Method and system for testing reliability of mechanical structure of battery system

Abstract

The invention provides a method and system for testing the reliability of a mechanical structure of a battery system, and belongs to the technical field of battery testing, and the method comprises the steps: measuring the reliability index of the mechanical structure of the battery system before and after the execution of a preset testing method for the battery system, the pre-test result comprises an initial test value and an initial judgment result, and the post-test result comprises an actual test value and an actual judgment result; calculating a reliability evaluation coefficient based on the initial test values and the actual test values of all the first indexes and the actual judgment results of all the second indexes when all the initial judgment results indicate that the test is passed; and evaluating the reliability of the mechanical structure of the battery system according to the reliability evaluation coefficient. According to the method, the multi-factor coupling test is performed on the battery system, and the reliability evaluation coefficient is calculated and graded by combining the mechanical structure reliability index change before and after the test, so that the reliability of the mechanical structure of the battery system is accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of battery testing, and in particular to a method and system for testing the reliability of a mechanical structure of a battery system. Background Art

[0002] With its high efficiency and pollution-free advantages, electric vehicles have gradually replaced internal combustion engine vehicles as the main means of transportation. As the main power supply source for electric vehicles, the reliability of the mechanical structure of lithium-ion power batteries not only affects the service life of the battery, but also affects the driving safety and personnel safety of electric vehicles.

[0003] The random vibration generated during the driving of electric vehicles will have a certain impact on the structure of the power battery system, causing fatigue fracture of the battery frame structure, affecting the reliability of the battery structure and the safety of the whole vehicle. The temperature change of the environment also has an impact on the power battery that cannot be ignored. In addition to directly affecting the discharge capacity of the power battery, the rapid temperature change (such as electric vehicles entering the basement from the outdoors in cold areas) will also exert multi-directional tensile effects on the shell and frame of the battery system, causing fatigue fracture and affecting driving safety. The driving environment of electric vehicles is complex, and several factors often act on the battery at the same time. For example, when electric vehicles are driving in a high temperature environment, the higher temperature will reduce the strength of the battery structure. In this case, the addition of vibration will cause greater damage to the mechanical structure of the entire battery than vibration alone. It can be seen that the influence of the coupling of multiple factors on the battery is different from that of a single factor, and there are great limitations in using only a single factor test to evaluate the reliability of the battery.

[0004] Therefore, how to improve the accuracy of reliability evaluation of the mechanical structure of the battery system has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present invention provides a battery system mechanical structure reliability testing method, system, electronic equipment and storage medium, which are used to solve the defects in the prior art and thus achieve accurate evaluation of the battery system mechanical structure reliability.

[0006] The present invention provides a method for testing the mechanical structure reliability of a battery system, comprising the following steps: Before and after executing a preset test method on the battery system, respectively, measuring a mechanical structure reliability index of the battery system to obtain a pre-test result and a post-test result, respectively, wherein the mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on a determination result, the pre-test result includes an initial test value and an initial determination result, and the post-test result includes an actual test value and an actual determination result; When all the initial determination results are test passed, calculating the reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all the first indicators and the actual determination results of all the second indicators; The mechanical structure reliability of the battery system is evaluated based on the reliability evaluation coefficient.

[0007] According to a method for testing the reliability of a mechanical structure of a battery system provided by the present invention, the reliability evaluation coefficient is calculated based on the initial test values ​​and actual test values ​​of all the first indicators and the actual determination results of all the second indicators, specifically including: Calculating the test result change rate of each first indicator based on the initial test value and the actual test value of each first indicator; Based on the actual determination result of each second indicator, obtaining an actual determination value of each second indicator; A reliability evaluation coefficient is calculated based on all of the test result change rates and all of the actual determination values.

[0008] According to a battery system mechanical structure reliability testing method provided by the present invention, the reliability evaluation coefficient is calculated based on all the test result change rates and all the actual determination values, specifically including: Calculating a first failure coefficient of each of the first indicators based on a change rate of each of the test results and a preset failure threshold of each of the first indicators; Based on each of the actual determination values, calculating a second failure coefficient of each of the second indicators; wherein, when the actual determination result is that the test passes, the actual determination value is 1, and when the actual determination result is that the test fails, the actual determination value is 0; A reliability evaluation coefficient is calculated based on all of the first failure coefficients, all of the second failure coefficients, a first preset weight coefficient of each of the first indicators, and a second preset weight coefficient of each of the second indicators.

[0009] According to a battery system mechanical structure reliability testing method provided by the present invention, the first failure coefficient of each first indicator is calculated based on the change rate of each test result and the preset failure threshold of each first indicator, specifically including: The first failure coefficient of each of the first indicators is calculated by the following formula: ; In the formula, is the first failure coefficient of the i-th first indicator, is the preset failure threshold of the i-th first indicator, is the test result change rate of the i-th first indicator, and n is the number of first indicators.

[0010] According to a battery system mechanical structure reliability testing method provided by the present invention, the second failure coefficient of each second indicator is calculated based on each actual determination value, specifically comprising: The second failure coefficient of each of the second indicators is calculated by the following formula: ; In the formula, is the second failure coefficient of the jth second index, is the actual judgment value of the jth second indicator, and m is the number of second indicators.

[0011] According to a method for testing the reliability of a mechanical structure of a battery system provided by the present invention, the reliability evaluation coefficient is calculated based on all the first failure coefficients, all the second failure coefficients, a first preset weight coefficient of each of the first indicators, and a second preset weight coefficient of each of the second indicators, specifically including: The reliability evaluation coefficient is calculated by the following formula: ; In the formula, is the reliability evaluation coefficient, is the first failure coefficient of the i-th first indicator, is the second failure coefficient of the jth second index, is the first preset weight coefficient of the i-th first indicator, is the second preset weight coefficient of the j-th second indicator, n is the number of first indicators, and m is the number of second indicators.

