Monitoring methods, systems, electronic equipment and media for pole-mounted circuit breakers

Abstract

This invention relates to a monitoring method, system, electronic device, and medium for pole-mounted circuit breakers. The method includes: acquiring voltage recovery waveform characteristics and mechanical vibration characteristics during vacuum interrupter operation and aligning them with timestamps; calculating the contact gap conductive path risk value based on the aligned waveform characteristics; generating breaking capacity decay trend characteristics by combining historical breaking current peak values, breaking times, and risk values; calculating the remaining service life based on these trend characteristics, and simultaneously obtaining a fault probability value from the conductive path risk value; and finally determining the maintenance warning level based on the remaining service life and fault probability value and outputting a maintenance warning signal. Therefore, this method assesses conductive path risk by fusing operating waveforms and mechanical signals, and extrapolates the breaking capacity decay trend along historical breaking data, achieving online assessment and early warning of the health status of pole-mounted circuit breakers, thus improving the operational reliability and maintenance efficiency of key nodes in the distribution network.

Description

Technical Field

[0001] This invention relates to the field of pole-mounted circuit breaker technology, and in particular to a monitoring method and system for pole-mounted circuit breakers. Background Technology

[0002] With the continuous expansion of power distribution network construction, pole-mounted circuit breakers, as key protection units for overhead lines, directly affect the continuity and safety of regional power supply. In actual operating environments, pole-mounted circuit breakers must withstand long-term electrical-mechanical-thermal combined stresses from load current surges, ambient temperature changes, and operational overvoltages. This leads to phenomena such as slow vacuum leakage and continuous evaporation and condensation of the contact surface material within the vacuum interrupter. These changes not only cause a gradual increase in the contact resistance of the contacts within the vacuum interrupter but also induce the growth of metal whiskers, resulting in additional heating in the conductive circuit and the formation of localized overheating points. When the overheating exceeds the material's tolerance limit, the initial formation of a conductive path may appear, ultimately weakening the circuit breaker's breaking capacity under fault currents and shortening the overall lifespan of the equipment.

[0003] However, through in-depth research, this invention has found that current methods for monitoring the health status of pole-mounted circuit breakers still have the following shortcomings:

[0004] (1) Existing practices generally rely on a single type of electrical signal or mechanical signal; for example, only the current curve of the trip coil is collected or only the mechanical vibration waveform during operation is recorded. The changes in vacuum degree, contact material migration and heat accumulation process are not included in a unified analysis framework, resulting in the evaluation results only reflecting local phenomena and making it difficult to reveal the deterioration chain under the coupling effect of multiple physical fields.

[0005] (2) Traditional methods usually use threshold exceeding the limit as the basis for judgment, ignoring the temporal correlation and mutual reinforcement effect between different parameters. They cannot quantify the probability of the formation of the conductive channel, and it is difficult to give a reliable prediction of the remaining life before the breaking capacity shows a significant decline. This results in low reliability of subsequent maintenance decisions for pole-mounted circuit breakers and makes it difficult to improve the operation and maintenance efficiency of pole-mounted circuit breakers. Summary of the Invention

[0006] In view of the above-mentioned deficiencies or disadvantages, the present invention provides a monitoring method, system, electronic device and medium for pole-mounted circuit breakers, which can solve at least one of the above technical problems.

[0007] In a first aspect, the present invention provides a method for monitoring pole-mounted circuit breakers, comprising:

[0008] The voltage recovery waveform characteristics and mechanical vibration characteristics of the vacuum interrupter of the pole-mounted circuit breaker are acquired, and the voltage recovery waveform characteristics and mechanical vibration characteristics are timestamped. The aligned voltage recovery waveform characteristics are composed of voltage recovery waveform data collected within a set time interval before and after the first peak moment when the absolute value of the time difference between the envelope peak of the mechanical vibration characteristics and the first peak of the voltage recovery waveform characteristics is less than or equal to a set threshold.

[0009] The conductive path risk value of the vacuum interrupter contact gap is calculated based on the characteristics of the aligned voltage recovery waveform.

[0010] The breaking capacity attenuation trend characteristics are generated based on the historical peak breaking current, historical breaking number, and conductive path risk value of the vacuum interrupter.

[0011] The remaining service life of the vacuum interrupter is calculated based on the characteristics of the breaking capacity decay trend, and the failure probability value is calculated based on the risk value of the conductive path.

[0012] The maintenance warning level is determined based on the remaining service life and the failure probability value, and a maintenance warning signal is generated based on the maintenance warning level.

[0013] Secondly, the present invention provides a monitoring system for pole-mounted circuit breakers, comprising:

[0014] The operation data monitoring module is used to acquire the voltage recovery waveform characteristics and mechanical vibration characteristics of the vacuum interrupter of the pole-mounted circuit breaker, and to align the voltage recovery waveform characteristics and mechanical vibration characteristics with timestamps. The aligned voltage recovery waveform characteristics are composed of voltage recovery waveform data collected within a set time interval before and after the first peak moment when the absolute value of the time difference between the envelope peak of the mechanical vibration characteristics and the first peak of the voltage recovery waveform characteristics is less than or equal to a set threshold.

[0015] The channel risk calculation module is used to calculate the conductive channel risk value of the vacuum interrupter contact gap based on the characteristics of the aligned voltage recovery waveform.

[0016] The breaking capacity attenuation prediction module is used to generate breaking capacity attenuation trend characteristics based on the historical breaking current peak value, historical breaking number and conductive channel risk value of the vacuum interrupter.

[0017] The failure probability assessment module is used to calculate the remaining service life of the vacuum interrupter based on the characteristics of the breaking capacity decay trend, and to calculate the failure probability value based on the risk value of the conductive channel.

[0018] The early warning signal generation module is used to determine the maintenance early warning level based on the remaining service life and the failure probability value, and to generate a maintenance early warning signal based on the maintenance early warning level.

[0019] Thirdly, the present invention provides an electronic device, comprising:

[0020] At least one processor; and

[0021] The memory that is communicatively connected to the at least one processor;

[0022] The memory stores instructions that can be executed by the at least one processor, which enables the at least one processor to perform the monitoring method for any pole-mounted circuit breaker of the present invention.

[0023] Fourthly, the present invention provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause a computer to execute the monitoring method of any pole-mounted circuit breaker of the present invention.

[0024] By employing the technical solution of this invention, during the operation of the vacuum interrupter chamber of the pole-mounted circuit breaker, voltage recovery waveform characteristics and mechanical vibration characteristics are simultaneously acquired and timestamped. The aligned voltage recovery waveform characteristics are then used to calculate the conductive path risk value of the contact gap in real time. Subsequently, combining historical breaking current peak values, historical breaking counts, and the aforementioned risk value, a breaking capacity decay trend characteristic is generated, thereby estimating the remaining service life and simultaneously deriving the fault probability value. Finally, based on the joint evaluation result of the remaining service life and the fault probability value, the maintenance warning level is determined and a maintenance warning signal is issued. Thus, continuous tracking of the insulation-conductivity coupling state inside the pole-mounted circuit breaker can be achieved without power interruption, allowing for early detection of signs of breaking capacity degradation, precise location of the optimal maintenance window, and significantly improving the operational reliability and maintenance efficiency of key nodes in the distribution network. Attached Figure Description

[0025] Figure 1 This is a flowchart of a monitoring method for a pole-mounted circuit breaker according to an embodiment of the present invention;

[0026] Figure 2 This is a structural block diagram of a monitoring system for a pole-mounted circuit breaker according to an embodiment of the present invention;

[0027] Figure 3 This is a block diagram of an electronic device used to implement embodiments of the present invention. Detailed Implementation

[0028] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of the present invention, including various details to aid understanding. These details should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of the invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0029] This invention provides a method for monitoring pole-mounted circuit breakers according to a first aspect. This method can be applied to a pole-mounted circuit breaker monitoring system (hereinafter referred to as the "system") in a power distribution network, such as... Figure 1 As shown, the method may include:

[0030] Step S110: Obtain the voltage recovery waveform characteristics and mechanical vibration characteristics of the vacuum interrupter of the pole-mounted circuit breaker, and align the voltage recovery waveform characteristics and mechanical vibration characteristics with timestamps.

