A composite insulator pollution flashover early warning method, device and equipment

Abstract

The present invention relates to the technical field of online monitoring and fault diagnosis of high-voltage power equipment, and discloses a composite insulator pollution flashover early warning method, device and equipment, comprising collecting standard space electric field signals and real-time space electric field signals of the space electric field where the composite insulator is located under standard working conditions and actual working conditions, calculating preset characteristic parameters, and constructing a reference data matrix and a real-time data matrix; the preset characteristic parameters include sampling period peak value, sampling period average effective value, peak factor, 2-7 harmonic content and total harmonic content; calculating the ratio of the real-time data matrix to the reference data matrix, obtaining the space electric field characteristic deviation matrix, calculating the average value of all elements in the matrix, and obtaining the space electric field characteristic deviation; comparing the space electric field characteristic deviation with a preset early warning threshold, if the space electric field characteristic deviation is greater than the preset early warning threshold, a pollution flashover early warning is performed.

Description

Technical Field

[0001] The present invention relates to the technical field of online monitoring and fault diagnosis of high-voltage power equipment, and in particular to a composite insulator pollution flashover early warning method, device and equipment. Background Art

[0002] Relevant scientific research institutions at home and abroad have conducted a lot of research on the flashover warning of composite insulator pollution, and have achieved many results in the application of pollution degree prediction, partial discharge prediction, pollution flashover warning, etc., including ultraviolet imaging method, infrared imaging method, acoustic emission detection technology, partial discharge measurement method and leakage current method. Ultraviolet imaging method is a method of monitoring the ultraviolet discharge pulse signal of the insulator remotely in a non-contact manner to obtain the surface pollution condition of the insulator; infrared imaging method can obtain the temperature information of the insulator surface, so as to judge the operation condition of the insulator; but they are affected by the environment, and ultraviolet and infrared imaging technology are sensitive to the surrounding environmental conditions. For example, changes in light intensity and temperature may affect the imaging effect, resulting in instability of the monitoring results, and it is difficult to use for real-time online monitoring. Acoustic emission detection technology, using the empirical mode decomposition method, realizes the effective identification of different discharge modes of insulators; the monitoring method of acoustic emission technology is relatively new, but there are still some basic problems to be solved, such as how to identify and eliminate noise interference, natural noise and other unknown mechanical noise in the operating environment. The leakage current method measures the effective value, maximum value and number of leakage current pulses as characteristic quantities to achieve real-time monitoring and early warning of pollution flashover; however, in the current application process, due to the complexity of the discharge process and the influence of environmental factors, the dangerous thresholds of leakage current are different, which makes it impossible to accurately select a reasonable alarm threshold. The partial discharge measurement method, based on the analysis of electromagnetic radiation signals, has been widely used in the detection of insulation fault defects in GIS, but it is still in the theoretical research stage in the field of online monitoring of insulation outside power transmission and distribution, and has not yet been put into practical engineering.

[0003] The spatial electric field signal, as a non-contact monitoring signal, can reflect the operating status of power equipment. In particular, existing studies have shown that the electric field signal will change during insulator discharge and flashover, and for deteriorated insulator strings, the electric field distribution will change. However, most of the existing public technologies use electric field characteristics such as amplitude to identify the insulator state, and are unable to use spatial electric field signals to accurately identify insulator flashover. In addition, due to the complexity of the insulator discharge process and the environmental interference of the spatial electric field, the monitoring results of the flashover warning are unstable. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the monitoring result is unstable due to the complexity of the insulator discharge process and the environmental interference of the space electric field.

[0005] In order to solve the above technical problems, the present invention provides a composite insulator pollution flashover early warning method, comprising:

[0006] Under standard working conditions, the standard space electric field signal of the space electric field where the composite insulator is located is collected;

[0007] Based on the standard space electric field signal, preset characteristic parameters are calculated to construct a reference data matrix; the preset characteristic parameters include sampling period peak value, sampling period average effective value, peak factor, 2-7 harmonic content and total harmonic content;

[0008] In actual working conditions, the real-time spatial electric field signal of the spatial electric field where the composite insulator is located is collected in real time;

[0009] Based on the real-time spatial electric field signal, the preset characteristic parameters are calculated and a real-time data matrix is ​​constructed;

[0010] Calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix;

[0011] Averaging the values ​​of all elements in the spatial electric field characteristic deviation matrix to obtain the spatial electric field characteristic deviation;

[0012] The spatial electric field characteristic deviation is compared with the preset warning threshold. If the spatial electric field characteristic deviation is greater than the preset warning threshold, a contamination flashover warning is issued.

