Breaker contact diagnosis method, device and equipment based on sectional loop resistor
By segmented circuit resistance detection and comprehensive analysis of resistance time series and operating mechanism pressure curves, the problem of insufficient diagnostic accuracy of circuit breaker contacts has been solved, enabling precise location and early warning of minute ablation points and slight pressure insufficiency.
Patent Information
- Application Number
- CN202511769171.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-01-13
AI Technical Summary
Existing technologies struggle to accurately locate internal faults in circuit breaker contacts, particularly minute ablation points and slight pressure deficiencies in the operating mechanism, resulting in insufficient diagnostic accuracy.
A segmented loop resistance detection method is adopted, which obtains resistance and thermograms by gradually increasing the DC current. Combined with the resistance time series and operating mechanism pressure curve during the slow opening and closing process, contact erosion and slight pressure deficiency are identified.
It improves the accuracy of circuit breaker contact diagnosis, enables early warning of faults, and can sensitively identify minute ablation points and slight pressure insufficiency.
Smart Images
Figure CN121324922A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of circuit breaker testing technology, and in particular to a method, apparatus and equipment for diagnosing circuit breaker contacts based on segmented loop resistance. Background Technology
[0002] Circuit breakers are crucial protective devices in power systems. A circuit breaker mainly consists of several parts: a contact system, an arc-extinguishing system, an operating mechanism, a trip unit, and a housing / frame. The contact system, typically including stationary and moving contacts, is the core of current connection and disconnection. Therefore, timely detection of the contact resistance of the contact system to diagnose the condition of the circuit breaker contacts is essential to ensuring the safe operation of the power system.
[0003] Ideally, the contact resistance of a contact system should be minimal. However, in actual operation, various factors can lead to increased contact resistance, such as: surface oxidation: oxide films form on the moving and stationary contacts when exposed to air, increasing contact resistance; decreased contact pressure: aging or wear of the operating mechanism may result in insufficient contact pressure; arcing damage: during short-circuit current interruption, the moving and stationary contacts may be burned by an electric arc, making the contact surface uneven; contaminants: mechanical impurities such as dust and carbides entering the contact surface of the moving and stationary contacts can also affect conductivity. Currently, contact resistance is mainly assessed and the condition of circuit breaker contacts is diagnosed through loop resistance testing.
[0004] However, the inventors discovered during the development of this invention that: since loop resistance detection involves applying a large DC current to the circuit breaker and then measuring the resistance of the entire conductive circuit, which includes terminals, conductors, contacts, etc., the measured value is the sum of the resistances of all components in the entire conductive circuit. Although existing technologies can effectively locate defects by segmenting measurements when the overall conductive circuit resistance of the circuit breaker is large, it is still impossible to accurately locate the fault when contact erosion occurs inside the circuit breaker (such as local fusion welding of arc contacts), especially for tiny erosion points smaller than 0.5 mm². Moreover, the operating mechanism may also fail to be identified by loop resistance detection when the pressure is slightly insufficient because its impact on the contact surface is small.
[0005] Therefore, there is an urgent need for a detection method that can accurately locate internal faults in the contacts and identify slight pressure deficiencies in the operating mechanism, so as to improve the diagnostic accuracy of circuit breaker contacts and achieve early warning of faults. Summary of the Invention
[0006] This invention provides a method, apparatus, and device for diagnosing circuit breaker contacts based on segmented loop resistance, in order to solve the problem of insufficient accuracy of traditional loop resistance detection in diagnosing circuit breaker contacts.
