Low-voltage distribution network fault location method based on power meter cooperative communication

Abstract

The application provides a low-voltage distribution network fault positioning method based on electric meter cooperative communication, which comprises the following steps: each smart electric meter monitors the electrical parameters of the node in real time; when any target smart electric meter in the plurality of smart electric meters determines that there is a fault according to the electrical parameters, the target smart electric meter generates initial fault information; the target smart electric meter sends the initial fault information to the adjacent smart electric meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology; and the main processor analyzes and determines the fault position and the fault type of the low-voltage distribution network according to the initial fault information and the communication topology. According to the application, each smart electric meter generates initial fault information based on the monitored electrical parameters in real time, and sends the initial fault information to the main processor through the communication topology, so that the fault detection efficiency is improved, the process is simple, and no additional manpower and material resources are needed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault positioning, in particular to a low-voltage distribution network fault positioning method based on power meter cooperative communication. BACKGROUND

[0002] The low-voltage distribution network is the terminal link of the power system and directly faces the general power users, and its reliability directly affects the user experience and economic benefits. However, the low-voltage distribution network has long lines, many branches, and a complex environment, and is easily affected by external damage, equipment aging, and adverse weather, and thus short-circuit and broken-line faults may occur.

[0003] In the prior art, manual inspection or installation of fault detection devices at key nodes is generally used to detect faults of the low-voltage distribution network.

[0004] However, the existing fault detection method has low efficiency, and the use of fault detection devices also requires additional installation, which is not only cumbersome but also brings a large additional investment. SUMMARY

[0005] The present application aims to solve the problems of low detection efficiency and cumbersome process in the prior art by providing a low-voltage distribution network fault positioning method based on power meter cooperative communication.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0007] In a first aspect, the present application provides a low-voltage distribution network fault positioning method based on power meter cooperative communication, applied to an intelligent power meter cooperative communication system, the system comprising: a plurality of intelligent power meters and a main processor, each of the plurality of intelligent power meters being in communication connection with the main processor, and a communication topology being formed between the plurality of intelligent power meters, the method comprising:

[0008] Each of the intelligent power meters monitors the electrical parameters of the node in real time;

[0009] When any target intelligent power meter in the plurality of intelligent power meters determines that there is a fault according to the electrical parameters, initial fault information is generated;

[0010] The target intelligent power meter sends the initial fault information to the adjacent intelligent power meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology;

[0011] The main processor analyzes and determines the fault location and fault type of the low-voltage distribution network according to the initial fault information and the communication topology.

[0012] Optionally, the target smart meter sends the initial fault information to the adjacent smart meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology, comprising:

[0013] The target smart meter sends the initial fault information to the adjacent smart meter according to the communication topology, and the initial fault information comprises a fault electrical parameter determined by the target smart meter and a corresponding fault timestamp;

[0014] After receiving the initial fault information, the adjacent smart meter reads its own electrical parameter corresponding to the fault timestamp according to the fault timestamp carried by the initial fault information;

[0015] The adjacent smart meter generates new fault information according to the initial fault information and its own electrical parameter, and sends the new fault information to the adjacent smart meter according to the communication topology, and the process is repeated in turn, and the final fault information is sent to the main processor after being processed by the smart meters on the topology path in turn.

[0016] Optionally, when any target smart meter in the plurality of smart meters determines that there is a fault according to the electrical parameter, the initial fault information is generated, comprising:

[0017] When any target smart meter in the plurality of smart meters detects a fault trigger condition according to the electrical parameter, the initial fault information is generated, wherein the fault trigger condition comprises at least one of the following: voltage instantaneous drop below a voltage preset threshold, voltage complete disappearance, and current instantaneous increase above a current preset threshold.

[0018] Optionally, the main processor determines the fault location and fault type of the low-voltage power distribution network according to the initial fault information and the communication topology, comprising:

[0019] The main processor determines a first fault meter with overvoltage or undervoltage in the last reported fault information and a second fault meter with complete voltage disappearance in the first reported fault information according to the initial fault information and the communication topology;

[0020] The main processor determines the fault location on the fault path between the first fault meter and the second fault meter according to the communication topology;

[0021] The main processor determines the fault type according to the electrical parameters of the upstream and downstream meters of the fault path.

[0022] Optionally, the main processor determines the fault type according to the electrical parameters of the upstream and downstream meters of the fault path, comprising:

[0023] If the main processor determines that the upstream electric meter of the fault path is overcurrent according to the electrical parameter of the upstream electric meter and that the downstream electric meter is under-voltage according to the electrical parameter of the downstream electric meter, the fault type is determined as a short-circuit fault.

[0024] Optionally, the main processor determines the fault type according to the electrical parameters of the upstream electric meter and the downstream electric meter of the fault path, including:

[0025] If the main processor determines that the current fluctuation of the upstream electric meter of the fault path is within a preset range according to the electrical parameter of the upstream electric meter and that the downstream electric meter is under-voltage according to the electrical parameter of the downstream electric meter, the fault type is determined as a broken line fault.

