Line grounding fault identification method and device based on traveling wave current similarity

Abstract

The present invention discloses a line grounding fault identification method based on traveling wave current similarity, comprising the following steps: obtaining a line traveling wave current waveform signal, marking a traveling wave current waveform signal that exceeds a traveling wave current threshold within a unit time, and forming a traveling wave current waveform marking array; if the number of marked traveling wave current waveform signals is greater than or equal to the marking number threshold, then taking any two traveling wave current waveforms and performing a number of equally segmented traveling wave current waveform processing respectively, and performing a number of current amplitude extraction processing from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays; performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine a number of traveling wave current amplitude curve functions; performing similarity processing based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix; performing arc grounding fault determination processing based on the traveling wave current similarity matrix; and realizing the identification of collector line arc grounding fault.

Description

Technical Field

[0001] The present invention relates to the technical field of line grounding fault identification, and in particular to a line grounding fault identification method and device based on traveling wave current similarity. Background Art

[0002] Collector lines are primarily overhead lines, operating in harsh environments and prone to numerous faults. Arc grounding is a common fault in collector lines during power system operation, posing a serious hazard to the safe operation of power grids. Currently, existing technologies can use zero-sequence current distortion characteristics to identify arc grounding faults in collector lines. However, these technologies are not very targeted and exhibit significant errors when high-resistance characteristics are not obvious. Existing technologies primarily utilize zero-sequence current distortion characteristics, which are often affected by factors such as high resistance and fault grounding configuration, resulting in changes in specific zero-sequence current distortion characteristics, causing significant deviations in the identification results.

[0003] Therefore, the research on the identification method of arc grounding fault in the collector line can identify arc grounding in areas with high incidence of arc faults, and can provide more abundant information for the safe maintenance and operation of the collector line, which is of great significance to improving the safe operation reliability of the collector line. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention provides a line grounding fault identification method based on traveling wave current similarity, which realizes marking based on the line traveling wave current waveform signal, current amplitude extraction, polynomial curve fitting and similarity processing, thereby determining whether there is an arc grounding fault in the line.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] The method for identifying line grounding faults based on traveling wave current similarity includes the following steps:

[0007] S101, obtaining a traveling wave current waveform signal of a line, and marking a traveling wave current waveform signal that exceeds a traveling wave current threshold value per unit time;

[0008] S102, forming a traveling wave current waveform marking array with the traveling wave current waveform signals marked within a unit time, and if the number of marked traveling wave current waveform signals is greater than or equal to a marking number threshold, executing step S103;

[0009] S103, based on the traveling wave current waveform mark array, randomly select two traveling wave current waveforms and perform a number of equally segmented traveling wave current waveform processing respectively, and perform a number of current amplitude extraction processing from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays;

[0010] S104, performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine several traveling wave current amplitude curve functions;

[0011] S105, performing similarity processing based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix;

[0012] S106 , performing arc grounding fault determination processing based on the traveling wave current similarity matrix.

[0013] Furthermore, several current amplitude extraction processes are performed from each segmented traveling wave current waveform, including: extracting the current amplitude corresponding to the first point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the middle point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the last point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the midpoint between the first point and the middle point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the midpoint between the middle point and the last point of each segmented traveling wave current waveform.

[0014] Furthermore, performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine a plurality of traveling wave current amplitude curve functions includes the following steps:

[0015] Establish the quadratic polynomial y = ax 2 +bx+c;

[0016] Substituting the traveling wave current amplitude array into the formula, several traveling wave current amplitude curve functions are obtained.

[0017] Furthermore, performing similarity processing based on the traveling wave current amplitude curve function includes: determining similarity values ​​of the traveling wave current amplitude curve function respectively. The calculation formula of the similarity value of the traveling wave current amplitude curve function is as follows:

[0018]

[0019] Among them, ρ is the similarity value of the traveling wave current amplitude curve function, y m (t) and y z (t) is the equation of n different curves, and T1 is the duration of the curve process.

[0020] Furthermore, the arc grounding fault determination process includes: if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is greater than or equal to the ratio threshold, it is determined that an arc grounding fault has occurred; if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is less than the ratio threshold, it is determined that an arc grounding fault has occurred.

