Fault positioning method and device for box-type substation

Abstract

The invention provides a fault positioning method and device for a box-type substation, and the method comprises the steps: obtaining a topological structure of the box-type substation, and recognizing all switch nodes and terminal equipment nodes; according to the current flow direction and the electric energy transmission path, establishing a directed graph model of the box-type substation; a sensor array is deployed on the switch node and the terminal equipment, electrical parameters of a deployment area are monitored in real time, fault detection and signal analysis are carried out according to a set threshold value, and a fault signal is determined; according to the current flow direction in the topological structure and a fault signal in the sensor data, analyzing the current flow direction at the fault moment, determining a monitoring area where the fault signal is located, and preliminarily positioning a fault area; and according to the change rate of the voltage and the current of the preliminarily positioned fault area, the distance from the fault point to the nearest sensor is calculated by combining cable parameters and transmission delay, the fault position is accurately positioned, and rapid and accurate positioning of the fault is realized.

Description

Technical Field

[0001] The invention relates to the technical field of substations, and in particular to a fault locating system for a box-type substation. Background Art

[0002] In the power system, a box-type substation (also called a combined substation or prefabricated substation) is a compact substation that integrates high-voltage equipment, transformers, and low-voltage equipment. It is widely used in urban buildings, residential areas, high-tech development zones, small factories, mines, oil fields, and other places, as well as temporary facilities or places where emergency power is needed. Box-type substations have the advantages of small footprint, low investment, quick installation, and reliable operation.

[0003] Although the box-type substation is designed with full consideration of safety and reliability, failures are still inevitable during actual operation due to factors such as external environment, operational errors, and equipment aging. Since box-type substations are usually closed structures with compact internal equipment layout, once a failure occurs, it is a very challenging task to quickly and accurately locate the fault point. Traditional fault location methods mainly rely on experience judgment and external test instruments. These methods are not only time-consuming and labor-intensive, but may also interfere with other equipment inside the substation.

[0004] Smarter fault location systems need to be able to automatically collect and analyze data, as well as make quick decisions. Existing technologies may include various sensors and data acquisition systems, but they often lack efficient data processing methods, especially when dealing with complex fault modes. In addition, rapid response after a fault is essential to maintaining stable operation of the power system, but existing technologies often fail to provide real-time fault analysis and location.

[0005] In addition, with the development of smart grids, higher requirements are placed on the intelligence level of substations. This includes but is not limited to real-time monitoring, fault warning, automatic isolation and power restoration. In this context, existing fault location methods and devices are not advanced enough to meet the future power grid's needs for automation and intelligence.

[0006] Therefore, how to develop a new box-type substation fault location method and device to improve the speed and accuracy of fault diagnosis, reduce power outage time, improve the reliability and efficiency of the entire power system, and realize rapid capture, intelligent analysis and precise positioning of fault signals has important practical application value. Summary of the invention

[0007] In view of this, in order to solve the problems of traditional fault location methods such as long time consumption, low accuracy and inability to achieve real-time fault processing, the purpose of the present invention is to propose a fault location method and device for a box-type substation. By adopting advanced sensor arrays, data processing units, machine learning modules and communication interfaces, the fault can be quickly and accurately located, and it has automatic isolation and repair suggestion functions to improve the stability and reliability of the power system.

[0008] Based on the above purpose, in a first aspect, the present invention provides a fault location method for a box-type substation, comprising the following steps:

[0009] Obtain the topological structure of the box-type substation and identify all switch nodes and terminal equipment nodes;

[0010] According to the current flow direction and power transmission path, a directed graph model of the box-type substation is established to reflect the directed edge relationship between nodes, and the power grid of the box-type substation is divided into multiple monitoring areas accordingly;

[0011] Deploy sensor arrays on switch nodes and terminal devices to monitor electrical parameters in the deployment area in real time, and report the electrical parameters collected by each sensor to the data processing unit in real time according to the assigned area identifier;

[0012] The data processing unit continuously monitors sensor data, sets thresholds for fault detection and signal analysis, and determines fault signals based on detected abnormal data;

[0013] According to the current flow direction in the topology structure and the fault signal in the sensor data, the current flow direction at the time of the fault is analyzed, the monitoring area where the fault signal is located is determined, and the fault area is preliminarily located;

[0014] Based on the change rate of voltage and current in the fault area, combined with cable parameters and transmission delay, the distance from the fault point to the nearest sensor is calculated to accurately locate the fault location;

[0015] After locating the fault location, the switch device of the corresponding switch node is automatically controlled to open or close, the fault section is isolated, and the fault location result is fed back.

[0016] As a further solution of the present invention, a directed graph model of a box-type substation is established according to the current flow direction and the electric energy transmission path, including the following steps:

[0017] Based on the switch nodes and terminal equipment nodes set on the topological structure of the box-type substation, all electrical connection data of the substation are collected;

[0018] According to the topological structure of the box-type substation, all the components in the substation are defined as nodes in the graph. According to the electrical connection data, the connection relationship between the nodes is determined, and the edges in the graph are defined accordingly.

