Fault positioning method and system for distribution transformer low-voltage switch

Abstract

The invention discloses a fault positioning method and system for a distribution transformer low-voltage switch, and relates to the technical field of distribution automation, and the method comprises the steps: collecting a live line current value and a zero line current value of a low-voltage distribution line, and storing the live line current value and the zero line current value in a database to form historical data; and judging whether the live wire current value is equal to the null line current value or not, and if not, calculating electric leakage point position information based on the live wire current value, the null line current value and historical data. According to the invention, by collecting and analyzing the voltage and current data of the low-voltage distribution line in real time and combining intelligent analysis of the historical database, rapid and accurate positioning of the electric leakage fault is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution automation, and in particular to a fault locating method and system for a distribution transformer low-voltage switch. Background Art

[0002] Since the low-voltage side of the distribution transformer directly supplies power to end users, its reliability and power supply quality directly affect the user's power experience. In the operation and maintenance of the distribution network, grounding faults on the low-voltage side of the distribution transformer are a common and more harmful type of fault. Traditional low-voltage distribution systems mainly rely on leakage protectors and overcurrent protection devices to achieve fault protection. Although this passive protection method can cut off the fault branch in time, it cannot accurately locate the fault point, resulting in low efficiency in fault finding and handling.

[0003] At present, low-voltage power distribution fault location mainly adopts manual inspection and measurement, which usually requires checking each branch line one by one. This traditional fault location method has the following problems: first, it requires multiple power outages for detection, which seriously affects the power supply reliability of users; second, the fault finding process is time-consuming, and it often takes 1-2 days to determine the location of the fault point; third, the manual troubleshooting method relies on the experience of maintenance personnel, and it is difficult to form a standardized fault handling process; finally, there is a lack of real-time monitoring means, and it is impossible to timely discover and warn potential fault hazards. These problems not only reduce power supply reliability and customer satisfaction, but also increase operation and maintenance costs. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the present invention provides a fault location method and system for a distribution transformer low-voltage switch, which can solve the problems mentioned in the background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for locating a fault of a distribution transformer low-voltage switch, comprising: collecting a live current value and a neutral current value of a low-voltage distribution line for locating a fault of a distribution transformer low-voltage switch, and storing the live current value and the neutral current value in a database to form historical data;

[0007] The fault location of the distribution transformer low-voltage switch determines whether the live line current value is equal to the neutral line current value, and when they are not equal, calculates the leakage point location information based on the live line current value, the neutral line current value and the historical data;

[0008] The fault location of the distribution transformer low-voltage switch generates an alarm message containing the leakage point location information and sends it to the terminal device.

[0009] As a preferred solution of the fault location method of the distribution transformer low-voltage switch of the present invention, wherein: the live line current value and the neutral line current value of the low-voltage distribution line are collected, and the live line current value and the neutral line current value are stored in a database to form historical data, including the following steps:

[0010] The fault location of the distribution transformer low-voltage switch collects the phase voltage value and the neutral voltage value of the low-voltage distribution line voltage monitoring point;

[0011] The fault location of the distribution transformer low-voltage switch collects the live current value and the neutral current value of the low-voltage distribution line;

[0012] The fault location of the distribution transformer low-voltage switch comprises the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value as sampling data, and when the continuous collection of the sampling data reaches a preset time threshold, the sampling data is stored in a database.

[0013] As a preferred solution of the fault location method of the distribution transformer low-voltage switch of the present invention, wherein: the collecting of the live line current value and the neutral line current value of the low-voltage distribution line comprises the following steps:

[0014] The fault location of the distribution transformer low-voltage switch calculates the difference between the live line current value and the neutral line current value;

[0015] Fault location of the distribution transformer low-voltage switch: if the difference is less than the preset current threshold, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are marked as normal working state data; if the difference is greater than or equal to the preset current threshold, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are marked as abnormal working state data;

[0016] The fault location of the distribution transformer low-voltage switch establishes a load characteristic data set of the low-voltage distribution line based on the normal working state data.

[0017] As a preferred solution of the fault location method of the distribution transformer low-voltage switch of the present invention, wherein: the judging whether the live line current value is equal to the neutral line current value, when they are not equal, calculating the leakage point location information based on the live line current value, the neutral line current value and the historical data, comprises the following steps:

[0018] The fault location of the distribution transformer low-voltage switch calculates the difference between the current live line current value and the neutral line current value. If the difference is greater than a preset current threshold, the leakage circuit resistance value is extracted based on the phase voltage value and the neutral line voltage value.

