Distribution line grounding fault location method and system based on wide area synchronization technology

Abstract

The present invention provides a method and system for locating grounding faults in distribution lines based on wide-area synchronization technology, and relates to the field of power distribution technology. The method comprises the following steps: constructing a distribution network model according to the structure of the distribution network, and configuring a synchronous vector measurement system PMU on the nodes of the distribution network model; constructing a corresponding GIS map system based on the distribution network model and the configured PMU, and associating the GIS map system with drone image acquisition; associating the GIS map system with the weather forecast information system and the distribution network operation and maintenance information system, and setting an early warning trigger mechanism between the marking points of the GIS map system and the associated information; selecting fault lines based on the principle of waveform similarity; sorting the fault line selection analysis results, and actively intervening and verifying the top-ranked selected lines; if the line selection is completed, the fault point is accurately located by the line fault point distance measurement method. The present invention is based on wide-area synchronization technology, and can realize accurate and rapid positioning of grounding faults in distribution network lines.

Description

Technical Field

[0001] The present invention relates to the field of power distribution technology, and in particular to a method and system for locating ground faults in power distribution lines based on wide area synchronization technology. Background Art

[0002] The characteristics of the distribution network are long power supply radius, many line branches, and imperfect measurement system. Accurately locating the fault section is an important condition for quickly troubleshooting distribution network faults. Single-phase grounding fault is the most frequent fault among all faults, accounting for about 80% of all faults. Single-phase grounding fault has the characteristics of unclear fault characteristics and susceptibility to noise interference, which makes it difficult to accurately locate single-phase grounding faults when they occur.

[0003] The problems in distribution network automation have always been that the line operation equipment is complicated, there are few collection points, the data is in different periods, and the metering data after the new energy is connected to the distribution network and the equipment required for the distribution network power quality monitoring are scattered and complicated, making it impossible to collect data in a unified manner for analysis.

[0004] Traditional distribution networks mainly collect measurement values ​​of target nodes through various types of equipment (FTU / DTU, etc.) on the distribution network lines. However, the measurement data collected does not have phase angle values ​​and time scales, and cannot guarantee the synchronization of the collected measurement data, unified time scales, and data accuracy. The existing equipment has limited intelligence, the collected line data are independent of each other, and the coverage rate of clock synchronization data analysis lines is not high.

[0005] Secondly, the existing equipment operation data is not interconnected, and it is impossible to centrally collect and analyze the data on site and upload the results to the main station. A large amount of data is uploaded to the main station for centralized analysis, which puts enormous pressure on the operation of the main station. The distribution network big data has scattered information and resources, different data formats, and insufficient throughput and processing capabilities for massive data, resulting in imperfections in the timeliness, integrity, and uniformity of distribution network data acquisition.

[0006] Thirdly, there is a large amount of data and information exchange between distribution network application systems. Since the equipment used in different areas of the distribution network comes from different manufacturers, and the application system models are different in form, there is a lack of strict and unified interface standards, resulting in low data sharing performance and poor system integration, thus forming "information islands".

[0007] For the above reasons, my country's distribution network has always had two major pain points in fault handling: inaccurate single-phase grounding protection and difficulty in rapid fault self-healing. Therefore, it is urgent to develop a distribution network fault location technology to improve the synchronization of different signals of the same node switch such as fault voltage and fault current at the distribution terminal, and ensure that the clocks of different distribution terminals on a distribution line are absolutely synchronized and the collected fault signals are absolutely synchronized in time. Summary of the invention

[0008] In order to solve the technical problems existing in the prior art, the embodiment of the present invention provides a method and system for locating ground faults in distribution lines based on wide area synchronization technology. The technical solution is as follows:

[0009] On the one hand, a method for locating a ground fault in a distribution line based on wide area synchronization technology is provided. The method is implemented by a distribution line ground fault locating device based on wide area synchronization technology. The method includes:

[0010] A distribution network model is constructed according to the structure of the distribution network, and a synchronous vector measurement system PMU is configured on the nodes of the distribution network model;

[0011] Based on the distribution network model and configured PMU, a corresponding GIS map system is constructed, the GIS map system is associated with the drone image acquisition module, and the dangerous factors affecting the distribution grounding are marked on the GIS map system, and the dangerous factors are regularly updated based on the on-site images collected by the drone image acquisition module in the later stage;

[0012] The marked GIS map system is associated with the weather forecast information system and the distribution network operation and maintenance information system respectively, and an early warning trigger mechanism is set between the marked points of the GIS map system and the associated information;

[0013] When a line grounding fault occurs at a certain time, a graded warning is issued to the corresponding area of ​​the GIS map system associated with external information, and then the rough positioning area is obtained;

[0014] Taking the coarse positioning area as the center of the circle, control the PMU measurement recording data in the area with a certain distance as the radius, perform fault line selection based on the waveform similarity principle according to the recording data, sort the fault line selection results, and determine the selected line in the first preset order as the fault line selection analysis result;

[0015] Actively intervene and verify the fault line selection analysis results to achieve further line selection and positioning;

[0016] If the line selection is completed, the fault point is located by the line fault point distance measurement method.

[0017] On the other hand, a distribution line ground fault location system based on wide area synchronization technology is provided, and the system is applied to a distribution line ground fault location method based on wide area synchronization technology, and the system includes:

[0018] A configuration unit, used for building a distribution network model according to the structure of the distribution network, and configuring a synchronous vector measurement system PMU on the nodes of the distribution network model;

[0019] The marking unit is used to build a corresponding GIS map system based on the distribution network model and the configured PMU, associate the GIS map system with the UAV image acquisition module, mark the dangerous factors affecting the distribution grounding on the GIS map system, and regularly update the dangerous factors based on the on-site images collected by the UAV image acquisition module in the later stage;

[0020] An association unit is used to associate the marked GIS map system with the weather forecast information system and the distribution network operation and maintenance information system respectively, and to set up an early warning trigger mechanism between the marked points of the GIS map system and the associated information;

[0021] The classification unit is used to give a classification warning to the corresponding area of ​​the GIS map system associated with external information when a line grounding fault occurs at a certain time, and then obtain the rough positioning area position;

[0022] The fault line selection unit is used to control the PMU measurement recording data in an area with a certain distance as the radius, taking the rough positioning area as the center of the circle, and performing fault line selection based on the waveform similarity principle according to the recording data, sorting the fault line selection results, and determining the selected line in the first preset order as the fault line selection analysis result;

[0023] Verification unit, used to actively intervene and verify the fault line selection analysis results to achieve further line selection and positioning;

[0024] The positioning unit is used to locate the fault point by using the line fault point distance measurement method after the line selection is completed.

