A meter box aging detection method and device based on vibration analysis

Abstract

The present invention provides a meter box aging detection method and device based on vibration analysis, the method comprising: S1, obtaining a meter box vibration signal collected by a vibration sensor; S2, obtaining a meter box signal to be analyzed after preprocessing the meter box vibration signal; S3, obtaining spectrum information of the meter box signal to be analyzed after fast Fourier transform based on the meter box signal to be analyzed, the spectrum information including the number of peak spectra in the spectrum and the frequency value of the main peak with the maximum energy; S4, obtaining initial data information of the meter box, the initial data information is the spectrum information detected for the first time after the meter box is installed; S5, obtaining n interval data information of the meter box, the interval data information is the spectrum information detected by the meter box at intervals of a period of time; S6, obtaining a comparison result after comparing the initial data information and the n interval data information respectively; S7, judging the status information of the meter box based on the comparison result.

Description

Technical Field

[0001] The present invention relates to the technical field of electric meter boxes, and in particular to a method and device for detecting aging of electric meter boxes based on vibration analysis. Background Art

[0002] After years of exposure to the wind and sun, the meter box will inevitably rust, turn yellow and brittle, age, and crack. The aging of the meter box is particularly obvious in areas with high temperature, high humidity, and high salt fog. For example, the meters in Hainan area are seriously aged after 2-3 years, and are prone to damage after aging. The aging of the meter box brings many hazards, such as the burning of the isolating switch after a water leak; short circuit after a water leak; inaccurate measurement of the internal meter; insufficient strength and damage in strong winds, etc.; endangering the safety of the meter. Therefore, in these areas, it is very necessary to conduct regular inspections of the meter box.

[0003] At present, the discovery of aging and damage of meter boxes mainly relies on regular manual inspections. Manual inspections are sometimes unable to accurately grasp the degree of aging and damage of the meter boxes. Since the meter boxes are scattered and some are in remote areas, it takes a lot of time and energy to inspect them by manpower alone, and the inspection costs are high. There is an urgent need for a method and device that can accurately determine the degree of aging and damage of the meter boxes remotely online without requiring manual labor to reach the area where the meter boxes are installed. Summary of the invention

[0004] The purpose of the present invention is to provide a meter box aging detection method and device based on vibration analysis. There is no need for manual labor to reach the area where the meter box is installed to detect the meter box. The degree of aging and damage of the meter box can be accurately known remotely online, which is convenient for replacing the aged and damaged meter boxes and ensuring the normal operation of the meter boxes. At the same time, it saves the time and energy of the staff and greatly reduces the inspection costs.

[0005] The present invention is implemented by the following technical solutions: A first aspect of the present invention discloses a meter box aging detection method based on vibration analysis, the method comprising:

[0006] S1, obtaining a meter box vibration signal collected by a vibration sensor;

[0007] S2, obtaining a meter box signal to be analyzed after preprocessing the meter box vibration signal;

[0008] S3, obtaining spectrum information of the signal to be analyzed in the meter box after performing fast Fourier transform on the signal to be analyzed in the meter box, wherein the spectrum information includes the number of peaks in the spectrum and the frequency value of the main peak with the maximum energy;

[0009] S4, obtaining initial data information of the meter box, where the initial data information is spectrum information detected for the first time after the meter box is installed;

[0010] S5, obtaining interval data information of the meter box n times, where the interval data information is spectrum information detected by the meter box at intervals;

[0011] S6, based on the initial data information and the n-time interval data information, respectively compare and obtain a comparison result;

[0012] S7. Based on the comparison result, determine the status information of the meter box.

[0013] Optionally, the step S1 specifically includes:

[0014] The Bluetooth SOC controls the micro vibrator to excite the meter box to vibrate;

[0015] The Bluetooth SOC controls the vibration sensor to collect the vibration signal of the meter box.

[0016] Optionally, the preprocessing specifically includes:

[0017] Remove part of the signal before the end of the vibration generated by the micro vibrator excitation meter box;

[0018] Remove the DC component of the subsequent meter box vibration signal.

[0019] Optionally, the obtaining of the comparison result after comparing the initial data information and the n-time interval data information respectively includes:

[0020] Compare the frequency values ​​of the first two main peaks with the maximum energy detected at the first time with the frequency values ​​of the first two main peaks with the maximum energy detected at intervals n times, and obtain the average value of the frequency value change of the first two main peaks with the maximum energy. Record the set of n average values ​​as A n ;

[0021] Compare the number of peak spectra of the first obvious peak detected with the number of peak spectra of the obvious peak detected after n intervals for n times respectively, and obtain the change in the number of peak spectra of the obvious peak. Record the set of n changes as B n .

