Low-voltage district table box physical topology identification method and system

Abstract

The present application relates to a kind of low-voltage area table box physical topology identification method and system.It includes low-voltage area system, to any user electric meter, the electric meter address of the user electric meter is modulated to HPLC network in on-off key control mode by carrier current signal, the table box molded case circuit breaker in HPLC network gathers carrier current signal, and according to the carrier current of table box molded case circuit breaker determined with the same table box of the current user electric meter of table box molded case circuit breaker of current user electric meter belongs;The table box molded case circuit breaker extracts and determines the electric meter address in carrier current signal, and the table box molded case circuit breaker sends the extracted and determined electric meter address to concentrator by HPLC network, to identify the table box physical topology of the current user electric meter.The present application can effectively realize the identification of low-voltage area table box physical topology based on the current table box operation mode, improve table box physical topology identification degree rate, reduce identification cost.

Description

TECHNICAL FIELD

[0001] The application relates to a topological identification method and system, in particular to a low-voltage transformer station box physical topological identification method and system. BACKGROUND

[0002] In recent years, in order to lead the business transformation and development by technological innovation, improve the operation quality of the intelligent metering system, fully support the power supply service and system construction centering on customers, fully exert the asset benefits of the intelligent electric meter, and reduce the operation cost of the power grid, higher requirements are put forward for the fine management level of the low-voltage transformer station. The low-voltage transformer station physical topology is the basis of the fine management of the transformer station, and the low-voltage transformer station physical topology includes a transformer station transformer-branch box / Π connection box-meter box-electric meter.

[0003] The low-voltage transformer station will change the low-voltage transformer station physical topology relationship in new construction, reconstruction, expansion, daily maintenance, repair and equipment change, wherein the transformer station transformer-branch box / Π connection box-meter box physical topology usually adopts the method of installing equipment, adopts the method of distortion current and pulse current, and the technology is mature. As for the meter box-electric meter physical topology, the current adopts the method of manual input, the method of 485 communication or the method of big data analysis, wherein the method of manual input has large workload and low efficiency, and is prone to errors; the method of 485 communication is to realize the identification of the meter box physical topology by using the 485 communication interface of the electric meter and the communication of the intelligent molded case circuit breaker of the meter box. This method has reduced the workload compared with the method of manual input, but the HPLC (low-voltage power line high-speed carrier communication) communication unit that has been installed in large quantities loses its due function; the method of big data analysis has long identification time and low identification rate. The above methods do not have large-scale promotion value.

[0004] The patent application file with the publication number CN110389269A discloses a low-voltage transformer station topological relationship identification method based on current optimization matching. The low-voltage transformer station topological relationship identification method can realize the identification of the low-voltage transformer station physical topology relationship without increasing equipment. The method can realize the identification of the transformer station transformer-branch box / Π connection box-meter box physical topology relationship. The distance between the adjacent meter boxes in the meter box-electric meter line is very close, and the reception and identification of the physical parameter signals between the adjacent meter boxes are easily affected, that is, the physical parameter signals of the electric meter can be received by two or more meter boxes at the same time, so that the attribution relationship between the meter box and the electric meter is difficult to determine, and the identification accuracy of the transformer station physical topology relationship is low.

[0005] The patent document with publication number CN113093063A discloses a meter box and meter relationship identification method and system based on current carrier. Each electric meter transmits a specific frequency characteristic current signal and superimposes it on the original power frequency current signal of the meter. The characteristic current signal carries the identity characteristic signal corresponding to the electric meter. The meter box receives the power frequency current signal transmitted by the corresponding meter and extracts the characteristic current signal in the power frequency current signal. The identity characteristic signal carried in the characteristic current signal received by the meter box is used to determine the corresponding meter belonging to the meter box, and the ownership relationship between the meter box and each corresponding meter is established. This method uses a 1000:1 mutual inductor. When the mutual inductor couples and extracts high-frequency signals, it will affect the extraction amplitude as the live wire passes through the center of the mutual inductor, which cannot meet the amplitude accuracy requirement of high-frequency signal coupling extraction. When extracting the frequency characteristics of high-frequency signals, the frequency will change with the change of power line current, which also cannot meet the frequency accuracy requirement. Ultimately, the meter box physical topology identification rate is low, which cannot meet the actual engineering needs.

