A method and system for detecting ultrasonic and distributed temperature on-line monitoring of a medium and low voltage bus

Abstract

This invention relates to the field of online monitoring technology for electrical equipment, and discloses a method and system for online monitoring of partial discharge ultrasonic detection and distributed temperature measurement in medium and low voltage busbars. The method includes: Step 1, establishing a coordinate chain for the busbar section, deploying distributed temperature measuring media and partial discharge ultrasonic detection units, and determining the coverage area; Step 2, collecting temperature and trigger data to obtain the average temperature and trigger time of the section; Step 3, determining the partial discharge ultrasonic event cluster, candidate ultrasonic anomaly sections, and their formation times; Step 4, determining candidate thermal anomaly sections, thermal anomaly zones, and their initial formation times; Step 5, determining the coupled anomaly objects; Step 6, determining the online monitoring status of the busbar section; Step 7, outputting the online monitoring status, anomaly sections, formation times, and section coordinate range, and generating an anomaly evidence chain record. This invention achieves segmented online correlation monitoring of partial discharge ultrasonic anomalies and temperature anomalies in medium and low voltage busbars.

Description

Technical Field

[0001] This invention belongs to the field of online monitoring technology for electrical equipment, specifically relating to an online monitoring method and system for partial discharge ultrasonic detection and distributed temperature measurement of medium and low voltage busbars. Background Technology

[0002] Medium and low voltage busbars are widely used in distribution cabinets, switchgear, prefabricated equipment, and various power distribution scenarios. Their operating status directly affects the continuity and stability of the power supply and distribution system. Busbars are constantly exposed to current, heat, vibration, and complex electromagnetic environments. Connection joints, corners, supporting insulation parts, and shell transition areas are prone to problems such as insulation aging, abnormal contact, partial discharge, and localized temperature rise. If these abnormalities are not detected in time, they can easily escalate into insulation breakdown, overheating damage, or even power outages.

[0003] Existing medium- and low-voltage busbar condition monitoring methods mostly rely on single parameters, such as detecting only temperature changes or only partial discharge signals. While temperature monitoring alone can identify heating locations, it lacks the ability to recognize early insulation abnormalities and transient discharge processes, and it's difficult to distinguish between temperature rises caused by overall load changes and those caused by local faults. Relying solely on partial discharge detection is easily affected by installation location, structural transmission paths, and environmental interference, resulting in a less intuitive correlation between detection results and specific busbar sections, and high subsequent verification costs. Furthermore, existing solutions often lack a unified segment representation in spatial positioning, making it difficult to directly correlate temperature results, discharge results, and final alarm results, leading to scattered monitoring results and hindering continuous online judgment for specific busbar sections. Summary of the Invention

[0004] This invention provides a method and system for ultrasonic detection of partial discharge and online monitoring of distributed temperature measurement in medium and low voltage busbars, solving the technical problems in the background art.

[0005] This invention provides a method for ultrasonic detection of partial discharge and distributed online temperature monitoring of medium and low voltage busbars, comprising the following steps:

[0006] Step 1: Obtain the location of the target low-voltage busbar, establish the busbar section coordinate chain, deploy distributed temperature measuring medium and partial discharge ultrasonic detection units, and determine the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain.

[0007] Step 2: Collect the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit.

[0008] Step 3: Determine the partial discharge ultrasound event cluster based on the triggering time, and determine the ultrasound candidate abnormal segment and formation time based on the coverage interval;

[0009] Step 4: Determine candidate thermal anomaly segments based on the average temperature of the segment and the temperature reference value, and determine the thermal anomaly zone and the time of its first formation based on the candidate thermal anomaly segments;

[0010] Step 5: Based on the formation time, the first formation time, and the spatial relationship between the ultrasound candidate abnormality segment and the thermal anomaly zone, determine the coupled anomaly object;

[0011] Step 6: Determine the online monitoring status of the bus section based on the positional relationship between the bus section and the ultrasonic candidate abnormal section, the thermal abnormal zone and the coupled abnormal object;

[0012] Step 7: Output the online monitoring status of the bus section, as well as the candidate abnormal sections of ultrasound, thermal anomaly zones, formation time, and section coordinate range, and generate an abnormal evidence chain record.

[0013] This invention also provides an online monitoring system for partial discharge ultrasonic detection and distributed temperature measurement of medium and low voltage busbars, comprising:

[0014] The busbar modeling module is used to obtain the location of the low-voltage busbar in the target, establish the busbar section coordinate chain, deploy the distributed temperature measuring medium and partial discharge ultrasonic detection unit, and determine the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain.

[0015] The data acquisition module is used to acquire the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit.

[0016] The ultrasound merging module is used to determine the partial discharge ultrasound event cluster based on the triggering time, and to determine the ultrasound candidate abnormal segment and formation time based on the coverage interval;

[0017] The thermal anomaly determination module is used to determine candidate thermal anomaly sections based on the average temperature of the section and the temperature reference value, and to determine the thermal anomaly zone and the time of its first formation based on the candidate thermal anomaly sections.

[0018] The coupling determination module is used to determine the coupling anomaly object based on the formation time, the first formation time, and the spatial relationship between the ultrasound candidate anomaly segment and the thermal anomaly zone;

[0019] The status determination module is used to determine the online monitoring status of the bus section based on the positional relationship between the bus section and the ultrasonic candidate abnormal section, the thermal abnormal zone and the coupled abnormal object;

[0020] The results output module is used to output the online monitoring status of the bus section, as well as the ultrasonic candidate abnormal sections, thermal anomaly zones, formation time, and section coordinate range, and to generate anomaly evidence chain records.

[0021] The beneficial effects of this invention are as follows: This invention uses the busbar section as a unified object, and processes the partial discharge ultrasonic detection results and distributed temperature measurement results accordingly. This not only provides the online monitoring status of each busbar section, but also gives the corresponding abnormal section range and time sequence information. Compared with methods relying solely on single temperature monitoring or single discharge monitoring, this solution can attribute ultrasonic anomalies and thermal anomalies to the same busbar section, making it easier to distinguish between local anomalies and overall operating condition fluctuations. Simultaneously, it can generate section-level output results and anomaly evidence chain records, making it easier to locate the abnormal location, verify the sequence of anomalies, and maintain the consistency and traceability of online monitoring results during subsequent investigations. Attached Figure Description

[0022] Figure 1 This is a flowchart of a method for ultrasonic detection of partial discharge and distributed online temperature monitoring of medium and low voltage busbars according to the present invention. Detailed Implementation

[0023] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0024] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of the present invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in one or more embodiments of the present invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] like Figure 1As shown, a method for ultrasonic detection of partial discharge and online monitoring of distributed temperature measurement in medium and low voltage busbars includes the following steps:

[0026] Step 1: Obtain the location of the target low-voltage busbar, establish the busbar section coordinate chain, deploy distributed temperature measuring medium and partial discharge ultrasonic detection units, and determine the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain.

[0027] Step 2: Collect the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit.