[0026] Optionally, the main processor determines the fault type according to the electrical parameters of the upstream electric meter and the downstream electric meter of the fault path, including:

[0027] The electrical parameters of the upstream electric meter and the downstream electric meter of the fault path are input into a pre-trained fault prediction large model, and the fault prediction large model outputs the fault type.

[0028] Optionally, the method further includes:

[0029] The main processor generates a fault report according to the fault location and the fault type;

[0030] The main processor sends the fault report to a management platform of the area where the fault location is located.

[0031] Optionally, the multiple smart electric meters adopt one or more combinations of the following communication modes: power line carrier communication, micro-power wireless communication, NB-IoT or 4G / 5G cellular communication.

[0032] In a second aspect, the present application provides a smart electric meter cooperative communication system, which comprises: multiple smart electric meters and a main processor, the multiple smart electric meters are in communication connection with the main processor, and a communication topology is formed among the multiple smart electric meters, and the main processor is used to execute the low-voltage distribution network fault positioning method based on electric meter cooperative communication as described in the first aspect.

[0033] The beneficial effects of the present application are: each smart meter monitors the electrical parameters of the node in real time, when any target smart meter in the plurality of smart meters determines that there is a fault according to the electrical parameters, the initial fault information is generated, the target smart meter sends the initial fault information to the adjacent smart meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology, and the main processor analyzes and determines the fault position and fault type of the low-voltage distribution network according to the initial fault information and the communication topology. The embodiment realizes full coverage of the circuit, reduces the cost of manpower and material resources, directly improves the operation and maintenance efficiency of the distribution network, shortens the fault outage time, and improves the user's power experience by real-time monitoring of each smart meter and cooperative verification of adjacent smart meters, thereby improving the fault positioning efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Figure 1 is a structural schematic diagram of a smart meter cooperative communication system provided by the embodiment of the present application;

[0036] Figure 2 is a flowchart of a low-voltage distribution network fault positioning method based on meter cooperative communication provided by the embodiment of the present application;

[0037] Figure 3 is a flowchart of an initial fault information transmission process provided by the embodiment of the present application;

[0038] Figure 4 is a flowchart of determining the fault position and fault type of the low-voltage distribution network provided by the embodiment of the present application. DETAILED DESCRIPTION

[0039] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be understood that the drawings in the present application serve only the purpose of illustration and description, and do not serve to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present application show the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowcharts can not be implemented in sequence, and the steps without logical context relationship can be reversed in sequence or implemented simultaneously. In addition, one or more other operations can be added to the flowcharts or one or more operations can be removed from the flowcharts under the guidance of the content of the present application.

[0040] In addition, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0042] In the prior art, to detect faults of a low-voltage power distribution network, manual inspection or installation of a fault detection device at key nodes is usually used, but such a detection method is low in efficiency, and the use of a fault detection device also requires additional installation, which is not only cumbersome but also brings a large additional investment.

[0043] Based on this, the present application proposes a low-voltage power distribution network fault positioning method based on meter cooperative communication. In the method, each smart meter monitors the electrical parameters of the node in real time. Once the smart meter determines that there is a fault according to the electrical parameters, it generates initial fault information, and sends the initial fault information to the adjacent smart meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology. The main processor analyzes and determines the fault location and fault type of the low-voltage power distribution network according to the initial fault information and the communication topology. The present application generates initial fault information in real time based on the monitoring of electrical parameters by each smart meter, and sends the initial fault information to the main processor through the communication topology, thereby improving the fault detection efficiency, the process is simple, and no additional manpower and material resources are required.

[0044] Figure 1This is a schematic diagram of the structure of a smart meter collaborative communication system provided in an embodiment of this application. Figure 1 As shown, the smart meter collaborative communication system can be applied in power distribution networks, such as low-voltage distribution networks. Taking a low-voltage distribution network as an example, it includes a distribution transformer T, a main line L0, and multiple branch lines L1, L2, L3, etc. Multiple electricity users can be distributed along these branch lines, and smart meters M1, M2, M3, etc., are installed on the lines connecting each user to the branch. Each smart meter connects to the main processor via power line communication (PLC) or a wireless communication network. Each smart meter has both point-to-point and broadcast communication capabilities to form a communication topology. The main processor can be a data concentrator unit (DCU) or a master station system. When the main processor is the master station system, each smart meter first connects to the DCU, and the DCU then communicates with the master station system via the public network.

[0045] Optionally, each smart meter not only has traditional electricity metering functions, but also integrates data acquisition, status sensing and communication interaction modules, and can act as a distributed monitoring node to capture the power grid status at its location in real time.

[0046] Optionally, the communication topology refers to the connection relationships and data transmission paths between smart meters within a region. The communication topology is pre-stored locally on each smart meter and in the main processor to define adjacent nodes for data transmission.

