A method and system for detecting partial discharge period of ring main unit

Abstract

The application relates to the technical field of discharge detection, in particular to a ring main unit local discharge period detection method and system. The method comprises the following steps: establishing a double-track reciprocating inspection coordinate chain along a ring main unit cabinet row, binding cabinet number, track number, inspection direction, detection point number, detection point reference coordinate and probe reference posture into a period detection reference event; controlling the inspection equipment to move along the double-track reciprocating inspection coordinate chain, collecting a local discharge detection signal when the inspection equipment reaches the corresponding detection point, constructing a pulse record set, and forming a locking sampling event with the cabinet number, the inspection direction, the detection point number and the sampling time. The application extracts pulse amplitude, pulse density and phase concentration features based on continuous closed period data, constructs a discharge evolution data chain, and combines a cross-cabinet response mark to distinguish the abnormality of the cabinet and the synchronous response of the adjacent cabinet, so that the stability, comparability and early warning accuracy of the ring main unit local discharge period detection are improved.

Description

Technical Field

[0001] This application relates to the field of discharge detection technology, specifically a method and system for detecting the partial discharge cycle of a ring main unit. Background Technology

[0002] Ring main units (RMNs) are commonly used switching devices in power distribution systems. They typically integrate busbar connections, switch contacts, cable terminals, and insulating partitions. During long-term operation, factors such as insulation aging, moisture absorption, poor contact, partial discharge, contaminant buildup inside the cabinet, and fluctuations in operating load can cause partial discharge within the RMN. In its early stages, partial discharge often manifests as weak, short-duration pulse signals with unstable locations. If its periodic trends are not identified in time, it can easily develop into insulation breakdown, phase-to-phase short circuits, or equipment shutdown.

[0003] Existing methods for detecting partial discharge in ring main units typically include manual inspection, fixed-point detection, online sensor monitoring, or mobile detection by inspection equipment. Manual inspection relies on the experience of the inspectors, and it is difficult to maintain consistent inspection intervals and locations. While fixed-point detection can continuously collect local signals, its coverage is limited and it is difficult to take into account the status of multiple cabinets and multiple detection points in an entire ring main unit.

[0004] While mobile inspection can expand the detection range, differences in arrival order, sampling direction, point mapping relationship, and sampling integrity may exist during reciprocating inspections. This makes it difficult to directly compare detection data for the same cabinet location across different inspection cycles. Furthermore, ring main units are typically arranged in rows, with electrical, mechanical, and spatial connections between adjacent cabinets. When a partial discharge intensifies in one cabinet location, synchronous pulse responses may also appear in the detection signals of adjacent cabinet locations. If judgment is based solely on the pulse amplitude or number of pulses from a single sample, cross-cabinet responses can easily be misinterpreted as independent discharge anomalies within the cabinet itself. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a method for detecting the periodic partial discharge of a ring main unit.

[0006] This application adopts the following technical solution: a method for periodic detection of partial discharge in a ring main unit, comprising:

[0007] Establish a double-track reciprocating inspection coordinate chain along the ring network cabinet row, and bind the cabinet position number, trajectory number, inspection direction, detection point number, detection point reference coordinates and probe reference attitude as periodic detection reference events;

[0008] Based on the periodic detection benchmark event, the inspection equipment is controlled to move along the double-track reciprocating inspection coordinate chain. When the inspection equipment reaches the corresponding detection point, the partial discharge detection signal is collected, a pulse record set is constructed, and a locked sampling event with cabinet number, inspection direction, detection point number and sampling time is formed.

[0009] Based on the locked sampling event, forward inspection data and reverse inspection data are uniformly mapped to the same cabinet position detection sequence to obtain a direction-normalized periodic detection sequence.

[0010] The periodic detection sequence based on direction normalization is compared item by item with the standard detection point list. Periods that have not completed the locking and sampling of all standard detection points are marked as non-closed period records, thus obtaining closed periodic detection sequences.

[0011] Based on the closed-cycle detection sequence, the pulse amplitude, pulse density and phase concentration characteristics of the same cabinet position in a continuous cycle are extracted, and a discharge evolution data chain is constructed according to the sampling time sequence.

[0012] Based on the discharge evolution data chain, cross-cabinet response flags are identified, and these flags are written into the single-cycle discharge status data of the corresponding inspection cycle. Based on the written single-cycle discharge status data, a cabinet position discharge risk trajectory is formed. According to the cabinet position discharge risk trajectory, a corresponding detection result is generated.

[0013] As a further description of the above technical solution: the method for obtaining the reference coordinates of the detection point includes:

[0014] Using the projection point of the center reference point of the first cabinet of the ring main unit on the cabinet installation reference surface as the origin, a three-dimensional inspection coordinate system is established. The X-axis is set along the arrangement direction of the ring main unit, the Y-axis is set along the direction perpendicular to the cabinet inspection surface, and the Z-axis is set along the height direction perpendicular to the cabinet installation reference surface.

[0015] During the on-site calibration phase, the first... The left and right boundary coordinates of the first ring main unit are determined, and the first ring main unit is determined based on the left and right boundary coordinates. The center coordinates and width of each ring network cabinet;

[0016] According to the The cabinet boundary coordinates and preset detection points of the first ring main unit are used to determine the first... The detection point number and reference coordinates of each ring main unit.

[0017] As a further description of the above technical solution: the method for constructing the pulse recording set includes:

[0018] When the inspection equipment reaches the first The p-th detection point of a ring main unit is located on the reference coordinates of the detection point on the r-th inspection trajectory, and the pose lock event is triggered when the detection probe is adjusted to the probe reference posture.

[0019] After the pose lock event is triggered, the inspection equipment remains in a stationary locked state for the duration corresponding to the start time of the lock sampling. The time interval within is used as the locking sampling window, and the sampling frequency is used accordingly. Collection duration Partial discharge detection signal within;

[0020] A preset pulse recognition threshold is set. When the amplitude of a certain peak in the local discharge detection signal is greater than the pulse recognition threshold, and the pulse width corresponding to the peak is within the allowable width range of the partial discharge pulse, the corresponding peak is marked as a valid partial discharge pulse. The pulse occurrence time, pulse amplitude, pulse width and corresponding power frequency phase are recorded to generate a pulse record set.

[0021] As a further description of the above technical solution: the method for obtaining the direction-normalized periodic detection sequence includes:

[0022] When there are locking sampling events formed by forward inspection and locking sampling events formed by reverse inspection within the same inspection cycle k, and the two correspond to the same cabinet number, the same trajectory number, the same detection point number and the same detection point reference coordinates, the two are determined as the corresponding sampling data formed by the same physical detection point under different inspection directions, and are uniformly mapped to the same coordinate normalized sampling position.

[0023] When both forward and reverse inspection sampling data exist at the same coordinate normalized sampling position, the locking sampling event with pose locking event, partial discharge detection signal and pulse record set is selected as the direction normalized sampling event. When both meet the requirements, the forward inspection sampling data is selected as the direction normalized sampling event.

[0024] All directional sampling events generated under the same cabinet number within the same inspection cycle are sorted according to trajectory number and detection point number to obtain the first... The direction-normalized cycle detection sequence of the ring main unit in the kth inspection cycle.

