Power distribution network fault positioning method and device, computer device and storage medium

Abstract

The application relates to a power distribution network fault positioning method and device, computer equipment and a storage medium. The method comprises the following steps: acquiring a fault type of a power distribution network and an initial fault positioning result of the power distribution network uploaded by a plurality of target detection terminals installed in the power distribution network; in the case that the fault type is a non-single-phase grounding short-circuit fault, splitting and combining one or more initial fault sections of the power distribution network contained in the initial fault positioning result to obtain a plurality of fault section combinations of the power distribution network; acquiring an expected fault section combination corresponding to each fault section combination; using each fault section combination and the initial fault positioning result to respectively correct the expected fault section combination corresponding to each fault section combination to obtain an expected state result of each fault section combination after correction; and obtaining a fault occurrence position of the power distribution network according to the expected state results after correction. The method can improve the accuracy of the fault occurrence position positioning.

Description

Technical Field

[0001] This application relates to the field of fault handling technology, and in particular to a method, apparatus, computer equipment and storage medium for locating faults in a power distribution network. Background Technology

[0002] Distribution networks are characterized by complex structures, variable operating modes, and a limited number of observable points, making them a frequent source of short-circuit faults in the entire power system. For a long time, investment and construction in my country's power industry have primarily focused on large generating units and transmission networks, severely restricting the development of fault location technologies in distribution networks. Therefore, achieving accurate fault location is extremely difficult and urgent. Accurate fault location in distribution networks is of great significance for reducing power outage time, minimizing economic losses, and improving power supply reliability.

[0003] Current methods for locating fault points in power distribution networks can be divided into three aspects: First, fault line selection, which identifies the faulty outgoing line among multiple outgoing lines of the busbar. This can only roughly determine which outgoing line is faulty and can only locate the fault area. Second, fault section location, which can determine the feeder section where the fault point is located and can locate the fault point between adjacent sectionalizing switches. Third, fault distance measurement, which can quantify the specific location of the fault point and can directly give the distance to the fault point.

[0004] However, the current fault location method has the problem of low accuracy. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, device, computer equipment, and storage medium for fault location in distribution networks that can improve the accuracy of fault location in distribution networks, in order to address the above-mentioned technical problems.

[0006] Firstly, this application provides a method for locating faults in a distribution network, the method comprising:

[0007] Obtain the fault types and initial fault location results for the distribution network uploaded by multiple target detection terminals installed in the distribution network;

[0008] In the case of a non-single-phase ground fault, one or more initial fault sections of the distribution network included in the initial fault location results are split and combined to obtain multiple fault section combinations of the distribution network.

[0009] Obtain the expected combination of fault sections corresponding to each combination of fault sections;

[0010] Using the combination of each fault segment and the initial fault location results, the expected combination of each fault segment is corrected to obtain the corrected expected state result of each fault segment combination.

[0011] Based on the corrected results of multiple expected states, the location of the fault in the distribution network is obtained.

[0012] In one embodiment, using each fault segment combination and the initial fault location result, the expected fault segment combination corresponding to each fault segment combination is corrected to obtain the corrected expected state result for each fault segment combination, including:

[0013] Compare the initial fault location results with the combinations of various expected fault segments;

[0014] If there is a location result in the fault segment combination, and the location result contained in the initial fault location result is less than or equal to the location result contained in the expected fault segment combination corresponding to the fault segment combination, then the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, no correction is performed.

[0015] If there are multiple location results in the fault segment combination, and the initial fault location result contains fewer or equal locations than the expected fault segment combination corresponding to the fault segment combination, then the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, the fault segment combination corresponding to the expected fault segment combination is removed.

[0016] In one embodiment, the location of a fault in the distribution network is determined based on multiple corrected desired state results, including:

[0017] Using the corrected expected state results, the various fault segment combinations, and the initial fault location results, the evaluation results corresponding to each fault segment combination are obtained.

[0018] By comparing multiple evaluation results, the actual fault sections of the distribution network can be determined;

[0019] Fault location is determined by fault measurement of the actual faulty section to obtain the location of the fault in the distribution network.

[0020] In one embodiment, fault location processing is performed on the actual faulty section to obtain the location of the fault in the distribution network, including:

[0021] Obtain the line type corresponding to the actual faulty section;

[0022] When the line type is a branch line, the target point is determined from the actual fault section, and the fault current signal of the target point is obtained; the target point can be any point in the actual fault section.

[0023] The evaluation value of the target point is obtained based on the phase angle of the fault current signal;

[0024] The target point corresponding to the minimum evaluation value is determined as the location of the fault.

