Method and system for predicting service life of power distribution connection point of ship coupled with condensation vibration

Abstract

The application discloses a kind of ship power distribution connection point life prediction method and system of fog condensation vibration coupling, it is related to ship electrical reliability and state monitoring technical field, including, the multiple-source operating data of target power distribution connection point is collected, data is preprocessed, equivalent contact resistance and equivalent temperature rise are calculated;Based on preprocessed data, calculate wetting effect factor, salt load factor and vibration fretting factor;Current load factor and temperature acceleration factor are defined, and the above-mentioned factor is combined to establish coupling damage evolution model, and the cumulative damage amount is obtained;State space model is defined, and the cumulative damage amount is state corrected according to equivalent contact resistance and equivalent temperature rise to calculate health index;According to health index, the cumulative damage amount after correction and future operating condition, remaining life is predicted and early warning information is output;The application can accurately reflect the degradation process under the coupling action of salt fog, condensation and vibration, improve the life prediction accuracy, meet the demand of ship predictive maintenance.

Description

Technical Field

[0001] This invention relates to the field of marine electrical reliability and condition monitoring technology, and in particular to a method and system for predicting the lifespan of marine power distribution connection points coupled with fog condensation vibration. Background Technology

[0002] Shipboard electrical distribution systems contain numerous conductive connection points, such as busbar connections in main and emergency distribution boards, circuit breaker input / output connections, cable terminal connections, and grounding busbar connections. These connections are exposed to high salt spray, high humidity, and continuous vibration environments, resulting in significant fluctuations in electrical and thermal loads. The connection interfaces are prone to degradation phenomena such as salt deposition, condensation, accelerated corrosion, fretting wear, decreased clamping force, and increased contact resistance. Ultimately, this leads to abnormal localized temperature rises, decreased power supply reliability, and even failure. Once contact deterioration occurs at these connection points, contact resistance increases, localized temperature rises rise, and consequently, conductor erosion, insulation aging, increased voltage drop, and protection malfunctions. In severe cases, it can even cause power outages, shutdowns, and electrical fires.

[0003] Analysis revealed that the typical failure process of ship electrical connection points is not a simple superposition of salt spray, damp heat, and vibration, but rather exhibits a distinct coupled chain characteristic: salt spray deposits on the connection point surface, forming a salt load; when the surface temperature of the connection point is lower than the ambient dew point temperature, condensation occurs on the surface; the condensation dissolves the deposited salt, forming a conductive electrolyte film; under vibration, the contact interface undergoes fretting, leading to periodic rupture of the corrosion film and oxide film; fresh metal is continuously exposed, and corrosion and wear mutually promote each other; contact resistance increases, and heat generation intensifies; the temperature rise further promotes stress relaxation, decreases clamping force, and damp heat effects; ultimately forming a positive feedback degradation process of "corrosion—wear—heat generation—loosening".

[0004] In existing technologies, condition assessment and lifespan prediction for power distribution connection points or electrical equipment generally employ manual inspection or threshold alarm schemes, single-factor environmental lifespan assessment schemes, single-parameter online monitoring schemes, and purely data-driven prediction schemes. Existing technologies have the following main shortcomings when conducting condition assessment and lifespan prediction for ship power distribution connection points: Single-factor analysis ignores coupling effects: Existing solutions mostly consider the effects of humidity, salt spray or vibration alone, failing to truly reflect the coupled degradation process of salt spray deposition, condensation triggering and vibration micro-motion in the ship environment, resulting in a large deviation between the evaluation results and the actual situation.

[0005] Inaccurate condensation detection: Ambient humidity is often used as a substitute for condensation status, which makes it impossible to accurately identify the timing of condensation and duration of wetting when the surface temperature of the connection point is lower than the dew point, and makes it difficult to assess its triggering effect on corrosion degradation.

[0006] Unquantified salt deposition: The lack of effective quantification of the actual salt deposition on the surface of the connection point makes it impossible to distinguish the differences in the intensity of salt spray under different ship types, compartments and ventilation conditions, resulting in a lack of specificity in the life model.

[0007] The characterization of vibration effects is coarse: degradation is evaluated based solely on vibration amplitude, failing to reveal the microscopic mechanisms such as fretting wear at the contact interface, corrosion film rupture, and clamping force attenuation caused by vibration.

[0008] Lack of remaining life prediction: Most technologies remain at the post-event stage of temperature rise or resistance over-limit alarms, and cannot provide health status trends and remaining life predictions, making it difficult to meet the needs of predictive maintenance and window-based maintenance for ships.

[0009] Lack of dynamic correction mechanism: Fixed models cannot be dynamically corrected by combining online operating state parameters such as contact resistance and temperature rise, resulting in insufficient adaptability and robustness of predictions under different operating conditions.

[0010] Therefore, there is an urgent need to propose a life prediction method for ship power distribution connection points to address the problems of low accuracy in life assessment, insufficient prediction lead time, and poor maintenance planning in the complex service environment of ships. Summary of the Invention

[0011] This invention provides a method and system for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling, in order to overcome the aforementioned technical problems.

[0012] To achieve the above objectives, the technical solution of the present invention is as follows: A method for predicting the lifespan of ship electrical connection points coupled with fog condensation vibration includes: S1: Collect multi-source operating data for the target power distribution connection point. The multi-source operating data includes ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point. S2: Preprocess the collected data, calculate the equivalent contact resistance based on the current and voltage drop, and calculate the equivalent temperature rise based on the working temperature of the connection point and the ambient temperature; S3: Calculate the wetting factor, salt load factor, and vibration micro-motion factor based on the preprocessed multi-source operating data; S4: Define the current load factor and the temperature acceleration factor, and establish a coupled damage evolution model based on the wetting effect factor, the salt load factor, the vibration fretting factor, the current load factor and the temperature acceleration factor to obtain the cumulative damage amount; the model formula corresponding to the coupled damage evolution model includes corrosion damage term, vibration fretting damage term and salt spray-condensation-vibration coupled enhanced damage term; S5: Define the state parameters in the state space model, use the state space model to correct the cumulative damage and state parameters according to the equivalent contact resistance and equivalent temperature rise, and calculate the health index according to the corrected state parameters; S6: Based on the health index, the corrected cumulative damage amount, and future operating conditions, predict the remaining lifespan of the power distribution connection point and output early warning information.

[0013] Furthermore, based on the preprocessed multi-source operational data, the wetting factor, salt load factor, and vibration fretting factor are calculated, including: S21. Calculate the dew point temperature based on the ambient temperature and the ambient relative humidity, and identify condensation events based on the difference between the surface temperature of the connection point and the dew point temperature, and then calculate the wetting factor. S22. Based on the salt deposition rate and surface salt load, calculate the cumulative salt load on the surface of the connection point, and then calculate the salt load factor; S23. Based on the vibration signal and clamping force, calculate the vibration fretting factor that characterizes the degree of fretting wear at the contact interface.

[0014] Furthermore, the dew point temperature is calculated based on the ambient temperature and relative humidity, and condensation events are identified based on the difference between the surface temperature at the connection point and the dew point temperature. This is followed by the calculation of the wetting factor, including: The dew point temperature is calculated based on the ambient temperature and relative humidity using the following formula:

[0015]

[0016] in, For the first Each sampling time, For the first Dew point temperature at each sampling time, and Let dew point be the empirical constant. As an intermediate variable, For the first The relative humidity of the environment at each sampling time For the first The ambient temperature at each sampling time; The calculation of continuous wetting duration includes: Define the condensation indicator variable, and its formula is:

[0017] Wherein, the condensation judgment margin is set as When satisfied When this occurs, a condensation event is determined to have taken place; The surface temperature of the connection point; For the first The surface temperature of the connection point at each sampling time. For the first Dew point temperature at each sampling time; Let the initial sampling time be The initial continuous wetting duration is For the first Each sampling time , The continuous wetting duration is calculated using a recursive method, and the formula is as follows:

[0018] in, , The time interval between adjacent sampling times; when At that time, if ,but ;like ,but ; The wetting factor is calculated based on the continuous wetting duration and the difference between surface temperature and dew point temperature. The formula is as follows:

[0019] in, For the first The wetting factor at each sampling time. The normalized constant for the duration of wetting is... and These are the weighting coefficients. Let be the temperature difference normalization constant. This refers to the surface temperature of the connection point.

