Positioning method and system based on dual-mode communication and RTK calibration

Abstract

The application provides a positioning method and system based on dual-mode communication and RTK calibration, belonging to the cross field of communication technology and positioning technology, which comprises the following steps: fusing the signal attenuation characteristics of HPLC and HRF communication modules, establishing a joint ranging model to generate the weighted relative distance between power equipment; constructing a communication network topology G to determine a backbone node set; acquiring the distance between the backbone node and the connected node by using real-time dynamic difference RTK technology; determining the weighted relative distance between the nodes based on the joint ranging model, generating a ranging error value, and determining the average ranging error of the station area by traversing all the backbone nodes; and correcting and updating the relative position between the power equipment obtained by the joint ranging model by using the average ranging error of the station area for all power equipment in the station area. The application can realize high-precision positioning of a large amount of power equipment in the station area, and provide an efficient and accurate equipment management and position tracking solution.

Description

TECHNICAL FIELD

[0001] The present application belongs to the cross field of communication technology and positioning technology, and particularly relates to power equipment positioning and addressing technology, and in particular to a method and system based on dual-mode communication and RTK high-precision positioning correction, which realizes high-precision positioning of a large number of power equipment in a transformer area, can be widely applied to smart grids and other related fields, and provides efficient and accurate equipment management and location tracking solutions. BACKGROUND

[0002] With the in-depth promotion of smart grid construction, accurate positioning of transformer area equipment has become a key technology for improving power grid management efficiency, realizing rapid fault positioning and line loss analysis. Traditional positioning methods mainly rely on manual inspection or single communication signal ranging technology, which has problems such as low positioning accuracy, poor anti-interference ability, and insufficient adaptability. Especially in complex transformer area environment, power line noise, multipath effect and device heterogeneity lead to variable signal attenuation characteristics, making the ranging error of single communication mode such as HPLC or HRF significantly increase, which is difficult to meet the demand of centimeter-level high-precision positioning.

[0003] In recent years, dual-mode communication technology HPLC+HRF has become a research hotspot due to its complementary characteristics: HPLC high-speed power line carrier has strong penetration in low frequency band, but is easily affected by load noise; HRF high-frequency radio frequency has high stability in non-line-of-sight scenarios, but has limited coverage. How to combine the signal attenuation characteristics of the two and the connection relationship of each device in the transformer area to construct a more robust joint ranging model has become the key to improving positioning accuracy. However, relying only on communication signal ranging still has the problem of cumulative error, and an external high-precision positioning reference needs to be introduced for dynamic calibration.

[0004] However, relying only on communication signal strength for ranging will introduce cumulative error, resulting in reduced positioning accuracy. Therefore, an external high-precision positioning reference needs to be introduced for dynamic correction to overcome the error caused by communication signal strength ranging. SUMMARY

[0005] The purpose of the present application is to solve the problems of signal attenuation and error accumulation in traditional methods, and to propose a combination of dual-mode communication ranging and RTK dynamic calibration technology, which realizes high-precision positioning and dynamic correction of a large number of power equipment in the transformer area, and has wide application prospects.

[0006] Compared with the prior art, the present application does not need to equip each terminal with an RTK module, but only a small number of backbone nodes can control the positioning error to sub-meter level, effectively reducing the deployment cost and improving the operation and maintenance efficiency, and has wide engineering application prospects.

[0007] The technical solution of the present application is:

[0008] The application provides a positioning method based on dual-mode communication and RTK calibration, which comprises the following steps:

[0009] S1, a joint ranging model is established by fusing the signal attenuation characteristics of the HPLC communication module and the HRF communication module, and a weighted relative distance between power equipment loaded with a dual-mode communication module is generated;

[0010] S2, a communication network topology G is constructed according to the communication connection relationship between power equipment in a transformer area, and a backbone node set is determined;

[0011] S3, the distance between the backbone nodes and the connected nodes is obtained by using the real-time dynamic difference RTK technology; the weighted relative distance between the nodes is determined based on the joint ranging model, the ranging error value is generated, and the transformer area average ranging error is determined by traversing all the backbone nodes;

[0012] S4, for all power equipment in the transformer area, the relative position between the power equipment obtained by the joint ranging model is corrected and updated by the transformer area average ranging error.

