Method and system for identifying insulation abnormity of secondary cable of power system

Abstract

The invention discloses a power system secondary cable insulation abnormity identification method and system, and relates to the technical field of power system protection, and the method comprises the steps: obtaining an insulation resistance data set of a power system secondary cable; judging whether the range of the insulation resistance data set exceeds a first preset threshold value or not; if yes, determining an interval coefficient based on the range, and determining a plurality of insulation resistance intervals based on the interval coefficient; respectively counting the number of the insulation resistance data of the insulation resistance data set in each insulation resistance interval; whether a target insulation resistance interval with the insulation resistance data number larger than zero and smaller than a second preset threshold exists or not is judged; if yes, whether the insulation resistance interval adjacent to the target insulation resistance interval meets the judgment condition based on a third preset threshold value or not is judged; and if yes, determining that the secondary cable in the target insulation resistance interval has insulation abnormity. According to the invention, the technical problems of complex operation and low anomaly detection accuracy in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of power system protection technology, specifically to a method and system for identifying insulation anomalies in secondary cables of a power system. Background Technology

[0002] As crucial components for signal transmission and power supply, secondary cables play a vital role in power systems. During operation, they are subject to both inherent limitations due to the electrical, load, and aging characteristics of the cable materials themselves, and external influences such as temperature, humidity, mechanical stress, and high-voltage, high-current surges. These factors contribute to the risk of damage to secondary cables, leading to varying degrees of insulation degradation and potentially causing faults such as short circuits to ground or inter-core short circuits, thus affecting the safe and reliable operation of the power system. Therefore, monitoring insulation anomalies in secondary cables is extremely important.

[0003] Currently, the main methods for monitoring insulation anomalies in secondary cables are: 1) feature identification based on signal injection, and 2) threshold comparison based on insulation resistance. The former involves periodically injecting specific signals into the cable circuit and locating insulation faults through feature analysis of the feedback quantities. This method requires additional excitation, is relatively complex to operate, and carries the risk of affecting normal system operation. The latter collects insulation resistance values ​​and compares them with a set alarm threshold; if the value exceeds the preset threshold, an insulation anomaly is identified. While this method is simple to operate, it can only perform static real-time comparisons and cannot analyze trends and anomaly characteristics. By the time an anomaly is detected, an insulation fault has already occurred. Therefore, it is necessary to improve insulation anomaly identification methods to enhance operational efficiency and reduce the failure rate. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for identifying insulation anomalies in secondary cables of a power system in order to solve at least one of the above-mentioned technical problems.

[0005] In a first aspect, embodiments of the present invention provide a method for identifying insulation anomalies in secondary cables of a power system, comprising: acquiring an insulation resistance dataset of secondary cables in a power system; the insulation resistance dataset includes multiple insulation resistance data, each insulation resistance data corresponding to a secondary cable in the power system, each insulation resistance data including the positive-to-ground insulation resistance and the negative-to-ground insulation resistance of the secondary cable; determining whether the range of the insulation resistance dataset exceeds a first preset threshold; the range includes the difference between the maximum and minimum values ​​of the positive-to-ground insulation resistance and the difference between the maximum and minimum values ​​of the negative-to-ground insulation resistance; if so, determining an interval coefficient based on the range, and determining multiple insulation resistance intervals based on the interval coefficient; counting the number of insulation resistance data falling into each insulation resistance interval; determining whether there exists a target insulation resistance interval with a number of insulation resistance data greater than zero and less than a second preset threshold; if so, determining whether adjacent insulation resistance intervals of the target insulation resistance interval meet a judgment condition based on a third preset threshold; if so, determining that the secondary cable in the target insulation resistance interval has an insulation anomaly.

[0006] Optionally, determining the interval coefficient based on the range includes: determining the segmentation coefficient based on a preset constraint relationship satisfied between the segmentation coefficient and the window coefficient; the window coefficient being the total number of the secondary cables; and determining the interval coefficient based on the range and the segmentation coefficient; wherein the preset constraint relationship includes: The interval coefficients include: In the formula, L is the segmentation coefficient, M is the window coefficient, a and b are the interval coefficients, and R... pmax and R pmin R represents the maximum and minimum values ​​of the insulation resistance to ground, respectively. nmax and R nmin These are the maximum and minimum values ​​of the negative-to-ground insulation resistance, respectively.

[0007] Optionally, the plurality of insulation resistance ranges include: In the formula, X i,j Represents the insulation resistance range, where i and j are range indices, and R p and R n These represent the positive insulation resistance to ground and the negative insulation resistance to ground, respectively.

[0008] Optionally, the judgment condition based on the third preset threshold includes: In the formula, C i-1,j-1 C i-1,j C i-1,j+1 C i,j-1 C i,j+1 C i+1,j-1 C i+1,j C i+1,j+1 These represent the insulation resistance range X. i,j The number of insulation resistance data within adjacent insulation resistance intervals, where V is the third preset threshold.