[0021] Furthermore, a line grounding fault identification device based on traveling wave current similarity is used to implement a collector line grounding fault identification method based on traveling wave similarity, comprising a monitoring module, a processing module and a judgment module;

[0022] A monitoring module is used to obtain the traveling wave current waveform signal of the line, mark the traveling wave current waveform signal that exceeds the traveling wave current threshold within a unit time, and form a traveling wave current waveform mark array;

[0023] a processing module for performing a plurality of equally segmented traveling wave current waveform processing on any two traveling wave current waveforms based on a traveling wave current waveform marker array, and extracting a plurality of current amplitudes from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays; performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine a plurality of traveling wave current amplitude curve functions; and performing similarity processing based on the traveling wave current amplitude curve functions to form a traveling wave current similarity matrix;

[0024] The judgment module is used to perform arc grounding fault judgment based on the similarity value of the traveling wave current amplitude curve function of the traveling wave current similarity matrix.

[0025] Furthermore, the arc grounding fault determination process includes: if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is greater than or equal to the ratio threshold, it is determined that an arc grounding fault has occurred; if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is less than the ratio threshold, it is determined that an arc grounding fault has occurred.

[0026] The beneficial effects of the present invention are as follows: the line grounding fault identification method based on traveling wave current similarity realizes marking based on the line traveling wave current waveform signal, current amplitude extraction, polynomial curve fitting and similarity processing, thereby determining whether there is an arc grounding fault in the line.

[0027] The organic combination of current traveling wave detection and similarity technology significantly reduces interference effects, improves the accuracy of effective traveling wave detection and identification, and realizes a method for identifying arc grounding faults in collector lines. This method can quickly and effectively identify arc grounding faults and eliminate interfering traveling waves, with high practicality. It can quickly and effectively identify and extract arc grounding faults in collector lines, has a high fault tolerance rate, and is simple, convenient, and effective to implement, with high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 It is a schematic diagram of the steps of the line grounding fault identification method based on traveling wave current similarity of the present invention. DETAILED DESCRIPTION

[0030] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0031] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0032] Example 1:

[0033] The method for identifying line grounding faults based on traveling wave current similarity includes the following steps:

[0034] S101, obtaining a traveling wave current waveform signal of a line, and marking a traveling wave current waveform signal that exceeds a traveling wave current threshold value per unit time;

[0035] Acquire the line traveling wave current waveform signal and perform traveling wave current waveform signal marking processing. The traveling wave current waveform signal marking processing includes: acquiring the line traveling wave current waveform signal based on the time series, and marking the traveling wave current waveform signal that exceeds the traveling wave current threshold within a unit time.

[0036] S102, forming a traveling wave current waveform marking array with the traveling wave current waveform signals marked within a unit time, and if the number of marked traveling wave current waveform signals is greater than or equal to a marking number threshold, executing step S103;

[0037] Based on the time series, the traveling wave current waveform signals of the line are acquired, and the traveling wave current waveform signals that exceed the traveling wave current threshold within a unit time are marked. The marked traveling wave current waveform signals within the unit time form a traveling wave current waveform mark array. If the number of marked traveling wave current waveform signals is greater than or equal to the mark number threshold, step S103 is executed.

[0038] For example, the traveling wave current waveform signal marked in unit time is used to form a traveling wave current waveform marking array, and the array W = [W1, W2, W3...W P ] indicates that if the number of marked items is greater than or equal to the marking quantity threshold, step S103 is executed.

[0039] S103, based on the traveling wave current waveform mark array, randomly select two traveling wave current waveforms and perform a number of equally segmented traveling wave current waveform processing respectively, and perform a number of current amplitude extraction processing from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays;

[0040] Based on the traveling wave current waveform tag array, any two traveling wave current waveforms are subjected to a plurality of equally segmented traveling wave current waveform processings. For example, the traveling wave current waveform W1 and the traveling wave current waveform W2 are subjected to a plurality of equally segmented traveling wave current waveform processings.

[0041] Several current amplitude extraction processes are performed from each segmented traveling wave current waveform. The several current amplitude extraction processes are performed from each segmented traveling wave current waveform, including: extracting the current amplitude corresponding to the first point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the middle point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the last point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the midpoint between the first point and the middle point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the midpoint between the middle point and the last point of each segmented traveling wave current waveform.

