Correlation analysis method, device and equipment for partial discharge signals and medium

Abstract

The application discloses a correlation analysis method, device and equipment for partial discharge signals and a medium, and relates to the technical field of partial discharge signal analysis. The method comprises the following steps: acquiring a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor; performing frequency division processing on the first partial discharge signal with the first frequency band by a software filtering method to obtain a partial discharge filtered partial signal with the second frequency band; and performing correlation calculation on the second partial discharge signal and the partial discharge filtered partial signal with the same frequency band to obtain a correlation calculation result. The application can synchronously obtain partial discharge signals of multiple frequency bands and software filtered signals, which can be used as a supplement of frequency division signals to further supplement the data source of correlation analysis, and can improve the reliability of correlation analysis.

Description

Technical Field

[0001] This invention relates to the field of partial discharge detection technology, and in particular to a method, apparatus, device, and medium for correlation analysis of partial discharge signals. Background Technology

[0002] With the continuous development of partial discharge detection technology, existing correlation analysis methods are widely used in the process of locating partial signal discharge in power cables.

[0003] Existing correlation analysis algorithms generally calculate the correlation coefficient directly based on the measured partial discharge signal. However, the transmission of partial discharge signals in cables causes attenuation and dispersion, meaning that the amplitude of signals of different frequencies is attenuated to different degrees during transmission. Since the same partial discharge signal contains many frequency components with different attenuation characteristics, the waveform of the transmitted signal differs significantly from the original signal, i.e., dispersion distortion occurs. This leads to a low correlation coefficient and misjudgment during correlation calculation.

[0004] Therefore, how to solve the problem of large errors in correlation calculation results caused by severe frequency attenuation and dispersion of partial discharge signals during correlation analysis has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a method, apparatus, device, and medium for correlation analysis of partial discharge signals, which solves the problem of large errors in correlation calculation results caused by severe frequency attenuation and dispersion of partial discharge signals during correlation analysis.

[0006] To address the aforementioned technical problems, the first aspect of this invention provides a correlation analysis method for partial discharge signals, comprising:

[0007] A first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band are acquired in a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor;

[0008] The first partial discharge signal with the first frequency band is frequency-divided by software filtering to obtain the partial discharge filtered signal with the second frequency band.

[0009] The correlation between the second partial discharge signal and the filtered partial discharge signal, which are in the same frequency band, is calculated to obtain the correlation calculation result.

[0010] As one preferred embodiment, the second partial discharge signal having a second frequency band includes a first partial discharge signal having a first frequency band, a second partial discharge signal having a second frequency band, and a third partial discharge signal having a third frequency band.

[0011] As one preferred embodiment, acquiring a first partial discharge signal having a first frequency band and a second partial discharge signal having a second frequency band in the power cable includes:

[0012] The partial discharge signal in the power cable is measured by the multi-frequency output sensor; the multi-frequency output sensor has a first gating channel, a second gating channel, a third gating channel and a fourth gating channel;

[0013] When the first selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal having the first frequency band;

[0014] When the second selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal with the first frequency division band;

[0015] When the third selection channel is selected, the multi-frequency output sensor outputs the second partial discharge signal with the second frequency division band;

[0016] When the fourth selection channel is selected, the multi-frequency output sensor outputs the third partial discharge electronic signal with the third frequency division band.

[0017] As one preferred embodiment, the step of performing frequency division processing on the first partial discharge signal having a first frequency band using a software filtering method to obtain a partial discharge filtered signal having a second frequency band includes:

[0018] Construct the frequency domain equations for a bandpass filter with the second frequency band as the cutoff frequency;

[0019] The first partial discharge signal with the first frequency band is subjected to Fourier transform and then multiplied with the frequency domain equation to obtain the frequency domain filtering result;

[0020] Perform an inverse Fourier transform on the frequency domain filtering result to obtain the partial discharge filtered signal with the second frequency band.

[0021] As one preferred embodiment, the partial discharge filtered signal having the second frequency band includes a first partial discharge filtered signal having the first frequency band, a second partial discharge filtered signal having the second frequency band, and a third partial discharge filtered signal having the third frequency band.