[0013] Further, the S1 comprises:

[0014] S11, the signal strength of the HPLC communication module and the HRF communication module is obtained, a signal attenuation model is constructed to calculate the single-channel distance between any to-be-measured node and adjacent nodes ;

[0015]

[0016] Wherein, represents the calculation of the absolute value; represents the single-channel signal receiving strength, and the unit ; represents the unit signal strength received at a distance of 1 meter from the selected to-be-measured node, and the unit ; represents an environmental attenuation factor;

[0017] S12, the collected signal strength is preprocessed, and the following formula is used to determine the HPLC communication module weighting coefficient and the HRF communication module weighting coefficient ;

[0018]

[0019] Wherein, , respectively represent the standard deviation of the signal strength of the HPLC and HRF channels;

[0020] S13, a joint ranging model is established by fusing the distance estimations of the HPLC communication module and the HRF communication module through a weighted average method, and a weighted relative distance between the selected to-be-measured node and the adjacent node is generated ;

[0021]

[0022] wherein, 、 respectively represent the HPLC channel distance and the HRF channel distance between any to-be-measured node and the adjacent node.

[0023] Further, the S12 comprises:

[0024] The signal strength is modeled as a probability distribution, the signal strength is filtered by multiple sampling, the maximum and minimum values in the signal strength are removed, and the standard deviations of the HPLC channel and the HRF channel signal strength are calculated respectively 、 ;

[0025] According to the standard deviation of the signal strength, the weighting coefficients of the HPLC communication module and the HRF communication module are determined and The weights of the distance estimations are adjusted through the weighting coefficients.

[0026] Further, the S2 comprises:

[0027] S21, according to the signal strength threshold, the connection relationship between devices is determined, and a communication network topology G containing all devices is generated;

[0028] S22, the minimum node cover set is solved by using an integer linear programming model, and a backbone node set is obtained, which ensures that the backbone node set covers all communication connection lines, at least one endpoint of each connection line is selected, and the key device is included in the backbone node set, and it is ensured that each sub-region in the topology contains at least one backbone node.

[0029] Further, the S21 comprises acquiring the signal strength between power devices in a power supply area, when the signal strength of any channel is greater than the preset connection threshold of the corresponding channel, the connection relationship between the devices exists; all devices in the power supply area are traversed to generate a communication network topology G.

[0030] Further, the S22 comprises:

[0031] S221, the communication network topology is initialized, a undirected graph containing device nodes and connection lines is generated, each node in the graph represents a power device, each connection line represents the communication or physical connection between devices, and an empty set Node_Cover is defined to store the minimum node cover set;

[0032] S222, select an uncovered connection line from the undirected graph, i.e. a connection line that is not covered by any node in Node_Cover;

[0033] S223, for the selected connection line, select one end point to join the Node_Cover set; preferably, each time select a node with higher degree, i.e. connected to more other nodes, to join the minimum node cover set;

[0034] S224, update the coverage state, delete the connection line connected to the selected node;

[0035] S225, repeat the selection and update until all connection lines are covered, generate the minimum node cover set as the backbone node set.

[0036] Further, S3 comprises:

[0037] S31, use real-time dynamic difference technology RTK to obtain the distance between any backbone node and the connected node ;

[0038] S32, obtain the weighted relative distance between the selected backbone node and the corresponding connected node based on the joint ranging model ;

[0039] S33, generate a ranging error value using the following formula , ;

[0040] S34, traverse all nodes in the backbone node set, obtain the ranging error value between each backbone node and the corresponding connected node, and take the average as the average ranging error of the transformer area.

[0041] Further, in S4, when the power equipment is connected to two or fewer nodes, update the relative position through the ranging error value; when the power equipment is connected to more than two nodes, use the centroid positioning algorithm to obtain the relative position, specifically, calculate the weighted centroid position of the connected corrected nodes as the accurate position of the target node, and continuously iterate the process to correct the positions of nodes connected to more than two nodes in the entire network.

[0042] Further, in S4, using the centroid positioning algorithm to obtain the relative position comprises:

[0043] selecting any to-be-corrected node, obtaining the coordinates of at least three corrected nodes connected to the to-be-corrected node , , and the weighted relative distance of the to-be-corrected node , , ;

[0044] Draw a circle with A, B, C points as the center and 、 、 the radius, take three intersection points of the intersection area 、 、 The coordinates are respectively 、 、 ,

[0045] The coordinates of the to-be-corrected node are obtained by using the following formula ;

[0046] .

