Method and system for contactor failure probability prediction

Abstract

The present application relates to the technical field of failure probability prediction, and particularly relates to a failure probability prediction method and system for a contactor. The method comprises the following steps: collecting operation characteristic quantities of a contactor contact assembly, an arc extinguishing link and an electromagnetic drive link when the contactor is in operation, and arranging the operation characteristic quantities into an initial operation sequence; calculating an initial operation bearing value of the contactor based on the initial operation sequence, and predicting an initial failure probability of the contactor; adjusting the action link of the contactor according to the initial failure probability, continuously collecting the operation characteristic quantities, arranging the operation characteristic quantities into an adjusted operation sequence in chronological order, and predicting an adjusted failure probability based on the operation sequence; and comparing the adjusted failure probability with the initial failure probability, and quantifying the deviation effect. The present application realizes dynamic evaluation and prediction of the failure probability of the contactor under different operation conditions by collecting the operation characteristic quantities in real time.

Description

Technical Field

[0001] This invention relates to the field of fault occurrence probability prediction technology, and in particular to a method and system for predicting the fault occurrence probability of contactors. Background Technology

[0002] Contactors, widely used electrical switching elements in power systems and automation equipment, primarily function to control the on / off state of circuits and bear a certain load capacity in control circuits. During long-term operation, contactors are affected by various factors such as contact wear, arc corrosion, coil aging, and thermal stress, leading to abnormal operation or even failure. Traditional contactor maintenance relies mainly on periodic inspections and experience-based judgment, which struggles to reflect the contactor's operating status in a timely manner and cannot provide early warnings of potential faults. Especially under high-frequency switching or complex operating conditions, contact wear and electromagnetic link performance degradation accumulate rapidly, making it difficult to accurately assess fault risk based solely on experience. Furthermore, current contactor fault analysis typically focuses on statistical lifespan or single-link monitoring, lacking a systematic integration of multi-link operating characteristics such as contacts, arc-extinguishing links, and electromagnetic drive links, and failing to dynamically quantify fault probabilities, thus limiting the scientific rigor and accuracy of maintenance decisions. Summary of the Invention

[0003] Therefore, it is necessary to provide a method and system for predicting the probability of contactor failures to solve at least one of the above-mentioned technical problems.

[0004] To achieve the above objective, a method for predicting the probability of contactor failure includes the following steps: Step S1: When the contactor is running, collect the operating characteristics of the contactor contact assembly, arc extinguishing link and electromagnetic drive link, and organize them into an initial operating sequence; calculate the initial operating load value of the contactor based on the initial operating sequence, and predict the probability of the initial failure of the contactor. Step S2: After determining the initial fault occurrence probability, combine the changes in the contactor's operating characteristics during operation to determine the fault-directing link; adjust the contactor's action link according to the fault-directing link, continuously collect operating characteristics, organize them into an adjusted operating sequence in chronological order, and predict the adjusted fault occurrence probability based on the operating sequence. Step S3: Compare the adjusted fault occurrence probability with the initial fault occurrence probability, quantify the offset effect, record the operating load value when the contactor reaches functional failure under acceleration conditions, set it as the fault criterion threshold, and calibrate the fault criterion threshold based on the offset effect. Step S4: Continuously calculate the real-time failure probability during the operation of the preset target contactor, compare the real-time failure probability with the calibrated fault criterion threshold, and output the failure probability prediction result of the target contactor.

[0005] The present invention also provides a fault probability prediction system for contactors, for performing the fault probability prediction method for contactors as described above, the fault probability prediction system for contactors comprising: The initial operating load value calculation module is used to collect the operating characteristics of the contactor contact assembly, arc extinguishing link, and electromagnetic drive link when the contactor is running, and organize them into an initial operating sequence; based on the initial operating sequence, the initial operating load value of the contactor is calculated, and the probability of initial failure of the contactor is predicted; The action link adjustment module is used to determine the fault-directing link after determining the initial fault occurrence probability, combined with the changing characteristics of the contactor's operating parameters during operation; adjust the contactor's action link according to the fault-directing link, continuously collect operating parameters, organize them into an adjusted operating sequence in chronological order, and predict the adjusted fault occurrence probability based on the operating sequence. The fault criterion threshold calibration module is used to compare the adjusted fault occurrence probability with the initial fault occurrence probability, quantify the offset effect, record the operating load value when the contactor reaches functional failure under accelerated conditions, set it as the fault criterion threshold, and calibrate the fault criterion threshold based on the offset effect. The fault occurrence probability prediction module is used to continuously calculate the real-time fault occurrence probability during the operation of the preset target contactor, compare the real-time fault occurrence probability with the calibrated fault criterion threshold, and output the fault occurrence probability prediction result of the target contactor.

[0006] The beneficial effects of this invention are as follows: By uniformly collecting and serializing the operational characterization quantities of the contactor contact assembly, arc extinguishing link, and electromagnetic drive link, a fault probability prediction mechanism centered on operational load is established, transforming contactor fault assessment from a single empirical judgment to a quantitative analysis based on the operational status of multiple links. Based on this, by making targeted adjustments to the action link and comparing the fault occurrence probabilities before and after the adjustments, an offset effect is introduced as an intermediate characterization quantity, explicitly expressing the impact of structural and action changes on fault risk, thereby improving the sensitivity and adaptability of fault prediction results to changes in actual operating conditions. Furthermore, this invention combines functional failure test results under accelerated operating conditions to calibrate the fault criterion threshold, ensuring that the obtained threshold accurately reflects the failure boundary of the contactor under different operational load conditions. This avoids the problems of fixed thresholds and insufficient generalization ability in traditional methods. During the actual operation of the target contactor, by calculating the fault occurrence probability in real time and comparing it with the calibrated fault criterion threshold, dynamic prediction of contactor fault risk is achieved, providing a more targeted basis for contactor operational status assessment and maintenance decisions. Attached Figure Description

