A partial discharge signal positioning method, device and equipment based on signal frequency domain amplitude attenuation characteristics and a storage medium

Abstract

The application discloses a partial discharge signal positioning method and device based on signal frequency domain amplitude attenuation characteristics, equipment and a storage medium, and the method comprises the following steps: obtaining a plurality of end synchronous time domain signals of a cable to be measured in a period of time, and obtaining a plurality of signal data groups; taking the pulse signal with the largest amplitude in each signal data group as a template pulse signal; taking the signal data groups other than the signal data group where the template pulse signal is located as a to-be-matched signal data group; taking the pulse signal in the to-be-matched signal data group as a to-be-matched pulse signal; obtaining a selected pulse signal corresponding to the to-be-matched signal group according to the matching degree of the to-be-matched pulse signal and the template pulse signal; performing Fourier transform on the template pulse signal and the selected pulse signal to determine the amplitude; and positioning the partial discharge signal of the cable to be measured according to the amplitude. Through the application, the distortion of the signal waveform can be avoided, and more accurate positioning of the partial discharge signal can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of partial discharge signal positioning, and in particular to a partial discharge signal positioning method and device based on signal frequency domain amplitude attenuation characteristics, a device, an apparatus and a storage medium. BACKGROUND

[0002] With the advent of the intelligent information age, electric energy has become an indispensable energy in people's daily life, and power supply reliability is related to people's daily life and production life. In the urban distribution network system, various voltage level power cables gradually form a complex distribution network. In the distribution system, the insulation state of the power cable is closely related to the partial discharge of the cable. The high-frequency current transformer method is one of the commonly used methods for detecting and positioning partial discharge signals in the cable. The working principle is to detect the high-frequency partial discharge signals flowing through the cable grounding wire through a Rogowski coil current transformer.

[0003] In the prior art, because the propagation speed and attenuation of different frequency components in the partial discharge signal in the cable are different, the signal waveform is distorted, which affects the positioning accuracy of the partial discharge signal.

[0004] Therefore, how to avoid the distortion of the signal waveform and realize more accurate positioning of the partial discharge signal is a problem that needs to be solved. SUMMARY

[0005] The present application provides a partial discharge signal positioning method, device, apparatus and storage medium based on signal frequency domain amplitude attenuation characteristics, which can avoid the distortion of the signal waveform and realize more accurate positioning of the partial discharge signal.

[0006] An embodiment of the present application provides a partial discharge signal positioning method based on signal frequency domain amplitude attenuation characteristics, comprising:

[0007] Respectively acquire a plurality of end-synchronous time domain signals of the cable in a period of time to obtain a plurality of signal data groups;

[0008] The pulse signal with the largest amplitude in each of the above signal data groups is taken as a template pulse signal;

[0009] The signal data group in which the above template pulse signal is located is taken as a selected signal data group, and the other signal data groups except the selected signal data group are taken as to-be-matched signal data groups; each pulse signal in the to-be-matched signal data group is taken as a to-be-matched pulse signal;

[0010] For each to-be-matched signal group, a matching degree of each to-be-matched pulse signal in the to-be-matched signal group and the template pulse signal is calculated, the to-be-matched pulse signal with the highest matching degree is taken as a selected pulse signal, and a selected pulse signal corresponding to each to-be-matched signal group is obtained;

[0011] For the selected pulse signal corresponding to each to-be-matched signal group, Fourier transform is performed on the template pulse signal and the selected pulse signal to determine signal component amplitudes of the template pulse signal and the selected pulse signal at the same frequency;

[0012] The cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance of the to-be-measured cable are obtained, and a distance from a partial discharge point to a cable end corresponding to the template pulse signal is calculated according to the signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, and the position of the partial discharge signal under each selected pulse signal is determined according to the distance.

[0013] Further, before the pulse signal with the maximum amplitude in each signal data group is taken as the template pulse signal, the following steps are further included:

[0014] The pulse extraction operation is repeatedly performed to extract pulse signals from the signal data group until the maximum value of the signal data group is 0, and a plurality of pulse signals are obtained;

[0015] The pulse extraction operation includes the following steps:

[0016] A signal maximum value point is searched in the current signal data group, and the current signal data group at the initial time is the original signal data group without the pulse signal being removed;

[0017] A signal zero-crossing point is searched on both sides of the signal maximum value point, and the signal between the two signal zero-crossing points is taken as a pulse signal, and then the pulse signal is extracted;

[0018] The extracted pulse signal is removed from the current signal data group to obtain an updated current signal data group.

