Accurate distribution line fault positioning method based on traveling wave distance measurement

Abstract

The invention discloses a power distribution line fault accurate positioning method based on a traveling wave distance measurement principle, and relates to the technical field of power system fault positioning. The method comprises the following steps: after detecting that a target distribution line has a fault, cutting off a power supply and sending a ranging traveling wave at one end of the line; identifying a terminal which firstly receives the traveling waves twice as a first target terminal, and screening out a second target terminal which only receives the traveling waves once; judging a fault path by combining the communication relationship between the first target terminal and the second target terminal; the distance of a fault point is calculated through a double-end traveling wave distance measurement principle, and the specific position of the fault point is determined in combination with line topology information. According to the method, the accuracy of fault positioning in a complex branch line is effectively improved by using the communication relation and traveling wave propagation characteristics between the power distribution terminals, and the method is particularly suitable for fault point identification near a line branch. The method is not influenced by line parameters and load changes, the communication burden is small, the distance measurement precision is high, and good practicability and popularization value are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system automation and intelligent distribution network, and specifically relates to a method for accurately locating distribution line faults based on the principle of traveling wave ranging. The method is particularly suitable for quickly identifying and locating fault points in medium and low voltage distribution lines with complex structures and numerous branches. Background Art

[0002] In power systems, distribution lines are the critical link between substations and users, and their operational reliability directly impacts power supply quality and grid security. Due to their complex structure, numerous branches, and short lengths, rapid and accurate fault location after a failure has always been a technical challenge.

[0003] Traditional fault location methods are primarily based on impedance methods or single-ended traveling wave ranging. However, these methods are susceptible to variations in line parameters, load fluctuations, and power supply characteristics, resulting in low ranging accuracy. This is particularly true in multi-branch distribution networks, where it is difficult to accurately determine whether the fault is located on the main line or a branch line. Furthermore, while some existing methods based on traveling wave ranging have improved ranging accuracy, they still exhibit significant uncertainty when addressing faults near line branches, failing to meet the distribution network's requirements for real-time and accurate fault location.

[0004] For example, Chinese patent application number CN116804694A discloses a distribution line fault location system and method. This method improves ranging accuracy by actively transmitting a traveling wave after a fault is detected, and using the time difference after the traveling wave is reflected at the fault point to perform ranging calculations. However, this solution does not fully consider the complex topology of the distribution line. In particular, when the fault point is located near the intersection of multiple branches, it can only determine the distance to a specific terminal, but cannot identify the specific fault path. This leads to ambiguous location results and still requires a large amount of manpower for on-site investigation.

[0005] Therefore, how to provide a method that can achieve high-precision and high-efficiency fault location in complex distribution networks, especially near line branch areas, has become a technical problem that needs to be solved urgently. Summary of the Invention

[0006] In order to solve the above-mentioned problems in the prior art, the present invention provides a method for accurately locating distribution line faults based on the traveling wave ranging principle. The method for accurately locating distribution line faults based on the traveling wave ranging principle combines the communication topology relationship between distribution terminals, the traveling wave propagation characteristics and the two-end ranging principle to achieve high-precision positioning of fault points in distribution lines, especially those located near line branches, and has good engineering practicality and promotion value.

[0007] The technical solution adopted in the present invention is:

[0008] A method for accurately locating distribution line faults based on the principle of traveling wave ranging. This method actively sends traveling waves after detecting a fault and uses the time information and communication relationship of multiple distribution terminals receiving the traveling waves to accurately identify and locate fault points in complex branch distribution lines.

[0009] The method for accurately locating distribution line faults based on the traveling wave ranging principle includes the following steps:

[0010] Step S110: After detecting that a fault occurs in the target distribution line, the power supply is cut off and a ranging traveling wave is sent at one end of the target distribution line;

[0011] Step S120: Identify the first distribution terminal on the target distribution line that receives two traveling waves as the first target terminal; the two traveling waves are a ranging traveling wave and a reflected traveling wave formed by reflection from the fault point;

[0012] Step S130: Among the adjacent power distribution terminals that have established communication connections with the first target terminal, select a terminal that has received only one traveling wave as the second target terminal;

[0013] Step S140: Determine whether the number of the second target terminal is one; if it is one, execute S150; otherwise, execute S160;

[0014] Step S150: determining target fault line information according to the device identifications of the first target terminal and the only second target terminal;

[0015] Step S160: determining multiple possible faulty lines according to the device identifiers of the first target terminal and multiple second target terminals, and taking the union or intersection of the lines to determine target faulty line information.