[0022] As one preferred embodiment, the multi-frequency output sensor includes a first multi-frequency output sensor and a second multi-frequency output sensor.

[0023] The correlation is calculated using the following formula:

[0024]

[0025] In the formula, R xy The correlation calculation result is given; T is the duration; S(x) is the second partial discharge signal or the partial discharge filtered signal obtained through the first multi-frequency output sensor; S(y) is the second partial discharge signal or the partial discharge filtered signal obtained through the second multi-frequency output sensor.

[0026] A second aspect of the present invention provides a correlation analysis apparatus for partial discharge signals, comprising:

[0027] The signal acquisition module is used to acquire a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in the power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor;

[0028] The filtering module is used to perform frequency division processing on the first partial discharge signal with the first frequency band using a software filtering method to obtain a partial discharge filtered signal with the second frequency band.

[0029] The correlation calculation module is used to perform correlation calculation on the second partial discharge signal and the partial discharge filtered signal with the same frequency band to obtain the correlation calculation result.

[0030] A third aspect of the present invention provides an electronic device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the correlation analysis method for partial discharge signals as described above.

[0031] A fourth aspect of the present invention provides a computer-readable storage medium comprising a stored computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the correlation analysis method for partial discharge signals as described above.

[0032] Compared with the prior art, the beneficial effects of the embodiments of the present invention are at least one of the following:

[0033] (1) This application uses a multi-frequency output sensor to collect high-frequency or low-frequency components in power cables—that is, partial discharge signals with different frequency characteristics—and outputs them through a gating channel for effective differentiation. This solves the problem that in the prior art, the sensor can only obtain a single signal and cannot effectively distinguish the different frequency bands of the signal. When the signal is transmitted over a long distance, the waveform dispersion distortion phenomenon is serious, resulting in poor accuracy of the correlation calculation results.

[0034] (2) The partial discharge signal output by the multi-frequency output sensor is classified into different frequency bands by a software filtering algorithm, providing supplementary waveforms for correlation analysis, further supplementing the data source for correlation analysis, and performing cross-correlation calculation with the frequency division signal output by the multi-frequency output sensor, solving the problem of insufficient data source for correlation analysis in existing methods and improving the reliability of correlation analysis. Attached Figure Description

[0035] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of a correlation analysis method for partial discharge signals provided in a certain embodiment of the present invention;

[0037] Figure 2 This is a flowchart of step S2 provided in a certain embodiment of the present invention;

[0038] Figure 3 This is a structural block diagram of a correlation analysis device for partial discharge signals provided in a certain embodiment of the present invention;

[0039] Figure 4 This is a structural diagram of an electronic device provided in a certain embodiment of the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this application, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. The terms "vertical," "horizontal," "left," "right," "upper," "lower," and similar expressions used herein are for illustrative purposes only and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] In one embodiment, such as Figure 1 As shown, the first aspect of the present invention provides a correlation analysis method for partial discharge signals, comprising:

[0045] S1. Acquire a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor; wherein, the second partial discharge signal with the second frequency band includes a first partial discharge electron signal with a first frequency band, a second partial discharge electron signal with a second frequency band, and a third partial discharge electron signal with a third frequency band.

[0046] Specifically, since there are usually a large number of interference signals at the partial discharge measurement site, and when the frequency of the interference signal is close to that of the partial discharge signal, it will also be input to the subsequent measurement terminal via an HFCT-type sensor. Therefore, in the process of partial discharge localization, most devices will first perform correlation analysis on the measured signals, and then select the time-domain signal with high correlation for localization analysis. This application uses a multi-frequency output sensor to collect partial discharge signals of different frequency bands in power cables. In use, the multi-frequency output sensor is clipped to the grounding wire or cable body of the power cable under test, and the grounding wire or cable body is placed inside the sensor. When a partial discharge signal exists in the cable, a high-frequency current signal will be generated transmitted by the grounding wire or cable body. For most partial discharge signals, the frequency range of the high-frequency current signal is in the range of 100kHz-30MHz. However, for different types of partial discharge, the frequency components contained in the high-frequency current signal often differ greatly. Therefore, if the frequency response curve of the sensor is fixed, it is impossible to guarantee good measurement signals for all types of partial discharge, and a high signal-to-noise ratio cannot be guaranteed.