[0042] A plurality of current amplitude extraction processes are performed from each segment of the traveling wave current waveform to form different traveling wave current amplitude arrays. For example, a plurality of current amplitude extraction processes are performed from each segment of the traveling wave current waveform W1 and the traveling wave current waveform W2 to form a traveling wave current amplitude array. and the traveling wave current amplitude array

[0043] S104, performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine several traveling wave current amplitude curve functions;

[0044] Based on the traveling wave current waveform marker array, any two traveling wave current waveforms are randomly selected and subjected to several equally segmented traveling wave current waveform processing, and several current amplitude extraction processing is performed from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays. Based on the traveling wave current amplitude arrays, polynomial curve fitting processing is performed to determine several traveling wave current amplitude curve functions. Based on the traveling wave current amplitude arrays, polynomial curve fitting processing is performed to determine several traveling wave current amplitude curve functions, including the following steps:

[0045] Establish the quadratic polynomial y = ax 2 +bx+c;

[0046] Substituting the traveling wave current amplitude array into the formula, several traveling wave current amplitude curve functions are obtained.

[0047] For example, based on the traveling wave current amplitude array Perform polynomial curve fitting to obtain several traveling wave current amplitude curve functions, which can be expressed as y1, y2, y3, ... n To represent the traveling wave current amplitude curve function. Based on the traveling wave current amplitude array Perform polynomial curve fitting to obtain several traveling wave current amplitude curve functions, which can be expressed by y n+1 ,y n+2 ,y n+3 ,……y 2n To represent the traveling wave current amplitude curve function.

[0048] S105, performing similarity processing based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix;

[0049] A polynomial curve fitting process is performed based on the traveling wave current amplitude array to determine a number of traveling wave current amplitude curve functions, and similarity processing is performed on the traveling wave current amplitude curve functions to form a traveling wave current similarity matrix.

[0050] The similarity processing based on the traveling wave current amplitude curve function includes: respectively determining similarity values ​​of the traveling wave current amplitude curve function. The calculation formula of the similarity value of the traveling wave current amplitude curve function is as follows:

[0051]

[0052] Among them, ρ is the similarity value of the traveling wave current amplitude curve function, y m (t) and y z (t) is the equation of n different curves, and T1 is the duration of the curve process.

[0053] For example, based on the traveling wave current amplitude array Perform polynomial curve fitting to obtain several traveling wave current amplitude curve functions y1, y2, y3, ...y n , similarity processing is performed based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix J. Based on the traveling wave current amplitude array Perform polynomial curve fitting to obtain several traveling wave current amplitude curve functions y n+1 ,y n+2 ,y n+3 ,……y 2n , similarity processing is performed based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix L.

[0054] S106, performing arc grounding fault determination based on the traveling wave current similarity matrix;

[0055] Similarity processing is performed based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix, and arc grounding fault determination processing is performed based on the traveling wave current similarity matrix.

[0056] The arc grounding fault determination process includes: if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is greater than or equal to the ratio threshold, it is determined that an arc grounding fault has occurred; if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is less than the ratio threshold, it is determined that an arc grounding fault has occurred.

[0057] For example, if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve functions of the traveling wave current similarity matrix J and the traveling wave current similarity matrix L that exceeds the similarity value threshold is greater than or equal to the ratio threshold, it is determined that an arc grounding fault has occurred; if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve functions of the traveling wave current similarity matrix J and the traveling wave current similarity matrix L that exceeds the similarity value threshold is less than the ratio threshold, it is determined that an arc grounding fault has occurred.

[0058] Example 2:

[0059] The difference from the first embodiment is that the traveling wave current waveform signal marked in a unit time constitutes a traveling wave current waveform marking array. If the number of marked traveling wave current waveform signals is less than the marking number threshold, step S101 is executed.

[0060] Example 3:

[0061] The difference from the second embodiment is that the line grounding fault identification device based on traveling wave current similarity is used to implement the collector line grounding fault identification method based on traveling wave similarity, including a monitoring module, a processing module and a judgment module;

[0062] A monitoring module is used to obtain the traveling wave current waveform signal of the line, mark the traveling wave current waveform signal that exceeds the traveling wave current threshold within a unit time, and form a traveling wave current waveform mark array;

[0063] a processing module for performing a plurality of equally segmented traveling wave current waveform processing on any two traveling wave current waveforms based on a traveling wave current waveform marker array, and extracting a plurality of current amplitudes from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays; performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine a plurality of traveling wave current amplitude curve functions; and performing similarity processing based on the traveling wave current amplitude curve functions to form a traveling wave current similarity matrix;

[0064] The judgment module is used to perform arc grounding fault judgment based on the similarity value of the traveling wave current amplitude curve function of the traveling wave current similarity matrix.

