Method for detecting battery temperature
By acquiring temperature values at multiple detection points within the cylindrical battery pack and performing intelligent corrections, the problem of accurate cell temperature feedback by sensors under complex operating conditions is solved, thereby improving the temperature measurement accuracy and safety of the battery management system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA FAW CO LTD
- Filing Date
- 2026-05-11
- Publication Date
- 2026-06-26
Smart Images
Figure CN122291748A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of batteries, and in particular to a method for detecting battery temperature. Background Technology
[0002] The power battery pack will have temperature sensors placed on multiple cells to monitor the real-time temperature distribution of the entire pack and adjust signals such as allowable power and current according to the temperature.
[0003] In existing technologies, temperature sensors within the power battery pack of cylindrical batteries are typically located on the shoulder of the top cover, or on the side of the cell, close to the top cover and away from the serpentine liquid cooling plate. Both methods can monitor battery temperature, but they cannot accurately reflect the true temperature of the cell in all scenarios. The specific reasons are as follows: (1) The temperature sensor located on the shoulder of the battery top cover is close to the terminal post and the busbar. When the power battery is charged or discharged at a large rate, the terminal post and the busbar will be affected by the current heat effect and the temperature will rise rapidly, which will directly cause the temperature sensor reading at the top cover to be falsely high and deviate from the actual temperature of the internal core. (2) The temperature sensor located on the side of the cylindrical cell is a certain distance from the terminal and busbar, and is less affected by the current heating effect. However, even if the temperature sensor is set on the side of the cell away from the serpentine liquid cooling plate, the distance between it and the serpentine liquid cooling plate is still relatively close. Moreover, the metal casing of the cylindrical battery has good thermal conductivity. When cooling or heating is turned on, due to the heat transfer and thermal inertia of the casing, the temperature change rate of the temperature sensor set on the casing will be slightly greater than the temperature change rate of the internal core, resulting in distorted readings.
[0004] In summary, static, single, and unprocessed temperature sensor data sources cannot cope with dynamic and complex operating conditions. Regardless of the fixed location of the temperature sensor used, if it is not analyzed according to the specific scenario, systematic errors will occur in some scenarios, causing the battery management system to adjust battery usage strategies based on erroneous data, thus affecting battery performance, lifespan, and safety. Summary of the Invention
[0005] The purpose of this application is to provide a method for detecting battery temperature, which can intelligently select a reliable temperature data source or perform temperature correction based on real-time operating conditions, so as to improve the accuracy of temperature measurement and reporting.
[0006] This application provides a method for detecting battery temperature, including the following steps: Obtain the first current temperature value of the battery at the first detection point and the second current temperature value at the second detection point; Determine whether the first current temperature value is less than the first preset temperature value, and whether the second current temperature value is less than the first preset temperature value; If so, determine the first current temperature value or the second current temperature value as the target temperature value; If not, calculate the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
[0007] In the above technical solution, further, after determining that the first current temperature value is less than the first preset temperature value and the second current temperature value is less than the first preset temperature value, the method further includes: Obtain the current average charge / discharge rate of the battery; Determine whether the current average charge / discharge rate is less than or equal to the first preset charge / discharge rate; If so, determine that the first current temperature value is the target temperature value; If not, obtain the current average charge / discharge rate within the second preset time period according to the first preset time interval; Determine whether the current average charge / discharge rate is continuously greater than the first preset charge / discharge rate; If so, determine that the second current temperature value is the target temperature value; If not, repeat the process of determining the first current temperature value as the target temperature value.
[0008] In the above technical solution, after determining the second current temperature value as the target temperature value, the method further includes: According to the third preset time interval, the current average charge / discharge rate within the fourth preset time interval is obtained and determined; Determine whether the current average charge / discharge rate is continuously less than the second preset charge / discharge rate; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of determining the second current temperature value as the target temperature value.
[0009] In the above technical solution, after determining the second current temperature value as the target temperature value, the method further includes: Obtain the activation information of the cooling device; After obtaining the activation information of the cooling device for a fourth preset time, determine whether the difference between the first current temperature value and the second current temperature value is less than a preset difference; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of determining the second current temperature value as the target temperature value.