[0007] In a first aspect, embodiments of the present invention provide a circuit breaker contact diagnosis method based on segmented loop resistance, comprising: Based on the circuit breaker contact diagnosis segmentation model, a progressively increasing DC current is applied to each segment of the circuit breaker to obtain the resistance and thermal diagram of each segment under each level of DC current. Based on the resistance of each segment under each level of high DC current and the thermogram, the first candidate fault area in the circuit breaker is determined; The circuit breaker is controlled to open and close slowly, and a preset large DC current is applied to the circuit breaker. The resistance time series of each contact segment in the circuit breaker segment and the pressure curve of the operating mechanism are collected simultaneously. Based on the time series of each resistor and the pressure curve of the operating structure, a second candidate fault region in the circuit breaker is determined. Based on the first candidate fault region and the second candidate fault region, the circuit breaker contact diagnosis result is determined.
[0008] Secondly, embodiments of the present invention provide a circuit breaker contact diagnostic device based on segmented loop resistance, comprising: The first acquisition module is used to apply progressively increasing DC currents to each segment of the circuit breaker based on the circuit breaker contact diagnostic segmentation model, and to acquire the resistance and thermal diagram of each segment under each level of DC current. The first processing module is used to determine the first candidate fault area in the circuit breaker based on the resistance of each segment under each level of DC high current and the thermal map. The second acquisition module is used to control the circuit breaker to open and close slowly, and to apply a preset DC high current to the circuit breaker, and to simultaneously acquire the resistance time series of each contact segment in the circuit breaker segment and the pressure curve of the operating mechanism. The second processing module is used to determine the second candidate fault region in the circuit breaker based on the resistance time series and the operating structure pressure curve. The diagnostic module is used to determine the circuit breaker contact diagnostic results based on the first candidate fault region and the second candidate fault region.
[0009] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect or any possible implementation thereof.
[0010] In this embodiment of the invention, based on the segmented model for circuit breaker contact diagnosis, progressively increasing DC currents are applied to each segment of the circuit breaker. The resistance and thermogram of each segment under each DC current level are obtained. Based on the resistance and thermogram of each segment under each DC current level, the first candidate fault area in the circuit breaker, i.e., the area where contact erosion may occur, is determined. Then, the circuit breaker is controlled to perform slow opening and closing, and a preset DC current is applied to the circuit breaker. Simultaneously, the resistance time series and operating mechanism pressure curve of each contact segment in the circuit breaker are collected. Based on the resistance time series and operating mechanism pressure curve, the second candidate fault area in the circuit breaker, i.e., the slight pressure deficiency of the operating mechanism that may occur in the circuit breaker, is determined. Then, based on the first and second candidate fault areas, the circuit breaker contact diagnosis results are comprehensively determined, making the circuit breaker contact diagnosis sensitive to small erosion points and slight pressure deficiency of the operating mechanism, improving the accuracy of circuit breaker contact diagnosis, and thus helping to achieve early fault warning. Attached Figure Description
[0011] Figure 1 This is a flowchart illustrating the implementation of the circuit breaker contact diagnosis method based on segmented loop resistance provided in this embodiment of the invention. Figure 2 This is a schematic diagram of the circuit breaker contact diagnostic device based on segmented loop resistance provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation
[0012] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[0013] See Figure 1 The document illustrates a flowchart of the implementation of a circuit breaker contact diagnosis method based on segmented loop resistance provided by an embodiment of the present invention, detailed below: Step 101: Based on the circuit breaker contact diagnosis segmentation model, apply progressively increasing DC currents to each segment of the circuit breaker in sequence, and obtain the resistance and thermal diagram of each segment under each level of DC current.
[0014] The circuit breaker contact diagnostic segmentation model is a model that segments the entire conductive circuit of the circuit breaker. For example, the circuit breaker contact diagnostic segmentation model may include input terminal segment, main body segment, stationary contact segment, moving contact segment, and output terminal segment. The input terminal segment may include external wiring terminals and bolts connecting the terminals to the conductor. The main body segment may include the internal copper busbar and connecting sleeve of the circuit breaker. The stationary contact segment may include a stationary contact base and stationary contact plates (including main contacts / arc contacts). The moving contact segment may include a moving contact rod and moving contact plates (including main contacts / arc contacts). The output terminal segment may include output terminals and bolts connecting the terminals to the conductor. Alternatively, depending on the specific circuit breaker type or actual needs, it can also be divided into incoming terminals, flexible connections (or copper busbars), stationary main contacts, moving main contacts, moving conductive rods, stationary arc contacts, moving arc contacts, arc-extinguishing chamber housing (conductive part) flexible connections (or copper busbars), and outgoing terminals to constitute the circuit breaker contact diagnostic segmentation model.
