A power distribution network framework state intelligent evaluation and auxiliary decision method and system

Abstract

This invention discloses an intelligent assessment and auxiliary decision-making method and system for the status of a distribution network, primarily relating to the field of distribution automation technology. It includes: establishing interfaces between safety zones I and IV of the distribution automation system to construct a network information database; extracting line structural features based on topology analysis and dividing the network into sections; assessing load balance from three dimensions: section load, transformer capacity, and number of transformers; integrating structural features and load parameters, and performing comprehensive judgment and analysis through standardized condition models, reverse power transmission analysis models, and multi-level protection verification models to generate an assessment and modification recommendation report. The beneficial effects of this invention are that it achieves automated and quantitative assessment and intelligent auxiliary decision-making for the status of the distribution network.

Description

Technical Field

[0001] This invention relates to the field of power distribution automation technology, specifically to an intelligent assessment and auxiliary decision-making method and system for the state of a power distribution network. Background Technology

[0002] With the continuous expansion of distribution network equipment and the increasing complexity of network structures, traditional distribution networks commonly exhibit structural problems during operation, such as uneven load distribution, unreasonable configuration of sectionalizing and interconnecting switches, high line losses, and poor utilization of grid resources. These problems directly lead to low standardization rates in line configuration, insufficient power supply reliability, and inadequate capacity to accommodate new elements such as distributed power sources, making it difficult to meet the continuously growing electricity load and the demand for high-standard power supply services. Therefore, conducting scientific and accurate analysis of the distribution network structure has become a crucial prerequisite for promoting the optimization and upgrading of distribution networks and improving their intelligence level.

[0003] Currently, the analysis and evaluation of distribution network structures mainly rely on the personal experience and manual operation of operation and maintenance personnel. Analysts need to simultaneously consult multiple independent systems or interfaces, manually query and record fragmented information such as line topology, equipment parameters, and real-time measurements, and complete structural analysis, load estimation, and weak point identification through offline calculations and subjective judgment. This method is not only labor-intensive and inefficient, but also highly dependent on the professional level of personnel, making it difficult to guarantee the objectivity and consistency of the analysis results. In addition, when the power grid structure or operation mode changes, the entire analysis process often needs to be repeated, lacking sustainable and automated analysis capabilities, and failing to provide real-time and effective decision support for the planning, construction, operation, and management of distribution networks.

[0004] Therefore, there is an urgent need for an intelligent technology solution that can automatically, efficiently, and comprehensively assess the status of the power distribution network and provide quantitative decision-making basis, in order to overcome the many shortcomings of the existing manual methods. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent assessment and auxiliary decision-making method and system for the state of a distribution network, which realizes automated and quantitative assessment and intelligent auxiliary decision-making for the state of the distribution network.

[0006] To achieve the above objectives, the present invention employs the following technical solution: On the one hand, the present invention provides an intelligent assessment and auxiliary decision-making method for the state of a power distribution network, comprising the following steps: S1. Data synchronization and database construction steps: Establish the data interface between Safety Zone I and Safety Zone IV of the distribution automation system, synchronize the power grid topology, electrical measurement and switch attribute data in Safety Zone I to Safety Zone IV, and build a distribution network structure information database; S2. Structural feature extraction steps: Based on the distribution network grid information database, topology analysis is performed starting from the substation outgoing switch to extract the structural features of the target line, and the line is divided into sections according to the location of the sectionalizing switches on the main line. The extracted structural features include: the uniqueness determination result of the main line, the type of erection method, the number of segments calculated based on the number of segment switches, and the classification results of the number and location of tie switches; S3. Load balancing assessment steps: Based on the line sections divided in step S2, assess the load balance of each section from three dimensions: section load distribution, transformer capacity distribution, and transformer quantity distribution. The dimensionality of the load distribution in the section is obtained based on current measurement data through a load calculation model. The distribution dimensions of transformer capacity and transformer quantity are obtained based on statistics from transformer ledger data. S4. Comprehensive Judgment and Report Generation Steps: First, the structural features extracted in step S2 and the load distribution parameters evaluated in step S3 are input into a preset network standardization condition model for calculation, and the result of determining whether the line is standardized is output. The network standardization condition model integrates the verification of three structural conditions: the uniqueness of the trunk line, the standardization of the number of segments, and the standardization of the interconnection configuration, as well as the verification of at least one of the three load distribution dimensions satisfying the balance threshold condition. Secondly, based on the switching power direction data, the reverse power transmission analysis model is used to output the analysis results of the reverse power transmission situation of the distributed power source; Meanwhile, based on the protection setting data, a multi-level protection verification model is used to output the completeness analysis results of short-circuit and grounding protection configuration; Finally, by combining the judgment results and analysis results, a report on the status assessment and modification recommendations for the space frame is generated.

