Partial discharge positioning method and device, nonvolatile storage medium and electronic equipment

Abstract

The invention discloses a partial discharge positioning method and device, a nonvolatile storage medium and electronic equipment. The method comprises the following steps: collecting a head end time domain partial discharge signal of the head end of a target cable and a tail end time domain partial discharge signal of the tail end of the target cable; based on the head-end time-domain partial discharge signal and the tail-end time-domain partial discharge signal, determining a response characteristic of the target cable to the frequency-domain partial discharge signal; based on the response characteristics, partial discharge results of the target cable are determined, and the partial discharge results are used for representing the possibility that partial discharge exists at different positions of the target cable; and determining a target position where partial discharge exists in the target cable based on the partial discharge result. According to the invention, the technical problem of low positioning accuracy of partial discharge of the cable in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of power systems, and more specifically, to a method and device for locating partial discharge, a non-volatile storage medium, and an electronic device. Background Art

[0002] With the continuous advancement of industrialization and urbanization, power cables, as the core carrier of modern power transmission, have a direct impact on the safety and stability of the power system due to their operational reliability. However, during long-term service, cables are susceptible to localized defects in the insulation medium due to the combined effects of complex operating conditions and external environmental factors. Partial discharge (PD) is a typical parameter that characterizes cable insulation defects under the action of power frequency electric fields. Therefore, locating PD in cables not only provides early warning of hidden dangers in cable lines, but also effectively inhibits the evolution of defects into permanent faults. This is of great significance for improving the efficiency of power system operation and maintenance and ensuring the reliable power supply of urban power grids.

[0003] Related art methods for locating partial discharge in cables primarily include threshold, peak, energy, and correlation methods. However, due to the dispersion and attenuation of partial discharge signals during cable transmission, these methods suffer from large positioning errors and are susceptible to interference. Consequently, related art methods suffer from low accuracy in locating partial discharge in cables.

[0004] To address the above-mentioned problems, no effective solutions have been proposed so far. Summary of the Invention

[0005] The embodiments of the present application provide a partial discharge locating method, apparatus, non-volatile storage medium, and electronic device to at least solve the technical problem of low accuracy in locating partial discharge of cables in the related art.

[0006] According to one aspect of an embodiment of the present application, a partial discharge locating method is provided, comprising: collecting a head-end time-domain partial discharge signal at a head-end of a target cable, and an end-end time-domain partial discharge signal at an end-end of the target cable; determining a response characteristic of the target cable to the frequency-domain partial discharge signal based on the head-end time-domain partial discharge signal and the end-end time-domain partial discharge signal; determining a partial discharge result of the target cable based on the response characteristic, wherein the partial discharge result is used to indicate the possibility of the presence of partial discharge at different locations of the target cable; and determining a target location in the target cable where the partial discharge exists based on the partial discharge result.

[0007] According to another aspect of an embodiment of the present application, a partial discharge locating device is provided, comprising: a signal acquisition module for acquiring a head-end time-domain partial discharge signal at a head-end of a target cable and a terminal time-domain partial discharge signal at a terminal of the target cable; a first determination module for determining a response characteristic of the target cable to a frequency-domain partial discharge signal based on the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal; a second determination module for determining a partial discharge result of the target cable based on the response characteristic, wherein the partial discharge result is used to indicate the possibility of partial discharge at different locations of the target cable; and a third determination module for determining a target location in the target cable where partial discharge exists based on the partial discharge result.

[0008] According to another aspect of an embodiment of the present application, a non-volatile storage medium is provided. The non-volatile storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executed by any one of the partial discharge locating methods.

[0009] According to another aspect of an embodiment of the present application, an electronic device is provided, comprising: one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement any one of the partial discharge locating methods.

[0010] In an embodiment of the present application, a time-domain partial discharge signal is collected from the head end of a target cable, and a time-domain partial discharge signal is collected from the tail end of the target cable; based on the time-domain partial discharge signal and the tail end time-domain partial discharge signal, the response characteristics of the target cable to the frequency-domain partial discharge signal are determined; based on the response characteristics, a partial discharge result of the target cable is determined, wherein the partial discharge result is used to indicate the possibility of partial discharge at different locations of the target cable; and based on the partial discharge result, the target location of the partial discharge in the target cable is determined. The purpose of determining the partial discharge result of the cable by collecting and analyzing the time-domain partial discharge signals at the head end and the tail end of the cable, and accurately locating the partial discharge of the cable based on the partial discharge result is achieved, thereby achieving the technical effect of improving the accuracy of the positioning result of the partial discharge of the cable, thereby solving the technical problem of low accuracy in locating the partial discharge of the cable in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0012] Figure 1 is a flow chart of an optional partial discharge locating method provided according to an embodiment of the present application;

