A gas detection temperature compensation method and system

Abstract

The application provides a gas detection temperature compensation method, belongs to the field of power battery production, and carries out airtightness test to obtain a detection value and a temperature difference of a gas source before and after the test, calculates a compensation value, compensates the detection value based on the compensation value, obtains a compensated value, carries out airtightness test on a battery pack after the battery pack is placed for a set time, obtains a detection value, compares the detection value and the compensated value, calculates a correction coefficient, calculates a mean value and a standard deviation of the correction coefficient, takes the mean value of the correction coefficient between the mean value and the standard deviation as a corrected correction coefficient, repeatedly tests until an absolute value of a difference between the compensated value and the detection value is less than a set pressure difference, calculates the compensation value, compensates detection data of the airtightness test, and further provides a system, and the accuracy of airtightness test of a battery pack is improved.

Description

Technical Field

[0001] This invention relates to the field of power battery manufacturing technology, and in particular to a gas detection temperature compensation method and system. Background Technology

[0002] As a core component of new energy electric vehicles and energy storage stations, battery packs must have good sealing performance from the initial design stage to meet the safety requirements of customers. Therefore, they must have good waterproof and dustproof performance.

[0003] The current mainstream method for air detection is to fill the test battery pack with a certain amount of high-pressure gas to simulate real working conditions, and test the leakage value of the battery pack by the pressure change inside the battery pack. However, because the test results are affected by the product itself and the ambient temperature during instrument testing, and the on-site materials and environment cannot be controlled, the test results will be deviated, causing abnormal leakage.

[0004] In the prior art, Chinese invention patent CN117951889A, entitled "A Temperature Compensation Method for Optimizing Differential Pressure Airtightness Testing Process," establishes a theoretical model of the differential pressure airtightness testing process, substitutes the test data into the theoretical model for fitting, obtains the coefficients in the model, and extracts the linear term coefficient as the leakage rate value based on theoretical research on the influence of leakage on differential pressure, thereby achieving a temperature compensation effect in the airtightness testing process. The drawback of this temperature compensation method is that there is a large difference between the theoretical model and the actual test specimen, and the temperature compensation effect has certain limitations. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to improve the accuracy of battery pack airtightness testing.

[0006] This invention solves the above-mentioned technical problems through the following technical solution: a gas detection temperature compensation method, comprising:

[0007] S1. Perform an airtightness test on the battery pack and obtain the test values. Based on the temperature difference of the gas source before and after the test, and the original correction factor, the compensation value is calculated. Based on compensation value For the detected values Compensation is performed to obtain the compensated value. ; S2. After allowing the battery pack to stand for a set time, perform an airtightness test and obtain the test values. Compare the detection values and the compensated values And based on the detection values and detection values Calculate the correction factor ; S3. Calculate the correction factor mean and standard deviation Select on the normal distribution curve arrive Correction coefficients between ,Will arrive Correction coefficient between mean As a correction factor after verification S4. Update the original correction coefficient with the verified correction coefficient, and repeat steps S1 to S3 until the compensated value is reached. With the detected values The absolute value of the difference is less than the set pressure difference.

[0008] S5. Calculate the compensation value based on the verified correction coefficient. And based on the compensation value Compensate the test data for airtightness.

[0009] This invention involves placing the battery pack in a static environment for a set time before conducting an airtightness test, and obtaining the test values. Less affected by ambient temperature, based on the measured values and detection values The correction coefficient was calculated, and statistical analysis revealed that it conformed to a normal distribution. Therefore, [the corrected coefficient was selected]. arrive The correction factor between them, and arrive The mean of the correction coefficients is used as the verified correction coefficient. The original correction coefficient is updated with the verified correction coefficient, and the test is repeated until the compensated value is obtained. With the detected values If the absolute value of the difference is less than the set pressure difference, the compensation value is calculated based on the calibrated correction coefficient when performing temperature compensation on the battery pack airtightness test results. Compensation value It is a more accurate compensation value, compared to using compensation values. The present invention compensates for the test data of airtightness test by using a compensation value. Compensating for the test data of airtightness test is a more reasonable compensation mechanism. Compared with the fixed compensation mode on the market, the air temperature compensation method of the present invention can greatly improve the stability and accuracy of the test system.

[0010] Preferably, the compensation value is calculated based on the temperature difference of the gas source before and after the test. The method is as follows:

[0011] in, To test the temperature difference of the air source before and after, The initial temperature, As the initial pressure, G This is the original correction factor.

