Method and system for evaluating insulation degradation degree of distribution line section based on distribution master station

Abstract

The present invention discloses a method and system for evaluating the insulation degradation degree of distribution line intervals based on a distribution master station, including obtaining a distribution line to be analyzed; determining one or more intervals to be analyzed according to the area surrounded by all automation equipment under the distribution line; obtaining historical fault data and real-time data of each interval, wherein both the historical data and the real-time data include indicators associated with the occurrence of ground faults; determining the insulation degradation factor of each interval according to the historical fault data and the real-time data based on a preset insulation degradation evaluation model; and evaluating the insulation degradation degree of the interval of the distribution line according to the insulation degradation factor. The present invention can effectively analyze the insulation degradation of each interval under the distribution line, thereby realizing the monitoring of the insulation degradation degree of each interval of the distribution line and positioning within a fine range.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution automation, and in particular to a method and system for evaluating insulation degradation degree of distribution line sections based on a power distribution master station. Background Art

[0002] With the development of my country's economy and construction, the grid structure of the distribution network is also gradually changing and optimizing. However, at present, my country's medium-voltage distribution network is still mainly based on overhead lines, and the neutral point ungrounded system or the neutral point arc suppression coil grounding system is the largest in the existing distribution network in my country, with the highest proportion and the widest distribution, that is, the small current grounding system. In the small current grounding system, single-phase grounding faults are the most frequent distribution network faults, accounting for about 75% to 80% of the total number of distribution network faults. And single-phase grounding faults are very likely to cause secondary faults, forming phase-to-phase short-circuit faults, etc. Therefore, paying attention to single-phase grounding faults, analyzing and studying the occurrence of single-phase grounding faults is an important means to improve the reliability and continuity of power supply in the distribution network.

[0003] For single-phase grounding faults in distribution networks, the current stage is still mainly based on fault diagnosis at the time of grounding fault occurrence, that is, timely analysis can be performed when the fault occurs, and rapid fault line selection and fault interval determination can be achieved. However, for research before the single-phase grounding fault occurs, there is currently no particularly effective solution in China, and it is still in the stage of multi-party exploration. The insulation degradation evaluation of the distribution network can, to a certain extent, reflect the insulation change trend before the single-phase grounding fault occurs. Through trend analysis, the status warning before the single-phase grounding fault accident occurs can be achieved, and the insulation defects of power equipment can be discovered and repaired in time to avoid permanent insulation breakdown and reduce the probability and frequency of single-phase grounding faults. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method and system for evaluating the insulation degradation degree of distribution line sections based on a distribution master station, which performs a comprehensive evaluation on each section of the distribution line and can effectively analyze the insulation degradation of each section.

[0005] In a first aspect, a method for evaluating insulation degradation degree of a distribution line section based on a distribution master station according to an embodiment of the present invention comprises the following steps:

[0006] Obtain the power distribution line to be analyzed;

[0007] Determine one or more sections to be analyzed according to the area enclosed by all automation equipment under the power distribution line;

[0008] Acquire historical fault data and real-time data of each of the intervals, wherein both the historical data and the real-time data include indicators associated with the occurrence of a ground fault;

[0009] Based on a preset insulation degradation evaluation model, according to the historical fault data and the real-time data, determining the insulation degradation factor of each of the intervals;

[0010] The insulation degradation degree of the distribution line is evaluated according to the insulation degradation factor.

[0011] The method for evaluating the insulation degradation degree of distribution line sections based on a distribution master station according to an embodiment of the present invention has at least the following beneficial effects:

[0012] Taking the area surrounded by all the automation equipment under the distribution line as the interval unit, the insulation degradation degree of the distribution line is analyzed, and the insulation degradation factor of all the intervals in the distribution line is obtained. The insulation degradation degree is evaluated according to the insulation degradation factor. The insulation degradation situation of each interval can be effectively analyzed, so as to realize the monitoring of the insulation degradation degree of each interval of the distribution line and the positioning within a fine range.