[0065] The arc grounding fault determination process includes: if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is greater than or equal to the ratio threshold, it is determined that an arc grounding fault has occurred; if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is less than the ratio threshold, it is determined that an arc grounding fault has occurred.

[0066] In the description of the present invention, it should be noted that the terms “first” and “second” are only used for distinction and description, and cannot be understood as indicating or implying relative importance.

[0067] The above is only for explaining the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention without creative work should be included in the scope of protection of the present invention.

Claims

1. A line grounding fault identification method based on traveling wave current similarity, characterized in that: The following steps are involved: S101, obtaining a traveling wave current waveform signal of a line, and marking a traveling wave current waveform signal that exceeds a traveling wave current threshold value within a unit time; S102, forming a traveling wave current waveform marking array with the traveling wave current waveform signals marked within the unit time, and if the number of marked traveling wave current waveform signals is greater than or equal to the marking number threshold, executing step S103; S103, based on the traveling wave current waveform mark array, randomly select two traveling wave current waveforms to perform a number of equally segmented traveling wave current waveform processes, and perform a number of current amplitude extraction processes from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays; S104, performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine a plurality of traveling wave current amplitude curve functions; S105, performing similarity processing based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix, including: respectively determining similarity values ​​of the traveling wave current amplitude curve function, and the calculation formula of the similarity value of the traveling wave current amplitude curve function is as follows: Among them, ρ is the similarity value of the traveling wave current amplitude curve function, y m (t) and y z (t) is the equation of n different curves, T1 is the duration of the curve process; S106. Performing arc grounding fault determination processing based on the traveling wave current similarity matrix, including: if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is greater than or equal to the ratio threshold, it is determined that an arc grounding fault has occurred; if the ratio of the number of similarity values ​​of the traveling wave current amplitude curve function in the traveling wave current similarity matrix that exceeds the similarity value threshold is less than the ratio threshold, it is determined that no arc grounding fault has occurred.

2. The line grounding fault identification method based on traveling wave current similarity according to claim 1 is characterized in that: The traveling wave current waveform signals marked in the unit time constitute a traveling wave current waveform marking array. If the number of marked traveling wave current waveform signals is less than the marking number threshold, step S101 is executed.

3. The line grounding fault identification method based on traveling wave current similarity according to claim 1 is characterized in that: The current amplitude extraction processing performed on several items from each segmented traveling wave current waveform includes: extracting the current amplitude corresponding to the first point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the middle point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the last point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the midpoint between the first point and the middle point of each segmented traveling wave current waveform; extracting the current amplitude corresponding to the midpoint between the middle point and the last point of each segmented traveling wave current waveform.

4. The line grounding fault identification method based on traveling wave current similarity according to claim 1 is characterized in that: The polynomial curve fitting process is performed based on the traveling wave current amplitude array to determine a plurality of traveling wave current amplitude curve functions, comprising the following steps: Establish the quadratic polynomial y = ax 2 +bx+c; Substituting the traveling wave current amplitude array into the formula, several traveling wave current amplitude curve functions are obtained.

5. A line grounding fault identification device based on traveling wave current similarity, characterized in that: Used to implement the line grounding fault identification method described in any one of claims 1 to 4, comprising a monitoring module, a processing module and a judgment module; A monitoring module is used to obtain a traveling wave current waveform signal of a line, mark a traveling wave current waveform signal that exceeds a traveling wave current threshold within a unit time, and form a traveling wave current waveform mark array; A processing module is used for randomly selecting two traveling wave current waveforms to perform several equally segmented traveling wave current waveform processings based on the traveling wave current waveform mark array, and performing several current amplitude extraction processings from each segmented traveling wave current waveform to form different traveling wave current amplitude arrays; performing polynomial curve fitting processing based on the traveling wave current amplitude array to determine several traveling wave current amplitude curve functions; Perform similarity processing based on the traveling wave current amplitude curve function to form a traveling wave current similarity matrix; The judgment module is used to perform arc grounding fault judgment processing based on the similarity value of the traveling wave current amplitude curve function of the traveling wave current similarity matrix.

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