[0007] Preferably, in step S2, the location classification of the tie switch specifically includes: no tie, tie with the busbar in the first section, tie only in the first section, tie with the busbar in the non-first section, tie with the station in the non-first section, and effective tie between stations in the non-first section.

[0008] Preferably, in step S2, the erection method categories are specifically divided into: pure overhead lines with only pole-mounted switches as the main line equipment, pure cable lines with only ring main units as the main line equipment, and mixed lines with both ring main units and pole-mounted switches as the main line equipment.

[0009] Preferably, in step S3, for pure overhead lines and mixed lines, the load calculation model is as follows: based on the section division, calculate the difference sequence composed of the current values ​​of the outgoing switch and each section switch to obtain the load value and proportion parameter of each section.

[0010] Preferably, in step S3, for pure cable lines, the load balancing assessment specifically involves: running the critical node identification model, calculating the ratio of the incoming switch current of each ring main unit to the outgoing switch current in the station, and identifying ring main units whose ratio falls within the preset balancing range as critical nodes.

[0011] Preferably, in step S3, the distribution parameters of the distribution transformer capacity and the distribution parameters of the distribution transformer quantity are obtained as follows: for each section divided in step S2, the total rated capacity and quantity of the distribution transformers connected to it are summarized, and its proportion relative to the total line is calculated.

[0012] Preferably, the calculation and judgment logic of the pre-set standardized space frame condition model in step S4 specifically includes the following sub-steps: S71. Structural Condition Verification: Determine whether the target line simultaneously meets the following three structural conditions: The only condition for the main trunk line: topology analysis shows that there is only one main trunk path from the substation outgoing switch; Segmentation compliance conditions: The number of main trunk segments of the line is within a preset reasonable range; for mixed lines, one ring main unit is considered as one segment; Connection compliance conditions: The connection switch configuration of the line conforms to the preset effective connection rules; the effective connection rules require that the number of connection switches does not exceed the preset upper limit, and that at least one connection switch is located in the middle or rear section of the line, and that the power supply on the opposite side of the connection switch comes from different substations; if the line is a pure cable line, then all its connection switches are automatic switches. S72. Load balancing condition verification: Determine whether there are at least one dimension of parameters in the three dimensions of section load distribution, transformer capacity distribution and transformer quantity distribution obtained in step S3 that meet the corresponding preset balancing threshold condition; the balancing threshold condition means that the parameter proportion of each section under this dimension is within an allowable fluctuation range centered on the theoretical average proportion. S73. Comprehensive Judgment: The model determines that the target line is a standardized line if and only if the target line passes all three structural conditions in step S71 and at least one load balancing condition in step S72; otherwise, it is determined to be a non-standardized line. For hybrid lines where the first section is the first ring network box, the first section is not included in the calculation when checking the load balancing conditions in step S72.

[0013] Preferably, the multi-level protection verification model in step S4 automatically identifies whether it meets the preset configuration requirements of three-level short-circuit protection and five-level grounding protection by comparing the coordination relationship between the protection settings and action time settings of outgoing switches, sectionalizing switches, branch switches and boundary switches in the line.

[0014] On the other hand, the present invention also provides an intelligent assessment and auxiliary decision-making system for the state of a distribution network structure to implement the above method, comprising: The data synchronization and storage module is used to execute the data synchronization and database building steps, and to establish and maintain the distribution network information database. The structural feature extraction module is used to perform the structural feature extraction steps and complete the line segment division and structural feature quantification. The load balancing assessment module is used to execute the load balancing assessment steps, run relevant calculation and statistical models, and output the load distribution parameters of the three dimensions. The comprehensive analysis and reporting module is used to perform the comprehensive judgment and report generation steps, integrate and run the standardized condition model, the reverse power transmission analysis model and the multi-level protection verification model, and generate an evaluation report.

