Intelligent evaluation method for operating state of vacuum circuit breaker

Abstract

The invention discloses an intelligent evaluation method for the operation state of a vacuum circuit breaker, particularly relates to the technical field of state evaluation of power distribution equipment, and is used for solving the problems that an existing vacuum circuit breaker mainly depends on regular maintenance and action frequency statistics, and lacks a multi-source measurement and online degradation evaluation means based on real working conditions. The degradation degree of the mechanism and the arc extinguish chamber is difficult to reflect timely and quantitatively; and a reliable decision basis is provided for a maintenance object and a maintenance opportunity. Multi-source signals such as coil current, main loop current and voltage, contact temperature, mechanism displacement vibration and the like are synchronously acquired under a unified time service reference, action stages are divided, and characteristics such as action time, speed, displacement, temperature rise gradient, current change rate, vibration amplitude and the like are extracted; the characteristic offset is calculated under the same working condition in combination with a single circuit breaker individual baseline model, so that the effects of performing refined online evaluation on the whole process of opening and closing under the real working condition and accurately reflecting the deviation degree of the relative health state are achieved.

Description

Technical Field

[0001] This invention relates to the field of power distribution equipment condition assessment technology, specifically to an intelligent assessment method for the operating status of a vacuum circuit breaker. Background Technology

[0002] In existing technologies, vacuum circuit breakers, as key switching equipment in medium-voltage substations and ring main units, rely primarily on periodic power outage tests, mechanical characteristic inspections, contact resistance tests, and infrared temperature monitoring for operational status assessment. In some scenarios, coil current waveform analysis or online monitoring of single-point temperature and vibration is introduced. These methods are mostly conducted during maintenance or under test conditions, resulting in a limited range of signal types. They lack synchronous recording of electrical, thermal, and mechanical quantities throughout the entire opening and closing process under a unified time reference. This makes it difficult to continuously characterize the entire opening and closing behavior under real load and environmental conditions, and can only provide coarse-grained conclusions such as "qualified," "basically qualified," and "unqualified," failing to reflect subtle degradation and evolution processes.

[0003] At the long-term operational assessment level, existing technologies generally set uniform thresholds based on equipment models, or configure alarm limits separately for operating time, coil current characteristics, and temperature rise levels based on experience. They lack individual baseline models for each circuit breaker, fail to distinguish the normal fluctuation range of characteristics under different operating conditions, and do not decompose characteristic deviations according to mechanism degradation, arc-extinguishing chamber degradation, and accumulated operational load. This results in assessment results that are insensitive to individual equipment differences and operating condition differences, easily leading to misjudgments and omissions under the same alarm threshold. Furthermore, existing methods generally do not establish a systematic correspondence between online assessment results and measured wear data obtained during planned maintenance and fault disassembly, such as spring preload status, pin wear, contact ablation depth, and creepage distance. They lack a closed-loop mechanism for incrementally correcting the assessment model and risk thresholds based on wear records, making it difficult to maintain consistency between the degradation index and actual physical degradation throughout the entire lifespan.

[0004] In summary, existing technologies cannot conduct refined and traceable online assessments of the operating behavior and degradation status of a single vacuum circuit breaker under different operating conditions based on multi-source signals throughout the entire opening and closing process under a unified timing reference. Furthermore, it is difficult to correlate the assessment results with the wear records formed by maintenance and disassembly in a closed loop, thus limiting the early identification of degradation trends and the quantitative classification of operational risk levels. Maintenance targets and maintenance time windows still mainly rely on experience, resulting in insufficient precision in condition-based maintenance and life management. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an intelligent evaluation method for the operating status of vacuum circuit breakers, thereby solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an intelligent assessment method for the operating status of a vacuum circuit breaker, comprising: S1. Under the time reference, collect the coil current waveform, main circuit current and voltage, contact temperature, and mechanism stroke vibration signal during the opening and closing process of the vacuum circuit breaker, and generate operation segment identifiers and operating condition labels for each action; S2. Divide the operation segment into stages: coil energization, mechanism energy release, contact movement, arc maintenance, and contact stabilization. Extract the characteristics of action time, speed, displacement, vibration amplitude, temperature rise gradient, and current change rate for each stage. S3. Select healthy action segments in the early stage of circuit breaker operation, normalize the characteristics according to the operating conditions, construct an individual baseline model for a single circuit breaker, and register the effective time of the baseline parameter version. S4. Calculate the offset between the new operating segment features and the individual baseline model of a single circuit breaker under the corresponding operating conditions. Based on the degradation mode dictionary, decompose the feature offset into mechanism degradation components, arc-extinguishing chamber degradation components, and operation cumulative load components. S5. Calculate the degradation index of the mechanism, the degradation index of the arc-extinguishing chamber, and the cumulative load index of operation based on the degradation components, and generate the operation risk level, maintenance objects, and maintenance time windows; S6. After completing the planned maintenance and fault disassembly inspection, the measured wear status is correlated with the historical assessment results, the degradation mode dictionary and risk level threshold are corrected by incremental update, and the model version is recorded for traceability.

[0007] Furthermore, S1 includes: Use the timekeeping reference of the station's timekeeping device as a time reference; A coil current detection unit, a main circuit current detection unit, a main circuit voltage detection unit, a contact temperature detection unit, a mechanism displacement detection unit, and a mechanism vibration detection unit are installed near the primary circuit and operating mechanism of the vacuum circuit breaker. Each detection unit is connected to the acquisition unit through an acquisition channel, and the acquisition channel has a fixed range, unit of measurement, and sampling rhythm. When the vacuum circuit breaker receives a tripping command and when it receives a closing command, the acquisition unit triggers sampling under the control of the timing reference, synchronously acquires the output signals of each detection unit on a unified time axis, and generates an operation segment identifier based on the circuit breaker number, timing timestamp, and action type.

[0008] Furthermore, the acquisition unit reads operating information from the protection device and monitoring system during sampling. The operating information includes operation nature markers, protection action types, breaking current range markers, and ambient temperature range markers. Within a predetermined time after the opening and closing actions are completed, the operation information is sorted out, the operating condition label is generated and bound to the corresponding operating segment identifier to obtain the operating segment record. The operating segment record includes the sampling sequence, the operating segment identifier and the operating condition label. Attach the acquisition channel version number and status code fields to the running segment record; And send the runtime segment record to the evaluation server; The evaluation server checks the corresponding record in the fragment library using the combination of the running fragment identifier and the channel version number as an idempotent key. If no corresponding record is found, the running fragment record is written to the fragment library.

[0009] Furthermore, S2 includes: The evaluation server reads the coil current waveform, main circuit current and voltage, contact temperature and mechanism stroke vibration signal corresponding to the running segment identifier based on the running segment records in the segment library; Based on the time stamp and the start and end points, abrupt change points and inflection points of each signal, the start and end times of the coil energizing stage, the mechanism energy release stage, the contact movement stage, the arc maintenance stage and the contact stabilization stage are determined. Calculate the action time, velocity, displacement, vibration amplitude, temperature rise gradient and current change rate at each stage, generate feature records and write them into the feature library; For runtime segments whose stage boundaries cannot be reliably identified, the runtime segment identifier is marked as a stage division failure state, and status code four is written into the corresponding feature record.

[0010] Furthermore, S3 includes: The evaluation server marks vacuum circuit breakers that meet the health criteria as healthy devices based on the test records. Healthy action segments are selected from the feature library according to the operation segment identifier, grouped according to the operating condition label, and statistically analyzed for the six types of action characteristics to obtain the reference center value and allowable fluctuation range. They are then collected according to the circuit breaker number to form an individual baseline model for each circuit breaker. The evaluation server generates a baseline parameter version with version number, effective time, and applicable operating condition set for the individual baseline model of a single circuit breaker, writes it to the read-only parameter library and generates an evidence chain record. When a baseline parameter version update request is received, it verifies the continuity of the version number and the integrity of the evidence chain record. If the verification fails, it marks the version conflict with status code five and keeps the active version unchanged.

[0011] Furthermore, S4 includes: When the individual baseline model of a single circuit breaker is in an active version, the evaluation server reads the current operating segment features from the feature library based on the operating segment identifier, and calculates the feature offset vector according to the current operating segment features and the reference center value in the individual baseline model of the single circuit breaker. Select a set of degradation patterns from the degradation pattern dictionary that meet the set threshold for similarity with the feature offset vector, and read the assigned weights corresponding to the action time feature, velocity feature, displacement feature, vibration amplitude feature, temperature rise gradient feature and current change rate feature. The feature offset vector is decomposed into mechanism degradation component, arc-extinguishing chamber degradation component and operational cumulative load component according to the assigned weights, and the mechanism degradation component, arc-extinguishing chamber degradation component and operational cumulative load component are written into the degradation record library along with the running segment identifier.