[0020] Furthermore, based on the salt deposition rate and surface salt load, the cumulative salt load on the junction surface is calculated, and then the salt load factor is calculated, including: At the initial moment Cumulative salt load The initial salt load obtained from the test If the target connection point is in a clean initial state, then take At subsequent sampling times, the cumulative salt load on the surface of the connection point at the next time step is recursively calculated based on the cumulative salt load of the previous time step and the current salt deposition rate. The formula is as follows:

[0021] in, For the first Cumulative salt load at each sampling time, For the first Salt deposition rate at each sampling time, This is the salt load attenuation coefficient; The salt load factor is calculated based on the cumulative salt load, and the formula is as follows:

[0022] in, For the first Salt load factor at each sampling time, This is the salt load weighting coefficient. is the salt loading normalization constant.

[0023] Furthermore, based on the vibration signal and clamping force, a vibration fretting factor characterizing the degree of fretting wear at the contact interface is calculated, including: Frequency domain analysis of the vibration signal yields the vibration power spectral density. The equivalent vibration acceleration and equivalent vibration frequency can be calculated based on the vibration power spectral density using the following formula:

[0024]

[0025] in, For the first Vibration power spectral density at each sampling time, For the first The equivalent vibration acceleration at each sampling time, For the first The equivalent vibration frequency at each sampling time. and To analyze the upper and lower limits of the frequency band, For frequency With vibrational power spectral density The product of these is used to calculate the first frequency moment of the vibration power spectral density; The equivalent fretting displacement of the interface is calculated based on the equivalent vibration acceleration and equivalent vibration frequency, and the formula is as follows:

[0026] in, For the first The equivalent micro-displacement of the interface at each sampling time. For equivalent quality, The structural transfer factor is... For the first The clamping force at each sampling moment, The clamping force influence index; The vibration fretting factor is calculated based on the equivalent fretting displacement and equivalent vibration frequency of the interface. The formula is as follows:

[0027] in, For the first Vibration micro-motion factor at each sampling time, Let be the displacement normalization constant. The frequency normalization constant is and The model exponential parameter is the vibration micro-motion factor.

[0028] Furthermore, a current load factor and a temperature acceleration factor are defined, and a coupled damage evolution model is established based on the wetting factor, the salt load factor, the vibration fretting factor, the current load factor, and the temperature acceleration factor to obtain the cumulative damage amount, including: S41. Define the current load factor and temperature acceleration factor as follows: The current load factor is shown below.

[0029] in, The current acceleration coefficient, For the first Current at each sampling time, Reference current; The temperature acceleration factor is shown below.

[0030] in, The temperature acceleration coefficient, For the first The operating temperature of the connection point at each sampling time. For reference temperature; S42. Establish a coupled damage evolution model to obtain the cumulative damage amount. The formula is as follows:

[0031] in, For the first The cumulative damage at each sampling time point The corrosion damage coefficient is... The vibration fretting damage coefficient is... For coupling-enhanced damage coefficient, Corrosion damage item, For vibration-induced fretting damage, The damage term is enhanced by salt spray-condensation-vibration coupling. 、 、 、 、 、 For model exponent parameters, For current load factor, This is the temperature acceleration factor.

[0032] Furthermore, the equivalent contact resistance is calculated based on the current and the voltage drop, and the equivalent temperature rise is calculated based on the operating temperature of the connection point and the ambient temperature, including: The contact resistance is calculated based on the current and the voltage drop, using the following formula:

[0033] in, For the first Contact resistance at each sampling time, For the first Voltage drop across the connection point at each sampling time For the first Connection point current at each sampling time; Temperature compensation is applied to the contact resistance to obtain the temperature-compensated equivalent contact resistance, and its formula is as follows:

[0034] in, For the first Equivalent contact resistance after temperature compensation at each sampling time. For conductor temperature coefficient, For reference temperature, For the first Operating temperature of the connection point at each sampling time; The equivalent temperature rise is calculated based on the operating temperature of the connection point and the ambient temperature. The formula is as follows:

[0035] in, For the first The equivalent temperature rise at each sampling time, For the first The ambient temperature at each sampling time This is the reference current.

[0036] Furthermore, state parameters are defined in the state-space model. The state-space model is used to correct the cumulative damage and state parameters based on the equivalent contact resistance and equivalent temperature rise. A health index is then calculated based on the corrected state parameters, including: Define the state parameters in the state-space model, and use the state-space model to correct the cumulative damage and state parameters based on the equivalent contact resistance and equivalent temperature rise, as follows: The state vector in the state-space model is defined as follows:

[0037] in, , Indicates the first State parameters at each sampling time. For the first The cumulative salt load on the surface of the connection point at each sampling time. For the first The cumulative damage at each sampling time point For the first The clamping force at each sampling moment; The observation vector in the state-space model is defined as:

[0038] in, For the first The equivalent contact resistance at each sampling time. For the first The operating temperature of the connection point at each sampling time. For the first Equivalent temperature rise at each sampling time; The state equation and observation equation are constructed based on the state vector and observation vector, and their formulas are as follows:

[0039]

[0040] in, For the input working condition vector, For process noise, To observe noise; A filtering method is used to correct the cumulative damage and state parameters based on the state equation and observation equation. The health index is calculated based on the corrected state parameters, and the formula is as follows:

[0041] in, This is a term related to contact resistance degradation. For temperature rise degradation term, This is a degenerate term for clamping force. This is an intermittent abnormal item. , respectively, are the weights of the corresponding degradation items; the contact resistance degradation item, temperature rise degradation item, clamping force degradation item, and intermittent anomaly item are normalized degradation indices of contact resistance, equivalent temperature rise, clamping force, and number of intermittent contact anomalies relative to their respective failure thresholds. The formula for the contact resistance degradation term is as follows:

[0042] in, For the first The corrected equivalent contact resistance at each sampling time. The initial contact resistance, This is the preset contact resistance threshold. The formula for the temperature rise degradation term is as follows:

[0043] in, For the initial equivalent temperature rise, This is the preset failure temperature rise threshold; For the first The corrected equivalent temperature rise at each sampling time; The formula for the clamping force degradation term is as follows:

[0044] in, The initial clamping force, For the first The corrected clamping force at each sampling time. The preset failure clamping force threshold; The formula for intermittent anomalies is as follows:

[0045] in, This represents the number of intermittent contact anomalies detected within a unit time window. This is a preset threshold for the number of abnormal occurrences; This indicates that the calculation results will be restricted to... to between.