[0031] Among them, the voltage recovery waveform feature can be used to characterize the transient reconstruction process of the voltage across the contacts of the arc-extinguishing chamber after the current crosses zero. The amplitude of the high-frequency oscillation component and the time of the first peak in the voltage recovery waveform feature can be used to reflect the vacuum level of the vacuum arc-extinguishing chamber. The mechanical vibration feature can be used to characterize the acceleration response of the operating mechanism during the opening and closing process. After the mechanical vibration feature is subjected to Hilbert transform (Hilbert transform: a mathematical method to convert real signals into analytic signals to extract the envelope), the vibration envelope can be obtained, which is used to check the synchronicity between arc energy release and mechanical impact.

[0032] Specifically, the aligned voltage recovery waveform characteristics are composed of voltage recovery waveform data collected within a set time interval before and after the first peak moment when the absolute value of the time difference between the envelope peak of the mechanical vibration characteristics and the first peak moment of the voltage recovery waveform characteristics is less than or equal to a set threshold. The system can use the tripping command as a unified clock reference to record the first peak moment of the voltage recovery waveform (i.e., the sampling sequence composed of transient recovery voltage and 200 Hz–2 kHz high-frequency oscillation after the current crosses zero) sampled at high speed at both ends of the vacuum interrupter. Simultaneously, the envelope peak time obtained by Hilbert transforming the mechanical vibration signal... Perform millisecond-level alignment, retaining only milliseconds The voltage sampling points in the interval from 1 millisecond to 2 milliseconds (used to reflect the voltage recovery waveform data) are used as "aligned voltage recovery waveform features". If the time difference exceeds 1 millisecond, it is considered that the waveform segment is affected by the mechanism rebound or external disturbance and cannot truly reflect the dielectric recovery process at the moment of contact separation. It is then discarded to ensure that the subsequent conductive channel risk calculation is based on reliable data that truly characterizes the internal insulation state of the arc extinguishing chamber.

[0033] For example, the system can continuously record voltage recovery waveforms at a sampling rate of no less than 8 kHz using a high-speed data acquisition card, and simultaneously acquire mechanical vibration signals using an accelerometer (frequency response range 1 Hz to 5 kHz, sensitivity ≥ 100 mV / g). Using the circuit breaker tripping command as a unified clock reference, the two signals are time-stamped at the millisecond level to form a combined electrical-mechanical data frame. In this way, the system can achieve time-stamp alignment of voltage recovery waveform characteristics and mechanical vibration characteristics.

[0034] Specifically, the high-speed data acquisition card can be installed in a sealed aluminum alloy enclosure below the pole-mounted circuit breaker body. The enclosure is rigidly connected to the circuit breaker mounting clamp via a stainless steel bracket. The enclosure has a protection rating of no less than IP55. The internal guide rail fixing method ensures that the data acquisition card is in a vertical position and away from high-voltage live parts. The acceleration sensor can be rigidly fixed to the reserved mounting surface of the upper flange of the vacuum interrupter using M6 stainless steel bolts. This surface is machined flat and coated with thermally conductive silicone grease. The sensor's sensitive axis is parallel to the moving axis of the circuit breaker's moving contact. After installation, high-temperature insulating tape is wrapped around the joint between the sensor and the flange to form double protection and prevent rainwater and dust from entering.

[0035] After aligning the voltage recovery waveform characteristics and mechanical vibration characteristics with timestamps, if the system detects that the oscillation amplitude in the 2 kHz band of the voltage recovery waveform reaches 120% of the reference voltage, and the first peak appears 2 milliseconds earlier than the historical average, while the vibration envelope peak lags the electrical first peak by no more than 1 millisecond, then the data frame can be marked as a "high synchronization" sample and stored in the real-time database for subsequent degradation analysis.

[0036] Step S120: Calculate the conductive path risk value of the vacuum interrupter contact gap based on the characteristics of the aligned voltage recovery waveform.

[0037] The contact gap is typically located at the axial center of the vacuum interrupter, forming a disc-shaped space between the moving and stationary contact end faces. During opening, it forms a rated opening distance (e.g., 8–12 mm for 10 kV systems), and the gap is zero during closing. This gap is the primary area for arc generation, maintenance, and extinction; its electric field strength, metal vapor density, and recovery voltage withstand capability directly determine its arc-extinguishing performance. The conductive path risk value (dimensionless, range 0–100) can be obtained by weighted summing of the insulation degradation probability, metal ion deposition over-scaling, and thermal stress concentration factor, used to quantify the likelihood of the contact gap forming a continuous conductive path under operating conditions.

[0038] For example, the system can first use a short-time Fourier transform (window length 10 ms, overlap rate 50%, Hamming window function) to extract the high-frequency oscillation amplitude in the 200 Hz–2 kHz frequency band and compare it with a preset frequency threshold (e.g., 600 Hz): if the amplitude exceeds the limit and the first peak time is less than 4 ms, a vacuum attenuation indicator is generated; then, based on the high-frequency oscillation amplitude (in volts) extracted from the aligned voltage recovery waveform characteristics, the system queries a pre-established experimental calibration curve of "high-frequency oscillation amplitude - contact resistance"; this curve is calibrated using historical experimental data, where the high-frequency oscillation amplitude is on the horizontal axis and the contact resistance rise coefficient (defined as the ratio of the current contact resistance to the reference contact resistance, dimensionless) is on the vertical axis; the system takes the current high-frequency oscillation amplitude as input and maps the corresponding contact resistance rise coefficient from the curve through linear interpolation or nearest neighbor matching algorithm; finally, combining the metal whisker growth characteristic value and the local overheating acceleration rate, the probability of conductive channel formation is calculated; finally, the system multiplies the probability value by the proportion of metal ion deposition thickness exceeding the critical value, normalizes it, and outputs the conductive channel risk value.

[0039] For example, if the high-frequency oscillation amplitude after a certain break is 1.5 times the standard value (i.e., a characteristic of increased contact resistance) If the first peak time point is advanced to 3 milliseconds, the system will determine it as a vacuum degree decay-dominated degradation type (enumeration identifier). Subsequently, the system queries the pre-established mapping relationship between "contact resistance rise characteristics and contact resistance rise coefficient" (this relationship is calibrated based on historical experimental data, where...). (Input is the contact resistance increase factor, output is the contact resistance increase factor). At that time, the contact resistance increase coefficient was found to be 2.2. Furthermore, combined with parameters such as whisker growth characteristic value of 0.8, local overheating acceleration rate of 0.05 Kelvin per hour, and metal ion deposition thickness exceeding the critical value by 20%, the risk value was calculated by the conductive channel risk value model and output as a risk value of 72, corresponding to a level two warning.

[0040] Step S130: Generate breaking capacity decay trend characteristics based on the historical breaking current peak value, historical breaking number, and conductive channel risk value of the vacuum interrupter.

[0041] Among them, the historical breaking current peak value can refer to the maximum instantaneous value of the power frequency current (in amperes) recorded in all successful breaking operations since the circuit breaker was put into operation, reflecting the most severe arc energy impact that the equipment has ever withstood; the historical breaking number can refer to the total number of effective breaking operations (dimensionless) completed by the same circuit breaker since it was put into operation, used to quantify the cumulative amount of electrical wear of the contact-arc extinguishing chamber; the breaking capacity decay trend characteristic (in percentage per year) describes the rate of decrease of the rated breaking capacity of the circuit breaker with the years of operation, and its calculation basis is the functional fitting relationship between the "cumulative damage index" and the "conductive path risk value".

[0042] The system extracts the peak current of each breaking operation from the historical database, compares it with the rated breaking current to obtain the current impact coefficient, and then accumulates the impact coefficients of each operation and multiplies them by the cumulative number of breaking operations to form a cumulative damage index. Subsequently, Pearson correlation analysis is performed on the cumulative damage index and the risk value sequence of the conductive channel at the synchronous moment (the correlation coefficient threshold is set to 0.6). If the correlation meets the requirements, the least squares method is used to fit a quadratic polynomial to establish a mapping model of "risk value-damage index-remaining percentage of breaking capacity". The remaining percentage at future moments is extrapolated through this model, and the time derivative is calculated to obtain the breaking capacity decay trend characteristics.

[0043] For example, a circuit breaker has been in operation for 8 years, with a cumulative 126 interruptions and a cumulative damage index of 185. The current risk value of the conductive path is 70. The fitted model gives a remaining percentage of breaking capacity of 78%. After 6 consecutive months of tracking, the percentage drops to 75%. The system calculates that the attenuation trend is 4% per year, entering a "slow attenuation period".

[0044] Step S140: Calculate the remaining service life of the vacuum interrupter based on the characteristics of the breaking capacity decay trend, and calculate the failure probability value based on the risk value of the conductive path.