[0012] Furthermore, the degradation mode dictionary is formed by the manufacturer based on the type test prototype and the failed prototype. The weights are assigned to satisfy non-negative constraints during construction and limit the total weight range of the mechanism degradation component, the arc-extinguishing chamber degradation component and the operational cumulative load component. When the evaluation server performs on-site calculations, it marks the running segment corresponding to the feature offset vector whose similarity to the degradation mode in the degradation mode dictionary is lower than a set threshold as a mode missing state. When performing degradation decomposition using the feature offset threshold rule, it selects the degradation component level of the mechanism, the degradation component level of the arc extinguishing chamber, and the cumulative load component level of the operation based on the threshold interval where the feature offset vector is located.

[0013] Furthermore, S5 includes: The evaluation server sets up sliding observation windows based on the number of actions and natural time in the degradation record library according to device number; Within each sliding observation window, the mechanism degradation component, arc-extinguishing chamber degradation component, and operational cumulative load component are read in the order of the running segment identifier. The mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index are calculated according to the normalization rule. The three types of indices are compared with the risk level threshold set to determine the operational risk level, and the maintenance objects and maintenance time windows are determined based on the combination relationship of the mechanism degradation index, arc extinguishing chamber degradation index and operation cumulative load index in the maintenance strategy library.

[0014] Furthermore, S6 includes: During planned maintenance and troubleshooting, the system measures the spring preload, pin wear, lubrication status, connecting rod clearance, contact erosion depth, and creepage distance of insulating components. It also generates wear records through the maintenance system, including the device number, maintenance time, and historical assessment result number. The assessment server reads wear records and obtains the mechanism degradation index, arc-extinguishing chamber degradation index, operational cumulative load index, and operational risk level from the assessment result library and degradation record library. It then associates each physical wear quantity with the mechanism degradation index, arc-extinguishing chamber degradation index, operational cumulative load index, and operational risk level to form a set of records labeled with the degree of degradation. The evaluation server incrementally updates the degradation pattern dictionary and risk level threshold set based on the record set, generates a model version number, and registers the corresponding evidence chain record in the read-only version repository.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By synchronously acquiring multi-source signals such as coil current, main circuit current and voltage, contact temperature, mechanism displacement and vibration under the time reference, the entire opening and closing process is divided into stages based on the operation segment identifier and operating condition label, and features such as action time, speed, displacement, temperature rise gradient, current change rate and vibration amplitude are extracted. Then, combined with the individual baseline model of a single circuit breaker, the feature offset is calculated under the same operating conditions. This achieves the effect of fine online evaluation of the entire opening and closing process of vacuum circuit breakers under real operating conditions, accurately reflects the degree of deviation of the action behavior from the healthy state, and supports the early identification of degradation trends.

[0016] 2. By mapping feature offsets to mechanism degradation components, arc-extinguishing chamber degradation components, and operational cumulative load components, the mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index are calculated based on a sliding observation window. Combined with the maintenance strategy library, the operation risk level, maintenance object, and maintenance time window are generated. At the same time, wear records are used to incrementally update the degradation mode dictionary and risk level thresholds and form an evidence chain in the version library. This achieves the effect of decomposable degradation mechanism, quantifiable operation risk, and traceable maintenance decision-making without changing the existing protection and control logic. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the intelligent evaluation method for the operating status of a vacuum circuit breaker according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example: Figure 1 A flowchart illustrating an intelligent assessment method for the operating status of a vacuum circuit breaker according to the present invention is provided. The intelligent assessment method for the operating status of a vacuum circuit breaker includes: S1. Under the time reference, collect the coil current waveform, main circuit current and voltage, contact temperature, and mechanism stroke vibration signal during the opening and closing process of the vacuum circuit breaker, and generate an operation segment identifier and operating condition label for each action. The specific implementation is as follows: In order to obtain multi-source signals of the entire process of opening and closing of vacuum circuit breakers under real working conditions at the substation site, the time reference output by the in-station time synchronization device is used as a unified time reference. The time reference refers to the unified time signal broadcast throughout the entire station, which is used to add a comparable timestamp to subsequent records. A current detection unit, a voltage detection unit, a temperature detection unit, a displacement detection unit, and a vibration detection unit are installed near the primary circuit and operating mechanism of each vacuum circuit breaker. The current detection unit is used to acquire the coil current changes of the opening and closing coils. The voltage detection unit is used to acquire the voltage changes of the main circuit. The temperature detection unit is arranged near the moving contact, stationary contact, or conductive conductor to measure the contact temperature. The displacement detection unit is fixed on the mechanism transmission chain or the part linked to the contact to measure the mechanism stroke. The vibration detection unit is fixed on the mechanism frame or switch cabinet housing to measure the vibration signal of the mechanism stroke. The above detection units are connected to the acquisition unit through acquisition channels. Each acquisition channel is pre-fixed with channel name, range, unit of measurement, and sampling rhythm during configuration. The range is used to limit the effective measurement interval, the unit of measurement is used to unify subsequent feature calculations, and the sampling rhythm is used to limit the sampling time interval of the channel.

[0020] Preferably, the current detection unit and the voltage detection unit can be implemented by current transformers and voltage transformers, the coil current detection can be implemented by current sensing elements, the temperature detection unit can be implemented by temperature sensing elements, the displacement detection unit can be implemented by displacement sensing elements, and the vibration detection unit can be implemented by acceleration sensing elements, but the specific device form is not limited to these.

[0021] When the vacuum circuit breaker receives a tripping or closing command from the protection or control device, the acquisition unit triggers a sampling process under the control of the timing reference. Each acquisition channel synchronously acquires the coil current waveform, main circuit current and voltage, contact temperature, and mechanism stroke vibration signal of the tripping and closing coils on a unified time axis according to a preset sampling rhythm. The coil current waveform refers to the ordered sample sequence of coil current changing over time, the main circuit current and voltage refers to the ordered sample sequence of main circuit current and voltage changing over time, the contact temperature refers to the ordered sample sequence of temperature of the conductive path near the contact changing over time, and the mechanism stroke vibration signal refers to the ordered sample sequence of mechanism displacement and mechanical vibration response changing over time.

[0022] To uniquely identify a complete opening or closing process in subsequent stages, the acquisition unit generates an operation segment identifier each time a sampling is triggered. The operation segment identifier is composed of the circuit breaker number, the time synchronization timestamp, and the action type. The circuit breaker number is a unique number within the station, the time synchronization timestamp is the trigger time recorded under the time synchronization reference, and the action type is used to indicate whether the operation is an opening or closing action. The operation segment identifier is unique within the station.

[0023] During the sampling process, the acquisition unit reads the operational information related to the current action from the protection device and monitoring system. The operational information includes at least whether the current action is a short circuit disconnection operation, whether it is an no-load operation or a load operation, the type of protection action, the breaking current range, and the ambient temperature range at the time of the action. The breaking current range is used to identify the pre-divided range in which the main circuit current amplitude is located, and the ambient temperature range is used to identify the pre-divided range in which the ambient temperature is located. The acquisition unit organizes the above operational information into operating condition tags, which are used to describe the operating condition category to which the current tripping or closing action belongs.

[0024] To ensure that the operating condition label is consistent with the corresponding sampling sequence, the acquisition unit completes the reading of the operating information and the organization of the operating condition label within a predetermined time after the completion of this opening or closing action, and binds the operating condition label with the corresponding operating segment identifier.

[0025] After a sampling operation is completed, the acquisition unit combines the sampling sequences of each channel under the same operation segment identifier, the operation segment identifier, and the operating condition label into an operation segment record. Locally, the sampling points of different channels are time-base aligned according to the time stamp, and the samples of each channel are unified to the same time scale. Sampling points that exceed the range are truncated according to the upper or lower limit of the range. Single-point sample loss caused by instantaneous interference can be filled by interpolation of samples from adjacent time points, thereby forming a continuous time series.

[0026] In the runtime segment record, the acquisition unit adds a channel version number to each acquisition channel. The channel version number increments when the configuration of the corresponding detection unit or channel changes, and is used to identify the hardware and configuration status corresponding to the runtime segment record. In addition, the runtime segment record sets a status code field, which includes at least status code one, status code two, and status code three. Status code one indicates that the timing reference is unavailable during this sampling process, which means that a reliable timing signal cannot be obtained. Status code two indicates that one or more acquisition channels have failed to acquire data, which means that the channel has no valid samples or the samples remain in an invalid marking state within the predetermined action window. Status code three indicates that the runtime segment identifier conflicts with an existing identifier in the segment library, which is used to indicate that there is an anomaly in the upstream command triggering or numbering management.

