Power distribution network fault positioning method, device, equipment, storage medium and product

Abstract

The application relates to a power distribution network fault positioning method, device, equipment, storage medium and product. The method comprises the following steps: acquiring discrete digital signals corresponding to three-phase voltage signals in a power distribution network; when it is monitored that a partial discharge traveling wave appears in the power distribution network, first time tag information when a first fault positioning device monitors the partial discharge traveling wave and second time tag information when a second fault positioning device monitors the partial discharge traveling wave are determined according to the discrete digital signals; and fault positioning is performed according to the first time tag information and the second time tag information, so that a fault positioning result of the power distribution network is obtained. The method can accurately position a partial discharge position in the power distribution network.

Description

Technical Field

[0001] This application relates to the field of power control and protection technology, and in particular to a method, apparatus, equipment, storage medium and product for locating faults in power distribution networks. Background Technology

[0002] With the development of smart power distribution network technology, the demand for online monitoring of power cable insulation status and accurate fault location is becoming increasingly urgent.

[0003] Traditional methods typically involve adapting the traveling wave front start point identification algorithm used in medium-voltage distribution network traveling wave ranging products to partial discharge monitoring devices. By monitoring the partial discharge traveling wave, fault location in the distribution network can be achieved.

[0004] However, traditional medium-voltage distribution network traveling wave ranging products are mainly designed for fault traveling wave ranging scenarios, with the fault traveling wave frequency band concentrated in the range of 5kHz to 100kHz; while the frequency band of partial discharge traveling waves is usually above 500kHz, and the frequency band characteristics are significantly different, making it difficult for traditional methods to accurately locate the partial discharge position in the distribution network. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, device, equipment, storage medium, and product for locating partial discharge in a power distribution network that can accurately pinpoint the location of partial discharge in the power distribution network, addressing the aforementioned technical problems.

[0006] Firstly, this application provides a method for locating faults in a distribution network, including:

[0007] Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0008] When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0009] Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network.

[0010] In one embodiment, the discrete digital signal includes a first digital signal and a second digital signal; the first digital signal is obtained by high-frequency sampling of the difference between the first phase voltage and the second phase voltage in the distribution network; the second digital signal is obtained by high-frequency sampling of the difference between the third phase voltage and the second phase voltage in the distribution network.

[0011] When a partial discharge wave is detected in the distribution network, the method for determining the first time-stamp information of the time when the first fault location device detects the partial discharge wave, based on the discrete digital signal, includes:

[0012] A first amplitude corresponding to the first digital signal is determined, and a second amplitude corresponding to the second digital signal is determined; the first amplitude is the maximum signal amplitude of the waveform corresponding to the first digital signal; the second amplitude is the maximum signal amplitude of the waveform corresponding to the second digital signal.

[0013] If the first amplitude is not less than the second amplitude, then when a partial discharge wave is detected, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined according to the first digital signal;

[0014] If the first amplitude is less than the second amplitude, then when a partial discharge wave is detected, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined according to the second digital signal.

[0015] In one embodiment, determining the first time stamp information corresponding to the wavefront start position of the partial discharge traveling wave based on the first digital signal includes:

[0016] Extract the digital signal containing the partial amplifier traveling wave from the first digital signal to obtain the effective digital signal;

[0017] Time-frequency feature analysis is performed on the effective digital signal to obtain the wavefront start position corresponding to the partial discharge traveling wave;

[0018] Based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined.

[0019] In one embodiment, the step of performing time-frequency feature analysis on the effective digital signal to obtain the wavefront start position corresponding to the partial discharge traveling wave includes:

[0020] Based on a preset window length and sliding step size, the effective digital signal is windowed to obtain multiple signal windows;

[0021] Perform a Discrete Fourier Transform on the digital signal within each signal window to obtain the complex sequence corresponding to each signal window;

[0022] Determine the time-frequency amplitude sequence based on the modulus of each element in each of the complex number sequences;

[0023] The starting position of the monotonically increasing time-frequency amplitude sequence is obtained by locating the maximum amplitude value and the position corresponding to the maximum amplitude value in the time-frequency amplitude sequence.

[0024] Based on the starting position, the window length, and the sliding step size, determine the candidate sampling point interval corresponding to the wavefront starting position;

[0025] Within the candidate sampling point interval, find the waveform abrupt change point in the effective digital signal, and take the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

[0026] In one embodiment, the step of locating the fault based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network includes:

[0027] The first time stamp information and the second time stamp information are matched to obtain at least one combination of time stamp information;

[0028] Based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and each of the aforementioned time stamp information combinations, at least one fault location information is determined;

[0029] The fault location result of the distribution network is determined based on the average distance corresponding to each fault location information.

[0030] In one embodiment, the three-phase voltage signal includes a first-phase voltage signal, a second-phase voltage signal, and a third-phase voltage signal;

[0031] Determining the discrete digital signal corresponding to the three-phase voltage signal includes:

[0032] The first line-mode signal is determined based on the difference between the first phase voltage signal and the second phase voltage signal;

[0033] The first line-mode signal is sampled at high frequency to obtain a first digital signal;

[0034] The second line-mode signal is determined based on the difference between the third-phase voltage signal and the second-phase voltage signal;

[0035] The second line-mode signal is sampled at high frequency to obtain the second digital signal;

[0036] The discrete digital signal is determined based on the first digital signal and the second digital signal.

[0037] Secondly, this application also provides a power distribution network fault location device, comprising:

[0038] The acquisition module is used to acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0039] The processing module is used to determine, based on the discrete digital signal, a first time stamp information when the first fault location device detects the partial discharge wave and a second time stamp information when the second fault location device detects the partial discharge wave, when a partial discharge wave is detected in the distribution network.

[0040] The positioning module is used to locate faults based on the first time stamp information and the second time stamp information, and obtain the fault location result of the distribution network.

[0041] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0042] Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0043] When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0044] Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network.

[0045] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0046] Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0047] When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0048] Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network.

[0049] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0050] Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0051] When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0052] Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network.

[0053] The aforementioned method, device, equipment, storage medium, and product for locating distribution network faults acquire three-phase voltage signals from the distribution network and convert them into corresponding discrete digital signals. When a partial discharge traveling wave is detected in the distribution network, the first and second fault location devices respectively determine the first and second time-scale information corresponding to the partial discharge traveling wave. Fault location is then performed based on the first and second time-scale information, ultimately outputting the distribution network fault location result. This method alleviates the shortcomings of traditional methods that cannot accurately locate the partial discharge location in the distribution network due to the large difference in frequency characteristics between the fault traveling wave and the partial discharge traveling wave, and insufficient algorithm adaptability, significantly improving the accuracy of partial discharge fault location in the distribution network. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of the partial discharge monitoring device in one embodiment;

[0056] Figure 2 This is a flowchart illustrating a power distribution network fault location method in one embodiment;

[0057] Figure 3 This is a schematic diagram of the overall process of a power distribution network fault location method in one embodiment;

[0058] Figure 4 This is a schematic diagram of the installation of a partial discharge monitoring device in a power grid fault location method in one embodiment.