[0046] Furthermore, based on the health index, the corrected cumulative damage amount, and future operating conditions, the remaining lifespan of the power distribution connection point is predicted, including: Obtain future operating conditions, which refer to information that describes the expected current load, ambient temperature, relative humidity, salt deposition rate and vibration level of the power distribution connection point in the future time period, obtained by extrapolating from the historical operating condition database, the current voyage operation plan or recent operating condition trends. At the current moment, the corrected cumulative damage, corrected salt load, and corrected clamping force are used as the initial state. Combined with the current load, ambient temperature, relative humidity, salt deposition rate, and vibration level in future operating conditions, the cumulative damage and health index at each future moment are recursively calculated, and the remaining life is calculated when the end of life is reached. The moment when any one of the failure thresholds—contact resistance, equivalent temperature rise, clamping force, number of intermittent abnormalities, health index, or cumulative damage—is first met is taken as the end of the service life. The formula is as follows:

[0047] When any of the calculated contact resistance, equivalent temperature rise, clamping force, number of intermittent abnormalities, cumulative damage, or health index satisfies the life-end time formula, the time difference between the current moment and that life-end time is calculated, which is the remaining life, and the formula is as follows:

[0048] in, To predict the time when the end of life is reached.

[0049] Based on the same inventive concept, a system for predicting the lifespan of ship power distribution connection points in the context of fog condensation vibration coupling is also proposed, comprising: The data acquisition module is used to collect multi-source operating data for the target power distribution connection point. The multi-source operating data includes ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point. The data preprocessing module is used to preprocess the collected data, calculate the equivalent contact resistance based on the current and the voltage drop, and calculate the equivalent temperature rise based on the operating temperature of the connection point and the ambient temperature. The factor calculation module is used to calculate the wetting factor, salt load factor, and vibration micro-motion factor based on preprocessed multi-source operating data. The coupled damage modeling module defines a current load factor and a temperature acceleration factor. Based on the wetting factor, the salt load factor, the vibration fretting factor, the current load factor, and the temperature acceleration factor, a coupled damage evolution model is established to obtain the cumulative damage amount. The model formula corresponding to the coupled damage evolution model includes a corrosion damage term, a vibration fretting damage term, and a salt spray-condensation-vibration coupled enhanced damage term. The state correction module is used to correct the cumulative damage amount and predefined state parameters based on the equivalent contact resistance and equivalent temperature rise using a state space model, and to calculate the health index based on the corrected state parameters. The lifespan prediction and early warning module is used to predict the remaining lifespan of the power distribution connection point based on the health index, the corrected cumulative damage amount, and future operating conditions, and output early warning information.

[0050] Beneficial effects: This invention provides a method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling, which has the following advantages: 1. This invention is more consistent with the actual service mechanism of ship power distribution connection points: This invention takes into account the coupling effect of salt spray deposition, condensation triggering and vibration micro-motion, and can more realistically reflect the degradation process of power distribution connection points in the ship environment.

[0051] 2. The present invention provides more accurate condensation identification: The present invention identifies condensation events by comparing the dew point temperature with the surface temperature of the connection point, instead of simply using relative humidity to replace condensation conditions, and can more accurately reflect the corrosion initiation time.

[0052] 3. This invention can quantify the impact of salt load: This invention introduces cumulative salt load instead of just salt spray exposure time, which can distinguish the differences in salt deposition under different cabins, different navigation conditions, and different ventilation conditions.

[0053] 4. The vibration effect of this invention is closer to the connection failure mechanism: This invention does not only represent damage with vibration amplitude, but further constructs a vibration micro-motion factor to reflect the fretting wear and contact instability caused by vibration.

[0054] 5. This invention corrects the model's state by using online contact resistance and equivalent temperature rise, which can adapt to different ship types, different connection structures and different installation positions, thereby improving prediction accuracy.

[0055] 6. This invention can output remaining life and support predictive maintenance: This invention can provide remaining life and maintenance time windows, which makes it easier for ships to schedule maintenance between voyages and within planned maintenance windows.

[0056] 7. This invention can reduce false alarms and missed alarms: This invention incorporates parameters such as contact resistance, temperature rise, clamping force attenuation and abnormal contact events into the health assessment, which helps to improve the reliability of diagnosis.

[0057] 8. This invention is suitable for online application in ship power distribution systems: This invention is applicable to the condition monitoring and predictive maintenance of main switchboards, emergency switchboards, engine room switchboards, deck equipment switch boxes and similar marine environment electrical connection structures, and has good engineering promotion value. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 A flowchart of the life prediction method for ship power distribution connection points based on fog condensation vibration coupling provided by the present invention. Figure 2This is a schematic diagram of the salt spray-condensation-vibration coupling degradation mechanism of the present invention; Figure 3 This is a flowchart of the condensation identification and wetting factor calculation process of the present invention; Figure 4 This is a schematic diagram of the online monitoring and life prediction system of the present invention; Figure 5 This is a schematic diagram illustrating the output of the health index and remaining lifespan in this invention; Figure 6 This is a schematic diagram of sensor installation in an embodiment of the present invention; Figure 7 This is a schematic diagram of an accelerated testing platform for model parameter calibration and verification in an embodiment of the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] This embodiment provides a method for predicting the lifespan of ship power distribution connection points coupled by fog condensation and vibration, such as... Figure 1 As shown, it includes: S1: Collect multi-source operating data for the target power distribution connection point. The multi-source operating data includes ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point. S2: Preprocess the collected data, calculate the equivalent contact resistance based on the current and voltage drop, and calculate the equivalent temperature rise based on the working temperature of the connection point and the ambient temperature; S3: Calculate the wetting factor, salt load factor, and vibration micro-motion factor based on the preprocessed multi-source operating data; S4: Define the current load factor and the temperature acceleration factor, and establish a coupled damage evolution model based on the wetting effect factor, the salt load factor, the vibration fretting factor, the current load factor and the temperature acceleration factor to obtain the cumulative damage amount; the model formula corresponding to the coupled damage evolution model includes corrosion damage term, vibration fretting damage term and salt spray-condensation-vibration coupled enhanced damage term; S5: Define the state parameters in the state space model, use the state space model to correct the cumulative damage and state parameters according to the equivalent contact resistance and equivalent temperature rise, and calculate the health index according to the corrected state parameters; S6: Based on the health index, the corrected cumulative damage amount, and future operating conditions, predict the remaining lifespan of the power distribution connection point and output early warning information.

[0062] Specifically, such as Figure 2 As shown, the degradation of shipboard electrical connection points is the result of the coupled effects of three factors: salt spray, temperature and humidity fluctuations, and mechanical vibration. Salt spray ingress creates a salt load on the connection point surface, while temperature and humidity fluctuations cause surface condensation. Together, these factors lead to salt dissolution, conductive film formation, and the initiation of electrochemical corrosion. Continuous mechanical vibration causes micro-displacement of the contact interface. Combined with electrochemical corrosion, the corrosion film / oxide film repeatedly ruptures, exposing fresh metal as new grains, ultimately leading to continuous deterioration of the contact interface. This deterioration causes increased contact resistance, increased local temperature rise, and weakened clamping force / aggravated loosening, accelerating degradation until failure. Furthermore, the temperature rise and loosening form a positive feedback loop, further amplifying condensation sensitivity and micro-motion degradation. Therefore, this invention collects data on ambient temperature and humidity, surface temperature, salt deposition or surface salt load, vibration, current, and voltage drop. Based on dew point temperature and surface temperature, it identifies condensation events, calculates cumulative salt load and vibration fretting factor, and establishes a damage evolution model including corrosion damage, vibration fretting damage, and coupled-enhanced damage. It then uses online contact resistance and equivalent temperature rise for condition correction, outputting a health index, remaining lifespan, risk level, and maintenance warning information. This method is applicable to predictive maintenance of power distribution connection points such as ship busbar joints, cable terminals, and circuit breaker terminals.

