A method and system for rapid location and search of lightning strike faults in power distribution lines

Abstract

The application provides a distribution network line lightning stroke fault rapid positioning and searching method and system, wherein the method comprises the following steps: obtaining line switch tripping information, tower information and ground flash information after the distribution network line lightning stroke fault; determining the longitude and latitude coordinates of the lightning stroke point according to the ground flash information; calculating and searching the line tower coordinates closest to the lightning stroke point, and determining the closest tower; taking the closest tower as the center, combining the tower basic data, lightning current and distance, carrying out tower overvoltage inversion calculation, comparing the overvoltage of the seven base towers, and determining the tower with the overvoltage exceeding the set condition as the fault tower; combining the service life and lightning stroke times of the fault tower to determine the priority order of the fault tower; and searching the fault point according to the priority order of the fault tower. The application realizes the rapid positioning and searching of the distribution network tower lightning stroke by using the existing data generated by each system, does not need to additionally increase hardware devices, and has low maintenance cost in the later period.

Description

Technical Field

[0001] This invention belongs to the field of power technology, specifically relating to a method and system for rapid location and search of lightning strike faults in distribution network lines. Background Technology

[0002] Lightning is a significant factor threatening the safety of power systems. It poses a serious threat to the safe operation of transmission lines, frequently causing insulator flashover accidents, and lightning strikes on transmission and distribution lines are a major cause of power outages. Direct lightning overvoltage occurs when a thundercloud directly strikes distribution lines, power towers, and other electrical equipment. This occurs because the extremely strong current from the thundercloud, after being transmitted to the ground through electrical equipment, creates a large voltage drop, resulting in lightning overvoltage. This is particularly problematic in mountainous areas, suburbs, and regions with poor transportation, significantly increasing the difficulty of routine maintenance and fault location. Overvoltage caused by lightning is called atmospheric overvoltage. This type of overvoltage is extremely dangerous. Atmospheric overvoltage can be divided into two basic forms: direct lightning overvoltage and induced lightning overvoltage. The electrothermal effect of lightning can generate lightning overvoltage, causing breakdown of electrical insulation, insulator flashover, switch tripping, and line outages. This severely impacts the safe operation of the distribution network, factory production, and residents' electricity experience. With long distribution network lines and wide coverage, and the randomness of lightning strikes, how to quickly and accurately locate fault points, shorten repair time, and restore power quickly, thereby improving power supply reliability, has become the unremitting pursuit of power supply companies.

[0003] Existing technology provides a method for identifying and locating lightning strike faults. This method uses the induced current obtained by adding a coupling ground wire and a high-frequency current device to infer the lightning strike point. However, this method has a large error and high initial investment and subsequent maintenance costs. Summary of the Invention

[0004] In view of this, the present invention aims to solve the problems of large errors in existing lightning strike fault identification and location methods that require the installation of coupling ground wires and high-frequency current devices, as well as high initial investment and subsequent operation and maintenance costs.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a method for rapidly locating and locating lightning strike faults in distribution network lines, comprising the following steps:

[0007] Obtain information on line switch tripping, tower information, and ground flash information after a lightning strike fault in the distribution network;

[0008] Determine the latitude and longitude coordinates of the lightning strike point based on the lightning strike information;

[0009] Calculate and find the coordinates of the nearest line tower to the lightning strike point to determine the nearest tower;

[0010] Seven towers centered on the nearest tower are selected. The tower overvoltage inversion calculation is carried out by combining tower foundation data, lightning current and distance. The overvoltage magnitude of the seven towers is compared and the towers with overvoltage exceeding the set conditions are identified as faulty towers.

[0011] The priority order of faulty towers is determined by combining their years of operation and the number of lightning strikes.

[0012] The fault location is located by prioritizing the faulty towers.

[0013] Furthermore, before determining the latitude and longitude coordinates of the lightning strike point based on the lightning information, the process also includes:

[0014] Based on the tripping information and ground flash information, determine whether the lightning strikes near the tripped line match in time and space. If so, the corresponding line is identified as a lightning strike fault.