[0012] According to a method for testing the mechanical structure reliability of a battery system provided by the present invention, the preset testing method specifically includes: At least one preset condition is selected from a plurality of preset conditions, and all the selected preset conditions are simultaneously applied to the battery system for testing, wherein the preset conditions include vibration, temperature, humidity, and charge and discharge.

[0013] According to a method for testing the reliability of a mechanical structure of a battery system provided by the present invention, the first indicators include: bolt torque, first-order natural frequency of the X-axis, first-order natural frequency of the Y-axis, first-order natural frequency of the Z-axis and maximum strain; the second indicators include: insulation resistance test pass judgment, air tightness test pass judgment and ultrasonic flaw detection pass judgment.

[0014] The present invention also provides a battery system mechanical structure reliability testing system, comprising the following modules: A test module, used to measure a mechanical structure reliability index of the battery system before and after executing a preset test method on the battery system, respectively, to obtain a pre-test result and a post-test result, respectively, wherein the mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on a determination result, the pre-test result includes an initial test value and an initial determination result, and the post-test result includes an actual test value and an actual determination result; A processing module, configured to calculate a reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all the first indicators and the actual determination results of all the second indicators when all the initial determination results are test passed; The evaluation module is used to evaluate the mechanical structure reliability of the battery system according to the reliability evaluation coefficient.

[0015] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for testing the mechanical structure reliability of a battery system as described in any one of the above is implemented.

[0016] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for testing the mechanical structure reliability of a battery system as described in any one of the above is implemented.

[0017] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned methods for testing the mechanical structure reliability of a battery system.

[0018] In summary, one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: By measuring the mechanical structure reliability index of the battery system before and after executing the preset test method on the battery system, the pre-test result and the post-test result are obtained, and at least one quantifiable first index and at least one second index based on the determination result are included, so as to realize the comprehensive capture and recording of the performance change of the battery system. The initial test value and the initial determination result in the pre-test result provide a reference benchmark for the subsequent performance comparison, while the actual test value and the actual determination result in the post-test result intuitively reflect the influence of the preset test method on the mechanical performance and functional state of the battery system. This before-and-after comparison measurement method enables the potential structural degradation, performance change or functional failure of the battery system during the test process to be accurately captured, thereby laying a data foundation for reliability evaluation. By calculating the reliability evaluation coefficient based on the initial test value and the actual test value of the first index and the actual determination result of the second index on the premise that all the initial determination results are passed, the multi-dimensional test data is integrated into a comprehensive quantitative index. In the calculation process, the data change before and after the test is compared with the preset failure threshold, and the performance degradation degree of each index of the battery system can be quantified. At the same time, by combining the weight coefficient, the key indicators that have a greater impact on the overall reliability are highlighted, making the evaluation results more scientific and engineering guiding. The introduction of this reliability evaluation coefficient not only improves the intuitiveness and comparability of the test results, but also can show the degree of influence of the test conditions on the comprehensive reliability of the battery system through a unified numerical expression. By evaluating the mechanical structure reliability of the battery system based on the reliability evaluation coefficient, a clear classification of the reliability status of the battery system is achieved, thereby achieving an accurate evaluation of the mechanical structure reliability of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is one of the flow charts of the method for testing the mechanical structure reliability of a battery system provided by the present invention.

[0021] Figure 2 This is the vibration test condition for vehicle battery packs or systems other than M1 and N1 provided by the present invention.

[0022] Figure 3 These are the vibration test conditions for M1 and N1 vehicle battery packs or systems provided by the present invention.

[0023] Figure 4It is a schematic diagram of the corresponding values ​​of the vibration time and the ambient temperature of the battery system provided by the present invention.

[0024] Figure 5 This is the second flow chart of the method for testing the mechanical structure reliability of a battery system provided by the present invention.

[0025] Figure 6 This is the third flow chart of the method for testing the mechanical structure reliability of a battery system provided by the present invention.

[0026] Figure 7 It is a structural schematic diagram of a battery system mechanical structure reliability testing system provided by the present invention.

[0027] Figure 8 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that, in the description of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0030] The terms "first", "second", etc. in the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" means at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0031] Combine the following Figure 1-Figure 8 The present invention describes a method, system, electronic device and storage medium for testing the mechanical structure reliability of a battery system.

[0032] Figure 1 This is one of the flow charts of the method for testing the mechanical structure reliability of the battery system provided by the present invention, such as Figure 1 As shown, including but not limited to the following steps: Step 1: Before and after executing a preset test method on the battery system, measure the mechanical structure reliability index of the battery system to obtain pre-test results and post-test results, respectively. The mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on the judgment result. The pre-test result includes an initial test value and an initial judgment result, and the post-test result includes an actual test value and an actual judgment result.

[0033] In a possible implementation manner, the preset test method specifically includes: At least one preset condition is selected from a plurality of preset conditions, and all the selected preset conditions are simultaneously applied to the battery system for testing, wherein the preset conditions include vibration, temperature, humidity, and charge and discharge.

[0034] In a possible implementation, the first indicator includes: bolt torque, first-order natural frequency of the X-axis, first-order natural frequency of the Y-axis, first-order natural frequency of the Z-axis, and maximum strain; the second indicator includes: insulation resistance test pass judgment, air tightness test pass judgment, and ultrasonic flaw detection pass judgment.