[0016] Furthermore, in step S110, the ranging traveling wave is actively sent by the starting power distribution terminal after the power is cut off.

[0017] Furthermore, in step S120, the first target terminal is the first distribution terminal that receives both the ranging traveling wave and the reflected traveling wave along the line propagation direction; the first target terminal is located upstream of the fault point and closest to the fault point.

[0018] Furthermore, in step S130, the second target terminal receives only one reflected traveling wave but no ranging traveling wave, indicating that the second target terminal is located downstream of the fault point; based on the fact that the first target terminal and the second target terminal can assist in determining the line segment where the fault point is located, information on the direction of the branch line is provided.

[0019] Furthermore, in S160, the determination of the union or intersection is performed based on a path analysis of the topology of the distribution lines and the communication relationship between the terminals.

[0020] Furthermore, after determining the target fault line information in step S150 or step S160, the following steps are performed:

[0021] Step S170, calculating the distance between the first target terminal and the fault point based on the time difference between the first target terminal receiving the ranging traveling wave and the reflected traveling wave and the traveling wave propagation speed;

[0022] The distance is calculated using the following formula:

[0023]

[0024] Where L is the distance between the first target terminal and the fault point; v is the propagation speed of the traveling wave in the conductor; T1 is the time when the first target terminal first receives the ranging traveling wave; T2 is the time when the first target terminal receives the reflected traveling wave for the second time;

[0025] Step S180: Determine the specific location of the fault point based on the target fault line information and distance information.

[0026] Furthermore, the distribution terminals establish communication connections between each other to transmit traveling wave arrival time information and device identification information; the master station system only needs to establish communication connections with the starting distribution terminal, the ending distribution terminal and the first target terminal.

[0027] Furthermore, the target fault line information is used to clearly determine whether the fault point is located on the main line or a branch line, thereby accurately locating the fault point near a complex branch area.

[0028] Furthermore, it also includes: multiple central distribution terminals record the time information of receiving the traveling wave; the time information is transmitted back to the starting distribution terminal step by step through the adjacent distribution terminals, and finally uploaded to the master station system.

[0029] Beneficial effects of the present invention:

[0030] The present invention provides a method for accurately locating distribution line faults based on the traveling wave ranging principle. Compared with the existing technology, it has the following significant beneficial effects:

[0031] 1. Improved fault location accuracy: By actively sending ranging traveling waves after a power outage and performing two-terminal ranging calculations based on the time difference between the ranging traveling wave received by the first target terminal and the reflected traveling wave, the system effectively avoids the impact of line parameter changes, load fluctuations, and power supply characteristics on the ranging results, significantly improving ranging accuracy.

[0032] 2. Accurately locate fault points in complex branch lines: Utilizing the communication relationship between the first and second target terminals, combined with the line topology structure to identify the fault path, it is possible to accurately determine whether the fault point is located on the main line or a branch line, resolving the problem of ambiguous positioning near line branches caused by traditional methods.

[0033] 3. Reduce the data processing burden of the master station: A two-to-two communication mechanism is adopted between distribution terminals. The master station only needs to establish communication connections with the starting distribution terminal, the ending distribution terminal, and the first target terminal. This reduces the amount of data interaction between the master station and the terminals and improves system operation efficiency.

[0034] 4. Strong adaptability and good economy: This method does not rely on a high-precision synchronous clock system. It can complete the transmission and analysis of time information using a distributed reading program, reducing equipment costs and operation and maintenance difficulties. It is suitable for various complex network structures such as medium and low voltage distribution networks.

[0035] 5. Improve troubleshooting efficiency: Fault location information can be directly output to the operation and maintenance system, assisting repair personnel to quickly locate the fault area, shorten power outage time, and improve power supply reliability.