[0025] As a further description of the above technical solution: the method for obtaining the direction-normalized periodic detection sequence further includes:

[0026] When there is only one locked sampling event in the same coordinate normalized sampling position for a single inspection direction, and the corresponding locked sampling event has a pose locking event, a partial discharge detection signal, and a pulse record set, the corresponding locked sampling event is taken as the direction normalized sampling event. When the conditions are not met, the sampling status is marked as missing.

[0027] As a further description of the above technical solution: the method for obtaining the closed-cycle detection sequence includes:

[0028] Read the first The direction-normalized cycle detection sequence of the ring main unit in the kth inspection cycle. and by cabinet number For indexing, retrieve the cabinet number from the periodic detection baseline event table. The corresponding total trajectory number r and detection point number p form the first... List of standard testing points corresponding to each ring main unit;

[0029] Direction-normalized periodic detection sequence The directional normalization sampling events in the data are compared item by item with the standard detection point list to determine the first... Whether the ring main unit has completed the locking and sampling of all standard test points and generated a closed-cycle test sequence or a non-closed-cycle record within the kth inspection cycle;

[0030] Multiple closed-cycle detection sequences that have been formed under the same cabinet position number are sorted in ascending order according to the inspection cycle number k to obtain the cabinet position closed-cycle sequence.

[0031] As a further description of the above technical solution: a method for detecting the partial discharge cycle of a ring main unit also includes:

[0032] When a non-closed periodic record is generated, a missing point record is generated for that non-closed periodic record; the missing point record includes the cabinet number. Inspection cycle number k, missing trajectory number r, missing detection point number p, and missing reason identifier;

[0033] The missing location records are used to generate a supplementary sampling instruction for the next inspection cycle.

[0034] As a further description of the above technical solution: the method for constructing the discharge evolution data chain includes:

[0035] Read the cabinet position closed cycle sequence The k-th closed-cycle detection sequence The corresponding complete pulse recording set , obtain the The pulse amplitude of the ring main unit in the kth inspection cycle Pulse density and phase concentration characteristics;

[0036] Preset pulse amplitude anomaly threshold, pulse density anomaly threshold, and phase concentration anomaly threshold, and compare them with the obtained first... The pulse amplitude, pulse density, and phase concentration characteristics of each ring main unit in the kth inspection cycle are compared to obtain a single-cycle anomaly flag group; the single-cycle anomaly flag group includes pulse amplitude anomaly flag, pulse density anomaly flag, and phase concentration anomaly flag;

[0037] The first The pulse amplitude, pulse density, phase concentration characteristics, single-cycle anomaly flag group, and single-cycle discharge status corresponding to the kth inspection cycle of each ring main unit are encapsulated to form single-cycle discharge status data. ;

[0038] Number the same cabinet Single-cycle discharge state data generated during the next continuous inspection cycle The discharge evolution data chain is obtained by arranging the inspection cycle numbers k in ascending order.

[0039] As a further description of the above technical solution: the method for obtaining the single-cycle anomaly flag group includes:

[0040] when At that time, the pulse amplitude abnormality flag will be displayed. Set to 1 otherwise set to 0;

[0041] when At that time, the pulse density abnormality flag will be displayed. Set to 1 otherwise set to 0;

[0042] when At that time, the phase concentration anomaly marker will be displayed. Set to 1 otherwise set to 0;

[0043] in, This is the threshold for abnormal pulse amplitude. The threshold for abnormal pulse density; This is the threshold for phase concentration anomalies. , and These are pulse amplitude, pulse density, and phase concentration characteristics, respectively.

[0044] As a further description of the above technical solution: the method for obtaining the single-cycle discharge state includes:

[0045] When the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag are all 0, the single-cycle discharge state is marked as normal.

[0046] When only one of the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag is 1, the single-cycle discharge state is marked as a single-characteristic abnormal state.

[0047] When two or more of the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag are 1, the single-cycle discharge state is marked as a multi-feature abnormal state.

[0048] As a further description of the above technical solution: the method for forming the cabinet discharge risk trajectory includes:

[0049] Read the first Discharge evolution data link of each ring network cabinet and adjacent cabinets -1 and +1 Discharge evolution data chain within the same inspection cycle;

[0050] When the Each ring network cabinet and adjacent cabinets When the single-cycle discharge states within the same inspection cycle k are all single-characteristic abnormal states or multi-characteristic abnormal states, read the first... Each ring network cabinet and adjacent cabinets The pulse record set within the corresponding inspection cycle is used to calculate the cross-cabinet correlation coefficient based on the pulse count sequence within the same sampling period;

[0051] When the Each ring network cabinet and adjacent cabinets If all abnormal states within the same inspection cycle k are single-feature or multi-feature abnormal states, and the cross-cabinet correlation coefficient is not less than the cross-cabinet correlation threshold, then the first... The cross-cabinet response flag of each ring main unit is set to 1 during the kth inspection cycle; otherwise, the cross-cabinet response flag is... Set to 0;

[0052] The cross-cabinet response flag is written into the single-cycle discharge status data to form a cabinet discharge risk trajectory.

[0053] As a further description of the above technical solution: the detection results include partial discharge early warning results, key re-inspection results, and normal detection results.

[0054] A partial discharge cycle detection system for a ring main unit, used to implement the aforementioned method for partial discharge cycle detection of a ring main unit, the system comprising:

[0055] The reference event construction module establishes a double-track reciprocating inspection coordinate chain along the ring network cabinet column, and binds the cabinet position number, trajectory number, inspection direction, detection point number, detection point reference coordinates and probe reference attitude as periodic detection reference events;

[0056] The sampling event locking module, based on the periodic detection reference event, controls the inspection equipment to move along the double-track reciprocating inspection coordinate chain. When the inspection equipment reaches the corresponding detection point, it collects the partial discharge detection signal, constructs a pulse record set, and forms a locked sampling event with cabinet number, inspection direction, detection point number and sampling time.

[0057] The sequence construction module, based on the locked sampling event, maps forward and reverse inspection data to the same cabinet position detection sequence to obtain a direction-normalized periodic detection sequence. Based on the direction-normalized periodic detection sequence, it compares each item with the standard detection point list and marks the period that has not completed the locked sampling of all standard detection points as a non-closed period record to obtain a closed period detection sequence.

[0058] The event chain construction module extracts the pulse amplitude, pulse density, and phase concentration characteristics of the same cabinet position within a continuous period based on the closed-cycle detection sequence, and constructs a discharge evolution data chain according to the order of sampling time.

[0059] The result generation module identifies cross-cabinet response flags based on the discharge evolution data chain, writes the cross-cabinet response flags into the single-cycle discharge status data of the corresponding inspection cycle, and forms a cabinet position discharge risk trajectory based on the written single-cycle discharge status data; and generates corresponding detection results based on the cabinet position discharge risk trajectory.