[0035] Specifically, in the test method for the mechanical structure reliability of the battery system, the implementation of step 1 is the basis of the entire method. Its core lies in comprehensively evaluating the performance changes and reliability status of the battery system under the test conditions by measuring and comparing the mechanical structure reliability indicators before and after the test. In order to achieve this goal, the battery system must first be pre-processed to ensure that it is in normal working condition and to eliminate any possible initial abnormalities. Pretreatment includes inspecting the appearance and structure of the battery system to confirm that it has no obvious mechanical damage or defects, and measuring and recording the capacity and internal resistance of the battery as benchmark data for subsequent performance evaluation.

[0036] Before executing the preset test method on the battery system, the battery system to be tested must first be installed on the vibration table according to the installation position of the test vehicle and the requirements of GB / T 2423.43. Acceleration sensors are attached to the key suspension points of the battery system, the center of the bottom keel, the front and rear high-voltage interfaces, etc., and can also be attached to specific locations according to the manufacturer's requirements. Strain gauges are attached near the acceleration sensors.

[0037] Then the mechanical structure reliability index of the battery system is measured to obtain the pre-test results. These indicators are divided into quantifiable first indicators and second indicators based on the judgment results. The first indicators include bolt torque, first-order natural frequency of the X axis, first-order natural frequency of the Y axis, first-order natural frequency of the Z axis, and maximum strain.

[0038] Among them, the torque of the screw bolts is the value of the bolt torque at key parts measured by using a torque wrench. The key parts include but are not limited to high-voltage copper busbar connecting bolts, high-voltage port connecting bolts, and upper cover bolts. The first-order natural frequency of the X-axis, the first-order natural frequency of the Y-axis, and the first-order natural frequency of the Z-axis are respectively swept in the X, Y, and Z directions using vibration test equipment. The frequency range of the sweep is 5 to 200 Hz, and the acceleration is 0.5g. During the sweep process, the sampling values ​​of each acceleration sensor are monitored, and the frequency of the first peak is used as the first-order natural frequency of the battery system, thereby obtaining the first-order natural frequencies in the X, Y, and Z directions. The maximum strain is detected in real time by strain gauges set at key locations, and the maximum strain is finally determined.

[0039] The second indicator includes the judgment of passing the insulation resistance test, the judgment of passing the air tightness test, and the judgment of passing the ultrasonic flaw detection. Among them, the insulation resistance test refers to the method used in Appendix B of GB 38031-2020. The air tightness test applies a pressure of 5KPa or the test pressure specified by the manufacturer to the battery pack, the pressure holding time is 60s, the test time is 30s, and the gas leakage of the battery pack after the test should not exceed 40Pa / min, or the leakage amount specified by the manufacturer. Ultrasonic flaw detection uses ultrasonic flaw detection equipment to detect the lifting ears and bottom center axis of the battery sample. Finally, the initial state of the battery system in terms of safety and structural integrity is evaluated by determining whether the test results meet the requirements.

[0040] All the above initial data form the pre-test results and provide a reference for post-test performance comparison.

[0041] Next, the preset test method is implemented on the battery system. The key to this method is to simulate the complex forces and environmental conditions of the battery system in the actual use environment, and to restore its actual working conditions to the maximum extent. By selecting vibration, temperature, humidity, and charging and discharging as preset conditions, and applying at least one condition at the same time (this solution preferably applies the four preset conditions of vibration, temperature, humidity, and charging and discharging at the same time), the battery system is comprehensively tested. During the test, standardized vibration conditions are applied through the vibration table, while the temperature and humidity environmental changes are controlled, and charge and discharge cycles are performed. The data acquisition equipment records the state parameters of the battery system during the test, such as strain, voltage, and temperature, in real time to ensure the safety and integrity of the entire test.

[0042] After the test is completed, the mechanical structure reliability indicators of the battery system are measured again to obtain the post-test results. At this stage, the actual value of the first indicator is remeasured, including the torque of the screws, the first-order natural frequency of the X-axis, the first-order natural frequency of the Y-axis, the first-order natural frequency of the Z-axis, and the maximum strain, and recorded as the actual test value; the second indicator is judged again by testing, such as insulation resistance detection, air tightness test, and ultrasonic flaw detection, and the actual judgment result of whether it meets the requirements after the test is recorded. By comparing the results before and after the test, the performance changes of the battery system under the preset conditions can be clearly observed. For battery systems loaded on vehicles other than M1 and N1, the vibration test parameters refer to GB 38031-2020 8.2.1 vibration test, such as Figure 2 As shown, Figure 2 This is the vibration test condition for vehicle battery packs or systems other than M1 and N1 provided by the present invention. For battery systems installed on M1 and N1 vehicles, the vibration test parameters are as follows: Figure 3 conduct, Figure 3The vibration test conditions for the M1 and N1 vehicle battery packs or systems provided by the present invention are as follows: The temperature and humidity requirements during the vibration of the battery system are as follows: Ambient temperature range: -20℃~55℃, the corresponding relationship between temperature and humidity and vibration time during the test is as follows: Figure 4 As shown, Figure 4 This is a schematic diagram of the vibration time and ambient temperature corresponding values ​​of the battery system provided by the present invention. The random process is cycled twice, the fixed frequency temperature is 25°C, and the humidity is 50%RH. During the test, the state of the minimum monitoring unit inside the test sample, such as voltage and temperature, needs to be monitored. After completing the test in each direction, observe for two hours.

