maintenance is completed.

[0107] If not, a false alarm message is returned to the server, and the server re-evaluates the fault.

[0108] It should be noted that the initial transient current in the conductor of the faulty line has the same polarity as the initial transient current in the metallic sheath of the faulty phase, but the opposite polarity to the initial transient current in the armor layer of the faulty phase. Furthermore, the fault current in the conductor of the faulty phase varies greatly. This indicates a short circuit between the conductor and the metallic sheath, resulting in a main insulation fault in the cable.

[0109] It should be noted that the initial transient current in the conductor of the faulty line does not change. The polarity of the initial transient current in the metallic sheath of the faulty phase is opposite to that in the armor layer of the faulty phase, and the amplitudes of both the fault current in the metallic sheath and the current in the armor layer change significantly. This indicates that the outer sheath fault occurs in the directly grounded metallic sheath cable due to damage to the outer sheath insulation.

[0110] In a preferred embodiment, a system for detecting faults in a single-core multi-circuit high-voltage cable system includes an auxiliary installation module, a first judgment module, and a second judgment module.

[0111] The auxiliary installation module is used to install an auxiliary detection module at fixed intervals on a single-core multi-circuit high-voltage cable. The auxiliary detection module is used to obtain the current parameters, voltage parameters and traveling wave signal parameters in the access circuit.

[0112] The first judgment module is used to obtain the first fault judgment result based on the current parameters and voltage parameters in the circuit and the fault judgment criteria.

[0113] The second judgment module is used to obtain a second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, and to complete the fault detection based on the first fault judgment result and the second fault judgment result.

[0114] The above-mentioned unit modules can be embedded in the processor of the computer device in hardware form or independent of it, or they can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of the above modules.

[0115] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6 As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for detecting faults in a single-core, multi-circuit high-voltage cable system. The display screen can be an LCD screen or an e-ink display screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0116] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0117] An auxiliary detection module is installed at fixed intervals on the single-core multi-circuit high-voltage cable. The auxiliary detection module is used to obtain the current parameters, voltage parameters and traveling wave signal parameters in the access circuit.

[0118] Based on the current and voltage parameters in the circuit, and combined with the fault judgment criteria, the first fault judgment result is obtained;

[0119] Based on the first fault judgment result, combined with the traveling wave signal parameters and fault location criteria, the second fault judgment result is obtained, and the fault detection is completed based on the first fault judgment result and the second fault judgment result.

[0120] Example 2

[0121] Reference Figure 2-5 As an embodiment of the present invention, a method and system for detecting faults in a single-core multi-circuit high-voltage cable system are provided. To verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0122] Based on the analysis of the single-core cable structure, the faults of 110kV high-voltage single-core transmission cables are divided into main insulation faults (i.e., short circuit between conductor and metal sheath) and outer sheath insulation faults (i.e., the metal sheath is directly grounded due to damage to the outer sheath insulation). Simulation models of main insulation faults and outer sheath insulation faults are established using PSCAD software.

[0123] 1. When a main insulation fault occurs in a cable, the current in the fault phase conductor layer, the current in the metallic sheath, and the current in the armor layer are as follows: Figure 2 As shown, the initial transient current in the conductor of the faulty line has the same polarity as the initial transient current in the metallic sheath of the faulty phase, but opposite in polarity to the initial transient current in the armor layer of the faulty phase. Furthermore, the amplitudes of the fault current in the conductor, the fault current in the metallic sheath, and the current in the armor layer all vary greatly. This indicates the presence of circulating current inside the cable. This phenomenon accelerates the aging of the cable's metallic sheath and armor layer, reducing their service life.

[0124] 2. When a main insulation fault occurs in a cable, the initial transient current in the conductor layer of the faulty line is as follows: Figure 3 As shown, the polarity of the initial transient current in the conductor layer is opposite to that in the conductor layer of the non-faulty phase. Moreover, the current amplitude of the conductor layer of the faulty phase in this line varies greatly. The peak current of the non-faulty phase is 1.797A, while the current of the metal sheath of the faulty phase is 122.96A, which is 68.43 times greater.

[0125] 3. When a cable experiences an outer sheath fault, the current in the faulty phase conductor layer, the current in the metallic sheath, and the current in the armor layer are as follows: Figure 4As shown. Clearly, the initial transient current in the conductor of the faulty line does not change. The polarity of the initial transient current in the metallic sheath of the faulty phase is opposite to that in the armor layer of the faulty phase, and the amplitudes of both the fault current in the metallic sheath and the armor current change significantly. The impact on the conductor's operating state during this fault is almost negligible.

[0126] 4. When a cable experiences an outer sheath fault, the initial transient current in the armor layer of the faulty line is as follows: Figure 5 As shown, the polarity of the initial transient current in the armor layer is opposite to that in the armor layer of the non-faulty phase, and voltage distortion occurs in the initial transient and the final transient.

