An evaluation method applied to an electromagnetic relay, an electronic device and a medium

Abstract

This application provides an evaluation method, electronic device, and medium for electromagnetic relays. The method includes: acquiring a first response time and test parameters at a test terminal, and a second response time based on a simulation terminal; calculating the difference between the first response time and the second response time; when the difference is greater than a difference threshold, correcting the simulation parameters at the simulation terminal according to the test parameters until the difference is less than or equal to the difference threshold; acquiring the simulation result output by the simulation terminal; and comparing the first response time with the response time threshold. The technical solution provided in this application solves the problem of insufficient accuracy in existing technologies caused by the mismatch between simulation and measured parameters.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic relay technology, and more specifically, to an evaluation method, electronic device, and medium for electromagnetic relays. Background Technology

[0002] In existing electromagnetic relay evaluation processes, there is a discrepancy between the actual test data at the testing end and the simulation data at the simulation end. This is because the initial simulation parameters at the simulation end do not match the actual test parameters at the testing end, resulting in a difference between the simulated response time and the actual test response time exceeding a reasonable range. Consequently, the simulation results cannot accurately reflect the actual state of the relay. Furthermore, traditional methods cannot simultaneously address fault tracing and remaining life prediction within the same evaluation process. It is difficult to accurately pinpoint the cause of relay response time exceeding the threshold based on distorted simulation results, nor can it accurately assess the remaining life of relays with acceptable response times based on the simulation results. This necessitates building separate systems to perform these two tasks, which is not only cumbersome but also leads to insufficient accuracy in the evaluation results due to inconsistent simulation benchmarks, making it impossible to form a comprehensive and reliable judgment on the relay's state. Summary of the Invention

[0003] In view of this, the purpose of the embodiments of this application is to provide an evaluation method, electronic device and medium for electromagnetic relays, which can improve the problem of insufficient accuracy of evaluation results in the prior art.

[0004] To achieve the above technical objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, embodiments of this application provide an evaluation method for electromagnetic relays, the method comprising:

[0006] The test terminal obtains the first response time and test parameters obtained from testing the electromagnetic relay under test, and the second response time obtained based on the simulation terminal corresponding to the test terminal.

[0007] Calculate the difference between the first response time and the second response time;

[0008] When the difference is greater than the difference threshold, the simulation parameters of the simulation terminal are corrected according to the test parameters until the difference based on the corrected simulation parameters is less than or equal to the difference threshold.

[0009] Obtain the simulation results output by the simulation terminal;

[0010] By comparing the first response time with the response time threshold, if the first response time is greater than the response time threshold, the cause of the fault that the first response time is greater than the response time threshold is obtained based on the simulation results; if the first response time is less than or equal to the response time threshold, the remaining life of the electromagnetic relay under test is obtained based on the simulation results.

[0011] According to the first aspect, the test parameters include the first coil steady-state current, contact voltage drop, and contact circuit operating current;

[0012] The simulation parameters include the coil equivalent resistance and the contact resistance of the contacts;

[0013] The step of correcting the simulation parameters of the simulation terminal based on the test parameters includes:

[0014] Based on the steady-state current of the first coil, the steady-state current of the second coil at the simulation terminal, and the equivalent resistance of the coil before correction, the corrected equivalent resistance of the coil is obtained;

[0015] The contact resistance is corrected based on the contact voltage drop and the operating current of the contact circuit to obtain the corrected contact resistance.

[0016] According to the first aspect, the simulation results include mechanical effect results, thermal effect results, electrical effect results, mechanical damping coefficient increase rate, temperature rise decay rate, and temperature rise decay rate;

[0017] The remaining life of the electromagnetic relay under test, based on the simulation results, is obtained, including:

[0018] Based on the mechanical and thermal effects during a first specified time period, a first mechanical fatigue damage is obtained; based on the mechanical and thermal effects during a second specified time period, a second mechanical fatigue damage is obtained; and based on the mechanical and thermal effects during a third specified time period, a third mechanical fatigue damage is obtained. The first, second, and third specified time periods constitute a total simulation period. The first, second, and third specified time periods are continuous. The first specified time period characterizes a period when the growth rate of the coil current at the simulation terminal is greater than 0; the second specified time period characterizes a period when the growth rate of the coil current at the simulation terminal is 0; and the third specified time period characterizes a period when the growth rate of the coil current at the simulation terminal is less than 0.

[0019] Based on the mechanical effect results, thermal effect results, and electrical effect results of the first specified time period, a first thermal aging damage and a first electrical damage are obtained; based on the mechanical effect results, thermal effect results, and electrical effect results of the second specified time period, a second thermal aging damage and a second electrical damage are obtained; and based on the mechanical effect results, thermal effect results, and electrical effect results of the third specified time period, a third thermal aging damage and a third electrical damage are obtained.

[0020] Based on the first weight corresponding to the first specified time period, and the first thermal aging damage, the first electrical damage, and the first mechanical fatigue damage, a first part of the damage is determined; based on the second weight corresponding to the second specified time period, and the second thermal aging damage, the second electrical damage, and the second mechanical fatigue damage, a second part of the damage is determined; and based on the third weight corresponding to the third specified time period, and the third thermal aging damage, the third electrical damage, and the third mechanical fatigue damage, a third part of the damage is determined.

[0021] The total damage for the total time period is determined based on the first part of the damage, the second part of the damage, and the third part of the damage.

[0022] Based on the mechanical damping coefficient increase rate, temperature rise decay rate, and temperature rise decay rate, aging characteristic values ​​are obtained, which are used to characterize the aging degree of the electromagnetic relay under test.

[0023] Based on the aging characteristic values ​​and the preset aging threshold, a dynamic threshold is determined;

[0024] When the total damage is less than the dynamic threshold, the remaining life of the electromagnetic relay under test is determined based on the dynamic threshold and the simulation results.

[0025] According to the first aspect, determining the remaining lifespan of the electromagnetic relay under test based on the dynamic threshold includes:

[0026] Based on the dynamic threshold, the cumulative damage of the electromagnetic relay under test that has been in service, and the damage rate per unit working cycle, the remaining number of working cycles is calculated. The damage rate per unit working cycle is determined based on the actual operating condition coupling correction coefficient of the electromagnetic relay under test, which is determined based on simulation results.

[0027] Based on the pre-set average daily working cycle count of the electromagnetic relay under test, the remaining working cycle count is converted into the remaining lifespan.

[0028] According to the first aspect, obtaining the fault cause characterizing the first response time being greater than the response time threshold based on the simulation results includes:

[0029] Based on the simulation results, a first specified time period, a second specified time period, and a third specified time period are obtained. The first specified time period, the second specified time period, and the third specified time period constitute the total simulation time period. The first specified time period, the second specified time period, and the third specified time period are continuous. The first specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is greater than 0. The second specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is 0. The third specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is less than 0.

[0030] The first comparison result is determined by comparing the first specified time period with the first time threshold; the second comparison result is determined by comparing the second specified time period with the second time threshold; and the third comparison result is determined by comparing the third specified time period with the third time threshold. The sum of the first time threshold, the second time threshold, and the third time threshold is the response time threshold.

[0031] The cause of the fault is determined based on at least one of the first comparison result, the second comparison result, and the third comparison result.

[0032] According to the first aspect, based on at least one of the first comparison result, the second comparison result, and the third comparison result, the cause of the fault is determined, including:

[0033] When the first comparison result indicates that the first specified time period is greater than the first time threshold, based on the simulation result, the maximum coil current in the first specified time period and the rate of change of the pull-in force in the first specified time period are obtained;

[0034] The fourth comparison result is determined by comparing the maximum coil current with the preset lower limit of the current qualification value, and the fifth comparison result is determined by comparing the rate of change of the attraction force with the preset lower limit of the rate of change value.

[0035] Based on the fourth and fifth comparison results, and using a pre-established knowledge base, the cause of the fault is determined. The knowledge base includes the correspondence between the fourth and fifth comparison results and the cause of the fault.

[0036] According to the first aspect, based on at least one of the first comparison result, the second comparison result, and the third comparison result, the cause of the fault is determined, including:

[0037] When the second comparison result indicates that the second specified time period is greater than the second time threshold, the first mechanical damping coefficient, the temperature rise of the coil, and the coil conduction resistance are obtained based on the simulation results for the second specified time period.

[0038] By comparing the first mechanical damping coefficient with the first coefficient threshold, a sixth comparison result is obtained; by comparing the temperature rise value with the temperature rise threshold, a seventh comparison result is obtained; and by comparing the coil conduction resistance with the resistance threshold, an eighth comparison result is obtained.

[0039] Based on the sixth, seventh, and eighth comparison results, and according to a pre-established knowledge base, the cause of the fault is determined. The knowledge base includes the correspondence between the sixth, seventh, and eighth comparison results and the cause of the fault.

[0040] According to the first aspect, based on at least one of the first comparison result, the second comparison result, and the third comparison result, the cause of the fault is determined, including:

[0041] When the third comparison result indicates that the third specified time period is greater than the third time threshold, then based on the simulation result, the second mechanical reset damping coefficient, coil circuit leakage rate and iron core residual flux within the third specified time period are obtained;

[0042] By comparing the second mechanical reset damping coefficient with the second coefficient threshold, the ninth comparison result is obtained; by comparing the coil circuit discharge rate with the crab stick rate threshold, the tenth comparison result is obtained; and by comparing the iron core remanent flux with the remanent magnetization threshold, the eleventh comparison result is obtained.

[0043] Based on the ninth, tenth, and eleventh comparison results, and using a pre-established knowledge base, the cause of the fault is determined. The knowledge base includes the correspondence between the ninth, tenth, and eleventh comparison results and the cause of the fault.

[0044] Secondly, embodiments of this application provide an electronic device, which includes a processor and a memory coupled to each other. The memory stores a computer program, and when the computer program is executed by the processor, the electronic device performs the above-described method.

[0045] Thirdly, embodiments of this application provide a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, which, when run on a computer, causes the computer to perform the above-described method.

[0046] The invention employing the above technical solution has the following advantages:

[0047] In the technical solution provided in this application, firstly, the first response time and test parameters obtained by the test terminal for testing the electromagnetic relay under test, and the second response time obtained by the corresponding simulation terminal are obtained. By calculating the difference between the two and comparing it with the difference threshold, the mismatch between the initial simulation parameters and the measured test parameters is accurately identified. When the difference is greater than the difference threshold, the simulation parameters of the simulation terminal are corrected based on the measured test parameters. The corrected simulation parameters are deployed to the simulation terminal and iterated repeatedly until the difference is less than or equal to the difference threshold, thereby eliminating the deviation between the test and simulation data and ensuring that the simulation results output by the simulation terminal can truly reflect the actual state of the relay. Based on this, by comparing the first response time with the response time threshold, both fault tracing and remaining life prediction are considered in the same evaluation process: when the first response time is greater than the response time threshold, the cause of the fault exceeding the threshold is located based on the corrected and reliable simulation results, avoiding fault tracing deviations caused by simulation distortion; when the first response time is less than or equal to the response time threshold, the remaining life is calculated based on the same corrected simulation results, ensuring the consistency and accuracy of the evaluation results, achieving a comprehensive and reliable judgment of the relay status, and solving the problem of insufficient accuracy caused by the mismatch between simulation and measured parameters in existing technologies. Attached Figure Description

[0048] This application can be further illustrated by the non-limiting embodiments given in the accompanying drawings. It should be understood that the following drawings only illustrate certain embodiments of this application and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained from these drawings without any inventive effort.