[0036] In summary, the present invention has the advantages of high ranging accuracy, wide adaptability, and light system burden. It is particularly suitable for distribution line environments with complex structures and numerous branches, and has good engineering application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction to the drawings required for use in the embodiments will be given below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0038] Figure 1 Schematic diagram of the flow of the method for accurately locating a distribution line fault based on the traveling wave ranging principle of the present invention;

[0039] Figure 2 This is a schematic diagram of the traveling wave ranging method of the present invention;

[0040] Figure 3 and Figure 4 This is a schematic diagram of a power distribution line failure according to the present invention. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] This embodiment provides a method for accurately locating distribution line faults based on the principle of traveling wave ranging, specifically for high-precision and rapid fault location in complex distribution lines with numerous branches, particularly when the fault is located near a line branch. This method, based on the principle of traveling wave ranging, is particularly suitable for medium and low voltage distribution lines with multiple branches and complex topologies. Upon detecting a line fault, this method cuts off power and transmits a ranging traveling wave. This method, combined with the communication relationship between distribution terminals and the traveling wave propagation time information, achieves high-precision fault location, particularly suitable for situations where the fault is located near a line branch.

[0043] The distribution line fault accurate location method based on the traveling wave ranging principle relies on a complete hardware system implementation; Figure 3 and Figure 4 As shown in the figure, the system mainly includes the following hardware devices:

[0044] The master station is the core control and data analysis unit of the entire system. It is mainly responsible for: responding to the received target distribution line information; determining the starting distribution terminal and the ending distribution terminal of the line based on the information of the target distribution line; establishing and maintaining communication connections with the starting distribution terminal, the ending distribution terminal and the first target terminal identified subsequently.

[0045] In this system, the target distribution line refers to the section of the line where the potential fault point has been roughly located through preliminary fault detection. Due to the wide range of this section, direct troubleshooting is inefficient, so further precise positioning is required using traveling wave ranging technology.

[0046] Distribution terminals: Distribution terminals are installed at key nodes on distribution lines and mainly include the following three categories:

[0047] 1. Starting distribution terminal: The starting distribution terminal is an end terminal of the target distribution line; it is responsible for actively sending ranging traveling waves after power failure; receiving the time information transmitted back by the first target terminal and uploading it to the master station.

[0048] 2. Termination distribution terminal: The termination distribution terminal can be the other end terminal of the line, or the end terminal without the next level branch.

[0049] If there is only one terminating distribution terminal, it will generate the traveling wave transmission end information after receiving the traveling wave for the first time and send it back to the master station; the master station triggers the execution of the reading program according to the traveling wave transmission end information.

[0050] If there are multiple terminating distribution terminals, the starting distribution terminal generates the traveling wave return end information after receiving the reflected traveling wave for the second time, and sends it back to the master station to trigger the reading program.

[0051] 3. Central distribution terminal: The central distribution terminal is distributed between the starting distribution terminal and the ending distribution terminal; the central distribution terminal records the time of the first reception of the traveling wave, that is, the first reception time; at the same time, the central distribution terminal records: the equipment identification information of the traveling wave signal transmitted to the previous central distribution terminal; the central distribution terminal is provided with a second reception time reading mechanism, which is used to compare the time recorded by itself with the time information from other terminals.

[0052] If the second receiving time of the current terminal is earlier than the received time, the second receiving time and device identification information of the current terminal will be sent to the previous terminal; if the second receiving time of the current terminal is later than the received time, the received time and device identification information will be forwarded to the previous terminal.

[0053] Through step-by-step communication between adjacent distribution terminals, the time information of the first target terminal receiving the reflected traveling wave is eventually transmitted back to the starting distribution terminal, and then uploaded to the master station by the starting distribution terminal.

[0054] Each distribution terminal includes the following core components:

[0055] Current transformer and voltage transformer: used to collect current and voltage signals on the line;

[0056] Data acquisition and processing unit: responsible for extracting traveling wave signals;

[0057] Central Processing Unit (CPU): executes data processing and control logic within the terminal;

[0058] GPS module: achieve high-precision time synchronization;

[0059] Communication unit: supports data interaction with other distribution terminals and the master station.

[0060] The main tasks of the distribution terminal are: collection and feature extraction of traveling wave signals; recording the arrival time of the initial traveling wave of the fault; communication with the master station system; collaborative communication and time information transmission between distribution terminals.

[0061] The identification process of the first target terminal and the second target terminal of the system is as follows:

[0062] After receiving the time and device identification information uploaded by the starting power distribution terminal, the master station identifies the first target terminal according to the device identification information, that is, the first terminal that receives the ranging traveling wave and the reflected traveling wave at the same time.