[0015] Preferably, the system is deployed in the safety zone IV of the power distribution automation system; the data synchronization and storage module receives data from safety zone I through a forward isolation device; the structural feature extraction module, load balancing assessment module, and comprehensive analysis and reporting module provide services in the form of software applications.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention achieves automatic acquisition and fusion of power grid topology, measurement and equipment data by automatically connecting the data interface between safety zone I and zone IV and building a dedicated database. It completely replaces the cumbersome process of relying on manual querying, recording and calculation between multiple systems, greatly improves the efficiency and objectivity of analysis, and reduces the dependence on human experience. 2. This invention conducts a systematic quantitative analysis from two major aspects: "structural characteristics" and "load balance". It not only covers structural indicators such as the uniqueness of the main line and the configuration of segmented connections, but also innovatively evaluates the load distribution balance from three dimensions: section load, transformer capacity, and number of transformers. This overcomes the limitations of the one-sided and qualitative analysis of traditional methods and provides a comprehensive and accurate profile of the health status of the power grid. 3. This invention transforms complex operating procedures and expert experience into automatically executable judgment logic through an integrated standardized condition model, reverse power transmission analysis model, and multi-level protection verification model. It can directly output a definite conclusion on whether the standard is met, specific weak links, and targeted improvement suggestions. The analysis results are directly transformed into decision-making basis that can guide planning, operation and maintenance, and improvement, which significantly improves the level of lean management of the distribution network. 4. This invention fully relies on and expands upon the data and architecture of existing power distribution automation systems, without the need for additional hardware equipment. It focuses on software upgrades and service deployment, resulting in low investment costs, short implementation cycles, quick results, and easy promotion and application within the power industry. It provides an efficient technical tool for improving the reliability of power supply in power distribution networks, the absorption capacity of distributed power sources, and overall operational efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system structure of the present invention; Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0018] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0019] In this invention, terms such as "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "side," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any component or element in this invention. They should not be construed as limiting the invention.

[0020] Example: This embodiment provides an intelligent assessment and auxiliary decision-making system for power distribution network structure. Its physical deployment strictly adheres to the security protection regulations for power monitoring systems, such as... Figure 1 As shown, the entire system is deployed in the distribution automation system safety zone IV (management information zone).

[0021] Data Synchronization and Storage Module: Through a forward isolation device authorized and configured by the power company, it securely communicates with the distribution automation master station system located in Safety Zone I (production control zone). It is responsible for synchronizing the required distribution network model (CIM / G format), real-time / historical measurement data (such as current, voltage, power) and switch equipment attribute ledger from Zone I on a regular basis (e.g., every 15 minutes) or in response to requests. After the synchronized data is cleaned, transformed and correlated, it is stored in a dedicated relational database (i.e., distribution network information database) in Safety Zone IV, providing unified and standardized data services for upper-level analysis. Structural Feature Extraction Module: This module loads topology and equipment data from the database and performs network topology analysis based on graph theory algorithms. It is based on physical connections and uses the substation outgoing switch as the unique root node to automatically deduce the electrical connections of the entire line, which is the foundation for all subsequent analyses. Load balancing assessment module: This module has built-in calculation logic for different line types, calls measurement data and ledger data in the database, and executes statistical and calculation models for load, capacity, and quantity; The comprehensive analysis and reporting module integrates the standardized condition model, the reverse power transmission analysis model, and the multi-level protection verification model. It schedules and processes the output results of the aforementioned modules, makes comprehensive judgments according to predetermined logic, and generates a structured evaluation report. Human-computer interface: Provided in the form of a web application, authorized users (such as operation and maintenance team members) can log in to the system through their office computers, select the target line to start the analysis, view the details of the analysis process, and browse and export the final evaluation report; All analysis modules are deployed as software services or applications on the application server in Security Zone IV, interacting with the database through the internal network to ensure the security and efficiency of the analysis process.

[0022] The following uses an actual power distribution line named "10kV Guangming Line" as an example to illustrate in detail the implementation process of the method of this invention (e.g. Figure 2 As shown in the figure, this line is assumed to be a typical overhead line, including sectionalizing switches, tie switches and several distribution transformers.

