Power distribution area fault positioning method, device and equipment

Abstract

The embodiment of the application provides a power distribution area fault positioning method, device and equipment. It relates to the technical field of power management. The method comprises the following steps: based on the dynamic topology of a low-voltage terminal and a low-voltage power distribution area, acquiring the fault waveform collected by each low-voltage terminal in a plurality of adjacent terminal groups; performing synchronous time sequence calibration on the fault waveforms collected by the low-voltage terminals of the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal groups; extracting the characteristic parameters of the calibration fault waveforms in the adjacent terminal groups to obtain the fault waveform features corresponding to the adjacent terminal groups; based on the fault types corresponding to the fault waveforms, performing weighted summation on the fault waveform features corresponding to the adjacent terminal groups to obtain the difference quantization indexes corresponding to the adjacent terminal groups; and based on the difference quantization indexes corresponding to the adjacent terminal groups, determining the fault interval of the low-voltage power distribution area. The application is used to achieve the effect of accurate and rapid fault positioning.

Description

Technical Field

[0001] This application relates to the field of power management technology, and in particular to a method, apparatus and equipment for locating faults in a distribution substation. Background Technology

[0002] Low-voltage distribution transformer substations are core power supply networks in power systems that directly face end users. Their complex line topology and susceptibility to external damage, weather conditions, and load fluctuations lead to frequent faults. Therefore, locating faults in low-voltage distribution transformer substations is a pressing issue that needs to be addressed.

[0003] In related technologies, a single electrical measurement point is set at the output terminal of the transformer in the low-voltage distribution area or at the main incoming line of the distribution area. By collecting the electrical parameters at the measurement point and judging based on preset thresholds or simple logic rules, the location and type of fault are determined. However, the accuracy and reliability of the fault location results are poor, resulting in low fault handling efficiency, long power outage time, and serious impact on power reliability. Summary of the Invention

[0004] This application provides a method, apparatus, and equipment for locating faults in distribution radio areas, so as to achieve accurate and rapid fault location.

[0005] In a first aspect, embodiments of this application provide a method for locating faults in a distribution transformer substation, applied to a fusion terminal deployed at a distribution transformer corresponding to a low-voltage distribution transformer substation. The fusion terminal is communicatively connected to multiple low-voltage terminals deployed at measurement points in the low-voltage distribution transformer substation, including:

[0006] Based on the dynamic topology of low-voltage terminals and low-voltage distribution transformer areas, fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups are obtained.

[0007] Synchronous timing calibration is performed on the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal groups;

[0008] Feature parameters are extracted from the calibration fault waveforms within adjacent terminal groups to obtain the fault waveform features corresponding to the adjacent terminal groups.

[0009] Based on the fault type corresponding to the fault waveform, the fault waveform features of adjacent terminal groups are weighted and summed to obtain the difference quantification index of adjacent terminal groups.

[0010] Based on the difference quantification index corresponding to adjacent terminal groups, the fault range of the low-voltage distribution transformer area is determined.

[0011] In one possible implementation, fault waveforms collected from low-voltage terminals in the same adjacent terminal group are synchronously time-calibrated to obtain calibrated fault waveforms corresponding to the adjacent terminal groups, including:

[0012] Perform a first-order difference operation on the fault waveform to obtain the instantaneous difference amplitude of the fault waveform;

[0013] The instantaneous time when the instantaneous differential amplitude of the fault waveform exceeds the sudden change threshold is taken as the fault sudden change moment of the fault waveform.

[0014] Using the fault change time of all fault waveforms in the same adjacent terminal group as the time reference, the timing deviation in the adjacent terminal group is obtained.

[0015] Based on the timing deviation, the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group are shifted and calibrated to obtain the calibrated fault waveforms.

[0016] In one possible implementation, the fault waveform features include: voltage features, distortion features, attenuation features, and phase features. Feature parameters are extracted from the calibration fault waveforms within adjacent terminal groups to obtain the fault waveform features corresponding to the adjacent terminal groups, including:

[0017] Fast Fourier Transform is used to decompose the calibration fault waveform into the fundamental wave and each harmonic, and the distortion characteristics and phase characteristics of adjacent terminal groups are obtained.

[0018] By performing waveform analysis on the calibration fault waveform, the voltage characteristics and attenuation characteristics of adjacent terminal groups are obtained.

[0019] In one possible implementation, based on the dynamic topology of low-voltage terminals and low-voltage distribution transformer areas, fault waveforms collected by each low-voltage terminal within multiple adjacent terminal groups are acquired, including:

[0020] Acquire the dynamic topology of the low-voltage distribution transformer area and the fault waveforms collected from multiple low-voltage terminals;

[0021] Based on dynamic topology, multiple low-voltage terminals are matched to obtain multiple adjacent terminal groups;

[0022] Based on the fault waveforms collected by the low-voltage terminal and the adjacent terminal groups, the fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups are obtained.

[0023] In one possible implementation, the dynamic topology is obtained in the following way:

[0024] Acquire the static topology of the low-voltage distribution transformer area and the switch opening and closing status collected from multiple low-voltage terminals;

[0025] Based on the switch's open / closed state, valid branches are selected from the static topology to obtain the dynamic topology.

[0026] In one possible implementation, before obtaining the dynamic topology by filtering valid branches in the static topology based on the switch's on / off state, the method further includes:

[0027] Acquire load currents from multiple low-voltage terminals;

[0028] The theoretical state of the switch is obtained by inversely deducing the switch state based on the load current;

[0029] Based on the theoretical state of the switch, the open and closed states of the switch are checked, and the open and closed states of the switch that fail the check are deleted.

[0030] One possible implementation involves determining the fault range of a low-voltage distribution transformer area based on the difference quantification index corresponding to adjacent terminal groups, including:

[0031] If the maximum value of the difference quantification index is greater than the preset threshold, the fault interval is determined to be between the adjacent terminal groups corresponding to the maximum value of the difference quantification index.

[0032] If the maximum value of the difference quantification index is less than or equal to the preset threshold, the fault range is determined to be the downstream end line of the low-voltage terminal.

[0033] Secondly, embodiments of this application provide a distribution transformer area fault location device, comprising a fusion terminal deployed at the distribution transformer corresponding to the low-voltage distribution transformer area, the fusion terminal being communicatively connected to multiple low-voltage terminals deployed at measurement points in the low-voltage distribution transformer area, and the distribution transformer area fault location device including:

[0034] The acquisition module is used to acquire fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups based on the dynamic topology of low-voltage terminals and low-voltage distribution radio areas.

[0035] The processing module is used to perform synchronous timing calibration on the fault waveforms collected by low-voltage terminals in the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal group; extract feature parameters from the calibration fault waveforms in the adjacent terminal group to obtain the fault waveform features corresponding to the adjacent terminal group; perform weighted summation on the fault waveform features corresponding to the adjacent terminal group based on the fault type corresponding to the fault waveform to obtain the difference quantification index corresponding to the adjacent terminal group; and determine the fault range of the low-voltage distribution transformer area based on the difference quantification index corresponding to the adjacent terminal group.

[0036] In one possible implementation, the processing module is specifically used for:

[0037] Perform a first-order difference operation on the fault waveform to obtain the instantaneous difference amplitude of the fault waveform;

[0038] The instantaneous time when the instantaneous differential amplitude of the fault waveform exceeds the sudden change threshold is taken as the fault sudden change moment of the fault waveform.

[0039] Using the fault change time of all fault waveforms in the same adjacent terminal group as the time reference, the timing deviation in the adjacent terminal group is obtained.

[0040] Based on the timing deviation, the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group are shifted and calibrated to obtain the calibrated fault waveforms.

[0041] In one possible implementation, the fault waveform characteristics include: voltage characteristics, distortion characteristics, attenuation characteristics, and phase characteristics. The processing module is further used for:

[0042] Fast Fourier Transform is used to decompose the calibration fault waveform into the fundamental wave and each harmonic, and the distortion characteristics and phase characteristics of adjacent terminal groups are obtained.

[0043] By performing waveform analysis on the calibration fault waveform, the voltage characteristics and attenuation characteristics of adjacent terminal groups are obtained.

[0044] In one possible implementation, the acquisition module is specifically used for:

[0045] Acquire the dynamic topology of the low-voltage distribution transformer area and the fault waveforms collected from multiple low-voltage terminals;

[0046] Based on dynamic topology, multiple low-voltage terminals are matched to obtain multiple adjacent terminal groups;

[0047] Based on the fault waveforms collected by the low-voltage terminal and the adjacent terminal groups, the fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups are obtained.

[0048] In one possible implementation, the dynamic topology is obtained in the following way:

[0049] Acquire the static topology of the low-voltage distribution transformer area and the switch opening and closing status collected from multiple low-voltage terminals;

[0050] Based on the switch's open / closed state, valid branches are selected from the static topology to obtain the dynamic topology.

[0051] In one possible implementation, before obtaining the dynamic topology by filtering valid branches in the static topology based on the switch's on / off state, the method further includes:

[0052] Acquire load currents from multiple low-voltage terminals;

[0053] The theoretical state of the switch is obtained by inversely deducing the switch state based on the load current;

[0054] Based on the theoretical state of the switch, the open and closed states of the switch are checked, and the open and closed states of the switch that fail the check are deleted.

[0055] In one possible implementation, the processing module is specifically used for:

[0056] If the maximum value of the difference quantification index is greater than the preset threshold, the fault interval is determined to be between the adjacent terminal groups corresponding to the maximum value of the difference quantification index.

[0057] If the maximum value of the difference quantification index is less than or equal to the preset threshold, the fault range is determined to be the downstream end line of the low-voltage terminal.