[0047] To address the aforementioned issues, this application employs a dual-end positioning method. Specifically, an HFCT sensor—a multi-frequency output sensor—is installed on each side of the cable for detection. The measured signals are then used for positioning using a time-difference method. The effective frequency band of the detected partial discharge signal is 0.1-30MHz. Therefore, the total range of the first and second frequency bands measured by the multi-frequency output sensors is the same, both 0.1-30MHz. However, the first partial discharge signal is a full-band signal within the effective range, corresponding to a frequency band of 0.1-30MHz. The second partial discharge signal consists of multiple sub-signals, and the second frequency band also consists of multiple frequency division bands. These include a first partial discharge signal with a first frequency division band of 0.1-12MHz, a second partial discharge signal with a second frequency division band of 12-20MHz, and a third partial discharge signal with a third frequency division band of 20-30MHz. This application uses a multi-frequency output sensor to collect partial discharge signals with different frequency characteristics in power cables, which solves the problem that in the prior art, the sensor can only obtain a single signal and cannot effectively distinguish different frequency bands of the signal, resulting in severe dispersion distortion during waveform transmission.

[0048] In one embodiment, step S1 includes:

[0049] The partial discharge signal in the power cable is measured by the multi-frequency output sensor; the multi-frequency output sensor has a first gating channel, a second gating channel, a third gating channel and a fourth gating channel;

[0050] When the first selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal having the first frequency band;

[0051] When the second selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal with the first frequency division band;

[0052] When the third selection channel is selected, the multi-frequency output sensor outputs the second partial discharge signal with the second frequency division band;

[0053] When the fourth selection channel is selected, the multi-frequency output sensor outputs the third partial discharge electronic signal with the third frequency division band.

[0054] Specifically, the multi-frequency output sensor in this application is designed to acquire the partial discharge signal required by the scheme. It adopts a four-channel design with four different windings. Each winding output terminal is equipped with a 4-to-1 selection switch. (1) Winding 1: Wideband winding, winding turns N=6, and the transmission impedance in the range of 0.1-30MHz is not less than 5V / A; (2) Winding 2: Low frequency winding, winding turns N=8, and the transmission impedance in the range of 0.1-12MHz is greater than 12V / A; (3) Winding 3: Medium frequency winding, winding turns N=4, and its transmission impedance in the range of 12-20MHz is greater than 12V / A; (4) Winding 4: High frequency winding, N=2, and its transmission impedance in the range of 20-30MHz is greater than 12V / A. The selection channels include: CH1 (output terminal of winding 1), CH2 (output terminal of winding 2), CH3 (output terminal of winding 3), and CH4 (output terminal of winding 4).

[0055] Among them, the selection channel CH1 is a normally open channel. Before detecting partial discharge or noise signals, CH1 is used to monitor all signals. Its uniform transmission impedance in each frequency band can be used to achieve real-time monitoring of all signals in a wide frequency band. When partial discharge or noise signals are detected, it is assumed that there may be partial discharge in the cable. Then, the host computer controls the selection of each channel of the sensor to synchronously obtain partial discharge signals of different frequency bands.

[0056] It should be noted that the four-channel sensor described in this application is adapted to a scheme that synchronously outputs four partial discharge signals. When there are five partial discharge signals, then there are five channels in the sensor. That is to say, the number of signals, the number of windings, and the number of channels correspond to each other. However, when setting the windings, the number of turns and the transmission impedance should be set with reference to their corresponding frequency characteristics. The setting conditions should be to enable them to have a good response in the corresponding frequency range.