[0006] In summary, how to quickly and effectively realize the physical topology identification of low-voltage area meter box is a technical problem that needs to be solved at present. SUMMARY

[0007] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a low-voltage area meter box physical topology identification method and system, which can effectively realize the physical topology identification of low-voltage area meter box based on the current meter box operation mode, improve the physical topology identification rate of meter box, and reduce the identification cost.

[0008] According to the technical scheme provided by the present application, the low-voltage area meter box physical topology identification method comprises a low-voltage area system, which comprises a concentrator based on HPLC network communication, a plurality of meter box molded case circuit breakers, and a plurality of user electric meters,

[0009] When identifying the physical topology of the meter box, for any user electric meter, the electric meter address of the user electric meter is modulated into the HPLC network by the carrier current signal in the on-off keying mode, the meter box molded case circuit breaker in the HPLC network collects the carrier current signal, and determines the meter box molded case circuit breaker belonging to the same meter box as the current user electric meter according to the carrier current collected by the meter box molded case circuit breaker.

[0010] After determining the meter box molded case circuit breaker belonging to the same meter box as the current user electric meter, the meter box molded case circuit breaker extracts and determines the electric meter address in the carrier current signal, and sends the extracted and determined electric meter address to the concentrator through the HPLC network to identify the physical topology of the meter box of the current user electric meter.

[0011] When the meter address is modulated to the HPLC network in the on-off keying mode through the carrier current signal, the meter address is encoded to obtain meter address encoding information, which includes a frame header field, a meter address field and a CRC check field.

[0012] The meter box molded case circuit breaker collects current through a flexible current transformer, and the collected current is processed through double-channel integral filtering to extract 50Hz power frequency current signals and carrier current signals respectively.

[0013] The meter box molded case circuit breaker determines the meter box molded case circuit breaker belonging to the same meter box as the current user meter according to the carrier current signal.

[0014] When the meter address in the carrier current signal is extracted and determined, the carrier current signal is decoded, and in the decoding process, ADC quantization processing, spectrum shifting processing, decimation filtering processing, sliding FFT frequency point energy extraction processing and bit determination processing are sequentially performed, and after decoding, the meter address in the carrier current signal is obtained.

[0015] Before the decoding process, the carrier current signal is processed by a window function for suppressing spectral leakage, and after the window function processing, the decoding process is performed, wherein the window function includes a Blackman window.

[0016] In the decimation filtering processing, a plurality of polyphase FIR decimation filters are used for decimation filtering.

[0017] When the meter box molded case circuit breaker belonging to the same meter box as the current user meter is determined, the carrier current signals of a plurality of meter box molded case circuit breakers are collected, and the meter box molded case circuit breaker with the maximum current value at the same frequency as the carrier current signal is determined as the meter box molded case circuit breaker belonging to the same meter box as the current user meter.

[0018] In the spectrum shifting processing, the spectrum shifting processing is as follows:

[0019]

[0020] Wherein, f0 is the actual shifted frequency, x is the carrier current signal, and y is the signal after spectrum shifting.

[0021] A low-voltage area meter box physical topology identification system, comprising a low-voltage area system, the low-voltage area system comprising a concentrator based on HPLC network communication, a plurality of meter box molded case circuit breakers and a plurality of user meters,

[0022] In the process of meter box physical topology identification, for any user meter, the user meter modulates its meter address into the HPLC network through a carrier current signal in on-off keying mode, the meter box molded case circuit breaker in the HPLC network collects the carrier current signal, and determines the meter box molded case circuit breaker belonging to the same meter box as the current user meter according to the carrier current collected by the meter box molded case circuit breaker;

[0023] After determining the meter box molded case circuit breaker belonging to the same meter box as the current user meter, the meter box molded case circuit breaker extracts and determines the meter address in the carrier current signal, and sends the extracted and determined meter address to the concentrator through the HPLC network, so as to identify the meter box physical topology of the current user meter.

[0024] When the meter address is modulated into the HPLC network through a carrier current signal in on-off keying mode, the meter address is encoded to obtain meter address encoding information, and the meter address encoding information includes a frame header field, a meter address field and a CRC check field.