[0009] Secondly, embodiments of the present invention also provide a power system secondary cable insulation anomaly identification system, used to implement a power system secondary cable insulation anomaly identification method provided in embodiments of the present invention; the system includes: an acquisition module, a first judgment module, a determination module, a statistics module, a second judgment module, and an identification module; wherein, the acquisition module is used to acquire an insulation resistance dataset of power system secondary cables; the insulation resistance dataset includes multiple insulation resistance data, each insulation resistance data corresponding to a power system secondary cable, and each insulation resistance data includes the positive-to-ground insulation resistance and the negative-to-ground insulation resistance of the secondary cable; the first judgment module is used to determine whether the range of the insulation resistance dataset exceeds a first preset threshold; the range includes the difference between the maximum and minimum values ​​of the positive-to-ground insulation resistance and the negative-to-ground insulation resistance. The difference between the maximum and minimum resistance values; the determining module is used to determine an interval coefficient based on the range if the range exceeds the first preset threshold, and to determine multiple insulation resistance intervals based on the interval coefficient; the statistics module is used to count the number of insulation resistance data points that fall into each insulation resistance interval; the second judgment module is used to determine whether there is a target insulation resistance interval with a number of insulation resistance data points greater than zero and less than the second preset threshold; the identification module is used to determine whether the adjacent insulation resistance intervals of the target insulation resistance interval meet the judgment condition based on the third preset threshold if there is a target insulation resistance interval with a number of insulation resistance data points greater than zero and less than the second preset threshold; if so, it is determined that the secondary cable in the target insulation resistance interval has an insulation abnormality.

[0010] Thirdly, embodiments of the present invention also provide an electronic device, including: a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the method provided in the embodiments of the present invention.

[0011] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the method provided in the embodiments of the present invention.

[0012] This invention provides a method and system for identifying insulation anomalies in secondary cables of a power system. By performing partitioned statistical analysis and logical analysis on the insulation resistance data of secondary cables in a power system, it achieves simple and efficient identification of insulation anomalies, alleviating the technical problems of complex operation and low anomaly detection accuracy in existing technologies. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 A flowchart of a method for identifying insulation anomalies in secondary cables of a power system, provided as an embodiment of the present invention; Figure 2 This is a schematic diagram of a power system secondary cable insulation anomaly identification system provided in an embodiment of the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1 Figure 1 This is a flowchart of a method for identifying insulation anomalies in secondary cables of a power system according to an embodiment of the present invention. Figure 1 As shown, the method specifically includes the following steps: Step S102: Obtain the insulation resistance dataset of the secondary cables in the power system.

[0017] Specifically, the insulation resistance dataset includes multiple insulation resistance data points, each corresponding to a secondary cable in a power system. Each insulation resistance data point includes the positive-to-ground insulation resistance and the negative-to-ground insulation resistance of the secondary cable.

[0018] In an optional embodiment provided by this invention, the insulation resistance data includes: {(R p1 R n1 ), (R p2 R n2 ), ..., (R) pk Rnk ), ..., (R) pM R nM )}, where R p R represents the insulation resistance to ground. n This represents the negative insulation resistance to ground. The subscript k is the serial number, which satisfies 1≤k≤M, where M is the window coefficient, i.e., the total number of secondary cables.

[0019] Step S104: Determine whether the range of the insulation resistance dataset exceeds the first preset threshold; if so, proceed to step S106.

[0020] The range includes the difference between the maximum and minimum values ​​of the positive-to-ground insulation resistance and the difference between the maximum and minimum values ​​of the negative-to-ground insulation resistance.

[0021] Specifically, first determine the maximum value R of the insulation resistance to ground. pmax Minimum value R pmin The maximum value of the negative insulation resistance to ground, R nmax Minimum value R nmin Then determine whether the following relationship is satisfied: In the formula, " indicates "or, where T is the first preset threshold.

[0022] Step S106 involves determining interval coefficients based on the range, and then determining multiple insulation resistance intervals based on these interval coefficients. Specifically, determining the interval system based on the range includes the following steps: Step S1061: Determine the segmentation coefficient based on the preset constraint relationship between the segmentation coefficient and the window coefficient; the window coefficient is the total number of secondary cables. Step S1063: Determine the interval coefficients based on the range and the segmentation coefficient.

[0023] The preset constraint relationships include: Interval coefficients include: In the formula, L is the segmentation coefficient, M is the window coefficient, a and b are the interval coefficients, and R... pmax and R pmin R represents the maximum and minimum values ​​of the insulation resistance to ground, respectively. nmax and R nmin These are the maximum and minimum values ​​of the negative-to-ground insulation resistance, respectively.