[0013] According to some embodiments of the present invention, the historical fault data includes first statistical data, second statistical data and third statistical data, the first statistical data is used to characterize the statistical data of different types of characteristics related to ground faults, the second statistical data is used to characterize the statistical data of transient faults occurring in different time periods, and the third statistical data is used to characterize the statistical data between two transient faults.

[0014] According to some embodiments of the present invention, the historical fault data includes the number of weak fault signals of grounding characteristics, the number of overvoltages, the number of transient faults within three months, the number of transient faults within one day, the number of transient faults within two hours, the time interval between the last two transient faults, and the duration of the most recent transient fault.

[0015] According to some embodiments of the present invention, the real-time data includes a current ground resistance value and a zero-sequence voltage effective value.

[0016] According to some embodiments of the present invention, the method of determining the insulation degradation factor of each of the intervals based on the preset insulation degradation evaluation model according to the historical fault data and the real-time data comprises the steps of:

[0017] constructing a standardized matrix according to the historical fault data and the real-time data;

[0018] Based on the entropy weight method, determining an entropy weight matrix according to the standardized matrix;

[0019] The insulation degradation factor of each of the intervals is determined according to the standardized matrix and the entropy weight matrix.

[0020] According to some embodiments of the present invention, the step of evaluating the insulation degradation degree of the distribution line according to the insulation degradation factor includes:

[0021] The insulation degradation level of the distribution line is determined according to the insulation degradation factor and different degradation level thresholds.

[0022] According to some embodiments of the present invention, the step of evaluating the insulation degradation degree of the distribution line according to the insulation degradation factor further includes:

[0023] At least one of evaluation display and maintenance alarm is performed according to the evaluation result of the insulation degradation degree of the distribution line.

[0024] In a second aspect, a distribution line section insulation degradation degree evaluation system based on a distribution master station according to an embodiment of the present invention includes:

[0025] A line input module, used to obtain the power distribution line to be analyzed;

[0026] An interval determination module, used to determine one or more intervals to be analyzed according to the area surrounded by all automation equipment under the distribution line;

[0027] A data acquisition module, used to acquire historical fault data and real-time data of each of the intervals, wherein both the historical data and the real-time data include indicators associated with the occurrence of a ground fault;

[0028] A data calculation module, used to determine the insulation degradation factor of each of the intervals according to the historical fault data and the real-time data based on a preset insulation degradation evaluation model;

[0029] A degradation evaluation module is used to evaluate the insulation degradation degree of the distribution line according to the insulation degradation factor.

[0030] In a third aspect, an electronic device according to an embodiment of the present invention includes a processor, wherein the processor is used to execute the above-mentioned method steps for evaluating the degree of insulation degradation between distribution line sections based on a distribution master station.

[0031] In a fourth aspect, according to a computer-readable storage medium of an embodiment of the present invention, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for evaluating the degree of insulation degradation between distribution line sections based on a distribution master station are implemented.

[0032] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0034] Figure 1 This is one of the flow charts of the steps of the method for evaluating the insulation degradation degree of distribution line sections based on a distribution master station according to an embodiment of the present invention;

[0035] Figure 2 This is a second flow chart of the steps of the method for evaluating the insulation degradation degree of a distribution line section based on a distribution master station according to an embodiment of the present invention;

[0036] Figure 3 The schematic diagram is a principle block diagram of a distribution line section insulation degradation degree evaluation system based on a distribution master station according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0038] In the description of the present invention, "several" means one or more, "multiple" means more than two, greater than, less than, and exceeding are understood as not including the number itself, and "above", "below", and "within" are understood as including the number itself. If there is a description of "first", "second", etc., it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0039] In the description of the present invention, unless otherwise clearly defined, words such as “setting”, “installation” and “connection” should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0040] Example 1