[0060] The beneficial effects of this application are as follows:

[0061] This application constructs a dual-track reciprocating inspection coordinate chain and periodic detection benchmark events, ensuring that each cabinet and each detection point has a unified spatial positioning benchmark, sampling event benchmark, and period comparison benchmark in different inspection cycles. By normalizing the direction of forward and reverse inspection data and removing cycles in which standard detection point sampling is not completed as non-closed cycle records, it ensures that the data sources for subsequent analysis are consistent, the points are complete, and the cycles are comparable. Furthermore, based on continuous closed cycle data, pulse amplitude, pulse density, and phase concentration characteristics are extracted to construct a discharge evolution data chain, and cross-cabinet response indicators are combined to distinguish between abnormalities in this cabinet and synchronous responses in adjacent cabinets, thereby improving the stability, comparability, and early warning accuracy of partial discharge cycle detection in ring network cabinets. Attached Figure Description

[0062] The present application will be further explained below with reference to the accompanying drawings and embodiments:

[0063] Figure 1 A flowchart of a method for detecting the partial discharge cycle of a ring main unit provided in Embodiment 1 of this application;

[0064] Figure 2 A flowchart illustrating the method for obtaining the reference coordinates of the detection point provided in Embodiment 1 of this application;

[0065] Figure 3 This is a flowchart of a method for constructing a pulse recording set provided in Embodiment 1 of this application;

[0066] Figure 4 This is a module connection diagram of a ring main unit partial discharge cycle detection system provided in Embodiment 2 of this application. Detailed Implementation

[0067] To make the technical means, inventive features, objectives, and effects of this application easier to understand, the application is further described below with reference to specific illustrations. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0068] Example 1:

[0069] Please see Figures 1-3 This application provides a technical solution: a method for periodic detection of partial discharge in a ring main unit, based on dual-track automatic reciprocating inspection, the method comprising:

[0070] S1: Establish a double-track reciprocating inspection coordinate chain along the ring main unit row, binding the unit position number, trajectory number, inspection direction, detection point number, detection point reference coordinates, and probe reference attitude as periodic detection reference events, so that each ring main unit has a unified spatial reference and event reference in different inspection cycles; in some implementation methods, the implementation steps include:

[0071] S101. Establish a three-dimensional inspection coordinate system with the projection point of the center reference point of the first cabinet of the ring network cabinet row onto the cabinet installation reference surface as the origin; wherein, the X-axis is set along the arrangement direction of the ring network cabinet row, and the direction from the first cabinet to the last cabinet is taken as the positive direction; the Y-axis is set along the direction perpendicular to the cabinet inspection surface, and the direction from the cabinet inspection surface to the first inspection trajectory is taken as the positive direction; the Z-axis is set along the height direction perpendicular to the cabinet installation reference surface, and the vertically upward direction is taken as the positive direction.

[0072] S102. During the on-site calibration phase, obtain the first... left boundary coordinates of the ring main unit and right boundary coordinates And based on the coordinates of the left boundary and right boundary coordinates Determine the first The center coordinates of each ring network cabinet Cabinet width .

[0073] Specifically, the center coordinates of the cabinet Cabinet width The calculation formula is:

[0074] ;

[0075] ;

[0076] in, Indicates the sequential number of the ring main unit in the cabinet row; Indicates the first The coordinates of the left boundary of the ring main unit in the X-axis direction; Indicates the first The coordinates of the right boundary of the ring main unit in the X-axis direction; Indicates the first The center coordinates of each ring main unit along the X-axis; Indicates the first The width of the ring network cabinet.

[0077] It should be noted that the coordinates of the left boundary and right boundary coordinates Dimensions are obtained through cabinet installation drawings, cabinet nameplate dimensions, or on-site calibration measurements. When using inspection equipment for on-site calibration, the equipment is controlled to move slowly along the X-axis. Laser rangefinders or track encoders are used to identify abrupt changes in cabinet side edges, door edges, or inter-cabinet gaps. The identified first... The boundary of the ring network cabinet is used as the coordinate of the left boundary. The first one identified The outer boundary of the ring network cabinet is used as the coordinate of the right boundary. .

[0078] S103. Establish a first inspection trajectory and a second inspection trajectory on both sides of the ring network cabinet row, respectively. The first inspection trajectory has a fixed horizontal coordinate. The second inspection trajectory has a fixed horizontal coordinate. .

[0079] Both the first and second inspection trajectories extend along the X-axis and are associated with the three-dimensional inspection coordinate system.

[0080] S104, according to the... The cabinet boundary coordinates and preset detection points of the first ring main unit are used to determine the first... The detection point number and reference coordinates of each ring main unit.

[0081] Specifically, the preset detection points include detection point number p and detection height. The relative position of the detection points along the width of the cabinet. Applicable trajectory number r and probe reference attitude Where p represents the detection point number, r represents the trajectory number, r=1 represents the first inspection trajectory, and r=2 represents the second inspection trajectory. This represents the relative position ratio of the p-th detection point along the width of the cabinet.

[0082] It should be noted that the detection point refers to the standard detection position where the inspection equipment performs posture locking and collects partial discharge detection signals in front of the ring main unit. The detection point is not randomly generated, but is determined during the on-site calibration stage based on the cabinet boundary position of the ring main unit, the functional areas inside the cabinet that are prone to partial discharge, the effective detection distance of the detection probe, and the inspection trajectory position.

[0083] No. The coordinates of the p-th detection point of a ring main unit in the X-axis direction Determine according to the following formula:

[0084] ;

[0085] No. The reference coordinates of the p-th detection point of the ring main unit on the r-th inspection trajectory are: ; ,in Indicates the first The reference coordinates of the p-th detection point of the ring main unit on the r-th inspection trajectory; This indicates the coordinates of the detection point along the X-axis. This represents the horizontal coordinate of the r-th inspection trajectory along the Y-axis. This represents the detection height of the p-th detection point along the Z-axis.

[0086] According to the arrival order of the inspection equipment, the reference coordinates of the detection points arranged sequentially along the X-axis on the same inspection trajectory are connected in series to form a single-track inspection coordinate chain, and the reversal connection relationship between the first inspection trajectory and the second inspection trajectory at the end of the cabinet column is used to form a double-track reciprocating inspection coordinate chain.

[0087] S105. Number the cabinet. Track number r, inspection direction d, detection point number p, detection point reference coordinates and probe reference posture Binding as a periodic detection baseline event Where d represents the inspection direction, d=+1 indicates inspection along the positive X-axis, and d=-1 indicates inspection along the negative X-axis. The periodic detection reference event... This serves as a unified event benchmark for subsequent inspection positioning, pose locking, sampling mapping, direction normalization, and periodic comparison.

[0088] In this embodiment, a double-track reciprocating inspection coordinate chain is established along the ring network cabinet column, and the cabinet position number, trajectory number, inspection direction, detection point number, detection point reference coordinates and probe reference attitude are bound as periodic detection reference events. This enables the inspection equipment to reach the same detection point according to a unified spatial reference and event reference in different inspection cycles, thereby improving the comparability between partial discharge detection data in different cycles.

[0089] S2: Based on the periodic detection reference event, the inspection equipment is controlled to move along the double-track reciprocating inspection coordinate chain. When the inspection equipment reaches the corresponding detection point, a partial discharge detection signal is collected, a pulse record set is constructed, and a locked sampling event with cabinet number, inspection direction, detection point number, and sampling time is formed; in some implementations, the implementation steps include:

[0090] S201. The inspection equipment moves along the double-track reciprocating inspection coordinate chain during the kth inspection cycle, where k represents the inspection cycle number; the inspection equipment detects the baseline event according to the cycle. Reference coordinates of the detection points and probe reference posture Execution and control are in place.

[0091] One inspection cycle refers to the complete reciprocating inspection process in which the inspection equipment starts from the first end of the cabinet, sequentially completes the sampling of all standard detection points on the first and second inspection tracks, and returns to the start of the cycle or reaches the preset end position of the cycle.

[0092] S202, When the inspection equipment reaches the... The reference coordinates of the p-th detection point of the ring main unit on the r-th inspection trajectory. And the detection probe is adjusted to the probe reference posture. When the pose lock event is triggered. .