[0015] Furthermore, the coordinates of the nearest power line tower to the lightning strike point are calculated and located to determine the nearest tower. This specifically includes:

[0016] Let the latitude and longitude coordinates of the lightning strike point be (LonA, LatA), and the latitude and longitude coordinates of the tower near the lightning strike point be (LonB, LatB);

[0017] The latitude and longitude coordinates are preprocessed as follows: positive longitude values ​​are taken for east longitude, negative longitude values ​​are taken for west longitude, 90° minus latitude values ​​are taken for north latitude, and 90° plus latitude values ​​are taken for south latitude to obtain new latitude and longitude coordinates (MLonA,MLatA) and (MLonB,MLatB) respectively.

[0018] The distance between each tower and the lightning strike point is calculated using the following formula, with the tower having the shortest distance being the nearest tower. The formula is as follows:

[0019] C=sin(MLatA)*sin(MLatB)+cos(MLatA)*cos(MLatB)*cos(MlonA-MLonB)

[0020] D = R * arccos(C) * π / 180

[0021] In the formula, R is the Earth's radius, and D is the distance between the tower and the point of impact.

[0022] Furthermore, by combining tower foundation data, lightning current, and distance, overvoltage inversion calculations were performed on the towers. The overvoltage magnitudes of the seven towers were compared, and towers with overvoltages exceeding set conditions were identified as faulty towers. Specifically, this included:

[0023] When the distance D is greater than the set distance, the induced overvoltage of the tower is calculated using the following formula:

[0024] U1=25*I*h / D

[0025] In the formula, h is the average height of the conductor, I is the lightning current, and D is the distance between the lightning strike point and the tower;

[0026] When the distance D is not greater than the set distance, calculate the direct lightning strike overvoltage of the tower. The direct lightning strike overvoltage includes backflashover overvoltage and backflashover overvoltage, and the calculation formulas are as follows:

[0027] Overvoltage formula:

[0028] U2=I*(1-K)*[β(R+L / 2.6)+h / 2.6]

[0029] In the formula, h is the average height of the conductor, I is the lightning current, R is the tower grounding resistance, L is the tower inductance, K is the coupling coefficient, and β is the tower current shunting coefficient;

[0030] Overvoltage formula:

[0031] U3 = IR

[0032] In the formula, I is the lightning current and R is the tower grounding resistance.

[0033] Furthermore, information on line switch tripping, tower information, and ground flashover information after a lightning strike fault in the distribution network line is obtained, specifically:

[0034] Obtain distribution network line switch tripping information actively pushed by the dispatch automation system, and actively extract line tower information from the distribution network geographic information system;

[0035] The trip information query lightning location system obtains lightning strike data within a set time range and a set line corridor radius of the trip time point.

[0036] Secondly, the present invention provides a rapid location and search system for lightning strike faults in distribution network lines, comprising:

[0037] The information acquisition unit is used to acquire information on line switch tripping, tower information, and ground flash information after a lightning strike fault in the distribution network line.

[0038] The fault tower calculation unit is used to determine the latitude and longitude coordinates of the lightning strike point based on the lightning information; calculate and find the coordinates of the line tower closest to the lightning strike point to determine the nearest tower; take 7 towers centered on the nearest tower, combine the tower foundation data, lightning current and distance to carry out tower overvoltage inversion calculation, compare the overvoltage magnitude of the 7 towers, and determine the towers whose overvoltage exceeds the set conditions as fault towers;

[0039] The fault location unit is used to determine the priority of faulty towers by combining their years of operation and the number of lightning strikes; and to locate the fault point by locating the faulty towers according to the priority order.

[0040] Furthermore, in the fault tower calculation unit, before determining the latitude and longitude coordinates of the lightning strike point based on the ground flash information, the following steps are also included:

[0041] Based on the tripping information and ground flash information, determine whether the lightning strikes near the tripped line match in time and space. If so, the corresponding line is identified as a lightning strike fault.