[0027] The operation segment record is sent to the evaluation server through the station's communication network. When the evaluation server receives the operation segment record, it uses the combination of the operation segment identifier and the channel version number as the idempotent key to check whether a record with the corresponding idempotent key already exists in the segment library. When it finds that the operation segment identifier is the same and the channel version number has not changed, the newly received record is regarded as a duplicate record and is not written to the segment library. This is to avoid duplicate storage and duplicate evaluation caused by communication retransmission and to ensure that subsequent processing corresponds one-to-one with the actual number of opening or closing on site.

[0028] The fragment library can be set as a relational database, a time-series database, or a file-based sequential storage collection. Running fragment records are stored centrally using the running fragment identifier as the retrieval key, ensuring that subsequent stage division and feature calculation can access the corresponding records as needed and in sequence.

[0029] This solution is applicable to indoor switch stations and outdoor substations with medium voltage levels that use vacuum circuit breakers as switching equipment. It can also be extended to some high-voltage substation scenarios while maintaining the same signal type.

[0030] Preferably, in application scenarios represented by 10 kV distribution lines, the acquisition unit can set the sampling rhythm to sample once every millisecond, so that the sampling accuracy can cover the rapid changes in the opening and closing process. At the same time, the duration of each running segment can be set to cover several hundred millisecond action windows from the start of coil energization to contact stabilization. The total time from the triggering of the opening or closing command to the writing of the running segment record into the segment library can be set to not exceed one second, so as to meet the requirements of real-time performance and integrity for subsequent evaluation without significantly increasing the communication load and storage pressure of the station control system.

[0031] S2. Within the operational segment, divide the process into stages: coil energization, mechanism energy release, contact movement, arc maintenance, and contact stabilization. Extract the characteristics of action time, velocity, displacement, vibration amplitude, temperature rise gradient, and current change rate for each stage. Specifically, this is implemented as follows: When the evaluation server is running on-site, it uses the running segment records stored in the segment library in chronological order as a basis. For each running segment record, it reads the coil current waveform, main circuit current and voltage, contact temperature, and mechanism stroke vibration signal corresponding to the running segment identifier one by one. The start and end points of the coil current waveform refer to the time position when the coil current starts to rise significantly from the static level until it approaches stability or drops rapidly. The abrupt change point of the main circuit current and voltage refers to the position where the amplitude of the main circuit current or voltage changes significantly near the moment of action. The obvious inflection point of the stroke vibration signal refers to the position where the slope of the mechanism displacement or mechanical vibration amplitude curve changes or the peak position appears during the action.

[0032] The evaluation server uses the timestamps carried by the running segments under a unified time reference to determine the start and end times of the coil energizing stage, mechanism energy release stage, contact movement stage, arc maintenance stage, and contact stabilization stage on the same time axis. The coil energizing stage is used to characterize the time interval from when the coil is energized to when the electromagnetic force is established. The mechanism energy release stage is used to characterize the time interval from when the energy storage unit of the mechanism releases energy to drive the transmission component to start. The contact movement stage is used to characterize the time interval from when the contact moves from the initial position to the final position of separation or closure. The arc maintenance stage is used to characterize the time interval from when the main circuit current is maintained through the arc channel until it is extinguished after the contact is opened. The contact stabilization stage is used to characterize the time interval from when the position and vibration of the contact gradually stabilize after it reaches the target position.

[0033] To mitigate the impact of on-site electromagnetic interference and mechanical vibration spikes on stage boundary identification, preferably, before locating the aforementioned change points, the evaluation server can use a configurable sliding window to calculate the local average value on each signal channel. The sliding window length is set during configuration in conjunction with the circuit breaker's rated voltage, rated current, and expected operating time to smooth out short-term jitter without obscuring the main trend of change in the operating process, making the identification of stage start and end times more stable and reliable.

[0034] After the phase division is completed, the evaluation server calculates the characteristic quantities related to the subsequent evaluation based on the sample sequence on a unified time axis within each phase. Among them, the action time characteristic refers to the actual duration of each phase, the velocity characteristic refers to the average rate of change of contact displacement within the phase or the rate of change of displacement during a specific time period, the displacement characteristic refers to the stroke increment of the contact within the phase, the vibration amplitude characteristic refers to the amplitude index of the mechanism stroke vibration signal within the phase, the temperature rise gradient characteristic refers to the rate of change of contact temperature within a given time interval, and the current change rate characteristic refers to the rate of change of coil current or main circuit current within the phase. The above characteristics are recorded using the same physical units as the original quantities and are organized together with the corresponding operation segment identifier, operating condition label and channel version number into a feature record.

[0035] Feature records are centrally stored in a feature library on the evaluation server. The feature library can be built in the form of relational storage, time-series storage, or sequential file storage. It uses the runtime segment identifier as the primary retrieval key and the action stage name and feature name as additional indexes, and is used to access the feature library as needed during subsequent baseline model construction, feature offset calculation, and degradation decomposition.

[0036] For operational segments whose phase boundaries cannot be reliably identified during the phase division process due to signal saturation, long-term missing segments, or channel status codes indicating acquisition anomalies, the evaluation server will mark the corresponding operational segment as a phase division failure and write status code four into the feature record corresponding to the operational segment. Status code four is used to indicate that the phase division logic cannot provide a reliable result. In this case, only the summary information of the original signal of the operational segment is saved in the segment library for manual spot checks by maintenance personnel. No feature record is generated for subsequent baseline models to avoid introducing features with uncertain phase boundaries into the baseline model and causing offset.

[0037] Regarding the deployment of the system within the station, the evaluation server can use a multi-threaded approach to perform stage division and feature calculation on the operation segments of different circuit breakers in parallel, in order to adapt to the frequent opening and closing of multiple vacuum circuit breakers in the same substation. However, when performing stage division and feature calculation on the same operation segment identifier, each calculation step should be completed in the time order in the segment library, so that the generated feature records are consistent with the on-site opening or closing sequence in time, and avoid order confusion caused by cross-thread processing.

[0038] Preferably, the time for stage division and feature calculation of a single operating segment can be set to no more than a few seconds, and an appropriate number of concurrent threads can be selected based on the number of circuit breakers in the substation, the maximum opening and closing frequency, and the computing power of the evaluation server. This ensures that the delay in stage division and feature calculation across the entire substation remains within an acceptable range when the substation is operating under high load, thereby meeting the real-time and stability requirements of continuous online evaluation without significantly increasing the hardware configuration of the evaluation server.

[0039] This solution is applicable to the online condition assessment of multiple vacuum circuit breakers configured in medium-voltage substations. It can also be extended to other substation operation scenarios with vacuum circuit breakers as the main switching equipment, while keeping the stage division logic and feature definition unchanged, to generate feature records that can be used for subsequent individual baseline modeling and degradation assessment in a unified manner.

[0040] S3. In the initial stage of circuit breaker operation, select healthy action segments, normalize the characteristics according to the operating conditions, construct an individual baseline model for each circuit breaker, and register the effective time of the baseline parameter version. The specific implementation is as follows: In the initial stage of circuit breaker commissioning, after completing routine factory tests and on-site acceptance tests and confirming that it is in good condition, the evaluation server uses the feature records in the feature library as a basis to establish an individual baseline model for each vacuum circuit breaker.

[0041] Factory routine test records refer to the factory inspection results of the circuit breaker conducted by the manufacturer in accordance with relevant standards, including at least the records of mechanical operation number test, closing and opening time measurement and insulation level verification; on-site acceptance test records refer to the results of the pre-commissioning confirmation test conducted under the organization of the operating unit after the circuit breaker is installed in place, including at least the records of power frequency withstand voltage test, insulation resistance measurement, secondary circuit inspection and trial closing test.

[0042] After accessing the aforementioned test records, the evaluation server marks circuit breakers that meet the requirements of test values ​​within the specified range, no abnormalities in visual inspection, and no defects registered by the operating unit as healthy devices. During the period in which this state lasts, the server selects the corresponding operating segment identifiers from the feature library to form a candidate set of healthy action segments.

