Radio frequency detection method and system for internal micro-defects of post insulator

Abstract

The invention belongs to the technical field of insulator detection, and particularly relates to a post insulator internal microdefect radio frequency detection method and system. N rectangular excitation ports are annularly arranged on the surface of a porcelain piece above a post insulator flange at equal intervals to form a radio frequency antenna array; extracting a rectangular excitation port and applying broadband excitation; taking the rectangular excitation port which is not extracted as a sampling port, and collecting a radio frequency waveform from the sampling port; and summarizing the waveform data, calculating an evaluation index, and judging the severity of the gap defect of the porcelain flange of the post insulator according to the evaluation index. According to the invention, the gap defect of the porcelain flange of the post insulator can be effectively detected, hidden dangers of the post insulator in operation of an electric power system can be eliminated in time, and safe and stable operation of the electric power system can be guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of insulator detection, and in particular relates to a radio frequency detection method and system for micro-defects inside a post insulator. Background Art

[0002] Post insulators are important electrical components with a wide range of uses and large numbers in transmission and distribution networks. Among them, post insulators are a commonly used type of post insulators, which are mainly composed of porcelain parts responsible for main insulation and flanges nested at both ends. During the production, assembly and long-term use of post insulators, tiny gap defects are prone to occur between porcelain parts and flanges. These defects may be caused by production processes, assembly processes, and long-term exposure to electromechanical loads, air pollution, and changes in temperature. These tiny defects may be in the form of holes, seams, cracks, etc. Under long-term operating conditions, these defects may gradually expand, resulting in a decrease in the insulation and mechanical properties of the post insulators, and ultimately causing power grid accidents. Compared with easily discovered defects such as scratches, notches, and tips on the surface of porcelain parts and flanges, the defects in the gap between porcelain parts and flanges are located inside the post insulators, and they are difficult to detect, thus forming a hidden danger of failure of the post insulators. Summary of the invention

[0003] The purpose of the present invention is to provide a radio frequency detection method and system for micro-defects inside a post insulator. The present invention performs transmission detection of gap defects in the porcelain flange of a post insulator through a radio frequency antenna array, which can provide reference data for post insulator manufacturers and detect inferior insulators in a timely manner. It can also check for hidden dangers in post insulators in the power system and avoid accidents of post insulators in the power system in a timely manner.

[0004] The present invention is implemented by the following technical solution: A radio frequency detection method for micro defects inside a post insulator, comprising the following steps: S1: N rectangular excitation ports are installed circumferentially and at equal intervals on the surface of the porcelain component above the flange of the support insulator to form a radio frequency antenna array; S2: Extract the rectangular excitation port and apply broadband excitation; S3: taking the rectangular excitation port that is not drawn in step S2 as a sampling port, and collecting the RF waveform from the sampling port; S4: Summarize the waveform data of step S3 and calculate the evaluation index according to the following formula: ; ; ; in, and is the intermediate variable, is the rounding down operator, m is the subscript of a single waveform data, M is the number of values ​​of each waveform data, n is the rectangular excitation port number, N is the number of rectangular excitation ports, is the axial plane mapping, x is the radial abscissa, y is the radial ordinate, is the set of extracted rectangular excitation ports, To group RF signals, for The complement of , range is the uniform step extraction operator, s is the extraction step, p is the advancement amount, e is the natural constant, is the particle size parameter, is the mapped spectrum after shape-preserving correction, is the two-dimensional Fourier transform operator, d is the distance from the long side of the rectangular port close to the flange to the flange opening, b is the width of the rectangular excitation port, k is the density parameter, σ is the ratio of the diameter to the long side of the rectangular excitation port, D is the diameter of the non-umbrella part of the post insulator porcelain, and Ω is the evaluation index; S5: Determine the severity of the gap defect in the porcelain flange of the post insulator based on the evaluation index.

[0005] Specifically, the length and width of the rectangular excitation port are equal, and the length of the rectangular excitation port is a, and the width is b. The number N of the rectangular excitation ports is selected according to the following formula: ; in, is the ceiling operator.

[0006] Specifically, the N rectangular excitation ports are numbered according to natural numbers from 0 to N-1, and the numbering order is counterclockwise. The extraction formula for extracting the rectangular excitation ports is as follows: .

[0007] Further preferably, the collected radio frequency signal data is grouped according to the extraction method described in step S2, and the radio frequency signal grouping is recorded as , each set of extraction step s and advancement amount p corresponds to one or several waveform data.