[0010] In the above technical solution, after determining the second current temperature value as the target temperature value, the method further includes: Determine whether the first current temperature value is greater than the second preset temperature value; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of determining the second current temperature value as the target temperature value.
[0011] In the above technical solution, after determining the temperature correction value as the target temperature value, it further includes: According to the third preset time interval, obtain the current average charge / discharge rate within the fourth preset time interval; Determine whether the current average charge / discharge rate is continuously less than the second preset charge / discharge rate; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
[0012] In the above technical solution, after determining the temperature correction value as the target temperature value, it further includes: Obtain the activation information of the cooling device; After obtaining the activation information of the cooling device for a fourth preset time, determine whether the difference between the first current temperature value and the second current temperature value is less than a preset difference; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
[0013] In the above technical solution, after determining the temperature correction value as the target temperature value, it further includes: Determine whether the first current temperature value is greater than the second preset temperature value; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
[0014] In the above technical solution, the first current temperature value is further set to T1, the second current temperature value is set to T2, and the temperature correction value is set to T3; The following relationship exists between multiple parameters: T3 = m × T1 + (1 - m) × T2, where m is the proportionality coefficient and m is between 0 and 1.
[0015] The above technical solution further includes a testing method; the testing method is used to obtain a first preset temperature value, a second preset temperature value, a first preset charge / discharge rate, a second preset charge / discharge rate, a first preset time, a second preset time, a third preset time, a fourth preset time, and a preset difference; the testing method includes: Step 1: Select multiple high-temperature simulation sampling points and multiple low-temperature simulation sampling points on the simulated battery pack according to the preset parameters of the simulated battery pack. Step 2: Set multiple first simulation temperature sensors and multiple second simulation temperature sensors at some high-temperature simulation acquisition points, and set multiple first simulation temperature sensors and multiple second simulation temperature sensors at some low-temperature simulation acquisition points; perform three-dimensional thermal simulation of the simulated battery pack under multiple simulated working conditions, so that the temperature detected by multiple first simulation temperature sensors and multiple second simulation temperature sensors includes the highest and lowest temperatures of the simulated battery pack under multiple simulated working conditions. Step 3: Manufacture a test battery pack based on the simulated battery pack; arrange a first test temperature sensor on the test battery pack to correspond to the position of the first simulated temperature sensor, and arrange a second test temperature sensor on the test battery pack to correspond to the position of the second simulated temperature sensor; embed first temperature sensing lines in multiple test cores of the test battery pack to detect the temperature of the test cores; set second temperature sensing lines at the heating and cooling components of the test battery pack to detect the ambient temperature; conduct multiple simulated operating condition tests on the test battery pack. Step 4: Acquire the first detection data detected by the first and second temperature sensors in the experiment; acquire the second detection data detected by the first and second temperature sensing lines; compare the differences between the first and second detection data under different simulated operating conditions, and evaluate the simulated operating conditions that require temperature selection and temperature correction. Step 5: Based on the test results, determine the first preset temperature value, the second preset temperature value, the first preset charge / discharge rate, the second preset charge / discharge rate, the first preset time, the second preset time, the third preset time, the fourth preset time, and the preset difference.
[0016] Compared with the prior art, the beneficial effects of this application are as follows: The battery temperature detection method provided in this application determines the accuracy of the first and second current temperature values by judging whether they are less than a first preset temperature value. If both are inaccurate, a temperature correction value is calculated and used as the target temperature value. This method intelligently selects the most reliable temperature data source or performs temperature correction based on real-time operating conditions, thereby estimating the actual temperature of the battery core. This improves the accuracy of temperature measurement and reporting, enabling the battery management system to execute battery power control commands and / or thermal management control commands based on the actual temperature, avoiding premature performance limitations or damage to battery life safety due to temperature distortion. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 A schematic diagram of the first process for the battery temperature detection method provided in this application; Figure 2 A schematic diagram of the second process for the battery temperature detection method provided in this application; Figure 3 A schematic diagram of the third process for the battery temperature detection method provided in this application; Figure 4 A first structural schematic diagram of the battery module provided in this application; Figure 5 This is a second structural schematic diagram of the battery module provided in this application; Figure 6 This is a partial structural diagram of the battery module provided in this application.