[0047] Next, refer to Figure 2 This paper introduces the steps and flow of a low-voltage distribution network fault location method based on meter collaborative communication. Figure 2 This is a flowchart illustrating a low-voltage distribution network fault location method based on meter collaborative communication provided in an embodiment of this application.

[0048] S201. Each smart meter monitors the electrical parameters of its node in real time.

[0049] Among them, electrical parameters are key electrical signal indicators that reflect the operating status of the power grid, mainly including voltage, current, phase angle, power, etc., which serve as the core basis for judging faults.

[0050] As an optional implementation, smart meters use built-in hardware modules such as voltage sensors and current transformers to collect electrical parameters of the node in real time. The collection frequency is typically on the order of milliseconds to ensure that instantaneous changes can be captured when a fault occurs. Specifically, the raw data collected by the smart meter is preprocessed by the microprocessor built into the meter, including filtering and calibration, and then stored in a local cache with timestamps. The processed data is then reported to the main controller at a frequency lower than the collection frequency.

[0051] S202, when any target smart meter in the plurality of smart meters determines that there is a fault according to the electrical parameter, initial fault information is generated.

[0052] Optionally, the fault can include short circuit, open circuit, under-voltage, over-current, etc., which can cause the electrical parameter to deviate from the normal range. Among them, short circuit is manifested as sudden increase of current, open circuit is manifested as sudden drop of voltage to 0, under-voltage is manifested as voltage lower than normal threshold, and over-current is manifested as current exceeding safe range.

[0053] Optionally, the initial fault information can be basic fault data generated by the smart meter that first detects the fault. The initial fault information can include: identification of the target smart meter, electrical parameter at the fault moment, fault timestamp when the fault occurs, and preliminary judged fault feature. Among them, the electrical parameter at the fault moment can include voltage value at voltage loss or current value at over-current. It is worth noting that the preliminary judged fault feature in the initial fault information can be the parameter performance that the target smart meter judges in real time according to the preset threshold and the electrical parameter, such as voltage loss or over-current. Exemplarily, if the smart meter M3 and the smart meter M4 are triggered first, the initial fault information of the smart meter M3 can be {ID: M3, Event: OverCurrent, V: 80V, I: 500A, Timestamp: t0}, and the initial fault information of the smart meter M4 can be {ID: M4, Event: VoltageLoss, V: 0V, I: 0A, Timestamp: t0}.

[0054] As an optional implementation, the target smart meter compares the real-time collected electrical parameter with the corresponding preset threshold through a preset fault detection algorithm, for example, when the electrical parameter exceeds the threshold and the maintenance time exceeds the preset time threshold, it is determined that a fault occurs. At this time, the target smart meter triggers the fault mode immediately, that is, extracts the electrical parameter at the fault moment from the local cache, combines the identity and timestamp of itself, and packages the initial fault information to provide basic data for subsequent cooperative communication.

[0055] S203, the target smart meter sends the initial fault information to the adjacent smart meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology.

[0056] Optionally, each smart meter can pre-store the identification and Internet Protocol Address (IP) address of the smart meter adjacent thereto in the local memory according to the communication topology, and when it is necessary to send information, the information is directly sent according to the identification of the adjacent smart meter stored in the local memory.

[0057] As an optional implementation, the target smart meter sends the initial fault information to the adjacent smart meter, and the adjacent smart meter determines the corresponding electrical parameter according to the fault timestamp in the initial fault information, and sends the electrical parameter and the initial fault information as new fault information to the main processor. The new fault information includes the initial fault information of the target smart meter and the electrical parameter of the adjacent smart meter.

[0058] As another optional implementation, after the target smart meter generates the initial fault information, the target smart meter sends the initial fault information to the adjacent smart meter. After the adjacent smart meter determines the electrical parameter according to the fault timestamp, the adjacent smart meter sends the electrical parameter and the initial fault information as new fault information to the smart meter adjacent to the adjacent smart meter, and so on, until all the smart meters in the topology path of the target smart meter generate the electrical parameter and generate the new fault information, and send the final fault information to the main processor. Optionally, the final fault information includes the initial fault information and the electrical parameter of all the smart meters in the topology path.

[0059] As another optional implementation, after the target smart meter generates the initial fault information, the target smart meter directly reports the initial fault information to the main processor, and simultaneously sends the initial fault information to the adjacent smart meter. The adjacent smart meter determines the electrical parameter of the adjacent smart meter at the fault timestamp according to the fault timestamp in the initial fault information, and sends the electrical parameter and the fault timestamp as new fault information to the main processor, and simultaneously sends the new fault information to the adjacent smart meter. In this way, all the smart meters in the topology path of the faulty smart meter report the fault information to the main processor, so that the main processor aligns the reported fault information according to the fault timestamp of the initial fault information.