[0058] Thirdly, embodiments of this application provide a distribution area fault location device, including: a memory and a processor;

[0059] The memory stores instructions that the computer executes;

[0060] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0061] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0062] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0063] The distribution transformer substation fault location method, apparatus, and equipment provided in this application acquire fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups based on the dynamic topology of the low-voltage terminal and the low-voltage distribution transformer substation. After synchronous timing calibration of the fault waveforms in the same adjacent terminal group, fault waveform features are extracted. Then, based on the fault type corresponding to the fault waveform, the fault waveform features of adjacent terminal groups are weighted and summed differently to obtain the difference quantification index corresponding to adjacent terminal groups. This can more accurately characterize the fault response differences between adjacent terminal groups under the conditions of complex topology of low-voltage distribution transformer substation and limited time synchronization accuracy of low-voltage terminals, thereby improving the fault interval location accuracy and stability of complex faults such as high-resistance grounding and intermittent short circuits. Attached Figure Description

[0064] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0065] Figure 1 A schematic diagram of a scenario for the distribution radio station fault location method provided in the embodiments of this application;

[0066] Figure 2 A flowchart illustrating the distribution area fault location method provided in this application embodiment. Figure 1 ;

[0067] Figure 3 A flowchart illustrating the distribution area fault location method provided in this application embodiment. Figure 1 ;

[0068] Figure 4 This is a schematic diagram of the structure of the distribution radio station fault location device provided in the embodiments of this application;

[0069] Figure 5 A schematic diagram of the structure of the distribution radio area fault location device provided in the embodiments of this application.

[0070] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0071] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application.

[0072] In related technologies, a single electrical measurement point is set at the output terminal of the transformer in the low-voltage distribution area or at the main incoming line of the distribution area. By collecting the electrical parameters at the measurement point and judging based on preset thresholds or simple logic rules, the location and type of fault are determined. However, the accuracy and reliability of the fault location results are poor, resulting in low fault handling efficiency, long power outage time, and serious impact on power reliability.

[0073] The distribution transformer substation fault location method provided in this application acquires fault waveforms collected by low-voltage terminals within multiple adjacent terminal groups. Then, it performs synchronous timing calibration on the fault waveforms of the same adjacent terminal group to reduce the impact of temporal deviations in waveforms recorded by multiple terminals. Subsequently, feature parameters are extracted from the calibrated fault waveforms to obtain corresponding fault waveform features. Combined with the fault type corresponding to the fault waveform, the fault waveform features of adjacent terminal groups are differentially weighted and summed to form a difference quantification index that characterizes the degree of difference between adjacent terminal groups. Finally, the fault interval of the low-voltage distribution transformer substation is determined based on the difference quantification index corresponding to each adjacent terminal group. This technical approach combines dynamic topology, waveform synchronization, feature extraction, and difference quantification for fault analysis. It is no longer limited to isolated judgments of single points or a small number of measurement points, but achieves fault interval identification that better conforms to the characteristics of complex low-voltage networks through comparisons between adjacent terminal groups, providing a foundation for rapid subsequent fault handling.

[0074] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0075] Figure 1 This is a schematic diagram of a scenario for the distribution radio station fault location method provided in the embodiments of this application, such as... Figure 1 As shown, the specific application scenario of this application embodiment includes a converged terminal 101 and a low-voltage terminal 102 deployed on a low-voltage power distribution line 10, wherein:

[0076] The terminal equipment system of the low-voltage distribution line 10 includes a fusion terminal 101 and several low-voltage terminals 102. The low-voltage terminals 102 are deployed in different locations according to monitoring needs: one low-voltage terminal 102 is installed in each of the two branch boxes 11 of the low-voltage distribution line 10 to monitor the operating status of the branch lines; one low-voltage terminal 102 is installed at the low-voltage busbar 12 of the low-voltage distribution line 10 to collect current and voltage data from all outgoing lines; and one low-voltage terminal 102 is installed in each user meter box 13 to achieve comprehensive coverage of the end-user side. The fusion terminal 101 is deployed at the 10kV distribution transformer 14 of the low-voltage distribution line 10, establishing a communication connection with each low-voltage terminal 102. It can acquire the operating information collected by each low-voltage terminal 102 in real time and detect and locate faults within the low-voltage distribution line 10 based on this information.

[0077] Optionally, the fusion terminal 101 is also used to periodically synchronize the time of each low-voltage terminal 102 to ensure the time consistency of the data collected by each terminal.

[0078] Figure 2 A flowchart illustrating the distribution area fault location method provided in this application embodiment. Figure 1 .like Figure 2 As shown, this distribution transformer substation fault location method is applied to a fusion terminal deployed at the distribution transformer corresponding to the low-voltage distribution transformer substation. The fusion terminal is communicatively connected to multiple low-voltage terminals deployed at the measurement points of the low-voltage distribution transformer substation, including:

[0079] S201. Based on the dynamic topology of low-voltage terminals and low-voltage distribution radio areas, acquire the fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups.

[0080] The fusion terminal of the power monitoring system is the core node for data aggregation, processing, and judgment. The fusion terminal is deployed at the distribution transformer corresponding to the low-voltage distribution transformer area. It establishes communication connections with multiple low-voltage terminals deployed at various monitoring points within the low-voltage distribution transformer area via wired power line carrier communication, low-power wireless communication, cellular wireless communication, or industrial Ethernet communication links. The low-voltage distribution transformer area constitutes the target network range for fault location, encompassing the main branches, sub-branches, user access points, and switch nodes extending downstream from the distribution transformer.

[0081] The low-voltage terminal is a distributed acquisition node used to continuously sample voltage, current or zero-sequence quantity at the corresponding measurement point, and to generate a fault waveform record file and upload it to the fusion terminal when a fault disturbance is detected.

[0082] For example, in a typical low-voltage distribution line, a low-voltage terminal is configured at the low-voltage busbar of the substation to monitor the voltage and current of all outgoing lines. A low-voltage terminal is also configured in each branch box of the low-voltage distribution line. If there are three branch boxes: branch box A, branch box B, and branch box C, then low-voltage terminal A is configured in branch box A; low-voltage terminal B is configured in branch box B; and low-voltage terminal C is configured in branch box C. Low-voltage monitoring terminals are also configured at the user meter boxes of the low-voltage distribution line. Furthermore, a fusion terminal is deployed at the 10kV distribution transformer. All low-voltage terminals within the low-voltage distribution line communicate with the fusion terminal through a communication channel, forming a power detection system.

[0083] Optionally, the converged terminal periodically synchronizes the time with each low-voltage terminal. However, due to the communication-based time synchronization method, the synchronization accuracy is low, resulting in a large time synchronization error between the converged terminal and the low-voltage terminals. A typical time synchronization error is usually around tens of milliseconds.

[0084] Dynamic topology is used to characterize the actual connection relationship of low-voltage distribution substations at the current operating moment. It reflects not only the pre-modeled static line structure, but also the impact of switch opening / closing status, branch switching status, and terminal online status on the effective connectivity. Adjacent terminal groups are sets of terminals distributed adjacent to each other along the electrical connection path under this dynamic topology, serving as the basic processing unit for subsequent waveform comparison and difference analysis.

[0085] Optionally, the dynamic topology of the low-voltage distribution radio area can be read from the local topology database.

[0086] Optionally, the static topology of the low-voltage distribution transformer area is read from the local topology database. This static topology may include the distribution transformer outgoing line relationships, branch node numbers, measurement point installation locations, line segment lengths, and upstream and downstream connections between line segments. Then, the fusion terminal periodically receives status data uploaded by each low-voltage terminal. This status data includes at least the terminal identifier, installed measurement point number, online status, sampling clock status, and the open / closed status of the measurement point's associated switch. Next, the fusion terminal performs effective branch filtering on the static topology based on the status data, removing branches in an open state from the current analysis graph and retaining branches in a closed state, thereby generating a dynamic topology graph representing the effective connection structure of the current transformer area.

[0087] Furthermore, the fusion terminal can also perform secondary correction of the dynamic topology by combining terminal communication connectivity information. For measurement points that are continuously offline and whose status data cannot be obtained, they are marked as unavailable nodes. When constructing adjacent terminal groups in the future, these nodes are skipped or the nearest online terminals upstream or downstream are used for replacement analysis.

[0088] Optionally, after acquiring the dynamic topology, the fusion terminal matches multiple low-voltage terminals according to the upstream and downstream electrical adjacency relationships of the lines within the dynamic topology. Specifically, starting from the outgoing node of the distribution transformer within the dynamic topology, it traverses each branch, grouping two or more low-voltage terminals that are electrically adjacent and located on the same continuous effective branch into an adjacent terminal group. For areas with branch nodes, backbone adjacent terminal groups and branch adjacent terminal groups can be constructed separately to ensure that there is a clear upstream and downstream correspondence between terminals within each group.

[0089] After a fault is triggered, the low-voltage terminal acquires the fault waveform within the fault time window and transmits it to the fusion terminal. The fault time window covers several cycles before and after the fault. Optionally, the fault time window can cover from 5 cycles before the fault to 20 cycles after the fault to ensure that both the fault abrupt change point can be identified and the attenuation process after the fault can be analyzed. In practical use, the fault time window can be set according to actual needs; this embodiment does not limit this setting.

[0090] Optionally, the low-voltage terminal can sample and monitor the voltage and current of the line in real time. When the voltage and current of the line exceed the fault detection activation threshold, the fault waveform within the fault time window is automatically latched. Furthermore, the sampling frequency of the low-voltage terminal is not less than 2kHz. The fault detection activation threshold is determined based on the electrical changes under normal operating conditions and fault conditions of the circuit. For ease of understanding, this application provides an example of a fault detection activation threshold. Those skilled in the art should understand that in actual operation, the fault detection activation threshold should be adjusted according to the actual electrical conditions.

