Power battery pack thermal runaway early warning method, device, equipment and storage medium

Abstract

This application provides a method, apparatus, device, and storage medium for thermal runaway early warning of a power battery pack. The battery cells within the power battery pack are equipped with bottom explosion-proof valves, forming a high-temperature exhaust channel for discharging high-temperature exhaust gas ejected from the bottom explosion-proof valves outside the power battery pack. The method includes: acquiring first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; determining a target temperature value based on the multiple first temperature data; comparing the target temperature value with a thermal runaway early warning temperature threshold, wherein the thermal runaway early warning temperature threshold is set based on the exhaust temperature characteristics detected by the multiple temperature monitoring points when the battery cell experiences thermal runaway; and triggering a thermal runaway alarm when the target temperature value reaches or exceeds the thermal runaway early warning temperature threshold.

Description

Technical Field

[0001] This application relates to the field of power battery system safety technology, and in particular to a method, device, equipment and storage medium for early warning of thermal runaway of a power battery pack. Background Technology

[0002] With the development of the new energy vehicle industry, the market has placed higher demands on fast charging technology. To meet the heat dissipation requirements of high-rate fast charging, the structure of power battery systems continues to evolve, and battery packs with bottom explosion-proof valve designs have attracted industry attention because they can achieve thermal and electrical separation.

[0003] Currently, thermal runaway detection in power batteries is primarily achieved by installing temperature sensors on individual battery cells. Specifically, these temperature sensors are positioned at the top of the battery cell to directly detect its temperature. When the detected temperature exceeds a preset threshold, the battery management system triggers an alarm signal.

[0004] However, existing detection methods have significant shortcomings for battery packs with bottom-mounted explosion-proof valves. When a battery experiences thermal runaway, high-temperature substances are ejected from the bottom valve body, and the temperature sensor installed on top of the battery cannot effectively detect these ejected high-temperature substances, causing the thermal runaway alarm to fail. Therefore, there is an urgent need for a technical solution that can effectively detect thermal runaway in battery packs with bottom-mounted explosion-proof valves. Summary of the Invention

[0005] This application provides a method, device, equipment, and storage medium for early warning of thermal runaway in a power battery pack, in order to solve the problem in the prior art that when a battery experiences thermal runaway, high-temperature substances are ejected from the bottom valve body, and the temperature sensor installed on the top of the battery cannot effectively detect these high-temperature ejected substances, resulting in the failure of the thermal runaway alarm.

[0006] In a first aspect, this application provides a method for early warning of thermal runaway in a power battery pack. The battery cells within the power battery pack are equipped with bottom explosion-proof valves. The power battery pack also has a high-temperature exhaust channel that connects the bottom explosion-proof valves to the outside of the power battery pack for discharging high-temperature exhaust. The method includes: Acquire first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; The target temperature value is determined based on multiple sets of the first temperature data; The target temperature value is compared with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway. A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold.

[0007] In one possible implementation, determining the target temperature value based on a plurality of the first temperature data includes: Determine the maximum value among multiple first temperature data; The maximum value is determined as the target temperature value.

[0008] In one possible implementation, the method further includes: By performing a preset number of battery pack-level thermal runaway tests, a historical temperature dataset is obtained. The historical temperature dataset consists of multiple subsets, each subset consisting of second temperature data collected from multiple temperature monitoring points during a single thermal runaway test when the cell enters a thermal runaway state. Based on the historical temperature dataset, the thermal runaway early warning temperature threshold is determined.

[0009] In one possible implementation, determining the thermal runaway warning temperature threshold based on the historical temperature dataset includes: For each subset constituting the historical temperature dataset, the minimum value is selected from all the second temperature data of the subset as a candidate value; The minimum value is selected from all candidate values ​​corresponding to the subsets as the thermal runaway early warning temperature threshold.

[0010] In one possible implementation, the method further includes: Monitor the pressure signal inside the power battery pack and calculate the rate of change of the pressure signal; The rate of change is compared with a preset pressure rate threshold; A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, and the rate of change reaches or exceeds the pressure rate threshold.

[0011] In one possible implementation, the method further includes: Periodically perform signal diagnosis on multiple temperature monitoring points; If the signal at any temperature monitoring point shows an abnormality within a preset number of consecutive cycles, the temperature monitoring point will be marked as a failed monitoring point. When performing the subsequent step of acquiring the first temperature data of multiple temperature monitoring points located in the high-temperature exhaust channel, the failed monitoring points are filtered out, and only the first temperature data of other valid temperature monitoring points are collected.

[0012] In one possible implementation, the method further includes: Acquire third temperature data from the cell temperature sensor located on the cell body; The third temperature data is compared with the cell warning temperature threshold. If the third temperature data reaches or exceeds the cell warning temperature threshold, a thermal runaway alarm is triggered, wherein the cell warning temperature threshold is higher than the thermal runaway warning temperature threshold and is set based on the maximum expected temperature difference between the thermal runaway warning temperature threshold and the cell body and the high-temperature exhaust channel.

[0013] Secondly, this application provides a thermal runaway early warning device for a power battery pack. The battery cells within the power battery pack are equipped with bottom explosion-proof valves. The power battery pack also has a high-temperature exhaust channel that connects the bottom explosion-proof valves to the outside of the power battery pack for discharging high-temperature exhaust. The device includes: The acquisition module is used to acquire first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; The determining module is used to determine the target temperature value based on multiple sets of the first temperature data; The comparison module is used to compare the target temperature value with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway. The triggering module is used to trigger a thermal runaway alarm when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold.