[0019] In the diagram: 101 - cylindrical battery; 102 - serpentine cooling plate; 103 - flexible circuit board; 104 - first temperature sensor; 105 - second temperature sensor. Detailed Implementation
[0020] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0021] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0022] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0023] Example 1 The battery temperature detection method provided in this application can be applied to vehicle battery packs, which include at least one battery module. Figures 4 to 6 As shown, the battery module includes components such as a cylindrical battery 101, a serpentine cooling plate 102, a flexible circuit board 103, and a temperature sensor.
[0024] To collect the temperature of the battery pack, a first temperature sensor 104 is arranged at the top cover of the cell in the center of the battery module. The first temperature sensor 104 is the top cover NTC (Negative Temperature Coefficient). Second temperature sensors 105 are arranged at the shoulders of the cells on both sides of the battery module, and the second temperature sensors 105 are located on the side of the cell away from the serpentine water-cooling plate. The second temperature sensors 105 are typically the side NTCs. The battery pack also includes a battery management system. Based on the temperature data detected by the first temperature sensor 104 and the second temperature sensor 105, the battery management system can adjust the battery usage strategy to improve battery performance, lifespan, and safety.
[0025] When the battery pack is operating normally, the core temperature detected by both the first temperature sensor 104 and the second temperature sensor 105 is within the battery's allowable temperature range. However, even if the core temperatures detected by both sensors are within the allowable temperature range, it does not mean that the detected temperature values accurately reflect the actual temperature of the core. The battery temperature detection method provided in this application provides more accurate detection of the actual temperature of the battery pack and can intelligently select a reliable temperature data source or perform temperature correction based on real-time operating conditions, thereby improving the accuracy of temperature measurement and reporting.
[0026] See Figure 1 As shown, the battery temperature detection method provided in this application includes the following steps: Obtain the first current temperature value of the battery at the first detection point and the second current temperature value at the second detection point; Determine whether the first current temperature value is less than the first preset temperature value, and whether the second current temperature value is less than the first preset temperature value; If so, determine the first current temperature value or the second current temperature value as the target temperature value; If not, calculate the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
[0027] In this embodiment, the first monitoring point of the battery is the top cover of the cell at the center of the battery module, where a first temperature sensor 104 is installed to detect a first current temperature value. The second monitoring point of the battery is the shoulder of the cell on both sides of the battery module, where a second temperature sensor 105 is installed to detect a second current temperature value.
[0028] Through operational condition simulation tests, the temperature changes of the battery pack during continuous charging and discharging can be determined, thereby obtaining the reference temperature values for the first and second monitoring points. A first preset temperature value is set to be 3 greater than the reference temperature value. When both the first current temperature value and the second current temperature value are greater than the first preset temperature value, it indicates that the temperatures detected by both temperature sensors have significant deviations. In this case, the temperature detected by the temperature sensors cannot be selected as the target temperature value. Therefore, a temperature correction strategy is considered for this operational scenario. The target temperature value is set as the temperature correction value. The temperature correction value can be calculated using the first and second current temperature values to estimate the actual temperature of the battery pack.
[0029] Specifically, the first current temperature value is set to T1, the second current temperature value is set to T2, and the temperature correction value is set to T3; the multiple parameters have the following relationship: T3=m×T1+(1-m)×T2, where m is a proportionality coefficient and m is between 0 and 1.
[0030] In this embodiment, the temperature correction value is calculated using a weighted average formula. Here, m is a proportionality coefficient used to balance the influence of T1 and T2. When m = 0.5, T3 is the average of T1 and T2; when m is close to 1, T3 is mainly affected by T1; when m is close to 0, T3 is mainly affected by T2. By setting the temperature correction value as the target temperature value, the system can dynamically adjust the target temperature according to actual conditions, thereby achieving more precise temperature control.