[0023] S1. Data synchronization and database creation steps: The system executes its tasks automatically according to the plan. The data synchronization and storage module obtains the latest data packet for the "10kV Guangming Line" from the Safety Zone I distribution automation master station through a forward isolation device. This data packet includes: Topology and diagram data: Single-line diagram model of the line, including switches S1 (substation outgoing switch), A1, A2 (pole-mounted sectionalizing switch), A5 (pole-mounted tie switch) and their connection relationships; Measurement data: Real-time values ​​of phase A current of switches S1, A1, and A2 (e.g., S1: 250A, A1: 180A, A2: 100A) and historical daily maximum current values; Equipment attribute data: Functional attributes of all switches such as "section" and "connection", as well as the distribution transformer ledger to which the line belongs (including distribution transformer ID, location, rated capacity such as 315kVA, 500kVA, etc.). After these data are parsed and correlated, they are updated to the storage area corresponding to "10kV Guangming Line" in the "Distribution Network Information Database" to complete the data preparation.

[0024] S2. Structural Feature Extraction Steps: The structural feature extraction module reads the data for "10kV Guangming Line" from the database and starts the analysis: Topology analysis and segment division: Traversing with outgoing switch S1 as the root node, the attributes of switches A1 and A2 are identified as "segmentation switches", thus determining the main path as S1→A1→A2→end of the line. Based on the location of the segmentation switches, the main line is automatically divided into three power supply segments: segment 1 (between S1 and A1), segment 2 (between A1 and A2), and segment 3 (after A2). Extracting structural features: Determination of the uniqueness of the trunk line: Topology analysis confirms that there is only one trunk path starting from S1, and there are no other parallel trunks. Therefore, it is determined to be "the trunk line is unique". Installation method category identification: Checking the equipment ledger, switches A1, A2, and A5 are identified as "pole-mounted switches" without ring main units, therefore the installation method is determined to be "pure overhead line"; Section quantity calculation: For a pure overhead line, the section quantity is the number of main line sectionalizing switches plus 1. The sectionalizing switches on the main line are A1 and A2, with a quantity of 2. Therefore, the result of the section quantity is 3. Identification and classification of tie switches: Identify switch A5 as a "tie switch". Analyze its location, which is in section 3 (end), belonging to the "rear section". Further analysis of its topological connection to the other end reveals that its power supply comes from another substation ("Chengxi Substation"). According to the classification rules, this situation is classified as "effective tie between non-first section and other substations", and the result of the tie switch count is 1.

[0025] S3, Load Balancing Assessment Steps: The load balancing evaluation module evaluates the load from three dimensions based on the three segments divided by S2: Section load distribution assessment: Obtain the current values ​​of switches S1, A1, and A2 under the current operating section (assumed to be 250A, 180A, and 100A).

[0026] Applying the load calculation model: Calculate the load of section 1 = S1 current - A1 current = 250A - 180A = 70A; Calculate the load of section 2 = A1 current - A2 current = 180A - 100A = 80A; Calculate the load of section 3 = A2 current = 100A (assuming there are no other sectionalizing switches after A2). Calculate the total load = 70A + 80A + 100A = 250A (consistent with the current in S1); Calculate the load percentage for each section: Section 1 percentage = 70 / 250 = 28%; Section 2 percentage = 80 / 250 = 32%; Section 3 percentage = 100 / 250 = 40%; Output section load distribution parameters: [{Section 1: 70A, 28%}, ​​{Section 2: 80A, 32%}, {Section 3: 100A, 40%}]; Section transformer capacity distribution assessment: According to the ledger, the total capacity of the distribution transformers belonging to each section is calculated. Assuming that the total capacity of the distribution transformers in section 1 is 2000kVA, that in section 2 is 2500kVA, that in section 3 is 3000kVA, and that the total capacity of the lines is 7500kVA. Calculate the proportion of transformer capacity in each section: Section 1 proportion = 2000 / 7500 ≈ 26.7%; Section 2 proportion = 33.3%; Section 3 proportion = 40%; Output transformer capacity distribution parameters: [{Section 1: 2000kVA, 26.7%}; {Section 2: 2500kVA, 33.3%}; {Section 3: 3000kVA, 40%}; Section transformer quantity distribution assessment: Count the number of distribution transformers in each section. Assume that section 1 has 5 transformers, section 2 has 6 transformers, section 3 has 7 transformers, for a total of 18 transformers: The percentage of transformers in each section is calculated as follows: Section 1: ≈27.8%; Section 2: ≈33.3%; Section 3: ≈38.9%. Output transformer quantity distribution parameters: [{Section 1: 5 units, 27.8%}; {Section 2: 6 units, 33.3%}; {Section 3: 7 units, 38.9%}.