[0059] Figure 5 This is a waveform recording diagram triggered by the partial discharge monitoring device 1 in a distribution network fault location method in one embodiment.

[0060] Figure 6 One embodiment of the distribution network fault location method and Calculation results diagram;

[0061] Figure 7 This is a schematic diagram of the original signal waveform within the interval where the wavefront of the power grid fault location method is located in one embodiment.

[0062] Figure 8 This is a structural block diagram of a power distribution network fault location device in one embodiment;

[0063] Figure 9This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0065] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0066] To clearly illustrate the application scenarios of this invention and the shortcomings of existing technologies, the background of power distribution network fault early warning and partial discharge monitoring is first explained. Specifically, the application of power distribution network fault early warning technology can identify potential faults before they occur, significantly reducing the damage caused by faults, improving power supply reliability, and reducing operation and maintenance costs.

[0067] In medium-voltage distribution networks dominated by overhead lines, various devices operate under harsh conditions for extended periods, potentially leading to insulation degradation. Degraded insulation can cause partial discharge (PD), which generates traveling waves that propagate to both sides of the line. PD monitoring devices can be used to monitor these traveling waves in real time and, in conjunction with adjacent PD monitoring devices, achieve dual-end PD ranging. Currently, traveling wave ranging products for medium-voltage distribution networks primarily focus on fault traveling wave ranging. While the traveling wave front start-point identification algorithm of these products can be ported to PD monitoring devices, fault traveling waves are mainly in the 5kHz-100kHz range with significant energy, exhibiting a clear difference from high-frequency interference and sensor noise. PD traveling waves, on the other hand, are primarily in the frequency band above 500kHz, with only one-tenth the energy of fault traveling waves, and are somewhat mixed with high-frequency interference and sensor noise. Directly porting the traveling wave front start-point identification algorithm from fault traveling wave ranging products would result in excessively large start-point identification errors and poor PD ranging performance. Meanwhile, the fault traveling wave only exists when the fault occurs, while the partial discharge traveling wave may persist for a long time. Therefore, if the partial discharge monitoring device runs a traditional wavefront start point identification algorithm, it will cause problems such as poor real-time performance and high power consumption. In addition, current traveling wave ranging devices rely on a backend system for ranging, but the partial discharge traveling wave signal is large and continuous. If it is continuously uploaded to the backend system, the upload volume will be too large, resulting in insufficient real-time performance, easy lag, and increased power consumption.

[0068] The power distribution network fault location method provided in this application can be applied to power distribution network fault location equipment. The power distribution network fault location equipment can be a terminal or a server; the terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, drones, low-altitude aircraft, IoT devices, and portable wearable devices. IoT devices can be smart speakers, smart TVs, smart air conditioners, smart vehicle equipment, projection equipment, etc. Portable wearable devices can be smartwatches, smart bracelets, head-mounted devices, etc. Head-mounted devices can be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0069] Optionally, the terminal can also be a partial discharge monitoring device. For example... Figure 1 As shown, the partial discharge monitoring device consists of a high-pass filter module, a line-mode synthesis and signal amplification module, an A / D sampling module (Analog-to-Digital Sampling Module), a calculation module, and a horizontal communication module. The high-pass filter module filters out interference signals while retaining the main frequency band of the partial discharge traveling wave; the line-mode synthesis and signal amplification module extracts and amplifies the line-mode components of the partial discharge traveling wave to make it more sensitive to partial discharge signals; the A / D sampling module converts analog signals into digital signals for subsequent lower-level computer calculation and processing; the calculation module runs a partial discharge traveling wave wavefront start point identification algorithm based on dual-source sliding window STFT (Short-Time Fourier Transform) (i.e., a distribution network fault location method) to calculate the partial discharge traveling wave wavefront start point and its time-stamped information; the horizontal communication module transmits the time-stamped information of the partial discharge traveling wave wavefront start point corresponding to the partial discharge trigger recording within a fixed time period horizontally.

[0070] In one exemplary embodiment, such as Figure 2 As shown, a method for locating faults in a power distribution network is provided. Taking the application of this method to a server as an example, the method includes:

[0071] Step 201: Obtain the discrete digital signals corresponding to the three-phase voltage signals in the distribution network.

[0072] Among them, the distribution network can be a medium-voltage distribution network mainly composed of overhead lines. The lines and power devices are in harsh outdoor conditions for a long time, which can easily lead to insulation degradation and partial discharge, thereby generating partial discharge traveling waves that propagate along the lines. The three-phase voltage signal can be a continuous analog voltage signal transmitted on the three-phase lines of the distribution network. The discrete digital signal can be a digital sampling sequence with time discreteness and amplitude quantization obtained by performing high-frequency synchronous sampling and quantization encoding of the three-phase voltage signal through an A / D sampling module.

[0073] Optionally, a partial discharge monitoring device can be used to sense and collect continuous analog voltage signals of the three-phase lines of the distribution network in real time. Using the built-in A / D sampling module of the device, the sampling frequency adapted to the high-frequency partial discharge traveling wave is used to perform synchronous high-frequency analog-to-digital conversion on the three-phase analog voltage signals. The continuously changing analog voltage waveform is converted into a sampling data sequence arranged in time sequence and whose amplitude is digitally quantized, thus obtaining the discrete digital signals corresponding to the three-phase voltage signals.

[0074] Step 202: When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0075] Among them, the partial discharge traveling wave can be a transient traveling wave signal excited by partial discharge of insulation deteriorated devices in the distribution network and propagating to both sides along the line; the first fault location device and the second fault location device can be two partial discharge monitoring and location devices installed at adjacent points on the medium-voltage distribution network line; the first time stamp information can be the standard time stamp information generated by the first fault location device based on the local high-precision clock of the device after identifying the start time of the partial discharge traveling wave front; the second time stamp information can be the standard time stamp information generated by the second fault location device based on the local high-precision clock of the device after identifying the start time of the partial discharge traveling wave front.

[0076] Optionally, the first fault location device and the second fault location device acquire their respective discrete digital signals in real time; the first fault location device and the second fault location device locate the wavefront starting sampling position of the local release wave based on the discrete digital signals in the device; and, in combination with the local clock reference and the sampling interval, convert the identified wavefront starting position into a standard timestamp, and generate the first time stamp information and the second time stamp information respectively.

[0077] Step 203: Perform fault location based on the first time-stamp information and the second time-stamp information to obtain the fault location result of the distribution network.

[0078] The fault location result can be the location information of partial discharge in the distribution network, and the location information represents the straight-line distance between the partial discharge point and the device (such as the first fault location device or the first fault location device) used as a reference point.