[0091] In a feasible example, the fault detection trigger thresholds include: overcurrent criterion, undervoltage criterion, voltage surge criterion, and residual current criterion, wherein:

[0092] The overcurrent criterion indicates that the amplitude of any phase current exceeds the preset overcurrent threshold, and the duration is greater than or equal to 20 milliseconds (to avoid false triggering by instantaneous inrush current). The preset overcurrent threshold can be twice the rated current of the line, or it can be adjusted according to the actual electrical conditions.

[0093] The undervoltage criterion indicates that the voltage amplitude of any phase is lower than a preset undervoltage threshold for a duration greater than or equal to 30 milliseconds. The preset undervoltage threshold can be 0.8 times the rated voltage, or it can be adjusted according to the actual electrical conditions.

[0094] The voltage mutation criterion indicates that if the change in voltage amplitude within 10 milliseconds exceeds 15% of the rated voltage, and the voltage deviates from the rated value range after the mutation, that is, if the rated voltage is 380V, and the change in voltage amplitude within 10 milliseconds is greater than or equal to 57V, a voltage mutation is determined to exist.

[0095] The residual current criterion indicates that the residual current amplitude exceeds a preset residual current threshold and the duration is greater than or equal to 20 milliseconds. Specifically, the residual current threshold can be between 5A and 10A in a power transformer directly grounded neutral point (Terre Terre, TT) system, and between 3A and 6A in a power supply neutral point directly grounded neutral point (Terre Neutre, TN) system.

[0096] The fusion terminal combines the fault waveforms collected by the low-voltage terminal with those of adjacent terminal groups to obtain the fault waveforms collected by each low-voltage terminal within multiple adjacent terminal groups. The fault waveform is time-domain data recorded by the low-voltage terminal when it detects a sudden voltage drop, a sudden current surge, an increase in harmonic distortion, or an abnormal change in phase angle. The fault waveform can capture the changes in electrical quantities before and after the fault occurs.

[0097] To ensure the comparability of acquired fault waveforms, the fusion terminal can perform integrity checks and format unification processing on the fault waveforms uploaded by low-voltage terminals. This includes checking the sampling rate, dimensions, phase identifier, timestamp format, and missing sample points. For example, if different low-voltage terminals have inconsistent sampling rates, they can be converted to a unified sampling frequency through resampling. For example, for waveforms with short-term sample loss, missing points can be filled in using linear interpolation or spline interpolation. Through integrity checks and format unification processing, the fusion terminal generates fault waveform datasets that correspond one-to-one with multiple adjacent terminal groups, and uses these fault waveform datasets as input for subsequent synchronization timing calibration.

[0098] By introducing dynamic topology constraints, the selected set of terminals is guaranteed to conform to the current actual line connection relationship. This avoids the incorrect selection of non-adjacent terminals for analysis under conditions of frequent changes in the topology of low-voltage distribution areas or complex branch conditions. This establishes an accurate data foundation for subsequent fault location and improves the applicability and reliability of fault location in complex topology scenarios.

[0099] S202. Perform synchronous timing calibration on the fault waveforms collected by the low-voltage terminals of the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal groups.

[0100] Synchronous timing calibration is used to eliminate time deviations caused by fault recording triggering, clock drift, communication upload delay, or local buffer write delay between different low-voltage terminals. Through synchronous timing calibration, fault waveforms collected by different low-voltage terminals within the same adjacent terminal group can have a consistent timing reference.

[0101] Calibrating fault waveforms refers to the unified reference waveform data formed after time alignment of fault waveforms, which serves as the direct input for subsequent feature parameter extraction. Since each terminal in a low-voltage distribution area may use a clock source of different precision, even if they all record the same fault event, the fault change position in their waveforms may have a sampling point level or even a millisecond level offset. If timing calibration is not performed first, the amplitude changes, phase deviations, and attenuation processes extracted later will be affected by misalignment, which will lead to distortion of the difference quantization results between adjacent terminal groups.

[0102] Specifically, the fusion terminal performs calibration processing for each adjacent terminal group. For multiple fault waveforms within a certain adjacent terminal group, the fusion terminal first performs preprocessing to improve the stability of fault abrupt change point identification. Optionally, the preprocessing includes at least one of the following: DC component removal, power frequency bandpass filtering, abnormal peak suppression, and amplitude normalization.

[0103] Subsequently, the fusion terminal performs differential analysis on each fault waveform, calculating the first-order difference between adjacent sampling points, the sliding window energy change, or the waveform slope change to pinpoint the abrupt change moment corresponding to the fault occurrence. Based on the abrupt change moment of the fault occurrence, the fault waveform is shifted along the time axis.

[0104] Optionally, joint calibration can be performed by combining the characteristic change times of fault waveforms within adjacent terminal groups. The abrupt change times in the fault waveforms are extracted from the fused terminals. Optionally, the abrupt change times include at least one of the following: the start point of a voltage sag, the occurrence time of a current peak, the zero-crossing point offset, and the moment of a harmonic distortion surge. Then, based on the abrupt change times in the fault waveforms, a multi-feature time stamp set is constructed. The optimal time offset of the multi-feature time stamp set relative to a unified reference is then calculated using the minimum error criterion. This approach can still achieve high alignment accuracy even when some fault abrupt changes are not sharp enough or when a single abrupt change point is significantly affected by noise.

[0105] Optionally, for three-phase terminal data, the fusion terminal can also perform calibration based on the fault-dominant phase and uniformly shift the waveforms of the remaining phases of the same terminal to maintain the phase timing relationship.

[0106] Optionally, after timing calibration is completed, the fusion terminal generates a set of calibration fault waveforms corresponding to adjacent terminal groups and evaluates the calibration quality to obtain evaluation indicators. These evaluation indicators may include at least one of the following: cross-correlation peak value, abrupt change point coincidence error, and mean square value of time deviation of key feature points. When the evaluation indicator falls below a preset threshold, the fusion terminal can reselect a reference waveform or switch calibration algorithms to obtain more stable calibration results.

[0107] By constructing a unified time reference framework, the feature misalignment problem caused by asynchronous sampling of multiple low-voltage terminals is reduced, enabling comparisons based on waveform differences between terminals to be established at the same fault time. For complex topologies and multi-measurement-point scenarios in low-voltage distribution substations, this significantly improves the comparability between waveforms of different terminals and reduces misjudgments caused by sampling time errors. Therefore, it is a key supporting step for achieving high-accuracy fault interval location.

[0108] S203. Extract feature parameters from the calibration fault waveforms within adjacent terminal groups to obtain the fault waveform features of the calibration fault waveforms.

[0109] Feature parameter extraction is used to convert calibration fault waveforms into quantifiable and comparable fault waveform features. Fault waveform features are a set of features that characterize the fault state. These features can reflect the differences between adjacent low-voltage terminals from dimensions such as amplitude changes, waveform distortion, fault process evolution, and phase angle relationships.

[0110] Optionally, the fault waveform characteristics include at least one of voltage characteristics, distortion characteristics, attenuation characteristics, and phase characteristics. Further, the voltage characteristics may include at least one of the following: the change in effective value before and after the fault, the lowest instantaneous voltage, the droop depth, the recovery time, and the three-phase unbalance. The distortion characteristics may include at least one of the following: total harmonic distortion rate, characteristic subharmonic amplitude, waveform peak factor, waveform skewness, or peak-to-trough asymmetry. The attenuation characteristics may include at least one of the following: fault transient oscillation envelope attenuation coefficient, peak attenuation rate, energy attenuation time constant, and energy integral value over several cycles after the fault. The phase characteristics may include at least one of the following: the change in phase angle between voltage and current, the phasor angle between corresponding terminals in the same group, the zero-sequence component phase shift, and the phase sequence shift between the three phases.

[0111] Because calibration fault waveforms have high dimensionality and a lot of redundant information, and different fault types have different emphases on the impact of calibration fault waveforms, directly comparing calibration fault waveforms is not only computationally intensive, but also difficult to reliably extract the essential differences in faults. Therefore, it is necessary to complete the feature representation under a unified time series benchmark.

[0112] The fusion terminal can perform windowed analysis on each calibration fault waveform in each adjacent terminal group. Optionally, multiple windows can be used when performing windowed analysis. For example, the windows may include a pre-fault window, a fault initiation window, and a post-fault evolution window. By using multiple windows for windowed analysis, steady-state reference quantities, abrupt response quantities, and decay process quantities can be extracted separately.

[0113] Optionally, the fusion terminal can perform fast Fourier transform, short-time Fourier transform, or discrete wavelet decomposition on the calibration fault waveform to extract distortion and transient features from the frequency domain or time-frequency domain.

[0114] Optionally, the fusion terminal can also extract steady-state and quasi-steady-state phase parameters based on the power frequency phasor estimation algorithm.

[0115] Optionally, after extraction, the fusion terminal can also standardize the fault waveform features to improve their stability. For example, the fault waveform features can be converted into dimensionless quantities based on the mean and standard deviation obtained from historical normal operating conditions. Alternatively, the fault waveform features can be normalized according to rated voltage, rated current, and typical line impedance parameters to eliminate the influence of differences in the basic magnitudes at different measurement points on subsequent comparisons.

[0116] Optionally, for multiple low-voltage terminals within an adjacent terminal group, feature vectors for each low-voltage terminal can be formed, and then feature differences, feature ratios, or feature change gradients between upstream and downstream terminals within the group can be calculated to obtain fault waveform features that are more suitable for characterizing the degree of abrupt changes in electrical state at adjacent locations.