[0013] Preferably, the peak factor is expressed as:

[0014] ;

[0015] in, represents the peak factor, Indicates the peak value of the sampling period, Indicates the average effective value of the sampling period.

[0016] Preferably, the acquisition of the 2nd to 7th harmonic content is expressed as:

[0017] Harmonic content of subharmonics , expressed as: ;

[0018] in, Indicates the voltage effective value of the fundamental wave, express The effective value of the voltage of the subharmonics; Indicates the harmonic order, .

[0019] Preferably, the acquisition of the total harmonic content is expressed as:

[0020] Total harmonic content , expressed as: ;

[0021] in, Indicates the voltage effective value of the fundamental wave, express The effective value of the voltage of the subharmonics, Indicates the harmonic order, , Represents the set of positive integers.

[0022] Preferably, calculating the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix includes:

[0023] Real-time data matrix , expressed as: ; represents the sampling period peak value in the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the sampling period average effective value of the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the peak factor in the real-time spatial electric field signal at the i-th moment under actual working conditions; They represent the 2nd to 7th harmonic contents in the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the total harmonic content in the real-time spatial electric field signal at the i-th moment under actual working conditions;

[0024] Benchmark Data Matrix , expressed as: ; Represents the sampling period peak value in the standard space electric field signal under standard working conditions; It represents the average effective value of the sampling period in the standard space electric field signal under standard working conditions; Indicates the peak factor in the standard space electric field signal under standard working conditions; They represent the 2nd to 7th harmonic contents in the standard space electric field signal under standard working conditions respectively; Represents the total harmonic content in the standard space electric field signal under standard working conditions;

[0025] The spatial electric field characteristic deviation matrix is ​​expressed as:

[0026] ;

[0027] in, represents the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions; It represents the sampling period peak value ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; It represents the ratio of the average effective value of the sampling period in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions. The expression is: ; It represents the peak factor ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; , , , , and , respectively represent the ratio of the 2nd to 7th harmonic content in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expressions are: , , , , , ; It represents the total harmonic content ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: .

[0028] Preferably, the values ​​of all elements in the spatial electric field characteristic deviation matrix are averaged to obtain the spatial electric field characteristic deviation, which is expressed as:

[0029] ;

[0030] in, It represents the deviation of the spatial electric field characteristics at the i-th moment under actual working conditions.

[0031] Preferably, the preset warning threshold value range is .

[0032] This embodiment provides a composite insulator pollution flashover warning device, including:

[0033] The reference data matrix construction module is used to collect the standard space electric field signal of the space electric field where the composite insulator is located under standard working conditions; based on the standard space electric field signal, the preset characteristic parameters are calculated to construct the reference data matrix; the preset characteristic parameters include the sampling period peak value, the sampling period average effective value, the peak factor, the 2nd to 7th harmonic content and the total harmonic content;

[0034] A real-time data matrix construction module is used to collect the real-time spatial electric field signal of the spatial electric field where the composite insulator is located in real time under actual working conditions; based on the real-time spatial electric field signal, calculate the preset characteristic parameters and construct the real-time data matrix;

[0035] The spatial electric field characteristic deviation calculation module is used to calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix; the values ​​of all elements in the spatial electric field characteristic deviation matrix are averaged to obtain the spatial electric field characteristic deviation;

[0036] The early warning module is used to compare the spatial electric field characteristic deviation with the preset early warning threshold. If the spatial electric field characteristic deviation is greater than the preset early warning threshold, a pollution flashover early warning is issued.

[0037] This embodiment provides a composite insulator pollution flashover early warning device, including:

[0038] A space electric field probe is used to collect space electric field signals of the space electric field where the composite insulator is located;

[0039] The composite insulator pollution flashover warning device is communicatively connected with the space electric field probe, obtains the standard space electric field signal and the real-time space electric field signal, and executes the steps of the composite insulator pollution flashover warning method as described above.

[0040] Preferably, the spatial electric field probe comprises a d-dot probe.