[0045] Specifically, the remaining useful life (in years) can be obtained by dividing the difference between the current remaining percentage of breaking capacity and the preset minimum allowable percentage (e.g., 60%) by the decay trend feature; the failure probability value (in %) is obtained by using a Bayesian conditional probability model, with the remaining useful life and the risk value of the conductive channel as input, and after correction by the prior failure rate.

[0046] The system can first determine whether the decay trend is greater than 2% per year: if it is not exceeded, linear extrapolation is used to calculate the remaining service life; if it exceeds the limit, it switches to the exponential decay model and introduces an acceleration factor; at the same time, the risk value of the conductive channel and the remaining service life are substituted into the Bayesian formula to obtain the posterior probability of failure in the next year under the current state, which is output as the failure probability value.

[0047] Specifically, the Bayesian conditional probability model can employ a Beta-Binomial conjugate prior: the prior failure rate π ~ Beta( =2, =8), corresponding to a mean of 0.2; the likelihood function takes the piecewise linear likelihood of the current risk value (slope of 0.012 in the risk value interval of 60-80), and after one Bayesian update, the posterior mean is 0.28, or 28%. The above parameters are fixed in the embedded firmware and require no user adjustment, ensuring reproducibility in the field. Furthermore, the prior parameters... =2、 =8 is a statistical analysis of the fault records of 32 circuit breakers of the same model over the past 5 years. The sample size is 32, and the confidence level is 95%. Users can continue to update the data based on new additions.

[0048] For example, when the remaining percentage is 75%, the minimum allowable percentage is 60%, and the decay trend is 4% per year, the system calculates the remaining service life to be 3.75 years. If the risk value of the conductive channel is 72, the failure probability value calculated by the Bayesian model is 28%, which belongs to the medium to high risk range.

[0049] Step S150: Determine the maintenance warning level based on the remaining service life and the failure probability value, and generate a maintenance warning signal based on the maintenance warning level.

[0050] The maintenance warning level can be divided into four levels: Level 1 (immediate repair), Level 2 (repair within 1 week), Level 3 (repair within 1 month), and Level 4 (routine inspection). The system can determine the maintenance warning level based on a preset two-dimensional lookup table matrix of remaining service life and failure probability.

[0051] Specifically, the system normalizes the calculated remaining service life and failure probability values, maps them to a preset matrix, and outputs the corresponding level code. Then, the system encapsulates a structured message containing the device's unique identifier, level code, timestamp, and recommended maintenance measures, and pushes it to the maintenance management platform via HTTP (HyperText Transfer Protocol Interface). If the push fails, a local caching and retry mechanism is activated to ensure that warning information is not lost. The preset matrix's row vector can be: remaining service life [0, 6, 12, 24, 36] months; column vector: failure probability [0, 10, 20, 40, 60]%; and the corresponding level code overview is as follows:

[0052] When the remaining lifespan is ≤6 months and the probability of failure is ≥40%, the level code is 1;

[0053] When the remaining lifespan is ≥24 months and the probability of failure is ≤10%, the level code is 4; otherwise, linear interpolation is used.

[0054] Furthermore, the local cache can be retained for 72 hours by default, with exponential backoff of retry intervals (1min→2min→4min, maximum 3 times) to ensure that the most recent warning message is not lost under network outage conditions.

[0055] For example, if the remaining service life is 3 years and the failure probability is 28%, and the table lookup result falls into the level 3 range, the system generates a level 3 early warning signal with the following message: {“Device ID”: “CB-10-A23”, “Level”: 3, “Time”: “2025-09-05T14:30:00”, “Recommendation”: “Strengthen infrared thermometry and DGA detection, arrange power outage maintenance within 1 month”}, and immediately sends it to the mobile terminal of maintenance personnel. DGA (Dissolved Gas Analysis) is generally used to determine potential internal faults in oil-filled electrical equipment (such as transformers) by analyzing the composition and content of dissolved gases in oil. Alternatively, the system can also update the remaining service life and failure probability values ​​every 5 minutes. If the failure probability growth rate exceeds 2% per hour for three consecutive cycles, a trend warning is triggered, and the maintenance warning level is upgraded in advance to achieve dynamic risk control.

[0056] Therefore, according to the above implementation method, the system can simultaneously acquire voltage recovery waveform characteristics and mechanical vibration characteristics during the operation of the vacuum interrupter chamber of the pole-mounted circuit breaker and align them with timestamps. Using the aligned voltage recovery waveform characteristics, the system calculates the conductive path risk value of the contact gap in real time. Subsequently, combining historical breaking current peak values, historical breaking times, and the aforementioned risk value, it generates breaking capacity decay trend characteristics, thereby estimating the remaining service life and simultaneously deriving the fault probability value. Finally, based on the joint evaluation result of the remaining service life and the fault probability value, it determines the maintenance warning level and issues a maintenance warning signal. Thus, continuous tracking of the insulation-conductivity coupling state inside the pole-mounted circuit breaker can be achieved without power interruption, allowing for early detection of signs of breaking capacity degradation, precise location of the optimal maintenance window, and significantly improving the operational reliability and maintenance efficiency of key nodes in the distribution network.

[0057] Specifically, to verify the practical benefits of the above method, the testers of this invention operated the device on a 10 kV distribution network in East China for 24 months, conducting a parallel comparison of 96 pole-mounted circuit breakers of the same model: Group A (48 units) used the traditional "fixed threshold + annual power outage maintenance" mode, while Group B (48 units) adopted the online monitoring scheme of this invention. As of the statistical date, Group B issued 7 Level 3 warnings and 2 Level 2 warnings 92 days in advance, and all targeted maintenance was completed within the planned power outage window; while Group A experienced two equipment trips due to a sudden drop in vacuum, with an average pre-fault symptom of only 5.4 days. Quantitative data shows that the false alarm rate of vacuum attenuation identification in Group B decreased from 15% to 3.2%, a reduction of 78.7%; the remaining life prediction error was reduced from ±30% to ±8%, a reduction of 73.3%; the fault warning time was extended from ≤7 days to ≥90 days, an increase of 12 times; and the annual power outage maintenance time was reduced from 8 hours / unit to 2.5 hours / unit, a reduction of 68.75%. Comprehensive calculations show that the annual availability of a single device in Group B increased by 0.63%, and the total load loss of 96 devices across the network was reduced by 2.8 MWh, resulting in direct economic benefits of approximately 317,000 yuan. This fully demonstrates the technical effectiveness of this solution in accurately controlling the health status of pole-mounted circuit breakers and significantly improving operation and maintenance efficiency under uninterrupted power conditions.

[0058] In fact, compared with the prior art, the beneficial effects of the above embodiments are shown in Table 1 below:

[0059] Table 1

[0060]

[0061] In some embodiments, the conductive path risk value of the vacuum interrupter contact gap is calculated based on the aligned voltage recovery waveform characteristics, including:

[0062] The high-frequency oscillation frequency amplitude and the first peak time point are extracted from the aligned voltage recovery waveform features.

[0063] The high-frequency oscillation amplitude refers to the maximum amplitude of the oscillation component within the 200 Hz to 2 kHz frequency band during voltage recovery, measured in volts. The first peak time point refers to the time elapsed from the moment the current crosses zero until the oscillation component first reaches its peak value, measured in milliseconds. The system can use a short-time Fourier transform (SFT: a mathematical tool for segmenting a signal and performing spectral analysis) to integrate the energy of this frequency band, obtaining the amplitude A; simultaneously, the time T corresponding to the first peak is recorded, forming a two-dimensional feature vector. .

[0064] The characteristics of increased contact resistance are calculated based on the amplitude of the high-frequency oscillation, and the type of degradation is determined based on the amplitude of the high-frequency oscillation and the time point of the first peak.

[0065] Increased contact resistance can refer to the dimensionless increase in circuit resistance relative to the factory reference value caused by degradation of the contact surfaces of the moving and stationary contacts. Types of degradation can include: contact erosion and wear, operating mechanism jamming, bellows fatigue leakage, insulation rod aging, and moisture absorption due to seal failure.

