FTU, DTU embedded distributed fault diagnosis method and terminal

Abstract

This application discloses an embedded distributed fault diagnosis terminal in the field of power distribution automation fault diagnosis technology. It extracts the characteristics of current and voltage slope changes by constructing a set of disturbance segments with time-series index. After aligning the start time of multiple channel changes, it generates a linkage control group. Then, it establishes branch mapping numbers by combining phase mapping and issues control commands to generate a list of tripping channels. Finally, it generates diagnostic results by monitoring current changes and standby channel status through closed-loop feedback. This solves the problems of delayed fault location and frequent misjudgments caused by the lack of multi-channel signal linkage fine identification and closed-loop verification in existing FTU and DTU diagnosis. It realizes the time-series alignment and closed-loop verification of fault features and improves the accuracy and isolation efficiency of fault channel screening under complex distribution networks.

Description

Technical Field

[0001] This invention relates to the field of power distribution automation fault diagnosis technology, and in particular to a distributed fault diagnosis method and terminal embedded in FTU and DTU. Background Technology

[0002] The field of fault diagnosis technology involves the identification, analysis, and judgment of abnormal or malfunctioning behaviors in the operation of power systems, aiming to promptly detect potential fault hazards and determine their location, nature, and development trend. Core aspects of this technology include: fault signal acquisition based on electrical quantities, fault feature extraction, fault type identification, fault location determination, and communication and recording of fault information. This field widely utilizes various methods such as transient current detection, zero-sequence current analysis, signal abrupt change criteria, state estimation analysis, and waveform pattern recognition, combined with communication networks and distribution automation terminals to construct intelligent monitoring systems, thereby improving the safety and maintenance efficiency of power grid operation. Especially in distribution networks, due to the complex line structure, numerous branches, and the widespread use of neutral point non-effective grounding methods, fault current characteristics are weak, making line selection and location difficult. Therefore, higher demands are placed on distributed, rapid, and accurate fault diagnosis technologies. Traditional FTU and DTU embedded distributed fault diagnosis terminals refer to those that embed fault judgment and location functions into feeder terminals or switchyard terminal equipment. They collect electrical information such as three-phase current and zero-sequence voltage locally, use transient current imbalance change criterion to identify the line and fault phase, and utilize edge-side processing units to determine the fault branch and section. These terminals are generally integrated into the existing enclosure structure of the FTU and DTU, directly using their instrument transformer resources for power sampling. They perform fault current analysis locally through built-in data processing programs and simultaneously upload diagnostic information to the distribution automation system via VPN communication technology. Traditional equipment mostly possesses functions such as current change detection, voltage anomaly identification, and waveform data playback. Fault identification is performed using fixed criteria or the fundamental frequency direction method, and location mainly relies on waveform differences or line selection logic judgment based on distributed deployment across the cross-section.

[0003] Existing technologies mainly rely on current surge criteria and waveform differences deployed at cross sections for judgment. They lack a fine identification mechanism for the linkage characteristics between multi-channel signals, making it difficult to identify the source and scope of the fault in a short time. Current surge detection is limited to single-point anomaly identification and fails to form an analytical logic for the continuous evolution of disturbances. There is a lack of effective time sequence correspondence between channels, which leads to the reliance on isolated signal judgment in the line selection process. The response results have accumulated biases, and the diagnostic strategy relies on fixed templates, making it difficult to cope with the dynamic characteristics changes brought about by changes in the power distribution network structure. This results in problems such as delayed fault location, inconsistent response, and frequent misjudgments, affecting the stable operation of the system and the accuracy of handling. Summary of the Invention

[0004] To address the technical problems existing in the prior art, embodiments of the present invention provide a method and terminal for embedded distributed fault diagnosis in FTU and DTU. One aspect provides a method for embedded distributed fault diagnosis in FTU and DTU, comprising the following steps: Embedded terminal acquisition steps: Acquire current and voltage signals from FTU and DTU, extract three-phase current and zero-sequence voltage curves, sample by time period index, identify current slope inflection points and voltage slope abrupt change points, mark disturbance periods, and generate disturbance segment sets; Transient feature identification steps: Based on the set of disturbance fragments, filter continuous slope change points within the channel, arrange the start time of the sudden change according to the channel number, align the current and voltage slope change positions, select the time difference channel group, and generate a linkage control group; Linkage judgment and control steps: Based on the linkage control group, extract the channel trigger feedback time, compare the response interval, verify the response channel, call the corresponding phase, match the feeder number in the ring network cabinet diagram, and establish the branch mapping number; Fault isolation execution steps: Based on the branch mapping number, send control commands to the pole-mounted switch through the DTU communication port, read the action feedback, and generate a trip channel list; Closed-loop feedback update steps: Read the trip channel list, monitor the sudden changes in current before and after, identify the fault channel, compare the power-on status of the backup channel, filter and match the fault characteristic channel, and generate embedded diagnostic results for FTU and DTU.

[0005] As a further embodiment of the present invention, the disturbance segment set includes three-phase current slope change segments, zero-sequence voltage slope abrupt change segments, disturbance location marker index, and continuous sampling period number; the linkage control group includes linkage channel number, abrupt change time point sequence, current and voltage channel pairing relationship, and minimum time interval identifier; the branch mapping number includes the phase to which the channel belongs, branch number, feeder channel mapping relationship, and ring main unit channel number; the trip channel list includes trip channel number, action execution marker, response feedback status, and target branch record item; and the FTU and DTU embedded diagnostic results include channel current change identifier, fault channel number, standby channel status change, and fault feature matching result.