[0019] Further, the calculation of the matching degree of each to-be-matched pulse signal in the to-be-matched signal group and the template pulse signal, the taking of the to-be-matched pulse signal with the highest matching degree as the selected pulse signal, and the obtaining of the selected pulse signal corresponding to each to-be-matched signal group include the following steps:

[0020] For each to-be-matched signal group, a distance between each sequence element in each to-be-matched pulse signal in the to-be-matched signal group and the sequence element of the to-be-matched pulse signal is calculated, and a distance matrix is obtained according to the distance;

[0021] The distance matrix is obtained by accumulating the distances between each element in the distance matrix, and the shortest path distance is extracted;

[0022] The correlation coefficient between the to-be-matched pulse signal and the template pulse signal is calculated.

[0023] According to the shortest path distance and the correlation coefficient, the matching coefficient between the to-be-matched pulse signal and the template pulse signal is calculated.

[0024] The matching coefficients between each to-be-matched pulse signal are compared with each other to obtain the minimum matching coefficient, and the to-be-matched pulse signal corresponding to the minimum matching coefficient is selected as the selected pulse signal, and then the selected pulse signal corresponding to each to-be-matched signal group is obtained.

[0025] Further, for the selected pulse signal corresponding to each to-be-matched signal group, the template pulse signal and the selected pulse signal are subjected to Fourier transform to determine the signal component amplitudes of the template pulse signal and the selected pulse signal at the same frequency, including:

[0026] The to-be-processed pulse signal is subjected to Fourier transform to obtain the frequency domain signal corresponding to the to-be-processed pulse signal: wherein the to-be-processed pulse signal is the template pulse signal or the selected pulse signal corresponding to each to-be-matched signal group;

[0027] According to the frequency domain signal, the amplitude-frequency characteristic curve of the template pulse signal and the selected pulse signal corresponding to each to-be-matched signal group is obtained.

[0028] The signal component amplitudes of the template pulse signal and the selected pulse signal corresponding to each to-be-matched signal group at the same frequency are obtained from the amplitude-frequency characteristic curve.

[0029] Further, the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance of the to-be-measured cable are obtained, and according to the signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated, and according to the distance, the position of the partial discharge signal under each selected pulse signal is determined, including:

[0030] According to the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, the signal propagation attenuation coefficient of the signal on the to-be-measured cable is calculated.

[0031] For each selected pulse signal corresponding to each to-be-matched signal group, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated according to the signal propagation attenuation coefficient, the cable length and the signal component amplitude, and then the position of the partial discharge signal under each selected pulse signal is obtained.

[0032] Based on the above-mentioned method embodiment, the application correspondingly provides a device embodiment;

[0033] The application provides a partial discharge signal positioning device based on signal frequency domain amplitude attenuation characteristics, comprising a signal acquisition module, a template pulse signal determination module, a to-be-matched pulse signal determination module, a selected pulse signal determination module, a signal component amplitude calculation module and a partial discharge signal position calculation module.

[0034] The signal acquisition module is used to acquire a plurality of end-synchronous time domain signals of a cable in a period of time to obtain a plurality of signal data groups.

[0035] The template pulse signal determination module is used to take the pulse signal with the largest amplitude in each signal data group as the template pulse signal.

[0036] The to-be-matched pulse signal determination module is used to take the signal data group where the template pulse signal is located as a selected signal data group, take the other signal data groups except the selected signal data group as to-be-matched signal data groups, and take each pulse signal in the to-be-matched signal data groups as to-be-matched pulse signals.

[0037] The selected pulse signal determination module is used to calculate the matching degree of each to-be-matched pulse signal in the to-be-matched signal group and the template pulse signal for each to-be-matched signal group, take the to-be-matched pulse signal with the highest matching degree as the selected pulse signal, and obtain the selected pulse signal corresponding to each to-be-matched signal group.

[0038] The signal component amplitude calculation module is used to perform Fourier transform on the template pulse signal and the selected pulse signal for each selected pulse signal corresponding to each to-be-matched signal group to determine a plurality of signal component amplitudes of the template pulse signal and the selected pulse signal at the same frequency.

[0039] The partial discharge signal position calculation module acquires the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance of the cable to be measured, calculates the distance from the partial discharge point to the cable end corresponding to the template pulse signal according to the plurality of signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, and determines the position of the partial discharge signal under each selected pulse signal according to the distance.

[0040] On the basis of the above-mentioned method embodiment, the application correspondingly provides a terminal device embodiment;

[0041] The application provides a terminal device, which comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, and the processor executes the computer program to realize the partial discharge signal positioning method based on signal frequency domain amplitude attenuation characteristics according to any one of the embodiments of the application.