[0031] In the optional schemes of this embodiment, see [link to relevant documentation]. Figure 2 As shown, Figure 2 The diagram illustrates a step following the determination that a first current temperature value is less than a first preset temperature value and a second current temperature value is less than the first preset temperature value. This step further includes: Obtain the current average charge / discharge rate of the battery; Determine whether the current average charge / discharge rate is less than or equal to the first preset charge / discharge rate; If so, determine the first current temperature value as the target temperature value; If not, obtain the current average charge / discharge rate within the second preset time period according to the first preset time interval; Determine whether the current average charge / discharge rate is continuously greater than the first preset charge / discharge rate; If so, determine the second current temperature value as the target temperature value; If not, repeat the process to determine the first current temperature value as the target temperature value.
[0032] In this embodiment, the temperature detected by the first temperature sensor 104 is generally closer to the actual temperature of the winding core, while the result detected by the second temperature sensor 105 is lower. That is, the result detected by the first temperature sensor 104 is more accurate than that detected by the second temperature sensor 105. Therefore, the strategy adopted is to prioritize the temperature value detected by the first temperature sensor 104 as the target temperature value, provided that the result detected by the first temperature sensor 104 does not deviate significantly. The accuracy of the first current temperature value is determined mainly by comparing the current average charge / discharge rate of the battery acquired in real time with a first preset charge / discharge rate. When the current average charge / discharge rate is high, the current flowing through the busbar is high, resulting in more heat generation in the busbar. Since the busbar is adjacent to the first temperature sensor 104, this affects the accuracy of the data detected by the first current temperature value. When the current average charge / discharge rate is low, the current flowing through the busbar is low, resulting in less heat generation in the busbar, and thus less impact on the first current temperature value detected by the first temperature sensor 104. In this case, the data of the first current temperature value is more accurate.
[0033] The first preset charge / discharge rate (referred to as C1) can be obtained through operating condition simulation tests. This first preset charge / discharge rate is the charge / discharge rate that causes the temperature rise detected by the top cover NTC (first temperature sensor 104) to be too rapid. When the real-time average charge / discharge rate is less than or equal to the first preset charge / discharge rate, it indicates that the temperature rise detected by the first temperature sensor 104 is normal, thus indicating that the detection result of the first temperature sensor 104 is relatively accurate. At this time, the first current temperature value is determined to be the target temperature value.
[0034] When the real-time average charge / discharge rate is greater than the first preset charge / discharge rate, it indicates that the instantaneous temperature rise of the first temperature sensor 104 is too rapid. In this case, the accuracy of the detection result from the first temperature sensor 104 is uncertain, and further evaluation of the current average charge / discharge rate is required. The system then determines whether the current average charge / discharge rate remains greater than the first preset charge / discharge rate within a second preset time interval, according to the first preset time interval. If the current average charge / discharge rate remains greater than the first preset charge / discharge rate, it indicates that the rapid temperature rise of the first temperature sensor 104 has lasted for a long period, and the detection result from the first temperature sensor 104 is inaccurate. In this case, the system needs to disable the first current temperature value detected by the first temperature sensor 104 and select the second current temperature value detected by the second temperature sensor 105 as the target temperature value.
[0035] The first and second preset times can also be obtained through operating condition simulation tests. The second preset time is the duration during which the battery temperature at the first monitoring point rises significantly under the first preset charge / discharge rate, typically 30 to 60 seconds. To ensure that this strategy can respond promptly to changes in instantaneous power and make corresponding adjustments, a fixed frequency needs to be maintained to monitor the current average charge / discharge rate in real time within the second preset time. This fixed frequency is typically 5 to 10 seconds per monitoring cycle, meaning the first preset time is 5 to 10 seconds.
[0036] In an optional embodiment, after determining the second current temperature value as the target temperature value, the method further includes: According to the third preset time interval, obtain the current average charge / discharge rate within the fourth preset time interval; Determine whether the current average charge / discharge rate is consistently lower than the second preset charge / discharge rate; If so, determine the first current temperature value as the target temperature value; If not, repeat the process to determine the second current temperature value as the target temperature value.