[0093] S203, Pose Locking Event Upon triggering, the inspection equipment remains in a stationary locked state for the duration following the start time of the locked sampling. The time interval within is used as the locking sampling window, and the sampling frequency is used accordingly. Collection duration Partial discharge detection signal inside .

[0094] in, This indicates the sampling frequency of the partial discharge detection signal. This indicates the duration of a single lock sampling, which is manually set and can optionally range from 3s to 5s, where n represents the signal sampling point number. Indicates the number of inspections within the k-th inspection cycle. The partial discharge detection signal is collected at the p-th detection point of the ring main unit under the r-th inspection trajectory and inspection direction d.

[0095] S204, Preset pulse recognition threshold, local discharge detection signal When the amplitude of a certain peak value exceeds the pulse identification threshold, and the pulse width corresponding to that peak value is within the allowable width range of partial discharge pulses, the peak value is marked as a valid partial discharge pulse. The pulse occurrence time, pulse amplitude, pulse width, and corresponding power frequency phase are recorded to generate a pulse record set. .

[0096] If the peak amplitude is not greater than the pulse identification threshold, or if the pulse width corresponding to the peak is not within the allowable width range of a partial discharge pulse, the peak will not be marked as a valid partial discharge pulse and will not be written into the pulse record set. .

[0097] It should be noted that the method for obtaining the pulse recognition threshold includes: dividing the locked sampling window into multiple candidate segments of equal length in chronological order; calculating the peak-to-peak value of each candidate segment; selecting candidate segments that are ranked from smallest to largest and fall within a predetermined proportion; merging the selected candidate segments as a noise reference segment; calculating the noise mean and noise standard deviation based on all sampling points within the noise reference segment; and using the sum of the noise mean and three times the noise standard deviation as the pulse recognition threshold. The predetermined proportion is determined based on the number of noise reference segments being no less than one-third of the total number of candidate segments.

[0098] The allowable width range of the partial discharge pulse is determined by the effective pulse width range in the sensor's technical parameters and corrected by combining historically confirmed effective partial discharge pulse width samples; specifically, the intersection of the sensor's allowable range and the historical effective pulse width range from the 5th percentile to the 95th percentile is taken as the allowable width range.

[0099] S205. Number the cabinet. Trajectory number r, inspection direction d, detection point number p, inspection cycle number k, sampling time, pose lock event Partial discharge detection signal and pulse recording set Encapsulated as a locked sampling event .

[0100] It should be noted that one lock sampling event corresponds to one lock sampling at a detection point in one inspection direction.

[0101] A directional normalized sampling event corresponds to the sampling result of the same detection point after directional normalization within one inspection cycle.

[0102] A closed-loop detection sequence consists of directional normalized sampling events of all standard detection points in the same cabinet within one inspection cycle.

[0103] In this embodiment, after the inspection equipment reaches the detection point, it triggers pose locking and collects partial discharge detection signals within the locked sampling window. Furthermore, a pulse record set is constructed based on the pulse recognition threshold and pulse width range, ensuring that the sampled data simultaneously includes cabinet number, trajectory number, inspection direction, detection point number, sampling time, and pulse characteristic information. This guarantees that each set of partial discharge detection data has a clear data source and spatial attribution, providing a complete data foundation for subsequent periodic normalization, closure judgment, and trend analysis.

[0104] S3: Based on the locked sampling event, forward and reverse inspection data are uniformly mapped to the same cabinet position detection sequence to obtain a direction-normalized periodic detection sequence; in some implementation methods, the implementation steps include:

[0105] S301, For any locked sampling event Read its corresponding cabinet number Track number r, detection point number p, and reference coordinates of the detection point and periodically detect benchmark events. Search for cabinets with the same location number. Same trajectory number r, same detection point number p, and same detection point reference coordinates When a corresponding benchmark record is found, it is determined that the locking sampling event belongs to the first... For each ring main unit, valid sampling data at the p-th detection point on the r-th inspection trajectory is retained as the locking sampling event; otherwise, it is marked as invalid sampling data and the locking sampling event is not retained.

[0106] S302. When a lock sampling event formed by a positive inspection exists within the same inspection cycle k, Locked sampling events formed by reverse inspection And the two correspond to the same cabinet number. Same trajectory number r, same detection point number p, and same detection point reference coordinates At that time, the two are identified as the corresponding sampling data formed by the same physical detection point under different inspection directions, and they are uniformly mapped to the same coordinate normalized sampling position.

[0107] S303. When both forward and reverse inspection sampling data exist at the same coordinate normalized sampling position, the locking sampling event with pose locking event, partial discharge detection signal, and pulse record set is preferentially selected as the direction normalization sampling event. When both requirements are met, the forward inspection sampling data is selected as the direction-normalized sampling event. .

[0108] S304. When there is only one locked sampling event in the same coordinate normalized sampling position for a single inspection direction, and this locked sampling event includes a pose locking event, a partial discharge detection signal, and a pulse recording set, the locked sampling event shall be regarded as a direction normalized sampling event. When the conditions are not met, the sampling status is marked as sampling missing. When no valid partial discharge pulse is identified within the locked sampling window, a pulse record set containing an empty set identifier is generated. The pulse record set containing the empty set identifier is still used as a complete pulse record set to participate in direction normalization and closure period determination.

[0109] S305. Number the same cabinet within the same inspection cycle k. All directions of the sampled event formed below Sort by trajectory number r and detection point number p to obtain the first... The direction-normalized cycle detection sequence of the ring main unit in the kth inspection cycle. The direction-normalized periodic detection sequence Used to indicate the first The set of test data of a ring main unit after removing differences in inspection direction during the kth inspection cycle.

[0110] In this embodiment, based on the locked sampling event, the forward and reverse inspection data are uniformly mapped to the same coordinate unified sampling position according to the cabinet number, trajectory number, detection point number, and detection point reference coordinate. This can eliminate the data differences caused by the different forward and reverse sampling sequences in the dual-track reciprocating inspection. At the same time, by comparing each item with the standard detection point list, it is determined whether the same cabinet has completed sampling of all standard detection points in a single inspection cycle. The cycle in which sampling is not completed is recorded as a non-closed cycle, so that the data entering the discharge evolution analysis all come from the complete closed cycle, reducing the risk of misjudgment caused by missed or missing sampling.

[0111] S4: Based on the direction-normalized periodic detection sequence, each item in the standard detection point list is compared. Periods that have not completed the locking and sampling of all standard detection points are marked as non-closed periodic records, thus obtaining a closed periodic detection sequence; in some implementations, the implementation steps include:

[0112] S401, Read the... The direction-normalized cycle detection sequence of the ring main unit in the kth inspection cycle. and by cabinet number For indexing, retrieve the cabinet number from the periodic detection baseline event table. The corresponding total trajectory number r and detection point number p form the first... List of standard testing points corresponding to each ring main unit.

[0113] The standard testing point list is used to represent the first... Each ring network cabinet should complete the locking and sampling of all standard testing points within one inspection cycle.

[0114] S402, Normalize the direction of the periodic detection sequence Directional normalization sampling events in Compare each item with the standard testing point list to determine the first item. Has the ring main unit completed the locking and sampling of all standard test points and generated a closed-loop test sequence within the kth inspection cycle? Or non-closed periodic records .