[0015] By sequentially applying progressively increasing DC currents to each section of the circuit breaker, and thus sequentially performing loop resistance detection on each section of the circuit breaker, for example, by sequentially applying currents of 100A, 200A, and 300A to each section of the circuit breaker, the resistance value can be recorded after each DC current has stabilized for a certain period of time (e.g., 3s), thus obtaining the resistance of each section under each DC current level.
[0016] In this embodiment, considering that if there are tiny ablation points between the moving and stationary contacts of the circuit breaker, the current density will increase non-linearly with the increase of the excitation current because the contact area of the tiny ablation points is extremely small, resulting in a sudden inflection point in the resistance value (the resistance of normal components changes slowly with the current), the inflection point is captured by applying progressively increasing DC currents to each section of the circuit breaker and obtaining the resistance of each section under each level of DC current to lock in the tiny defects.
[0017] Furthermore, to improve the accuracy of circuit breaker contact diagnosis results, this embodiment also acquires thermal maps of each segment under each level of DC high current by using, for example, an infrared camera or thermal imager when applying progressively increasing DC high current to each segment of the circuit breaker. Since any abnormal increase in contact resistance on the contacts and their connecting components due to ablation, oxidation, or insufficient pressure will be converted into a significant increase in local temperature, the thermal map can most directly convert microscopic resistance differences into macroscopic temperature differences, thereby improving diagnostic accuracy.
[0018] Step 102: Determine the first candidate fault area in the circuit breaker based on the resistance and thermal diagram of each segment under each level of high DC current.
[0019] In one embodiment, step 102 includes: For each segment, determine whether the resistance of the segment changes abruptly under each stage of high DC current, and determine the first candidate fault segment based on the determination result.
[0020] For each segment, a second candidate fault segment is determined based on the thermal map of that segment under each level of high DC current.
[0021] The first candidate fault area in the circuit breaker is determined based on the first candidate fault segment and the second candidate fault segment.
[0022] In one embodiment, determining whether the resistance of the segment changes abruptly under each stage of high DC current, and determining the first candidate fault segment based on the determination result, includes: For each segment, determine whether the resistance of that segment under each level of high DC current exceeds the normal resistance range of that segment under each level of high DC current.
[0023] If the resistance of a segment under a certain level of high DC current exceeds the normal resistance range of that segment under the same level of high DC current, that segment is identified as a first candidate fault segment.
[0024] For example, this embodiment can establish a "normal threshold library," that is, based on healthy circuit breakers of the same model and service life, statistically analyze the resistance range of each segment under different DC high currents, which serves as the normal resistance range for each segment under each level of DC high current. For example, the normal resistance range for the moving contact segment includes: 5-8 μΩ at 100A, 4-7 μΩ at 200A, and 3-6 μΩ at 300A. After obtaining the resistance of the moving contact segment at 100A, 200A, and 300A, it can be compared with the corresponding normal resistance range. If its resistance under each DC high current does not exceed the corresponding normal resistance range, it can be determined that the moving contact segment is likely free of faults such as micro-abrasion points. If its resistance under a certain DC high current exceeds the corresponding normal resistance range, for example, its resistance at 300A is 12 μΩ, which is about twice that of 3-6 μΩ, it can be preliminarily identified that the moving contact segment has a micro-abrasion point fault, and thus the moving contact segment can be considered as a first candidate fault segment.