[0025] On the other hand, a distribution line ground fault locating device based on wide area synchronization technology is provided, and the distribution line ground fault locating device based on wide area synchronization technology comprises: a processor; a memory, wherein computer readable instructions are stored in the memory, and when the computer readable instructions are executed by the processor, any one of the distribution line ground fault locating methods based on wide area synchronization technology is implemented.

[0026] On the other hand, a computer-readable storage medium is provided, wherein at least one instruction is stored in the storage medium, and the at least one instruction is loaded and executed by a processor to implement any one of the above-mentioned distribution line grounding fault location methods based on wide area synchronization technology.

[0027] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0028] 1. The present invention constructs a corresponding GIS map system based on the distribution network model and the configured PMU, and locates the line grounding fault point in sequence from "surface" to "line" to "point". The positioning efficiency is fast and the accuracy is good. It can avoid the blindness of pure theoretical calculation due to the unclear signal characteristics of the grounding fault, and can also avoid the large workload and low efficiency of manual inspection.

[0029] 2. The present invention constructs a corresponding GIS map system based on the distribution network model and the configured PMU, and associates it with the distribution network operation and maintenance system and the weather forecast system information. After associating the distribution network operation and maintenance information, geographical risk factors and weather information, which are possible external causes, with the distribution network location information, when a distribution network line grounding fault occurs, it is first roughly located in the area related to these factors, thus realizing the "surface" positioning of the grounding fault, which will greatly improve the efficiency of fault positioning.

[0030] 3. The present invention selects fault lines based on the principle of waveform similarity. The S transform can truly and accurately show the characteristic differences between the panoramic waveforms of the faulty line and the sound line. By calculating the sum of the correlation coefficients between the lines, the line most likely to fail can be selected without manually setting the threshold. Then, the signal injection method is used to verify and test these lines most likely to fail, so that the faulty line can be accurately located.

[0031] 4. The present invention uses PMU to collect on-site fault signals, avoiding the problem that the measurement data collected by various types of equipment (FTU / DTU) of the existing distribution network lines have no phase angle value and no time scale, and cannot ensure the synchronization and accuracy of the collected measurement data. Only PMU is used to measure the recorded data, and the data format is unified. 5G technology is used for wireless data transmission, with a large coverage range and good real-time performance.

[0032] 5. When a line grounding fault occurs at a certain time, the GIS map system associated with external information performs graded warnings in the corresponding area, and then obtains the rough positioning area position, and controls the PMU measurement and recording data in the area with a certain distance as the radius with the rough positioning area position as the center of the circle. PMUs that are not determined as "rough positioning area positions" do not need to measure and record wave data, avoiding the problem of uploading a large amount of data to the main station for centralized analysis, which puts a huge pressure on the operation of the main station, and also reduces the impact of redundant data on fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A flow chart of a method for locating a ground fault in a power distribution line based on wide area synchronization technology provided by an embodiment of the present invention;

[0035] Figure 2 A flow chart of the steps of selecting a fault line based on the waveform similarity principle in a method for locating a ground fault in a distribution line based on wide area synchronization technology provided by an embodiment of the present invention;

[0036] Figure 3 A topological diagram of a distribution network system of a distribution line ground fault location system based on wide area synchronization technology provided by an embodiment of the present invention;

[0037] Figure 4 A block diagram of the principle of association between a distribution network system and an external system of a distribution line ground fault location system based on wide area synchronization technology provided by an embodiment of the present invention;

[0038] Figure 5 A functional block diagram of a synchronous vector measurement device PMU provided in an embodiment of the present invention;

[0039] Figure 6 It is a block diagram of a distribution line ground fault location system based on wide area synchronization technology provided by an embodiment of the present invention;

[0040] Figure 7 It is a structural schematic diagram of a distribution line ground fault locating device based on wide area synchronization technology provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0042] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0043] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same.

[0044] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0045] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0046] The embodiment of the present invention provides a method for locating a ground fault in a distribution line based on wide area synchronization technology. The method can be implemented by a distribution line ground fault locating device based on wide area synchronization technology. The distribution line ground fault locating device based on wide area synchronization technology can be a terminal or a server. Figure 1 The flow chart of the method for locating ground faults in distribution lines based on wide area synchronization technology is shown. The processing flow of the method may include the following steps:

[0047] S1. Construct a distribution network model according to the structure of the distribution network, and configure a synchronous vector measurement system PMU on the nodes of the distribution network model.

[0048] S2. Build a corresponding GIS map system based on the distribution network model and configured PMU, associate the GIS map system with the UAV image acquisition module, mark the dangerous factors affecting distribution grounding on the GIS map system, and regularly update the dangerous factors based on the on-site images collected by the UAV image acquisition module in the later stage.

[0049] In a feasible implementation, for example, drones photograph the natural environment around power facilities such as lines, poles, and transformers, and all factors that are close to power facilities and equipment and may cause line grounding faults are marked as points. These factors that may cause power grounding faults may change over time, such as building demolition and reconstruction, road reconstruction, or tree felling. Drones will regularly update and collect image information for this situation, and GIS will re-mark factors with location changes.

[0050] S3, associate the marked GIS map system with the weather forecast information system and the distribution network operation and maintenance information system respectively, and set up an early warning trigger mechanism between the marked points of the GIS map system and the associated information;

[0051] S4. When a line grounding fault occurs at a certain time, a graded warning is issued to the corresponding area of ​​the GIS map system associated with external information, and then the rough positioning area is obtained.

[0052] In a feasible implementation, for example, if there is thunderstorm or strong wind in a certain area, the distribution network in this area is marked yellow. If the distribution network really has a ground fault during the above-mentioned bad weather, the distribution network in this area is marked red as the rough location of the ground fault area. For another example, according to the distribution network operation and maintenance information, if there is a line that has just been repaired in a certain area, or the components of the line in this area are about to expire, the distribution network in this area is marked red.