[0037] In this embodiment, after masking the first current temperature value, the masking of the first current temperature value is stopped if the following situation occurs. Specifically, the process is performed according to a third preset time interval to determine whether the current average charge / discharge rate within a fourth preset time period is continuously less than the second preset charge / discharge rate (which can be simply referred to as C2, where C1 is greater than C2, and specifically, C1 is generally two to three times C2). The second preset charge / discharge rate can be obtained through a working condition simulation test, and the second preset charge / discharge rate is the discharge rate when the vehicle is traveling at a relatively high constant speed. When the real-time acquired current average charge / discharge rate is continuously less than the second preset charge / discharge rate, it indicates that even if the temperature rise detected by the first temperature sensor 104 is relatively fast in an instant, it is in an accurate detection state over a long period of time. If so, the masking of the first current temperature value is released, that is, the first current temperature value is reselected as the target temperature value. If not, the masking of the first current temperature value is maintained, and the second current temperature value is selected as the target temperature value.
[0038] The third and fourth preset times can also be obtained through operating condition simulation tests. The fourth preset time is the time it takes for the average battery temperature to drop by 2 to 3 degrees Celsius after the battery cooling device is turned on. To ensure that this strategy can respond promptly to changes in instantaneous power and make corresponding adjustments, a fixed frequency needs to be maintained to monitor the current average charge and discharge rate in real time within the fourth preset time. This fixed frequency is generally 5 to 10 seconds per cycle, that is, the third preset time is 5 to 10 seconds.
[0039] In an optional embodiment, after determining the second current temperature value as the target temperature value, the method further includes: Obtain the activation information of the cooling device; After obtaining the start-up information of the cooling device for a fourth preset time, determine whether the difference between the first current temperature value and the second current temperature value is less than a preset difference; If so, determine the first current temperature value as the target temperature value; If not, repeat the process to determine the second current temperature value as the target temperature value.
[0040] In this embodiment, after the first current temperature value is masked, the masking of the first current temperature value is stopped if the following situation occurs. Specifically, when the charging and discharging current is large, the battery management system will activate the cooling device to cool the battery. After the cooling device has been activated for a period of time (as shown by the serpentine cooling plate 102 in the figure), the first temperature sensor 104 will be controlled by the bus to make its detection result more stable and accurate. At this time, the difference between the first current temperature value and the second current temperature value can be calculated. When the difference is less than a preset difference, it indicates that the deviation of the detection result of the first temperature sensor 104 is small, and the masking of the first current temperature value can be removed, that is, the first current temperature value is reselected as the target temperature value. Otherwise, the masking of the first current temperature value is maintained, and the second current temperature value is selected as the target temperature value.
[0041] In an optional embodiment, after determining the second current temperature value as the target temperature value, the method further includes: Determine whether the first current temperature value is greater than the second preset temperature value; If so, determine the first current temperature value as the target temperature value; If not, repeat the process to determine the second current temperature value as the target temperature value.
[0042] In this embodiment, after masking the first current temperature value, the masking of the first current temperature value is stopped if the following situation occurs: Specifically, the second preset temperature value is 5 less than the temperature value at which the battery triggers a thermal runaway alarm. When the first current temperature value is greater than the second preset temperature value, it indicates that the temperature detected by the first temperature sensor 104 has approached the temperature value at which the battery triggers a thermal runaway alarm. At this time, in order to ensure battery safety, the masking of the first current temperature value is lifted, that is, the first current temperature value is reselected as the target temperature value so that the battery management system can make corresponding responses in a timely manner. Otherwise, the masking of the first current temperature value is maintained, and the second current temperature value is selected as the target temperature value.
[0043] Example 2 The battery temperature detection method in this second embodiment is an improvement on the above embodiments. The technical content disclosed in the above embodiments will not be described again, and the content disclosed in the above embodiments also belongs to the content disclosed in this second embodiment.
[0044] In the optional schemes of this embodiment, see [link to relevant documentation]. Figure 3 As shown, Figure 3 The steps following the determination of the temperature correction value as the target temperature value are shown, and these steps also include: According to the third preset time interval, obtain the current average charge / discharge rate within the fourth preset time interval; Determine whether the current average charge / discharge rate is consistently lower than the second preset charge / discharge rate; If so, determine the first current temperature value as the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first and second current temperature values; determine the temperature correction value as the target temperature value.