[0047] A positioning method based on dual-mode communication and RTK calibration adopts a system, the system comprises:

[0048] Joint ranging module: for establishing a joint ranging model by fusing the signal attenuation characteristics of the HPLC communication module and the HRF communication module, and generating the weighted relative distance between the power equipment loaded with the dual-mode communication module;

[0049] Topology construction module: for constructing a communication network topology G according to the communication connection relationship between the power equipment in the transformer area, and determining a backbone node set;

[0050] Error calculation module: for obtaining the distance between the backbone nodes and the connected nodes by using real-time dynamic difference RTK technology; determining the weighted relative distance between the nodes based on the joint ranging model, generating a ranging error value, and traversing all the backbone nodes to determine the average ranging error of the transformer area;

[0051] Position correction module: for all power equipment in the transformer area, correcting and updating the relative position between the power equipment obtained by the joint ranging model through the average ranging error of the transformer area.

[0052] The beneficial effects of the present application are:

[0053] The application discloses a positioning method based on dual-mode communication and RTK calibration, and aims at the problems of low positioning accuracy of power equipment in a transformer area, strong interference of a complex environment, and dynamic change of a communication network topology service scene.

[0054] The method of the application introduces an external high-precision positioning reference for dynamic correction to overcome the error caused by communication signal strength ranging, and simultaneously adopts real-time kinematic differential RTK technology as high-precision positioning in the satellite navigation field, which can provide extremely high positioning accuracy in an open environment and can perform real-time dynamic differential correction, thereby providing an accurate reference for the ranging result of the dual-mode communication signal and further improving the positioning accuracy of the whole system.

[0055] Other features and advantages of the application will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0056] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and wherein:

[0057] Figure 1 A flow chart of the positioning method based on dual-mode communication and RTK calibration of the application is shown.

[0058] Figure 2 A schematic view of the relative position obtained by the centroid positioning algorithm of the application is shown. DETAILED DESCRIPTION

[0059] The preferred embodiments of the application will be described in detail with reference to the drawings. Although the preferred embodiments of the application are shown in the drawings, it should be understood that the application can be implemented in various forms and should not be limited by the embodiments described herein.

[0060] Example 1

[0061] Figure 1 A flow chart of the positioning method based on dual-mode communication and RTK calibration of the application is shown.

[0062] AsFigure 1 As shown, the present application provides a positioning method based on dual-mode communication and RTK calibration, aiming to realize high-precision positioning of a large number of devices in a transformer area, which comprises the following steps:

[0063] S1, by fusing the signal attenuation characteristics of the HPLC communication module and the HRF communication module, a joint ranging model is established to generate the weighted relative distance between the power equipment loaded with the dual-mode communication module, specifically;

[0064] S11, signal attenuation model: obtain the signal strength of the HPLC communication module and the HRF communication module, combine the environmental attenuation factor, and construct a signal attenuation model to calculate the single-channel distance between any to-be-measured node and the adjacent node ;

[0065] ;

[0066] wherein, represents the calculation of the absolute value; represents the single-channel signal receiving strength, unit ; represents the unit signal strength received at a distance of 1 meter from the selected to-be-measured node, unit ; represents the environmental attenuation factor;

[0067] S12, signal quality evaluation: filter the collected signal strength, eliminate the maximum and minimum values in the signal strength, and calculate the standard deviation of the HPLC channel and HRF channel signal strength , , the following formula is used to determine the HPLC communication module weighting coefficient and the HRF communication module weighting coefficient , the weighting coefficient is used to adjust the weight of distance estimation;

[0068]

[0069] S13, weighted ranging model: by weighted average method, the joint ranging model is established by fusing the distance estimation of the HPLC communication module and the HRF communication module to generate the weighted relative distance between the selected to-be-measured node and the adjacent node ;

[0070] ;

[0071] wherein, , respectively represent the HPLC channel distance and HRF channel distance between any to-be-measured node and the adjacent node.