[0007] Figure 1 This is a flowchart illustrating the steps of a method for predicting the probability of failure in a contactor. Figure 2 This is a schematic diagram of a fault probability prediction system for contactors. Figure 3 A schematic diagram of a ceramic-encapsulated high-voltage DC contactor. The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0008] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0009] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0010] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0011] To achieve the above objectives, please refer to Figures 1 to 3 A method for predicting the probability of failure in a contactor includes the following steps: Step S1: When the contactor is running, collect the operating characteristics of the contactor contact assembly, arc extinguishing link and electromagnetic drive link, and organize them into an initial operating sequence; calculate the initial operating load value of the contactor based on the initial operating sequence, and predict the probability of the initial failure of the contactor. Step S2: After determining the initial fault occurrence probability, combine the changes in the contactor's operating characteristics during operation to determine the fault-directing link; adjust the contactor's action link according to the fault-directing link, continuously collect operating characteristics, organize them into an adjusted operating sequence in chronological order, and predict the adjusted fault occurrence probability based on the operating sequence. Step S3: Compare the adjusted fault occurrence probability with the initial fault occurrence probability, quantify the offset effect, record the operating load value when the contactor reaches functional failure under acceleration conditions, set it as the fault criterion threshold, and calibrate the fault criterion threshold based on the offset effect. Step S4: Continuously calculate the real-time failure probability during the operation of the preset target contactor, compare the real-time failure probability with the calibrated fault criterion threshold, and output the failure probability prediction result of the target contactor.

[0012] All specific values ​​involved in this embodiment are exemplary parameters used to clearly illustrate the technical operation process and are not the only limitation of the present invention.

[0013] In one embodiment, a DC contactor with a rated operating voltage of 750V and a rated current of 400A is selected as the test object. The contactor is connected to an adjustable DC power supply and a resistive load circuit, so that it performs periodic engaging and disengaging actions under rated operating conditions. During the operation of the contactor, a contact stroke detection unit and a contact reaction force detection unit are respectively installed at the contact assembly, an arc current acquisition channel is installed in the arc extinguishing link, and a coil current and moving iron core displacement acquisition channel is installed in the electromagnetic drive link. The above-mentioned operational characteristic quantities are synchronously collected at a fixed sampling period and organized into an initial operating sequence according to the action time sequence.

[0014] Based on the initial operating sequence, the peak contact reaction force, arc duration, and stable displacement segment of the moving iron core in each operating cycle are summarized and calculated. The various operating characteristics are combined into the corresponding operating load value according to the preset weight. The changing trend of the operating load value in multiple consecutive operating cycles is used as input to predict the probability of initial fault occurrence of the contactor in the current operating state.

[0015] After obtaining the initial probability of fault occurrence, the change characteristics of the operating parameters of the contactor during the stable operation phase are further extracted. The change amplitude between adjacent sampling times is statistically analyzed, and the location of the structural link where the change amplitude of the operating parameters is concentrated is identified, thereby determining the fault-directing link of the contactor.

[0016] Based on the characteristic that the changes in the operating parameters are mainly concentrated in the arc extinguishing process, the identified fault pointing link is limited to the arc extinguishing link, and the contactor's action link is adjusted accordingly based on the fault pointing link, and the installation direction and magnetic path position of the magnet assembly inside the contactor are rearranged.

[0017] After adjustment, the contactor is reconnected to the operating circuit and continues to perform periodic switching operations under the same conditions as the initial test. Operating characteristics under the adjusted state are acquired using the same sampling method as the initial acquisition, and then arranged chronologically to form the adjusted operating sequence. Based on this adjusted operating sequence, the operating load value is recalculated, and the adjusted fault probability is predicted.

[0018] After obtaining the adjusted failure probability, the adjusted failure probability is paired with the initial failure probability one by one according to the same action cycle, and the probability difference is calculated. ,according to The offset effect is recorded by sorting the contacts by size; then, the same contactor with structural adjustments is placed under accelerated operating conditions with increased switching frequency, and its operating load value is continuously monitored. When the contactor fails to engage or release, the operating load value at that moment is locked as the initial fault criterion threshold. Probability difference Essentially, this is a quantitative characterization of the performance stability changes of the contactor before and after structural adjustments. This change is intrinsically related to the shift in the material's tolerance limit. A sensitivity coefficient k, obtained through prior experimental calibration, is introduced. This sensitivity coefficient characterizes the correspondence between the change in the failure probability of this contactor model and the change in its operating load limit. Based on this sensitivity coefficient, according to the formula... The threshold correction coefficient was calculated. ,in Indicates relative to the initial fault criterion threshold The relative correction ratio. Based on the calibration formula. Initial fault criterion threshold Perform interval calibration to obtain the fault criterion threshold after calibration. , This represents the effective criterion threshold for predicting the probability of failure during subsequent operation, given the current contactor model and structural adjustment status.

[0019] After calibration, the calibrated fault criterion threshold is applied to the operation of another target contactor of the same model. The real-time fault occurrence probability during actual operation is continuously calculated, and the real-time fault occurrence probability is compared with the calibrated fault criterion threshold to output the fault occurrence probability prediction result corresponding to the target contactor.

[0020] In another embodiment, a ceramic-encapsulated DC contactor with a rated operating voltage of 1000V and a rated current of 630A was selected as a sample and installed in a constant-temperature environmental chamber to maintain the ambient temperature at 60°C. During the contactor's switching operations, the contact stroke of the contact assembly, the coil current change in the electromagnetic drive link, and the arc current waveform in the arc extinguishing link were collected. These operational characteristics were uniformly marked with timestamps and organized to form an initial operating sequence. Based on the distribution of operational characteristics in each operating cycle of the initial operating sequence, the corresponding operating load value was calculated, and the probability of initial fault occurrence of the contactor under high-temperature operating conditions was predicted accordingly. After determining the initial fault occurrence probability, considering the significant changes in temperature rise-related indicators in the operational characteristics, the contactor's operating link was adjusted to be limited to the thermal management link. Temperature acquisition elements were placed at the heated locations inside the contactor housing, and the internal temperature rise sampling path was re-established. After the adjustment was completed, the contactor continued to perform continuous switching operations under the same environmental conditions. Operational characteristics were collected according to the same sampling rules as before the adjustment, and the adjusted operating sequence was formed according to the action sequence. Based on the adjusted operating sequence, the operating load value is recalculated and the adjusted failure probability is predicted.