[0079] Optionally, the first time stamp information and the second time stamp information are matched in a time sequence to form a combination of time stamp information corresponding to the same partial discharge event; the line transmission distance between the first fault location device and the second fault location device, as well as the standard transmission speed of the partial discharge traveling wave, are retrieved; finally, the line distance of the device with the partial discharge point distance as the reference point is calculated by combining the line distance, the standard transmission speed of the partial discharge traveling wave, and each combination of time stamp information, thus obtaining the fault location result of the distribution network.

[0080] In the aforementioned distribution network fault location method, the three-phase voltage signals of the distribution network are collected and converted into corresponding discrete digital signals. When a partial discharge traveling wave is detected in the distribution network, the first and second fault location devices respectively determine the first and second time-scale information corresponding to the partial discharge traveling wave. Fault location is then performed based on the first and second time-scale information, and the final distribution network fault location result is output. This method alleviates the shortcomings of traditional methods that cannot accurately locate the partial discharge location in the distribution network due to the large difference in frequency band characteristics between the fault traveling wave and the partial discharge traveling wave, and insufficient algorithm adaptability, thus significantly improving the accuracy of partial discharge fault location in the distribution network.

[0081] In an exemplary embodiment, when a partial discharge wave is detected in the distribution network, the first time stamp information of the first fault location device when the partial discharge wave is detected is determined based on the discrete digital signal, including: determining a first amplitude corresponding to the first digital signal and determining a second amplitude corresponding to the second digital signal; if the first amplitude is not less than the second amplitude, then when the partial discharge wave is detected, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined based on the first digital signal; if the first amplitude is less than the second amplitude, then when the partial discharge wave is detected, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined based on the second digital signal.

[0082] The discrete digital signal includes a first digital signal and a second digital signal; the first digital signal is obtained by high-frequency sampling of the difference between the first phase voltage and the second phase voltage in the distribution network; the second digital signal is obtained by high-frequency sampling of the difference between the third phase voltage and the second phase voltage in the distribution network; the first amplitude is the maximum signal amplitude of the waveform corresponding to the first digital signal; the second amplitude is the maximum signal amplitude of the waveform corresponding to the second digital signal.

[0083] Optionally, determine the wavefront starting point to analyze the channel, and compare the maximum values ​​of line mode 1 (i.e., the first digital signal) and line mode 2 (i.e., the second digital signal). (i.e., the first amplitude) and (i.e., the second value), if Then, taking line mode 1 as the starting point of the wavefront to analyze the channel, the calculation is performed. Otherwise, take line modulus 2 as the starting point of the wavefront to analyze the channel and calculate... .

[0084] Optionally, the starting point of the local release waveguide can be converted into time stamp information. The conversion method is as follows:

[0085]

[0086] in, The time stamp information of the starting point of the waveguide for the release of the bureau (i.e., the first time stamp information). The trigger time for the waveform file. This represents the total number of crystal oscillators in the device.

[0087] In this embodiment, by performing differential calculations on the voltages between different phases of the distribution network and high-frequency sampling to form two independent line-mode discrete digital signals, the electromagnetic coupling between phases and power frequency common-mode interference are effectively suppressed, highlighting the effective characteristics of high-frequency weak-energy partial discharge traveling waves. By comparing the maximum amplitude of the two digital signals, the signal channel with more significant partial discharge characteristics and stronger anti-interference ability is adaptively selected, alleviating the limitations of the traditional single fixed signal channel. Based on the selected signal, the starting position of the partial discharge traveling wavefront is identified and time stamp information is generated, effectively reducing the identification error caused by noise and signal aliasing, and improving the accuracy and stability of wavefront positioning and time stamp generation.

[0088] In an exemplary embodiment, determining the first time stamp information corresponding to the wavefront start position of the partial discharge wave based on the first digital signal includes: extracting a digital signal containing the partial discharge wave from the first digital signal to obtain an effective digital signal; performing time-frequency feature analysis on the effective digital signal to obtain the wavefront start position corresponding to the partial discharge wave; and determining the first time stamp information corresponding to the wavefront start position of the partial discharge wave based on the wavefront start position and the timing information corresponding to the effective digital signal.

[0089] Among them, the effective digital signal can be a segment of discrete digital signal containing the complete waveform of the partial discharge event, which is saved by triggering the waveform recording action when a partial discharge event is detected; the wavefront start position can be the sampling point position where the energy of the partial discharge traveling wave waveform begins to jump abruptly; the timing information can be the high-frequency sampling interval, sampling timing reference, and local crystal oscillator clock scale information corresponding to the effective digital signal.

[0090] Optionally, from the selected first digital signal, a discrete digital signal segment containing the complete waveform of the partial discharge event is obtained, which is saved by triggering the waveform recording action when the partial discharge event is detected; i.e., the effective digital signal; time-frequency feature analysis is performed on the effective digital signal, and the waveform change law of the partial discharge traveling wave is identified by the joint time-frequency features, thereby identifying the wavefront start position corresponding to the partial discharge traveling wave; the inherent sampling interval and timing reference of the effective digital signal are obtained, and time conversion is performed by combining the wavefront start position with the local clock of the equipment to determine the first time stamp information corresponding to the partial discharge traveling wave.

[0091] In this embodiment, effective digital signals are obtained by truncating local waveforms, which effectively reduces the computational power consumption and data transmission load of the fault location equipment. At the same time, the time-frequency feature analysis method is used to adapt to the signal characteristics of high-frequency weak energy partial discharge waves, accurately identifying the starting position of the partial discharge wavefront. Then, the sampling timing information is combined to accurately convert and generate time stamp information, reducing the error of wavefront identification and time stamp conversion.

[0092] In an exemplary embodiment, time-frequency feature analysis is performed on the effective digital signal to obtain the wavefront start position corresponding to the partial discharge traveling wave. This includes: applying a sliding window to the effective digital signal based on a pre-set window length and sliding step size to obtain multiple signal windows; performing a discrete Fourier transform on the digital signal within each signal window to obtain a complex sequence corresponding to each signal window; determining the time-frequency amplitude sequence based on the magnitude of each element in each complex sequence; locating the monotonically increasing start position in the time-frequency amplitude sequence based on the maximum amplitude value and the position corresponding to the maximum amplitude value; determining the candidate sampling point interval corresponding to the wavefront start position based on the start position, window length, and sliding step size; and searching for waveform abrupt change points in the effective digital signal within the candidate sampling point interval, and using the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

[0093] Here, the window length can be the number of sampling points contained in a single signal window that is preset; the sliding step size can be the number of sampling points between the starting positions of two adjacent signal windows during the sliding windowing process; the signal window can be each independent time-domain sampled data segment obtained after sliding windowing; the complex sequence can be an ordered set of complex numbers obtained after a single signal window undergoes a discrete Fourier transform, with each complex number carrying both signal amplitude and phase information; the modulus can be the modulus of a single complex number in the complex sequence, representing the absolute magnitude of the signal energy; and the time-frequency amplitude sequence can be obtained by sequentially processing each complex sequence. After obtaining the magnitude of the elements, the amplitude sequence is formed by arranging them in the original time sequence to reflect the energy changes in the time and frequency dimensions of the signal. The starting position can be the starting point where the time and frequency amplitudes start from the stable baseline and continuously rise, entering a monotonically increasing trend, and trace back from the position of the largest amplitude. The candidate sampling point interval can be the range of sampling point numbers that may exist in the effective digital signal at the wavefront starting point. The waveform abrupt change point can be the sampling point in the effective digital signal where the amplitude changes instantaneously or the waveform shows obvious distortion. The sampling point position can be the corresponding number position of the sampling point in the time sequence of the effective digital signal.