[0006] As a further aspect of the present invention, the inflection point of the current slope and the abrupt change point of the voltage slope refer to the characteristic points where the slope of the current and voltage signals changes direction and abruptly over time, thus verifying the timing and nature of the disturbance.

[0007] As a further aspect of the present invention, the "phase" refers to the phase in the power system monitored and controlled by the channel and equipment, including phase A, phase B and phase C, which identify the affiliation of phase current and phase voltage.

[0008] On the other hand, an embedded distributed fault diagnosis terminal for FTU and DTU is provided to implement the aforementioned embedded distributed fault diagnosis method for FTU and DTU, including: An embedded terminal acquisition module is used to implement the embedded terminal acquisition steps; The transient feature recognition module is used to implement the transient feature recognition steps; The linkage judgment and control module is used to implement the linkage judgment and control steps; The fault isolation execution module is used to implement the fault isolation execution steps; The closed-loop feedback update module is used to implement the closed-loop feedback update steps.

[0009] As a further aspect of the present invention, the embedded terminal acquisition module includes: The data stream receiving submodule acquires the current and voltage input signals of the feeder terminal unit (FTU) and the switch station terminal unit (DTU), samples the three-phase current and zero-sequence voltage, and generates a continuous sampling timing sequence in time order. The power change detection submodule calls the continuous sampling time sequence to extract current and voltage data, calculates the slope of the current change rate and identifies the inflection point, calculates the slope of the zero-sequence voltage and identifies the abrupt change point, and generates a set of current inflection points and voltage abrupt change points. The disturbance segment construction submodule identifies the time period of disturbance occurrence based on the combination of marked positions in the set of current inflection points and voltage change points, extracts continuous disturbance segments and combines them into blocks to obtain a set of disturbance segments.

[0010] As a further aspect of the present invention, the transient feature recognition module includes: The slope change direction screening submodule, based on the set of disturbance fragments, judges the change in slope sign of sampling points in the channel, filters the position sequence of continuous slope change, classifies and summarizes it according to channel number, and generates channel slope change direction sequence group. The starting point time arrangement submodule calls the channel starting point time in the channel slope change sequence group, arranges the first change point of the differentiated channel in numerical order, calculates the time difference, and establishes the channel starting time sequence. The linkage channel determination submodule matches the current and voltage channel reversal times based on the channel start time sequence, calculates the time interval between channels, filters the minimum interval combination, and obtains the linkage control group.

[0011] As a further aspect of the present invention, the linkage judgment and control module includes: The feedback time extraction submodule extracts the feedback time marker after the channel is triggered based on the linkage control group, calculates the difference between the trigger and feedback time of the channel, compares the response interval values ​​of all channels, obtains the shortest response channel number, and generates a response channel identifier. The phase-channel matching submodule calls the channel information corresponding to the response channel identifier, reads the phase markers contained in the channel, establishes a channel-phase mapping by comparing the channel number with the corresponding phase relationship table, and obtains the channel matching result; Based on the channel matching results, the branch number mapping submodule compares the channel number map of the ring main unit, extracts the feeder number to which the channel belongs, and establishes a binding relationship with the original channel number to obtain the branch mapping number.

[0012] As a further aspect of the present invention, the fault isolation execution module includes: The control command issuing submodule, based on the branch mapping number, calls the communication port address of the embedded diagnostic in the DTU where the corresponding branch is located, writes the switch control command to the pole-mounted switch action interface and starts the execution status flag, and establishes the control channel execution identifier; The action response reading submodule detects the action response data returned by the feedback channel based on the control channel execution identifier, reads the response flag field and identifies the channel number of the executed instruction, and obtains the action verification channel list. The trip branch recording submodule calls all channel number information in the action verification channel list, records the corresponding branch number to the operation execution log table, marks the trip status bit and archives it centrally, and generates a trip channel list.

[0013] As a further aspect of the present invention, the closed-loop feedback update module includes: The current mutation detection submodule reads the channel numbers of all executed actions in the trip channel list, monitors the current change value in the corresponding channel during the continuous period before and after the trip, compares the difference between the last sample value before the trip and the first sample value after the trip, filters the channel numbers whose difference is greater than the current mutation threshold, and obtains the current mutation channel set; the current mutation threshold refers to the minimum current difference standard for judging whether the channel current has changed before and after the trip. The backup channel comparison submodule calls the channel number in the current change channel set, retrieves the current status of the associated backup channel, detects whether the backup channel has a power-on status improvement behavior during the period after the trip, records the status change channel number, and generates a set of on / off status change channels. The diagnostic result generation submodule compares the channel number in the channel set of the on / off state change channel with the previous tripped channel, selects the channel combination that forms a primary / standby switch and has a sudden change characteristic after the trip, and marks it into the FTU and DTU channel classification structure according to the channel affiliation, and generates embedded diagnostic results for FTU and DTU.