[0042] On the basis of the above-mentioned method embodiment, the application correspondingly provides a storage medium embodiment;

[0043] The application provides a storage medium, which comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, and the processor executes the computer program to realize the partial discharge signal positioning method based on signal frequency domain amplitude attenuation characteristics according to any one of the embodiments of the application.

[0044] The embodiments of the application have the following beneficial effects:

[0045] This invention provides a method, apparatus, device, and storage medium for locating partial discharge signals based on the amplitude attenuation characteristics of signals in the frequency domain. The method first acquires several end-synchronous time-domain signals of the cable under test over a period of time, obtaining several signal data groups. Then, the pulse signal with the largest amplitude in each of the aforementioned signal data groups is used as a template pulse signal. Next, the signal data group containing the template pulse signal is designated as the selected signal data group, and the other signal data groups are designated as signal data groups to be matched. Each pulse signal in the signal data groups to be matched is designated as a pulse signal to be matched. Then, for each signal data group to be matched, the degree of matching between each pulse signal to be matched and the template pulse signal is calculated, and the signal with the highest degree of matching is selected. The pulse signal to be matched is used as the selected pulse signal to obtain the selected pulse signal corresponding to each group of signals to be matched. Then, for the selected pulse signal corresponding to each group of signals to be matched, the template pulse signal and the selected pulse signal are subjected to Fourier transform to determine the amplitude of several signal components of the template pulse signal and the selected pulse signal at the same frequency. Then, the cable length, distributed resistance, distributed conductance, distributed inductance and distributed capacitance of the cable under test are obtained. Based on the amplitude of the several signal components, cable length, distributed resistance, distributed conductance, distributed inductance and distributed capacitance, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated. Based on the distance, the position of the partial discharge signal under each selected pulse signal is determined. Therefore, this invention transforms the positioning signal pair from the time domain to the frequency domain through Fourier transform. Based on the propagation consistency of signals of the same frequency at the same cable end and the amplitude-frequency attenuation characteristics, the signal is located, avoiding signal distortion in the time domain. Therefore, the positioning error caused by distortion is reduced, and the accuracy of partial discharge signal positioning is improved. Attached Figure Description

[0046] Figure 1 This is a flowchart illustrating a partial discharge signal localization method based on the amplitude attenuation characteristics of a signal in the frequency domain, provided by one embodiment of the invention.

[0047] Figure 2 This is a schematic diagram of dual-end signal acquisition based on a GPS time synchronization cable according to an embodiment of the present invention.

[0048] Figure 3 This is a schematic diagram of the amplitude-frequency characteristic curve of a template pulse signal and a selected pulse signal, and the Fourier transform, provided in an embodiment of the present invention.

[0049] Figure 4 This is a schematic diagram of a device for locating partial discharge signals based on the amplitude attenuation characteristics of signals in the frequency domain, provided by an embodiment of the present invention. Detailed Implementation

[0050] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0051] like Figure 1 As shown, an embodiment of the present invention provides a method for locating partial discharge signals based on the amplitude attenuation characteristics of signals in the frequency domain, comprising:

[0052] Step S101: Acquire the synchronization time domain signals of several ends of the cable under test over a period of time to obtain several signal data groups;

[0053] Specifically, such as Figure 2 As shown, taking a cable at both ends as an example, high-frequency current transformers are connected at the grounding wires of multiple ends of the cable. Based on a GPS time synchronization system and control by a host computer, synchronous signal acquisition at multiple ends is achieved. In the figure, 1 is the satellite antenna, 2 is the host computer, and 3 is the high-frequency current transformer. The host computer controls the signal acquisition unit at both ends of the cable to simultaneously acquire partial discharge pulse signals over a period of time based on the GPS time synchronization pulse signal. The acquired partial discharge signals are saved locally and uploaded to the host computer, where the partial discharge source is located.

[0054] Step S102: Take the pulse signal with the largest amplitude in each of the above signal data groups as the template pulse signal;

[0055] In a preferred embodiment, before using the pulse signal with the largest amplitude in each of the above-mentioned signal data groups as the template pulse signal, the method further includes:

[0056] Repeat the pulse extraction operation to extract pulse signals from the signal data group until the maximum value of the signal in the signal data group is 0, and obtain a number of pulse signals;

[0057] Among them, the above pulse extraction operation:

[0058] Find the maximum value point of the signal in the current signal data set; where the initial current signal data set is the original signal data set without removing pulse signals;

[0059] Using the maximum value of the signal as the center, find the zero-crossing points of the signal on both sides, take the signal between the two zero-crossing points as a pulse signal, and then extract the pulse signal;

[0060] The extracted pulse signal is removed from the current signal data set to obtain the updated current signal data set.