[0019] The fault location of the distribution transformer low-voltage switch calculates the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line;

[0020] The fault location of the distribution transformer low-voltage switch converts the electrical distance of the leakage point into the position information of the leakage point.

[0021] As a preferred solution of the fault location method of the distribution transformer low-voltage switch of the present invention, wherein: the electrical distance of the leakage point is calculated based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line, comprising the following steps:

[0022] The fault location of the distribution transformer low-voltage switch extracts the historical load data of the same time period as the current sampling time from the load characteristic data set;

[0023] The fault location of the distribution transformer low-voltage switch establishes a unit length resistance reference value based on the historical load data, and calculates the initial electrical distance according to the ratio of the leakage circuit resistance value to the unit length resistance reference value;

[0024] If the initial electrical distance is greater than the preset distance threshold, the initial electrical distance is compensated based on the phase voltage value to obtain the leakage point electrical distance; if the initial electrical distance is less than or equal to the preset distance threshold, the initial electrical distance is used as the leakage point electrical distance.

[0025] As a preferred solution of the fault location method of the distribution transformer low-voltage switch of the present invention, the generating of the alarm information including the leakage point location information and sending it to the terminal device comprises the following steps:

[0026] The fault location of the distribution transformer low-voltage switch generates an alarm data packet with the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value;

[0027] The fault location of the distribution transformer low-voltage switch sends the alarm data packet to the terminal device through the wireless communication module.

[0028] As a preferred solution of the fault location method of the distribution transformer low-voltage switch of the present invention, wherein: the generating of the alarm data packet by the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value comprises the following steps:

[0029] The fault location of the distribution transformer low-voltage switch performs timestamp marking on the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value;

[0030] Fault location of the low-voltage switch of the distribution transformer: if the difference between the live current value and the neutral current value lasts for more than a preset time period, the priority of the alarm data packet is marked as urgent, otherwise it is marked as normal;

[0031] The fault location of the distribution transformer low-voltage switch packages the data with the timestamp and the priority mark into the alarm data packet.

[0032] To further solve the above technical problems, the present invention provides the following technical solutions: A system for locating faults of distribution transformer low-voltage switches, comprising: a data acquisition module for collecting phase voltage values, neutral line voltage values, live line current values ​​and neutral line current values ​​of low-voltage distribution lines;

[0033] A state analysis module, for judging the working state of the low-voltage distribution line based on the equality relationship between the live current value and the neutral current value, and if the live current value is equal to the neutral current value, forming sampling data with the phase voltage value, the neutral voltage value, the live current value and the neutral current value;

[0034] A data storage module, used for storing the sampled data into a database to form historical data;

[0035] A fault detection module, used for calculating the difference between the current live line current value and the neutral line current value, and if the difference is greater than a preset current threshold, extracting the leakage circuit resistance value based on the phase voltage value and the neutral line voltage value;

[0036] A distance calculation module, used to calculate the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line;

[0037] A position conversion module, used for converting the electrical distance of the leakage point into the position information of the leakage point;

[0038] An alarm generating module, used for generating an alarm data packet from the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value;

[0039] The information transmission module is used to send the alarm data packet to the terminal device through the wireless communication module.

[0040] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the fault location method of the distribution transformer low-voltage switch are implemented as described above.

[0041] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the fault location method for the distribution transformer low-voltage switch as described above are implemented.

[0042] The beneficial effects of the present invention are as follows: by real-time collection and analysis of voltage and current data of low-voltage distribution lines, combined with intelligent analysis of historical databases, rapid and accurate positioning of leakage faults is achieved. Among them, the state analysis method based on the equal relationship between live wire current and neutral wire current avoids the blindness of traditional manual segment-by-segment troubleshooting, and significantly improves the efficiency of fault analysis and judgment; by establishing a standardized historical database and introducing load characteristic analysis, the limitations of traditional methods that rely on personnel experience are overcome, making the fault location process more objective and reliable; the positioning method of leakage circuit resistance value calculation combined with electrical distance compensation is adopted to solve the technical problem of insufficient accuracy of traditional positioning methods; finally, through modular system design and the application of wireless communication technology, real-time push of fault information is achieved, so that maintenance personnel can respond in time and accurately treat the problem, thereby shortening the traditional troubleshooting time of 1-2 days to minutes, while ensuring power supply reliability and significantly improving operation and maintenance efficiency and customer satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0044] Figure 1 is a flow chart of the overall method in the present invention;

[0045] Figure 2 It is a system interaction diagram in the present invention;

[0046] Figure 3 Establish a flow chart for the database in the present invention;

[0047] Figure 4 This is a flow chart of fault point distance determination in the present invention;

[0048] Figure 5 A diagram of a computer device in the present invention. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0051] Example 1, reference Figure 1 , which is an embodiment of the present invention, provides a fault location method for a distribution transformer low-voltage switch.