[0115] Generate closed-cycle detection sequence Or non-closed periodic records The methods include:

[0116] When each trajectory number r and detection point number p in the standard detection point list has a corresponding direction normalization sampling event. At that time, the judgment of the first Each ring main unit completes a closed detection cycle within the kth inspection cycle and normalizes the corresponding direction into a cycle detection sequence. Determined as a closed-cycle detection sequence .

[0117] When any trajectory number r or detection point number p in the standard detection point list does not form a corresponding directional normalized sampling event. At that time, the judgment of the first If a ring main unit fails to complete a closed detection cycle within the kth inspection cycle, the corresponding direction will be normalized to a cycle detection sequence. Marked as a non-closed periodic record .

[0118] S403, When generating a non-closed periodic record For non-closed periodic records Generate a record of missing locations; the record of missing locations includes the cabinet number. The inspection cycle number k, the missing trajectory number r, the missing detection point number p, and the missing reason identifier are specified.

[0119] The non-closed periodic record It is only used for supplementary sampling and verification, and is not used as input data for subsequent discharge evolution data chains.

[0120] Based on the missing point records, a supplementary sampling instruction is generated for the next inspection cycle; the supplementary sampling instruction is used to enable the inspection equipment to prioritize reaching the reference coordinates of the detection point corresponding to the missing trajectory number r and the missing detection point number p in the next inspection cycle. Then, the pose locking and partial discharge detection signal acquisition are re-executed.

[0121] S404. Number the same cabinet location Multiple closed-cycle detection sequences have already been formed. Sort the cabinet locations by inspection cycle number k in ascending order to obtain the cabinet location closed cycle sequence, which is represented as: This serves as input data for the subsequent construction of the discharge evolution data chain.

[0122] In this embodiment, the pulse amplitude, pulse density and phase concentration features of the same cabinet position in a continuous inspection cycle are extracted based on the closed-cycle detection sequence. The partial discharge change state is characterized by the single-cycle abnormal flag group and the single-cycle discharge state data. This can avoid the problem of parallel event conflict when multiple abnormal features appear at the same time, and make the discharge state expression in a single inspection cycle more unified and clear.

[0123] S5: Based on the closed-cycle detection sequence, extract the pulse amplitude, pulse density, and phase concentration characteristics of the same cabinet location within a continuous cycle, and construct a discharge evolution data chain according to the sampling time sequence. This discharge evolution data chain is used to characterize the continuous process of partial discharge in the same cabinet location evolving from a weak anomaly to a high-risk state. In some implementation methods, the steps include:

[0124] S501, Read the cabinet position closed cycle sequence The k-th closed-cycle detection sequence The corresponding complete pulse recording set , obtain the The pulse amplitude of the ring main unit in the kth inspection cycle Pulse density and phase concentration characteristics; when the first When there is no effective partial discharge pulse in the kth inspection cycle of a ring main unit, the pulse amplitude, pulse density and phase concentration characteristics are all set to zero.

[0125] Specifically, pulse amplitude By the The 95th percentile of the amplitude of all effective partial discharge pulses within the kth inspection cycle of a ring main unit is determined as follows: ;in, Indicates the pulse amplitude; Indicates the first The amplitude of the i-th effective partial discharge pulse within the k-th inspection cycle of a ring main unit; This represents the 95th percentile value of all effective partial discharge pulse amplitudes.

[0126] Pulse density It is determined according to the ratio of the number of effective partial discharge pulses to the total effective sampling time of the closed-cycle detection sequence; specifically... ,in, Indicates pulse density; Indicates the first The number of effective partial discharge pulses in the kth inspection cycle of a ring main unit; Indicates the first The total effective sampling time of the closed-loop detection sequence within the k-th inspection cycle of the ring main unit. This is the sum of the lock sampling durations for all directional normalized sampling events within the closed-cycle detection sequence.

[0127] Phase Concentration Characteristics It is determined according to the degree of circumferential concentration of the power frequency phase corresponding to the effective partial discharge pulse; specifically, ;in, Indicates phase concentration characteristics; Indicates the number of effective partial discharge pulses; This represents the power frequency phase corresponding to the i-th effective partial discharge pulse; This represents the sum of the power frequency phase cosine values ​​of all effective partial discharge pulses; It represents the sum of the sinusoidal values ​​of the power frequency phase of all effective partial discharge pulses. The closer the value is to 1, the more concentrated the partial discharge pulses are within a fixed phase interval. It should be noted that when the number of effective partial discharge pulses... When the value is greater than 0, the phase concentration characteristic is calculated according to the above formula; when... When the value is 0, the phase concentration feature is set to 0.

[0128] S502, preset pulse amplitude abnormality threshold, pulse density abnormality threshold, and phase concentration abnormality threshold, and the obtained first... By comparing the pulse amplitude, pulse density, and phase concentration characteristics of each ring main unit during the kth inspection cycle, a single-cycle anomaly marker group is obtained. The single-cycle anomaly flag group includes pulse amplitude anomaly flags, pulse density anomaly flags, and phase concentration anomaly flags.

[0129] Specifically, methods for obtaining single-cycle anomaly marker sets include:

[0130] when At that time, the pulse amplitude abnormality flag will be displayed. Set to 1 otherwise set to 0.

[0131] when At that time, the pulse density abnormality flag will be displayed. Set to 1 otherwise set to 0.

[0132] when At that time, the phase concentration anomaly marker will be displayed. Set to 1 otherwise set to 0.

[0133] in, ; Indicates an abnormal pulse amplitude; Indicates an abnormal pulse density; This indicates an abnormal phase concentration; a value of 1 indicates that the corresponding feature exceeds the abnormal threshold, and a value of 0 indicates that the corresponding feature does not exceed the abnormal threshold.

[0134] It should be noted that the methods for setting the thresholds for abnormal pulse amplitude, abnormal pulse density, and abnormal phase concentration include:

[0135] Based on the same cabinet number in the historical normal inspection cycle The corresponding closed-cycle detection sequence is used as the benchmark sample. The benchmark mean and standard deviation of pulse amplitude, pulse density, and phase concentration characteristics are calculated respectively, and corresponding anomaly thresholds are set.

[0136] ;

[0137] ;

[0138] ;

[0139] in, Indicates the first The abnormal pulse amplitude threshold of each ring main unit; Indicates the first The abnormal pulse density threshold of a ring main unit; Indicates the first The abnormal threshold of phase concentration for each ring main unit.

[0140] It should be noted that the historical normal inspection cycle is a closed inspection cycle that has been confirmed by manual review, online monitoring records, or operation and maintenance records to have no partial discharge abnormalities.

[0141] S503, the first The pulse amplitude, pulse density, phase concentration characteristics, single-cycle anomaly flag group, and single-cycle discharge status corresponding to the kth inspection cycle of each ring main unit are encapsulated to form single-cycle discharge status data. Single-cycle discharge states include normal state, single-feature abnormal state, and multi-feature abnormal state.

[0142] The method for obtaining the single-cycle discharge state includes: based on the single-cycle abnormal flag group. Determine the first Single-cycle discharge state of the k-th inspection cycle of the ring main unit ;

[0143] Specifically, when the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag are all 0, the single-cycle discharge state is marked as normal; when only one of the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag is 1, the single-cycle discharge state is marked as single-feature abnormality state; when two or more of the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag are 1, the single-cycle discharge state is marked as multi-feature abnormality state.

