A single-phase ground fault detection method and system

Abstract

The present application provides a single-phase ground fault detection system, comprising: an unmanned mobile detection module, used to detect a detection signal in a distribution line; a signal injection module, used to inject a preset detection signal into the distribution line; a feeder terminal module, used to obtain power data of each distribution section in the distribution line; and a processing center, used for data processing and controlling other modules; wherein the unmanned mobile detection module, the signal injection module and the feeder terminal module are communicatively connected to the processing center; wherein the unmanned mobile detection module comprises an unmanned mobile module, a signal detection module, a camera module, a positioning module and a communication module, wherein the signal detection module, the camera module, the positioning module and the communication module are respectively arranged in the unmanned mobile module, and the communication module is communicatively connected to the processing center.

Description

Technical Field

[0001] The present application relates to the field of electric power, and in particular to a single-phase grounding fault detection method and system. Background Art

[0002] In power systems, single-phase grounding faults are a common type of fault that occurs when one phase of the conductor accidentally contacts the earth or grounding equipment. This fault may be caused by a variety of reasons, such as aging of insulation materials, equipment damage, external factors such as tree branches or animal interference, etc. Single-phase grounding faults may cause system voltage imbalance, equipment overheating, protection device malfunction, and in severe cases may even cause fire or endanger personal safety.

[0003] In order to detect and handle single-phase grounding faults in a timely manner, the power industry has developed a variety of technical methods. Currently, the widely used technologies include impedance method, traveling wave method and artificial intelligence assisted diagnosis.

[0004] These methods all have some limitations. For example, the impedance method is greatly affected by path impedance, line load and power supply parameters. For distribution lines with multiple branches, the impedance method cannot eliminate pseudo fault points. The refraction and reflection of the traveling wave method at the wave impedance discontinuity point will make the traveling wave waveform measured at one end of the line particularly complex, and it is difficult to correctly identify the reflected wave of the fault point, making ranging difficult. The artificial intelligence method relies on a large amount of high-quality historical data. Summary of the invention

[0005] The present application provides a single-phase ground fault detection system, comprising:

[0006] Unmanned mobile detection module, used to detect detection signals in distribution lines;

[0007] A signal injection module, used to inject a preset detection signal into the distribution line;

[0008] A feeder terminal module, used to obtain power data of each distribution section in the distribution line; and

[0009] Processing center, used for data processing and controlling other modules;

[0010] Wherein, the unmanned movement detection module, the signal injection module and the feeder terminal module are communicatively connected to the processing center;

[0011] Among them, the unmanned motion detection module includes an unmanned motion module, a signal detection module, a camera module, a positioning module and a communication module. The signal detection module, the camera module, the positioning module and the communication module are respectively arranged in the unmanned motion module, and the communication module is communicatively connected to the processing center.

[0012] By adopting the above technical scheme, the single-phase grounding fault detection system can determine the section where the single-phase grounding fault occurs in the distribution line through the feeder terminal module, and determine the phase where the single-phase grounding fault occurs, and inject the detection signal into the faulty phase through the signal injection module, and move in the section where the single-phase grounding fault occurs through the unmanned mobile detection module and receive the strength of the detection signal, and then determine the occurrence location of the single-phase grounding fault according to the change in the strength of the detection signal, which can improve the efficiency, accuracy and coverage of fault detection.

[0013] Optionally, the phase grounding fault detection system further includes a single-phase grounding fault detection strategy, comprising the following steps:

[0014] A1, obtaining node power data of each distribution node through each feeder terminal module on a preset distribution line;

[0015] A2, the processing center determines the subsequent distribution nodes of each distribution node according to the preset distribution topology data;

[0016] A3, the processing center determines the single-phase grounding fault section according to the node power data of each distribution node and the corresponding subsequent distribution node;

[0017] A4, the processing center determines the ground fault phase according to the node power data of the subsequent distribution node corresponding to the single-phase ground fault section;

[0018] A5, injecting a preset detection signal into the ground fault phase at a preset injection signal frequency through the signal injection module;

[0019] A6, determining the route location information of the single-phase grounding fault section according to the power distribution topology data and defining it as the fault route location information;

[0020] A7, moving the unmanned mobile detection module in the single-phase grounding fault section according to the fault route location information to determine the single-phase grounding fault point.

[0021] By adopting the above technical solution, the single-phase grounding fault detection system can determine the adjacent distribution nodes through the power grid topology data, and determine whether there is a single-phase grounding fault in the line section between them according to the power data of the adjacent distribution nodes, and determine the corresponding fault phase, and then inject a detection signal into the fault phase, and use the unmanned mobile detection module to move along the line section and obtain the strength of the detection signal, and finally determine the fault point of the single-phase grounding according to the change in the strength of the detection signal, which can greatly reduce the workload of manual detection and reduce personnel risks, while also improving the fault location speed, facilitating rapid maintenance and repair, and improving the reliability and service quality of the power grid.

[0022] Optionally, the single-phase grounding fault detection strategy further includes the following steps for determining the single-phase grounding fault point:

[0023] B1, when the unmanned motion detection module moves, the signal detection module continuously receives the signal strength value corresponding to the injected signal frequency, and simultaneously obtains the corresponding signal positioning data through the positioning module;

[0024] B2, calculating the corresponding signal strength difference according to two adjacent signal strength values, and determining the signal positioning interval according to the corresponding signal positioning data;

[0025] B3, determining the signal strength difference with the largest value among all signal strength differences and determining the single-phase grounding fault point according to the corresponding signal positioning data.

[0026] By adopting the above technical solution, the single-phase grounding fault detection system can realize efficient and accurate fault point location through the continuous movement of the unmanned mobile detection module and real-time signal strength measurement, combined with accurate positioning data. By calculating the difference between adjacent signal strengths and associating it with the position information, the system can capture the area with the most significant signal strength change, thereby accurately locating the fault point, which not only improves the positioning efficiency of the grounding position, but also avoids the risk of electric shock that may be caused by manual detection.