[0041] Please refer to Figure 1, this embodiment discloses a method for evaluating the insulation degradation degree of distribution line intervals based on a distribution master station, including steps S100 to S500. Among them, before discussing the evaluation method of this embodiment in detail, it should be understood that the distribution master station, namely the distribution automation master station system (Master Station System of Distribution Automation), is the core part of the distribution automation system, which is mainly used to realize basic functions such as distribution network data collection and monitoring and extended functions such as power grid topology analysis applications, and has the function of information interaction with other application information systems, providing technical support for distribution network dispatching command and production management. The distribution master station is matched with the distribution terminal (Remote Terminal Unit of Distribution Automation System). The distribution terminal is a general term for various remote monitoring and control units installed at the site of the medium-voltage distribution network. The distribution terminal mainly includes the distribution switch monitoring terminal (i.e. FTU, feeder terminal), the distribution transformer monitoring terminal (i.e. TTU, distribution transformer terminal), the switch station and the monitoring terminal of the public and customer distribution station (i.e. DTU, station terminal), etc. The distribution terminal is an automated device installed under the distribution line, which can communicate with the distribution master station. The distribution circuit refers to the line that sends power from the step-down substation to the distribution transformer or sends power from the distribution substation to the power user. The following is a detailed discussion of each step.

[0042] S100: Obtain a power distribution line to be analyzed.

[0043] Please refer to Figure 2 In this embodiment, the distribution line is acquired by pushing from the main station side of the distribution master station. For example, in the daily operation process, the main station side sorts multiple distribution lines in chronological order. When a 10KV distribution line needs to be analyzed for insulation degradation, the distribution line ID of the 10KV distribution line is pushed to obtain the distribution line to be analyzed. Of course, the user can input the distribution line ID according to actual needs to obtain the distribution line to be analyzed. It should be noted that after obtaining the distribution line with analysis, the distribution line to be analyzed can also be confirmed. When the distribution line to be analyzed is an automated line, step S200 is executed.

[0044] S200. Determine one or more sections to be analyzed according to the area enclosed by all automation equipment under the power distribution line.

[0045] In the distribution network, typical grid structures mainly include radial overhead grids, "hand in hand" ring overhead grids, multi-segment multi-connection grids, etc. Taking the radial overhead grid as an example, the radial overhead grid is composed of several unconnected radial overhead feeders, each of which is a 10KV outgoing line switch of the main substation as the power source point and is arranged in a tree-like manner. The radial overhead feeder can also be divided into many feeder segments by using a segment switch. Each segment switch is equipped with a corresponding feeder terminal (automation equipment). Two adjacent feeder terminals divide the distribution line into an independent area, which is an interval. By analogy, multiple segment switches on the distribution line can divide the distribution line into multiple intervals. It should be conceived that for distribution lines with other grid structures (such as multi-segment multi-connection), other switch devices, such as connecting switches, can also be set, and the automation equipment installed on the adjacent switch devices can also separate the distribution line into an interval.

[0046] S300: Acquire historical fault data and real-time data of each interval, wherein both the historical data and the real-time data include indicators associated with the occurrence of a ground fault.

[0047] In the small current grounding system of the distribution network, single-phase grounding faults occur most frequently. When a single-phase grounding fault occurs, the small current grounding system mainly has the following characteristics: for line voltage, the phase-to-phase voltage is still symmetrical and has no impact on users; for phase voltage, the voltage of the fault phase decreases, and the voltage of the non-fault phase increases. When single-phase metallic grounding is performed, the voltage of the fault phase is zero, and the voltage of the non-fault phase increases to the line voltage value (overvoltage). In this way, when evaluating the degree of insulation degradation, effective parameters can be selected for analysis based on the characteristics of the single-phase grounding fault. For example, the historical fault data of this embodiment includes first statistical data, and the first statistical data is used to characterize statistical data of different types of characteristics related to grounding faults. Specifically, the first statistical data includes the number of weak fault signals of grounding characteristics and the number of overvoltages. In order to further improve the accuracy of insulation degradation evaluation, the historical fault data of this embodiment also includes second statistical data and third statistical data. The second statistical data is used to characterize the statistical data of instantaneous faults in different time periods, and the third statistical data is used to characterize the statistical data between two instantaneous faults. Specifically, the second statistical data includes the number of instantaneous faults within three months, the number of instantaneous faults within one day, and the number of instantaneous faults within two hours. The third statistical data includes the time interval between the last two instantaneous faults and the duration of the most recent instantaneous fault. In this embodiment, the second statistical data selects indicators with a larger time span as analysis parameters, the indicators have a relatively obvious stage stratification, and the indicator range is wide enough, which is conducive to improving the accuracy of the analysis.