[0053] S5. With the coarse positioning area as the center of the circle, control the PMU measurement recording data within the area with a certain distance as the radius, perform fault line selection based on the waveform similarity principle according to the recording data, sort the fault line selection results, and determine the selected line in the front preset order as the fault line selection analysis result.

[0054] S6. Actively intervene and verify the fault line selection analysis results to achieve further line selection and positioning.

[0055] S7. If the line selection is completed, the fault point is located by the line fault point distance measurement method.

[0056] In this embodiment, the early warning trigger mechanism between the marking points and the associated information of the GIS map system in step S3 is specifically:

[0057] S31. When the GIS map system receives the zero-sequence voltage and zero-sequence current data from the PMU, it determines that a fault has occurred, and the server adds all the received fault information to the power distribution GIS database; wherein the fault information includes the PMU ID number, zero-sequence voltage, zero-sequence current, phase and amplitude.

[0058] S32. Based on the ID number of the PMU, combined with the risk factors affecting the power distribution grounding, operation and maintenance information, and weather information, predict the location where a fault may occur within a certain area where the PMU with the corresponding ID number is located, specifically:

[0059] According to the ID number of the PMU, retrieve the area range information of the PMU corresponding to the ID number on the GIS map;

[0060] Retrieve operation and maintenance information, hazard factors and weather information of electrical equipment within the area;

[0061] If the adverse conditions of operation and maintenance information, dangerous factors and weather information all occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 90%;

[0062] If any two of the adverse conditions of operation and maintenance information, dangerous factors and weather information occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 60%;

[0063] If any of the adverse conditions of operation and maintenance information, dangerous factors and weather information occurs at the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 30%;

[0064] Among them, unfavorable situations of operation and maintenance information include the recent construction or replacement of equipment and lines or the expiration of equipment service life;

[0065] Unfavorable situations of risk factors include buildings, forests, trees, roads, construction sites, factories, rivers or landslides next to distribution lines;

[0066] Adverse conditions of weather information include rain, snow, strong wind, thunder and lightning or haze.

[0067] The above method is based on the sorting out of the causes of the existing distribution line grounding faults. The main causes of the existing distribution line grounding faults are:

[0068] The main reasons for single-phase grounding faults are as follows: (1) The wire breaks and falls to the ground or rests on the crossarm. (2) The wire is not tied or fixed firmly in the insulator and falls to the crossarm or the ground. (3) The wire is too far away from the building due to wind deflection. (4) The transformer high-voltage down conductor is broken. (5) The single-phase insulation of the high-voltage winding of the distribution transformer is broken or grounded. (6) Insulator breakdown. (7) The insulation of the branch fuse on the line is broken. (8) One end of the tie strap of the upper crossarm of the wire on the same pole falls off and rests on the lower row of wires. (9) Lightning strikes the line. (10) The tree passage is blocked, causing the tree to touch the wire. (11) Bird damage. (12) Floating objects (such as plastic sheets, kites, etc.). (13) Other accidental or unknown reasons.

[0069] The above reasons are due to weather, geographical location, human factors (such as power operation and maintenance), and internal reasons of power facilities and equipment. Therefore, after associating these possible external reasons with the distribution network location information, when a distribution network line grounding fault occurs, the first rough range is located in the area related to these factors, which will greatly improve the efficiency of fault location.

[0070] S33. Based on the fault information and the location where the fault may occur, a topological analysis is performed on the entire distribution network by using a fault segmentation location algorithm to obtain a probabilistic classification result of the fault location; wherein the fault segmentation location algorithm is specifically:

[0071] The direction from the substation side to the load terminal is defined as the current reference direction, and the path from the power supply side to the fault point is called the fault path;

[0072] Definition 1: The fault section refers specifically to the section where the ground fault occurs in the distribution line;

[0073] Definition 2: If the busbar passes through certain measuring points before reaching the fault point through the fault path, the fault point is said to be downstream of these measuring points, otherwise the fault point is said to be upstream of these measuring points;

[0074] If at some measuring point among certain measuring points, the zero-sequence current lags the zero-sequence voltage by 90°, it means that the measuring point is in the fault path and the fault point is downstream of the measuring point; if at some measuring point among certain measuring points, the zero-sequence current leads the zero-sequence voltage by 90°, it means that the measuring point is not in the fault path and the fault point is upstream of the measuring point.

[0075] S34. According to the probabilistic classification result of the fault location, obtain the device ID of the GIS map system, then mark the obtained device ID location on the GIS map system, and highlight it on the GIS map system.

[0076] like Figure 2 As shown, in this embodiment, step S5 performs fault line selection based on the waveform similarity principle, specifically:

[0077] S51, based on the recorded wave data collected by the PMU on each line in the coarse positioning area, the current traveling wave signal of each line is transformed to obtain the zero-mode component of the current traveling wave :

[0078]

[0079] In the formula, represents the first line mode current, represents the second line mode current, is the zero mode current, represents the first phase current, represents the second phase current, is the third phase current;

[0080] The zero-mode component of the current traveling wave of each line is obtained by using S transformation Perform time-frequency domain analysis to obtain the time-frequency spectrum matrix of each line ;

[0081] Time-frequency spectrum matrix for each line Perform pairwise correlation analysis to obtain the similarity correlation coefficient matrix R:

[0082]

[0083] Where m is the line number, m=1, 2, ..., n;

[0084] Calculate the sum of the elements in each row of the similarity correlation coefficient matrix R to obtain the comprehensive correlation coefficient R of each route m ,Right now

[0085]

[0086]

[0087] In the formula, R mj is the correlation coefficient between line m and line j, and the sum of the elements in each row of the solved matrix is ​​taken as the comprehensive correlation coefficient of each line to amplify the difference between the faulty line and the sound line;

[0088] S54, according to the comprehensive correlation coefficient matrix The polarity and amplitude relationship between the elements in the formula form the fault line selection criterion, namely:

[0089]

[0090] The above formula indicates that if the comprehensive correlation coefficient of the mth line is the smallest and its positive and negative polarities are opposite to those of the other n-1 lines, then the mth line is determined to be a faulty line and the other lines are sound lines;

[0091] according to The fault line selection results are sorted, and the selection lines that are ranked in a front preset order are screened out, and the screened selection lines are determined as the fault line selection analysis results.