[0043] The insulation test record here refers to the inspection results of the insulation performance of the circuit breaker and its primary isolating components, used to determine whether there is a risk of insulation degradation at a certain voltage level; the mechanical characteristic test record refers to the measurement results of indicators such as the closing and opening time, synchronicity, bounce, closing speed, and opening speed of the circuit breaker, used to determine whether the mechanism operation is smooth and reliable; the protection action record refers to the record of the action commands and action results issued by the protection device to the circuit breaker during a period of time in the initial stage of operation, used to determine whether there are any malfunctions or failures to operate.

[0044] The evaluation server uses the running segment identifier as an index to find the feature records generated in the feature library during the time period when all three types of records meet the specified range and no false operation or failure to operate is recorded. The running segment identifiers corresponding to these feature records are classified into the healthy action segment set. The healthy action segment refers to the running segment collected under representative operating conditions during the period when the circuit breaker is in a confirmed healthy state, which can be used as a reference for normal features.

[0045] To ensure that the individual baseline model can cover typical operating conditions, the evaluation server groups the feature records in the set of healthy action segments according to the operating condition labels. The operating condition labels consist of information such as the operating nature, breaking current range, and ambient temperature range carried in the aforementioned operating segment records, and are used to characterize the load level and environmental conditions corresponding to the operating segment.

[0046] Within each operating condition group, the evaluation server statistically analyzes the action time characteristics, velocity characteristics, displacement characteristics, vibration amplitude characteristics, temperature rise gradient characteristics, and current change rate characteristics. The action time characteristic refers to the measured duration of each stage; the velocity characteristic refers to the rate of displacement change during the contact movement stage; the displacement characteristic refers to the stroke increment of the contact from the initial position to the target position; the vibration amplitude characteristic refers to the amplitude index of the mechanism's stroke vibration signal in each stage; the temperature rise gradient characteristic refers to the rate of change of the contact temperature within a given time interval; and the current change rate characteristic refers to the rate of change of the coil current or main circuit current in each stage.

[0047] During the calculation process, the evaluation server can first remove abnormal feature records that deviate significantly from most samples. Then, within the same working condition group, it can calculate the reference center value reflecting the typical level and the upper and lower boundaries reflecting the allowable fluctuation range for each type of feature. The reference center value can be obtained by statistically analyzing the central tendency of features in healthy action segments, and the allowable fluctuation range can be determined by the degree of dispersion of features in healthy samples, thus forming a description of the normal range of six types of features under this working condition.

[0048] Based on this, the evaluation server will collect the feature reference center values ​​and allowable fluctuation ranges indexed by the operating condition label according to the circuit breaker number, forming a single circuit breaker individual baseline model for the vacuum circuit breaker. The single circuit breaker individual baseline model is used to describe the normal level and normal fluctuation boundary of the circuit breaker's operating time characteristics, speed characteristics, displacement characteristics, vibration amplitude characteristics, temperature rise gradient characteristics, and current change rate characteristics under different operating condition labels corresponding to load current ranges, ambient temperature ranges, and operating types.

[0049] To ensure that these reference ranges are traceable and manageable in subsequent assessments, the assessment server generates a baseline parameter version for each circuit breaker after completing the construction of the individual baseline model. The baseline parameter version includes a version number, an effective time, and an applicable set of operating conditions. The version number is used to distinguish the parameter sets obtained in different stages of construction or update. The effective time is used to mark the time point when the version is used for online assessment. The applicable set of operating conditions is used to mark the range of operating condition labels covered by the version.

[0050] The evaluation server writes the baseline parameter version along with the main parameter summary of the individual baseline model into the site's read-only parameter library. The parameter summary may include information such as the reference center value, allowable fluctuation range, and number of healthy action segments for each working condition group. The server also generates a corresponding evidence chain record in the read-only parameter library. The evidence chain record is used to record the correspondence between the baseline parameter version and the set of healthy action segments that participated in the construction. It includes at least the baseline parameter version number, the construction time, and the identifier of each running segment in the set of healthy action segments, thereby providing a basis for subsequent traceability of the evaluation results.

[0051] After the individual baseline model is built, the evaluation server marks the current baseline parameter version as the active version. The active version refers to the version actually used in the degradation analysis and operational evaluation. To prevent the misinformation of offset features into the baseline when the circuit breaker has degraded but has not yet been identified, the evaluation server requires that any subsequent baseline update requests can only be initiated by authorized operation and maintenance accounts through the station control configuration interface. When the station control configuration interface receives a baseline update request, it checks the continuity of the version number and the completeness of the evidence chain record. Only when the new version number increments relative to the existing version number in a predetermined manner and the corresponding evidence chain record exists and is complete, is it allowed to write the new baseline parameter version into the read-only parameter library and replace the active version. If, during the check, it is found that the version number is not continuous with the existing version number, or the new version lacks the corresponding evidence chain record, the evaluation server marks the update request as a version lock conflict and returns it to the configuration interface with status code five. Status code five is used to indicate that the baseline parameter version has not taken effect due to number conflict or missing evidence chain. In this case, the original active version is kept for operational evaluation.

[0052] The above baseline construction process is applicable to various medium-voltage scenarios in substations where vacuum circuit breakers are used as switching equipment. In actual deployment, the size of the healthy action segment set can be flexibly selected according to the type of circuit breaker, the initial operation time, and the coverage of operating conditions.

[0053] Preferably, in application scenarios represented by 10 kV distribution lines, a single circuit breaker can select several healthy action segments during a healthy operation period after commissioning to construct an individual baseline model of the single circuit breaker. The operating conditions are divided by combining three categories of load current (low, medium, and high) and two environmental temperature categories (winter and summer). Under each combination of current and temperature ranges, reference center values ​​and allowable fluctuation ranges for action time characteristics, velocity characteristics, displacement characteristics, vibration amplitude characteristics, temperature rise gradient characteristics, and current change rate characteristics are established. This ensures that the baseline model has sufficient coverage in common operating conditions, making it easier to identify characteristic change trends that deviate from the healthy state during subsequent long-term operation.

[0054] S4. Calculate the offset between the new operating segment features and the baseline model of the individual circuit breaker under the corresponding operating conditions. Based on the degradation mode dictionary, decompose the feature offset into mechanical degradation components, arc-extinguishing chamber degradation components, and operational cumulative load components. Specifically, the implementation is as follows: When the individual baseline model of a single circuit breaker is in an active version and effective in the operational evaluation, each time a new operational segment feature is written to the feature library, the evaluation server first searches for the corresponding operating condition label in the aforementioned segment library and feature library based on the operational segment identifier attached to the operational segment feature. Under the indication of the active baseline parameter version, it reads the reference center values ​​and allowable fluctuation ranges of the action time feature, velocity feature, displacement feature, vibration amplitude feature, temperature rise gradient feature, and current change rate feature corresponding to the operating condition label from the individual baseline model of the single circuit breaker. It then compares each of the six types of features in the current operational segment with the reference center values ​​to obtain the feature offset vector describing the degree of deviation of the current feature from the baseline. The feature offset vector refers to the set of offsets calculated for each of the six types of features under the same operating condition, used to centrally characterize the overall deviation pattern of the current opening or closing action relative to the individual baseline model.

[0055] To correlate feature offsets with specific degradation mechanisms, the evaluation server decomposes the feature offset vectors based on a degradation mode dictionary. This dictionary refers to a set of feature offset patterns generated by the manufacturer based on type test prototypes and faulty prototypes. Type test prototypes are standard prototypes that have undergone repeated operation under experimental conditions, with characteristic changes recorded at each stage. Faulty prototypes are prototypes that have undergone comparative tests under preset mechanical failure, arc-extinguishing chamber degradation, and high-frequency operating load conditions. During the testing process, the manufacturer collects a large number of operational segment features and organizes the offsets of these test samples relative to the healthy baseline. Representative offset combinations are abstracted into degradation modes. Each degradation mode record assigns a set of weights across the dimensions of action time, velocity, displacement, vibration amplitude, temperature gradient, and current change rate, describing the contribution ratio of each feature in the offset mode to the mechanical degradation component, arc-extinguishing chamber degradation component, and cumulative operating load component.

[0056] The degradation component of the mechanism refers to the contribution of degradation to the operating time, stroke and vibration characteristics caused by wear, clearance changes and deterioration of lubrication conditions of the operating mechanism. The degradation component of the arc-extinguishing chamber refers to the contribution of contact erosion, vacuum reduction and other factors to the degradation of temperature rise characteristics and current change characteristics. The cumulative load component of operation refers to the contribution of the overall cumulative stress caused by frequent interruption current and environmental stress to the characteristic offset. The allocation weight refers to the distribution ratio of each characteristic offset among the above three types of degradation components under a certain degradation mode.