[0027] Optionally, the single-phase grounding fault detection strategy further includes the following steps for determining the single-phase grounding fault section:

[0028] C1, obtains three-phase current data from the node power data of the distribution node and calculates and generates corresponding node zero-sequence current data;

[0029] C2, obtains three-phase voltage data from the node power data of the distribution node and calculates and generates corresponding node zero-sequence voltage data;

[0030] C3, determining the corresponding node zero-sequence current relative phase according to the node zero-sequence current data and the node zero-sequence voltage data;

[0031] C4, acquiring three-phase current data from the node power data of the subsequent distribution node and calculating and generating the corresponding zero-sequence current data of the subsequent node;

[0032] C5, acquiring three-phase voltage data from the node power data of the subsequent distribution node and calculating and generating the corresponding subsequent node zero-sequence voltage data;

[0033] C6, determining the corresponding subsequent node zero-sequence current relative phase according to the subsequent node zero-sequence current data and the subsequent node zero-sequence voltage data;

[0034] C7, determining the corresponding zero-sequence current phase difference according to the node zero-sequence current relative phase and the subsequent node zero-sequence current relative phase;

[0035] C8, if the zero-sequence current phase difference is greater than the preset phase difference threshold, the distribution line between the distribution node and the subsequent distribution node is defined as a single-phase grounding fault section.

[0036] By adopting the above technical scheme, the single-phase grounding fault detection system can calculate the zero-sequence current and zero-sequence voltage by analyzing the three-phase current and voltage data of the distribution node and its subsequent nodes, and compare the zero-sequence current phase difference between adjacent nodes to locate the fault section. The method based on zero-sequence quantity analysis can effectively identify single-phase grounding faults without being affected by factors such as load imbalance, thereby improving the accuracy and reliability of fault detection. It can not only quickly locate the fault section, but also provide an important basis for the subsequent precise fault point positioning.

[0037] Optionally, the single-phase ground fault detection strategy further includes the following steps for determining the ground fault phase:

[0038] D1, determine the corresponding phase voltage values ​​according to the three-phase voltage data of the subsequent distribution node;

[0039] D2, determine the minimum value among the corresponding phase voltage values ​​of each phase and define the corresponding phase as the suspected grounding phase, and define the other phases as normal phases;

[0040] D3, if the phase voltage value of the suspected grounded phase is less than the preset phase voltage lower threshold, and the phase voltage values ​​of each normal phase are greater than the preset phase voltage upper threshold, the suspected grounded phase is determined to be a ground fault phase;

[0041] D4, if the phase voltage of the ground fault phase is less than the preset metallic grounding phase voltage threshold, the preset grounding type information is assigned as complete grounding;

[0042] D5, if the phase voltage of the ground fault phase is greater than or equal to the metallic grounding phase voltage threshold, the grounding type information is assigned as incomplete grounding.

[0043] By adopting the above technical solution, the single-phase grounding fault detection system can quickly lock the suspected grounding phase by comparing the phase voltage values, and then further verify it by setting upper and lower thresholds, which can effectively reduce the misjudgment rate. At the same time, by introducing the metallic grounding phase voltage threshold, it can preliminarily distinguish between complete grounding and incomplete grounding, providing more information support for subsequent fault handling, and providing more detailed fault information for operation and maintenance personnel, which is conducive to fast and effective fault handling.

[0044] Optionally, the single-phase grounding fault detection system further includes a fault feature collection strategy, and the fault feature collection strategy includes the following steps:

[0045] E1, at a single-phase grounding fault point, the camera module of the unmanned mobile detection module acquires image data of the corresponding distribution line and defines it as fault image data;

[0046] E2, obtaining corresponding environmental data through the feeder terminal module corresponding to the single-phase grounding fault section and defining it as fault environmental data, and obtaining corresponding power data and defining it as fault power data;

[0047] E3, according to the single-phase grounding fault point, obtain the corresponding regional meteorological data from the preset meteorological database and define it as fault meteorological data;

[0048] E4, combining fault image data, fault environment data, fault power data, fault meteorological data and grounding type information to generate a single-phase grounding fault feature data set.

[0049] By adopting the above technical solution, the single-phase grounding fault detection system can form a comprehensive and detailed fault feature data set by comprehensively collecting multi-dimensional fault-related data, thereby providing a multi-angle and comprehensive fault feature information. This comprehensive data collection method can improve the accuracy and depth of subsequent fault analysis, and help to better understand the causes and environmental factors of the fault. At the same time, the rich data set also provides valuable basic data for future fault prediction, preventive maintenance and power grid optimization, and can be used to train specific recognition models for the prediction of single-phase grounding faults. Through this systematic data collection and integration, fault diagnosis can be more effectively performed, maintenance strategies can be formulated, and the reliability and stability of the power grid can be continuously improved.

[0050] Optionally, the single-phase ground fault detection system further includes a line inspection strategy, and the line inspection strategy includes the following steps:

[0051] F1, generate the corresponding single-phase grounding identification model based on the single-phase grounding fault feature data set training;

[0052] F2, controlling the unmanned mobile detection module to move on the distribution line and acquiring corresponding distribution line image data;

[0053] F3, obtaining positioning data through the unmanned detection module and defining it as inspection positioning information;

[0054] F4, determining the corresponding feeder terminal module according to the inspection positioning information and the power distribution topology data and obtaining the corresponding power data and environmental data defined as inspection power data and inspection environmental data;

[0055] F5, obtain corresponding meteorological data from the meteorological database according to the inspection positioning information and define it as inspection meteorological data;

[0056] F6, generating a ground fault probability prediction value through a single-phase grounding identification model based on distribution line image data, inspection power data, inspection environment data, and inspection meteorological data;

[0057] F7: If the predicted value of the ground fault probability is greater than the preset response threshold, a preset suspected ground fault warning message is issued.

[0058] By adopting the above technical solution, the single-phase grounding fault detection system can use the collected comprehensive fault feature data to train the single-phase grounding identification model, thereby realizing intelligent and automated fault prediction. Through the continuous inspection of the unmanned mobile detection module, multi-dimensional data can be collected in real time, and the trained model can be used for real-time analysis and prediction, which not only improves the efficiency and coverage of the inspection, but also can timely discover potential fault hazards, significantly improve the safety and reliability of the power grid, and also reduce the cost and risk of manual inspection. In addition, it can continuously accumulate data, further optimize the prediction model, and form a virtuous cycle of intelligent maintenance system.