[0094] Optionally, upon triggering waveform recording, a windowed DFT operation is performed starting from the first point of the waveform file (i.e., the effective digital signal). Assume the total number of points in the waveform file is... The window length is The sliding step size is The total number of windows (i.e., multiple signal windows) constructed in this way. for:

[0095]

[0096] in, This indicates rounding down, so for the th... The first window The method for applying windows to data is as follows:

[0097]

[0098] in, This is the data matrix after the first windowing, where rows represent window numbers and columns represent specific elements within each window. For window functions.

[0099] right Proceed window by window The DFT operation for each component can be represented as:

[0100]

[0101] in, for The result after DFT (i.e., the complex sequence), taking the first... The component is the one closest to the dominant frequency band of the partial amplifier traveling wave. Since the partial amplifier traveling wave is dominated by signals above 500kHz, therefore, the following is selected: The component closest to 1MHz can be expressed as:

[0102]

[0103] in, This indicates rounding to the nearest integer.

[0104] From the first part of the waveform recording file Windowed DFT operations are performed on each point. The total number of windows thus formed is... for:

[0105]

[0106] For the first The first window The method for applying windows to data is as follows:

[0107]

[0108] in, This is the second windowed data matrix, where rows represent window numbers and columns represent specific elements within each window.

[0109] right Proceed window by window The DFT operation for each component can be represented as:

[0110]

[0111] in, for The result after DFT (i.e., complex sequence). The meaning and method of acquisition are the same as above.

[0112] Find them separately and model , Instantaneous frequency amplitude sequence:

[0113]

[0114] in, , They are respectively The real and imaginary parts, , They are respectively The real and imaginary parts.

[0115] Search separately , The maximum values ​​are denoted as follows: , (The maximum amplitude value in the instantaneous frequency amplitude value sequence), its corresponding , The element indices are respectively , Starting from the position of the maximum value (i.e., the position corresponding to the largest amplitude), search backwards for the starting point of monotonically increasing, denoted as . , (That is, the starting position of the monotonically increasing sequence), which means:

[0116]

[0117] in, , The corresponding left sampling point numbers of the sliding window interval are as follows: , The serial numbers of the right sampling points are respectively , ,Pick:

[0118]

[0119] This allows us to determine the sampling point interval where the local release wavefront is located: That is, the interval of candidate sampling points.

[0120] View interval Does it contain any obvious turning points? The definition of an obvious turning point is as follows: If the first... Point satisfies:

[0121]

[0122] Then define the first The point is a significant abrupt change point, i.e., a waveform abrupt change point.

[0123] If the interval If there is a clear mutation point, then the clear mutation point is denoted as the first one. This point is the starting point of the local broadcast waveguide; otherwise, it is counted. Then the first The point is the starting point of the release waveguide.

[0124] In this embodiment, by combining sliding windowing with discrete Fourier transform to perform time-frequency joint feature analysis on the effective digital signal, the influence of high-frequency interference and sensor noise on the masking effect of high-frequency weak energy partial discharge wave is effectively mitigated. At the same time, a coarse-fine combined positioning method is adopted, which first traces the starting point of energy increase, then reverse-engineers the candidate sampling interval, and finally performs a local fine search for waveform change points. This reduces the amount of computational data and can accurately capture the weak jump characteristics of the partial discharge wave, effectively reducing the identification deviation of the wavefront starting position.

[0125] In an exemplary embodiment, fault location is performed based on first time-stamp information and second time-stamp information to obtain fault location results of the distribution network, including: matching the first time-stamp information and the second time-stamp information to obtain at least one combination of time-stamp information; determining at least one fault location information based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and each combination of time-stamp information; and determining the fault location results of the distribution network based on the average distance corresponding to each fault location information.

[0126] Among them, the time stamp information combination can be a pair of first time stamp information and second time stamp information after matching, which serves as the input data pair for a single fault location; the transmission line distance can be the known physical line length of the power distribution line between the first fault location device and the second fault location device; the traveling wave transmission speed can be the preset wave speed of the partial discharge traveling wave propagating in the overhead line of the power distribution network; and the fault location information can be the distance position of the fault point on the line corresponding to a single time stamp combination.

[0127] Optionally, the first fault location device and the second fault location device can send the first time stamp information and the second time stamp information to the server respectively. The server calculates the fault location information based on the first time stamp information and the second time stamp information, and then takes the average value of each fault location information to determine the fault location result of the distribution network.

[0128] Optionally, the fault location result of the distribution network can be calculated using either the first fault location device or the second fault location device. Specifically, the partial discharge monitoring device (i.e., the first fault location device) sends the time stamp information of the starting point of the partial discharge traveling wavefront corresponding to the partial discharge trigger recording within the specified time period to the adjacent partial discharge monitoring device (i.e., the second fault location device) via horizontal communication at fixed intervals. Assuming there are a total of... The first time-stamped information (i.e., the first time-stamped information) is denoted as... , ... After receiving the time stamp information, adjacent devices check the time stamp information of the starting point of the traveling wavefront of the partial discharge (PD) corresponding to their own partial discharge trigger recordings within the same time period, assuming they have a total of [number missing]. The first time-stamped information (i.e., the second time-stamped information) is denoted as... , ... Iterate through the two sets of time stamp information one by one to find the time stamps that satisfy the following formula.

[0129]

[0130] in, Let the time delay be a fixed value. Assume that after the above steps, a total of [values] are found. The time-stamped information that satisfies the above formula, i.e., the successfully matched time-stamped information (i.e., the combination of time-stamped information), are denoted as follows: , ... .

[0131] The distance measurement performed on this set of time-stamped information pairs can be expressed as:

[0132]

[0133] in, This indicates the distance between the partial discharge point and device 1 (i.e., fault location information). This indicates the distance of the transmission line between device 1 and device 2 (i.e., the transmission line distance). The value represents the propagation speed of the traveling wave along the transmission line (i.e., the traveling wave propagation speed). The average of the two-end ranging results is calculated, and the final ranging result is output. , can be represented as:

[0134]

[0135] In this embodiment, by performing event matching on the dual-end time stamp information to form an effective time stamp combination, the accuracy of ranging data pairing is ensured. Then, by combining the line distance between devices and the traveling wave transmission speed, the fault location is calculated group by group, and the average value of multiple fault locations is calculated. This effectively alleviates the ranging fluctuations caused by wavefront identification error, sampling timing deviation and on-site electromagnetic interference, and improves the accuracy of partial discharge fault location in medium-voltage distribution networks.