[0063] Subsequently, the master station sends a target read instruction to the first target terminal;

[0064] After the first target terminal responds, the first target terminal reads the time information recorded by all adjacent distribution terminals communicating with it, and selects the terminal that has received only one traveling wave as the second target terminal;

[0065] Then, the device identifications of the first target terminal and the second target terminal, as well as the time information of the first target terminal receiving the traveling wave twice are fed back to the master station;

[0066] Finally, the master station determines the fault line path based on the above information and calculates the specific location of the fault point in combination with the distance measurement formula.

[0067] The communication mechanism of the system is as follows:

[0068] A pairwise communication mechanism is adopted between distribution terminals to ensure that time information can be efficiently transmitted between adjacent terminals.

[0069] During the entire communication process: the master station only needs to establish communication connections with the starting distribution terminal, the ending distribution terminal and the first target terminal. The information exchange between other distribution terminals is completed by the local communication network, which greatly reduces the communication and data processing pressure of the master station system.

[0070] For example, in Figure 3 In the topology shown, central distribution terminal No. 1 communicates with the starting distribution terminal, distribution terminals No. 2, No. 4, and No. 6; central distribution terminal No. 2 communicates with distribution terminals No. 3, No. 1, No. 4, and No. 6. All information is transmitted back through adjacent terminals step by step, ultimately converging to the starting distribution terminal and reporting to the master station.

[0071] In summary, the system achieves rapid and accurate identification of fault points in distribution lines, especially near complex branch areas, through efficient collaboration between the master station and distribution terminals, combined with the characteristics of traveling wave propagation and the communication relationship between distribution terminals.

[0072] Furthermore, based on the above system, Figure 1 As shown, the distribution line fault accurate location method based on the traveling wave ranging principle is performed according to the following steps:

[0073] Step S110: After detecting that a fault occurs in the target distribution line, the power supply is cut off, and a ranging traveling wave is sent at one end of the target distribution line.

[0074] The triggering condition of this step is: when the master station or the starting distribution terminal detects a short circuit, grounding or other fault on the target distribution line, it is triggered.

[0075] The operations in this step are as follows: immediately cut off the power supply and isolate the fault area; send a controllable ranging traveling wave signal at one end of the target distribution line, that is, the starting distribution terminal; the ranging traveling wave propagates along the line and generates reflection when encountering the fault point to form a reflected traveling wave.

[0076] The purpose of this step is to: cut off the power supply to avoid the influence of power supply and load changes on the ranging results, reduce the disturbance of traveling waves, and improve the stability of ranging; and obtain more accurate traveling wave propagation time information in a pure environment after power failure.

[0077] like Figure 2 As shown in the figure, after a distribution line fault occurs, only the distribution terminals upstream of the fault point can receive the ranging wave and its reflected wave, which is reflected from the fault point. For example, the first target terminal (the terminal on the left in the figure) can receive the ranging wave at T1 and the reflected wave at T2. The terminal downstream of the fault point (the terminal on the right in the figure) can only receive the reflected wave once. By recording the time difference between the two arrival waves, the distance between the first target terminal and the fault point can be calculated.

[0078] Step S120: Identify the first distribution terminal on the target distribution line that receives two traveling waves as the first target terminal; the two traveling waves are respectively a ranging traveling wave and a reflected traveling wave formed by reflection from the fault point.

[0079] The identification mechanism of this step is: each distribution terminal continuously monitors the arrival time of the traveling wave signal; the first terminal that receives both the ranging traveling wave and the reflected traveling wave is marked as the first target terminal.

[0080] The selection basis for this step is: the terminal is located upstream of the fault point and closest to the fault point, and is the only terminal that can receive two traveling waves.

[0081] The purpose of this step is to serve as the core reference point for subsequent fault path identification and distance calculation.

[0082] like Figure 3 As shown in the figure, after the starting distribution terminal sends the ranging wave, the ranging wave passes through the middle distribution terminal No. 1 and then transmits to No. 6 and the fault point. The fault point reflects it to form a reflected wave. If No. 1 receives the reflected wave first, it is selected as the first target terminal.

[0083] Step S130: Among the adjacent power distribution terminals that have established communication connections with the first target terminal, select a terminal that has received only one traveling wave as the second target terminal.