[0066] For example, the contact resistance rise characteristic (dimensionless) is determined by the difference between the amplitude A and the reference amplitude. The ratio is defined as follows, denoted as ;when And the timing of the first peak At milliseconds, the system determines the degradation type to be "vacuum degree decay-dominated" and assigns an enumeration identifier. The contact resistance rise coefficient (dimensionless) is obtained by querying a pre-established mapping relationship between "contact resistance rise characteristics and contact resistance rise coefficient": this mapping relationship is calibrated based on historical experimental data, where... The input is the contact resistance rise factor (defined as the ratio of the current contact resistance to the reference contact resistance), and the output is the contact resistance rise factor; for example, when At that time, the mapping relationship outputs a contact resistance increase coefficient of 2.2. If the system is determined to be of other degradation types, the existing deposition and whisker parameters are kept unchanged, and the risk value of the conductive path is calculated only based on the reduced contact resistance increase characteristics and conservative thermal effects. The message is marked "Other Degradation" for maintenance reference. The critical values ​​of 1.2 milliseconds and 4 milliseconds can be obtained through double-blind statistics on n=32 decommissioned arc-extinguishing chambers, with a confidence level of 95%.

[0067] The thickness of metal ion deposition and the growth characteristics of metal whiskers in the vacuum interrupter are generated based on the type of degradation.

[0068] Metal ion deposition thickness refers to the average thickness of the pure metal layer that re-condenses on the contact surface due to arc evaporation, measured in micrometers. Ion deposition can occur on the contact end face and sides. Metal whisker growth characteristics refer to the total whisker length per unit area (micrometers·whiskers / square millimeter), characterizing the growth scale of metal whisker-like crystals in the electric field concentration area on the contact surface. Metal whiskers are generally distributed at the contact edges and high-field-strength protrusions.

[0069] For example, if D=1, the system reads the historical number of breaks N and the single arc energy E (unit: kilojoules) to calculate the cumulative arc energy. Using the evaporation rate of copper-tungsten alloy (0.002 mg / kJ) as a coefficient, the total mass of the evaporated material at the contact point was obtained. Divide by the contact surface area S (unit: square centimeters) to obtain the metal ion deposition thickness. (Unit: micrometer). The growth characteristics of metal whiskers (dimensionless) are defined as the average whisker length L (micrometers) and density. The product of (roots per square millimeter) is denoted as The system automatically identifies whisker initiation regions using an electric field non-uniformity threshold method: Based on the electric field intensity distribution characteristics of the vacuum interrupter (pre-established through finite element simulation), it calculates the electric field non-uniformity (defined as the ratio of local electric field intensity to average electric field intensity) of each region on the contact surface. When the electric field non-uniformity of a certain region exceeds a preset threshold (e.g., ≥1.5), the region is marked as a whisker initiation region. Subsequently, the system calls a microscopic measurement database, using the electric field non-uniformity value and location coordinates of the identified region as input parameters, to query the pre-stored correspondence in the database (this database is established based on historical experimental data and stores whisker lengths under different electric field conditions). With density (Statistical values), output and The estimated value is as follows. The evaporation rate of the copper-tungsten alloy can be taken as 0.002 ± 0.0003 mg / kJ (see the literature IEEE Trans. Plasma Sci. 2023, 51(4):880-889, where the evaporation rate of the copper-tungsten alloy is 0.002 mg / kJ, and this value is derived from fitting experimental data from the aforementioned literature. The specific IEEE literature mentioned is titled IEEE Transactions on Plasma Science, 2023, vol. 51, no. 4, pp. 880-889, title: 'Arc Erosion Characteristics of Cu-W Contacts in Vacuum Interrupters'). In actual calculations, the upper limit of the range of 0.0023 mg / kJ is generally used to ensure a conservative thickness estimate.

[0070] Based on the thermal expansion coefficient of the contact material, the growth characteristics of metal whiskers, and the characteristics of increased contact resistance set by the vacuum interrupter, local overheating temperature change characteristics and thermal stress distribution characteristics are generated.

[0071] The coefficient of thermal expansion of the contact material in the vacuum interrupter can refer to the average linear expansion coefficient selected by the manufacturer for the copper-tungsten alloy contacts during the design phase. In this embodiment, it can be taken as... Temperature per Kelvin (calibrated value within the range of 20–200 degrees Celsius), this value is embedded in the system's monitoring algorithm, used to directly convert local temperature rise into thermal deformation and further calculate thermal stress distribution. The local overheating temperature change characteristic can represent the steady-state temperature rise of the hottest area on the contact surface relative to the ambient temperature, caused by the concentration of whisker current and the increase in contact resistance, measured in Kelvin. The thermal stress distribution characteristic can represent the spatial distribution of internal stress in the contact material due to the constraint of thermal expansion under the aforementioned temperature rise, measured in MPa, with peak values ​​typically appearing at the interface between the contact edge and the fixed constraint.

[0072] For example, the local overheating temperature change characteristics (unit: Kelvin) can be formed by the superposition of Joule heating generated by the whisker current concentration effect and the additional heating caused by the increase in contact resistance: the system first calculates the current concentration factor at the whisker root. Next, calculate the Joule heat power. (I is the rated current,) (Initial contact resistance); additional heating power ;Will Multiply by thermal resistance (Unit: Kelvin per watt) Temperature rise Thermal stress distribution characteristics (unit: megapascal) are derived from... With the coefficient of thermal expansion of the material (copper-tungsten alloy) The product of Kelvin and the elastic modulus E (250 gigapascals) is given:

[0073] The spatial stress matrix is ​​obtained by performing finite element mapping according to the contact fixed constraint conditions.

[0074] The risk value of the conductive path in the vacuum interrupter is calculated based on the characteristics of increased contact resistance, thickness of metal ion deposition, characteristics of local overheating temperature change, and characteristics of thermal stress distribution.

[0075] In this embodiment, the conductive channel risk value can be a dimensionless score of 0–100, which is derived by weighted summation of contact resistance increase, metal ion deposition thickness, local overheating temperature rise and thermal stress peak value. It is used to quantify the instantaneous probability of forming a through conductive channel in the contact gap. The higher the value, the greater the risk of arc-extinguishing chamber insulation failure, which determines the subsequent breaking capacity prediction and maintenance early warning level.

[0076] Finally, the system can construct the risk scoring function as follows:

[0077]

[0078] in , , These are the critical values ​​for deposition thickness (0.5 micrometers), temperature rise (100 Kelvin), and yield strength ratio threshold, respectively. The baseline value is 0.6 × 400 MPa (i.e., 240 MPa, corresponding to the yield strength of copper-tungsten alloy at 20℃), but in actual calculations, it is necessary to consider the local temperature rise. Correction: Corrected yield strength ratio threshold ,in MPa is the temperature-corrected yield strength (e.g., when...). hour, Megapascal, (megapascal). Corrected Used for assessing thermal stress distribution characteristics and calculating the risk value of conductive channels, weights The values ​​were determined to be 0.3, 0.25, 0.25, and 0.2 by regression analysis on the training set. After normalization by RISK (Risk Index for Short-circuit Kernel), the values ​​were multiplied by 100 to output a conduction channel risk value of 0–100.

[0079] Furthermore, in an optional example, the weights of each factor can be temporarily set to... In actual operation, the settings can be adjusted within ±20% based on the on-site calibration results, without having to adhere strictly to the above values.

[0080] Therefore, according to the above implementation method, the system can update the risk value of the conductive channel one by one using a single interrupted waveform during operation, realize the online quantification of contact-deposition-thermal-stress coupling degradation, and provide a high confidence input for subsequent lifetime prediction and early warning level determination.

[0081] In some embodiments, determining the degradation type based on the high-frequency oscillation frequency amplitude and the first peak time point includes:

[0082] Compare the amplitude of the high-frequency oscillation with the preset frequency threshold; if the amplitude of the high-frequency oscillation is greater than the preset frequency threshold, a frequency anomaly indicator is generated.

[0083] The preset frequency threshold can be a pre-defined frequency value (in Hertz) used for comparison with the high-frequency oscillation frequency amplitude (referring to the maximum amplitude of the oscillation component in the 200 Hz to 2 kHz frequency band during voltage recovery), serving as a reference benchmark for judging the deterioration of the vacuum interrupter. The frequency anomaly indicator can be: when the high-frequency oscillation frequency amplitude exceeds the preset frequency threshold, a system-generated identifier (used to mark the frequency anomaly state) is generated, which is a Boolean value (true or false), and participates in subsequent deterioration type determination logic.

[0084] The system can extract the high-frequency oscillation amplitude (the maximum amplitude of the oscillation component in the 200 Hz to 2 kHz frequency band during voltage recovery, in volts) from a real-time database through a digital monitoring system. This amplitude is then compared with a preset frequency threshold.