[0057] When the evaluation server is used in the field, for each newly formed feature offset vector, several degradation modes with high similarity to the feature offset vector are selected from the degradation mode dictionary. The similarity here refers to the degree of consistency between the feature offset vector and the mode in terms of offset direction and relative magnitude. It can be measured by comparing the differences between each feature offset direction and its normalized amplitude. According to the preset similarity threshold, modes with similarity below the threshold are eliminated, and a set of candidate mode combinations that meet the similarity requirements are retained. Within the candidate mode set, the evaluation server superimposes the feature offset vector onto the three types of degradation components according to the predetermined weight combination rules to obtain the numerical representation of the current operation segment in terms of the mechanism degradation component, the arc extinguishing chamber degradation component, and the operational cumulative load component.

[0058] To ensure the physical validity of the decomposition results, the degradation pattern dictionary applies non-negative constraints to all assigned weights during construction and controls the total weight of each degradation component within a set range. During on-site decomposition, a degradation component is only considered valid if the product of the feature offset and the corresponding assigned weight is within a reasonable range and the overall combination satisfies the magnitude constraint. Otherwise, the degradation component is considered insignificant and is not included in the degradation component calculation results of this running segment, thereby avoiding misleading the determination of degradation components by minor noise or abnormal patterns.

[0059] After the evaluation server completes the calculation of the degradation components of the mechanism, the arc-extinguishing chamber, and the cumulative load components of operation, it writes the values ​​of these three types of degradation components, along with the operating segment identifier, the operating condition label, and the current baseline parameter version number, into the degradation record library. The degradation record library is used to centrally store the degradation decomposition results of each circuit breaker under each operating segment in chronological order, providing a basis for subsequent statistical analysis of degradation index and operating risk level within the observation window.

[0060] If the similarity between the feature offset vector of a certain running segment and each combination of modes in the degradation mode dictionary is lower than the similarity threshold, or if all modes that meet the similarity requirements cannot pass the amplitude constraint check after being superimposed, the evaluation server determines that the running segment cannot obtain a reliable decomposition result under the existing degradation mode dictionary, marks the corresponding running segment as a mode missing state, and records the feature offset vector, working condition label, and baseline parameter version number in the log. The mode missing state is used to indicate the working conditions and offset types that need to be added when expanding the degradation mode dictionary in the future.

[0061] For operating units that do not yet have the conditions to develop a degradation mode dictionary based on type test prototypes and failure prototypes, another implementation mode can be adopted. In this mode, the manufacturer predefines feature offset threshold rules based on the type test results. The feature offset threshold rules refer to setting several value intervals for each feature offset and establishing a correspondence between the interval combination and the three types of degradation component levels. When running in the field, after the evaluation server reads the feature offset vector, it does not need to perform similarity matching and continuous decomposition. Instead, it directly selects the corresponding mechanism degradation component level, arc-extinguishing chamber degradation component level, and operational cumulative load component level based on the threshold interval combination where the feature offset is located. The level marking can use graded identifiers to indicate the degree of degradation.

[0062] The implementation based on feature offset threshold rules maintains the same technical idea as the implementation based on degradation mode dictionary in terms of degradation mechanism classification and differentiation of three types of degradation components. Both complete the degradation mechanism decomposition by mapping multidimensional feature offsets to three components: mechanism degradation, arc-extinguishing chamber degradation, and operational cumulative load. The only difference is that different parameter organization methods and allocation methods are used in the field implementation, which is an equivalent replacement of the degradation decomposition link.

[0063] Preferably, in the 10 kV application scenario of medium-voltage substations, manufacturers can, during the type testing phase, apply different degrees of mechanical wear, different arc-extinguishing chamber life stages, and different operating frequencies to several prototypes, collect a large number of action characteristics, and organize them into several representative degradation modes. These modes are then written into a degradation mode dictionary. At the same time, depending on the operating unit's configuration of online computing resources, the manufacturer can choose whether to use a similarity matching method for continuous degradation decomposition on-site, or to use a preset threshold range method for graded degradation judgment. This ensures the rationality of the degradation mechanism classification while balancing the accuracy of the evaluation and the complexity of the system.

[0064] S5. Based on the degradation components, calculate the degradation index of the mechanism, the degradation index of the arc-extinguishing chamber, and the cumulative operating load index to generate the operational risk level, maintenance targets, and maintenance time windows. The specific implementation is as follows: With the degradation record database continuously accumulating records, the evaluation server sets a sliding observation window based on the number of operations and natural time for the same vacuum circuit breaker in order to reflect the degradation trend within the actual operating cycle. The sliding observation window refers to selecting a number of consecutive opening or closing operation segments on the same circuit breaker and covering a continuous natural time interval. Within this time interval, the start and end points of the observation window and the number of operation segments included can be configured according to the operating unit's needs for evaluation frequency and sensitivity. The window is continuously pushed forward on the time axis by moving, and the statistics are updated each time it moves based on the operation segments that newly enter the window and move out of the window.

[0065] Within each sliding observation window, the evaluation server reads the corresponding mechanism degradation components, arc-extinguishing chamber degradation components, and operational cumulative load components from the degradation record library according to the time sequence of the operation segment identifier. The mechanism degradation component refers to the degradation amount caused by factors such as wear of the operating mechanism, clearance changes, and spring performance decay. The arc-extinguishing chamber degradation component refers to the degradation amount caused by factors such as contact erosion, vacuum degree changes, and insulation structure aging. The operational cumulative load component refers to the cumulative stress caused by high-frequency operation, high-current interruption, and environmental stress superposition. Within the sliding observation window, the evaluation server statistically analyzes the amplitude levels and changing trends of the above three types of degradation components and separately marks operation segments that show a significant jump in amplitude or a sudden change in trend within a short period of time for identifying suspicious actions in subsequent operation and maintenance analysis.

[0066] After completing the statistical analysis of degradation components within the sliding observation window, the evaluation server calculates the mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index according to pre-calibrated normalization rules. The normalization rules refer to converting degradation components of different dimensions and scales into dimensionless indices within the zero-to-one range according to a set scaling relationship. During the conversion process, the possible range of changes of degradation components throughout the entire life cycle, the degree of impact on operational reliability, and the safety margin preset by the operating unit can be comprehensively considered, so that the combination of the mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index can reflect the relative degree of degradation of the current circuit breaker in terms of mechanism status, arc-extinguishing chamber status, and operational cumulative load.

[0067] After calculating the three types of indices, the evaluation server associates the index values ​​with the current model version number. The model version number is used to identify the version status of the degradation pattern dictionary, baseline model, and normalization rules to ensure that the meaning of the index is consistent with the model used.

[0068] Subsequently, the assessment server compares the three types of indices with a risk level threshold set. The risk level threshold set refers to a pre-defined combination of multi-level boundary points within the range of zero to one for the institutional degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index, used to classify different operational risk levels. During the comparison process, the assessment server determines the magnitude relationship and combination of the three types of indices. For example, when the arc-extinguishing chamber degradation index is close to the upper limit and the operational cumulative load index is at a relatively high level, the current operational risk level is determined to be a higher level; when all three types of indices are at a low level and change slowly within the sliding observation window, the operational risk level is determined to be a lower level.

[0069] To provide actionable maintenance recommendations, the assessment server, based on the determined operational risk level, selects the corresponding maintenance targets and time windows according to the combination relationships of the mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index in the pre-set maintenance strategy library. The maintenance strategy library refers to a set of rules established by the operating unit based on equipment type, operating procedures, and maintenance strategies. The rule set provides a correspondence between priority maintenance parts and suggested scheduling times for different combinations of degradation indices. For example, when the mechanism degradation index continues to rise in multiple sliding observation windows while the arc-extinguishing chamber degradation index remains at a low level, the maintenance strategy library can identify the mechanism maintenance unit as the maintenance target and mark the maintenance time window as a recent arrangement. When the arc-extinguishing chamber degradation index is higher than the preset threshold and the operational cumulative load index is close to the upper limit, the maintenance strategy library can provide a recommendation to arrange for the arc-extinguishing chamber replacement or power outage maintenance as soon as possible.

[0070] After completing the operational risk level determination and maintenance decision, the assessment server compiles the device number, operational risk level, three types of degradation indices, maintenance object, maintenance time window, model version number, and baseline parameter version into a unified assessment result, which is then written into the assessment result database. The assessment result database is used to centrally store the records of each assessment and decision in chronological order. At the same time, the assessment server sends each new assessment result to the operation and maintenance management system and asset management system in the form of a message through the site communication channel. The message carries a status code field, which includes the aforementioned status codes one to five, used to indicate whether there are incomplete information or version conflicts in the data collection stage, stage division stage, feature extraction stage, baseline construction stage, and version management stage. When any one of status codes one to five is active, the operation and maintenance management system can identify that there is a potential information missing or parameter abnormality in the current assessment result, and prompt the operation and maintenance personnel to manually review or supplement the verification on the interface.