[0136] In an exemplary embodiment, determining the discrete digital signal corresponding to the three-phase voltage signal includes: determining a first linear analog signal based on the difference between the first phase voltage signal and the second phase voltage signal; performing high-frequency sampling on the first linear analog signal to obtain a first digital signal; determining a second linear analog signal based on the difference between the third phase voltage signal and the second phase voltage signal; performing high-frequency sampling on the second linear analog signal to obtain a second digital signal; and determining the discrete digital signal based on the first digital signal and the second digital signal.

[0137] The three-phase voltage signal includes the first-phase voltage signal, the second-phase voltage signal, and the third-phase voltage signal.

[0138] The first line-mode signal can be an analog signal obtained by performing a difference operation between the first phase voltage signal and the second phase voltage signal; the second line-mode signal can be an analog signal obtained by performing a difference operation between the third phase voltage signal and the second phase voltage signal.

[0139] Optionally, the high-pass filter circuit in the partial discharge monitoring device will filter the frequency at... The following signal filtering retains frequencies within the range of The above signals are respectively denoted as , , That is, the three-phase voltage signal.

[0140] The filtered signal is then synthesized using a line-mode synthesis method, as shown in the following equation.

[0141]

[0142] in, It is a 1-mode signal (i.e., the first line-mode signal). The signal is a 2-mode voltage (i.e., the second line-mode signal). Then, the line-mode signal in the above formula is sampled by a high-frequency A / D converter, as shown in the following formula.

[0143]

[0144] in, Sampling point number Let be the sampling interval. Using the above equation, the high-frequency discrete linear mode signal can be obtained. (i.e., the first digital signal) (i.e., the second digital signal).

[0145] In this embodiment, by performing phase-to-phase difference calculation on the three-phase voltage signals of the distribution network to construct two independent line-mode signals, it is possible to effectively suppress three-phase common-mode interference and phase-to-phase electromagnetic coupling interference, highlighting the effective characteristics of high-frequency weak-energy partial discharge traveling waves. At the same time, the two line-mode signals are sampled at high frequency to form dual-channel discrete digital signals, which not only completely preserves the high-frequency waveform information of the partial discharge traveling waves, but also constructs redundant signal channels to facilitate subsequent adaptive optimization analysis, reducing the impact of noise and interference on partial discharge feature extraction.

[0146] In one exemplary embodiment, such as Figure 3 As shown, taking a distance of 973m between two partial discharge monitoring devices as an example, the overall process of the power distribution network fault location method is explained as follows:

[0147] Optionally, the signal on the line is subjected to high-pass filtering and line-mode synthesis, and then the synthesized signal is subjected to high-frequency A / D sampling to obtain the sampled high-frequency signal.

[0148] In this embodiment, there are two partial discharge monitoring devices, such as... Figure 4 As shown. Figure 4 In the partial discharge monitoring device shown, the high-pass filter circuit filters the frequency at... Filter out signals below kHz, retain frequencies above kHz. The above signals are respectively denoted as , , .

[0149] The filtered signal is then synthesized using a line-mode synthesis method, as shown in the following equation.

[0150]

[0151] in, , The voltages are 1-mode and 2-mode, respectively. Then, the line-mode signal in the above formula is sampled by a high-frequency A / D converter, as shown in the following formula.

[0152]

[0153] in, Sampling point number Let be the sampling interval. Using the above equation, the high-frequency discrete linear mode signal can be obtained. , .

[0154] Optionally, a dual-source sliding window STFT algorithm is used to identify the start point of the partial discharge wavefront in the data saved after trigger recording, and the identified start point information of the partial discharge wavefront is converted into time stamp information. Specifically:

[0155] Determine the wavefront starting point to analyze the channel, and compare the maximum values ​​of line mode 1 and line mode 2. and ,like Then, taking line mode 1 as the starting point of the wavefront to analyze the channel, the calculation is performed. Otherwise, take line modulus 2 as the starting point of the wavefront to analyze the channel and calculate... In this embodiment, one of the recorded waveforms triggered by the partial discharge monitoring device 1 is as follows: Figure 5 As shown. By Figure 5 It can be seen that, Therefore, taking line modulus 2 as the starting point of the wavefront to analyze the channel, the calculation... .

[0156] After the waveform recording is triggered, a windowed DFT operation is performed starting from the first point in the waveform file. Assume the total number of points in the waveform file is... The window length is The sliding step size is The total number of windows thus formed for:

[0157]

[0158] in, This indicates rounding down to the nearest integer. In this embodiment, , , ,but .

[0159] For the first The first window The method for applying windows to data is as follows:

[0160]

[0161] in, This is the data matrix after the first windowing, where rows represent window numbers and columns represent specific elements within each window. For the window function, in this embodiment, the window function is: .

[0162] right Proceed window by window The DFT operation for each component is shown in the following formula.

[0163]

[0164] In the above formula, for The result after DFT, take the first... The component is the one closest to the dominant frequency band of the partial amplifier traveling wave. Since the partial amplifier traveling wave is dominated by signals above 500kHz, therefore, the following is selected: The component closest to 1MHz is shown in the following formula.

[0165]

[0166] in, This indicates rounding to the nearest integer. In this embodiment, MHz, so .

[0167] From the first part of the waveform recording file Windowed DFT operations are performed on each point. The total number of windows thus formed is... for:

[0168]

[0169] In this embodiment, .

[0170] For the first The first window The method for applying windows to data is as follows:

[0171]

[0172] in, This is the second windowed data matrix, where rows represent window numbers and columns represent specific elements within each window.

[0173] right Proceed window by window The DFT operation for each component is shown in the following formula.

[0174]

[0175] In the above formula, for The result after DFT The meaning and method of acquisition are the same as above.

[0176] Find them separately and model , ,Right now:

[0177]

[0178] in, , They are respectively The real and imaginary parts, , They are respectively The real and imaginary parts.

[0179] Search separately , The maximum values ​​are denoted as follows: , Its corresponding , The element indices are respectively , Starting from the position of the maximum value, search backwards for the starting point of the monotonically increasing sequence, denoted as . , That is:

[0180]

[0181] In this embodiment, , The calculation results are as follows Figure 6 As shown. Therefore, , . , The corresponding left sampling point numbers of the sliding window interval are as follows: , The serial numbers of the right sampling points are respectively , ,Pick:

[0182]

[0183] This allows us to determine the sampling point interval where the local release wavefront is located: .

[0184] In this embodiment, , The corresponding left sampling point numbers for the sliding window intervals are 1528 and 1524, and the right sampling point numbers are 1536 and 1532. Therefore... , Interval The waveform of the original signal is as follows Figure 7 As shown.

[0185] View interval Does it contain any obvious turning points? The definition of an obvious turning point is as follows: If the first... Point satisfies:

[0186]

[0187] Then define the first The point represents a significant abrupt change.