[0024] Specifically, the multiple insulation resistance ranges include: In the formula, X i,j Represents the insulation resistance range, where i and j are range indices, and R... p and R n These represent the positive insulation resistance to ground and the negative insulation resistance to ground, respectively.

[0025] Step S108: Count the number of insulation resistance data points that fall within each insulation resistance range of the insulation resistance dataset.

[0026] Step S110: Determine whether there is a target insulation resistance range where the number of insulation resistance data is greater than zero and less than the second preset threshold; if so, proceed to step S112.

[0027] Specifically, determine whether the following conditions are met: In the formula, C i,j For falling within the insulation resistance range X i,j The number of insulation resistance data within, where U is the second preset threshold.

[0028] Step S112: Determine whether the adjacent insulation resistance intervals of the target insulation resistance interval meet the judgment condition based on the third preset threshold; if so, proceed to step S114.

[0029] Specifically, the judgment conditions based on the third preset threshold include: In the formula, C i-1,j-1 C i-1,j C i-1,j+1 C i,j-1 C i,j+1 C i+1,j-1 C i+1,j C i+1,j+1 These represent the insulation resistance range X. i,j The number of insulation resistance data points within adjacent insulation resistance intervals, where V is the third preset threshold. It should be noted that when the index i=0, the i-1 related items are not included; when i=L, the i+1 related items are not included; when the index j=0, the j-1 related items are not included; when j=L, the j+1 related items are not included.

[0030] Step S114: Determine that there is an insulation abnormality in the secondary cable within the target insulation resistance range. Optionally, an insulation abnormality alarm may be issued simultaneously.

[0031] This invention provides a method for identifying insulation anomalies in secondary cables of a power system. The method uses three levels of discrimination conditions to identify insulation anomalies in secondary cables. The specific principle of insulation anomaly identification is as follows: (1) Based on the first-level discrimination condition (i.e. step S104), determine whether the overall deviation of the positive and negative insulation resistance of the secondary cable to ground is within the threshold range. If the deviation is too large, it means that some cables may have insulation abnormalities, and proceed to the second-level discrimination for further analysis.

[0032] (2) Based on the second-level discrimination condition (i.e. step S110), the positive and negative insulation resistance to ground is divided into intervals, and the cable distribution in each interval is analyzed. When the number of cables falling into a certain interval is less than the threshold, it means that these cables may have insulation abnormalities, and the third-level discrimination is further confirmed.

[0033] (3) Expand the analysis interval by using the third-level discrimination condition (i.e., step S112) to include directly adjacent intervals in the statistics for final determination. If the number of cables is still less than the threshold after including adjacent intervals, then the cable insulation in the intervals selected in the second-level discrimination condition is determined to be abnormal.

[0034] This invention achieves simple and efficient identification of insulation anomalies by performing partitioned statistical analysis and logical analysis on the insulation resistance data of secondary cables in power systems, thus alleviating the technical problems of complex operation and low accuracy of anomaly detection in existing technologies.

[0035] Example 2 Figure 2 This is a schematic diagram of a power system secondary cable insulation anomaly identification system provided according to an embodiment of the present invention. Figure 2 As shown, the system includes: an acquisition module 10, a first judgment module 20, a determination module 30, a statistics module 40, a second judgment module 50, and an identification module 60.

[0036] Specifically, module 10 is used to acquire the insulation resistance dataset of the secondary cable of the power system. The insulation resistance dataset includes multiple insulation resistance data, each insulation resistance data corresponds to a secondary cable of the power system, and each insulation resistance data includes the positive insulation resistance to ground and the negative insulation resistance to ground of the secondary cable.

[0037] The first judgment module 20 is used to determine whether the range of the insulation resistance dataset exceeds a first preset threshold; the range includes the difference between the maximum and minimum values ​​of the positive ground insulation resistance and the difference between the maximum and minimum values ​​of the negative ground insulation resistance.

[0038] The determining module 30 is used to determine interval coefficients based on the range if the range exceeds a first preset threshold, and to determine multiple insulation resistance intervals based on the interval coefficients. The statistics module 40 is used to count the number of insulation resistance data points that fall within each insulation resistance range of the insulation resistance dataset.

[0039] The second judgment module 50 is used to determine whether there is a target insulation resistance range where the number of insulation resistance data is greater than zero and less than the second preset threshold.

[0040] The identification module 60 is used to determine whether the adjacent insulation resistance intervals of the target insulation resistance interval meet the judgment condition based on the third preset threshold if there is a target insulation resistance interval with a number of insulation resistance data greater than zero and less than the second preset threshold; if so, it is determined that there is an insulation abnormality in the secondary cable within the target insulation resistance interval.

[0041] The present invention also provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and running on the processor, wherein the processor executes the computer program to implement the method provided in the embodiments of the present invention.