[0092] The above method uses S transform to truly and accurately show the characteristic differences between the panoramic waveforms of the faulty line and the sound line. By calculating the sum of the correlation coefficients between the lines, a more sensitive distribution network fault line selection can be achieved without manually setting the threshold.

[0093] In this embodiment, active intervention verification is performed on the top-ranked selected lines, specifically using a signal injection method. This method uses the underlying principle of fault-generated signals. When the system generates this fault (assuming that the grounded phase is phase A), a special signal current of a specific frequency is injected into the grounded phase (phase A), and the signal current is induced to the primary side. A loop is created between the voltage transformer, the faulty phase, the faulty line, and the grounding point. The induced current of this injected current passes through this loop and enters the ground from the grounding point. Use signal detection equipment to detect the current status of each loop. If a line has information about the injected signal, it can be determined as a faulty line.

[0094] The waveform similarity principle was used to further select the fault line, and the line with the highest probability of grounding fault was basically located. Finally, the signal injection method was used to verify and test the lines with the highest probability of fault, and the faulty line could be accurately located.

[0095] Finally, the present invention adopts the fault point distance measurement method to measure the fault distance of the precisely located fault line, and adopts the impedance method or the fault recording analysis method, wherein: (1) The impedance method is based on the power frequency electrical quantity, and by establishing the voltage balance equation, the reactance between the fault point and the measurement point is solved by the numerical analysis method, thereby the approximate location of the fault can be deduced. According to the different electrical quantities used, the impedance method is divided into two types: the single-end method and the double-end method. (2) The fault recording analysis method uses various electrical quantities recorded at the time of the fault, and the technical personnel conduct a comprehensive analysis afterwards to obtain the fault location. With the development of computer technology and artificial intelligence technology, the fault recording analysis method can be quickly completed by automated equipment. Finally, the fault point location is manually verified along the distance measurement. If it is found, it is repaired. If it is not found, it continues to start step S2 and locates it according to the process.

[0096] like Figure 3 As shown, the present invention also provides a distribution line ground fault location system based on wide area synchronization technology, including a distribution network PMU and a distribution automation master station, and multiple distribution network PMUs are respectively installed at various nodes in the distribution network, that is, Figure 3 In the QL11, QL12, QL13, QL21, QL22, QL23, ..., QLn1, QLn2 and QLn3, each line QL1-QLn is connected to the substation bus through the circuit breaker QF1-QFn, each distribution network PMU establishes a communication link with the distribution automation master station, and each distribution network PMU also establishes a communication link with the PMU configured at the adjacent node. The transmission mode of the communication link adopts 5G wireless communication. Each distribution network PMU in the distribution network starts the fault recording based on the unified ground fault start-up criterion, and uploads the fault recording data to the distribution automation master station, such as Figure 4 As shown, where:

[0097] 1. The distribution automation master station communicates with the weather forecast server, distribution network operation and maintenance server and GIS map server and integrates information;

[0098] 2. The weather forecast server provides weather forecast information for the area where the distribution network is located;

[0099] 3. The distribution network operation and maintenance server stores the topological structure of the distribution network and the type, equipment ID, construction time, overhaul time, maintenance information, and service life information of its electrical equipment; the electrical equipment includes but is not limited to power supplies, poles, transformers, switches, lines, loads, PMUs, and DTU / FTUs;

[0100] 4. The GIS map server receives the dangerous factor information that causes grounding faults in the distribution network captured by the drone and updates the GIS map marking information; the dangerous factor information includes buildings, forests, trees, roads, construction sites, factories, rivers, and landslides next to the distribution lines.

[0101] The wide area measurement system (WAMS) adopted in the present invention collects real-time information based on the phasor measurement unit (PMU) as the basic unit, and transmits it to the dispatching center through the transmission layer for real-time data processing, thereby realizing the monitoring of the entire power system. PMU uses the global positioning system (GPS) as a unified time scale to measure various state quantities of each node and line in the system. PMU plays a huge role in WAMS. It uses a series of algorithms to calculate the phasors of the parameters of the various parameters of the monitored nodes, and quickly sends the synchronized phasors to the dispatching center.

[0102] The timing signal of the unified time scale of PMU is provided by GPS, so that the data collected by the entire power system are unified under the same time scale, realizing wide-area measurement. PMU is the plant station part of WAMS. Its main function is to collect and analyze the state quantity on the node at each time point through the time scale provided by GPS, and transmit it to the local data set control center or the system data set control center at high speed through the communication system. PMU has many advantages such as high precision, fast response, and wide-area synchronization. The measurement accuracy of PMU in WAMS depends largely on the combination of GPS's "time synchronization" and "frequency synchronization": First, "time synchronization" can ensure that all PMUs in the power grid collect data at the same time point when collecting data, ensuring that the data transmitted to PDC is wide-area synchronized; second, "frequency synchronization" can ensure that the time interval of each sampling of PMU data is consistent, ensuring that the data collected at each sampling point is measured at the same time scale.

[0103] like Figure 5 As shown in the figure, the PMU consists of four modules, namely the microprocessor (i.e. the measurement unit in the figure), the GPS receiver (i.e. the GPS clock in the figure), the signal transmission module (i.e. the signal transmission unit in the figure) and the communication module. The voltage and current state quantities in the power grid are collected by PT and CT and input into the signal transmission unit. After A / D conversion and filtering, the high-precision digital signal obtained enters the measurement unit. This is based on the phasor value of the GPS synchronization reference time calculated by the microprocessor, combined with the synchronization reference time to form a data frame and transmitted to the communication module.

[0104] The measurement accuracy of PMU depends on the coordination of its "frequency synchronization" and "time synchronization". Because "frequency synchronization" ensures the frequency adaptive and equally spaced synchronous sampling of the measured phasor, thus ensuring the integrity of the DFT data window and the accuracy of the algorithm. "Time synchronization" ensures that the measured phasor in different places is synchronously sampled in time, thus ensuring the synchronous interception of the DFT data window.

