Distribution line fault point distance measurement method based on panoramic information

Abstract

The invention provides a distribution line fault point distance measurement method based on panoramic information, and relates to the technical field of power systems. The distribution line fault point distance measurement method based on panoramic information comprises the steps that a first terminal acquires first time under the condition that a distribution line generates fault electromagnetic waves; under the condition that the at least two second terminals obtain the second time, the at least two second time is transmitted to the first terminal; the first terminal determines a first distance according to the line topology information, the wave velocity of the fault electromagnetic wave, the first time and the at least two second times; and the first terminal determines a third terminal and a fourth terminal adjacent to the fault point location according to the first distance and the line topology information, and determines a target distance between the fault point location and the third terminal, and the third terminal and the fourth terminal are terminals in the first terminal and the at least two second terminals. According to the invention, when the fault electromagnetic wave is generated in the distribution line, the fault point location generated by the fault electromagnetic wave is positioned.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method for measuring the distance to a distribution line fault point based on panoramic information. Background Art

[0002] As a hub connecting the transmission side and the power consumption side, the safe and stable operation of the distribution network is of great significance to the power supply.

[0003] Once a distribution line fault occurs, the corresponding protection action is activated, tripping the faulty section. At this point, the fault point needs to be located and repaired manually to restore power. Therefore, how to quickly and accurately identify the fault point of the distribution line has become an urgent problem to be solved. Summary of the Invention

[0004] This application aims to solve one of the technical problems existing in the prior art or related technologies.

[0005] To this end, the present application proposes a method for measuring the distance to a distribution line fault point based on panoramic information.

[0006] In view of this, according to the present application, a distribution line fault point ranging method based on panoramic information is proposed, which is applied to a distribution system. The distribution system includes a first terminal and at least two second terminals. The first terminal and the at least two second terminals are arranged on the distribution line, and the first terminal is located at the outlet position of the distribution line. The distribution line fault point ranging method based on panoramic information includes: when a fault electromagnetic wave is generated in the distribution line, the first terminal obtains a first time, and the first time is the time when the fault electromagnetic wave is transmitted to the first terminal; when the at least two second terminals obtain the second time, they respectively transmit at least two second times to the first terminal, and the at least two second times are the time when the fault electromagnetic wave is transmitted to the at least two second terminals; the first terminal determines a first distance based on line topology information, the wave velocity of the fault electromagnetic wave, the first time and the at least two second times, where the first distance is the electrical distance between the fault point and the first terminal, and the fault point is the point where the fault electromagnetic wave is generated; the first terminal determines a third terminal and a fourth terminal adjacent to the fault point based on the first distance and the line topology information, and determines a target distance between the fault point and the third terminal, where the third terminal and the fourth terminal are terminals among the first terminal and the at least two second terminals.

[0007] In this technical solution, when a fault electromagnetic wave is generated in a distribution line, it is transmitted along the distribution line to a first terminal and at least two second terminals, allowing the first terminal and at least two second terminals to capture electromagnetic wave information about the fault electromagnetic wave. The first terminal can record the first time the fault electromagnetic wave is transmitted to the first terminal, and the at least two second terminals can respectively record the second time the fault electromagnetic wave is transmitted to each second terminal. It should be noted that during the distance measurement process of the distribution line, the data processing process can be performed entirely by the first terminal. Therefore, after the second terminal obtains the corresponding second time, it transmits the second time to the first terminal.

[0008] In this technical solution, the line topology information records the topology of the distribution line and is stored in the first terminal. This topology information includes the adjacency matrix of the distribution line, the electrical distance from the first terminal to each second terminal, and path information for each distribution branch. The adjacency matrix reflects the topological location of the first terminal and each second terminal in the distribution line. The velocity of the fault electromagnetic wave is the velocity of the electromagnetic wave of the current in the distribution line.

[0009] In this technical solution, the first terminal can determine the target branch in the distribution line where the fault point is located based on the calculated first distance and line topology information, that is, the two ends of the target branch are the third terminal and the fourth terminal respectively, and the third terminal and the fourth terminal are terminals between the first terminal and the at least two second terminals. It should be noted that the number of two-end ranging results is at least two, and the at least two two-end ranging results correspond one-to-one to the at least two second terminals. The maximum value of the at least two two-end ranging results is used as the first distance, and the second terminal corresponding to the first distance can be determined. Based on the line topology information and the second terminal corresponding to the first distance, the first terminal can determine the target branch in the distribution line where the fault point is located, and determine the target distance between the fault point and the third terminal at the head end of the target branch.

[0010] In the technical solution of the present application, when a fault electromagnetic wave is generated in a distribution line, the first terminal can record the first time when the fault electromagnetic wave is transmitted to the first terminal, and at least two corresponding second times when the fault electromagnetic wave is transmitted to at least two second terminals, and at least two second terminals can transmit the obtained second time to the first terminal for processing. The first terminal is based on the principle of D-type electromagnetic waves, and uses the first time of arrival of the fault electromagnetic wave at the first terminal to calculate the second time of each second terminal one by one, obtains the two-end ranging results between the multiple second terminals and the first terminal, and selects the maximum value thereof to determine the first distance, and uses the first distance as the distance from the fault point to the first terminal. Then, the first terminal determines the path information of the distribution branch from the first terminal to each second terminal based on the line topology information, and converts the first distance of the preliminary ranging result into the target branch where the fault point is located, and the target distance between the fault point and the third terminal at the starting point of the target branch according to the path information of the distribution branch, and uses the target distance as the positioning result of the fault point, so as to achieve the effect of locating the fault point generated by the fault electromagnetic wave when the fault electromagnetic wave is generated in the distribution line.