[0025] In one embodiment, acquiring the fault current signal at the target point includes:

[0026] Acquire the fault current signal and fault voltage signal at the location of the fault;

[0027] Obtain the wave impedance and equivalent impedance of the faulty section, as well as the first impedance coefficient corresponding to the wave impedance and the second impedance coefficient corresponding to the equivalent impedance; wherein, the first impedance coefficient and the second impedance coefficient are determined based on the distance between the target point and the preset end of the faulty section.

[0028] The target impedance is obtained based on the wave impedance, the first impedance coefficient, the equivalent impedance, and the second impedance coefficient.

[0029] The fault current signal at the target point is obtained based on the fault current signal, the fault voltage signal, and the target impedance.

[0030] In one embodiment, obtaining the wave impedance of the faulty section includes:

[0031] Obtain the unit line resistance, unit line inductance, and unit line capacitance of the actual fault section;

[0032] The wave impedance is obtained from the unit line resistance, unit line inductance, and unit line capacitance.

[0033] Secondly, this application also provides a power distribution network fault location device, the device comprising:

[0034] The fault result acquisition module is used to acquire the fault types of the distribution network and the initial fault location results of the distribution network uploaded by multiple target detection terminals installed in the distribution network.

[0035] The fault combination module is used to split and combine one or more initial fault sections of the distribution network contained in the initial fault location results when the fault type is a non-single-phase ground short-circuit fault, to obtain multiple fault section combinations of the distribution network.

[0036] The expected section acquisition module is used to acquire the expected fault section combination corresponding to each fault section combination;

[0037] The expected correction module is used to correct the expected fault segment combination corresponding to each fault segment combination by using each fault segment combination and the initial fault location result, so as to obtain the expected state result after correction of each fault segment combination.

[0038] The fault location determination module is used to determine the location of the fault in the distribution network based on the corrected results of multiple expected states.

[0039] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method described above.

[0040] Fourthly, this application also provides a computer-readable storage medium. This computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of the above-described method.

[0041] Fifthly, this application also provides a computer program product. This computer program product includes a computer program that, when executed by a processor, implements the steps of the above-described method.

[0042] The aforementioned distribution network fault location method, apparatus, computer equipment, storage medium, and computer program product acquire fault types and initial fault location results uploaded by multiple target detection terminals installed in the distribution network. In the case of a non-single-phase ground fault, one or more initial fault segments of the distribution network included in the initial fault location results are split and combined to obtain multiple fault segment combinations. The desired fault segment combinations corresponding to each fault segment combination are obtained. Using each fault segment combination and the initial fault location results, the desired fault segment combinations corresponding to each fault segment combination are corrected to obtain corrected desired state results for each fault segment combination. Based on the corrected multiple desired state results, the fault location in the distribution network is obtained. Compared with traditional technologies, this application, by correcting the desired fault segment combinations corresponding to each fault segment combination, can determine a unique fault segment combination as the faulty segment, thus avoiding multiple fault segment combinations that could be identified as the faulty segment, thereby improving the accuracy of fault segment location and ultimately improving the accuracy of fault location. Attached Figure Description

[0043] Figure 1 This is an application environment diagram of the power distribution network fault location method in one embodiment;

[0044] Figure 2 This is a flowchart illustrating a power distribution network fault location method in one embodiment;

[0045] Figure 3 This is a flowchart illustrating the steps of obtaining the location of a fault in a distribution network based on multiple corrected desired state results in one embodiment.

[0046] Figure 4This is a flowchart illustrating the steps of performing fault location measurement on an actual faulty section in one embodiment to obtain the location of the fault in the distribution network.

[0047] Figure 5 This is a flowchart illustrating a distribution network fault location method in a specific embodiment.

[0048] Figure 6 This is a structural block diagram of a power distribution network fault location device in one embodiment;

[0049] Figure 7 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] Distribution networks are characterized by complex structures, variable operating modes, and a limited number of observable points, making them a frequent source of short-circuit faults in the entire power system. While numerous theoretical methods exist for fault location in distribution networks, most struggle to address fault location in distribution-controlled networks. In recent years, with the gradual development of distribution automation engineering and extensive research by scholars on synchronous phasor measurement units (PMUs) suitable for distribution networks, the high precision, high sampling rate, clock synchronization, and phasor measurement capabilities of PMUs have provided new ideas and solutions for distribution network fault location. This is of great significance for accurately locating fault points, reducing outage time, minimizing economic losses, and improving power supply reliability. Currently, research on fault location in distribution networks can be divided into three aspects: First, fault line selection, which identifies the faulty outgoing line among multiple outgoing lines of a busbar. This can only roughly determine which outgoing line is faulty and can only locate the fault area, resulting in poor positioning accuracy. Second, fault section location, which can determine the feeder section where the fault point is located and can pinpoint the fault point to the area between adjacent sectionalizing switches, but cannot provide the distance to the fault point. Third, fault ranging, which can quantify the specific location of the fault point and directly provide the distance to the fault point, with the most accurate positioning results. All three research directions essentially belong to fault location, but they have different requirements for fault location accuracy, and their implementation difficulty increases progressively.