[0061] In this preferred embodiment, the pulse signals are extracted from the signal data set by repeatedly performing the pulse extraction operation until the signal maximum value in the signal data set is 0, and then the pulse signal with the largest amplitude is selected from the pulse signals as the template pulse signal.

[0062] Step S103: The signal data set in which the template pulse signal is located is selected as the selected signal data set, and the signal data sets other than the selected signal data set are selected as the to-be-matched signal data sets; and each pulse signal in the to-be-matched signal data set is selected as the to-be-matched pulse signal.

[0063] In this step, the signal data set in which the template pulse signal is located is selected as the selected signal data set, and the signal data sets other than the selected signal data set are selected as the to-be-matched signal data sets; and each pulse signal in the to-be-matched signal data set is selected as the to-be-matched pulse signal.

[0064] Step S104: For each to-be-matched signal set, the matching degree of each to-be-matched pulse signal in the to-be-matched signal set with the template pulse signal is calculated, and the to-be-matched pulse signal with the highest matching degree is selected as the selected pulse signal, thereby obtaining the selected pulse signal corresponding to each to-be-matched signal set.

[0065] In a preferred embodiment, the calculation of the matching degree of each to-be-matched pulse signal in the to-be-matched signal set with the template pulse signal for each to-be-matched signal set, the selection of the to-be-matched pulse signal with the highest matching degree as the selected pulse signal, and the obtaining of the selected pulse signal corresponding to each to-be-matched signal set include:

[0066] For each to-be-matched signal set, the distance between each sequence element in each to-be-matched pulse signal in the to-be-matched signal set and the sequence element of the to-be-matched pulse signal is calculated, and a distance matrix is obtained according to the distance.

[0067] Preferably, the DTW signal analysis method is combined with the correlation coefficient method to obtain the matching coefficient of each to-be-matched pulse signal in the to-be-matched signal set with the template pulse signal.

[0068] Specifically, the distance between each sequence element in each to-be-matched pulse signal in the to-be-matched signal set and the sequence element of the to-be-matched pulse signal is calculated by the following formula, and a distance matrix is obtained according to the distance.

[0069] M(i,j)=(S(i)-T l (j)) 2 ;

[0070] In the formula, M represents the distance matrix, M(i, j) represents the distance between the ith sequence element of the template pulse signal and the jth sequence element of the ith pulse signal in the set of pulse signals to be matched, S(i) represents the ith sequence element of the template pulse signal, T l (j) represents the jth sequence element of the ith pulse signal to be matched in the set of pulse signals to be matched.

[0071] The distance between each element in the distance matrix is accumulated to obtain a plurality of path distances after accumulation, and the shortest path distance is extracted;

[0072] Specifically, the shortest path distance is calculated by the following formula:

[0073]

[0074] In the formula, D represents the shortest path distance, f(i k ,j k ) represents a normalization function, i k represents an element in the kth row of the distance matrix, j k represents an element in the kth column of the distance matrix, M(i k ,j k ) represents an element in the kth row and kth column of the distance matrix.

[0075] Preferably, the size of D can reflect the matching degree between the template pulse signal and each pulse signal to be matched in the set of pulse signals to be matched.

[0076] The correlation coefficient between the pulse signal to be matched and the template pulse signal is calculated;

[0077] Specifically, the correlation coefficient is calculated by the following formula:

[0078]

[0079] In the formula, p x,y represents the correlation coefficient, x(t) represents the template pulse signal, and y(t) represents a pulse signal in the set of pulse signals to be matched.

[0080] According to the shortest path distance and the correlation coefficient, a matching coefficient between the pulse signal to be matched and the template pulse signal is calculated;

[0081] Specifically, the matching coefficient is calculated by the following formula:

[0082] k = a · D + (1-a) · p x,y ;

[0083] In the formula, k represents the matching coefficient, a represents a weighting coefficient, and the weighting coefficient can be set according to the actual cable operation condition.

[0084] The matching coefficients between the to-be-matched pulse signals are compared with each other to obtain a minimum matching coefficient, and the to-be-matched pulse signal corresponding to the minimum matching coefficient is taken as a selected pulse signal, and then the selected pulse signal corresponding to each to-be-matched signal group is obtained.

[0085] Preferably, through this preferred embodiment, the recognition accuracy of the template pulse signals and the selected pulse signals generated by the same partial discharge from the collected cable signals is effectively improved, and the problem of low recognition matching accuracy caused by the inconsistent distortion degrees of the partial discharge signal waveforms reaching the cable ends due to the position of the partial discharge signal being biased to one end is effectively solved.