[0022] Optionally, judging the status information of the meter box based on the comparison result specifically includes:

[0023] If A n If there is a value greater than the first threshold value in the data, it is determined that the meter box is in an aging state;

[0024] If A n There is a value greater than the second threshold value and B n If there is a value greater than the third threshold value, it is determined that the meter box is in a damaged state.

[0025] The second aspect of the present invention discloses a meter box aging detection device based on vibration analysis, which is used to implement the meter box aging detection method based on vibration analysis as described in the first aspect of the present invention, and the device comprises:

[0026] A micro vibrator is used to excite the meter box to vibrate;

[0027] A vibration sensor is used to collect vibration signals generated after the meter box is excited;

[0028] Bluetooth SOC, used to obtain the vibration signal of the meter box collected by the vibration sensor, perform data analysis, and transmit the analysis results to the electric meter via Bluetooth, and then transmit them to the remote terminal through the electric meter;

[0029] Power supply, used to power micro vibrator, vibration sensor and Bluetooth SOC.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention provides a meter box aging detection method and device based on vibration analysis. First, a meter box vibration signal collected by a vibration sensor is acquired, the meter box vibration signal is preprocessed to obtain a meter box signal to be analyzed, the meter box signal to be analyzed is fast Fourier transformed to obtain the frequency spectrum information of the meter box signal to be analyzed, the frequency spectrum information detected for the first time after the meter box is installed and the frequency spectrum information detected by the meter box after a period of time are acquired, and the comparison results are obtained after the comparison results are compared. Through the comparison results, the status information of the meter box can be accurately known, and the status information of the meter box is transmitted to the electric meter, and the electric meter transmits it to the remote terminal. The staff does not need to reach the area where the meter box is installed to detect the meter box to accurately know the status of the meter box, which is convenient for replacing the aged and damaged meter box and ensuring the normal operation of the meter box. At the same time, the time and energy of the staff are effectively saved and the inspection cost is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A flow chart of a meter box aging detection method based on vibration analysis provided by the present invention.

[0034] Figure 2 A structural block diagram of a meter box aging detection device based on vibration analysis provided by the present invention.

[0035] Figure 3 This is a vibration signal diagram collected when the meter box provided by the present invention is intact.

[0036] Figure 4 This is a vibration signal diagram collected when the meter box provided by the present invention is aged.

[0037] Figure 5 This is a vibration signal diagram collected when the meter box provided by the present invention is damaged.

[0038] Figure 6 The vibration signal spectrum when the meter box provided by the present invention is intact.

[0039] Figure 7 The present invention provides a vibration signal spectrum of a meter box during aging.

[0040] Figure 8 The vibration signal spectrum when the meter box provided by the present invention is damaged. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0042] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0043] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0044] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0045] In order to fully understand the present invention, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0046] See also Figure 1 The first aspect of the present invention discloses a meter box aging detection method based on vibration analysis, the method comprising:

[0047] S1, obtaining a meter box vibration signal collected by a vibration sensor;

[0048] S2, obtaining a meter box signal to be analyzed after preprocessing the meter box vibration signal;

[0049] S3, obtaining spectrum information of the signal to be analyzed in the meter box after performing fast Fourier transform on the signal to be analyzed in the meter box, wherein the spectrum information includes the number of peaks in the spectrum and the frequency value of the main peak with the maximum energy;

[0050] S4, obtaining initial data information of the meter box, where the initial data information is spectrum information detected for the first time after the meter box is installed;

[0051] S5, obtaining interval data information of the meter box n times, where the interval data information is spectrum information detected by the meter box at intervals;

[0052] S6, based on the initial data information and the n-time interval data information, respectively compare and obtain a comparison result;

[0053] S7. Based on the comparison result, determine the status information of the meter box.

[0054] Discrete Fourier Transform (DFT), Fourier analysis method is the most basic method of signal analysis, Fourier transform is the core of Fourier analysis, through which the signal is transformed from time domain to frequency domain, and then the spectral structure and change law of the signal are studied. Fast Fourier Transform (FFT) is a general term for efficient and fast calculation methods of discrete Fourier transform using computers.