[0049] Figure 1 A flowchart illustrating an evaluation method for electromagnetic relays provided in an embodiment of this application.

[0050] Figure 2 The circuit diagram of the electromagnetic relay under test provided in the embodiments of this application is shown.

[0051] Figure 3 A flowchart illustrating a method for determining remaining lifetime provided in an embodiment of this application.

[0052] Figure 4 Provided for the embodiments of this application Figure 3 The flowchart for A7. Detailed Implementation

[0053] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that similar or identical parts are referred to by the same reference numerals in the drawings or description. Implementations not shown or described in the drawings are forms known to those skilled in the art. In the description of this application, terms such as "first" and "second" are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0054] This application provides an electronic device that may include a processing module and a storage module. The storage module stores a computer program, which, when executed by the processing module, enables the electronic device to perform the corresponding steps in the evaluation method for electromagnetic relays described below.

[0055] Please refer to Figure 1 This application also provides an evaluation method for electromagnetic relays, which can be applied to the aforementioned electronic devices, and the steps of the method can be executed or implemented by the electronic devices. The electronic devices can be, but are not limited to, personal computers, smartphones, etc. The application to electromagnetic relays may include the following steps:

[0056] S110, acquire the first response time and test parameters obtained by the test terminal when testing the electromagnetic relay under test, and the second response time obtained based on the simulation terminal corresponding to the test terminal;

[0057] S120, calculate the difference between the first response time and the second response time;

[0058] S130, when the difference is greater than the difference threshold, the simulation parameters of the simulation terminal are corrected according to the test parameters, and the corrected simulation parameters are deployed to the simulation terminal until the difference is less than or equal to the difference threshold.

[0059] S140, Obtain the simulation results output by the simulation terminal;

[0060] S150, compare the first response time with the response time threshold. If the first response time is greater than the response time threshold, then based on the simulation results, obtain the fault cause that indicates the first response time is greater than the response time threshold. If the first response time is less than or equal to the response time threshold, then based on the simulation results, obtain the remaining life of the electromagnetic relay under test.

[0061] In the above implementation, the technical solution first compares the difference between the measured data at the test end and the initial data at the simulation end, and iteratively corrects the simulation parameters with the test parameters to match the parameter system of the simulation end with the actual test state of the electromagnetic relay under test, eliminating the deviation between simulation and actual measurement, and ensuring that the simulation results output by the simulation end can truly reflect the actual working conditions and operating status of the relay. Then, based on the matched simulation results, two evaluation objectives are achieved in the same process: when the measured response time of the relay exceeds the threshold, the cause of the fault is quantitatively analyzed and located based on the real simulation results; when the measured response time is qualified, the remaining life is calculated based on the simulation results. This achieves the integration of simulation and actual measurement, so that both fault tracing and remaining life assessment are supported by simulation data that fits reality, ensuring the accuracy and reliability of the two evaluation results.

[0062] The following is a detailed explanation of each step in the evaluation method applied to electromagnetic relays:

[0063] In the S110, the test terminal is built on an electromagnetic relay comprehensive performance test bench, configured with a power supply module, data acquisition module, sensor detection module, load simulation module, vibration simulation module, and main control module. The power supply module provides the rated operating voltage / current to the electromagnetic relay under test. The load simulation module simulates the actual load conditions of its service life. The vibration simulation module is rigidly connected to the relay mounting base via a vibration table, and can apply adjustable frequency and amplitude vibration excitation according to actual service scenarios (such as elevators and industrial control equipment) to reproduce the vibration environment of the relay in actual operation. The sensor detection module deploys sensors for current, voltage, vibration, temperature rise, and displacement, synchronously collecting real-time test parameters under vibration conditions. The data acquisition module accurately captures the first response time of the relay from energization to contact closure. The main control module completes the storage, processing, and transmission of all test data. The purpose of this test terminal is to conduct actual performance tests on the electromagnetic relay under simulated actual vibration conditions, obtaining the first response time and full-dimensional test parameters that truly reflect the actual service state of the relay. This provides a practical benchmark for parameter correction in the simulation terminal, and also serves as a basis for determining whether the relay response time exceeds the standard.

[0064] like Figure 2 The diagram shown is a schematic circuit diagram of the electromagnetic relay under test. In this embodiment, the test terminal also includes a vibration table, which is used to provide vibration to the electromagnetic relay under test. The vibration parameters can be adjusted. In this embodiment, the input signal is input from node FL1 or node FL2 and output from node 22, 20 or 24. Therefore, the first response time in this embodiment is characterized as the time difference between the input signal and the output signal.

[0065] The simulation platform, based on finite element simulation software, constructs a multi-field coupled simulation model of electromagnetism, thermodynamics, mechanics, and vibration, using the physical structure and factory calibration parameters of the electromagnetic relay under test. First, a three-dimensional geometric model is established according to the actual dimensions and material parameters of components such as the relay coil, core, armature, contacts, and base. Coupled boundary conditions for electromagnetism, thermodynamics, and mechanics are defined, and relevant physical equations for electromagnetic induction, heat conduction, and mechanical motion are embedded. Simultaneously, vibration excitation parameters (frequency, amplitude, and vibration direction) applied by the test end are imported. Vibration load boundaries consistent with reality are added to the model to recreate the relay's stress and operation state under vibration conditions. Initial simulation parameters match the relay's standard rated parameters. The second response time of the relay under vibration conditions is obtained through simulation. The function of this simulation platform is to recreate the complete operation process of the relay under vibration conditions in a simulation environment. The initially output second response time provides a comparison benchmark for subsequent parameter correction. After correction using measured parameters under vibration conditions from the test end, a full-dimensional simulation result that closely reflects the actual vibration service state of the relay can be output.

[0066] Therefore, the second response time is characterized as the action response time of the electromagnetic relay under test from energization to contact closure, obtained by simulation in a multi-field coupled simulation model of electromagnetic-thermal-mechanical-vibration that imports the same vibration excitation parameters from the test end and matches the standard rated parameters of the electromagnetic relay under test. This response time is completely consistent with the test scenario of the first response time of the test end.

[0067] Test parameters are used to characterize the test results generated by the test terminal during the test. For example, test parameters may include the steady-state current of the first coil, the contact voltage drop, the operating current of the contact circuit, and the bounce time of the first contact.

[0068] The first coil steady-state current refers to the effective value of the current when the current in the coil circuit rises to a stable value without significant fluctuation after the electromagnetic relay under test is energized, under the actual test conditions simulating actual vibration. This value is the electrical parameter of the relay electromagnetic excitation link entering a stable working state, reflecting the actual current flow state of the coil under actual working conditions.

[0069] Contact voltage drop refers to the voltage drop generated when current flows through the contact parts of the moving and stationary contacts after the contacts of the electromagnetic relay under test are closed under actual test conditions. It is determined by the contact resistance and the circuit operating current and is a key parameter characterizing the contact state and electrical contact reliability.

[0070] The contact circuit operating current refers to the effective value of the load current flowing through the contact circuit after the contacts of the electromagnetic relay under test are closed under the actual test conditions. This value simulates the contact current flow conditions when the relay is actually in service, reflects the working state of the contacts under actual load, and is an electrical parameter belonging to a different circuit from the coil current.

[0071] In S130, when the difference exceeds the threshold, it indicates that the deviation between the initial output second response time of the simulation terminal and the measured first response time of the test terminal exceeds the reasonable range. This reflects a mismatch between the initial simulation parameters of the simulation terminal and the actual measured operating conditions and physical state of the electromagnetic relay under test (such as the initial parameters not conforming to the actual vibration conditions of the relay, component aging / performance degradation state, actual current flow / contact characteristics, etc.). This causes the simulation model to fail to accurately reproduce the actual operation process of the relay, and the simulation results lack reference value for the actual state. If subsequent fault tracing or remaining life assessment is carried out directly based on the distorted simulation model output results, the assessment results will be out of touch with the actual situation and lack accuracy. Therefore, it is necessary to correct the simulation parameters through the actual test parameters of the test terminal to ensure that the parameter system of the simulation model is accurately matched with the actual measured state and operating conditions of the relay, eliminate the deviation between simulation and measurement, ensure the authenticity and effectiveness of the simulation results, and provide reliable simulation data support for subsequent assessments.

[0072] In this embodiment, the simulation parameters are various quantitative parameters used in the simulation model built on the simulation end to reproduce the actual measured working conditions and physical characteristics of the electromagnetic relay under test. They form the basis for simulating the relay's action process, outputting the second response time, and subsequent simulation results, and correspond one-to-one with the test parameters on the testing end. The simulation parameters in this embodiment can include three categories: 1. Working condition simulation parameters, i.e., parameters simulating the actual test scenario, such as vibration excitation parameters (frequency, amplitude) and power supply parameters applied to the simulation model; 2. Relay's own physical simulation parameters, such as coil DC resistance, core permeability, mechanical damping coefficient, and initial contact resistance; 3. Circuit simulation parameters, such as the equivalent impedance of the coil circuit and the load matching parameters of the contact circuit. It can be understood that the initial simulation parameters are directly deployed in the finite element model on the simulation end by relevant personnel when establishing the finite element model.

[0073] The difference threshold is a critical value used to measure whether the deviation between the response time of the test end and the simulation end is within a reasonable and acceptable range. It is a quantitative threshold that fits the actual test and simulation characteristics and is obtained through multiple calibration tests of brand-new standard electromagnetic relays of the same batch. The specific process is as follows: Select brand-new standard electromagnetic relays of the same model and batch as the electromagnetic relay under test, complete multiple sets (generally no less than 30 sets) of first response time measurements at the test end under fixed actual test conditions, and at the same time, build a model at the simulation end according to the initial standard parameters to complete multiple sets of second response time simulations. Calculate the difference between the measured and simulated response times for each set, perform statistical analysis on all differences (calculate the standard deviation and mean after removing outliers), and determine the reasonable upper limit of deviation as the difference threshold in combination with the acceptable requirements for the deviation between simulation and measured in engineering practice.

[0074] Therefore, it is understandable that when the difference is not greater than the difference threshold, it proves that the test end and the simulation end have formed a good match, and it can directly enter S140.

[0075] In this embodiment, when the difference is greater than the difference threshold, the simulation parameters that need to be adjusted include the coil equivalent resistance and the contact resistance. These two parameters directly affect the response time of the electromagnetic relay and are highly correlated with the actual working conditions / relay status at the test end. The remaining parameters are fixed parameters in the evaluation scenario of this embodiment and have no significant impact on the difference between the simulation and the actual response time.