[0019] Determine the direction of the edge according to the actual flow direction of the current, and use the graphics library in the programming language to input the data of the nodes and edges to build a directed graph model of the substation;

[0020] By simulating the flow of current in the substation, we verify whether the directed graph model reflects the actual power transmission path; and adjust the direction of the edges in the directed graph and add missing connections based on the test results.

[0021] As a further solution of the present invention, all electrical connection data of the substation include connection data of transformers, switches, cable lines and load elements; and equipment parameters of impedance and rated current between the power supply end and the load end.

[0022] As a further solution of the present invention, the direction of the edge determined according to the actual flow direction of the current is the direction from the power supply end to the load end, which is used to characterize the actual transmission direction of the electric energy in the directed graph model.

[0023] As a further solution of the present invention, after constructing the directed graph model of the substation, it also includes: identifying all source nodes (power supply ends) and sink nodes (load ends) in the directed graph model.

[0024] As a further solution of the present invention, the directed graph model of the substation also includes a dynamic update mechanism for updating the directed graph model to reflect the new current flow direction and power transmission path when the internal configuration or load condition of the substation changes.

[0025] As a further solution of the present invention, the power grid of the box-type substation is divided into multiple monitoring areas, including the following steps:

[0026] According to the topological structure of the box-type substation and the directed graph model of the substation, the key nodes in the substation are identified, where the key nodes are the branch points or convergence points in the flow of electric energy;

[0027] According to the power flow direction and the key nodes of the substation, the key nodes covering the power transmission path are determined as monitoring points;

[0028] According to the topological structure of the monitoring point in the box-type substation and the position of the monitoring point in the power transmission path, the power grid is divided into multiple monitoring areas; wherein each monitoring area includes at least one monitoring point;

[0029] And based on the directed edge relationships between nodes, clear regional boundaries are defined for each monitoring area.

[0030] As a further solution of the present invention, a sensor array is deployed on the switch node and the terminal device, and the sensor array includes a current transformer (CT), a voltage transformer (VT), a power metering sensor and a temperature sensor, and real-time monitoring of electrical parameters of the deployment area including voltage, current, power, power factor, frequency and temperature; the fault location method of the box-type substation also includes establishing a communication network between the sensor array and a data acquisition unit (DAU for short) to collect data from the sensor array in real time.

[0031] As a further solution of the present invention, in a data processing unit, setting a threshold value for fault detection and signal analysis includes the following steps:

[0032] Determine the normal operating range of each electrical parameter based on historical data and equipment operating parameters, and set thresholds: including warning thresholds and critical thresholds;

[0033] Using a data processing unit to receive monitoring data reported by the sensor array in real time, and perform real-time analysis based on set warning thresholds and critical thresholds to detect any electrical parameters that exceed preset thresholds;

[0034] When an electrical parameter exceeds a critical threshold or exhibits an abnormal pattern, it is flagged as a fault signal.

[0035] As a further solution of the present invention, the fault area is initially located, comprising the following steps: traversing the electrical parameter data before and after the fault moment according to the timestamp of the marked fault signal, and analyzing the change of the current flow direction in combination with the topological structure of the box-type substation and the directed graph model;

[0036] According to the change of current flow direction and the system load condition when the fault occurs, a potential fault area with at least one fault signal is determined in multiple monitoring areas divided by the power grid, and the fault area is preliminarily located.

[0037] As a further solution of the present invention, accurately locating the fault position includes the following steps:

[0038] According to the preliminary positioning of the fault area, the sensors at the fault signal location collect the waveform data of voltage and current at the time of the fault, and record the current and voltage change rates when the fault occurs;

[0039] Determine the cable parameters of the cable where the fault signal is located according to the power transmission path: resistance, reactance and dielectric constant of the cable, determine the inductance and propagation speed of the cable;

[0040] According to the current and voltage change rates when the fault occurs and the cable parameters of the cable, the transient behavior of the voltage and current at the time of the fault is analyzed, and the arrival time and reflection time of the transient traveling wave are determined according to the traveling wave generated by the fault;

[0041] Using the principle of traveling wave method, according to the propagation speed and arrival time of traveling wave in the cable, the distance from the fault point to the sensor is calculated to accurately locate the fault position.

[0042] As a further solution of the present invention, when calculating the distance from the fault point to the sensor, the distance is calculated using the time difference between the arrival time of the traveling wave recorded by the sensor and the time when the fault occurs. The distance calculation formula is:

[0043]

[0044] Where D is the distance from the fault point to the nearest sensor, V is the propagation speed of the traveling wave in the cable, and T is the time it takes for the traveling wave to reach the sensor.

[0045] Among them, the propagation speed V of the traveling wave in the cable is determined by the dielectric constant of the cable, and the calculation formula is:

[0046]

[0047] Where V is the propagation velocity of the traveling wave; μ is the magnetic permeability of the medium. For power cables made of non-magnetic materials, the magnetic permeability of free space is used. Magnetic Permeability The value of is 4π×10 -7 H / m; ε is the absolute permittivity of the medium, expressed as the dielectric constant ε γ Permittivity to free space The product of Permittivity of free space The value is 8.854×10 -12 F / m.