[0011] In some technical solutions, optionally, the first terminal determines the first distance based on line topology information, a wave velocity of the fault electromagnetic wave, the first time, and at least two second times, including:

[0012] The first terminal determines at least two second distances based on line topology information, wave velocity, the first time, and at least two second times, where the at least two second distances are dual-end ranging results between the first terminal and the second terminal. The first terminal extracts the maximum value of the at least two second distances and determines it as the first distance.

[0013] In this technical solution, the at least two second distances are dual-end ranging results corresponding one-to-one to the at least two terminals, and the first distance is the maximum value of the at least two second distances.

[0014] In this technical solution, at least two second distances correspond to at least two second terminals one by one. The maximum value among the at least two second distances is selected as the preliminary distance measurement result, that is, the first distance is used as the distance from the fault point to the first terminal.

[0015] In the technical solution of the present application, the first terminal calculates the first time and the second time according to the principle of electromagnetic waves to obtain a two-end ranging result between multiple second terminals and the first terminal, that is, at least two second distances, and selects the maximum value of the at least two second distances to determine the first distance, and uses the first distance as the preliminary ranging result, that is, the distance from the fault point to the first terminal, thereby completing the preliminary ranging of the fault point that generates the fault electromagnetic wave relative to the first terminal.

[0016] In some technical solutions, optionally, the first terminal determines at least two second distances respectively according to the line topology information, the wave velocity, the first time, and the at least two second times, including:

[0017] At least two third distances between the at least two second terminals and the first terminal are determined according to the line topology information; and at least two second distances are determined according to the at least two third distances, wave velocity, the first time, and the at least two second times.

[0018] In this technical solution, the line topology information includes third distances between the first terminal and each second terminal. In the process of calculating the ranging results between the first terminal and each second terminal based on the dual-end ranging principle, at least two third distances are respectively used as the full length of the ranging line.

[0019] In the technical solution of the present application, based on the third distance between the first terminal and each second terminal, as well as the wave velocity, the first time and the at least two second times and the first formula, the second distance between the first terminal and the at least two second terminals, that is, the dual-end ranging result, can be accurately calculated to improve the accuracy of subsequent positioning of the fault point.

[0020] In some technical solutions, optionally, after the first terminal determines a third terminal and a fourth terminal adjacent to the fault point based on the first distance and the line topology information, and determines a target distance between the fault point and the third terminal, the method for measuring the fault point of a distribution line based on panoramic information further includes:

[0021] The first terminal determines, based on the location information of the third terminal and the fourth terminal, a third time and a fourth time among the at least two second times of the first time, wherein the third time is the time when the fault electromagnetic wave is transmitted to the third terminal, and the fourth time is the time when the fault electromagnetic wave is transmitted to the fourth terminal; the first terminal determines, based on the third time and the fourth time, a fourth distance between the fault point and the third terminal; and the first terminal verifies and updates the target distance based on the fourth distance.

[0022] In this technical solution, since corresponding terminals are configured at the head and end positions of each distribution branch in the distribution line, the terminal at the head end position of the target branch is determined as the third terminal, and the terminal at the end position of the target branch is determined as the fourth terminal.

[0023] In this technical solution, since the first terminal has already obtained the second time corresponding to each second terminal, after determining the third and fourth terminals at both ends of the target branch, the first terminal can determine the third time corresponding to the third terminal and the fourth time corresponding to the fourth terminal. Based on the third and fourth times, a two-terminal ranging calculation is then performed on the third and fourth terminals to obtain a fourth distance, which represents the electrical distance between the fault location and the third terminal.

[0024] In the technical solution of the present application, the target distance is the electrical distance between the fault point obtained by preliminary positioning and the third terminal at the head end of the target branch, and the fourth distance is the electrical distance between the fault point and the third terminal obtained by double-end ranging based on the third terminal and the fourth terminal on the target branch. It can be seen that the fourth distance and the target distance are both the distances between the third terminal and the fault point, and the calculation method of the target distance and the fourth distance is different, so the target distance can be verified and updated by the fourth distance, thereby improving the accuracy of the final target distance, thereby improving the accuracy of the ranging.

[0025] In some technical solutions, optionally, the first terminal determines a fourth distance between the fault location and the third terminal based on the third time and the fourth time, including:

[0026] The line length between the third terminal and the fourth terminal is determined according to the line topology information; and the fourth distance is determined according to the line length, the third time, the fourth time, and the wave velocity.

[0027] In the technical solution of the present application, the terminals at the beginning and end of the target branch are the third terminal and the fourth terminal respectively. Therefore, the electrical distance between the third terminal and the fourth terminal is the branch length of the target branch.

[0028] In the technical solution of the present application, in the process of performing two-end ranging on the third terminal and the fourth terminal, the branch length of the target branch is used as the electrical distance between the third terminal and the fourth terminal, and the branch length, the third time, the fourth time and the wave velocity are substituted into the second formula to obtain the fourth distance, thereby further improving the accuracy of line ranging.

[0029] In some technical solutions, optionally, the first terminal verifies and updates the target distance according to the fourth distance, including:

[0030] The first terminal calculates a distance difference between the target distance and the fourth distance; if the distance difference is less than a difference threshold, the target distance is updated based on the fourth distance; if the distance difference is greater than or equal to the difference threshold, it is determined that the target distance is incorrect, and the process returns to executing the steps of the first terminal obtaining the first time and at least two second terminals obtaining the second time.