[0071] This method positions the assessment server as a unit for operational status analysis and maintenance suggestion generation within the security boundary. It only provides maintenance suggestions to the operation and maintenance management system and asset management system through the aforementioned assessment messages, without directly sending opening or closing commands to vacuum circuit breakers or protection devices, nor actively modifying protection device settings, blocking logic, and automatic reclosing strategies. Both organizational and technical measures ensure that the assessment function does not interfere with the action criteria and execution links of the existing protection and control systems. The parameter configuration interface used to configure sliding observation window parameters, normalization rules, risk level threshold sets, and maintenance strategy library contents is only open to authorized operation and maintenance accounts. Any parameter changes must be completed in the station control configuration interface after identity authentication. After receiving parameter changes, the assessment server registers the version information, modification time, and modification source of the new parameters in a read-only version repository, forming a version history to meet the requirements of operation and maintenance audit and operational compliance.

[0072] The above-mentioned process for calculating the degradation index and determining the operational risk level based on the sliding observation window is applicable to various switchgear and ring main units in medium-voltage substations that use vacuum circuit breakers as switching equipment. In scenarios with different voltage levels and different load characteristics, adaptation can be achieved by adjusting the length of the sliding observation window, the normalization rules, and the risk level threshold parameters.

[0073] Preferably, in field applications represented by 10 kV distribution lines, the sliding observation window can be set to include the most recent 10 or so opening and closing operations and cover the operating time of the most recent 10 days. This ensures that each observation window contains a sufficient number of operation samples without spanning an excessively long time span. When the degradation index of the mechanism reaches 0.6 within the sliding observation window and continues to rise in the next two adjacent observation windows, the evaluation server can determine the current operational risk level as "attention level" and provide a key attention prompt in the operation and maintenance management system interface. When the degradation index of the arc-extinguishing chamber exceeds 0.7 and the cumulative operating load index approaches 0.9, the operational risk level can be determined as "early warning level," and the maintenance strategy library can provide suggestions for arranging power outage maintenance or replacing the arc-extinguishing chamber as soon as possible. This provides a quantitative basis based on the degradation index for the circuit breaker's maintenance plan and asset decision-making without changing the existing protection operation logic.

[0074] S6. After completing the planned maintenance and fault disassembly inspection, the measured wear status is correlated with the historical assessment results. The degradation mode dictionary and risk level threshold are corrected using an incremental update method, and the model version is recorded for traceability. The specific implementation is as follows: During planned maintenance and troubleshooting, maintenance personnel, based on equipment operating procedures and manufacturer technical documents, measure and record the physical condition of key components after the vacuum circuit breaker is de-energized and disconnected. The measurements include at least the preload of the mechanism springs, pin wear, lubrication condition, connecting rod clearance, contact erosion depth, and creepage distance of insulating components. The preload of the mechanism springs refers to the compression or energy storage level of the energy-storing springs in the operating mechanism when in the non-operated position, reflecting the margin of the mechanism's output torque. Pin wear refers to the decrease in pin diameter or change in ellipticity at each rotating hinge point of the transmission mechanism. Quantitative values ​​reflect the degree of looseness of the hinged parts of the mechanism; lubrication condition refers to the coverage and deterioration of the lubricating medium on the transmission components and guide sliding surfaces of the mechanism, reflecting whether the friction conditions have deteriorated; link clearance refers to the fit clearance between the link, rocker arm and guide components of the mechanism, reflecting the overall tightness of the transmission chain; contact ablation depth refers to the depth of the pit formed by the burning of the working surface material of the moving and stationary contacts in the arc extinguishing chamber, reflecting the degree of contact life consumption; creepage distance of insulation components refers to the surface distance along the insulation surface that can form a leakage current path, reflecting the impact of surface contamination and aging on insulation margin.

[0075] After completing the above measurements, maintenance personnel use the maintenance system to register the corresponding measurement results as wear records. Wear records refer to a set of physical wear records formed for a certain device during a planned maintenance or fault dismantling process. Each wear record is accompanied by at least the device number, maintenance time, and historical assessment result number within a certain period before the maintenance. The historical assessment result number is used to point to the operation risk level and degradation index record generated by the assessment server and stored in the assessment result database before the maintenance.

[0076] The evaluation server reads new wear records from the maintenance system at set time intervals. The time interval can be set to several days or several weeks, depending on the maintenance frequency and data update rhythm of the operating unit. After reading the new wear record, the evaluation server retrieves the mechanism degradation index, arc-extinguishing chamber degradation index, cumulative operating load index, and operating risk level for the corresponding time period from the evaluation result database and degradation record database based on the device number, maintenance time, and historical evaluation result number. These quantities are correlated with the mechanism spring preload status, pin wear, lubrication status, connecting rod clearance, contact ablation depth, and creepage distance of insulating components reflected in the same wear record to form a set of records with true degradation degree labels. The true degradation degree label refers to the wear amount and status description directly given by on-site disassembly inspection, which is used as a calibration reference for the degradation index and degradation mode dictionary.

[0077] Based on the labeled record set, the evaluation server incrementally updates the assigned weights in the degradation pattern dictionary and the hierarchical boundaries in the risk level threshold set in chronological order. Incremental update refers to making small adjustments to the assigned weights and threshold positions using newly added wear records without overturning the existing pattern and threshold framework, so that the correspondence between degradation components and degradation indices and measured wear states gradually converges. In actual execution, the evaluation server can read each batch of wear records that meet the representativeness requirements in chronological order, make local adjustments to the corresponding degradation patterns and thresholds, and generate a new model version number after each adjustment. The model version number is used to identify the current combination state of the degradation pattern dictionary and risk level thresholds.

[0078] While generating a new model version number, the evaluation server registers the core parameter summaries before and after the update, the update timestamp, and the wear record set number that participated in this update in the read-only version repository, forming a continuous chain of evidence records. The chain of evidence records are used to support the tracing of the degradation mode and threshold boundary source on which the evaluation results of a certain operational stage are based in subsequent audits, ensuring that the model evolution process can be traced back in both order and content.

[0079] When the number of wear records collected during a certain operating phase is insufficient to cover the main operating conditions, or when the measurement results are concentrated on a few abnormal operating conditions and do not meet the preset requirements, the evaluation server can postpone the execution of incremental updates according to the threshold set by the operating unit, and only archive these wear records in the maintenance system and read-only version repository, without adjusting the existing degradation mode dictionary and risk level threshold, so as to avoid excessive parameter shifts caused by a single maintenance sample or weakening the applicability of the model to other operating conditions.

[0080] Before a new model version is put into operation, authorized operations and maintenance personnel confirm the model version update through the station control interface. During the confirmation process, the station control interface automatically checks the continuity between the model version number and the existing version number, as well as the completeness of the corresponding evidence chain records. Only when the model version increments according to predetermined rules and the evidence chain records are complete will the model version be marked as active and replace the original active version. If the check finds that the model version number jumps, the evidence chain records are missing, or the correlation is inconsistent, the evaluation server will mark the model version as inactive and will not use it for online evaluation. Corresponding prompt information will be recorded in the read-only version repository and the operations and maintenance management system interface, thereby ensuring that the model update meets the traceability requirements in terms of sequential control and idempotency control.

[0081] This method is applicable to both routine planned maintenance and fault dismantling scenarios using vacuum circuit breakers in substations. Under different voltage levels and operating strategies, the wear record summary cycle and incremental update frequency can be flexibly set according to the maintenance cycle and dismantling frequency.

[0082] Preferably, in application scenarios represented by 10 kV distribution lines, the operating unit can import the wear records generated from planned maintenance and fault dismantling completed that year into the maintenance system after the circuit breaker has been running continuously for about a year. At this point, the evaluation server performs a centralized incremental update on the degradation mode dictionary and risk level threshold, so that the correspondence between the mechanism degradation components, arc-extinguishing chamber degradation components, and operational cumulative load components and the measured wear state is corrected as a whole. After the centralized update, a small adjustment can be set every six months based on the newly added wear records to ensure that the model continuously conforms to the field degradation patterns. After multiple rounds of centralized updates and small adjustments, the operating unit observes a gradual decrease in deviation when comparing the mechanism degradation index, arc-extinguishing chamber degradation index, and dismantling inspection results. This verifies that the incremental update mechanism based on wear records effectively improves the credibility of the evaluation results and the ability to reflect the actual wear state in long-term operation.