[0048] In a second aspect, the present invention provides a fault location device for a box-type substation, comprising:

[0049] Data Acquisition Unit (DAU): communicates with the sensor array to collect electrical parameters in real time;

[0050] Data processing unit: receives data from the data acquisition unit, sets warning thresholds and critical thresholds, performs fault detection and signal analysis, and preliminarily locates the fault area;

[0051] Model building module: input substation topology, node and edge data to build a directed graph model;

[0052] Region division module: Identify key nodes, divide the power grid into multiple monitoring areas, and define clear regional boundaries;

[0053] Fault location module: uses topology structure and real-time electrical parameter data, combined with fault signals and current change rate, to accurately locate the fault location;

[0054] Control unit: automatically controls the corresponding switch nodes according to the fault location results and isolates the fault area.

[0055] Communication network: used to connect the data acquisition unit, sensor array, and data processing unit and transmit data;

[0056] User interface: visualizes topology and fault information, and provides a user interface for monitoring, control, and troubleshooting.

[0057] In another aspect of the present invention, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, any one of the above-mentioned methods for locating faults in a box-type substation according to the present invention is executed.

[0058] In another aspect of the present invention, a computer-readable storage medium is provided, which stores computer program instructions. When the computer program instructions are executed, any one of the above-mentioned methods for locating faults in a box-type substation according to the present invention is implemented.

[0059] Compared with the prior art, the present invention provides a method and device for locating a fault in a box-type substation, which has the following beneficial effects:

[0060] 1. Improved accuracy and speed of fault location: By integrating real-time monitoring of electrical parameters with advanced signal processing technology, this device can quickly and accurately identify faults, greatly reducing the time for fault location. The application of the traveling wave method in the present invention provides accurate fault distance measurement and reduces the possibility of mislocation.

[0061] 2. Real-time monitoring and automatic control: Continuous monitoring function ensures real-time update of system status, which helps to immediately detect and respond to faults; automatic control function allows the system to automatically isolate the fault area when a fault is detected, reducing delays and errors in human operations.

[0062] 3. Reduce the impact of power outages: Rapidly locating and isolating the fault area means that power supply to non-fault areas can be restored quickly, thereby reducing the scope and duration of power outages and alleviating the impact on users.

[0063] 4. Optimize maintenance work: The accuracy of fault location makes maintenance work more targeted, improves maintenance efficiency, reduces maintenance costs, and can also reduce the on-site operation time of maintenance personnel and reduce safety risks.

[0064] 5. Easy system upgrade and maintenance: It can be enhanced through remote updates, making the system easy to expand and maintain. The recording and analysis of fault data can help further optimize system design and maintenance strategies. The real-time response and precise control of the system enhance the stability and reliability of the power grid and help prevent the spread of faults.

[0065] In summary, the fault location method and device of the box-type substation of the present invention not only improves the fault location efficiency and safety of power supply, but also reduces operating costs, enhances the stability and reliability of the system, and significantly contributes to reducing operation and maintenance costs.

[0066] These and other aspects of the present application will be more concise and understandable in the following description of the embodiments. It should be understood that the above general description and the following detailed description are only exemplary and explanatory and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0068] In the figure:

[0069] Figure 1 The present invention is a flowchart of a method for locating a fault in a box-type substation according to an embodiment of the present invention.

[0070] Figure 2 The present invention provides a flowchart for establishing a directed graph model in a fault location method for a box-type substation according to an embodiment of the present invention.

[0071] Figure 3 The present invention is a flowchart of a method for locating a fault in a box-type substation divided into multiple monitoring areas according to an embodiment of the present invention.

[0072] Figure 4 The present invention is a flowchart of accurately locating a fault position in a fault locating method for a box-type substation according to an embodiment of the present invention.

[0073] Figure 5 The figure is a structural block diagram of a fault location device for a box-type substation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0074] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0075] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. 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.

[0076] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are intended to distinguish two non-identical entities or non-identical parameters with the same name. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, other steps or units inherent to a process, method, device, product or equipment that includes a series of steps or units.

[0077] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0078] The flowcharts shown in the accompanying drawings are only examples and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may also be decomposed, combined or partially merged, so the actual execution order may change according to actual conditions.