[0031] In this technical solution, the target distance is used as the positioning result of one fault point, and the fourth distance is used as the positioning result of another fault point. By calculating the distance difference between the target distance and the fourth distance and comparing the distance difference with the difference threshold, the accuracy of the fault point positioning based on dual-end ranging can be verified.

[0032] Specifically, when the distance difference is less than the difference threshold, it is determined that the difference between the target distance and the fourth distance is small, that is, the calculation results of the two different calculation processes are similar, and the ranging process is determined to be relatively accurate. At this time, the target distance is updated using the fourth distance to further improve the accuracy of the updated target distance. When the distance difference is greater than or equal to the difference threshold, it is determined that the difference between the target distance and the fourth distance is large, that is, the calculation results of the two different calculation processes are far apart, and the ranging process is determined to be inaccurate. At this time, the first terminal returns to the step of obtaining the first time, and the second terminal returns to the step of obtaining the second time. The second terminal retransmits the re-acquired second time to the first terminal.

[0033] In the technical solution of the present application, the accuracy of the ranging result is judged by whether the distance difference between the target distance and the fourth distance is less than the difference threshold. If the ranging result is determined to be accurate, the target distance updated by the fourth distance is used as the final ranging result. Otherwise, the ranging is determined to have failed and the ranging is performed again, thereby further improving the accuracy of the final target distance.

[0034] In some technical solutions, optionally, updating the target distance based on the fourth distance includes: determining an average value of the distances between the fourth distance and the target distance as the updated target distance.

[0035] In the technical solution of the present application, in the process of updating the target distance through the fourth distance, the average distance between the fourth distance and the target distance is calculated, and the average distance is determined as the updated target distance. That is, by calculating the average of the distances obtained by two different methods, the updated target distance can be obtained, which further improves the accuracy of the distance measurement of the distribution line.

[0036] In some technical solutions, optionally, determining an average value of the distances between the fourth distance and the target distance as the updated target distance includes uploading the updated target distance to the master station.

[0037] In the technical solution of the present application, the branch information including the target branch and the updated target distance as the final ranging result are uploaded to the main station as the ranging result. The main station system can determine the target branch where the fault point is located based on the branch information, and determine the specific location of the fault point on the target branch based on the updated target distance.

[0038] In some technical solutions, optionally, the power distribution line includes a multi-segmented and multi-branched radial power distribution line.

[0039] In the technical solution of this application, the distribution lines have characteristics such as multiple segments, multiple branches, radial topology, and complex T-connected lines. In order to achieve the requirements of accurately and quickly locating the fault points where fault electromagnetic waves are generated in the distribution lines, multiple terminal devices need to be distributed in the distribution lines. The setting principle is to be at the beginning and end of each line, at reasonable sections on long-distance trunk lines, and at each branch node, so as to improve the accuracy of locating the fault points where fault electromagnetic waves are generated in the distribution lines.

[0040] In some technical solutions, optionally, the fault point includes the fault point, and the fault electromagnetic wave includes the fault initial electromagnetic wave.

[0041] In the technical solution of the present application, when a fault occurs in the distribution line, the fault point will generate an initial fault electromagnetic wave. The distance measurement method of the present application can determine the distance between the fault point and the third terminal located at the head end of the target branch, thereby accurately locating the fault point.

[0042] Additional aspects and advantages of the present application will become apparent in the following description or may be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0044] Figure 1 A flow chart of a method for measuring the distance to a distribution line fault point based on panoramic information provided in some embodiments of the present application is shown;

[0045] Figure 2 One of the schematic diagrams of a power distribution system provided in some embodiments of the present application is shown;

[0046] Figure 3 shows a double-end distance principle diagram provided in some embodiments of the present application;

[0047] Figure 4 A flow chart of a method for locating a power distribution line fault provided in some embodiments of the present application is shown;

[0048] Figure 5 A second schematic diagram of a power distribution system provided in some embodiments of the present application is shown. DETAILED DESCRIPTION

[0049] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the features of this embodiment and the embodiments can be combined with each other.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0051] Refer to the following Figures 1 to 5 A method for measuring fault points in a power distribution line based on panoramic information according to some embodiments of the present application is described.

[0052] According to one embodiment of the present application, Figure 1 A flow chart of a method for measuring the distance to a distribution line fault point based on panoramic information is shown in some embodiments of the present application. Figure 1 As shown, a distribution line fault point distance measurement method based on panoramic information is proposed, which is applied to a distribution system. The distribution system includes a first terminal and at least two second terminals. The first terminal and the at least two second terminals are arranged on the distribution line. The first terminal is located at the outlet position of the distribution line.

[0053] Figure 2 One of the schematic diagrams of the power distribution system provided in some embodiments of the present application is shown, Figure 2 As shown, the distribution line 202 in the distribution system 200 includes multiple distribution branches, such as: branch one, branch two, branch three, branch four and branch five, the first terminal 204 is set at the outlet position of the distribution line, and multiple second terminals 206 are set at intervals on the distribution line 202, and a distribution branch is formed between the first terminal 204 and any two adjacent terminals among the multiple second terminals 206.