[0063] In a specific embodiment, the method for collecting multi-source operating data for the target power distribution connection point, including ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point, is as follows: A monitoring unit is established for the target power distribution connection point to collect ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current and voltage drop across the connection point. When the temperature sensor is placed on the surface of the connection point, the working temperature of the connection point can be taken as the surface temperature of the connection point; when there is a temperature difference between the temperature measuring point and the contact interface, the working temperature of the connection point can be calculated from the surface temperature of the connection point through a temperature correction model. Voltage sampling terminals are set on both sides of the contact interface at the power distribution connection point, and the voltage drop at the connection point is obtained by the four-terminal method to reduce the influence of the conductor's resistance on the measurement results. The power distribution connection points include, but are not limited to, busbar splicing points, cable lug crimp terminals, circuit breaker inlet and outlet terminals, terminal blocks, and grounding connection points.

[0064] In a specific embodiment, the scheme for preprocessing the collected data, calculating the equivalent contact resistance based on the current and voltage drop, and calculating the equivalent temperature rise based on the operating temperature of the connection point and the ambient temperature is as follows: Perform time synchronization, filtering, and anomaly handling on the collected data; The equivalent contact resistance is calculated based on the current and the voltage drop, and the equivalent temperature rise is calculated based on the connection point temperature and the ambient temperature, as follows: The contact resistance is calculated based on the current and the voltage drop, using the following formula:

[0065] in, For the first Contact resistance at each sampling time, For the first Voltage drop across the connection point at each sampling time For the first The connection point current at each sampling time; when When the current is less than the preset threshold, no effective resistance calculation is performed to avoid low-load noise interference; Temperature compensation is applied to the contact resistance to obtain the temperature-compensated equivalent contact resistance, and its formula is as follows:

[0066] in, For the first Equivalent contact resistance after temperature compensation at each sampling time. For conductor temperature coefficient, For reference temperature, it is 20°C in this embodiment. For the first Operating temperature of the connection point at each sampling time; The equivalent temperature rise is calculated based on the operating temperature of the connection point and the ambient temperature. The formula is as follows:

[0067] in, For the first The equivalent temperature rise at each sampling time, For the first The ambient temperature at each sampling time For reference current, the rated current or typical operating current can be used.

[0068] In a specific embodiment, the scheme for calculating the wetting factor, salt load factor, and vibration fretting factor based on preprocessed multi-source operating data is as follows: S21. Calculate the dew point temperature based on the ambient temperature and relative humidity, identify condensation events based on the difference between the surface temperature at the connection point and the dew point temperature, and then calculate the wetting factor. The specific process is as follows: Figure 3 As shown, it includes: The dew point temperature is calculated based on the ambient temperature and relative humidity using the following formula:

[0069]

[0070] in, For the first Each sampling time, For the first Dew point temperature at each sampling time, and As empirical constants for dew point, in this embodiment, a = 17.27 and b = 237.7 are used. For dimensionless intermediate variables, For the first The relative humidity of the environment at each sampling time For the first The ambient temperature at each sampling time; The calculation of continuous wetting duration includes: Define the condensation indicator variable, and its formula is:

[0071] Wherein, the condensation judgment margin is set as In this embodiment, the temperature is set to 0℃~2℃, when the following conditions are met. When this occurs, a condensation event is determined to have taken place; For the first The surface temperature of the connection point at each sampling time. For the first Dew point temperature at each sampling time; If the condensation determination criteria are not met, it is determined that no condensation event has occurred at the current sampling time, the continuous wetting duration is set to zero or the current wetting event is terminated, and the wetting effect factor is set to the baseline value. The subsequent damage evolution model will continue to be calculated based on salt load, vibration, current and temperature data; Let the initial sampling time be The initial continuous wetting duration is For the first Each sampling time , The continuous wetting duration is calculated using a recursive method, and the formula is as follows:

[0072] in, , The time interval between adjacent sampling times; when At that time, if ,but ;like ,but ; The wetting factor is calculated based on the continuous wetting duration and the difference between surface temperature and dew point temperature. The formula is as follows:

[0073] in, For the first The wetting factor at each sampling time. The normalized constant for the duration of wetting is... and These are the weighting coefficients. Let be the temperature difference normalization constant. The surface temperature of the connection point; S22. The cumulative salt load is obtained by integrating the salt deposition rate over time, and a salt load decay term is introduced to characterize the effects of salt shedding, migration, or natural removal. Therefore, based on the salt deposition rate and surface salt load, the cumulative salt load on the junction surface is calculated, and then the salt load factor is calculated, including: At the initial moment Cumulative salt load The initial salt load obtained from the test If the target connection point is in a clean initial state, then take At subsequent sampling times, the cumulative salt load on the surface of the connection point at the next time step is recursively calculated based on the cumulative salt load of the previous time step and the current salt deposition rate. The formula is as follows:

[0074] in, For the first Cumulative salt load at each sampling time, For the first Salt deposition rate at each sampling time, This is the salt load attenuation coefficient; If the system is equipped with a surface salt load sensor, the measured surface salt load can also be directly used as the cumulative salt load input. The salt load factor is calculated based on the cumulative salt load, and the formula is as follows:

[0075] in, For the first Salt load factor at each sampling time, This is the salt load weighting coefficient. This is the salt loading normalization constant; S23. Based on the vibration signal and clamping force, calculate the vibration fretting factor characterizing the degree of fretting wear at the contact interface, including: Frequency domain analysis of the vibration signal yields the vibration power spectral density. The equivalent vibration acceleration and equivalent vibration frequency can be calculated based on the vibration power spectral density using the following formula:

[0076]

[0077] in, For the first Vibration power spectral density at each sampling time, For the first The equivalent vibration acceleration at each sampling time point; in this embodiment, the root mean square acceleration is analyzed within the frequency band. For the first The equivalent vibration frequency at each sampling time. and To analyze the upper and lower limits of the frequency band, For frequency With vibrational power spectral density The product of these is used to calculate the first frequency moment of the vibration power spectral density; The equivalent fretting displacement of the interface is calculated based on the equivalent vibration acceleration and equivalent vibration frequency, and the formula is as follows:

[0078] in, For the first The equivalent micro-displacement of the interface at each sampling time. For equivalent quality, The structural transfer factor is... For the first The clamping force at each sampling moment, The clamping force influence index; The vibration fretting factor is calculated based on the equivalent fretting displacement and equivalent vibration frequency of the interface. The formula is as follows:

[0079] in, For the first Vibration micro-motion factor at each sampling time, Let be the displacement normalization constant. The frequency normalization constant is and The model exponential parameter is the vibration micro-motion factor.

[0080] The clamping force can be a directly measured value; if it cannot be directly measured on site, it can also be estimated by parameters such as the short-time fluctuation standard deviation of contact resistance, vibration transmission characteristics, and equivalent temperature rise rate.

[0081] In a specific embodiment, a current load factor and a temperature acceleration factor are defined, and a coupled damage evolution model is established based on the wetting effect factor, the salt load factor, the vibration fretting factor, the current load factor, and the temperature acceleration factor to obtain the cumulative damage amount; the model formula corresponding to the coupled damage evolution model includes a corrosion damage term, a vibration fretting damage term, and a salt spray-condensation-vibration coupled enhanced damage term, and the following scheme is used: S41. Define the current load factor and temperature acceleration factor as follows: The current load factor is shown below.

[0082] in, The current acceleration coefficient, For the first Current at each sampling time, Reference current; The temperature acceleration factor is shown below.

[0083] in, The temperature acceleration coefficient, For the first The operating temperature of the connection point at each sampling time. For reference temperature; S42. Establish a coupled damage evolution model to obtain the cumulative damage amount. The formula is as follows:

[0084] in, For the first The cumulative damage at each sampling time point The corrosion damage coefficient is... The vibration fretting damage coefficient is... For coupling-enhanced damage coefficient, Corrosion damage item, For vibration-induced fretting damage, The damage term is enhanced by salt spray-condensation-vibration coupling. 、 、 、 、 、 For model exponent parameters, For current load factor, This is the temperature acceleration factor.