[0014] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: By constructing a set of disturbance segments with time-series indexes and performing alignment analysis on the start time of slope abrupt changes in current and voltage channels, combined with a multi-channel linkage relationship determination mechanism, accurate identification of the disturbance response sequence between channels is achieved. Furthermore, by linking branch mapping numbers with control commands and using a closed-loop feedback verification mechanism based on current abrupt changes after tripping and changes in the status of backup channels, the reliability and accuracy of fault channel identification are improved, thereby enhancing the completeness of fault judgment and the execution efficiency of anomaly isolation under complex power distribution network structures. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall steps of the terminal and method in this application; Figure 2 This is a flowchart of the embedded terminal acquisition module in this application; Figure 3 This is a flowchart of the transient feature recognition module in this application; Figure 4 This is a flowchart of the linkage judgment and control module in this application; Figure 5 This is a flowchart of the fault isolation execution module in this application; Figure 6 This is a flowchart of the closed-loop feedback update module in this application. Detailed Implementation

[0017] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0018] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0019] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0020] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0021] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0022] This invention provides a method for embedded distributed fault diagnosis in FTU and DTU, such as... Figure 1 As shown, it includes the following steps: Embedded terminal acquisition steps: acquire current and voltage input signals from feeder terminal (FTU) and switch station terminal (DTU), extract three-phase current curves and zero-sequence voltage curves, establish sampling indexes according to continuous time periods, identify inflection points of current slope and abrupt changes in voltage rise slope, and construct segment blocks by marking the locations of disturbances in the sampling period to generate a disturbance segment set. Transient feature identification steps: Based on the set of disturbance fragments, filter the sequence of points with continuous slope direction changes in the channel, arrange the time of the mutation start point according to the channel number, compare the time alignment judgment with the position of the current slope and voltage slope change in the channel, select the channel group with the smallest time interval as the linkage object, and generate the linkage control group; Linkage judgment and control steps: Based on the linkage control group, extract the feedback time stamp after the channel is triggered, obtain the channel with the shortest response interval by comparing the response interval of each channel, call the phase to which the channel belongs, match the feeder number in the ring network cabinet channel number map, establish the corresponding relationship, and generate the branch mapping number; Fault isolation execution steps: According to the branch mapping number, call the corresponding DTU embedded diagnostic module communication port, write the control command to the pole-mounted switch action interface, read the action response flag in the feedback channel, establish a record entry for the target branch that has completed the command execution, and generate a trip channel list; Closed-loop feedback update steps: Read the channels that have performed actions in the trip channel list, monitor the changes in current on / off performance, detect the channel numbers of sudden changes in current difference before and after the action, compare whether the changes in the power-on status of the backup channel are valid, screen the target channels with fault characteristic matching performance, and generate embedded diagnostic results for FTU and DTU.

[0023] The disturbance segment set includes three-phase current slope change segments, zero-sequence voltage slope abrupt change segments, disturbance location marker index, and continuous sampling period number. The linkage control group includes linkage channel number, abrupt change time point sequence, current and voltage channel pairing relationship, and minimum time interval identifier. The branch mapping number includes the phase to which the channel belongs, branch number, feeder channel mapping relationship, and ring main unit channel number. The trip channel list includes trip channel number, action execution marker, response feedback status, and target branch record item. The FTU and DTU embedded diagnostic results include channel current change identifier, fault channel number, standby channel status change, and fault feature matching results.

[0024] Based on the same inventive concept, this application also discloses an embodiment of an FTU / DTU embedded distributed fault diagnosis terminal, used to implement the aforementioned FTU / DTU embedded distributed fault diagnosis method, including: An embedded terminal acquisition module is used to implement the embedded terminal acquisition steps; The transient feature recognition module is used to implement the transient feature recognition steps; The linkage judgment and control module is used to implement the linkage judgment and control steps; The fault isolation execution module is used to implement the fault isolation execution steps; The closed-loop feedback update module is used to implement the closed-loop feedback update steps.

[0025] Specifically, such as Figure 2 As shown, the embedded terminal acquisition module includes: The data stream receiving submodule acquires the current and voltage input signals of the feeder terminal unit (FTU) and the switch station terminal unit (DTU), samples the three-phase current and zero-sequence voltage, and generates a continuous sampling timing sequence in time order. First, a stable connection is established based on the communication link with the FTU and DTU terminals. The raw data values ​​of three-phase current and three-phase voltage are extracted from the terminal devices at set sampling intervals. Each sampling operation requires reading the Ia, Ib, and Ic three-phase current signals recorded in the FTU device, and simultaneously reading the Ua, Ub, and Uc three-phase voltage input values ​​from the DTU terminal. After reading, the current and voltage data undergo validity verification and amplitude range judgment. The amplitude range is set based on the device's rated parameters and the statistical interval of historical operating data. When the sampled value exceeds a preset proportional threshold within the rated range, or the change amplitude between adjacent sampling points exceeds a set abrupt change threshold, it is judged as abnormal data. Abnormal data is corrected by removing it and interpolating based on adjacent valid sampling points, and the abnormal data is marked and recorded. After completing the data verification and correction, the current current and voltage data at the current moment are encapsulated into a time-based... In the data structure with labels, the zero-sequence voltage signal is further calculated. The zero-sequence voltage value at each moment is obtained by taking the arithmetic mean of the three-phase voltages. At the same time, the amplitude of the sampled current value is normalized according to the maximum and minimum current values ​​recorded in the historical sampling data. After normalization, the dimensional differences of current values ​​in different terminal devices can be unified, improving the feasibility of data comparison. Next, the phase-to-phase current difference needs to be calculated for each time point to assess whether there is distortion or fluctuation in the current. When the difference between two or three phases exceeds the empirical threshold, it is marked and saved. This process needs to be continuously carried out and the data is continuously sorted. Finally, a complete sampling sequence is constructed in chronological order, with each entry containing three-phase current, zero-sequence voltage, normalized value, and difference analysis result. The data sequence is continuously supplemented and updated in this way until the entire electrical state record is completed, and a continuous sampling time sequence is generated in chronological order.