[0105] Unlike traditional remote terminal units (RTUs), PMUs can not only measure the amplitude of voltage and current in the power grid, but also the phase angle of each parameter, which brings great convenience to analysts. In addition, the addition of the GPS system allows the parameters measured by the PMU to be synchronized in time, so that analysts can intuitively derive the direct relationship between the parameters of each node in the power grid without conversion.

[0106] The distribution network PMU of the present invention is based on the unified GPS / BD dual-mode timing or B-code synchronization timing of the entire network, with an accuracy of less than 1us. This ensures that the time synchronization error between different distribution terminals in the distribution network is less than 1us, and the data sampling precision synchronization error of different switches is less than 1us. Based on the collected multi-source data information and in conjunction with the precise time scale, synchronous analysis of line data, distribution network line status monitoring, power quality detection, fault analysis and fault handling are achieved. This ensures that the data for fault analysis of the distribution terminal or FA analysis of the main station is absolutely synchronized and has high fidelity, improves the accuracy of the grounding fault analysis algorithm, and accurately analyzes single-phase grounding faults at the distribution terminal.

[0107] In summary, the present invention builds a corresponding GIS map system based on the distribution network model and the configured PMU, and associates it with the distribution network operation and maintenance system and the weather forecast system information. After associating the distribution network operation and maintenance information, geographical risk factors and weather information, which are possible external causes, with the distribution network location information, when a distribution network line grounding fault occurs, it is first roughly located in the area related to these factors, thus realizing the "surface" positioning of the grounding fault, which will greatly improve the efficiency of fault positioning.

[0108] Secondly, after the "surface" positioning is completed, the fault line is selected based on the principle of waveform similarity. The S transform can truly and accurately show the characteristic differences between the panoramic waveforms of the faulty line and the sound line. By calculating the sum of the correlation coefficients between the lines, the line most likely to fail can be selected without manually setting the threshold. Then, the signal injection method is used to verify and test these lines most likely to fail, so that the faulty line can be accurately located.

[0109] Finally, the fault point distance measurement method is used to measure the fault distance of the accurately located faulty line, and the impedance method or fault recording analysis method is used to calculate the fault point. The fault point location is verified on site, and repairs are carried out if found. If not found, the positioning steps are restarted from the beginning.

[0110] In summary, the present invention constructs a corresponding GIS map system based on the distribution network model and the configured PMU, and locates the line grounding fault point in sequence from "surface" to "line" to "point". The positioning efficiency is fast and the accuracy is good. It can avoid the blindness of performing pure theoretical calculations due to the unclear signal characteristics of the grounding fault, and can also avoid the large workload and low efficiency of manual inspections.

[0111] PMU is used to collect on-site fault signals to avoid the problem that the measurement data collected by various types of equipment (FTU / DTU) on the existing distribution network lines have no phase angle value and no time stamp, and cannot guarantee the synchronization and accuracy of the collected measurement data. Since only PMU is used to measure the recorded data, the data format is unified. 5G technology is used for wireless data transmission, with a large coverage range and good real-time performance.

[0112] When a line grounding fault occurs at a certain time, the GIS map system associated with external information will issue a graded warning in the corresponding area, and then obtain the rough positioning area position. With the rough positioning area position as the center of the circle, the PMU measurement and recording data in the area with a certain distance as the radius is controlled. PMUs that are not defined as "rough positioning area positions" do not need to measure and record data, avoiding the problem of uploading a large amount of data to the main station for centralized analysis, which will cause huge operating pressure on the main station and reduce the impact of redundant data on fault detection.

[0113] Figure 6 The invention is a block diagram of a distribution line ground fault location system based on wide area synchronization technology according to an exemplary embodiment. The system is used in a distribution line ground fault location method based on wide area synchronization technology. Figure 6 The system includes a configuration unit 610, a marking unit 620, an association unit 630, a classification unit 640, a fault line selection unit 650, a verification unit 660 and a positioning unit 670. Among them:

[0114] A configuration unit 610 is used to construct a distribution network model according to the structure of the distribution network, and configure a synchronous vector measurement system PMU on the nodes of the distribution network model;

[0115] The marking unit 620 is used to build a corresponding GIS map system based on the distribution network model and the configured PMU, associate the GIS map system with the drone image acquisition module, mark the risk factors affecting the distribution grounding on the GIS map system, and regularly update the risk factors based on the field images collected by the drone image acquisition module at a later stage;

[0116] The association unit 630 is used to associate the marked GIS map system with the weather forecast information system and the power distribution network operation and maintenance information system, and set an early warning trigger mechanism between the marked points of the GIS map system and the associated information;

[0117] The classification unit 640 is used to perform a classification warning on the corresponding area of ​​the GIS map system associated with external information when a line grounding fault occurs at a certain time, and then obtain the rough positioning area position;

[0118] The fault line selection unit 650 is used to control the PMU in an area with a certain distance as a radius to measure the recorded wave data with the rough positioning area as the center, perform fault line selection based on the waveform similarity principle according to the recorded wave data, sort the fault line selection results, and determine the selected line in the first preset order as the fault line selection analysis result;

[0119] Verification unit 660, used to actively intervene and verify the fault line selection analysis results to achieve further line selection and positioning;

[0120] The positioning unit 670 is used to locate the fault point by using the line fault point distance measurement method if the line selection is completed.

[0121] Optionally, the associating unit 630 is further configured to:

[0122] When the GIS map system receives the zero-sequence voltage and zero-sequence current data from the PMU, it determines that a fault has occurred, and the server adds all the received fault information to the power distribution GIS database; the fault information includes the PMU ID number, zero-sequence voltage, zero-sequence current, phase and amplitude;

[0123] Based on the PMU ID number, combined with the risk factors affecting power distribution grounding, operation and maintenance information, and weather information, predict the location of possible faults within a certain area where the PMU with the corresponding ID number is located;

[0124] Based on the fault information and the possible fault location, the entire distribution network is topologically analyzed through the fault segmentation location algorithm to obtain the probabilistic classification result of the fault location;

[0125] According to the probabilistic classification result of the fault location, the device ID of the GIS map system is obtained, and then the obtained device ID location is marked on the GIS map system and highlighted on the GIS map system.