[0059] The present application also provides a single-phase ground fault detection method, which is characterized by comprising the following steps:

[0060] G1, obtain node power data of each distribution node in the preset distribution line;

[0061] G2, determining the subsequent distribution nodes of each distribution node according to the preset distribution topology data;

[0062] G3, determining the single-phase grounding fault section according to the node power data of each distribution node and the corresponding subsequent distribution node;

[0063] G4, determining the ground fault phase according to the node power data of the subsequent distribution node corresponding to the single-phase ground fault section;

[0064] G5, injecting a preset detection signal into the ground fault phase at a preset injection signal frequency;

[0065] G6, determining the route location information of the single-phase grounding fault section according to the power distribution topology data and defining it as the fault route location information;

[0066] G7, moves the preset unmanned mobile detection module to the single-phase grounding fault section according to the fault route location information;

[0067] G8, when the unmanned motion detection module moves, continuously receiving the signal strength value corresponding to the injected signal frequency, and simultaneously acquiring the corresponding signal positioning data;

[0068] G9, sequentially calculating corresponding signal strength differences according to two adjacent signal strength values, and determining a signal positioning interval according to corresponding signal positioning data;

[0069] G10, determine the signal strength difference with the largest value among all signal strength differences and determine the single-phase grounding fault point according to the corresponding signal positioning data.

[0070] By adopting the above technical solution, the single-phase grounding fault detection system can determine the adjacent distribution nodes through the power grid topology data, and determine whether there is a single-phase grounding fault in the line section between them according to the power data of the adjacent distribution nodes, and determine the corresponding fault phase, and then inject a detection signal into the fault phase, and use the unmanned mobile detection module to move along the line section and obtain the strength of the detection signal, and finally determine the single-phase grounding fault point according to the change in the strength of the detection signal, which can greatly reduce the workload of manual detection and reduce personnel risks, while also improving the fault location speed, facilitating rapid maintenance and repair, and improving the reliability and service quality of the power grid.

[0071] In summary, the present application includes at least one of the following beneficial technical effects:

[0072] 1. The feeder terminal module can be used to determine the section where the single-phase grounding fault occurs in the distribution line, and the phase where the single-phase grounding fault occurs, and the detection signal can be injected into the faulty phase through the signal injection module, and the unmanned mobile detection module can move in the section where the single-phase grounding fault occurs and receive the strength of the detection signal, and then determine the occurrence location of the single-phase grounding fault according to the change in the strength of the detection signal, which can improve the efficiency, accuracy and coverage of fault detection.

[0073] 2. Adjacent distribution nodes can be determined through grid topology data, and whether there is a single-phase grounding fault in the line section between them can be determined based on the power data of the adjacent distribution nodes, and the corresponding fault phase can be determined. Then, a detection signal can be injected into the fault phase, and the unmanned mobile detection module 10 can move along the line section and obtain the strength of the detection signal. Finally, the single-phase grounding fault point can be determined based on the change in the strength of the detection signal. This can greatly reduce the workload of manual detection and reduce personnel risks. At the same time, it also improves the speed of fault location, facilitates rapid maintenance and repair, and improves the reliability and service quality of the power grid.

[0074] 3. The continuous movement of the unmanned mobile detection module and real-time signal strength measurement, combined with precise positioning data, can achieve efficient and accurate fault point positioning. By calculating the difference in adjacent signal strengths and associating it with the location information, the system can capture the area with the most significant signal strength change, thereby accurately locating the fault point, which not only improves the efficiency of grounding location positioning, but also avoids the risk of electric shock that may be caused by manual detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 The diagram is a schematic diagram of the principle of a single-phase grounding fault detection system of the present invention.

[0076] Figure 2 The present invention is a schematic diagram of a process of a single-phase grounding fault detection method. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0078] The embodiments of the present application are further described in detail below in conjunction with the drawings in the specification.

[0079] refer to Figure 1 The present application provides a single-phase grounding fault detection system for detecting and locating a single-phase grounding fault in a power distribution line. The single-phase grounding fault detection system comprises:

[0080] An unmanned mobile detection module 10, used to detect the injected detection signal in the power distribution line;

[0081] A signal injection module 20, used to inject a preset detection signal into the distribution line;

[0082] A feeder terminal module 30, used to obtain power data of each distribution section in the distribution line; and

[0083] Processing center 40, used for data processing and controlling other modules;

[0084] Wherein, the unmanned movement detection module 10, the signal injection module 20 and the feeder terminal module 30 are communicatively connected to the processing center 40;

[0085] Among them, the unmanned motion detection module includes an unmanned motion module 11, a signal detection module 12, a camera module 13, a positioning module 14 and a communication module 15. The signal detection module 12, the camera module 13, the positioning module 14 and the communication module 15 are respectively arranged in the unmanned motion module 11, and the communication module 15 is communicatively connected to the processing center 40.

[0086] The unmanned movement detection module 10 is mainly used to detect the detection signal injected into the distribution line, and determine the single-phase grounding position in the distribution line according to the detected signal strength.

[0087] The signal injection module 20 is mainly used to inject a detection signal of a specific frequency into the determined grounded phase, so that the unmanned movement detection module 10 can detect the corresponding signal strength and determine the single-phase grounding position according to the signal strength.

[0088] The feeder terminal module 30 is mainly used to detect power-related data of each distribution node to determine the line section where a single-phase grounding fault occurs.

[0089] Preferably, the signal injection module 20 may be integrated into the feeder terminal module 30 .

[0090] The processing center 40 is mainly used to process data and control each module.

[0091] The unmanned mobile module 11 is mainly used to move along the line section where a single-phase grounding fault occurs to detect the signal strength of the detection signal injected on the line; the unmanned mobile module 11 can be a drone or an unmanned vehicle.

[0092] The signal detection module 12 is mainly used to detect the electromagnetic signal of the same frequency generated by the injection of the detection signal in the distribution line, and then determine the grounding position according to the change of the electromagnetic signal strength. The signal strength will be significantly weakened before and after the grounding position.