[0144] S504. Number the same cabinet location Single-cycle discharge state data generated during the next continuous inspection cycle The discharge evolution data chain is obtained by arranging the inspection cycle numbers k in ascending order. .

[0145] The discharge evolution data chain It is used to characterize the normal, single-feature abnormal, multi-feature abnormal, decline, and recurrence process of partial discharge characteristics in the same cabinet position during continuous inspection cycles.

[0146] S6: Based on the discharge evolution data chain, identify the cross-cabinet response flag, write the cross-cabinet response flag into the single-cycle discharge status data of the corresponding inspection cycle, and form a cabinet position discharge risk trajectory based on the written single-cycle discharge status data. Based on the cabinet position discharge risk trajectory, generate the corresponding detection result.

[0147] For cabinet positions with continuously increasing partial discharge warnings that are not explained by cross-cabinet responses, the cabinet positions with intermittent and recurring sudden increases will have their partial discharge warnings re-inspected; and cabinet positions without continuous abnormalities will have their partial discharge warnings checked normally. In some implementation methods, the steps include:

[0148] S601, Read the first Discharge evolution data link of each ring network cabinet and adjacent cabinets -1 and +1 Discharge evolution data chain within the same inspection cycle.

[0149] S602, when the first Each ring network cabinet and adjacent cabinets When the single-cycle discharge states within the same inspection cycle k are all single-characteristic abnormal states or multi-characteristic abnormal states, read the first... Each ring network cabinet and adjacent cabinets The pulse record set within this inspection cycle is used to calculate the cross-cabinet correlation coefficient based on the pulse count sequence within the same sampling period. .

[0150] Where h represents the number of digits. The adjacent cabinet positions of the ring main unit, h is taken as -1 and +1 is the actual cabinet number that exists in the cabinet; when the first When a ring network cabinet is the first or last cabinet, only the discharge evolution data chain of the adjacent cabinet on one side that actually exists is read.

[0151] Specifically, cross-cabinet correlation coefficient The methods for obtaining it include:

[0152] ;

[0153] in, Indicates the first The cross-cabinet correlation coefficient between a ring main unit and its h-th adjacent ring main unit during the k-th inspection cycle; Indicates the first The sampling period of the kth inspection cycle of a ring network cabinet is divided into multiple equal-length sub-periods to form a pulse counting sequence; The sampling time period of the h-th adjacent ring network cabinet in the k-th inspection cycle is divided into multiple equal-length sub-time periods to form a pulse counting sequence; This represents the covariance of two pulse counting sequences; express Standard deviation; express The standard deviation.

[0154] Among them, when the first When the standard deviation of the pulse counting sequence of the h-th ring main unit or the pulse counting sequence of the h-th adjacent ring main unit is zero, it indicates that there is no counting fluctuation in the corresponding pulse counting sequence within each equal-length sub-time period. In this case, the cross-unit correlation coefficient division calculation is not performed, and the h-th pulse counting sequence within this inspection cycle is... The cross-cabinet correlation coefficient between the h-th ring main unit and its adjacent ring main unit is set to 0.

[0155] It should be noted that the specific method for forming the partial discharge pulse number sequence after dividing the sampling period into multiple equal-length sub-segments is as follows: the number of sub-segments for each locked sampling window is preset and remains unchanged in the same batch of detections; each locked sampling window is divided into multiple equal-length sub-segments according to the number of sub-segments.

[0156] For any directional normalized sampling event corresponding to a locked sampling window, the starting sampling time of the locked sampling window is used as the dividing point, and the ending sampling time of the locked sampling window is used as the dividing point. Multiple continuous and non-overlapping sub-time periods are formed in chronological order.

[0157] Subsequently, the pulse occurrence times in the pulse record set corresponding to the locked sampling window are read, the number of effective partial discharge pulses in each equal-length sub-segment is counted, and the number of pulses corresponding to each equal-length sub-segment is arranged in chronological order to obtain the pulse counting sub-sequence of the locked sampling window.

[0158] Following the above method, for the first The locked sampling windows corresponding to the normalized sampling events in all directions within the k-th inspection cycle of each ring main unit are divided and counted to obtain multiple pulse counting subsequences. Then, according to the fixed order of trajectory number and detection point number, each pulse counting subsequence is sequentially concatenated to obtain the k-th ring main unit. The pulse counting sequence of the kth inspection cycle of a ring main unit.

[0159] The number of sub-segments is preset based on the duration of a single lock sampling and the statistical stability of partial discharge pulses; when prior calibration data is lacking, each lock sampling window is divided into ten equal-length sub-segments.

[0160] It should be noted that the cross-cabinet correlation coefficient is... Used to characterize the The degree of synchronization of the partial discharge pulse rhythm between a ring main unit and its adjacent h-th ring main unit within the same inspection cycle k. When A larger value indicates that the pulse counts of the two cabinet positions show strong consistency over time, suggesting that the first... The abnormal state of a ring main unit may be related to the discharge response of adjacent units; when When the value is small, it indicates that the consistency of pulse counts between the two cabinet positions is weak over time, suggesting that the first... Abnormal conditions in a single ring main unit are more likely to originate from independent discharge changes within that unit.

[0161] When the Each ring network cabinet and adjacent cabinets Within the same inspection cycle k, all conditions are either single-feature or multi-feature abnormal states; cross-cabinet correlation coefficient. Not less than the cross-cabinet related threshold, the first Cross-cabinet response flags of a ring main unit during the kth inspection cycle Set to 1; otherwise, set the cross-cabinet response flag. Set to 0. Where, Indicates the first The cross-cabinet response flag of the kth inspection cycle of the ring main unit; the cross-cabinet correlation threshold is determined based on the cross-cabinet correlation coefficient of adjacent cabinets in the historical normal inspection cycle; specifically, the maximum value of the cross-cabinet correlation coefficient of adjacent cabinets in the historical normal inspection cycle is counted, and the maximum value plus the preset safety margin is used as the cross-cabinet correlation threshold, and the preset safety margin is 0.05.

[0162] S603, Cross-cabinet response flag Write single-cycle discharge state data This forms a risk trajectory for cabinet discharge. .

[0163] Specifically, the trajectory of discharge risks in the cabinet. Represented as:

[0164] );

[0165] in, Indicates the first The discharge risk trajectory of each ring network cabinet; Indicates the cabinet location number; k indicates the inspection cycle number; Indicates the pulse amplitude; Indicates pulse density; Indicates phase concentration characteristics; Indicates a single-cycle abnormality marker group; Indicates a single-cycle discharge state; This indicates a cross-cabinet response flag.

[0166] S604, Based on the discharge risk trajectory of the cabinet position The analysis generates detection results, which include partial discharge early warning results, key re-inspection results, and normal detection results.

[0167] If the first The single-cycle discharge status of a ring main unit within L consecutive closed inspection cycles. All are either single-feature or multi-feature abnormal states, and the cross-cabinet response flags correspond to the inspection cycle. All values ​​are 0, outputting partial discharge early warning results.

[0168] L is determined based on the maximum number of consecutive cycles of abnormal states occurring in the same cabinet location in historical normal operation data. Specifically, it involves counting the maximum number of consecutive occurrences of single-feature or multi-feature abnormal states during the historical normal operation phase, adding 1 to the maximum number of consecutive occurrences as L, and setting the number of observation cycles W according to the re-inspection response requirements, with W not being less than L.