[0117] Optionally, fault type information is provided in advance. This fault type information includes categories such as suspected short-circuit fault, grounding fault, open-circuit fault, or poor contact fault. The fusion terminal can also extract key features according to the fault type. For example, for short-circuit faults, the voltage descent depth and transient current phase change characteristics can be enhanced. For poor contact faults, the high-frequency distortion, intermittent fluctuations, and harmonic content characteristics can be enhanced. For open-circuit faults, the three-phase imbalance and zero-sequence component characteristics can be enhanced.

[0118] By mapping calibration fault waveforms to structured fault waveform features, the fusion terminal can describe fault response differences in a unified, low-dimensional and physically meaningful way. This not only reduces computational complexity but also improves the pertinence of difference analysis under different fault scenarios, providing an implementable data representation basis for accurate localization under multiple fault types.

[0119] S204. Based on the fault type corresponding to the fault waveform, the fault waveform features corresponding to adjacent terminal groups are weighted and summed to obtain the difference quantification index corresponding to adjacent terminal groups.

[0120] Fault type is used to indicate the fault condition corresponding to the fault waveform. Different fault types have different sensitivities in voltage characteristics, distortion characteristics, attenuation characteristics and phase characteristics. Therefore, it is necessary to assign different weights to each type of feature according to the fault type.

[0121] The difference quantification index is a quantitative result that comprehensively reflects the degree of difference in fault waveform characteristics between upstream and downstream measuring points within adjacent terminal groups. The larger the value of the difference quantification index, the higher the probability that the adjacent terminal group crosses the fault point or is located near the fault influence boundary. The construction of the difference quantification index allows the originally scattered multidimensional features to be mapped into a scalar that can be directly sorted and thresholded, thus facilitating the comparison of multiple adjacent terminal groups within the low-voltage distribution transformer area.

[0122] First, determine the fault type corresponding to this fault event. The fault type can be output by an independent fault identification module, or it can be determined by the fusion terminal based on the basic characteristics of the calibrated fault waveform. Optionally, the fusion terminal classifies the fault into types such as phase-to-phase short circuit, single-phase grounding, open circuit, overload disturbance, or poor contact based on the voltage drop mode, three-phase imbalance degree, zero-sequence quantity change, harmonic distribution, and fault duration, according to the basic characteristics of the calibrated fault waveform, in order to obtain the fault type corresponding to the fault time.

[0123] Next, based on the fault type corresponding to the fault waveform, a set of feature weights corresponding to that fault type is retrieved from a preset weight library to obtain the weights of the fault waveform features in calculating the difference quantification index. The preset weight library is obtained based on the fault waveform feature performance of different fault types. Optionally, based on the historical fault waveform feature performance of different fault types, the weights corresponding to different fault types are fitted and determined to obtain a preset weight library containing weights corresponding to multiple fault types.

[0124] For example, if the voltage characteristic difference of a certain adjacent terminal group is denoted as... The difference in distortion characteristics is denoted as The difference in attenuation characteristics is denoted as The phase characteristic difference is denoted as Then the difference quantification index It can be represented as:

[0125]

[0126] in, This represents the weighting coefficient for the voltage characteristic differences under the current fault type; This represents the weighting coefficient for the difference in distortion characteristics under the current fault type; The weighting coefficients represent the differences in attenuation characteristics under the current fault type; This represents the weighting coefficient of the phase feature differences under the current fault type. The purpose of the above formula is to fuse the differences in features across different physical dimensions according to their importance in relation to the fault type, avoiding the equating of features insensitive to a certain type of fault with key features. To ensure comparability, each difference feature can be normalized or subjected to interval mapping before being substituted into the formula.

[0127] Under the premise of the above formula, the preset weight library can be expressed as: Short circuit fault: Grounding fault: ; Disconnection fault: This embodiment is merely an example and is not intended to be limiting.

[0128] Voltage characteristic differences It can be formed by combining the absolute difference in voltage sag depth between the upstream and downstream terminals within an adjacent terminal group. If the voltage represented by the fault waveform of the upstream low-voltage terminal within an adjacent terminal group is... The voltage represented by the fault waveform of the downstream low-voltage terminal in the adjacent terminal group is The voltage characteristic difference It can be represented as:

[0129]

[0130] Distortion feature differences It can be composed of the difference in total harmonic distortion (THD), the difference in characteristic subharmonic amplitude, and the difference in peak factor. For example, if the THD represented by the fault waveform of the upstream low-voltage terminal within an adjacent terminal group is... The total harmonic distortion rate (THD) of the fault waveform of the downstream low-voltage terminal within the adjacent terminal group is [missing value]. Then the difference in distortion characteristics It can be represented as:

[0131]

[0132] Differences in attenuation characteristics It can be composed of the difference in transient envelope attenuation coefficient, the difference in energy integral, and the difference in peak attenuation time. Phase characteristic differences. It can be composed of the main phase angle deviation, the zero-sequence phase difference, and the change in the three-phase angle.

[0133] The fusion terminal can first complete the calculation of upstream and downstream differences within the group at the feature layer, and then perform weighted summation according to fault type at the indicator layer to obtain the difference quantification indicator corresponding to each adjacent terminal group.

[0134] Optionally, the weight set can be preset by rules, or it can be adaptively updated based on the statistical results of historical fault samples. For example, the fusion terminal can dynamically adjust the weights according to the contribution of each feature to the positioning accuracy in similar historical faults, so that the weight allocation is closer to the actual operating characteristics of the transformer area.

[0135] To suppress the impact of outliers on the results, the fusion terminal can also apply amplitude limiting functions, robust standardization, or median filtering to smooth each difference feature before summing. For adjacent terminal groups consisting of multiple terminals, the fusion terminal can also first calculate the differences between each pair of terminals within the group, then assign internal weights according to topological adjacency relationships, and finally obtain the group-level difference quantification index.

[0136] By incorporating fault type information into the feature fusion process, the differential quantification index can highlight the most discriminative feature dimensions for different fault mechanisms, avoiding the problem of insufficient adaptability of a single fixed-weight strategy under multiple fault type conditions. Therefore, the fused terminal can more accurately characterize the differences in anomaly levels between adjacent terminal groups, improving the consistency and reliability of location analysis in complex fault scenarios in low-voltage distribution transformer areas.

[0137] S205. Based on the difference quantification index corresponding to adjacent terminal groups, determine the fault range of the low-voltage distribution transformer area.

[0138] The fault range is the final output location result, used to indicate the line range where the fault is located within the low-voltage distribution transformer area. The fault range can correspond to the line segment between two adjacent measuring points, a certain branch segment, or, when the terminal measuring point has reached the end of the branch, to the downstream end of the line.

[0139] After obtaining the differential quantification indicators corresponding to multiple adjacent terminal groups, the converged terminal maps the differential quantification indicators according to the spatial order in the dynamic topology to form a differential distribution map within the transformer area, thereby determining the location of the interval most likely to fail.

[0140] The fusion terminal can traverse the differential quantification indicators of all adjacent terminal groups and compare them sequentially in the direction extending from the downstream of the distribution transformer to the end. When the differential quantification indicator of an adjacent terminal group is significantly higher than that of its upstream and downstream groups, it can be determined that the fault point is likely located within the line section covered by that adjacent terminal group.

[0141] Optionally, the fusion terminal first calculates the maximum value among the differential quantification indicators of all adjacent terminal groups and determines the target adjacent terminal group corresponding to the maximum value. When the maximum value is greater than a preset threshold, the line segment between the upstream and downstream terminals of the target adjacent terminal group is determined as the fault interval. When the maximum value does not reach the preset threshold, but the differential quantification indicators of several adjacent terminal groups at the end continue to rise, the fault can be determined as being located in the downstream end line by combining the end topology characteristics. The preset threshold is used to characterize the difference between faulty lines and non-faulty lines in terms of differential quantification indicators. The preset threshold can be determined based on the circuit's performance under fault and non-fault conditions. Optionally, the preset threshold can be tuned offline based on historical positioning samples, different transformer area sizes, terminal deployment density, and noise levels, or it can be adaptively adjusted during operation based on the indicator distribution under normal operating conditions. Optionally, the preset threshold can be adaptively adjusted according to different fault types.

[0142] Optionally, when determining the fault range, not only the maximum index of a single adjacent terminal group is considered, but also the variation trend of multiple consecutive adjacent terminal groups is taken into account for comprehensive judgment. For example, if the variation quantification index of a certain group of adjacent terminals increases sharply, while the index of the downstream adjacent terminal group corresponding to the adjacent terminal group drops again, the fault range can be locked between that adjacent terminal group and its adjacent nodes. Furthermore, if multiple consecutive adjacent terminal groups maintain relatively high variation quantification indices, the fault range can be further narrowed by combining branch bifurcation relationships and terminal fault phase consistency information.

[0143] Optionally, for low-voltage distribution substations with multi-branch structures, the maximum local difference quantification index can be calculated on the main trunk and each branch, and then the global optimal fault interval can be selected using the branch affiliation relationship.

[0144] Optionally, in cases where communication anomalies cause missing indicators for individual adjacent terminal groups, upstream and downstream interpolation, adjacent group trend extrapolation, or replacement with the most recent valid group can be used to maintain positioning continuity.

[0145] After determining the fault range, the fault range identifier, corresponding upstream and downstream terminal numbers, branch name, fault type, and differential quantitative index value can be output. The results are then sent to the main station system or the substation maintenance terminal to guide on-site inspection, isolation, and emergency repair.

[0146] By utilizing the quantitative comparison of differences between multiple adjacent terminal groups, the original location method relying on single-point anomaly judgment is transformed into an interval identification method based on topological constraints and inter-group difference distribution. This is more in line with the network characteristics of low-voltage distribution transformer areas, which have many branches, rapid topological changes, and complex fault manifestations. By combining maximum value determination, threshold comparison, and topological trend analysis, the fusion terminal can improve the accuracy and reliability of fault interval location under multiple fault types and complex connection conditions, and provide a clear line range basis for subsequent rapid handling.