[0052] Figure 1 The overall flow chart of a fault location method for a distribution transformer low-voltage switch is shown, comprising: S1: collecting the live current value and the neutral current value of the low-voltage distribution line, and storing the live current value and the neutral current value in a database to form historical data;

[0053] S2: Determine whether the live wire current value is equal to the neutral wire current value. If they are not equal, calculate the leakage point location information based on the live wire current value, the neutral wire current value and historical data;

[0054] S3: Generate an alarm message containing the location information of the leakage point and send it to the terminal device.

[0055] Furthermore, collecting the live line current value and the neutral line current value of the low voltage distribution line, and storing the live line current value and the neutral line current value in a database to form historical data, includes the following steps:

[0056] S11: Collecting phase voltage values ​​and neutral voltage values ​​at voltage monitoring points of low-voltage distribution lines;

[0057] S12: collecting the live line current value and the neutral line current value of the low voltage distribution line;

[0058] S13: The phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are combined into sampling data, and when the continuous collection of sampling data reaches a preset time threshold, the sampling data is stored in a database.

[0059] Furthermore, collecting the live line current value and the neutral line current value of the low voltage distribution line includes the following steps:

[0060] S121: Calculate the difference between the live wire current value and the neutral wire current value;

[0061] S122: if the difference is less than the preset current threshold, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are marked as normal working state data; if the difference is greater than or equal to the preset current threshold, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are marked as abnormal working state data;

[0062] S123: Establish a load characteristic data set of the low-voltage distribution line based on the normal working state data.

[0063] The S1 step of the present invention synchronously collects the phase voltage value, neutral line voltage value, live line current value and neutral line current value of the low-voltage distribution line, and establishes a standardized historical database based on the equal relationship between the live line current value and the neutral line current value, thereby solving the technical problems in the prior art that the operation status of the distribution line is difficult to monitor in real time and the normal working parameters are difficult to quantify. Its core principle is: first, synchronous sampling of voltage and current is realized to ensure the time consistency of data; second, effective data is screened by comparing the equal relationship between the live line current value and the neutral line current value to avoid abnormal data interference; finally, the screened data is stored in time series and a load characteristic data set is established. The innovation of this step is reflected in: by establishing a standardized historical database, an accurate characterization of the normal operation characteristics of the distribution line is achieved, a reliable data basis is provided for subsequent fault location, and the subjectivity of the traditional method that only relies on experience judgment is overcome; through real-time data collection and analysis, the system can capture the slight changes in the line parameters in time, which provides the possibility for early warning of faults; at the same time, the accumulation of historical data can also be used to analyze the load change law and guide the optimization of operation and maintenance strategies, which are functional effects that are difficult to achieve by simple superposition of the prior art.

[0064] Further, it is determined whether the live wire current value is equal to the neutral wire current value. If they are not equal, the leakage point location information is calculated based on the live wire current value, the neutral wire current value and historical data, including the following steps:

[0065] S21: Calculate the difference between the current live line current value and the neutral line current value. If the difference is greater than a preset current threshold, extract the leakage circuit resistance value based on the phase voltage value and the neutral line voltage value.

[0066] S22: Calculate the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line;

[0067] The S22 step of the present invention solves the technical problem of unstable positioning accuracy caused by load fluctuations in the prior art by establishing a historical data analysis model based on time characteristics and combining a dynamic compensation mechanism to realize accurate calculation of the distance of the leakage point. Its core principle is: first, historical data of the same time period as the current fault occurrence time is extracted from the load characteristic data set. This data matching method based on time characteristics takes into account the periodic change law of the distribution line load; then, a unit length resistance reference value is established based on the matched historical data, and the reference value reflects the standard electrical characteristics of the line under normal operation; finally, the initial electrical distance is determined by the ratio of the leakage circuit resistance value to the unit length resistance reference value, and voltage compensation correction is performed in combination with a preset distance threshold. The innovation of this step is reflected in: by introducing data analysis in the time dimension, the positioning deviation caused by ignoring the dynamic characteristics of the load in the traditional method is overcome; by establishing an adaptive resistance reference model, accurate positioning under different load conditions is achieved; at the same time, the design of the dynamic compensation mechanism effectively solves the problem of cumulative error during long-distance positioning, and the combined application of these technical features significantly improves the adaptability and reliability of fault positioning.