[0025] The advantages of the present application are as follows: without changing the HPLC network formed by the user meter, the meter box molded case circuit breaker and the concentrator in online operation, in the process of meter box physical topology identification, the meter address is modulated onto the power line through a high-speed carrier current signal in on-off keying mode, after the signal is extracted by using a flexible current transformer in the meter box intelligent molded case circuit breaker, the meter address is extracted through decoding, and the meter box physical topology identification is realized; wherein, the flexible current transformer solves the problems of the influence of the power line passing through the transformer position on the amplitude accuracy and the influence of the fundamental current on the amplitude accuracy of the high-frequency signal. In the decoding process, the current noise of the non-fixed frequency high-speed carrier signal frequency point is suppressed from the time domain, the frequency spectrum shift processing and decimation filtering processing are introduced, and the success rate and stability of the extraction of the fixed frequency high-speed carrier current signal are improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a system block diagram of the existing low-voltage area system.

[0027] Figure 2 It is a schematic diagram of the principle of meter box physical topology identification.

[0028] Figure 3 It is a schematic diagram of the present application in which the meter address is modulated through a carrier current signal in on-off keying mode.

[0029] Figure 4 It is a schematic diagram of the present application in which the meter box molded case circuit breaker collects the carrier current signal.

[0030] Figure 5 It is a flowchart of the decoding process of the present application.

[0031] Figure 6 A schematic diagram of the extraction filtering process of the present application.

[0032] Figure 7 A flow chart of the meter box physical topology identification of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described below in conjunction with specific drawings and examples.

[0034] Under the current meter box operation mode, the low-voltage transformer area system can effectively identify the low-voltage transformer area meter box physical topology, improve the identification rate, and reduce the identification cost. The present application includes a low-voltage transformer area system, which comprises a concentrator based on HPLC network communication, a plurality of meter box molded case circuit breakers, and a plurality of user electricity meters.

[0035] When identifying the meter box physical topology, any user electricity meter modulates its electricity meter address through a carrier current signal in on-off keying to the HPLC network. The meter box molded case circuit breaker in the HPLC network collects the carrier current signal and determines the meter box molded case circuit breaker of the same meter box as the current user electricity meter according to the carrier current collected by the meter box molded case circuit breaker.

[0036] After determining the meter box molded case circuit breaker of the same meter box as the current user electricity meter, the meter box molded case circuit breaker extracts and determines the electricity meter address in the carrier current signal and sends the extracted and determined electricity meter address to the concentrator through the HPLC network to identify the meter box physical topology of the current user electricity meter.

[0037] Specifically, the low-voltage transformer area system specifically refers to a low-voltage power supply area of a low-voltage transformer area transformer. The specific conditions of the low-voltage transformer area system are consistent with the existing conditions. Generally, when identifying the low-voltage transformer area meter box physical topology, the low-voltage transformer area system includes a concentrator, a plurality of meter box molded case circuit breakers, and a plurality of user electricity meters. The concentrator, the meter box molded case circuit breaker, and the user electricity meter are based on HPLC network communication, specifically referring to the concentrator, any meter box molded case circuit breaker, and any user electricity meter having HPLC communication capability. The concentrator, the meter box molded case circuit breaker, and the user electricity meter specifically implement the HPLC communication capability in a manner consistent with the existing conditions, subject to the requirement of achieving HPLC communication capability. Here, no further description is given. When the concentrator, the meter box molded case circuit breaker, and the user electricity meter are based on HPLC network communication, the concentrator can specify the meter box molded case circuit breaker and the corresponding user electricity meter to transmit and receive information. The information transmission and reception based on HPLC network communication can be selected as needed.

[0038] In the embodiment of the present application, when the concentrator, the meter box molded case circuit breaker and the user electric meter can communicate based on HPLC, the low-voltage transformer area meter box physical topology identification can be realized under the existing meter box operation mode. Figure 1 A specific implementation of the low-voltage transformer area is shown in the figure, which specifically includes a low-voltage transformer area transformer, a transformer area total meter adaptedly connected with the low-voltage transformer area transformer, a transformer molded case circuit breaker and a concentrator. The low-voltage transformer area transformer is connected with a cable branch box 1 and a cable branch box 2 through the transformer molded case circuit breaker. The cable branch box 1 and the cable branch box 2 are both connected with several meter boxes. Generally, at least one meter box molded case circuit breaker and several user electric meters are arranged in one meter box. The specific conditions of the low-voltage transformer area transformer, the transformer area total meter, the concentrator, the transformer molded case circuit breaker, the cable branch box, the meter box molded case circuit breaker and the user electric meter in the meter box are all consistent with the existing ones, which are well known to those skilled in the art and will not be described here.