[0048] Different from the ground fault diagnosis method, the evaluation method of this embodiment is applied before the ground fault occurs, so the real-time data used for analysis can include static parameters and dynamic parameters. For example, the real-time data of this embodiment includes the current ground resistance value and the zero-sequence voltage effective value, and the combination of multiple parameters is conducive to the accuracy of the analysis.

[0049] According to the characteristics of the single-phase grounding fault, this embodiment combines the historical fault data and the real-time data and uses them as the analysis index, which can improve the accuracy of the subsequent analysis. In addition, according to the characteristics of the single-phase grounding fault, this embodiment reasonably determines the first statistical data, the second statistical data and the third statistical data from a large number of indicators, and selects effective analysis indicators, which is conducive to further improving the rationality and accuracy of the subsequent analysis.

[0050] S400, based on a preset insulation degradation evaluation model, according to historical fault data and real-time data, determine the insulation degradation factor of each interval.

[0051] This embodiment determines the insulation degradation factor according to historical fault data and real-time data, which can provide a quantitative analysis basis for insulation degradation analysis, thereby quantitatively analyzing the abstract insulation degradation degree. Among them, the insulation degradation evaluation model is a comprehensive evaluation model based on the TOPSIS method (echnique for Order Preference by Similarity to an IdealSolution) and entropy weight correction. The basic model is constructed using the TOPSIS method, and the entropy weight method is applied to objectively assign weights to each indicator in the basic model, thereby correcting the data reliability problem of the weight assignment of each indicator of the TOPSIS method. Among them, the historical fault data and real-time data as input parameters of the insulation degradation evaluation model can be obtained and dynamically updated in real time, and the input parameters remove constants that depend on experience settings, which is convenient for later setting and improves the objectivity and accuracy of analysis.

[0052] The following will discuss step S400 in detail based on the construction process of the insulation degradation evaluation model, wherein step S400 includes steps S410 to S430.

[0053] The TOPSIS method is a commonly used comprehensive evaluation method within a group. It can make full use of the information of the original data. Its results can accurately reflect the gap between the evaluation schemes. This method has no strict restrictions on data distribution and sample content, and data calculation is simple and easy.

[0054] The TOPSIS method uses a distance scale to measure sample gaps. The use of a distance scale requires the index attributes to be processed in the same direction. The index types of the TOPSIS method include extremely large and extremely small. The extremely large value means that the larger the expected index value, the better. On the contrary, the extremely small value means that the smaller the expected index value, the better. Please refer to Table 1. According to the degree of influence of different data on the occurrence of ground faults, this embodiment determines the index type of each parameter in the historical fault data and the real-time data.

[0055] Table 1

[0056] Serial number Insulation degradation evaluation model indicators Indicator Type 1 Number of weak ground fault signal Very large 2 Overvoltage times Very large 3 Number of transient failures within three months Very large 4 Number of instantaneous faults in one day Very large 5 Number of instantaneous faults within two hours Very large 6 Time interval between two recent transient faults Very small 7 Duration of the most recent transient fault Very large 8 Current ground resistance value Very small 9 Zero sequence voltage effective value Very large

[0057] S410. Construct a standardized matrix based on historical fault data and real-time data.

[0058] According to Table 1, the number of indicators of the insulation degradation evaluation model is 9. Assuming that the distribution line has n (n ≥ 1) intervals, the indicator parameters of the n intervals (i.e., historical fault data and real-time data) can form the following judgment matrix:

[0059]

[0060] In the formula, each row represents the 9 index parameters of each interval under the distribution line.

[0061] When applying the TOPSIS method, it is usually necessary to convert extremely small indicators into extremely large indicators. Since all indicators in the matrix X are positive numbers, the forward conversion formula is:

[0062]

[0063] In the formula, x′ nm is the element of the mth element in the nth row of the matrix X after normalization, then the normalized matrix is ​​recorded as X', and the jth element in the i-th row of the matrix X' is recorded as x' ij .