[0041] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0042] The composite insulator contamination flashover early warning method described in the present invention collects reference data of the composite insulator low-voltage end space electric field characteristics including the peak value within the space electric field signal period, average effective value extraction, peak factor, 2-7 harmonic content of the space electric field signal, and total harmonic content THD to form a reference data matrix; and collects the composite insulator low-voltage end space electric field characteristics in real time, and calculates the space electric field characteristic deviation with the reference data matrix, so as to use the space electric field characteristic deviation as the judgment basis for composite insulator contamination flashover early warning. The present invention can more comprehensively and accurately evaluate the contamination state and flashover risk of the insulator by comprehensively considering a variety of signal characteristic parameters and their deviations in the space electric field, which not only improves the efficiency of online real-time monitoring of composite insulator contamination flashover, but also reduces the early warning judgment error caused by subjective human judgment, and improves the stability and reliability of the flashover early warning monitoring results. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0044] Figure 1 It is a flow chart of the steps of the composite insulator pollution flashover early warning method provided by the present invention;

[0045] Figure 2It is a pollution flashover warning flow chart provided by the present invention;

[0046] Figure 3 This is the principle diagram of the d-dot probe;

[0047] Figure 4 It is the equivalent circuit diagram of the d-dot probe. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0049] As a non-contact monitoring signal, the spatial electric field signal can reflect the operating status of the power equipment. In particular, existing studies have shown that the electric field signal will change during the discharge and flashover of the insulator, and the electric field distribution of the deteriorated insulator string will change. Therefore, the present invention uses the spatial electric field signal to provide an early warning of the flashover of the insulator; refer to Figure 1 As shown, the step flow chart of the composite insulator pollution flashover early warning method of the present invention comprises the following specific steps:

[0050] S101: under standard working conditions, collecting standard space electric field signals of the space electric field where the composite insulator is located;

[0051] S102: Based on the standard spatial electric field signal, calculate preset characteristic parameters and construct a reference data matrix; the preset characteristic parameters include sampling period peak value, sampling period average effective value, peak factor, 2-7 harmonic content and total harmonic content;

[0052] S103: in actual working conditions, real-time spatial electric field signals of the spatial electric field where the composite insulator is located are collected in real time;

[0053] S104: Based on the real-time spatial electric field signal, calculate the preset characteristic parameters and construct a real-time data matrix;

[0054] S105: Calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix;

[0055] S106: averaging the values ​​of all elements in the spatial electric field characteristic deviation matrix to obtain the spatial electric field characteristic deviation;

[0056] S107: Compare the spatial electric field characteristic deviation with a preset warning threshold. If the spatial electric field characteristic deviation is greater than the preset warning threshold, a contamination flashover warning is issued.

[0057] Specifically, the preset characteristic parameters include the sampling period peak value, the sampling period average effective value, the peak factor, the 2nd to 7th harmonic content and the total harmonic content, which are respectively expressed as:

[0058] ① The peak factor is expressed as: ;in, represents the peak factor, Indicates the peak value of the sampling period, Indicates the average effective value of the sampling period;

[0059] ② Harmonic content of subharmonics , expressed as: ;in, Indicates the voltage effective value of the fundamental wave, express The effective value of the voltage of the subharmonics; Indicates the harmonic order, ;

[0060] ③Total harmonic content , expressed as: ;in, Indicates the voltage effective value of the fundamental wave, express The effective value of the voltage of the subharmonics, Indicates the harmonic order, , represents a set of positive integers;

[0061] Specifically, the ratio of the real-time data matrix to the reference data matrix is ​​calculated to obtain the spatial electric field characteristic deviation matrix, including:

[0062] S105-1: Building a real-time data matrix , expressed as: ; represents the sampling period peak value in the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the sampling period average effective value of the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the peak factor in the real-time spatial electric field signal at the i-th moment under actual working conditions; They represent the 2nd to 7th harmonic contents in the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the total harmonic content in the real-time spatial electric field signal at the i-th moment under actual working conditions;

[0063] S105-2: Building a Benchmark Data Matrix , expressed as: ; Represents the sampling period peak value in the standard space electric field signal under standard working conditions; It represents the average effective value of the sampling period in the standard space electric field signal under standard working conditions; Indicates the peak factor in the standard space electric field signal under standard working conditions; They represent the 2nd to 7th harmonic contents in the standard space electric field signal under standard working conditions respectively; Represents the total harmonic content in the standard space electric field signal under standard working conditions;

[0064] S105-3: Calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix, which is expressed as:

[0065] ;

[0066] in, represents the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions; It represents the sampling period peak value ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; It represents the ratio of the average effective value of the sampling period in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions. The expression is: ; It represents the peak factor ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; , , , , and , respectively represent the ratio of the 2nd to 7th harmonic content in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expressions are: , , , , , ; It represents the total harmonic content ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: .