[0012] Preferably, based on detection values and detection values The correction factor is calculated as follows:

[0013] in, For correction factor, To test the temperature difference of the air source before and after, The initial temperature, This is the initial pressure.

[0014] Preferably, the mean of the correction coefficient The calculation method is as follows:

[0015] Standard deviation of correction factor The calculation method is as follows:

[0016] in, For the first i One correction factor, , This represents the total number of correction factors.

[0017] Preferably, the compensation value is calculated based on the correction coefficient after verification. The method is as follows:

[0018] in, This is the correction coefficient after verification.

[0019] A more accurate compensation value can be calculated based on the verified correction coefficients. .

[0020] Preferably, based on compensation value The method for compensating for the airtightness test data is as follows:

[0021] in, For the compensated test data, This is the test data for airtightness.

[0022] Preferably, the calculation method for the temperature difference of the gas source before and after the test is as follows:

[0023] in, To test the temperature difference of the air source before and after, The temperature measured by the temperature sensor inside the battery pack housing. The ambient temperature.

[0024] Preferably, the set time is 6 hours and the set pressure difference is 1.5 Pa.

[0025] Based on the battery pack's recovery curve, the battery pack's resting time was determined to be 6 hours. After resting for 6 hours, an airtightness test was conducted, and the obtained test values ​​were... It is less affected by ambient temperature.

[0026] Preferably, when performing an airtightness test on the battery pack, the airtightness tester is installed on the explosion-proof valve interface of the battery pack through an air outlet fixture. The quick-connect interface of the air outlet fixture is connected to the airtightness tester through an air pipe, and the tightening port of the fixture is installed on the outer shell of the air outlet fixture through a tightening limit block.

[0027] The present invention also provides a gas detection temperature compensation system, comprising: The primary test module is used to perform airtightness testing on the battery pack and obtain the test values. Based on the temperature difference of the gas source before and after the test, and the original correction factor, the compensation value is calculated. Based on compensation value For the detected values Compensation is performed to obtain the compensated value. ; The secondary testing module is used to perform an airtightness test after the battery pack has been left to stand for a set time, and to obtain the test values. Compare the detection values and the compensated values And based on the detection values and detection values Calculate the correction factor ; The secondary calibration module is used to calculate the correction factor. mean and standard deviation Select on the normal distribution curve arrive Correction coefficients between ,Will arrive Correction coefficient between mean As the correction coefficient after verification

[0028] The iterative calculation module is used to update the original correction coefficient with the verified correction coefficient, and the test is repeated until the compensated value matches the detected value. The absolute value of the difference is less than the set differential pressure; The compensation module is used to calculate the compensation value based on the verified correction coefficients. And based on the compensation value Compensate the test data for airtightness. Attached Figure Description

[0029] Figure 1 This is a flowchart of a gas detection temperature compensation method provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of a gas detection temperature compensation method provided in Embodiment 1 of the present invention; Figure 3 In the gas source temperature compensation method provided in Embodiment 1 of the present invention, the compensation value is the gas source temperature difference before and after the same test. A graph showing the relationship between the measured values ​​and the actual values. Figure 4 This is a schematic diagram of the normal distribution of the correction coefficient in a gas detection temperature compensation method provided in Embodiment 1 of the present invention; Figure 5 In the gas source temperature compensation method provided in Embodiment 1 of the present invention, the compensation value is the gas source temperature difference before and after the same test. A graph showing the relationship between the measured values ​​and the actual values. Figure 6 This is a schematic diagram of the outlet tooling in a gas detection temperature compensation method provided in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the chamber temperature sensor in a gas detection temperature compensation method provided in Embodiment 1 of the present invention; In the diagram: 10 air pipe, 20 chamber temperature sensor, 21 semiconductor thermistor sensor, 22 insulation layer, 23 data cable, 30 tooling quick connector, 40 tightening limit block, 50 tooling tightening port. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides a gas detection temperature compensation method, including the following steps: Step 1: Perform an airtightness test on the battery pack and obtain the test values. Based on the temperature difference of the gas source before and after the test, and the original correction factor, the compensation value is calculated. Based on compensation value For the detected values Compensation is performed to obtain the compensated value. .