[0045] In this embodiment, after temperature correction, the temperature correction is lifted if the following condition occurs. The condition for lifting the temperature correction is the same as the first condition for lifting the shielding of the first current temperature value. Specifically, the process is performed to determine whether the current average charge / discharge rate within a fourth preset time period is continuously less than the second preset charge / discharge rate according to a third preset time interval. The second preset charge / discharge rate can be obtained through a working condition simulation test, and the second preset charge / discharge rate is the discharge rate when the vehicle is traveling at a constant speed at a relatively high speed. When the real-time acquired current average charge / discharge rate is continuously less than the second preset charge / discharge rate, it indicates that the first temperature sensor 104 is in an accurate detection state for a relatively long period of time, and the results detected by the first temperature sensor 104 and the second temperature sensor 105 do not need to be corrected. At this time, the first current temperature value is reselected as the target temperature value. Otherwise, the steps of calculating the temperature correction value and determining the temperature correction value as the target temperature value are repeated.
[0046] In an optional embodiment, after determining the temperature correction value as the target temperature value, the method further includes: Obtain the activation information of the cooling device; After obtaining the start-up information of the cooling device for a fourth preset time, determine whether the difference between the first current temperature value and the second current temperature value is less than a preset difference; If so, determine the first current temperature value as the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first and second current temperature values; determine the temperature correction value as the target temperature value.
[0047] In this embodiment, after temperature correction, the temperature correction is lifted if the following condition occurs. The condition for lifting the temperature correction is the same as the second condition for lifting the shielding of the first current temperature value. Specifically, after the cooling device has been turned on for a period of time (the serpentine cooling plate 102 shown in the figure), the first temperature sensor 104 is controlled by the busbar to make its detection result more stable and accurate. At this time, the difference between the first current temperature value and the second current temperature value can be calculated. When the difference is less than a preset difference, it indicates that the deviation of the detection result of the first temperature sensor 104 is small, and the first current temperature value can be reselected as the target temperature value. Otherwise, the steps of calculating the temperature correction value and determining the temperature correction value as the target temperature value are repeated.
[0048] In an optional embodiment, after determining the temperature correction value as the target temperature value, the method further includes: Determine whether the first current temperature value is greater than the second preset temperature value; If so, determine the first current temperature value as the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first and second current temperature values; determine the temperature correction value as the target temperature value.
[0049] In this embodiment, after temperature correction, the correction is lifted if the following occurs: Specifically, the second preset temperature value is 5 less than the temperature at which the battery triggers a thermal runaway alarm. When the first current temperature value is greater than the second preset temperature value, it indicates that the temperature detected by the first temperature sensor 104 is approaching the temperature at which the battery triggers a thermal runaway alarm. In this case, to ensure battery safety, the correction for the first and second current temperature values is lifted, and the first current temperature value is reselected as the target temperature value so that the battery management system can take timely action. Otherwise, the steps of calculating the temperature correction value and determining the temperature correction value as the target temperature value are repeated.
[0050] Example 3 The battery temperature detection method in this embodiment three is an improvement on any of the above embodiments. The technical content disclosed in the above embodiments will not be described again, and the content disclosed in the above embodiments also belongs to the content disclosed in this embodiment two.