[0060] The topology path is a path formed by the smart meters having strong correlation with the electrical parameter of the target smart meter in the entire communication network in combination with the communication topology structure of the low-voltage distribution network. The communication topology is a connection structure formed by the meters according to the physical route, such as the main line or the branch line, and the connection structure is, for example, a tree structure or a chain structure. For example, the smart meter M1, the smart meter M2 and the smart meter M3 in the branch L1 are adjacent in turn, and the smart meter M1, the smart meter M2 and the smart meter M3 are located in the same topology path.

[0061] S204, the main processor determines the fault location and the fault type of the low-voltage distribution network according to the initial fault information and the communication topology analysis.

[0062] Optionally, the main processor analyzes the initial fault information, the communication topology and the self electrical parameters of the smart meters on the topology path to determine the fault location and the fault type of the low-voltage power distribution network.

[0063] The fault location refers to a specific line section in the power distribution network where the fault occurs, and can be located to a line between two adjacent smart meters, such as the L1 branch line between the smart meter M2 and the smart meter M3.

[0064] As an optional implementation, after receiving the final fault information, the main processor determines the fault location in combination with the communication topology, which includes: comparing the initial fault information of the target smart meter and the electrical parameters of the smart meters on the topology path of the target smart meter to identify and determine the state mutation position, and taking the state mutation position as the fault location. The state mutation position can be a pair of adjacent nodes from the fault state meter to the normal state meter. For example, the smart meter M3 is in a voltage loss state, and the smart meter M2 adjacent to the smart meter is in a normal state, and the fault location is the line section between the smart meter M2 and the smart meter M3.

[0065] The step of determining the fault type includes: determining the fault type based on the initial fault information of the target smart meter, the electrical parameters of the smart meters on the topology path of the target smart meter, and the preset voltage threshold and current threshold.

[0066] In this embodiment, each smart meter monitors the electrical parameters of the node in real time, and when any target smart meter in the plurality of smart meters determines that there is a fault according to the electrical parameters, initial fault information is generated. The target smart meter sends the initial fault information to the adjacent smart meter according to the communication topology, so as to send the initial fault information to the main processor through the communication topology. The main processor analyzes and determines the fault location and the fault type of the low-voltage power distribution network according to the initial fault information and the communication topology. In this embodiment, the real-time monitoring of each smart meter and the cooperative verification of adjacent smart meters can improve the fault positioning efficiency, realize full coverage of the circuit, reduce the cost of manpower and material resources, directly improve the operation and maintenance efficiency of the power distribution network, shorten the fault outage time, and improve the user's power experience.

[0067] Figure 3 is a flowchart of an initial fault information transmission process provided by an embodiment of the present application. Next, referring to Figure 3 The process in which the target smart meter sends the initial fault information to the adjacent smart meter according to the communication topology in step S203 is introduced.

[0068] S301, the target smart meter sends initial fault information to adjacent smart meters according to a communication topology, the initial fault information comprising: a fault electrical parameter determined by the target smart meter and a corresponding fault timestamp.

[0069] Optionally, the target smart meter can determine an upstream smart meter and a downstream smart meter in the topology path based on the communication topology, and both the upstream smart meter and the downstream smart meter are regarded as adjacent smart meters. The upstream smart meter is a smart meter close to a power supply end, and the downstream smart meter is a smart meter away from the power supply end.

[0070] Specifically, the target smart meter can communicate by using PLC or wireless ad hoc network. When a fault occurs, the target smart meter can switch from a normal operation mode to a fault communication mode, pause non-urgent data transmission such as normal power consumption data, and preferentially occupy a communication resource to send initial fault information, so as to ensure timeliness.

[0071] Optionally, the initial fault information is packaged in a preset protocol format, for example, including a frame header, a target smart meter identifier, a fault parameter, a timestamp, and a check code. The check code is used for verifying data integrity by an adjacent smart meter, so as to avoid errors in transmission. If the verification fails, retransmission is requested.

[0072] Optionally, the target smart meter first sends a fault notification broadcast to all adjacent smart meters, triggers the adjacent smart meters to enter a cooperative listening state, and then sends complete initial fault information in a directional manner, so as to reduce invalid communication.

[0073] S302, after receiving the initial fault information, the adjacent smart meter reads self electrical parameters corresponding to the fault timestamp according to the fault timestamp carried in the initial fault information.

[0074] The self electrical parameters refer to voltage, current, phase, and the like collected by the adjacent smart meter at the precise time of the fault timestamp. Optionally, each smart meter is internally provided with a time sequence database, and high-frequency collection data in a preset time period are stored in real time in the form of a key-value pair of a timestamp electrical parameter, so as to ensure that the parameters at the fault time can be traced back.

[0075] Optionally, the time deviation of all smart meters in the power distribution network can be controlled within a preset time by using a clock signal in a PLC carrier or a network time protocol. After receiving the initial fault information, the adjacent smart meter extracts the fault timestamp and accurately locates the electrical parameters at the time in the local cache.