[0026] The power change detection submodule calls the continuous sampling time sequence to extract current and voltage data, calculates the slope of the current change rate and identifies the inflection point, calculates the slope of the zero-sequence voltage and identifies the abrupt change point, and generates a set of current inflection points and voltage abrupt change points. First, the normalized current and zero-sequence voltage terms in the sequence are read sequentially according to time. When extracting current data, several continuous segments are divided according to a fixed sliding window method. The current change trend of each segment is numerically analyzed, and the rate of change is evaluated by the point-to-point change amplitude between currents. By comparing the data difference between the end of the current window and the end of the previous window, the acceleration or deceleration of the current change trend is identified. After cascading the results of multiple windows, the fluctuation of the current change rate over time can be deduced. Based on this, the turning points where the current trend reverses or the rate of change changes abruptly are identified and recorded as current inflection points. Similarly, The extraction of zero-sequence voltage data also needs to be carried out according to the same time window, and its change amplitude within a continuous time interval should be evaluated. For segments with numerical jumps in a short period of time, key identification and marking should be carried out. The identification of voltage mutation points can be combined with actual operating experience to determine the judgment criteria for mutation changes, such as setting reference boundary values ​​to judge the manifestation of mutation behavior. When the mutation amplitude is greater than several times the normal fluctuation, it can be regarded as the occurrence of a mutation event. The identification of voltage mutation points needs to mark the time and location index, and save them in parallel with the current inflection point data. At this point, two sets of key change event location sets have been constructed, which can be used by other sub-modules to generate current inflection point and voltage mutation point sets.

[0027] The disturbance segment construction submodule identifies the time period of disturbance occurrence based on the combination of marked positions in the set of current inflection points and voltage change points, extracts continuous disturbance segments and combines them into blocks to obtain a set of disturbance segments; First, all time indices in the current and voltage event set need to be paired according to their occurrence time. Each pair represents a current change point and a voltage anomaly point. The time difference between each pair is analyzed. When the time difference is within an acceptable disturbance response time threshold, it indicates that the two points may belong to different stages of the same disturbance event. This time pair is then recorded as the initial disturbance clue, and the time range before and after it is traced back to construct a complete disturbance period boundary. After selecting the initial segment, all continuous current and voltage samples within the segment are statistically analyzed to identify whether there are continuous fluctuations. For example, if the continuous current value fluctuation exceeds the standard range of the historical average, the segment is considered to belong to the actual disturbance area. The process needs to be extended forward or backward segment by segment until the current and voltage fluctuations tend to stabilize. Then, the identified multiple disturbance segments are saved as independent events. The time interval between any two disturbance segments is checked. If the time interval between two disturbance segments is less than the preset minimum disturbance interval threshold, they are determined to be continuous events under the same disturbance chain. The minimum disturbance interval threshold is determined based on the distribution of adjacent disturbance response times obtained from historical disturbance event statistics, or it is set according to a multiple of the system sampling period. Two segments need to be spliced ​​together to merge into a complete disturbance block. Finally, all the constructed disturbance segments are collected into a set and complete event boundary data is provided for subsequent analysis modules to obtain the disturbance segment set.

[0028] Specifically, such as Figure 3 As shown, the transient feature recognition module includes: The slope change direction screening submodule, based on the perturbation fragment set, judges the change in slope sign of sampling points in the channel, filters the position sequence of continuous slope direction change, classifies and summarizes it according to channel number, and generates channel slope change direction sequence group. The process of judging the change in the slope sign of sampling points in a channel begins with the call operation of the disturbance segment set. The sampling data sequence of the corresponding current or voltage channel in the disturbance segment is loaded segment by segment, and the data is classified and processed according to the channel number. The data stream of each channel is decomposed into a set of single-point amplitudes arranged in ascending order of time. During processing, the difference between the values ​​of any two adjacent sampling points is calculated to determine the trend of the slope direction change. If the value of the current sampling point is higher than the previous sampling point, the slope direction of the current segment is marked as positive; if it is lower than the previous sampling point, it is marked as negative. When a change in the slope direction between two consecutive points is detected, it is judged as a slope change event. The operation continuously applies to all adjacent point pairs in the entire perturbation data segment, records the location index of all locations where the slope sign changes, and organizes and saves their corresponding timestamps and channel numbers. Within a channel, if the interval between multiple consecutive change events is lower than the set interference removal threshold, it is determined that this type of change is caused by noise and is excluded. The remaining part is regarded as a valid change point. After filtering the valid points, the change points are integrated in chronological order to extract the change trend sequence. Each channel forms a set of continuous slope change point sequences. Then, the slope change point sequences of all channels are classified according to the channel number, and the change information set structure of the component channels is constructed. All channels are summarized and assembled to generate channel slope change sequence groups.

[0029] The starting point time arrangement submodule calls the channel starting point time in the channel slope change sequence group, arranges the first change point of the differentiated channel in numerical order, calculates the time difference, and establishes the channel starting time sequence. First, the timestamp corresponding to the first change point in the slope change point sequence recorded by each channel is read and regarded as the starting change time of that channel. This time point is uniformly represented in absolute timestamp format to ensure comparability across channels. Then, the starting time of all channels is arranged in order of channel number to form a pairing list consisting of channel number and starting time. On this basis, the time difference calculation operation is performed, that is, the starting time of the previous channel is subtracted from the starting time of the current channel one by one to form a time difference list between channels. This time difference reflects the order of channel change response. The calculation result needs to be checked to see if there is a case where the starting point of a certain channel is much earlier or later than that of other channels. Channels with obvious time differences are marked as abnormal, which can be used later to determine abnormal response behavior or channel offset status. During this process, the sorting and comparison of time difference values ​​must keep the channel number order unchanged to ensure the contextual consistency of data and the traceability of results. After summarizing all starting time and time difference values, a time series set arranged in order of channel number and with a time difference description field is constructed, and finally the channel starting time series is established.