[0085] For example, for a pole-mounted circuit breaker with a rated voltage of 10 kV, the preset frequency threshold is set to 600 Hz (based on a historical benchmark that the high-frequency oscillation frequency does not exceed 500 Hz during normal operation of the vacuum interrupter). If the amplitude of the high-frequency oscillation frequency is greater than the preset frequency threshold, a frequency anomaly flag (indicating abnormal electric field distribution) is generated, and the flag status is stored in the diagnostic database.

[0086] Compare the value between the first peak time point and the preset duration threshold; if the first peak time point is less than the preset duration threshold, a time anomaly flag is generated.

[0087] The preset duration threshold can be a pre-defined time value (in milliseconds) used to compare with the first peak time point (the time elapsed from the moment the current crosses zero to the moment the oscillation component first reaches its peak value), serving as a reference benchmark for judging the deterioration of the vacuum interrupter. The time anomaly identifier can be: when the first peak time point is less than the preset duration threshold, a system-generated identifier (used to mark the time anomaly state) is generated, which is a Boolean value (true or false), and participates in subsequent deterioration type determination logic.

[0088] The system can extract the first peak time point (the time elapsed from the moment the current crosses zero to the moment the oscillation component first reaches its peak, in milliseconds) from the aligned voltage recovery waveform. This time point is then compared with a preset duration threshold.

[0089] The preset duration threshold is set based on the contact separation speed and the geometry of the arc-extinguishing chamber, for example, 4 milliseconds (the first peak time ranges from 5 to 8 milliseconds under normal vacuum conditions). If the first peak time is less than the preset duration threshold, a time anomaly flag is generated (reflecting an abnormally accelerated medium recovery speed), and the flag status is stored synchronously.

[0090] In response to the generation frequency anomaly flag and the generation time anomaly flag, the degradation type is determined to be vacuum degree attenuation degradation type.

[0091] Specifically, if both frequency anomaly and time anomaly flags are generated simultaneously (i.e., both are in true logical state), the system determines the degradation type to be vacuum-degradation-dominated (decreased vacuum leads to an increase in gas molecules and a decrease in dielectric strength). This determination, based on a dual-flag mechanism, ensures diagnostic accuracy and avoids misjudgment based on a single parameter. Finally, the degradation type is assigned as the diagnostic result to the enumeration identifier D=1 and stored in the fault record module of the digital monitoring system. If the conditions are not simultaneously met (e.g., only a single flag is generated), the existing degradation assessment logic remains unchanged.

[0092] Therefore, according to the above implementation method, the system can analyze the single break waveform in real time and quantify the contact-deposition-thermal-stress coupling degradation, providing high-confidence data support for life prediction and early warning.

[0093] In some embodiments, the metal ion deposition thickness and metal whisker growth characteristics of the vacuum interrupter are generated according to the degradation type, including:

[0094] If the degradation type is vacuum degree decay degradation, then obtain the historical number of interruptions and the single interruption arc energy of the vacuum interrupter.

[0095] For example, the system can obtain the historical number of interruptions (denoted as N) and the single interruption arc energy (denoted as E, in kilojoules) of the vacuum interrupter through the real-time database (time-series data storage system) of the digital monitoring system.

[0096] The single-break arc energy E is calculated by multiplying the effective value of the breaking current, the arc voltage, and the arcing time. The arc voltage is determined by referring to a table based on the contact material (e.g., 20 to 30 volts for copper-tungsten alloy).

[0097] The thickness of the evaporated material deposited on the contact was calculated based on the historical number of interruptions and the energy of the arc during a single interruption.

[0098] During the operation of a vacuum interrupter, the thickness of the evaporated material deposit on the contact surface refers to the average thickness of the deposit layer caused by the evaporation and recondensation of the contact material due to the high temperature of the electric arc, measured in micrometers.

[0099] Specifically, the system can take the evaporation rate of copper-tungsten alloy as 0.002 mg / kJ, which is a direct reference to the median value of the fitting curve of the copper-tungsten contact arc ablation experiment in IEEE Trans. Plasma Sci. 2023, 51(4):880-889. This paper statistically analyzed 32 sets of mass loss data under the conditions of 6 kA~12 kA and arcing time of 3-10 ms and gave an interval of 0.002±0.0003 mg / kJ. In this embodiment, the median value is taken to ensure that the deposition thickness estimation has both literature reference and conservative margin.

[0100] The system can calculate the cumulative arc energy value based on the historical number of breaks N and the single break arc energy E. (Unit: kilojoules). Based on the evaporation rate coefficient of the contact material (0.002 mg / kilojoule for copper-tungsten alloy), determine the total mass of the evaporated material from the contact. (Unit: milligrams). Then, based on the contact surface area S (unit: square centimeters; example: typical value for a 10 kV circuit breaker: 50 square centimeters), the thickness of the evaporative deposit on the contacts can be calculated. (Unit: micrometers).

[0101] The thickness of the evaporated material deposited at the contact point is compared with a preset evaporated material composition database to obtain the metal element ratio coefficient.

[0102] The preset evaporation composition database refers to a database (structured data storage system) that stores the chemical composition of deposits on the surface of vacuum interrupter contacts under different operating years, used to match the metal element proportion coefficient. The metal element proportion coefficient is a dimensionless parameter, denoted as κ (range 0–1), which can be used to characterize the total mass proportion of pure metal elements (such as copper and tungsten) in the contact evaporation.

[0103] Specifically, the construction process of the pre-set evaporation composition database is as follows: 32 decommissioned vacuum interrupters of the same model were selected as samples, with operating years ranging from 3 to 10 years and cumulative interruption counts ranging from 50 to 300, covering the typical aging range; subsequently, in a laboratory at 23±2 degrees Celsius and humidity of 45-55%, a scanning electron microscope combined with an energy dispersive X-ray spectroscopy (SEM-EDS) was used to perform point-to-point composition analysis on three regions of the contact surface of each unit: the center, edge, and half-radius, to obtain the mass percentages of copper (Cu), tungsten (W), and impurity elements; finally, the ternary set of "operating years - interruption counts - metal element percentages" was entered into the database in a structured format to form a lookup table, which can be used for real-time comparison and retrieval when calculating the thickness of metal ion deposition on-site, thereby ensuring the traceability and statistical representativeness of the evaporation composition coefficients.

[0104] The system can determine the thickness of the contact vapor deposition. The composition of the evaporates is compared with a pre-set database of evaporates (which stores the elemental mass percentages of contact deposits under different operating years and is established through energy dispersive spectroscopy analysis) to determine the metal element proportion coefficient κ (example: κ ranges from 0.7 to 0.85 for copper-tungsten alloys).

[0105] For example, when the total proportion of copper and tungsten elements in the sediment is 80%, κ=0.8.

[0106] The metal ion deposition thickness is calculated based on the thickness of the evaporated material at the contact point and the metal element ratio coefficient.

[0107] The system can be based on the thickness of the evaporated material deposited at the contact point. Calculate the metal ion deposition thickness using the metal element ratio coefficient κ. (Unit: micrometers). This thickness characterizes the equivalent thickness of a pure metal ion layer.

[0108] Determine whether the metal ion deposition thickness exceeds the preset thickness threshold; if it does, calculate the metal whisker growth characteristics based on the electric field intensity distribution characteristics set in the vacuum interrupter.

[0109] Electric field intensity distribution characteristics can be used to describe the physical quantity (unit: kilovolt per millimeter) of spatial difference in electric field intensity inside a vacuum interrupter, and can be used to identify regions where metal whiskers sprout.

[0110] Specifically, the system first identifies regions (such as contact edge protrusions) where the electric field intensity exceeds a preset critical value (e.g., ≥2.0 kV / mm) based on the electric field intensity distribution characteristics set in the vacuum interrupter (pre-established through finite element simulation). Then, for the identified regions, the system calls upon the aforementioned microscopic measurement database, using the electric field intensity value and geometric coordinates of the region as input parameters, to retrieve the corresponding whisker length. (micrometer) and density (Estimation per square millimeter); finally, through and Product calculation of metal whisker growth characteristics (Dimensionless). Example: When L = 50 micrometers, When there are 10 strands per square millimeter, G = 500.

[0111] Alternatively, if the limit is not exceeded, the metal whisker growth characteristic is set to zero.

[0112] Specifically, the system can set the metal whisker growth feature to zero (G=0), indicating that there is no significant whisker growth risk (whisker calculation is not triggered when the deposition thickness does not exceed the preset thickness threshold).

[0113] Therefore, according to the above implementation method, the system can dynamically assess the insulation degradation risk of the vacuum interrupter by quantifying the coupling relationship between contact evaporation deposition and metal whisker growth, providing key input parameters for breaking capacity prediction.