[0013] Figure 2 is a structural block diagram of an optional partial discharge locating method provided according to an embodiment of the present application;

[0014] Figure 3 is a schematic diagram of an optional cable partial discharge detection method provided in accordance with an embodiment of the present application;

[0015] Figure 4 This is a schematic diagram of an optional head-end time-domain partial discharge signal provided according to an embodiment of the present application;

[0016] Figure 5 is a schematic diagram of an optional terminal time-domain partial discharge signal provided according to an embodiment of the present application;

[0017] Figure 6 is a schematic diagram of an optional partial discharge diagnosis result provided according to an embodiment of the present application;

[0018] Figure 7 This is a schematic diagram of an optional partial discharge locating device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0020] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] For ease of description, some nouns or terms involved in the embodiments of the present application are explained below:

[0022] High-frequency current sensors are sensors used to detect and measure high-frequency current signals. High-frequency current sensors can capture current changes with frequencies much higher than conventional power frequencies (such as 50Hz or 60Hz (Hertz)). They are often used to detect and analyze partial discharge problems and electromagnetic compatibility problems in power equipment.

[0023] Frequency band modulation technology selectively enhances or weakens specific frequency components of the signal, thereby improving the signal-to-noise ratio, positioning accuracy or communication quality. It is widely used in communications, radar, audio processing and power system detection.

[0024] According to an embodiment of the present application, a method embodiment of a partial discharge locating method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0025] Figure 1 is a flow chart of an optional partial discharge locating method provided according to an embodiment of the present application, such as Figure 1 As shown, the method includes the following steps:

[0026] Step S102, collecting a head-end time-domain partial discharge signal of a target cable head-end and a terminal time-domain partial discharge signal of a target cable terminal;

[0027] As you can see, the signal acquisition device deployed at the headend of the target cable collects the time-domain partial discharge signal at the headend of the target cable, while the signal acquisition device deployed at the tailend of the target cable collects the time-domain partial discharge signal at the tailend of the target cable. This dual-end partial discharge signal acquisition method ensures comprehensive capture of partial discharge signals, improving the accuracy and reliability of partial discharge location results.

[0028] Optionally, high-frequency current sensors can be used to collect time-domain partial discharge signals at the cable's headend and tailend. By deploying high-frequency current sensors at both the cable's headend and tailend, and orienting their reference directions toward the center of the target cable being tested, the accuracy and consistency of the collected time-domain partial discharge signals can be ensured. The reference direction of the high-frequency current sensors refers to the positive direction used by the sensors when measuring high-frequency current signals, ensuring consistent and comparable signal measurements.

[0029] Step S104, determining the response characteristics of the target cable to the frequency domain partial discharge signal based on the head-end time domain partial discharge signal and the terminal time domain partial discharge signal;

[0030] It can be understood that frequency-domain conversion and analysis of the target cable's head-end and tail-end time-domain PD signals yields the target cable's response characteristics to the frequency-domain PD signals. Determining these response characteristics not only allows for more precise analysis of the propagation characteristics of the frequency-domain PD signals within the target cable, but also avoids blind analysis of full-band frequency-domain PD signals, improving the efficiency and accuracy of cable PD location.

[0031] In an optional embodiment, based on the head-end time-domain partial discharge signal and the end-end time-domain partial discharge signal, the response characteristics of the target cable to the frequency-domain partial discharge signal are determined, including: performing frequency domain conversion on the head-end time-domain partial discharge signal and the end-end time-domain partial discharge signal respectively to obtain the head-end frequency-domain partial discharge signal and the end-end frequency-domain partial discharge signal; determining the head-end effective frequency band of the head-end frequency-domain partial discharge signal and the end-end effective frequency band of the end-end frequency-domain partial discharge signal; and determining the response characteristics based on the head-end frequency-domain partial discharge signal, the end-end frequency-domain partial discharge signal, the head-end effective frequency band, and the end-end effective frequency band.

[0032] It can be understood that the frequency domain conversion of the head-end time-domain partial discharge signal produces the head-end frequency-domain partial discharge signal, while the frequency domain conversion of the tail-end time-domain partial discharge signal produces the tail-end frequency-domain partial discharge signal. Frequency band control technology is used to determine the head-end effective frequency band of the head-end frequency-domain partial discharge signal and the tail-end effective frequency band of the tail-end frequency-domain partial discharge signal. Based on the head-end frequency-domain partial discharge signal, the tail-end frequency-domain partial discharge signal, the head-end effective frequency band, and the tail-end effective frequency band, the response characteristics of the target cable to the frequency-domain partial discharge signal are determined. By determining the effective frequency band, the analysis can be focused on the most sensitive and informative frequency bands of the partial discharge signal, enhancing the ability to identify partial discharges. Furthermore, determining the effective frequency band helps reduce the risk of misjudgment due to background noise and non-partial discharge signals, thereby improving the accuracy and reliability of positioning results.

