A topology identification method, medium and terminal based on segmented characteristic current signal

Abstract

The present invention is applicable to the technical field of low-voltage power distribution, and relates to a topology identification method, medium and terminal based on segmented characteristic current signals. In combination with the broadband carrier communication technology of the local network, the time synchronization and signaling content transmission between the signal sending end and the signal receiving end are realized, and at the same time, a characteristic current staggered transmission mechanism of the three-phase line based on the zero crossing point is implemented in the time domain, which greatly reduces the intensity of the line background current and increases the duty cycle of the characteristic current signal, which is beneficial to reduce the heat generation rate of the sending end equipment and reduces its influence on the operation of the electric meter. The information transmission and time synchronization functions of the power line carrier communication network are fully utilized to realize the optimization of the topology identification process; the power of the line background current noise can be effectively reduced, thereby increasing the signal-to-noise ratio of the received signal and improving the detection performance of the synchronization signal; the current range required for detection is effectively reduced, which can reduce the requirements for hardware, thereby reducing the cost of the equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-voltage power distribution, and in particular relates to a topology identification method, a medium and a terminal based on segmented characteristic current signals. Background Art

[0002] Affected by many factors, in the power user electricity consumption information collection system, the affiliation between the user's electric energy meter and the transformer substation recorded in the collection file may be inconsistent with the actual situation. Therefore, it is necessary to identify the corresponding relationship between the user's electric energy meter and the actual transformer substation through technical means to correct the collection file of the concentrator. The correct substation user-transformer relationship file is an important basis for substation line loss analysis, topology identification, and fault diagnosis.

[0003] At present, the household-to-substation relationship identification solution based on characteristic current has received much attention from power grid companies. Its essence is to install a module in the smart meter. The meter is responsible for providing power and control signals to the module. When the smart meter receives a command from the main station or concentrator, it will start the characteristic current transmission module and generate a certain characteristic current between the live and neutral wires. This current conforms to the corresponding frequency domain law, and a receiving terminal with current signal sampling and analysis functions is installed at the corresponding position of the line. It will report the detection results of the characteristic current signal to the main station. Finally, the main station realizes the topology identification of the entire substation by comparing and analyzing all time parameters. Although this technology can quickly realize automatic identification of household transformer relationships for a large number of electricity meters, in actual applications, there is not much space left for the characteristic current transmission module in the smart meter. A large amount of heat will be generated during the transmission time period of the characteristic current, which may easily have an adverse effect on the overall operation of the meter. Moreover, this technology has very high performance requirements on the signal sampling accuracy and transformation ratio of the current transformer of the characteristic current receiving terminal, and the cost is relatively high. Since the line background current amplitude at the signal receiving end is very large, the background noise amplitude in the frequency domain will also increase accordingly, thereby reducing the signal-to-noise ratio of the received signal in the frequency domain and reducing the detection performance of the characteristic current signal. In addition, during the signal transmission process, the characteristic current transmission module of the user's meter is very easy to couple with the lines on other phases to produce signals with smaller amplitudes but similar waveforms, thereby affecting the signal detection and household transformer relationship identification performance of the receiving module.

[0004] Therefore, how to reduce the cost and heat dissipation of the equipment and improve the detection performance and topology recognition performance of the characteristic current signal is an urgent problem to be solved by people in this technical field. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a topology identification method based on segmented characteristic current signals to solve the problems in the prior art of high cost, poor heat dissipation capability, low detection performance and topology identification performance of characteristic current signals of topology identification equipment; in addition, the present invention also provides a topology identification medium and terminal based on segmented characteristic current signals.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a topology identification method based on a segmented characteristic current signal, comprising the following steps:

[0008] S10, assuming that there are X meters to be identified in the carrier subnet of the concentrator Q in a certain area to be identified, the master station system sends a command to implement the household transformer relationship identification to the concentrator Q;

[0009] S20, after receiving the command, the concentrator Q randomly selects three electric meters with different phases, and sends a signaling to the three electric meters and the characteristic current detection terminal in the area through a beacon management message newly defined in the beacon signal;

[0010] S30, after receiving the command, the electric meter corresponding to the signaling content sends a characteristic current signal of a specified format within a specified time period according to the content requirements, and after the characteristic current detection terminal in the station area receives the command, the current transformers of the three phases thereof respectively perform current signal sampling on their respective phase lines within the corresponding time period;

[0011] S40, after the current transformer completes segmented sampling in each phase, the sampling signals are merged, the characteristic current detection terminal determines whether there is a synchronization signal in the sampling signal, outputs the determination result and reports it to the concentrator;