[0072] S2, according to the communication connection relationship between the power equipment in the transformer area, a communication network topology G is constructed, and a backbone node set is determined, specifically;

[0073] S21, the signal strength between the power equipment in the transformer area is obtained, and when the signal strength of any channel is greater than the preset connection threshold of the corresponding channel, there is a connection relationship between the equipment; all the devices in the transformer area are traversed to generate a communication network topology G;

[0074] S22, the minimum node cover set is solved by using an integer linear programming model, and a backbone node set is obtained, which ensures that the backbone node set covers all the communication connection lines, and at least one endpoint of each connection line is selected, and the key equipment is included in the backbone node set, which ensures that each sub-area in the topology contains at least one backbone node, including:

[0075] S221, initialize the communication network topology to generate an undirected graph containing device nodes and connection lines, each node in the graph represents a power equipment, and each connection line represents the communication or physical connection between the equipment, and define an empty set Node_Cover to store the minimum node cover set;

[0076] S222, select the connection line that is not covered from the undirected graph, that is, the connection line that is not covered by any node in Node_Cover;

[0077] S223, for the selected connection line, select an endpoint to join the Node_Cover set; preferably, the node with higher degree, i.e. connected to more other nodes, is selected to join the minimum node cover set each time;

[0078] S224, update the coverage state and delete the connection line connected to the selected node;

[0079] S225, repeat the selection and update until all connection lines are covered, generate the minimum node cover set as the backbone node set.

[0080] Wherein, the minimum device node set is solved, an integer linear programming model is established, and the node set in the approximate solution is the backbone node.

[0081] Objective function:

[0082]

[0083] Constraint condition:

[0084]

[0085] In the formula: , input graph structure; , node set (such as transformer, meter, switch, etc.); , a connection set (communication link or electrical connection); , decision variable; , vertex is selected; , vertex is not selected.

[0086] , is a core constraint condition, requiring covering all nodes in the communication network graph of the transformer area, and each connection has at least one endpoint selected.

[0087] , represents the key equipment must be selected, requires the main transformer must be in the backbone node set, and requires that in each relay layer, as long as one node in the relay layer belongs to the backbone node.

[0088] , represents the regional coverage requirement, at least one device node in each sub-region in the transformer area is selected as a backbone node.

[0089] S3, adopt real-time dynamic difference RTK technology to obtain the distance between the backbone node and the connected node; determine the weighted relative distance between the nodes based on the joint ranging model, generate the ranging error value, traverse all the backbone nodes to determine the average ranging error of the transformer area; wherein each node in the backbone node set is artificially RTK high-precision positioning, which can be performed by the field staff to the corresponding equipment, and the RTK positioning is performed by using the back clip, the back clip is RFID Beidou back clip produced by Nanjing Linyang Electric Power Technology Co., Ltd., and the model is TLY6611RB, specifically;

[0090] S31, adopt real-time dynamic difference technology RTK to obtain the distance between any backbone node and the connected node ;

[0091] S32, obtain the weighted relative distance between the selected backbone node and the corresponding connected node based on the joint ranging model ;

[0092] S33, generate the ranging error value by using the following formula , ;

[0093] S34, traverse all the nodes in the backbone node set, obtain the ranging error value between each backbone node and the corresponding connected node, and take the average value as the average ranging error of the transformer area.

[0094] Wherein, the weighted ranging model estimates a rough distance value by fusing the attenuation characteristics of HPLC and HRF signals The distance value is affected by signal propagation environment, noise, path loss and other factors, so there may be some errors; the precise distance is obtained by combining RTK high-precision positioning technology , and the mathematical model of error correction is obtained as above .

[0095] S4, for all power equipment in the transformer area, the relative positions between the power equipment obtained by the joint ranging model are updated by the transformer area average ranging error correction.

[0096] According to the error , the estimated result of the weighted ranging model can be corrected to the precise distance value:

[0097]

[0098] The backbone node is represented by a data structure, and its data includes the node position, the number of adjacent points, the received adjacent point signal strength, and the corrected distance from the adjacent point.

[0099] According to the number of adjacent points, the node can be divided into a hanging node and a center node. Among them, the hanging node refers to a node connected to only one other node through an edge. The hanging node cannot be solved by the positioning algorithm through the known positions of the remaining connected points, and can only obtain the corrected position and relative distance relative to the transformer. For the center node with adjacent point number ≥ 3, the precise position can be solved according to the centroid positioning algorithm.

[0100] In one example, when the power equipment is connected to only two nodes or less, the relative position is updated by the ranging error value; when the power equipment is connected to more than two nodes, the centroid positioning algorithm is used to obtain the relative position, specifically, the weighted centroid position of the connected corrected nodes is calculated as the precise position of the target node, and the process is iterated continuously to correct the position of the node connected to more than two nodes in the entire network.