[0025] In one embodiment, determining whether the resistance of the segment changes abruptly under each stage of high DC current, and determining the first candidate fault segment based on the determination result, includes: For each segment, calculate the difference in resistance between each adjacent two stages of high DC current.
[0026] Each difference value corresponding to each segment is compared with the corresponding preset difference threshold.
[0027] If at least one difference among the differences corresponding to a certain segment is greater than the corresponding preset difference threshold, then that segment is determined as a first candidate fault segment.
[0028] For example, besides directly comparing the resistance of each segment under each high DC current level with its corresponding normal resistance range to determine whether a sudden change in resistance has occurred, the difference can also be calculated for judgment. The preset difference threshold for each pair of adjacent levels can be the same or different; it can be a specific value or a range of values. For instance, for the moving contact segment, the preset difference threshold for 100A and 200A is 1-3μΩ, and the preset difference threshold for 200A and 300A is 1-4μΩ. Assuming the difference between the resistance of the moving contact segment at 100A and 200A is 2μΩ, and the difference between the resistance at 200A and 300A is 6μΩ, then a minor ablation point fault can be preliminarily identified in the moving contact segment, thus making the moving contact segment a first candidate fault segment.
[0029] In one embodiment, for each segment, a second candidate fault segment is determined based on the thermal map of that segment under each stage of high DC current, including: For each segment, based on the thermal map of that segment under each level of high DC current, it is determined whether there are high-temperature points in that segment with temperatures exceeding a preset temperature threshold.
[0030] If at least one heat map corresponding to a certain segment contains a high-temperature point with a temperature greater than a preset temperature threshold, then that segment is identified as a second candidate fault segment.
[0031] In this embodiment, in addition to determining the first candidate fault segment based on the resistance of each segment under each level of DC high current, the system also makes a judgment based on the thermal map of each segment under each level of DC high current. Then, the second candidate fault segment is determined based on the judgment result of the thermal map. On this basis, the first candidate fault area in the circuit breaker can be determined by taking the union of the first candidate fault segment and the second candidate fault segment, thereby accurately identifying all possible contact faults in the circuit breaker.
[0032] Step 103: Control the circuit breaker to perform slow opening and closing, and apply a preset large DC current to the circuit breaker. Simultaneously collect the resistance time series of each contact segment in the circuit breaker and the pressure curve of the operating mechanism.
[0033] The circuit breaker's contact segments can include stationary contact segments and moving contact segments. For example, the circuit breaker can be controlled to perform slow opening and closing, and a 100A current can be applied to it. Based on this, the resistance of each contact segment in the circuit breaker's sections can be simultaneously collected during the slow opening and closing process, forming a resistance time series. Simultaneously, the pressure of the circuit breaker's operating mechanism during the slow opening and closing process can be collected, forming an operating mechanism pressure curve. Furthermore, based on the contact resistance and operating mechanism pressure during the circuit breaker's opening and closing process, a comprehensive diagnosis can be made to determine whether there is a slight pressure deficiency in the operating mechanism requiring an early warning.
[0034] Step 104: Based on the time series of each resistor and the operating structure pressure curve, determine the second candidate fault region in the circuit breaker.
[0035] In one embodiment, step 104 includes: Based on the time series of each resistor and the pressure curve of the operating structure, the correlation coefficient between the resistance of each contact segment and the pressure of the operating mechanism, as well as the contact response time and resistance settling time of each contact segment, are extracted.
[0036] Based on the correlation coefficient, contact response time, and resistance settling time, the second candidate fault region in the circuit breaker is determined.
[0037] In one embodiment, based on the time series of each resistor and the pressure curve of the operating mechanism, the correlation coefficient between the resistance of each contact segment in the circuit breaker and the pressure of the operating mechanism is extracted, including: For each resistance time series, determine the minimum resistance value of the contact segment corresponding to that resistance time series.