[0039] The meter box physical topology identification specifically refers to determining the parent node of the user electric meter and identifying the electric meter address of the current user electric meter through the determined parent node for any user electric meter. The parent node is generally the meter box molded case circuit breaker belonging to the same meter box as the user electric meter. The determined parent node and the electric meter address of the current user electric meter are sent to the concentrator, thereby realizing the meter box physical topology identification.

[0040] In the process of the meter box physical topology identification, generally, the corresponding meter box molded case circuit breaker and user electric meter are sequentially specified by the concentrator to perform HPLC network communication, and based on the HPLC network communication, the time is not repeated, that is, only the meter box molded case circuit breaker or the user electric meter transmits the carrier signal based on the HPLC network at the same time. Generally, before the meter box physical topology identification is performed, the topology identification of the meter box molded case circuit breaker is realized.

[0041] Therefore, in the process of the meter box physical topology identification, the any user electric meter is the user electric meter specified by the concentrator. After the user electric meter is specified or selected by the concentrator, it becomes the current user electric meter. In the process of topology identification, the current user electric meter modulates its electric meter address through the carrier current signal in the on-off keying mode to the HPLC network. The meter box molded case circuit breaker in the HPLC network collects the carrier current signal, and determines the meter box molded case circuit breaker belonging to the same meter box as the current user electric meter according to the carrier current collected by the meter box molded case circuit breaker.

[0042] In the embodiment of the present application, the current user meter modulates its meter address into the HPLC network through the carrier current signal in on-off keying mode, specifically, modulating the carrier signal containing the meter address onto the power line; the carrier current signal is a high-speed carrier signal with fixed frequency, modulated in on-off keying mode, specifically, encoding the meter address with digital signals of "1" and "0". The specific case of modulating the carrier current signal into the HPLC network in on-off keying mode can be referred to Figure 3 Description.

[0043] In the implementation, when the meter address is modulated into the HPLC network through the carrier current signal in on-off keying mode, the meter address is encoded to obtain meter address encoding information, which includes a frame header field, a meter address field and a CRC check field. Generally, the meter address encoding information can be determined according to the frame header field, and CRC check can be performed through the CRC (cyclic redundancy check) check field. The specific case of the meter address field is related to the address of each user meter.

[0044] One specific implementation case of the meter address encoding information is given in Table 1, specifically:

[0045] Table 1: Meter address framing format

[0046] Field Length (bytes) Remark Frame header 2 0xEB90 Electric meter address 4 CRC check 1 For checking data receiving validity

[0047] Further, when determining the meter box molded case circuit breaker belonging to the same meter box as the current user meter, the meter box molded case circuit breakers collecting the carrier current signals are determined, and the meter box molded case circuit breaker with the same frequency as the carrier current signal and the largest current value is determined as the meter box molded case circuit breaker belonging to the same meter box as the current user meter.

[0048] As shown in Figure 2 , the principle diagram for determining the parent node corresponding to the current user meter, specifically, when the user meter A1 is the current user meter and sends the high-speed carrier current signal with fixed frequency to the power line, the current signals I1-I5 with the same frequency are generated at each branch of the low-voltage area, and according to Kirchhoff's law:

[0049]

[0050] As can be seen from the above current relationship, the carrier current signal I1 received by the meter box molded case circuit breaker in the meter box A with fixed frequency is always greater than the carrier current signal I5 received by the meter box molded case circuit breaker in the meter box B with fixed frequency; that is, by detecting and collecting the carrier current with fixed frequency at each meter box inlet, the principle of the maximum fixed frequency current in the same meter box can be used to identify the user meter box and the parent node of the user meter box, that is, the meter box molded case circuit breaker belonging to the same meter box as the current user meter can be determined.

[0051] In order to effectively collect the carrier current signal, in the embodiment of the present application, the distribution box molded case circuit breaker uses a flexible current transformer to collect the current, and the collected current is processed by a double-channel integral filter to extract the 50Hz power frequency current signal and the carrier current signal respectively.

[0052] The distribution box molded case circuit breaker determines the distribution box molded case circuit breaker belonging to the same distribution box as the current user electric meter according to the carrier current signal.