[0021] The probability of failure before and after adjustment is compared and analyzed to obtain the corresponding offset effect. The contactor is then operated under accelerated switching conditions, and the changes in the operating load value are continuously recorded. When the contactor fails to maintain normal operation under accelerated conditions, the operating load value at the corresponding moment is recorded and used as the fault criterion threshold. Based on the offset effect, the fault criterion threshold is calibrated within a range to form a calibrated fault criterion threshold suitable for this type of contactor.

[0022] In subsequent operation, the calibrated fault criterion threshold is applied to the real-time operation monitoring of the target contactor. By continuously calculating the real-time fault occurrence probability and comparing it with the calibrated fault criterion threshold, the probability of the target contactor fault occurrence can be predicted.

[0023] Please refer to [link / reference needed] for further information. Figure 3 The core functions of a ceramic-encapsulated high-voltage DC contactor are achieved through the coordinated operation of three major systems: contacts, electromagnetic drive, and arc extinguishing. The contact system (including stationary contacts and moving contacts) is responsible for directly connecting and disconnecting the main circuit and is the core of current carrying. The electromagnetic system (including the moving iron core, shaft, and reaction spring) serves as the drive mechanism, providing the mechanical power to reliably operate the contacts. The arc extinguishing system, composed of a ceramic cover, magnets, and a magnetically conductive structure, is filled with an arc-extinguishing gas (such as hydrogen). When an arc is generated during contact disconnection, the magnetic field generated by the magnets rapidly elongates and cools the arc, thereby reliably extinguishing it and ensuring the safe disconnection of the high-voltage DC circuit. Together, these systems form the physical basis for contactor operation, condition monitoring, and fault prediction.

[0024] Preferably, step S2 includes: After determining the initial probability of failure, the fault risk of the contactor is analyzed by link orientation based on the change characteristics of the contactor's operating parameters to determine the fault-directing link. After determining the fault-directing link, the contactor's operating link is adjusted, including: adjustment of the contactor's arc extinguishing link, deployment of the contactor's thermal management link, and simulation drive adjustment of the contactor's electromagnetic link. After the action link adjustment is completed, the adjusted contactor is connected to the operating circuit and performs continuous switching operations under limited operating conditions. Each switching process is taken as an action cycle to form the adjusted operating process. Calculate the operating load value of the contactor within the operating cycle, and during operation, obtain the operating characteristic quantities at a fixed sampling frequency and organize them into an adjusted operating sequence; Based on the adjusted operating sequence, the operational risks under the adjusted state are predicted, and the probability of failure after adjustment is obtained.

[0025] In one embodiment, after calculating the initial fault probability of the contactor, the changes in the operational characteristics in the initial operating sequence are analyzed. The changes in contact reaction force, arc current, and coil current within the continuous operating cycle are statistically analyzed, and characteristics exceeding a preset threshold are mapped to the structural positions of the contactor. Comparison reveals that the concentrated changes are mainly distributed in the arc current-related characteristic region, thus identifying the contactor's arc-extinguishing link as the fault-pointing link. After identifying the arc-extinguishing link as the fault-pointing link, targeted adjustments are made to the contactor's operating link. The magnetic path assembly in the arc-extinguishing chamber is reassembled, and the installation direction of the magnet assembly is adjusted to ensure that the magnetic field area of ​​the arc-extinguishing link corresponds to the contact breaking path. After adjustment, the contactor is connected to the same operating circuit as the initial test, and continuous switching operations are performed under rated voltage and rated load conditions. Each engagement and release process is considered an independent operating cycle, forming the adjusted operating process. During operation, the operational characteristics of the contact assembly, arc extinguishing link, and electromagnetic drive link are collected at the same sampling frequency as the initial test, and the collected data are organized into an adjusted operating sequence according to the action time sequence. Based on the adjusted operating sequence, the operating load value in each action cycle is recalculated, and the probability of failure of the contactor in the adjusted state is predicted accordingly.

[0026] In another embodiment, after obtaining the initial failure probability of the contactor, the temperature-related operational characteristics in the initial operating sequence are analyzed in detail. By comparing the cumulative trend of the internal temperature change of the contactor over multiple operating cycles, it is found that the temperature rise-related characteristics exhibit a continuous deviation during operation, and the degree of deviation is significantly higher than that of other characteristics. Based on this, the thermal management link of the contactor is identified as the fault-indicating link. After identifying the thermal management link as the fault-indicating link, the operating link of the contactor is adjusted accordingly. Temperature acquisition elements are deployed at the heated locations inside the contactor housing, and the temperature rise sampling path is replanned so that the temperature acquisition range covers the contact area and the coil area. After the adjustment is completed, the contactor is connected to the operating circuit, and continuous switching operations are performed under the set ambient temperature conditions. Each switching process is taken as an operating cycle, forming the adjusted operating process. During continuous operation, the operational characteristics of the contactor in each operating cycle are acquired at a fixed sampling frequency and organized into the adjusted operating sequence according to the acquisition time sequence. Based on the operating sequence, the operating load value corresponding to each operating cycle is calculated, and the failure probability of the contactor under the thermal management link adjustment state is further predicted.

[0027] Preferably, based on the changing characteristics of the contactor's operating parameters, a fault-pointing analysis is performed on the contactor's fault risk to determine the fault-pointing links, including: After determining the probability of initial fault occurrence, the sequence of operating characteristics of the contactor during the stable operation phase is extracted; In the sequence of characterization quantities, the change amplitude between adjacent sampling times is calculated, and the range of characterization quantities with change amplitude exceeding the preset change threshold is identified based on the preset change threshold. Within the identified range of characterization quantities, determine the contactor structural link position corresponding to the characterization quantity, and record the changes in characterization quantities at different link positions in sequence; After the recording is completed, the frequency of changes exceeding the threshold in the characteristic quantities of each link location is statistically analyzed to form the change distribution results corresponding to each link; Based on the frequency and magnitude of changes in each link, the link with the highest risk level is identified as the fault-pointing link.