[0032] The method for calculating the temperature difference of the gas source before and after the test is as follows:

[0033] in, To test the temperature difference of the air source before and after, The temperature measured by the temperature sensor inside the battery pack housing. The ambient temperature.

[0034] The compensation value was calculated based on the temperature difference of the gas source before and after the test. The method is as follows:

[0035] in, To test the temperature difference of the air source before and after, The initial temperature, As the initial pressure, This is the original correction factor.

[0036] Step 2: After the battery pack has been left to stand for a set time, an airtightness test is performed. In this embodiment, the set time is 6 hours, and the test values ​​are obtained. Compare the detection values and the compensated values And based on the detection values and detection values Calculate the correction factor .

[0037] Based on detection values and detection values Calculate the correction factor The method is as follows:

[0038] in, For correction factor, To test the temperature difference of the air source before and after, The initial temperature, This is the initial pressure.

[0039] Step 3: Calculate the correction factor mean and standard deviation Mean of correction factor The calculation method is as follows:

[0040] in, to For the 1st to the 1st n One correction factor, This represents the total number of correction factors.

[0041] Standard deviation of correction factor The calculation method is as follows:

[0042] in, For the first i One correction factor, , This represents the total number of correction factors.

[0043] Select on the normal distribution curve arrive Correction coefficients between and calculate arrive Correction coefficient between mean ,Will arrive Correction coefficient between mean As a correction factor after verification. See also Figure 4 ,pass ±3 (Theoretically, a 99.73% pass rate is achieved, but anomalies are identified.) Secondary control measures are implemented, and the mean is recalculated to update the original correction coefficient. G This process is repeated until the compensated value matches the measured value after resting. The process stops when the absolute value of the difference is less than the equipment error (1.5 Pa in this embodiment).

[0044] Step 4: Update the original correction coefficients with the verified correction coefficients. G Repeat steps S1 to S3, that is, perform an airtightness test on the battery pack and obtain the test values. The compensation value is calculated based on the temperature difference of the gas source before and after the test and the correction coefficient after verification. :

[0045] Based on compensation value For the detected values Compensation is performed to obtain the compensated value. Until the compensated value With the detected values The absolute value of the difference is less than the set differential pressure; in this embodiment, the set differential pressure is 1.5 Pa, and the set differential pressure is the equipment error. If the compensated value... With the detected values If the absolute value of the difference is less than 1.5 Pa, it indicates that it is within the equipment error range; if the compensated value With the detected values If the absolute value of the difference is greater than 1.5 Pa, the original correction factor should be replaced with the verified correction factor. G Repeat the test until the compensated value is reached. With the detected values The absolute value of the difference is less than 1.5 Pa.

[0046] Step 5: Based on the verified correction coefficients and compensation values Calculate the compensation value And based on the compensation value Compensate the test data for airtightness.

[0047] The compensation value is calculated based on the verified correction coefficient. The method is as follows:

[0048] in, This is the correction factor after verification.

[0049] Based on compensation value The method for compensating for the airtightness test data is as follows:

[0050] in, For the compensated test data, This is the test data for airtightness.

[0051] See Figure 3 and Figure 5 , Figure 3 The compensation value is the temperature difference of the gas source before and after the same test. A graph showing the relationship between the measured values ​​and the actual values. Figure 5 The compensation value is the temperature difference of the gas source before and after the same test. A comparison of the curves showing the relationship between the measured values ​​and the actual values ​​reveals that... Figure 3 Medium compensation value The fluctuations are significant, based on the compensation value. Compensating for test data is inaccurate. The method of this invention calculates the compensation value. Compensation value The fluctuations are relatively small, based on the compensation value. Compensating for test data can significantly improve its accuracy. (See figure) The maximum leakage value, Minimum leakage value, The value is less than 1.5 Pa.

[0052] This invention involves placing the battery pack in a static environment for a set time before conducting an airtightness test, and obtaining the test values. Less affected by ambient temperature, based on the measured values and detection values The correction factor was calculated, and statistical analysis showed that the correction factor met the requirements. Figure 4 The distribution shown is normal, therefore we choose... arrive The correction factor between them, and arrive The mean of the correction coefficients is used as the verified correction coefficient. The original correction coefficient is updated with the verified correction coefficient, and the test is repeated until the compensated value is obtained. With the detected values If the absolute value of the difference is less than the set pressure difference, the compensation value is calculated based on the calibrated correction coefficient when performing temperature compensation on the battery pack airtightness test results. Compensation value It is a more accurate compensation value, compared to using compensation values. The present invention compensates for the test data of airtightness test by using a compensation value. Compensating for the test data of airtightness test is a more reasonable compensation mechanism. Compared with the fixed compensation mode on the market, the air temperature compensation method of the present invention can greatly improve the stability and accuracy of the test system.