[0033] Alternatively, the transfer function of the cable to the frequency domain signal can be used as the response characteristic of the cable to the frequency domain partial discharge signal. The transfer function of the cable can be realized in the following ways:

[0034]

[0035] Among them, Γ pd is the transfer function of the cable; N1 and N2 are the frequency indexes of the upper and lower limits of the transfer function of the cable obtained according to the frequency band control technology.

[0036] In an optional embodiment, frequency domain conversion is performed on the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal respectively to obtain the head-end frequency-domain partial discharge signal and the terminal frequency-domain partial discharge signal, including: preprocessing the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal respectively to obtain a standard head-end signal and a standard terminal signal; performing frequency domain conversion on the standard head-end signal by Fourier transform to obtain the head-end frequency-domain partial discharge signal; and performing frequency domain conversion on the standard terminal signal by Fourier transform to obtain the terminal frequency-domain partial discharge signal.

[0037] It is understood that the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal are preprocessed separately, such as by zero-padding and Hilbert transform. Zero-padding ensures that the signal length of the time-domain partial discharge signal meets the requirements of the discrete Fourier transform, preventing spectrum leakage; the Hilbert transform converts the time-domain partial discharge signal into an analytical signal for subsequent frequency domain analysis. The standard head-end signal and the standard terminal signal obtained after preprocessing are converted to the frequency domain using Fourier transform to obtain the head-end frequency-domain partial discharge signal and the terminal frequency-domain partial discharge signal, respectively. The reflection characteristics of partial discharge signals in cables are more pronounced in the frequency domain. Therefore, by converting time-domain partial discharge to frequency-domain partial discharge, frequency information can be utilized to improve the accuracy of cable partial discharge location.

[0038] Optionally, zero-padding and Hilbert transform can be used to pre-process the cable's time-domain partial discharge (PD) signal. Zero-padding adds zeros to the end of the PD signal, extending the PD signal at both the head and tail ends to the same length, facilitating subsequent discrete Fourier transforms. Hilbert transform analyzes the spectral characteristics of the PD signal to convert it into a complex signal (i.e., an analytical signal), providing richer signal information for subsequent frequency-domain analysis.

[0039] Optionally, the zero padding and Hilbert transform of the head-end time-domain partial discharge signal and the tail-end time-domain partial discharge signal may be implemented in the following manner:

[0040] u d10 =[u d1 ,0]

[0041]

[0042] u d20 =[u d2 ,0]

[0043]

[0044] Among them, u d1 and u d2The time domain partial discharge signal at the beginning and the end of the cable are measured respectively; u d10 and u d20 are the time domain partial discharge signal at the beginning and end of the cable respectively and the zero-filled time domain partial discharge signal at the end; H is the Hilbert transform; and They are the complex signals after Hilbert transform of the time domain partial discharge signal at the beginning and end of the cable after zero filling and the time domain partial discharge signal at the end.

[0045] Optionally, the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal may be converted into the head-end frequency-domain partial discharge signal and the terminal frequency-domain partial discharge signal by using a discrete Fourier transform. The discrete Fourier transform of the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal may be implemented as follows:

[0046]

[0047] Among them, U d1 and U d2 are the frequency domain expressions of the partial discharge signals measured at the beginning and end of the cable, respectively (i.e., the expressions of the frequency domain partial discharge signal at the beginning and the frequency domain partial discharge signal at the end); j represents the imaginary part; k is the frequency domain sequence index; n is the time domain sequence index; N is the sequence number; f is the frequency sequence; T s is the signal sampling rate.

[0048] In an optional embodiment, determining a head-end effective frequency band of a head-end frequency-domain partial discharge signal and a tail-end effective frequency band of a tail-end frequency-domain partial discharge signal includes: determining a target signal having the largest amplitude among a plurality of sampling point signals included in the head-end frequency-domain partial discharge signal, and a target amplitude and a target frequency corresponding to the target signal; determining a first frequency and a second frequency of the head-end frequency-domain partial discharge signal based on the target amplitude and a predetermined amplitude threshold, wherein the first frequency is less than the target frequency and the second frequency is greater than the target frequency; determining the head-end effective frequency band based on the first frequency and the second frequency; and determining the tail-end effective frequency band using the method for determining the head-end effective frequency band.