[0054] In this embodiment, in order to achieve the requirement of accurate and rapid positioning of the fault point generating the fault electromagnetic wave in the distribution line, the first terminal and the second terminal need to be distributed in the distribution line. Figure 2 As shown, the distribution branch between the master terminal T1 and the slave terminal T2 is branch one, the distribution branch between the slave terminal T2 and the slave terminal T3 is branch two, the distribution branch between the master terminal T1 and the slave terminal T4 is branch three, the distribution branch between the slave terminal T4 and the slave terminal T5 is branch four, and the distribution branch between the slave terminal T4 and the slave terminal T6 is branch five.

[0055] like Figure 1 As shown, the method for measuring the fault point of a distribution line based on panoramic information includes:

[0056] Step 102: When a fault electromagnetic wave is generated in a power distribution line, the first terminal obtains a first time, where the first time is the time when the fault electromagnetic wave is transmitted to the first terminal.

[0057] Step 104: After obtaining the second time, the at least two second terminals transmit the at least two second times to the first terminal respectively, where the at least two second times are the time when the fault electromagnetic wave is transmitted to the at least two second terminals;

[0058] In this embodiment, when a fault electromagnetic wave is generated in a distribution line, the fault electromagnetic wave is transmitted along the distribution line to a first terminal and at least two second terminals, so that the first terminal and the at least two second terminals can each capture electromagnetic wave information of the fault electromagnetic wave. The first terminal can record the first time the fault electromagnetic wave is transmitted to the first terminal, and the at least two second terminals can each record the second time the fault electromagnetic wave is transmitted to each second terminal. It should be noted that during the distance measurement process of the distribution line, the data processing process can be performed entirely by the first terminal. Therefore, after the second terminal obtains the corresponding second time, it transmits the second time to the first terminal.

[0059] For example, a first measuring point is provided at the first terminal, and a second measuring point is correspondingly provided at each second terminal. The first terminal can determine the time when the fault electromagnetic wave is transmitted to the first terminal as T1 through the first measuring point, and each second measuring point can determine the corresponding second time as T2, ... T n , the second terminal transmits the second time to the first terminal.

[0060] Step 106: The first terminal determines a first distance based on the line topology information, the velocity of the fault electromagnetic wave, the first time, and at least two second times. The first distance is the electrical distance between the fault point and the first terminal. The fault point is the point where the fault electromagnetic wave is generated.

[0061] In this embodiment, the line topology information records the topology of the distribution line and is stored in the first terminal. The line topology information includes the adjacency matrix of the distribution line, the electrical distance from the first terminal to each second terminal, and path information for each distribution branch. The adjacency matrix can reflect the topological location of the first terminal and each second terminal in the distribution line. The velocity of the fault electromagnetic wave is the velocity of the electromagnetic wave of the current in the distribution line.

[0062] Figure 3 The double-end distance principle diagram provided in some embodiments of the present application is shown as follows: Figure 3 As shown in the figure, based on the two-terminal ranging algorithm, the time difference between the fault electromagnetic wave reaching the measurement points at both ends of the distribution line is used to calculate the location of the fault point. The calculation formula (1) is as follows:

[0063] ; (1)

[0064] in, Indicates the distance between the fault point and measurement point 1, L is the total length of the line, and They represent the time when the fault electromagnetic wave reaches the line measurement point 1 and measurement point 2 respectively, and v is the wave velocity of the fault electromagnetic wave.

[0065] In this embodiment, the electrical distance between the first terminal and each second terminal is used as the total line length L in the above formula (1), and the second time and the first time are used as t1 and t2 in the above formula (1) for calculation. The two-terminal ranging results between the first terminal and each second terminal can be obtained, and the maximum value of the two-terminal ranging results is used as the first distance.

[0066] In step 108, the first terminal determines a third terminal and a fourth terminal adjacent to the fault point based on the first distance and the line topology information, and determines a target distance between the fault point and the third terminal. The third terminal and the fourth terminal are terminals among the first terminal and the at least two second terminals.

[0067] In this embodiment, the first terminal can determine the target branch in the distribution line where the fault point is located based on the calculated first distance and line topology information, that is, the two ends of the target branch are the third terminal and the fourth terminal respectively, and the third terminal and the fourth terminal are terminals between the first terminal and the at least two second terminals. It should be noted that the number of two-end ranging results is at least two, and the at least two two-end ranging results correspond one-to-one to the at least two second terminals. The maximum value of the at least two two-end ranging results is used as the first distance, and the second terminal corresponding to the first distance can be determined. Based on the line topology information and the second terminal corresponding to the first distance, the first terminal can determine the target branch in the distribution line where the fault point is located, and determine the target distance between the fault point and the third terminal at the head end of the target branch.

[0068] It should be noted that the panoramic information includes a variety of information on the distribution line, including: the time for the fault electromagnetic wave to be transmitted to the first terminal and at least two second terminals, the wave velocity of the fault electromagnetic wave, voltage information, current information, and information at each switch on the distribution line.

[0069] For example, the number q of the second terminal corresponding to the first distance is recorded, and the number of the fourth terminal at the end of the distribution branch where the fault point is located is known. , can be read to the first terminal With the second terminal The sequential path information of each branch passed between the two nodes can be obtained from the stored adjacency matrix, and the length of each sequential branch passed can be calculated and converted into the branch number s of the target branch where the fault point is located, and the target distance from the third terminal at the head end of the branch. .