[0052] Fault line selection and fault section location methods, due to their limitations in positioning accuracy, are no longer able to quickly and effectively solve various short-circuit fault location problems in actual power distribution networks. Fault ranging, however, can quantify the location of the fault point and provide its distance. It avoids the need for extensive manpower and resources for line inspection, significantly reduces losses caused by power outages, and greatly improves power supply reliability, resulting in substantial social and economic benefits.

[0053] Based on the current fault location method, which suffers from low accuracy, this application proposes a fault location method, device, computer equipment, and storage medium that can improve the accuracy of fault location in the power distribution network.

[0054] The power distribution network fault location method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104 or located on a cloud or other network server. The data storage system can store initial fault location results, fault segment combinations, and expected fault segment combinations, etc. Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc. Portable wearable devices can include smartwatches, smart bracelets, head-mounted devices, etc. Server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0055] In one embodiment, such as Figure 2 As shown, a method for fault location in a distribution network is provided, which can be applied to... Figure 1 Taking server 104 as an example, the following steps are included:

[0056] Step S202: Obtain the fault types and initial fault location results of the distribution network uploaded by multiple target detection terminals installed in the distribution network.

[0057] In this context, the target detection terminal refers to the terminal used to upload fault information, such as an FTU (Feeder Terminal Unit). The fault type refers to the type of fault occurring in the distribution network, such as a single-phase ground fault, a two-phase ground fault, a two-phase short circuit, or a three-phase short circuit. The initial fault location result refers to the result of locating the fault section based on the fault information uploaded by the target detection terminals. For example, if the distribution network has five target detection terminals, and the first and fourth target detection terminals upload fault current information, then the sections where the first and fourth target detection terminals are located are considered fault sections, and the initial fault location result can be obtained based on this information.

[0058] Specifically, the distribution network is equipped with multiple target detection terminals. In the event of a fault in the distribution network, fault information from these terminals at the moment of the fault is acquired. This fault information can be a fault current signal. Based on the uploaded fault information, an initial fault location result is obtained. This initial fault location result can be processed to obtain the final fault location result. Both the initial and final fault location results are segment location results. Furthermore, the fault types uploaded by the multiple target detection terminals can be acquired. Different processing methods can be used for fault location based on different fault types, thereby improving the accuracy of fault location.

[0059] Step S204: In the case of a non-single-phase ground fault, one or more initial fault sections of the distribution network included in the initial fault location results are split and combined to obtain multiple fault section combinations of the distribution network.

[0060] Among them, non-single-phase-to-ground short-circuit faults refer to faults other than single-phase-to-ground short-circuit faults, such as two-phase-to-ground short-circuit faults. Fault segment combination refers to combining one or more fault segments included in the initial fault location result. For example, if the initial fault location result includes three fault segments (e.g., S1 segment, S3 segment, and S7 segment respectively), splitting and combining these three fault segments can yield 7 combination results, including: S1 fault, S3 fault, S7 fault, S1 and S3 fault, S1 and S7 fault, S3 and S7 fault, and S1, S3, and S7 fault.

[0061] Specifically, in the case of a non-single-phase-to-ground short-circuit fault, one or more initial fault segments included in the initial fault location result are split and combined to obtain multiple fault segment combinations of the distribution network. These multiple fault segment combinations can be processed using an evaluation function to obtain the fault segment combination with the best evaluation, which is then used as the final fault location result. It can be understood that if the initial fault location result contains only one fault segment, then the fault segment combination is the initial fault location result itself, and subsequent processing can be used to correct this fault segment combination to obtain a more accurate fault location result.

[0062] Step S206: Obtain the expected combination of fault sections corresponding to each combination of fault sections.

[0063] Among them, the expected fault segment combination refers to the status result uploaded by the expected target detection terminal based on the fault segment combination.

[0064] Specifically, by combining fault segments, the expected fault segment combination corresponding to the fault segment combination is obtained. The expected fault segment combination can include the expected states of multiple target detection terminals. The expected state of the target detection terminal is an OR function of the states of each downstream segment of the target detection terminal. That is, as long as each downstream segment of the target detection terminal has uploaded fault information, the expected state of the target detection terminal is the fault information state.

[0065] Step S208: Using each fault segment combination and the initial fault location result, the expected fault segment combination corresponding to each fault segment combination is corrected to obtain the corrected expected state result of each fault segment combination.

[0066] Specifically, the fault location results contained in each fault segment combination can be judged, and the initial fault location results and the expected fault segment combination can be compared. Based on the judgment and comparison results, it is determined whether to correct the expected fault segment combination corresponding to the fault segment combination. If the expected fault segment combination is to be corrected, the correction process is performed based on the initial fault location results and the expected fault segment combination to obtain the corrected expected fault segment combination.

