Line distance measurement method and system based on power line dual-mode communication time delay

Abstract

The invention discloses a line distance measurement method and system based on power line dual-mode communication time delay, and the method comprises the steps: taking PLC and HRF dual-mode communication as a basis, and obtaining the electrical length of a line between a node and a transformer in a transformer area through the measurement based on the PLC communication time delay; the geometric space distance between the node and the area transformer is obtained based on HRF wireless communication measurement, the two measurement modes can switch the main role and the auxiliary role according to the signal-to-noise ratio or the received signal strength variance, and finally the measured line electrical length and the geometric space distance are fused to obtain the line distance. The line distance between any node in the transformer area and the transformer in the transformer area can be accurately measured, and the distance measurement precision is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power line distance measurement, and in particular to a line distance measurement method and system based on power line dual-mode communication delay, electronic equipment, and a computer-readable storage medium. Background Art

[0002] Power line communication technology is a wired communication method that uses power lines as an information transmission medium for data transmission. It communicates by loading a modulated carrier signal on the power lines of the power grid, so it is also called power line carrier communication. It is currently widely used in business scenarios such as power consumption information collection and automated power distribution in medium and low voltage distribution networks. In addition, in addition to realizing data communication functions, power line carrier communication can also use carrier signals to realize power line ranging functions. Currently, commonly used power line ranging methods include traveling wave method, impedance method, single-mode communication delay method, etc. However, the traveling wave method requires high-frequency sampling equipment, resulting in high measurement costs. The ranging accuracy of the impedance method is significantly affected by changes in the power grid load, making it difficult to ensure the accuracy of ranging. The single-mode communication delay method is easily interfered by noise and cannot guarantee ranging accuracy. Therefore, existing power line ranging methods are unable to accurately measure line distances and have poor ranging accuracy. Summary of the Invention

[0003] The present invention provides a line distance measurement method and system based on power line dual-mode communication delay, an electronic device, and a computer-readable storage medium, which can accurately measure the line distance between any node in a substation and the substation transformer, greatly improving the distance measurement accuracy.

[0004] According to one aspect of the present invention, a line distance measurement method based on power line dual-mode communication delay is provided. A main control unit is configured on the transformer side of the substation area, and a dual-mode communication terminal is configured on each node side of the substation area. The dual-mode communication terminal supports both PLC wired communication and HRF wireless communication. The main control unit is responsible for unified scheduling of dual-mode communication resources, including the following contents:

[0005] Send a PLC communication test packet to the dual-mode communication terminal on the node side, and calculate the link distance based on the round-trip delay measurement result of the PLC communication test packet;

[0006] Send a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculate the spatial distance based on the classic path loss model;

[0007] The line distance between the node and the substation transformer is calculated based on the link distance and spatial distance.

[0008] Furthermore, the process of sending a PLC communication test packet to the dual-mode communication terminal on the node side and calculating the link distance based on the round-trip delay measurement result of the PLC communication test packet includes the following:

[0009] Sending a time calibration frame to the dual-mode communication terminal at a first moment, sending a ranging request frame to the dual-mode communication terminal at a second moment, recording the arrival times of the two frames and calculating the arrival time difference between the two frames;

[0010] Based on the transmission time difference and arrival time difference of the two frames, the offset error coefficient between the main control unit clock and the dual-mode communication terminal clock is calculated;

[0011] Obtaining a processing time of the dual-mode communication terminal and correcting the processing time based on an offset error coefficient;

[0012] Based on the sending time and response time of the ranging request and the corrected processing time, the round-trip delay of pure propagation is calculated, and the link distance between the node and the substation transformer is calculated.

[0013] Furthermore, the offset error coefficient is calculated based on the following formula:

[0014]

[0015] Wherein, β represents the offset error coefficient, t1 and t2 represent the sending time of the two frames, and t1′ and t2′ represent the arrival time of the two frames.

[0016] Furthermore, the process of sending a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculating the spatial distance based on the classic path loss model includes the following:

[0017] Obtain a set of received signal strength sequences and remove outliers from the sequences;

[0018] Perform first-order FIR Gaussian smoothing on the sequence after removing outliers;

[0019] Calculate the median and mean of the received signal strength in the smoothed sequence, and use the average of the median and mean as the stable strength mean of the received signal strength sequence;

[0020] Based on the stable strength mean and the currently measured received signal strength, the spatial distance between the node and the transformer in the substation is calculated.