[0068] S23: Convert the electrical distance of the leakage point into the position information of the leakage point.

[0069] Further, the electrical distance of the leakage point is calculated based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line, including the following steps:

[0070] S221: extracting historical load data of the same time period as the current sampling time from the load characteristic data set;

[0071] S222: establishing a reference value of resistance per unit length based on historical load data, and calculating an initial electrical distance according to a ratio of the leakage loop resistance value to the reference value of resistance per unit length;

[0072] S223: If the initial electrical distance is greater than the preset distance threshold, the initial electrical distance is compensated based on the phase voltage value to obtain the leakage point electrical distance; if the initial electrical distance is less than or equal to the preset distance threshold, the initial electrical distance is used as the leakage point electrical distance.

[0073] The S2 step of the present invention realizes the rapid and accurate positioning of the leakage fault through a multi-stage linkage fault positioning mechanism, and solves the technical problems of long time consumption, low positioning accuracy, and multiple power outage detection in the prior art. Its core principle is: first, the fault detection module realizes rapid identification of the fault by calculating the difference between the live wire current value and the neutral wire current value in real time and comparing it with the preset current threshold; when it is confirmed that a leakage fault occurs, the leakage circuit resistance value is extracted based on the real-time collected phase voltage value and neutral wire voltage value, and the resistance value reflects the electrical characteristics from the fault point to the monitoring point; secondly, the distance calculation module innovatively introduces a historical data analysis mechanism, by extracting the historical load data of the same time period as the current sampling time from the historical database, establishing a unit length resistance reference value, and calculating the initial electrical distance in combination with the leakage circuit resistance value; in order to improve the positioning accuracy, the system also designs an adaptive correction mechanism based on voltage compensation. When the initial electrical distance exceeds the preset threshold, the distance is dynamically compensated by analyzing the phase voltage value, which effectively overcomes the positioning error caused by uneven line load in the traditional method; finally, the position conversion module converts the compensated electrical distance into actual physical position information. The innovation of this step is reflected in the following aspects: by establishing a standardized fault location model, the traditional location method that relies on manual experience is transformed into data-driven intelligent positioning, which significantly improves the positioning efficiency and accuracy; by introducing historical data analysis of time feature matching, the influence of load fluctuations on positioning accuracy is overcome; by designing a multi-level compensation mechanism, accurate positioning at different fault distances is achieved. The organic combination of these technical features forms a complete set of fault location solutions, which avoids the drawbacks of frequent power outages in traditional methods while ensuring positioning accuracy, greatly improving power supply reliability and customer satisfaction.

[0074] Furthermore, generating an alarm message including the location information of the leakage point and sending it to the terminal device comprises the following steps:

[0075] S31: Generate an alarm data packet with the leakage point location information, phase voltage value, neutral line voltage value, live line current value and neutral line current value;

[0076] S32: Send the alarm data packet to the terminal device through the wireless communication module.

[0077] Further, generating an alarm data packet with the leakage point location information, phase voltage value, neutral line voltage value, live line current value and neutral line current value includes the following steps:

[0078] S311: Timestamp the leakage point location information, phase voltage value, neutral line voltage value, live line current value and neutral line current value;

[0079] S312: if the difference between the live wire current value and the neutral wire current value continues to exceed a preset time period, the priority of the alarm data packet is marked as urgent, otherwise it is marked as normal;

[0080] S313: Pack the data with the timestamp and priority mark into an alarm data packet.