[0085] In a specific embodiment, the state parameters in the state-space model are defined, and the cumulative damage and state parameters are corrected using the state-space model based on the equivalent contact resistance and equivalent temperature rise. The health index is then calculated based on the corrected state parameters. Define the state parameters in the state-space model, and use the state-space model to correct the cumulative damage and state parameters based on the equivalent contact resistance and equivalent temperature rise, as follows: The state vector in the state-space model is defined as follows:

[0086] in, , Indicates the first State parameters at each sampling time. For the first The cumulative salt load on the surface of the connection point at each sampling time. For the first The cumulative damage at each sampling time point For the first The clamping force at each sampling moment; The observation vector in the state-space model is defined as:

[0087] in, For the first The equivalent contact resistance at each sampling time. For the first The operating temperature of the connection point at each sampling time. For the first Equivalent temperature rise at each sampling time; The state equation and observation equation are constructed based on the state vector and observation vector, and their formulas are as follows:

[0088]

[0089] in, For the input working condition vector, For process noise, To observe noise; The cumulative damage and state parameters are corrected by a filtering method based on the state equation and the observation equation. The state correction algorithm can be any one of extended Kalman filtering, unscented Kalman filtering and particle filtering, which are common techniques used by those skilled in the art, and therefore will not be described in detail. The health index is calculated based on the corrected state parameters, and the formula is as follows:

[0090] in, This is a term related to contact resistance degradation. For temperature rise degradation term, This is a degenerate term for clamping force. This is an intermittent abnormal item. , respectively, are the weights of the corresponding degradation items; the contact resistance degradation item, temperature rise degradation item, clamping force degradation item, and intermittent anomaly item are normalized degradation indices of contact resistance, equivalent temperature rise, clamping force, and number of intermittent contact anomalies relative to their respective failure thresholds. The formula for the contact resistance degradation term is as follows:

[0091] in, For the first The corrected equivalent contact resistance at each sampling time. The initial contact resistance, This is the preset contact resistance threshold. The formula for the temperature rise degradation term is as follows:

[0092] in, For the initial equivalent temperature rise, This is the preset failure temperature rise threshold; For the first The corrected equivalent temperature rise at each sampling time; The formula for the clamping force degradation term is as follows:

[0093] in, The initial clamping force, For the first The corrected clamping force at each sampling time. The preset failure clamping force threshold; The formula for intermittent anomalies is as follows:

[0094] in, This represents the number of intermittent contact anomalies detected within a unit time window. This is a preset threshold for the number of abnormal occurrences; This indicates that the calculation results will be restricted to... to between.

[0095] In a specific embodiment, the scheme for predicting the remaining lifespan of the power distribution connection point and outputting early warning information based on the health index, the corrected cumulative damage amount, and future operating conditions is as follows: Obtain future operating conditions, which refer to information that describes the expected current load, ambient temperature, relative humidity, salt deposition rate and vibration level of the power distribution connection point in the future time period, obtained by extrapolating from the historical operating condition database, the current voyage operation plan or recent operating condition trends. At the current moment, the corrected cumulative damage, corrected salt load, and corrected clamping force are used as the initial state. Combined with the current load, ambient temperature, relative humidity, salt deposition rate, and vibration level in future operating conditions, the cumulative damage and health index at each future moment are recursively calculated, and the remaining life is calculated when the end of life is reached. The moment when any one of the failure thresholds—contact resistance, equivalent temperature rise, clamping force, number of intermittent abnormalities, health index, or cumulative damage—is first met is taken as the end of the service life. The formula is as follows:

[0096] When any of the calculated contact resistance, equivalent temperature rise, clamping force, number of intermittent abnormalities, cumulative damage, or health index satisfies the life-end time formula, the time difference between the current moment and that life-end time is calculated, which is the remaining life, and the formula is as follows:

[0097] in, To predict the time when the end of life is reached; Specifically, in this embodiment, if The value range is 1.5 to 1.8 times the initial contact resistance. The value range is 25℃~35℃; The value range is 0.65 to 0.75 of the initial clamping force.

[0098] This embodiment also provides a ship power distribution connection point life prediction system based on fog condensation vibration coupling, such as... Figure 4 As shown, it includes: The data acquisition module is used to collect multi-source operating data for the target power distribution connection point. The multi-source operating data includes ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point. The data preprocessing module is used to preprocess the collected data, calculate the equivalent contact resistance based on the current and the voltage drop, and calculate the equivalent temperature rise based on the operating temperature of the connection point and the ambient temperature. The factor calculation module is used to calculate the wetting factor, salt load factor, and vibration micro-motion factor based on preprocessed multi-source operating data. The coupled damage modeling module defines a current load factor and a temperature acceleration factor. Based on the wetting factor, the salt load factor, the vibration fretting factor, the current load factor, and the temperature acceleration factor, a coupled damage evolution model is established to obtain the cumulative damage amount. The model formula corresponding to the coupled damage evolution model includes a corrosion damage term, a vibration fretting damage term, and a salt spray-condensation-vibration coupled enhanced damage term. The state correction module is used to correct the cumulative damage amount and predefined state parameters based on the equivalent contact resistance and equivalent temperature rise using a state space model, and to calculate the health index based on the corrected state parameters. The lifespan prediction and early warning module is used to predict the remaining lifespan of the power distribution connection point based on the health index, the corrected cumulative damage amount, and future operating conditions, and output early warning information. The final output includes: current health index, remaining life expectancy, risk level, maintenance warning information, suggested maintenance window, and optional dominant degradation factor identification results. The output results are as follows: Figure 5 As shown.

[0099] Example 1: Life Prediction of Busbar Connection Points in Ship Low-Voltage Switchgear 1. Monitoring objects A busbar and cable lug connection point in the low-voltage distribution cabinet of the ship's engine room was selected as the monitoring object. This connection point uses a tin-plated copper busbar, tin-plated copper cable terminals, and a bolt-tightening structure, with a rated operating current of 280A.

[0100] After the connection point is installed, its initial contact resistance is measured using the four-terminal method as follows:

[0101] The installation torque corresponds to the initial clamping force. .

[0102] 2. Sensor Arrangement like Figure 6 As shown, the following sensors are arranged near the power distribution connection points inside the power distribution cabinet: Ambient temperature and humidity sensor, surface temperature sensor, salt load sensor, triaxial vibration sensor, current sensor and voltage sampling terminal; Data collected by each sensor is sent to the data acquisition unit, processed by the edge processor, and the lifespan is predicted by calling the model parameter library. Finally, the results are output through the early warning display terminal.

[0103] 3. Sampling parameters The sampling period is set as follows: Ambient temperature and humidity, surface temperature, and operating temperature: collected every 10 seconds; Current and voltage drop: collected every 1 second; Vibration signal: Waveforms are collected every 10 minutes; Salt load: Updated every 5 minutes.

[0104] 4. Data preprocessing and state variable calculation When the operating current satisfies At that time, the measured contact resistance is calculated, and then temperature compensation is performed to obtain the equivalent contact resistance; Simultaneously, calculate the reference current. The equivalent temperature rise is below; 5. Condensation identification The dew point calculation formula is used to obtain Let the condensation judgment margin be... ; When satisfied Condensation is detected at this time, and the duration of continuous wetting begins to accumulate. .