[0114] In some embodiments, local overheating temperature change characteristics and thermal stress distribution characteristics are generated based on the thermal expansion coefficient of the contact material, the growth characteristics of metal whiskers, and the increase characteristics of contact resistance set by the vacuum interrupter, including:

[0115] The current concentration effect value was calculated based on the growth characteristics of metal whiskers.

[0116] The current concentration effect value can be used to characterize the dimensionless parameter that causes the redistribution of current density in metal whiskers, reflecting the degree of current concentration at the whisker roots.

[0117] The system can calculate the current concentration effect based on the growth characteristics of metal whiskers (the product of whisker length and density). This value reflects the degree of current density concentration at the whisker root and is equal to the square root of the growth characteristics of the metal whiskers.

[0118] For example, when the whisker length is 50 micrometers and the density is 10 whiskers per square millimeter, the current concentration effect value is approximately 22.36.

[0119] The accumulated thermal effect value is calculated based on the current concentration effect value and the reference thermal conductivity parameters of the vacuum interrupter; the accumulated thermal effect value is used to characterize the difference between the Joule heat generated by the current concentration effect and the normal conduction heat.

[0120] The baseline thermal conductivity parameter can be used to characterize the thermal resistance of the contact material under standard thermal conductivity conditions (unit: Kelvin per watt), and is used to convert electrical power loss into temperature rise.

[0121] The system can calculate whisker Joule heat power using the current concentration effect value and reference thermal conductivity parameters (standard thermal resistance of contact material, unit: Kelvin per watt). The accumulated thermal effect value is the difference between whisker Joule heat and normal conduction heat. In a typical scenario, with a rated current of 630 amperes and an initial contact resistance of 20 microohms, whisker Joule heat can be 99.2 watts higher than normal heat.

[0122] The local overheating acceleration rate is calculated based on the ratio of the accumulated thermal effect to the current operating time of the vacuum interrupter.

[0123] Current operating time refers to the cumulative operating time of the vacuum interrupter from its factory commissioning to the present moment, in hours. This information can be obtained from the equipment log of the pole-mounted circuit breaker. Local overheating acceleration rate refers to the increase in heat accumulation per unit time (unit: watts per hour), reflecting the accelerating trend of temperature rise.

[0124] The system can divide the accumulated thermal effect by the current operating time of the vacuum interrupter (in hours) to obtain the local overheating acceleration rate (in watts per hour). This parameter characterizes the growth trend of the temperature rise rate.

[0125] For example, when the heat effect accumulation is 50 watts and the running time is 1000 (hours), the acceleration rate is 0.05 watts per hour.

[0126] The cumulative temperature rise is calculated based on the temperature rise per unit time determined by the local overheating acceleration rate and the cumulative operating time of the vacuum interrupter.

[0127] The cumulative runtime refers to the continuous running time within the current monitoring period (default 3 months), in hours. It can be automatically calculated by the system's real-time clock module. If a power outage occurs during the period and exceeds 24 hours, the timer will be reset. This is used to calculate the local overheating acceleration level.

[0128] In other words, cumulative runtime is a localized, periodic slice of time, focusing on the accumulation of short-term thermal effects; while current runtime is a global, continuous total of time, driving decisions throughout the entire life cycle. The two complement each other in the condition assessment of vacuum interrupters, ensuring the timeliness and historical integrity of degradation analysis.

[0129] Cumulative temperature rise can refer to the steady-state temperature increase (unit: Kelvin) caused by the accumulation of thermal effects within a specific cumulative operating time of a vacuum interrupter.

[0130] The system can determine the temperature rise per unit time (in Kelvin per hour) based on the local overheating acceleration rate, and then multiply it by the cumulative operating time to obtain the cumulative temperature rise (in Kelvin). The steady-state temperature rise caused by long-term operation directly affects the oxidation process of the contact material.

[0131] The additional heating power is calculated based on the characteristics of increased contact resistance, and the temperature rise generated by the additional heating power is added to the cumulative temperature rise to obtain the characteristics of local overheating temperature change.

[0132] Additional heating power can refer to the increased power loss due to increased contact resistance (unit: watts).

[0133] The system can calculate the additional heat generation power (power loss caused by the increase in contact resistance) by analyzing the characteristics of increased contact resistance. The temperature rise generated by this power is then added to the aforementioned cumulative temperature rise to generate a local overheating temperature change characteristic (unit: Kelvin).

[0134] For example, when the contact resistance increases to 1.5 times the initial value, the additional heat generation temperature rises by 49.6 Kelvin (the reference thermal resistance is 0.5 Kelvin per watt).

[0135] The thermal stress distribution characteristics were calculated based on the local overheating temperature change characteristics and the thermal expansion coefficient of the contact material of the vacuum interrupter.

[0136] The characteristics of local overheating temperature change can be defined as the steady-state temperature rise (unit: Kelvin) of the hottest area on the contact surface relative to the ambient temperature, which comprehensively reflects the thermal effects of current concentration and contact resistance degradation.

[0137] The system can calculate thermal deformation based on the characteristics of local overheating temperature changes and the thermal expansion coefficient of the contact material (e.g., 12 parts per million Kelvin for copper-tungsten alloy). A spatial distribution of thermal stress (unit: MPa) is generated under mechanical constraints using finite element method mapping (numerical simulation). A high-risk area is marked when the peak stress exceeds 60% of the material's yield strength (400 MPa) (i.e., 240 MPa). Here, 400 MPa is the yield strength of the copper-tungsten alloy at 20 degrees Celsius; local temperature rise is considered. Then, press Megapascal correction, when When =100K, The threshold was lowered to 382 MPa, corresponding to a revised high-risk threshold of 229 MPa. The temperature coefficient of 0.18 MPa / Kelvin can be found in *Powder Metallurgy*, 2021, 64:351-359, specifically in the paper titled 'Thermal Expansion Properties of Tungsten-Copper Composites', where K refers to thermodynamic temperature.

[0138] Therefore, according to the above implementation method, the system can quantify the coupled effects of current concentration and increased contact resistance on local overheating and thermal stress, providing key physical field parameters for predicting the risk of conductive channels.

[0139] In some embodiments, the breaking capacity decay trend characteristics are generated based on the historical breaking current peak value, historical breaking number, and conductive path risk value of the vacuum interrupter, including:

[0140] Obtain the historical risk value sequence of the conductive path risk value of the vacuum interrupter over time.

[0141] The historical risk value sequence can be an ordered set of data showing how the risk value of the conductive channel in the vacuum interrupter changes over time.

[0142] The system can obtain historical risk value sequences of the conductive channels in the vacuum interrupter over time through the time-series database (time-series data storage platform) of the digital monitoring system. This sequence is sorted by timestamp, with a sampling interval of 24 hours, covering data throughout the entire equipment lifecycle.

[0143] The current impact coefficient is generated based on the ratio of the historical peak breaking current to the rated breaking current of the vacuum interrupter.

[0144] The rated breaking current can be the maximum current value (unit: kiloampere) that the vacuum interrupter is designed to safely break.

[0145] The system can extract the historical peak value of the breaking current (unit: kiloampere) for each breaking operation, divide it by the rated breaking current of the vacuum interrupter (unit: kiloampere), and generate the current impact coefficient (dimensionless).

[0146] For example, when the peak breaking current is 20 kA and the rated value is 16 kA, the impact factor is 1.25; or, if the breaking current exceeds the rated value by 150% (i.e., the impact factor > 1.5), it is marked as a short-circuit impact event.

[0147] The cumulative damage index is calculated based on the current impact coefficient and the cumulative number of interruption operations of the vacuum interrupter.

[0148] The current impact coefficient can be the ratio of the peak value of a single breaking current to the rated breaking current (dimensionless); the cumulative number of breaking operations can be the total number of breaking operations performed by the vacuum interrupter since it was put into operation (dimensionless); the cumulative damage index can be a parameter used to quantify the degree of damage to the overall equipment caused by historical breaking operations (dimensionless).

[0149] The system can calculate the cumulative damage index (dimensionless) based on the current impact coefficient and the cumulative number of interruption operations (i.e., the total number of historical interruptions). Specifically, the calculation method can be: summing the impact coefficients of each interruption.

[0150] For example, if there are 100 cumulative fractures and an average impact coefficient of 1.2, the cumulative damage index is 120.

[0151] Pearson correlation analysis was performed on the cumulative damage index and the historical risk value series to generate a damage risk mapping relationship.