[0064] The matrix X' is normalized to obtain the normalized matrix Z. The jth element in the i-th row of the normalized matrix Z is denoted as Z ij ,but

[0065]

[0066]

[0067] S420: Based on the entropy weight method, determine the entropy weight matrix according to the standardized matrix.

[0068] According to the standardized matrix, determine the probability matrix P, where the elements in P are p ij ,

[0069]

[0070] Then the probability matrix P

[0071]

[0072] Determine the information entropy e of each indicator according to the probability matrix P j and entropy weight E, where e j is the information entropy of the jth index, then

[0073]

[0074] E=[e1 e2 … e9] (8)

[0075] Determine the information utility value d based on the information entropy matrix j and information utility matrix D, then

[0076] d j =1-e j (9)

[0077] D=[d1 d2 … d9] (10)

[0078] Determine the entropy weight ω of each indicator according to the information utility matrix D j And the entropy weight matrix W, then

[0079]

[0080] W=[ω1 ω2 … ω9] (12)

[0081] S430: Determine the insulation degradation factor of each interval according to the normalization matrix and the entropy weight matrix.

[0082] According to the standardized matrix, determine the maximum value matrix Z in the jth index max and the minimum matrix Z min ,but

[0083] Z max =[max{z 11 ,z 21 ,…,z n1 max{z 12 ,z 22 ,…,z n2} … max{z 19 ,z 29 ,…,z n9}]

[0084] Z min =[min{z 11 ,z21 ,…,z n1 min{z 12 ,z 22 ,…,z n2} … min{z 19 ,z 29 ,…,z n9}]

[0085] In the formula, max is the maximum value operation, and min is the minimum value operation.

[0086] Determine the matrix Z between each element in the i-th interval and the maximum value max The corresponding maximum value in Distance And determine the relationship between each element in the i-th interval and the minimum matrix Z min The corresponding minimum value in The distance between And use entropy weight ω j Correction, then

[0087]

[0088]

[0089] According to distance and distance Determine the insulation degradation factor φ of the i-th interval i ,

[0090]

[0091] Then the insulation degradation factor matrix of each section of the distribution line is recorded as

[0092]

[0093] In the insulation degradation factor matrix, as long as the insulation degradation factor φ i If it is within the preset degradation range, the corresponding section under the distribution line can be determined as the insulation degradation section.

[0094] S500. Evaluate the insulation degradation degree of the distribution line according to the insulation degradation factor.

[0095] This embodiment performs a visual evaluation on the abstract insulation degradation degree so that the user can intuitively understand the insulation degradation degree. The visual evaluation includes displaying the insulation degradation degree in the form of numerical values, tables or graphs. Specifically, step S500 includes step S510,

[0096] S510: Determine the interval insulation degradation level of the distribution line according to the insulation degradation factor and different degradation level thresholds.

[0097] For example, the insulation degradation levels are divided into severe, general and mild, and each level is set with a corresponding threshold range. According to the size of the insulation degradation factor, the level corresponding to the insulation degradation degree of the distribution line interval can be determined, so as to perform quantitative analysis.

[0098] Step S500 further includes step S520,

[0099] S520. Execute at least one of evaluation display and maintenance alarm according to the evaluation result of the insulation degradation degree of the distribution line section.

[0100] According to the evaluation results, combined with the distribution automation system, the sections with insulation degradation can be displayed through alarms, and the abstract insulation degradation degree can be digitized and visualized, so that maintenance personnel can quickly locate the sections that need maintenance and improve work efficiency. It is also possible to issue maintenance alarms for sections with high insulation degradation, so that active maintenance can be carried out before the grounding fault occurs, which is conducive to reducing the probability of single-phase grounding faults caused by insulation degradation and the probability of secondary grounding faults.