[0070] In an embodiment of the present application, when a fault electromagnetic wave is generated in a distribution line, the first terminal can record the first time when the fault electromagnetic wave is transmitted to the first terminal, and at least two corresponding second times when the fault electromagnetic wave is transmitted to at least two second terminals, and at least two second terminals can transmit the acquired second time to the first terminal for processing. The first terminal is based on the principle of D-type electromagnetic waves, and uses the first time of arrival of the fault electromagnetic wave of the first terminal to calculate the second time of each second terminal one by one, obtains the two-end ranging results between the multiple second terminals and the first terminal, and selects the maximum value thereof to determine the first distance, and uses the first distance as the distance from the fault point to the first terminal. Then, the first terminal determines the path information of the distribution branch from the first terminal to each second terminal based on the line topology information, and converts the first distance of the preliminary ranging result into the target branch where the fault point is located, and the target distance between the fault point and the third terminal at the starting point of the target branch according to the path information of the distribution branch, and uses the target distance as the positioning result of the fault point, so as to achieve the effect of locating the fault point generated by the fault electromagnetic wave when a fault electromagnetic wave is generated in the distribution line.

[0071] In some embodiments, optionally, the first terminal determines the first distance based on line topology information, a wave velocity of the fault electromagnetic wave, the first time, and at least two second times, including:

[0072] The first terminal determines at least two second distances based on line topology information, wave velocity, the first time, and at least two second times, where the at least two second distances are dual-end ranging results between the first terminal and the second terminal. The first terminal extracts the maximum value of the at least two second distances and determines it as the first distance.

[0073] In this embodiment, the at least two second distances are dual-end ranging results corresponding one-to-one to the at least two terminals, and the first distance is the maximum value of the at least two second distances.

[0074] In this embodiment, the at least two second distances correspond to the at least two second terminals one-to-one. The maximum value among the at least two second distances is selected as the preliminary distance measurement result, that is, the first distance is taken as the distance from the fault point to the first terminal.

[0075] For example, the expression (2) of the first distance is as follows:

[0076] ; (2)

[0077] in, is the first distance, These are at least two second distances corresponding to at least two second terminals respectively.

[0078] In an embodiment of the present application, the first terminal calculates the first time and the second time according to the principle of electromagnetic waves to obtain a two-end ranging result between multiple second terminals and the first terminal, that is, at least two second distances, and selects the maximum value of the at least two second distances to determine the first distance, and uses the first distance as the preliminary ranging result, that is, the distance from the fault point to the first terminal, thereby completing the preliminary ranging of the fault point that generates the fault electromagnetic wave relative to the first terminal.

[0079] In some embodiments, optionally, the first terminal determines at least two second distances respectively according to the line topology information, the wave velocity, the first time, and the at least two second times, including:

[0080] At least two third distances between the at least two second terminals and the first terminal are determined according to the line topology information; and at least two second distances are determined according to the at least two third distances, wave velocity, the first time, and the at least two second times.

[0081] In this embodiment, the line topology information includes third distances between the first terminal and each second terminal. In the process of respectively calculating the ranging results between the first terminal and each second terminal based on the dual-end ranging principle, at least two third distances are respectively used as the full length of the ranging line.

[0082] In an embodiment of the present application, based on the third distance between the first terminal and each second terminal, as well as the wave velocity, the first time and the at least two second times and the first formula, the second distance between the first terminal and the at least two second terminals can be accurately calculated, that is, the two-end ranging result, thereby improving the accuracy of subsequent positioning of the fault point.

[0083] Exemplarily, the first equation (3) includes:

[0084] ; (3)

[0085] in, is the second distance, is the third distance, is the wave speed, For the second time, For the first time.

[0086] In the embodiment of the present application, the electromagnetic wave speed is , at least two third distances corresponding to at least two second terminals and at least two second times , and the first time of the first terminal , are substituted into the above first formula (3) in sequence, and the two-terminal ranging results of at least two second terminals and the first terminal can be accurately calculated. , further improving the accuracy of the dual-end ranging results, thereby improving the accuracy of subsequent line ranging of the fault point.

[0087] In some embodiments, optionally, after the first terminal determines a third terminal and a fourth terminal adjacent to the fault point based on the first distance and the line topology information, and determines a target distance between the fault point and the third terminal, the method for measuring the fault point of a power distribution line based on panoramic information further includes:

[0088] The first terminal determines, based on the location information of the third terminal and the fourth terminal, a third time and a fourth time among the at least two second times of the first time, wherein the third time is the time when the fault electromagnetic wave is transmitted to the third terminal, and the fourth time is the time when the fault electromagnetic wave is transmitted to the fourth terminal; the first terminal determines, based on the third time and the fourth time, a fourth distance between the fault point and the third terminal; and the first terminal verifies and updates the target distance based on the fourth distance.

[0089] In this embodiment, since the head and end positions of each distribution branch in the distribution line are configured with corresponding terminals, the terminal at the head end position of the target branch is determined as the third terminal, and the terminal at the end position of the target branch is determined as the fourth terminal.

[0090] Exemplarily, the first terminal obtains two terminal devices M and N corresponding to the head and end of the target branch s according to the stored branch information of each branch in the distribution branch, where M is the terminal corresponding to the head end of the target branch s, and N is the terminal corresponding to the end end of the target branch s.

[0091] In this embodiment, since the first terminal has already obtained the second time corresponding to each second terminal, after determining the third and fourth terminals at both ends of the target branch, the first terminal can determine the third time corresponding to the third terminal and the fourth time corresponding to the fourth terminal. Based on the third and fourth times, a two-terminal ranging calculation is then performed on the third and fourth terminals to obtain a fourth distance, which represents the electrical distance between the fault location and the third terminal.