[0028] In one embodiment, after obtaining the initial fault probability of the contactor, a stable operating phase is selected from the contactor's operation. The continuously collected operational characteristics within this phase are organized to form a sequence of operational characteristics for the stable operating phase. These operational characteristics include sampling data related to contact action, arc state, and coil current. A point-by-point comparison is performed on the data at adjacent sampling times in the operational characteristics sequence to calculate the corresponding change amplitude. Sampling intervals with change amplitudes exceeding a preset change threshold are marked as abnormal change intervals. For each abnormal change interval, based on the correspondence between the sampling location of the operational characteristics and the internal structure of the contactor, the structural link location corresponding to that operational characteristics is determined, and abnormal changes belonging to the same structural link are recorded in the same link record item. After recording all abnormal change intervals, the abnormal change records corresponding to each structural link are statistically analyzed, calculating the frequency of abnormal changes and the cumulative change amplitude within each link to form a change distribution result for each structural link. Based on the change distribution results of each structural link, the links with higher frequency and larger change amplitude of abnormal changes are identified as the fault-prone links of the contactor.

[0029] Preferably, the adjustment of the contactor's arc extinguishing link is as follows: After determining the fault location link, the magnetic field range of the contactor's arc-extinguishing link is adjusted. During the adjustment process, an arc magnetohydrodynamic model is established based on the arc-extinguishing chamber structure in the contactor. The model simulates the morphological trajectory of the arc under the magnetic field and determines the target distribution of the magnetic field domain. After determining the target distribution, the arrangement position and polarity direction of the permanent magnets in the contactor are replanned, and a uniform magnetic field area is constructed inside the arc-extinguishing chamber to complete the assembly and positioning of the magnetic path. After completing the assembly and positioning of the magnetic path, the arc extinguishing link and the contactor's contact assembly are reassembled according to the operating sequence to complete the adjustment of the contactor's arc extinguishing link.

[0030] In one embodiment, after determining that the fault-pointing link of the contactor is the arc-extinguishing link, the range of the magnetic field within the arc-extinguishing area is adjusted based on the structural parameters of the contactor's arc-extinguishing chamber. Structural parameters such as the contact separation gap, the arrangement of the arc-extinguishing grid plates, and the initial placement of the permanent magnets within the arc-extinguishing chamber are obtained, and a spatial model of the arc-extinguishing chamber is established based on these parameters. In this spatial model, the arc generation location and arc propagation direction are introduced to construct a magnetohydrodynamic simulation model of the arc within the arc-extinguishing chamber. The model simulates the arc's stretching path and offset trajectory under different magnetic field distributions. By comparing the arc offset distance and arc-extinguishing time under different magnetic field distributions, the magnetic field distribution that can rapidly offset the arc to the arc-extinguishing grid plate area is determined as the target magnetic field distribution. After determining the target magnetic field distribution, the arrangement and polarity direction of the permanent magnets within the arc-extinguishing chamber are replanned according to this target distribution, ensuring that the main magnetic field area covers the initial arc formation area and the arc migration path. Subsequently, the permanent magnets are reassembled and repositioned according to the planning results, forming a continuous and stable magnetic field region inside the arc-extinguishing chamber. After completing the magnetic path assembly and positioning, the adjusted arc extinguishing link and contactor contact assembly are reassembled according to the predetermined action sequence, and the assembled contactor is subjected to a continuity test to confirm that the arc extinguishing link adjustment is complete.

[0031] Preferably, the thermal management link of the contactor is specifically configured as follows: After determining the faulty link, thermal field monitoring was deployed for the contactor's thermal management link. During the deployment process, temperature acquisition elements are placed at the heated locations in the thermal management link, and a temperature rise sampling path is established. After the temperature rise sampling path is established, the contactor is triggered to perform continuous switching actions, and the internal temperature change of the contactor is recorded.

[0032] In one embodiment, after determining that the faulty link of the contactor is a thermal management link, thermal field monitoring is implemented in the thermal management area inside the contactor. Based on the contactor's structural composition, the contact assembly, conductive connection parts, and areas inside the housing prone to heat concentration are identified as the main heat-affected locations of the thermal management link. During the thermal field monitoring deployment, temperature acquisition elements are respectively placed at the heat-affected locations, ensuring close contact between each element and its corresponding structural component to guarantee that the temperature acquisition results reflect the actual heating state. Subsequently, according to the spatial layout of the contactor's internal structure, the sampling sequence of each temperature acquisition element is planned to establish a temperature rise sampling path covering the main heat-affected locations. After the temperature rise sampling path is established, the deployed contactor is connected to the operating circuit, triggering the contactor to perform continuous switching actions under limited operating conditions. During the switching process, the output of each temperature acquisition element is synchronously recorded according to a preset sampling frequency, forming a sequence of internal temperature changes that varies with the number of switching operations, used to reflect the temperature rise characteristics of the contactor's thermal management link during operation.

[0033] In another embodiment, after determining that the faulty link is a thermal management link, a zoned thermal field monitoring deployment is implemented for the thermal management link based on the contactor's operating characteristics under acceleration conditions. According to the structural heat distribution of the contactor under high-frequency switching conditions, the thermal management link is divided into multiple thermal monitoring zones, and key heat-affected locations within each zone are identified. During the thermal field monitoring deployment, temperature acquisition elements are deployed at the key heat-affected locations in each thermal monitoring zone. Based on the orientation of the contactor's internal structure, temperature acquisition elements within the same zone are connected sequentially to form a segmented temperature rise sampling path. This method allows the temperature acquisition results to reflect the temperature rise trend in different thermal monitoring zones. After completing the temperature rise sampling path construction, the contactor is controlled to perform continuous switching actions under set acceleration conditions, continuously acquiring temperature data from each temperature acquisition element throughout the switching process. The acquired temperature data is organized according to the sampling path sequence to obtain the internal temperature change corresponding to each thermal monitoring zone, which is used to characterize the heat accumulation of the thermal management link at different operating stages.