[0053] In specific implementation, the current user electric meter transmits a fixed frequency high-speed carrier current signal and couples to the power line, and a flexible current transformer is used to collect the fixed frequency high-speed carrier current signal, wherein the frequency of the high-speed carrier current signal can be selected as required, such as 120KHz, and the specific value is subject to the requirement of meeting the HPLC network communication.

[0054] When collecting the current by the flexible current transformer, the current signals of two frequencies, i.e. the 50Hz power frequency current signal and the fixed frequency high-speed carrier current signal, are collected at the same time, as shown in the following figure. Figure 4 The flexible current transformer can adopt the existing common form, and due to the existence of distributed energy storage devices in the low-voltage area, the current of the fixed frequency high-speed carrier current signal will be transmitted to other line branches, and the use of the flexible current transformer can improve the accuracy and reliability of current collection.

[0055] In specific implementation, a double-channel integral filter circuit is arranged in the flexible current transformer, which can realize integral filter processing, and after the double-channel integral filter circuit processing, the 50Hz power frequency current signal and the fixed frequency high-speed carrier current signal can be extracted respectively, so as to extract and identify the user electric meter address according to the extracted fixed frequency high-speed carrier current signal. The double-channel integral filter circuit can adopt the existing common form, and the specific form can be selected as required, as long as it can extract the power frequency current signal and the carrier current signal.

[0056] Further, when the distribution box molded case circuit breaker extracts and determines the electric meter address in the carrier current signal, the carrier current signal is decoded and processed, and in the decoding process, the ADC quantization processing, the spectrum shift processing, the decimation filter processing, the sliding FFT frequency point energy extraction processing and the bit determination processing are sequentially performed, and after decoding, the electric meter address in the carrier current signal is obtained.

[0057] In specific implementation, before the decoding processing, the carrier current signal is processed by a window function for suppressing spectrum leakage, and after the window function processing, the decoding processing is performed, wherein the window function includes the Blackman window.

[0058] In this embodiment of the invention, after acquiring the fixed-frequency high-speed carrier current signal, a Fast Fourier Transform (FFT) is required. Due to spectral leakage, current noise from the non-fixed-frequency high-speed carrier signal will leak into the frequency spectrum of the fixed-frequency high-speed carrier current signal, affecting the extraction of the fixed-frequency high-speed carrier current signal. By selecting an appropriate window function, spectral leakage can be suppressed, such as using the Blackman window with the highest sidelobe suppression ratio.

[0059] like Figure 5 As shown, the decoding process includes sequential ADC quantization, spectrum shifting, decimation filtering, sliding FFT frequency point energy extraction, and bit determination, to obtain the meter address from the carrier current signal after decoding. Sliding FFT frequency point energy extraction specifically refers to extracting digital values ​​based on frequency values; the magnitude of the value represents the energy level. Sliding is a common debugging technique, well-known to those skilled in the art, and will not be elaborated upon here.

[0060] Specifically, ADC quantization is essentially analog-to-digital conversion. ADC quantization can employ commonly used analog-to-digital conversion methods to achieve the required conversion. After ADC quantization, spectrum shifting, decimation filtering, and sliding FFT frequency point energy extraction, bit values ​​composed of "0" and "1" are obtained. The bit determination process, based on the meter address framing format, ultimately yields the corresponding user's meter address. The process of obtaining the user's meter address through bit determination is related to the meter address framing format and will not be detailed here.

[0061] During spectrum shifting, the spectrum shifting process is as follows:

[0062]

[0063] in, f0 The fixed frequency at which the user's electricity meter transmits the carrier current signal is also the actual frequency shifted. x is the carrier current signal, and y is the signal after the frequency shift.

[0064] During FFT transformation, due to spectral leakage, current noise at non-characteristic frequencies leaks onto the spectral lines at characteristic frequencies, affecting the extraction of characteristic current signals. While spectral leakage can be suppressed by selecting an appropriate window function, it cannot be completely eliminated. Since spectral leakage spreads outward from the frequency point, appropriately increasing the number of FFT points can further suppress the influence of current noise at non-characteristic frequencies. This can be achieved using existing techniques, which are consistent with current methods and will not be elaborated upon here.

[0065] Furthermore, by using a digital filter to directly suppress current noise at non-characteristic frequencies in the time domain, the influence of current noise at non-characteristic frequencies can be further suppressed. In summary, by introducing spectrum shifting and decimation filtering, the success rate and stability of characteristic current analysis are improved; the characteristic current is the current signal generated by a high-speed carrier signal at a fixed frequency.