[0057] S2. The first partial discharge signal with the first frequency band is subjected to frequency division processing by software filtering to obtain the partial discharge filtered signal with the second frequency band;

[0058] In one embodiment, step S2 is as follows Figure 2 As shown, it includes:

[0059] S21. Construct the frequency domain equations for a bandpass filter with the second frequency band as the cutoff frequency; specifically, the second frequency band consists of three sub-bands, so there are also three corresponding frequency domain equations. The cutoff frequencies of the 0.1-12MHz bandpass filter are: f1 = 0.1MHz, f2 = 12MHz, and their corresponding frequency domain equations are:

[0060]

[0061] The cutoff frequencies of the 12-20MHz bandpass filter are f2 = 12MHz and f3 = 20MHz, and its corresponding frequency domain equation is:

[0062]

[0063] The cutoff frequencies of the 20-30MHz bandpass filter are f3 = 20MHz and f4 = 30MHz, and its corresponding frequency domain equation is:

[0064]

[0065] S22. Perform a Fourier transform on the first partial discharge signal with the first frequency band and multiply it by the frequency domain equation to obtain the frequency domain filtering result;

[0066] S23. Perform an inverse Fourier transform on the frequency domain filtering result to obtain the partial discharge filtered signal with the second frequency band; wherein, the partial discharge filtered signal with the second frequency band includes a first partial discharge filtered signal with the first frequency band, a second partial discharge filtered signal with the second frequency band, and a third partial discharge filtered signal with the third frequency band.

[0067] Specifically, this application obtains frequency-divided signals for each frequency band through software filtering. The frequency characteristics of these signals match those of the frequency-divided signals acquired by the sensors. These signals can be used as a supplement to the hardware-output frequency-divided signals to further supplement the data sources for correlation analysis and improve the reliability of the correlation analysis.

[0068] S3. Perform correlation calculation on the second partial discharge signal and the partial discharge filtered signal with the same frequency band to obtain the correlation calculation result; wherein, the multi-frequency output sensor includes a first multi-frequency output sensor and a second multi-frequency output sensor;

[0069] The correlation is calculated using the following formula:

[0070]

[0071] In the formula, R xy The correlation calculation result is given; T is the duration; S(x) is the second partial discharge signal or the partial discharge filtered signal obtained through the first multi-frequency output sensor; S(y) is the second partial discharge signal or the partial discharge filtered signal obtained through the second multi-frequency output sensor.

[0072] Specifically, the above processing method is required for all dual-ended multi-frequency output sensors—HFCTs. Let the two sensors be HFCT1 and HFCT2. After completing the signal acquisition process described above, the following signals from the two test points can be obtained, as shown in the table below:

[0073]

[0074]

[0075] In performing correlation calculations, this application uses the second partial discharge signal or partial discharge filtered signal obtained from the first multi-frequency output sensor and the second partial discharge signal or partial discharge filtered signal obtained from the second multi-frequency output sensor. Please refer to the table below for specific calculation principles:

[0076]

[0077] Wherein, S(x) is the data in the left column of the table above, and S(y) is the data in the middle column of the table above. All of the above data have been normalized. After the above correlation calculation is completed, the average of the 12 correlation results is used as the basis for determining the correlation of the data measured by the two multi-frequency output sensors.

[0078] This application addresses the problem of significant errors in correlation calculation results caused by severe frequency attenuation and dispersion of partial discharge signals during correlation analysis of partial discharge signals. A correlation analysis method for partial discharge signals is designed to achieve this. The method acquires a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band from a power cable. These signals are measured by a multi-frequency output sensor. The first partial discharge signal with the first frequency band is frequency-divided using software filtering to obtain a filtered partial discharge signal with the second frequency band. Correlation calculation is then performed on the second partial discharge signal with the same frequency band and the filtered partial discharge signal to obtain the correlation calculation result. This approach can simultaneously acquire partial discharge signals from multiple frequency bands and software-filtered signals, which can supplement the frequency-divided signals, further enriching the data source for correlation analysis and improving the reliability of the correlation analysis.

[0079] It should be noted that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order requirement for the execution of these steps, and they can be executed in other orders.