[0042] Furthermore, in the fault tower calculation unit, the coordinates of the line tower closest to the lightning strike point are calculated and located to determine the nearest tower. This specifically includes:

[0043] Let the latitude and longitude coordinates of the lightning strike point be (LonA, LatA), and the latitude and longitude coordinates of the tower near the lightning strike point be (LonB, LatB);

[0044] The latitude and longitude coordinates are preprocessed as follows: positive longitude values ​​are taken for east longitude, negative longitude values ​​are taken for west longitude, 90° minus latitude values ​​are taken for north latitude, and 90° plus latitude values ​​are taken for south latitude to obtain new latitude and longitude coordinates (MLonA,MLatA) and (MLonB,MLatB) respectively.

[0045] The distance between each tower and the lightning strike point is calculated using the following formula, with the tower having the shortest distance being the nearest tower. The formula is as follows:

[0046] C=sin(MLatA)*sin(MLatB)+cos(MLatA)*cos(MLatB)*cos(MlonA-MLonB)

[0047] D = R * arccos(C) * π / 180

[0048] In the formula, R is the Earth's radius, and D is the distance between the tower and the point of impact.

[0049] Furthermore, in the faulty tower calculation unit, the tower overvoltage inversion calculation is carried out by combining tower foundation data, lightning current, and distance. The overvoltage magnitudes of the seven towers are compared, and towers with overvoltages exceeding the set conditions are identified as faulty towers. Specifically, this includes:

[0050] When the distance D is greater than the set distance, the induced overvoltage of the tower is calculated using the following formula:

[0051] U1=25*I*h / D

[0052] In the formula, h is the average height of the conductor, I is the lightning current, and D is the distance between the lightning strike point and the tower;

[0053] When the distance D is not greater than the set distance, calculate the direct lightning strike overvoltage of the tower. The direct lightning strike overvoltage includes backflashover overvoltage and backflashover overvoltage, and the calculation formulas are as follows:

[0054] Overvoltage formula:

[0055] U2=I*(1-K)*[β(R+L / 2.6)+h / 2.6]

[0056] In the formula, h is the average height of the conductor, I is the lightning current, R is the tower grounding resistance, L is the tower inductance, K is the coupling coefficient, and β is the tower current shunting coefficient;

[0057] Overvoltage formula:

[0058] U3 = IR

[0059] In the formula, I is the lightning current and R is the tower grounding resistance.

[0060] Furthermore, the information acquisition unit acquires information such as line switch tripping, tower information, and ground flash information after a lightning strike fault on the distribution network line. Specifically:

[0061] Obtain distribution network line switch tripping information actively pushed by the dispatch automation system, and actively extract line tower information from the distribution network geographic information system;

[0062] The trip information query lightning location system obtains lightning strike data within a set time range and a set line corridor radius of the trip time point.

[0063] In summary, this invention provides a method and system for rapid location and search of lightning strike faults in distribution network lines. The method includes acquiring information on line switch tripping, tower information, and ground flash information after a lightning strike fault in the distribution network line; determining the latitude and longitude coordinates of the lightning strike point based on the ground flash information; calculating and finding the coordinates of the nearest line tower to the lightning strike point; selecting seven towers centered on the nearest tower, and performing overvoltage inversion calculations on the towers based on tower foundation data, lightning current, and distance; comparing the overvoltage magnitudes of the seven towers, and identifying towers with overvoltages exceeding set conditions as faulty towers; determining the priority order of faulty towers based on their years of operation and number of lightning strikes; and locating the fault point according to the priority order of the faulty towers. This invention achieves rapid location and search of lightning strike faults in distribution network towers by utilizing existing data generated by various systems, without requiring additional hardware equipment, resulting in low maintenance costs. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0065] Figure 1 This is a flowchart illustrating a method for quickly locating and finding lightning strike faults in distribution network lines, as provided in an embodiment of the present invention. Detailed Implementation