[0030] The linkage channel determination submodule matches the current and voltage channel reversal times based on the channel start time sequence, calculates the time interval between channels, filters the minimum interval combination, and obtains the linkage control group. First, the start times of each channel marked as a current channel in the channel start time series are read one by one and compared with the start times of all voltage channels. The time difference between each pair of combinations is calculated. After obtaining the time difference, it is determined whether the difference is within the preset linkage judgment threshold range. This range needs to be set based on the typical time interval when the current and voltage channels respond in linkage in previous samples. The linkage judgment threshold is determined statistically based on the typical time interval when the current and voltage channels respond in linkage in historical operating samples, or it can be set based on the system sampling period, communication delay characteristics, and network structure scale. The parameters can also be configured according to the actual operating conditions. Generally, this threshold is set to no more than 0.1 seconds. For example, if the start time of a current channel is 1.04 seconds, If a voltage channel has a time difference of 1.11 seconds, the time difference is 0.07 seconds, which is within the effective linkage range. Record this pairing relationship. Repeat this operation to screen all current and voltage channel combinations. When multiple voltage channels meet the linkage conditions with a certain current channel, compare the time differences of these combinations and select the pair with the smallest difference as the effective linkage pair. If multiple combinations have completely identical time differences, prioritize the current channel with the earlier number. If the current channel numbers are also identical, compare the voltage channel number order and select the first group as the final result. This pairing process continues until all channel combinations have been screened. The channels corresponding to all combinations with the smallest time intervals are extracted to form a pairing structure, which is finally integrated into the linkage control group.

[0031] Specifically, such as Figure 4 As shown, the linkage judgment and control module includes: The feedback time extraction submodule extracts the feedback time marker after the channel is triggered based on the linkage control group, calculates the difference between the trigger and feedback time of the channel, compares the response interval values ​​of all channels, obtains the shortest response channel number, and generates a response channel identifier. First, all linkage channel pairing information is read from the linkage control group, and the trigger time point of each channel is obtained. Within each linkage channel pair, the triggering channel and the linked channel are identified. The trigger time typically refers to the time point of the first identified direction-changing event in the current channel. The feedback time is extracted from the time of the first direction-changing point in the corresponding voltage channel slope direction-changing sequence. Then, the difference between the feedback time and the trigger time of each channel pair is calculated to obtain the response time interval for each pair. This time interval is obtained through direct subtraction, and its unit is uniformly seconds. For example, the trigger time of the current channel in a certain channel pair is 3.42 seconds. If the voltage channel feedback time is 3.57 seconds, then the response interval is 0.15 seconds. After calculating the time difference for all channel pairs, these time intervals need to be compared pairwise to find the minimum value. The results of each interval are recorded and bound to the channel number. For multiple channel pairs with the same minimum response time, the original channel numbers are read and compared sequentially. The channel with the smallest number is selected as the shortest response channel. This channel is the fast feedback channel. Its feedback time tag, channel ID, linkage relationship index and other metadata are recorded in this channel, and a complete identification structure is constructed to finally generate the response channel identifier.

[0032] The phase-channel matching submodule calls the channel information corresponding to the response channel identifier, reads the phase markers contained in the channel, establishes the channel-phase mapping by comparing the channel number with the corresponding phase relationship table, and obtains the channel matching result; The channel number index extracted from the channel identifier is used to call the corresponding channel attribute data table. The phase identifier preset during the channel configuration stage is extracted from the table. This identifier is usually distinguished by phases A, B, and C, and can be directly mapped to a logical number according to the table structure. Then, the complete channel number and phase identifier comparison information is read from the configured phase relationship lookup table to determine whether the phase mark corresponding to the current channel number matches the target logic. If they match, the channel affiliation is confirmed. If they do not match, the historical phase configuration record is further checked to prevent misjudgment due to on-site numbering errors or channel mixing. Subsequently, the confirmed channel number and its phase code are bound together. All operations compare the field values ​​of structured data fields. Fuzzy matching or indirect marking is not allowed. For a typical example, if the channel number is CH05 and the phase is marked as C in the lookup table, the mapping pair "CH05→C" is established, and the mapping result is written into the channel matching result structure. At the same time, the verification field and timestamp field in the structure are updated for subsequent modules to reference, thus obtaining the channel matching result.

[0033] The branch number mapping submodule, based on the channel matching results, compares the ring main unit channel number map, extracts the feeder number to which the channel belongs, and establishes a binding relationship with the original channel number to obtain the branch mapping number; By referring to the pre-established and stored ring main unit channel number map, the feeder number to which the channel belongs is extracted and a binding relationship is established with the original channel number; the ring main unit channel number map is stored in the local configuration table of the master station system or DTU terminal, and is maintained through periodic synchronization or topology change triggered update mechanism. When the power distribution network topology changes, the map is updated by the master station sending update data or by the terminal self-learning correction method to ensure the accuracy and consistency of the channel mapping relationship; Referring to the ring main unit channel numbering map, which is a three-layer numbering mapping table of channels, feeders, and branches pre-set during system configuration, each record contains fields such as channel number, feeder number, and branch number. The operation begins by reading all channel number information from the channel matching result structure, and then retrieving the record row with the exact same channel number from the numbering map. The corresponding feeder number field value is extracted as the feeder assignment number for the current channel. Simultaneously, the original channel number is compared to confirm that they are the same logical entity. After confirming that the two are the same logical entity, a relationship is established between the channel and feeder number in the system data structure. Bind the mapping relationship. The format of the mapping relationship is required to be one-to-one. Duplicate binding or null value binding is prohibited. If no corresponding record is found for any channel number, it is marked as an anomaly and enters the manual review queue. For channel numbers that are successfully mapped, such as CH07, the corresponding feeder number in the spectrum is F3-2. Then, the mapping relationship CH07→F3-2 is established. This mapping data will be appended to the branch mapping structure list. Each item in this list contains fields such as original channel number, matching phase, feeder number, and establishment time. Obtain the branch mapping number.