[0021] Furthermore, the following contents are also included:

[0022] The link distance and spatial distance are measured multiple times, and the line distance between the node and the substation transformer is obtained by weighted fusion calculation based on the multiple measurement results of the link distance and spatial distance.

[0023] Furthermore, the line distance between the node and the transformer in the substation is calculated based on the following formula:

[0024]

[0025] Among them, D fused represents the line distance between the node and the transformer in the substation, L and Respectively represent the link distance and spatial distance between the node and the transformer in the substation, ω L and represents the weight coefficient, and Represent the variance of multiple measurement results of link distance and spatial distance respectively.

[0026] Furthermore, the variance of multiple measurement results of link distance and spatial distance is calculated based on the following formula:

[0027]

[0028] Where v represents the transmission speed of the carrier signal, represents the variance of the processing time of the dual-mode communication terminal, M represents the number of measurements, represents the processing time of the dual-mode communication terminal during the kth measurement, represents the average processing time of the dual-mode communication terminal in M ​​measurements, Indicates the variance of the received signal strength, n represents the path loss index, RSSI k represents the received signal strength at the kth measurement, Indicates the average received signal strength in M ​​measurements.

[0029] In addition, the present invention also provides a line distance measurement system based on power line dual-mode communication delay, in which a main control unit is configured on the transformer side of the substation area and a dual-mode communication terminal is configured on each node side of the substation area. The dual-mode communication terminal supports both PLC wired communication and HRF wireless communication. The main control unit is responsible for unified scheduling of dual-mode communication resources, including:

[0030] A link distance measurement module is used to send a PLC communication test packet to the dual-mode communication terminal on the node side and calculate the link distance based on the round-trip delay measurement result of the PLC communication test packet;

[0031] The spatial distance measurement module is used to send a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculate the spatial distance based on the classic path loss model;

[0032] The line distance calculation module is used to calculate the line distance between the node and the substation transformer based on the link distance and spatial distance.

[0033] In addition, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor is configured to execute the steps of the above method by calling the computer program stored in the memory.

[0034] In addition, the present invention also provides a computer-readable storage medium for storing a computer program for measuring line distance based on power line dual-mode communication delay, wherein the computer program executes the steps of the above-mentioned method when running on a computer.

[0035] The present invention has the following beneficial effects:

[0036] The line distance measurement method based on power line dual-mode communication delay of the present invention is based on PLC and HRF dual-mode communication. It can obtain the line electrical length between the node and the substation transformer based on PLC communication delay measurement, and obtain the geometric space distance between the node and the substation transformer based on HRF wireless communication measurement. The two measurement methods can switch the primary and auxiliary roles according to the signal-to-noise ratio or the received signal strength variance. Finally, the measured line electrical length and geometric space distance are integrated to obtain the line distance. The line distance between any node in the substation and the substation transformer can be accurately measured, which greatly improves the distance measurement accuracy.

[0037] In addition, the line distance measurement system based on power line dual-mode communication delay of the present invention also has the above advantages.

[0038] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 This is a flow chart of a line distance measurement method based on power line dual-mode communication delay according to a preferred embodiment of the present application;

[0041] Figure 2 yes Figure 1 Schematic diagram of the sub-process of step S1;

[0042] Figure 3 yes Figure 1 Schematic diagram of the sub-process of step S2;

[0043] Figure 4This is another flow chart of a line distance measurement method based on power line dual-mode communication delay according to a preferred embodiment of the present application;

[0044] Figure 5 This is a schematic diagram of the module structure of a line distance measurement system based on power line dual-mode communication delay in another embodiment of the present application. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] Reference Figure 1 The preferred embodiment of the present application provides a line distance measurement method based on power line dual-mode communication delay. A main control unit is configured on the transformer side of the substation area, and a dual-mode communication terminal is configured on each node side of the substation area. The dual-mode communication terminal supports both PLC wired communication and HRF wireless communication. The main control unit is responsible for unified scheduling of dual-mode communication resources. The line distance measurement method includes the following contents:

[0047] Step S1: Send a PLC communication test packet to the dual-mode communication terminal on the node side, and calculate the link distance based on the round-trip delay measurement result of the PLC communication test packet;

[0048] Step S2: Send a micro-power wireless communication test packet to the dual-mode communication terminal on the node side, and calculate the spatial distance based on the classic path loss model;

[0049] Step S3: Calculate the line distance between the node and the transformer in the substation based on the link distance and the spatial distance.