[0093] The camera module 13 is mainly used to obtain image data, especially to capture image data at the grounding position, so as to determine the cause of the grounding fault.

[0094] The positioning module 14 is used to obtain positioning data to ensure that the unmanned mobile module 11 can move accurately and provide accurate ground fault positioning information when the ground fault position is found.

[0095] The communication module 15 is mainly used for data and control command communication between the unmanned motion detection module 10 and the processing center 40 .

[0096] Through the above technical scheme, the single-phase grounding fault detection system can determine the section where the single-phase grounding fault occurs in the distribution line through the feeder terminal module 30, and determine the phase where the single-phase grounding fault occurs, and inject the detection signal into the faulty phase through the signal injection module 20, and move the unmanned mobile detection module 10 in the section where the single-phase grounding fault occurs and receive the strength of the detection signal, and then determine the occurrence location of the single-phase grounding fault according to the change in the strength of the detection signal, which can improve the efficiency, accuracy and coverage of fault detection.

[0097] Furthermore, the single-phase grounding fault detection system also includes a single-phase grounding fault detection strategy, including the following steps:

[0098] A1, obtaining node power data of each distribution node through each feeder terminal module 30 on a preset distribution line;

[0099] The distribution line is a pre-selected power grid line that needs to be tested for single-phase ground faults;

[0100] The node power data is the power-related data at each distribution node, such as voltage, current, power and other related data;

[0101] By setting the feeder terminal module 30 at each power distribution node, the corresponding power data can be acquired in real time.

[0102] A2, the processing center 40 determines the subsequent distribution nodes of each distribution node according to the preset distribution topology data;

[0103] The distribution topology data is the data of the connection relationship between the distribution nodes corresponding to the distribution lines, which can be detected and obtained in advance;

[0104] The subsequent distribution node is a distribution node that is located after a certain distribution node determined according to the distribution direction in the distribution topology data.

[0105] A3, the processing center 40 determines the single-phase grounding fault section according to the node power data of each distribution node and the corresponding subsequent distribution node;

[0106] The single-phase grounding fault section is a line section where a single-phase grounding fault exists in the line between two adjacent distribution nodes;

[0107] Determine whether there is a single-phase grounding fault in the line between two adjacent distribution nodes based on power data. For example, the voltage changes of each phase can be used to determine whether there is a single-phase grounding fault between two adjacent distribution nodes. The phase voltages of the two nodes can be compared. In the case of a single-phase grounding fault, the voltage of the faulty phase will drop significantly, while the voltages of the other two phases may rise slightly; or judge by phase current, the current of the grounding fault phase will increase sharply; or judge a single-phase grounding fault based on zero-sequence current, a single-phase grounding fault will produce an obvious zero-sequence current.

[0108] A4, the processing center 40 determines the ground fault phase according to the node power data of the subsequent distribution node corresponding to the single-phase ground fault section;

[0109] The ground fault phase is a phase where a single-phase ground fault occurs, and can be determined by different methods according to power data, such as the method exemplified in step A3.

[0110] A5, injecting a preset detection signal into the ground fault phase at a preset injection signal frequency through the signal injection module 20;

[0111] The injection signal frequency is a preset frequency value, which is used to determine the frequency of the detection signal;

[0112] The detection signal is an AC signal set according to the frequency of the injection signal;

[0113] The injection signal frequency can be set according to the frequency of the AC power in the distribution network. In order to avoid interference from the fundamental wave and harmonics of the original AC power in the power grid, the fundamental wave frequency of the injection signal current can be set between the nth harmonic and the n+1th harmonic of the power frequency (n is a positive integer) to prevent the interference of the power frequency fundamental wave and its harmonics on the detection signal. For example, if the frequency of the AC power in the distribution network is 50Hz, and the harmonics are 100Hz, 150Hz, 200Hz, 250Hz, etc., then the frequency between two adjacent harmonics can be selected to inject the detection signal, for example, 175Hz can be selected;

[0114] Among them, the detection signal can be injected into the secondary side of the PT.

[0115] A6, determining the route location information of the single-phase grounding fault section according to the power distribution topology data and defining it as the fault route location information;

[0116] The route positioning information is the positioning information corresponding to the single-phase grounding fault section. The positioning data of two adjacent distribution nodes can be obtained according to the distribution nodes corresponding to the single-phase grounding fault section and the distribution topology data, thereby determining the route positioning information;

[0117] The fault route location information is the route location information of the single-phase grounding fault section.

[0118] A7, moving the unmanned mobile detection module 10 in the single-phase grounding fault section according to the fault route location information to determine the single-phase grounding fault point;

[0119] By controlling the movement of the unmanned mobile detection module 10 in the single-phase grounding fault section and detecting the intensity change of the detection signal of the line in the single-phase grounding fault section, the fault point where the single-phase grounding occurs, that is, the single-phase grounding fault point, can be determined.

[0120] Through the above steps, the single-phase grounding fault detection system can determine the adjacent distribution nodes through the power grid topology data, and determine whether there is a single-phase grounding fault in the line section between them according to the power data of the adjacent distribution nodes, and determine the corresponding fault phase, and then inject a detection signal into the fault phase, and use the unmanned mobile detection module 10 to move along the line section and obtain the strength of the detection signal, and finally determine the single-phase grounding fault point according to the change in the strength of the detection signal, which can greatly reduce the workload of manual detection and reduce personnel risks, while also improving the fault location speed, facilitating rapid maintenance and repair, and improving the reliability and service quality of the power grid.

[0121] Furthermore, the single-phase grounding fault detection strategy further includes the following steps for determining the single-phase grounding fault point:

[0122] B1, when the unmanned motion detection module 10 moves, the signal detection module 12 continuously receives the signal strength value corresponding to the injected signal frequency, and simultaneously obtains the corresponding signal positioning data through the positioning module 14;

[0123] The signal strength value is the strength of the electromagnetic wave signal with the same frequency as the injected signal detected by the signal detection module 12;

[0124] The signal positioning data is positioning data synchronously acquired when the signal detection module 12 detects the signal, and is used to match the signal strength to identify the signal strength detected at each position;

[0125] When a signal current of a specific frequency is injected into the distribution line, the line will emit an electromagnetic wave signal of the same frequency to the surrounding area. The grounding position can be determined by monitoring the change in the signal strength of the electromagnetic wave of the corresponding frequency. Since the injected detection signal flows into the earth along the grounding position, there is a large difference in the signal strength before and after the grounding position, which can be clearly detected.