[0066] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0067] Lightning is a significant factor threatening the safety of power systems. It poses a serious threat to the safe operation of transmission lines, frequently causing insulator flashover accidents, and lightning strikes on transmission and distribution lines are a major cause of power outages. Direct lightning overvoltage occurs when a thundercloud directly strikes distribution lines, power towers, and other electrical equipment. This occurs because the extremely strong current from the thundercloud, after being transmitted to the ground through electrical equipment, creates a large voltage drop, resulting in lightning overvoltage. This is particularly problematic in mountainous areas, suburbs, and regions with poor transportation, significantly increasing the difficulty of routine maintenance and fault location. Overvoltage caused by lightning is called atmospheric overvoltage. This type of overvoltage is extremely dangerous. Atmospheric overvoltage can be divided into two basic forms: direct lightning overvoltage and induced lightning overvoltage. The electrothermal effect of lightning can generate lightning overvoltage, causing breakdown of electrical insulation, insulator flashover, switch tripping, and line outages. This severely impacts the safe operation of the distribution network, factory production, and residents' electricity experience. With long distribution network lines and wide coverage, and the randomness of lightning strikes, how to quickly and accurately locate fault points, shorten repair time, and restore power quickly, thereby improving power supply reliability, has become the unremitting pursuit of power supply companies.

[0068] The following methods for locating lightning strike faults are provided in the existing technology:

[0069] (1) By employing several distributed voltage monitoring sensors to monitor the line status, when the sensors detect a lightning overvoltage, the monitored voltage characteristic data is uploaded to the background positioning host. The background host extracts and analyzes the collected data, and uses the phase transition characteristics of the first overvoltage signal generated when the line is struck by lightning relative to the system power frequency voltage per cycle to determine the location of the lightning strike point. This application combines pulse signal injection and the phase transition characteristics of lightning overvoltage to achieve accurate location of lightning strikes on transmission and distribution lines. This method uses the method of installing sensors, which are themselves susceptible to lightning strikes and damage, and increases the initial investment and subsequent maintenance costs.

[0070] (2) By selecting several lightning strike monitoring points in a 10kV distribution line, a coupled ground wire is constructed between the two towers where the lightning strike monitoring points are located. The relationship between the induced current amplitude of the ground wire at each monitoring point and the lightning current amplitude and the distance to the lightning strike point is obtained through simulation, and a positioning database is constructed. A high-frequency current monitoring device is used to obtain the induced current generated by the surge arrester or coupled ground wire during a lightning strike, and the data is transmitted to the system backend. A lightning positioning system based on lightning electromagnetic signals is used to obtain the lightning current amplitude at the time of the fault. The lightning current amplitude is imported into the positioning database for fuzzy positioning of the lightning strike location. Based on the fuzzy positioning of the lightning strike, the circuit breaker tripping situation, and the lightning protection performance of the line, the fuzzy positioning of the lightning fault location is performed. This method uses the method of adding a coupled ground wire and a high-frequency current device to obtain the induced current to back-deduce the lightning strike point, which has a large error and high initial investment and subsequent operation and maintenance costs.

[0071] (3) By acquiring the real-time voltage waveform of the point to be measured on the transmission line, it is determined whether the current voltage of the point to be measured on the transmission line is an overvoltage. If the current voltage is an overvoltage, several voltage acquisition points are selected from both sides of the point to be measured on the transmission line. Then, based on the voltage values ​​of the several voltage acquisition points and the distance between the voltage acquisition points on the same side of the point to be measured on the transmission line, the voltage attenuation coefficient of the transmission line is calculated. Finally, based on the voltage attenuation coefficient of the transmission line and the distance between the voltage acquisition points on both sides of the point to be measured on the transmission line, the location of the lightning fault on the transmission line is determined. This method is applicable to traveling wave distance measurement and is suitable for transmission lines above 110kV. It is not very practical for distribution lines with many branches.

[0072] (4) By placing several numbered sensors on the insulating porcelain insulators, surge arresters, circuit breakers, disconnect switches, or transformers of energized transmission lines on poles or towers, the sensors detect lightning strikes and generate induced electromotive force. Each sensor has a signal transmission circuit, which communicates with a terminal signal receiving device via a satellite positioning and navigation system to determine the location of the lightning strike. This method requires satellite communication to determine the lightning strike location; positioning time errors and limitations in communication levels will all affect the final positioning accuracy.

[0073] It is evident that the existing method requires the installation of additional equipment, resulting in significant upfront investment and ongoing maintenance costs.

[0074] Based on this, the present invention provides a method and system for rapid location and search of lightning strike faults in distribution network lines.