[0034] Preferably, the electromagnetic link simulation drive adjustment of the contactor specifically includes: After determining the faulty link, simulation-driven adjustments are performed on the contactor's electromagnetic link. Based on the structure of the contactor, an action domain coupling model of the electromagnetic link is established, and the electromagnetic response and mechanical displacement during the attraction process are simulated according to the model. The range of attraction force variation and displacement stability are recorded. After the simulation is completed, the parameters of the electromagnetic link are adjusted according to the range of attraction force variation and displacement stability to complete the simulation-driven adjustment of the electromagnetic link.

[0035] In one embodiment, after determining that the faulty link of the contactor is the electromagnetic link, a simulation-driven adjustment is performed on the contactor's electromagnetic link. Based on the existing structural parameters of the contactor, an electromagnetic link action domain coupling model including the coil, iron core, and moving contact assembly is established, enabling the model to reflect the correlation between electromagnetic response and mechanical motion. After the model is established, the contactor's closing process is used as the simulation object to simulate the dynamic process of the electromagnetic link under energized conditions. During the simulation, the electromagnetic response generated after the coil is energized is calculated in chronological order, and the displacement changes of the moving iron core and related mechanical components are simultaneously acquired. The range of the closing force change over time and whether the displacement fluctuates are recorded during the closing process. After the simulation is completed, the range of closing force changes and the corresponding displacement changes are jointly analyzed. When there is a correspondence between the range of closing force changes and the displacement fluctuations, this correspondence is used as the basis for parameter adjustment. The relevant structural parameters or driving parameters in the electromagnetic link are adjusted until the range of closing force changes and the stability of displacement during the closing process meet the preset conditions, thus completing the simulation-driven adjustment of the electromagnetic link.

[0036] In another embodiment, after determining that the faulty link is an electromagnetic link, a phased simulation-driven adjustment is performed on the electromagnetic link based on the contactor's engagement characteristics under different operating conditions. According to the contactor's structure, an action domain coupling model reflecting the electromagnetic response, mechanical displacement, and their interaction is established, distinguishing between the initial, middle, and stable engagement stages. During the simulation, the engagement process at each stage is simulated, acquiring electromagnetic response data and mechanical displacement change data for each stage. The engagement force variation range and displacement stability characteristics are recorded for each stage. By comparing the simulation results of different stages, the engagement force variation range that significantly affects displacement stability during engagement is identified. After completing the phased simulation, the relevant parameters of the electromagnetic link are adjusted specifically for the identified engagement force variation range, and the adjusted parameters are re-introduced into the action domain coupling model for verification simulation. When the simulation results at each stage show that the engagement force variation range converges and the displacement change tends to stabilize, the simulation-driven adjustment of the electromagnetic link is confirmed to be complete.

[0037] Most importantly, based on the adjusted operating sequence, the operational risks under the adjusted state are predicted, resulting in the following adjusted failure probabilities: After obtaining the adjusted execution sequence, the adjusted execution sequence is segmented according to the action cycle; Extract the response points in each action cycle and establish a corresponding mapping record between the action response points and the running load; The mapping records for different time periods are categorized into a load change grouping table according to the trend of changes in operational load. After the load change grouping table is established, the stability of the action response in each group is compared, the action segments that deviate from the stable range are marked, and the distribution location of the deviation is recorded. After marking is completed, the occurrence density of deviation intervals is statistically analyzed. The occurrence density is used as a risk measurement factor, and the probability of failure under the adjusted state is predicted based on the magnitude of the risk measurement factor.

[0038] In one embodiment, after adjusting the contactor's actuation chain and acquiring the adjusted operating sequence, each engagement and release process of the contactor is considered a complete actuation cycle. The continuously acquired operating sequence is divided into multiple independent periodic data segments according to the actuation cycle. For each actuation cycle, key response points characterizing the actuation response state are extracted from the corresponding data segment. These response points include the electromagnetic response point at the start of engagement, the mechanical response point at the moment of contact closure, and the state recovery point at the end of release. The operating load values ​​corresponding to each response point are then associated one by one, forming a one-to-one mapping record between the actuation response point and the operating load value. After obtaining multiple sets of mapping records, the mapping records are categorized according to the changing trend of the operating load value as the actuation cycle progresses. Mapping records with a continuously increasing load value are categorized into the high load change group, mapping records with small and stable load value changes are categorized into the stable load group, and mapping records with periodic declines or increased fluctuations in the load value are categorized into the fluctuating load group, thereby constructing a load change grouping table. Subsequently, within each load change group, the time position, amplitude changes, and repeatability of the same type of action response point in multiple action cycles are compared to determine the stable interval of the action response within each group. Action cycles deviating from this stable interval are marked as deviation action segments, and the occurrence position of these deviation action segments in the overall operating sequence is recorded. After marking all deviation action segments, the occurrence frequency of deviation action segments in different load change groups is statistically analyzed, and the occurrence density of deviation action segments is calculated by combining this with the total number of action cycles covered by each group. This occurrence density is then introduced as a risk measurement factor into the fault prediction model. Based on the magnitude of the risk measurement factor corresponding to different load change groups, the probability of contactor failure under adjustment conditions is predicted.

[0039] Preferably, step S3 includes: The adjusted failure probability is paired with the initial failure probability, and the probability difference between the two is calculated. After the probability difference is calculated, the differences are sorted by size to form a bias effect record table; After the offset effect record table is established, the contactor is triggered to perform continuous switching actions during acceleration conditions, and the operating load value corresponding to the contactor reaching functional failure is recorded during the execution process. After the failure load value is recorded, the failure load value is used as the initial fault criterion threshold and compared with the difference range in the offset effect record table. The initial fault criterion threshold is calibrated based on the offset magnitude corresponding to the difference interval to obtain the calibrated fault criterion threshold.