[0067] Step S210: Based on the corrected multiple expected state results, the location of the fault in the distribution network is obtained.

[0068] Specifically, based on the corrected results of multiple desired states, the best combination of fault sections can be evaluated, and this combination of fault sections can be used as the fault location section of the distribution network. The specific fault location information can be obtained by processing this fault location section.

[0069] In this embodiment, the fault types and initial fault location results of the distribution network uploaded by multiple target detection terminals installed in the distribution network are obtained. When the fault type is a non-single-phase ground fault, one or more initial fault segments of the distribution network included in the initial fault location results are split and combined to obtain multiple fault segment combinations of the distribution network. The expected fault segment combinations corresponding to each fault segment combination are obtained. Using each fault segment combination and the initial fault location results, the expected fault segment combinations corresponding to each fault segment combination are corrected to obtain the corrected expected state results for each fault segment combination. Based on the corrected multiple expected state results, the fault location of the distribution network is obtained. Compared with traditional technologies, this application, by correcting the expected fault segment combinations corresponding to each fault segment combination, can determine a unique fault segment combination as the faulty segment, thus avoiding obtaining multiple fault segment combinations that could be considered as the faulty segment, thereby improving the accuracy of fault segment location and consequently improving the accuracy of fault location.

[0070] In a specific embodiment, the initial fault location result can be represented by a matrix. If the FTU has uploaded fault current information, the value is 1; otherwise, the value is 0. For example, the matrix [1 0 0 0 1] can be obtained, which indicates that the 1st and 5th FTUs have uploaded fault current information. By splitting and grouping this matrix, three results can be obtained: [1 0 0 00], [0 0 0 0 1], and [1 0 0 0 1]. That is, the above three matrices correspond to three types of distribution network fault situations. If the 1st FTU is upstream of the other four FTUs and the 5th FTU is downstream of the other four FTUs, the expected fault segment combination obtained according to [1 0 0 0 0] is [1 0 0 0 0], the expected fault segment combination obtained according to [0 0 0 0 1] is [1 1 1 1 1], and the expected fault segment combination obtained according to [1 0 0 0 1] is [1 1 1 1 1]. The combinations [1 0 0 0 0], [1 1 1 11], and [1 1 1 1 1] are modified to obtain the corrected expected fault segment combinations. Using these corrected combinations and the evaluation function of the fault segment combinations, the evaluation value of each combination can be obtained. The fault segment combination with the lowest evaluation value is taken as the actual fault segment of the distribution network. This method avoids multiple fault segment combinations from being identified as faulty segments, thereby improving the accuracy of fault segment location and ultimately, the accuracy of fault location.

[0071] In one embodiment, using each fault segment combination and the initial fault location result, the expected fault segment combination corresponding to each fault segment combination is corrected to obtain the corrected expected state result for each fault segment combination, including:

[0072] Compare the initial fault location results with the combinations of various expected fault segments;

[0073] If there is a location result in the fault segment combination, and the location result contained in the initial fault location result is less than or equal to the location result contained in the expected fault segment combination corresponding to the fault segment combination, then the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, no correction is performed.

[0074] If there are multiple location results in the fault segment combination, and the initial fault location result contains fewer or equal locations than the expected fault segment combination corresponding to the fault segment combination, then the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, the fault segment combination corresponding to the expected fault segment combination is removed.

[0075] Here, "location result" refers to the fault information uploaded by the target detection terminal. One location result indicates that one target detection terminal has uploaded fault information. Multiple location results indicate that more than one target detection terminal has uploaded fault information.

[0076] Specifically, the location results contained in the initial fault location results are compared with the location results contained in each expected fault segment combination; and the number of location results present in the fault segment combination is determined.

[0077] If there is a location result in the fault segment combination, and the initial fault location result contains fewer or equal locations than the expected fault segment combination corresponding to that fault segment combination, then an XOR operation is performed on the expected fault segment combination and the initial fault location result, and the difference between the XOR operation result and the expected fault segment combination is used as the corrected expected fault segment combination; otherwise, no correction is performed.

[0078] If there are two or more location results in a fault section combination, and the initial fault location result contains fewer or equal locations than the expected fault section combination corresponding to the fault section combination, then an XOR operation is performed on the expected fault section combination and the initial fault location result, and the difference between the XOR operation result and the expected fault section combination is used as the corrected expected fault section combination. Otherwise, the fault section combination corresponding to the expected fault section combination is not processed, that is, the fault section combination is not considered a correct distribution network fault section.

[0079] In this embodiment, the location result of the fault segment combination is judged, and the initial fault location result is compared with the expected fault segment combination. Correction processing is performed based on the judgment and comparison results, thereby improving the accuracy of fault segment location and thus improving the accuracy of fault location.