[0081] The S3 step of the present invention generates a standardized alarm data packet by integrating the leakage point location information with the phase voltage value, neutral line voltage value, live line current value and neutral line current value collected in real time, and realizes the real-time push of alarm information through wireless communication technology, which solves the technical problems of untimely transmission of fault information and lack of standardization of fault handling process in the prior art. Its core principle is: firstly, the fault location result is associated with the voltage and current data at the time of the fault occurrence, so as to ensure the integrity and traceability of the fault information; secondly, by standardizing the alarm data, the accurate classification of the fault type and the quantitative judgment of the fault level are realized; finally, the real-time push of alarm information and the closed-loop management of fault handling are realized by wireless communication technology. The innovation of this step is reflected in: by establishing a complete fault information data chain, not only the rapid response to the fault is realized, but also the data support is provided for the subsequent fault analysis and preventive maintenance; through the standardized alarm processing process, the professional skill requirements of the maintenance personnel are reduced, and the standardization of fault handling is improved; at the same time, the whole process data of the fault handling automatically recorded by the system provides a reliable basis for the health status assessment and predictive maintenance of the equipment, which are the functional effects that are difficult to achieve by traditional manual inspection and experience judgment.

[0082] In summary, the present invention can quickly and accurately locate the leakage fault point by real-time monitoring of voltage and current data, combined with intelligent analysis algorithms, and achieve timely discovery and rapid processing of faults. Its significant technical effects are reflected in: realizing online monitoring of distribution line voltage and current, providing accurate positioning function of leakage faults, reducing power outage time, and improving fault processing efficiency and customer satisfaction.

[0083] Example 2, reference Figure 2 , as an embodiment of the present invention, provides a fault location system for a distribution transformer low-voltage switch, comprising:

[0084] A data acquisition module is used to collect phase voltage values, neutral line voltage values, live line current values ​​and neutral line current values ​​of low-voltage distribution lines;

[0085] The state analysis module is used to judge the working state of the low-voltage distribution line based on the equal relationship between the live current value and the neutral current value. If the live current value is equal to the neutral current value, the phase voltage value, the neutral voltage value, the live current value and the neutral current value are combined into sampling data;

[0086] A data storage module, used for storing the sampled data into a database to form historical data;

[0087] The fault detection module is used to calculate the difference between the current live line current value and the neutral line current value. If the difference is greater than a preset current threshold, the leakage circuit resistance value is extracted based on the phase voltage value and the neutral line voltage value.

[0088] A distance calculation module, used to calculate the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line;

[0089] A position conversion module, used for converting the electrical distance of the leakage point into the position information of the leakage point;

[0090] The alarm generation module is used to generate an alarm data packet with the leakage point location information, phase voltage value, neutral line voltage value, live line current value and neutral line current value;

[0091] The information transmission module is used to send the alarm data packet to the terminal device through the wireless communication module.

[0092] It should be noted that the phase voltage value, neutral line voltage value, live line current value and neutral line current value of the low-voltage distribution line are collected in real time through the data acquisition module, and the collected data are transmitted to the state analysis module and the data storage module at the same time; the state analysis module judges the working state of the line based on the equal relationship between the live line current value and the neutral line current value. When the two are equal, the data storage module stores the corresponding sampled data in the database to form historical data; when the fault detection module finds that the live line current value is not equal to the neutral line current value, the system starts the fault location process. At this time, the distance calculation module calculates the electrical distance of the leakage point through an intelligent algorithm based on the currently detected leakage circuit resistance value and the historical load characteristic data in the database. Subsequently, the position conversion module converts the electrical distance into the actual leakage point location information; finally, the alarm generation module integrates the leakage point location information with the currently collected voltage and current data to form an alarm data packet, and sends the alarm information to the terminal device in real time through the information transmission module to guide maintenance personnel to carry out precise treatment.

[0093] Example 3, reference Figure 3 and Figure 4 , is an embodiment of the present invention, and provides a distribution transformer low-voltage switch with a fault location function.

[0094] 400V low-voltage substations often need to troubleshoot leakage faults in power supply lines. The conventional detection and troubleshooting method is to connect each branch line one by one for inspection and then accurately locate the leakage fault point. This method cannot quickly analyze and troubleshoot faults, and it often takes 1 day or even several days to find the leakage fault point. During the troubleshooting process, residential users also need to be temporarily shut down, which is not only time-consuming but also reduces customer satisfaction.

[0095] The distribution transformer low-voltage switch with fault location function is composed of a special voltage monitoring module 1, a special current monitoring module 2, a special main control module 3, a special wireless communication module 4, a special handheld terminal 5, etc. It can intelligently calculate the load-related data through the real-time monitoring of voltage and current values, accurately determine the branch leakage and remotely alarm, and establish a low-voltage area load database. When the leakage phenomenon is detected, the relevant data values ​​between the leakage point and the device are calculated according to the intelligent algorithm, and the distance value is calculated, thereby achieving accurate positioning.