[0147] The distribution substation fault location method provided in this application acquires fault waveforms from each low-voltage terminal in multiple adjacent terminal groups based on the dynamic topology of low-voltage terminals and the low-voltage distribution substation. It performs synchronous timing calibration on the fault waveforms acquired by low-voltage terminals in the same adjacent terminal group to obtain calibrated fault waveforms corresponding to the adjacent terminal groups. It extracts feature parameters from the calibrated fault waveforms within the adjacent terminal groups to obtain fault waveform features. Based on the fault type corresponding to the fault waveforms, it performs a weighted summation of the fault waveform features corresponding to the adjacent terminal groups to obtain a difference quantification index corresponding to the adjacent terminal groups. Based on the difference quantification index corresponding to the adjacent terminal groups, it determines the fault range of the low-voltage distribution substation. In this embodiment, by integrating dynamic topology construction, multi-point fault waveform acquisition, intra-group synchronous timing calibration, fault feature extraction, and difference quantification analysis combined with fault type, the fusion terminal can determine the line range of the fault based on the comparable difference relationship between adjacent terminal groups under complex topology and multiple fault types in the low-voltage distribution substation. This reduces location errors caused by topology changes, timing deviations, and single feature distortions, improving the accuracy, stability, and engineering applicability of fault range location. It should be understood that the above examples are for illustrative purposes only and are not intended to be limiting.

[0148] Figure 3 A flowchart illustrating the distribution area fault location method provided in this application embodiment. Figure 2 ,like Figure 3 As shown, in this embodiment... Figure 2 Based on the embodiments, the method for locating faults in distribution radio areas is described in detail. The method includes:

[0149] In one possible implementation, step S202 may further include:

[0150] S2021. Perform a first-order difference operation on the fault waveform to obtain the instantaneous difference amplitude of the fault waveform.

[0151] First-order difference operations are used to extract the changes between adjacent sampling points, making the abrupt changes in the fault waveform stand out from the continuous background fluctuations. The instantaneous difference amplitude is the absolute value or amplitude form of the difference result, used to reflect the intensity of the change at a certain sampling moment.

[0152] For fault waveforms collected by multiple low-voltage terminals within the same adjacent terminal group, the difference between adjacent sampling points is first calculated for each fault waveform according to the sampling interval, and the amplitude of the fault waveform is taken to form an instantaneous difference sequence.

[0153] For example, consider two low-voltage terminals within the same adjacent terminal group: the fault waveform collected by low-voltage terminal A. Fault waveforms collected by low-voltage terminal B First-order difference operations are performed on each waveform to extract abrupt change features, thereby obtaining the instantaneous difference amplitude of the fault waveform. The instantaneous difference amplitude is used to reflect the rate of change of the fault waveform.

[0154] Fault waveform instantaneous difference amplitude It can be represented as:

[0155]

[0156] Fault waveform instantaneous difference amplitude It can be represented as:

[0157]

[0158] in, This is the minimum sampling time interval for the terminal.

[0159] S2022. The instantaneous time when the instantaneous differential amplitude of the fault waveform is greater than the sudden change threshold shall be taken as the fault sudden change moment of the fault waveform.

[0160] A mutation threshold is used to distinguish between normal disturbances and significant mutations caused by faults. The value of the mutation threshold can be preset by combining historical fault samples, sampling accuracy, and on-site noise levels. Optionally, the mutation threshold is obtained by calibrating waveform difference data under normal operating conditions. For example, the mutation threshold is set to a value between 3 and 5 times the maximum waveform difference value during normal operation.

[0161] The fault abrupt change moment is the time point when the waveform amplitude change first or significantly exceeds the threshold, used as a time reference for waveform alignment at each terminal. When the instantaneous differential amplitude at a certain moment exceeds the abrupt change threshold, that moment is recorded as the fault abrupt change moment for that waveform.

[0162] For example, the mutation thresholds of different adjacent terminal groups can be different to flexibly adapt to the electrical characteristics between the trunk and branches within a low-voltage distribution substation.

[0163] Furthermore, if the same adjacent terminal group includes two low-voltage terminals: low-voltage terminal A and low-voltage terminal B, the mutation threshold of the adjacent terminal group can be calculated using the following formula:

[0164]

[0165] in, , It is the differential amplitude of the waveform when low-voltage terminal A is operating normally; It is the differential amplitude of the waveform when the low-voltage terminal B is operating normally.

[0166] For example, the fault waveform of low-voltage terminal A instantaneous difference amplitude Record this moment as the moment of sudden fault change in low-voltage terminal A. Fault waveform of low-voltage terminal B instantaneous difference amplitude Record this moment as the moment of sudden fault change in low-voltage terminal B. The moment of sudden failure is the initial moment when the failure occurs.

[0167] S2023. Use the fault change time of all fault waveforms in the same adjacent terminal group as the time reference to obtain the timing deviation in the adjacent terminal group.

[0168] Timing deviation describes the time misalignment of abrupt change moments between terminals within the same group. By comparing the abrupt change moments of each fault waveform within the same adjacent terminal group, the time difference relative to a reference moment within the same adjacent terminal group is calculated, thus obtaining the timing deviation within the adjacent terminal group. The reference moment can be the earliest occurrence of the abrupt change moment, or it can be the statistical center value of multiple abrupt change moments.

[0169] Optionally, the time difference relative to the reference time within the same adjacent terminal group is calculated using the fault abrupt change time as the time reference, thus obtaining the timing deviation within the adjacent terminal group.

[0170] For example, if the same adjacent terminal group includes two low-voltage terminals: low-voltage terminal A and low-voltage terminal B, where the sudden fault change time of low-voltage terminal A is... The moment of sudden fault change in low-voltage terminal B. Then timing deviation It can be represented as:

[0171]

[0172] S2024. Based on the timing deviation, the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group are shifted and calibrated to obtain the calibrated fault waveforms.

[0173] Translation calibration involves shifting the waveform forward or backward along the time axis according to the corresponding deviation to obtain a calibration fault waveform under a unified time scale.

[0174] Based on the timing deviation, each fault waveform is shifted and calibrated to align the abrupt changes in the waveforms within the same adjacent terminal group, outputting the calibrated fault waveform, which is then used for subsequent feature extraction and differential quantification analysis.

[0175] Optionally, if the same adjacent terminal group includes two low-voltage terminals: low-voltage terminal A and low-voltage terminal B, and the fault change time of low-voltage terminal B is... The moment of sudden failure with low-voltage terminal A There is a timing deviation in comparison. The fault waveform of low-voltage terminal B is then shifted and calibrated to obtain a calibrated fault waveform, and the fault waveform of low-voltage terminal A is directly used as the calibrated fault waveform. Furthermore, the fault waveform of low-voltage terminal B... Perform translation calibration to obtain the calibration fault waveform. It can be represented as:

[0176]

[0177] After calibration, the moment of sudden fault change in low-voltage terminal B. This achieves time alignment of fault waveforms between low-voltage terminal A and low-voltage terminal B, eliminating the impact of terminal time errors on subsequent waveform difference calculations.

[0178] By adopting the aforementioned synchronous timing calibration method, waveform misalignment caused by low-voltage terminal sampling start time, communication delay, and local clock drift can be eliminated, ensuring that fault waveforms within the same adjacent terminal group have a unified time reference. Therefore, in subsequent fault waveform feature extraction and inter-group difference comparison, the interference of time deviation on feature calculation results can be reduced, improving the accuracy and stability of fault interval location and enhancing the reliability of multi-terminal joint analysis under complex topology conditions.

[0179] In one possible implementation, step S203 may further include:

[0180] S2031. Using Fast Fourier Transform, the calibration fault waveform is decomposed into the fundamental wave and each harmonic to obtain the distortion characteristics and phase characteristics of adjacent terminal groups.

[0181] Fault waveform features are used to characterize the state differences of calibration fault waveforms from both time and frequency domains. Voltage features are used to reflect the changes in voltage amplitude and waveform shape before and after the fault. Distortion features are used to reflect the degree of waveform distortion. Attenuation features are used to reflect the law of amplitude reduction over time. Phase features are used to reflect phase shift or phase difference.

[0182] Fast Fourier Transform is used to map time-domain waveforms to the frequency domain to extract the amplitude and phase relationships between the fundamental wave and each harmonic, thereby forming distortion and phase characteristics.

[0183] Optionally, distortion features are at least one feature capable of representing the distortion properties of the calibration fault waveform. Phase features are at least one feature capable of representing the phase properties of the calibration fault waveform.

[0184] Optionally, the fault waveform can be decomposed into a fundamental frequency and its harmonics using a Fast Fourier Transform (FFT). The decomposition yields the fundamental voltage amplitude, the nth harmonic voltage amplitude, and the fundamental phase angle. Then, based on the fundamental voltage amplitude, the nth harmonic voltage amplitude, and the fundamental phase angle obtained from the decomposition, the distortion characteristics are derived.

[0185] For example, if the distortion characteristic is the total harmonic distortion rate and the phase characteristic is the fundamental phase angle, the same adjacent terminal group includes two low-voltage terminals: low-voltage terminal A and low-voltage terminal B, wherein the calibration fault waveform of low-voltage terminal A... calibration fault waveform of low voltage terminal B The calibration fault waveforms are then converted using a Fast Fourier Transform. and calibration fault waveform This refers to the fundamental frequency and its harmonics. For calibration fault waveforms... Decomposition yields the fundamental voltage amplitude nth harmonic voltage amplitude Phase angle with fundamental wave For calibration fault waveforms Decomposition yields the fundamental voltage amplitude nth harmonic voltage amplitude Phase angle with fundamental wave .