[0080] In one embodiment, such as Figure 3 As shown, based on the corrected results of multiple desired states, the location of the fault in the distribution network is obtained, including:

[0081] Step S302: Using the corrected expected state results, the combination of each fault section, and the initial fault location results, obtain the evaluation results corresponding to each combination of fault sections.

[0082] Step S304: Compare multiple evaluation results to determine the actual fault section of the distribution network;

[0083] Step S306: Perform fault location processing on the actual fault section to obtain the location of the fault in the distribution network.

[0084] Specifically, based on the evaluation function of the fault segment combination, the corrected expected state results, each fault segment combination, and the initial fault location results can be calculated to obtain the evaluation results corresponding to each fault segment combination. Multiple evaluation results are compared, and the fault segment combination corresponding to the smallest evaluation value is determined as the actual fault segment of the distribution network. Fault location processing is performed on the actual fault segment to obtain the fault location in the distribution network; where fault location processing can be performed separately for main line faults and branch line faults.

[0085] In this embodiment, the evaluation results corresponding to each combination of fault sections are obtained through the expected state results, each combination of fault sections and the initial fault location results. The location of the fault in the distribution network is obtained by performing fault ranging processing on the actual fault section, which can improve the accuracy of fault location.

[0086] In a specific example, the evaluation value of each combination of fault sections can be obtained using the following expression:

[0087]

[0088] Among them, F i (S B ) For each faulty section, combine S B The evaluation function value, I j This is the initial fault location result. For fault section combination S B The corresponding expected fault section combination, SB (j) represents the combination of fault sections, ω is the weighting coefficient (0<ω<1), and N is the number of FTUs.

[0089] It can be done in the following ways Make corrections:

[0090] when At that time, if but Corrected expected state result like The corrected expected state result

[0091] when At that time, if Then neither correction nor evaluation is performed (no evaluation function is used for this S). B (j) Process it), otherwise Corrected expected state result Among them, S B (j) I j Both are 1×N matrices, and each element in the matrix has a value of 0 or 1.

[0092] In this embodiment, the above method is used to... Corrective actions can improve the accuracy of fault location.

[0093] In one embodiment, such as Figure 4 As shown, fault location processing is performed on the actual faulty section to obtain the location of the fault in the distribution network, including:

[0094] Step S402: Obtain the line type corresponding to the actual faulty section;

[0095] Step S404: When the line type is a branch line, determine the target point from the actual fault section and obtain the fault current signal of the target point; the target point is any point in the actual fault section.

[0096] Step S406: Obtain the evaluation value of the target point based on the phase angle of the fault current signal;

[0097] Step S408: Determine the target point corresponding to the minimum evaluation value as the location of the fault.

[0098] The line type refers to the type of lines included in the distribution network, which can be branch lines or main lines. The evaluation value of the target point is obtained based on the rating function of the phase angle of the fault circuit signal corresponding to the target point. The fault current signal can include zero-sequence fault current signal, positive-sequence fault current signal, and negative-sequence fault current signal.

[0099] Specifically, the line type corresponding to the actual faulty section is obtained. If the line type is a branch line, any point in the actual faulty section is determined as the target point, and the fault current signal of the target point (any point) is obtained; based on the phase angle of the zero-sequence fault current signal, the phase angle of the positive-sequence fault current signal, and the phase angle of the negative-sequence fault current signal of any point, the evaluation value of any point is obtained; the target point corresponding to the minimum evaluation value is determined as the location of the fault.

[0100] In this embodiment, by utilizing the phase angle of the fault current signal, the evaluation value of the target point is obtained, and the fault location is determined based on the minimum evaluation value, thereby improving the accuracy of fault location.

[0101] In one embodiment, acquiring the fault current signal at the target point includes:

[0102] Acquire the fault current signal and fault voltage signal at the location of the fault;

[0103] Obtain the wave impedance and equivalent impedance of the faulty section, as well as the first impedance coefficient corresponding to the wave impedance and the second impedance coefficient corresponding to the equivalent impedance; wherein, the first impedance coefficient and the second impedance coefficient are determined based on the distance between the target point and the preset end of the faulty section.

[0104] The target impedance is obtained based on the wave impedance, the first impedance coefficient, the equivalent impedance, and the second impedance coefficient.

[0105] The fault current signal at the target point is obtained based on the fault current signal, the fault voltage signal, and the target impedance.