[0034] Specifically, such as Figure 5 As shown, the fault isolation execution module includes: The control command issuing submodule, based on the branch mapping number, calls the communication port address of the embedded diagnostic in the DTU where the corresponding branch is located, writes the switch control command to the pole-mounted switch action interface and starts the execution status flag, and establishes the control channel execution identifier; First, extract the feeder number corresponding to each channel from the branch mapping number structure, and then look up the DTU address information bound to it based on the feeder number. Read the communication port address field registered in the DTU configuration table to confirm whether the address is online. If the status code is not a fault or disconnection indicator, load the port address as the target address for sending control commands. Then, find the corresponding pole-mounted switch control interface number based on the selected channel number. This interface number must be consistent with the record in the DTU control interface table. Read the interface type field to determine whether write operation is supported. If supported, construct a control command frame and assemble the format for sending control commands. The command frame content must include the target switch number, the action field, and the action delay field. The code includes information such as the execution confirmation bit. For example, for channel number CH08, which is mapped to DTU port 192.168.0.22 and switch interface number SW05, a command frame with the format [CH08, SW05, action: closing, delay: 0.1 seconds, confirmation: 1] needs to be constructed. This frame data is sent to the DTU target port via TCP protocol. The sending behavior is recorded as a control task number and written into the control command record table. At the same time, the control action execution flag is written into the status management field in the DTU device and the value is set to active state 1 for subsequent response identification. Finally, the current control channel number, control task number, and execution flag are associated and recorded in the control channel execution identifier structure to establish the control channel execution identifier.

[0035] The action response reading submodule detects the action response data returned by the feedback channel based on the control channel execution identifier, reads the response flag field and identifies the channel number of the instruction that has been executed, and obtains the action verification channel list. Extract all active control task numbers and their corresponding channel numbers from the generated control channel execution identifiers. Use these as indexes to poll and retrieve the corresponding response flag fields in the DTU status data buffer. Each poll must determine whether the current response field has changed from the initial value of 0 to the response completion status 1, and this status change must be completed within the specified response time limit after the control command is issued. For example, if the response time limit is set to 3 seconds, if no status flag change is received within this period, the control task is marked as unresponsive. Otherwise, continue to read the actual execution channel number information in the feedback field and check it against the expected channel number in the control task. If they match, the channel number is added to the action verification channel list. If they do not match or are empty, the current channel is removed and an exception log is recorded. Based on this, all successfully verified channel numbers are appended to the action verification channel list structure, which will contain the execution channel number, response timestamp, response code status, and comparison status fields to obtain the action verification channel list.

[0036] The trip branch recording submodule calls the action verification channel list to record all channel number information, records the corresponding branch number to the operation execution log table, marks the trip status bit and archives it centrally, and generates a trip channel list; The system reads channel numbers one by one from the action verification channel list and performs a branch number lookup operation for each channel number. It calls the channel number field in the branch mapping data structure for precise matching to extract the feeder number or branch number bound to each channel. After confirming the number, it constructs a log entry. Each record must include the channel number, branch number, operation type field, status flag field, and record time field. The operation type field is set to "tripped", the status flag field is set to "action completed", and the record time field is extracted from the current system timestamp as the local time record. All constructed record entries are written to the operation execution log table. The table must support index field updates and time range retrieval for subsequent statistical analysis. Then, all branch numbers that have successfully completed log writing are extracted again and assembled into a list structure. Each branch number is marked as "tripped" and stored centrally in the trip record archive area. The archive area will be partitioned and saved according to the daily time directory, and finally, a trip channel list is generated.

[0037] Specifically, such as Figure 6 As shown, the closed-loop feedback update module includes: The current surge detection submodule reads the channel numbers of all executed actions in the trip channel list, monitors the current change value in the corresponding channel during the continuous period before and after the trip, compares the difference between the last sample value before the trip and the first sample value after the trip, filters the channel numbers whose difference is greater than the current surge threshold, and obtains the current surge channel set. First, extract the channel numbers in the list order and load their corresponding trip timestamps one by one. Then, call the channel to take current data sequences with a fixed sampling period length before and after the trip time. The first segment of current data extracts continuous data from 1 second before the trip time to the trip time, and the second segment of current data extracts continuous data within 0.5 seconds after the trip. Take the last sampling point of the data segment before the trip as the pre-trip reference value and the first valid sampling point of the data segment after the trip as the post-trip reference value. Calculate the current amplitude difference between the two values. This difference is the current surge amplitude before and after the trip. All channels are processed in this way. After processing, all difference results are filtered according to the set current surge threshold. The current surge threshold is set based on the statistical results of current fluctuation characteristics under normal operating conditions. The normal operating conditions are classified according to feeder load level, operating condition type, and distributed power supply access. The distribution characteristics of current fluctuations are statistically analyzed under different operating conditions, and the historical data within the preset time window are used as the basis for the analysis. The statistical distribution of the fluctuation amplitude of the sampled data is calculated, and the 95th percentile value is selected as the benchmark threshold. The time window length is set according to the system sampling cycle and operational stability requirements, for example, sampling data from 5 to 15 consecutive minutes is used for statistics. At the same time, the current mutation threshold can be dynamically adjusted according to the real-time operating status. When a change in load level or operating mode is detected, the current fluctuation characteristics within the corresponding statistical window are recalculated to update the mutation threshold, thereby ensuring the accuracy and adaptability of the judgment under different operating scenarios. If the operating current of a feeder is ±20A in the pre-trip fluctuation range, the mutation threshold can be set to 40A. If the current of a channel is 132A before the trip and 86A after the trip, the difference is 46A, which is greater than the threshold, and it is judged as a mutation channel. If the current of a channel is 60A before the trip and 55A after the trip, the difference is 5A, which is lower than the threshold, and it is judged as a non-mutation channel. After all channels are judged, the mutation channel numbers are collected and recorded to obtain the current mutation channel set.