[0028] Step 3: Determine the partial discharge ultrasound event cluster based on the triggering time, and determine the ultrasound candidate abnormal segment and formation time based on the coverage interval;

[0029] Step 4: Determine candidate thermal anomaly segments based on the average temperature of the segment and the temperature reference value, and determine the thermal anomaly zone and the time of its first formation based on the candidate thermal anomaly segments;

[0030] Step 5: Based on the formation time, the first formation time, and the spatial relationship between the ultrasound candidate abnormality segment and the thermal anomaly zone, determine the coupled anomaly object;

[0031] Step 6: Determine the online monitoring status of the bus section based on the positional relationship between the bus section and the ultrasonic candidate abnormal section, the thermal abnormal zone and the coupled abnormal object;

[0032] Step 7: Output the online monitoring status of the bus section, as well as the candidate abnormal sections of ultrasound, thermal anomaly zones, formation time, and section coordinate range, and generate an abnormal evidence chain record.

[0033] In one embodiment of the present invention, when conducting partial discharge ultrasonic testing and distributed temperature measurement online monitoring on a target low-voltage busbar, the spatial structure of the busbar under test is first uniformly modeled. The busbar segment coordinate chain referred to here is a continuous sequence of segments established along the actual extension path of the target low-voltage busbar. Subsequent temperature sampling positions, candidate ultrasonic anomaly segments, thermal anomaly zones, and online monitoring status are all based on this segment sequence for unified positioning. The coverage area referred to here is the effective detection range corresponding to a single partial discharge ultrasonic testing unit along the actual extension direction of the target low-voltage busbar; the temperature sampling position represents the value position of the distributed temperature measurement medium on the busbar segment coordinate chain.

[0034] Specifically, in step 11, the system acquires the location information of the incoming end, outgoing end, connection joint, corner, supporting insulation, branch outlet, and shell transition of the target low-voltage busbar, and arranges them according to the actual extension path of the target low-voltage busbar. Here, the actual extension path order refers to the sequence of unfolding from the starting end to the ending end along the actual conductor route, rather than the proximity relationship on the plan view.

[0035] It should be noted that some corner locations may be close to their preceding positions on the plane, but in the actual route of the busbar, they should still be placed after their subsequent positions. Through the above processing, the division of each subsequent busbar section has a unified starting and ending point basis.

[0036] In step 12, based on the sequentially arranged position information, the system divides the path interval between two sequentially adjacent positions into a busbar segment, and establishes a coordinate chain for each busbar segment according to their sequential relationship. That is, each busbar segment is defined by the preceding and following positions; any temperature sampling position or coverage area falling within this path interval can be assigned to the corresponding busbar segment. This not only breaks down the continuous busbar body into calculable discrete segments, but also allows subsequent temperature data to correspond with partial discharge ultrasonic detection results under the same spatial reference.

[0037] Subsequently, in step 13, the system continuously deploys distributed temperature sensing media along the coordinate chain of the busbar segments, ensuring that the distributed temperature sensing media covers each busbar segment, and the temperature sampling positions of the distributed temperature sensing media within each busbar segment are determined as the temperature sampling positions of the corresponding busbar segments. Simultaneously, partial discharge ultrasonic detection units are deployed at connection joint locations, corner locations, support insulation locations, and shell transition locations. Continuous deployment here means that the distributed temperature sensing media passes through each busbar segment sequentially along the actual route of the busbar without interruption between segments. Temperature sampling positions represent locations where temperature values ​​can be output; these locations will be aggregated by busbar segment in subsequent processing. Connection joint locations, corner locations, support insulation locations, and shell transition locations are chosen as the deployment locations for partial discharge ultrasonic detection units because these locations typically correspond to areas of structural change or insulation boundary change, making them more suitable for establishing the attribution relationship between partial discharge ultrasonic detection results and specific busbar segments.

[0038] For example, when an anomaly occurs near a certain connection joint, the partial discharge ultrasonic detection unit can provide the triggering results for the surrounding area, while the distributed temperature sensing medium can continuously provide temperature changes in the same section.

[0039] In step 14, the system determines the installation location and effective coverage range of each partial discharge ultrasonic detection unit, determines the coverage interval of each partial discharge ultrasonic detection unit on the coordinate chain of the bus section based on the installation location and effective coverage range of each partial discharge ultrasonic detection unit, and determines the bus section that overlaps with each coverage interval as the corresponding bus section of the corresponding partial discharge ultrasonic detection unit.

[0040] The effective coverage area is determined based on the installation location of the partial discharge ultrasonic detection unit, the location of its adjacent structures, and the segment distribution in the busbar section coordinate chain. Specifically, the system first reads the installation location of a single partial discharge ultrasonic detection unit, and then, along the actual extension direction of the target low-voltage busbar, searches for the locations of adjacent connection joints, corners, supporting insulation parts, branch outlets, and housing transition parts on both sides of the installation location. Subsequently, taking the installation location as the center and combining the path boundaries between the adjacent structural locations on both sides, the effective coverage area of ​​the partial discharge ultrasonic detection unit on the busbar section coordinate chain is determined. In other words, the effective coverage area is not an arbitrarily set length interval, but rather the detection range corresponding to the actual structural location of the partial discharge ultrasonic detection unit and the boundaries of the adjacent busbar sections.

[0041] Furthermore, when the partial discharge ultrasonic detection unit is installed near a connection joint, corner, supporting insulation, or housing transition, the system can use the nearest section boundary on both sides of the installation location as the left and right boundaries of the effective coverage area. If the distance from the installation location to the two section boundaries is inconsistent, the effective coverage area corresponding to the partial discharge ultrasonic detection unit may also differ on both sides. After this processing, the coverage area of ​​each partial discharge ultrasonic detection unit can directly fall into the bus section coordinate chain and establish a clear overlap relationship with the corresponding bus section. Subsequently, when determining the ultrasonic candidate abnormal section corresponding to the partial discharge ultrasonic event cluster, it is not necessary to re-estimate the detection range.

[0042] The effective coverage area here refers to the detection range that can be assigned along the actual extension direction of the target low-voltage busbar, centered on the installation location of the partial discharge ultrasonic testing unit. The overlap relationship here indicates that the path range of a certain busbar segment on the busbar segment coordinate chain at least partially overlaps with a certain coverage interval. Through this correspondence, a single partial discharge ultrasonic testing unit is no longer just an installation point, but is transformed into a detection object with a clear connection to several busbar segments. For example, when a partial discharge ultrasonic testing unit is installed near the transition part of the housing, and its effective coverage area spans two adjacent busbar segments, these two busbar segments can be simultaneously identified as the corresponding busbar segments of this partial discharge ultrasonic testing unit.

[0043] Through the above implementation process, the target low- and medium-voltage busbars are first organized into a unified busbar segment coordinate chain. The temperature sampling locations of the distributed temperature sensing medium and the coverage areas of the partial discharge ultrasonic detection unit are then mapped onto this coordinate chain. Through this processing, the subsequently obtained average segment temperature can correspond to a specific busbar segment, and the subsequently obtained partial discharge ultrasonic event clusters and ultrasonic candidate anomaly segments can also correspond to a specific detection range. This allows temperature measurement results and partial discharge ultrasonic detection results to be aggregated and judged under the same measured object and the same segment level. This maintains the consistency of positioning during online monitoring and enables the correlation analysis of partial discharge anomalies and thermal anomalies of the low- and medium-voltage busbars based on a unified coordinate system.