[0101] Further, the centroid positioning algorithm for obtaining the relative position includes:

[0102] Select any node to be corrected, and obtain the coordinates of at least three corrected nodes connected to the node to be corrected 、 、 and the weighted relative distance from the node to be corrected 、 、 ;

[0103] Draw a circle with the above A, B, C points as the center 、 、 ; take the three intersection points in the intersection region as the precise position of the node to be corrected 、 、 , the coordinates of the intersection points are respectively 、 、 For the intersection point , then:

[0104]

[0105] Transformed into matrix form:

[0106] In the formula:

[0107]

[0108] The coordinates of the intersection point are:

[0109] .

[0110] Similarly, the coordinates of the intersection point , are:

[0111] .

[0112] .

[0113] Suppose the coordinates of the node to be positioned are , and through calculation, we can obtain:

[0114] .

[0115] Embodiment 2

[0116] The application provides a system for a positioning method based on dual-mode communication and RTK calibration, which comprises:

[0117] The joint ranging module is used for establishing a joint ranging model by fusing the signal attenuation characteristics of the HPLC communication module and the HRF communication module, and generating a weighted relative distance between power equipment loaded with a dual-mode communication module;

[0118] The topology construction module is used for constructing a communication network topology G according to the communication connection relationship between power equipment in a transformer area, and determining a backbone node set;

[0119] The error calculation module is used for acquiring the distance between a backbone node and a connected node by using real-time dynamic difference RTK technology; determining the weighted relative distance between the nodes based on the joint ranging model, generating a ranging error value, and traversing all the backbone nodes to determine the average ranging error of the transformer area;

[0120] The position correction module: for all power equipment in the transformer area, the relative position between the power equipment obtained by the joint ranging model is updated through the average ranging error correction of the transformer area.

[0121] When the system of the application is applied, each terminal does not need to be equipped with an RTK module, and positioning errors can be controlled at sub-meter level through a small number of backbone nodes, effectively reducing deployment costs and improving operation and maintenance efficiency, and having a wide engineering application prospect.

[0122] The above has described the embodiments of the application, the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A positioning method based on dual-mode communication and RTK calibration, characterized in that, The method comprises the following steps: S1, by fusing the signal attenuation characteristics of the HPLC communication module and the HRF communication module, a joint ranging model is established to generate the weighted relative distance between the power equipment loaded with the double-mode communication module; S2, according to the communication connection relationship between the power equipment in the transformer area, a communication network topology G is constructed, and a backbone node set is determined; S3, the distance between the backbone node and the connected node is obtained by using the real-time dynamic difference RTK technology; the weighted relative distance between the nodes is determined based on the joint ranging model, the ranging error value is generated, and the transformer area average ranging error is determined by traversing all the backbone nodes; S4, for all power equipment in the transformer area, the relative position between the power equipment obtained by the transformer area average ranging error correction update joint ranging model is updated.

2. The positioning method based on dual-mode communication and RTK calibration of claim 1, wherein The S1 comprises: S11, acquire the signal strength of the HPLC communication module and the HRF communication module, construct a signal attenuation model to calculate the single-channel distance between any to-be-measured node and adjacent nodes ; ； wherein, represents calculating absolute value; represents single channel signal receiving strength, unit dB; represents the unit signal strength received at a distance of 1 meter from the selected to be measured node, unit dB; represents environmental attenuation factor; S12, pre-process the collected signal strength, and determine the HPLC communication module weighting coefficient and the HRF communication module weighting coefficient using the following formula ;​ ； wherein, , respectively represent the standard deviation of the signal intensity of the HPLC and HRF channels; S13, a joint ranging model is established by fusing the distance estimations of the HPLC communication module and the HRF communication module through a weighted average method, to generate a weighted relative distance between the selected to-be-measured node and the adjacent nodes ; ； wherein, , respectively represent the HPLC channel distance and HRF channel distance between any node under test and adjacent nodes.

3. The positioning method based on dual-mode communication and RTK calibration of claim 2, wherein The S12 comprises: The signal strength is modeled as a probability distribution, and the signal strength of multiple samplings is filtered to eliminate the maximum and minimum values, and the standard deviations of the signal strengths of the HPLC channel and the HRF channel are calculated respectively , ; determining a weighting factor for the HPLC communication module and the HRF communication module based on a standard deviation of signal strength and adjusting the weight of the distance estimate by the weighting factor.