[0076] The equivalent resistance of the coil and the contact resistance directly reflect the actual contact state of the contacts and are related to the mechanical fit and bounce characteristics of the contacts. They affect the time it takes for the contacts to close stably from initial contact. Both are parameters that play a key role in regulating the response time and are also parameters that are prone to performance changes in relays due to aging and operating conditions during actual service. They are the main causes of deviations between the initial parameters of the simulation end and the measured state of the test end, resulting in response time differences exceeding the threshold. The other parameters in the electromagnetic relay simulation model, such as the magnetic permeability of the iron core material, vibration excitation parameters, number of coil turns, and contact spring stiffness, are all fixed parameters or non-sensitive parameters in the evaluation scenario of this embodiment. Among them, the vibration excitation parameters and the number of coil turns are fixed parameters of the operating conditions / structure that have been accurately simulated at the test end and matched in advance at the simulation end, and have no deviation from the actual state of the relay. The magnetic permeability of the iron core and the contact spring stiffness have a lower impact on the response time than the equivalent resistance of the coil and the contact resistance of the contacts in this embodiment. Therefore, this embodiment focuses on the coil equivalent resistance and contact resistance, which have the most significant impact on response time and are the main causes of deviation, and makes targeted corrections. This can not only accurately eliminate the difference between the simulated and measured response time, but also make the correction process of simulation parameters simpler and more efficient. It avoids the problems of excessive complexity of the simulation model and low correction efficiency caused by meaningless multi-parameter adjustments, while ensuring that the corrected simulation model can truly reflect the actual electrical characteristics of the relay.

[0077] Based on this, such as Figure 3 As shown, the correction of simulation parameters in S130 can be specifically as follows:

[0078] The corrected equivalent resistance of the coil is obtained based on the steady-state current of the first coil, the steady-state current of the second coil at the simulation end, and the equivalent resistance of the coil before correction.

[0079] The process of correcting the equivalent resistance of the coil is represented by the following formula.

[0080]

[0081] This represents the corrected equivalent resistance of the coil;

[0082] This represents the equivalent resistance of the coil before correction;

[0083] This represents the steady-state current of the first coil;

[0084] This represents the steady-state current of the second coil.

[0085] The equivalent resistance of the coil is a parameter that affects the steady-state current of the coil (with the voltage fixed). The steady-state current of the coil directly determines the current rise rate and the magnetic field establishment speed of the electromagnetic excitation link, which is the key to the response time. The coil equivalent resistance corrected by this formula can make the steady-state current of the coil at the simulation end completely consistent with the measured value at the test end, thus eliminating the deviation between simulation and measurement.

[0086] The first coil steady-state current is a quantitative electrical parameter directly acquired by the test end after completing the actual test of the electromagnetic relay under simulated actual vibration conditions. The specific acquisition process is as follows: the test end provides the electromagnetic relay under test with the rated power supply voltage consistent with actual service. In the actual test scenario with preset vibration excitation, the current time sequence change data after the coil is energized is collected in real time by a high-precision current sensor connected in series with the coil circuit. When the coil current rises to a stable value and there is no obvious fluctuation within a preset time period (e.g., 5ms) (fluctuation amplitude ≤ ±1%), the stable current value is recorded, which is the first coil steady-state current. This value is the real steady-state current value of the relay coil under actual working conditions and actual physical state. It is directly captured and stored by the data acquisition module of the test end and used as the actual measurement benchmark for simulation parameter correction.

[0087] The steady-state current of the second coil is a quantified electrical parameter obtained by simulation deduction in the simulation model before correction. The specific acquisition process is as follows: The simulation end builds a simulation model that is completely matched with the actual test scenario of the test end according to the initially preset simulation parameters such as the coil equivalent resistance (the power supply voltage, vibration excitation parameters, and load conditions are all consistent with the test end). The simulation software solves the time sequence equation of the electrical characteristics of the coil circuit to simulate the entire process from the coil being energized to the current stabilization. The current value when the coil current rises to a constant and unfluctuating state in the simulation model is extracted, which is the steady-state current of the second coil. This value is the theoretical steady-state current value deduced by the simulation end based on the initial parameters. It is the simulation reference value for comparison with the steady-state current of the first coil at the test end, and then the coil equivalent resistance is corrected.

[0088] In S130, the contact resistance can be corrected based on the contact voltage drop and the contact circuit operating current to obtain the corrected contact resistance.

[0089] Based on this, this embodiment implements the process of correcting the contact resistance of the contact point using the following formula.

[0090]

[0091] This indicates the corrected contact resistance.

[0092] This indicates the measured contact voltage drop at the test terminal;

[0093] This indicates the actual measured operating current of the contact circuit at the test terminal.

[0094] The corrected contact resistance can accurately match the actual contact state of the electromagnetic relay contacts under test, eliminating the deviation between the initial theoretical parameters and the measured state at the simulation end. From the perspective of contact electrical contact characteristics, it ensures the accuracy of the simulation model in restoring the mechanical action links (contact closure and bounce) of the relay. Combined with the correction of the coil equivalent resistance, it eliminates the response time deviation between simulation and actual measurement from the perspective of electromagnetic excitation and contact action, and finally achieves the correction goal of the first difference ≤ difference threshold.

[0095] In this embodiment, This refers to the electrical parameters directly acquired by the test end after the electromagnetic relay under test has achieved stable contact closure under simulated actual vibration conditions. Specifically, in the contact circuit of the test end, the detection end of a high-precision differential voltage sensor is connected in parallel across the moving and stationary contacts of the electromagnetic relay under test. When the test end detects that the relay coil current reaches the first coil steady-state current, and the moving and stationary contacts achieve stable closure without bouncing (determined by a displacement sensor / current sensor), the voltage sensor acquires the voltage difference across the contacts in real time. This stable, fluctuation-free voltage difference is the measured contact voltage drop. The data is directly stored by the test terminal data acquisition module, and the acquisition process is synchronized with the vibration excitation condition, which is consistent with the actual service condition of the relay.

[0096] This refers to the steady-state current of the contact load circuit synchronously acquired by the test terminal under the same measured conditions as described above. The specific process is as follows: In the contact load circuit of the test terminal (independent of the coil circuit), a high-precision current sensor is connected in series. The test terminal constructs a load condition (such as resistive / inductive load) consistent with the actual service of the relay through a load simulation module. When the relay contacts are stably closed, the contact circuit forms a complete current-carrying loop. When the current sensor detects that the circuit current rises to a stable value and the fluctuation range is ≤±1%, the stable current value is recorded as the measured operating current of the contact circuit. and To ensure that the synchronously acquired matching parameters reflect the contact electrical characteristics under the same measured condition, the two parameters are used to collect matching parameters.

[0097] Understandably, once the simulation parameters are corrected, the simulation is performed again, and the difference between the first and second response times is calculated again. If the condition is met, S140 is performed; otherwise, the simulation parameters are corrected again in the above manner until the difference is less than or equal to the difference threshold.

[0098] It is understandable that deploying simulation parameters on the simulation end means replacing the original initial parameters of the coil equivalent resistance and contact resistance in the model with parameter values ​​that are calculated from the measured parameters at the test end and are consistent with the actual state of the electromagnetic relay under test, so that the electrical parameters of the simulation model match the actual measured state of the relay.

[0099] In S140, the simulation result is characterized as the result obtained by simulation after the difference is greater than the difference threshold. The simulation result in this embodiment may include mechanical effect result, thermal effect result, electrical effect result, mechanical damping coefficient increase rate, temperature rise decay rate and temperature rise decay rate.

[0100] Based on this, when the first response time exceeds the response time threshold, it indicates that the actual action response time of the electromagnetic relay under test, from energization to stable contact closure under simulated actual vibration conditions, exceeds the preset qualified standard. This indicates an abnormality in the actual operating state of its electromagnetic excitation, contact action, and other operational processes, and it can no longer meet the timing performance requirements for normal service. Therefore, under these conditions, it is necessary to assess the cause of the fault. Thus, the method for assessing the cause of the fault in S150 of this embodiment may include:

[0101] Based on the simulation results, a first specified time period, a second specified time period, and a third specified time period are obtained. The first specified time period, the second specified time period, and the third specified time period constitute the total simulation time period. The first specified time period, the second specified time period, and the third specified time period are continuous. The first specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is greater than 0. The second specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is 0. The third specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is less than 0.

[0102] The first comparison result is determined by comparing the first specified time period with the first time threshold; the second comparison result is determined by comparing the second specified time period with the second time threshold; and the third comparison result is determined by comparing the third specified time period with the third time threshold. The sum of the first time threshold, the second time threshold, and the third time threshold is the response time threshold.

[0103] The cause of the fault is determined based on at least one of the first comparison result, the second comparison result, and the third comparison result.

[0104] Based on this, the simulation results also include coil current timing results. In this example, the three specified time periods are all obtained based on the coil current timing output by the corrected simulation model at the simulation end. This result is the continuous timing data (including current value, timestamp, current change rate and other quantitative information) of the coil loop current as a function of time, output by the simulation end after completing the simulation derivation using the corrected coil equivalent resistance and contact resistance as parameters. It is the simulation result characterizing the dynamic change process of the current in the electromagnetic excitation link of the relay, and it is also the only data basis for dividing the three specified time periods.

[0105] After the simulation terminal re-completes the full-process simulation based on the corrected simulation parameters, it will output a complete time-series curve of the coil current from the initial value (0) to the steady-state value to the zero value after de-energization, along with the corresponding digital dataset. By quantifying the current growth rate and extracting the time interval from this time-series data, the first, second, and third specified time periods that are continuous and constitute the total simulation period can be accurately divided. The specific steps are as follows:

[0106] Extracting basic coil current timing data: Exporting a two-dimensional dataset containing timestamps (t) and corresponding coil current values ​​(I) from the simulation results. Simultaneously, using the numerical calculation function of the simulation software, the dataset is differentiated to obtain the coil current growth rate (di / dt) at any time point, forming three-dimensional quantitative data of "time-current-current growth rate".

[0107] Traverse the three-dimensional quantization data, filter out all continuous time points where the current growth rate di / dt > 0, and extract the start timestamp (t1 start) and end timestamp (t1 end) of this time interval. This time interval is the first specified period, corresponding to the growth stage of the coil current from 0 to the steady state value.

[0108] The second specified time period is defined as follows: After the first specified time period ends, the subsequent data is traversed to filter out all continuous time points where the current growth rate di / dt = 0. The start timestamp (t2 at the beginning, coinciding with the end of t1) and end timestamp (t2 at the end) of this time interval are extracted. This time interval is always the second specified time period, corresponding to the stable stage where the coil current maintains a steady-state value without change. It can be understood that in the steady-state state where the coil current growth rate is 0 corresponding to the second specified time period, the coil current value output by the simulation terminal is not absolutely constant due to the influence of simulation accuracy, model perturbation, and small fluctuations in actual operating conditions. There will be slight fluctuations. The fluctuations in temperature will correspond to small fluctuations in the current growth rate, which will be close to 0, but not strictly zero. In this embodiment, the simulation end will automatically filter out such small fluctuations by setting a preset fluctuation threshold. That is, a threshold range for judging the current growth rate is set (such as di / dt∈[-ε,+ε], where ε is a very small value much greater than 0). When the coil current growth rate falls into this threshold range, it is judged as a steady state with a growth rate of 0. In this way, the continuous time interval of the second specified time period can be accurately extracted, avoiding the interference of small fluctuations on the division of time periods and ensuring the accuracy and continuity of the division of the first, second and third specified time periods.