[0083] In the operational scenario shown in this embodiment: In an indoor switch station represented by a 10 kV distribution line, after the station's time synchronization device is put into use, the operating unit broadcasts the time synchronization reference to each switch cabinet and the evaluation server. Several switch cabinets using vacuum circuit breakers as switching equipment are selected as online evaluation objects within the bus section and feeder bay. A current detection unit, voltage detection unit, temperature detection unit, displacement detection unit, and vibration detection unit are arranged near the primary circuit and operating mechanism of one of the vacuum circuit breakers, which is numbered as device one. Each detection unit is connected to the acquisition unit through the acquisition channel. Before being put into operation, the acquisition unit completes the unified configuration of channel name, range, unit of measurement, sampling rhythm, and channel version number. After the segment library, feature library, degradation record library, and evaluation result library are initialized, a communication connection is established with the station control system.

[0084] When the circuit breaker undergoes routine factory tests and on-site acceptance tests during the no-load operation phase, and completes mechanical characteristic tests, insulation tests, and protection action tests and is confirmed to be in a healthy state, the operating unit will import the corresponding test records into the evaluation server, and the evaluation server will mark the circuit breaker as a healthy device accordingly.

[0085] During a subsequent operating cycle, when the protection device issues a tripping or closing command to the circuit breaker according to the dispatching instructions, the acquisition unit triggers a sampling process under the control of the timing reference. Each acquisition channel synchronously acquires the coil current waveform, main circuit current and voltage, contact temperature, and mechanism travel vibration signal of the tripping and closing coils on a unified time axis at a millisecond-level sampling rhythm. At the same time, it reads the operating information of this action from the protection device and the monitoring system, and organizes whether it is an no-load operation or a load operation, whether it is a short-circuit clearing operation, the interval of the breaking current during the action, and the interval of the ambient temperature into operating condition tags. After the sampling is completed, the sampling sequence of each channel under the same operating segment identifier, the operating segment identifier, and the operating condition tags are organized into an operating segment record and sent to the evaluation server.

[0086] When the evaluation server receives a running segment record, it uses the combination of the running segment identifier and the channel version number as the idempotent key to check whether a corresponding record already exists in the segment library. It only writes a new record if the idempotent key has not yet appeared. Before writing, it performs time base alignment, overrange truncation, and missing sample interpolation on the sampling points of each channel to ensure that the time series of the records in the segment library are continuous and correspond one-to-one with a single action on site.

[0087] As the circuit breaker completes multiple opening and closing operations in a healthy state, the segment library gradually accumulates operating segment records with operating condition tags. The evaluation server periodically reads new operating segment records from the segment library and uses the start and end points of the coil current waveform, the abrupt changes in the main circuit current and voltage, and the obvious inflection points of the mechanism's stroke vibration signal to divide the coil energizing stage, mechanism energy release stage, contact movement stage, arc maintenance stage, and contact stabilization stage on a unified time axis. Within each stage, the action time characteristics, velocity characteristics, displacement characteristics, vibration amplitude characteristics, temperature rise gradient characteristics, and current change rate characteristics are calculated to form feature records and written into the feature library. When dividing the stages, all signal channels can be smoothed using sliding windows of appropriate length according to the configuration to reduce the impact of instantaneous interference on boundary identification. When it is found that a certain operating segment has a missing timing reference, channel acquisition failure, or severe signal saturation, status code one, status code two, or status code four is registered in the feature record of that segment, and the segment features are not included in the subsequent baseline construction.

[0088] As the number of feature records in the health state in the feature library reaches the lower limit of the number of health action segments set by the operating unit, the evaluation server selects the corresponding operating segment identifier as the set of health action segments based on the imported factory routine test records, on-site acceptance test records, and protection action records, within the time period that meets the requirements of qualified test values ​​and no defect registration, no erroneous action, or no failure to operate records. The feature records are grouped according to the operating condition tags of the health action segments. The action time characteristics, speed characteristics, displacement characteristics, vibration amplitude characteristics, temperature rise gradient characteristics, and current change rate characteristics of each stage are statistically analyzed in the low, medium, and high load current ranges and the winter and summer ambient temperature ranges, respectively. The reference center value and allowable fluctuation range of each feature under different operating conditions are obtained. The individual baseline model of a single circuit breaker is constructed using the circuit breaker number as an index, and a baseline parameter version containing the version number, effective time, and applicable operating condition set is generated and written to the read-only parameter library, marked as an active version, forming an evidence chain of the source of the baseline parameters in the read-only parameter library.

[0089] Subsequently, after the circuit breaker enters the normal load operation phase, whenever a new operating segment is recorded and the phase division and feature calculation are completed, and the new feature record is written into the feature library, the evaluation server determines the operating condition label and active baseline parameter version based on the operating segment identifier, extracts the reference center value and allowable fluctuation range under the same operating condition from the individual baseline model, calculates the feature offset vector of the current operating segment, and calls the degradation mode dictionary built by the manufacturer based on the type test prototype and the failure prototype to decompose the feature offset vector into the mechanism degradation component, the arc-extinguishing chamber degradation component, and the operational cumulative load component. Under the premise of satisfying the similarity threshold and amplitude constraints, the values ​​of the three types of degradation components are obtained, and written into the degradation record library along with the operating segment identifier, operating condition label, and baseline parameter version number. Operating segments that cannot find a suitable degradation mode are marked as mode missing states.

[0090] As the degradation record database accumulates, the evaluation server sets up sliding observation windows based on the number of actions and natural time at the circuit breaker number dimension. Within each observation window, it reads three types of degradation components in the order of the operation segment identifier, statistically analyzes the amplitude level and trend, calculates the mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index, and compares the three indices with the risk level threshold set to determine the operational risk level. At the same time, it queries the maintenance strategy database for the maintenance object and maintenance time window corresponding to the current index combination, forming an evaluation result containing the device number, operational risk level, three indices, maintenance object, maintenance time window, model version number, and baseline parameter version. This result is written into the evaluation result database and sent to the operation and maintenance management system and asset management system in the form of a message through the station communication channel. The message carries status codes one to five to prompt the operation and maintenance management system to identify whether there is a risk of incomplete information in this evaluation. At the safety boundary, no opening or closing commands are issued to the vacuum circuit breaker and protection device, and no settings and blocking logic are modified.

[0091] After several months of operation, when the circuit breaker enters the planned maintenance phase, maintenance personnel, under de-energized and disconnected conditions, measure the spring preload, pin wear, lubrication status, connecting rod clearance, contact ablation depth, and creepage distance of insulating components. The measurement results are recorded as wear records through the maintenance system, along with the unit number, maintenance time, and historical assessment result numbers from a period prior to the maintenance. The assessment server retrieves new wear records from the maintenance system at set time intervals, correlates these wear records with the three types of degradation indices and operational risk levels within the corresponding time period, forming a set of records labeled with the actual degree of degradation. This process is repeated when the wear record requirements are met. Under the conditions of sufficient number and representativeness requirements, incremental updates are performed on the weight allocation in the degradation mode dictionary and the hierarchical boundaries in the risk level threshold set in chronological order. Each update generates a new model version number, and the parameter summary before and after the update, the update timestamp, and the wear record set number participating in the update are registered in a read-only version repository. Authorized maintenance personnel confirm the new model version on the station control interface. This allows the individual baseline model of a single circuit breaker, the degradation mode dictionary, and the risk level threshold to continuously absorb field wear information throughout the entire operating life cycle, gradually improving the ability of the mechanism degradation index and the arc-extinguishing chamber degradation index to reflect the actual wear state.

[0092] Preferably, in this 10kV switch station, the No. 1 circuit breaker accumulated several dozen healthy operation segments under different load current levels and seasonal temperature conditions during its first year of operation. After the baseline parameter version was constructed, it completed nearly one hundred opening and closing operations within a year. The mechanism degradation index calculated by the evaluation server based on the sliding observation window remained below 0.3 for a long time, while the arc-extinguishing chamber degradation index remained below 0.2. The operational risk level remained at a low level. During the planned maintenance at the end of the year, the wear of the mechanism pin and the contact ablation depth were measured to be below the allowable range. After the incremental update, the degradation mode dictionary showed that... The allocation weight of the response mode was slightly adjusted. In the following year, when the circuit breaker experienced high-frequency operating conditions, the mechanism degradation index rose to around 0.6 and continued to rise slowly in two consecutive observation windows. The assessment server judged the operational risk level as "attention level" and gave a suggestion to arrange mechanism maintenance in the operation and maintenance management system. In the subsequent maintenance, it was confirmed that the mechanism linkage clearance increased and the lubrication condition deteriorated significantly, indicating that the above online assessment results were consistent with the measured wear state. Thus, without affecting the original protection action logic, long-term tracking of the vacuum circuit breaker's operating status and intelligent assessment for maintenance were achieved.