[0086] In this preferred embodiment, the distances between the sequence elements in each to-be-matched pulse signal in the to-be-matched signal group and the sequence elements of the to-be-matched pulse signal are calculated, the shortest path distances between the elements in the distance matrix are calculated, the correlation coefficients between the to-be-matched pulse signal and the template pulse signal are calculated, the matching coefficients between the to-be-matched pulse signal and the template pulse signal are calculated through the shortest path distances and the correlation coefficients, the to-be-matched pulse signal corresponding to the minimum matching coefficient is obtained, and finally the selected pulse signal corresponding to each to-be-matched signal group is obtained.

[0087] Step S105: For the selected pulse signal corresponding to each to-be-matched signal group, Fourier transform is performed on the template pulse signal and the selected pulse signal to determine the signal component amplitudes of the template pulse signal and the selected pulse signal at the same frequency.

[0088] In a preferred embodiment, the Fourier transform performed on the template pulse signal and the selected pulse signal to determine the signal component amplitudes of the template pulse signal and the selected pulse signal at the same frequency for the selected pulse signal corresponding to each to-be-matched signal group includes:

[0089] Fourier transform is performed on the to-be-processed pulse signal to obtain a frequency domain signal corresponding to the to-be-processed pulse signal, wherein the to-be-processed pulse signal is the template pulse signal or the selected pulse signal corresponding to each to-be-matched signal group.

[0090] Specifically, Fourier transform is performed on the to-be-processed pulse signal through the following formula:

[0091]

[0092] In the formula, F(jω) represents the pulse signal to be processed after Fourier transform, and f(t) represents the pulse signal to be processed in the time domain.

[0093] Based on the above frequency domain signal, the amplitude-frequency characteristic curves of the template pulse signal and the selected pulse signal corresponding to each of the above signal groups to be matched are obtained;

[0094] The amplitude of the template pulse signal at the same frequency and the amplitude of the selected pulse signal corresponding to each of the signal groups to be matched are obtained from the amplitude-frequency characteristic curves.

[0095] Indicative, such as Figure 3 As shown, Figure 3 Part a is a schematic diagram of the amplitude-frequency characteristic curve of the template pulse signal in the time domain, where U m This represents the voltage amplitude of the template pulse signal mentioned above. Figure 3 Part b is a schematic diagram of the amplitude-frequency characteristic curve of a selected pulse signal in the time domain, where U t This represents the voltage amplitude of the selected pulse signal mentioned above. Figure 3 Part c is the frequency domain diagram of the template pulse signal in the time domain after Fourier transform. Figure 3 The d part is the frequency domain diagram of a selected pulse signal in the time domain after Fourier transform.

[0096] Preferably, assuming the selected signal frequencies are f1, f2, ..., f n To ensure signal validity, the highest frequency fn should be less than 30MHz to prevent noise from interfering with the positioning results. Signal frequencies f1, f2, ..., f... n Template pulse signal U m The amplitude of the signal component is denoted as U m1 U m2 、…、U mn U t1 A selected pulse signal U t The amplitude of the signal component is denoted as U t2 、…、U tn .

[0097] In this preferred embodiment, the template pulse signal in the frequency domain and the selected pulse signal corresponding to each group of signals to be matched are obtained by Fourier transform, and then the amplitude values ​​of several signal components of the template pulse signal and the selected pulse signal corresponding to each group of signals to be matched at the same frequency are obtained.

[0098] Step S106: obtaining the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance of the cable to be tested, and calculating the distance from the partial discharge point to the cable end corresponding to the template pulse signal according to the signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, and determining the position of the partial discharge signal under each selected pulse signal according to the distance.

[0099] In a preferred embodiment, the above-mentioned obtaining the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance of the cable to be tested, and calculating the distance from the partial discharge point to the cable end corresponding to the template pulse signal according to the signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, and determining the position of the partial discharge signal under each selected pulse signal according to the distance, comprises:

[0100] According to the distributed resistance, the distributed conductance, the distributed inductance and the distributed capacitance, the signal propagation attenuation coefficient of the signal on the cable to be tested is calculated.

[0101] Specifically, the signal propagation attenuation coefficient of the signal in the cable to be tested is calculated by the following formula:

[0102]

[0103] In the formula, a represents the signal propagation attenuation coefficient, and the value of a is related to the signal frequency, so for a signal of a certain frequency, a can be considered as a constant, R0 represents the distributed resistance, G0 represents the distributed conductance, ω0 represents the angular frequency, L0 represents the distributed inductance, and C0 represents the distributed capacitance.