[0012] S50, the concentrator Q respectively makes X electric meters execute characteristic current signal transmission once, and respectively receives the detection results of the characteristic current detection terminal for the X characteristic current signal transmissions, and determines whether the electric meter belongs to the transformer in this area according to the detection results;

[0013] S60, the concentrator Q reports the list of electric meters that are determined to belong to the area and the list of electric meters that are not affiliated to the area to the master station. After the master station receives the information reported by the concentrator Q, if there are electric meters that are not affiliated to the area, the master station will remove the electric meters that are not affiliated to the area from the white list of the area, and send the new white list to the concentrator Q;

[0014] S70. After receiving the new white list, the concentrator Q sends a signal to the electric meters that do not belong to this subnet based on the power line carrier communication technology, requesting them to withdraw from the network. After receiving the withdrawal signal, the electric meter actively leaves the subnet and searches for other carrier subnets to join the network.

[0015] Further, in step S50, if the detection result corresponding to Y1 of the X meters is that a synchronization signal exists, the concentrator Q determines that Y1 meter belongs to the transformer of this substation; if the detection result corresponding to Y2 of the X meters is that a synchronization signal does not exist, the concentrator Q commands Y2 meters to send characteristic current signals again.

[0016] Furthermore, if there are still meters whose corresponding detection results show that there is no synchronization signal, the concentrator Q will classify them as meters with unclear household-transformer relationships. Within the allowed identification time or when the number of times the characteristic current of the meter is sent does not reach the upper limit, the concentrator Q will repeat the test on the meters with unclear household-transformer relationships.

[0017] Furthermore, in step S20, the type of topology identification message newly added in the beacon management message is as follows:

[0018] The name of the management message is household change relationship identification message, and the type values ​​include State Grid 0xAB and Southern Grid 0xAB. The function is to notify a user meter with characteristic current sending capability to send characteristic current signals in a specified mode within a specified time period.

[0019] Furthermore, the content of the newly added topology identification message is as follows:

[0020] The name is network short address 1, the length is 12 bits, and it is the network short address of the carrier module of a certain A-phase user electricity meter to be notified. If it is all zero, it means that the meter does not exist;

[0021] The name is network short address 2, the length is 12 bits, and it is the network short address of the carrier module of a certain B-phase user meter to be notified. If it is all zero, it means that the meter does not exist;

[0022] The name is network short address 3, the length is 12 bits, and it is the network short address of the carrier module of a C-phase user meter to be notified. If it is all zeros, it means that the meter does not exist;

[0023] The name is reserved and has a length of 4 bits.

[0024] The name is the message sequence number, which is 8 bits long and is used to identify the sequence number of this message. The initial value is 0 and it is a sequentially increasing value, which restarts after reaching 255.

[0025] The current transmission start time named as phase A is 32 bits long and indicates the base time of the carrier network. For the user electric meter of phase A, the characteristic current signal will be transmitted at this time point; for the user electric meter of phase B, the characteristic current signal will be transmitted 10 / 3 milliseconds later than this time point; and for the user electric meter of phase C, the characteristic current signal will be transmitted 20 / 3 milliseconds later than this time point;

[0026] The name is the time length of the segmented characteristic current signal, which is 16 bits long and represents the time length of a single segment characteristic current signal in units of 0.1 milliseconds.

[0027] Furthermore, the duration of the segmented characteristic signal sent by the Y2 electricity meter for the second time is half of the first time.

[0028] Furthermore, in step S10, the household change relationship identification time is early morning.

[0029] In a second aspect, the present invention further provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0030] In a third aspect, the present invention further provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method as described above.

[0031] Compared with the prior art, the topology identification method, medium and terminal based on segmented characteristic current signals provided by the present invention have at least the following beneficial effects:

[0032] In the prior art, the signal sampling accuracy and transformation ratio performance requirements of the current transformer of the characteristic current receiving terminal are very high, and the cost is relatively high; since the line background current amplitude at the signal receiving end is very large, the background noise amplitude in the frequency domain will also increase accordingly, thereby reducing the signal-to-noise ratio of the received signal in the frequency domain and reducing the detection performance of the characteristic current signal; in addition, during the signal transmission process, the characteristic current transmission module of the user's meter is very easy to couple with the lines on other phases to produce signals with smaller amplitudes but similar waveforms, thereby affecting the signal detection and user-transformer relationship recognition performance of the receiving module. The process of the present invention is simple and easy to operate. It is further combined with the broadband carrier communication technology of the local network to realize the time synchronization and signaling content transmission between the signal sending end and the signal receiving end. At the same time, a characteristic current staggered transmission mechanism of the three-phase line based on the zero crossing point is implemented in the time domain, which greatly reduces the intensity of the line background current and increases the duty cycle of the characteristic current signal, which is beneficial to reduce the heat generation rate of the sending end equipment and reduce its impact on the operation of the electric meter. It makes full use of the information transmission and time synchronization functions of the power line carrier communication network to achieve the optimization of the topology identification process; it can effectively reduce the power of the line background current noise, thereby increasing the signal-to-noise ratio of the received signal and improving the detection performance of the synchronization signal; the current range required for detection is effectively reduced, which can reduce the requirements for hardware, thereby reducing the cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the scheme of the present invention, a brief introduction is given below to the figures required for use in the description of the embodiments. Obviously, the figures described below are some embodiments of the present invention. For ordinary technicians in this field, other figures can be obtained based on these figures without paying any creative work.

[0034] Figure 1 A flowchart of a topology identification method based on segmented characteristic current signals provided by an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of characteristic circuit transmission of a user electric meter on a three-phase line in a topology identification method based on segmented characteristic current signals provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0038] The present invention provides a topology recognition method based on segmented characteristic current signals, which is applied to the recognition process of the household transformer relationship of the electric meter. The topology recognition method based on segmented characteristic current signals comprises the following steps:

[0039] S10, assuming that there are X meters to be identified in the carrier subnet of the concentrator Q in a certain area to be identified, the master station system sends a command to implement the household transformer relationship identification to the concentrator Q;

[0040] S20, after receiving the command, the concentrator Q randomly selects three electric meters with different phases, and sends a signaling to the three electric meters and the characteristic current detection terminal in the area through a beacon management message newly defined in the beacon signal;

[0041] S30, after receiving the command, the electric meter corresponding to the signaling content sends a characteristic current signal of a specified format within a specified time period according to the content requirements, and after the characteristic current detection terminal in the station area receives the command, the current transformers of the three phases thereof respectively perform current signal sampling on their respective phase lines within the corresponding time period;

[0042] S40, after the current transformer completes segmented sampling in each phase, the sampling signals are merged, the characteristic current detection terminal determines whether there is a synchronization signal in the sampling signal, outputs the determination result and reports it to the concentrator;

[0043] S50, the concentrator Q respectively makes X electric meters execute characteristic current signal transmission once, and respectively receives the detection results of the characteristic current detection terminal for the X characteristic current signal transmissions, and determines whether the electric meter belongs to the transformer in this area according to the detection results;

[0044] S60, the concentrator Q reports the list of electric meters that are determined to belong to the area and the list of electric meters that are not affiliated to the area to the master station. After the master station receives the information reported by the concentrator Q, if there are electric meters that are not affiliated to the area, the master station will remove the electric meters that are not affiliated to the area from the white list of the area, and send the new white list to the concentrator Q;

[0045] S70. After receiving the new white list, the concentrator Q sends a signal to the electric meters that do not belong to this subnet based on the power line carrier communication technology, requesting them to withdraw from the network. After receiving the withdrawal signal, the electric meter actively leaves the subnet and searches for other carrier subnets to join the network.

[0046] The present invention has a simple process and convenient operation, effectively reduces the cost and heat dissipation of equipment, and improves the detection performance and topology recognition performance of characteristic current signals.

[0047] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0048] The present invention provides a topology recognition method based on segmented characteristic current signals, which is applied to the recognition process of household transformer relationship of electric meters. It is assumed that both the household transformer relationship recognition terminal and the electric meter have power line broadband carrier communication capability. Figure 1 to Figure 2 In this embodiment, the topology identification method based on the segmented characteristic current signal includes the following steps:

[0049] S10, assuming that there are a total of X user meters with household change relationships to be identified in the carrier subnet of the concentrator Q in a certain area to be identified, the master station system sends a command to the concentrator Q, requiring it to implement household change relationship identification;

[0050] In this embodiment, the greater the background current intensity on the line, the greater the interference intensity on the characteristic current signal. Therefore, the household transformer relationship identification process is performed during the period when the power load level in the substation area is low, such as the early morning period.