[0092] In an embodiment of the present application, the target distance is the electrical distance between the fault point obtained by preliminary positioning and the third terminal at the head end of the target branch, and the fourth distance is the electrical distance between the fault point and the third terminal obtained by double-end ranging based on the third terminal and the fourth terminal on the target branch. It can be seen that the fourth distance and the target distance are both the distances between the third terminal and the fault point, and the calculation method of the target distance and the fourth distance is different, so the target distance can be verified and updated by the fourth distance, thereby improving the accuracy of the final target distance, thereby improving the accuracy of the ranging.

[0093] In some embodiments, optionally, the first terminal determines a fourth distance between the fault location and the third terminal based on the third time and the fourth time, including:

[0094] The line length between the third terminal and the fourth terminal is determined according to the line topology information; and the fourth distance is determined according to the line length, the third time, the fourth time, and the wave velocity.

[0095] In the embodiment of the present application, the terminals at the beginning and end of the target branch are the third terminal and the fourth terminal respectively. Therefore, the electrical distance between the third terminal and the fourth terminal is the branch length of the target branch.

[0096] In an embodiment of the present application, in the process of performing two-end ranging on the third terminal and the fourth terminal, the branch length of the target branch is used as the electrical distance between the third terminal and the fourth terminal, and the branch length, the third time, the fourth time and the wave velocity are substituted into the second formula to obtain the fourth distance, thereby further improving the accuracy of line ranging.

[0097] In some embodiments, optionally, the second equation (4) includes:

[0098] ; (4)

[0099] in, is the fourth distance, For the third time, For the fourth time, is the branch length of the target branch, is the wave speed.

[0100] In the embodiment of the present application, the electromagnetic wave speed is , the branch length of the target branch and the third time corresponding to the third terminal, as well as the fourth time corresponding to the fourth terminal, can accurately calculate the dual-end ranging result of the third terminal and the fourth terminal, and use the dual-end ranging result as the fourth distance between the third terminal and the fault point, further improving the accuracy of line ranging.

[0101] In some embodiments, optionally, the first terminal verifies and updates the target distance according to the fourth distance, including:

[0102] The first terminal calculates a distance difference between the target distance and the fourth distance; if the distance difference is less than a difference threshold, the target distance is updated based on the fourth distance; if the distance difference is greater than or equal to the difference threshold, it is determined that the target distance is incorrect, and the process returns to executing the steps of the first terminal obtaining the first time and at least two second terminals obtaining the second time.

[0103] In this embodiment, the target distance is used as the positioning result of one fault point, and the fourth distance is used as the positioning result of another fault point. By calculating the distance difference between the target distance and the fourth distance, and comparing the distance difference with the difference threshold, the accuracy of the fault point positioning based on dual-end ranging can be verified.

[0104] Specifically, when the distance difference is less than the difference threshold, it is determined that the difference between the target distance and the fourth distance is small, that is, the calculation results of the two different calculation processes are similar, and the ranging process is determined to be relatively accurate. At this time, the target distance is updated using the fourth distance to further improve the accuracy of the updated target distance. When the distance difference is greater than or equal to the difference threshold, it is determined that the difference between the target distance and the fourth distance is large, that is, the calculation results of the two different calculation processes are far apart, and the ranging process is determined to be inaccurate. At this time, the first terminal returns to the step of obtaining the first time, and the second terminal returns to the step of obtaining the second time. The second terminal retransmits the re-acquired second time to the first terminal.

[0105] For example, the accuracy of the ranging process is determined by the following relational expression (5). If the following relational expression (5) is satisfied, it is determined that the ranging process is correct.

[0106] ; (5)

[0107] in, is the target distance, is the fourth distance, and L is the difference threshold, that is, the preset electromagnetic wave ranging difference tolerance.

[0108] In the embodiment of the present application, the accuracy of the ranging result is judged by whether the distance difference between the target distance and the fourth distance is less than the difference threshold. If the ranging result is determined to be accurate, the target distance updated by the fourth distance is used as the final ranging result. Otherwise, the ranging is determined to have failed and the ranging is performed again, thereby further improving the accuracy of the final target distance.

[0109] In some embodiments, optionally, updating the target distance based on the fourth distance includes: determining an average value of the distances between the fourth distance and the target distance as the updated target distance.

[0110] In an embodiment of the present application, in the process of updating the target distance through the fourth distance, the average distance between the fourth distance and the target distance is calculated, and the average distance is determined as the updated target distance. That is, by calculating the average of the distances obtained by two different methods, the updated target distance can be obtained, which further improves the accuracy of the distance measurement of the distribution line.

[0111] In some embodiments, optionally, determining an average value of the distances between the fourth distance and the target distance as the updated target distance includes uploading the updated target distance to the master station.

[0112] In an embodiment of the present application, the branch information including the target branch and the updated target distance as the final ranging result are uploaded to the main station as the ranging result. The main station system can determine the target branch where the fault point is located based on the branch information, and determine the specific location of the fault point on the target branch based on the updated target distance.

[0113] Exemplarily, the line topology information includes at least one of the following:

[0114] adjacency matrix, electrical distance between a first terminal and at least two second terminals, and path information of at least two distribution branches in a distribution line.