[0101] This embodiment provides a complete set of evaluation strategies for determining the insulation degradation degree of a 10KV line in a distribution network. The entropy weight method is used to adjust the weights of indicators related to ground faults, such as the number of ground characteristic weak faults, the number of overvoltages, the number of instantaneous faults within three months, the number of instantaneous faults within one day, the number of instantaneous faults within two hours, the time interval between the last two instantaneous faults, and the duration of the most recent instantaneous fault, the current grounding resistance value, and the effective value of the zero-sequence voltage. The weights of the indicators are adjusted based on the original global data of the distribution line to obtain the weight relationship matrix of each indicator parameter in the insulation degradation degree evaluation. At the same time, the TOPSIS method is used to analyze the insulation degradation degree of the distribution line with the area surrounded by all automation equipment under the distribution line as the interval unit, and the insulation degradation factors of all intervals in the distribution line are obtained. The insulation degradation degree is evaluated according to the insulation degradation factor, which can effectively analyze the insulation degradation of each interval, thereby realizing the monitoring of the insulation degradation degree of each interval of the distribution line and positioning within a fine range. Ultimately, the insulation degradation monitoring of each section of the distribution line can be realized, the degree of insulation degradation is transformed from an abstract process to a data visualization process, and the insulation degradation section is represented in the form of an alarm, which is conducive to the timely maintenance of the distribution line, thereby improving the safety of the distribution network operation.

[0102] Example 2

[0103] Please refer to Figure 3The embodiment of the present invention discloses a distribution line section insulation degradation degree evaluation system based on a distribution master station, including a line input module 100, a section determination module 200, a data acquisition module 300, a data calculation module 400 and a degradation evaluation module 500:

[0104] The line input module 100 is used to obtain the power distribution line to be analyzed;

[0105] The interval determination module 200 is used to determine one or more intervals to be analyzed according to the area surrounded by all automation equipment under the distribution line;

[0106] The data acquisition module 300 is used to acquire historical fault data and real-time data of each interval, wherein both the historical data and the real-time data include indicators associated with the occurrence of ground faults;

[0107] The data calculation module 400 is used to determine the insulation degradation factor of each interval based on the preset insulation degradation evaluation model according to the historical fault data and the real-time data;

[0108] The degradation evaluation module 500 is used to evaluate the insulation degradation degree of the distribution line according to the insulation degradation factor.

[0109] This embodiment uses the area surrounded by all automation equipment under the distribution line as the interval unit, analyzes the insulation degradation degree of the distribution line, obtains the insulation degradation factor of all intervals in the distribution line, and evaluates the insulation degradation degree according to the insulation degradation factor, which can effectively analyze the insulation degradation of each interval, thereby realizing the monitoring and fine-range positioning of the insulation degradation degree of each interval of the distribution line. Finally, the insulation degradation monitoring of each interval of the distribution line is realized, the insulation degradation degree is transformed from abstract to data visualization, and the insulation degradation interval is expressed in the form of an alarm, which is conducive to the timely maintenance of the distribution line, thereby improving the safety of the distribution network operation.

[0110] It should be noted that the distribution line section insulation degradation degree evaluation system based on the distribution master station of this embodiment is a general model of the distribution line section insulation degradation degree evaluation method based on the distribution master station of Example 1. Therefore, the contents not involved in this embodiment can refer to Example 1 and will not be repeated in this embodiment.

[0111] Example 3

[0112] An embodiment of the present invention discloses an electronic device, comprising a processor, wherein the processor is used to execute the above-mentioned method steps for evaluating the insulation degradation degree of a distribution line section based on a distribution master station.

[0113] It should be noted that the contents not mentioned in this embodiment regarding the method for evaluating the degree of insulation degradation of distribution line sections based on the power distribution master station can be referred to in Example 1, and will not be repeated in this embodiment.

[0114] Example 4

[0115] An embodiment of the present invention discloses a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the above-mentioned method for evaluating the degree of insulation degradation of distribution line sections based on a distribution master station are implemented.

[0116] It should be noted that the contents not mentioned in this embodiment regarding the method for evaluating the degree of insulation degradation of distribution line sections based on the power distribution master station can be referred to in Example 1, and will not be repeated in this embodiment.