[0126] For example, a fixed detection interval distance may be set, and each time the unmanned motion detection module 10 moves a fixed distance, the signal strength is detected once and the signal positioning data is acquired once.

[0127] B2, calculating the corresponding signal strength difference according to two adjacent signal strength values, and determining the signal positioning interval according to the corresponding signal positioning data;

[0128] The signal strength difference is the difference between the signal strength values ​​obtained from two adjacent signal detections;

[0129] The signal positioning interval is the spatial range determined by the signal positioning data corresponding to two adjacent signal detections. For example, the positioning information during the first signal detection is 100 meters from the starting point, and the positioning information during the second signal detection is 110 meters from the detection starting point. The signal positioning interval is 100 to 110 meters. The signal positioning interval can have various data forms, and can also be GPS positioning data, etc.

[0130] B3, determining the signal strength difference with the largest value among all signal strength differences and determining the single-phase grounding fault point according to the corresponding signal positioning data;

[0131] The single-phase grounding fault point is the fault point location data calculated from the signal location data corresponding to the maximum signal strength difference;

[0132] For example, after the unmanned mobile detection module 10 moves through the single-phase grounding fault section and detects the detection signal strength, it is found that the signal strength difference between 150 meters and 160 meters from the detection starting point is the largest, then it can be determined that the grounding position is within this range, and the grounding position can be centrally estimated to be at 155 meters, which is convenient for subsequent further detection or emergency repairs by staff.

[0133] Through the above steps, the single-phase grounding fault detection system can achieve efficient and accurate fault point location through the continuous movement of the unmanned mobile detection module and real-time signal strength measurement, combined with accurate positioning data. By calculating the difference between adjacent signal strengths and associating it with the position information, the system can capture the area where the signal strength changes most significantly, thereby accurately locating the fault point, which not only improves the efficiency of locating the grounding position, but also avoids the risk of electric shock that may be caused by manual detection.

[0134] Furthermore, the single-phase grounding fault detection strategy further includes the following steps for determining the single-phase grounding fault section:

[0135] C1, obtains three-phase current data from the node power data of the distribution node and calculates and generates corresponding node zero-sequence current data;

[0136] The three-phase current data is the current data of each phase in the node current data obtained by the feeder terminal module 30 at the power distribution node;

[0137] The node zero-sequence current data is the zero-sequence current data at the distribution node calculated based on the three-phase current data.

[0138] C2, obtains three-phase voltage data from the node power data of the distribution node and calculates and generates corresponding node zero-sequence voltage data;

[0139] The three-phase voltage data is the voltage data of each phase in the node voltage data obtained by the feeder terminal module 30 at the power distribution node;

[0140] The node zero-sequence voltage data is the zero-sequence voltage data at the distribution node calculated based on the three-phase voltage data.

[0141] C3, determining the corresponding node zero-sequence current relative phase according to the node zero-sequence current data and the node zero-sequence voltage data;

[0142] The relative phase of the node zero-sequence current is the phase difference between the zero-sequence current and the zero-sequence voltage at the distribution node.

[0143] C4, acquiring three-phase current data from the node power data of the subsequent distribution node and calculating and generating the corresponding zero-sequence current data of the subsequent node;

[0144] The subsequent node zero-sequence current data is the zero-sequence current data at the subsequent distribution node calculated based on the three-phase current data.

[0145] C5, acquiring three-phase voltage data from the node power data of the subsequent distribution node and calculating and generating the corresponding subsequent node zero-sequence voltage data;

[0146] The subsequent node zero-sequence voltage data is the zero-sequence voltage data at the subsequent distribution node calculated based on the three-phase voltage data.

[0147] C6, determining the corresponding subsequent node zero-sequence current relative phase according to the subsequent node zero-sequence current data and the subsequent node zero-sequence voltage data;

[0148] The relative phase of the zero-sequence current of the subsequent node is the phase difference between the zero-sequence current and the zero-sequence voltage at the subsequent distribution node.

[0149] C7, determining the corresponding zero-sequence current phase difference according to the node zero-sequence current relative phase and the subsequent node zero-sequence current relative phase;

[0150] The zero-sequence current phase difference is the difference between the relative phase of the zero-sequence current of a node and the relative phase of the zero-sequence current of the subsequent node;

[0151] If the zero-sequence current at the distribution node lags the zero-sequence voltage by about 90°, and the zero-sequence current at the subsequent distribution node leads the zero-sequence voltage by about 90°, that is, the zero-sequence current phase difference between the two nodes is close to 180°, then it can be determined that a single-phase grounding fault exists in the distribution line between the distribution node and the subsequent distribution node.

[0152] C8, if the zero-sequence current phase difference is greater than the preset phase difference threshold, the distribution line between the distribution node and the subsequent distribution node is defined as a single-phase grounding fault section;

[0153] The phase difference threshold is a preset reference value used to determine whether the zero-sequence current phase difference reaches the standard for being determined as single-phase grounding. For example, the phase difference threshold can be set to 150°.

[0154] Through the above steps, the single-phase grounding fault detection system can calculate the zero-sequence current and zero-sequence voltage by analyzing the three-phase current and voltage data of the distribution node and its subsequent nodes, and compare the zero-sequence current phase difference between adjacent nodes to locate the fault section. The method based on zero-sequence quantity analysis can effectively identify single-phase grounding faults without being affected by factors such as load imbalance, thereby improving the accuracy and reliability of fault detection. It can not only quickly locate the fault section, but also provide an important basis for subsequent precise fault point positioning.

[0155] Furthermore, the single-phase ground fault detection strategy further includes the following steps for determining the ground fault phase:

[0156] D1, determine the corresponding phase voltage values ​​according to the three-phase voltage data of the subsequent distribution node;

[0157] The phase voltage value is the phase voltage of each phase measured at the subsequent distribution node.