[0049] It can be understood that the signal point with the largest amplitude is found from the multiple sampling point signals included in the head-end frequency-domain partial discharge signal as the target signal. An amplitude threshold (e.g., 5%) is pre-set to define the upper and lower bounds of the head-end effective frequency band. Based on the amplitude threshold, the first frequency (lower than the target frequency) and the second frequency (higher than the target frequency) of the head-end frequency-domain partial discharge signal are determined. The first frequency and the second frequency are located on the left and right sides of the target frequency, respectively, and the resulting frequency band range is the smallest to ensure that the partial discharge characteristics are captured to the greatest extent. The head-end effective frequency band is determined with the first and second frequencies as the boundaries. Similarly, the end effective frequency band is determined according to the method for determining the head-end effective frequency band. By determining the effective frequency band, the frequency band range can be precisely controlled, thereby improving the positioning accuracy of partial discharge and reducing positioning errors caused by a wide spectrum.

[0050] Optionally, the frequency band control technology can be used to determine the effective frequency band of the head end and the effective frequency band of the end end, and then determine the effective frequency band of the transfer function, as well as the frequency index of the upper and lower limits. For the head end frequency domain partial discharge signal, first, the frequency domain expression U of the head end partial discharge signal obtained at the head end of the cable is obtained. d1 The maximum value of (i.e. target signal) and record its corresponding frequency (i.e. target frequency); secondly, take U d1 The two frequency points (i.e., the first frequency signal point and the second frequency signal point) corresponding to 5% of the maximum value (i.e., the predetermined amplitude threshold) of the cable are respectively used as the effective frequency band range of the head-end frequency domain partial discharge signal (i.e., the head-end effective frequency band), and it is ensured that these two frequency points are located on the left and right sides of the maximum frequency point, and the obtained effective frequency band range is minimized. Similarly, for the terminal frequency domain partial discharge signal, first, the terminal partial discharge signal frequency domain expression U obtained at the cable end is taken. d2 Maximum value and record its corresponding frequency; secondly, take U d2 The two frequency points corresponding to 5% of the maximum value are used as the effective frequency band of the terminal frequency domain partial discharge signal (i.e., the terminal effective frequency band). These two frequency points are ensured to be located on the left and right sides of the maximum frequency point, and the resulting effective frequency band is minimized. Finally, the intersection of the head-end effective frequency band and the terminal effective frequency band is taken as the effective frequency band of the cable transfer function. The frequency indexes of the upper and lower limits of the effective frequency band are N1 and N2, respectively.

[0051] Step S106, determining a partial discharge result of the target cable based on the response characteristics, wherein the partial discharge result is used to indicate the possibility of partial discharge at different locations of the target cable;

[0052] As can be understood, the target cable's partial discharge diagnostic function is determined based on the target cable's response characteristics to the frequency-domain partial discharge signal. The partial discharge diagnostic function is then used to determine the target cable's partial discharge results. These partial discharge results quantify the likelihood of partial discharge at different locations on the target cable. By combining spectrum analysis with the partial discharge diagnostic function, the target location of partial discharge in the cable can be precisely identified, improving the accuracy of partial discharge location.

[0053] In an optional embodiment, determining a partial discharge result of a target cable based on the response characteristics includes: determining a phase constant of the target cable and a length of the target cable, wherein the phase constant represents a phase change rate per unit length when a partial discharge signal propagates in the target cable; and determining the partial discharge result based on the phase constant, length, and response characteristics.

[0054] As can be understood, the target cable's material and structural parameters determine the target cable's phase constant, representing the rate of phase change per unit length of the partial discharge signal as it propagates through the target cable. The target cable's partial discharge results are determined based on the target cable's phase constant, the target cable's length, and the target cable's response to the frequency-domain partial discharge signal. By combining frequency-domain analysis of the cable's phase constant and cable length, cable partial discharge can be more accurately identified, improving the accuracy of partial discharge location results.

[0055] Alternatively, the phase constant of the cable may be determined based on parameters such as the geometric dimensions, dielectric constant, conductor resistance and inductance of the cable.

[0056] Alternatively, the partial discharge result can be determined by constructing a partial discharge diagnostic function for the cable. The partial discharge diagnostic function can be implemented as follows:

[0057]

[0058] Where D(x) is the cable's partial discharge diagnostic function; x is the distance from the cable's head end; β is the cable's phase constant; C is the Chebyshev window function; and Δf is the frequency interval. The partial discharge diagnostic function can be used to determine partial discharge results at different cable locations.

[0059] Step S108: determining a target location where partial discharge exists in the target cable based on the partial discharge result.

[0060] As can be understood, the PD results of the target cable are analyzed to determine the target location of PD within the target cable. By analyzing the PD results, it is possible to determine whether the PD is located within the cable and its specific location within the cable, providing early warning of cable faults. This also avoids blind inspections of the entire cable or its surrounding areas, simplifies cable maintenance processes, and improves grid operation and maintenance efficiency.