[0043] The effect of this measurement method is that the rate of change of the test results of the first indicator quantifies the degree of performance degradation of the battery system during the test process, reflecting the trend of changes in mechanical properties; and the judgment result of the second indicator provides an intuitive judgment of whether the battery system still meets the requirements in terms of key functions. This method of combining quantifiable data with functional judgment not only provides comprehensive data support for subsequent reliability evaluation, but also helps to discover possible weak links in the battery system under real working conditions, thereby providing a scientific basis for design optimization and process improvement. At the same time, through this precise comparison before and after the test, the credibility and objectivity of the test results can be guaranteed to the greatest extent, laying a solid foundation for the reliability grading evaluation of the battery system. Therefore, the implementation of step 1 effectively achieves the basic goal of the test method, that is, to comprehensively and accurately obtain the performance status of the battery system and its changes under the test conditions.

[0044] Step 2: When all initial determination results are test passed, the reliability evaluation coefficient is calculated based on the initial test values ​​and actual test values ​​of all first indicators and the actual determination results of all second indicators.

[0045] In the test method for the mechanical structure reliability of the battery system, the implementation of step 2 is to convert the mechanical structure reliability index data obtained before and after the test into a quantitative reliability evaluation coefficient. This process is the core of realizing reliability evaluation. The failure coefficient is calculated by the rate of change of the test results of the first indicator, and combined with the actual judgment value of the second indicator, the reliability status of the battery system under the preset test method is comprehensively evaluated. The purpose of doing this is to integrate multi-dimensional test data into a comprehensive indicator that can intuitively and quantitatively reflect the reliability level of the battery system, thereby providing a scientific basis for subsequent grading evaluation and design optimization.

[0046] It should be noted that at the beginning of step 2, it is necessary to ensure that all initial judgment results are "test passed". This prerequisite is set to exclude the possible congenital defects or abnormalities of the test samples before the test, so as to ensure the effectiveness and pertinence of the subsequent evaluation results. If there are situations that do not meet the requirements in the initial judgment results, it cannot be ensured that the measured rate of change or judgment value is only derived from the influence of the test process, which will directly affect the credibility of the evaluation coefficient.

[0047] In one possible implementation, refer to Figure 5 , Figure 5 FIG. 2 is a flow chart of a method for testing the mechanical structure reliability of a battery system provided by the present invention. Figure 5 As shown, step 2 specifically includes steps 21-23: Step 21: Based on the initial test value and the actual test value of each first indicator, calculate the test result change rate of each first indicator.

[0048] In the specific implementation, the first indicator includes the bolt torque retention rate, the change rate of the first-order natural frequency of the X-axis, the change rate of the first-order natural frequency of the Y-axis, the change rate of the first-order natural frequency of the Z-axis, and the maximum strain. The key to calculating the change rate of the test result is to use the initial test value before the test and the actual test value after the test respectively.

[0049] More specifically, the bolt torque retention rate first records the number of bolts at key locations of the battery system and measures the bolt torque of bolts at each key location before executing a preset test method on the battery system. After executing the preset test method on the battery system, the bolt torque of bolts at each key location is remeasured, and the number of bolts with a bolt torque lower than 60% of the original bolt torque is counted. Finally, the bolt torque retention rate is calculated using the following formula: ; In the formula, is the bolt torque retention rate, N is the number of bolts at key locations of the battery system, The number of bolts whose bolt torque is lower than 60% of the original bolt torque after the preset test method is performed on the battery system.

[0050] The change rate of the first-order natural frequency of the Z axis is calculated by the following formula: ; In the formula, is the rate of change of the first-order natural frequency of the Z axis, is the first natural frequency of the Z axis before the preset test method is performed on the battery system, is the first-order natural frequency of the Z axis after a preset test method is performed on the battery system.

[0051] The change rate of the first-order natural frequency of the Y-axis is calculated by the following formula: ; In the formula, is the rate of change of the first-order natural frequency of the Y axis, is the first natural frequency of the Y-axis before the preset test method is performed on the battery system, is the first-order natural frequency of the Y-axis after a preset test method is performed on the battery system.

[0052] The rate of change of the first-order natural frequency of the X-axis is calculated by the following formula: ; In the formula, is the rate of change of the first-order natural frequency of the X-axis, is the first natural frequency of the X-axis before the preset test method is performed on the battery system, is the first-order natural frequency of the X-axis after a preset test method is performed on the battery system.

[0053] The maximum strain is directly expressed as a percentage, using To express.

[0054] Step 22: Based on the actual determination result of each second indicator, obtain the actual determination value of each second indicator.

[0055] Specifically, the second indicator includes the insulation resistance test pass judgment, the air tightness test pass judgment and the ultrasonic flaw detection pass judgment. First, the insulation resistance test is judged. According to the standardized test process, the insulation performance of the battery system is measured using an insulation resistance tester and compared with the predetermined insulation resistance threshold. If the measured value meets the requirements, it is judged as "passed", and the actual judgment value is recorded as 1; otherwise, it is judged as "failed", and the actual judgment value is recorded as 0. Among them, the insulation resistance threshold is 100V / Ω. The detection of insulation resistance is directly related to the electrical safety of the battery system. The actual judgment value after assignment can reflect whether the indicator meets the reliability requirements.

[0056] The airtightness test is then judged. By applying a specified pressure to the battery system and detecting the amount of gas leakage, its sealing performance is judged to be qualified. If the leakage is lower than the specified value, the judgment result is "passed", and the actual judgment value is recorded as 1; if it exceeds the specified value, the judgment result is "failed", and the actual judgment value is recorded as 0. Among them, the specified value is 40Pa / min. The airtightness test reflects the sealing integrity of the battery system, which directly affects the durability and safety of the battery in actual use.