[0104] For each selected pulse signal corresponding to the to-be-matched signal group, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated according to the signal propagation attenuation coefficient, the cable length and the signal component amplitude, and then the position of the partial discharge signal under each selected pulse signal is obtained.

[0105] Specifically, according to the transmission line theory, the amplitude attenuation of a single frequency signal in the cable conforms to the exponential decay law, so the attenuation law of the single frequency signal can be obtained by the following formula:

[0106] U0=U i e -αl ;

[0107] In the formula, U i represents the initial voltage amplitude of the single frequency signal, and U o represents the voltage amplitude of the single frequency signal after propagating a distance l.

[0108] Specifically, when the number of ends is two, the position of the partial discharge signal under the selected pulse signal is taken as the final position of the partial discharge signal of the cable to be measured; when the number of ends is more than two, the number of occurrences of each position is counted according to the position of the partial discharge signal under each selected pulse signal, and the position with the largest number of occurrences is taken as the final position of the partial discharge signal of the cable to be measured.

[0109] Specifically, therefore, when the number of ends is two, the distance of the partial discharge to the cable end corresponding to the template pulse signal can be calculated by the following formula:

[0110]

[0111] When the number of ends is more than two, the distance of the partial discharge point corresponding to each selected pulse signal to the cable end corresponding to the template pulse signal can be calculated by the following formula:

[0112]

[0113] In the formula, l i represents the distance of the partial discharge point to the cable end corresponding to the template pulse signal when the number of ends is two, l represents the distance of the partial discharge point corresponding to each selected pulse signal to the cable end corresponding to the template pulse signal when the number of ends is more than two, L represents the cable length, and U mi represents the signal component amplitude of the template pulse signal at frequency i, U ti represents the signal component amplitude of the selected pulse signal at frequency i, and ε i represents a weighting coefficient, the weighting coefficients at different frequencies are all the same, are all 1 / n, and satisfy

[0114] In this preferred embodiment, the position of the partial discharge signal under each selected pulse signal is obtained through the signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance, and the distributed capacitance.

[0115] In this step, the final position of the partial discharge signal of the cable to be measured is obtained by analyzing the obtained position of the partial discharge signal.

[0116] On the basis of the method embodiment, the application provides a device embodiment.

[0117] As Figure 4 shown, an embodiment of the application provides a device for positioning a partial discharge signal based on signal frequency domain amplitude attenuation characteristics, which comprises:

[0118] The signal acquisition module, the template pulse signal determination module, the to-be-matched pulse signal determination module, the selected pulse signal determination module, the signal component amplitude calculation module, and the partial discharge signal position calculation module;

[0119] The signal acquisition module is configured to acquire a plurality of end-synchronous time-domain signals of the cable in a period of time to obtain a plurality of signal data sets.

[0120] The template pulse signal determination module is configured to determine the pulse signal with the largest amplitude in each of the signal data sets as the template pulse signal.

[0121] The to-be-matched pulse signal determination module is configured to determine the signal data set in which the template pulse signal is located as a selected signal data set, determine the signal data sets other than the selected signal data set as to-be-matched signal data sets, and determine the pulse signals in the to-be-matched signal data sets as to-be-matched pulse signals.

[0122] The selected pulse signal determination module is configured to calculate, for each to-be-matched signal data set, the matching degree of each to-be-matched pulse signal in the to-be-matched signal data set with the template pulse signal, determine the to-be-matched pulse signal with the highest matching degree as the selected pulse signal, and obtain the selected pulse signal corresponding to each to-be-matched signal data set.

[0123] The signal component amplitude calculation module is configured to perform Fourier transform on the template pulse signal and the selected pulse signal corresponding to each to-be-matched signal data set to determine a plurality of signal component amplitudes of the template pulse signal and the selected pulse signal at the same frequency.

[0124] The partial discharge signal position calculation module is configured to acquire the cable length, the distributed resistance, the distributed conductance, the distributed inductance, and the distributed capacitance of the cable, calculate the distance from the partial discharge point to the end of the cable corresponding to the template pulse signal according to the plurality of signal component amplitudes, the cable length, the distributed resistance, the distributed conductance, the distributed inductance, and the distributed capacitance, and determine the position of the partial discharge signal under each selected pulse signal according to the distance.

[0125] It should be noted that the apparatus embodiments described above are only illustrative, and the modules described above as separate components can or can not be physically separated, and the components shown as modules can or can not be physical modules, i.e., can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment according to actual needs. In addition, the connection relationship between the modules in the apparatus embodiments provided by the present application indicates that there is a communication connection between them, which can be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor. The above schematic diagram is only an example of a partial discharge signal positioning device based on signal frequency domain amplitude attenuation characteristics, and does not constitute a limitation on a partial discharge signal positioning device based on signal frequency domain amplitude attenuation characteristics, which can include more or fewer components than the diagram, or combine certain components, or different components.