[0096] Under normal circumstances without ground leakage, the line live current IL is equal to the neutral current IN. The switch monitors IL and IN in real time through the special current monitoring module 2, and analyzes whether IL is equal to IN through the special main control module 3. If so, all the data monitored at this time are recorded, and the range of values ​​under normal conditions is calculated through autonomous learning analysis, and the data is summarized and organized into a library; if not, the resistance value from the switch to the leakage point is calculated based on the values ​​monitored by the special voltage monitoring module 1 and the special current monitoring module 2, and the distance between the leakage point and the switch is determined through the special main control module 3 intelligent analysis. After the result is obtained, the alarm information (including the distance of the leakage point) is sent to the special handheld terminal 5 through the special wireless communication module 4 to remind the operator to go to the site for processing in time.

[0097] It can solve the problem of no monitoring of line voltage and current values ​​in the substation area. The switch is easy to install. After installation, it can monitor the line voltage and current values ​​in real time. Through intelligent calculation, it can accurately judge the branch leakage situation and accurately locate the leakage fault point, reduce the power outage duration, improve troubleshooting efficiency, and enhance customer satisfaction. It is worthy of application and promotion.

[0098] Example 4, reference Figure 5 , is an embodiment of the present invention, which is different from the previous embodiment in that: if the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0099] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0100] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0101] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0102] Example 5 is an embodiment of the present invention, which provides a fault location method for a distribution transformer low-voltage switch. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0103] In order to verify the fault location effect of the present invention, the present invention selected 10 typical low-voltage substations in a city's distribution network for a 6-month comparative test. The experimental scheme was designed using a double-blind control method, and these substations were randomly divided into an experimental group and a control group. The experimental group installed the fault location system of the present invention, and the control group maintained the traditional manual inspection method. During the test, the present invention set simulated leakage faults at different distance points (simulating different degrees of grounding faults through adjustable resistors) to record key indicators such as fault location time, positioning accuracy, and power outage duration. To ensure the reliability of the test data, each test point was tested 5 times, and the test was performed at different time periods (peak, valley, and flat) to evaluate the impact of load fluctuations on the positioning effect.

[0104] During the experimental data collection process, the present invention focuses on three core performance indicators of the system: first, positioning accuracy, which is evaluated by calculating the deviation between the fault point location output by the system and the actual fault point location; second, response time, including fault detection time and positioning calculation time; and finally, reliability indicators, which are measured by statistically analyzing the success rate and false alarm rate of fault location. At the same time, the present invention also establishes a complete test environment parameter recording mechanism, including influencing factors such as ambient temperature, humidity, and line load rate, to ensure the comparability and repeatability of experimental data. For each test, the present invention records the fault characteristics, system response process, and positioning results in detail to form a standardized test report.

[0105] Table 1 Performance comparison of fault location systems in substations

[0106]

[0107]

[0108] Through the statistical analysis of comparative test data, it can be concluded that the fault location system of the present invention is significantly superior to the traditional manual inspection method in various performance indicators. In terms of positioning time, the average positioning time of the present invention is only 3.5-5.5 minutes, while the traditional method takes 125-180 minutes, and the time efficiency is improved by 97.2%; in terms of positioning accuracy, the positioning error of the present invention is controlled within the range of 2.1-3.5 meters, while the error of the traditional method is between 8.5-12.8 meters, and the accuracy is improved by 73.8%; it is particularly noteworthy that the present invention realizes power-off-free detection, reducing the power outage time of 95-150 minutes in the traditional method to 0, greatly improving the power supply reliability; in terms of fault location success rate, the present invention maintains a high level of 96.2%-98.5%, which is 15-20 percentage points higher than the traditional method; the system false alarm rate is also significantly controlled, from 3.5%-5.8% of the traditional method to 0.5%-1.2%; these performance improvements are directly reflected in customer satisfaction, and the present invention has obtained a high score of 93.8-95.2 points, which is more than 25 points higher than the traditional method. The data also show that even under heavy load conditions, the present invention still maintains stable performance indicators, reflecting good environmental adaptability and reliability.

[0109] It is important to note that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for locating a fault of a distribution transformer low-voltage switch, characterized in that: include: Collecting the live line current value and the neutral line current value of the low-voltage distribution line, and storing the live line current value and the neutral line current value in a database to form historical data; Determine whether the live line current value is equal to the neutral line current value, and when they are not equal, calculate the leakage point location information based on the live line current value, the neutral line current value and the historical data; Generate an alarm message containing the leakage point location information and send it to the terminal device.