[0057] Finally, the results of the ultrasonic flaw detection test are judged. Use ultrasonic flaw detection equipment to scan the key structural parts of the battery system (such as the lugs or the bottom center axis) to check whether there are microcracks or other structural defects. If no abnormalities are found in the test results, it is judged as "passed" and the actual judgment value is recorded as 1; if structural defects are detected, it is judged as "failed" and the actual judgment value is recorded as 0. The ultrasonic flaw detection pass judgment value intuitively reflects whether there are problems with the mechanical strength and integrity of the battery system.

[0058] Through this process, the actual judgment value of the second indicator is accurately extracted and digitized, ensuring that the results of each indicator can be effectively integrated into the reliability evaluation model. The effectiveness of this method is reflected in many aspects. First, it realizes the digitization of qualitative results, eliminating the limitation that qualitative judgments are difficult to directly apply in subsequent calculations. Second, the simple form of the actual judgment value of 1 or 0 greatly improves the efficiency of data processing while maintaining the authenticity and traceability of the judgment results.

[0059] Step 23: Calculate the reliability evaluation coefficient based on the change rate of all test results and all actual judgment values.

[0060] In the test method for the reliability of the mechanical structure of the battery system, the implementation of step 23 is to calculate the reliability evaluation coefficient based on the change rate of the test results of the first indicator and the actual judgment value of the second indicator. The core of this step is to integrate various test data and obtain a comprehensive indicator through weighted calculation to fully reflect the mechanical structure reliability level of the battery system under the preset test conditions. The reason for this calculation is that the change or judgment result of a single indicator is difficult to fully evaluate the overall state of the battery system, and the reliability evaluation coefficient can scientifically reveal the comprehensive reliability status of the battery system by assigning different weights to all indicators according to their importance.

[0061] In one possible implementation, refer to Figure 6 , Figure 6 FIG. 3 is a flow chart of a method for testing the mechanical structure reliability of a battery system provided by the present invention. Figure 6 As shown, step 23 specifically includes steps 231-233: Step 231: Calculate the first failure coefficient of each first indicator based on the change rate of each test result and the preset failure threshold of each first indicator.

[0062] In a possible implementation manner, the first failure coefficient of each first indicator is calculated by the following formula: ; In the formula, is the first failure coefficient of the i-th first indicator, is the preset failure threshold of the i-th first indicator, is the test result change rate of the i-th first indicator, and n is the number of first indicators.

[0063] In the test method for the mechanical structure reliability of the battery system, the implementation of step 231 is to quantify the degree of degradation of each key mechanical performance indicator of the battery system under the preset test conditions by calculating the first failure coefficient of each first indicator. The core goal of this process is to compare the rate of change of the test results with the preset failure threshold to obtain a quantitative value of the degree of each indicator when it is close to the failure state. The reason for doing this is to ensure that the impact of the change of each first indicator on the overall reliability evaluation can be reasonably expressed, especially when the change of certain indicators may directly threaten the reliability of the mechanical structure of the battery system. The calculation of the failure coefficient provides accurate data support for the subsequent weighted integration.

[0064] In the specific implementation process, the calculation of the first failure coefficient is based on the change rate of the test result of the first indicator. , the change rate of each test result The corresponding preset failure threshold Compare and calculate the first failure coefficient According to the above embodiment, n is 5. ( i =1, 2, ...5) is the failure threshold determined by industry standards or empirical data, representing the maximum performance variation range that each indicator can tolerate. Specifically, for the bolt torque retention rate, the failure threshold is usually set at 60%, indicating that the bolt should still maintain at least 40% of the initial torque after the test. By comparing the actual rate of change with this preset failure threshold, the degree of loosening of the bolt can be quantified. If the torque change rate approaches or exceeds the threshold, the failure coefficient The value of will be close to 1 or reach a failure state, reflecting that the reliability of the bolt has been significantly reduced. Similarly, for the first-order natural frequency change rate, the preset failure threshold is usually set to 10%, indicating that the stiffness of the battery system should not drop significantly by more than 10%. For the calculation of the maximum strain, the preset failure threshold is set to 2%, indicating that the key parts of the battery system should maintain a low deformation level under test conditions. Therefore, the specific values ​​of the preset failure thresholds are 0.4, 0.1, 0.1, 0.1, and 0.02, respectively.

[0065] By comparing the change rate of the test results with the preset failure threshold, the impact of the test conditions on the structural integrity can be intuitively reflected. The closer the calculated first failure coefficient value is to 0, the smaller the performance change of the indicator is, and it is far away from the failure state; the closer the value is to 1, the more serious the performance degradation of the indicator is, and it may be close to failure.

[0066] Step 232: Based on each actual judgment value, calculate the second failure coefficient of each second indicator; wherein, when the actual judgment result is that the test passes, the actual judgment value is 1, and when the actual judgment result is that the test fails, the actual judgment value is 0.

[0067] In a possible implementation manner, the second failure coefficient of each second indicator is calculated by the following formula: ; In the formula, is the second failure coefficient of the jth second index, is the actual judgment value of the jth second indicator, and m is the number of second indicators.

[0068] In the test method for the reliability of the mechanical structure of the battery system, the implementation of step 232 is to calculate each second failure coefficient through the actual judgment value of the second indicator to quantify the reliability status of the battery system in terms of key functionality and safety. The core purpose of this step is to convert the qualitative data based on the judgment results into quantitative expressions that can be directly used for mathematical calculations, so as to ensure that these functional indicators can effectively participate in the comprehensive reliability evaluation. The reason for this processing is that although the test results of the second indicator directly reflect the functional status of the battery system in the form of "pass" or "fail", this form is difficult to integrate with other quantifiable indicators. By calculating the failure coefficient, the impact of these indicators can be fully expressed in the evaluation process.