[0079] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0080] See also Figure 1 As shown, an embodiment of the present invention provides a fault location method for a box-type substation, the method comprising the following steps:

[0081] S1. Obtain the topological structure of the box-type substation and identify all switch nodes and terminal device nodes;

[0082] S2. According to the current flow direction and the power transmission path, a directed graph model of the box-type substation is established to reflect the directed edge relationship between nodes, and the power grid of the box-type substation is divided into multiple monitoring areas accordingly;

[0083] S3, deploying sensor arrays on switch nodes and terminal devices to monitor electrical parameters of the deployment area in real time, and reporting the electrical parameters collected by each sensor to the data processing unit in real time according to the assigned area identifier;

[0084] S4, the data processing unit continuously monitors the sensor data, sets the threshold value for fault detection and signal analysis, and determines the fault signal based on the detected abnormal data;

[0085] S5. Analyze the current flow direction at the time of the fault according to the current flow direction in the topological structure and the fault signal in the sensor data, determine the monitoring area where the fault signal is located, and preliminarily locate the fault area;

[0086] S6. Based on the change rate of the voltage and current in the fault area initially located, combined with the cable parameters and transmission delay, the distance from the fault point to the nearest sensor is calculated to accurately locate the fault location;

[0087] S7. After locating the fault position, the switch device of the corresponding switch node is automatically controlled to open or close, the fault section is isolated, and the fault location result is fed back.

[0088] The fault location method of the box-type substation of the present invention can quickly and accurately locate the fault point through intelligent monitoring and data analysis, thereby shortening the power outage time, improving the reliability of power supply, and the speed and accuracy of fault diagnosis. In the above steps S1 and S2, the Internet of Things technology is used to obtain the topological structure data inside the substation in real time, and the obtained topological structure data is analyzed, so as to update the topological structure diagram of the substation in real time; moreover, the deployed sensor array not only measures electrical parameters, but also monitors various physical parameters such as temperature and vibration, providing more comprehensive data support for fault analysis. After the sensor data is reported, when the fault area is initially located, the positioning accuracy is improved by fault simulation and historical data comparison. When the fault point is accurately located, the high-frequency traveling wave principle of the cable and the time difference positioning method are used, combined with the accurate calculation of cable parameters and transmission delay, to improve the positioning accuracy of the fault point. When isolating the fault section, automatic control can be realized, the fault section can be quickly cut off by the intelligent switching device, the fault impact range is minimized, and the network is automatically reconstructed by the intelligent system to restore the power supply to the non-fault area.

[0089] Therefore, the fault location method of the box-type substation of the present invention realizes rapid response and processing of the box-type substation fault. The whole process is highly automated, from fault detection to isolation, which can be completed in the shortest time, greatly improving the reliability and self-healing ability of the power grid.

[0090] In this embodiment, see Figure 2 As shown, according to the current flow direction and the power transmission path, a directed graph model of a box-type substation is established, including the following steps:

[0091] S101. Based on the switch nodes and terminal device nodes set on the topological structure of the box-type substation, all electrical connection data of the substation are collected.

[0092] In this step, an intelligent sensor network is deployed to collect electrical connection data of each switch node and terminal equipment in the substation in real time. All electrical connection data of the substation includes connection data of transformers, switches, cable lines and load elements; as well as equipment parameters such as impedance and rated current between the power supply end and the load end.

[0093] S102, defining all components in the substation as nodes in a graph according to the topological structure of the box-type substation, determining the connection relationship between the nodes according to the electrical connection data, and defining the edges in the graph accordingly.

[0094] In this step, based on the definition in graph theory, the electrical components of the substation are mapped as nodes in the graph, including transformers, switches, cable lines, etc., while the electrical connection data are defined as edges in the graph.

[0095] S103. Determine the direction of the edge according to the actual flow direction of the current, and use the graphics library in the programming language to input the data of the nodes and edges to build a directed graph model of the substation.

[0096] In this step, the direction of the edge determined according to the actual flow direction of the current is the direction from the power supply end to the load end, which is used to represent the actual transmission direction of electric energy in the directed graph model.

[0097] After constructing the directed graph model of the substation, the method further includes: identifying all source nodes (power supply ends) and sink nodes (load ends) in the directed graph model.

[0098] S104. Verify whether the directed graph model reflects the actual power transmission path by simulating the flow of current in the substation; and adjust the direction of the edges in the directed graph and add missing connections according to the verification results.

[0099] In this step, the inspection results are used to adjust the directed graph model to ensure that it accurately represents the actual operating state. When adding missing connections, new nodes or edges are added to the model to include components or connections that were not previously considered.

[0100] In this embodiment, the directed graph model of the substation is constructed to further include a dynamic update mechanism, which is used to update the directed graph model to reflect the new current flow direction and power transmission path when the internal configuration or load condition of the substation changes.

[0101] For example, it is assumed that the substation contains two power supply terminals (source nodes A and B) and three load terminals (sink nodes X, Y and Z). The power supply terminals are connected to the load terminals through a series of switches and transformers. In actual operation, A and B may provide different power outputs according to demand, and the demand of load terminals X, Y and Z will also change over time. Among them, in the data collection stage, the output parameters of the power supply terminals A and B and the input parameters of the load terminals X, Y and Z are collected through sensors connected to the switch nodes and terminal devices. In the graph model construction stage, the connection relationship between nodes A and B, X, Y and Z is determined according to the collected electrical connection data, and a directed graph model is established. In the graph model, the connection relationship between nodes is represented by edges, and the direction of the edge points from the power supply terminal to the load terminal. In the simulation verification stage, the current flow direction is simulated by simulation software to verify the accuracy of the graph model. If it is found that the direction of the edge does not match the actual current flow direction, or there is a missing connection, it is adjusted. Finally, in the dynamic update mechanism, when the internal configuration or load situation of the substation changes, the directed graph model is automatically updated.