[0105] 6. Salt Load Quantification Let the salt load normalization constant be... The salt load attenuation coefficient is Calculate the salt load and obtain the salt load factor; 7. Calculation of vibration micro-motion factor The vibration power spectrum in the 20Hz–300Hz frequency band was analyzed to obtain the equivalent vibration acceleration and equivalent frequency. , , , , , , ,calculate : 8. Coupled Damage Evolution Model Based on the prior accelerated test calibration, the model parameters can be taken as follows: 、 、 、 、 、 、 、 、 、 、

[0106] The cumulative damage is then updated as follows:

[0107] in:

[0108] 9. Online status correction Extended Kalman filtering is used to correct the state variables.

[0109] Each time a new batch of online monitoring data is acquired, that is, , and Recursive corrections are performed to improve adaptability to actual working conditions.

[0110] 10. Health Index and Failure Criteria The health index is calculated by weighting the following four factors: Increase in contact resistance; Equivalent temperature rise; Clamping force attenuation; Number of intermittent contact abnormalities.

[0111] Let the weights be: 、 、 、

[0112] Right now:

[0113] The failure endpoint criterion is set to satisfy any of the following conditions: ； ； ； 。

[0114] 11. Remaining lifespan output The system updates every 10 minutes. Current health index, remaining life expectancy, risk level, and recommended maintenance window.

[0115] when and At that time, a scheduled maintenance will be indicated; when or When this happens, prompt for priority processing.

[0116] Example 2: Online Application Example of Power Distribution Cabinets in Actual Ship Engine Rooms The method of this invention was deployed at a circuit breaker outgoing connection point in the power distribution cabinet of a ship's engine room. This location is close to the power equipment and is subject to continuous vibration, temperature and humidity fluctuations, and salt spray penetration.

[0117] After running continuously for 45 days, the system identified multiple valid condensation events and found that: The cumulative salt load gradually increases, the condensation and wetting time shows an upward trend, the vibration micro-motion factor increases significantly during high load periods, and the contact resistance shows an accelerated growth trend.

[0118] On day 38, the system predicted a remaining lifespan of approximately 295 hours for the connection point, with a health index of 0.88, and prompted maintenance to be scheduled. During the subsequent planned shutdown and maintenance, significant corrosion products were found at the connection point interface, bolt torque decreased upon retesting, and contact resistance increased significantly compared to the initial value. These results demonstrate that the risk trend predicted by the method of this invention is consistent with the actual degradation situation.

[0119] Example 3: Alternative Example When There is No Direct Clamping Force Sensor In some field situations, it is inconvenient to install direct clamping force sensors. In such cases, clamping force estimation methods can be used.

[0120] Let the clamping force estimation function be:

[0121] in, This represents the standard deviation of short-time fluctuations in contact resistance. It is a characteristic quantity of vibration transmission; This is the equivalent temperature rise.

[0122] By establishing an estimation function using calibration data of similar connection structures, vibration micro-motion factor calculation and life prediction can still be achieved without directly installing force sensors.

[0123] Example 4: System Example The system of this invention is installed in a power distribution cabinet and acquires multi-source information through environmental temperature and humidity sensors, surface temperature sensors, salt load sensors, triaxial vibration sensors, current sensors, and voltage sampling terminals. The data is uploaded to an edge processor via a data acquisition unit, which then calls the model parameter library to perform the following functions: Data preprocessing, dew point and condensation identification, salt load calculation, vibration micro-motion factor calculation, coupled damage update, condition correction, health index and remaining life calculation, risk level display and alarm output, and finally output maintenance suggestions on the early warning display terminal.

[0124] Example 5: Model Parameter Calibration Example like Figure 7 As shown, an accelerated testing platform consisting of a salt spray environment chamber, a temperature and humidity control unit, a vibration table, a current-carrying power supply, and a sample fixture was established.

[0125] Samples of electrical connection points with different materials, connection structures, and installation torques were mounted on sample holders and operated under set salt spray, condensation cycle, vibration, and flow conditions. The results were recorded. Contact resistance; Temperature rise; Vibration characteristics; Salt load; Failure time.

[0126] The corrosion damage coefficient, vibration fretting damage coefficient, coupling enhancement damage coefficient, and related index parameters are fitted using experimental results to provide a parameter basis for field applications.

[0127] Example 6: Parameter Calibration and Verification Process Example To illustrate the engineering implementation process of the method of the present invention, this embodiment provides a parameter calibration and verification process applicable to a life prediction model of ship power distribution connection points. It should be noted that the purpose of this embodiment is to illustrate how the present invention can be implemented and how to acquire parameters, run the model, and verify the results, and is not limited to a specific experimental result.

[0128] 1. Test subjects Several sets of power distribution connection point samples of the same specification were selected as the parameter calibration objects. The power distribution connection point samples can adopt a busbar and cable lug bolt connection structure, or a circuit breaker inlet / outlet connection structure, a terminal block connection structure, or a grounding connection structure. The sample material can be tin-plated copper, bare copper, coated copper alloy, aluminum, or a copper-aluminum transition connection structure.

[0129] The same or controllable installation torque was used for each sample during installation to ensure that the clamping conditions were comparable.

[0130] 2. Platform Structure like Figure 7 As shown, an accelerated testing platform for model parameter calibration and validation is established. The platform includes: The system includes: a salt spray environment chamber to provide a salt spray deposition environment; a temperature and humidity control unit to regulate the ambient temperature and relative humidity inside the chamber and create a condensation cycle; a vibration table to apply mechanical vibration loads; a current-carrying power supply to provide operating current to the sample; a sample clamp to fix the sample at the power connection point; an ambient temperature and humidity sensor; a surface temperature sensor; a salt load sensor; a triaxial vibration sensor; a current sensor; a voltage sampling terminal; and a data acquisition unit.

[0131] The voltage sampling terminals are preferably located on both sides of the contact interface at the power distribution connection point, and the voltage drop is collected using the four-terminal method to improve the accuracy of contact resistance measurement.

[0132] 3. Sampling parameter settings The sampling method for each parameter can be set as follows: 1) Ambient temperature and relative humidity: periodic sampling; 2) Surface temperature and connection point operating temperature: periodic sampling; 3) Current and voltage drop: High-frequency or near real-time sampling; 4) Vibration signal: Acquire the original vibration waveform according to the set time window and extract the frequency domain features; 5) Salt deposition rate and / or surface salt load: Updated according to the set cycle.

[0133] The sampling period can be set according to the system's computing power, storage capacity, equipment importance, and on-site deployment conditions.

[0134] 4. Parameter calibration process In this embodiment, the model parameter calibration process includes the following steps: Step V1: Basic Status Acquisition of Connection Points After the specimens are installed, the initial contact resistance, initial installation torque, initial clamping state, and initial temperature rise characteristics of each specimen are collected and recorded as the basis for subsequent model initialization.

[0135] Step V2: Apply salt spray, condensation, vibration, and flow coupling conditions. A salt spray deposition environment is applied in a salt spray environment chamber, and a condensation cycle is formed through a temperature and humidity control unit; at the same time, a mechanical vibration load is applied using a vibration table, and a current is provided by a current-carrying power supply, so that the sample operates under the combined effects of salt spray, condensation, vibration and electrothermal conditions.

[0136] Step V3: Collect multi-source data During the sample operation, parameters such as ambient temperature, relative humidity, surface temperature, connection point operating temperature, salt deposition rate and / or surface salt load, vibration signal, current and voltage drop were continuously collected.

[0137] Step V4: Construct intermediate state variables Based on the collected data, calculate the contact resistance, equivalent contact resistance after temperature compensation, equivalent temperature rise under reference current, dew point temperature, condensation state, continuous wetting duration, wetting effect factor, cumulative salt load, salt load factor, and vibration fretting factor.