[0038] The backup channel comparison submodule calls the channel number in the current change channel set, retrieves the current status of the associated backup channel, detects whether the backup channel has a power-on status upgrade behavior during the period after the trip, records the status change channel number, and generates a set of on / off status change channels. The process of retrieving the current status of the associated backup channels begins by calling the primary and backup channel mapping table for each sudden channel number, retrieving its configured backup channel number, and monitoring its current data during the period after the trip. Specifically, within a time period of 1 to 3 seconds after the tripping time of the primary channel, the current data sequence of the backup channel is read, the initial value and the end value are extracted and compared to determine whether there is a continuous upward trend. If the increase exceeds the power-on status judgment threshold, it is judged as a power-on status upgrade. The threshold setting principle refers to the upper limit of the no-load current fluctuation of the backup channel. For example, the current fluctuation of the backup channel in the no-load state generally does not exceed 2A. If the current of a certain backup channel rises steadily from 2.1A to 28.5A after the tripping, and the current shows an upward trend at multiple consecutive sampling points, it is judged that the power-on behavior is established. If the increase of a certain channel is 1.3A and the duration does not exceed two sampling points, the channel is excluded and the change is not recorded. All backup channel numbers that meet the power-on upgrade judgment are recorded in the status change channel list, and the power-on start time and duration fields are added. Finally, they are summarized into a set of on / off status change channels.

[0039] The diagnosis result generation submodule compares the channel number in the channel set for the on / off state change with the previous tripped channel, filters the channel combination that forms a primary / standby switch and has a sudden change characteristic after the trip, and marks it into the FTU and DTU channel classification structure according to the channel affiliation, and generates embedded diagnosis results for FTU and DTU. The process involves comparing the channel numbers in the on / off state change channel set with the preceding tripped channels. Based on the tripped channel number, the main channel number is read one by one, and a corresponding backup channel number record is retrieved from the on / off state change channel set. If a main-off / backup on relationship exists between the two channels within a time period after the trip, and the time points are adjacent, the combination is determined to be a main-backup switching event. Further verification is then conducted to determine if the main channel in this combination belongs to the current mutation channel set. If so, the main channel is confirmed to have mutation characteristics, and it is bound to the corresponding backup channel as a valid diagnostic pair. This pair structure includes key fields such as main channel number, backup channel number, mutation amplitude, and switching time difference. After pairing, the equipment unit type to which the main channel belongs is determined. If the main channel number prefix is ​​an FTU number segment, it is recorded in the FTU channel classification structure; if it is a DTU number segment, it is recorded in the DTU channel classification structure. An independent index is established in each structure, and the switching type field is labeled. Finally, all combination structures are archived and organized into a structured list, generating embedded diagnostic results for FTU and DTU.

[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A FTU, DTU-embedded distributed fault diagnosis method, characterized in that, Includes the following steps: Embedded terminal acquisition steps: Acquire current and voltage signals from FTU and DTU, extract three-phase current and zero-sequence voltage curves, sample by time period index, identify inflection points of current slope and abrupt changes in voltage slope, mark disturbance periods, and generate a set of disturbance segments; Transient feature identification steps: Based on the set of disturbance fragments, filter continuous slope change points within the channel, arrange the start time of the sudden change according to the channel number, align the current and voltage slope change positions, select the time difference channel group, and generate a linkage control group; Linkage judgment and control steps: Based on the linkage control group, extract the channel trigger feedback time, compare the response interval, verify the response channel, call the corresponding phase, match the feeder number in the ring network cabinet diagram, and establish the branch mapping number; Fault isolation execution steps: Based on the branch mapping number, send control commands to the pole-mounted switch through the DTU communication port, read the action feedback, and generate a trip channel list; Closed-loop feedback update steps: Read the trip channel list, monitor the sudden changes in current before and after, identify the fault channel, compare the power-on status of the backup channel, filter and match the fault characteristic channel, and generate embedded diagnostic results for FTU and DTU.

2. The FTU, DTU-embedded distributed fault diagnosis method according to claim 1, characterized in that: The disturbance segment set includes three-phase current slope change segments, zero-sequence voltage slope abrupt change segments, disturbance location marker index, and continuous sampling period number. The linkage control group includes linkage channel number, abrupt change time point sequence, current and voltage channel pairing relationship, and minimum time interval identifier. The branch mapping number includes the phase to which the channel belongs, branch number, feeder channel mapping relationship, and ring main unit channel number. The trip channel list includes trip channel number, action execution marker, response feedback status, and target branch record item. The FTU and DTU embedded diagnostic results include channel current change identifier, fault channel number, standby channel status change, and fault feature matching results.