[0186] The distortion characteristics of low-voltage terminal A can then be obtained as follows:

[0187]

[0188] The distortion characteristics of low-voltage terminal B are as follows:

[0189]

[0190] Distortion features of adjacent terminal groups for: .

[0191] Phase characteristics of adjacent terminal groups for: .

[0192] After completing the timing calibration of the same adjacent terminal group, the fusion terminal performs sampling point alignment and amplitude normalization on the calibration fault waveform to reduce the impact of differences in sampling conditions between different low-voltage terminals. Subsequently, the calibration fault waveform is input into the Fast Fourier Transform module to obtain the fundamental frequency component and several higher harmonic components. The distortion characteristics are determined based on the proportion of each harmonic amplitude to the fundamental amplitude, and the phase characteristics are determined based on the phase angle difference between the fundamental and each harmonic.

[0193] S2032. By performing waveform analysis on the calibration fault waveform, the voltage characteristics and attenuation characteristics of adjacent terminal groups are obtained.

[0194] Waveform analysis is used to identify the peak, valley, envelope changes, and amplitude change trends of calibration fault waveforms, thereby forming voltage characteristics and attenuation characteristics.

[0195] For voltage and attenuation characteristics, time-domain envelope extraction and trend fitting are performed on the calibration fault waveform. By combining the voltage amplitude, peak change, and attenuation slope at the initial moment of the fault, the corresponding voltage change description and attenuation change description are obtained.

[0196] Optionally, the voltage characteristic is at least one characteristic capable of representing the voltage properties in the calibration fault waveform. The attenuation characteristic is at least one characteristic capable of representing the attenuation properties in the calibration fault waveform.

[0197] For example, if the voltage characteristic is the difference in voltage peak values, the same adjacent terminal group includes two low-voltage terminals: low-voltage terminal A and low-voltage terminal B, wherein the calibration fault waveform of low-voltage terminal A... calibration fault waveform of low voltage terminal B Then we can obtain:

[0198] Peak voltage of low-voltage terminal A for:

[0199] Peak voltage of low-voltage terminal A for:

[0200] Voltage characteristics It can be represented as:

[0201]

[0202] in:

[0203] For example, if the attenuation characteristic is the difference in amplitude attenuation rate, and the same adjacent terminal group includes two low-voltage terminals: low-voltage terminal A and low-voltage terminal B, wherein the calibration fault waveform of low-voltage terminal A... The initial peak value within is The stable peak value is and decay time is ; Calibration fault waveform of low-voltage terminal B The initial peak value within is The stable peak value is and decay time is Then we can obtain:

[0204] Amplitude attenuation rate of low-voltage terminal A for:

[0205]

[0206] Amplitude attenuation rate of low-voltage terminal B for:

[0207]

[0208] Attenuation characteristics for .

[0209] The above method can simultaneously capture fault characteristics such as voltage drop, waveform distortion, amplitude attenuation, and phase shift, and configure different weights according to the fault type, so that the difference quantification index is more in line with the actual fault mechanism, thereby improving the distinguishability of the comparison results of adjacent terminal groups and the reliability of fault interval location.

[0210] In one possible implementation, step S201 may further include:

[0211] S2011. Obtain the dynamic topology of the low-voltage distribution transformer area and the fault waveforms collected from multiple low-voltage terminals.

[0212] First, fault waveforms from multiple low-voltage terminals are acquired, and the dynamic topology of the low-voltage distribution transformer area is acquired simultaneously. The dynamic topology data may include terminal addresses, line branch relationships, upstream and downstream relationships, and connectivity identifiers.

[0213] S2012. Based on dynamic topology, multiple low-voltage terminals are matched to obtain multiple adjacent terminal groups.

[0214] Based on the adjacency and branch affiliation relationships in the dynamic topology, multiple low-voltage terminals are matched, and physically adjacent terminals with topological associations are merged into the same adjacent terminal group, resulting in multiple adjacent terminal groups.

[0215] S2013. Based on the fault waveforms collected by the low-voltage terminals and the adjacent terminal groups, the fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups are obtained.

[0216] Based on the correspondence between each low-voltage terminal and its adjacent terminal group, the collected fault waveforms are aggregated so that the fault waveforms collected by each low-voltage terminal in the same adjacent terminal group are mapped to the corresponding group, forming a fault waveform set organized by group, which can be used for subsequent synchronous timing calibration, feature extraction and differential quantification analysis.

[0217] Optionally, the process of mapping the fault waveforms collected by each low-voltage terminal in the same adjacent terminal group to the corresponding group can be implemented using an association table of terminal identifiers and group identifiers. In practical applications, this association table can also use other data organization methods, which are not limited in this embodiment.

[0218] The electrical adjacency relationships between low-voltage terminals are determined by dynamic topology, and then the fault waveforms are grouped into the corresponding adjacent terminal groups according to the adjacency relationship, thereby avoiding the isolated use of sampling results from a single terminal. Since the low-voltage terminals in the same adjacent terminal group are located in close proximity to the power grid, the fault waveforms collected by the low-voltage terminals have a strong correlation in terms of propagation path and timing characteristics, thus providing a consistent data foundation for subsequent synchronization calibration and difference analysis.

[0219] By adopting this implementation method, the fault waveform attribution within the low-voltage distribution transformer area can be kept consistent with the real-time topology, reducing the analysis deviation caused by terminal grouping errors and waveform mismatches, improving the accuracy and reliability of subsequent fault interval location, and enhancing the ability to uniformly collect fault information from multiple terminals under complex topology conditions.

[0220] In one possible implementation, the dynamic topology is obtained by: acquiring the static topology of the low-voltage distribution transformer area and the switch opening and closing status collected by multiple low-voltage terminals; and filtering valid branches in the static topology based on the switch opening and closing status to obtain the dynamic topology.

[0221] Static topology is used to characterize the pre-established line connections in low-voltage distribution substations. Static topology can be generated from substation archives, line ledgers, or field modeling results. Optionally, static topology is stored in the local database of the converged terminal.

[0222] Low-voltage terminals are installed at various measuring points within the transformer area to collect the switch opening and closing status corresponding to each measuring point and transmit this status to the fusion terminal in real-time or near real-time. The switch opening and closing status indicates whether the corresponding branch is currently connected. After receiving the statuses uploaded by each low-voltage terminal, the fusion terminal performs a step-by-step evaluation of each branch in the static topology, excluding branches that are in a disconnected state, under maintenance / isolation state, or inconsistent with the current operating status from the static topology, and retaining connected branches consistent with the current switch status, thereby generating a dynamic topology that reflects the real-time operating relationships of the transformer area.

[0223] Optionally, the static topology can be stored using a graph structure. In the static topology, nodes correspond to the output terminals of the distribution transformer, branch nodes, and the measurement points where each low-voltage terminal is located, while branches correspond to conductor segments or switch control segments.

[0224] The selectable switch open / close status can be represented by a binary quantity, status code, or status frame with timestamp, so that the converged terminal can verify the validity of the status.

[0225] The fusion terminal filters out timeout data based on the timestamp in the status frame and performs consistency comparison on the status of multiple sources within the same sampling period to avoid topology misjudgment caused by communication jitter. After the effective branches obtained by filtering form a dynamic topology, they can be directly used for subsequent matching of adjacent terminal groups and fault interval location, so that fault analysis is always based on the current real connectivity relationship.

[0226] By generating a dynamic topology using the above method, the topology structure can be updated synchronously with switch operations and transformer operating status, avoiding the inclusion of disconnected branches in fault analysis and reducing the positioning deviation caused by a static, unchanging topology. Since the dynamic topology only retains currently valid branches, the subsequent division of adjacent terminal groups better reflects the actual power transmission path, thereby improving the accuracy and reliability of fault section identification.

[0227] In one possible implementation, before selecting valid branches in the static topology based on the switch opening and closing status to obtain the dynamic topology, the method further includes: acquiring load currents collected from multiple low-voltage terminals; inferring the switch status based on the load current to obtain the theoretical switch status; and verifying the switch opening and closing status based on the theoretical switch status, deleting switch opening and closing statuses that fail the verification.

[0228] Load current is used to characterize the actual energized load at each low-voltage terminal measurement point. It can be acquired in real time by current acquisition units installed at the ends of each branch, branch node, or user access point in the distribution area, and uploaded to the converged terminal via a communication link. Optionally, load current can be acquired through the low-voltage terminal.

[0229] The theoretical state of a switch indicates the expected open / closed state of each switch under the current load current distribution conditions. The theoretical state can be inferred based on current continuity, current differences between adjacent measuring points, and branch current distribution. The switch open / closed state, on the other hand, is the remote signaling status reported by the low-voltage terminal, characterizing the reported on / off information of the corresponding switch.

[0230] For example, after receiving load currents uploaded by multiple low-voltage terminals, the branch association relationship in the static topology is combined to determine whether there is current flow in a certain branch, and the theoretical state of the switch corresponding to that branch is deduced accordingly.

[0231] If a switch is in the open state, the load current of its downstream branch should be interrupted or significantly reduced. If a switch is in the closed state, the current relationship between its upstream and downstream measuring points should meet the preset consistency constraints.

[0232] Optionally, based on the actual energized load at each low-voltage terminal measurement point, the load current downstream of the switch change is obtained. The switch state is then deduced from the load current downstream of the switch change to obtain the theoretical switch state.

[0233] For example, if the load current of a downstream branch of a switch should be interrupted or significantly reduced, i.e., the downstream current should be greater than or equal to the error setting value, then the theoretical switching state of the switch is determined to be the open state. Here, the error setting value is a value that takes into account sampling error. The value of the error setting value can be set according to the actual circuit conditions. For example, the error setting value is 0.3A.