[0053] When performing an airtightness test on the battery pack, the airtightness tester is installed on the explosion-proof valve interface of the battery pack through the air outlet fixture. (See [reference needed]). Figure 6 The quick-connect interface 30 of the outlet fixture is connected to the air tightness tester via the air pipe 10. The tightening port 50 is mounted on the outer shell of the outlet fixture via the tightening limit block 40. The chamber temperature sensor 20 is located inside the outlet fixture. (See attached image) Figure 7The enclosure temperature sensor 20 includes a semiconductor thermistor sensor 21. One end of the semiconductor thermistor sensor 21 is wrapped by an insulating layer 22 and connected to the computing unit via a data cable 23 for real-time data transmission. The enclosure temperature sensor 20 of this invention uses a semiconductor thermistor temperature sensor, which offers higher accuracy (up to 0.01℃) compared to traditional thermistors and infrared temperature sensors. This allows for precise control of the enclosure, room temperature, and air source temperature, enhancing temperature monitoring capabilities.

[0054] Figure 1 The calculation unit shown executes the entire calculation process for the aforementioned target correction coefficient. The calculation unit includes a PC device with a built-in display, software, serial port, and storage unit. Data from the enclosure temperature sensor, indoor temperature sensor, and pipe temperature sensor are sent to the PC via the serial port to generate real-time curves. The AI ​​software identifies abnormal curves based on curve changes and calculates the theoretical compensation value using the ideal gas equation PV=NRT. Compensation value Finally, the value needs to be multiplied by a correction factor after secondary calibration to obtain the final calculated value, which is then fed back to the AI ​​software for secondary learning and optimization. The AI ​​software learns the relationship between the temperature anomaly curve and the correction factor in real time, and optimizes the compensation model by processing large batches of learning test data under multiple conditions over a long period of time.

[0055] By establishing an AI learning model through comparison of data from two retests and one compensation test, the data results are closer to the retest values ​​under normal conditions, thus effectively solving the problem of large-scale retests caused by temperature in the factory.

[0056] Example 2 This embodiment provides a gas detection temperature compensation system, including: The primary test module is used to perform airtightness testing on the battery pack and obtain the test values. Based on the temperature difference of the gas source before and after the test, and the original correction factor, the compensation value is calculated. Based on compensation value For the detected values Compensation is performed to obtain the compensated value. .

[0057] The compensation value was calculated based on the temperature difference of the gas source before and after the test. The method is as follows:

[0058] in, To test the temperature difference of the air source before and after, The initial temperature, As the initial pressure, This is the original correction factor.

[0059] The secondary testing module is used to perform an airtightness test after the battery pack has been left to stand for a set time. In this embodiment, the set time is 6 hours, and the test values ​​are obtained. Compare the detection values and the compensated values And based on the detection values and detection values Calculate the correction factor .

[0060] Based on detection values and detection values The correction factor is calculated as follows:

[0061] in, For correction factor, To test the temperature difference of the air source before and after, The initial temperature, This is the initial pressure.

[0062] The secondary calibration module is used to calculate the correction factor. mean and standard deviation Select on the normal distribution curve arrive Correction coefficients between ,Will arrive Correction coefficient between mean As a correction factor after verification.

[0063] Mean of correction factor The calculation method is as follows:

[0064] Standard deviation of correction factor The calculation method is as follows:

[0065] in, For the first i One correction factor, , This represents the total number of correction factors.

[0066] The iterative calculation module is used to update the original correction coefficient with the verified correction coefficient, and the test is repeated until the compensated value matches the detected value. The absolute value of the difference is less than the set differential pressure. In this embodiment, the set differential pressure is 1.5 Pa.

[0067] The compensation module is used to calculate the compensation value based on the verified correction coefficients. And based on the compensation value Compensate the test data for airtightness.

[0068] The compensation value is calculated based on the verified correction coefficient. The method is as follows:

[0069] in, This is the correction factor after verification.

[0070] Based on compensation value The method for compensating for the airtightness test data is as follows:

[0071] in, For the compensated test data, This is the test data for airtightness.