[0115] In an embodiment of the present application, the line topology information includes an adjacency matrix of static topology information between each terminal on the distribution line. The line topology information also includes the electrical distance between the first terminal and at least two second terminals. The line topology information also includes the path information of each distribution branch in the distribution line, and the line topology information is stored in the first terminal, which facilitates the first terminal to locate the fault point based on the line topology information.

[0116] Exemplarily, the adjacency matrix (6) includes:

[0117] ; (6)

[0118] in, is an adjacency matrix, where i and j represent the rows and columns of the matrix, respectively. w represents the electrical distance between two adjacent terminals. 0 indicates that the diagonal elements of the matrix, i.e., the rows and columns, coincide, and ∞ indicates that the two terminals are not adjacent. A first terminal stores static topological information between the first terminal and at least two second terminals on a distribution line by storing the adjacency matrix. This adjacency matrix can be used to determine the positional relationships between multiple terminals.

[0119] In some embodiments, optionally, the power distribution line comprises a multi-segment and multi-branch radial power distribution line.

[0120] In the embodiments of the present application, the distribution lines have characteristics such as multiple segments, multiple branches, radial topology, and complex T-connections. In order to accurately and quickly locate the fault point where the distribution line generates fault electromagnetic waves, multiple terminal devices need to be distributed throughout the distribution line. The arrangement principle is to be at the beginning and end of each line, at reasonable sections on long-distance trunk lines, and at each branch node, so as to improve the accuracy of locating the fault point where the fault electromagnetic waves are generated in the distribution line.

[0121] In some embodiments, optionally, the fault point includes the fault point, and the fault electromagnetic wave includes the fault initial electromagnetic wave.

[0122] In an embodiment of the present application, when a fault occurs in the distribution line, the fault point will generate an initial fault electromagnetic wave. The distance measurement method of the present application can determine the distance between the fault point and the third terminal located at the head end of the target branch, thereby accurately locating the fault point.

[0123] Figure 4 FIG. 1 shows a flow chart of a method for locating a distribution line fault provided in some embodiments of the present application. Figure 4 As shown, the distribution line fault location method based on electromagnetic wave ranging includes:

[0124] Step 402, setting parameters such as the length of each distribution branch in the distribution line, the trunk line length, and the wave speed;

[0125] The line topology information in any of the above embodiments includes parameters such as the length of the distribution branch line and the length of the trunk line.

[0126] Step 404: When a fault occurs, the time when the initial electromagnetic wave of the fault reaches each terminal is obtained;

[0127] In the embodiment of the present application, the time of arrival at each terminal includes a first time of arrival at the first terminal and a second time of arrival at each second terminal.

[0128] Step 406: Calculate the fault distance Dn between the first terminal and each second terminal respectively according to the principle of two-terminal ranging;

[0129] In the embodiment of the present application, the fault distance Dn is the second distance in any of the above embodiments.

[0130] Step 408: Select the maximum value from the multiple fault distances as the preliminary fault location result, that is, the distance Lp from the fault point to the first terminal;

[0131] In the embodiment of the present application, the preliminary fault location result is the first distance in any of the above embodiments.

[0132] Step 410: Convert Lp into branch information of the target branch where the fault point is located and the distance Ls between the fault point and the starting point of the target branch according to the pre-stored distribution branch path from the second terminal to the first terminal;

[0133] In the embodiment of the present application, Ls is the target distance in any of the above embodiments;

[0134] Step 412: Obtain the third terminal M and the fourth terminal N at both ends of the target branch where the fault point is located according to the branch information of the target branch, and calculate the distance L between the fault point and the third terminal M according to Tm and Tn. M , L M is the fourth distance in any of the above embodiments.

[0135] In the embodiment of the present application, Tm is the third time in any of the above embodiments, and Tn is the fourth time in any of the above embodiments;

[0136] Step 414: Determine whether If the result is yes, execute step 416, otherwise return to execute step 402;

[0137] Step 416, upload (L S +L M ) / 2 and the branch information of the target branch.

[0138] Figure 5 The second schematic diagram of the power distribution system provided in some embodiments of the present application is shown as follows: Figure 5 As shown, the master terminal T1 is the first terminal, and the slave terminals T2, T3, T4, T5, and T6 are the second terminals. Arrow A shows the transmission direction of the fault initial electromagnetic wave, and arrow B shows the transmission direction of the arrival time of the fault initial electromagnetic wave transmitted from the slave terminals T2, T3, T4, T5, and T6 to the master terminal T1. When a fault occurs, the master terminal T1 obtains the time when the fault initial electromagnetic wave reaches the master terminal T1, and receives the time when the fault initial electromagnetic wave sent by the slave terminals T2, T3, T4, T5, and T6 arrives at each slave terminal. Based on the principle of two-terminal ranging, the master terminal T1 calculates the fault distance between the first terminal and each second terminal respectively, selects the maximum value from the multiple fault distances as the preliminary fault location result, that is, the distance from the fault point N to the first terminal, and converts this distance into branch information of the target branch and the distance L between the fault point N and the starting point of the target branch based on the pre-stored line topology information of the distribution line. S , for example: the branch number of the branch, such as Figure 5The "branch four" in the target command is the master terminal T1. The master terminal T1 calculates the distance between the two terminals based on the arrival time of the initial electromagnetic wave of the fault of the slave terminal T4 and the arrival time of the initial electromagnetic wave of the fault of T5 at both ends of the target branch. M The master terminal T1 determines When the master terminal T1 determines that the dual-end ranging result is accurate, (L S +L M ) / 2 as the distance between the fault point N and the slave terminal T4, and the fourth branch between the slave terminal T4 and the slave terminal T5 as the target branch, and the branch number of the target branch and the distance between the fault point N and the slave terminal T4 as the positioning information of the fault point N are reported to the master station.