[0067] In this embodiment, the values ​​of all elements in the spatial electric field characteristic deviation matrix are averaged to obtain the spatial electric field characteristic deviation at the i-th moment under actual working conditions, which is expressed as:

[0068] .

[0069] The present invention provides a composite insulator pollution flashover early warning method based on the deviation of spatial electric field characteristics, which can collect the spatial electric field characteristics of the low-voltage end of the composite insulator in real time, including the peak value of the spatial electric field signal sampling period , Average effective value of sampling period , Peak Factor , 10 groups of benchmark data points of 2-7 harmonic content of spatial electric field signal and total harmonic content THD; the deviation can also be calculated through the collected spatial electric field characteristic information, so that the spatial electric field characteristic deviation can be used as the basis for judging the composite insulator pollution flashover warning. This method not only improves the efficiency of online monitoring of composite insulator pollution flashover, but also reduces the warning judgment error caused by subjective human judgment.

[0070] Based on the above embodiments, in the embodiments of the present invention, the pollution flashover warning method for composite insulators provided by the present invention is used to perform pollution flashover warning; Figure 2 As shown in the figure, it is a pollution flashover warning flow chart, which specifically includes: space electric field signal acquisition, space electric field characteristic parameter extraction and space electric field characteristic deviation calculation; specifically:

[0071] S201: spatial electric field signal acquisition, which is achieved through a spatial electric field probe. The spatial electric field probe is used to monitor the spatial electric field value at the low-voltage end of the insulator string, which value can reflect the operating status of the insulator;

[0072] S202: Extraction of spatial electric field characteristic parameters, including peak value extraction within a spatial electric field signal sampling period, average effective value extraction within a spatial electric field signal sampling period, peak factor calculation, and spatial electric field signal harmonic analysis.

[0073] S202-1: Extract the peak value within the sampling period of the spatial electric field signal, extract the maximum peak value of the spatial electric field sinusoidal signal sampling period, and record it as ;

[0074] S202-2: Extract the average effective value of the spatial electric field signal sampling period, extract the average effective value of the spatial electric field sinusoidal signal sampling period, and record it as ;

[0075] S202-3: The peak factor is calculated by the ratio of the peak value to the average effective value within the spatial electric field signal sampling period, which is recorded as , expressed as: ;

[0076] S202-4: Harmonic analysis of the spatial electric field signal, using Fourier transform to perform harmonic content analysis on the spatial electric field signal to obtain harmonic contents at different harmonic frequencies;

[0077] The 2nd to 7th harmonic content and total harmonic content of the spatial electric field signal As the characteristic points of the spatial electric field signal, they are recorded as , , , , , , .

[0078] S203: Calculate the deviation of the spatial electric field characteristics, and calculate the spatial electric field signal characteristics of the critical flashover spatial electric field signal, including the peak value of the spatial electric field signal sampling period , average effective value of the sampling period , peak factor , 2nd-7th harmonic content of spatial electric field signal , , , , , , total harmonic content As 10 sets of benchmark data points, form the initial matrix , expressed as:

[0079] ;

[0080] The matrix obtained from the i-th monitoring data is , expressed as:

[0081] ;

[0082] The spatial electric field characteristic deviation matrix is: :

[0083] ;

[0084] It should be noted that under normal operating conditions The value of the matrix element is less than the corresponding Elements, spatial electric field characteristic deviation , expressed as:

[0085] ;

[0086] The composite insulator pollution flashover early warning based on the spatial electric field characteristic deviation takes the spatial electric field characteristic deviation as the judgment basis for the composite insulator pollution flashover early warning, and issues an early warning according to the calculation result of the spatial electric field characteristic deviation. A value is arbitrarily selected as the warning threshold, that is, if the deviation is greater than the warning threshold, it indicates that the flashover warning state has been entered. Specifically, the deviation value data in this embodiment is derived from the data of the composite insulation flashover process test in the high-voltage test laboratory; the warning value is the test data at the moment when the arc develops violently; during the test, the initial deviation of the arc violent development is as low as 1.5, and the deviation before the critical flashover is less than 2, so the value in this embodiment is It should be noted that this value is different for different types of insulators, and the warning threshold should be adjusted based on laboratory test results or field operation experience.