[0055] The micro vibrator is installed on the wall of the meter box. The micro vibrator can stimulate the meter box to vibrate while generating vibration. The vibration sensor in the meter box can synchronously sample the vibration signal of the meter box. s (t), obtain the meter box vibration signal x collected by the vibration sensor s (t), the vibration signal x s (t) is preprocessed to obtain the meter box signal to be analyzed x(t). The meter box signal to be analyzed x(t) is transformed by fast Fourier transform to obtain the spectrum information of the meter box signal to be analyzed x(t). The number of peak spectra with obvious peaks in the spectrum N is counted. f And the frequency values ​​of the first two main peaks with the largest energy f i An obvious peak refers to a peak with a 3dB bandwidth less than 2Hz. The spectrum information obtained from the first run test after the meter box is installed is used as the initial data information, that is, the reference data. Thereafter, at regular intervals, for example, the frequency information obtained from the run test once every half a month is used as the interval data information. After running n times, n groups of interval data information are obtained. The comparison results can be obtained by comparing the initial data information and the n groups of interval data information respectively. According to the comparison results, the status information of the meter box can be accurately judged. The status information of the meter box includes the meter box being in good condition, the meter box being in aging condition, and the meter box being in damaged condition. The status information of the meter box is transmitted to the electric meter, and the electric meter transmits it to the remote terminal, so that the staff can replace the meter box after knowing it.

[0056] Furthermore, step S1 specifically includes:

[0057] The Bluetooth SOC controls the micro vibrator to excite the meter box to vibrate;

[0058] The Bluetooth SOC controls the vibration sensor to collect the vibration signal of the meter box.

[0059] The Bluetooth SOC can control the micro vibrator to simulate the hammer to produce a 200ms instantaneous vibration, which is used to stimulate the meter box to produce a free damping vibration. After the micro vibrator is stimulated to vibrate, the Bluetooth SOC controls the vibration sensor to synchronously sample the meter box vibration signal x within 2s. s (t).

[0060] Furthermore, the preprocessing specifically includes:

[0061] Remove part of the signal before the end of the vibration generated by the micro vibrator excitation meter box;

[0062] Remove the DC component of the subsequent meter box vibration signal.

[0063] The vibration signal x generated by the micro vibrator to stimulate the meter box s (t) Remove the partial signal before the end of vibration, and remove the subsequent meter box vibration signal x s The DC component of (t) is obtained to obtain the meter box signal to be analyzed x(t), which is convenient for the subsequent fast Fourier transform of the meter box signal to be analyzed x(t).

[0064] Furthermore, based on the initial data information and the n-time interval data information, comparison results are obtained after comparison, including:

[0065] Compare the frequency values ​​of the first two main peaks with the maximum energy detected at the first time with the frequency values ​​of the first two main peaks with the maximum energy detected at intervals n times, and obtain the average value of the frequency value change of the first two main peaks with the maximum energy. Record the set of n average values ​​as A n ;

[0066] Compare the number of peak spectra of the first obvious peak detected with the number of peak spectra of the obvious peak detected after n intervals for n times respectively, and obtain the change in the number of peak spectra of the obvious peak. Record the set of n changes as B n .

[0067] After the meter box is installed, the first run test is performed to obtain the frequency values ​​of the first two main peaks with the largest energy in the spectrum and the number of peak spectra with obvious peaks. The subsequent run test is performed every half a month to obtain the frequency values ​​of the first two main peaks with the largest energy and the number of peak spectra with obvious peaks. The first and subsequent frequency values ​​are compared respectively. The test is performed every half a month for a total of n times, that is, the frequency value of the first test is compared with the frequency value of the n tests respectively. Due to the long-term operation of the meter box, it will cause aging and damage, etc. The frequency values ​​of the first two main peaks with the largest energy obtained in the subsequent test will change compared with the first time. The set of average values ​​of the changes in n frequency values ​​is recorded as A n , the number of peak spectra with obvious peaks detected for the first time and the number of peak spectra with obvious peaks detected for n times are compared n times respectively, and the set of changes in the number of peak spectra with obvious peaks is recorded as B n .

[0068] Further, based on the comparison result, the status information of the meter box is judged, specifically including:

[0069] If A nIf there is a value greater than the first threshold value in the data, it is determined that the meter box is in an aging state;

[0070] If A n There is a value greater than the second threshold value and B n If there is a value greater than the third threshold value, it is determined that the meter box is in a damaged state.