[0038] The peak pressure of the operating mechanism is determined based on the pressure curve of the operating structure.
[0039] Calculate the correlation coefficient between the minimum resistance and the peak pressure of the operating mechanism, and use it as the correlation coefficient between the resistance of that contact segment in the circuit breaker and the pressure of the operating mechanism.
[0040] For example, the correlation coefficient between the minimum resistance and the peak pressure of the operating mechanism can be calculated using methods such as Spearman correlation coefficient and Pearson correlation coefficient. A threshold for the correlation coefficient under normal conditions can be determined; for instance, 0.8 can be set as the threshold for the correlation coefficient under normal conditions. A condition is considered normal when the correlation coefficient between the minimum resistance and the peak pressure of the operating mechanism is greater than or equal to 0.8. This allows for the subsequent determination of the second candidate fault region in the circuit breaker based on the correlation coefficient between the resistance of the contact segments and the operating mechanism pressure.
[0041] In one embodiment, based on the time series of each resistor and the operating structure pressure curve, the contact response time of each contact segment in the circuit breaker is extracted, including: The time point at which the pressure of the operating mechanism rises to the preset pressure threshold is determined from the pressure curve of the operating structure and recorded as the first time point.
[0042] For each resistance time series, the time point at which the resistance decrease value of the corresponding contact segment is determined from the resistance time series is the preset resistance threshold value, and is recorded as the second time point.
[0043] Calculate the time interval between the first time point and each second time point, and use it as the contact response time of each contact segment in the circuit breaker.
[0044] For example, the time interval from when the operating mechanism pressure rises to 10% of the rated value to when the resistance of the contact segment drops to 50% of the reference value can be determined, and this time interval can be defined as the contact response time of the contact segment. For example, a normal range of contact response time for the contact segment can also be determined, such as 5-15 ms, so that a second candidate fault region in the circuit breaker can be subsequently determined based on the contact response time and corresponding normal range of each contact segment in the circuit breaker.
[0045] In one embodiment, based on the time series of each resistor, the resistance settling time of each contact segment in the circuit breaker is extracted, including: For each resistance time series, the time range in which the resistance fluctuation amplitude is less than or equal to a preset fluctuation ratio is determined, and this range is used as the resistance stabilization time of the contact segment corresponding to the resistance time series.
[0046] For example, the time when the resistance fluctuation amplitude after contact is less than or equal to 1% can be extracted from the resistance time series and used as the resistance settling time of the corresponding contact segment. For example, the normal range of the resistance settling time can be less than or equal to 20ms, so that the second candidate fault area in the circuit breaker can be determined based on the resistance settling time and the corresponding normal range.
[0047] In one embodiment, determining a second candidate fault region in the circuit breaker based on the correlation coefficient, contact response time, and resistance settling time includes: Determine whether at least two of the correlation coefficient, contact response time, and resistance settling time exceed their respective normal ranges.
[0048] If at least two of the correlation coefficient, contact response time, and resistance settling time exceed the corresponding normal range, the second candidate fault area in the circuit breaker is determined to be the operating mechanism.
[0049] For example, if the contact time is greater than 5ms and the correlation coefficient between the pressure and resistance of the operating mechanism is less than 0.6, then the operating mechanism is judged to have slightly insufficient pressure.
[0050] Step 105: Determine the circuit breaker contact diagnosis results based on the first candidate fault area and the second candidate fault area.
[0051] For example, a diagnostic report containing "abnormal segment location, fault type, severity, and recommended handling measures" can be generated as the circuit breaker contact diagnostic result based on the first and second candidate fault areas. Examples include: "Arc contact segment 3, 0.3mm² micro-ablation point, re-inspection recommended within one month," and "Operating mechanism linkage section, pressure less than 8%, adjustment of spring preload recommended."
