Single-phase earth fault signal gravity center frequency extraction method, system, chip and equipment
By performing low-pass filtering, normalization and bandpass filtering on single-phase grounding fault signals, calculating the center of gravity frequency of the signal, solving the problems of difficulty in fault line selection and positioning in the existing technology, and achieving more accurate fault diagnosis.
Patent Information
- Application Number
- CN202311541288.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-17
- Publication Date
- 2025-03-14
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
When handling single-phase grounding fault signals, it is difficult to accurately select and locate faults, mainly due to the large zero-sequence impedance, complex grounding patterns, and environmental noise interference.
The single-phase grounding fault signal is preprocessed by low-pass filtering, normalization and bandpass filtering, and the center of gravity frequency of the signal is calculated to provide characteristic quantities for fault line selection and positioning.
By extracting the center of gravity frequency of the signal, the influence of environmental noise and interference can be effectively reduced, the accuracy of fault line selection and positioning can be improved, and a characteristic quantity for fault line selection and positioning can be provided.
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Figure CN119619697A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of distribution network fault signal processing, and in particular relates to a method, system, chip and device for extracting the centroid frequency of a single-phase grounding fault signal. Background Art
[0002] The advantage of a low-current grounding system is that the zero-sequence current of a grounding fault is small, but the weak zero-sequence current is often mixed with various interference signals, which increases the difficulty of accurately selecting the line for fault judgment. For a long time, people have done a lot of research on this issue, and based on different principles, have proposed many solutions, developed line selection devices, and achieved certain applications in actual work. From the perspective of field use, the line selection effects of these methods are not very ideal, and there are widespread cases of misselection and missed selection. The main reasons are:
[0003] (1) The zero-sequence impedance of the small current grounding system is large and is affected by the fault grounding transition impedance and various interference factors. The fault current is relatively weak and the difference between the fault line and the non-fault line is not obvious;
[0004] (2) The grounding forms are complex and varied, such as metal grounding, lightning discharge grounding, tree branch grounding, resistance grounding, poor insulation grounding, arc grounding, etc. Arc grounding includes short-gap discharge arc, long-gap discharge arc, intermittent arc, etc. Therefore, the fault characteristic quantity measured by the fault line selection device has great uncertainty, and no line selection method can guarantee to be effective for all fault types.
[0005] After the fault signal is transmitted to the substation through overhead lines or cables, it will be attenuated, and the interference of certain intensity of environmental noise will affect the effect of single-phase grounding fault diagnosis. Therefore, it is necessary to filter the signal to reduce the impact of environmental noise on the fault signal.
[0006] The center of gravity frequency can describe the frequency of the signal component with a larger component in the frequency spectrum, and reflect the distribution of the signal power spectrum. In other words, for a given frequency band range, the energy contained in the frequency range below the center of gravity frequency is half of the total signal energy. The center of gravity frequency is a weighted average with the amplitude of the power spectrum as the weight, so the center of gravity frequency will move to a position with a larger power spectrum amplitude. The patent of this invention collects and processes the signal, and finally calculates the center of gravity frequency of the signal, providing a basis for subsequent single-phase grounding fault line selection and positioning. Summary of the invention
[0007] The technical problem to be solved by the present invention is to provide a method, system, chip and device for extracting the centroid frequency of a single-phase grounding fault signal in view of the deficiencies in the above-mentioned prior art, so as to solve the technical problem of the difficulty in line selection and positioning of a single-phase grounding fault.
[0008] The present invention adopts the following technical solutions:
[0009] A method for extracting the centroid frequency of a single-phase grounding fault signal comprises the following steps: collecting the single-phase grounding fault signal of a distribution network line; performing low-pass filtering on the single-phase grounding fault signal of the distribution network line; normalizing the signal after the low-pass filtering; performing band-pass filtering on the normalized signal; and calculating the centroid frequency of the signal using the obtained signal.
[0010] Specifically, the single-phase grounding fault signal x of the distribution network line is:
[0011] x=s*S S +t*S t
[0012] Where s represents the amplitude of the steady-state component of the fault signal, t represents the amplitude of the transient component of the fault signal, S S is the steady-state component of the fault signal, S t is the transient component of the fault signal.
[0013] Specifically, hardware filtering is used to perform low-pass filtering on the single-phase grounding fault signal of the distribution network line.