[0051] In an optional embodiment, the battery temperature detection method further includes a testing method; the testing method is used to obtain a first preset temperature value, a second preset temperature value, a first preset charge / discharge rate, a second preset charge / discharge rate, a first preset time, a second preset time, a third preset time, a fourth preset time, and a preset difference; the testing method includes: Step 1: Select multiple high-temperature simulation sampling points and multiple low-temperature simulation sampling points on the simulated battery pack according to the preset parameters of the simulated battery pack. Step 2: Set multiple first simulation temperature sensors and multiple second simulation temperature sensors at some high-temperature simulation acquisition points, and set multiple first simulation temperature sensors and multiple second simulation temperature sensors at some low-temperature simulation acquisition points; perform three-dimensional thermal simulation of the simulated battery pack under multiple simulated working conditions, so that the temperature detected by multiple first simulation temperature sensors and multiple second simulation temperature sensors includes the highest and lowest temperatures of the simulated battery pack under multiple simulated working conditions. Step 3: Manufacture a test battery pack based on the simulated battery pack; arrange a first test temperature sensor on the test battery pack to correspond to the position of the first simulated temperature sensor, and arrange a second test temperature sensor on the test battery pack to correspond to the position of the second simulated temperature sensor; embed first temperature sensing lines in multiple test cores of the test battery pack to detect the temperature of the test cores; set second temperature sensing lines at the heating and cooling components of the test battery pack to detect the ambient temperature; conduct multiple simulated operating condition tests on the test battery pack. Step 4: Obtain the first detection data detected by the first test temperature sensor and the second test temperature sensor; obtain the second detection data detected by the first temperature sensing line and the second temperature sensing line; compare the differences between the first detection data and the second detection data under different simulated working conditions, and evaluate the simulated working conditions that require temperature selection and temperature correction. Step 5: Based on the test results, determine the first preset temperature value, the second preset temperature value, the first preset charge / discharge rate, the second preset charge / discharge rate, the first preset time, the second preset time, the third preset time, the fourth preset time, and the preset difference.
[0052] In this embodiment, the specific steps of the experimental method are as follows: Step 1: Based on the preset input conditions such as battery pack capacity, fast charging time, and battery pack size, select multiple potential highest and lowest temperature points in the simulated battery pack as high-temperature simulation acquisition points and low-temperature simulation acquisition points. Step 2: Conduct 3D thermal simulations covering various operating conditions to preliminarily determine the arrangement scheme of the top NTC and side NTCs. The operating conditions in the 3D thermal simulation should cover as many usage scenarios as possible for new energy vehicles and meet the requirements of the thermal management system; Step 3: Design battery pack bench tests. Integrate temperature sensors into multiple cores of the battery pack, and place these sensors on the serpentine liquid cooling plate, the top cover of the cores, and the aluminum core above them to collect full-temperature field data. Test conditions should include charging / discharging scenarios from low to high rates, and should cover the battery's allowable temperature range to verify the temperature distribution and changes under different conditions. These conditions include, but are not limited to: low-temperature / normal-temperature / high-temperature fast charging, low-temperature / high-temperature continuous aggressive driving, high-speed driving, high-temperature cooling, and low-temperature heating. Step 4: After completing the test, integrate the test data, compare the temperature difference between each NTC and the temperature collected by the temperature sensing line at each location under different working conditions, and evaluate the working conditions that require temperature shielding or correction. Step 5: Based on the measured results, confirm the calibration values of the first preset temperature value, the second preset temperature value, the first preset charge / discharge rate, the second preset charge / discharge rate, the first preset time, the second preset time, the third preset time, the fourth preset time, and the preset difference, complete the strategy formulation, and apply and verify it in subsequent vehicle or bench tests, and continuously optimize it.
[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. In addition, those skilled in the art can understand that although some embodiments herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are meant to be within the scope of this application and form different embodiments.
Claims
1. A method of detecting a temperature of a battery, characterized by, Includes the following steps: Obtain the first current temperature value of the battery at the first detection point and the second current temperature value at the second detection point; Determine whether the first current temperature value is less than the first preset temperature value, and whether the second current temperature value is less than the first preset temperature value; If so, determine the first current temperature value or the second current temperature value as the target temperature value; If not, calculate the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
2. The method of claim 1, wherein After determining that the first current temperature value is less than the first preset temperature value and the second current temperature value is less than the first preset temperature value, the method further includes: Obtain the current average charge / discharge rate of the battery; Determine whether the current average charge / discharge rate is less than or equal to the first preset charge / discharge rate; If so, determine that the first current temperature value is the target temperature value; If not, obtain the current average charge / discharge rate within the second preset time period according to the first preset time interval; Determine whether the current average charge / discharge rate is continuously greater than the first preset charge / discharge rate; If so, determine that the second current temperature value is the target temperature value; If not, repeat the process of determining the first current temperature value as the target temperature value.