[0234] If the downstream branch of a switch has a load current, meaning the downstream current should be greater than or equal to the minimum load current, then the theoretical state of the switch is determined to be closed. The minimum load current is the minimum value considering the circuit under load. The minimum load current value can be set according to the actual circuit conditions. For example, the minimum load current value is equal to the error setting value.

[0235] Optionally, to avoid misjudging the theoretical switching state caused by sudden current changes, the load current is sampled multiple times. When the switching state derived from multiple load current samplings is consistent, this switching state is taken as the theoretical switching state. Optionally, the multiple samplings can be performed continuously within a certain interval. The interval is a predefined time data. Specifically, for circuits with frequent switching state changes, a smaller interval can be used to accurately respond to changes in the switching state. For circuits with infrequent switching state changes, a larger interval can be used to reduce computational burden. Furthermore, the number of sampling rounds can be adjusted according to actual conditions. For example, the number of sampling rounds is 12.

[0236] The theoretical switch state derived from the load current is compared one by one with the switch opening and closing state reported by the low-voltage terminal. When the two are consistent, the switch opening and closing state is retained; when the two are inconsistent, the switch opening and closing state is deleted to eliminate erroneous states caused by communication abnormalities, remote signaling false alarms, or transient interference.

[0237] By performing the above verification, the original switch status can be screened before generating the dynamic topology, so that the switch status participating in the subsequent effective branch screening is closer to the actual operating status of the transformer area, thereby reducing the impact of erroneous switch information on the topology reconstruction results.

[0238] By adopting this implementation method, the consistency of remote signaling status can be verified by utilizing the physical correlation between load current and switch on / off state, reducing the probability of misjudgment caused by relying solely on switch-reported information, and improving the accuracy and stability of dynamic topology construction, thereby enhancing the reliability of subsequent fault zone location.

[0239] In one possible implementation, step S205 may further include:

[0240] Step S2051: If the maximum value of the difference quantification index is greater than the preset threshold, the fault interval is determined to be between adjacent terminal groups corresponding to the maximum value of the difference quantification index; if the maximum value of the difference quantification index is less than or equal to the preset threshold, the fault interval is determined to be the downstream end line of the low-voltage terminal.

[0241] The preset threshold is used to distinguish between faults within a section and faults at the end of the line. The preset threshold value can be set based on historical fault samples of the transformer area, line length, terminal sampling error, and noise level to ensure the stability and adaptability of the judgment results.

[0242] Adjacent terminal groups are used as difference comparison units and are typically composed of low-voltage terminals that are topologically adjacent and electrically continuous. The low-voltage terminals serve as reference nodes for determining downstream end lines. When no significant difference peak is observed, it indicates that the fault characteristics fail to provide sufficient differentiation between adjacent terminal groups, and therefore the fault is attributed to the downstream end line of the low-voltage terminal.

[0243] After the converged terminal summarizes the difference quantification indicators corresponding to each adjacent terminal group, it first compares the size of each indicator and determines the maximum value, and then compares the maximum value with the preset threshold.

[0244] If the maximum value exceeds the threshold, it is considered that the fault waveform characteristics have changed significantly between the corresponding adjacent terminal groups, indicating that the fault point is located in the line segment between the adjacent terminal groups. The fusion terminal outputs this segment as the fault interval accordingly.

[0245] If the maximum value does not exceed the threshold, it indicates that the difference between adjacent terminal groups is not sufficient to support the segmentation of the interval. In this case, the fusion terminal will directly locate the fault interval as the downstream end line of the low-voltage terminal to avoid missegmentation due to insufficient feature differences.

[0246] For example, the threshold comparison described above can be performed in real time by an embedded processor in conjunction with a stored threshold table. In practical applications, other processor models can also be selected, and this application embodiment does not limit this.

[0247] This solution determines the fault range by comparing the maximum difference value with a threshold. When the difference is significant, it achieves fine-grained positioning between adjacent terminal groups; when the difference is insignificant, it reverts to the range of the last line segment. This ensures that the positioning results reflect both local abrupt changes in complex topologies and avoid over-segmentation in weak feature scenarios. This improves the accuracy and reliability of fault range positioning in low-voltage distribution transformer areas, reduces misjudgments and omissions, and provides a clearer basis for subsequent maintenance and repair.

[0248] This application's embodiments apply to fault location scenarios in low-voltage distribution transformer areas within residential communities. The low-voltage distribution lines in such areas typically have a radial or tree-like structure, including main lines, branch boxes, and user meter boxes. The lines may simultaneously include underground cables and overhead lines.

[0249] Taking a residential community as an example, one integrated distribution terminal is installed at the 10kV distribution transformer within the distribution area. Six low-voltage terminals are installed at the low-voltage busbar outgoing terminals, main line branch boxes, and user meter boxes. These low-voltage terminals are designated as: Low-voltage Terminal 1, Low-voltage Terminal 2, Low-voltage Terminal 3, Low-voltage Terminal 4, Low-voltage Terminal 5, and Low-voltage Terminal 6. The integrated distribution terminal establishes communication connections with each low-voltage terminal. When a low-voltage terminal detects a fault event such as a short circuit, grounding, or open circuit in the distribution area, it sends a fault waveform to the integrated distribution terminal.

[0250] After a fault event occurs, the fusion terminal acquires the static topology of the low-voltage distribution area, as well as the switch opening and closing status and load current data sent by each low-voltage terminal.

[0251] The static topology can be pre-configured with the converged terminal as the root node, low-voltage terminal 1 as the first-level node, low-voltage terminal 2 as the second-level node, and low-voltage terminals 3, 4, 5, and 6 as the third-level nodes.

[0252] The fusion terminal infers the theoretical state of the corresponding switch based on the load current at each measuring point, and then verifies the theoretical state of the switch with the collected switch open / closed state. For example, if the switch connected to the low-voltage terminal corresponding to a user's meter box is in the closed state, but the downstream load current of the low-voltage terminal is 0A, it can be determined that the switch open / closed state has failed the verification, and the switch open / closed state will be deleted.

[0253] By verifying the switch opening and closing status, valid branches with conducting relationships are selected from the static topology to form a dynamic topology that reflects the current operating connection relationships. For example, when the switch of the branch box where low-voltage terminal 2 is located is closed and the switch of the branch of low-voltage terminal 3 is open, the fusion terminal retains the fusion terminal, low-voltage terminal 1, low-voltage terminal 2 and the remaining conducting branches, and removes the downstream branch where low-voltage terminal 3 is located, thus obtaining the dynamic topology.

[0254] Then, multiple low-voltage terminals are matched according to the electrical adjacency relationship in the dynamic topology to obtain multiple adjacent terminal groups. For example, the adjacent terminal groups include low-voltage terminal 1 and low-voltage terminal 2; low-voltage terminal 2 and low-voltage terminal 4; and low-voltage terminal 4 and low-voltage terminal 5.

[0255] Then, the fault waveforms collected by each low-voltage terminal during the fault occurrence are retrieved, and the fault waveforms are assigned to the corresponding adjacent terminal groups to obtain the fault waveforms collected by each low-voltage terminal in the adjacent terminal group.

[0256] Subsequently, synchronous timing calibration is performed on the fault waveforms collected by each low-voltage terminal within the same adjacent terminal group. For each fault waveform, the fusion terminal performs a first-order differential operation to obtain the instantaneous differential amplitude at each sampling time, and identifies the instantaneous time when the instantaneous differential amplitude is greater than the abrupt change threshold as the fault abrupt change time of the fault waveform. Using the fault abrupt change times of all fault waveforms within the same group as the timing reference, the timing deviation of each fault waveform relative to the timing reference is calculated, and the corresponding fault waveform is time-axis shifted and calibrated according to the timing deviation to obtain the calibrated fault waveform corresponding to the adjacent terminal group.

[0257] Subsequently, fault waveform features were extracted from the calibration fault waveforms within each adjacent terminal group. For each calibration fault waveform, a Fast Fourier Transform was used to decompose the waveform into the fundamental frequency and each harmonic, and the relevant parameters of the harmonic components were extracted from the decomposition results as distortion features. At the same time, waveform analysis was performed on the calibration fault waveforms to obtain voltage features characterizing voltage changes during the fault period, and attenuation features characterizing the relationship between waveform amplitude and time.

[0258] Based on the fault type corresponding to the fault waveform, the voltage characteristics, distortion characteristics, attenuation characteristics and phase characteristics of each calibration fault waveform in the same adjacent terminal group are differentially weighted and summed to obtain the differential quantitative index corresponding to the adjacent terminal group.

[0259] After obtaining the difference quantification indicators corresponding to multiple adjacent terminal groups, the difference quantification indicators are compared. When the maximum value of the difference quantification indicator is greater than a preset threshold, the fault interval is determined as the line segment between the adjacent terminal groups corresponding to that maximum value.

[0260] For example, when the difference quantification index corresponding to low-voltage terminal 1 and low-voltage terminal 2 is the maximum value and is greater than the preset threshold, the fault interval is determined as the line segment between low-voltage terminal 1 and low-voltage terminal 2.

[0261] For example, when the maximum value of the differential quantification index is less than or equal to a preset threshold, the fault range is determined to be the downstream end line of the low-voltage terminal. After the fault range is determined, the location result along with the fault type can be sent to the power distribution operation and maintenance terminal, so that operation and maintenance personnel can go to the corresponding branch box, meter box or end line location to handle the situation.