[0087] Based on the above embodiments, the embodiments of the present invention further provide a composite insulator pollution flashover warning device, comprising:

[0088] The reference data matrix construction module is used to collect the standard space electric field signal of the space electric field where the composite insulator is located under standard working conditions; based on the standard space electric field signal, the preset characteristic parameters are calculated to construct the reference data matrix; the preset characteristic parameters include the sampling period peak value, the sampling period average effective value, the peak factor, the 2nd to 7th harmonic content and the total harmonic content;

[0089] The reference data matrix construction module is used to collect the real-time spatial electric field signal of the spatial electric field where the composite insulator is located in real time under actual working conditions; based on the real-time spatial electric field signal, calculate the preset characteristic parameters and construct the real-time data matrix;

[0090] The reference data matrix construction module is used to calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix; the values ​​of all elements in the spatial electric field characteristic deviation matrix are averaged to obtain the spatial electric field characteristic deviation;

[0091] The early warning module is used to compare the spatial electric field characteristic deviation with the preset early warning threshold. If the spatial electric field characteristic deviation is greater than the preset early warning threshold, a pollution flashover early warning is issued.

[0092] The composite insulator pollution flashover warning device of this embodiment is used to implement the aforementioned composite insulator pollution flashover warning method. Therefore, the specific implementation method of the composite insulator pollution flashover warning device can be seen in the embodiment part of the composite insulator pollution flashover warning method in the previous text, for example, the benchmark data matrix construction module is used to implement steps S101 and S102 in the above-mentioned composite insulator pollution flashover warning method; the benchmark data matrix construction module is used to implement steps S103 and S104 in the above-mentioned composite insulator pollution flashover warning method; the benchmark data matrix construction module is used to implement steps S105 and S106 in the above-mentioned composite insulator pollution flashover warning method; the warning module is used to implement step S107 in the above-mentioned composite insulator pollution flashover warning method, so its specific implementation method can refer to the description of the corresponding various parts of the embodiment, which will not be repeated here.

[0093] Based on the above embodiments, the embodiments of the present invention further provide a composite insulator pollution flashover warning device, including:

[0094] A space electric field probe is used to collect space electric field signals of the space electric field where the composite insulator is located;

[0095] The composite insulator pollution flashover warning device is communicatively connected with the space electric field probe, obtains the standard space electric field signal and the real-time space electric field signal, and executes the steps of the composite insulator pollution flashover warning method as described above.

[0096] Specifically, the spatial electric field probe comprises a d-dot probe. Figure 3 The figure shows the principle diagram of the d-dot probe. The space electric field probe adopts the capacitive coupling principle and uses the coupling capacitor C M The changing electric field signal E 0 (t) is induced into a voltage signal U M (t) Output, the output voltage signal is the spatial electric field signal required for composite insulator pollution flashover warning. Figure 4 The figure shows the equivalent circuit diagram of the D-dot probe. The D-dot probe is actually a first-order RC circuit. The output of the probe measures the resistance R M The voltage signal at both ends is directly proportional to the first-order differential of the electric displacement vector in the space where the probe is located with respect to time.

[0097] The composite insulator contamination flashover early warning method described in the present invention collects 10 reference data of the composite insulator low-voltage end space electric field characteristics including the peak value within the space electric field signal period, the average effective value extraction, the peak factor, the 2-7 harmonic content of the space electric field signal, and the total harmonic content THD to form a reference data matrix; and collects the composite insulator low-voltage end space electric field characteristics in real time, and calculates the space electric field characteristic deviation with the reference data matrix, so as to use the space electric field characteristic deviation as the judgment basis for composite insulator contamination flashover early warning. The present invention can more comprehensively and accurately evaluate the contamination state and flashover risk of the insulator by comprehensively considering a variety of signal characteristic parameters and their deviations in the space electric field, which not only improves the efficiency of online real-time monitoring of composite insulator contamination flashover, but also reduces the early warning judgment error caused by subjective human judgment, and improves the stability and reliability of the flashover early warning monitoring results.