[0109] Divide the third specified time period: After the second specified time period ends, continue to traverse the subsequent data, filter out all continuous time points where the current growth rate di / dt < 0, and extract the start timestamp (t3 starts, coinciding with t2 ends) and end timestamp (t3 ends) of this time interval. This time interval is always the third specified time period, corresponding to the decay stage of the coil current from steady state value to 0.

[0110] The entire acquisition process is automatically completed by the data analysis module on the simulation end, and the division of time periods is achieved based on the quantitative determination of the current growth rate.

[0111] In this embodiment, the three designated time periods correspond to the working stages of electromagnetic relay electromagnetic excitation, steady-state holding, and turn-off action, respectively. Whether the duration of each time period exceeds the threshold directly reflects whether the operating state of the corresponding stage is abnormal. The essence of the relay response time exceeding the threshold is that the overall action time is increased due to the timing abnormality of one or more working stages. By analyzing the comparison results of the duration of each time period with the corresponding threshold, the specific working stage where the abnormality occurs can be located. Combined with the working mechanism of each stage, the specific cause of the response time exceeding the standard can be determined from the root. At the same time, using the comparison results of each time period as the basis for judgment can achieve accurate tracing of the cause of the fault, avoid indiscriminate overall investigation, and make the determination of the cause of the fault more targeted. Moreover, by combining single or multiple comparison results, all fault scenarios such as single-stage abnormality and multi-stage coupling abnormality of relay can be covered, ensuring the comprehensiveness and accuracy of fault cause determination.

[0112] Therefore, in this embodiment, the cause of the fault is determined in the following specific way.

[0113] When the first comparison result indicates that the first specified time period is greater than the first time threshold, based on the simulation result, the maximum coil current in the first specified time period and the rate of change of the pull-in force in the first specified time period are obtained; the maximum coil current is compared with a preset current qualified lower limit value to determine the fourth comparison result, and the rate of change of the pull-in force is compared with a preset rate of change lower limit value to determine the fifth comparison result; based on the fourth comparison result and the fifth comparison result, the cause of the fault is determined based on a pre-established knowledge base, wherein the knowledge base includes the correspondence between the fourth comparison result and the fifth comparison result and the cause of the fault.

[0114] In this embodiment, the maximum coil current is derived from the simulation results of the above-mentioned coil current timing results. The maximum coil current extracted in the first specified time period is the peak current that the coil can reach in this stage, which directly reflects the actual current carrying capacity of the coil circuit. It is related to the coil equivalent resistance and power supply matching. By comparing it with the fourth comparison result of the current qualified lower limit value, it can be determined whether the coil has insufficient current carrying capacity (such as the current building being blocked due to excessive equivalent resistance).

[0115] The rate of change of the attraction force within the first specified time period is the rate of change of the electromagnetic attraction force over time. It directly reflects the efficiency of magnetic field establishment and the speed of attraction force generation. It is related to the coil current growth rate and the magnetic coupling characteristics of the iron core. By comparing it with the fifth comparison result of the qualified lower limit of the rate of change, it can be determined whether there is a problem of magnetic field establishment lag and slow attraction force generation.

[0116] The pre-established knowledge base is built based on electromagnetic relay design principles, fault cases, and measured data. It includes a one-to-one correspondence between the fourth and fifth comparison results (such as "maximum coil current is below the lower limit and the rate of change of pull-in force is below the lower limit", "only the maximum coil current is below the lower limit", "only the rate of change of pull-in force is below the lower limit", etc.) and specific fault causes (such as abnormal increase in coil equivalent resistance, decrease in core permeability, poor contact in coil circuit, magnetic leakage in magnetic circuit, etc.). There is no need to perform complex mechanism analysis. By directly matching the combination of the two comparison results in the knowledge base, the specific fault cause of the timing abnormality of the electromagnetic excitation link can be quickly and accurately determined. This ensures the pertinence and accuracy of fault tracing and enables rapid determination of fault causes by relying on a standardized knowledge base, which is suitable for the efficient evaluation needs in engineering practice.

[0117] The first specified time period corresponds to the electromagnetic excitation stage where the electromagnetic relay coil current increases, the magnetic field is established, and the attraction force is generated. If this time period exceeds the first time threshold, it indicates that the time taken for the relay to reach a steady state from energization exceeds the acceptable standard, and there is a timing abnormality in the electromagnetic excitation stage. The driving force of this stage is the coil current establishment speed and the electromagnetic attraction force generation efficiency, which directly determine the excitation stage time. Therefore, by extracting the two characteristic parameters of the maximum coil current and the rate of change of attraction force in this time period from the simulation results, comparing them with the preset threshold, and matching the corresponding relationship based on the knowledge base, the specific fault cause of the excitation stage can be accurately located.

[0118] In this embodiment, the fourth comparison result includes: ① Maximum coil current < lower limit of current qualification (denoted as A, abnormal); ② Maximum coil current ≥ lower limit of current qualification (denoted as A-, normal).

[0119] The fifth comparison results include: ① the rate of change of attraction force < the lower limit of the rate of change (marked as B, abnormal); ② the rate of change of attraction force ≥ the lower limit of the rate of change (marked as B-, normal).

[0120] Fourth comparison result A + Fifth comparison result B (lower maximum current + lower rate of change of attraction force)

[0121] Causes of matching failure: Abnormally increased equivalent coil resistance (e.g., coil aging, poor winding contact, coil circuit oxidation), or a slight drop in coil power supply circuit voltage (power supply fluctuations under actual / simulated operating conditions). Related logic: Increased equivalent coil resistance is the cause in this embodiment, directly leading to a slow coil current build-up speed and the inability of the maximum coil current to reach the acceptable lower limit within the first specified time period. Since current drives electromagnetic attraction, insufficient current directly causes a lag in magnetic field establishment, and the rate of change of attraction force over time decreases synchronously. Ultimately, these two factors cause the first specified time period to time out.

[0122] Fourth comparison result A+; Fifth comparison result B- (low maximum current + normal rate of change of attraction force)

[0123] Cause of the fault: Slight magnetic leakage exists in the relay's magnetic circuit (e.g., increased gap in the iron core joints, slight magnetization attenuation in the iron core material), and the coil's current-carrying capacity is not significantly affected. Related logic: Magnetic leakage in the magnetic circuit increases the efficiency of converting coil current into electromagnetic attraction force (the rate of change of attraction force is normal or even slightly higher). However, the leakage consumes some magnetic field energy. To generate sufficient attraction force, the coil will continuously increase the current within the first specified time period, but due to magnetic circuit losses, it cannot reach the qualified maximum current value; the "ineffective time" of current establishment increases, ultimately causing the first specified time period to time out.

[0124] Fourth comparison result A-+; Fifth comparison result B (maximum current normal + low rate of change in attraction force).

[0125] Causes of matching failure: Decreased core permeability (e.g., core aging, surface corrosion, loose core laminations), or a slight increase in mechanical resistance in the electromagnetic excitation circuit (e.g., impurities between the armature and the core, slightly excessive preload of the reset spring). Related logic: The coil circuit is normal, therefore the maximum coil current within the first specified time period can reach the acceptable lower limit (normal). However, decreased core permeability reduces the efficiency of current conversion into attraction force. Even with normal current, magnetic field establishment will lag, and the rate of change of attraction force will be lower than the lower limit. If the mechanical resistance is slightly increased, the attraction force needs to overcome greater resistance to push the armature, resulting in a reduced "effective rate of change" of attraction force. Ultimately, both lead to increased time consumption for attraction force generation within the first specified time period, causing the time period to exceed the limit.

[0126] Fourth comparison result A-+; Fifth comparison result B- (maximum current normal + rate of change of attraction force normal)

[0127] Causes of the fault: Deviation between the vibration excitation parameters under simulated / actual operating conditions and the relay's compatibility (e.g., vibration frequency resonating with coil current), or minor structural assembly deviations not covered by the simulation model (e.g., slight jamming of the armature displacement guide slot). Related logic: The parameters for coil current flow and magnetic circuit conversion are normal, ruling out abnormalities in the electrical and magnetic components; vibration resonance interferes with the stable establishment of the coil current, or slight structural jamming delays the attraction force pushing the armature, indirectly increasing the "effective timing" of the first specified time period. This is a time period timeout caused by operating condition / structural auxiliary factors, and is the only fault cause when electrical and magnetic parameters are normal.

[0128] The simulation results also include the mechanical damping coefficient, coil temperature rise, and coil conduction resistance for the second specified time period. After the simulation terminal completes the full-process simulation derivation based on the corrected coil equivalent resistance and contact resistance, it will synchronously output continuous time-series data in multiple dimensions of mechanics, heat, and electricity. For the second specified time period (coil current steady state, growth rate is 0), the mechanical motion characteristic data of the relay moving parts (armature, contacts, etc.) in the simulation model are directly extracted during this time period. The damping coefficient is calculated in real time by the damping coefficient algorithm built into the model to obtain the mechanical damping coefficient for this time period. The simulated coil temperature values ​​at the beginning and end of this time period are extracted, and the difference between the two is calculated to obtain the coil temperature rise during this time period. At the same time, the simulated real-time equivalent resistance value of the coil circuit under steady-state current during this time period is extracted as the coil conduction resistance for this time period. All three are steady-state quantification parameters for the second specified time period, which are automatically extracted and calculated by the simulation terminal and accurately matched with the electrical, thermal, and mechanical steady-state operating conditions of this time period.

[0129] In at least one embodiment, the cause of the fault can be determined based on the simulation results described above as follows:

[0130] When the second comparison result indicates that the second specified time period is greater than the second time threshold, based on the simulation result, the mechanical damping coefficient, the temperature rise value of the coil, and the coil conduction resistance for the second specified time period are obtained; the mechanical damping coefficient is compared with the first coefficient threshold to obtain the sixth comparison result; the temperature rise value is compared with the temperature rise threshold to obtain the seventh comparison result; and the coil conduction resistance is compared with the resistance threshold to obtain the eighth comparison result; based on the sixth comparison result, the seventh comparison result, and the eighth comparison result, the cause of the fault is determined according to a pre-established knowledge base, wherein the knowledge base includes the correspondence between the sixth comparison result, the seventh comparison result, and the eighth comparison result and the cause of the fault.