[0158] D2, determine the minimum value among the corresponding phase voltage values ​​of each phase and define the corresponding phase as the suspected grounding phase, and define the other phases as normal phases;

[0159] The suspected grounded phase is the phase with the lowest phase voltage value, which may be grounded;

[0160] The normal phase is the ungrounded phase.

[0161] D3, if the phase voltage value of the suspected grounded phase is less than the preset phase voltage lower threshold, and the phase voltage values ​​of each normal phase are greater than the preset phase voltage upper threshold, the suspected grounded phase is determined to be a ground fault phase;

[0162] The phase voltage lower threshold is a preset reference value, which is used to determine whether the phase voltage value of the suspected grounded phase is low enough to be determined as a single-phase grounding fault;

[0163] The phase voltage upper threshold is a preset reference value used to determine whether the phase voltage value of each normal phase is high enough to be determined as a single-phase grounding fault;

[0164] Generally, when a single-phase grounding fault occurs, if it is completely grounded, the phase voltage of the grounded phase is close to 0, and the voltage value of the normal phase will be close to the line voltage; if it is incompletely grounded, the phase voltage of the grounded phase will be lower than the phase voltage during normal operation, and the voltage value of the normal phase will be higher than the phase voltage during normal operation and lower than the line voltage;

[0165] For example, for a 220V three-phase AC distribution line, when it is not completely grounded, the voltage value of the grounded phase will usually be significantly less than 220V, while the voltage value of the normal phase will exceed 220V and be less than 380V. When it is completely grounded, the voltage value of the grounded phase is close to 0, and the voltage value of the normal phase is close to 380V.

[0166] D4, if the phase voltage of the ground fault phase is less than the preset metallic grounding phase voltage threshold, the preset grounding type information is assigned as complete grounding;

[0167] The metallic grounding phase voltage threshold is a preset reference value used to determine whether the grounding fault phase has reached the standard for being determined as metallic grounding; for example, 50% of the rated phase voltage can be used as the metallic grounding phase voltage threshold, and for a 220V AC distribution line, 110V is used as the metallic grounding phase voltage threshold;

[0168] The grounding type information is a preset state parameter used to define the type of the single-phase grounding fault.

[0169] D5, if the phase voltage of the ground fault phase is greater than or equal to the metallic grounding phase voltage threshold, the grounding type information is assigned as incomplete grounding;

[0170] Through the above steps, the single-phase grounding fault detection system can quickly lock the suspected grounding phase by comparing the phase voltage values, and then further verify it by setting upper and lower thresholds, which can effectively reduce the misjudgment rate. At the same time, by introducing the metallic grounding phase voltage threshold, it can preliminarily distinguish between complete grounding and incomplete grounding, providing more information support for subsequent fault handling, and providing more detailed fault information for operation and maintenance personnel, which is conducive to fast and effective fault handling.

[0171] Furthermore, the single-phase grounding fault detection system further includes a fault feature collection strategy, and the fault feature collection strategy includes the following steps:

[0172] E1, at the single-phase grounding fault point, the camera module 13 of the unmanned mobile detection module 10 acquires the image data of the corresponding distribution line and defines it as fault image data;

[0173] The fault image data is an image of the distribution line taken at the single-phase grounding fault point, which can be transmitted back to the processing center 40 for the backstage staff to determine the single-phase grounding fault, and can also be used as training data for training the automatic recognition model.

[0174] E2, obtaining corresponding environmental data and defining it as fault environmental data through the feeder terminal module 30 corresponding to the single-phase grounding fault section, and obtaining corresponding power data and defining it as fault power data;

[0175] The environmental data may be the temperature, humidity, noise and other related data of the surrounding environment obtained by the feeder terminal module 30;

[0176] The fault environment data is the environment data of the single-phase grounding fault section, which is used to reflect the operating environment factors when a single-phase grounding fault occurs in the single-phase grounding fault section, and can be a collection of environment data of two distribution points corresponding to the single-phase grounding fault section;

[0177] The fault power data is the power data of the single-phase grounding fault section, which is used to reflect the change of power factors when a single-phase grounding fault occurs in the single-phase grounding fault section. It can be the collection of power data of two distribution points corresponding to the single-phase grounding fault section.

[0178] E3, according to the single-phase grounding fault point, obtain the corresponding regional meteorological data from the preset meteorological database and define it as fault meteorological data;

[0179] The meteorological database is a pre-set database used to obtain meteorological data;

[0180] The fault meteorological data is the meteorological data corresponding to the single-phase grounding fault section when a grounding fault occurs.

[0181] E4, combining fault image data, fault environment data, fault power data, fault meteorological data and grounding type information to generate a single-phase grounding fault feature data set.

[0182] The single-phase grounding fault characteristic dataset is a collection of various data corresponding to the single-phase grounding fault section.

[0183] Through the above steps, the single-phase grounding fault detection system can form a comprehensive and detailed fault feature data set by comprehensively collecting multi-dimensional fault-related data, thereby providing a multi-angle and comprehensive fault feature information. This comprehensive data collection method can improve the accuracy and depth of subsequent fault analysis, and help to better understand the causes and environmental factors of the fault. At the same time, the rich data set also provides valuable basic data for future fault prediction, preventive maintenance and power grid optimization, and can be used to train specific recognition models for the prediction of single-phase grounding faults. Through this systematic data collection and integration, fault diagnosis can be more effectively performed, maintenance strategies can be formulated, and the reliability and stability of the power grid can be continuously improved.

[0184] Furthermore, the single-phase grounding fault detection system also includes a line inspection strategy, including the following steps:

[0185] F1, generate the corresponding single-phase grounding identification model based on the single-phase grounding fault feature data set training;

[0186] The single-phase grounding identification model is a machine learning model trained based on the single-phase grounding fault characteristic data, and is used to identify and predict single-phase grounding faults in distribution lines.

[0187] F2, controlling the unmanned movement detection module 10 to move on the power distribution line and acquiring corresponding power distribution line image data;

[0188] The distribution line image data is an image of the distribution line acquired by the camera module 13 of the unmanned motion detection module 10 .