[0076] Optionally, after receiving the initial fault information, the adjacent smart meter triggers a priority interrupt, that is, pauses a low-priority task such as screen display updating, and preferentially executes timestamp analysis and parameter reading, so as to ensure that the processing is completed within a short time and the information transmission is avoided to be delayed.

[0077] S303, the adjacent smart meter generates new fault information according to the electrical parameters and the initial fault information, and sends the new fault information to the adjacent smart meter according to the communication topology, and the process is repeated in turn, and the final fault information is sent to the main processor after being processed by the smart meters on the topology path in turn.

[0078] Optionally, the new fault information always retains the original fault information, and the electrical parameters of the current smart meter are sequentially added to form a chain data structure.

[0079] Optionally, when the following three situations are encountered, the iteration is stopped and the final fault information is sent to the main processor: first, when the fault information is transmitted to the smart meter directly connected to the main processor, the meter no longer transmits to other meters, but directly sends the fault information to the main processor. Second, if the smart meter at the end of the distribution network, such as the smart meter M3 at the downstream of the branch line, has no downstream adjacent meter in its topology path, the smart meter sends the fault information to the main processor. Third, a maximum transmission hop count is preset, and if the transmission count exceeds the maximum transmission hop count, the iteration is automatically stopped and the fault information is sent to the main processor to prevent infinite loop of information in the ring topology. The current hop count can be recorded in the fault information.

[0080] Optionally, if the electrical parameter information corresponding to the same meter or the initial fault information of the target smart meter is transmitted to the same meter through different paths, the meter, for example, the intersection node of the branch line and the main line, can merge the duplicate data by comparing the time stamp and the meter identifier to avoid the main processor receiving redundant information.

[0081] In this embodiment, the received fault information is processed by the adjacent smart meters in turn, and the final fault information is sent to the main processor, so that the fault information is detected from a single point to node cooperation verification, which not only ensures the integrity of the data, but also improves the communication efficiency.

[0082] As an optional implementation, when any target smart meter in the plurality of smart meters determines that there is a fault according to the electrical parameters in the above step S202, the process of generating initial fault information is as follows: when any target smart meter in the plurality of smart meters detects a fault trigger condition according to the electrical parameters, the initial fault information is generated, wherein the fault trigger condition includes at least one of the following: the voltage instantaneous drop below the voltage preset threshold, the voltage completely disappears, and the current instantaneous increase above the current preset threshold.

[0083] Wherein, the voltage transient drop below the voltage preset threshold means that the voltage value detected by the smart meter suddenly drops in a very short time and is lower than the preset normal voltage threshold, but does not completely drop to zero. For example, the single-phase user end voltage suddenly drops below 150V and the duration is greater than 10ms, which triggers the condition. The causes of the condition can be short-circuit fault, sudden start of heavy load, or poor line contact, etc.

[0084] The voltage completely disappears means that the voltage value detected by the smart meter suddenly drops to 0V and lasts for a certain time. The causes of the voltage completely disappearing are usually as follows: line breakage, distribution transformer tripping, and total switch opening.

[0085] The current transient increase above the current preset threshold means that the current value detected by the smart meter suddenly increases in a very short time and exceeds the preset safe current threshold. The causes of the current transient increase above the current preset threshold are usually as follows: short-circuit fault, user end equipment failure, and line overload.

[0086] Optionally, each smart meter judges whether the electrical parameter reaches the fault triggering condition in real time during operation, and if so, generates initial fault information. Multiple smart meters can simultaneously detect the fault triggering condition and simultaneously generate initial fault information.

[0087] In the embodiment, the target smart meter detects the fault triggering condition according to the electrical parameter and generates the initial fault information, thereby ensuring that the fault can be quickly captured and the interference can be effectively filtered, laying a foundation for subsequent cooperative verification and main processor analysis.

[0088] Next, referring to Figure 4 The process of the main processor determining the fault location and fault type of the low-voltage distribution network according to the initial fault information and the communication topology in step S204 is introduced. Among them, Figure 4 is a flowchart of determining the fault location and fault type of the low-voltage distribution network provided by the embodiment of the application.

[0089] S401, the main processor determines the first fault meter with overvoltage or undervoltage in the last reported fault information and the second fault meter with voltage completely disappearing in the first reported fault information according to the initial fault information and the communication topology.

[0090] Optionally, in the low-voltage power distribution network fault, the voltage overvoltage or undervoltage and voltage completely disappear exist clear spatial correlation, that is, the upstream of the fault point may only appear voltage abnormal overvoltage or undervoltage, and the downstream will be caused by the fault to completely disappear voltage. By identifying the first fault meter and the second fault meter, the range of the fault occurrence can be quickly locked. Exemplarily, if a line is broken at a certain point, the meter upstream of the broken point may appear undervoltage due to the change of the line impedance, and the downstream meter is completely lost voltage, and the section between the two is the fault location.