[0051] S20. After receiving the command, the concentrator Q randomly selects three meters with different phases, and sends a signal to the three meters and the characteristic current detection terminal in the area through a beacon management message newly defined in the beacon signal. The newly defined description is as follows:

[0052] The beacon signal originates from the network master node (concentrator) and is forwarded to all nodes in the network through the relay of the network slave nodes. It is the core means for the master node to implement orderly subnet management and channel resource scheduling. The definition of the payload field in the beacon signal in the broadband carrier communication standard of the State Grid and the Southern Power Grid is as follows Table 1:

[0053] Table 1

[0054]

[0055] Furthermore, in this embodiment, the beacon management message part is defined as shown in Table 2 below:

[0056] Table 2

[0057]

[0058] Furthermore, in this embodiment, the type definition and content description of the management message are as shown in Table 3 below:

[0059] Table 3

[0060]

[0061] Furthermore, in this embodiment, in order to realize the household change relationship identification in the distribution station area, a new beacon management message is added, which is specifically defined in the following Table 4:

[0062] Table 4

[0063]

[0064] Furthermore, in this embodiment, the content of the newly added topology identification message is defined as shown in Table 5 below:

[0065] Table 5

[0066]

[0067] In this embodiment, in the broadband carrier communication network protocol, the concentrator Q will assign a 12-bit network short address to each network access node to identify the unique identity of the node in the network. At the same time, during the network operation, the concentrator Q will carry its own time data in the beacon signal to serve as the network reference time (NTB) of the entire network, thereby realizing periodic time synchronization of communication nodes in the entire network.

[0068] In this embodiment, the essence of the improved scheme is to utilize the high-precision time synchronization mechanism of the power line broadband carrier communication network to divide the continuously transmitted characteristic current signal of the original scheme into multiple segmented signals of the same length. The sending time intervals of these segmented signals are the same (10 milliseconds, that is, the time interval between two adjacent zero crossing points of 50Hz alternating current) and their time positions are located on the left and right sides of the zero crossing point of the phase line.

[0069] In this embodiment, although the zero-crossing point position of the alternating current may be affected by various factors and may cause random jitter, generally speaking, the time amplitude of the left and right jitters is small and presents a uniform distribution characteristic. When the concentrator Q decides the start time of the current transmission of the A phase, it can continuously measure the time position of the zero-crossing point of the A phase line voltage signal, and then calculate an average value, which is used as the basis for decision-making, and try to make the subsequent segmented characteristic current signal located in the lowest amplitude area of ​​the background current of the line, that is, the center point of the segmented characteristic current signal coincides with the zero-crossing point.

[0070] S30. After receiving the command, the electric meter corresponding to the signaling content sends the characteristic current signal of the specified format within the specified time period as required by the content; and after the characteristic current detection terminal in this substation receives the command, the current transformers of its three phases sample the current signals on their respective phase lines within the corresponding time period.

[0071] S40. After the current transformer completes segmented sampling in each phase, the sampling signals are merged, and then the signal processing and analysis module of the characteristic current detection terminal determines whether there is a synchronization signal in the sampling signal, outputs the determination result (whether there is a synchronization signal), and reports the determination result to the concentrator Q.

[0072] Specifically, the content of this embodiment does not involve a decision algorithm for detecting whether a synchronization signal of a terminal exists, and the algorithm of the existing solution may continue to be used, which will not be described in detail here.

[0073] S50, the concentrator Q respectively allows X meters to execute the above-mentioned characteristic current signal transmission once, and respectively receives the detection results of the detection terminal for the X characteristic current signal transmissions. Assuming that the detection result corresponding to Y1 meters is the presence of synchronization signals, the concentrator Q considers that the Y1 meters belong to the transformer of this substation. If the detection result corresponding to the remaining Y2 meters (Y2>0) is the absence of synchronization signals, the concentrator Q will respectively allow the Y2 meters to execute the above-mentioned characteristic current signal transmission once, wherein the time length of this round of segmented characteristic signals is half of the first round. The shorter the time length of the segmented characteristic signals, although the time length of a complete characteristic current signal is longer, the smaller the amplitude of the line background current in the time period corresponding to each segmented current signal, the lower the interference, which is beneficial to improving the signal-to-noise ratio of the receiving signal at the receiving end.

[0074] S60, the concentrator Q receives the detection results of the Y2 characteristic current signals sent by the detection terminal. Similarly, if the detection result corresponding to a certain meter is that there is a synchronization signal, the concentrator Q considers that the meter belongs to the transformer in this area;

[0075] Furthermore, in this embodiment, if there are still meters whose corresponding detection results are that there is no synchronization signal, the concentrator Q will classify these meters as a set of meters with unclear household-transformer relationships. Within the allowed identification time or when the number of times the characteristic current of the meter is sent does not reach the upper limit, the concentrator Q can further repeat the test on these meters with unclear household-transformer relationships.