[0044] In one embodiment of the present invention, after establishing the bus section coordinate chain, temperature sampling locations, and coverage area of ​​the partial discharge ultrasonic detection unit, the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit are further collected to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit. Here, the full-length temperature data refers to the continuous temperature data set output by the distributed temperature measuring medium along the actual extension path of the target low-voltage bus; the section average temperature refers to the average result of the temperature values ​​corresponding to all temperature sampling locations within the same bus section; and the trigger time indicates the specific time point at which the partial discharge ultrasonic detection unit triggers within a preset monitoring period. Through this processing, the continuous temperature measurement results are aggregated to the bus section level, and the discrete trigger results are organized into sortable time information, which can then be used for determining thermal anomaly zones and partial discharge ultrasonic event clusters, respectively.

[0045] Step 21: The system collects temperature data along the entire length of the actual extension path of the distributed temperature measuring medium along the target low-voltage busbar according to a preset monitoring cycle, and also collects trigger data from each partial discharge ultrasonic detection unit within the same preset monitoring cycle. The emphasis on the same preset monitoring cycle is to ensure that the temperature data and trigger data are based on the same time reference, avoiding inconsistencies between the temperature and trigger results at different time periods.

[0046] It should be noted that the trigger data is not directly equivalent to the trigger time, but rather the original trigger record generated by the partial discharge ultrasonic detection unit within the monitoring period, which still needs to be further processed.

[0047] In step 22, the system extracts the temperature values ​​corresponding to the temperature sampling locations within each busbar segment based on the busbar segment coordinate chain. It then sums all temperature values ​​within the same busbar segment and divides the sum by the number of temperature sampling locations within that segment to obtain the average temperature of each busbar segment. In other words, although the distributed temperature sensing medium outputs continuous temperature information along the line, this embodiment does not directly use single-point temperatures as the basis for subsequent judgments. Instead, it first aggregates the data to the busbar segment level. For example, if a busbar segment has multiple temperature sampling locations, the temperature values ​​at these locations are first aggregated to obtain an average segment temperature. If a busbar segment corresponds to only one temperature sampling location, the temperature value at that location can also be directly used as the average segment temperature of that busbar segment. This maintains consistency between the temperature measurement results and the busbar structure segmentation, and ensures that subsequent temperature rise analysis falls on a clearly defined measured segment.

[0048] In step 23, the system arranges the trigger data of each partial discharge ultrasonic detection unit within the same preset monitoring period according to the triggering sequence and records the triggering time of each partial discharge ultrasonic detection unit. Here, the triggering sequence refers to the temporal order of each triggering event of the same partial discharge ultrasonic detection unit within the monitoring period. Through the above processing, the original trigger data is transformed into triggering time results that can be directly used for timing merging. For example, if a partial discharge ultrasonic detection unit triggers three times consecutively within a monitoring period, the system records the triggering times corresponding to these three triggers in sequence. Subsequently, the system can determine whether these triggering times belong to the same partial discharge ultrasonic event cluster based on the time intervals between these triggering times.

[0049] Through the above implementation process, this embodiment converts the continuous temperature results output by the distributed temperature measurement medium into the section average temperature at the bus section level, and simultaneously organizes the trigger data output by the partial discharge ultrasonic detection unit into trigger times. This ensures that the temperature data is consistent with the bus section coordinate chain and that the partial discharge ultrasonic detection results have a clear temporal sequence basis. This allows the temperature measurement link and the partial discharge ultrasonic detection link to form stable and corresponding intermediate results during the online monitoring of medium and low voltage buses, providing a unified data foundation for subsequent thermal anomaly and coupling anomaly determination.

[0050] In one embodiment of the present invention, after obtaining the trigger time of each partial discharge ultrasonic detection unit and the coverage area of ​​each partial discharge ultrasonic detection unit on the bus section coordinate chain, a partial discharge ultrasonic event cluster is further determined based on the trigger time, and an ultrasonic candidate anomaly segment and formation time are determined based on the coverage area. Here, a partial discharge ultrasonic event cluster refers to a set of trigger times within the same preset monitoring period, whose time intervals satisfy the synchronicity constraint; the formation time refers to the earliest trigger time in the same partial discharge ultrasonic event cluster; and the ultrasonic candidate anomaly segment represents the range of anomaly segments that can be assigned to on the bus section coordinate chain corresponding to the same partial discharge ultrasonic event cluster. Through this processing, the discrete trigger time results are organized into ultrasonic anomaly objects with temporal and spatial boundaries, which can then be correlated with thermal anomaly zones for subsequent analysis.

[0051] Specifically, in step 31, the system summarizes the trigger times of each partial discharge ultrasound detection unit within the same preset monitoring period and arranges them according to the order of triggering to form a trigger time sequence. Here, the trigger time sequence refers to the sorting result obtained by placing the trigger times that were originally scattered in different partial discharge ultrasound detection units into the same time sequence.

[0052] It should be noted that the sorting object here refers to the trigger times generated by all partial discharge ultrasonic testing units within the same preset monitoring period, rather than the local sorting within a single partial discharge ultrasonic testing unit. This processing ensures that the time intervals between subsequent adjacent trigger times have a unified basis for comparison.

[0053] In step 32, the system compares the time intervals between adjacent trigger times in the trigger time sequence, groups trigger times with time intervals not exceeding a preset time window into the same partial discharge ultrasound event cluster, and determines the earliest trigger time in each partial discharge ultrasound event cluster as the formation time. The preset time window here refers to a pre-defined time range used to constrain which trigger times should belong to the same partial discharge ultrasound anomaly process. That is, if the time interval between two adjacent trigger times does not exceed the preset time window, the system considers these two trigger times to belong to the same event; if it exceeds this time range, a new partial discharge ultrasound event cluster is formed starting from the next trigger time. For example, if multiple trigger times occur consecutively within the same preset monitoring period, and the adjacent time intervals are all small, these trigger times will be grouped into the same partial discharge ultrasound event cluster, and its earliest trigger time will be used as the formation time.

[0054] Subsequently, in step 33, the system identifies partial discharge ultrasonic detection units with trigger times belonging to the same partial discharge ultrasonic event cluster, and extracts the coverage area corresponding to the partial discharge ultrasonic detection unit. This means that the system does not directly use a single trigger time to determine the spatial location, but first traces back the partial discharge ultrasonic detection units that generated these trigger times, and then extracts the coverage area of ​​these partial discharge ultrasonic detection units on the bus section coordinate chain. Through the above processing, a clear attribution relationship is established between the partial discharge ultrasonic event cluster and the partial discharge ultrasonic detection units, providing a direct basis for subsequent spatial segment determination.