[0075] The following is a detailed description of an embodiment of a method for rapid location and search of lightning strike faults in distribution network lines provided by the present invention.

[0076] Please see Figure 1 This embodiment provides a method for quickly locating and finding lightning strike faults in distribution network lines, including the following steps:

[0077] S100: Obtain information on line switch tripping, tower information, and ground flash information after a lightning strike fault on a distribution network line.

[0078] It should be noted that the tripping information of distribution network line switches is actively pushed by the dispatch automation system, while the information of line towers is actively extracted from the distribution network geographic information system.

[0079] After obtaining the trip information, the trip information is used to query the lightning location system to obtain lightning strike data within a set time range and a set line corridor radius at the trip time point, that is, to obtain lightning strike data within a set range.

[0080] S200: Determine the latitude and longitude coordinates of the lightning strike point based on the lightning information.

[0081] In one embodiment, before determining the latitude and longitude coordinates of the lightning strike point, it is also necessary to determine whether the lightning strikes near the tripped line match in time and space based on the tripping information and ground flash information. If so, the corresponding line is determined to be a lightning strike fault.

[0082] S300: Calculate and find the coordinates of the nearest line tower to the lightning strike point, and determine the nearest tower.

[0083] In one embodiment, the process for determining the nearest tower is as follows:

[0084] S301: Let the latitude and longitude coordinates of the lightning strike point be (LonA, LatA), and the latitude and longitude coordinates of the tower near the lightning strike point be (LonB, LatB);

[0085] S302: The latitude and longitude coordinates are preprocessed. Specifically, the positive longitude value is taken for east longitude, the negative longitude value is taken for west longitude, the latitude value is taken as 90 minus the latitude value for north latitude, and the latitude value is taken as 90 plus the latitude value for south latitude to obtain new latitude and longitude coordinates (MLonA,MLatA) and (MLonB,MLatB) respectively.

[0086] S303: Calculate the distance between each tower and the lightning strike point according to the following formula, and take the tower with the shortest distance as the nearest tower. The calculation formula is as follows:

[0087] C=sin(MLatA)*sin(MLatB)+cos(MLatA)*cos(MLatB)*cos(MlonA-MLonB)

[0088] D = R * arccos(C) * π / 180

[0089] In the formula, R is the Earth's radius, taken as 6371.00 km, and D is the distance between the tower and the lightning strike point.

[0090] S400: Take the 7 towers centered on the nearest tower, and perform tower overvoltage inversion calculation by combining tower foundation data, lightning current and distance. Compare the overvoltage magnitude of the 7 towers, and identify the towers whose overvoltage exceeds the set conditions as faulty towers.

[0091] In one embodiment, the overvoltage U calculation includes the calculation of induced lightning overvoltage and direct lightning overvoltage.

[0092] When the distance D is greater than the set distance, the induced overvoltage of the tower is calculated using the following formula:

[0093] U1=25*I*h / D

[0094] In the formula, h is the average height of the conductor, I is the lightning current, and D is the distance between the lightning strike point and the tower;

[0095] When the distance D is not greater than the set distance, calculate the direct lightning strike overvoltage of the tower. The direct lightning strike overvoltage includes backflashover overvoltage and backflashover overvoltage, and the calculation formulas are as follows:

[0096] Overvoltage formula:

[0097] U2=I*(1-K)*[β(R+L / 2.6)+h / 2.6]

[0098] In the formula, h is the average height of the conductor, I is the lightning current, R is the tower grounding resistance, L is the tower inductance, K is the coupling coefficient, and β is the tower current shunting coefficient;

[0099] Overvoltage formula:

[0100] U3 = IR

[0101] In the formula, I is the lightning current and R is the tower grounding resistance.

[0102] In actual calculations, if the overvoltage U exceeds the discharge voltage U50 of 50% of the lightning impulse on the tower and equipment insulation, it is identified as a faulty tower and the corresponding tower number is obtained.

[0103] S500: Determine the priority order of faulty towers by combining their years of operation and the number of lightning strikes.

[0104] S600: Locate the fault point by prioritizing the faulty tower.