[0008] Further preferably, the method of judging the severity of the gap defect of the porcelain flange of the post insulator according to the evaluation index is as follows: ; In the formula, A represents the severity of the defect in the flange gap of the post insulator porcelain part. If A is 0, the flange gap of the post insulator porcelain part is normal. If A is 1, there is a slight defect in the flange gap of the post insulator porcelain part. If A is 2, there is a serious defect in the flange gap of the post insulator porcelain part and it needs to be replaced in time according to the relevant maintenance specifications of the power system.

[0009] A radio frequency detection system for micro defects inside a post insulator, comprising: Rectangular excitation ports are installed at equal intervals in the annular direction on the surface of the porcelain above the flange of the post insulator; An excitation source, used to extract a rectangular excitation port and apply a corresponding broadband excitation; A sampling module, used for collecting radio frequency waveforms from a sampling port; The data processing module calculates the evaluation index according to the waveform data, and determines the severity of the gap defect of the porcelain flange of the support insulator according to the evaluation index.

[0010] The present invention can effectively detect the gap defects of the porcelain flange of the post insulator, timely eliminate the hidden dangers of the post insulators in operation of the power system, and help to ensure the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the installation of the rectangular excitation port. DETAILED DESCRIPTION

[0012] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0013] Reference Figure 1 , a radio frequency detection method for micro defects inside a post insulator, the steps are as follows: S1: N rectangular excitation ports 100 are installed circumferentially and evenly spaced on the surface 200 of the porcelain component above the flange of the support insulator to form a radio frequency antenna array, such as Figure 1 As shown, the rectangular excitation port 100 has the same length and width, and the length of the rectangular excitation port 100 is a, the width is b, and the number of the rectangular excitation ports 100 is N, which can be selected according to the following formula: ; In the above formula, is the rounding up operator, k is the density parameter, σ is the ratio of the diameter to the long side of the rectangular excitation port, and D is the diameter of the non-umbrella part of the post insulator porcelain.

[0014] S2: extract the rectangular excitation port 100 and apply the corresponding broadband excitation; The N rectangular excitation ports 100 are numbered according to natural numbers from 0 to N-1, and the numbering order is counterclockwise. The corresponding rectangular excitation port 100 is extracted from the N rectangular excitation ports 100 to apply broadband excitation. The extraction method is as follows: ; in, is the set of 100 extracted rectangular excitation ports, range is the uniform step extraction operator, s is the extraction step, and p is the advancement amount; S3: taking the rectangular excitation port 100 that is not drawn in step S2 as a sampling port, and collecting a radio frequency waveform from the sampling port; The sampling port is responsible for collecting the RF signal emitted by the rectangular excitation port 100 to which the broadband excitation is applied. The collected RF signal data is grouped according to the extraction method described in step S2. The RF signal grouping is recorded as Each set of extraction step s and advancement amount p corresponds to one or more waveform data. for The complement of corresponds to the rectangular excitation port 100 that is not extracted in step S2, and m is the subscript of a single waveform data.

[0015] S4: Summarize the waveform data of step S3 and calculate the evaluation index according to the following formula: ; ; ; in, and is the intermediate variable, is the rounding down operator, M is the number of values ​​of each waveform data, n is the rectangular excitation port number, N is the total number of rectangular excitation ports, is the axial plane mapping, x is the radial abscissa, y is the radial ordinate, e is a natural constant, is the particle size parameter, is the mapped spectrum after shape-preserving correction, is the two-dimensional Fourier transform operator, d is the distance from the long side of the rectangular port close to the flange side to the flange opening, and Ω is the evaluation index.

[0016] S5: Determine the severity of the gap defect of the porcelain flange of the post insulator based on the evaluation index: ; In the formula, A represents the severity of the defect in the flange gap of the post insulator porcelain part. If A is 0, the flange gap of the post insulator porcelain part is normal. If A is 1, there is a slight defect in the flange gap of the post insulator porcelain part. If A is 2, there is a serious defect in the flange gap of the post insulator porcelain part and it needs to be replaced in time according to the relevant maintenance specifications of the power system.

[0017] A radio frequency detection system for micro defects inside a post insulator, comprising: Rectangular excitation ports are installed at equal intervals in the annular direction on the surface of the porcelain above the flange of the post insulator; An excitation source, used to extract a rectangular excitation port and apply a corresponding broadband excitation; A sampling module, used for collecting radio frequency waveforms from a sampling port; The data processing module calculates the evaluation index according to the waveform data, and determines the severity of the gap defect of the porcelain flange of the support insulator according to the evaluation index.