[0050] It can be understood that the line distance measurement method based on power line dual-mode communication delay of this embodiment is based on PLC and HRF dual-mode communication. The electrical length of the line between the node and the substation transformer can be measured based on the PLC communication delay, and the geometric space distance between the node and the substation transformer can be measured based on the HRF wireless communication. The two measurement methods can switch the primary and auxiliary roles according to the signal-to-noise ratio or the received signal strength variance. Finally, the measured line electrical length and geometric space distance are fused to obtain the line distance. The line distance between any node in the substation and the substation transformer can be accurately measured, which greatly improves the distance measurement accuracy.

[0051] Among them, before conducting line distance measurement, power line carrier couplers and micro-power wireless acquisition terminals are deployed on the main line and several branch lines of the substation. Specifically, the main control unit CCO is deployed on the transformer side of the substation, which is responsible for unified scheduling of dual-mode communication resources. Dual-mode communication terminals are deployed at various nodes in the substation (such as meter boxes, branch end users, etc.). They are equipped with HPLC modulation and demodulation modules and HRF micro-power wireless transceiver modules, and can support PLC wired communication and HRF wireless communication at the same time.

[0052] Among them, in step S1, the main control unit CCO sends a PLC communication test packet to the dual-mode communication terminal of each node respectively, and records the round-trip delay from sending to receiving. Based on the round-trip delay result and the known medium characteristics of the line, the electrical length of the line between the dual-mode communication terminal of each node and the main control unit CCO can be calculated.

[0053] Preferably, Figure 2 As shown, in step S1, the process of sending a PLC communication test packet to the dual-mode communication terminal on the node side and calculating the link distance based on the round-trip delay measurement result of the PLC communication test packet includes the following:

[0054] Step S11: sending a time calibration frame to the dual-mode communication terminal at a first moment, sending a ranging request frame to the dual-mode communication terminal at a second moment, recording the arrival times of the two frames and calculating the arrival time difference between the two frames;

[0055] Step S12: Calculating the offset error coefficient between the main control unit clock and the dual-mode communication terminal clock based on the transmission time difference and arrival time difference of the two frames;

[0056] Step S13: obtaining the processing time of the dual-mode communication terminal, and correcting the processing time based on the offset error coefficient;

[0057] Step S14: Based on the sending time and response time of the ranging request and the corrected processing time, the round-trip delay of pure propagation is calculated, and the link distance between the node and the substation transformer is calculated.

[0058] Specifically, the main control unit CCO first sends a time calibration frame to the dual-mode communication terminal of a node at the first time t1, and then sends a ranging request frame to it at the second time t2. The dual-mode communication terminal on the node side records the arrival time t1′ and t2′ of the two frames, calculates the arrival time difference between the two frames, and then returns it to the main control unit CCO. The arrival time difference between the two frames can be expressed as: Δt rx =t′2-t′1.

[0059] Then, the main control unit CCO receives the arrival time difference Δt of the two frames. rxThen, the transmission time difference Δt of the two frames is combined act = t2-t1, calculate the offset error coefficient between the main control unit clock and the dual-mode communication terminal clock. The offset error coefficient is calculated based on the following formula:

[0060]

[0061] Where β represents the offset error coefficient, t1 and t2 represent the sending times of the two frames, and t′1 and t′2 represent the arrival times of the two frames.

[0062] Then, the dual-mode communication terminal processes the time Δt tx The main control unit CCO corrects the processing time based on the offset error coefficient, which can be expressed as: tx =βΔt tx , τ tx Indicates the processing time after correction.

[0063] Finally, the main control unit CCO receives a response from the dual-mode communication terminal regarding the ranging request at the third time t3, and then calculates the pure propagation round-trip delay based on the following formula: ΔT = t3 - t2 - τ tx , ΔT represents the round-trip delay, and then the link distance L between the node and the transformer in the substation is calculated based on the delay-distance model. The expression of the delay-distance model is: v represents the transmission speed of the carrier signal, which is related to the transmission medium of the power line.