[0106] Specifically, the target current signal can be obtained from the fault voltage signal and the target impedance, and the fault current signal at the target point can be obtained from the difference between the fault current signal and the target current signal. Specifically, the zero-sequence fault current signal at the target point can be obtained from the zero-sequence fault current signal at the fault location, the zero-sequence fault voltage signal at the fault location, and the target zero-sequence impedance; the positive-sequence fault current signal at the target point can be obtained from the positive-sequence fault current signal at the fault location, the positive-sequence fault voltage signal at the fault location, and the target positive-sequence impedance; and the negative-sequence fault current signal at the target point can be obtained from the negative-sequence fault current signal at the fault location, the negative-sequence fault voltage signal at the fault location, and the target negative-sequence impedance.

[0107] In this embodiment, the fault current signal of the target point is obtained through the fault current signal, the fault voltage signal, and the target impedance. This provides basic data for obtaining the minimum evaluation value and determining the target point corresponding to the minimum evaluation value as the location of the fault.

[0108] In one embodiment, obtaining the wave impedance of the faulty section includes:

[0109] Obtain the unit line resistance, unit line inductance, and unit line capacitance of the actual fault section;

[0110] The wave impedance is obtained from the unit line resistance, unit line inductance, and unit line capacitance.

[0111] Specifically, the zero-sequence impedance can be obtained from the zero-sequence unit line resistance, zero-sequence unit line inductance, and zero-sequence unit line capacitance; the positive-sequence impedance can be obtained from the positive-sequence unit line resistance, positive-sequence unit line inductance, and positive-sequence unit line capacitance; and the negative-sequence impedance can be obtained from the negative-sequence unit line resistance, negative-sequence unit line inductance, and negative-sequence unit line capacitance.

[0112] In this embodiment, the wave impedance is obtained by measuring the unit line resistance, unit line inductance, and unit line capacitance, which provides a data basis for obtaining the fault current signal.

[0113] In a specific embodiment, the evaluation value of the target point can be obtained using the following expression:

[0114]

[0115] in, These are the zero-sequence, positive-sequence, and negative-sequence fault current phasors at the target point, respectively.

[0116]

[0117]

[0118]

[0119] in, The fault current phasor flows from terminal M to the fault point; γ is the fault voltage phasor at the fault point; (i) The propagation coefficient of the line is denoted by ; L is the total length of the line. The wave impedance of the line; Let i be the equivalent impedance of the transformer and its load. i = 0, 1, 2 represent zero-sequence, positive-sequence, and negative-sequence impedances, respectively.

[0120]

[0121]

[0122] in, These represent the resistance, inductance, capacitance, and admittance per unit length of the line, respectively.

[0123] In one embodiment, when the fault type is a single-phase ground fault, the zero-sequence segment admittance algorithm is used to determine the actual fault segment of the distribution network.

[0124] In one embodiment, when the line type is a trunk line, the location of the fault is determined using a dual-ended synchronous phasor algorithm.

[0125] In a specific embodiment, such as Figure 5 As shown, when a fault occurs in the distribution network, the FTU uploads the fault information to the master station. For faults that are not single-phase ground faults, the improved matrix method is used to determine the fault section; for faults that are single-phase ground faults, the zero-sequence section admittance method is used to determine the fault section. The difference in positive-sequence voltage phasors at each branch bus within the section is calculated by the dual-terminal PMU of the main line at the time of the fault to determine whether the fault occurred in the main distribution line or a branch line. For different fault sections, the dual-terminal synchronous phasor method and the improved single-terminal ground fault location algorithm are used to locate the fault in the main line and the branch line, respectively. Here, "Y" indicates proceeding to the next step, and "N" indicates performing a second judgment.

[0126] For example, the improved matrix algorithm for fault segment location of non-single-phase ground faults can filter segment location results and eliminate false fault segments when there are missed fault information uploaded by the FTU. First, the original expected fault segment combinations of the FTU in the artificial intelligence evaluation function are corrected. Then, each fault segment combination is evaluated, and finally, the fault segment combination with the smallest evaluation function value is taken as the final fault segment location result. Specifically, when... At that time, if but Corrected expected state result like The corrected expected state result

[0127] when At that time, if Then neither correction nor evaluation is performed (no evaluation function is used for this S). B (j) Process it), otherwise Corrected expected state result Among them, S B (j) I j Both are 1×N matrices, and each element in the matrix has a value of 0 or 1.

[0128] The evaluation value for each fault section combination is obtained using the following expression:

[0129]

[0130] Among them, F i (S B ) For each faulty section, combine S B The evaluation function value, I j This is the initial fault location result. For fault section combination S B The corresponding expected fault section combination, S B (j) represents the combination of fault sections, ω is the weighting coefficient (0<ω<1), and N is the number of FTUs.

[0131] For example, using an improved single-ended ground fault location algorithm to locate a branch line fault and obtain the fault location may include the following steps:

[0132] The evaluation value of the target point is obtained using the following expression:

[0133]

[0134] in, These are the zero-sequence, positive-sequence, and negative-sequence fault current phasors at the target point, respectively.