[0066] During the decimation filtering process, several polyphase FIR decimation filters are used for decimation filtering. Figure 6 The diagram illustrates a specific implementation of decimation filtering. Specifically, decimation filtering is combined with spectrum shifting, which involves frequency shifting of the required data (i.e., the data obtained from the two integration channels: a 50Hz power frequency current signal and a fixed-frequency high-speed carrier current signal). This not only suppresses current noise at non-fixed-frequency high-speed carrier signal points but also reduces the sampling frequency, indirectly improving the frequency resolution of the Fast Fourier Transform. Balancing computational power and actual filtering effect, the filter used in practice has a decimation rate M = 32 and an order of 96. Generally, the specific value of M is determined based on debugging experience.

[0067] like Figure 7 The diagram shows a flowchart of the physical topology identification process for the meter box according to the present invention. Specifically, the concentrator controls the initiation of physical topology identification. The entire topology identification process is scheduled and completed by the concentrator. The concentrator only needs to periodically query the identification status, and after completion, it reads the physical topology identification result. The main steps include:

[0068] Step 1: Collect information on adjacent meters of the smart molded case circuit breaker in the meter box, which will be used to select the smart molded case circuit breaker in the meter box that will forward the meter's transmission command.

[0069] Specifically, the information of adjacent meters of the smart meter box of the concentrator is the identification of the distribution area to obtain the information of the distribution area equipment. The specific methods and processes for collecting the information of adjacent meters of the smart molded case circuit breaker in the meter box are consistent with the existing methods and are well known to those skilled in the art, and will not be described in detail here.

[0070] Step 2: Clear the set of historical characteristic current information received by the molded case circuit breaker in the meter box;

[0071] Step 3: The concentrator names all the molded case circuit breakers in the meter boxes and the user meters, and transmits high-speed carrier current signals of fixed frequency in sequence to ensure that each device transmits in sequence without time overlap.

[0072] Step 4: The concentrator queries and saves the set of fixed-frequency high-speed carrier current signals received by the molded case circuit breaker in the meter box. The fixed-frequency high-speed carrier current signal contains the received meter address and its energy level; the parent node of each user's meter is calculated, and the concentrator waits for the physical topology result to be queried.

[0073] Specifically, referring to the above description, the physical topology result queried by the concentrator is the meter box physical topology for each user meter parent node.

[0074] In the above steps, the implementation process of the specific steps can refer to the above description, which will not be described in detail here.

[0075] In summary, the low-voltage area meter box physical topology identification system comprises a low-voltage area system, the low-voltage area system comprises a concentrator based on HPLC network communication, a plurality of meter box molded case circuit breakers, and a plurality of user meters.

[0076] When identifying the meter box physical topology, for any user meter, the user meter modulates its meter address into the HPLC network through the carrier current signal in on-off keying mode, the meter box molded case circuit breaker in the HPLC network collects the carrier current signal, and determines the meter box molded case circuit breaker belonging to the same meter box as the current user meter according to the carrier current collected by the meter box molded case circuit breaker.

[0077] After determining the meter box molded case circuit breaker belonging to the same meter box as the current user meter, the meter box molded case circuit breaker extracts and determines the meter address in the carrier current signal, and sends the extracted and determined meter address to the concentrator through the HPLC network, so as to identify the meter box physical topology of the current user meter.

[0078] In specific implementation, the low-voltage area system, the specific implementation of the meter box physical topology identification mode and process are consistent with the above, and the specific implementation can refer to the above description, which will not be described here.

[0079] In summary, the present application does not change the HPLC network formed by the online running user meter, meter box molded case circuit breaker and concentrator, in the identification of the meter box physical topology, the meter address is modulated onto the power line in on-off keying mode through the high-speed carrier current signal, after the signal is extracted by the flexible current transformer in the meter box intelligent molded case circuit breaker, the meter address is extracted by decoding, and the meter box physical topology identification is realized; wherein, the flexible current transformer solves the problems of the influence of the power line passing through the transformer position on the amplitude accuracy and the influence of the fundamental current on the high-frequency signal amplitude accuracy. In the decoding process, the current noise of the non-fixed frequency high-speed carrier signal frequency point is suppressed from the time domain, the frequency spectrum shift processing and extraction filtering processing are introduced, and the success rate and stability of the fixed frequency high-speed carrier current signal extraction are improved.