[0061] In an optional embodiment, based on the partial discharge result, a target position where partial discharge exists in the target cable is determined, including: determining an initial position and an area determination result of the partial discharge of the target cable based on the partial discharge result, wherein the area determination result is used to indicate whether the partial discharge is located inside the target cable; and determining the target position based on the initial position and the area determination result.

[0062] As can be understood, the initial location of the partial discharge in the target cable and the region determination result, indicating whether the partial discharge is located within the target cable, are determined based on the partial discharge results. Based on these initial location and region determination results, the target location of the partial discharge in the target cable is determined. Determining the region determination result effectively distinguishes signals from inside and outside the cable, enabling accurate determination of whether partial discharge is occurring within the target cable even in complex environments, thereby eliminating the impact of external interference on the partial discharge location results.

[0063] Optionally, the cable's partial discharge diagnosis function can be used to determine the cable's partial discharge location function and area determination function. The partial discharge location function is used to determine the initial location of the cable's partial discharge (i.e., the partial discharge location result), and the area determination function is used to determine the cable's area determination result. The cable's partial discharge location function and area determination function can be implemented as follows:

[0064] D loc (x)=|D(x)|

[0065] D ch (x) = real(D(x))

[0066] Among them, D loc is the partial discharge location function of the cable, which is obtained by taking the modulus value of D(x); D ch is the area determination function of the cable, which is obtained by taking the real part of D(x).

[0067] In an optional embodiment, determining the target position based on the initial position and the area determination result includes: when the area determination result indicates that the partial discharge is located inside the target cable, determining the target position based on the initial position and the length of the target cable.

[0068] As can be understood, if the area determination result indicates that the PD is located within the target cable, the target location of the PD is determined based on the initial location of the PD within the target cable and the length of the target cable. By combining the initial location and the cable length, the actual location of the PD point within the cable can be more accurately determined, thereby improving the efficiency and accuracy of cable maintenance and repair work.

[0069] Optionally, obtain the partial discharge location function D loc The maximum value of is taken as the pseudo-location result of partial discharge. Substitute the pseudo-location result into the area judgment function D ch The area determination result is obtained. If the area determination result is positive, the partial discharge is determined to be inside the cable. The proposed location result is the distance from the target location to the end of the partial discharge minus the distance from the beginning of the cable. Combined with the cable length, the target location of the partial discharge can be determined. If the area determination result is negative, the partial discharge is determined to be outside the cable. The partial discharge location is the distance between the two sensors (i.e., the high-frequency current sensor at the beginning of the cable and the high-frequency current sensor at the end of the cable).

[0070] Through the above steps S102 to S108, the purpose of determining the partial discharge results of the cable by collecting and analyzing the time domain partial discharge signals at the beginning and end of the cable, and accurately locating the partial discharge of the cable based on the partial discharge results can be achieved, thereby achieving the technical effect of improving the accuracy of the positioning results of the partial discharge of the cable, and thus solving the technical problem of low accuracy in positioning the partial discharge of the cable existing in the related art.

[0071] Based on the above-described embodiments and optional embodiments, this application proposes an optional method implementation for locating partial discharges. This implementation collects and analyzes time-domain partial discharge signals at the beginning and end of a cable to propose a dual-end cable partial discharge location method based on frequency-domain reflectometry. This method addresses the problems of poor positioning accuracy, weak anti-interference capabilities, and the inability to clearly determine the location of cable partial discharges in PD location methods.

[0072] Figure 2 is a structural block diagram of an optional partial discharge location method provided according to an embodiment of the present application, such as Figure 2 As shown in FIG, the steps of the cable partial discharge double-end location method based on the frequency domain reflection method include:

[0073] Step S1: Detecting the partial discharge detection signals at the beginning and end of the cable (i.e., the time domain partial discharge signal at the beginning and the end of the cable) by a high-frequency current sensor, with the reference direction of the high-frequency current sensor pointing to the center of the detected cable.

[0074] Step S2: performing zero padding and Hilbert transform on the detected partial discharge detection signals at the beginning and end of the cable.

[0075] The implementation method of zero padding of the time-domain partial discharge signal at the beginning and the end of the cable is the same as described above and will not be repeated here.

[0076] Step S3 , performing discrete Fourier transform on the Hilbert transformed PD complex signal (ie, the head-end time-domain PD signal and the terminal time-domain PD signal after zero padding and Hilbert transform) to obtain the frequency domain representation of the head and terminal.

[0077] The implementation methods of Hilbert transform and discrete Fourier transform of the time-domain partial discharge signal at the beginning and the end of the cable are the same as those described above and will not be repeated here.