[0055] In step 34, the system determines whether there is a common overlapping interval among the aforementioned coverage intervals. If a common overlapping interval exists, it is identified as a candidate ultrasonic anomaly segment; if no common overlapping interval exists, the interval between the earliest starting position and the latest ending position of each coverage interval is identified as a candidate ultrasonic anomaly segment. Here, the common overlapping interval refers to the section of the busbar that overlaps with multiple coverage intervals. If this common overlapping interval can be obtained, it indicates that multiple partial discharge ultrasonic detection units have a common pointing relationship to the same anomaly location. If no common overlapping interval exists, it means that the coverage areas of these partial discharge ultrasonic detection units do not completely overlap. In this case, the interval enclosed by the outermost boundary is used as the candidate ultrasonic anomaly segment, thus preserving the spatial range represented by all relevant coverage intervals. For example, if the coverage intervals corresponding to three partial discharge ultrasonic detection units have a common overlapping portion in the middle, this common overlapping portion can be directly used as a candidate ultrasonic anomaly segment; if the three coverage intervals only have adjacent overlaps without a common overlapping portion, the interval between the earliest starting point and the latest ending point is used as the candidate ultrasonic anomaly segment.

[0056] Through the above implementation process, the system first organizes the trigger times within the same preset monitoring period into an ordered sequence of trigger times, then completes the division of partial discharge ultrasonic event clusters according to a preset synchronous window, and finally converts the temporal merging results into spatial segment results through the coverage range of the partial discharge ultrasonic detection unit. This not only converges the originally discrete and scattered trigger times into abnormal events with a unified formation time, but also converges the local detection results of a single partial discharge ultrasonic detection unit into ultrasonic candidate anomaly segments on the bus section coordinate chain. For medium and low voltage bus online monitoring scenarios, this processing method makes the partial discharge ultrasonic detection results not only temporally traceable but also spatially attributable, facilitating subsequent correspondence and judgment with thermal anomaly bands obtained from distributed temperature measurement at the same bus section level.

[0057] In one embodiment of the present invention, after the average temperature of each busbar section has been obtained, candidate thermal anomaly sections are further determined based on the average temperature of the sections and the temperature reference value, and the thermal anomaly zone and the time of its first formation are determined on this basis.

[0058] The temperature benchmark value is not a temporarily assigned fixed value, but is established based on the historical temperature results of the target low-voltage bus during the initial stable operation phase. Specifically, within a preset filing period after the target low-voltage bus is put into online monitoring, the system continuously collects the average temperature of each bus section over multiple monitoring cycles, and summarizes the corresponding average temperature results for each bus section. Subsequently, the average temperatures of multiple bus sections obtained within the preset filing period for the same bus section are statistically processed, and the statistical results are determined as the temperature benchmark value corresponding to that bus section. The preset filing period here refers to the time period during which the target low-voltage bus operates relatively stably and no known abnormal alarms occur.

[0059] Furthermore, to avoid interference from individual short-term fluctuations on the temperature reference value, the average temperatures of multiple sections within the same busbar segment during the preset filing period can be arranged in ascending order. After removing the highest and lowest values, the remaining average temperatures are averaged to obtain the corresponding temperature reference value for that busbar segment. This process ensures that the temperature reference value still represents the normal temperature level of the busbar segment under normal operating conditions, but it is less affected by occasional fluctuations. If the target low-voltage busbar remains in a normal state for an extended period during subsequent online monitoring, the temperature reference value can be updated during a new stable operating period to ensure that the subsequent calculation of segment temperature rise is consistent with the current equipment status. Here, the temperature reference value refers to the reference temperature value pre-established for each busbar segment, used to represent the normal temperature level of that busbar segment under normal operating conditions. The segment temperature rise represents the degree of increase in the current segment's average temperature relative to the reference temperature value. The difference between adjacent segments represents the level of local temperature difference between the current busbar segment and its adjacent busbar segments. A candidate thermal anomaly segment represents a busbar segment that simultaneously meets both the temperature rise condition and the local difference condition within the current monitoring period. A persistent thermal anomaly segment represents a busbar segment that has been repeatedly identified as a candidate thermal anomaly segment over multiple consecutive monitoring periods. A thermal anomaly zone represents a continuous anomaly range formed by merging consecutively adjacent persistent thermal anomaly segments on the busbar segment coordinate chain. The initial formation time indicates the monitoring period corresponding to when the thermal anomaly zone was first identified.

[0060] Specifically, in step 41, the system subtracts the corresponding temperature reference value from the average temperature of each busbar section to obtain the temperature rise of that section. Through this processing, each busbar section is no longer judged solely based on its currently measured absolute temperature, but is first converted into an offset relative to its normal operating level. This is more suitable for online monitoring scenarios of medium and low voltage busbars, because the normal operating temperatures of different installation locations and structural parts may not be consistent. Directly comparing absolute temperatures could easily misinterpret normal temperature differences caused by structural variations as abnormalities.

[0061] Based on this, for the busbar section located in the middle, the average temperature of this section is taken, and the average temperature of the preceding and following busbar sections is subtracted to obtain the difference between adjacent sections; this difference between adjacent sections can be expressed as: ,in, Indicates the first The intermediate busbar section in the first The difference between adjacent segments in each monitoring period Indicates the first The intermediate busbar section in the first The average temperature of the section over a monitoring period, Indicates the first The intermediate busbar section preceding the previous busbar section in the first The average temperature of the section over a monitoring period, Indicates the first The next busbar section is in the middle of the first busbar section. The average temperature of the section over a monitoring period, Indicates the bus section number, and The corresponding busbar segment is neither the first busbar segment nor the last busbar segment. Indicates the first Each monitoring cycle. The difference between adjacent sections here represents the degree of local temperature deviation of the current intermediate busbar section relative to the average temperature level of its preceding and following adjacent busbar sections.

[0062] For the first and last busbar sections, the temperature difference between adjacent sections is obtained by subtracting the average temperature of the only adjacent busbar section from its average temperature. In other words, the middle sections use a two-sided reference, while the first and last sections use a one-sided reference. This processing allows the system to see not only whether a busbar section has risen relative to its own reference, but also whether that section exhibits localized bulges relative to neighboring sections. For example, if a busbar section heats up synchronously due to overall load changes, the section's temperature rise may increase, but the difference between adjacent sections may not be significant; conversely, if a connection point experiences localized heating, both the section's temperature rise and the difference between adjacent sections will typically increase simultaneously.

[0063] Next, in step 42, the system compares the temperature rise of the section with a preset temperature rise threshold and the difference between adjacent sections with a preset difference threshold. When both the temperature rise of the section and the difference between adjacent sections meet the threshold conditions, the corresponding bus section is identified as a candidate section for thermal anomaly. This approach uses dual constraints instead of relying solely on a single temperature rise result. This is because during bus operation, the overall temperature may rise, or localized heat concentration may occur. Judging solely based on the temperature rise of the section could easily lead to the overall temperature rise being mistakenly included in the anomaly assessment; judging solely based on the difference between adjacent sections might overlook situations where the temperature of the current section has significantly deviated from the normal range, but adjacent sections are also changing synchronously. Through this process, the candidate section for thermal anomaly must both rise relative to its own baseline and exhibit localized differences among neighboring sections, thus making the thermal anomaly assessment more closely reflect the actual state changes of the measured object.