[0117] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for evaluating insulation degradation degree of distribution line sections based on a distribution master station, characterized in that: Includes steps: Obtain the power distribution line to be analyzed; Determine one or more sections to be analyzed according to the area enclosed by all automation equipment under the power distribution line; Acquire historical fault data and real-time data of each of the intervals, wherein the historical fault data and the real-time data both include indicators associated with the occurrence of a ground fault; Based on a preset insulation degradation evaluation model, according to the historical fault data and the real-time data, determining the insulation degradation factor of each of the intervals; Evaluating the insulation degradation degree of the distribution line according to the insulation degradation factor; The historical fault data includes first statistical data, second statistical data and third statistical data, wherein the first statistical data is used to characterize the statistical data of different types of faults caused by ground faults, the second statistical data is used to characterize the statistical data of instantaneous faults in different time periods, and the third statistical data is used to characterize the statistical data between two instantaneous faults; The historical fault data includes the number of grounding characteristic weak fault signals, the number of overvoltages, the number of transient faults within three months, the number of transient faults within one day, the number of transient faults within two hours, the time interval between the last two transient faults, and the duration of the most recent transient fault; The real-time data includes the current grounding resistance value and the effective value of the zero-sequence voltage; The method of determining the insulation degradation factor of each of the intervals based on the preset insulation degradation evaluation model according to the historical fault data and the real-time data comprises the following steps: According to the historical fault data and the real-time data, a standardized matrix Z is constructed. , Where n≥1; Based on the entropy weight method, the entropy weight matrix W is determined according to the standardized matrix. W = [ω1 ω2 … ω9]; Determining the insulation degradation factor of each of the intervals according to the standardized matrix Z and the entropy weight matrix W; According to the standardized matrix Z, determine the maximum value matrix Z in the jth index max and the minimum matrix Z min ,but Z max ＝ [max{z 11 ,With 21 ,…,With n1 }max{from 12 ,With 22 ,…,With n2 }…max{of 19 ,With 29 ,…,With n9 }], With min =[min{z 11 ,With 21 ,…,With n1 }min{z 12 ,With 22 ,…,With n2 }…min{z 19 ,With 29 ,…,With n9 }] Wherein, j = (1, 2, ..., 9), max is the maximum value operation, and min is the minimum value operation; Determine the matrix Z between each element in the i-th interval and the maximum value max The corresponding maximum value in Distance And determine the relationship between each element in the i-th interval and the minimum matrix Z min The corresponding minimum value in The distance between And use entropy weight ω j Correction, then According to distance and distance Determine the insulation degradation factor φ of the i-th interval i , , Then the insulation degradation factor matrix of each section of the distribution line is recorded as The step of evaluating the insulation degradation degree of the distribution line according to the insulation degradation factor includes: The insulation degradation level of the distribution line is determined according to the insulation degradation factor and different degradation level thresholds.

2. The method for evaluating insulation degradation degree of distribution line sections based on a distribution master station according to claim 1, characterized in that: The step of evaluating the insulation degradation degree of the distribution line according to the insulation degradation factor includes: At least one of evaluation display and maintenance alarm is performed according to the evaluation result of the insulation degradation degree of the distribution line.

3. A distribution line section insulation degradation evaluation system based on a distribution master station, characterized in that: The evaluation system is used to implement the method for evaluating the degree of insulation degradation of distribution line sections based on a distribution master station according to claim 1 or 2, and comprises: A line input module, used to obtain the power distribution line to be analyzed; An interval determination module, used to determine one or more intervals to be analyzed according to the area surrounded by all automation equipment under the distribution line; A data acquisition module, used to acquire historical fault data and real-time data of each of the intervals, wherein the historical fault data and the real-time data both include indicators associated with the occurrence of a ground fault; A data calculation module, used to determine the insulation degradation factor of each of the intervals according to the historical fault data and the real-time data based on a preset insulation degradation evaluation model; A degradation evaluation module is used to evaluate the insulation degradation degree of the distribution line according to the insulation degradation factor.

4. An electronic device, comprising a processor, characterized in that: The processor is used to execute the steps of the method for evaluating the degree of insulation degradation of distribution line sections based on a distribution master station as described in any one of claims 1 to 2.

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the degree of insulation degradation of a distribution line section based on a distribution master station as described in any one of claims 1 to 2 are implemented.

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