[0027] S4. Comprehensive Judgment and Report Generation Steps: The comprehensive analysis and reporting module receives all the output results from S2 and S3, starts the three core models for parallel analysis, and summarizes and generates a report. Operating the standardized condition model for the space frame: S71. Structural condition verification: (a) The only condition for the main line: According to the result of S2, it is "yes"; (b) Segmentation compliance conditions: S2 obtains 3 segments, the preset reasonable range is 3-5 segments (as per regional guidelines), 3≥3 and≤5, so it is judged as "yes"; (c) Communication compliance condition: S2 obtains 1 communication switch (≤ preset upper limit, such as 3), located in the later section, and it is a valid communication between different stations. Therefore, it is judged as "yes"; S72. Load balancing condition verification: Theoretical average percentage: For the three segments, the theoretical average is 33.3%; Preset allowable fluctuation range: set to ±20% of the theoretical average, i.e. [26.7%, 40%]; Verification of three dimensions: Load dimensions: The proportions of each section are 28%, 32%, and 40%, all within the acceptable range, and thus pass. Capacity dimension: The proportions of each segment are 26.7%, 33.3%, and 40%, all within the range and pass; Quantitative dimension: The proportions of each segment are 27.8%, 33.3%, and 38.9%, all within the range, and thus pass. At least one dimension (actually all three) passed the verification; S73, Comprehensive Judgment: Structural conditions: (a) is, (b) is, and (c) is; all three structural conditions are satisfied. Load balancing requirements: At least one dimension must pass the verification; Therefore, the "10kV Guangming Line" was determined to be a "standardized line"; Running the reverse power transmission analysis model: The model queries the database to obtain historical data on the direction of active power for all switches (S1, A1, A2, and branch switches) on the "10kV Guangming Line" within the query period (such as the most recent month). Statistics revealed that during the midday peak of photovoltaic power generation, a certain branch switch consistently exhibited negative active power (flowing to the substation), with the maximum reverse current recorded at 15A. Output backfeed analysis results: There is distributed power backfeeding in the line, with a maximum backfeed current of 15A, which occurs in the XX branch; Running a multi-level protection verification model: The model retrieves the protection setting data for all switches on the "10kV Guangming Line" from the database; Short-circuit three-level protection verification: Check the instantaneous overcurrent and overcurrent protection settings of outgoing switch S1 (level 1), sectionalizing switch A1 (level 2), and sectionalizing switch A2 (level 3). Verify whether the model satisfies the condition (S1) > (A1) > (A2), and whether the time setting coordination satisfies the condition (S1) > (A1) > (A2). Assume the verification passes. Grounding protection level 5 verification: Check the zero-sequence protection settings of S1, A1, A2, two important branch switches, and several user boundary switches. Verify whether there are at least five different delay periods and reasonable protection levels with matching settings. Assume that the verification found that user boundary switches are generally not configured with grounding protection, resulting in less than five protection levels. The multi-level protection analysis results show that the short-circuit three-level protection is fully configured and correctly coordinated; the grounding protection is only configured with three levels, which does not meet the five-level protection requirements; and the user's sectionalizing switch protection is missing. Generate the final evaluation report: The module integrates all the above results to generate a structured report, the core content of which includes: Basic information about the line: "10kV Guangming Line", a purely overhead line; Assessment conclusion: Standardized route; Detailed analysis: Structural assessment: There is only one main line, with 3 sections (meeting the standard), and the connection configuration meets the requirements for effective connection. Load balancing: All three evaluation dimensions show good results, indicating balanced distribution; Backfeeding situation: Distributed photovoltaic backfeeding exists, with a maximum of 15A. Overvoltage and other issues need to be monitored. Protection configuration: Short circuit protection configuration is adequate, but grounding protection level is insufficient; Renovation suggestions: Operational recommendations: For photovoltaic backfeeding, it is recommended to monitor the voltage of relevant nodes and optimize reactive power control strategies; Protection and rectification: It is recommended to add grounding protection function to the user's boundary switch and improve the five-level grounding protection sequence.