[0064] It can be understood that the present invention calculates the clock deviation between the dual-mode communication terminal clock and the main control unit clock, and corrects the processing time of the dual-mode communication terminal based on the clock deviation, thereby achieving timing synchronization between the dual-mode communication terminal and the main control unit, correcting the impact of multipath attenuation and electromagnetic environment interference on the delay, improving the calculation accuracy of the round-trip delay, and thus improving the accuracy of the link distance calculation.

[0065] In addition, the distance measured based on the power line carrier is the electrical length of the line, which is different from the actual spatial distance. The distance measurement based on HRF is mainly to measure the spatial distance between the main control unit CCO and the dual-mode communication terminal. Therefore, in step S2, the main control unit CCO sends a micro-power wireless communication test packet to the dual-mode communication terminal on the node side respectively, and calculates the spatial distance based on the classic path loss model. Among them, the expression of the classic path loss model is: RSSI(d)=RSSI0-10nlg(d)+N(0,σ 2 ), where RSSI(d) represents the received signal strength at a distance of d, RSSI0 represents the received signal strength at the reference point (d = 1m), n represents the path loss index, N(0,σ 2) represents Gaussian noise.

[0066] Preferably, Figure 3 As shown, the process of sending a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculating the spatial distance based on the classic path loss model includes the following:

[0067] Step S21: Obtain a set of received signal strength sequences and remove outliers from the sequences;

[0068] Step S22: performing first-order FIR Gaussian smoothing on the sequence after removing outliers;

[0069] Step S23: Calculate the median and mean of the received signal strengths in the smoothed sequence, and use the average of the median and mean as the stable strength mean of the received signal strength sequence;

[0070] Step S24: Based on the stable strength mean and the currently measured received signal strength, the spatial distance between the node and the transformer in the substation is calculated.

[0071] Specifically, first obtain a set of original RSSI sequences {r1, r2, ..., r N}, and then calculate the outlier statistics according to the Dixon criterion: If Q>Q α (N), then r max and r min is considered as an outlier and removed, where Q α (N) represents the Dixon test threshold, which is a function of the significance level α, α is generally 0.5, r max and r min Indicates the maximum and minimum values ​​in the RSSI sequence.

[0072] Then, the RSSI sequence after removing outliers is smoothed by first-order FIR Gaussian, which can be expressed as:

[0073]

[0074] Among them, r k ′ represents the RSSI of the kth frame after Gaussian smoothing, L represents the half-width of the Gaussian window, l represents the sample offset index from the center of the Gaussian window, σ represents the standard deviation of the Gaussian window, which is adaptively adjusted according to the standard deviation of the original sequence, and g(l) represents the Gaussian window coefficient, satisfying Σg(l)=1.

[0075] Next, the median and mean received signal strengths in the smoothed RSSI sequence are calculated, where the median can be expressed as: The mean can be expressed as: R B =mean{r′k} k , taking the average of the median and mean as the stable strength mean of the received signal strength sequence, it can be expressed as:

[0076] Finally, based on the stable intensity mean The spatial distance between the node and the transformer in the substation is calculated based on the following formula:

[0077] It can be understood that the present invention realizes composite filtering processing of the RSSI sequence by removing outliers, performing first-order FIR Gaussian smoothing, and averaging the median and mean of the original RSSI sequence, which can accurately calculate the stable intensity mean, correct the influence of multipath attenuation and electromagnetic environment interference on the delay, and improve the accuracy of spatial distance calculation.

[0078] In addition, in step S3, the link distance L and the space distance The average value of the two can be used as the final line distance, or the final line distance can be calculated by weighted summation, and the weight coefficient is set according to engineering experience.

[0079] Preferably, Figure 4 As shown, the line distance measurement method based on power line dual-mode communication delay also includes the following contents:

[0080] Step S4: Measure the link distance and the spatial distance multiple times, and perform weighted fusion calculation based on the multiple measurement results of the link distance and the spatial distance to obtain the line distance between the node and the substation transformer.

[0081] Specifically, in order to further improve the accuracy of line distance measurement, step S1 and step S2 are repeatedly performed to obtain multiple measurement results of link distance and space distance, and the link distance L in the multiple measurement results is

[0082] and spatial distance There will be a certain degree of volatility, which characterizes the stability of the two distance measurement methods. Therefore, the present invention first calculates the variance of multiple measurement results of link distance and spatial distance based on the following formula:

[0083]

[0084] Where v represents the transmission speed of the carrier signal, represents the variance of the processing time of the dual-mode communication terminal, M represents the number of measurements, represents the processing time of the dual-mode communication terminal during the kth measurement, represents the average processing time of the dual-mode communication terminal in M ​​measurements, Indicates the variance of the received signal strength, n represents the path loss index, RSSI k represents the received signal strength at the kth measurement, Indicates the average received signal strength in M ​​measurements.