[0069] In specific operations, the insulation resistance test measures the insulation resistance value of the battery system to determine whether it meets the safety requirements. If the test result meets the predetermined threshold standard, it is judged as "passed", the actual judgment value is 1, and the failure coefficient If the test result does not meet the standard, it is judged as "failed", and the actual judgment value is 0. If it is 0, it means the function is disabled.

[0070] For the airtightness test, the specified pressure is applied to the battery system and the gas leakage is detected to determine whether its sealing performance is qualified. When the leakage is lower than the predetermined threshold standard, it is judged as "passed", the actual judgment value is 1, and the failure coefficient is When the leakage exceeds the threshold, it is judged as "failed", the actual judgment value is 0, and the failure coefficient Also 0.

[0071] Similarly, in the ultrasonic flaw detection test, the flaw detection equipment is used to check whether there are microcracks or other structural defects in the key parts of the battery system. If no abnormality is found in the test results, it is judged as "passed", and the actual judgment value is 1, and the failure coefficient If the test result is defective, it is judged as "failed", the actual judgment value is 0, and the failure coefficient Also 0.

[0072] By calculating the second failure coefficient in this way, the importance and reliability status of the second indicator in the evaluation model can be intuitively expressed. When the failure coefficient is 1, it means that the indicator is not affected by the test conditions and the function is completely normal; when the failure coefficient is 0, it means that the indicator has completely failed after the test and the reliability has dropped significantly. By incorporating all second failure coefficients into the evaluation system, the performance of the battery system in terms of functionality and safety can be fully considered, ensuring the comprehensiveness and scientificity of the final evaluation results.

[0073] Step 233: Calculate the reliability evaluation coefficient based on all first failure coefficients, all second failure coefficients, the first preset weight coefficient of each first indicator, and the second preset weight coefficient of each second indicator.

[0074] In a possible implementation, the reliability evaluation coefficient is calculated by the following formula: ; In the formula, is the reliability evaluation coefficient, is the first failure coefficient of the i-th first indicator, is the second failure coefficient of the jth second index, is the first preset weight coefficient of the i-th first indicator, is the second preset weight coefficient of the j-th second indicator, n is the number of first indicators, and m is the number of second indicators.

[0075] In the test method for the reliability of the mechanical structure of the battery system, the implementation of step 233 is based on all the first failure coefficients and the second failure coefficients, combined with the preset weight coefficients of each first indicator and the second indicator, to calculate the reliability evaluation coefficient. The core purpose of this step is to construct a unified evaluation index through weighted integration to quantitatively reflect the comprehensive reliability level of the battery system under the preset test conditions. The reason for doing this is to highlight the key indicators that have a greater impact on the overall reliability in the test results of multiple indicators, and at the same time ensure that the impact of each indicator is reasonably incorporated into the evaluation system, so as to achieve a comprehensive and accurate reliability assessment.

[0076] In specific implementation, a preset weight coefficient is assigned to each indicator according to its influence on the reliability of the mechanical structure of the battery system. and the weight coefficient of the second indicator The setting of is determined based on empirical data and industry standards, with the purpose of highlighting the key indicators that have a greater impact on reliability while avoiding excessive interference of secondary indicators on the overall evaluation results. For example, the bolt torque retention rate may be crucial to structural stability, and its weight may be higher; if the ultrasonic flaw detection results detect defects in key parts, its impact on reliability may be greater, and it also needs to be given a higher weight. In this solution, ( i =1, 2, ...5) takes values ​​of 0.7, 0.3, 0.6, 0.6, and 0.65 respectively. ( j =1, 2, 3) take values ​​of 0.5, 0.5, 0.5 respectively.

[0077] After the weight coefficient is set, the weighted geometric mean calculation is performed through the formula to integrate all failure coefficients into a reliability evaluation coefficient. The advantage of this calculation method is that it can amplify the impact of key indicators while ensuring the objectivity and accuracy of the evaluation results. If the failure coefficient of a key indicator is close to the failure state (such as close to 1), it will have an impact on the calculation. The value of can have a significant impact, warning of potential problems with this indicator.

[0078] Through this integrated calculation, we finally get It is a quantitative reliability evaluation result, usually ranging from 0 to 1. The closer the value is to 1, the higher the mechanical structure reliability of the battery system is, and the less the test conditions affect it; the closer the value is to 0, the more serious the performance degradation of the battery system is during the test, and the reliability is significantly reduced. This result can intuitively reflect the comprehensive reliability level of the battery system under the test conditions.

[0079] Step 3: Evaluate the mechanical structure reliability of the battery system based on the reliability evaluation coefficient.

[0080] In the test method for the mechanical structure reliability of the battery system, the implementation of step 3 is based on the calculated reliability evaluation coefficient , to grade and evaluate the mechanical structure reliability of the battery system. The core purpose of this process is to intuitively reflect the reliability status of the battery system by converting complex test data and comprehensive calculation results into easy-to-understand grade assessments, and to provide a scientific basis for product design improvements, quality control, and usage decisions. The reason for this graded evaluation is that although simple numerical results can quantify the reliability level, they are difficult to apply directly in actual engineering. Through grading, not only can the reliability level of the battery system be clearly defined, but also specific directions can be provided for subsequent improvements and applications.

[0081] In the specific implementation process, the reliability evaluation coefficient The value range of is usually between 0 and 1, indicating the continuous state of the battery system from complete failure to full reliability. For the convenience of practical use, according to empirical data and industry standards, The numerical range of is divided into multiple levels. Exemplarily, the grading rules are as follows: When When When This grading standard takes full account of the use requirements and industry application characteristics of the battery system and can accurately locate its reliability level.