[0091] As an optional implementation, after the main processor receives the final fault information, it first sorts the data according to the identification of the smart meter, the time stamp and the electrical parameter, and screens out all the fault meters that report overvoltage, undervoltage and voltage completely disappear, and excludes the meters in normal state.

[0092] Among them, along the topology path from the power supply end to the user end, the voltage state of each fault meter is checked in sequence on the communication topology path, the demarcation point of overvoltage or undervoltage and voltage completely disappearing is found, and the last overvoltage or undervoltage meter upstream of the demarcation point is taken as the first fault meter. Along the same topology path, the first smart meter reporting voltage completely disappearing downstream of the first fault meter is found, which is the second fault meter.

[0093] Exemplarily, a topology path includes in sequence: transformer T, smart meter M1, smart meter M2, smart meter M3 and smart meter M4, smart meter M1 and smart meter M2 appear undervoltage, and smart meter M3 and smart meter M4 appear lost voltage, then smart meter M2 is taken as the first fault meter, and smart meter M3 is taken as the second fault meter.

[0094] Optionally, if no meter meeting the conditions is found, for example, all fault meters are lost voltage, then the state of the distribution transformer is combined to determine that the fault is between the distribution transformer and the first lost voltage meter, so as to avoid missing judgment.

[0095] S402, the main processor determines the fault location on the fault path between the first fault meter and the second fault meter according to the communication topology.

[0096] Optionally, the main processor extracts the physical line path between the first fault meter and the second fault meter according to the communication topology, and the path is the core range of fault troubleshooting.

[0097] Specifically, by using the pre-stored communication topology, it is confirmed whether the first faulty meter and the second faulty meter are directly adjacent nodes. If so, the fault location is directly determined to be the line segment between the first faulty meter and the second faulty meter. If not, the status of the smart meter between the first faulty meter and the second faulty meter is further analyzed, such as whether it was not reported due to a communication failure, thereby narrowing down the fault node to the nearest abnormal and normal node.

[0098] Optionally, the information about the determined fault location may include: line name, starting point, ending point, and distance estimate, where the distance estimate is the distance between the starting point and the ending point.

[0099] Optionally, the fault location can be visualized via text or a map, and an alarm message can be generated. For example, the system automatically generates an alarm message stating: "A fault has occurred on line XX in area XX, with the estimated location between smart meter M3 (address: XX Road, XX No.) and smart meter M4 (address: XX Road, XX No.)", and dispatches a work order to the maintenance personnel.

[0100] S403: The main processor determines the fault type based on the electrical parameters corresponding to the upstream and downstream meters in the fault path.

[0101] Optionally, the upstream meter is the first faulty meter and all smart meters upstream of the first faulty meter, and the downstream meter is all smart meters downstream of the second faulty meter.

[0102] Specifically, the main processor can determine the fault type based on the voltage and current parameters of the upstream and downstream meters along the fault path.

[0103] In this embodiment, the first fault meter and the second fault meter are determined based on the initial fault information and the communication topology. Then, the fault location between the first fault meter and the second fault meter is determined based on the communication topology. The fault type is determined based on the electrical parameters corresponding to the upstream and downstream meters, thereby forming a fault diagnosis closed loop and providing accurate decision-making basis for the efficient operation and maintenance of low-voltage distribution networks.

[0104] As an optional implementation, in step S403 above, the main processor determines the fault type based on the electrical parameters corresponding to the upstream and downstream meters of the fault path using three methods.

[0105] Specifically, the first method is as follows: if the main processor determines the overcurrent of the upstream meter based on the electrical parameters of the upstream meter in the fault path, and determines the undervoltage of the downstream meter based on the electrical parameters of the downstream meter, then the fault type is determined to be a short-circuit fault.

[0106] Optionally, the short-circuit fault is manifested as a low-impedance abnormal loop in the line, such as direct contact between a phase line and a phase line or between a phase line and a zero line, resulting in a sharp increase in current, and the downstream of the short-circuit point is completely powered off due to the current being shunted by the abnormal loop. The upstream electric meter needs to bear the super-large current generated by the short circuit because it is close to the power supply end, and the downstream electric meter loses current and voltage because the current is cut off at the short-circuit point, forming the characteristics of overcurrent in the upstream and loss of voltage in the downstream.

[0107] In this embodiment, whether the upstream electric meter overflows and whether the downstream electric meter loses voltage are determined, so that the fault type is determined to be a short-circuit fault, which is efficient and accurate.

[0108] The second method is: if the main processor determines that the current fluctuation of the upstream electric meter of the fault path is within a preset range according to the electrical parameters of the upstream electric meter, and determines that the downstream electric meter loses voltage according to the electrical parameters of the downstream electric meter, then the fault type is determined to be a broken-line fault.