[0098] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0099] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0100] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0101] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0102] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A composite insulator pollution flashover early warning method, characterized in that: include: Under standard working conditions, the standard space electric field signal of the space electric field where the composite insulator is located is collected; Based on the standard space electric field signal, preset characteristic parameters are calculated to construct a reference data matrix; the preset characteristic parameters include sampling period peak value, sampling period average effective value, peak factor, 2-7 harmonic content and total harmonic content; In actual working conditions, the real-time spatial electric field signal of the spatial electric field where the composite insulator is located is collected in real time; Based on the real-time spatial electric field signal, the preset characteristic parameters are calculated and a real-time data matrix is ​​constructed; Calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix, including: Real-time data matrix , expressed as: ; represents the sampling period peak value in the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the sampling period average effective value of the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the peak factor in the real-time spatial electric field signal at the i-th moment under actual working conditions; They represent the 2nd to 7th harmonic contents in the real-time spatial electric field signal at the i-th moment under actual working conditions; represents the total harmonic content in the real-time spatial electric field signal at the i-th moment under actual working conditions; Benchmark Data Matrix , expressed as: ; Represents the sampling period peak value in the standard space electric field signal under standard working conditions; It represents the average effective value of the sampling period in the standard space electric field signal under standard working conditions; Indicates the peak factor in the standard space electric field signal under standard working conditions; They represent the 2nd to 7th harmonic contents in the standard space electric field signal under standard working conditions respectively; Represents the total harmonic content in the standard space electric field signal under standard working conditions; The spatial electric field characteristic deviation matrix is ​​expressed as: ; in, represents the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions; It represents the sampling period peak value ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; It represents the ratio of the sampling period average effective value in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions. The expression is: ; It represents the peak factor ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; , , , , and , respectively represent the ratio of the 2nd to 7th harmonic content in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expressions are: , , , , , ; It represents the total harmonic content ratio in the spatial electric field characteristic deviation matrix at the i-th moment under actual working conditions, and the expression is: ; Averaging the values ​​of all elements in the spatial electric field characteristic deviation matrix to obtain the spatial electric field characteristic deviation; The spatial electric field characteristic deviation is compared with the preset warning threshold. If the spatial electric field characteristic deviation is greater than the preset warning threshold, a contamination flashover warning is issued.

2. The composite insulator pollution flashover early warning method according to claim 1 is characterized in that: The peak factor is expressed as: ； in, represents the peak factor, Indicates the peak value of the sampling period, Indicates the average effective value of the sampling period.

3. The composite insulator pollution flashover early warning method according to claim 1 is characterized in that: The acquisition of the 2nd to 7th harmonic content is expressed as: Harmonic content of subharmonics , expressed as: ; in, Indicates the voltage effective value of the fundamental wave, express The effective value of the voltage of the subharmonics; Indicates the harmonic order, .

4. The composite insulator pollution flashover early warning method according to claim 1 is characterized in that: The acquisition of the total harmonic content is expressed as: Total harmonic content , expressed as: ; in, Indicates the voltage effective value of the fundamental wave, express The effective value of the voltage of the subharmonic, Indicates the harmonic order, , Represents the set of positive integers.

5. The composite insulator pollution flashover early warning method according to claim 1 is characterized in that: The values ​​of all elements in the spatial electric field characteristic deviation matrix are averaged to obtain the spatial electric field characteristic deviation, which is expressed as: ; in, It represents the deviation of the spatial electric field characteristics at the i-th moment under actual working conditions.

6. The composite insulator pollution flashover early warning method according to claim 1 is characterized in that: The preset warning threshold value range is .

7. A device based on the composite insulator pollution flashover early warning method according to any one of claims 1 to 6, characterized in that: include: A reference data matrix building module is used to collect standard space electric field signals of the space electric field where the composite insulator is located under standard working conditions; Based on the standard space electric field signal, preset characteristic parameters are calculated to construct a reference data matrix; the preset characteristic parameters include sampling period peak value, sampling period average effective value, peak factor, 2-7 harmonic content and total harmonic content; A real-time data matrix building module is used to collect real-time spatial electric field signals of the spatial electric field where the composite insulator is located in real time under actual working conditions; Based on the real-time spatial electric field signal, the preset characteristic parameters are calculated and a real-time data matrix is ​​constructed; A spatial electric field characteristic deviation calculation module is used to calculate the ratio of the real-time data matrix to the reference data matrix to obtain the spatial electric field characteristic deviation matrix; Averaging the values ​​of all elements in the spatial electric field characteristic deviation matrix to obtain the spatial electric field characteristic deviation; The early warning module is used to compare the spatial electric field characteristic deviation with the preset early warning threshold. If the spatial electric field characteristic deviation is greater than the preset early warning threshold, a pollution flashover early warning is issued.

8. A composite insulator pollution flashover warning device, characterized in that: include: A space electric field probe is used to collect space electric field signals of the space electric field where the composite insulator is located; The composite insulator pollution flashover warning device is communicatively connected to the space electric field probe, obtains the standard space electric field signal and the real-time space electric field signal, and executes the steps of the composite insulator pollution flashover warning method as described in any one of claims 1 to 6.

9. The composite insulator pollution flashover warning device according to claim 8, characterized in that: The spatial electric field probe comprises a d-dot probe.

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