[0052] This invention first applies progressively increasing DC currents to each segment of the circuit breaker based on a segmented contact diagnostic model. The resistance and thermograms of each segment under each DC current level are then obtained. Based on these data, a first candidate fault region (i.e., an area where contact erosion may occur) is identified. The circuit breaker is then controlled to perform slow opening and closing, and a preset DC current is applied. Simultaneously, the resistance time series and operating mechanism pressure curves of each contact segment are collected. Based on these data, a second candidate fault region (i.e., a slight pressure deficiency in the operating mechanism) is identified. Finally, the circuit breaker contact diagnostic results are comprehensively determined based on both the first and second candidate fault regions. This makes the circuit breaker contact diagnostics more sensitive to minute erosion points and slight pressure deficiencies in the operating mechanism, improving diagnostic accuracy and facilitating early fault warning.
[0053] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.
[0054] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.
[0055] Figure 2 A schematic diagram of the circuit breaker contact diagnostic device based on segmented loop resistance provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below: like Figure 2 As shown, the circuit breaker contact diagnostic device based on segmented loop resistance includes: The first acquisition module 21 is used to apply progressively increasing DC currents to each segment of the circuit breaker based on the circuit breaker contact diagnostic segmentation model, and to acquire the resistance and thermal diagram of each segment under each level of DC current.
[0056] The first processing module 22 is used to determine the first candidate fault area in the circuit breaker based on the resistance and thermal diagram of each segment under each level of DC high current.
[0057] The second acquisition module 23 is used to control the circuit breaker to perform slow opening and closing, and to apply a preset DC high current to the circuit breaker, and to synchronously acquire the resistance time series of each contact segment in the circuit breaker and the pressure curve of the operating mechanism.
[0058] The second processing module 24 is used to determine the second candidate fault region in the circuit breaker based on the resistance time series and the operating structure pressure curve.
[0059] The diagnostic module 25 is used to determine the circuit breaker contact diagnostic results based on the first candidate fault area and the second candidate fault area.
[0060] This invention first applies progressively increasing DC currents to each segment of the circuit breaker based on a segmented contact diagnostic model. The resistance and thermograms of each segment under each DC current level are then obtained. Based on these data, a first candidate fault region (i.e., an area where contact erosion may occur) is identified. The circuit breaker is then controlled to perform slow opening and closing, and a preset DC current is applied. Simultaneously, the resistance time series and operating mechanism pressure curves of each contact segment are collected. Based on these data, a second candidate fault region (i.e., a slight pressure deficiency in the operating mechanism) is identified. Finally, the circuit breaker contact diagnostic results are comprehensively determined based on both the first and second candidate fault regions. This makes the circuit breaker contact diagnostics more sensitive to minute erosion points and slight pressure deficiencies in the operating mechanism, improving diagnostic accuracy and facilitating early fault warning.
[0061] In one possible implementation, the first processing module 22 is specifically used for: For each segment, determine whether the resistance of the segment changes abruptly under each stage of high DC current, and determine the first candidate fault segment based on the determination result.
[0062] For each segment, a second candidate fault segment is determined based on the thermal map of that segment under each level of high DC current.
[0063] The first candidate fault area in the circuit breaker is determined based on the first candidate fault segment and the second candidate fault segment.
[0064] In one possible implementation, the first processing module 22 is specifically used for: For each segment, determine whether the resistance of that segment under each level of high DC current exceeds the normal resistance range of that segment under each level of high DC current; If the resistance of a segment under a certain level of high DC current exceeds the normal resistance range of that segment under that level of high DC current, the segment is identified as a first candidate fault segment.
[0065] In one possible implementation, the first processing module 22 is specifically used for: For each segment, based on the thermal map of that segment under each level of high DC current, it is determined whether there are high-temperature points in that segment with temperatures exceeding a preset temperature threshold.
[0066] If at least one heat map corresponding to a certain segment contains a high-temperature point with a temperature greater than a preset temperature threshold, then that segment is identified as a second candidate fault segment.