3. The method for detecting battery temperature according to claim 2, characterized in that, After determining the second current temperature value as the target temperature value, the process also includes: According to the third preset time interval, the current average charge / discharge rate within the fourth preset time interval is obtained; Determine whether the current average charge / discharge rate is continuously less than the second preset charge / discharge rate; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of determining the second current temperature value as the target temperature value.
4. The method for detecting battery temperature according to claim 2, characterized in that, After determining the second current temperature value as the target temperature value, the process also includes: Obtain the activation information of the cooling device; After obtaining the activation information of the cooling device for a fourth preset time, determine whether the difference between the first current temperature value and the second current temperature value is less than a preset difference; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of determining the second current temperature value as the target temperature value.
5. The method of claim 2, wherein the step of detecting the temperature of the battery is performed by a temperature sensor. After determining the second current temperature value as the target temperature value, the process also includes: Determine whether the first current temperature value is greater than the second preset temperature value; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of determining the second current temperature value as the target temperature value.
6. The method of claim 1, wherein After determining the temperature correction value as the target temperature value, the following is also included: According to the third preset time interval, obtain the current average charge / discharge rate within the fourth preset time interval; Determine whether the current average charge / discharge rate is continuously less than the second preset charge / discharge rate; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
7. The method of claim 1, wherein the step of detecting the temperature of the battery is performed by a temperature sensor. After determining the temperature correction value as the target temperature value, the following is also included: Obtain the activation information of the cooling device; After obtaining the activation information of the cooling device for a fourth preset time, determine whether the difference between the first current temperature value and the second current temperature value is less than a preset difference; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
8. The method for detecting battery temperature according to claim 1, characterized in that, After determining the temperature correction value as the target temperature value, the following is also included: Determine whether the first current temperature value is greater than the second preset temperature value; If so, determine that the first current temperature value is the target temperature value; If not, repeat the process of calculating the temperature correction value based on the first current temperature value and the second current temperature value; determine the temperature correction value as the target temperature value.
9. The method for detecting battery temperature according to claim 1, characterized in that, The first current temperature value is set to T1, the second current temperature value is set to T2, and the temperature correction value is set to T3; The following relationship exists between multiple parameters: T3 = m × T1 + (1 - m) × T2, where m is the proportionality coefficient and m is between 0 and 1.
10. The method for detecting battery temperature according to claim 1, characterized in that, It also includes a test method; the test method is used to obtain a first preset temperature value, a second preset temperature value, a first preset charge / discharge rate, a second preset charge / discharge rate, a first preset time, a second preset time, a third preset time, a fourth preset time, and a preset difference; The test method includes: Step 1: Select multiple high-temperature simulation sampling points and multiple low-temperature simulation sampling points on the simulated battery pack according to the preset parameters of the simulated battery pack. Step 2: Set multiple first simulation temperature sensors and multiple second simulation temperature sensors at some high-temperature simulation acquisition points, and set multiple first simulation temperature sensors and multiple second simulation temperature sensors at some low-temperature simulation acquisition points; perform three-dimensional thermal simulation of the simulated battery pack under multiple simulated working conditions, so that the temperature detected by multiple first simulation temperature sensors and multiple second simulation temperature sensors includes the highest and lowest temperatures of the simulated battery pack under multiple simulated working conditions. Step 3: Manufacture a test battery pack based on the simulated battery pack; arrange a first test temperature sensor on the test battery pack to correspond to the position of the first simulated temperature sensor, and arrange a second test temperature sensor on the test battery pack to correspond to the position of the second simulated temperature sensor; embed first temperature sensing lines in multiple test cores of the test battery pack to detect the temperature of the test cores; set second temperature sensing lines at the heating and cooling components of the test battery pack to detect the ambient temperature; conduct multiple simulated operating condition tests on the test battery pack. Step 4: Acquire the first detection data detected by the first and second temperature sensors in the experiment; acquire the second detection data detected by the first and second temperature sensing lines; compare the differences between the first and second detection data under different simulated operating conditions, and evaluate the simulated operating conditions that require temperature selection and temperature correction. Step 5: Based on the test results, determine the first preset temperature value, the second preset temperature value, the first preset charge / discharge rate, the second preset charge / discharge rate, the first preset time, the second preset time, the third preset time, the fourth preset time, and the preset difference.