[0169] If the first A ring main unit exhibits a single-feature or multi-feature abnormal state within W consecutive closed inspection cycles, but does not meet the condition of outputting partial discharge early warning results for L consecutive closed inspection cycles, and there is at least one cross-cabinet response flag corresponding to the abnormal state in the inspection cycle. If the value is 0, output the results of the key re-inspection.

[0170] If the first If a ring main unit exhibits a single-feature or multi-feature abnormal state within W consecutive closed inspection cycles, then the cross-unit response flag for each inspection cycle containing the abnormal state will be read sequentially. When all abnormal states are in the same inspection cycle, the cross-cabinet response flag is displayed. When both are 1, a normal detection result is output.

[0171] If the first No single-feature or multi-feature abnormal states were found in any of the ring main units within W consecutive closed inspection cycles, and normal test results were output.

[0172] In this embodiment, the discharge evolution data chain of adjacent cabinets within the same inspection cycle is read, and the cross-cabinet correlation coefficient is calculated based on the pulse counting sequence. When the pulses of adjacent cabinets show a high degree of rhythm synchronization, a cross-cabinet response flag is set, thereby distinguishing between independent discharge anomalies in this cabinet and synchronous responses formed by conduction or coupling between adjacent cabinets. By writing the cross-cabinet response flag into the cabinet discharge risk trajectory, this application can differentiate between continuous anomalies, intermittent anomalies, and cross-cabinet responses, improving the accuracy of partial discharge early warning results, key re-inspection results, and normal detection results.

[0173] Example 2:

[0174] Please see Figure 4 This application provides a technical solution: a partial discharge cycle detection system for a ring main unit, which is used to implement the aforementioned method for detecting the partial discharge cycle of a ring main unit. The system includes:

[0175] The reference event construction module establishes a double-track reciprocating inspection coordinate chain along the ring network cabinet row, and binds the cabinet position number, trajectory number, inspection direction, detection point number, detection point reference coordinates and probe reference attitude as periodic detection reference events.

[0176] The sampling event locking module, based on the periodic detection reference event, controls the inspection equipment to move along the double-track reciprocating inspection coordinate chain. When the inspection equipment reaches the corresponding detection point, it collects the partial discharge detection signal, constructs a pulse record set, and forms a locked sampling event with cabinet number, inspection direction, detection point number and sampling time.

[0177] The sequence construction module, based on the locked sampling event, maps forward and reverse inspection data to the same cabinet position detection sequence to obtain a direction-normalized periodic detection sequence. Based on the direction-normalized periodic detection sequence, it compares each item with the standard detection point list and marks the period that has not completed the locked sampling of all standard detection points as a non-closed period record to obtain a closed period detection sequence.

[0178] The event chain construction module extracts the pulse amplitude, pulse density, and phase concentration characteristics of the same cabinet position within a continuous period based on the closed-cycle detection sequence, and constructs a discharge evolution data chain according to the order of sampling time.

[0179] The result generation module identifies cross-cabinet response flags based on the discharge evolution data chain, writes the cross-cabinet response flags into the single-cycle discharge status data of the corresponding inspection cycle, and forms a cabinet position discharge risk trajectory based on the written single-cycle discharge status data; and generates corresponding detection results based on the cabinet position discharge risk trajectory.

[0180] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the partial discharge cycle of a ring main unit, characterized in that, include: Establish a double-track reciprocating inspection coordinate chain along the ring network cabinet row, and bind the cabinet position number, trajectory number, inspection direction, detection point number, detection point reference coordinates and probe reference attitude as periodic detection reference events; Based on the periodic detection benchmark event, the inspection equipment is controlled to move along the double-track reciprocating inspection coordinate chain. When the inspection equipment reaches the corresponding detection point, the partial discharge detection signal is collected, a pulse record set is constructed, and a locked sampling event with cabinet number, inspection direction, detection point number and sampling time is formed. Based on the locked sampling event, forward inspection data and reverse inspection data are uniformly mapped to the same cabinet position detection sequence to obtain a direction-normalized periodic detection sequence. The periodic detection sequence based on direction normalization is compared item by item with the standard detection point list. Periods that have not completed the locking and sampling of all standard detection points are marked as non-closed period records, thus obtaining closed periodic detection sequences. Based on the closed-cycle detection sequence, the pulse amplitude, pulse density and phase concentration characteristics of the same cabinet position in a continuous cycle are extracted, and a discharge evolution data chain is constructed according to the order of sampling time. Based on the discharge evolution data chain, cross-cabinet response flags are identified, and the cross-cabinet response flags are written into the single-cycle discharge status data of the corresponding inspection cycle. Based on the written single-cycle discharge status data, a cabinet position discharge risk trajectory is formed, and a corresponding detection result is generated according to the cabinet position discharge risk trajectory. Methods for generating cross-cabinet response flags include: Read the first The discharge evolution data chain of each ring main unit and the discharge evolution data chain of adjacent units within the same inspection cycle; The cross-cabinet correlation coefficient is calculated based on the pulse counting sequence within the same sampling period, and the cross-cabinet response flag is determined based on the cross-cabinet correlation coefficient.

2. The method for detecting the partial discharge cycle of a ring main unit according to claim 1, characterized in that, The method for obtaining the reference coordinates of the detection point includes: Using the projection point of the center reference point of the first cabinet of the ring main unit on the cabinet installation reference surface as the origin, a three-dimensional inspection coordinate system is established. The X-axis is set along the arrangement direction of the ring main unit, the Y-axis is set along the direction perpendicular to the cabinet inspection surface, and the Z-axis is set along the height direction perpendicular to the cabinet installation reference surface. During the on-site calibration phase, the first... The left and right boundary coordinates of the first ring main unit are determined, and the first ring main unit is determined based on the left and right boundary coordinates. The center coordinates and width of each ring network cabinet; According to the The cabinet boundary coordinates and preset detection points of the first ring main unit are used to determine the first... The detection point number and reference coordinates of each ring network cabinet.

3. The method for detecting the partial discharge cycle of a ring main unit according to claim 1, characterized in that, The method for constructing the pulse recording set includes: When the inspection equipment reaches the first The p-th detection point of a ring main unit is located on the reference coordinates of the detection point on the r-th inspection trajectory, and the pose lock event is triggered when the detection probe is adjusted to the probe reference posture. After the pose lock event is triggered, the inspection equipment remains in a stationary locked state for the duration corresponding to the start time of the lock sampling. The time interval within is used as the locking sampling window, and the sampling frequency is used accordingly. Collection duration Partial discharge detection signal within; A preset pulse recognition threshold is set. When the amplitude of a certain peak in the local discharge detection signal is greater than the pulse recognition threshold, and the pulse width corresponding to the peak is within the allowable width range of the partial discharge pulse, the corresponding peak is marked as a valid partial discharge pulse. The pulse occurrence time, pulse amplitude, pulse width and corresponding power frequency phase are recorded to generate a pulse record set.

4. The method for detecting the partial discharge cycle of a ring main unit according to claim 3, characterized in that, The method for obtaining the direction-normalized periodic detection sequence includes: When there are locking sampling events formed by forward inspection and locking sampling events formed by reverse inspection within the same inspection cycle k, and the two correspond to the same cabinet number, the same trajectory number, the same detection point number and the same detection point reference coordinates, the two are determined as the corresponding sampling data formed by the same physical detection point under different inspection directions, and are uniformly mapped to the same coordinate normalized sampling position. When both forward and reverse inspection sampling data exist at the same coordinate normalized sampling position, the locking sampling event with pose locking event, partial discharge detection signal and pulse record set is selected as the direction normalized sampling event. When both meet the requirements, the forward inspection sampling data is selected as the direction normalized sampling event. All directional sampling events generated under the same cabinet number within the same inspection cycle are sorted according to trajectory number and detection point number to obtain the first... The direction-normalized cycle detection sequence of the ring main unit in the kth inspection cycle.