[0014] Furthermore, the hardware filtering uses a Butterworth low-pass filter.
[0015] Specifically, the normalized signal x′ is:
[0016]
[0017] Among them, x is the signal collected and processed by low-pass filtering, x min is the minimum value of signal x, x max is the maximum value of signal x.
[0018] Specifically, the upper cutoff frequency of the bandpass filtering process is 50 kHz, and the lower cutoff frequency is 250 Hz.
[0019] Specifically, the signal center of gravity frequency S is calculated as follows:
[0020]
[0021] Among them, f k is the frequency amplitude of the corresponding point, P(k) is the corresponding power spectrum value, and N is the number of sampling points.
[0022] In a second aspect, an embodiment of the present invention provides a system for extracting centroid frequency of a single-phase ground fault signal, comprising:
[0023] Acquisition module, collecting single-phase grounding fault signals of distribution network lines;
[0024] The first filtering module performs low-pass filtering on the single-phase grounding fault signal of the distribution network line obtained by the acquisition module;
[0025] A normalization module, performing normalization processing on the signal processed by the low-pass filtering of the first filtering module;
[0026] A second filtering module performs bandpass filtering on the signal normalized by the normalization module;
[0027] The extraction module calculates the centroid frequency of the signal using the signal obtained by the second filtering module.
[0028] In a third aspect, a chip includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for extracting the centroid frequency of a single-phase grounding fault signal when executing the computer program.
[0029] In a fourth aspect, an embodiment of the present invention provides an electronic device, including a chip, which, when executed, implements the steps of the above-mentioned method for extracting the centroid frequency of a single-phase grounding fault signal.
[0030] Compared with the prior art, the present invention has at least the following beneficial effects:
[0031] A method for extracting the centroid frequency of a single-phase ground fault signal obtains a frequency domain feature of a ground fault signal by filtering and normalizing the collected data and calculating the centroid frequency of the signal.
[0032] Furthermore, the use of hardware filtering to perform low-pass filtering on the single-phase grounding fault signal of the distribution network line can filter out noise signals and eliminate the impact of line lightning strikes or operational overvoltages on the system.
[0033] Furthermore, the use of a Butterworth low-pass filter in hardware filtering can ensure that the frequency response curve in the channel is as flat as possible without ripples, and gradually decreases to zero in the stop band.
[0034] Furthermore, the upper cutoff frequency of the bandpass filter is 50kHz and the lower cutoff frequency is 250Hz, which can filter out most of the noise and interference, while reducing the influence of the DC and fundamental wave components.
[0035] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.
[0036] In summary, the present invention combines the advantages of the Butterworth low-pass filter and the waveform centroid frequency calculation method to process the single-phase grounding fault signal into a characteristic quantity that characterizes the occurrence of the fault, which not only reduces the influence of environmental noise and interference, but also reduces the influence of the fundamental wave and DC components on the calculation.
[0037] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Figure 1 It is a flow chart of the present invention;
[0039] Figure 2 This is a schematic diagram of a Butterworth low-pass filter;
[0040] Figure 3 A schematic diagram of a computer device provided by an embodiment of the present invention.
[0041] Figure 4 The block diagram of a chip provided according to an embodiment of the present invention. DETAILED DESCRIPTION
[0042] 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0043] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.
[0044] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.
[0045] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.
[0046] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.
[0047] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.
[0048] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.
[0049] The present invention provides a method for extracting the centroid frequency of a single-phase grounding fault signal, which collects system fault current and voltage signals, performs environmental noise filtering, normalizes and performs bandpass filtering, and finally obtains the centroid frequency of the signal by calculation, aiming to eliminate the influence of environmental noise and obtain a characteristic quantity for fault line selection and positioning.
[0050] The present invention provides a method for extracting the centroid frequency of a single-phase ground fault signal, comprising the following steps:
[0051] S1. Data collection and extraction of single-phase ground fault signals of distribution network lines;
[0052] The collected fault signal includes a current signal or a voltage signal, and the fault signal x is:
[0053] x=s*S S +t*S t
[0054] Among them, s represents the steady-state classification of the fault signal, t represents the transient component of the fault signal, and x is the collected signal.
[0055] S2, low-pass filtering the raw data to filter out high-frequency noise;
[0056] See also Figure 2 The low-pass filtering of the signal is realized by hardware filtering, and the hardware filtering is a Butterworth low-pass filter, where C1=39.34nF, C2=127.32nF, C3=39.34nF, L1=257.52μH, L2=257.52μH.