[0126] On the basis of the above-mentioned method embodiments, the present application correspondingly provides terminal device embodiments.

[0127] Another embodiment of the present application provides a terminal device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the partial discharge signal positioning method based on signal frequency domain amplitude attenuation characteristics according to any one of the embodiments of the present application.

[0128] For example, in this embodiment, the computer program can be divided into one or more modules, and the one or more modules are stored in the memory and executed by the processor to complete the present application. The one or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the device.

[0129] The terminal device can be a desktop computer, a notebook computer, a palm computer, a cloud server, and other computing devices. The device can include, but is not limited to, a processor and a memory.

[0130] The processor can be a central processing module (CPU), and can also be 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. The general-purpose processor can be a microprocessor or can also be any conventional processor, etc. The processor is a control center of the device, and is connected with various parts of the device through various interfaces and lines.

[0131] The memory can be used to store the computer program and / or the module, and the processor realizes various functions of the device by running or executing the computer program and / or the module stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function, etc. In addition, the memory can include a high-speed random access memory, and can also include a nonvolatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory devices.

[0132] On the basis of the method embodiment, the application provides a storage medium embodiment.

[0133] Another embodiment of the application provides a storage medium, which includes a stored computer program, wherein the computer program controls a device where the storage medium is located to execute a partial discharge signal positioning method based on signal frequency domain amplitude attenuation characteristics according to any one of the embodiments of the application when the computer program is running.

[0134] In this embodiment, the storage medium is a computer readable storage medium, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, an executable file, or some intermediate form. The computer readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0135] Compared with the prior art, the above-mentioned embodiments of the present application can avoid signal waveform distortion and achieve more accurate positioning of partial discharge signals.

[0136] The above is the preferred embodiment of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which are also considered within the scope of protection of the present application.

Claims

1. A method for locating partial discharge signals based on the amplitude attenuation characteristics of signals in the frequency domain, characterized in that, include: Several end-synchronization time-domain signals of the cable under test are acquired over a period of time to obtain several signal data sets; The pulse signal with the largest amplitude in each of the aforementioned signal data groups is used as the template pulse signal; The signal data group containing the template pulse signal is selected as the selected signal data group, and the other signal data groups besides the selected signal data group are selected as the signal data groups to be matched; each pulse signal in the signal data group to be matched is selected as the pulse signal to be matched. For each group of signal data to be matched, calculate the degree of matching between each pulse signal to be matched and the template pulse signal in the group of signal data to be matched, and take the pulse signal with the highest degree of matching as the selected pulse signal to obtain the selected pulse signal corresponding to each group of signal data to be matched. For each selected pulse signal corresponding to a group of signal data to be matched, perform a Fourier transform on the template pulse signal and the selected pulse signal to determine the amplitude of several signal components of the template pulse signal and the selected pulse signal at the same frequency. The cable length, distributed resistance, distributed conductance, distributed inductance, and distributed capacitance of the cable under test are obtained. Based on the amplitude of the signal components, cable length, distributed resistance, distributed conductance, distributed inductance, and distributed capacitance, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated. Based on the distance, the position of the partial discharge signal under each selected pulse signal is determined.

2. The partial discharge signal localization method based on the frequency domain amplitude attenuation characteristics of a signal according to claim 1, characterized in that, Before using the pulse signal with the largest amplitude in each of the aforementioned signal data groups as the template pulse signal, the process further includes: Repeat the pulse extraction operation to extract pulse signals from the signal data group until the maximum value of the signal in the signal data group is 0, and obtain a number of pulse signals; The pulse extraction operation includes: Find the maximum value point of the signal in the current signal data set; where the initial current signal data set is the original signal data set without removing pulse signals; Using the maximum value of the signal as the center, find the zero-crossing points of the signal on both sides, take the signal between the two zero-crossing points as a pulse signal, and then extract the pulse signal; The extracted pulse signal is removed from the current signal data set to obtain the updated current signal data set.