3. The FTU, DTU-embedded distributed fault diagnosis method according to claim 1, characterized in that: The inflection point of the current slope and the abrupt change point of the voltage slope refer to the characteristic points where the slope of the current and voltage signals changes direction and abruptly over time, which verify the timing and nature of the disturbance.

4. The FTU, DTU-embedded distributed fault diagnosis method according to claim 1, characterized in that: The term "phase" refers to the phase in the power system monitored and controlled by the channel and equipment, including phase A, phase B, and phase C, which identifies the affiliation of phase current and phase voltage.

5. An FTU, DTU-embedded distributed fault diagnosis terminal, characterized in that, The method for implementing the FTU / DTU embedded distributed fault diagnosis method according to any one of claims 1 to 4 includes: An embedded terminal acquisition module is used to implement the embedded terminal acquisition steps; The transient feature recognition module is used to implement the transient feature recognition steps; The linkage judgment and control module is used to implement the linkage judgment and control steps; The fault isolation execution module is used to implement the fault isolation execution steps; The closed-loop feedback update module is used to implement the closed-loop feedback update steps.

6. The FTU, DTU-embedded distributed fault diagnosis terminal according to claim 5, characterized in that, The embedded terminal acquisition module includes: The data stream receiving submodule acquires the current and voltage input signals of the feeder terminal unit (FTU) and the switch station terminal unit (DTU), samples the three-phase current and zero-sequence voltage, and generates a continuous sampling timing sequence in time order. The power change detection submodule calls the continuous sampling time sequence to extract current and voltage data, calculates the slope of the current change rate and identifies the inflection point, calculates the slope of the zero-sequence voltage and identifies the abrupt change point, and generates a set of current inflection points and voltage abrupt change points. The disturbance segment construction submodule identifies the time period of disturbance occurrence based on the combination of marked positions in the set of current inflection points and voltage change points, extracts continuous disturbance segments and combines them into blocks to obtain a set of disturbance segments.

7. The FTU, DTU-embedded distributed fault diagnosis terminal according to claim 5, characterized in that, The transient feature recognition module includes: The slope change direction screening submodule, based on the set of disturbance fragments, judges the change in slope sign of sampling points in the channel, filters the position sequence of continuous slope change, classifies and summarizes it according to channel number, and generates channel slope change direction sequence group. The starting point time arrangement submodule calls the channel starting point time in the channel slope change sequence group, arranges the first change point of the differentiated channel in numerical order, calculates the time difference, and establishes the channel starting time sequence. The linkage channel determination submodule matches the current and voltage channel reversal times based on the channel start time sequence, calculates the time interval between channels, filters the minimum interval combination, and obtains the linkage control group.

8. The FTU, DTU-embedded distributed fault diagnosis terminal according to claim 5, characterized in that, The linkage judgment and control module includes: The feedback time extraction submodule extracts the feedback time marker after the channel is triggered based on the linkage control group, calculates the difference between the trigger and feedback time of the channel, compares the response interval values ​​of all channels, obtains the shortest response channel number, and generates a response channel identifier. The phase-channel matching submodule calls the channel information corresponding to the response channel identifier, reads the phase markers contained in the channel, establishes a channel-phase mapping by comparing the channel number with the corresponding phase relationship table, and obtains the channel matching result; Based on the channel matching results, the branch number mapping submodule compares the channel number map of the ring main unit, extracts the feeder number to which the channel belongs, and establishes a binding relationship with the original channel number to obtain the branch mapping number. 9.The FTU, DTU-embedded distributed fault diagnosis terminal of claim 5, wherein, The fault isolation execution module includes: The control command issuing submodule, based on the branch mapping number, calls the communication port address of the embedded diagnostic in the DTU where the corresponding branch is located, writes the switch control command to the pole-mounted switch action interface and starts the execution status flag, and establishes the control channel execution identifier; The action response reading submodule detects the action response data returned by the feedback channel based on the control channel execution identifier, reads the response flag field and identifies the channel number of the executed instruction, and obtains the action verification channel list. The trip branch recording submodule calls all channel number information in the action verification channel list, records the corresponding branch number to the operation execution log table, marks the trip status bit and archives it centrally, and generates a trip channel list.

10. The FTU, DTU-embedded distributed fault diagnosis terminal according to claim 5, characterized in that, The closed-loop feedback update module includes: The current mutation detection submodule reads the channel numbers of all executed actions in the trip channel list, monitors the current change value in the corresponding channel during the continuous period before and after the trip, compares the difference between the last sample value before the trip and the first sample value after the trip, filters the channel numbers whose difference is greater than the current mutation threshold, and obtains the current mutation channel set; the current mutation threshold refers to the minimum current difference standard for judging whether the channel current has changed before and after the trip. The backup channel comparison submodule calls the channel number in the current change channel set, retrieves the current status of the associated backup channel, detects whether the backup channel has a power-on status improvement behavior during the period after the trip, records the status change channel number, and generates a set of on / off status change channels. The diagnostic result generation submodule compares the channel number in the channel set of the on / off state change channel with the previous tripped channel, selects the channel combination that forms a primary / standby switch and has a sudden change characteristic after the trip, and marks it into the FTU and DTU channel classification structure according to the channel affiliation, and generates embedded diagnostic results for FTU and DTU.

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