[0102] The above-mentioned fault location method of box-type substation ensures the accuracy and practicality of the directed graph model through intelligent data collection and processing. The dynamic nature of the graph model can timely reflect the changes in the internal configuration or load conditions of the substation, improve the flexibility and efficiency of the substation operation, and this implementation can greatly improve the operational reliability of the substation, reduce the failure rate, and provide a powerful tool for fault diagnosis and energy management.

[0103] In this embodiment, see Figure 3 As shown, the power grid of the box-type substation is divided into multiple monitoring areas, including the following steps:

[0104] S201. According to the topological structure of the box-type substation and the directed graph model of the substation, key nodes in the substation are identified, wherein the key nodes are branch points or convergence points in the flow of electric energy.

[0105] S202, determining key nodes covering the power transmission path as monitoring points according to the power flow direction and key nodes of the substation;

[0106] S203, dividing the power grid into a plurality of monitoring areas according to the topological structure of the monitoring point in the box-type substation and the position of the monitoring point in the power transmission path; wherein each monitoring area includes at least one monitoring point;

[0107] S204: Based on the directed edge relationship between the nodes, a clear area boundary is defined for each monitoring area.

[0108] Exemplarily, it is assumed that there is a box-type substation, which includes two incoming lines (source nodes A and B), a main transformer (key node T), and three outgoing lines connected to loads in three different areas (sink nodes X, Y and Z). Among them, in the key node identification stage, node T is identified as a key node as the main distribution point of electric energy. In the monitoring point determination stage, monitoring points are set on the incoming and outgoing lines of node T, and monitoring points are set on load aggregation points X, Y and Z. In the grid division stage, three monitoring areas are divided with the monitoring point as the center, and each area includes a load aggregation point and a transmission path to the point. In the area boundary definition stage, the input and output boundaries of each monitoring area are determined, that is, the path from the source node to the load aggregation point.

[0109] In summary, through the above steps, the power grid of the box-type substation can be divided into multiple monitoring areas, and the electrical parameters of each area can be monitored in real time by the sensor array deployed at the key nodes. This partition monitoring method enhances the transparency of the power grid and enables operation and maintenance personnel to respond to faults in the substation more quickly and accurately. The communication network between the deployed sensor array and DAU ensures the real-time and accuracy of the monitoring data, and provides data support for the rapid location and processing of faults in the box-type substation. Ultimately, the implementation of this method will improve the reliability and stability of the box-type substation, reduce maintenance costs, and improve service quality.

[0110] Among them, a sensor array is deployed on the switch node and the terminal device, and the sensor array includes a current transformer (CT), a voltage transformer (VT), a power metering sensor and a temperature sensor, and the electrical parameters of the deployment area including voltage, current, power, power factor, frequency and temperature are monitored in real time; the fault location method of the box-type substation also includes establishing a communication network between the sensor array and a data acquisition unit (DAU for short) to collect data from the sensor array in real time.

[0111] In this embodiment, in the data processing unit, setting a threshold to perform fault detection and signal analysis includes the following steps:

[0112] Determine the normal operating range of each electrical parameter based on historical data and equipment operating parameters, and set thresholds: including warning thresholds and critical thresholds;

[0113] Using a data processing unit to receive monitoring data reported by the sensor array in real time, and perform real-time analysis based on set warning thresholds and critical thresholds to detect any electrical parameters that exceed preset thresholds;

[0114] When an electrical parameter exceeds a critical threshold or exhibits an abnormal pattern, it is flagged as a fault signal.

[0115] In this embodiment, initially locating the fault area includes the following steps:

[0116] According to the timestamp of the marked fault signal, the electrical parameter data before and after the fault is traversed, and the change of current flow direction is analyzed by combining the topological structure of the box-type substation and the directed graph model;

[0117] According to the change of current flow direction and the system load condition when the fault occurs, a potential fault area with at least one fault signal is determined in multiple monitoring areas divided by the power grid, and the fault area is preliminarily located.

[0118] In this embodiment, when the data processing unit receives a signal that exceeds a critical threshold, it will traverse the relevant electrical parameter data according to the timestamp, especially the data before and after the fault occurs. Combined with the topological structure and directed graph model of the box-type substation, the data processing unit analyzes the changes in the current flow direction at the time of the fault, thereby determining the potential fault area, and further narrowing the scope of the fault area by analyzing the system load conditions and fault signals, thereby achieving the purpose of preliminarily locating the fault.