[0188] If the interval If there is a clear mutation point, then the clear mutation point is denoted as the first one. This point is the starting point of the local broadcast waveguide; otherwise, it is counted. Then the first The point is the starting point of the release waveguide.

[0189] In this embodiment, the following conditions are met: and Therefore, the starting point of the release waveguide is .

[0190] The starting point of the release waveguide is converted into time-stamped information using the following method:

[0191]

[0192] in, For the time stamp information of the starting point of the waveguide for release by the bureau, The trigger time for the waveform file. This represents the total number of crystal oscillators in the device. In this embodiment, viewing the device's waveform recording information reveals that... ns, ,therefore, ns.

[0193] Optionally, the partial discharge monitoring device sends the start point time stamp information of the partial discharge traveling wavefront to adjacent partial discharge monitoring devices via lateral communication. Upon receiving the start point time stamp, the adjacent partial discharge monitoring devices perform time stamp matching and double-end ranging on the successfully matched partial discharge traveling wave signals, outputting the ranging result. Specifically:

[0194] Partial discharge monitoring device (device 1) sends the start point time stamp information of the partial discharge traveling wavefront corresponding to the partial discharge trigger recording within the specified time period to the adjacent partial discharge monitoring device (device 2) via lateral communication at fixed intervals. Assume there are a total of Each time-stamped information is denoted as , ... After receiving the time stamp information, adjacent devices check the time stamp information of the starting point of the traveling wavefront of the partial discharge (PD) corresponding to their own partial discharge trigger recordings within the same time period, assuming they have a total of [number missing]. Each time-stamped information is denoted as , ... Iterate through the two sets of time stamp information one by one to find the time stamps that satisfy the following formula.

[0195]

[0196] in, Let the time delay be a fixed value. Assume that after the above steps, a total of [values] are found. The time stamp information that satisfies the above formula, i.e., the time stamp information that is successfully matched, is denoted as follows: , ... .

[0197] Regarding this The time-stamped information pairs are used for two-end distance measurement, as shown in the following formula.

[0198]

[0199] in, This indicates the distance of the partial discharge point from device 1. This indicates the distance of the transmission line between device 1 and device 2. The distance is represented by the propagation speed of the local discharge wave along the transmission line. The average of the ranging results at both ends is calculated, and the final ranging result is output. As shown in the following formula.

[0200]

[0201] In this embodiment, the partial discharge monitoring device 1 sends the start point time stamp information of the partial discharge traveling wave front corresponding to the partial discharge trigger recording within 1 second to the adjacent partial discharge monitoring device 2. m, ms. After matching according to the above steps, the time-stamp information of successfully matched pairs and the corresponding ranging results are shown in Table 1.

[0202] Table 1:

[0203] Serial Number <![CDATA[t 1i / ns]]> <![CDATA[T 2i / ns]]> <![CDATA[x i / m]]> 1 78949010 78947721 679.85 2 154777220 154776047 662.45 3 273838285 273836973 683.3 4 323416711 323415496 668.75 5 345309903 345308705 666.2 6 379115963 379114696 676.55 7 458942554 458941250 682.1 8 632114619 632113433 664.4 9 793730794 793729553 672.65 10 828731303 828730010 680.45 11 992556535 992555348 664.55

[0204] therefore, m. After on-site inspection, the actual distance between the partial discharge point and the partial discharge monitoring device was approximately 671m. Therefore, the ranging error was 1.84m, and the ranging effect met the requirements of engineering applications.

[0205] To more comprehensively demonstrate this solution, this embodiment presents a method for locating faults in a distribution network, specifically including:

[0206] 1. Determine the first line-mode signal based on the difference between the first phase voltage signal and the second phase voltage signal;

[0207] 2. The first line-mode signal is sampled at high frequency to obtain the first digital signal; the first digital signal is obtained by sampling the difference between the first phase voltage and the second phase voltage in the distribution network at high frequency.

[0208] 3. Determine the second line-mode signal based on the difference between the third-phase voltage signal and the second-phase voltage signal;

[0209] 4. The second line-mode signal is sampled at high frequency to obtain the second digital signal; the second digital signal is obtained by sampling the difference between the third phase voltage and the second phase voltage in the distribution network at high frequency.

[0210] The discrete digital signal is determined based on the first digital signal and the second digital signal;

[0211] 5. Determine the first amplitude corresponding to the first digital signal, and determine the second amplitude corresponding to the second digital signal; the first amplitude is the maximum signal amplitude of the waveform corresponding to the first digital signal; the second amplitude is the maximum signal amplitude of the waveform corresponding to the second digital signal.

[0212] 6. If the first amplitude is not less than the second amplitude, then when a partial discharge wave is detected, the digital signal containing the partial discharge wave is extracted from the first digital signal to obtain the effective digital signal; the effective digital signal is subjected to time-frequency characteristic analysis to obtain the wavefront start position corresponding to the partial discharge wave; based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined.

[0213] 7. If the first amplitude is less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the starting position of the wavefront of the local transmission wave is determined according to the second digital signal, as well as the second time stamp information when the second fault location device detects the local transmission wave;

[0214] 8. Match the first time stamp information and the second time stamp information to obtain at least one combination of time stamp information;

[0215] 9. Determine at least one fault location based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and the combination of each time stamp information;

[0216] 10. Determine the fault location result of the distribution network based on the average distance corresponding to each fault location information.

[0217] The specific process of the above steps can be found in the description of the above method embodiments. The implementation principle and technical effect are similar, and will not be repeated here.

[0218] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0219] Based on the same inventive concept, this application also provides a distribution network fault location device for implementing the distribution network fault location method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more distribution network fault location device embodiments provided below can be found in the limitations of the distribution network fault location method described above, and will not be repeated here.

[0220] In one exemplary embodiment, such as Figure 8 As shown, a power distribution network fault location device is provided, comprising: an acquisition module 81, a processing module 82, and a location module 83, wherein:

[0221] The acquisition module 81 is used to acquire the discrete digital signals corresponding to the three-phase voltage signals in the distribution network;

[0222] The processing module 82 is used to determine, based on discrete digital signals, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave, when a partial discharge wave is detected in the distribution network.

[0223] The positioning module 83 is used to locate faults based on the first time stamp information and the second time stamp information, and obtain the fault location result of the distribution network.

[0224] In one embodiment, the processing module 82 is further configured to:

[0225] Determine a first amplitude value corresponding to a first digital signal, and determine a second amplitude value corresponding to a second digital signal; the first amplitude value is the maximum signal amplitude value of the waveform corresponding to the first digital signal; the second amplitude value is the maximum signal amplitude value of the waveform corresponding to the second digital signal.

[0226] If the first amplitude is not less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the starting position of the wavefront of the local transmission wave is determined according to the first digital signal.

[0227] If the first amplitude is less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the start position of the wavefront of the local transmission wave is determined according to the second digital signal.