[0078] Step S4: Calculate the cable transfer function and, using frequency band control techniques, determine the effective frequency band of the transfer function (i.e., the frequency band range determined by the intersection of the headend effective frequency band and the tailend effective frequency band). This in turn determines the frequency indexes of the upper and lower limits of the transfer function. Frequency-domain partial discharge signal data within the headend effective frequency band and the tailend effective frequency band is retained.

[0079] The method for determining the transfer function of the cable and the method for determining the effective frequency band are the same as those described above and will not be repeated here.

[0080] Step S5: performing spectrum analysis on the transfer function to obtain a partial discharge diagnostic function of the cable.

[0081] The method for determining the partial discharge diagnostic function of the cable is the same as described above and will not be repeated here.

[0082] Step S6: determining the cable's partial discharge location function and area determination function through the cable's partial discharge diagnosis function.

[0083] The determination method of the partial discharge location function and the area determination function of the cable is the same as described above and will not be repeated here.

[0084] Step S7: determining the initial position of the cable partial discharge (ie, the partial discharge proposed positioning result) according to the maximum value of the partial discharge positioning function, and determining the target position of the partial discharge according to the initial position.

[0085] Get the partial discharge location function D loc The maximum value of is taken as the pseudo-location result of partial discharge. Substitute the pseudo-location result into the area judgment function D chThe area determination result is obtained. If the area determination result is positive, the partial discharge is determined to be inside the cable. The proposed location result is the distance from the target location to the end of the partial discharge minus the distance from the beginning of the cable. Combined with the cable length, the target location of the partial discharge can be determined. If the area determination result is negative, the partial discharge is determined to be outside the cable. The partial discharge location is the distance between the two sensors (i.e., the high-frequency current sensor at the beginning of the cable and the high-frequency current sensor at the end of the cable).

[0086] Figure 3 is a schematic diagram of an optional cable partial discharge detection provided in an embodiment of the present application, such as Figure 3 The following diagram shows a test scenario for a cable with a partial discharge defect using the frequency domain reflectometry-based dual-end cable partial discharge location method. The cable is a 10kV (kilovolt) distribution cable, 600 meters long. A partial discharge defect was located 200 meters from the cable head end using a partial discharge signal generator. Figure 3 Middle Z L Indicates the cable line impedance, Z S Represents the signal source impedance, Z D At the voltage measurement points at the beginning and end of the cable, high-frequency current sensors are used to collect the time-domain partial discharge signals at the beginning and end of the cable.

[0087] Figure 4 is an optional schematic diagram of a head-end time-domain partial discharge signal provided according to an embodiment of the present application, such as Figure 4 Shown is based on Figure 3 Schematic diagram of the time domain partial discharge signal at the head end of the cable obtained from the test scenario. The horizontal axis is time, in ns (nanoseconds); the vertical axis is voltage value, in mV (millivolts).

[0088] Figure 5 is an optional terminal time-domain partial discharge signal schematic diagram provided according to an embodiment of the present application, such as Figure 5 Shown is based on Figure 3 Schematic diagram of the time domain partial discharge signal at the end of the cable obtained from the test scenario. The horizontal axis is time, in ns (nanoseconds); the vertical axis is voltage value, in mV (millivolts).

[0089] Figure 6 is a schematic diagram of an optional partial discharge diagnosis result provided according to an embodiment of the present application, such as Figure 6 Shown is based on Figure 3Schematic diagram of the partial discharge diagnosis results of the cable obtained from the test scenario. The horizontal axis is the distance from the cable head end, in meters; the vertical axis is the normalized amplitude of the partial discharge location function and the regional determination function. The solid line is the local location curve, which represents the normalized amplitude of the partial discharge location function at different distances; the dotted line is the regional determination curve, which represents the normalized amplitude of the regional determination function at different distances. Figure 6 As shown, the peak of the local location curve is 200.6 m, and the corresponding regional determination curve is positive. Therefore, it can be determined that the partial discharge defect is located inside the cable. 200.6 m is the difference between the target location of the partial discharge defect and the cable end, and the distance from the cable head end. Considering the total cable length of 600 m, the target location of the partial discharge can be calculated to be 199.7 m.

[0090] In summary, a dual-end location method for cable partial discharge based on frequency domain reflectometry can well determine the existence area and target location of cable partial discharge defects.

[0091] The above optional implementation method achieves at least the following effects: the dual-end partial discharge signal acquisition method at the head end and the end end ensures the comprehensive capture of the partial discharge signal, thereby improving the accuracy and reliability of the partial discharge positioning results; by determining the transfer function of the cable and using the frequency band control technology to determine the effective frequency band range of the transfer function, the anti-interference ability in the partial discharge positioning process and the accuracy of the partial discharge positioning results can be improved; by constructing the partial discharge positioning function and the area determination function through the cable partial discharge diagnostic function, it is possible to not only determine whether the cable partial discharge exists inside the cable, but also accurately determine the target position of the partial discharge.