[0119] For example, assume that a box-type substation contains three monitoring areas: A, B and C. Each area has an independent monitoring point to collect electrical parameter data. In the threshold setting stage, historical data show that the current in area A does not exceed 100A under normal circumstances. Therefore, the early warning threshold can be set to 90A and the critical threshold to 110A. In the fault detection stage, the data processing unit receives the current monitoring data of area A and finds that the current value rises to 115A in an instant, exceeding the critical threshold, and the system immediately marks it as a fault signal. In the preliminary positioning of the fault area stage, the data before and after the fault is analyzed, and it is found that the current in area A rises sharply, while no abnormalities are found in other areas. Combined with the topological structure of the power grid, the analysis confirms that the fault is likely to occur in area A or on its power supply path.

[0120] The above-mentioned embodiment uses a threshold value to detect and preliminarily locate the internal fault of the box-type substation. By setting the early warning threshold value and the critical threshold value, it is possible to issue an early warning in time and mark the fault signal when the electrical parameters are abnormal. The present invention can significantly improve the accuracy and response speed of fault detection. Furthermore, combined with the analysis of real-time data and the topological structure of the box-type substation, the fault area can be preliminarily located quickly and accurately, thereby laying the foundation for subsequent detailed fault diagnosis and repair work. This strategy not only optimizes the operation and maintenance process, but also reduces the losses caused by faults and improves the reliability and safety of the power grid.

[0121] In this embodiment, see Figure 4 As shown, accurately locating the fault location includes the following steps:

[0122] S301, obtaining the waveform data of voltage and current at the time of the fault by sensors at the position of the fault signal according to the preliminary positioning of the fault area, and recording the current and voltage change rates when the fault occurs;

[0123] S302, determining the cable parameters of the cable where the fault signal is located according to the power transmission path: resistance, reactance and dielectric constant of the cable, and determining the inductance and propagation speed of the cable;

[0124] S303, analyzing the transient behavior of voltage and current at the time of the fault according to the current and voltage change rates when the fault occurs and the cable parameters of the cable, and determining the arrival time and reflection time of the transient traveling wave according to the traveling wave generated by the fault;

[0125] S304. Using the principle of the traveling wave method, according to the propagation speed and arrival time of the traveling wave in the cable, the distance from the fault point to the sensor is calculated to accurately locate the fault position.

[0126] When calculating the distance from the fault point to the sensor, the distance is calculated using the time difference between the arrival time of the traveling wave recorded by the sensor and the time when the fault occurs. The distance calculation formula is:

[0127]

[0128] Where D is the distance from the fault point to the nearest sensor, V is the propagation speed of the traveling wave in the cable, and T is the time it takes for the traveling wave to reach the sensor.

[0129] Among them, the propagation speed V of the traveling wave in the cable is determined by the dielectric constant of the cable, and the calculation formula is:

[0130]

[0131] Where V is the propagation velocity of the traveling wave; μ is the magnetic permeability of the medium. For power cables made of non-magnetic materials, the magnetic permeability of free space is used. Magnetic Permeability The value of is 4π×10 -7 H / m; ε is the absolute permittivity of the medium, expressed as the dielectric constant ε γ Permittivity to free space The product of Permittivity of free space The value is 8.854×10 -12 F / m.

[0132] For example, assume that in an electric power system, the sensor records the transient waveforms of current and voltage when a fault occurs. Preliminary positioning shows that the fault occurs in a specific cable segment. In the waveform data collection stage, the sensor records a sharp drop in voltage and current at the moment of the fault. In the cable parameter determination stage, it is known that the cable resistance is 0.5Ω / km, the reactance is 0.1Ω / km, and the dielectric constant is 2.5. In the traveling wave transient behavior analysis stage, through the waveform data, it is found that the arrival time of the traveling wave is 2ms and the reflection time is 4ms. In the traveling wave method calculation stage, the propagation speed of the traveling wave is calculated based on the dielectric constant. Substituting the above given values ​​of the permeability and permittivity of free space, we get the propagation velocity. Then using The distance between the fault point and the sensor is calculated.

[0133] The above embodiment is a method for accurately locating the fault position of the power system, which collects voltage and current waveform data at the time of the fault through sensors, then calculates the propagation speed of the traveling wave according to the cable parameters, and finally calculates the distance from the fault point to the sensor using the arrival time and propagation speed of the traveling wave. The above steps combine modern sensing technology and advanced data analysis methods, improve the speed and accuracy of fault location, and are of great significance for maintaining the stability and reliability of the power system.

[0134] The fault location method of the box-type substation of the embodiment of the present invention can quickly and accurately locate the cable fault position in the box-type substation, greatly reducing the power outage time and maintenance cost of the power system, and improving the reliability and stability of the power system. At the same time, the implementation of the method does not require a power outage for the entire system, so it can also ensure that the normal operation of the substation is not affected, which is of great significance for ensuring the efficient operation of the power grid and reducing the economic losses caused by faults.