[0126] Optionally, the associating unit 630 is further configured to:

[0127] According to the ID number of the PMU, retrieve the area range information of the PMU corresponding to the ID number on the GIS map;

[0128] Retrieving operation and maintenance information, hazard factors and weather information of electrical equipment within the scope information of the area;

[0129] If the adverse conditions of operation and maintenance information, risk factors and weather information all occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 90%;

[0130] If any two of the adverse conditions of operation and maintenance information, dangerous factors and weather information occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 60%;

[0131] If any of the adverse conditions of operation and maintenance information, risk factors and weather information occurs at the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 30%;

[0132] Among them, unfavorable situations of operation and maintenance information include the recent construction or replacement of equipment and lines or the expiration of equipment service life;

[0133] Unfavorable situations of risk factors include buildings, forests, trees, roads, construction sites, factories, rivers or landslides next to distribution lines;

[0134] Adverse conditions of weather information include rain, snow, strong wind, thunder and lightning or haze.

[0135] Optionally, the fault segmentation location algorithm includes:

[0136] The direction from the substation side to the load terminal is defined as the current reference direction, and the path from the power supply side to the fault point is called the fault path;

[0137] Definition 1: The fault section refers specifically to the section where the ground fault occurs in the distribution line;

[0138] Definition 2: If the busbar passes through certain measuring points before reaching the fault point through the fault path, the fault point is said to be downstream of these measuring points, otherwise the fault point is said to be upstream of these measuring points;

[0139] If at some measuring point among certain measuring points, the zero-sequence current lags the zero-sequence voltage by 90°, it means that the measuring point is in the fault path and the fault point is downstream of the measuring point; if at some measuring point among certain measuring points, the zero-sequence current leads the zero-sequence voltage by 90°, it means that the measuring point is not in the fault path and the fault point is upstream of the measuring point.

[0140] Optionally, the fault line selection unit 650 is configured to:

[0141] According to the recorded data collected by PMU on each line in the rough positioning area, the current traveling wave signal of each line is transformed to obtain the zero-mode component of the current traveling wave :

[0142]

[0143] In the formula, represents the first line mode current, represents the second line mode current, is the zero mode current, represents the first phase current, represents the second phase current, is the third phase current;

[0144] The zero-mode component of the current traveling wave of each line is obtained by using S transformation Perform time-frequency domain analysis to obtain the time-frequency spectrum matrix of each line ;

[0145] Time-frequency spectrum matrix for each line Perform pairwise correlation analysis to obtain the similarity correlation coefficient matrix R:

[0146]

[0147] Where m is the line number, m=1, 2, ..., n;

[0148] Calculate the sum of the elements in each row of the similarity correlation coefficient matrix R to obtain the comprehensive correlation coefficient R of each route m ,Right now

[0149]

[0150]

[0151] In the formula, R mj is the correlation coefficient between line m and line j, and the sum of the elements in each row of the solved matrix is ​​taken as the comprehensive correlation coefficient of each line to amplify the difference between the faulty line and the sound line;

[0152] According to the comprehensive correlation coefficient matrix The polarity and amplitude relationship between the elements in the formula form the fault line selection criterion, namely:

[0153]

[0154] The above formula indicates that if the comprehensive correlation coefficient of the mth line is the smallest and its positive and negative polarities are opposite to those of the other n-1 lines, then the mth line is determined to be a faulty line and the other lines are sound lines;

[0155] according to The fault line selection results are sorted, and the selection lines that are ranked in a front preset order are screened out, and the screened selection lines are determined as the fault line selection analysis results.

[0156] Optionally, the verification unit 660 is used to:

[0157] The signal injection method is used to actively intervene and verify the fault line selection analysis results.

[0158] Optionally, the fault point distance measurement method is an impedance method or a fault recording analysis method.

[0159] In the embodiments of the present invention, 1. The present invention constructs a corresponding GIS map system based on the distribution network model and the configured PMU, and locates the line grounding fault point in sequence from "surface" to "line" to "point". The positioning efficiency is fast and the accuracy is good. It can avoid the blindness of performing pure theoretical calculations due to the unclear signal characteristics of the grounding fault, and can also avoid the large workload and low efficiency of manual inspections.

[0160] 2. The present invention constructs a corresponding GIS map system based on the distribution network model and the configured PMU, and associates it with the distribution network operation and maintenance system and the weather forecast system information. After associating the distribution network operation and maintenance information, geographical risk factors and weather information, which are possible external causes, with the distribution network location information, when a distribution network line grounding fault occurs, it is first roughly located in the area related to these factors, thus realizing the "surface" positioning of the grounding fault, which will greatly improve the efficiency of fault positioning.

[0161] 3. The present invention selects fault lines based on the principle of waveform similarity. The S transform can truly and accurately show the characteristic differences between the panoramic waveforms of the faulty line and the sound line. By calculating the sum of the correlation coefficients between the lines, the line most likely to fail can be selected without manually setting the threshold. Then, the signal injection method is used to verify and test these lines most likely to fail, so that the faulty line can be accurately located.

[0162] 4. The present invention uses PMU to collect on-site fault signals, avoiding the problem that the measurement data collected by various types of equipment (FTU / DTU) of the existing distribution network lines have no phase angle value and no time scale, and cannot ensure the synchronization and accuracy of the collected measurement data. Only PMU is used to measure the recorded data, and the data format is unified. 5G technology is used for wireless data transmission, with a large coverage range and good real-time performance.

[0163] 5. When a line grounding fault occurs at a certain time, the GIS map system associated with external information performs graded warnings in the corresponding area, and then obtains the rough positioning area position, and controls the PMU measurement and recording data in the area with a certain distance as the radius with the rough positioning area position as the center of the circle. PMUs that are not determined as "rough positioning area positions" do not need to measure and record wave data, avoiding the problem of uploading a large amount of data to the main station for centralized analysis, which puts a huge pressure on the operation of the main station, and also reduces the impact of redundant data on fault detection.

[0164] Figure 7 is a schematic diagram of the structure of a distribution line ground fault location device based on wide area synchronization technology provided by an embodiment of the present invention, such as Figure 7 As shown, the distribution line ground fault location device based on wide area synchronization technology may include the above Figure 6The power distribution line ground fault location system based on wide area synchronization technology is shown. Optionally, the power distribution line ground fault location device 710 based on wide area synchronization technology may include a first processor 2001 .

[0165] Optionally, the distribution line ground fault location device 710 based on the wide area synchronization technology may further include a memory 2002 and a transceiver 2003 .