[0064] Subsequently, in step 43, the system counts the number of times each bus section is identified as a candidate thermal anomaly section within multiple consecutive monitoring cycles, and identifies bus sections whose counts reach a preset duration threshold as persistent thermal anomaly sections. The introduction of statistics across multiple consecutive monitoring cycles is to distinguish between single fluctuations and continuous anomalies. That is, if a bus section briefly meets the conditions within a single monitoring cycle, it will not directly enter the subsequent thermal anomaly zone construction; instead, its persistence in subsequent monitoring cycles will be observed. This preserves the tracking of persistently hot areas while reducing the impact of instantaneous disturbances on the judgment results.

[0065] For example, if a busbar section only rises briefly within a single cycle and then returns to normal, the section is usually not further classified as a persistent thermal anomaly section; if a section repeatedly meets the conditions in multiple consecutive cycles, the section will be identified as a persistent thermal anomaly section.

[0066] In step 44, the system merges consecutively adjacent continuous thermal anomaly segments on the bus section coordinate chain into a thermal anomaly zone, and determines the monitoring period corresponding to when this thermal anomaly zone is first identified as the initial formation time. Here, "consecutively adjacent" means that these continuous thermal anomaly segments are connected sequentially on the bus section coordinate chain, with no breaks in between that were not identified as continuous thermal anomaly segments. Through this merging process, the system outputs no longer several discrete anomaly segments, but rather a thermal anomaly zone that represents a continuous anomaly range.

[0067] For online monitoring, this zoning result is more suitable for subsequent spatial correspondence with candidate ultrasound anomaly segments, and also more suitable for directly representing the start and end positions of the anomaly range. For example, if two adjacent busbar segments are identified as persistent thermal anomaly segments for multiple consecutive cycles, these two busbar segments will be merged into a single thermal anomaly zone, rather than being treated as two independent anomaly points.

[0068] Through the above implementation process, the system first converts the average temperature of each busbar section into the section temperature rise, then determines candidate thermal anomaly sections by combining the differences between adjacent sections, and then obtains continuous thermal anomaly sections through continuous monitoring cycle statistics, ultimately forming thermal anomaly zones and their initial formation time. Through this processing, the thermal monitoring results gradually converge from single temperature values ​​to anomalies with section continuity and a time starting point, thus placing them at the same level as the ultrasonic candidate anomaly sections and formation times obtained from the ultrasonic side. This maintains the segmented representation in the online measurement process of medium and low voltage buses and provides a unified and comparable basis for subsequent coupled judgment of ultrasonic and thermal anomalies.

[0069] In one embodiment of the present invention, after obtaining the ultrasonic candidate anomaly segment, formation time, thermal anomaly zone, and initial formation time, a coupled anomaly object is further determined based on the formation time, the initial formation time, and the spatial relationship between the ultrasonic candidate anomaly segment and the thermal anomaly zone. Here, a coupled anomaly object refers to a unified anomaly object formed when the ultrasonic anomaly result and the thermal anomaly result in the same low-voltage busbar simultaneously satisfy constraints in terms of temporal sequence and spatial proximity. The corresponding determination unit represents the determination object formed by combining an ultrasonic candidate anomaly segment, the formation time corresponding to the ultrasonic candidate anomaly segment, a thermal anomaly zone, and the initial formation time corresponding to the thermal anomaly zone. The temporal interval represents the time difference between the initial formation time and the formation time. The spatial overlap represents the proportion of the overlapping portion of the ultrasonic candidate anomaly segment and the thermal anomaly zone on the busbar segment coordinate chain. The minimum segment interval represents the closest distance between the two when there is no overlap.

[0070] Specifically, in step 51, the system pairs each candidate ultrasound anomaly segment with each thermal anomaly band one by one, and incorporates the formation time and initial formation time of each pairing to form a corresponding judgment unit. In other words, instead of first screening potentially related segments based on experience and then making local comparisons, the system first pairs all candidate ultrasound anomaly segments with all thermal anomaly bands sequentially before proceeding to the next judgment. After this processing, each corresponding judgment unit simultaneously carries ultrasound-side spatial results, thermal-side spatial results, and its own temporal information, eliminating the need to repeatedly search for the original object during subsequent temporal and spatial judgments.

[0071] In step 52, the system performs temporal and spatial judgments on each corresponding determination unit. First, the initial formation time is subtracted from the formation time to obtain the temporal interval. When the temporal interval is not less than zero and not greater than a preset secondary duration threshold, the corresponding determination unit is determined to satisfy the temporal succession relationship. This means that the thermal anomaly band should appear after the candidate ultrasound anomaly segment, and the time difference between the two should not exceed a predefined duration range. If the thermal anomaly band appears first, or the time interval between the two is too long, subsequent coupling determination is not performed.

[0072] After completing the time-based judgment, the system continues to determine the spatial overlap and minimum segment interval. The spatial overlap is calculated as follows: the length of the overlap between the ultrasound candidate anomaly segment and the thermal anomaly zone is used as the numerator, and the combined overall coverage length is used as the denominator. The minimum segment interval is the shortest distance between the ultrasound candidate anomaly segment and the thermal anomaly zone. If the two overlap, the minimum segment interval is zero. For example, if an ultrasound candidate anomaly segment covers three adjacent busbar segments, and a thermal anomaly zone covers two of those busbar segments, then they have a non-zero spatial overlap. If they do not overlap but are separated only by a very short segment boundary, then the spatial overlap is zero, and the minimum segment interval is still relatively small.

[0073] Next, in step 53, the system determines the coupling anomaly object based on the temporal succession relationship, spatial overlap, and minimum segment interval. When the corresponding judgment unit satisfies the temporal succession relationship and the spatial overlap is not less than the preset overlap threshold, the corresponding judgment unit is determined as a coupling anomaly object; when the corresponding judgment unit satisfies the temporal succession relationship, the spatial overlap is less than the preset overlap threshold, but the minimum segment interval is not greater than the preset interval threshold, the corresponding judgment unit is also determined as a coupling anomaly object.

[0074] The former scenario indicates that the candidate ultrasound anomaly segment and the thermal anomaly zone have a relatively clear overlap range on the generatrix segment coordinate chain. The latter scenario indicates that although the two have not formed a sufficient overlap, they still maintain a close spatial relationship and conform to the order of evolution in time. Therefore, they are still classified into the same coupled anomaly object.

[0075] After the above processing, the system consolidates the originally separate ultrasonic and thermal anomaly results into a unified coupled anomaly object. This allows for the judgment of the formation time and the initial formation time on the same timeline, and also allows for the comparison of ultrasonic candidate anomaly segments and thermal anomaly zones on the same busbar segment coordinate chain. When determining the online monitoring status subsequently, the separate ultrasonic and thermal anomalies are no longer processed; instead, the coupled anomaly object is used directly as a higher-level judgment basis, thus ensuring consistency in both time and space for the online monitoring results of medium and low voltage buses.

[0076] In one embodiment of the present invention, after obtaining the ultrasonic candidate anomaly segment, the thermal anomaly zone, and the coupled anomaly object, the online monitoring status of the bus segment is further determined based on the positional relationship between the bus segment and the ultrasonic candidate anomaly segment, the thermal anomaly zone, and the coupled anomaly object. Here, the positional relationship refers to whether there is overlap between the range of the bus segment on the bus segment coordinate chain and the range of the segment corresponding to the corresponding object. The range of the coupled anomaly object refers to the combined range of the ultrasonic candidate anomaly segment and the thermal anomaly zone within the same coupled anomaly object on the bus segment coordinate chain. The online monitoring status represents the segment-level determination result of the system for the current anomaly attributes of each bus segment, and in this embodiment, includes coupled anomaly status, independent thermal anomaly status, discharge leader status, and normal status.