[0135] The zero-sequence, positive-sequence, and negative-sequence fault current phasors at the target point can be obtained using the following expressions:

[0136]

[0137]

[0138]

[0139] in, The fault current phasor flows from terminal M to the fault point; γ is the fault voltage phasor at the fault point; (i) The propagation coefficient of the line is denoted by ; L is the total length of the line. The wave impedance of the line; Let i be the equivalent impedance of the transformer and its load. i = 0, 1, 2 represent zero-sequence, positive-sequence, and negative-sequence impedances, respectively.

[0140] γ can be obtained using the following expression (i) as well as

[0141]

[0142]

[0143] in, These represent the resistance, inductance, capacitance, and admittance per unit length of the line, respectively.

[0144] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0145] Based on the same inventive concept, this application also provides a distribution network fault location device for implementing the distribution network fault location method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more distribution network fault location device embodiments provided below can be found in the limitations of the distribution network fault location method described above, and will not be repeated here.

[0146] In one embodiment, such as Figure 6 As shown, a power distribution network fault location device 500 is provided, including: a fault result acquisition module 510, a fault combination module 520, a desired section acquisition module 530, a desired correction module 540, and a fault location determination module, wherein:

[0147] The fault result acquisition module 510 is used to acquire the fault types of the distribution network and the initial fault location results of the distribution network uploaded by multiple target detection terminals installed in the distribution network.

[0148] The fault combination module 520 is used to split and combine one or more initial fault sections of the distribution network included in the initial fault location result when the fault type is a non-single-phase ground short-circuit fault, so as to obtain multiple fault section combinations of the distribution network.

[0149] The expected section acquisition module 530 is used to acquire the expected fault section combination corresponding to each fault section combination.

[0150] The expected correction module 540 is used to correct the expected fault segment combination corresponding to each fault segment combination by using each fault segment combination and the initial fault location result, so as to obtain the expected state result after correction of each fault segment combination.

[0151] The fault location determination module 550 is used to determine the location of the fault in the distribution network based on the corrected results of multiple expected states.

[0152] In one embodiment, the desired correction module includes a comparison unit and a judgment unit.

[0153] The comparison unit compares the initial fault location result with each expected fault segment combination. The judgment unit, when there is only one location result in a fault segment combination, determines whether to correct the expected fault segment combination using the expected fault segment combination and the initial fault location result if the initial fault location result contains fewer or equal locations than the expected fault segment combination corresponding to the fault segment combination; otherwise, no correction is performed. Similarly, when there are multiple location results in a fault segment combination, if the initial fault location result contains fewer or equal locations than the expected fault segment combination corresponding to the fault segment combination, the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, the fault segment combination corresponding to the expected fault segment combination is removed.

[0154] In one embodiment, fault location determination includes an evaluation result acquisition unit, a fault section determination unit, and a fault location determination unit.

[0155] The evaluation result acquisition unit is used to obtain the evaluation results corresponding to each fault segment combination by using the corrected expected state results, each fault segment combination and the initial fault location results; the fault segment determination unit is used to compare multiple evaluation results to determine the actual fault segment of the distribution network; the fault location determination unit is used to perform fault ranging processing on the actual fault segment to obtain the fault location of the distribution network.

[0156] In one embodiment, the fault location determination unit includes a line type acquisition unit, a current acquisition unit, an evaluation value acquisition unit, and a minimum value unit.

[0157] The line type acquisition unit is used to acquire the line type corresponding to the actual fault section; the current acquisition unit is used to determine the target point from the actual fault section and acquire the fault current signal of the target point when the line type is a branch line; the target point can be any point in the actual fault section; the evaluation value acquisition unit is used to obtain the evaluation value of the target point according to the phase angle of the fault current signal; the minimum value unit is used to determine the target point corresponding to the minimum evaluation value as the location of the fault.

[0158] In one embodiment, the current acquisition unit includes a fault location signal acquisition unit, an impedance acquisition unit, a target impedance determination unit, and a current signal determination unit.

[0159] The fault location signal acquisition unit is used to acquire the fault current signal and fault voltage signal at the location where the fault occurs;

[0160] The impedance acquisition unit is used to acquire the wave impedance and equivalent impedance of the fault section, as well as the first impedance coefficient corresponding to the wave impedance and the second impedance coefficient corresponding to the equivalent impedance; wherein, the first impedance coefficient and the second impedance coefficient are determined according to the distance between the target point and the preset end of the fault section; the target impedance determination unit is used to obtain the target impedance according to the wave impedance, the first impedance coefficient, the equivalent impedance and the second impedance coefficient; the current signal determination unit is used to obtain the fault current signal of the target point according to the fault current signal, the fault voltage signal and the target impedance.

[0161] In one embodiment, the impedance acquisition unit includes a unit data acquisition unit and a wave impedance determination unit.