[0105] Specifically, the priority number of the faulty tower can be sent to the mobile phones of the repair personnel via the company's internal SMS system so that they can locate the fault.

[0106] This embodiment provides a method for rapidly locating lightning strike faults in distribution network lines. It utilizes existing data generated by various systems to quickly locate lightning strikes on distribution network towers without requiring additional hardware, resulting in low maintenance costs. Furthermore, it uses an enterprise SMS system to send fault location information to maintenance personnel's mobile phones, enabling real-time fault reporting. This overcomes the timeliness issues associated with manual queries, automating fault querying, location, and reporting, reducing workload and easing the burden on relevant staff.

[0107] The above is a detailed description of an embodiment of a method for quickly locating and finding lightning strike faults in distribution network lines according to the present invention. The following will provide a detailed description of an embodiment of a system for quickly locating and finding lightning strike faults in distribution network lines according to the present invention.

[0108] This embodiment provides a rapid location and search system for lightning strike faults in distribution network lines, including: an information acquisition unit, a fault tower calculation unit, and a fault point investigation unit.

[0109] In this embodiment, the information acquisition unit is used to acquire information on line switch tripping, tower information, and ground flash information after a lightning strike fault on the distribution network line.

[0110] The information acquisition unit acquires information on line switch tripping, tower information, and ground flash information following a lightning strike fault on the distribution network line. Specifically:

[0111] Obtain distribution network line switch tripping information actively pushed by the dispatch automation system, and actively extract line tower information from the distribution network geographic information system;

[0112] The trip information query lightning location system obtains lightning strike data within a set time range and a set line corridor radius of the trip time point.

[0113] In this embodiment, the fault tower calculation unit is used to determine the latitude and longitude coordinates of the lightning strike point based on the lightning information; calculate and find the coordinates of the line tower closest to the lightning strike point to determine the nearest tower; take 7 towers centered on the nearest tower, combine the tower foundation data, lightning current and distance to carry out tower overvoltage inversion calculation, compare the overvoltage magnitude of the 7 towers, and determine the towers whose overvoltage exceeds the set conditions as fault towers.

[0114] In the fault tower calculation unit, before determining the latitude and longitude coordinates of the lightning strike point based on the ground flash information, the following steps are also included:

[0115] Based on the tripping information and ground flash information, determine whether the lightning strikes near the tripped line match in time and space. If so, the corresponding line is identified as a lightning strike fault.

[0116] Furthermore, in the fault tower calculation unit, the coordinates of the line tower closest to the lightning strike point are calculated and located to determine the nearest tower. This specifically includes:

[0117] Let the latitude and longitude coordinates of the lightning strike point be (LonA, LatA), and the latitude and longitude coordinates of the tower near the lightning strike point be (LonB, LatB);

[0118] The latitude and longitude coordinates are preprocessed as follows: positive longitude values ​​are taken for east longitude, negative longitude values ​​are taken for west longitude, 90° minus latitude values ​​are taken for north latitude, and 90° plus latitude values ​​are taken for south latitude to obtain new latitude and longitude coordinates (MLonA,MLatA) and (MLonB,MLatB) respectively.

[0119] The distance between each tower and the lightning strike point is calculated using the following formula, with the tower having the shortest distance being the nearest tower. The formula is as follows:

[0120] C=sin(MLatA)*sin(MLatB)+cos(MLatA)*cos(MLatB)*cos(MlonA-MLonB)

[0121] D = R * arccos(C) * π / 180

[0122] In the formula, R is the Earth's radius, and D is the distance between the tower and the point of impact.