[0077] Specifically, in step 61, the system determines whether each busbar segment overlaps with any candidate ultrasound anomaly segment. If overlap exists, the system determines that the busbar segment and the candidate ultrasound anomaly segment have a positional relationship; if no overlap exists, the system determines that the busbar segment and the candidate ultrasound anomaly segment do not have a positional relationship. In other words, the system does not directly assign a state to a busbar segment based on whether a partial discharge ultrasound detection unit is triggered, but first checks whether the busbar segment actually falls within the spatial range corresponding to the candidate ultrasound anomaly segment. After this processing, the ultrasound results are transferred from the detection unit level to the busbar segment level. For example, if a candidate ultrasound anomaly segment spans two adjacent busbar segments, both busbar segments will be determined to have a positional relationship with that candidate ultrasound anomaly segment.

[0078] In step 62, the system uses the rules for determining positional relationships based on overlap from step 61 to determine the positional relationship between each busbar segment and any thermal anomaly zone. Subsequently, the system merges the ultrasonic candidate anomaly segment and the thermal anomaly zone corresponding to the coupled anomaly object into a segment range corresponding to the coupled anomaly object, and continues to use the same overlap judgment rules to determine the positional relationship between each busbar segment and the segment range corresponding to any coupled anomaly object. The reason for judging the positional relationship of the thermal anomaly zone first, and then the positional relationship of the coupled anomaly object, is that the thermal anomaly zone itself represents the thermal anomaly range, while the coupled anomaly object represents the comprehensive anomaly range after time and space correspondence has been completed; the judgment levels for the two are different. It should be noted that the segment range corresponding to the coupled anomaly object is not a newly added independent detection result, but rather a unified spatial range formed by merging the existing ultrasonic candidate anomaly segments and thermal anomaly zones within the same coupled anomaly object. With this approach, subsequent state judgments do not need to repeatedly compare the two segment ranges separately, but can directly focus on the coupled anomaly object.

[0079] In step 63, the system determines the online monitoring status based on the aforementioned positional relationship determination results. When a positional relationship exists between a bus section and a coupled anomaly object, the corresponding bus section is determined to be in a coupled anomaly state. When no positional relationship exists between a bus section and a coupled anomaly object, but a positional relationship exists between a bus section and a thermal anomaly zone, the corresponding bus section is determined to be in an independent thermal anomaly state. The reason for using the order of first determining the coupled anomaly state and then determining the independent thermal anomaly state is that the coupled anomaly object already represents the corresponding result of ultrasonic anomaly and thermal anomaly at the same bus section level, and its determination priority is higher than that of a separate thermal anomaly. That is to say, as long as a bus section has fallen into the section range corresponding to the coupled anomaly object, it is no longer assigned a separate thermal state, but is directly classified into a coupled anomaly state.

[0080] In step 64, the system continues to assess bus segments that have not yet been classified into the aforementioned states. When there is no positional relationship between a bus segment and a coupled abnormal object, no positional relationship between a bus segment and a thermal anomaly zone, but a positional relationship exists between a bus segment and a candidate ultrasonic anomaly segment, the corresponding bus segment is designated as a discharge leader state. When there is no positional relationship between a bus segment and a coupled abnormal object, no positional relationship between a bus segment and a thermal anomaly zone, and no positional relationship between a bus segment and a candidate ultrasonic anomaly segment, the corresponding bus segment is designated as a normal state. Here, the discharge leader state indicates that the bus segment has shown ultrasonic-side abnormality clues, but has not yet formed a persistent thermal-side abnormality or coupling anomaly; the normal state indicates that the bus segment does not fall within the segment range of any of the aforementioned abnormal objects. In this way, each bus segment will only receive one online monitoring state, and multiple concurrent states will not occur simultaneously.

[0081] Based on the steps described above, it can be seen that the system first converts candidate ultrasonic anomaly sections, thermal anomaly zones, and coupled anomaly objects into spatial attribution relationships consistent with the coordinate chain of the busbar sections, and then assigns a state to each busbar section in a fixed order. This not only unifies the partial discharge ultrasonic detection results, distributed temperature measurement results, and coupling results to the busbar section level, but also organizes anomaly results from different sources into a unique section-level online monitoring state.

[0082] In one embodiment of the present invention, after obtaining the online monitoring status, ultrasonic candidate abnormal sections, thermal anomaly zones, formation times, and initial formation times of each busbar segment, the online monitoring status, ultrasonic candidate abnormal sections, thermal anomaly zones, formation times, and segment coordinate ranges of each busbar segment are further output, and an anomaly evidence chain record is generated. Here, the segment-level output result refers to the output content formed by organizing the status results, spatial range, and anomaly-related information corresponding to a single busbar segment as an index. The anomaly evidence chain record represents the record result of organizing the ultrasonic and thermal time information related to the abnormal busbar segment in chronological order, used to represent the timeline of the abnormal evolution of the busbar segment.

[0083] Specifically, in step 71, the system extracts, based on the busbar segments, candidate ultrasonic anomaly segments that overlap with each busbar segment and their corresponding formation times, thermal anomaly zones that overlap with each busbar segment and their corresponding first formation times, and the coordinate range of each busbar segment. In other words, the system first gathers the anomaly objects and time information related to each busbar segment as the center, rather than directly outputting all anomaly objects in a flat manner. This makes the boundaries of the anomaly information corresponding to each busbar segment clearer. It should be noted that the formation time corresponds only to candidate ultrasonic anomaly segments, and the first formation time corresponds only to thermal anomaly zones; both retain their original meanings in the output stage and do not substitute for each other. For example, if a busbar segment only overlaps with candidate ultrasonic anomaly segments but not with thermal anomaly zones, the output information corresponding to that busbar segment includes the formation time but not the first formation time.

[0084] In step 72, the system constructs the segment-level output results for each bus section based on its online monitoring status, section coordinate range, ultrasonic candidate anomaly sections, thermal anomaly zones, formation time, and initial formation time. This construction is not a simple concatenation of fields; rather, it places the status information, spatial information, and anomaly information corresponding to the same bus section into the same output unit. This allows subsequent result display, report generation, and record retention to be directly focused on a single bus section, eliminating the need to return to previous steps to search for corresponding content item by item. If the online monitoring status of a bus section is a coupling anomaly state, the segment-level output results typically include ultrasonic candidate anomaly sections, thermal anomaly zones, formation time, and initial formation time simultaneously; if it is a discharge leader state, it typically only includes ultrasonic candidate anomaly sections and their formation time.