[0162] The unit data acquisition unit is used to acquire the unit line resistance, unit line inductance, and unit line capacitance of the actual fault section; the wave impedance determination unit is used to obtain the wave impedance based on the unit line resistance, unit line inductance, and unit line capacitance.

[0163] Each module in the aforementioned power distribution network fault location device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0164] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media to run. The database stores initial fault location results, desired fault segment combinations, and desired state result data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a power distribution network fault location method.

[0165] Those skilled in the art will understand that Figure 7The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0166] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0167] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, performs the steps of the methods described above.

[0168] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0169] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0170] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0171] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for locating faults in a power distribution network, characterized in that, The method includes: Obtain the fault types and initial fault location results for the power distribution network uploaded by multiple target detection terminals installed in the power distribution network; In the case where the fault type is a non-single-phase ground fault, one or more initial fault sections of the distribution network included in the initial fault location result are split and combined to obtain multiple fault section combinations of the distribution network. Obtain the expected combination of fault sections corresponding to each combination of fault sections; Using the various fault segment combinations and the initial fault location results, the expected fault segment combinations corresponding to each fault segment combination are corrected to obtain the corrected expected state results of each fault segment combination. Based on the corrected multiple expected state results, the location of the fault in the distribution network is obtained.

2. The method according to claim 1, characterized in that, The step involves using the various fault segment combinations and the initial fault location results to correct the expected fault segment combinations corresponding to each fault segment combination, thereby obtaining the corrected expected state results for each fault segment combination, including: The initial fault location results are compared with the combinations of each expected fault segment; If there is a location result in the fault segment combination, and the location result contained in the initial fault location result is less than or equal to the location result contained in the expected fault segment combination corresponding to the fault segment combination, then the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, no correction is performed. If there are multiple location results in the fault segment combination, and the initial fault location result contains fewer or equal locations than the expected fault segment combination corresponding to the fault segment combination, then the expected fault segment combination is corrected using the expected fault segment combination and the initial fault location result; otherwise, the fault segment combination corresponding to the expected fault segment combination is removed.

3. The method according to claim 1, characterized in that, The step of determining the location of the fault in the distribution network based on the corrected multiple expected state results includes: Using the corrected expected state results, the fault segment combinations, and the initial fault location results, the evaluation results corresponding to the fault segment combinations are obtained. By comparing multiple evaluation results, the actual fault section of the distribution network can be determined; The actual faulty section is subjected to fault location measurement processing to obtain the location of the fault in the power distribution network.

4. The method according to claim 3, characterized in that, The actual faulty section is then subjected to fault location processing. Determining the location of the fault in the power distribution network includes: Obtain the line type corresponding to the actual faulty section; When the line type is a branch line, a target point is determined from the actual fault section, and the fault current signal of the target point is obtained; the target point is any point in the actual fault section. The evaluation value of the target point is obtained based on the phase angle of the fault current signal; The target point corresponding to the minimum evaluation value is determined as the location of the fault.

5. The method according to claim 4, characterized in that, The step of acquiring the fault current signal at the target point includes: Obtain the fault current signal and fault voltage signal at the location where the fault occurred; Obtain the wave impedance and equivalent impedance of the faulty section, as well as the first impedance coefficient corresponding to the wave impedance and the second impedance coefficient corresponding to the equivalent impedance; wherein, the first impedance coefficient and the second impedance coefficient are determined based on the distance between the target point and the preset end of the faulty section. The target impedance is obtained based on the wave impedance, the first impedance coefficient, the equivalent impedance, and the second impedance coefficient. The fault current signal at the target point is obtained based on the fault current signal, the fault voltage signal, and the target impedance.

6. The method according to claim 5, characterized in that, The process of obtaining the wave impedance of the faulty section includes: Obtain the unit line resistance, unit line inductance, and unit line capacitance of the actual fault section; The wave impedance is obtained based on the unit line resistance, the unit line inductance, and the unit line capacitance.

7. A power distribution network fault location device, characterized in that, The device includes: The fault result acquisition module is used to acquire the fault type of the distribution network and the initial fault location result of the distribution network uploaded by multiple target detection terminals installed in the distribution network. The fault combination module is used to split and combine one or more initial fault sections of the distribution network included in the initial fault location result when the fault type is a non-single-phase ground short-circuit fault, so as to obtain multiple fault section combinations of the distribution network. The expected section acquisition module is used to acquire the expected fault section combination corresponding to each fault section combination; The expected correction module is used to use the various fault segment combinations and the initial fault location results to correct the expected fault segment combinations corresponding to each fault segment combination, so as to obtain the expected state results after the correction of each fault segment combination. The fault location determination module is used to determine the location of the fault in the distribution network based on the corrected multiple expected state results.

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

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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