[0138] Step V5: Fitting model parameters Based on the operating process data of the sample under coupled conditions, the parameters in the coupled damage model are fitted, including but not limited to: corrosion damage coefficient, vibration fretting damage coefficient, coupling enhancement damage coefficient, correlation index parameters, current load factor parameters, temperature acceleration factor parameters, and health index weight parameters.

[0139] The above parameters can be obtained through least squares fitting, recursive estimation, state-space identification, or other suitable engineering calibration methods.

[0140] Step V6: Configure State Correction Strategy After the model parameters are initially determined, a state correction mechanism based on online contact resistance and / or equivalent temperature rise is established.

[0141] Extended Kalman filtering, unscented Kalman filtering, or particle filtering can be used to dynamically correct state variables such as cumulative salt load, cumulative damage, and clamping force.

[0142] 5. Model Execution and Lifetime Prediction Process After parameter calibration is completed, the method of the present invention is deployed in the online monitoring system of actual ship power distribution connection points or test platforms.

[0143] When the system is running, according to Figure 1 The process shown is executed.

[0144] 6. Verification Method Description When further verification of the technical effects of the present invention is required, the following comparative verification methods can be used: 1) The method of the present invention is compared with the temperature rise threshold method only to compare the differences between the two in terms of early warning lead time, remaining lifetime output capability and alarm effectiveness; 2) The method of the present invention is compared with the salt spray + vibration model only to verify the impact of condensation identification and wetting factors on lifetime prediction; 3) The method of the present invention is compared with a model that does not perform online state correction to verify the effect of the online state correction mechanism on the model's adaptability and stability.

[0145] The above comparisons can be conducted under the same test samples, the same operating conditions, and the same failure criteria to evaluate the prediction accuracy, early warning capability, and engineering applicability of different methods.

[0146] 7. Example of Failure Criterion The following conditions shall be used as criteria for determining whether a connection point has reached the end of its lifespan: 1) The equivalent contact resistance after temperature compensation reaches a set multiple of the initial contact resistance; 2) The equivalent temperature rise under the reference current reaches the preset temperature rise threshold; 3) The clamping force drops to the set lower limit; 4) The number of intermittent abnormal contacts per unit time exceeds the preset threshold; 5) The health index reaches the preset failure threshold.

[0147] 8. Output Results The system's final output includes: current health index, remaining life expectancy, risk level, dominant deterioration factors, maintenance warning information, and suggested maintenance window.

[0148] This embodiment demonstrates that the present invention can not only achieve engineering deployment through a clear parameter calibration process and state correction process, but also provide a clear implementation path for subsequent verification based on test platform or actual ship operation data.

[0149] The present invention is not limited to the specific embodiments described above. Without departing from the spirit of the present invention, the following modifications can be made: The materials for power distribution connection points can be copper, aluminum, or copper-aluminum transition connection structures; Different types of salt load sensing methods can be used, including surface conductivity type, deposition sheet conversion type or ion measurement type; The vibration analysis frequency band can be adjusted according to the equipment location; The state correction algorithm can adopt different recursive estimation methods according to the computing power conditions; Future mission profiles can be obtained based on historical databases, voyage plans, or real-time trend forecasts; The output results can be further labeled with the dominant degradation mode, such as corrosion-dominated, vibration-dominated, or damp-heat-dominated.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting the lifespan of ship power distribution connection points coupled by fog condensation and vibration, characterized in that, include: S1: Collect multi-source operating data for the target power distribution connection point. The multi-source operating data includes ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point. S2: Preprocess the collected data, calculate the equivalent contact resistance based on the current and voltage drop, and calculate the equivalent temperature rise based on the working temperature of the connection point and the ambient temperature; S3: Calculate the wetting factor, salt load factor, and vibration micro-motion factor based on the preprocessed multi-source operating data; S4: Define the current load factor and the temperature acceleration factor, and establish a coupled damage evolution model based on the wetting effect factor, the salt load factor, the vibration fretting factor, the current load factor and the temperature acceleration factor to obtain the cumulative damage amount; the model formula corresponding to the coupled damage evolution model includes corrosion damage term, vibration fretting damage term and salt spray-condensation-vibration coupled enhanced damage term; S5: Define the state parameters in the state space model, use the state space model to correct the cumulative damage and state parameters according to the equivalent contact resistance and equivalent temperature rise, and calculate the health index according to the corrected state parameters; S6: Based on the health index, the corrected cumulative damage amount, and future operating conditions, predict the remaining lifespan of the power distribution connection point and output early warning information.

2. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 1, characterized in that, The wetting factor, salt load factor, and vibration fretting factor were calculated based on the preprocessed multi-source operational data, including: S21. Calculate the dew point temperature based on the ambient temperature and the ambient relative humidity, identify condensation events based on the difference between the surface temperature of the connection point and the dew point temperature, and then calculate the wetting factor. S22. Based on the salt deposition rate and surface salt load, calculate the cumulative salt load on the surface of the connection point, and then calculate the salt load factor; S23. Based on the vibration signal and clamping force, calculate the vibration fretting factor that characterizes the degree of fretting wear at the contact interface.

3. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 2, characterized in that, The dew point temperature is calculated based on the ambient temperature and relative humidity, and condensation events are identified based on the difference between the surface temperature at the connection point and the dew point temperature. The wetting factor is then calculated, including: The dew point temperature is calculated based on the ambient temperature and relative humidity using the following formula: in, For the first Each sampling time, For the first Dew point temperature at each sampling time, and Let dew point be the empirical constant. As an intermediate variable, For the first The relative humidity of the environment at each sampling time For the first The ambient temperature at each sampling time; The calculation of continuous wetting duration includes: Define the condensation indicator variable, and its formula is: Wherein, the condensation judgment margin is set as When satisfied When this occurs, a condensation event is determined to have taken place; For the first The surface temperature of the connection point at each sampling time. For the first Dew point temperature at each sampling time; Let the initial sampling time be The initial continuous wetting duration is For the first Each sampling time , The continuous wetting duration is calculated using a recursive method, and the formula is as follows: in, , The time interval between adjacent sampling times; when At that time, if ,but ;like ,but ; The wetting factor is calculated based on the duration of continuous wetting and the difference between surface temperature and dew point temperature. The formula is as follows: in, For the first The wetting factor at each sampling time. The normalized constant for the duration of wetting is... and These are the weighting coefficients. Let be the temperature difference normalization constant. This refers to the surface temperature of the connection point.

4. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 2, characterized in that, Based on the salt deposition rate and surface salt load, the cumulative salt load on the junction surface is calculated, and then the salt load factor is calculated, including: At the initial moment Cumulative salt load The initial salt load obtained from the test If the target connection point is in a clean initial state, then take In subsequent sampling times, the cumulative salt load on the surface of the connection point at the next time step is recursively calculated based on the cumulative salt load of the previous time step and the current salt deposition rate. The formula is as follows: in, For the first Cumulative salt load at each sampling time, For the first Salt deposition rate at each sampling time, This is the salt load attenuation coefficient; The salt load factor is calculated based on the cumulative salt load, and the formula is as follows: in, For the first Salt load factor at each sampling time. This is the salt load weighting coefficient. is the salt loading normalization constant.

5. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 2, characterized in that, Based on the vibration signal and clamping force, calculate the vibration fretting factor characterizing the degree of fretting wear at the contact interface, including: Frequency domain analysis of the vibration signal yields the vibration power spectral density. The equivalent vibration acceleration and equivalent vibration frequency can be calculated based on the vibration power spectral density using the following formula: in, For the first Vibration power spectral density at each sampling time, For the first The equivalent vibration acceleration at each sampling time, For the first The equivalent vibration frequency at each sampling time. and To analyze the upper and lower limits of the frequency band, For frequency With vibrational power spectral density The product of these is used to calculate the first frequency moment of the vibration power spectral density; The equivalent fretting displacement of the interface is calculated based on the equivalent vibration acceleration and equivalent vibration frequency, and the formula is as follows: in, For the first The equivalent micro-displacement of the interface at each sampling time. For equivalent quality, The structural transfer factor is... For the first The clamping force at each sampling moment, The clamping force influence index; The vibration fretting factor is calculated based on the equivalent fretting displacement and equivalent vibration frequency of the interface. The formula is as follows: in, For the first Vibration micro-motion factor at each sampling time, Let be the displacement normalization constant. The frequency normalization constant is and The model exponential parameter is the vibration micro-motion factor.

6. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 1, characterized in that, Define the current load factor and the temperature acceleration factor, and establish a coupled damage evolution model based on the wetting factor, the salt load factor, the vibration fretting factor, the current load factor, and the temperature acceleration factor to obtain the cumulative damage amount, including: S41. Define the current load factor and temperature acceleration factor as follows: The current load factor is shown below. in, The current acceleration coefficient, For the first Current at each sampling time, Reference current; The temperature acceleration factor is shown below. in, The acceleration coefficient is the temperature. For the first The operating temperature of the connection point at each sampling time. For reference temperature; S42. Establish a coupled damage evolution model to obtain the cumulative damage amount. The formula is as follows: in, For the first The cumulative damage at each sampling time point. The corrosion damage coefficient is... The vibration fretting damage coefficient is... For coupling-enhanced damage coefficient, Corrosion damage item, For vibration-induced fretting damage, The damage term is enhanced by salt spray-condensation-vibration coupling. 、 、 、 、 、 For model exponent parameters, For current load factor, This is the temperature acceleration factor.

7. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 1, characterized in that, The equivalent contact resistance is calculated based on the current and the voltage drop, and the equivalent temperature rise is calculated based on the operating temperature of the connection point and the ambient temperature, including: The contact resistance is calculated based on the current and the voltage drop, using the following formula: in, For the first Contact resistance at each sampling time, For the first Voltage drop across the connection point at each sampling time For the first Connection point current at each sampling time; Temperature compensation is applied to the contact resistance to obtain the temperature-compensated equivalent contact resistance, and its formula is as follows: in, For the first Equivalent contact resistance after temperature compensation at each sampling time. For conductor temperature coefficient, For reference temperature, For the first Operating temperature of the connection point at each sampling time; The equivalent temperature rise is calculated based on the operating temperature of the connection point and the ambient temperature. The formula is as follows: in, For the first The equivalent temperature rise at each sampling time, For the first The ambient temperature at each sampling time This is the reference current.

8. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 7, characterized in that, Define state parameters in the state-space model, and use the state-space model to correct the cumulative damage and state parameters based on the equivalent contact resistance and equivalent temperature rise. Then, calculate the health index based on the corrected state parameters, including: Define the state parameters in the state-space model, and use the state-space model to correct the cumulative damage and state parameters based on the equivalent contact resistance and equivalent temperature rise, as follows: Define the state vector in the state-space model as: in, , Indicates the first State parameters at each sampling time. For the first The cumulative salt load on the surface of the connection point at each sampling time. For the first The cumulative damage at each sampling time point. For the first The clamping force at each sampling moment; The observation vector in the state-space model is defined as: in, For the first The equivalent contact resistance at each sampling time. For the first The operating temperature of the connection point at each sampling time. For the first Equivalent temperature rise at each sampling time; The state equation and observation equation are constructed based on the state vector and observation vector, and their formulas are as follows: in, For the input working condition vector, For process noise, To observe noise; A filtering method is used to correct the cumulative damage and state parameters based on the state equation and observation equation. The health index is calculated based on the corrected state parameters, and the formula is as follows: in, This is a term related to contact resistance degradation. For temperature rise degradation term, This is a degenerate term for clamping force. This is an intermittent abnormal item. , respectively, are the weights of the corresponding degradation items; the contact resistance degradation item, temperature rise degradation item, clamping force degradation item, and intermittent anomaly item are normalized degradation indices of contact resistance, equivalent temperature rise, clamping force, and number of intermittent contact anomalies relative to their respective failure thresholds. The formula for the contact resistance degradation term is as follows: in, For the first The corrected equivalent contact resistance at each sampling time. The initial contact resistance, This is the preset contact resistance threshold. The formula for the temperature rise degradation term is as follows: in, For the initial equivalent temperature rise, This is the preset failure temperature rise threshold; For the first The corrected equivalent temperature rise at each sampling time; The formula for the clamping force degradation term is as follows: in, The initial clamping force, For the first The corrected clamping force at each sampling time. The preset failure clamping force threshold; The formula for intermittent anomalies is as follows: in, This represents the number of intermittent contact anomalies detected within a unit time window. This is a preset threshold for the number of abnormal occurrences; This indicates that the calculation results will be restricted to... to between.

9. The method for predicting the lifespan of ship power distribution connection points based on fog condensation vibration coupling according to claim 1, characterized in that, Based on the aforementioned health index, the corrected cumulative damage amount, and future operating conditions, the remaining lifespan of the power distribution connection points is predicted, including: Obtain future operating conditions, which refer to information that describes the expected current load, ambient temperature, relative humidity, salt deposition rate and vibration level of the power distribution connection point in the future time period, obtained by extrapolating from the historical operating condition database, the current voyage operation plan or recent operating condition trends. At the current moment, the corrected cumulative damage, corrected salt load, and corrected clamping force are used as the initial state. Combined with the current load, ambient temperature, relative humidity, salt deposition rate, and vibration level in future operating conditions, the cumulative damage and health index at each future moment are recursively calculated, and the remaining life is calculated when the end of life is reached. The moment when any one of the failure thresholds—contact resistance, equivalent temperature rise, clamping force, number of intermittent abnormalities, health index, or cumulative damage—is first met is taken as the end of the service life. The formula is as follows: When any of the calculated contact resistance, equivalent temperature rise, clamping force, number of intermittent abnormalities, cumulative damage, or health index satisfies the life-end time formula, the time difference between the current moment and that life-end time is calculated, which is the remaining life, and the formula is as follows: in, To predict the time when the end of life is reached.

10. A system for predicting the lifespan of ship power distribution connection points using the fog condensation vibration coupling method described in claim 1, characterized in that, include: The data acquisition module is used to collect multi-source operating data for the target power distribution connection point. The multi-source operating data includes ambient temperature, ambient relative humidity, connection point surface temperature, connection point operating temperature, salt deposition rate, surface salt load, vibration signal, clamping force, current, and voltage drop across the connection point. The data preprocessing module is used to preprocess the collected data, calculate the equivalent contact resistance based on the current and the voltage drop, and calculate the equivalent temperature rise based on the operating temperature of the connection point and the ambient temperature. The factor calculation module is used to calculate the wetting factor, salt load factor, and vibration micro-motion factor based on preprocessed multi-source operating data. The coupled damage modeling module defines a current load factor and a temperature acceleration factor. Based on the wetting factor, the salt load factor, the vibration fretting factor, the current load factor, and the temperature acceleration factor, a coupled damage evolution model is established to obtain the cumulative damage amount. The model formula corresponding to the coupled damage evolution model includes a corrosion damage term, a vibration fretting damage term, and a salt spray-condensation-vibration coupled enhanced damage term. The state correction module is used to correct the cumulative damage amount and predefined state parameters based on the equivalent contact resistance and equivalent temperature rise using a state space model, and to calculate the health index based on the corrected state parameters. The lifespan prediction and early warning module is used to predict the remaining lifespan of the power distribution connection point based on the health index, the corrected cumulative damage amount, and future operating conditions, and output early warning information.

Images