[0080] In another embodiment, such as Figure 3 As shown, a second aspect of the present invention provides a correlation analysis apparatus for partial discharge signals, comprising:

[0081] Signal acquisition module 10 is used to acquire a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor;

[0082] The filtering module 20 is used to perform frequency division processing on the first partial discharge signal with the first frequency band using a software filtering method to obtain a partial discharge filtered signal with the second frequency band.

[0083] The correlation calculation module 30 is used to perform correlation calculation on the second partial discharge signal and the partial discharge filtered signal with the same frequency band to obtain the correlation calculation result.

[0084] It should be noted that the various modules in the aforementioned correlation analysis device for partial discharge signals can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. For specific limitations regarding the correlation analysis device for partial discharge signals, please refer to the limitations of the correlation analysis method for partial discharge signals described above; both have the same function and role, and will not be repeated here.

[0085] A third aspect of the present invention provides an electronic device comprising:

[0086] Processor, memory, and bus;

[0087] The bus is used to connect the processor and the memory;

[0088] The memory is used to store operation instructions;

[0089] The processor is configured to execute instructions by calling the operation instructions, causing the processor to perform operations corresponding to a correlation analysis method for partial discharge signals as shown in the first aspect of this application.

[0090] In one alternative embodiment, an electronic device is provided, such as Figure 4 As shown, Figure 4 The illustrated electronic device 5000 includes a processor 5001 and a memory 5003. The processor 5001 and the memory 5003 are connected, for example, via a bus 5002. Optionally, the electronic device 5000 may also include a transceiver 5004. It should be noted that in practical applications, the transceiver 5004 is not limited to one type, and the structure of this electronic device 5000 does not constitute a limitation on the embodiments of this application.

[0091] Processor 5001 may be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 5001 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0092] Bus 5002 may include a path for transmitting information between the aforementioned components. Bus 5002 may be a PCI bus or an EISA bus, etc. Bus 5002 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0093] The memory 5003 may be a ROM or other type of static storage device capable of storing static information and instructions, RAM or other type of dynamic storage device capable of storing information and instructions, or it may be an EEPROM, CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0094] The memory 5003 is used to store application code that executes the scheme of this application, and its execution is controlled by the processor 5001. The processor 5001 is used to execute the application code stored in the memory 5003 to implement the content shown in any of the foregoing method embodiments.

[0095] Among them, electronic devices include, but are not limited to: mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (such as in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers.

[0096] The fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a correlation analysis method for partial discharge signals as shown in the first aspect of this application.

[0097] Another embodiment of this application provides a computer-readable storage medium storing a computer program that, when run on a computer, enables the computer to execute the corresponding content in the aforementioned method embodiments.

[0098] Furthermore, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0099] In summary, this invention discloses a method, apparatus, device, and medium for correlation analysis of partial discharge signals. The method includes acquiring a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band from a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor; the first partial discharge signal with the first frequency band is frequency-divided using a software filtering method to obtain a filtered partial discharge signal with the second frequency band; and the second partial discharge signal with the same frequency band and the filtered partial discharge signal are used to perform correlation calculation to obtain the correlation calculation result. This invention can simultaneously acquire partial discharge signals and software-filtered signals from multiple frequency bands, which can be used as a supplement to the frequency-divided signals to further supplement the data source for correlation analysis and improve the reliability of the correlation analysis.