[0040] In one embodiment, after obtaining the adjusted fault occurrence probability, the adjusted fault occurrence probability is paired one by one with the corresponding initial fault occurrence probability according to the same operating stage, and the probability difference between the two is calculated for each pairing result. Subsequently, the obtained probability differences are sorted according to their numerical values, and an offset effect record table is established based on the sorting results, recording the operating stage identifier corresponding to each probability difference. After the offset effect record table is established, the contactor is placed under a preset acceleration condition, and under this condition, the contactor is triggered to perform continuous switching actions. During the continuous switching process, the contactor's operating load data is continuously collected. When the contactor fails to complete the expected switching action, it is confirmed that it has reached a functional failure, and the corresponding operating load value at that moment is recorded. After the failure load value is recorded, the recorded operating load value is set as the initial fault criterion threshold, and this initial fault criterion threshold is compared one by one with the sorted probability difference intervals in the offset effect record table. Based on the offset amplitude corresponding to different difference intervals, the initial fault criterion threshold is adjusted within the corresponding interval to form a calibrated fault criterion threshold.

[0041] Preferably, after the offset effect recording table is established, the contactor is triggered to perform continuous switching actions during acceleration conditions. During execution, the operating load value corresponding to the contactor reaching functional failure is recorded, including: After the offset effect record table is established, the contactor will be set to operate stably under the acceleration conditions. After the acceleration condition stabilizes, a continuous on / off command is issued to the contactor to keep the contactor’s engagement and release actions continuous, and the number of on / off operations is monitored in real time throughout the entire operation. During continuous switching, the operating load data of the contactor is acquired; When a sudden change in the operating load data is detected and the contactor cannot complete its action, confirm the time corresponding to the contactor action and lock the operating load value recorded at that time.

[0042] In one embodiment, after the offset effect recording table is established, the contactor is connected to a preset acceleration operating environment, and the voltage, current, and switching frequency of the acceleration condition are uniformly loaded to bring the acceleration condition into a stable state under continuous operation. After confirming that the acceleration condition is stable, a continuous switching command is issued to the contactor, causing the contactor's engaging and disengaging actions to be continuously and cyclically executed according to a preset rhythm, and the number of switching operations is accumulated and recorded in real time throughout the entire operation. During the execution of continuous switching operations, the operating load data of the contactor in each switching cycle is synchronously collected and recorded in the switching sequence. When a significant change in the operating load data is detected between adjacent switching cycles, and the contactor cannot complete a complete engaging or disengaging action in the current switching cycle, it is determined that the contactor has reached a functional failure state, and the time corresponding to the switching cycle is locked, and the operating load value at that time is extracted and recorded.

[0043] In another embodiment, after establishing the offset effect recording table, the contactor is placed under a set acceleration condition and operated. A pre-run method is used to maintain a stable output under the acceleration condition before continuous switching. After the acceleration condition stabilizes, a continuous switching control signal is sent to the contactor, causing it to repeatedly perform engaging and disengaging actions within a fixed switching cycle. The number of switching operations completed is recorded in segments during operation. During continuous switching, the contactor's operating load data is collected in units of switching cycles, and the operating load data is associated with and stored with the corresponding number of switching operations. When an abnormal change in the operating load data relative to the previous switching cycle is detected, and the contactor experiences an interruption or fails to reach a predetermined state within the current cycle, this switching cycle is determined to be a functional failure cycle, and the operating load data collected within this cycle is locked as the operating load value corresponding to when the contactor reaches functional failure.

[0044] Preferably, the initial fault criterion threshold is calibrated based on the offset magnitude corresponding to the difference interval, resulting in the calibrated fault criterion threshold, which includes: After sorting the differences based on the offset effect record table, the offset amplitude corresponding to each difference interval is extracted, and the offset amplitude is compared with the set interval of the initial fault judgment threshold. During the comparison process, the correction ratio of each interval is determined in order of the magnitude of the offset. For intervals with larger offsets, threshold correction is performed first, and the adjusted interval range is recorded after correction. After the initial correction is completed, the continuity of the thresholds in all correction intervals is checked. If discontinuity is detected, the corresponding thresholds are readjusted based on the average correction ratio of adjacent intervals. After the continuity of the interval is confirmed, all the corrected threshold data are summarized to form the fault judgment threshold.

[0045] In one embodiment, after obtaining the offset effect record table and sorting the differences, the offset effect record table is divided into several consecutive difference intervals according to the order of the differences from smallest to largest. Each difference interval corresponds to an offset amplitude interval. The fault criterion threshold interval originally set by the contactor is used as a reference. For example, the operating load value threshold is divided into low load, medium load, and high load intervals, and the offset amplitude corresponding to each difference interval is mapped to the aforementioned threshold intervals. During the mapping process, the maximum offset amplitude value within each difference interval is first read as the main offset of that interval. Then, the correction priority of each interval is determined sequentially according to the size of the main offset. For difference intervals with larger main offsets, the corresponding fault criterion threshold interval is corrected according to a preset correction ratio coefficient. For example, the upper or lower limit of the threshold is shifted up or down proportionally, and the corresponding correction interval range is recorded after the correction is completed. For difference intervals with smaller main offsets, threshold correction is performed after the correction of high-priority intervals is completed to avoid threshold overlap caused by simultaneous adjustment of multiple intervals.

[0046] After initial threshold correction for each difference interval, a continuity check is performed on all corrected fault criterion threshold intervals to detect whether there are breaks or overlaps at the upper and lower boundaries of adjacent threshold intervals. When a discontinuity is detected between two adjacent intervals, the correction ratios corresponding to those two intervals are read, their average correction ratio is calculated, and the boundary positions are readjusted based on this average correction ratio to ensure numerical continuity between adjacent intervals. This detection and adjustment process is repeated until all threshold intervals form a continuous distribution across the entire range. All corrected interval threshold data are then aggregated to form a fault criterion threshold set for subsequent fault determination.

[0047] Of particular importance, step S4 includes: During the operation of the preset target contactor, the current acquisition unit deployed on the contact assembly, the induction monitoring node of the electromagnetic drive coil, and the temperature acquisition unit at the arc extinguishing link temperature rise position continuously acquire the operating characteristics of the target contactor during operation, and organize them into a real-time operating sequence according to the sampling time sequence. In the real-time operation sequence, the rate of change of contact current, voltage and coil inductance voltage are calculated respectively, and the current operating load value is determined based on the preset current, voltage and temperature rise threshold of each channel signal. After the operating load value is determined, the corresponding real-time fault risk coefficient is calculated; After the real-time fault risk coefficient is formed, the risk coefficients of each link are weighted and integrated into the preset comprehensive risk model to obtain the real-time fault occurrence probability. The real-time fault occurrence probability is then compared with the calibrated fault criterion threshold one by one. After the comparison is completed, the failure probability prediction result of the target contactor is output based on the difference between the real-time failure probability and the threshold.