2. The fault location method of the distribution transformer low-voltage switch according to claim 1, characterized in that: The method of collecting the live line current value and the neutral line current value of the low-voltage distribution line and storing the live line current value and the neutral line current value in a database to form historical data includes the following steps: Collect phase voltage and neutral voltage values ​​at voltage monitoring points of low-voltage distribution lines; Collecting the live line current value and the neutral line current value of the low voltage distribution line; The phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are combined into sampling data, and when the sampling data is continuously collected to reach a preset time threshold, the sampling data is stored in a database.

3. The fault location method of the distribution transformer low-voltage switch according to claim 2, characterized in that: The collecting of the live line current value and the neutral line current value of the low voltage distribution line comprises the following steps: Calculating the difference between the live line current value and the neutral line current value; If the difference is less than the preset current threshold, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are marked as normal working state data; if the difference is greater than or equal to the preset current threshold, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value are marked as abnormal working state data; A load characteristic data set of the low-voltage power distribution line is established based on the normal working status data.

4. The fault location method of the distribution transformer low-voltage switch according to claim 3, characterized in that: The determining whether the live line current value is equal to the neutral line current value, and when they are not equal, calculating the leakage point location information based on the live line current value, the neutral line current value and the historical data, comprises the following steps: Calculate the difference between the current live line current value and the neutral line current value, and if the difference is greater than a preset current threshold, extract the leakage loop resistance value based on the phase voltage value and the neutral line voltage value; Calculating the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line; The electrical distance of the leakage point is converted into the position information of the leakage point.

5. The fault location method of the distribution transformer low-voltage switch according to claim 4, characterized in that: The method of calculating the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage power distribution line comprises the following steps: Extracting historical load data of the same time period as the current sampling time from the load characteristic data set; Establishing a unit length resistance reference value based on the historical load data, and calculating an initial electrical distance according to a ratio of the leakage loop resistance value to the unit length resistance reference value; If the initial electrical distance is greater than the preset distance threshold, the initial electrical distance is compensated based on the phase voltage value to obtain the leakage point electrical distance; if the initial electrical distance is less than or equal to the preset distance threshold, the initial electrical distance is used as the leakage point electrical distance.

6. The fault location method of the distribution transformer low-voltage switch according to claim 5, characterized in that: The generating of the alarm information including the leakage point location information and sending the alarm information to the terminal device comprises the following steps: Generate an alarm data packet with the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value; The alarm data packet is sent to the terminal device through a wireless communication module.

7. The fault location method of the distribution transformer low-voltage switch according to claim 6, characterized in that: The step of generating an alarm data packet from the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value, and the neutral line current value comprises the following steps: Performing timestamp marking on the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value; If the difference between the live current value and the neutral current value lasts for more than a preset time period, the priority of the alarm data packet is marked as urgent, otherwise it is marked as normal; The data with the timestamp and the priority mark are packaged into the alarm data packet.

8. A system using the fault location method of the distribution transformer low-voltage switch according to any one of claims 1 to 7, characterized in that: include: A data acquisition module is used to collect phase voltage values, neutral line voltage values, live line current values ​​and neutral line current values ​​of low-voltage distribution lines; A state analysis module, for judging the working state of the low-voltage distribution line based on the equality relationship between the live current value and the neutral current value, and if the live current value is equal to the neutral current value, forming sampling data with the phase voltage value, the neutral voltage value, the live current value and the neutral current value; A data storage module, used for storing the sampled data into a database to form historical data; A fault detection module, used for calculating the difference between the current live line current value and the neutral line current value, and if the difference is greater than a preset current threshold, extracting the leakage circuit resistance value based on the phase voltage value and the neutral line voltage value; A distance calculation module, used to calculate the electrical distance of the leakage point based on the leakage loop resistance value and the load characteristic data set of the low-voltage distribution line; A position conversion module, used for converting the electrical distance of the leakage point into the position information of the leakage point; An alarm generating module, used for generating an alarm data packet from the leakage point location information, the phase voltage value, the neutral line voltage value, the live line current value and the neutral line current value; The information transmission module is used to send the alarm data packet to the terminal device through the wireless communication module.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the fault location method for the distribution transformer low-voltage switch according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the fault location method for a distribution transformer low-voltage switch according to any one of claims 1 to 7 are implemented.

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