[0262] Figure 4 This is a schematic diagram of the structure of the distribution radio station fault location device provided in the embodiments of this application, as shown below. Figure 4 As shown, the distribution transformer area fault location device 40 provided in this embodiment is deployed at the fusion terminal at the distribution transformer corresponding to the low-voltage distribution transformer area. The fusion terminal is communicatively connected to multiple low-voltage terminals deployed at the measurement points of the low-voltage distribution transformer area. The distribution transformer area fault location device 40 includes:

[0263] The acquisition module 401 is used to acquire fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups based on the dynamic topology of low-voltage terminals and low-voltage distribution radio areas.

[0264] The processing module 402 is used to perform synchronous timing calibration on the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal group; extract feature parameters from the calibration fault waveforms in the adjacent terminal group to obtain the fault waveform features corresponding to the adjacent terminal group; perform weighted summation on the fault waveform features corresponding to the adjacent terminal group based on the fault type corresponding to the fault waveform to obtain the difference quantification index corresponding to the adjacent terminal group; and determine the fault range of the low-voltage distribution transformer area based on the difference quantification index corresponding to the adjacent terminal group.

[0265] In one possible implementation, the processing module 402 is specifically used for:

[0266] Perform a first-order difference operation on the fault waveform to obtain the instantaneous difference amplitude of the fault waveform;

[0267] The instantaneous time when the instantaneous differential amplitude of the fault waveform exceeds the sudden change threshold is taken as the fault sudden change moment of the fault waveform.

[0268] Using the fault change time of all fault waveforms in the same adjacent terminal group as the time reference, the timing deviation in the adjacent terminal group is obtained.

[0269] Based on the timing deviation, the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group are shifted and calibrated to obtain the calibrated fault waveforms.

[0270] In one possible implementation, the fault waveform characteristics include: voltage characteristics, distortion characteristics, attenuation characteristics, and phase characteristics. The processing module 402 is further configured to:

[0271] Fast Fourier Transform is used to decompose the calibration fault waveform into the fundamental wave and each harmonic, and the distortion characteristics and phase characteristics of adjacent terminal groups are obtained.

[0272] By performing waveform analysis on the calibration fault waveform, the voltage characteristics and attenuation characteristics of adjacent terminal groups are obtained.

[0273] In one possible implementation, the acquisition module 401 is specifically used for:

[0274] Acquire the dynamic topology of the low-voltage distribution transformer area and the fault waveforms collected from multiple low-voltage terminals;

[0275] Based on dynamic topology, multiple low-voltage terminals are matched to obtain multiple adjacent terminal groups;

[0276] Based on the fault waveforms collected by the low-voltage terminal and the adjacent terminal groups, the fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups are obtained.

[0277] In one possible implementation, the dynamic topology is obtained in the following way:

[0278] Acquire the static topology of the low-voltage distribution transformer area and the switch opening and closing status collected from multiple low-voltage terminals;

[0279] Based on the switch's open / closed state, valid branches are selected from the static topology to obtain the dynamic topology.

[0280] In one possible implementation, before obtaining the dynamic topology by filtering valid branches in the static topology based on the switch's on / off state, the method further includes:

[0281] Acquire load currents from multiple low-voltage terminals;

[0282] The theoretical state of the switch is obtained by inversely deducing the switch state based on the load current;

[0283] Based on the theoretical state of the switch, the open and closed states of the switch are checked, and the open and closed states of the switch that fail the check are deleted.

[0284] In one possible implementation, the processing module 402 is specifically used for:

[0285] If the maximum value of the difference quantification index is greater than the preset threshold, the fault interval is determined to be between the adjacent terminal groups corresponding to the maximum value of the difference quantification index.

[0286] If the maximum value of the difference quantification index is less than or equal to the preset threshold, the fault range is determined to be the downstream end line of the low-voltage terminal.

[0287] The distribution area fault location device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0288] Figure 5 This is a schematic diagram of the structure of a power distribution area fault location device provided in an embodiment of this application. Figure 5 As shown, the distribution transformer area fault location device 50 provided in this embodiment includes at least one processor 501 and a memory 502. Optionally, the distribution transformer area fault location device 50 further includes a communication component 503. The processor 501, memory 502, and communication component 503 are connected via a bus 504.

[0289] In a specific implementation, at least one processor 501 executes computer execution instructions stored in memory 502, causing at least one processor 501 to perform the above-described method.

[0290] The specific implementation process of processor 501 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0291] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0292] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0293] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0294] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0295] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0296] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random-Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0297] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0298] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0299] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0300] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0301] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0302] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0303] Finally, it should be noted that other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope.

Claims

1. A method for locating faults in a distribution radio area, characterized in that, A fusion terminal is applied to the distribution transformers corresponding to low-voltage distribution transformer areas. The fusion terminal is communicatively connected to multiple low-voltage terminals deployed at measurement points in the low-voltage distribution transformer area. The fault location method for the distribution transformer area includes: Based on the dynamic topology of the low-voltage terminal and the low-voltage distribution transformer area, the fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups are obtained. Synchronous timing calibration is performed on the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal group; Feature parameters are extracted from the calibration fault waveforms within the adjacent terminal groups to obtain the fault waveform features corresponding to the adjacent terminal groups. Based on the fault type corresponding to the fault waveform, the fault waveform features corresponding to the adjacent terminal groups are weighted and summed to obtain the difference quantification index corresponding to the adjacent terminal groups. Based on the difference quantification index corresponding to the adjacent terminal groups, the fault range of the low-voltage distribution transformer area is determined.

2. The method for locating faults in a distribution radio area according to claim 1, characterized in that, The step of synchronously timing-calibrating the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group to obtain the calibrated fault waveforms corresponding to the adjacent terminal group includes: Perform a first-order difference operation on the fault waveform to obtain the instantaneous difference amplitude of the fault waveform; The instantaneous time when the instantaneous differential amplitude of the fault waveform is greater than the sudden change threshold is taken as the fault sudden change moment of the fault waveform. The timing deviation within the adjacent terminal group is obtained by using the fault change time of all fault waveforms in the same adjacent terminal group as the timing reference. Based on the timing deviation, the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group are shifted and calibrated to obtain calibrated fault waveforms.

3. The method for locating faults in a distribution radio area according to claim 1, characterized in that, The fault waveform features include: voltage features, distortion features, attenuation features, and phase features. The step of extracting feature parameters from the calibration fault waveforms within the adjacent terminal groups to obtain the fault waveform features corresponding to the adjacent terminal groups includes: The calibration fault waveform is decomposed into fundamental and harmonic waves using fast Fourier transform to obtain the distortion and phase characteristics corresponding to the adjacent terminal groups. By performing waveform analysis on the calibration fault waveform, the voltage characteristics and attenuation characteristics corresponding to the adjacent terminal groups are obtained.

4. The method for locating faults in a distribution substation according to any one of claims 1 to 3, characterized in that, The method of acquiring fault waveforms collected by each low-voltage terminal within multiple adjacent terminal groups based on the dynamic topology of the low-voltage terminal and the low-voltage distribution transformer area includes: Acquire the dynamic topology of the low-voltage distribution transformer area and the fault waveforms collected by multiple low-voltage terminals; Based on the dynamic topology, multiple low-voltage terminals are matched to obtain multiple adjacent terminal groups; Based on the fault waveform collected by the low-voltage terminal and the adjacent terminal group, the fault waveform collected by each low-voltage terminal in the multiple adjacent terminal groups is obtained.

5. The method for locating faults in a distribution radio station area according to any one of claims 1 to 3, characterized in that, The dynamic topology is obtained through the following method: Obtain the static topology of the low-voltage distribution transformer area and the switch opening / closing status collected by multiple low-voltage terminals; Based on the switch's open / closed state, valid branches are selected from the static topology to obtain the dynamic topology.

6. The method for locating faults in a distribution radio station area according to claim 5, characterized in that, Before obtaining the dynamic topology by filtering valid branches in the static topology based on the switch's on / off state, the process further includes: Acquire the load current collected by multiple low-voltage terminals; Based on the load current, the switch state is deduced to obtain the theoretical switch state; Based on the theoretical state of the switch, the open / closed state of the switch is checked, and the open / closed state of the switch that fails the check is deleted.

7. The method for locating faults in a distribution radio station area according to any one of claims 1 to 3, characterized in that, The method of determining the fault range of the low-voltage distribution transformer area based on the difference quantification index corresponding to adjacent terminal groups includes: If the maximum value of the difference quantification index is greater than a preset threshold, then the fault interval is determined to be between the adjacent terminal groups corresponding to the maximum value of the difference quantification index. If the maximum value of the difference quantification index is less than or equal to the preset threshold, then the fault range is determined to be the downstream end line of the low-voltage terminal.

8. A fault location device for a distribution radio station area, characterized in that, A fusion terminal is deployed at the distribution transformer corresponding to the low-voltage distribution transformer area. The fusion terminal is communicatively connected to multiple low-voltage terminals deployed at the measurement points of the low-voltage distribution transformer area. The fault location method for the distribution transformer area includes: The acquisition module is used to acquire fault waveforms collected by each low-voltage terminal in multiple adjacent terminal groups based on the dynamic topology of the low-voltage terminal and the low-voltage distribution transformer area. The processing module is used to perform synchronous timing calibration on the fault waveforms collected by the low-voltage terminals in the same adjacent terminal group to obtain the calibration fault waveforms corresponding to the adjacent terminal group; extract feature parameters from the calibration fault waveforms in the adjacent terminal group to obtain the fault waveform features corresponding to the adjacent terminal group; perform weighted summation on the fault waveform features corresponding to the adjacent terminal group based on the fault type corresponding to the fault waveform to obtain the difference quantification index corresponding to the adjacent terminal group; and determine the fault range of the low-voltage distribution transformer area based on the difference quantification index corresponding to the adjacent terminal group.

9. A fault location device for a distribution radio area, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the distribution radio area fault location method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the distribution radio area fault location method as described in any one of claims 1-7.

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