[0057] S3, normalizing the filtered data;
[0058] The signal normalization processing formula is:
[0059]
[0060] Among them, x is the signal collected and processed by low-pass filtering, x min is the minimum value of signal x, x max is the maximum value of signal x, and x′ is the normalized signal.
[0061] S4, performing bandpass filtering on the data;
[0062] Software bandpass filtering reduces the impact of DC and power frequency components on the center of gravity frequency calculation;
[0063] The data was band-pass filtered with an upper cut-off frequency of 50 kHz and a lower cut-off frequency of 250 Hz to reduce the influence of DC and power frequency components on the subsequent center of gravity frequency calculation.
[0064] S5. Calculate the center of gravity frequency of the signal.
[0065] The signal center of gravity frequency S is calculated as follows:
[0066]
[0067] Among them, f k is the frequency amplitude of the corresponding point, P(k) is the corresponding power spectrum value, N is the number of sampling points, and S is the calculated signal centroid frequency.
[0068] In another embodiment of the present invention, a single-phase grounding fault signal center of gravity frequency extraction system is provided, which can be used to implement the above-mentioned single-phase grounding fault signal center of gravity frequency extraction method. Specifically, the single-phase grounding fault signal center of gravity frequency extraction system includes an acquisition module, a first filtering module, a normalization module, a second filtering module and an extraction module.
[0069] Among them, the acquisition module collects the single-phase grounding fault signal of the distribution network line;
[0070] The first filtering module performs low-pass filtering on the single-phase grounding fault signal of the distribution network line obtained by the acquisition module;
[0071] A normalization module, performing normalization processing on the signal processed by the low-pass filtering of the first filtering module;
[0072] A second filtering module performs bandpass filtering on the signal normalized by the normalization module;
[0073] The extraction module calculates the centroid frequency of the signal using the signal obtained by the second filtering module.
[0074] In another embodiment of the present invention, a terminal device is provided, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the single-phase ground fault signal center of gravity frequency extraction method, including:
[0075] Collect the single-phase grounding fault signal of the distribution network line; perform low-pass filtering on the obtained single-phase grounding fault signal of the distribution network line; normalize the signal after low-pass filtering; perform band-pass filtering on the normalized signal; and use the obtained signal to calculate the center of gravity frequency of the signal.
[0076] See also Figure 3 , the terminal device is a computer device, and the computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, the method for calculating the fluid composition in the reservoir transformation wellbore in the embodiment is realized. To avoid repetition, it is not described one by one here. Alternatively, when the computer program 63 is executed by the processor 61, the functions of each model / unit in the centroid frequency extraction system of the single-phase grounding fault signal in the embodiment are realized. To avoid repetition, it is not described one by one here.
[0077] The computer device 60 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will appreciate that Figure 3 This is only an example of the computer device 60 and does not constitute a limitation of the computer device 60. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, buses, etc.
[0078] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.
[0079] The memory 62 may be an internal storage unit of the computer device 60, such as a hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the computer device 60.
[0080] Furthermore, the memory 62 may include both an internal storage unit of the computer device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or is to be output.
[0081] See also Figure 4 , the terminal device is a chip, and the chip 600 of this embodiment includes a processor 622, which may be one or more, and a memory 632 for storing a computer program executable by the processor 622. The computer program stored in the memory 632 may include one or more modules, each corresponding to a set of instructions. In addition, the processor 622 may be configured to execute the computer program to execute the above-mentioned single-phase ground fault signal centroid frequency extraction method.
[0082] In addition, the chip 600 may further include a power supply component 626 and a communication component 650, wherein the power supply component 626 may be configured to perform power management of the chip 600, and the communication component 650 may be configured to implement communication, for example, wired or wireless communication, of the chip 600. In addition, the chip 600 may further include an input / output (I / O) interface 658. The chip 600 may operate based on an operating system stored in the memory 632.
[0083] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory, or a non-volatile memory (Non-Volatile Memory), such as at least one disk memory.