[0048] In one embodiment, before the target contactor is put into actual operation, a current acquisition unit is installed at the contact assembly to collect the working current signal during the contact switching process in real time. Simultaneously, induction monitoring nodes are set at both ends of the electromagnetic drive coil to acquire the induced voltage change signal generated during coil engagement and disengagement. A temperature acquisition unit is installed at the temperature rise location near the arc generation area in the arc extinguishing link to continuously monitor the temperature change of the arc extinguishing link. During contactor operation, the signals output by the above acquisition units are synchronously sampled according to a preset unified sampling clock and arranged in chronological order to form a real-time operation sequence. After the real-time operation sequence is formed, the rate of change between adjacent sampling times is calculated for the contact current signal, contact voltage signal, and coil induced voltage signal, and each rate of change is compared with the corresponding current threshold, voltage threshold, and temperature rise threshold. When the rate of change or absolute value of any channel exceeds the corresponding threshold, the load state corresponding to that channel is included in the operating load calculation. After comprehensively considering the load states of each channel, the operating load value at the current moment is determined. Based on the operating load value, a pre-established risk mapping relationship is further invoked to calculate the real-time fault risk coefficient corresponding to the current load state. After the real-time fault risk coefficient is calculated, the risk coefficients corresponding to the contact assembly, electromagnetic drive link, and arc extinguishing link are introduced into the comprehensive risk model according to preset weights. The risks of each link are weighted and fused to obtain the real-time fault occurrence probability of the target contactor at the current moment. Subsequently, the real-time fault occurrence probability is compared with the calibrated fault criterion thresholds one by one, and the fault occurrence probability prediction result of the target contactor under the current operating state is output based on the comparison results.

[0049] It should be noted that you should refer to [link / reference]. Figure 2 The present invention also provides a fault probability prediction system for contactors, for performing the fault probability prediction method for contactors as described above, the fault probability prediction system for contactors comprising: The initial operating load value calculation module 101 is used to collect the operating characteristics of the contactor contact assembly, arc extinguishing link and electromagnetic drive link when the contactor is running, and organize them into an initial operating sequence; calculate the initial operating load value of the contactor based on the initial operating sequence, and predict the probability of the initial failure of the contactor; The action link adjustment module 102 is used to determine the fault-directing link after determining the initial fault occurrence probability, and in combination with the change characteristics of the contactor's operating characteristics during operation; adjust the contactor's action link according to the fault-directing link, continuously collect operating characteristics, organize them into an adjusted operating sequence in chronological order, and predict the adjusted fault occurrence probability based on the operating sequence. The fault criterion threshold calibration module 103 is used to compare the adjusted fault occurrence probability with the initial fault occurrence probability, quantify the offset effect, record the operating load value when the contactor reaches functional failure under acceleration conditions, set it as the fault criterion threshold, and calibrate the fault criterion threshold based on the offset effect. The fault occurrence probability prediction module 104 is used to continuously calculate the real-time fault occurrence probability during the operation of the preset target contactor, compare the real-time fault occurrence probability with the calibrated fault criterion threshold, and output the fault occurrence probability prediction result of the target contactor.

[0050] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for predicting the probability of failure in a contactor, characterized in that, Includes the following steps: Step S1: When the contactor is running, collect the operating characteristics of the contactor contact assembly, arc extinguishing link and electromagnetic drive link, and organize them into an initial operating sequence; The initial operating load value of the contactor is calculated based on the initial operating sequence, and the probability of initial failure of the contactor is predicted. Step S2: After determining the initial probability of fault occurrence, combine the characteristics of the contactor's operating parameters during operation to determine the fault-directed link; Based on the fault-pointing link, the action link of the contactor is adjusted, the operation characteristics are continuously collected, and the adjusted operation sequence is organized in chronological order. Based on the operation sequence, the probability of the adjusted fault occurrence is predicted. Step S3: Compare the adjusted fault occurrence probability with the initial fault occurrence probability, quantify the offset effect, record the operating load value when the contactor reaches functional failure under acceleration conditions, set it as the fault criterion threshold, and calibrate the fault criterion threshold based on the offset effect. Step S4: Continuously calculate the real-time failure probability during the operation of the preset target contactor, compare the real-time failure probability with the calibrated fault criterion threshold, and output the failure probability prediction result of the target contactor.

2. The method for predicting the probability of failure in a contactor according to claim 1, characterized in that, Step S2 includes: After determining the initial probability of failure, the fault risk of the contactor is analyzed by link orientation based on the change characteristics of the contactor's operating parameters to determine the fault-directing link. After determining the fault-directing link, the contactor's operating link is adjusted, including: adjustment of the contactor's arc extinguishing link, deployment of the contactor's thermal management link, and simulation drive adjustment of the contactor's electromagnetic link. After the action link adjustment is completed, the adjusted contactor is connected to the operating circuit and performs continuous switching operations under limited operating conditions. Each switching process is taken as an action cycle to form the adjusted operating process. Calculate the operating load value of the contactor within the operating cycle, and during operation, obtain the operating characteristic quantities at a fixed sampling frequency and organize them into an adjusted operating sequence; Based on the adjusted operating sequence, the operational risks under the adjusted state are predicted, and the probability of failure after adjustment is obtained.