[0131] This embodiment directly extracts three types of parameters from the simulation results: the mechanical damping coefficient (mean), the coil temperature rise (temperature difference at the beginning and end of the time period), and the coil on-resistance (mean) within the second specified time period. These three parameters are then compared with preset threshold values ​​for the first coefficient (upper limit for acceptable mechanical damping coefficient), temperature rise (upper limit for acceptable coil temperature rise), and resistance (upper limit for acceptable coil on-resistance), respectively. Only the "exceeding / not exceeding threshold" determination is made, specifically:

[0132] Sixth comparison result: ① Mechanical damping coefficient > first coefficient threshold (denoted as C, abnormal); ② Mechanical damping coefficient ≤ first coefficient threshold (denoted as C-, normal).

[0133] Seventh comparison result: ① Coil temperature rise > temperature rise threshold (denoted as D, abnormal); ② Coil temperature rise ≤ temperature rise threshold (denoted as D-, normal).

[0134] Eighth comparison result: ① Coil on-resistance > resistance threshold (denoted as E, abnormal); ② Coil on-resistance ≤ resistance threshold (denoted as E-, normal).

[0135] Output results: After comparison, the unique combination of the three comparison results (such as C+D+E, C+D-+E-, C-+D+E, etc.) is obtained and used as the unique keyword for knowledge base retrieval.

[0136] Sixth comparison result C + Seventh comparison result D + Eighth comparison result E (Mechanical damping coefficient exceeds threshold + Temperature rise exceeds threshold + On-resistance exceeds threshold)

[0137] The matching fault is caused by the jamming of the relay moving parts (such as dust accumulation, corrosion or deformation of the armature or contact guide groove) combined with coil aging (such as wear of the coil insulation layer, oxidation of the winding or partial breakage of strands); the associated logic is that the jamming of the moving parts directly causes a sharp increase in the mechanical damping coefficient, the aging of the coil causes the conduction resistance to increase abnormally, the heating effect during the current carrying process is aggravated, which leads to the temperature rise exceeding the threshold. The coupling of the three types of characteristics of mechanical, thermal and electrical is abnormal, which causes the mechanical action to be hindered in the steady state stage and the electrothermal characteristics to be continuously abnormal, ultimately resulting in a significant increase in the time consumption of the second specified time period.

[0138] Sixth comparison result: C+; Seventh comparison result: D+; Eighth comparison result: E- (Mechanical damping coefficient exceeds threshold + Temperature rise exceeds threshold + On-resistance is normal).

[0139] The matching fault is caused by lubrication failure of the relay mechanical transmission mechanism (such as lack of oil in the shaft or spring, or dry grease) combined with blockage of the coil heat dissipation structure (such as dust accumulation in the heat dissipation groove or poor contact of the heat sink). The associated logic is that lubrication failure directly leads to an increase in the mechanical damping coefficient, and blockage of the heat dissipation structure prevents the heat generated by the normal current flow of the coil from being dissipated in time, thus causing the temperature rise to exceed the threshold. The coil itself has no problems such as aging or poor contact, and the on-resistance remains normal. The abnormal coupling of mechanical and thermal characteristics affects both the steady-state operation and heat dissipation, and the time consumption of the second specified time period increases.

[0140] Sixth comparison result C+; Seventh comparison result D-+; Eighth comparison result E (mechanical damping coefficient exceeds threshold + temperature rise is normal + conduction resistance exceeds threshold).

[0141] The matching fault is caused by poor contact between the moving and stationary contacts of the relay (such as excessive contact gap or burn-out protrusion on the contact surface) combined with poor contact in the local winding of the coil (such as loose winding joint or loose coil crimping). The associated logic is that poor contact leads to increased damping during mechanical action. Poor contact in the local winding of the coil only causes an abnormal increase in conduction resistance without causing a significant heating effect. The temperature rise remains within the acceptable range. Abnormal coupling between mechanical and electrical characteristics increases the time required for mechanical contact and electrical path establishment in the steady state phase, resulting in the timeout of the second specified time period.

[0142] Sixth comparison result: C+; Seventh comparison result: D-+; Eighth comparison result: E- (Mechanical damping coefficient exceeds threshold + temperature rise is normal + conduction resistance is normal).

[0143] The cause of the matching fault is an abnormal increase in the preload of the relay reset spring (such as spring fatigue deformation or excessive preload during assembly) combined with resonance of moving parts under vibration conditions (such as vibration frequency matching the natural frequency of the armature and contacts). The related logic is that the increase in the preload of the reset spring is the reason for the mechanical damping coefficient exceeding the threshold. Vibration resonance further interferes with the steady-state operation of the mechanical parts, while the current carrying capacity and heating characteristics of the coil are normal, and the conduction resistance and temperature rise remain normal. This is a pure mechanical characteristic abnormality combined with the interference of the operating conditions, which leads to an increase in the steady-state operation time in the second specified period.

[0144] Sixth comparison result C-+; Seventh comparison result D+; Eighth comparison result E (Mechanical damping coefficient normal + temperature rise exceeds threshold + conduction resistance exceeds threshold)

[0145] The matching fault is caused by a slight short circuit in the coil circuit (such as partial damage to the insulation layer of the coil winding or leakage between the coil and the iron core), which is superimposed on the abnormal increase in the coil's conduction resistance due to the short circuit. The associated logic is that the partial short circuit in the coil directly causes the conduction resistance to increase. During the current flow, the Joule heating effect at the short circuit point is aggravated, causing the coil temperature rise to exceed the threshold. However, the moving parts of the relay, such as the armature and contacts, do not have problems such as jamming or poor contact, and the mechanical damping coefficient remains normal. This is a pure electrical and thermal characteristic coupling abnormality, which leads to an abnormal coil electrothermal state in the steady state stage and an increase in the time consumption of the second specified period.

[0146] Sixth comparison result: C-+; Seventh comparison result: D+; Eighth comparison result: E- (Mechanical damping coefficient normal + temperature rise exceeds threshold + conduction resistance normal)

[0147] The matching fault is caused by the actual operating environment temperature being too high during testing / simulation (such as the relay being used near high-temperature equipment), coupled with the inherently low heat dissipation efficiency of the coil itself (such as insufficient adaptability of the heat dissipation structure during the product design stage). The associated logic is that the coil itself has no aging, short circuit, or other problems, and the on-resistance remains normal. However, if the operating environment temperature is too high, coupled with the poor heat dissipation efficiency of the coil, heat will accumulate even with normal current flow, causing the temperature rise to exceed the threshold. The mechanical components have no abnormal operating status, which is a timeout of the second specified period caused by a purely thermal characteristic abnormality.

[0148] Sixth comparison result C-+; Seventh comparison result D-+; Eighth comparison result E (Mechanical damping coefficient normal + temperature rise normal + conduction resistance exceeds threshold).

[0149] The matching fault is caused by oxidation, corrosion, or poor contact of the coil terminals (such as loose terminal crimping or oxide layer at the connection point). The associated logic is that the contact problem of the terminals only causes an abnormal increase in the overall conduction resistance of the coil. Since the increase in resistance does not reach the level that causes significant heat generation, the coil temperature rise remains normal. At the same time, there are no abnormalities in the mechanical moving parts of the relay, and the mechanical damping coefficient is qualified. It belongs to a single abnormality of pure electrical characteristics, which increases the time required to establish the current path of the coil in the steady state stage, and the second specified time period expires.

[0150] Sixth comparison result: C-+; Seventh comparison result: D-+; Eighth comparison result: E- (Mechanical damping coefficient normal + temperature rise normal + conduction resistance normal)

[0151] The matching failure is caused by a mismatch between the vibration excitation parameters and the steady-state operating frequency of the relay, or by slight assembly gap deviations of the relay not covered by the simulation model (such as uneven assembly gaps between the armature and the core, or slight deviations in the contact installation position). The associated logic is that the mechanical, thermal, and electrical parameters of the relay are all within the acceptable range, eliminating direct anomalies in each dimension. Instead, it is a problem with the parameter adaptability of the vibration condition or a slight assembly structure deviation, which indirectly interferes with the normal operating sequence of the relay in the steady-state stage, causing the timeout of the second specified time period to exceed the threshold. This is a timeout problem caused by operating conditions and assembly auxiliary factors.

[0152] In at least one embodiment, the method for determining the cause of the fault based on the above simulation results can be as follows: when the third comparison result indicates that the third specified time period is greater than the third time threshold, then based on the simulation results, the second mechanical reset damping coefficient, the coil circuit leakage rate, and the core residual flux within the third specified time period are obtained; the second mechanical reset damping coefficient is compared with the second coefficient threshold to obtain the ninth comparison result; the coil circuit leakage rate is compared with the leakage rate threshold to obtain the tenth comparison result; and the core residual flux is compared with the residual magnetism threshold to obtain the eleventh comparison result; based on the ninth comparison result, the tenth comparison result, and the eleventh comparison result, the cause of the fault is determined based on a pre-established knowledge base, wherein the knowledge base includes the correspondence between the ninth comparison result, the tenth comparison result, and the eleventh comparison result and the cause of the fault.

[0153] This embodiment directly extracts three types of parameters from the simulation results within the third specified time period: the average value of the second mechanical reset damping coefficient, the average value of the coil circuit discharge rate, and the average value of the core residual magnetic flux. These three parameters are then compared with preset threshold values ​​for the second coefficient (upper acceptable limit for the second mechanical reset damping coefficient), the discharge rate threshold (lower acceptable limit for the coil circuit discharge rate), and the residual magnetic flux threshold (upper acceptable limit for the core residual magnetic flux). Only the "exceeding / not exceeding threshold" judgment is made. Specifically: Ninth comparison result: ① Second mechanical reset damping coefficient > Second coefficient threshold (denoted as F, abnormal); ② Second mechanical reset damping coefficient ≤ second coefficient threshold (denoted as F-, normal) Tenth comparison result: ① Coil circuit leakage rate < leakage rate threshold (denoted as G, abnormal); ② Coil circuit leakage rate ≥ leakage rate threshold (denoted as G-, normal) Eleventh comparison result: ① Iron core residual magnetic flux > residual magnetic threshold (denoted as H, abnormal); ② Iron core residual magnetic flux ≤ residual magnetic threshold (denoted as H-, normal) Result output: After comparison, a unique combination of three comparison results (such as F+G+H, F+G-+H-, F-+G+H, etc.) is obtained, which serves as the unique keyword for knowledge base retrieval.

[0154] The matching fault of the ninth comparison result F + the tenth comparison result G + the eleventh comparison result H (second mechanical reset damping coefficient exceeds the threshold + low current discharge rate of coil circuit + residual magnetic flux of iron core exceeds the threshold) is caused by the jamming of the relay reset moving parts (such as dust and rust accumulation in the armature reset guide groove, and jamming and deformation of the reset spring), coupled with poor contact of the coil circuit current discharge circuit (such as loose connection of the current discharge resistor, loose circuit wiring) and magnetization decay of the iron core material (such as loose iron core laminations, surface corrosion leading to abnormal magnetic hysteresis characteristics). The related logic is that the jamming of the reset parts directly causes a sharp increase in the second mechanical reset damping coefficient, poor contact of the current discharge circuit causes the coil current discharge speed to slow down, and the excessive residual magnetic flux of the iron core will generate a continuous residual electromagnetic attraction to hinder the reset action. The abnormal coupling of the three types of characteristics of mechanical, circuit and magnetic circuit causes the mechanical action to be blocked, the current discharge to be slow and the residual magnetic interference to be superimposed during the reset stage, which ultimately leads to a significant increase in the time consumption of the third specified time period.