[0084] The processor may load and execute one or more instructions stored in a computer-readable storage medium to implement the corresponding steps of the method for extracting the centroid frequency of a single-phase ground fault signal in the above embodiment; the processor may load and execute the following steps:
[0085] Collect the single-phase grounding fault signal of the distribution network line; perform low-pass filtering on the obtained single-phase grounding fault signal of the distribution network line; normalize the signal after low-pass filtering; perform band-pass filtering on the normalized signal; and use the obtained signal to calculate the center of gravity frequency of the signal.
[0086] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0087] The method and system for extracting the centroid frequency of a single-phase grounding fault signal proposed in the present invention uses MATLAB / Simulink simulation software to carry out effect simulation and build a complete simulation model of the distribution network, including transformers, lines, distribution transformers and loads, etc., with a total of 18 outgoing lines with a length of 10km to 18.5km. Based on this model, a study on the extraction of the centroid frequency of a single-phase grounding fault signal is carried out, and single-phase grounding faults with different transition resistance values and fault phases on different lines and different positions are set respectively. The centroid frequency of the signal is extracted in real time using the method of the present invention.
[0088] The results show that the signal centroid frequency characteristics extracted by the centroid frequency extraction method proposed in the present invention have obvious distinction before and after the fault occurs, have strong robustness, and will change monotonically with the location of the fault, which can be used as a basis for positioning.
[0089] In summary, the present invention provides a method, system, chip and device for extracting the centroid frequency of a single-phase grounding fault signal, which performs environmental noise filtering, normalization processing and bandpass filtering on the collected fault current or voltage signal, and obtains the centroid frequency of the signal by calculation, aiming to eliminate the influence of environmental noise and obtain a characteristic quantity for fault line selection and positioning.
[0090] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.
[0091] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0092] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.
[0093] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
[0094] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0095] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.
[0096] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.
[0097] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0098] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.
[0099] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.
[0100] The above contents are only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.
Claims
1. A method for extracting the centroid frequency of a single-phase ground fault signal, characterized in that: Collect the single-phase grounding fault signal of the distribution network line; perform low-pass filtering on the single-phase grounding fault signal of the distribution network line; then normalize the signal after low-pass filtering; perform band-pass filtering on the normalized signal; and use the obtained signal to calculate the center of gravity frequency of the signal.
2. The method for extracting the centroid frequency of a single-phase ground fault signal according to claim 1, characterized in that: The single-phase grounding fault signal x of the distribution network line is: x=s*S S +t*S t Where s represents the amplitude of the steady-state component of the fault signal, t represents the amplitude of the transient component of the fault signal, S S is the steady-state component of the fault signal, S t is the transient component of the fault signal.
3. The method for extracting the centroid frequency of a single-phase ground fault signal according to claim 1, characterized in that: Hardware filtering is used to perform low-pass filtering on the single-phase grounding fault signal of the distribution network line.
4. The method for extracting the centroid frequency of a single-phase ground fault signal according to claim 3, characterized in that: The hardware filtering uses a Butterworth low-pass filter.
5. The method for extracting centroid frequency of single-phase ground fault signal according to claim 1, characterized in that: The normalized signal x′ is: Among them, x is the signal collected and processed by low-pass filtering, x min is the minimum value of signal x, x max is the maximum value of signal x.
6. The method for extracting the centroid frequency of a single-phase ground fault signal according to claim 1, characterized in that: The upper cutoff frequency of the bandpass filter is 50kHz, and the lower cutoff frequency is 250Hz.
7. The method for extracting centroid frequency of a single-phase ground fault signal according to claim 1, characterized in that: The centroid frequency S of the signal is calculated as follows: Among them, f k is the frequency amplitude of the corresponding point, P(k) is the corresponding power spectrum value, and N is the number of sampling points.
8. A single-phase ground fault signal centroid frequency extraction system, characterized in that: include: Acquisition module, collecting single-phase grounding fault signals of distribution network lines; The first filtering module performs low-pass filtering on the single-phase grounding fault signal of the distribution network line obtained by the acquisition module; A normalization module, performing normalization processing on the signal processed by the low-pass filtering of the first filtering module; A second filtering module performs bandpass filtering on the signal normalized by the normalization module; The extraction module calculates the centroid frequency of the signal using the signal obtained by the second filtering module.
9. A chip, characterized in that: a memory having a computer program stored thereon; A processor, configured to execute the computer program in the memory to implement the steps of the method according to any one of claims 1 to 7.
10. An electronic device, characterized in that: Comprising the chip as claimed in claim 9.