[0071] A is a set of average values ​​of frequency value changes n and the set B of changes in the number of peak spectra with obvious peaks n , the first threshold can be set to 1Hz, the second threshold can be set to 2Hz, and the third threshold can be set to 2. n and B n are all sets of multiple values. When A n If a value greater than 1Hz appears in the frequency spectrum, it indicates that the structure of the meter box has aged. n There is no value greater than 2 in the table, so it is impossible to determine whether the meter box structure is damaged. n A value greater than 2 Hz appears in B n When a value greater than 2 appears in the value, it indicates that the structure of the meter box is damaged.

[0072] See also Figure 2 The second aspect of the present invention discloses a meter box aging detection device based on vibration analysis, which is used to implement the time-varying temperature control method of the oil-paper insulation bushing as described in the first aspect of the present invention, and the device comprises:

[0073] A micro vibrator is used to excite the meter box to vibrate;

[0074] A vibration sensor is used to collect vibration signals generated after the meter box is excited;

[0075] Bluetooth SOC, used to obtain the vibration signal of the meter box collected by the vibration sensor, perform data analysis, and transmit the analysis results to the electric meter via Bluetooth, and then transmit them to the remote terminal through the electric meter;

[0076] Power supply, used to power micro vibrator, vibration sensor and Bluetooth SOC.

[0077] Bluetooth SOC is a system-level chip with the functions of data collection, data analysis and data transmission. The remote terminal can be a computer. The power supply can convert the mains power of the meter box into weak DC power to power the micro vibrator, vibration sensor and Bluetooth SOC. The micro vibrator is similar to a mobile phone vibrator. The micro vibrator is attached to the wall of the meter box. After the micro vibrator generates vibration, it can stimulate the meter box to vibrate. The vibration sensor can use a MEMS vibration sensor chip, which is installed in the meter box. It can sense the vibration generated by the meter box after being stimulated by the micro vibrator and collect the vibration signal of the meter box.s (t), Bluetooth SOC can collect the vibration signal x collected by the vibration sensor s (t), after preprocessing, the meter box signal to be analyzed x(t) is obtained, and then data analysis is performed, and the final analysis result, that is, the status information of the meter box, is uploaded to the meter, and the meter then uploads it to the remote terminal for the staff to know.

[0078] The calculation formula for the stiffness change and vibration mode change of the meter box caused by the structural change of the meter box is as follows:

[0079] k=P / δ

[0080] P represents the constant force acting on the meter box structure, and δ represents the deformation of the meter box caused by the force;

[0081] When the meter box material ages, such as a plastic meter box becomes brittle, the deformation caused by force will become larger and the stiffness will decrease. The vibration mode refers to the inherent vibration form of the elastic or elastic system itself.

[0082] The undamped vibration equation for a first-order degree of freedom system is given by:

[0083]

[0084] m represents the mass of the system, and k represents the stiffness of the system;

[0085] The natural vibration frequency of the system is calculated as follows:

[0086]

[0087] ω n Represents the natural vibration frequency of the system;

[0088] The vibration response of the system is calculated as follows:

[0089] x(t)=c1sinω n t+c2sinω n t

[0090] Both c1 and c2 represent amplitude coefficients.

[0091] A single degree of freedom has only one vibration mode, and the natural vibration frequency is ω n , if the system stiffness k decreases, the natural vibration frequency ω n Will also decrease accordingly.

[0092] The general structure is basically a multi-degree-of-freedom system with multiple vibration modes, which also correspond to multiple natural frequencies. When the structure of the multi-degree-of-freedom system changes, the vibration mode will also change accordingly. For example, when the meter box structure is initially aged, the stiffness decreases, the vibration mode is similar, but the natural vibration frequency will decrease; when the meter box structure ages further, the stiffness decreases significantly and the vibration damping increases; when the meter box structure is deformed or damaged, the structure becomes more complex, the degrees of freedom increase, and the number of natural vibration frequencies will also increase accordingly.

[0093] For example, see Figures 3 to 5 The micro vibrator generates vibration to excite the meter box to vibrate. The vibration sensor collects the meter box vibration signal with a sampling rate of 2KHz. After the meter box is excited, the vibration signal gradually decays. The one-second signal at the beginning of the collection is taken as an example for analysis.