[0082] After the classification is completed, the weak links of the battery system can be further analyzed based on the reliability level assessment results. By back-testing the test data and calculating the failure coefficient, the specific causes can be located. For example, if the first failure coefficient of the first-order natural frequency change rate is close to 1, it means that the performance of this indicator has been seriously degraded; if the actual judgment value of a second indicator is 0, it means that the functional indicator has completely failed. Based on this information, targeted improvement suggestions can be put forward, such as optimizing the design of the bolts to improve the torque retention rate, enhancing the sealing performance to improve the airtightness, or strengthening the structural strength of key parts to reduce the degradation of dynamic performance.

[0083] Reference Figure 7 , Figure 7 : is a schematic diagram of the structure of a battery system mechanical structure reliability test system provided by the present invention, the system comprises: A test module, used to measure the mechanical structure reliability index of the battery system before and after executing a preset test method on the battery system, respectively, to obtain a pre-test result and a post-test result, respectively, wherein the mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on a determination result, the pre-test result includes an initial test value and an initial determination result, and the post-test result includes an actual test value and an actual determination result; A processing module, configured to calculate a reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all first indicators and the actual determination results of all second indicators when all initial determination results are test passed; The evaluation module is used to evaluate the mechanical structure reliability of the battery system according to the reliability evaluation coefficient.

[0084] In a possible implementation manner, the processing module is further configured to: Calculate the test result change rate of each first indicator based on the initial test value and the actual test value of each first indicator; Based on the actual determination result of each second indicator, obtaining the actual determination value of each second indicator; The reliability evaluation coefficient is calculated based on the change rate of all test results and all actual judgment values.

[0085] In a possible implementation manner, the processing module is further configured to: Calculating a first failure coefficient of each first indicator based on a change rate of each test result and a preset failure threshold of each first indicator; Based on each actual determination value, a second failure coefficient of each second indicator is calculated; wherein, when the actual determination result is that the test passes, the actual determination value is 1, and when the actual determination result is that the test fails, the actual determination value is 0; A reliability evaluation coefficient is calculated based on all first failure coefficients, all second failure coefficients, a first preset weight coefficient of each first indicator, and a second preset weight coefficient of each second indicator.

[0086] In a possible implementation manner, the processing module is further configured to calculate the first failure coefficient of each first indicator by using the following formula: ; In the formula, is the first failure coefficient of the i-th first indicator, is the preset failure threshold of the i-th first indicator, is the test result change rate of the i-th first indicator, and n is the number of first indicators.

[0087] In a possible implementation manner, the processing module is further configured to calculate the second failure coefficient of each second indicator by using the following formula: ; In the formula, is the second failure coefficient of the jth second index, is the actual judgment value of the jth second indicator, and m is the number of second indicators.

[0088] In a possible implementation manner, the processing module is further configured to calculate a reliability evaluation coefficient using the following formula: ; In the formula, is the reliability evaluation coefficient, is the first failure coefficient of the i-th first indicator, is the second failure coefficient of the jth second index, is the first preset weight coefficient of the i-th first indicator, is the second preset weight coefficient of the j-th second indicator, n is the number of first indicators, and m is the number of second indicators.

[0089] In a possible implementation, the test module is further used to select at least one preset condition from a plurality of preset conditions, and to simultaneously apply all the selected preset conditions to the battery system for testing, wherein the preset conditions include vibration, temperature, humidity, and charging and discharging.

[0090] It should be noted that the battery system mechanical structure reliability testing system provided by the present invention can execute the battery system mechanical structure reliability testing method of any of the above embodiments during specific operation, which will not be elaborated in this embodiment.

[0091] Figure 8 is a schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 8 As shown, the electronic device may include: a processor 810 (processor), a communication interface 820 (CommunicationsInterface), a memory 830 (memory) and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the test method for the mechanical structure reliability of the battery system, the method comprising: measuring the mechanical structure reliability index of the battery system before and after executing the preset test method on the battery system, respectively, obtaining the pre-test result and the post-test result, respectively, the mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on the determination result, the pre-test result includes the initial test value and the initial determination result, and the post-test result includes the actual test value and the actual determination result; when all the initial determination results are test passed, the reliability evaluation coefficient is calculated based on the initial test values ​​and the actual test values ​​of all the first indicators, and the actual determination results of all the second indicators; and the mechanical structure reliability of the battery system is evaluated according to the reliability evaluation coefficient.

[0092] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0093] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, and when the program instructions are executed by a computer, the computer can execute the battery system mechanical structure reliability test method provided in the above embodiments, the method including: measuring the mechanical structure reliability index of the battery system before and after executing a preset test method on the battery system, respectively, to obtain pre-test results and post-test results, respectively, the mechanical structure reliability index including at least one quantifiable first index and at least one second index based on a determination result, the pre-test result including an initial test value and an initial determination result, and the post-test result including an actual test value and an actual determination result; when all initial determination results are test passed, calculating the reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all first indicators, and the actual determination results of all second indicators; and evaluating the mechanical structure reliability of the battery system according to the reliability evaluation coefficient.

[0094] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by the processor 810, is implemented to execute the battery system mechanical structure reliability test method provided in the above-mentioned embodiments, the method comprising: measuring the mechanical structure reliability index of the battery system before and after executing a preset test method on the battery system, respectively, to obtain pre-test results and post-test results, respectively, the mechanical structure reliability index comprising at least one quantifiable first index and at least one second index based on a determination result, the pre-test result comprising an initial test value and an initial determination result, and the post-test result comprising an actual test value and an actual determination result; when all initial determination results are test passed, calculating the reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all first indicators, and the actual determination results of all second indicators; and evaluating the mechanical structure reliability of the battery system according to the reliability evaluation coefficient.