[0189] F3, obtaining positioning data through the unmanned detection module 10 and defining it as inspection positioning information;

[0190] The inspection positioning information is positioning information data acquired by the positioning module 14 of the unmanned detection module 10 .

[0191] F4, determining the corresponding feeder terminal module 30 according to the inspection positioning information and the power distribution topology data and obtaining the corresponding power data and environmental data defined as inspection power data and inspection environmental data;

[0192] The inspection power data and inspection environment data are the power data and environment data of two distribution nodes corresponding to the distribution section determined according to the inspection positioning information.

[0193] F5, obtain corresponding meteorological data from the meteorological database according to the inspection positioning information and define it as inspection meteorological data;

[0194] The inspection meteorological data is the meteorological data at the current moment obtained from the meteorological database based on the inspection positioning information.

[0195] F6, generating a ground fault probability prediction value through a single-phase grounding identification model based on distribution line image data, inspection power data, inspection environment data, and inspection meteorological data;

[0196] The fault probability prediction value is the predicted probability value of the single-phase grounding fault generated by the single-phase grounding identification model according to the input data.

[0197] F7: If the predicted value of the ground fault probability is greater than the preset response threshold, a preset suspected ground fault warning message is issued.

[0198] The response threshold is a pre-set reference value used to determine whether the predicted value of the ground fault probability meets the standard for making a response action;

[0199] The suspected grounding warning information is a pre-set warning message used to warn background staff of the possible existence of a single-phase grounding fault.

[0200] Through the above steps, the single-phase grounding fault detection system can use the collected comprehensive fault feature data to train the single-phase grounding identification model, thereby realizing intelligent and automated fault prediction. Through the continuous inspection of the unmanned mobile detection module, it can collect multi-dimensional data in real time, and use the trained model for real-time analysis and prediction, which not only improves the efficiency and coverage of the inspection, but also can timely discover potential fault hazards, significantly improve the safety and reliability of the power grid, and also reduce the cost and risk of manual inspection. In addition, it can continuously accumulate data, further optimize the prediction model, and form a virtuous cycle of intelligent maintenance system.

[0201] The present application also provides a single-phase ground fault detection method, comprising the following steps:

[0202] G1, obtain node power data of each distribution node in the preset distribution line;

[0203] G2, determining the subsequent distribution nodes of each distribution node according to the preset distribution topology data;

[0204] G3, determining the single-phase grounding fault section according to the node power data of each distribution node and the corresponding subsequent distribution node;

[0205] G4, determining the ground fault phase according to the node power data of the subsequent distribution node corresponding to the single-phase ground fault section;

[0206] G5, injecting a preset detection signal into the ground fault phase at a preset injection signal frequency;

[0207] G6, determining the route location information of the single-phase grounding fault section according to the power distribution topology data and defining it as the fault route location information;

[0208] G7, moving the preset unmanned mobile detection module 10 in the single-phase grounding fault section according to the fault route location information;

[0209] G8, when the unmanned motion detection module 10 moves, continuously receiving the signal strength value corresponding to the injected signal frequency, and simultaneously acquiring the corresponding signal positioning data;

[0210] G9, sequentially calculating corresponding signal strength differences according to two adjacent signal strength values, and determining a signal positioning interval according to corresponding signal positioning data;

[0211] G10, determine the signal strength difference with the largest value among all signal strength differences and determine the single-phase grounding fault point according to the corresponding signal positioning data.

[0212] Through the above steps, the single-phase grounding fault detection system can determine the adjacent distribution nodes through the power grid topology data, and determine whether there is a single-phase grounding fault in the line section between them according to the power data of the adjacent distribution nodes, and determine the corresponding fault phase, and then inject a detection signal into the fault phase, and use the unmanned mobile detection module 10 to move along the line section and obtain the strength of the detection signal, and finally determine the fault point of the single-phase grounding according to the change in the strength of the detection signal, which can greatly reduce the workload of manual detection and reduce personnel risks, while also improving the fault location speed, facilitating rapid maintenance and repair, and improving the reliability and service quality of the power grid.

[0213] The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Any feature disclosed in this specification (including the abstract and drawings), unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

Claims

1. A single-phase ground fault detection system, characterized in that: include: Unmanned mobile detection module, used to detect detection signals in distribution lines; A signal injection module, used to inject a preset detection signal into the distribution line; Feeder terminal module, used to obtain power data of each distribution section in the distribution line; and Processing center, used for data processing and controlling other modules; Wherein, the unmanned movement detection module, the signal injection module and the feeder terminal module are communicatively connected to the processing center; Wherein, the unmanned mobile detection module includes an unmanned mobile module, a signal detection module, a camera module, a positioning module and a communication module, the signal detection module, the camera module, the positioning module and the communication module are respectively arranged in the unmanned mobile module, and the communication module is communicatively connected to the processing center; The single-phase grounding fault detection system further includes a single-phase grounding fault detection strategy, including the following steps: A1, obtaining node power data of each distribution node through each feeder terminal module on a preset distribution line; A2, the processing center determines the subsequent distribution nodes of each distribution node according to the preset distribution topology data; A3, the processing center determines the single-phase grounding fault section according to the node power data of each distribution node and the corresponding subsequent distribution node; A4, the processing center determines the ground fault phase according to the node power data of the subsequent distribution node corresponding to the single-phase ground fault section; A5, injecting a preset detection signal into the ground fault phase at a preset injection signal frequency through the signal injection module; A6, determining the route location information of the single-phase grounding fault section according to the power distribution topology data and defining it as the fault route location information; A7, moving the unmanned mobile detection module in the single-phase grounding fault section according to the fault route location information to determine the single-phase grounding fault point; The single-phase grounding fault detection strategy further includes the following steps for determining the single-phase grounding fault section: C1, obtains three-phase current data from the node power data of the distribution node and calculates and generates corresponding node zero-sequence current data; C2, obtains three-phase voltage data from the node power data of the distribution node and calculates and generates corresponding node zero-sequence voltage data; C3, determining the corresponding node zero-sequence current relative phase according to the node zero-sequence current data and the node zero-sequence voltage data; C4, acquiring three-phase current data from the node power data of the subsequent distribution node and calculating and generating the corresponding zero-sequence current data of the subsequent node; C5, acquiring three-phase voltage data from the node power data of the subsequent distribution node and calculating and generating the corresponding subsequent node zero-sequence voltage data; C6, determining the corresponding subsequent node zero-sequence current relative phase according to the subsequent node zero-sequence current data and the subsequent node zero-sequence voltage data; C7, determining the corresponding zero-sequence current phase difference according to the node zero-sequence current relative phase and the subsequent node zero-sequence current relative phase; C8, if the zero-sequence current phase difference is greater than the preset phase difference threshold, the distribution line between the distribution node and the subsequent distribution node is defined as a single-phase grounding fault section.