[0152] The damage risk mapping relationship can be constructed by a mathematical correlation model between the cumulative damage index and the risk value of the conductive channel.

[0153] The system can perform Pearson correlation analysis (a statistical correlation calculation method) on cumulative damage indicators and historical risk value sequences to generate damage risk mapping relationships:

[0154] If the correlation coefficient exceeds 0.6 (preset threshold), the least squares method is used to fit the linear equation. (y is the risk value, x is the damage index); otherwise, a conservative linear relationship is retained. .

[0155] By substituting the conductive channel risk value and cumulative damage index into the damage risk mapping relationship, the remaining percentage of breaking capacity is calculated.

[0156] The remaining breaking capacity percentage can refer to the remaining proportion of the current breaking capacity relative to the rated value (unit: percentage).

[0157] The system can substitute the current conductive channel risk value and cumulative damage index into the damage risk mapping relationship to calculate the remaining percentage of breaking capacity (unit: percentage). The formula is:

[0158] ;

[0159] For example, if a=0.8, b=5, and the damage index is 120, then the remaining percentage is... .

[0160] The breaking capacity decay trend characteristic is generated based on the remaining percentage of breaking capacity.

[0161] The breaking capacity decay trend characteristic can be used as a parameter to describe how the remaining percentage of breaking capacity changes over time.

[0162] The system can generate breaking capacity decay trend characteristics based on the remaining percentage of breaking capacity at consecutive time points, including:

[0163] Attenuation phase division:

[0164] Remaining percentage > 80%: Stable period (annual decay rate < 1%);

[0165] 40% to 80%: Slow decline period (annual decline rate 1% to 3%)

[0166] <40%: Accelerated decay period (annual decay rate >3%).

[0167] Trend characterization: Calculate the average decay rate over a three-month window and output the slope value (unit: percentage per month).

[0168] Therefore, according to the above implementation method, the system can accurately predict the decay trend of the breaking capacity of the vacuum interrupter based on the quantitative correlation model of current impact-risk accumulation, and provide data support for remaining life assessment and maintenance decision-making.

[0169] In some embodiments, the remaining service life of the vacuum interrupter is calculated based on the breaking capacity decay trend characteristics, and the failure probability value is calculated based on the conductive path risk value, including:

[0170] The decay rate feature is extracted from the decay trend feature of the breaking capacity.

[0171] The decay rate characteristic can refer to the rate at which the remaining percentage of breaking capacity decreases over time (in percentages per month), and is used to quantify the rate of performance degradation of a vacuum interrupter.

[0172] The system can extract the decay rate (in percentage per month) from the characteristics of the decay trend of breaking capacity. This parameter is obtained by calculating the slope of a linear regression of the remaining percentage data for three consecutive months.

[0173] For example, when the remaining percentage drops from 80% to 77%, the decay rate is 1 percentage point per month.

[0174] The difference between the remaining percentage of breaking capacity and the preset minimum allowable percentage is calculated, and the difference is divided by the attenuation rate characteristic to calculate the remaining service life.

[0175] The preset minimum allowable percentage is set according to the circuit breaker design specifications. Specifically, the preset minimum allowable percentage is the minimum remaining breaking capacity (unit: percentage) allowed by the circuit breaker design specifications (determined according to international standard IEC 62271-100 and equipment nameplate parameters, with a typical value of 20%). The equipment is prohibited from operation if it is lower than this value.

[0176] The system can first obtain the remaining percentage of the current breaking capacity (unit: percentage), then calculate the difference between the remaining percentage and the preset minimum allowable percentage (set according to the circuit breaker design specification, the typical value is 20%) (unit: percentage); finally, divide the difference by the attenuation rate (unit: percentage per month) to obtain the remaining service life (unit: month).

[0177] For example, if the current remaining percentage is 40%, the minimum allowable value is 20%, and the decay rate decreases by 1 percentage point per month, then the remaining service life... Months.

[0178] The risk value of the conductive channel and the remaining service life are input into a preset failure probability model based on Bayesian conditional probability, so that the failure probability model can calculate the failure probability value.

[0179] The failure probability model based on Bayesian conditional probability can be a statistical prediction algorithm that takes the risk value of the conductive channel and the remaining service life as input and outputs the probability of failure (in percentage).

[0180] The system can input the conductive channel risk value (0-100 dimensionless) and remaining useful life (in months) into a failure probability model (statistical prediction algorithm) based on Bayesian conditional probability. This model can calculate the failure probability value through the following steps:

[0181] Based on historical fault data of the same type of circuit breaker, a baseline fault rate for different risk value ranges is loaded (example: when the risk value is >80, the baseline fault rate is 30%).

[0182] Specifically, the baseline failure rate can be obtained from 5 years of field statistics of 50 pole-mounted circuit breakers (10 kV / 630 amps) of the same model: a total of 182,500 hours of operation, with 3 vacuum degree decay failures and 2 contact erosion failures recorded. According to the formula of "number of failures ÷ total number of units per year", the baseline failure rate for vacuum degree decay is 1.2% / year and the baseline failure rate for contact erosion is 0.8% / year. When loading the model, the corresponding baseline value is automatically matched according to the real-time determined degradation type, and then the Bayesian update is performed to ensure that the prior probability is consistent with the actual historical failure level of the equipment.

[0183] The probability value is adjusted based on the remaining useful life—the probability increases by a factor of 1.5 when the remaining useful life is less than 6 months, and by a factor of 0.8 when the remaining useful life is greater than 24 months.

[0184] The combined risk value and lifespan correction factor output the failure probability value (unit: percentage).

[0185] For example, with a risk value of 75 and a remaining service life of 10 months, the probability of failure = baseline failure rate 25% × 1.2 (lifetime correction factor) = 30%.

[0186] Therefore, according to the above implementation method, the system can accurately quantify the remaining lifespan and immediate failure risk of the vacuum interrupter, providing a dual quantitative basis for graded maintenance decisions.

[0187] Figure 2 This is a structural block diagram of a monitoring system for a pole-mounted circuit breaker according to an embodiment of the present invention.

[0188] like Figure 2 As shown, the monitoring system for this pole-mounted circuit breaker includes:

[0189] The data monitoring module 210 is used to acquire the voltage recovery waveform characteristics and mechanical vibration characteristics of the vacuum interrupter of the pole-mounted circuit breaker, and to align the voltage recovery waveform characteristics and mechanical vibration characteristics with timestamps. The aligned voltage recovery waveform characteristics consist of voltage recovery waveform data collected within a set time interval before and after the first peak value when the absolute value of the time difference between the envelope peak value of the mechanical vibration characteristics and the first peak value of the voltage recovery waveform characteristics is less than or equal to a set threshold.

[0190] The channel risk calculation module 220 is used to calculate the conductive channel risk value of the vacuum interrupter contact gap based on the characteristics of the aligned voltage recovery waveform.

[0191] The breaking capacity attenuation prediction module 230 is used to generate breaking capacity attenuation trend characteristics based on the historical breaking current peak value, historical breaking number and conductive channel risk value of the vacuum interrupter.

[0192] The failure probability assessment module 240 is used to calculate the remaining service life of the vacuum interrupter based on the characteristics of the breaking capacity decay trend, and to calculate the failure probability value based on the risk value of the conductive channel.

[0193] The early warning signal generation module 250 is used to determine the maintenance early warning level based on the remaining service life and the failure probability value, and to generate a maintenance early warning signal based on the maintenance early warning level.

[0194] The specific functions and examples of each module and submodule of the device in this embodiment of the invention can be found in the relevant descriptions of the corresponding steps in the above method embodiments, and will not be repeated here.

[0195] According to embodiments of the present invention, the above-described method of the present invention can be applied to an electronic device and a readable storage medium.

[0196] Figure 3 A schematic block diagram of an example electronic device 600 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0197] like Figure 3 As shown, the electronic device 600 includes a computing unit 601, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 602 or a computer program loaded from a storage unit 608 into a random access memory (RAM) 603. The RAM 603 may also store various programs and data required for the operation of the electronic device 600. The computing unit 601, ROM 602, and RAM 603 are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0198] Multiple components in electronic device 600 are connected to I / O interface 605, including: input unit 606, such as keyboard, mouse, etc.; output unit 607, such as various types of displays, speakers, etc.; storage unit 608, such as disk, optical disk, etc.; and communication unit 609, such as network card, modem, wireless transceiver, etc. Communication unit 609 allows electronic device 600 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0199] The computing unit 601 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 601 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 601 performs the various methods and processes described above, such as a method for monitoring a pole-mounted circuit breaker. For example, in some embodiments, a method for monitoring a pole-mounted circuit breaker may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 608. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 600 via ROM 602 and / or communication unit 609. When the computer program is loaded into RAM 603 and executed by the computing unit 601, one or more steps of the method for monitoring a pole-mounted circuit breaker described above may be performed. Alternatively, in other embodiments, the computing unit 601 may be configured by any other suitable means (e.g., by means of firmware) to perform a monitoring method for a pole-mounted circuit breaker.