[0042] The present invention also provides a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the method provided in the embodiments of the present invention.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0044] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for identifying abnormality of secondary cable insulation of a power system, characterized by, The method comprises the following steps: obtaining an insulation resistance data set of power system secondary cables; the insulation resistance data set comprises a plurality of insulation resistance data, each insulation resistance data corresponding to a power system secondary cable, and each insulation resistance data comprising positive and negative ground insulation resistances of the secondary cable; determining whether a range difference of the insulation resistance data set exceeds a first preset threshold; the range difference comprises a difference between a maximum value and a minimum value of the positive ground insulation resistance and a difference between a maximum value and a minimum value of the negative ground insulation resistance; if yes, determining an interval coefficient based on the range difference, and determining a plurality of insulation resistance intervals based on the interval coefficient; respectively counting the number of insulation resistance data in each insulation resistance interval into which the insulation resistance data set falls; determining whether there is a target insulation resistance interval in which the number of insulation resistance data is greater than zero and less than a second preset threshold; if yes, determining whether adjacent insulation resistance intervals of the target insulation resistance interval satisfy a determination condition based on a third preset threshold; if yes, determining that the secondary cable in the target insulation resistance interval has insulation abnormality.

2. The method of claim 1, wherein: The method comprises the following steps: determining a segmentation coefficient based on a preset constraint relationship satisfied between the segmentation coefficient and a window coefficient; the window coefficient is the total number of the secondary cables; determining the interval coefficient based on the range difference and the segmentation coefficient; wherein the preset constraint relationship comprises: the interval coefficient comprises: In the formula, L is the division coefficient, M is the window coefficient, a, b are the interval coefficients, R pmax and R pmin are the maximum and minimum values of the positive ground insulation resistance, respectively, R nmax and R nmin are the maximum and minimum values of the negative ground insulation resistance, respectively.

3. The method of claim 2, wherein: the plurality of insulation resistance intervals comprise: In the formula, X i,j represents the insulation resistance interval, i, j are interval indexes, R p and R n respectively represent the positive-to-ground insulation resistance and the negative-to-ground insulation resistance.

4. The method of claim 3, wherein: the determination condition based on the third preset threshold comprises: In the formula, C i-1,j-1 , C i-1,j , C i-1,j+1 , C i,j-1 , C i,j+1 , C i+1,j-1 , C i+1,j , C i+1,j+1 respectively represent the number of insulation resistance data in the adjacent insulation resistance interval of the insulation resistance interval X i,j , and V is the third preset threshold value.

5. An electric power system secondary cable insulation abnormality identification system characterized by comprising: The method for identifying insulation abnormality of power system secondary cables according to any one of claims 1-4; the system comprises an acquisition module, a first determination module, a determination module, a counting module, a second determination module and an identification module; wherein, the acquisition module is configured to obtain an insulation resistance data set of power system secondary cables; the insulation resistance data set comprises a plurality of insulation resistance data, each insulation resistance data corresponding to a power system secondary cable, and each insulation resistance data comprising positive and negative ground insulation resistances of the secondary cable; the first determination module is configured to determine whether a range difference of the insulation resistance data set exceeds a first preset threshold; the range difference comprises a difference between a maximum value and a minimum value of the positive ground insulation resistance and a difference between a maximum value and a minimum value of the negative ground insulation resistance; the determination module is configured to, if the range difference exceeds the first preset threshold, determine an interval coefficient based on the range difference, and determine a plurality of insulation resistance intervals based on the interval coefficient; the counting module is configured to respectively count the number of insulation resistance data in each insulation resistance interval into which the insulation resistance data set falls; the second determination module is configured to determine whether there is a target insulation resistance interval in which the number of insulation resistance data is greater than zero and less than a second preset threshold; if yes, determining whether adjacent insulation resistance intervals of the target insulation resistance interval satisfy a determination condition based on a third preset threshold; if yes, determining that the secondary cable in the target insulation resistance interval has insulation abnormality. The identification module is configured to, if there is a target insulation resistance interval with a number of insulation resistance data greater than zero and less than a second preset threshold, determine whether adjacent insulation resistance intervals of the target insulation resistance interval satisfy a judgment condition based on a third preset threshold; and if yes, determine that the secondary cable in the target insulation resistance interval has insulation abnormality.

6. An electronic device, comprising: The computer program comprises computer program elements for performing the steps of the method according to any one of claims 1 to 4 when the computer program is run on a computer. The computer readable storage medium stores computer instructions, and the computer instructions are executed by the processor to implement the method according to any one of claims 1 to 4.

7. A computer readable storage medium characterized in that, The computer readable storage medium stores computer instructions, and the computer instructions are executed by the processor to implement the method according to any one of claims 1 to 4.

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