[0085] Then, the line distance between the node and the substation transformer is calculated based on the following formula:

[0086]

[0087] Among them, D fused represents the line distance between the node and the transformer in the substation, L and Respectively represent the link distance and spatial distance between the node and the transformer in the substation, ω L and represents the weight coefficient, and Represent the variance of multiple measurement results of link distance and spatial distance respectively.

[0088] It can be understood that the present invention realizes that the fusion weight of the two distance weighted fusions can be adaptively adjusted according to the variance of the two distance measurement results, and the link quality is dynamically quantified by the jitter variance, so that the distance fusion with the minimum mean square error can be achieved. When a certain link is disturbed, its corresponding weight is automatically attenuated, which is conducive to further improving the accuracy of line distance measurement.

[0089] In addition, if Figure 5 As shown, another embodiment of the present invention further provides a line distance measurement system based on power line dual-mode communication delay, preferably using the line distance measurement method described above, configuring a main control unit on the transformer side of the substation area, and configuring a dual-mode communication terminal on each node side of the substation area, the dual-mode communication terminal supports both PLC wired communication and HRF wireless communication, and the main control unit is responsible for unified scheduling of dual-mode communication resources. The line distance measurement system includes:

[0090] A link distance measurement module is used to send a PLC communication test packet to the dual-mode communication terminal on the node side and calculate the link distance based on the round-trip delay measurement result of the PLC communication test packet;

[0091] The spatial distance measurement module is used to send a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculate the spatial distance based on the classic path loss model;

[0092] The line distance calculation module is used to calculate the line distance between the node and the substation transformer based on the link distance and spatial distance.

[0093] It can be understood that the line distance measurement system based on power line dual-mode communication delay of this embodiment is based on PLC and HRF dual-mode communication. It can obtain the electrical length of the line between the node and the substation transformer based on PLC communication delay measurement, and obtain the geometric space distance between the node and the substation transformer based on HRF wireless communication measurement. The two measurement methods can switch the primary and auxiliary roles according to the signal-to-noise ratio or the received signal strength variance. Finally, the measured line electrical length and geometric space distance are integrated to obtain the line distance. The line distance between any node in the substation and the substation transformer can be accurately measured, which greatly improves the distance measurement accuracy.

[0094] In addition, the line distance measurement system further includes:

[0095] The weighted fusion calculation module is used to measure the link distance and spatial distance multiple times, and perform weighted fusion calculation based on the multiple measurement results of the link distance and spatial distance to obtain the line distance between the node and the substation transformer.

[0096] In addition, another embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor is configured to execute the steps of the above method by calling the computer program stored in the memory.

[0097] In addition, another embodiment of the present invention further provides a computer-readable storage medium for storing a computer program for measuring line distance based on power line dual-mode communication delay, wherein the computer program executes the steps of the above-described method when running on a computer.

[0098] Common computer-readable storage media include: floppy disks, flexible disks, hard disks, magnetic tape, any other magnetic media, CD-ROMs, any other optical media, punch cards, paper tape, any other physical medium with a pattern of holes, random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), flash-erasable programmable read-only memory (FLASH-EPROM), any other memory chip or cartridge, or any other medium that can be read by a computer. Instructions can further be transmitted or received via a transmission medium. The term transmission medium may include any tangible or intangible medium that can be used to store, encode, or carry instructions for execution by a machine, and includes digital or analog communication signals or other intangible media that facilitate communication of such instructions. Transmission media include coaxial cables, copper wire, and fiber optics, including the wires of a bus used to transmit a computer data signal.

[0099] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0100] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0101] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0102] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0103] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0104] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

[0105] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A line distance measurement method based on power line dual-mode communication delay, wherein a main control unit is configured on the transformer side of the substation area, and a dual-mode communication terminal is configured on each node side of the substation area. The dual-mode communication terminal supports both PLC wired communication and HRF wireless communication. The main control unit is responsible for unified scheduling of dual-mode communication resources. The method is characterized by: Includes the following: Send a PLC communication test packet to the dual-mode communication terminal on the node side, and calculate the link distance based on the round-trip delay measurement result of the PLC communication test packet; Send a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculate the spatial distance based on the classic path loss model; The line distance between the node and the substation transformer is calculated based on the link distance and spatial distance.