[0200] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0201] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0202] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0203] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0204] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0205] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0206] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0207] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the principles of this invention should be included within the scope of protection of this invention.

Claims

1. A monitoring method for pole-mounted circuit breakers, characterized in that, include: The voltage recovery waveform characteristics and mechanical vibration characteristics of the vacuum interrupter of the pole-mounted circuit breaker are obtained, and the voltage recovery waveform characteristics and mechanical vibration characteristics are timestamped. The aligned voltage recovery waveform feature is composed of voltage recovery waveform data collected within a set time interval before and after the first peak moment when the absolute value of the time difference between the envelope peak of the mechanical vibration feature and the first peak of the voltage recovery waveform feature is less than or equal to a set threshold. The conductive path risk value of the vacuum interrupter contact gap is calculated based on the aligned voltage recovery waveform characteristics. The breaking capacity attenuation trend characteristics are generated based on the historical peak breaking current of the vacuum interrupter, the historical number of breaking times, and the risk value of the conductive channel. The remaining service life of the vacuum interrupter is calculated based on the characteristics of the breaking capacity decay trend, and the failure probability value is calculated based on the risk value of the conductive channel. The maintenance warning level is determined based on the remaining service life and the failure probability value, and a maintenance warning signal is generated based on the maintenance warning level.

2. The method according to claim 1, characterized in that, The step of calculating the conductive path risk value of the vacuum interrupter contact gap based on the aligned voltage recovery waveform characteristics includes: The high-frequency oscillation frequency amplitude and the first peak time point are extracted from the aligned voltage recovery waveform features; The contact resistance increase characteristics are calculated based on the high-frequency oscillation frequency amplitude, and the degradation type is determined based on the high-frequency oscillation frequency amplitude and the first peak time point; The metal ion deposition thickness and metal whisker growth characteristics of the vacuum interrupter are generated according to the degradation type. Based on the thermal expansion coefficient of the contact material set in the vacuum interrupter, the growth characteristics of the metal whiskers, and the increase in contact resistance, local overheating temperature change characteristics and thermal stress distribution characteristics are generated. The risk value of the conductive path of the vacuum interrupter is calculated based on the contact resistance increase characteristics, the metal ion deposition thickness, the local overheating temperature change characteristics, and the thermal stress distribution characteristics.

3. The method according to claim 2, characterized in that, The step of determining the degradation type based on the high-frequency oscillation frequency amplitude and the first peak time point includes: Compare the magnitude of the high-frequency oscillation frequency amplitude with the preset frequency threshold. If the amplitude of the high-frequency oscillation is greater than the preset frequency threshold, a frequency anomaly flag is generated. Compare the numerical values ​​between the first peak time point and the preset duration threshold; If the time of the first peak is less than the preset duration threshold, a time anomaly flag is generated. In response to generating the frequency anomaly identifier and the time anomaly identifier, the degradation type is determined to be a vacuum attenuation degradation type.

4. The method according to claim 3, characterized in that, The process of generating the metal ion deposition thickness and metal whisker growth characteristics of the vacuum interrupter according to the degradation type includes: If the degradation type is vacuum degree decay degradation type, then obtain the historical number of interruptions and the single interruption arc energy of the vacuum interrupter. The thickness of the evaporated material deposited on the contact is calculated based on the historical number of interruptions and the energy of the single interruption arc. The thickness of the evaporated material deposited at the contact point is compared with a preset evaporated material composition database to obtain the metal element ratio coefficient; The metal ion deposition thickness is calculated based on the contact evaporation deposition thickness and the metal element ratio coefficient. Determine whether the metal ion deposition thickness exceeds a preset thickness threshold; If it exceeds the limit, the growth characteristics of the metal whiskers are calculated based on the electric field intensity distribution characteristics set in the vacuum interrupter. If the value is not exceeded, the metal whisker growth characteristic is set to zero.

5. The method according to claim 4, characterized in that, The generation of local overheating temperature change characteristics and thermal stress distribution characteristics based on the thermal expansion coefficient of the contact material set in the vacuum interrupter chamber, the growth characteristics of the metal whiskers, and the increase characteristics of the contact resistance includes: The current concentration effect value was calculated based on the aforementioned metal whisker growth characteristics. The accumulated thermal effect value is calculated based on the current concentration effect value and the reference thermal conductivity parameter of the vacuum interrupter; the accumulated thermal effect value is used to characterize the difference between the Joule heat generated by the current concentration effect and the normal conduction heat. The local overheating acceleration rate is calculated based on the ratio of the accumulated thermal effect value to the current operating time of the vacuum interrupter. The cumulative temperature rise is calculated based on the temperature rise per unit time determined by the local overheating acceleration rate and the cumulative operating time of the vacuum interrupter. The additional heating power is calculated based on the contact resistance increase characteristic, and the temperature rise generated by the additional heating power is added to the cumulative temperature rise to obtain the local overheating temperature change characteristic; The thermal stress distribution characteristics are calculated based on the local overheating temperature change characteristics and the thermal expansion coefficient of the contact material of the vacuum interrupter.

6. The method according to claim 1, characterized in that, The process of generating breaking capacity attenuation trend characteristics based on the historical breaking current peak value, historical breaking number, and the conductive channel risk value of the vacuum interrupter includes: Obtain the historical risk value sequence of the conductive channel risk value of the vacuum interrupter over time; The current impact coefficient is generated based on the ratio of the historical peak breaking current to the rated breaking current of the vacuum interrupter. The cumulative damage index is calculated based on the current impact coefficient and the cumulative number of interruption operations of the vacuum interrupter. Perform Pearson correlation analysis between the cumulative damage index and the historical risk value sequence to generate a damage risk mapping relationship; Substitute the conductive channel risk value and the cumulative damage index into the damage risk mapping relationship to calculate the remaining percentage of breaking capacity. The breaking capacity decay trend feature is generated based on the remaining percentage of the breaking capacity.

7. The method according to claim 6, characterized in that, The remaining service life of the vacuum interrupter is calculated based on the breaking capacity attenuation trend characteristics, and the failure probability value is calculated based on the conductive channel risk value, including: The attenuation rate feature is extracted from the attenuation trend feature of the breaking capacity; The difference between the remaining percentage of breaking capacity and the preset minimum allowable percentage is calculated, and the difference is divided by the attenuation rate characteristic to calculate the remaining service life; the preset minimum allowable percentage is set according to the circuit breaker design specifications. The risk value of the conductive channel and the remaining service life are input into a preset failure probability model based on Bayesian conditional probability, so that the failure probability model can calculate the failure probability value.

8. A monitoring system for a pole-mounted circuit breaker, characterized in that, include: The data monitoring module is used to acquire the voltage recovery waveform characteristics and mechanical vibration characteristics of the vacuum interrupter of the pole-mounted circuit breaker, and to align the voltage recovery waveform characteristics and mechanical vibration characteristics with timestamps. The aligned voltage recovery waveform feature is composed of voltage recovery waveform data collected within a set time interval before and after the first peak moment when the absolute value of the time difference between the envelope peak of the mechanical vibration feature and the first peak of the voltage recovery waveform feature is less than or equal to a set threshold. The channel risk calculation module is used to calculate the conductive channel risk value of the vacuum interrupter contact gap based on the aligned voltage recovery waveform characteristics. The breaking capacity attenuation prediction module is used to generate breaking capacity attenuation trend characteristics based on the historical breaking current peak value, historical breaking number and the risk value of the conductive channel of the vacuum interrupter. The failure probability assessment module is used to calculate the remaining service life of the vacuum interrupter based on the breaking capacity decay trend characteristics, and to calculate the failure probability value based on the conductive channel risk value. The early warning signal generation module is used to determine the maintenance early warning level based on the remaining service life and the failure probability value, and to generate a maintenance early warning signal based on the maintenance early warning level.

9. An electronic device, comprising: At least one processor; as well as The memory that is communicatively connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-7.

10. A non-transitory computer-readable storage medium storing computer instructions, wherein, Computer instructions are used to cause a computer to perform the method according to any one of claims 1-7.

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