Claims

1. A low-voltage transformer area metering box physical topology identification method applied to a low-voltage transformer area system, the low-voltage transformer area system comprising a concentrator based on HPLC network communication, a plurality of metering box molded case circuit breakers and a plurality of user electricity meters, characterized in that: when identifying the metering box physical topology, for any user electricity meter, the user electricity meter modulates its electricity meter address into the HPLC network through a carrier current signal in on-off keying mode, the metering box molded case circuit breaker in the HPLC network collects the carrier current signal, and determines the metering box molded case circuit breaker belonging to the same metering box as the current user electricity meter according to the carrier current collected by the metering box molded case circuit breaker; after determining the metering box molded case circuit breaker belonging to the same metering box as the current user electricity meter, the metering box molded case circuit breaker extracts and determines the electricity meter address in the carrier current signal, and sends the extracted and determined electricity meter address to the concentrator through the HPLC network to identify the metering box physical topology of the current user electricity meter; when identifying the metering box physical topology, the corresponding metering box molded case circuit breaker and user electricity meter are specified by the concentrator to perform HPLC network communication in turn, and based on the HPLC network communication, it is not repeated in time, that is, only the metering box molded case circuit breaker or the user electricity meter transmits a carrier signal based on the HPLC network at the same time; when the electricity meter address is modulated into the HPLC network through a carrier current signal in on-off keying mode, the electricity meter address is encoded to obtain electricity meter address encoding information, the electricity meter address encoding information comprising a frame header field, an electricity meter address field and a CRC check field; when the metering box molded case circuit breaker extracts and determines the electricity meter address in the carrier current signal, the carrier current signal is decoded, and in the decoding process, it comprises ADC quantization processing, spectrum shift processing, decimation filtering processing, sliding FFT frequency point energy extraction processing and bit decision processing in turn, and after decoding, the electricity meter address in the carrier current signal is obtained; the metering box molded case circuit breaker collects current using a flexible current transformer, and the collected current is subjected to double-channel integral filtering processing to extract 50Hz power frequency current signals and carrier current signals respectively; the metering box molded case circuit breaker determines the metering box molded case circuit breaker belonging to the same metering box as the current user electricity meter according to the carrier current signal; when determining the metering box molded case circuit breaker belonging to the same metering box as the current user electricity meter, the metering box molded case circuit breaker with the largest current value at the same frequency as the carrier current signal is determined as the metering box molded case circuit breaker belonging to the same metering box as the current user electricity meter from a plurality of metering box molded case circuit breakers collecting carrier current signals. Before decoding processing, the carrier current signal is subjected to window function processing for suppressing spectral leakage, and after window function processing, decoding processing is performed, wherein the window function comprises a Blackman window.

2. The low-voltage district table box physical topology identification method according to claim 1, characterized in that: In the decimation filtering processing, a plurality of polyphase FIR decimation filters are used for decimation filtering.

3. The low-voltage district table box physical topology identification method according to claim 1, characterized in that: In the spectrum shift processing, the spectrum shift processing is as follows:

4. The low-voltage district table box physical topology identification method according to claim 1, characterized in that, in ​ ； wherein, is the actual shifted frequency, is the carrier current signal, is the signal after frequency shifting.

5. A low-voltage transformer area meter box physical topology identification system for implementing the method of any one of claims 1-4, comprising a low-voltage transformer area system including a concentrator based on HPLC network communication, a plurality of meter box molded case circuit breakers, and a plurality of user electricity meters, characterized in that: when performing meter box physical topology identification, for any user electricity meter, the user electricity meter modulates its own electricity meter address into the HPLC network through a carrier current signal in on-off keying mode, the meter box molded case circuit breaker in the HPLC network collects the carrier current signal, and determines the meter box molded case circuit breaker of the same meter box as the current user electricity meter according to the carrier current collected by the meter box molded case circuit breaker; after determining the meter box molded case circuit breaker of the same meter box as the current user electricity meter, the meter box molded case circuit breaker extracts and determines the electricity meter address in the carrier current signal, and the meter box molded case circuit breaker sends the extracted and determined electricity meter address to the concentrator through the HPLC network to identify the meter box physical topology of the current user electricity meter. ​

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