2. The line distance measurement method based on power line dual-mode communication delay according to claim 1, characterized in that: The process of sending a PLC communication test packet to the dual-mode communication terminal on the node side and calculating the link distance based on the round-trip delay measurement result of the PLC communication test packet includes the following: Sending a time calibration frame to the dual-mode communication terminal at a first moment, sending a ranging request frame to the dual-mode communication terminal at a second moment, recording the arrival times of the two frames and calculating the arrival time difference between the two frames; Based on the transmission time difference and arrival time difference of the two frames, the offset error coefficient between the main control unit clock and the dual-mode communication terminal clock is calculated; Obtaining a processing time of the dual-mode communication terminal and correcting the processing time based on an offset error coefficient; Based on the sending time and response time of the ranging request and the corrected processing time, the round-trip delay of pure propagation is calculated, and the link distance between the node and the substation transformer is calculated.

3. The line distance measurement method based on power line dual-mode communication delay according to claim 2, characterized in that: Calculate the offset error coefficient based on the following formula: Wherein, β represents the offset error coefficient, t1 and t2 represent the sending time of the two frames, and t1′ and t2′ represent the arrival time of the two frames.

4. The line distance measurement method based on power line dual-mode communication delay according to claim 1, characterized in that: The process of sending a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculating the spatial distance based on the classic path loss model includes the following: Obtain a set of received signal strength sequences and remove outliers from the sequences; Perform first-order FIR Gaussian smoothing on the sequence after removing outliers; Calculate the median and mean of the received signal strength in the smoothed sequence, and use the average of the median and mean as the stable strength mean of the received signal strength sequence; Based on the stable strength mean and the currently measured received signal strength, the spatial distance between the node and the transformer in the substation is calculated.

5. The line distance measurement method based on power line dual-mode communication delay according to any one of claims 1 to 4, characterized in that: Also included: The link distance and spatial distance are measured multiple times, and the line distance between the node and the substation transformer is obtained by weighted fusion calculation based on the multiple measurement results of the link distance and spatial distance.

6. The line distance measurement method based on power line dual-mode communication delay according to claim 5, characterized in that: The line distance between the node and the transformer in the substation is calculated based on the following formula: Among them, D fused represents the line distance between the node and the transformer in the substation, L and Respectively represent the link distance and spatial distance between the node and the transformer in the substation, ω L and represents the weight coefficient, and Represent the variance of multiple measurement results of link distance and spatial distance respectively.

7. The line distance measurement method based on power line dual-mode communication delay according to claim 6, characterized in that: The variance of multiple measurements of link distance and spatial distance is calculated based on the following formula: Where v represents the transmission speed of the carrier signal, represents the variance of the processing time of the dual-mode communication terminal, M represents the number of measurements, represents the processing time of the dual-mode communication terminal during the kth measurement, represents the average processing time of the dual-mode communication terminal in M ​​measurements, Indicates the variance of the received signal strength, n represents the path loss index, RSSI k represents the received signal strength at the kth measurement, Indicates the average received signal strength in M ​​measurements.

8. A line distance measurement system based on power line dual-mode communication delay, wherein a main control unit is configured on the transformer side of the substation area, and a dual-mode communication terminal is configured on each node side of the substation area. The dual-mode communication terminal supports both PLC wired communication and HRF wireless communication. The main control unit is responsible for unified scheduling of dual-mode communication resources. The system is characterized by: include: A link distance measurement module is used to send a PLC communication test packet to the dual-mode communication terminal on the node side and calculate the link distance based on the round-trip delay measurement result of the PLC communication test packet; The spatial distance measurement module is used to send a micro-power wireless communication test packet to the dual-mode communication terminal on the node side and calculate the spatial distance based on the classic path loss model; The line distance calculation module is used to calculate the line distance between the node and the substation transformer based on the link distance and spatial distance.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a computer program, and the processor is configured to execute the steps of the method according to any one of claims 1 to 7 by calling the computer program stored in the memory.

10. A computer-readable storage medium for storing a computer program for measuring line distance based on power line dual-mode communication delay, characterized in that: When the computer program is run on a computer, the steps of the method according to any one of claims 1 to 7 are executed.

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