[0123] Furthermore, in the faulty tower calculation unit, the tower overvoltage inversion calculation is carried out by combining tower foundation data, lightning current, and distance. The overvoltage magnitudes of the seven towers are compared, and towers with overvoltages exceeding the set conditions are identified as faulty towers. Specifically, this includes:

[0124] When the distance D is greater than the set distance, the induced overvoltage of the tower is calculated using the following formula:

[0125] U1=25*I*h / D

[0126] In the formula, h is the average height of the conductor, I is the lightning current, and D is the distance between the lightning strike point and the tower;

[0127] When the distance D is not greater than the set distance, calculate the direct lightning strike overvoltage of the tower. The direct lightning strike overvoltage includes backflashover overvoltage and backflashover overvoltage, and the calculation formulas are as follows:

[0128] Overvoltage formula:

[0129] U2=I*(1-K)*[β(R+L / 2.6)+h / 2.6]

[0130] In the formula, h is the average height of the conductor, I is the lightning current, R is the tower grounding resistance, L is the tower inductance, K is the coupling coefficient, and β is the tower current shunting coefficient;

[0131] Overvoltage formula:

[0132] U3 = IR

[0133] In the formula, I is the lightning current and R is the tower grounding resistance.

[0134] In this embodiment, the fault location unit is used to determine the priority order of faulty towers by combining the years of operation of the faulty towers and the number of lightning strikes; and to locate the fault point according to the priority order of the faulty towers.

[0135] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for quickly locating a lightning stroke fault of a distribution network line, characterized in that, The method comprises the following steps: Obtain line switch tripping information, tower information and ground lightning information after lightning fault of a distribution network line; Determine the longitude and latitude coordinates of the lightning point according to the ground lightning information; Calculate and find the line tower coordinates closest to the lightning point, and determine the closest tower; Take the 7-base towers centered on the closest tower, combine tower basic data, lightning current and distance, and carry out tower overvoltage inversion calculation, compare the overvoltages of the 7-base towers, and determine the tower whose overvoltage exceeds the set condition as the fault tower; Determine the priority order of the fault tower in combination with the service life and lightning strike times of the fault tower; Find the fault point of the fault tower according to the priority order; Combine tower basic data, lightning current and distance, and carry out tower overvoltage inversion calculation, compare the overvoltages of the 7-base towers, and determine the tower whose overvoltage exceeds the set condition as the fault tower, specifically comprising: When the distance D is greater than the set distance, calculate the induced overvoltage of the tower, and the calculation formula is as follows: U1=25*I*h / D In the formula, h is the average height of the conductor, I is the lightning current, and D is the distance between the lightning point and the tower; When the distance D is not greater than the set distance, the direct lightning overvoltage of the tower is calculated, and the direct lightning overvoltage includes back strike overvoltage and shielding failure overvoltage, and the calculation formulas are as follows: Back strike overvoltage formula: U2=I*(1-K)*[β(R+L / 2.6)+h / 2.6] In the formula, h is the average height of the conductor, I is the lightning current, R is the tower grounding resistance, L is the tower inductance, K is the coupling coefficient, and β is the tower shunt coefficient; Shielding failure overvoltage formula: U3=IR In the formula, I is the lightning current, and R is the tower grounding resistance; Obtain line switch tripping information, tower information and ground lightning information after lightning fault of a distribution network line, specifically: Obtain the distribution network line switch tripping information actively pushed by the dispatching automation system, and actively extract the line tower information in the distribution network geographic information system; Query the lightning positioning system from the tripping information, and obtain the lightning data within the set time range and within the set line corridor radius at the tripping time point.

2. The method of claim 1, wherein, Before determining the longitude and latitude coordinates of the lightning point according to the ground lightning information, it further comprises: Determine whether the lightning near the tripped line matches in time and space according to the tripping information and the ground lightning information, and if so, determine the corresponding line as a lightning fault.

3. The method of claim 1, wherein, Calculate and find the line tower coordinates closest to the lightning point, and determine the closest tower, specifically comprising: Record the longitude and latitude coordinates of the lightning point as (LonA, LatA), and the longitude and latitude coordinates of the tower near the lightning point as (LonB, LatB); Preprocess the longitude and latitude coordinates, specifically taking the positive value of the longitude for the east longitude, taking the negative value of the longitude for the west longitude, taking the value of 90 minus the latitude for the north latitude, and taking the value of 90 plus the latitude for the south latitude to obtain new longitude and latitude coordinates (MLonA, MLatA) and (MLonB, MLatB); Calculate the distance between each tower and the lightning point according to the following formula, and take the tower with the shortest distance as the closest tower, and the calculation formula is as follows: C=sin(MLatA)*sin(MLatB)+cos(MLatA)*cos(MLatB)*cos (MlonA-MLonB) D=R*arccos(C)*π / 180 In the formula, R is the radius of the earth, and D is the distance between the tower and the lightning point.