[0166] The first processor 2001, the memory 2002 and the transceiver 2003 may be connected via a communication bus.

[0167] Combine the following Figure 7 The components of the distribution line ground fault location device 710 based on the wide area synchronization technology are specifically introduced:

[0168] The first processor 2001 is the control center of the distribution line ground fault location device 710 based on the wide area synchronization technology, which can be a processor or a general term for multiple processing elements. For example, the first processor 2001 is one or more central processing units (CPUs), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiment of the present invention, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (field programmable gate arrays, FPGAs).

[0169] Optionally, the first processor 2001 can execute various functions of the distribution line ground fault location device 710 based on the wide area synchronization technology by running or executing a software program stored in the memory 2002 and calling data stored in the memory 2002 .

[0170] In a specific implementation, as an embodiment, the first processor 2001 may include one or more CPUs, such as Figure 7 CPU0 and CPU1 are shown in FIG.

[0171] In a specific implementation, as an embodiment, the distribution line ground fault location device 710 based on wide area synchronization technology may also include multiple processors, such as Figure 7The first processor 2001 and the second processor 2004 are shown in FIG. Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0172] The memory 2002 is used to store the software program for executing the solution of the present invention, and is controlled to be executed by the first processor 2001. The specific implementation method can refer to the above method embodiment, which will not be repeated here.

[0173] Optionally, the memory 2002 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 2002 may be integrated with the first processor 2001, or may exist independently, and may be connected to the first processor 2001 through the interface circuit ( Figure 7 (not shown) is coupled to the first processor 2001, which is not specifically limited in this embodiment of the present invention.

[0174] The transceiver 2003 is used to communicate with a network device or a terminal device.

[0175] Optionally, the transceiver 2003 may include a receiver and a transmitter ( Figure 7 The receiver is used to implement a receiving function, and the transmitter is used to implement a sending function.

[0176] Optionally, the transceiver 2003 may be integrated with the first processor 2001, or may exist independently, and may be connected to the first processor 2001 through the interface circuit ( Figure 7 (not shown) is coupled to the first processor 2001, which is not specifically limited in this embodiment of the present invention.

[0177] It should be noted that Figure 7 The structure of the distribution line ground fault location device 710 based on wide area synchronization technology shown in the figure does not constitute a limitation on the router. The actual knowledge structure identification device may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0178] In addition, the technical effects of the distribution line ground fault location device 710 based on wide area synchronization technology can refer to the technical effects of the distribution line ground fault location method based on wide area synchronization technology described in the above method embodiment, which will not be repeated here.

[0179] It should be understood that the first processor 2001 in the embodiment of the present invention may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0180] It should also be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0181] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable system. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0182] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0183] In the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0184] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0185] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0186] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices, systems and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0187] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of the system or unit, which can be electrical, mechanical or other forms.

[0188] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0189] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0190] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0191] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for locating ground faults in distribution lines based on wide area synchronization technology, characterized in that: The following steps are involved: A distribution network model is constructed according to the structure of the distribution network, and a synchronous vector measurement system PMU is configured on the nodes of the distribution network model; Based on the distribution network model and configured PMU, a corresponding GIS map system is constructed, the GIS map system is associated with the drone image acquisition module, and the dangerous factors affecting the distribution grounding are marked on the GIS map system, and the dangerous factors are regularly updated based on the on-site images collected by the drone image acquisition module in the later stage; The marked GIS map system is associated with the weather forecast information system and the distribution network operation and maintenance information system respectively, and an early warning trigger mechanism is set between the marked points of the GIS map system and the associated information; When a line grounding fault occurs at a certain time, a graded warning is issued to the corresponding area of ​​the GIS map system associated with external information, and then the rough positioning area is obtained; Taking the coarse positioning area as the center of the circle, control the PMU measurement recording data in the area with a certain distance as the radius, perform fault line selection based on the waveform similarity principle according to the recording data, sort the fault line selection results, and determine the selected line in the first preset order as the fault line selection analysis result; Actively intervene and verify the fault line selection analysis results to achieve further line selection and positioning; If the line selection is completed, the fault point location is performed by the line fault point distance measurement method; The setting of the warning trigger mechanism between the marking points and the associated information of the GIS map system includes: When the GIS map system receives the zero-sequence voltage and zero-sequence current data from the PMU, it determines that a fault has occurred, and the server adds all the received fault information to the power distribution GIS database; the fault information includes the PMU ID number, zero-sequence voltage, zero-sequence current, phase and amplitude; Based on the PMU ID number, combined with the risk factors affecting power distribution grounding, operation and maintenance information, and weather information, predict the location of possible faults within a certain area where the PMU with the corresponding ID number is located; Based on the fault information and the possible fault location, the entire distribution network is topologically analyzed through the fault segmentation location algorithm to obtain the probabilistic classification result of the fault location; According to the probabilistic classification result of the fault location, the device ID of the GIS map system is obtained, and then the location of the obtained device ID is marked on the GIS map system and highlighted on the GIS map system; The predicted location of a possible fault within a certain area where the PMU with the corresponding ID number is located includes: According to the ID number of the PMU, retrieve the area range information of the PMU corresponding to the ID number on the GIS map; Retrieving operation and maintenance information, hazard factors and weather information of electrical equipment within the scope information of the area; If the adverse conditions of operation and maintenance information, risk factors and weather information all occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 90%; If any two of the adverse conditions of operation and maintenance information, dangerous factors and weather information occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 60%; If any of the adverse conditions of operation and maintenance information, risk factors and weather information occurs at the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 30%; Among them, unfavorable situations of operation and maintenance information include the recent construction or replacement of equipment and lines or the expiration of equipment service life; Unfavorable situations of risk factors include buildings, forests, trees, roads, construction sites, factories, rivers or landslides next to distribution lines; Adverse conditions of weather information include rain, snow, strong wind, thunder and lightning or haze.