[0095] The system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0096] Through the description of the above implementation modes, those skilled in the art can clearly understand that each implementation mode can be implemented by means of software plus a necessary general hardware platform, or of course by hardware. Based on such an understanding, the above technical solution can essentially or in other words be embodied in the form of a software product that contributes to the prior art. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the reliability of a battery system mechanical structure, characterized in that: include: Before and after executing a preset test method on the battery system, respectively, measuring a mechanical structure reliability index of the battery system to obtain a pre-test result and a post-test result, respectively, wherein the mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on a determination result, the pre-test result includes an initial test value and an initial determination result, and the post-test result includes an actual test value and an actual determination result; When all the initial determination results are test passed, calculating the reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all the first indicators and the actual determination results of all the second indicators; The mechanical structure reliability of the battery system is evaluated based on the reliability evaluation coefficient.

2. The method for testing the mechanical structure reliability of a battery system according to claim 1, characterized in that: The calculating of the reliability evaluation coefficient based on the initial test values ​​and the actual test values ​​of all the first indicators and the actual determination results of all the second indicators specifically includes: Calculating the test result change rate of each first indicator based on the initial test value and the actual test value of each first indicator; Based on the actual determination result of each second indicator, obtaining an actual determination value of each second indicator; A reliability evaluation coefficient is calculated based on all of the test result change rates and all of the actual determination values.

3. The method for testing the mechanical structure reliability of a battery system according to claim 2, characterized in that: The calculating of the reliability evaluation coefficient based on all the test result change rates and all the actual determination values ​​specifically includes: Calculating a first failure coefficient of each of the first indicators based on a change rate of each of the test results and a preset failure threshold of each of the first indicators; Based on each of the actual determination values, calculating a second failure coefficient of each of the second indicators; wherein, when the actual determination result is that the test passes, the actual determination value is 1, and when the actual determination result is that the test fails, the actual determination value is 0; A reliability evaluation coefficient is calculated based on all of the first failure coefficients, all of the second failure coefficients, a first preset weight coefficient of each of the first indicators, and a second preset weight coefficient of each of the second indicators.

4. The method for testing the mechanical structure reliability of a battery system according to claim 3, characterized in that: The calculating the first failure coefficient of each of the first indicators based on the change rate of each of the test results and the preset failure threshold of each of the first indicators specifically includes: The first failure coefficient of each of the first indicators is calculated by the following formula: ； In the formula, is the first failure coefficient of the i-th first indicator, is the preset failure threshold of the i-th first indicator, is the test result change rate of the i-th first indicator, and n is the number of first indicators.

5. The method for testing the mechanical structure reliability of a battery system according to claim 3, characterized in that: The calculating, based on each of the actual determination values, a second failure coefficient of each of the second indicators specifically includes: The second failure coefficient of each of the second indicators is calculated by the following formula: ； In the formula, is the second failure coefficient of the jth second index, is the actual judgment value of the jth second indicator, and m is the number of second indicators.

6. The method for testing the mechanical structure reliability of a battery system according to claim 3, characterized in that: The calculating of the reliability evaluation coefficient based on all the first failure coefficients, all the second failure coefficients, the first preset weight coefficient of each of the first indicators, and the second preset weight coefficient of each of the second indicators specifically includes: The reliability evaluation coefficient is calculated by the following formula: ； In the formula, is the reliability evaluation coefficient, is the first failure coefficient of the i-th first indicator, is the second failure coefficient of the jth second index, is the first preset weight coefficient of the i-th first indicator, is the second preset weight coefficient of the j-th second indicator, n is the number of first indicators, and m is the number of second indicators.

7. The method for testing the mechanical structure reliability of a battery system according to claim 1, characterized in that: The preset test method specifically includes: At least one preset condition is selected from a plurality of preset conditions, and all the selected preset conditions are simultaneously applied to the battery system for testing, wherein the preset conditions include vibration, temperature, humidity, and charge and discharge.

8. The method for testing the mechanical structure reliability of a battery system according to claim 1, characterized in that: The first indicators include: bolt torque, first-order natural frequency of the X-axis, first-order natural frequency of the Y-axis, first-order natural frequency of the Z-axis and maximum strain; the second indicators include: insulation resistance test pass judgment, air tightness test pass judgment and ultrasonic flaw detection pass judgment.

9. A battery system mechanical structure reliability testing system, characterized in that: include: A test module, used to measure a mechanical structure reliability index of the battery system before and after executing a preset test method on the battery system, respectively, to obtain a pre-test result and a post-test result, respectively, wherein the mechanical structure reliability index includes at least one quantifiable first index and at least one second index based on a determination result, the pre-test result includes an initial test value and an initial determination result, and the post-test result includes an actual test value and an actual determination result; A processing module, configured to calculate a reliability evaluation coefficient based on the initial test values ​​and actual test values ​​of all the first indicators and the actual determination results of all the second indicators when all the initial determination results are test passed; The evaluation module is used to evaluate the mechanical structure reliability of the battery system according to the reliability evaluation coefficient.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for testing the mechanical structure reliability of the battery system as described in any one of claims 1 to 8 is implemented.

11. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for testing the mechanical structure reliability of a battery system as claimed in any one of claims 1 to 8 is implemented.

12. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for testing the mechanical structure reliability of a battery system as claimed in any one of claims 1 to 8 is implemented.

Images