[0084] The screening criteria for this step are: only one traveling wave is received, that is, only the reflected traveling wave is received; at the same time, the original ranging traveling wave is not received.

[0085] The identification method of this step is: obtaining the traveling wave reception record of each second terminal through the communication network; filtering out the terminal that receives the traveling wave only once as the second target terminal.

[0086] The purpose of this step is to assist in determining the line segment where the fault point is located and to provide information on the direction of the branch line.

[0087] like Figure 3 As shown, terminal No. 1 is the first target terminal, and terminals No. 2 and No. 4 communicating with it can only receive the reflected traveling wave once, and are therefore determined to be the second target terminals.

[0088] Step S140: Determine whether the number of the second target terminal is one; if it is one, execute S150; otherwise, execute S160.

[0089] The logical judgment of this step is: if there is only one second target terminal, the fault point is clearly located in the branch where the terminal is located; if there are multiple second target terminals, the fault point may be located near the intersection of multiple branches.

[0090] The decision-making mechanism of this step is: the master station automatically judges based on the collected terminal information.

[0091] The purpose of this step is to distinguish fault scenarios of different complexities and adopt different strategies to handle them; and to provide a basis for subsequent path determination.

[0092] like Figure 3 As shown in FIG, if the first target terminal No. 1 has two second target terminals, such as No. 2 and No. 4, it means that the fault point may be in the intersection area of ​​multiple branches and further analysis is required.

[0093] Step S150: determining target fault line information according to the device identifiers of the first target terminal and the only second target terminal.

[0094] This step is applicable when the fault point is located on a single path.

[0095] The specific operation of this step is: according to the communication relationship between the first target terminal and the only second target terminal, the line segment where the fault point is located is determined.

[0096] The output result of this step is: obtaining a unique fault line path; then jumping to S170 to calculate the distance and locate the fault point.

[0097] like Figure 4 As shown, if there is only one second target terminal, such as No. 2 in the figure, the master station can determine that the fault point is located on the line between No. 6 and No. 2.

[0098] Step S160: determining multiple possible faulty lines according to the device identifiers of the first target terminal and multiple second target terminals, and taking the union or intersection of the lines to determine target faulty line information.

[0099] This step is applicable when the fault point is near the intersection of multiple branch lines.

[0100] The specific operations of this step are: respectively list the communication paths between the first target terminal and each second target terminal; take the intersection / union of these paths to obtain all possible fault paths; finally, further narrow the scope based on the geographical topology structure.

[0101] The result output of this step is: obtaining the minimum line set including the fault point; then jumping to S170 to perform distance calculation and final fault point location.

[0102] like Figure 3 As shown, the master station takes the union of the fault lines 1 to 2 and 1 to 4 and determines that the fault point is located in the intersection area of ​​these two lines.

[0103] Step S170, calculating the distance between the first target terminal and the fault point based on the time difference between the first target terminal receiving the ranging traveling wave and the reflected traveling wave and the traveling wave propagation speed;

[0104] The distance is calculated using the following formula:

[0105]

[0106] Where L is the distance between the first target terminal and the fault point; v is the propagation speed of the traveling wave in the conductor; T1 is the time when the first target terminal first receives the ranging traveling wave; T2 is the time when the first target terminal receives the reflected traveling wave for the second time.

[0107] The purpose of this step is to achieve high-precision single-point distance measurement and provide basic data for the next step of spatial positioning.

[0108] like Figure 3 and Figure 4 As shown in Figure 1, by calculating the time difference between terminal 1 and the fault point, the distance between it and the fault point can be obtained.

[0109] Step S180: Determine the specific location of the fault point based on the target fault line information and distance information.

[0110] This step integrates the fault distance from S170 and the target fault line information from S150 / S160.

[0111] This step is implemented by: based on the known line topology, reverse engineering along the target fault line to accurately locate the specific tower number or kilometer mark of the fault point.

[0112] The output of this step is the precise geographic location of the fault point, which can be directly used by operation and maintenance personnel to locate and repair the fault on site.

[0113] like Figure 4 As shown, No. 6 is the first target terminal and No. 2 is the second target terminal. Based on this, the master station determines that the faulty line is the line segment from No. 6 to No. 2, and determines the specific location of the fault point by combining the distance measurement formula.