[0028] Extended explanations for different line types: 1. For hybrid circuits: If the main line includes one ring main unit (HW1) and one pole-mounted sectionalizing switch (A1), then according to the rules, the ring main unit HW1 is considered as a sectionalizing point, and the pole-mounted sectionalizing switch A1 is also a sectionalizing point. Therefore, the number of sections is calculated as follows: the number of sectionalizing points plus 1, that is, the sum of the number of ring main units (M) and the number of pole-mounted sectionalizing switches (N) plus 1. In this example, M=1 and N=1, so the number of sections is 1+1+1=3 sections. Section division and load calculation: After dividing the sections into S1-A1, A1-HW1, and HW1, the load calculation model still uses the current difference method. For example, the currents of S1 and A1 and the incoming switch current of HW1 are obtained and subtracted in turn to obtain the load of each section. Special rule application: If the first equipment on the line is a ring main unit, the "first section" (the section from the substation outgoing switch S1 to the first ring main unit HW1) is not included in the load balancing calculation. This is because this section is a cable outgoing section, and its electrical characteristics and load distribution pattern are fundamentally different from the sections that use overhead lines or mixed lines. It is not very meaningful to compare its balance with the subsequent sections in engineering, and it may distort the evaluation results. In this case, when calculating the theoretical average load ratio of each section, the denominator is adjusted to the total number of sections actually included in the calculation. This total number is the number of remaining sections excluding the first section that is not included in the calculation, that is, the sum of the number of sectionalizing switches (N) on the main line pole and the number of ring main units (M) (N+M+1). 2. For pure cable lines: Segmentation Analysis: According to the rules, pure cable lines do not undergo segmentation rationality analysis similar to that of overhead lines because their structure is based on ring main units, and the segmentation concept is different. Key node identification model: For example, a pure cable line has 3 ring main units (HW1, HW2, HW3). The model calculates the historical maximum current of the incoming line switch of each ring main unit. The highest historical current of the outgoing line switch in the station ratio Assuming a theoretical equilibrium distribution, the three ring main units... The ratio should be approximately 33.3%, with an allowable fluctuation range of ±20%, i.e. [26.7%, 40%]. If the calculated R1=30%, R2=35%, and R3=50%, then the ratio of HW1 and HW2 falls within the range and is identified as a "critical node"; the ratio of HW3 exceeds the limit, indicating that the branch is overloaded and unevenly distributed.

[0029] The above is a detailed description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for intelligent assessment and auxiliary decision-making of distribution network structure status, characterized in that, Includes the following steps: S1. Data synchronization and database construction steps: Establish the data interface between Safety Zone I and Safety Zone IV of the distribution automation system, synchronize the power grid topology, electrical measurement and switch attribute data in Safety Zone I to Safety Zone IV, and build a distribution network structure information database; S2. Structural feature extraction steps: Based on the distribution network grid information database, topology analysis is performed starting from the substation outgoing switch to extract the structural features of the target line, and the line is divided into sections according to the location of the sectionalizing switches on the main line. The extracted structural features include: the uniqueness determination result of the main line, the type of erection method, the number of segments calculated based on the number of segment switches, and the classification results of the number and location of tie switches; S3. Load balancing assessment steps: Based on the line sections divided in step S2, assess the load balance of each section from three dimensions: section load distribution, transformer capacity distribution, and transformer quantity distribution. The dimensionality of the load distribution in the section is obtained based on current measurement data through a load calculation model. The distribution dimensions of transformer capacity and transformer quantity are obtained based on statistics from transformer ledger data. S4. Comprehensive Judgment and Report Generation Steps: First, the structural features extracted in step S2 and the load distribution parameters evaluated in step S3 are input into a preset network standardization condition model for calculation, and the result of determining whether the line is standardized is output. The network standardization condition model integrates the verification of three structural conditions: the uniqueness of the trunk line, the standardization of the number of segments, and the standardization of the interconnection configuration, as well as the verification of at least one of the three load distribution dimensions satisfying the balance threshold condition. Secondly, based on the switching power direction data, the reverse power transmission analysis model is used to output the analysis results of the reverse power transmission situation of the distributed power source; Meanwhile, based on the protection setting data, a multi-level protection verification model is used to output the completeness analysis results of short-circuit and grounding protection configuration; Finally, by combining the judgment results and analysis results, a report on the status assessment and modification recommendations for the space frame is generated.

2. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 1, characterized in that, In step S2, the specific classification of the position of the tie switch includes: no tie, tie with the busbar in the first section, tie only in the first section, tie with the busbar in the non-first section, tie with the station in the non-first section, and effective tie at a different station in the non-first section.

3. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 1, characterized in that, In step S2, the erection method categories are specifically divided into: pure overhead lines with only pole-mounted switches as the main line equipment, pure cable lines with only ring main units as the main line equipment, and mixed lines with both ring main units and pole-mounted switches as the main line equipment.

4. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 3, characterized in that, In step S3, for pure overhead lines and mixed lines, the load calculation model is as follows: based on the section division, calculate the difference sequence composed of the current values ​​of the outgoing switch and each section switch to obtain the load value and proportion parameter of each section.

5. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 3, characterized in that, In step S3, for pure cable lines, the load balancing assessment specifically involves: running the critical node identification model, calculating the ratio of the incoming switch current of each ring main unit to the outgoing switch current in the station, and identifying ring main units whose ratio falls within the preset balancing range as critical nodes.

6. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 1, characterized in that, In step S3, the distribution parameters of the distribution transformer capacity and the distribution parameters of the distribution transformer quantity are obtained as follows: for each section divided in step S2, the total rated capacity and quantity of the distribution transformers connected to it are summarized, and its proportion relative to the total line is calculated.

7. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 1, characterized in that, The pre-set standardized condition model for the space frame in step S4 includes the following sub-steps in its calculation and judgment logic: S71. Structural Condition Verification: Determine whether the target line simultaneously meets the following three structural conditions: The only condition for the main trunk line: topology analysis shows that there is only one main trunk path from the substation outgoing switch; Segmentation compliance conditions: The number of main trunk segments of the line is within a preset reasonable range; For mixed lines, one ring main unit is considered as one segment; Connection compliance conditions: The connection switch configuration of the line conforms to the preset effective connection rules; the effective connection rules require that the number of connection switches does not exceed the preset upper limit, and that at least one connection switch is located in the middle or rear section of the line, and that the power supply on the opposite side of the connection switch comes from different substations; if the line is a pure cable line, then all its connection switches are automatic switches. S72. Load balancing condition verification: Determine whether there are at least one dimension of parameters in the three dimensions of section load distribution, transformer capacity distribution and transformer quantity distribution obtained in step S3 that meet the corresponding preset balancing threshold condition; the balancing threshold condition means that the parameter proportion of each section under this dimension is within an allowable fluctuation range centered on the theoretical average proportion. S73. Comprehensive Judgment: The model determines that the target line is a standardized line if and only if the target line passes all three structural conditions in step S71 and at least one load balancing condition in step S72; otherwise, it is determined to be a non-standardized line. For hybrid lines where the first section is the first ring network box, the first section is not included in the calculation when checking the load balancing conditions in step S72.

8. The intelligent assessment and auxiliary decision-making method for the state of a distribution network according to claim 1, characterized in that, The multi-level protection verification model in step S4 automatically identifies whether it meets the preset configuration requirements of three-level short-circuit protection and five-level grounding protection by comparing the coordination relationship between the protection settings and action time settings of outgoing switches, sectionalizing switches, branch switches and boundary switches in the line.

9. An intelligent assessment and auxiliary decision-making system for the distribution network structure status of implementing the method according to any one of claims 1 to 8, characterized in that, include: The data synchronization and storage module is used to execute the data synchronization and database building steps, and to establish and maintain the distribution network information database. The structural feature extraction module is used to perform the structural feature extraction steps and complete the line segment division and structural feature quantification. The load balancing assessment module is used to execute the load balancing assessment steps, run relevant calculation and statistical models, and output the load distribution parameters of the three dimensions. The comprehensive analysis and reporting module is used to perform the comprehensive judgment and report generation steps, integrate and run the standardized condition model, the reverse power transmission analysis model and the multi-level protection verification model, and generate an evaluation report.

10. The intelligent assessment and auxiliary decision-making system for the state of a distribution network according to claim 9, characterized in that, The system is deployed in the safety zone IV of the power distribution automation system; the data synchronization and storage module receives data from safety zone I through a forward isolation device; the structural feature extraction module, load balancing assessment module, and comprehensive analysis and reporting module provide services in the form of software applications.

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