[0067] In one possible implementation, the second processing module 24 is specifically used for: Based on the time series of each resistor and the pressure curve of the operating structure, the correlation coefficient between the resistance of each contact segment and the pressure of the operating mechanism, as well as the contact response time and resistance settling time of each contact segment, are extracted.
[0068] Based on the correlation coefficient, contact response time, and resistance settling time, the second candidate fault region in the circuit breaker is determined.
[0069] In one possible implementation, the second processing module 24 is specifically used for: For each resistance time series, determine the minimum resistance value of the contact segment corresponding to that resistance time series.
[0070] The peak pressure of the operating mechanism is determined based on the pressure curve of the operating structure.
[0071] Calculate the correlation coefficient between the minimum resistance and the peak pressure of the operating mechanism, and use it as the correlation coefficient between the resistance of that contact segment in the circuit breaker and the pressure of the operating mechanism.
[0072] In one possible implementation, the second processing module 24 is specifically used for: The time point at which the pressure of the operating mechanism rises to the preset pressure threshold is determined from the pressure curve of the operating structure and recorded as the first time point.
[0073] For each resistance time series, the time point at which the resistance decrease value of the corresponding contact segment is determined from the resistance time series is the preset resistance threshold value, and is recorded as the second time point.
[0074] Calculate the time interval between the first time point and each second time point, and use it as the contact response time of each contact segment in the circuit breaker.
[0075] In one possible implementation, the second processing module 24 is specifically used for: For each resistance time series, the time range in which the resistance fluctuation amplitude is less than or equal to a preset fluctuation ratio is determined, and this range is used as the resistance stabilization time of the contact segment corresponding to the resistance time series.
[0076] Figure 3 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. For example... Figure 3 As shown, the electronic device 3 of this embodiment includes a processor 30 and a memory 31. The memory 31 stores a computer program 32. When the processor 30 executes the computer program 32, it implements the steps in the various method embodiments described above. Alternatively, when the processor 30 executes the computer program 32, it implements the functions of each module / unit in the various device embodiments described above.
[0077] For example, computer program 32 may be divided into one or more modules / units, which are stored in memory 31 and executed by processor 30 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 32 in electronic device 3.
[0078] Electronic device 3 may include, but is not limited to, processor 30 and memory 31. Those skilled in the art will understand that... Figure 3 This is merely an example of electronic device 3 and does not constitute a limitation on electronic device 3. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 3 may also include input / output devices, network access devices, buses, etc.
[0079] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.
[0080] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.
[0081] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.
Claims
1. A method for diagnosing circuit breaker contacts based on segmented loop resistance, characterized in that, include: Based on the circuit breaker contact diagnosis segmentation model, a progressively increasing DC current is applied to each segment of the circuit breaker to obtain the resistance and thermal diagram of each segment under each level of DC current. Based on the resistance of each segment under each level of high DC current and the thermogram, the first candidate fault area in the circuit breaker is determined; The circuit breaker is controlled to open and close slowly, and a preset large DC current is applied to the circuit breaker. The resistance time series of each contact segment in the circuit breaker segment and the pressure curve of the operating mechanism are collected simultaneously. Based on the time series of each resistor and the pressure curve of the operating structure, a second candidate fault region in the circuit breaker is determined. Based on the first candidate fault region and the second candidate fault region, the circuit breaker contact diagnosis result is determined.
2. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 1, characterized in that, Based on the resistance of each segment under each level of high DC current and the thermogram, the first candidate fault region in the circuit breaker is determined, including: For each segment, determine whether the resistance of the segment changes abruptly under each stage of high DC current, and determine the first candidate fault segment based on the determination result; For each segment, a second candidate fault segment is determined based on the thermogram of that segment under each level of high DC current; The first candidate fault region in the circuit breaker is determined based on the first candidate fault segment and the second candidate fault segment.
3. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 2, characterized in that, For each segment, determine whether the resistance of that segment changes abruptly under each stage of high DC current. Based on the determination result, determine the first candidate fault segment, including: For each segment, determine whether the resistance of that segment under each level of high DC current exceeds the normal resistance range of that segment under each level of high DC current; If the resistance of a segment under a certain level of high DC current exceeds the normal resistance range of that segment under that level of high DC current, the segment is identified as a first candidate fault segment.
4. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 2, characterized in that, For each segment, based on the thermogram of that segment under each stage of high DC current, a second candidate fault segment is determined, including: For each segment, based on the thermogram of that segment under each level of high DC current, determine whether there are high temperature points in that segment with temperatures exceeding a preset temperature threshold. If at least one of the heat maps corresponding to a certain segment contains a high-temperature point with a temperature greater than a preset temperature threshold, then that segment is determined as a second candidate fault segment.
5. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 1, characterized in that, Based on the time series of each resistor and the pressure curve of the operating structure, a second candidate fault region in the circuit breaker is determined, including: Based on the time series of each resistance and the pressure curve of the operating structure, the correlation coefficient between the resistance of each contact segment and the pressure of the operating mechanism in the circuit breaker, as well as the contact response time and resistance stabilization time of each contact segment, are extracted. The second candidate fault region in the circuit breaker is determined based on the correlation coefficient, the contact response time, and the resistance stabilization time.
6. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 5, characterized in that, Based on the time series of each resistance and the pressure curve of the operating structure, the correlation coefficient between the resistance of each contact segment in the circuit breaker and the pressure of the operating mechanism is extracted, including: For each of the resistance time series, determine the minimum resistance value of the contact segment corresponding to that resistance time series; Based on the pressure curve of the operating structure, the peak pressure of the operating mechanism is determined; Calculate the correlation coefficient between the minimum resistance and the peak pressure of the operating mechanism, and use it as the correlation coefficient between the resistance of the contact segment in the circuit breaker and the pressure of the operating mechanism.
7. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 5, characterized in that, Based on the time series of each resistor and the pressure curve of the operating structure, the contact response time of each contact segment in the circuit breaker is extracted, including: From the pressure curve of the operating structure, determine the time point at which the pressure of the operating mechanism rises to the preset pressure threshold, and record it as the first time point; For each of the resistance time series, the time point at which the resistance decrease value of the corresponding contact segment is determined from the resistance time series is a preset resistance threshold, and is recorded as the second time point; Calculate the time interval between the first time point and each of the second time points, and use it as the contact response time of each contact segment in the circuit breaker.
8. The circuit breaker contact diagnosis method based on segmented loop resistance according to claim 5, characterized in that, Based on the time series of each resistance, the resistance settling time of each contact segment in the circuit breaker is extracted, including: For each resistance time series, the time range in which the resistance fluctuation amplitude is less than or equal to a preset fluctuation ratio is determined as the resistance stabilization time of the contact segment corresponding to the resistance time series.
9. A circuit breaker contact diagnostic device based on segmented loop resistance, characterized in that, include: The first acquisition module is used to apply progressively increasing DC currents to each segment of the circuit breaker based on the circuit breaker contact diagnostic segmentation model, and to acquire the resistance and thermal diagram of each segment under each level of DC current. The first processing module is used to determine the first candidate fault area in the circuit breaker based on the resistance of each segment under each level of DC high current and the thermal map. The second acquisition module is used to control the circuit breaker to open and close slowly, and to apply a preset DC high current to the circuit breaker, and to simultaneously acquire the resistance time series of each contact segment in the circuit breaker segment and the pressure curve of the operating mechanism. The second processing module is used to determine the second candidate fault region in the circuit breaker based on the resistance time series and the operating structure pressure curve. The diagnostic module is used to determine the circuit breaker contact diagnostic results based on the first candidate fault region and the second candidate fault region.
10. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method as described in any one of claims 1 to 8.