[0092] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0093] This embodiment also provides a partial discharge locating device for implementing the aforementioned embodiments and preferred implementations. Details already described will not be repeated. As used below, the terms "module" and "device" may refer to a combination of software and / or hardware that implements a predetermined function. While the devices described in the following embodiments are preferably implemented using software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0094] According to an embodiment of the present application, a device embodiment for implementing a partial discharge locating method is also provided. Figure 7 is a schematic diagram of a partial discharge locating device according to an embodiment of the present application, such as Figure 7As shown, the partial discharge locating device includes a signal acquisition module 702, a first determination module 704, a second determination module 706, and a third determination module 708. The device is described below.

[0095] The signal acquisition module 702 is used to acquire the time-domain partial discharge signal of the head end of the target cable and the time-domain partial discharge signal of the end end of the target cable;

[0096] A first determination module 704 is connected to the signal acquisition module 702 and is used to determine the response characteristics of the target cable to the frequency domain partial discharge signal based on the head-end time domain partial discharge signal and the terminal time domain partial discharge signal;

[0097] A second determining module 706, connected to the first determining module 704, is configured to determine a partial discharge result of the target cable based on the response characteristics, wherein the partial discharge result is used to indicate the possibility of partial discharge at different locations of the target cable;

[0098] The third determining module 708 is connected to the second determining module 706 and is configured to determine a target location where partial discharge exists in the target cable based on the partial discharge result.

[0099] In a partial discharge locating device provided in an embodiment of the present application, a signal acquisition module 702 is provided for collecting a time-domain partial discharge signal at the head end of a target cable and a time-domain partial discharge signal at the end end of a target cable; a first determination module 704 is connected to the signal acquisition module 702 and is used to determine the response characteristics of the target cable to the frequency-domain partial discharge signal based on the head end time-domain partial discharge signal and the end end time-domain partial discharge signal; a second determination module 706 is connected to the first determination module 704 and is used to determine the partial discharge result of the target cable based on the response characteristics, wherein the partial discharge result is used to indicate the possibility of partial discharge at different positions of the target cable; and a third determination module 708 is connected to the second determination module 706 and is used to determine the target position where partial discharge exists in the target cable based on the partial discharge result. The device achieves the purpose of determining the partial discharge result of the cable by collecting and analyzing the time-domain partial discharge signals at the head end and the end end of the cable, and accurately locating the partial discharge of the cable based on the partial discharge result, thereby achieving the technical effect of improving the accuracy of the partial discharge location result of the cable, thereby solving the technical problem of low accuracy in locating partial discharge of the cable in the related art.

[0100] It should be noted that the above modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following ways: the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0101] It should be noted that the signal acquisition module 702, first determination module 704, second determination module 706, and third determination module 708 correspond to steps S102 to S108 in the embodiment. The examples and application scenarios implemented by these modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above embodiment. It should be noted that the above modules, as part of the device, can be run on a computer terminal.

[0102] It should be noted that the optional or preferred implementation of this embodiment can be found in the relevant description in the embodiment, which will not be repeated here.

[0103] The above-mentioned partial discharge locating device may further include a processor and a memory. The signal acquisition module 702, the first determination module 704, the second determination module 706, the third determination module 708, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to implement corresponding functions.

[0104] The processor includes a kernel, which retrieves the corresponding program unit from memory. There can be one or more kernels. Memory may include non-permanent memory in a computer-readable medium, random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory includes at least one memory chip.

[0105] An embodiment of the present application provides a non-volatile storage medium having a program stored thereon, which implements a partial discharge locating method when executed by a processor.

[0106] An embodiment of the present application provides an electronic device comprising a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are performed: collecting a head-end time-domain partial discharge signal from a head-end of a target cable and a terminal time-domain partial discharge signal from a terminal of the target cable; determining the response characteristics of the target cable to the frequency-domain partial discharge signal based on the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal; determining partial discharge results of the target cable based on the response characteristics, wherein the partial discharge results indicate the likelihood of partial discharge at different locations of the target cable; and determining target locations in the target cable where partial discharge occurs based on the partial discharge results. The device herein may be a server, a PC, or the like.

[0107] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program that is initialized with the following method steps: collecting a head-end time-domain partial discharge signal at a head-end of a target cable and an end-end time-domain partial discharge signal at an end-end of the target cable; determining a response characteristic of the target cable to the frequency-domain partial discharge signal based on the head-end time-domain partial discharge signal and the end-end time-domain partial discharge signal; determining a partial discharge result of the target cable based on the response characteristic, wherein the partial discharge result is used to indicate the possibility of partial discharge at different locations of the target cable; and determining a target location in the target cable where partial discharge occurs based on the partial discharge result.