[0228] In one embodiment, the processing module 82 is further configured to:

[0229] The effective digital signal is obtained by extracting the digital signal containing the partial amplifier traveling wave from the first digital signal;

[0230] Time-frequency characteristic analysis of the effective digital signal is performed to obtain the wavefront start position corresponding to the partial discharge traveling wave;

[0231] Based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the local release wave is determined.

[0232] In one embodiment, the processing module 82 is further configured to:

[0233] Based on a preset window length and sliding step size, the effective digital signal is windowed to obtain multiple signal windows;

[0234] Perform Discrete Fourier Transform on the digital signal within each signal window to obtain the complex sequence corresponding to each signal window;

[0235] Determine the time-frequency amplitude sequence based on the modulus of each element in each complex number sequence;

[0236] The starting position of the monotonically increasing time-frequency amplitude sequence is obtained by locating the maximum amplitude value and its corresponding position in the time-frequency amplitude sequence.

[0237] Based on the starting position, window length, and sliding step size, determine the candidate sampling point interval corresponding to the starting position of the wavefront;

[0238] Within the candidate sampling point interval, find the waveform abrupt change point in the effective digital signal, and take the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

[0239] In one embodiment, the positioning module 83 is further configured to:

[0240] Match the first time stamp information and the second time stamp information to obtain at least one combination of time stamp information;

[0241] Based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and the combination of each time stamp information, at least one fault location information is determined.

[0242] The fault location results of the distribution network are determined based on the average distance corresponding to each fault location information.

[0243] In one embodiment, the acquisition module 81 is further configured to:

[0244] The first line-mode signal is determined based on the difference between the first phase voltage signal and the second phase voltage signal;

[0245] The first linear analog signal is sampled at high frequency to obtain the first digital signal;

[0246] The second line-mode signal is determined based on the difference between the third-phase voltage signal and the second-phase voltage signal;

[0247] The second linear signal is sampled at high frequency to obtain the second digital signal;

[0248] The discrete digital signal is determined based on the first digital signal and the second digital signal.

[0249] Each module in the aforementioned power distribution network fault location device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0250] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 9As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores fault location results for the power distribution network. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a power distribution network fault location method.

[0251] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0252] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0253] Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0254] When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0255] Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location results of the distribution network.

[0256] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0257] Determine a first amplitude value corresponding to a first digital signal, and determine a second amplitude value corresponding to a second digital signal; the first amplitude value is the maximum signal amplitude value of the waveform corresponding to the first digital signal; the second amplitude value is the maximum signal amplitude value of the waveform corresponding to the second digital signal.

[0258] If the first amplitude is not less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the starting position of the wavefront of the local transmission wave is determined according to the first digital signal.

[0259] If the first amplitude is less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the start position of the wavefront of the local transmission wave is determined according to the second digital signal.

[0260] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0261] The effective digital signal is obtained by extracting the digital signal containing the partial amplifier traveling wave from the first digital signal;

[0262] Time-frequency characteristic analysis of the effective digital signal is performed to obtain the wavefront start position corresponding to the partial discharge traveling wave;

[0263] Based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the local release wave is determined.

[0264] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0265] Based on a preset window length and sliding step size, the effective digital signal is windowed to obtain multiple signal windows;

[0266] Perform Discrete Fourier Transform on the digital signal within each signal window to obtain the complex sequence corresponding to each signal window;

[0267] Determine the time-frequency amplitude sequence based on the modulus of each element in each complex number sequence;

[0268] The starting position of the monotonically increasing time-frequency amplitude sequence is obtained by locating the maximum amplitude value and its corresponding position in the time-frequency amplitude sequence.

[0269] Based on the starting position, window length, and sliding step size, determine the candidate sampling point interval corresponding to the starting position of the wavefront;

[0270] Within the candidate sampling point interval, find the waveform abrupt change point in the effective digital signal, and take the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

[0271] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0272] Match the first time stamp information and the second time stamp information to obtain at least one combination of time stamp information;

[0273] Based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and the combination of each time stamp information, at least one fault location information is determined.

[0274] The fault location results of the distribution network are determined based on the average distance corresponding to each fault location information.

[0275] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0276] The first line-mode signal is determined based on the difference between the first phase voltage signal and the second phase voltage signal;

[0277] The first linear analog signal is sampled at high frequency to obtain the first digital signal;

[0278] The second line-mode signal is determined based on the difference between the third-phase voltage signal and the second-phase voltage signal;

[0279] The second linear signal is sampled at high frequency to obtain the second digital signal;

[0280] The discrete digital signal is determined based on the first digital signal and the second digital signal.

[0281] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0282] Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network;

[0283] When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal.

[0284] Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location results of the distribution network.

[0285] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0286] Determine a first amplitude value corresponding to a first digital signal, and determine a second amplitude value corresponding to a second digital signal; the first amplitude value is the maximum signal amplitude value of the waveform corresponding to the first digital signal; the second amplitude value is the maximum signal amplitude value of the waveform corresponding to the second digital signal.

[0287] If the first amplitude is not less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the starting position of the wavefront of the local transmission wave is determined according to the first digital signal.

[0288] If the first amplitude is less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the start position of the wavefront of the local transmission wave is determined according to the second digital signal.

[0289] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0290] The effective digital signal is obtained by extracting the digital signal containing the partial amplifier traveling wave from the first digital signal;

[0291] Time-frequency characteristic analysis of the effective digital signal is performed to obtain the wavefront start position corresponding to the partial discharge traveling wave;

[0292] Based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the local release wave is determined.

[0293] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0294] Based on a preset window length and sliding step size, the effective digital signal is windowed to obtain multiple signal windows;

[0295] Perform Discrete Fourier Transform on the digital signal within each signal window to obtain the complex sequence corresponding to each signal window;

[0296] Determine the time-frequency amplitude sequence based on the modulus of each element in each complex number sequence;

[0297] The starting position of the monotonically increasing time-frequency amplitude sequence is obtained by locating the maximum amplitude value and its corresponding position in the time-frequency amplitude sequence.

[0298] Based on the starting position, window length, and sliding step size, determine the candidate sampling point interval corresponding to the starting position of the wavefront;

[0299] Within the candidate sampling point interval, find the waveform abrupt change point in the effective digital signal, and take the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

[0300] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0301] Match the first time stamp information and the second time stamp information to obtain at least one combination of time stamp information;

[0302] Based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and the combination of each time stamp information, at least one fault location information is determined.

[0303] The fault location results of the distribution network are determined based on the average distance corresponding to each fault location information.

[0304] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0305] The first line-mode signal is determined based on the difference between the first phase voltage signal and the second phase voltage signal;

[0306] The first linear analog signal is sampled at high frequency to obtain the first digital signal;

[0307] The second line-mode signal is determined based on the difference between the third-phase voltage signal and the second-phase voltage signal;

[0308] The second linear signal is sampled at high frequency to obtain the second digital signal;

[0309] The discrete digital signal is determined based on the first digital signal and the second digital signal.