[0155] The ninth comparison result F+, the tenth comparison result G+, and the eleventh comparison result H- (second mechanical reset damping coefficient exceeds the threshold + low current discharge rate of coil circuit + normal residual magnetic flux of iron core) are caused by the lubrication failure of the relay reset transmission mechanism (such as lack of oil in the reset shaft, hardening of grease) superimposed on the performance degradation of the current discharge element in the coil circuit (such as the drift of the current discharge resistor value, and the decrease in the reverse conduction performance of the diode). The related logic is that the lubrication failure of the reset transmission mechanism directly leads to the increase of the second mechanical reset damping coefficient. The performance degradation of the current discharge element makes the coil circuit unable to quickly discharge the residual current. However, the magnetic characteristics of the iron core are not abnormal, and the residual magnetic flux is kept within the qualified range. The abnormal coupling of mechanical and circuit characteristics leads to the mechanical action being stuck during the reset stage and the current discharge time being increased. The third specified time period is overdue.

[0156] The ninth comparison result F+, the tenth comparison result G-+, and the eleventh comparison result H (second mechanical reset damping coefficient exceeds threshold + coil circuit leakage rate is normal + iron core residual magnetic flux exceeds threshold) match the fault cause is an abnormal increase in the relay reset spring preload (such as spring fatigue hardening, excessive assembly preload) superimposed on the long-term magnetic saturation of the iron core (such as coil overcurrent causing deterioration of iron core magnetic characteristics, and the peeling off of the magnetic coating on the iron core surface); the associated logic is that the increase in the reset spring preload will directly increase the reset mechanical damping coefficient, the iron core magnetic saturation will cause the residual magnetic flux to exceed the standard, and the residual electromagnetic attraction will further hinder the reset action, while the coil circuit leakage element and circuit are normal, the leakage rate is maintained as qualified, the mechanical and magnetic circuit characteristics are abnormally coupled, resulting in double interference from mechanical resistance and residual magnetic attraction during the reset stage, and the time consumption of the third specified period is increased.

[0157] The ninth comparison result F+, the tenth comparison result G-+, and the eleventh comparison result H- (second mechanical reset damping coefficient exceeds threshold + coil circuit leakage rate is normal + iron core residual magnetic flux is normal) match fault is caused by assembly deviation of relay reset moving parts (such as uneven armature and iron core reset gap, slight contact reset positioning deviation) superimposed on resonance of reset parts under vibration conditions (such as vibration frequency matching the natural frequency of reset mechanism); the related logic is that the assembly deviation of reset parts is the core reason for the second mechanical reset damping coefficient exceeding threshold. Vibration resonance will further interfere with the normal movement of reset mechanical parts. The coil circuit leakage rate is normal and the iron core residual magnetic flux is not abnormal. Excluding circuit and magnetic circuit dimension problems, it belongs to pure mechanical characteristic abnormality superimposed on the interference of the working condition, which leads to the increase in the reset action time of the third specified period.

[0158] The ninth comparison result F-+, the tenth comparison result G+, and the eleventh comparison result H (the second mechanical reset damping coefficient is normal + the coil circuit leakage rate is low + the iron core residual magnetic flux exceeds the threshold) are caused by the coil circuit leakage circuit being open or partially open (such as broken leakage circuit wires, poor contact due to oxidation of terminals) and the iron core magnetic circuit closure gap being enlarged (such as aging of the sealing gasket between the iron core and the armature, dust accumulation in the gap leading to increased magnetic leakage). The associated logic is that the abnormal leakage circuit directly causes a decrease in the coil current discharge rate, the enlarged iron core magnetic circuit gap causes abnormal hysteresis characteristics, and the excessive residual magnetic flux generates residual attraction. However, the reset mechanical components have no problems such as jamming or abnormal preload. The second mechanical reset damping coefficient remains normal. It belongs to the abnormal coupling of circuit and magnetic circuit characteristics, which leads to slow current discharge and residual magnetism hindering the action during the reset stage. The third specified time period is overdue.

[0159] The ninth comparison result F-+, the tenth comparison result G+, and the eleventh comparison result H- (the second mechanical reset damping coefficient is normal + the coil circuit leakage rate is low + the iron core residual magnetic flux is normal) are due to the performance degradation of the coil circuit filter capacitor (such as a decrease in capacitance or an increase in leakage current) or the parameter deviation of the current limiting component in the leakage circuit (such as an abnormal increase in the resistance of the current limiting resistor). The associated logic is that the operation state of the relay reset mechanical component is normal, the second mechanical reset damping coefficient is qualified, the iron core magnetic characteristics are normal and the residual magnetic flux is within the threshold. The only problem is that the performance of the electronic components in the leakage circuit is deteriorated, which causes the residual current in the coil to be unable to be discharged quickly. During the reset phase, the current is delayed in returning to zero, resulting in a delayed start-up of the action. This is due to the increased time consumption of the third specified period caused by the abnormality of the pure circuit characteristics.

[0160] The ninth comparison result F-+ tenth comparison result G-+ eleventh comparison result H (second mechanical reset damping coefficient normal + coil circuit leakage rate normal + iron core residual magnetic flux exceeds threshold) indicates that the matching fault is caused by the iron core working under high temperature conditions for a long time, resulting in the decay of magnetic permeability (such as high temperature aging of iron core material, damage to the insulation layer between laminations), or the iron core magnetic fatigue caused by frequent switching of relays (such as long-term high-frequency operation leading to increased iron core hysteresis loss); the associated logic is that the reset mechanical components operate smoothly, the second mechanical reset damping coefficient is normal, and the coil circuit leakage rate meets the qualified standard. Only the residual magnetic flux exceeds the standard due to the deterioration of the iron core's own magnetic characteristics. The residual electromagnetic attraction will continue to hinder the reset action, so that the reset stage needs to overcome additional attraction to complete the action. This belongs to the third specified time period timeout caused by the abnormality of pure magnetic circuit characteristics.

[0161] The ninth comparison result F-+, the tenth comparison result G-+, and the eleventh comparison result H- (the second mechanical reset damping coefficient is normal + the coil circuit leakage rate is normal + the iron core residual magnetic flux is normal) indicate that the matching fault is caused by the mismatch between the vibration excitation parameters and the relay reset operating frequency, or by slight assembly deviations in the relay reset structure not covered by the simulation model (such as slight deviation in the installation position of the reset spring or uneven gaps in the armature reset limit block). The associated logic is that the three core parameters of the relay—mechanical, circuit, and magnetic circuit—are all within the qualified range, eliminating direct abnormalities in each dimension. Rather, it is a problem of parameter adaptability under vibration conditions or slight assembly deviations in the reset structure, which indirectly interferes with the normal working sequence of the relay reset stage, causing the time consumed in the third specified time period to exceed the threshold. This is a timeout problem caused by operating conditions and assembly auxiliary factors.

[0162] In this embodiment, when the first response time is less than or equal to the response time threshold, the remaining life of the electromagnetic relay under test is obtained based on the simulation results. This is because when the first response time is less than or equal to the response time threshold, it indicates that the overall action sequence of the electromagnetic relay under test meets the qualified standard under the actual test conditions simulating actual vibration. The three core working links of electromagnetic excitation, steady-state holding, and reset shutdown have no obvious faults and are in normal working condition. At this time, its remaining life is obtained based on the simulation results.

[0163] Therefore, in at least one embodiment, such as Figure 3 As shown, based on the simulation results, the remaining life of the electromagnetic relay under test can be obtained through the following steps:

[0164] A1: Based on the mechanical and thermal effects during the first specified time period, a first mechanical fatigue damage is obtained; based on the mechanical and thermal effects during the second specified time period, a second mechanical fatigue damage is obtained; and based on the mechanical and thermal effects during the third specified time period, a third mechanical fatigue damage is obtained. The first, second, and third specified time periods constitute the total simulation time period. The first, second, and third specified time periods are continuous. The first specified time period characterizes a time period where the growth rate of the coil current at the simulation end is greater than 0; the second specified time period characterizes a time period where the growth rate of the coil current at the simulation end is 0; and the third specified time period characterizes a time period where the growth rate of the coil current at the simulation end is less than 0.

[0165] A2: Based on the mechanical effect results, thermal effect results, and electrical effect results of the first specified time period, obtain the first thermal aging damage and the first electrical damage; based on the mechanical effect results, thermal effect results, and electrical effect results of the second specified time period, obtain the second thermal aging damage and the second electrical damage; and based on the mechanical effect results, thermal effect results, and electrical effect results of the third specified time period, obtain the third thermal aging damage and the third electrical damage.

[0166] A3: Based on the first weight corresponding to the first specified time period, and the first thermal aging damage, the first electrical damage and the first mechanical fatigue damage, determine the first part of the damage; based on the second weight corresponding to the second specified time period, and the second thermal aging damage, the second electrical damage and the second mechanical fatigue damage, determine the second part of the damage; and based on the third weight corresponding to the third specified time period, and the third thermal aging damage, the third electrical damage and the third mechanical fatigue damage, determine the third part of the damage.

[0167] A4: Determine the total damage for the total time period based on the first part of the damage, the second part of the damage, and the third part of the damage;

[0168] A5: Based on the mechanical damping coefficient increase rate, temperature rise decay rate, and temperature rise decay rate, aging characteristic values ​​are obtained, which are used to characterize the aging degree of the electromagnetic relay under test.

[0169] A6: Determine the dynamic threshold based on the aging characteristic values ​​and the preset aging threshold;

[0170] A7: When the total damage is less than the dynamic threshold, the remaining life of the electromagnetic relay under test is determined based on the dynamic threshold and the simulation results.

[0171] In A1, the mechanical effect results applied to the calculation of the first mechanical fatigue damage include the mechanical damping coefficient over a first specified time period. Impact value of armature movement (These are all time-period characteristic peak values, reflecting the mechanical resistance and impact intensity of armature engagement during the excitation phase, which are the core causes of fatigue damage); the thermal effect results include the coil temperature at the end of the first specified time period.

[0172]

[0173]

[0174] This indicates the relay's normal temperature reference value, typically 25℃.

[0175] This indicates the first type of mechanical fatigue damage;

[0176] This represents the first thermal stress correction factor.

[0177] The mechanical effect results applied to the second mechanical fatigue damage include the mechanical damping coefficient over a second specified time period. Contact stress at contact points The thermal effect results include the coil temperature rise setpoint for the second specified time period. Duration of temperature rise (Unit: seconds).

[0178]

[0179]

[0180] This indicates the second type of mechanical fatigue damage.

[0181] This represents the second thermal stress correction factor.

[0182] The mechanical effect results applied to the third mechanical fatigue damage include the mechanical recovery damping coefficient over a specified third time period. , Reset spring deformation Thermal stress results include residual temperature rise. .