[0094] Analyze the vibration signal of the meter box collected after the meter box is first excited, and record the number of peak spectra N f and the frequency value f of the two main peaks with the largest energy i .

[0095] See also Figures 6 to 8 After the new meter box is stimulated, there are only two obvious peaks in the spectrum, and the actual frequency values ​​are 124Hz and 281Hz. After the meter box is aged, there are three obvious peaks in the spectrum, and the actual frequency values ​​are 122Hz, 278Hz, and 288Hz. That is, the frequency values ​​of the corresponding first two main peaks with the largest energy have shifted by 2Hz and 3Hz respectively, and the average value of the frequency value change is 2.5Hz, which is greater than 1Hz, indicating that the meter box has aged. However, since the number of peak spectra has increased by 1 and is less than 2, it cannot be determined whether the meter box is damaged.

[0096] After the meter box is aged, there are multiple peak spectra with obvious peaks in the frequency spectrum. The actual frequency values ​​of the first 6 obvious peaks are 120Hz, 274Hz, 290Hz, 345Hz, 47Hz, and 187Hz. The corresponding frequency values ​​of the first two main peaks with the largest energy are offset by 4Hz and 7Hz respectively. The average value of the frequency value change is 5.5Hz, which is greater than 2Hz. The number of peak spectra has increased by 4 compared to the first time, which is greater than 2. It is judged that the meter box is damaged. The Bluetooth SOC will transmit the analysis data to the meter, and the meter will transmit it to the remote terminal, so that the staff can replace the aging and damaged meter box after knowing it.

[0097] 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, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A meter box aging detection method based on vibration analysis, characterized in that: The method comprises: S1, obtaining a meter box vibration signal collected by a vibration sensor; The step S1 specifically includes: The Bluetooth SOC controls the micro vibrator to excite the meter box to vibrate; The Bluetooth SOC controls the vibration sensor to collect the vibration signal of the meter box; S2, obtaining a meter box signal to be analyzed after preprocessing the meter box vibration signal; The pre-processing specifically includes: Remove part of the signal before the end of the vibration generated by the micro vibrator excitation meter box; Remove the DC component of the subsequent meter box vibration signal; S3, obtaining spectrum information of the signal to be analyzed in the meter box after performing fast Fourier transform on the signal to be analyzed in the meter box, wherein the spectrum information includes the number of peaks in the spectrum and the frequency value of the main peak with the maximum energy; S4, obtaining initial data information of the meter box, where the initial data information is spectrum information detected for the first time after the meter box is installed; S5, obtaining interval data information of the meter box n times, where the interval data information is spectrum information detected by the meter box at intervals; S6, based on the initial data information and the n-time interval data information, respectively compare and obtain a comparison result; S7. Based on the comparison result, determine the status information of the meter box.

2. The method for detecting meter box aging based on vibration analysis according to claim 1 is characterized in that: The comparison results are obtained by comparing the initial data information and the n-time interval data information respectively, specifically including: Compare the frequency values ​​of the first two main peaks with the maximum energy detected at the first time with the frequency values ​​of the first two main peaks with the maximum energy detected at intervals n times, and obtain the average value of the frequency value change of the first two main peaks with the maximum energy. Record the set of n average values ​​as A n ; Compare the number of peak spectra of the first obvious peak detected with the number of peak spectra of the obvious peak detected after n intervals for n times respectively, and obtain the change in the number of peak spectra of the obvious peak. Record the set of n changes as B n .

3. The method for detecting meter box aging based on vibration analysis according to claim 2 is characterized in that: The determining of the status information of the meter box based on the comparison result specifically includes: If A n If there is a value greater than the first threshold value in the data, it is determined that the meter box is in an aging state; If A n There is a value greater than the second threshold value and B n If there is a value greater than the third threshold value, it is determined that the meter box is in a damaged state.

4. A meter box aging detection method based on vibration analysis according to any one of claims 1 to 3, characterized in that: The method is applied to a meter box aging detection device based on vibration analysis, and the device comprises: A micro vibrator is used to excite the meter box to vibrate; A vibration sensor is used to collect vibration signals generated after the meter box is excited; Bluetooth SOC, used to obtain the vibration signal of the meter box collected by the vibration sensor, perform data analysis, and transmit the analysis results to the electric meter via Bluetooth, and then transmit them to the remote terminal through the electric meter; Power supply, used to power micro vibrator, vibration sensor and Bluetooth SOC.

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