[0093] All calculations involved in the embodiments are dimensionless numerical calculations, and the preset parameters and thresholds in the calculations are set by those skilled in the art according to the actual situation.

[0094] It should be noted that this invention can be deployed on the device itself to realize embedded applications, or it can run on a PC or other terminal with a user interface, thereby meeting various hardware environments and usage requirements.

[0095] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wireless or wired transmission; wired transmission methods include optical fiber, twisted pair, coaxial cable, etc.; wireless transmission includes infrared, microwave, etc. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center containing one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0096] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0097] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0098] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0099] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0100] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0101] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0102] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for intelligently evaluating the operating status of a vacuum circuit breaker, characterized in that, include: S1. Under the time reference, collect the coil current waveform, main circuit current and voltage, contact temperature, and mechanism stroke vibration signal during the opening and closing process of the vacuum circuit breaker, and generate operation segment identifiers and operating condition labels for each action; S2. Divide the operation segment into stages: coil energization, mechanism energy release, contact movement, arc maintenance, and contact stabilization. Extract the characteristics of action time, speed, displacement, vibration amplitude, temperature rise gradient, and current change rate for each stage. S3. Select healthy action segments in the early stage of circuit breaker operation, normalize the characteristics according to the operating conditions, construct an individual baseline model for a single circuit breaker, and register the effective time of the baseline parameter version. S4. Calculate the offset between the new operating segment features and the individual baseline model of a single circuit breaker under the corresponding operating conditions. Based on the degradation mode dictionary, decompose the feature offset into mechanism degradation components, arc-extinguishing chamber degradation components, and operation cumulative load components. S5. Calculate the degradation index of the mechanism, the degradation index of the arc-extinguishing chamber, and the cumulative load index of operation based on the degradation components, and generate the operation risk level, maintenance objects, and maintenance time windows; S6. After completing the planned maintenance and fault disassembly inspection, the measured wear status is correlated with the historical assessment results, the degradation mode dictionary and risk level threshold are corrected by incremental update, and the model version is recorded for traceability.

2. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 1, characterized in that, S1 includes: Use the timekeeping reference of the station's timekeeping device as a time reference; A coil current detection unit, a main circuit current detection unit, a main circuit voltage detection unit, a contact temperature detection unit, a mechanism displacement detection unit, and a mechanism vibration detection unit are installed near the primary circuit and operating mechanism of the vacuum circuit breaker. Each detection unit is connected to the acquisition unit through an acquisition channel, and the acquisition channel has a fixed range, unit of measurement, and sampling rhythm. When the vacuum circuit breaker receives a tripping command and when it receives a closing command, the acquisition unit triggers sampling under the control of the timing reference, synchronously acquires the output signals of each detection unit on a unified time axis, and generates an operation segment identifier based on the circuit breaker number, timing timestamp, and action type.

3. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 2, characterized in that: During sampling, the acquisition unit reads operating information from the protection device and monitoring system. The operating information includes operation nature markers, protection action types, breaking current range markers, and ambient temperature range markers. Within a predetermined time after the opening and closing actions are completed, the operation information is sorted out, the operating condition label is generated and bound to the corresponding operating segment identifier to obtain the operating segment record. The operating segment record includes the sampling sequence, the operating segment identifier and the operating condition label. Attach the acquisition channel version number and status code fields to the running segment record; And send the runtime segment record to the evaluation server; The evaluation server checks the corresponding record in the fragment library using the combination of the running fragment identifier and the channel version number as an idempotent key. If no corresponding record is found, the running fragment record is written to the fragment library.

4. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 1, characterized in that, S2 include: The evaluation server reads the coil current waveform, main circuit current and voltage, contact temperature and mechanism stroke vibration signal corresponding to the running segment identifier based on the running segment records in the segment library; Based on the time stamp and the start and end points, abrupt change points and inflection points of each signal, the start and end times of the coil energizing stage, the mechanism energy release stage, the contact movement stage, the arc maintenance stage and the contact stabilization stage are determined. Calculate the action time, velocity, displacement, vibration amplitude, temperature rise gradient and current change rate at each stage, generate feature records and write them into the feature library; For runtime segments whose stage boundaries cannot be reliably identified, the runtime segment identifier is marked as a stage division failure state, and status code four is written into the corresponding feature record.

5. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 1, characterized in that, S3 includes: The evaluation server marks vacuum circuit breakers that meet the health criteria as healthy devices based on the test records. Healthy action segments are selected from the feature library according to the operation segment identifier, grouped according to the operating condition label, and statistically analyzed for the six types of action characteristics to obtain the reference center value and allowable fluctuation range. They are then collected according to the circuit breaker number to form an individual baseline model for each circuit breaker. The evaluation server generates a baseline parameter version with version number, effective time, and applicable operating condition set for the individual baseline model of a single circuit breaker, writes it to the read-only parameter library and generates an evidence chain record. When a baseline parameter version update request is received, it verifies the continuity of the version number and the integrity of the evidence chain record. If the verification fails, it marks the version conflict with status code five and keeps the active version unchanged.

6. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 1, characterized in that, S4 include: When the individual baseline model of a single circuit breaker is in an active version, the evaluation server reads the current operating segment features from the feature library based on the operating segment identifier, and calculates the feature offset vector according to the current operating segment features and the reference center value in the individual baseline model of the single circuit breaker. Select a set of degradation patterns from the degradation pattern dictionary that meet the set threshold for similarity with the feature offset vector, and read the assigned weights corresponding to the action time feature, velocity feature, displacement feature, vibration amplitude feature, temperature rise gradient feature and current change rate feature. The feature offset vector is decomposed into mechanism degradation component, arc-extinguishing chamber degradation component and operational cumulative load component according to the assigned weights, and the mechanism degradation component, arc-extinguishing chamber degradation component and operational cumulative load component are written into the degradation record library along with the running segment identifier.

7. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 6, characterized in that: The degradation mode dictionary is formed by the manufacturer based on type test prototypes and failed prototypes. The weights are assigned during construction to satisfy non-negativity constraints and limit the total weight range of mechanism degradation components, arc-extinguishing chamber degradation components, and operational cumulative load components. When the evaluation server performs on-site calculations, it marks the running segment corresponding to the feature offset vector whose similarity to the degradation mode in the degradation mode dictionary is lower than a set threshold as a mode missing state. When performing degradation decomposition using the feature offset threshold rule, it selects the degradation component level of the mechanism, the degradation component level of the arc extinguishing chamber, and the cumulative load component level of the operation based on the threshold interval where the feature offset vector is located.

8. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 1, characterized in that, S5 include: The evaluation server sets up sliding observation windows based on the number of actions and natural time in the degradation record library according to device number; Within each sliding observation window, the mechanism degradation component, arc-extinguishing chamber degradation component, and operational cumulative load component are read in the order of the running segment identifier. The mechanism degradation index, arc-extinguishing chamber degradation index, and operational cumulative load index are calculated according to the normalization rule. The three types of indices are compared with the risk level threshold set to determine the operational risk level, and the maintenance objects and maintenance time windows are determined based on the combination relationship of the mechanism degradation index, arc extinguishing chamber degradation index and operation cumulative load index in the maintenance strategy library.

9. The intelligent evaluation method for the operating status of a vacuum circuit breaker according to claim 1, characterized in that, S6 include: During planned maintenance and troubleshooting, the system measures the spring preload, pin wear, lubrication status, connecting rod clearance, contact erosion depth, and creepage distance of insulating components. It also generates wear records through the maintenance system, including the device number, maintenance time, and historical assessment result number. The assessment server reads wear records and obtains the mechanism degradation index, arc-extinguishing chamber degradation index, operational cumulative load index, and operational risk level from the assessment result library and degradation record library. It then associates each physical wear quantity with the mechanism degradation index, arc-extinguishing chamber degradation index, operational cumulative load index, and operational risk level to form a set of records labeled with the degree of degradation. The evaluation server incrementally updates the degradation pattern dictionary and risk level threshold set based on the record set, generates a model version number, and registers the corresponding evidence chain record in the read-only version repository.

Images