[0139] It should be clarified that in the claims, specification and drawings of this application, the term "plurality" refers to two or more. Unless otherwise clearly defined, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the purpose of more conveniently describing this application and making the description process simpler, and is not intended to indicate or imply that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation. Therefore, these descriptions cannot be understood as limitations on this application. The terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood based on the specific circumstances of the above data.

[0140] In the claims, specification, and drawings of this application, the terms "one embodiment," "some embodiments," "a specific embodiment," and the like mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of this application. In the claims, specification, and drawings of this application, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0141] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for measuring the distance between distribution line fault points based on panoramic information, characterized in that: Applied to a power distribution system, the power distribution system includes a first terminal and at least two second terminals, the first terminal and at least two second terminals are arranged on the power distribution line, the first terminal is located at the outlet of the power distribution line, and the power distribution line fault point distance measurement method based on panoramic information includes: In the case where a fault electromagnetic wave is generated on the power distribution line, the first terminal acquires a first time, where the first time is the time when the fault electromagnetic wave is transmitted to the first terminal; When the at least two second terminals obtain the second time, they respectively transmit the at least two second times to the first terminal, where the at least two second times are respectively the time when the fault electromagnetic wave is transmitted to the at least two second terminals; The first terminal determines a first distance based on line topology information, a wave velocity of the fault electromagnetic wave, the first time, and at least two of the second times, where the first distance is an electrical distance between a fault point and the first terminal, and the fault point is a point where the fault electromagnetic wave is generated. The first terminal determines a third terminal and a fourth terminal adjacent to the fault point based on the first distance and the line topology information, and determines a target distance between the fault point and the third terminal, where the third terminal and the fourth terminal are terminals among the first terminal and at least two second terminals.

2. The method for measuring the distance to a distribution line fault point based on panoramic information according to claim 1, characterized in that: The first terminal determines the first distance according to line topology information, the wave velocity of the fault electromagnetic wave, the first time, and at least two of the second times, including: The first terminal determines at least two second distances according to the line topology information, the wave velocity, the first time, and at least two second times, where the at least two second distances are two-end ranging results between the first terminal and the second terminal; The first terminal extracts the maximum value of at least two of the second distances and determines it as the first distance.

3. The method for measuring the distance to a distribution line fault point based on panoramic information according to claim 2, characterized in that: The first terminal determines at least two second distances respectively according to the line topology information, the wave speed, the first time, and at least two second times, including: determining, according to the line topology information, at least two third distances between at least two of the second terminals and the first terminal; At least two second distances are determined based on at least two third distances, the wave velocity, the first time, and at least two second times.

4. The method for measuring the distance to a distribution line fault point based on panoramic information according to any one of claims 1 to 3, characterized in that: After the first terminal determines a third terminal and a fourth terminal adjacent to the fault point based on the first distance and the line topology information, and determines a target distance between the fault point and the third terminal, the method for measuring the fault point of a power distribution line based on panoramic information further includes: The first terminal determines, based on the location information of the third terminal and the fourth terminal, a third time and a fourth time among the at least two second times of the first time, wherein the third time is the time when the fault electromagnetic wave is transmitted to the third terminal, and the fourth time is the time when the fault electromagnetic wave is transmitted to the fourth terminal; The first terminal determines a fourth distance between the fault point and the third terminal according to the third time and the fourth time; The first terminal verifies and updates the target distance according to the fourth distance.

5. The method for measuring the distance to a distribution line fault point based on panoramic information according to claim 4, characterized in that: The first terminal determining, based on the third time and the fourth time, a fourth distance between the fault point and the third terminal, including: determining, according to the line topology information, a line length between the third terminal and the fourth terminal; The fourth distance is determined based on the line length, the third time, the fourth time, and the wave speed.

6. The method for measuring the distance to a distribution line fault point based on panoramic information according to claim 4, characterized in that: The first terminal verifies and updates the target distance according to the fourth distance, including: Calculating, by the first terminal, a distance difference between the target distance and the fourth distance; When the distance difference is less than a difference threshold, updating the target distance based on the fourth distance; When the distance difference is greater than or equal to the difference threshold, it is determined that the target distance is incorrect, and the process returns to the step of the first terminal acquiring the first time and the at least two second terminals acquiring the second time.

7. The method for measuring the distance to a distribution line fault point based on panoramic information according to claim 6, characterized in that: The updating of the target distance based on the fourth distance includes: An average distance between the fourth distance and the target distance is determined as the updated target distance.

8. The method for measuring the distance to a distribution line fault point based on panoramic information according to claim 7, characterized in that: The step of determining an average distance between the fourth distance and the target distance as the updated target distance includes: The updated target distance is uploaded to the master station.

9. The method for measuring the distance to a distribution line fault point based on panoramic information according to any one of claims 1 to 3, characterized in that: The power distribution line comprises a multi-segment and multi-branch radial power distribution line.

10. The method for measuring the distance to a distribution line fault point based on panoramic information according to any one of claims 1 to 3, characterized in that: The fault point includes a fault point, and the fault electromagnetic wave includes a fault initial electromagnetic wave.

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