[0310] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0311] Determine a first amplitude value corresponding to a first digital signal, and determine a second amplitude value corresponding to a second digital signal; the first amplitude value is the maximum signal amplitude value of the waveform corresponding to the first digital signal; the second amplitude value is the maximum signal amplitude value of the waveform corresponding to the second digital signal.

[0312] If the first amplitude is not less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the starting position of the wavefront of the local transmission wave is determined according to the first digital signal.

[0313] If the first amplitude is less than the second amplitude, then when the local transmission wave is detected, the first time stamp information corresponding to the start position of the wavefront of the local transmission wave is determined according to the second digital signal.

[0314] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0315] The effective digital signal is obtained by extracting the digital signal containing the partial amplifier traveling wave from the first digital signal;

[0316] Time-frequency characteristic analysis of the effective digital signal is performed to obtain the wavefront start position corresponding to the partial discharge traveling wave;

[0317] Based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the local release wave is determined.

[0318] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0319] Based on a preset window length and sliding step size, the effective digital signal is windowed to obtain multiple signal windows;

[0320] Perform Discrete Fourier Transform on the digital signal within each signal window to obtain the complex sequence corresponding to each signal window;

[0321] Determine the time-frequency amplitude sequence based on the modulus of each element in each complex number sequence;

[0322] The starting position of the monotonically increasing time-frequency amplitude sequence is obtained by locating the maximum amplitude value and its corresponding position in the time-frequency amplitude sequence.

[0323] Based on the starting position, window length, and sliding step size, determine the candidate sampling point interval corresponding to the starting position of the wavefront;

[0324] Within the candidate sampling point interval, find the waveform abrupt change point in the effective digital signal, and take the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

[0325] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0326] Match the first time stamp information and the second time stamp information to obtain at least one combination of time stamp information;

[0327] Based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and the combination of each time stamp information, at least one fault location information is determined.

[0328] The fault location results of the distribution network are determined based on the average distance corresponding to each fault location information.

[0329] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0330] The first line-mode signal is determined based on the difference between the first phase voltage signal and the second phase voltage signal;

[0331] The first linear analog signal is sampled at high frequency to obtain the first digital signal;

[0332] The second line-mode signal is determined based on the difference between the third-phase voltage signal and the second-phase voltage signal;

[0333] The second linear signal is sampled at high frequency to obtain the second digital signal;

[0334] The discrete digital signal is determined based on the first digital signal and the second digital signal.

[0335] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0336] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0337] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0338] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for locating faults in a power distribution network, characterized in that, The method includes: Acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network; When a partial discharge wave is detected in the distribution network, the first time stamp information when the first fault location device detects the partial discharge wave and the second time stamp information when the second fault location device detects the partial discharge wave are determined based on the discrete digital signal. Fault location is performed based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network.

2. The method according to claim 1, characterized in that, The discrete digital signal includes a first digital signal and a second digital signal; the first digital signal is obtained by high-frequency sampling of the difference between the first phase voltage and the second phase voltage in the distribution network; the second digital signal is obtained by high-frequency sampling of the difference between the third phase voltage and the second phase voltage in the distribution network. When a partial discharge wave is detected in the distribution network, the method for determining the first time-stamp information of the time when the first fault location device detects the partial discharge wave, based on the discrete digital signal, includes: A first amplitude corresponding to the first digital signal is determined, and a second amplitude corresponding to the second digital signal is determined; the first amplitude is the maximum signal amplitude of the waveform corresponding to the first digital signal; the second amplitude is the maximum signal amplitude of the waveform corresponding to the second digital signal. If the first amplitude is not less than the second amplitude, then when a partial discharge wave is detected, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined according to the first digital signal; If the first amplitude is less than the second amplitude, then when a partial discharge wave is detected, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined according to the second digital signal.

3. The method according to claim 2, characterized in that, The step of determining the first time-stamp information corresponding to the wavefront start position of the partial discharge wave based on the first digital signal includes: Extract the digital signal containing the partial amplifier traveling wave from the first digital signal to obtain the effective digital signal; Time-frequency feature analysis is performed on the effective digital signal to obtain the wavefront start position corresponding to the partial discharge traveling wave; Based on the wavefront start position and the timing information corresponding to the effective digital signal, the first time stamp information corresponding to the wavefront start position of the partial discharge wave is determined.

4. The method according to claim 3, characterized in that, The step of performing time-frequency feature analysis on the effective digital signal to obtain the wavefront start position corresponding to the partial discharge traveling wave includes: Based on a preset window length and sliding step size, the effective digital signal is windowed to obtain multiple signal windows; Perform a Discrete Fourier Transform on the digital signal within each signal window to obtain the complex sequence corresponding to each signal window; Determine the time-frequency amplitude sequence based on the modulus of each element in each of the complex number sequences; The starting position of the monotonically increasing time-frequency amplitude sequence is obtained by locating the maximum amplitude value and the position corresponding to the maximum amplitude value in the time-frequency amplitude sequence. Based on the starting position, the window length, and the sliding step size, determine the candidate sampling point interval corresponding to the wavefront starting position; Within the candidate sampling point interval, find the waveform abrupt change point in the effective digital signal, and take the sampling point position corresponding to the waveform abrupt change point as the wavefront start position corresponding to the partial discharge traveling wave.

5. The method according to any one of claims 1 to 4, characterized in that, The step of locating the fault based on the first time-stamped information and the second time-stamped information to obtain the fault location result of the distribution network includes: The first time stamp information and the second time stamp information are matched to obtain at least one combination of time stamp information; Based on the transmission line distance between adjacent devices, the traveling wave transmission speed, and each of the aforementioned time stamp information combinations, at least one fault location information is determined; The fault location result of the distribution network is determined based on the average distance corresponding to each fault location information.

6. The method according to any one of claims 1 to 4, characterized in that, The three-phase voltage signal includes a first-phase voltage signal, a second-phase voltage signal, and a third-phase voltage signal; Determining the discrete digital signal corresponding to the three-phase voltage signal includes: The first line-mode signal is determined based on the difference between the first phase voltage signal and the second phase voltage signal; The first line-mode signal is sampled at high frequency to obtain a first digital signal; The second line-mode signal is determined based on the difference between the third-phase voltage signal and the second-phase voltage signal; The second line-mode signal is sampled at high frequency to obtain the second digital signal; The discrete digital signal is determined based on the first digital signal and the second digital signal.

7. A power distribution network fault location device, characterized in that, The device includes: The acquisition module is used to acquire the discrete digital signals corresponding to the three-phase voltage signals in the power distribution network; The processing module is used to determine, based on the discrete digital signal, a first time stamp information when the first fault location device detects the partial discharge wave and a second time stamp information when the second fault location device detects the partial discharge wave, when a partial discharge wave is detected in the distribution network. The positioning module is used to locate faults based on the first time stamp information and the second time stamp information, and obtain the fault location result of the distribution network.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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