[0108] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0109] 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 produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. 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.

[0110] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work 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 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0112] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0113] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0114] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0115] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0116] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0117] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for locating partial discharge, characterized in that: include: Collecting a head-end time-domain partial discharge signal of a target cable head end and a terminal time-domain partial discharge signal of a target cable terminal end; Determining a response characteristic of the target cable to a frequency domain partial discharge signal based on the head-end time domain partial discharge signal and the terminal time domain partial discharge signal; Determining partial discharge results of the target cable based on the response characteristics, wherein the partial discharge results are used to indicate the possibility of partial discharge at different locations of the target cable; Based on the partial discharge result, a target location where partial discharge exists in the target cable is determined.

2. The method according to claim 1, characterized in that The determining, based on the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal, a response characteristic of the target cable to the frequency-domain partial discharge signal comprises: Performing frequency domain conversion on the head-end time domain partial discharge signal and the terminal time domain partial discharge signal respectively to obtain a head-end frequency domain partial discharge signal and a terminal frequency domain partial discharge signal; Determining a first-end effective frequency band of the first-end frequency-domain partial discharge signal and a last-end effective frequency band of the last-end frequency-domain partial discharge signal; The response characteristic is determined based on the first-end frequency-domain partial discharge signal, the last-end frequency-domain partial discharge signal, the first-end effective frequency band, and the last-end effective frequency band.

3. The method according to claim 2, characterized in that The performing frequency domain conversion on the head-end time domain partial discharge signal and the terminal time domain partial discharge signal respectively to obtain a head-end frequency domain partial discharge signal and a terminal frequency domain partial discharge signal, comprising: Preprocessing the head-end time-domain partial discharge signal and the terminal time-domain partial discharge signal respectively to obtain a standard head-end signal and a standard terminal signal; Performing frequency domain conversion on the standard head-end signal by Fourier transform to obtain the head-end frequency domain partial discharge signal; The standard terminal signal is converted into a frequency domain by using the Fourier transform method to obtain the terminal frequency domain partial discharge signal.

4. The method according to claim 2, characterized in that The determining of the first-end effective frequency band of the first-end frequency-domain partial discharge signal and the last-end effective frequency band of the last-end frequency-domain partial discharge signal comprises: Determining a target signal having the largest amplitude among a plurality of sampling point signals included in the head-end frequency-domain partial discharge signal, and a target amplitude and a target frequency corresponding to the target signal; Determining a first frequency and a second frequency of the head-end frequency-domain partial discharge signal based on the target amplitude and a predetermined amplitude threshold, wherein the first frequency is less than the target frequency and the second frequency is greater than the target frequency; Determining the head-end effective frequency band based on the first frequency and the second frequency; The end effective frequency band is determined in the same manner as the head end effective frequency band.

5. The method according to claim 1, wherein The determining of the partial discharge result of the target cable based on the response characteristic includes: Determining a phase constant of the target cable and a length of the target cable, wherein the phase constant represents a phase change rate per unit length when a partial discharge signal propagates in the target cable; The partial discharge result is determined based on the phase constant, the length, and the response characteristic.

6. The method according to any one of claims 1 to 5, characterized in that The determining, based on the partial discharge result, a target location where the partial discharge exists in the target cable includes: Determining an initial location and a region determination result of the partial discharge of the target cable based on the partial discharge result, wherein the region determination result is used to indicate whether the partial discharge is located inside the target cable; The target position is determined based on the initial position and the area determination result.

7. The method according to claim 6, characterized in that The determining of the target position based on the initial position and the area determination result includes: In a case where the area determination result indicates that the partial discharge is located inside the target cable, the target position is determined based on the initial position and the length of the target cable.

8. A partial discharge locating device, characterized in that: include: A signal acquisition module, configured to acquire a head-end time-domain partial discharge signal of a target cable head end and an end-end time-domain partial discharge signal of a target cable end; A first determining module is configured to determine a response characteristic of the target cable to a frequency domain partial discharge signal based on the head-end time domain partial discharge signal and the terminal time domain partial discharge signal; a second determining module, configured to determine a partial discharge result of the target cable based on the response characteristic, wherein the partial discharge result is used to indicate the possibility of partial discharge at different locations of the target cable; The third determining module is configured to determine a target location where partial discharge exists in the target cable based on the partial discharge result.

9. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor and executing the partial discharge locating method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: include: One or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the partial discharge locating method according to any one of claims 1 to 7.

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