4. A lightning stroke fault fast positioning and searching system for distribution network line, characterized in that, It comprises the following steps: An information acquisition unit is configured to acquire line switch tripping information, tower information, and ground lightning information after lightning fault of a distribution network line. A fault tower calculation unit is configured to determine the longitude and latitude coordinates of a lightning point according to the ground lightning information, calculate and search for line tower coordinates closest to the lightning point, determine a closest tower, take seven base towers centered on the closest tower, combine tower basic data, lightning current, and distance to carry out tower overvoltage inversion calculation, compare overvoltage of the seven base towers, and determine a tower whose overvoltage exceeds a set condition as a fault tower. A fault point investigation unit is configured to determine a priority order of the fault tower in combination with a service life and lightning strike times of the fault tower, and find a fault point of the fault tower according to the priority order. In the fault tower calculation unit, the tower overvoltage inversion calculation is carried out in combination with tower basic data, lightning current, and distance, overvoltage of the seven base towers is compared, and a tower whose overvoltage exceeds a set condition is determined as a fault tower, and specifically comprises the following steps. When the distance D is greater than a set distance, the induced overvoltage of the tower is calculated, and the calculation formula is as follows: U1=25*I*h / D In the formula, h is the average height of the conductor, I is the lightning current, and D is the distance between the lightning point and the tower. When the distance D is not greater than the set distance, the direct lightning overvoltage of the tower is calculated, and the direct lightning overvoltage includes back strike overvoltage and shielding failure overvoltage, and the calculation formulas are as follows, respectively. Back strike overvoltage formula: U2=I*(1-K)*[β(R+L / 2.6)+h / 2.6] In the formula, h is the average height of the conductor, I is the lightning current, R is the tower grounding resistance, L is the tower inductance, K is the coupling coefficient, and β is the tower diversion coefficient. Shielding failure overvoltage formula: U3=IR In the formula, I is the lightning current, and R is the tower grounding resistance. In the information acquisition unit, the line switch tripping information, tower information, and ground lightning information after lightning fault of the distribution network line are acquired, and specifically as follows. The distribution network line switch tripping information actively pushed by a dispatching automation system is acquired, and line tower information in a distribution network geographic information system is actively extracted. The lightning location system is queried from the tripping information to acquire lightning data within a set time range and within a set line corridor radius of a tripping time point.

5. The system for fast locating and searching of lightning stroke faults of distribution lines according to claim 4, characterized in that, In the fault tower calculation unit, before the longitude and latitude coordinates of the lightning point are determined according to the ground lightning information, the following steps are further included. It is determined whether lightning near the tripped line matches in time and space according to the tripping information and the ground lightning information, and if so, the corresponding line is determined as a lightning fault.

6. The system for fast locating and searching of lightning stroke faults of distribution network lines according to claim 4, characterized in that, In the fault tower calculation unit, the closest line tower coordinates to the lightning point are calculated and searched, and the closest tower is determined, and specifically comprises the following steps. Record the longitude and latitude coordinates of the lightning stroke point as (LonA, LatA), and the longitude and latitude coordinates of the tower near the lightning stroke point as (LonB, LatB); Preprocess the longitude and latitude coordinates, specifically, take the positive value of longitude for east longitude, take the negative value of longitude for west longitude, take the value of 90-latitude for north latitude, and take the value of 90+latitude for south latitude to obtain new longitude and latitude coordinates (MLonA, MLatA) and (MLonB, MLatB); Calculate the distance between each tower and the lightning stroke point according to the following formula and take the tower with the shortest distance as the nearest tower, and the calculation formula is as follows: C=sin(MLatA)*sin(MLatB)+cos(MLatA)*cos(MLatB)*cos (MlonA-MLonB) D=R*arccos(C)*π / 180 In the formula, R is the radius of the earth, and D is the distance between the tower and the lightning stroke point.

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