[0183]

[0184] This indicates mechanical fatigue damage.

[0185]

[0186] Indicates the third thermal stress correction factor

[0187] In A2, the mechanical effect results refer to the core quantitative data of the mechanical dimension of the relay generated by electromagnetic drive, mechanical motion, and vibration coupling during the corresponding time period, including mechanical damping coefficient, contact stress of moving parts, spring deformation, contact bounce impact value, etc., reflecting the actual effects of mechanical actions such as force, deformation, and impact on the components; the thermal effect results refer to the core quantitative data of the thermal dimension of the relay generated by coil current flow and circuit loss during the corresponding time period, including coil temperature rise, local hot spot temperature, duration of temperature rise, thermal stress value, etc., reflecting the actual thermal effects of heat energy accumulation and heat conduction; the electrical effect results refer to the core quantitative data of the electrical dimension of the relay generated by coil current flow, contact conductivity, and circuit leakage during the corresponding time period, including coil current, contact voltage drop, coil conduction resistance, circuit leakage rate, etc., reflecting the actual electrical effects of electrical conduction, electrical loss, and electromagnetic conversion.

[0188] In this embodiment, the mechanical effect results for the first specified time period are extracted as the mechanical damping coefficient and the armature motion impact value; the thermal effect results are the coil temperature rise rate and the coil temperature at the end of the time period; and the electrical effect results are the coil current growth rate and the coil equivalent resistance. For the second specified time period, the mechanical effect results are extracted as the average mechanical damping coefficient and the contact stress at the contact points; the thermal effect results are the coil temperature rise setpoint and the duration of the temperature rise; and the electrical effect results are the coil steady-state current and the coil conduction resistance. For the third specified time period, the mechanical effect results are extracted as the second mechanical reset damping coefficient and the reset spring deformation; the thermal effect results are the coil cooling rate and the residual temperature rise; and the electrical effect results are the coil circuit leakage rate and the core residual magnetic induction current. All parameters are the steady-state average or time period characteristic values ​​within the corresponding time period, directly extracted from the corrected multi-field coupling simulation results.

[0189] The core of thermal aging damage is calculated based on thermal effect results, superimposed with mechanical effect correction factors. (Fitting the mechanical effect results using an empirical formula) The worse the mechanical properties, the better the mechanical properties, ∈[0.9,1.1]. The larger the value, the higher the damage correction (the unified formula for calculating thermal aging damage across different time periods is as follows:)

[0190] n=1,2,3

[0191] Thermal aging damage in the nth time period ( This indicates the first stage of thermal aging damage. This indicates the second thermal aging damage. (Indicates third thermal aging damage)

[0192] This is the mechanical effect correction coefficient for the nth time period, obtained by fitting the mechanical effect results for the corresponding time period.

[0193] The thermal response damage baseline function for the nth time period is calculated from the thermal effect parameters for the corresponding time period.

[0194] In the specific calculation, the thermal effect results for each time period are substituted into... The baseline value of thermal effect damage is obtained, and then the mechanical effect results during the same period are fitted using a preset empirical formula. .

[0195] In this embodiment, It is calculated based on the core parameters of the thermal effect in the nth time period, using a preset thermal aging damage baseline function. The function form is derived from the thermal aging test data of the relay material. Taking the second specified time period as an example: the thermal effect result is the coil temperature rise setpoint. Duration of temperature rise

[0196] The basic function is:

[0197] Calculation logic: Substituting the coil temperature rise setpoint and duration for the specified time period into the function, the baseline value of thermal effect damage is directly obtained. The function for different time periods will be adapted to the corresponding thermal effect parameters. For example, the first time period focuses on the temperature rise rate, while the third time period focuses on the residual temperature rise, and the coefficients and variables in the formula will be adjusted accordingly.

[0198] It is the first The correction coefficients obtained by substituting the mechanical effect results of the time period into the empirical fitting formula have a value range of [0.9, 1.1]. The worse the mechanical characteristics, the closer the coefficient is to 1.1, and the greater the correction magnitude for the damage. Taking the second specified time period as an example: the mechanical effect result is the mean mechanical damping coefficient. Contact stress at contact points The fitting formula is:

[0199]

[0200] Calculation logic: Substituting the mechanical damping coefficient and contact stress for the given time period into the formula yields the mechanical effect correction coefficient for that time period. The fitting formulas for different time periods will be adapted to the corresponding mechanical effect parameters. For example, the first time period uses the mechanical damping coefficient and armature impact value, while the third time period uses the reset damping coefficient and spring deformation. The formula coefficients will be adjusted based on measured data.

[0201] The calculation method for electrical damage is as follows:

[0202] n=1,2,3

[0203] Electrical damage in the nth time period;

[0204] The electrical effect damage baseline function for the nth time period is calculated from the core parameters of the electrical effect for the corresponding time period.

[0205] In this example,

[0206]

[0207]

[0208] This represents the steady-state current of the coil during the second specified time period. This indicates the coil on-resistance during the second specified time period.

[0209] This indicates the rate of increase of the coil current during the first specified time period. This indicates the equivalent resistance of the coil during the first specified time period.

[0210] This indicates the leakage rate of the coil circuit during the third specified time period. This represents the residual magnetic induced current in the iron core during the third specified time period.

[0211] In A3, the weight values ​​are not fixed, but are determined based on the relay design principles, actual operating data, and aging test results. The weight values ​​are greater for periods that have a greater impact on the remaining lifespan and have a higher proportion of duration.

[0212] In terms of duration, longer periods have higher weights. For example, the second designated period usually accounts for more than 90% of a single cycle, so it has the highest weight. In terms of damage intensity, even shorter periods with severe effects will receive higher weights. For example, although the first designated period only accounts for 5%, its high damage intensity due to rapid current rise and mechanical impact will result in a higher weight than the third designated period, which has the same duration but milder damage. At the same time, the weights will be dynamically adjusted according to the actual operating conditions. In frequent switching scenarios, the weights of the first and third designated periods will be increased, while in long-term steady-state operation scenarios, the weight of the second designated period will be further increased.

[0213] In this embodiment, aging characteristic values ​​are calculated to characterize the overall aging degree of the electromagnetic relay under test. The core parameters involved in the calculation are the mechanical damping coefficient increase rate and the temperature rise decay rate. Combined with conventional adaptation logic, the on-resistance increase rate is supplemented. All three types of parameters are extracted from the corrected multi-field coupling simulation results and are comprehensive quantitative values ​​for the entire working cycle, directly reflecting the aging and decay trend of the core performance.

[0214] The mechanical damping coefficient growth rate is the percentage increase of the current mechanical damping coefficient relative to its brand-new state. A larger growth rate indicates more severe aging of the mechanical components. The temperature rise decay rate is the rate at which the coil temperature rise decreases. A smaller rate indicates more severe aging of the heat dissipation performance and insulation layer. The conduction resistance growth rate is the percentage increase of the current conduction resistance relative to its brand-new state. A larger growth rate indicates more severe aging of the electrical components.

[0215] Before calculating the aging characteristic values, the three types of parameters need to be quantified. Since the units of the three are different, they need to be normalized to dimensionless values ​​from 0 to 1. The normalization is based on the new state value and the ultimate aging value of each parameter (calibrated by the relay aging test, such as the mechanical damping coefficient growth rate of 0 when it is new and 0.8 when it is ultimate).

[0216] The mechanical damping coefficient growth rate and the on-resistance growth rate are normalized in a conventional manner; the closer the value is to 1, the more severe the aging. The temperature rise decay rate, being the least severe, is normalized in reverse to ensure a positive correlation between the normalized value and the degree of aging. After normalization, the aging characteristic value is calculated using weighted averages. The weights are set based on the influence of the three parameters on aging. The industry-standard weights are 0.2 for the mechanical damping coefficient growth rate, 0.4 for the temperature rise decay rate, and 0.4 for the on-resistance growth rate. These weights can be fine-tuned according to the usage scenario (e.g., increasing the weight of mechanical parameters in scenarios with frequent mechanical actions). The final aging characteristic value ranges from 0 to 1; the closer the value is to 1, the more severe the aging of the relay; the closer it is to 0, the closer it is to a brand-new state.

[0217] Next, the dynamic threshold is determined based on the aging characteristic values ​​and the preset aging threshold. The preset aging threshold is a fixed reference value for the relay to reach its aging limit, calibrated by the manufacturer through aging tests, and is generally set to 0.8. When this value is reached, the relay performance deteriorates significantly and approaches failure. At the same time, the basic total damage threshold needs to be determined, which is the maximum total damage value that a brand-new relay can withstand, generally set to 0.9, representing the relay's strongest damage tolerance in its brand-new state. The dynamic threshold is the total damage threshold adapted to the current aging characteristic values. The core logic is that the higher the degree of aging, the smaller the remaining total damage that the relay can withstand, and the lower the dynamic threshold; the lower the degree of aging, the higher the dynamic threshold, avoiding the drawback of fixed thresholds being unable to adapt to different aging states. The dynamic threshold is calculated by linearly decreasing the base total damage threshold with the aging characteristic value. When the relay is in a brand new state (aging characteristic value is 0), the dynamic threshold is equal to the base total damage threshold. When the aging characteristic value reaches the preset aging threshold (0.8), the dynamic threshold drops to 0, indicating that the relay has no remaining damage tolerance and is close to failure. When the aging characteristic value is between 0 and 0.8, the dynamic threshold decreases linearly with the increase of the aging characteristic value, accurately matching the damage tolerance limit under the current aging state.

[0218] Finally, when the total damage is less than the dynamic threshold, the remaining lifespan is determined based on the dynamic threshold and simulation results. If the total damage is less than the dynamic threshold, it means the relay's current comprehensive damage has not exceeded its damage tolerance threshold under aging conditions, and it still possesses effective working performance. In this case, calculating the remaining lifespan has engineering significance. If the total damage is greater than or equal to the dynamic threshold, it is determined to be severely aged, with no remaining lifespan. The core of calculating the remaining lifespan is combining the "remaining tolerable damage amount" and the "damage accumulation rate per unit loss." The remaining tolerable damage amount is the difference between the dynamic threshold and the current total damage, reflecting the upper limit of damage the relay can still withstand. The damage accumulation rate per unit loss is extracted from the simulation results and is the comprehensive value of thermal, electrical, and mechanical losses throughout the relay's entire operating cycle. It characterizes the damage generated per unit time (or per on / off cycle) under actual operating conditions. The calculation requires combining the weights of three specified time periods to obtain the comprehensive accumulation rate for the entire cycle. At the same time, refer to the rated remaining life of the relay in its brand-new state (manufacturer's specification, such as rated operating hours, rated number of switching), divide the remaining tolerable damage by the damage accumulation rate per unit loss, and the remaining life can be obtained. The unit of remaining life can be switched according to the actual scenario (time or number of switching) to ensure that the result matches the actual service requirements of the relay.

[0219] In this embodiment, as Figure 4 As shown, A7 may specifically include the following steps:

[0220] A71: The damage rate per unit working cycle is calculated by combining the actual operating condition coupling correction coefficient of the electromagnetic relay under test, wherein the actual operating condition coupling correction coefficient is determined based on simulation results.