[0109] Optionally, the broken-line fault is manifested as a physical breakage of the line, such as a breakage of a phase line or a zero line. The breakage of the line causes the downstream of the fault point to be completely disconnected from the power supply end, forming an open circuit state, so that the downstream loses voltage due to the absence of a current path. The upstream still maintains a normal current range without overcurrent due to the absence of an abnormal loop, and only a slight decrease due to the disconnection of the downstream user, forming the characteristics of normal current in the upstream and loss of voltage in the downstream.

[0110] Optionally, after the downstream electric meter reports loss of voltage, the main processor immediately sends a low-voltage wake-up instruction to it. If the downstream electric meter can normally respond to the instruction, it proves that its power supply is not disconnected, and only the power grid side loses voltage, so the electric meter itself is excluded from the fault. If it cannot respond, it means that the smart electric meter has failed, and a fault alarm signal needs to be sent according to the identification of the smart electric meter. The fault alarm signal includes the identification of the faulty smart electric meter.

[0111] In this embodiment, whether the current fluctuation of the upstream electric meter is within a preset range and whether the downstream electric meter loses voltage are determined, so that the fault type is determined to be a broken-line fault, which is efficient and accurate.

[0112] The third method is: the electrical parameters of the upstream electric meter and the electrical parameters of the downstream electric meter of the fault path are input into a pre-trained fault prediction large model, and the fault prediction large model outputs the fault type.

[0113] The training process of the fault prediction large model includes: converting the electrical parameters of the smart meters upstream and downstream of the fault path in the sample data into features understandable by the model, i.e., converting the voltage and current waveform segments within a preset time period before and after the fault into time sequence features, converting the peak values, change rates and fluctuation amplitudes of the voltage and current into mutation features, and converting the time difference between the upstream and downstream meters, the upstream and downstream current ratio and the upstream and downstream voltage ratio into correlation features. A time sequence classification model is used to train the model through sample data, and the fault prediction large model is obtained through iterative correction of the model.

[0114] After the fault occurs, the main processor extracts the real-time electrical parameters of the upstream and downstream meters at the fault time and before and after the fault, arranges them into input vectors according to the format during training, and inputs the input vectors into the pre-trained fault prediction large model. The model calculates through multiple layers of network and outputs the probability of each fault type. The type with the highest probability is taken as the final fault type, and key influence features are output at the same time, such as "upstream current change rate reaching 15A / ms is the main basis" when the model judges a short circuit, thereby improving the explainability.

[0115] In this embodiment, the fault type is predicted by the fault prediction large model, which is suitable for systems with many branches and complex fault scenarios in the distribution network, and can improve the fault type judgment accuracy and robustness while maintaining real-time performance.

[0116] As an optional implementation, the low-voltage distribution network fault location method based on meter cooperative communication further includes the following method:

[0117] Optionally, the main processor generates a fault report according to the fault location and the fault type.

[0118] The fault report can include: basic information, fault location, fault type, key parameter basis, influence range and processing suggestion. The basic information can include the fault occurrence time, the substation name and the line number, the key parameter basis can be the electrical parameters of the target fault meter and the preliminary judgment, the influence range includes the user range covered by the target fault meter and the meters with abnormal electrical parameters, and the processing suggestion can be a suggestion generated based on the fault location and the fault type.

[0119] Exemplarily, if a short-circuit fault occurs between the smart meter M2 and the smart meter M3 of the L1 branch, a fault report is generated:

Emergency Fault Report

[0120] Optionally, the main processor sends the fault report to the management platform of the area where the fault location is located.

[0121] Optionally, the management platform can be a local operation terminal, a power supply dispatching center platform, and a user notification platform, etc., and the local operation terminal can be used by on-site repair personnel.

[0122] In this embodiment, the main processor generates a fault report according to the fault location and the fault type, and the main processor sends the fault report to the management platform of the area where the fault location is located, thereby greatly shortening the fault response time and improving the power supply reliability.

[0123] Optionally, the communication mode between the plurality of smart meters is one or a combination of the following: power line carrier communication, micro-power wireless communication, NB-IoT or 4G / 5G cellular communication.

[0124] The power line carrier communication is a communication mode that uses the low-voltage power line where the smart meter is located as the transmission medium and realizes data interaction through the loading of high-frequency signals. This mode does not need to lay additional communication lines, directly reuses the existing power network, has extremely low deployment cost, and has consistent coverage with the power line, can naturally match the power distribution network topology, and is suitable for short-distance communication.

[0125] The micro-power wireless communication realizes wireless data transmission by using low-power radio frequency signals and supports point-to-point or ad hoc networks. This mode is flexible to deploy, is not interfered by the power line, has high reliability and low power consumption.

[0126] Narrowband Internet of Things (NB-IoT) is a narrowband Internet of Things technology based on operator cellular networks, which has very wide coverage and is suitable for scattered meters in rural and suburban areas, and has low power consumption.