[0127] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

[0128] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0129] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0130] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0131] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0132] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0133] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for detecting faults in a single-core multi-circuit high-voltage cable system, characterized in that, include, An auxiliary detection module is installed at fixed intervals on the single-core multi-circuit high-voltage cable. The auxiliary detection module is used to acquire the current parameters, voltage parameters and traveling wave signal parameters in the access circuit. Based on the current and voltage parameters in the circuit, and combined with the fault judgment criteria, the first fault judgment result is obtained; Based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, a second fault judgment result is obtained, and the fault detection is completed based on the first fault judgment result and the second fault judgment result. The method of installing an auxiliary detection module at fixed intervals on the single-core multi-circuit high-voltage cable includes, An auxiliary detection module is installed at the beginning and end of each loop. The fixed intervals are determined by the length of the loop and the required accuracy for fault detection after determining the beginning and end positions of each loop, and are expressed by the following formula: in, Indicates a fixed distance value. This indicates the distance between the start and end positions of each loop. Indicates the number of auxiliary detection modules installed. Indicates the required precision value; The fault judgment criteria include: Under normal operating conditions, the polarity and amplitude of the initial transient current in the conductor layer of the line are obtained. If a fault occurs in the line and the polarity of the initial transient current in the conductor layer is reversed, it is initially identified as a main insulation fault. Then, the current amplitude of the conductor layer is obtained. If the current amplitude of the conductor layer changes by more than 50% after the fault occurs, it is determined that a main insulation fault has occurred. Under normal operating conditions, the polarity of the initial transient current and the voltage amplitude in the armor layer of the line are obtained. If a fault occurs in the line and the polarity of the initial transient current in the armor layer is reversed, it is initially identified as an outer sheath fault. Then, the initial and final transient voltage amplitudes are obtained. If the initial transient and final transient voltage amplitudes exhibit voltage distortion after the fault occurs, it is determined that an outer sheath fault has occurred at this time. The step of obtaining the second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, includes: The fault location criteria include obtaining the arrival time of the traveling wave of each auxiliary detection module of the circuit when the fault occurs, determining the three auxiliary detection modules with the shortest time, and the three auxiliary detection modules must be three adjacent auxiliary detection modules, denoted as auxiliary detection modules A, A+1 and A+2, and the time when the first traveling wave arrives at the three auxiliary detection modules is denoted as T1, T2 and T3. If T1>T3>T2, then the fault occurs between auxiliary detection modules A+1 and A+2. The specific fault location is indicated as follows: in, This is the distance from the auxiliary detection module A+1; If T3 > T1 > T2, then the fault occurs between auxiliary detection modules A and A+1. The specific fault location is indicated as follows: in, This is the distance from the auxiliary detection module A+1; If T1=T3>T2, then the fault occurs at the auxiliary detection module A+1, and the specific fault location is the location of the auxiliary detection module A+1.

2. The method for detecting faults in a single-core multi-circuit high-voltage cable system as described in claim 1, characterized in that, The fault location criteria also include If T1>T3>T2, then the fault occurs between auxiliary detection modules A+1 and A+2. The specific location of the fault in the entire loop is represented as follows: in, This is the distance from the starting position of the loop.

3. The method for detecting faults in a single-core multi-circuit high-voltage cable system as described in claim 2, characterized in that, The fault location criteria also include If T3 > T1 > T2, then the fault occurs between auxiliary detection modules A and A+1. The specific fault location in the entire loop is represented as follows: in, The distance from the starting position of the loop; If T1 = T3 > T2, then the fault occurs at the auxiliary detection module A+1. The specific fault location in the entire loop is represented as follows: Where k represents the number of auxiliary detection modules that have been installed in front of auxiliary detection module A+2.

4. The method for detecting faults in a single-core multi-circuit high-voltage cable system as described in claim 3, characterized in that: The step of obtaining the second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, further includes: If the first fault judgment result is that a main insulation fault has occurred, after determining the specific location of the fault according to the fault location criteria, the coordinates of the specific location of the main insulation fault are sent to the operation and maintenance personnel. The coordinates consist of the specific label of the auxiliary detection module and the specific distance from that label. When the fault is to the left of the auxiliary detection module, the distance is negative; when the fault is to the right of the auxiliary detection module, the distance is positive. After obtaining the coordinate information, the maintenance personnel rush to the site to confirm whether the fault is a short circuit between the conductor and the metal sheath. If so, they return confirmation information to the server, perform maintenance on the fault, and send a completion message after the maintenance is completed. If not, a false alarm message is returned to the server, and the server re-evaluates the fault. If the first fault judgment result is that an outer sheath fault has occurred, after determining the specific location of the fault according to the fault location criteria, the coordinates of the specific location of the outer sheath fault are sent to the maintenance personnel. The coordinates consist of the specific label of the auxiliary detection module and the specific distance from that label. When the fault is to the left of the auxiliary detection module, the distance is negative; when the fault is to the right of the auxiliary detection module, the distance is positive. After obtaining the coordinate information, the maintenance personnel rush to the site to confirm whether the fault is due to damage to the outer sheath insulation, causing the metal sheath to be directly grounded. If so, they return confirmation information to the server, perform maintenance on the fault, and send a completion message after the maintenance is completed. If not, a false alarm message is returned to the server, and the server re-evaluates the fault.

5. A system for applying the method for detecting faults in a single-core multi-circuit high-voltage cable system as described in claim 1, characterized in that: This includes an auxiliary installation module, a first judgment module, and a second judgment module. An auxiliary installation module is provided, which is used to install an auxiliary detection module at fixed intervals on a single-core multi-circuit high-voltage cable. The auxiliary detection module is used to acquire the current parameters, voltage parameters, and traveling wave signal parameters in the access circuit. The first judgment module is used to obtain a first fault judgment result based on the current parameters and voltage parameters in the circuit and the fault judgment criteria. The second judgment module is used to obtain a second fault judgment result based on the first fault judgment result, combined with the traveling wave signal parameters and the fault location criteria, and to complete fault detection based on the first fault judgment result and the second fault judgment result.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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