[0072] The method for calculating the temperature difference of the gas source before and after the test is as follows:

[0073] in, To test the temperature difference of the air source before and after, The temperature measured by the temperature sensor inside the battery pack housing. The ambient temperature.

[0074] When conducting an airtightness test on the battery pack, the airtightness tester is installed on the explosion-proof valve interface of the battery pack through the air outlet fixture. The quick-connect interface of the air outlet fixture is connected to the airtightness tester through an air pipe, and the tightening port of the fixture is installed on the outer shell of the air outlet fixture through a tightening limit block.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas detection temperature compensation method, characterized in that: include: S1. Perform an airtightness test on the battery pack and obtain the test values. Based on the temperature difference of the gas source before and after the test, and the original correction factor, the compensation value is calculated. Based on compensation value For the detected values Compensation is performed to obtain the compensated value. ; S2. After allowing the battery pack to stand for a set time, perform an airtightness test and obtain the test values. Compare the detection values and the compensated values And based on the detection values and detection values Calculate the correction factor ; S3. Calculate the correction factor mean and standard deviation Select on the normal distribution curve arrive Correction coefficients between ,Will arrive Correction coefficient between mean As a correction factor after verification; S4. Update the original correction coefficient with the verified correction coefficient, and repeat steps S1 to S3 until the compensated value matches the detected value. The absolute value of the difference is less than the set differential pressure; S5. Calculate the compensation value based on the verified correction coefficient. And based on the compensation value Compensate the test data for airtightness.

2. The gas detection temperature compensation method according to claim 1, characterized in that: The compensation value was calculated based on the temperature difference of the gas source before and after the test. The method is as follows: in, To test the temperature difference of the air source before and after, The initial temperature. As the initial pressure, This is the original correction factor.

3. The gas detection temperature compensation method according to claim 1, characterized in that: Based on detection values and detection values The correction factor is calculated as follows: in, For correction factor, To test the temperature difference of the air source before and after, The initial temperature. This is the initial pressure.

4. The gas detection temperature compensation method according to claim 1, characterized in that: Mean of correction factor The calculation method is as follows: Standard deviation of correction factor The calculation method is as follows: in, For the first i One correction factor, , This represents the total number of correction factors.

5. The gas detection temperature compensation method according to claim 1, characterized in that: The compensation value is calculated based on the verified correction coefficient. The method is as follows: in, This is the correction factor after verification.

6. The gas detection temperature compensation method according to claim 1, characterized in that: Based on compensation value The method for compensating for the airtightness test data is as follows: in, For the compensated test data, This is the test data for airtightness testing.

7. The gas detection temperature compensation method according to claim 1, characterized in that: The method for calculating the temperature difference of the gas source before and after the test is as follows: in, To test the temperature difference of the air source before and after, The temperature measured by the temperature sensor inside the battery pack housing. The ambient temperature.

8. The gas detection temperature compensation method according to claim 1, characterized in that: The set time is 6 hours, and the set pressure difference is 1.5 Pa.

9. The gas detection temperature compensation method according to claim 1, characterized in that: When conducting an airtightness test on the battery pack, the airtightness tester is installed on the explosion-proof valve interface of the battery pack through the air outlet fixture. The quick-connect interface of the air outlet fixture is connected to the airtightness tester through an air pipe, and the tightening port of the fixture is installed on the outer shell of the air outlet fixture through a tightening limit block.

10. A gas detection temperature compensation system, characterized in that: include: The primary test module is used to perform airtightness testing on the battery pack and obtain the test values. Based on the temperature difference of the gas source before and after the test, and the original correction factor, the compensation value is calculated. Based on compensation value For the detected values Compensation is performed to obtain the compensated value. ; The secondary testing module is used to perform an airtightness test after the battery pack has been left to stand for a set time, and to obtain the test values. Compare the detection values and the compensated values And based on the detection values and detection values Calculate the correction factor ; The secondary calibration module is used to calculate the correction factor. mean and standard deviation Select on the normal distribution curve arrive Correction coefficients between ,Will arrive Correction coefficient between mean As a correction factor after verification; The iterative calculation module is used to update the original correction coefficient with the verified correction coefficient, and the test is repeated until the compensated value matches the detected value. The absolute value of the difference is less than the set differential pressure; The compensation module is used to calculate the compensation value based on the verified correction coefficients. And based on the compensation value Compensate the test data for airtightness.

Images