[0085] In step 73, for bus sections whose online monitoring status is abnormal, the system merges the formation time and the first formation time, arranges them in chronological order, generates an anomaly evidence chain record, and outputs the section-level output results for each bus section, as well as the anomaly evidence chain record corresponding to the bus section whose online monitoring status is abnormal. The merging and sorting here means that the ultrasonic and thermal time information associated with the same bus section is unified into a single time series and then arranged in chronological order. The anomaly evidence chain record generated in this way more easily reflects whether the anomaly was triggered by partial discharge ultrasound first, or whether a thermal anomaly zone appeared subsequently. For example, if a bus section first corresponds to a formation time and then to an first formation time, the anomaly evidence chain record can present these two time points in chronological order, thus making the anomaly development process of that section clearer.

[0086] After this processing, the system output is no longer just a single status label, but a segment-level result with segment coordinate range, abnormal segment information, and time clues. For ultrasonic partial discharge detection and distributed temperature measurement online monitoring of medium and low voltage busbars, this output method can not only pinpoint the online monitoring status to a specific busbar segment, but also gather abnormal clues from both the ultrasonic and thermal sides along the same time chain, making subsequent verification, comparison, and recording smoother.

[0087] This invention also provides an online monitoring system for partial discharge ultrasonic detection and distributed temperature measurement of medium and low voltage busbars, comprising:

[0088] The busbar modeling module is used to obtain the location of the low-voltage busbar in the target, establish the busbar section coordinate chain, deploy the distributed temperature measuring medium and partial discharge ultrasonic detection unit, and determine the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain.

[0089] The data acquisition module is used to acquire the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit.

[0090] The ultrasound merging module is used to determine the partial discharge ultrasound event cluster based on the triggering time, and to determine the ultrasound candidate abnormal segment and formation time based on the coverage interval;

[0091] The thermal anomaly determination module is used to determine candidate thermal anomaly sections based on the average temperature of the section and the temperature reference value, and to determine the thermal anomaly zone and the time of its first formation based on the candidate thermal anomaly sections.

[0092] The coupling determination module is used to determine the coupling anomaly object based on the formation time, the first formation time, and the spatial relationship between the ultrasound candidate anomaly segment and the thermal anomaly zone;

[0093] The status determination module is used to determine the online monitoring status of the bus section based on the positional relationship between the bus section and the ultrasonic candidate abnormal section, the thermal abnormal zone and the coupled abnormal object;

[0094] The results output module is used to output the online monitoring status of the bus section, as well as the ultrasonic candidate abnormal sections, thermal anomaly zones, formation time, and section coordinate range, and to generate anomaly evidence chain records.

[0095] It should be noted that the interval and threshold sizes are set for ease of comparison. The size of the threshold depends on the amount of sample data and the base number set by those skilled in the art for each set of sample data, as long as it does not affect the proportional relationship between the parameter and the quantized value. Furthermore, the above formulas are all dimensionless calculations, and the formulas are derived from software simulations using a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0096] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of the present embodiments, all of which are within the protection scope of the present embodiments.

Claims

1. A method for ultrasonic detection of partial discharge and distributed temperature measurement online monitoring of medium and low voltage busbars, characterized in that, Includes the following steps: Step 1: Obtain the location of the target low-voltage busbar, establish the busbar section coordinate chain, deploy distributed temperature measuring medium and partial discharge ultrasonic detection units, and determine the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain. Step 2: Collect the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit. Step 3: Determine the partial discharge ultrasound event cluster based on the triggering time, and determine the ultrasound candidate abnormal segment and formation time based on the coverage interval; Step 4: Determine candidate thermal anomaly segments based on the average temperature of the segment and the temperature reference value, and determine the thermal anomaly zone and the time of its first formation based on the candidate thermal anomaly segments; Step 5: Based on the formation time, the first formation time, and the spatial relationship between the ultrasound candidate abnormality segment and the thermal anomaly zone, determine the coupled anomaly object; Step 6: Determine the online monitoring status of the bus section based on the positional relationship between the bus section and the ultrasonic candidate abnormal section, the thermal abnormal zone and the coupled abnormal object; Step 7: Output the online monitoring status of the bus section, as well as the candidate abnormal sections of ultrasound, thermal anomaly zones, formation time, and section coordinate range, and generate an abnormal evidence chain record.

2. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, The location of the target low-voltage busbar is obtained, a coordinate chain for the busbar section is established, distributed temperature sensing media and partial discharge ultrasonic detection units are deployed, and the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain is determined, including: Step 11: Obtain the location information of the incoming end, outgoing end, connection joint, corner, support insulation, branch lead-out and shell transition of the target low-voltage busbar, and arrange them in the order of the actual extension path of the target low-voltage busbar. Step 12: Based on the sequentially arranged position information, divide the path interval between two sequentially adjacent positions into a busbar segment, and establish a busbar segment coordinate chain according to the sequential relationship of each busbar segment; Step 13: Continuously deploy distributed temperature measuring media along the coordinate chain of the busbar section so that the distributed temperature measuring media covers each busbar section, and determine the temperature sampling position of the distributed temperature measuring media within the range of each busbar section as the temperature sampling position of the corresponding busbar section. At the same time, deploy partial discharge ultrasonic detection units at the connection joint position, corner position, support insulation position and shell transition position. Step 14: Determine the installation location and effective coverage range of each partial discharge ultrasonic testing unit. Based on the installation location and effective coverage range of each partial discharge ultrasonic testing unit, determine the coverage interval of each partial discharge ultrasonic testing unit on the coordinate chain of the bus section, and determine the bus section that overlaps with each coverage interval as the corresponding bus section of the corresponding partial discharge ultrasonic testing unit.

3. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, The full-length temperature data of the distributed temperature sensing medium and the trigger data of each partial discharge ultrasonic detection unit are collected to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit, including: Step 21: Collect the full-length temperature data of the distributed temperature measuring medium along the actual extension path of the target low-voltage busbar according to the preset monitoring cycle, and collect the trigger data of each partial discharge ultrasonic detection unit within the same preset monitoring cycle. Step 22: Based on the coordinate chain of the bus section, extract the temperature values ​​corresponding to the temperature sampling positions within each bus section. Add up all the temperature values ​​within the same bus section and divide by the number of temperature sampling positions within the same bus section to obtain the average temperature of each bus section. Step 23: Arrange the trigger data of each partial discharge ultrasonic detection unit in the same preset monitoring cycle according to the order of triggering, and record the triggering time of each partial discharge ultrasonic detection unit.

4. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, Based on the triggering time, partial-exposure ultrasound event clusters are determined, and based on the coverage area, candidate ultrasound abnormality segments and their formation times are determined, including: Step 31: Summarize the trigger times of each partial discharge ultrasound detection unit within the same preset monitoring cycle, and arrange them in the order of triggering to form a trigger time sequence; Step 32: Compare the time intervals between adjacent trigger times in the trigger time sequence, group trigger times with time intervals not greater than a preset synchronicity window into the same partial discharge ultrasound event cluster, and determine the earliest trigger time in each partial discharge ultrasound event cluster as the formation time; Step 33: Determine the partial discharge ultrasonic detection units that have trigger times belonging to the same partial discharge ultrasonic event cluster, and extract the coverage area corresponding to the partial discharge ultrasonic detection unit. Step 34: When there is a common overlapping interval in the coverage interval, the common overlapping interval is determined as a candidate ultrasound abnormality segment; when there is no common overlapping interval, the interval between the earliest start position and the latest end position in each coverage interval is determined as a candidate ultrasound abnormality segment.

5. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, Based on the average temperature of the aforementioned section and the temperature reference value, candidate thermal anomaly sections are determined, and based on these candidate thermal anomaly sections, thermal anomaly zones and their initial formation times are determined, including: Step 41: For each busbar section, subtract the corresponding temperature reference value from the average temperature of the section to obtain the section temperature rise; subtract the average of the average temperatures of the preceding and following busbar sections from the average temperature of the middle busbar section to obtain the difference between adjacent sections; and subtract the average temperature of the only adjacent busbar section from the average temperature of the first and last busbar sections to obtain the difference between adjacent sections. Step 42: Compare the temperature rise of the section with a preset temperature rise threshold, and compare the difference between adjacent sections with a preset difference threshold. When both the temperature rise of the section and the difference between adjacent sections meet the threshold conditions, the corresponding bus section is determined as a candidate section for thermal anomaly. Step 43: Count the number of times each bus section is identified as a candidate section for thermal anomaly in multiple consecutive monitoring cycles, and identify the bus section whose number of times reaches a preset continuous threshold as a continuous thermal anomaly section. Step 44: Merge consecutively adjacent continuous thermal anomaly segments on the coordinate chain of the bus section into a thermal anomaly zone, and determine the monitoring period corresponding to when the thermal anomaly zone is first identified as the first formation time.

6. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, Based on the formation time, the initial formation time, and the spatial relationship between the candidate ultrasound anomaly segment and the thermal anomaly zone, the coupled anomaly object is determined, including: Step 51: Pair each candidate ultrasound abnormality segment with each thermal anomaly zone one by one, and incorporate the formation time and first formation time of each pairing to form a corresponding judgment unit; Step 52: Subtract the formation time from the first formation time in each corresponding judgment unit to obtain the time interval. When the time interval is not less than zero and not greater than the preset secondary duration threshold, the time sequence relationship is determined. Divide the length of the overlap between the ultrasound candidate abnormal segment and the thermal abnormal zone by the overall coverage length after merging to obtain the spatial overlap, and determine the minimum segment interval between the two. Step 53: When the temporal succession relationship is satisfied and the spatial overlap is not less than the preset overlap threshold, the corresponding judgment unit is determined as a coupling abnormal object; when the temporal succession relationship is satisfied, the spatial overlap is less than the preset overlap threshold and the minimum segment interval is not greater than the preset interval threshold, the corresponding judgment unit is determined as a coupling abnormal object.

7. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, Based on the positional relationship between the busbar section and the ultrasonic candidate anomaly section, the thermal anomaly zone, and the coupled anomaly object, the online monitoring status of the busbar section is determined, including: Step 61: Determine whether each busbar segment overlaps with any candidate ultrasound abnormality segment. If there is an overlap, determine that there is a positional relationship between the busbar segment and the candidate ultrasound abnormality segment; if there is no overlap, determine that there is no positional relationship between the busbar segment and the candidate ultrasound abnormality segment. Step 62: Using the rules for determining positional relationships based on overlap relationships in Step 61, determine the positional relationship between each busbar segment and any thermal anomaly zone; merge the ultrasonic candidate anomaly segment and thermal anomaly zone corresponding to the coupled anomaly object into the segment range corresponding to the coupled anomaly object, and use the rules for determining positional relationships based on overlap relationships in Step 61 to determine the positional relationship between each busbar segment and the segment range corresponding to any coupled anomaly object. Step 63: When there is a positional relationship between a bus section and a coupled abnormal object, the corresponding bus section is determined to be in a coupled abnormal state; when there is no positional relationship between a bus section and a coupled abnormal object but there is a positional relationship between a bus section and a thermal abnormal zone, the corresponding bus section is determined to be in an independent thermal abnormal state. Step 64: When there is no positional relationship between the bus section and the coupled abnormal object, no positional relationship between the bus section and the thermal abnormal zone, but a positional relationship exists between the bus section and the ultrasonic candidate abnormal section, the corresponding bus section is determined to be in the discharge leader state; when there is no positional relationship between the bus section and the coupled abnormal object, no positional relationship between the bus section and the thermal abnormal zone, and no positional relationship between the bus section and the ultrasonic candidate abnormal section, the corresponding bus section is determined to be in the normal state.

8. The method for ultrasonic detection and distributed temperature measurement online monitoring of partial discharge in medium and low voltage busbars according to claim 1, characterized in that, Output the online monitoring status of the busbar section, as well as the candidate ultrasonic anomaly sections, thermal anomaly zones, formation times, and section coordinate ranges, and generate anomaly evidence chain records, including: Step 71: Based on the busbar segments, extract the candidate ultrasound anomaly segments that overlap with each busbar segment and their corresponding formation times, extract the thermal anomaly zones that overlap with each busbar segment and their corresponding first formation times, and extract the segment coordinate range of each busbar segment. Step 72: Based on the online monitoring status, section coordinate range, ultrasonic candidate abnormal sections, thermal anomaly zones, formation time, and first formation time of each busbar section, construct the section-level output results corresponding to each busbar section; Step 73: For bus sections whose online monitoring status is not normal, merge the formation time and the first formation time and arrange them in chronological order to generate an abnormal evidence chain record, and output the section-level output results of each bus section and the abnormal evidence chain record corresponding to the bus section whose online monitoring status is not normal.

9. A medium- and low-voltage busbar partial discharge ultrasonic detection and distributed temperature measurement online monitoring system, characterized in that, The method for ultrasonic detection and distributed temperature measurement of partial discharge in medium and low voltage busbars as described in any one of claims 1-8 includes: The busbar modeling module is used to obtain the location of the low-voltage busbar in the target, establish the busbar section coordinate chain, deploy the distributed temperature measuring medium and partial discharge ultrasonic detection unit, and determine the coverage area of ​​each partial discharge ultrasonic detection unit on the busbar section coordinate chain. The data acquisition module is used to acquire the full-length temperature data of the distributed temperature measuring medium and the trigger data of each partial discharge ultrasonic detection unit to obtain the section average temperature of the bus section and the trigger time of the partial discharge ultrasonic detection unit. The ultrasound merging module is used to determine the partial discharge ultrasound event cluster based on the triggering time, and to determine the ultrasound candidate abnormal segment and formation time based on the coverage interval; The thermal anomaly determination module is used to determine candidate thermal anomaly sections based on the average temperature of the section and the temperature reference value, and to determine the thermal anomaly zone and the time of its first formation based on the candidate thermal anomaly sections. The coupling determination module is used to determine the coupling anomaly object based on the formation time, the first formation time, and the spatial relationship between the ultrasound candidate anomaly segment and the thermal anomaly zone; The status determination module is used to determine the online monitoring status of the bus section based on the positional relationship between the bus section and the ultrasonic candidate abnormal section, the thermal abnormal zone and the coupled abnormal object; The results output module is used to output the online monitoring status of the bus section, as well as the ultrasonic candidate abnormal sections, thermal anomaly zones, formation time, and section coordinate range, and to generate anomaly evidence chain records.

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