[0114] Based on the above key steps of fault detection, ranging wave transmission, first target terminal identification, second target terminal screening, fault path judgment, distance calculation, and final fault point location, this distribution line fault precise location method based on the traveling wave ranging principle achieves precise location of the fault point in the distribution line, especially solving the problem that the existing technology has difficulty in accurately identifying the fault path near the line branch. This distribution line fault precise location method based on the traveling wave ranging principle uses the transmission of ranging waves after power failure to reduce interference and improve ranging accuracy; identifies the fault path through the communication relationship between the first target terminal and the second target terminal; combines the two-end ranging principle with line topology information to achieve rapid location of the fault point; the master station only needs to communicate with a small number of key terminals, reducing the system burden; and is particularly suitable for distribution line environments with complex structures and numerous branches.

[0115] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for accurately locating distribution line faults based on the principle of traveling wave ranging, characterized by: This method for accurately locating distribution line faults based on the traveling wave ranging principle actively sends a ranging traveling wave after detecting a fault, and uses the time information and communication relationship of multiple distribution terminals receiving the traveling wave to accurately identify and locate the fault point in complex branch distribution lines. The method for accurately locating distribution line faults based on the traveling wave ranging principle includes the following steps: Step S110: After detecting that a fault occurs in the target distribution line, the power supply is cut off and a ranging traveling wave is sent at one end of the target distribution line; Step S120: Identify the first distribution terminal on the target distribution line that receives two traveling waves as the first target terminal; the two traveling waves are a ranging traveling wave and a reflected traveling wave formed by reflection from the fault point; Step S130: Among the adjacent power distribution terminals that have established communication connections with the first target terminal, select a terminal that has received only one traveling wave as the second target terminal; Step S140: Determine whether the number of the second target terminal is one; if it is one, execute S150; otherwise, execute S160; Step S150: determining target fault line information according to the device identifications of the first target terminal and the only second target terminal; Step S160: determining multiple possible faulty lines according to the device identifiers of the first target terminal and multiple second target terminals, and taking the union or intersection of the lines to determine target faulty line information.

2. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1 is characterized in that: In step S110, the ranging traveling wave is actively sent by the starting power distribution terminal after power failure.

3. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1 is characterized in that: In step S120, the first target terminal is the first distribution terminal that receives both the ranging traveling wave and the reflected traveling wave along the line propagation direction; the first target terminal is located upstream of the fault point and closest to the fault point.

4. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1 is characterized in that: In step S130, the second target terminal receives only one reflected traveling wave but no ranging traveling wave, indicating that the second target terminal is located downstream of the fault point. Therefore, the first target terminal and the second target terminal can assist in determining the line segment where the fault point is located and provide information on the direction of the branch line.

5. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1 is characterized in that: In S160, the determination of the union or intersection is performed based on a path analysis of the topology of the power distribution lines and the communication relationship between the terminals.

6. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1, characterized in that: After determining the target fault line information in step S150 or step S160, the following steps are performed: Step S170, calculating the distance between the first target terminal and the fault point based on the time difference between the first target terminal receiving the ranging traveling wave and the reflected traveling wave and the traveling wave propagation speed; The distance is calculated using the following formula: Where L is the distance between the first target terminal and the fault point; v is the propagation speed of the traveling wave in the conductor; T1 is the time when the first target terminal first receives the ranging traveling wave; T2 is the time when the first target terminal receives the reflected traveling wave for the second time; Step S180: Determine the specific location of the fault point based on the target fault line information and distance information.

7. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1, characterized in that: The distribution terminals establish communication connections between each other to transmit the traveling wave arrival time information and device identification information; the master station system only needs to establish communication connections with the starting distribution terminal, the ending distribution terminal and the first target terminal.

8. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to claim 1, characterized in that: The target fault line information is used to clearly determine whether the fault point is located on the main line or a branch line, thereby accurately locating the fault point near a complex branch area.

9. The method for accurately locating distribution line faults based on the traveling wave ranging principle according to any one of claims 1 to 8, characterized in that: Also includes: Multiple central power distribution terminals record the time information of receiving the traveling wave; The time information is transmitted back to the starting distribution terminal step by step through the adjacent distribution terminals, and finally uploaded to the master station system.

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