[0100] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts among the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; refer to the description of the method embodiments for relevant details. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0101] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A correlation analysis method for partial discharge signals, characterized in that, include: A first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band are acquired in a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor; the second partial discharge signal with the second frequency band includes a first partial discharge electron signal with a first frequency division band, a second partial discharge electron signal with a second frequency division band, and a third partial discharge electron signal with a third frequency division band. The first partial discharge signal with a first frequency band is frequency-divided by a software filtering method to obtain a partial discharge filtered signal with a second frequency band; the partial discharge filtered signal with the second frequency band includes a first partial discharge filtered signal with the first frequency band, a second partial discharge filtered signal with the second frequency band, and a third partial discharge filtered signal with the third frequency band. The correlation between the second partial discharge signal and the filtered partial discharge signal with the same frequency band is calculated to obtain the correlation calculation result. The acquisition of a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in the power cable includes: The partial discharge signal in the power cable is measured by the multi-frequency output sensor; the multi-frequency output sensor has a first gating channel, a second gating channel, a third gating channel and a fourth gating channel; When the first selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal having the first frequency band; When the second selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal with the first frequency division band; When the third selection channel is selected, the multi-frequency output sensor outputs the second partial discharge signal with the second frequency division band; When the fourth selection channel is selected, the multi-frequency output sensor outputs the third partial discharge electronic signal with the third frequency division band; The step of performing frequency division processing on the first partial discharge signal with a first frequency band using a software filtering method to obtain a partial discharge filtered signal with a second frequency band includes: Construct the frequency domain equations for a bandpass filter with the second frequency band as the cutoff frequency; The first partial discharge signal with the first frequency band is subjected to Fourier transform and then multiplied with the frequency domain equation to obtain the frequency domain filtering result; Perform an inverse Fourier transform on the frequency domain filtering result to obtain the partial discharge filtered signal with the second frequency band.

2. The correlation analysis method for partial discharge signals according to claim 1, characterized in that, The multi-frequency output sensor includes a first multi-frequency output sensor and a second multi-frequency output sensor; The correlation is calculated using the following formula: In the formula, The result is the correlation calculation result; T Duration; The partial discharge signal obtained by the first multi-frequency output sensor or the partial discharge filtered signal; The partial discharge signal or the partial discharge filtered signal obtained by the second multi-frequency output sensor.

3. A correlation analysis device for partial discharge signals, characterized in that, include: The signal acquisition module is used to acquire a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in a power cable; the first partial discharge signal with the first frequency band and the second partial discharge signal with the second frequency band are measured by a multi-frequency output sensor; the second partial discharge signal with the second frequency band includes a first partial discharge electron signal with a first frequency division band, a second partial discharge electron signal with a second frequency division band, and a third partial discharge electron signal with a third frequency division band. The filtering module is used to perform frequency division processing on the first partial discharge signal having a first frequency band using a software filtering method to obtain a partial discharge filtered signal having a second frequency band; the partial discharge filtered signal having the second frequency band includes a first partial discharge filtered signal having the first frequency band, a second partial discharge filtered signal having the second frequency band, and a third partial discharge filtered signal having the third frequency band. The correlation calculation module is used to perform correlation calculation on the second partial discharge signal and the partial discharge filtered signal with the same frequency band to obtain the correlation calculation result; The acquisition of a first partial discharge signal with a first frequency band and a second partial discharge signal with a second frequency band in the power cable includes: The partial discharge signal in the power cable is measured by the multi-frequency output sensor; the multi-frequency output sensor has a first gating channel, a second gating channel, a third gating channel and a fourth gating channel; When the first selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal having the first frequency band; When the second selection channel is selected, the multi-frequency output sensor outputs the first partial discharge signal with the first frequency division band; When the third selection channel is selected, the multi-frequency output sensor outputs the second partial discharge signal with the second frequency division band; When the fourth selection channel is selected, the multi-frequency output sensor outputs the third partial discharge electronic signal with the third frequency division band; The step of performing frequency division processing on the first partial discharge signal with a first frequency band using a software filtering method to obtain a partial discharge filtered signal with a second frequency band includes: Construct the frequency domain equations for a bandpass filter with the second frequency band as the cutoff frequency; The first partial discharge signal with the first frequency band is subjected to Fourier transform and then multiplied with the frequency domain equation to obtain the frequency domain filtering result; Perform an inverse Fourier transform on the frequency domain filtering result to obtain the partial discharge filtered signal with the second frequency band.

4. An electronic device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the correlation analysis method for partial discharge signals as described in any one of claims 1 to 2.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the correlation analysis method for partial discharge signals as described in any one of claims 1 to 2.

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