[0221] A72: Based on the dynamic threshold, the cumulative damage of the electromagnetic relay under test that has been in service, and the damage rate per unit working cycle, the number of remaining working cycles is calculated.

[0222] A73: Based on the pre-set daily average number of working cycles of the electromagnetic relay under test, the remaining number of working cycles is converted into the actual remaining lifespan.

[0223] In step A71, the damage rate per unit working cycle of the electromagnetic relay under test is first calculated by combining the actual operating condition coupling correction coefficient. This rate represents the total aging damage generated when the relay completes one full working cycle. The actual operating condition coupling correction coefficient is determined by simulation results and is quantitatively adapted to the vibration, temperature, load, and other operating conditions of the relay in actual service to match the actual working conditions on site. First, the basic unit working cycle damage rate of the relay (the theoretical damage rate without operating condition coupling) is obtained through simulation results. Then, this basic rate is multiplied by the actual operating condition coupling correction coefficient to finally obtain the actual unit working cycle damage rate that reflects the real operating conditions on site. A coefficient greater than 1 indicates that the actual operating conditions will aggravate the damage, while a coefficient less than 1 indicates that the actual operating conditions have a mitigating effect on the damage, ensuring that the calculated damage rate is consistent with the actual operating state of the relay.

[0224] In step A72, the remaining number of working cycles is calculated based on the dynamic threshold, the cumulative damage of the electromagnetic relay currently in service, and the damage rate per unit working cycle obtained in step A71. First, the cumulative damage of the relay currently in service is subtracted from the dynamic threshold to obtain the remaining accumulative damage that the relay can withstand in its current aging state. This value represents the upper limit of damage that the relay can continue to withstand from its current state to the damage threshold. Then, this remaining accumulative damage is divided by the damage rate per unit working cycle. The result is the remaining number of working cycles of the electromagnetic relay under test. This number reflects the total number of complete working cycles that the relay can still complete normally under actual operating conditions.

[0225] In step A73, the remaining number of working cycles calculated in step A72 is converted into the actual remaining lifespan based on the pre-set average daily working cycle count of the electromagnetic relay under test. The average daily working cycle count is pre-statistically set based on the actual usage scenarios of the relay, representing the average number of complete working cycles completed in a day under normal service conditions. Dividing the remaining number of working cycles by the average daily working cycle count yields the actual remaining lifespan in units of time, usually in days, but can be further converted to months, years, etc., depending on actual needs. The final result directly reflects the remaining normal service time of the relay under actual operating conditions.

[0226] In this embodiment, the processing module can be an integrated circuit chip with signal processing capabilities. The processing module can be a general-purpose processor. For example, the processor can be a Central Processing Unit (CPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application.

[0227] The storage module can be, but is not limited to, random access memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, etc.

[0228] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the electronic device described above can be referred to the corresponding steps in the aforementioned method, and will not be elaborated further here.

[0229] This application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the methods described in the above embodiments.

[0230] Based on the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by hardware or by using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This software product can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, mobile hard drive, etc.) and includes several instructions to cause a computer device (such as a personal computer, electronic device, or network device, etc.) to execute the methods described in the various implementation scenarios of this application.

[0231] In the embodiments provided in this application, it should be understood that the disclosed methods can also be implemented in other ways. The method embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, program segment, or part of code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0232] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An evaluation method applied to an electromagnetic relay, characterized by, The method includes: The test terminal obtains the first response time and test parameters obtained from testing the electromagnetic relay under test, and the second response time obtained based on the simulation terminal corresponding to the test terminal. Calculate the difference between the first response time and the second response time; When the difference is greater than the difference threshold, the simulation parameters of the simulation terminal are corrected according to the test parameters until the difference based on the corrected simulation parameters is less than or equal to the difference threshold. Obtain the simulation results output by the simulation terminal; By comparing the first response time with the response time threshold, if the first response time is greater than the response time threshold, the cause of the fault that the first response time is greater than the response time threshold is obtained based on the simulation results; if the first response time is less than or equal to the response time threshold, the remaining life of the electromagnetic relay under test is obtained based on the simulation results. The simulation results include mechanical effect results, thermal effect results, electrical effect results, mechanical damping coefficient increase rate, temperature rise decay rate, and temperature rise decay rate. The remaining life of the electromagnetic relay under test, based on the simulation results, is obtained, including: Based on the mechanical and thermal effects during a first specified time period, a first mechanical fatigue damage is obtained; based on the mechanical and thermal effects during a second specified time period, a second mechanical fatigue damage is obtained; and based on the mechanical and thermal effects during a third specified time period, a third mechanical fatigue damage is obtained. The first, second, and third specified time periods constitute a total simulation period. The first, second, and third specified time periods are continuous. The first specified time period characterizes a period when the growth rate of the coil current at the simulation terminal is greater than 0; the second specified time period characterizes a period when the growth rate of the coil current at the simulation terminal is 0; and the third specified time period characterizes a period when the growth rate of the coil current at the simulation terminal is less than 0. Based on the mechanical effect results, thermal effect results, and electrical effect results of the first specified time period, a first thermal aging damage and a first electrical damage are obtained; based on the mechanical effect results, thermal effect results, and electrical effect results of the second specified time period, a second thermal aging damage and a second electrical damage are obtained; and based on the mechanical effect results, thermal effect results, and electrical effect results of the third specified time period, a third thermal aging damage and a third electrical damage are obtained. Based on the first weight corresponding to the first specified time period, and the first thermal aging damage, the first electrical damage, and the first mechanical fatigue damage, a first part of the damage is determined; based on the second weight corresponding to the second specified time period, and the second thermal aging damage, the second electrical damage, and the second mechanical fatigue damage, a second part of the damage is determined; and based on the third weight corresponding to the third specified time period, and the third thermal aging damage, the third electrical damage, and the third mechanical fatigue damage, a third part of the damage is determined. Based on the first part of the damage, the second part of the damage, and the third part of the damage, determine the total damage for the total time period; Based on the mechanical damping coefficient increase rate, temperature rise decay rate, and temperature rise decay rate, aging characteristic values ​​are obtained, which are used to characterize the aging degree of the electromagnetic relay under test. Based on the aging characteristic values ​​and the preset aging threshold, a dynamic threshold is determined; When the total damage is less than the dynamic threshold, the remaining life of the electromagnetic relay under test is determined based on the dynamic threshold. Based on the simulation results, the fault causes characterizing the first response time being greater than the response time threshold are obtained, including: Based on the simulation results, a first specified time period, a second specified time period, and a third specified time period are obtained. The first specified time period, the second specified time period, and the third specified time period constitute the total simulation time period. The first specified time period, the second specified time period, and the third specified time period are continuous. The first specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is greater than 0. The second specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is 0. The third specified time period is used to characterize the time period in which the growth rate of the coil current at the simulation end is less than 0. The first comparison result is determined by comparing the first specified time period with the first time threshold; the second comparison result is determined by comparing the second specified time period with the second time threshold; and the third comparison result is determined by comparing the third specified time period with the third time threshold. The sum of the first time threshold, the second time threshold, and the third time threshold is the response time threshold. The cause of the fault is determined based on at least one of the first comparison result, the second comparison result, and the third comparison result.

2. The method according to claim 1, characterized in that, The test parameters include the steady-state current of the first coil, the contact voltage drop, and the working current of the contact circuit; The simulation parameters include the coil equivalent resistance and the contact resistance of the contacts; The step of correcting the simulation parameters of the simulation terminal based on the test parameters includes: Based on the steady-state current of the first coil, the steady-state current of the second coil at the simulation terminal, and the equivalent resistance of the coil before correction, the corrected equivalent resistance of the coil is obtained; The contact resistance is corrected based on the contact voltage drop and the operating current of the contact circuit to obtain the corrected contact resistance.

3. The method according to claim 1, characterized in that, Determining the remaining lifespan of the electromagnetic relay under test based on the dynamic threshold includes: Based on the dynamic threshold, the cumulative damage of the electromagnetic relay under test that has been in service, and the damage rate per unit working cycle, the remaining number of working cycles is calculated. The damage rate per unit working cycle is determined based on the actual operating condition coupling correction coefficient of the electromagnetic relay under test, which is determined based on simulation results. Based on the pre-set average daily working cycle count of the electromagnetic relay under test, the remaining working cycle count is converted into the remaining lifespan.

4. The method according to claim 1, characterized in that, Based on at least one of the first comparison result, the second comparison result, and the third comparison result, the cause of the fault is determined, including: When the first comparison result indicates that the first specified time period is greater than the first time threshold, based on the simulation result, the maximum coil current in the first specified time period and the rate of change of the pull-in force in the first specified time period are obtained; The fourth comparison result is determined by comparing the maximum coil current with the preset lower limit of the current qualification value, and the fifth comparison result is determined by comparing the rate of change of the attraction force with the preset lower limit of the rate of change value. Based on the fourth and fifth comparison results, and using a pre-established knowledge base, the cause of the fault is determined. The knowledge base includes the correspondence between the fourth and fifth comparison results and the cause of the fault.

5. The method according to claim 4, characterized in that, Based on at least one of the first comparison result, the second comparison result, and the third comparison result, the cause of the fault is determined, including: When the second comparison result indicates that the second specified time period is greater than the second time threshold, the first mechanical damping coefficient, the temperature rise value of the coil, and the coil conduction resistance are obtained based on the simulation result for the second specified time period. By comparing the first mechanical damping coefficient with the first coefficient threshold, a sixth comparison result is obtained; by comparing the temperature rise value with the temperature rise threshold, a seventh comparison result is obtained; and by comparing the coil conduction resistance with the resistance threshold, an eighth comparison result is obtained. Based on the sixth, seventh, and eighth comparison results, and according to a pre-established knowledge base, the cause of the fault is determined. The knowledge base includes the correspondence between the sixth, seventh, and eighth comparison results and the cause of the fault.

6. The method according to claim 4, characterized in that, Based on at least one of the first comparison result, the second comparison result, and the third comparison result, the cause of the fault is determined, including: When the third comparison result indicates that the third specified time period is greater than the third time threshold, then based on the simulation result, the second mechanical reset damping coefficient, coil circuit leakage rate and core residual flux within the third specified time period are obtained; By comparing the second mechanical reset damping coefficient with the second coefficient threshold, the ninth comparison result is obtained; by comparing the coil circuit discharge rate with the crab stick rate threshold, the tenth comparison result is obtained; and by comparing the iron core remanent flux with the remanent magnetization threshold, the eleventh comparison result is obtained. Based on the ninth, tenth, and eleventh comparison results, and using a pre-established knowledge base, the cause of the fault is determined. The knowledge base includes the correspondence between the ninth, tenth, and eleventh comparison results and the cause of the fault.

7. An electronic device, characterized in that, The electronic device includes a processor and a memory coupled together, the memory storing a computer program that, when executed by the processor, causes the electronic device to perform the method as described in any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 6.

Images