2. The single-phase grounding fault detection system according to claim 1, characterized in that: The single-phase grounding fault detection strategy further includes the following steps for determining the single-phase grounding fault point: B1, when the unmanned motion detection module moves, the signal detection module continuously receives the signal strength value corresponding to the injected signal frequency, and simultaneously obtains the corresponding signal positioning data through the positioning module; B2, calculating the corresponding signal strength difference according to two adjacent signal strength values, and determining the signal positioning interval according to the corresponding signal positioning data; B3, determining the signal strength difference with the largest value among all signal strength differences and determining the single-phase grounding fault point according to the corresponding signal positioning data.

3. The single-phase grounding fault detection system according to claim 2, characterized in that: The single-phase ground fault detection strategy further comprises the following steps for determining the ground fault phase: D1, determine the corresponding phase voltage values ​​according to the three-phase voltage data of the subsequent distribution node; D2, determine the minimum value among the corresponding phase voltage values ​​of each phase and define the corresponding phase as the suspected grounding phase, and define the other phases as normal phases; D3, if the phase voltage value of the suspected grounded phase is less than the preset phase voltage lower threshold, and the phase voltage values ​​of each normal phase are greater than the preset phase voltage upper threshold, the suspected grounded phase is determined to be a ground fault phase; D4, if the phase voltage of the ground fault phase is less than the preset metallic grounding phase voltage threshold, the preset grounding type information is assigned as complete grounding; D5, if the phase voltage of the ground fault phase is greater than or equal to the metallic grounding phase voltage threshold, the grounding type information is assigned as incomplete grounding.

4. The single-phase grounding fault detection system according to claim 3, characterized in that: Further comprising a fault feature collection strategy, the fault feature collection strategy comprising the following steps: E1, at a single-phase grounding fault point, the camera module of the unmanned mobile detection module acquires image data of the corresponding distribution line and defines it as fault image data; E2, obtaining corresponding environmental data through the feeder terminal module corresponding to the single-phase grounding fault section and defining it as fault environmental data, and obtaining corresponding power data and defining it as fault power data; E3, according to the single-phase grounding fault point, obtain the corresponding regional meteorological data from the preset meteorological database and define it as fault meteorological data; E4, combining fault image data, fault environment data, fault power data, fault meteorological data and grounding type information to generate a single-phase grounding fault feature data set.

5. The single-phase grounding fault detection system according to claim 4, characterized in that: Further comprising a line inspection strategy, the line inspection strategy The following steps are involved: F1, generate the corresponding single-phase grounding identification model based on the single-phase grounding fault feature data set training; F2, controlling the unmanned mobile detection module to move on the distribution line and acquiring corresponding distribution line image data; F3, obtaining positioning data through the unmanned detection module and defining it as inspection positioning information; F4, determining the corresponding feeder terminal module according to the inspection positioning information and the power distribution topology data and obtaining the corresponding power data and environmental data defined as inspection power data and inspection environmental data; F5, obtain corresponding meteorological data from the meteorological database according to the inspection positioning information and define it as inspection meteorological data; F6, generating a ground fault probability prediction value through a single-phase grounding identification model based on distribution line image data, inspection power data, inspection environment data, and inspection meteorological data; F7: If the predicted value of the ground fault probability is greater than the preset response threshold, a preset suspected ground fault warning message is issued.

6. A single-phase ground fault detection method, characterized in that: The following steps are involved: Obtain node power data of each distribution node on a preset distribution line; Determine the subsequent distribution nodes of each distribution node according to the preset distribution topology data; Determine the single-phase grounding fault section according to the node power data of each distribution node and the corresponding subsequent distribution node; Determine the ground fault phase according to the node power data of the subsequent distribution node corresponding to the single-phase ground fault section; injecting a preset detection signal into the ground fault phase at a preset injection signal frequency; Determine route location information of a single-phase grounding fault section according to distribution topology data and define the route location information as fault route location information; According to the fault route location information, a preset unmanned mobile detection module is moved to the single-phase grounding fault section; When the unmanned motion detection module moves, continuously receiving the signal strength value corresponding to the injected signal frequency, and simultaneously acquiring the corresponding signal positioning data; Calculating corresponding signal strength differences according to two adjacent signal strength values ​​in sequence, and determining a signal positioning interval according to corresponding signal positioning data; Determine the signal strength difference with the largest value among all signal strength differences and determine the single-phase grounding fault point according to the corresponding signal positioning data; The single-phase grounding fault detection method further comprises the following steps for determining the single-phase grounding fault section: Obtain three-phase current data from the node power data of the distribution node and calculate and generate corresponding node zero-sequence current data; Obtain three-phase voltage data from node power data of distribution nodes and calculate and generate corresponding node zero-sequence voltage data; Determine the corresponding node zero-sequence current relative phase according to the node zero-sequence current data and the node zero-sequence voltage data; Obtain three-phase current data from node power data of subsequent distribution nodes and calculate and generate corresponding subsequent node zero-sequence current data; Obtain three-phase voltage data from node power data of subsequent distribution nodes and calculate and generate corresponding subsequent node zero-sequence voltage data; Determine the corresponding subsequent node zero-sequence current relative phase according to the subsequent node zero-sequence current data and the subsequent node zero-sequence voltage data; Determine a corresponding zero-sequence current phase difference according to a node zero-sequence current relative phase and a subsequent node zero-sequence current relative phase; If the zero-sequence current phase difference is greater than a preset phase difference threshold, the distribution line between the distribution node and the subsequent distribution node is defined as a single-phase grounding fault section.

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