3. The partial discharge signal localization method based on the frequency domain amplitude attenuation characteristics of a signal according to claim 2, characterized in that, For each group of signal data to be matched, the matching degree between each pulse signal to be matched and the template pulse signal in the group of signal data to be matched is calculated, and the pulse signal with the highest matching degree is selected as the selected pulse signal, thus obtaining the selected pulse signal corresponding to each group of signal data to be matched, including: For each group of signal data to be matched, calculate the distance between each sequence element of each pulse signal to be matched in the group of signal data to be matched and the sequence element of the pulse signal to be matched, and obtain a distance matrix based on the distance. The distances between each pair of elements in the distance matrix are summed to obtain several path distances, and the shortest path distance is extracted. The correlation coefficient between the pulse signal to be matched and the template pulse signal is calculated. Based on the shortest path distance and the correlation coefficient, the matching coefficient between the pulse signal to be matched and the template pulse signal is calculated. The matching coefficients of each pulse signal to be matched are compared with each other to obtain the minimum matching coefficient. The pulse signal to be matched corresponding to the minimum matching coefficient is taken as the selected pulse signal, and then the selected pulse signal corresponding to each group of signal data to be matched is obtained.

4. The partial discharge signal localization method based on the frequency domain amplitude attenuation characteristics of a signal according to claim 3, characterized in that, For each selected pulse signal corresponding to a group of signal data to be matched, a Fourier transform is performed on the template pulse signal and the selected pulse signal to determine the amplitudes of several signal components of the template pulse signal and the selected pulse signal at the same frequency, including: Perform a Fourier transform on the pulse signal to be processed to obtain the frequency domain signal corresponding to the pulse signal to be processed: wherein the pulse signal to be processed is the template pulse signal or the selected pulse signal corresponding to each group of signal data to be matched; Based on the frequency domain signal, the amplitude-frequency characteristic curves of the template pulse signal and the selected pulse signal corresponding to each group of signal data to be matched are obtained; The amplitude of the template pulse signal at the same frequency and the amplitude of the selected pulse signal corresponding to each group of signal data to be matched are obtained from the amplitude-frequency characteristic curve.

5. The partial discharge signal localization method based on the frequency domain amplitude attenuation characteristics of a signal according to claim 4, characterized in that, The process involves acquiring the cable length, distributed resistance, distributed conductance, distributed inductance, and distributed capacitance of the cable under test. Based on the amplitude of several signal components, cable length, distributed resistance, distributed conductance, distributed inductance, and distributed capacitance, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated. Based on this distance, the location of the partial discharge signal under each selected pulse signal is determined, including: Based on the distributed resistance, distributed conductance, distributed inductance, and distributed capacitance, the signal propagation attenuation coefficient on the cable under test is calculated. For each selected pulse signal corresponding to the signal data group to be matched, the distance from the partial discharge point to the cable end corresponding to the template pulse signal is calculated based on the signal propagation attenuation coefficient, the cable length, and the signal component amplitude, thereby obtaining the position of the partial discharge signal under each selected pulse signal.

6. A partial discharge signal location device based on the amplitude attenuation characteristics of a signal in the frequency domain, characterized in that, include: The module includes a signal acquisition module, a template pulse signal determination module, a pulse signal to be matched determination module, a selected pulse signal determination module, a signal component amplitude calculation module, and a partial discharge signal location calculation module. The signal acquisition module is used to acquire several end-synchronization time-domain signals of the cable under test within a certain period of time, and obtain several signal data groups. The template pulse signal determination module is used to select the pulse signal with the largest amplitude in each of the signal data groups as the template pulse signal; The pulse signal determination module is used to take the signal data group where the template pulse signal is located as the selected signal data group, and take other signal data groups other than the selected signal data group as the signal data group to be matched; and take each pulse signal in the signal data group to be matched as the pulse signal to be matched. The selected pulse signal determination module is used to calculate the matching degree between each pulse signal to be matched and the template pulse signal in each group of signal data to be matched, and take the pulse signal with the highest matching degree as the selected pulse signal to obtain the selected pulse signal corresponding to each group of signal data to be matched. The signal component amplitude calculation module is used to perform Fourier transform on the template pulse signal and the selected pulse signal for each selected pulse signal corresponding to the signal data group to be matched, and determine the amplitude of several signal components of the template pulse signal and the selected pulse signal at the same frequency. The partial discharge signal location calculation module obtains the cable length, distributed resistance, distributed conductance, distributed inductance, and distributed capacitance of the cable under test. Based on the amplitude of the signal components, cable length, distributed resistance, distributed conductance, distributed inductance, and distributed capacitance, it calculates the distance from the partial discharge point to the cable end corresponding to the template pulse signal. Based on the distance, it determines the location of the partial discharge signal under each selected pulse signal.

7. A terminal device, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement a partial discharge signal localization method based on the frequency domain amplitude attenuation characteristics of a signal as described in any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device where the storage medium is located to perform a partial discharge signal localization method based on the frequency domain amplitude attenuation characteristics of a signal as described in any one of claims 1 to 5.

Images