2. The method for locating ground faults in distribution lines based on wide area synchronization technology according to claim 1, characterized in that: The fault segmentation location algorithm includes: The direction from the substation side to the load terminal is defined as the current reference direction, and the path from the power supply side to the fault point is called the fault path; Definition 1: The fault section refers specifically to the section where the ground fault occurs in the distribution line; Definition 2: If the busbar passes through certain measuring points before reaching the fault point through the fault path, the fault point is said to be downstream of these measuring points, otherwise the fault point is said to be upstream of these measuring points; If at some measuring point among certain measuring points, the zero-sequence current lags the zero-sequence voltage by 90°, it means that the measuring point is in the fault path and the fault point is downstream of the measuring point; if at some measuring point among certain measuring points, the zero-sequence current leads the zero-sequence voltage by 90°, it means that the measuring point is not in the fault path and the fault point is upstream of the measuring point.

3. The method for locating ground faults in distribution lines based on wide area synchronization technology according to claim 1, characterized in that: The method of performing fault line selection based on waveform similarity principle according to the recorded data, sorting the fault line selection results, and determining the selected lines in the first preset order as the fault line selection analysis results includes: According to the recorded data collected by PMU on each line in the rough positioning area, the current traveling wave signal of each line is transformed to obtain the zero-mode component of the current traveling wave : ； In the formula, represents the first line mode current, represents the second line mode current, is the zero mode current, represents the first phase current, represents the second phase current, is the third phase current; The zero-mode component of the current traveling wave of each line is obtained by using S transformation Perform time-frequency domain analysis to obtain the time-frequency spectrum matrix of each line ; Time-frequency spectrum matrix for each line Perform pairwise correlation analysis to obtain the similarity correlation coefficient matrix R: ； Where m is the line number, m=1, 2, ..., n; Calculate the sum of the elements in each row of the similarity correlation coefficient matrix R to obtain the comprehensive correlation coefficient R of each route m ,Right now ； ； In the formula, R mj is the correlation coefficient between line m and line j, and the sum of the elements in each row of the solved matrix is ​​taken as the comprehensive correlation coefficient of each line to amplify the difference between the faulty line and the sound line; According to the comprehensive correlation coefficient matrix The polarity and amplitude relationship between the elements in the formula form the fault line selection criterion, namely: ； The above formula indicates that if the comprehensive correlation coefficient of the mth line is the smallest and its positive and negative polarities are opposite to those of the other n-1 lines, then the mth line is determined to be a faulty line and the other lines are sound lines; according to The fault line selection results are sorted, and the selection lines that are ranked in a front preset order are screened out, and the screened selection lines are determined as the fault line selection analysis results.

4. The method for locating ground faults in distribution lines based on wide area synchronization technology according to claim 1, characterized in that: The active intervention verification of the fault line selection analysis result includes: The signal injection method is used to actively intervene and verify the fault line selection analysis results.

5. The method for locating ground faults in distribution lines based on wide area synchronization technology according to claim 1, characterized in that: The fault point distance measurement method is an impedance method or a fault recording analysis method.

6. A distribution line ground fault location system based on wide area synchronization technology, wherein the distribution line ground fault location system based on wide area synchronization technology is used to implement the distribution line ground fault location method based on wide area synchronization technology as claimed in any one of claims 1 to 5, characterized in that: include: A configuration unit, used for building a distribution network model according to the structure of the distribution network, and configuring a synchronous vector measurement system PMU on the nodes of the distribution network model; The marking unit is used to build a corresponding GIS map system based on the distribution network model and the configured PMU, associate the GIS map system with the UAV image acquisition module, mark the dangerous factors affecting the distribution grounding on the GIS map system, and regularly update the dangerous factors based on the on-site images collected by the UAV image acquisition module in the later stage; An association unit is used to associate the marked GIS map system with the weather forecast information system and the distribution network operation and maintenance information system respectively, and to set up an early warning trigger mechanism between the marked points of the GIS map system and the associated information; The classification unit is used to give a classification warning to the corresponding area of ​​the GIS map system associated with external information when a line grounding fault occurs at a certain time, and then obtain the rough positioning area position; The fault line selection unit is used to control the PMU measurement recording data in an area with a certain distance as the radius, taking the rough positioning area as the center of the circle, and performing fault line selection based on the waveform similarity principle according to the recording data, sorting the fault line selection results, and determining the selected line in the first preset order as the fault line selection analysis result; Verification unit, used to actively intervene and verify the fault line selection analysis results to achieve further line selection and positioning; A positioning unit, used to locate the fault point by using the line fault point distance measurement method after the line selection is completed; Wherein, the association unit is further used for: When the GIS map system receives the zero-sequence voltage and zero-sequence current data from the PMU, it determines that a fault has occurred, and the server adds all the received fault information to the power distribution GIS database; the fault information includes the PMU ID number, zero-sequence voltage, zero-sequence current, phase and amplitude; Based on the PMU ID number, combined with the risk factors affecting power distribution grounding, operation and maintenance information, and weather information, predict the location of possible faults within a certain area where the PMU with the corresponding ID number is located; Based on the fault information and the possible fault location, the entire distribution network is topologically analyzed through the fault segmentation location algorithm to obtain the probabilistic classification result of the fault location; According to the probabilistic classification result of the fault location, the device ID of the GIS map system is obtained, and then the location of the obtained device ID is marked on the GIS map system and highlighted on the GIS map system; According to the ID number of the PMU, retrieve the area range information of the PMU corresponding to the ID number on the GIS map; Retrieving operation and maintenance information, hazard factors and weather information of electrical equipment within the scope information of the area; If the adverse conditions of operation and maintenance information, risk factors and weather information all occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 90%; If any two of the adverse conditions of operation and maintenance information, dangerous factors and weather information occur within the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 60%; If any of the adverse conditions of operation and maintenance information, risk factors and weather information occurs at the time when the PMU measures the fault signal, the probability of line fault in the area is determined to be 30%; Among them, unfavorable situations of operation and maintenance information include the recent construction or replacement of equipment and lines or the expiration of equipment service life; Unfavorable situations of risk factors include buildings, forests, trees, roads, construction sites, factories, rivers or landslides next to distribution lines; Adverse conditions of weather information include rain, snow, strong wind, thunder and lightning or haze.

7. A distribution line ground fault location device based on wide area synchronization technology, characterized in that: The distribution line ground fault location device based on wide area synchronization technology includes: processor; A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the method according to any one of claims 1 to 5 is implemented.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program codes, which can be called by a processor to execute the method according to any one of claims 1 to 5.

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