5. The method for detecting the partial discharge cycle of a ring main unit according to claim 4, characterized in that, The method for obtaining a direction-normalized periodic detection sequence further includes: When there is only one locked sampling event in the same coordinate normalized sampling position for a single inspection direction, and the corresponding locked sampling event has a pose locking event, a partial discharge detection signal, and a pulse record set, the corresponding locked sampling event is taken as the direction normalized sampling event. When the conditions are not met, the sampling status is marked as missing.

6. The method for detecting the partial discharge cycle of a ring main unit according to claim 1, characterized in that, The method for obtaining the closed-cycle detection sequence includes: Read the first The direction-normalized cycle detection sequence of the ring main unit in the kth inspection cycle and by cabinet number For indexing, retrieve the cabinet number from the periodic detection baseline event table. The corresponding total trajectory number r and detection point number p form the first... List of standard testing points corresponding to each ring main unit; Direction-normalized periodic detection sequence The directional normalization sampling events in the data are compared item by item with the standard detection point list to determine the first... Whether the ring main unit has completed the locking and sampling of all standard test points and generated a closed-cycle test sequence or a non-closed-cycle record within the kth inspection cycle; Multiple closed-cycle detection sequences that have been formed under the same cabinet position number are sorted in ascending order according to the inspection cycle number k to obtain the cabinet position closed-cycle sequence.

7. The method for detecting the partial discharge cycle of a ring main unit according to claim 6, characterized in that, Also includes: When a non-closed periodic record is generated, a missing point record is generated for the non-closed periodic record. The missing location record includes the cabinet number. Inspection cycle number k, trajectory number r, detection point number p, and missing reason identifier; The missing data point records are used to generate a supplementary sampling instruction for the next inspection cycle.

8. The method for detecting the partial discharge cycle of a ring main unit according to claim 1, characterized in that, The method for constructing the discharge evolution data link includes: Read the cabinet position closed cycle sequence The k-th closed-cycle detection sequence Obtain the corresponding complete pulse record set, and obtain the first pulse record. Characteristics of pulse amplitude, pulse density, and phase concentration of a ring main unit during the kth inspection cycle; Preset pulse amplitude anomaly threshold, pulse density anomaly threshold, and phase concentration anomaly threshold, and compare them with the obtained first... The pulse amplitude, pulse density, and phase concentration characteristics of each ring main unit in the kth inspection cycle are compared to obtain a single-cycle anomaly flag group; the single-cycle anomaly flag group includes pulse amplitude anomaly flag, pulse density anomaly flag, and phase concentration anomaly flag; The first The pulse amplitude characteristics, pulse density characteristics, phase concentration characteristics, single-cycle abnormality flag group, and single-cycle discharge status corresponding to the k-th inspection cycle of each ring main unit are encapsulated to form single-cycle discharge status data. ; Number the same cabinet Single-cycle discharge state data generated during the next continuous inspection cycle The discharge evolution data chain is obtained by arranging the inspection cycle numbers k in ascending order.

9. The method for detecting the partial discharge cycle of a ring main unit according to claim 8, characterized in that, The method for obtaining the single-cycle anomaly flag group includes: when At that time, the pulse amplitude abnormality flag will be displayed. Set to 1 otherwise set to 0; when At that time, the pulse density abnormality flag will be displayed. Set to 1 otherwise set to 0; when At that time, the phase concentration anomaly marker will be displayed. Set to 1 otherwise set to 0; in, This is the threshold for abnormal pulse amplitude. The threshold for abnormal pulse density; This is the threshold for phase concentration anomalies. , and These are pulse amplitude, pulse density, and phase concentration characteristics, respectively.

10. The method for detecting the partial discharge cycle of a ring main unit according to claim 9, characterized in that, The method for obtaining the single-cycle discharge state includes: When the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag are all 0, the single-cycle discharge state is marked as normal. When only one of the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag is 1, the single-cycle discharge state is marked as a single-characteristic abnormal state. When two or more of the pulse amplitude abnormality flag, pulse density abnormality flag, and phase concentration abnormality flag are 1, the single-cycle discharge state is marked as a multi-feature abnormal state.

11. The method for detecting the partial discharge cycle of a ring main unit according to claim 10, characterized in that, The method for forming the cabinet discharge risk trajectory includes: Read the first Discharge evolution data link of each ring network cabinet The discharge evolution data link between adjacent cabinets within the same inspection cycle; When the When the single-cycle discharge status of a ring main unit and its adjacent unit within the same inspection cycle k is a single-characteristic abnormal state or a multi-characteristic abnormal state, the first cycle discharge status is read. The pulse record set of each ring network cabinet and its adjacent cabinets within the corresponding inspection cycle, and the cross-cabinet correlation coefficient is calculated based on the pulse count sequence within the same sampling period; When the If a ring main unit and its adjacent unit are both in a single-feature or multi-feature abnormal state within the same inspection cycle k, and the cross-unit correlation coefficient is not less than the cross-unit correlation threshold, then the ring main unit will be... The cross-cabinet response flag of each ring main unit is set to 1 during the kth inspection cycle; otherwise, the cross-cabinet response flag is set to 0. The cross-cabinet response flag is written into the single-cycle discharge status data to form a cabinet discharge risk trajectory.

12. The method for detecting the partial discharge cycle of a ring main unit according to claim 1, characterized in that, The test results include partial discharge early warning results, key re-inspection results, and normal test results.

13. A partial discharge cycle detection system for a ring main unit, used to implement the partial discharge cycle detection method for a ring main unit according to any one of claims 1-12, characterized in that, The system includes: The reference event construction module establishes a double-track reciprocating inspection coordinate chain along the ring network cabinet column, and binds the cabinet position number, trajectory number, inspection direction, detection point number, detection point reference coordinates and probe reference attitude as periodic detection reference events; The sampling event locking module, based on the periodic detection reference event, controls the inspection equipment to move along the double-track reciprocating inspection coordinate chain. When the inspection equipment reaches the corresponding detection point, it collects the partial discharge detection signal, constructs a pulse record set, and forms a locked sampling event with cabinet number, inspection direction, detection point number and sampling time. The sequence construction module, based on the locked sampling event, maps forward and reverse inspection data to the same cabinet position detection sequence to obtain a direction-normalized periodic detection sequence. Based on the direction-normalized periodic detection sequence, it compares each item with the standard detection point list and marks the period that has not completed the locked sampling of all standard detection points as a non-closed period record to obtain a closed period detection sequence. The event chain construction module extracts the pulse amplitude, pulse density, and phase concentration characteristics of the same cabinet position within a continuous period based on the closed-cycle detection sequence, and constructs a discharge evolution data chain according to the order of sampling time. The result generation module identifies cross-cabinet response flags based on the discharge evolution data chain, writes the cross-cabinet response flags into the single-cycle discharge status data of the corresponding inspection cycle, and forms a cabinet position discharge risk trajectory based on the written single-cycle discharge status data; and generates corresponding detection results based on the cabinet position discharge risk trajectory.

Images