[0135] It should be noted that the above figures are only schematic illustrations of the processes included in the method according to an exemplary embodiment of the present invention, and are not intended to be limiting. It is easy to understand that the processes shown in the above figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0136] It should be understood that, although described in a certain order, these steps are not necessarily performed in sequence in the above order. Unless there is clear explanation in this article, the execution of these steps does not have strict order restriction, and these steps can be performed in other orders. Moreover, a part of the steps of the present embodiment may include a plurality of steps or a plurality of stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a part of the steps or stages in other steps or other steps.

[0137] In the second aspect of the embodiment of the present invention, see Figure 5 As shown, the present invention also provides a fault locating device for a box-type substation, comprising:

[0138] Data Acquisition Unit (DAU): communicates with the sensor array to collect electrical parameters in real time;

[0139] Data processing unit: receives data from the data acquisition unit, sets warning thresholds and critical thresholds, performs fault detection and signal analysis, and preliminarily locates the fault area;

[0140] Model building module: input substation topology, node and edge data to build a directed graph model;

[0141] Region division module: Identify key nodes, divide the power grid into multiple monitoring areas, and define clear regional boundaries;

[0142] Fault location module: uses topology structure and real-time electrical parameter data, combined with fault signals and current change rate, to accurately locate the fault location;

[0143] Control unit: automatically controls the corresponding switch nodes according to the fault location results and isolates the fault area.

[0144] Communication network: used to connect the data acquisition unit, sensor array, and data processing unit and transmit data;

[0145] User interface: visualizes topology and fault information, and provides a user interface for monitoring, control, and troubleshooting.

[0146] In summary, the fault location device of the box-type substation of the present invention is used to perform the steps of the fault location method of the box-type substation, which will not be repeated here. The fault location device of the box-type substation realizes a fast and accurate fault location method through the close cooperation of the above modules, and enhances the operational safety and reliability of the box-type substation. Through automated monitoring and control, it helps to reduce power outage time, reduce maintenance costs, and improve service stability and efficiency.

[0147] According to a third aspect of an embodiment of the present invention, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method of any one of the above embodiments is implemented.

[0148] The computer device includes a processor and a memory, and may also include: an input device and an output device. The processor, memory, input device and output device may be connected via a bus or other means, and the input device may receive input digital or character information, and generate signal input related to the migration of fault location of the box-type substation. The output device may include display devices such as a display screen.

[0149] As a non-volatile computer-readable storage medium, the memory can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as the program instructions / modules corresponding to the fault location method of the box-type substation in the embodiment of the present application. The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating device, an application required for at least one function; the data storage area may store data created by the use of the fault location method of the box-type substation, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the local module via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0150] The processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip in some embodiments. The processor is generally used to control the overall operation of the computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data. The processors of multiple computer devices of the computer device of this embodiment execute various functional applications and data processing of the server by running non-volatile software programs, instructions and modules stored in the memory, that is, implementing the steps of the fault location method of the box-type substation of the above method embodiment.

[0151] It should be understood that, in the absence of mutual conflicts, all the embodiments, features and advantages described above for the fault location method of the box-type substation according to the present invention are also applicable to the fault location and storage medium of the box-type substation according to the present invention.

[0152] It will also be appreciated by those skilled in the art that various exemplary logic blocks, modules, circuits and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, a general description has been given of the functions of various schematic components, blocks, modules, circuits and steps. Whether this function is implemented as software or hardware depends on specific applications and the design constraints imposed on the entire device. Those skilled in the art can implement the function in various ways for each specific application, but this implementation decision should not be interpreted as causing a departure from the scope disclosed in the embodiments of the present invention.

[0153] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0154] It should be understood that, as used herein, the singular form "a" or "an" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the items listed in association. The serial numbers of the embodiments disclosed in the above embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments.

[0155] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A fault location method for a box-type substation, characterized in that: The following steps are involved: Obtain the topological structure of the box-type substation and identify all switch nodes and terminal equipment nodes; According to the current flow direction and power transmission path, a directed graph model of the box-type substation is established to reflect the directed edge relationship between nodes, and the power grid of the box-type substation is divided into multiple monitoring areas accordingly; Deploy sensor arrays on switch nodes and terminal devices to monitor electrical parameters in the deployment area in real time, and report the electrical parameters collected by each sensor to the data processing unit in real time according to the assigned area identifier; The data processing unit continuously monitors sensor data, sets thresholds for fault detection and signal analysis, and determines fault signals based on detected abnormal data; According to the current flow direction in the topology structure and the fault signal in the sensor data, the current flow direction at the time of the fault is analyzed, the monitoring area where the fault signal is located is determined, and the fault area is preliminarily located; Based on the change rate of voltage and current in the fault area, combined with cable parameters and transmission delay, the distance from the fault point to the nearest sensor is calculated to accurately locate the fault location; After locating the fault location, the switch device of the corresponding switch node is automatically controlled to open or close, the fault section is isolated, and the fault location result is fed back.