3. The method for predicting the probability of contactor failure according to claim 2, characterized in that, Based on the changing characteristics of contactor operating parameters, a fault-pointing analysis is performed on the contactor's fault risk to determine the fault-pointing links, including: After determining the probability of initial fault occurrence, the sequence of operating characteristics of the contactor during the stable operation phase is extracted; In the sequence of characterization quantities, the change amplitude between adjacent sampling times is calculated, and the range of characterization quantities with change amplitude exceeding the preset change threshold is identified based on the preset change threshold. Within the identified range of characterization quantities, determine the contactor structural link position corresponding to the characterization quantity, and record the changes in characterization quantities at different link positions in sequence; After the recording is completed, the frequency of changes exceeding the threshold in the characteristic quantities of each link location is statistically analyzed to form the change distribution results corresponding to each link; Based on the frequency and magnitude of changes in each link, the link with the highest risk level is identified as the fault-pointing link.

4. The method for predicting the probability of failure in a contactor according to claim 2, characterized in that, The specific adjustment of the contactor's arc extinguishing link is as follows: After determining the fault location link, the magnetic field range of the contactor's arc-extinguishing link is adjusted. During the adjustment process, an arc magnetohydrodynamic model is established based on the arc-extinguishing chamber structure in the contactor. The model simulates the morphological trajectory of the arc under the magnetic field and determines the target distribution of the magnetic field domain. After determining the target distribution, the arrangement position and polarity direction of the permanent magnets in the contactor are replanned, and a uniform magnetic field area is constructed inside the arc-extinguishing chamber to complete the assembly and positioning of the magnetic path. After completing the assembly and positioning of the magnetic path, the arc extinguishing link and the contactor's contact assembly are reassembled according to the operating sequence to complete the adjustment of the contactor's arc extinguishing link.

5. The method for predicting the probability of failure in a contactor according to claim 2, characterized in that, The thermal management link of the contactor is specifically deployed as follows: After determining the faulty link, thermal field monitoring was deployed for the contactor's thermal management link. During the deployment process, temperature acquisition elements are placed at the heated locations in the thermal management link, and a temperature rise sampling path is established. After the temperature rise sampling path is established, the contactor is triggered to perform continuous switching actions, and the internal temperature change of the contactor is recorded.

6. The method for predicting the probability of failure in a contactor according to claim 2, characterized in that, The specific adjustments to the electromagnetic link simulation drive of the contactor are as follows: After determining the faulty link, simulation-driven adjustments are performed on the contactor's electromagnetic link. Based on the structure of the contactor, an action domain coupling model of the electromagnetic link is established, and the electromagnetic response and mechanical displacement during the attraction process are simulated according to the model. The range of attraction force variation and displacement stability are recorded. After the simulation is completed, the parameters of the electromagnetic link are adjusted according to the range of attraction force variation and displacement stability to complete the simulation-driven adjustment of the electromagnetic link.

7. The method for predicting the probability of failure in a contactor according to claim 1, characterized in that, Step S3 includes: The adjusted failure probability is paired with the initial failure probability, and the probability difference between the two is calculated. After the probability difference is calculated, the differences are sorted by size to form a bias effect record table; After the offset effect record table is established, the contactor is triggered to perform continuous switching actions during acceleration conditions, and the operating load value corresponding to the contactor reaching functional failure is recorded during the execution process. After the failure load value is recorded, the failure load value is used as the initial fault criterion threshold and compared with the difference range in the offset effect record table. The initial fault criterion threshold is calibrated based on the offset magnitude corresponding to the difference interval to obtain the calibrated fault criterion threshold.

8. The method for predicting the probability of failure in a contactor according to claim 7, characterized in that, After the offset effect recording table is established, the contactor is triggered to perform continuous switching actions during acceleration conditions. During the execution, the operating load value corresponding to the contactor reaching functional failure is recorded, including: After the offset effect record table is established, the contactor will be set to operate stably under the acceleration conditions. After the acceleration condition stabilizes, a continuous on / off command is issued to the contactor to keep the contactor’s engagement and release actions continuous, and the number of on / off operations is monitored in real time throughout the entire operation. During continuous switching, the operating load data of the contactor is acquired; When a sudden change in the operating load data is detected and the contactor cannot complete its action, confirm the time corresponding to the contactor action and lock the operating load value recorded at that time.

9. The method for predicting the probability of failure in a contactor according to claim 7, characterized in that, Based on the offset magnitude corresponding to the difference interval, the initial fault criterion threshold is calibrated by interval calibration to obtain the calibrated fault criterion threshold, which includes: After sorting the differences based on the offset effect record table, the offset amplitude corresponding to each difference interval is extracted, and the offset amplitude is compared with the set interval of the initial fault judgment threshold. During the comparison process, the correction ratio of each interval is determined in order of the magnitude of the offset. For intervals with larger offsets, threshold correction is performed first, and the adjusted interval range is recorded after correction. After the initial correction is completed, the continuity of the thresholds in all correction intervals is checked. If discontinuity is detected, the corresponding thresholds are readjusted based on the average correction ratio of adjacent intervals. After the continuity of the interval is confirmed, all the corrected threshold data are summarized to form the fault judgment threshold.

10. A fault probability prediction system for contactors, characterized in that, For performing the fault occurrence probability prediction method for contactors as described in claim 1, the fault occurrence probability prediction system for contactors includes: The initial operating load value calculation module is used to collect the operating characteristics of the contactor contact assembly, arc extinguishing link, and electromagnetic drive link when the contactor is running, and organize them into an initial operating sequence; based on the initial operating sequence, the initial operating load value of the contactor is calculated, and the probability of initial failure of the contactor is predicted; The action link adjustment module is used to determine the fault-directing link after determining the initial fault occurrence probability, combined with the changing characteristics of the contactor's operating parameters during operation; adjust the contactor's action link according to the fault-directing link, continuously collect operating parameters, organize them into an adjusted operating sequence in chronological order, and predict the adjusted fault occurrence probability based on the operating sequence. The fault criterion threshold calibration module is used to compare the adjusted fault occurrence probability with the initial fault occurrence probability, quantify the offset effect, record the operating load value when the contactor reaches functional failure under accelerated operating conditions, set it as the fault criterion threshold, and calibrate the fault criterion threshold based on the offset effect. The fault occurrence probability prediction module is used to continuously calculate the real-time fault occurrence probability during the operation of the preset target contactor, compare the real-time fault occurrence probability with the calibrated fault criterion threshold, and output the fault occurrence probability prediction result of the target contactor.

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