4. The positioning method based on dual-mode communication and RTK calibration of claim 1, wherein The S2 comprises: S21, according to the signal strength threshold, the connection relationship between the devices is determined, and a communication network topology G containing all devices is generated; S22, the minimum node cover set is solved by using the integer linear programming model, and the backbone node set is obtained, which ensures that the backbone node set covers all the communication connection lines, and at least one endpoint of each connection line is selected, and the key equipment is included in the backbone node set, which ensures that each sub-area in the topology contains at least one backbone node.

5. The positioning method based on dual-mode communication and RTK calibration of claim 4, wherein The S21 comprises obtaining the signal strength between the power equipment in the transformer area, and when the signal strength of any channel is greater than the preset connection threshold of the corresponding channel, there is a connection relationship between the devices; the communication network topology G is generated by traversing all the devices in the transformer area.

6. The positioning method based on dual-mode communication and RTK calibration of claim 4, wherein The S22 comprises: S221, initialize the communication network topology, generate an undirected graph containing device nodes and connection lines, each node in the graph represents a power equipment, each connection line represents the communication or physical connection between the devices, and define an empty set Node_Cover to store the minimum node cover set; S222, select the connection line that is not covered from the undirected graph, that is, the connection line that is not covered by any node in Node_Cover; S223, for the selected connection line, select an endpoint to join the Node_Cover set; S224, update the coverage state and delete the connection line connected with the selected node; S225, repeat the selection and update until all the connection lines are covered, generate the minimum node cover set as the backbone node set.

7. The positioning method based on dual-mode communication and RTK calibration of claim 6, wherein In S223, each time, the node with higher degree, that is, connected with more other nodes, is selected to join the minimum node cover set.

8. The positioning method based on dual-mode communication and RTK calibration of claim 1, wherein S3 Comprise: S31, adopt real-time dynamic difference technique RTK to obtain distance between any backbone node and connected node ; S32, obtaining the weighted relative distance between the selected backbone node and the corresponding connected node based on the joint ranging model ; S33, generate the ranging error value by using the following formula , ; S34, traverse all the nodes in the backbone node set, obtain the ranging error value between each backbone node and the corresponding connected node, and take the mean value as the transformer area average ranging error.

9. The positioning method based on dual-mode communication and RTK calibration of claim 1, wherein In S4, when the power equipment is connected with only two or less nodes, the relative position is updated by the ranging error value; when the power equipment is connected with more than two nodes, the relative position is obtained by using the centroid positioning algorithm, specifically, the weighted centroid position of the connected corrected nodes is calculated as the accurate position of the target node, and the process is iterated to correct the position of the node connected with more than two nodes in the entire network.

10. The positioning method based on dual-mode communication and RTK calibration of claim 9, wherein In S4, the relative position obtained by using the centroid positioning algorithm comprises: Selecting any node to be corrected, obtaining the coordinates of at least three corrected nodes connected to the node to be corrected and the weighted relative distance of the corrected nodes to the node to be corrected ; Get the above A, B, C point as the center of the circle, Draw a circle with radius, take the three intersection points of the intersection area , the coordinates are , , , the coordinates of the node to be corrected are obtained by the following formula ; 。 11. A positioning system based on dual-mode communication and RTK calibration for implementing the positioning method based on dual-mode communication and RTK calibration according to any one of claims 1-10, characterized in that, The system comprises: Joint ranging module: for establishing a joint ranging model by fusing the signal attenuation characteristics of the HPLC communication module and the HRF communication module, and generating a weighted relative distance between power equipment loaded with a dual-mode communication module; Topology construction module: for constructing a communication network topology G according to the communication connection relationship between power equipment in the transformer area, and determining a backbone node set; Error calculation module: for acquiring the distance between the backbone nodes and the connected nodes by using the real-time dynamic difference RTK technology; determining the weighted relative distance between the nodes based on the joint ranging model, generating a ranging error value, and determining the average ranging error of the transformer area by traversing all the backbone nodes; Position correction module: for all power equipment in the transformer area, correcting and updating the relative position between the power equipment obtained by the joint ranging model through the average ranging error of the transformer area.

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