2. The fault location method of a box-type substation according to claim 1, characterized in that: According to the current flow direction and power transmission path, a directed graph model of the box-type substation is established, including the following steps: Based on the switch nodes and terminal equipment nodes set on the topological structure of the box-type substation, all electrical connection data of the substation are collected; According to the topological structure of the box-type substation, all the components in the substation are defined as nodes in the graph. According to the electrical connection data, the connection relationship between the nodes is determined, and the edges in the graph are defined accordingly. Determine the direction of the edge according to the actual flow direction of the current, and use the graphics library in the programming language to input the data of the nodes and edges to build a directed graph model of the substation; By simulating the flow of current in the substation, we verify whether the directed graph model reflects the actual power transmission path; and adjust the direction of the edges in the directed graph and add missing connections based on the test results.

3. The fault location method of a box-type substation according to claim 2, characterized in that: All electrical connection data of the substation include connection data of transformers, switches, cable lines and load elements; as well as equipment parameters of impedance and rated current between the power supply end and the load end.

4. The fault location method of a box-type substation according to claim 3, characterized in that: The direction of the edge determined according to the actual flow direction of the current is the direction from the power supply end to the load end, which is used to represent the actual transmission direction of electric energy in the directed graph model; wherein, after constructing the directed graph model of the substation, it also includes: All source nodes and sink nodes are identified in the directed graph model; the source node is the power supply end, and the sink node is the load end.

5. The fault location method of a box-type substation according to claim 4, characterized in that: The directed graph model for constructing the substation also includes a dynamic update mechanism, which is used to update the directed graph model to reflect the new current flow direction and power transmission path when the internal configuration or load situation of the substation changes.

6. The fault location method of a box-type substation according to claim 1, characterized in that: Divide the power grid of the box-type substation into multiple monitoring areas, including the following steps: According to the topological structure of the box-type substation and the directed graph model of the substation, the key nodes in the substation are identified, where the key nodes are the branch points or convergence points in the flow of electric energy; According to the power flow direction and the key nodes of the substation, the key nodes covering the power transmission path are determined as monitoring points; According to the topological structure of the monitoring point in the box-type substation and the position of the monitoring point in the power transmission path, the power grid is divided into multiple monitoring areas; wherein each monitoring area includes at least one monitoring point; And based on the directed edge relationships between nodes, clear regional boundaries are defined for each monitoring area.

7. The fault location method of a box-type substation according to claim 6, characterized in that: In the data processing unit, setting a threshold for fault detection and signal analysis includes the following steps: Determine the normal operating range of each electrical parameter based on historical data and equipment operating parameters, and set thresholds: including warning thresholds and critical thresholds; Using a data processing unit to receive monitoring data reported by the sensor array in real time, and perform real-time analysis based on set warning thresholds and critical thresholds to detect any electrical parameters that exceed preset thresholds; When an electrical parameter exceeds a critical threshold or exhibits an abnormal pattern, it is flagged as a fault signal.

8. The fault location method of a box-type substation according to claim 7, characterized in that: Initially locate the fault area, including the following steps: According to the timestamp of the marked fault signal, the electrical parameter data before and after the fault is traversed, and the change of current flow direction is analyzed by combining the topological structure and directed graph model of the box-type substation: According to the change of current flow direction and the system load condition when the fault occurs, a potential fault area with at least one fault signal is determined in multiple monitoring areas divided by the power grid, and the fault area is preliminarily located.

9. The fault location method of a box-type substation according to claim 8, characterized in that: Accurately locate the fault location, including the following steps: According to the preliminary positioning of the fault area, the sensors at the fault signal location collect the waveform data of voltage and current at the time of the fault, and record the current and voltage change rate when the fault occurs; Determine the cable parameters of the cable where the fault signal is located according to the power transmission path: resistance, reactance and dielectric constant of the cable, determine the inductance and propagation speed of the cable; According to the current and voltage change rates when the fault occurs and the cable parameters of the cable, the transient behavior of the voltage and current at the time of the fault is analyzed, and the arrival time and reflection time of the transient traveling wave are determined according to the traveling wave generated by the fault; Using the principle of traveling wave method, according to the propagation speed and arrival time of traveling wave in the cable, the distance from the fault point to the sensor is calculated to accurately locate the fault position.

10. A fault location device for a box-type substation, characterized in that: The method for locating a fault in a box-type substation according to any one of claims 1 to 9 is used, wherein the fault locating device of the box-type substation comprises: Data acquisition unit: communicates with the sensor array and collects electrical parameters in real time; Data processing unit: receives data from the data acquisition unit, sets warning thresholds and critical thresholds, performs fault detection and signal analysis, and preliminarily locates the fault area; Model building module: input substation topology, node and edge data to build a directed graph model; Region division module: Identify key nodes, divide the power grid into multiple monitoring areas, and define clear regional boundaries; Fault location module: uses topology structure and real-time electrical parameter data, combined with fault signals and current change rate, to accurately locate the fault location; Control unit: automatically controls the corresponding switch nodes according to the fault location results and isolates the fault area. Communication network: used to connect the data acquisition unit, sensor array, and data processing unit and transmit data; User interface: visualizes topology and fault information, and provides a user interface for monitoring, control, and troubleshooting.

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