[0127] Fourth-Generation Mobile Communication Technology / Fifth-Generation Mobile Communication Technology (4G / 5G) cellular communication is to realize high-speed and low-latency data transmission by using the 4G / 5G network of an operator, and this mode has low delay and wide coverage.

[0128] Optionally, the above modes can be combined for use, such as PLC in the transformer area, NB-IoT or 4G / 5G cellular communication for long-distance communication, so as to balance the cost, reliability and practicability.

[0129] In this embodiment, power line carrier communication, micro-power wireless communication, NB-IoT or 4G / 5G cellular communication is used between the plurality of smart meters, so as to improve the reliability and reduce the energy consumption.

[0130] The embodiment of the present application also provides a smart meter cooperative communication system, which comprises a plurality of smart meters and a main processor, the plurality of smart meters are in communication connection with the main processor, and a communication topology is formed between the plurality of smart meters, and the main processor is used to execute the low-voltage power distribution network fault positioning method based on meter cooperative communication.

[0131] The above is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which shall be covered within the protection scope of the present application.

Claims

1. A method for fault location in low-voltage distribution networks based on meter collaborative communication, characterized in that, A collaborative communication system for smart meters is provided, the system comprising: multiple smart meters and a main processor, wherein each of the multiple smart meters is communicatively connected to the main processor, and a communication topology is formed among the multiple smart meters; the method includes: Each of the aforementioned smart meters monitors the electrical parameters of its respective node in real time; When any target smart meter among the multiple smart meters determines that a fault exists based on the electrical parameters, initial fault information is generated; The target smart meter sends the initial fault information to adjacent smart meters according to the communication topology. The initial fault information includes: the fault electrical parameters determined by the target smart meter and the corresponding fault timestamp. After receiving the initial fault information, the adjacent smart meter reads its own electrical parameters corresponding to the fault timestamp carried by the initial fault information. The adjacent smart meters generate new fault information based on their own electrical parameters and the initial fault information, and send the new fault information to the adjacent smart meters according to the communication topology, and so on. After being processed by the smart meters on the topology path, the final fault information is sent to the main processor. The main processor determines the fault location and fault type of the low-voltage distribution network based on the final fault information and the communication topology analysis.

2. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 1, characterized in that, When any target smart meter among the plurality of smart meters determines that a fault exists based on the electrical parameters, initial fault information is generated, including: When any target smart meter among the plurality of smart meters detects a fault triggering condition based on the electrical parameters, initial fault information is generated. The fault triggering condition includes at least one of the following: voltage instantaneously drops below a preset voltage threshold, voltage completely disappears, or current instantaneously increases above a preset current threshold.

3. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 2, characterized in that, The main processor determines the fault location and fault type of the low-voltage distribution network based on the final fault information and the communication topology analysis, including: The main processor determines, based on the final fault information and the communication topology, the first fault meter with overvoltage or undervoltage in the last reported fault information and the second fault meter with completely lost voltage in the first reported fault information. The main processor determines the fault location on the fault path between the first fault meter and the second fault meter according to the communication topology. The main processor determines the fault type based on the electrical parameters corresponding to the upstream and downstream meters of the fault path.

4. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 3, characterized in that, The main processor determines the fault type based on the electrical parameters corresponding to the upstream and downstream meters in the fault path, including: If the main processor determines that the upstream meter has an overcurrent based on the electrical parameters of the upstream meter in the fault path, and determines that the downstream meter has a voltage loss based on the electrical parameters of the downstream meter, then the fault type is determined to be a short-circuit fault.

5. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 3, characterized in that, The main processor determines the fault type based on the electrical parameters corresponding to the upstream and downstream meters in the fault path, including: If the main processor determines that the current fluctuation of the upstream meter is within a preset range based on the electrical parameters of the upstream meter in the fault path, and determines that the downstream meter is undervoltage based on the electrical parameters of the downstream meter, then the fault type is determined to be an open-circuit fault.

6. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 3, characterized in that, The main processor determines the fault type based on the electrical parameters corresponding to the upstream and downstream meters in the fault path, including: The electrical parameters of the upstream meter and the downstream meter of the fault path are input into a pre-trained fault prediction model, and the fault prediction model outputs the fault type.

7. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 3, characterized in that, The method further includes: The main processor generates a fault report based on the fault location and the fault type; The main processor sends the fault report to the management platform of the area where the fault is located.

8. The low-voltage distribution network fault location method based on meter collaborative communication according to claim 1, characterized in that, The multiple smart meters communicate with each other using one or more of the following methods in combination: power line carrier communication, low-power wireless communication, NB-IoT, or 4G / 5G cellular communication.

9. A smart meter collaborative communication system, characterized in that, The smart meter collaborative communication system includes: multiple smart meters and a main processor, wherein the multiple smart meters are all communicatively connected to the main processor, and a communication topology is formed among the multiple smart meters, and the main processor is used to execute the low-voltage distribution network fault location method based on meter collaborative communication as described in any one of claims 1-8.

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