[0076] In this embodiment, there is no restriction on the maximum value of the number of repeated tests and the specific length of the allowed identification time, and the user can set them independently according to the actual performance of the equipment and the actual application requirements of the station area.

[0077] Furthermore, in this embodiment, after completing the above-mentioned identification process, if there are still meters whose corresponding detection results are still that there is no synchronization signal, the concentrator Q will classify these meters as a set of meters that do not belong to this substation, and the concentrator Q will report the list of meters that belong to this substation and the list of meters that do not belong to this substation to the main station. After the main station receives the information reported by the concentrator Q, if there are meters that do not belong to this substation, the main station will remove these meters from the white list of the substation and send the new white list to the concentrator Q.

[0078] S70. After receiving the new whitelist, the concentrator Q will send a signal to the meters that do not belong to this area based on the power line carrier communication technology, requiring them to withdraw from the network. After receiving the withdrawal signal, these meters will actively leave this subnet and look for other carrier subnets to join the network.

[0079] In order to verify the accuracy of a topology identification method based on segmented characteristic current signals provided in an embodiment of the present invention, a residential electricity substation was selected with the support of the power grid company to carry out a performance test of the scheme. After on-site investigation, it was found that the substation had 3 distribution boxes, 30 meter boxes, and 425 user meters.

[0080] When using the existing traditional solution, the entire topology identification process takes a total of about 160 minutes, and the topology identification results of 10 meters in the topology map of the current area are erroneous; when using the topology identification method of the embodiment of the present invention, the entire topology identification process takes a total of about 45 minutes, and the topology identification result of only one meter in the topology map of the current area is erroneous.

[0081] From the test results, it can be seen that the new solution has significant improvements in topology recognition time performance and recognition accuracy performance compared with the existing solutions, and can effectively help power grid management departments improve the level of intelligence in power grid operation.

[0082] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, any one of the methods in the present embodiment is implemented.

[0083] An embodiment of the present invention further provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes any one of the methods in this embodiment.

[0084] The computer-readable storage medium in this embodiment can be understood by ordinary technicians in this field: all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to the computer program. The aforementioned computer program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes.

[0085] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication with each other. The memory is used to store computer programs, the communication interface is used to communicate, and the processor and the transceiver are used to run computer programs so that the electronic terminal executes each step of the above method.

[0086] The topology identification method, medium and terminal based on segmented characteristic current signal described in the above-mentioned embodiments are compared with the prior art. In the prior art, the signal sampling accuracy and transformation ratio performance requirements of the current transformer of the characteristic current receiving terminal are very high, and the cost is relatively high. Since the line background current amplitude at the signal receiving end is very large, the background noise amplitude in the frequency domain will also increase accordingly, thereby reducing the signal-to-noise ratio of the received signal in the frequency domain and reducing the detection performance of the characteristic current signal. In addition, during the signal transmission process, the characteristic current transmission module of the user's meter is very easy to couple with the lines on other phases to produce signals with smaller amplitudes but similar waveforms, thereby affecting the signal detection and user-transformer relationship identification performance of the receiving module. The process of the present invention is simple and easy to operate. It is further combined with the broadband carrier communication technology of the local network to realize the time synchronization and signaling content transmission between the signal sending end and the signal receiving end. At the same time, a characteristic current staggered transmission mechanism of the three-phase line based on the zero crossing point is implemented in the time domain, which greatly reduces the intensity of the line background current and increases the duty cycle of the characteristic current signal, which is beneficial to reduce the heat generation rate of the sending end equipment and reduce its impact on the operation of the electric meter. It makes full use of the information transmission and time synchronization functions of the power line carrier communication network to achieve the optimization of the topology identification process; it can effectively reduce the power of the line background current noise, thereby increasing the signal-to-noise ratio of the received signal and improving the detection performance of the synchronization signal; the current range required for detection is effectively reduced, which can reduce the requirements for hardware, thereby reducing the cost of the equipment.