[0018] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A radio frequency detection method for micro defects inside a post insulator, characterized in that: Here are the steps: S1: N rectangular excitation ports are installed circumferentially and at equal intervals on the surface of the porcelain component above the flange of the support insulator to form a radio frequency antenna array; S2: Extract the rectangular excitation port and apply broadband excitation; S3: taking the rectangular excitation port that is not drawn in step S2 as a sampling port, and collecting the RF waveform from the sampling port; S4: Summarize the waveform data of step S3 and calculate the evaluation index according to the following formula: ； ； ； in, and is the intermediate variable, is the rounding down operator, m is the subscript of a single waveform data, M is the number of values ​​of each waveform data, n is the rectangular excitation port number, N is the number of rectangular excitation ports, is the axial plane mapping, x is the radial abscissa, y is the radial ordinate, is the set of extracted rectangular excitation ports, To group RF signals, for The complement of , range is the uniform step extraction operator, s is the extraction step, p is the advancement amount, e is the natural constant, is the particle size parameter, is the mapped spectrum after shape-preserving correction, is the two-dimensional Fourier transform operator, d is the distance from the long side of the rectangular port close to the flange to the flange opening, b is the width of the rectangular excitation port, k is the density parameter, σ is the ratio of the diameter to the long side of the rectangular excitation port, D is the diameter of the non-umbrella part of the post insulator porcelain, and Ω is the evaluation index; S5: Determine the severity of the gap defect in the porcelain flange of the post insulator based on the evaluation index.

2. The radio frequency detection method for micro defects inside a post insulator according to claim 1, characterized in that: The rectangular excitation port has the same length and width, and the length of the rectangular excitation port is a, and the width is b. The number N of the rectangular excitation ports is selected according to the following formula: ； in, is the ceiling operator.

3. The radio frequency detection method for micro defects inside a post insulator according to claim 1, characterized in that: The N rectangular excitation ports are numbered according to natural numbers from 0 to N-1 in a counterclockwise order. The extraction formula for extracting the rectangular excitation ports is as follows: 。 4. The radio frequency detection method for micro defects inside a post insulator according to claim 1, characterized in that: The collected RF signal data is grouped according to the extraction method described in step S2, and the RF signal grouping is recorded as , each set of extraction step s and advancement amount p corresponds to one or several waveform data.

5. The radio frequency detection method for micro defects inside a post insulator according to claim 1, characterized in that: The method of judging the severity of the gap defect of the porcelain flange of the post insulator according to the evaluation index is as follows: ； In the formula, A represents the severity of the defect in the flange gap of the post insulator porcelain part. If A is 0, the flange gap of the post insulator porcelain part is normal. If A is 1, there is a slight defect in the flange gap of the post insulator porcelain part. If A is 2, there is a serious defect in the flange gap of the post insulator porcelain part and it needs to be replaced in time according to the relevant maintenance specifications of the power system.

6. A radio frequency detection system for micro defects inside a post insulator, characterized in that: include: Rectangular excitation ports are installed at equal intervals in the annular direction on the surface of the porcelain above the flange of the post insulator; An excitation source, used to extract a rectangular excitation port and apply a corresponding broadband excitation; A sampling module, used for collecting radio frequency waveforms from a sampling port; The data processing module calculates the evaluation index according to the waveform data, and determines the severity of the gap defect of the porcelain flange of the post insulator according to the evaluation index; The evaluation index is calculated as follows: ； ； ； in, and is the intermediate variable, is the rounding down operator, m is the subscript of a single waveform data, M is the number of values ​​of each waveform data, n is the rectangular excitation port number, N is the number of rectangular excitation ports, is the axial plane mapping, x is the radial abscissa, y is the radial ordinate, is the set of extracted rectangular excitation ports, To group RF signals, for The complement of , range is the uniform step extraction operator, s is the extraction step, p is the advancement amount, e is the natural constant, is the particle size parameter, is the mapped spectrum after shape-preserving correction, is the two-dimensional Fourier transform operator, d is the distance from the long side of the rectangular port close to the flange to the flange opening, b is the width of the rectangular excitation port, k is the density parameter, σ is the ratio of the diameter to the long side of the rectangular excitation port, D is the diameter of the non-umbrella part of the post insulator porcelain, and Ω is the evaluation index.

7. The radio frequency detection system for micro defects inside post insulators according to claim 6, characterized in that: The rectangular excitation port has the same length and width, and the length of the rectangular excitation port is a, and the width is b. The number N of the rectangular excitation ports is selected according to the following formula: ； in, is the ceiling operator.

8. The radio frequency detection system for micro defects inside post insulators according to claim 6, characterized in that: Number the N rectangular excitation ports according to natural numbers from 0 to N-1. The extraction formula for extracting the rectangular excitation ports is as follows: 。

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