[0087] Obviously, the embodiments described above are only preferred embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A topology identification method based on segmented characteristic current signals, characterized in that: The following steps are involved: S10, assuming that there are X meters to be identified in the carrier subnet of the concentrator Q in a certain area to be identified, the master station system sends a command to implement the household transformer relationship identification to the concentrator Q; S20, after receiving the command, the concentrator Q randomly selects three electric meters with different phases, and sends a signaling to the three electric meters and the characteristic current detection terminal in the area through a beacon management message newly defined in the beacon signal; S30, after receiving the command, the electric meter corresponding to the signaling content sends a characteristic current signal of a specified format within a specified time period according to the content requirements, and after the characteristic current detection terminal in the station area receives the command, the current transformers of the three phases thereof respectively perform current signal sampling on their respective phase lines within the corresponding time period; S40, after the current transformer completes segmented sampling in each phase, the sampling signals are merged, the characteristic current detection terminal determines whether there is a synchronization signal in the sampling signal, outputs the determination result and reports it to the concentrator; S50, the concentrator Q respectively makes X electric meters execute characteristic current signal transmission once, and respectively receives the detection results of the characteristic current detection terminal for the X characteristic current signal transmissions, and determines whether the electric meter belongs to the transformer in this area according to the detection results; S60, the concentrator Q reports the list of electric meters that are determined to belong to the area and the list of electric meters that are not affiliated to the area to the master station. After the master station receives the information reported by the concentrator Q, if there are electric meters that are not affiliated to the area, the master station will remove the electric meters that are not affiliated to the area from the white list of the area, and send the new white list to the concentrator Q; S70. After receiving the new white list, the concentrator Q sends a signal to the electric meters that do not belong to this subnet based on the power line carrier communication technology, requesting them to withdraw from the network. After receiving the withdrawal signal, the electric meter actively leaves the subnet and searches for other carrier subnets to join the network.

2. A topology identification method based on segmented characteristic current signals according to claim 1, characterized in that: In step S50, if the detection result corresponding to Y1 of the X meters is that there is a synchronization signal, the concentrator Q determines that Y1 meter belongs to the transformer in this substation; if the detection result corresponding to Y2 of the X meters is that there is no synchronization signal, the concentrator Q instructs Y2 meters to send characteristic current signals again.

3. A topology identification method based on segmented characteristic current signals according to claim 2, characterized in that: If there are still meters whose corresponding detection results show that there is no synchronization signal, the concentrator Q will classify them as meters with unknown household-transformer relationships. Within the allowed identification time or when the number of times the characteristic current of the meter is sent does not reach the upper limit, the concentrator Q will repeat the test on the meters with unknown household-transformer relationships.

4. A topology identification method based on segmented characteristic current signals according to claim 1, characterized in that: In step S20, the newly added topology identification message type in the beacon management message is as follows: The name of the management message is household change relationship identification message, and the type values ​​include State Grid 0xAB and Southern Grid 0xAB. The function is to notify a user meter with characteristic current sending capability to send characteristic current signals in a specified mode within a specified time period.

5. A topology identification method based on segmented characteristic current signals according to claim 4, characterized in that: The content of the newly added topology identification message is as follows: The name is network short address 1, the length is 12 bits, and it is the network short address of the carrier module of a certain A-phase user electricity meter to be notified. If it is all zero, it means that the meter does not exist; The name is network short address 2, the length is 12 bits, and it is the network short address of the carrier module of a certain B-phase user meter to be notified. If it is all zero, it means that the meter does not exist; The name is network short address 3, the length is 12 bits, and it is the network short address of the carrier module of a C-phase user meter to be notified. If it is all zeros, it means that the meter does not exist; The name is reserved and has a length of 4 bits. The name is the message sequence number, which is 8 bits long and is used to identify the sequence number of this message. The initial value is 0 and it is a sequentially increasing value, which restarts after reaching 255. The name is the current sending start time of phase A, with a length of 32 bits, which represents the reference time of the carrier network. For the user electric meter of phase A, the characteristic current signal will start to be sent at this time point; For the user electricity meter of phase B, the transmission will be delayed by 10 / 3 milliseconds based on the time point; and for the user electricity meter of phase C, the transmission will be delayed by 20 / 3 milliseconds based on the time point; The name is the time length of the segmented characteristic current signal, which is 16 bits long and represents the time length of a single segment characteristic current signal in units of 0.1 milliseconds.

6. A topology identification method based on segmented characteristic current signals according to claim 2, characterized in that: The duration of the segmented characteristic signal sent by the Y2 meter for the second time is half of the first time.

7. A topology identification method based on segmented characteristic current signals according to claim 1, characterized in that: In the step S10, the household change relationship identification time is early morning.

8. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

9. An electronic terminal, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method according to any one of claims 1 to 7.

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