[0014] In one possible implementation, the determining module is specifically used for: Determine the maximum value among multiple first temperature data; The maximum value is determined as the target temperature value.

[0015] In one possible implementation, the device further includes a testing module for: By performing a preset number of battery pack-level thermal runaway tests, a historical temperature dataset is obtained. The historical temperature dataset consists of multiple subsets, each subset consisting of second temperature data collected from multiple temperature monitoring points during a single thermal runaway test when the cell enters a thermal runaway state. Based on the historical temperature dataset, the thermal runaway early warning temperature threshold is determined.

[0016] In one possible implementation, the test module is further configured to: For each subset constituting the historical temperature dataset, the minimum value is selected from all the second temperature data of the subset as a candidate value; The minimum value is selected from all candidate values ​​corresponding to the subsets as the thermal runaway early warning temperature threshold.

[0017] In one possible implementation, the device further includes a monitoring module for: Monitor the pressure signal inside the power battery pack and calculate the rate of change of the pressure signal; The rate of change is compared with a preset pressure rate threshold; A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, and the rate of change reaches or exceeds the pressure rate threshold.

[0018] In one possible implementation, the device further includes a diagnostic module for: Periodically perform signal diagnosis on multiple temperature monitoring points; If the signal at any temperature monitoring point shows an abnormality within a preset number of consecutive cycles, the temperature monitoring point will be marked as a failed monitoring point. When performing the subsequent step of acquiring the first temperature data of multiple temperature monitoring points located in the high-temperature exhaust channel, the failed monitoring points are filtered out, and only the first temperature data of other valid temperature monitoring points are collected.

[0019] In one possible implementation, the triggering module is further configured to: Acquire third temperature data from the cell temperature sensor located on the cell body; The third temperature data is compared with the cell warning temperature threshold. If the third temperature data reaches or exceeds the cell warning temperature threshold, a thermal runaway alarm is triggered, wherein the cell warning temperature threshold is higher than the thermal runaway warning temperature threshold and is set based on the maximum expected temperature difference between the thermal runaway warning temperature threshold and the cell body and the high-temperature exhaust channel.

[0020] Thirdly, this application provides an apparatus comprising: a processor and a memory, wherein the processor is configured to execute a thermal runaway warning program for a power battery pack stored in the memory, thereby implementing the thermal runaway warning method for a power battery pack as described in any one of the first aspects.

[0021] Fourthly, this application provides a storage medium storing one or more programs that can be executed by one or more processors to implement the thermal runaway early warning method for the power battery pack described in any one aspect.

[0022] Compared with the prior art, the technical solution provided in this application has the following advantages: This application proposes a thermal runaway early warning scheme to match the structural characteristics of battery packs equipped with bottom explosion-proof valves and high-temperature exhaust channels. This scheme shifts the monitoring target from the cell body to the exhaust flow path. First, it monitors the temperature at multiple key locations within the exhaust channel to ensure direct capture of the high-temperature medium generated by thermal runaway. Then, it fuses multiple temperature signals to extract representative temperature values, effectively improving detection reliability. Finally, it compares these values ​​with a warning threshold specifically calibrated based on exhaust characteristics, forming a decision-making mechanism suitable for bottom exhaust conditions. Through this scheme, the system can promptly trigger an alarm by monitoring changes in thermal characteristics within the exhaust channel when thermal runaway occurs, effectively solving the technical challenge of detecting failures of traditional top-mounted temperature sensors in novel battery pack structures. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0026] Figure 1 This is a schematic diagram of the structure of a power battery pack provided in an embodiment of this application; Figure 2 A flowchart illustrating an embodiment of a thermal runaway early warning method for a power battery pack provided in this application; Figure 3 A flowchart illustrating an embodiment of another thermal runaway early warning method for a power battery pack provided in this application; Figure 4 A flowchart illustrating an embodiment of a thermal runaway early warning method for a power battery pack provided in this application. Figure 5 A block diagram illustrating an embodiment of a thermal runaway early warning device for a power battery pack provided in this application. Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. 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.

[0028] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0029] To address the technical problem in existing technologies where high-temperature substances are ejected from the bottom valve body when a battery experiences thermal runaway, and the temperature sensor installed on the top of the battery cannot effectively detect these high-temperature ejected substances, leading to the failure of the thermal runaway alarm, this application provides a thermal runaway early warning method for a power battery pack. This method can promptly trigger an alarm by monitoring changes in the thermal characteristics within the exhaust channel when a battery experiences thermal runaway, thereby effectively solving the technical challenge of the failure of traditional top-mounted temperature sensors in novel battery pack structures.

[0030] Figure 1 This is a schematic diagram of the structure of a power battery pack provided in an embodiment of this application.

[0031] In one embodiment, such as Figure 1 As shown, the power battery pack includes a top cover, a housing, and a bottom plate. Battery cells are housed within the housing, and an explosion-proof valve is located at the bottom of each battery cell. This invention monitors and provides early warning for the emission of the bottom explosion-proof valve. A high-temperature exhaust channel is constructed between the housing and the bottom plate, and this channel is connected to the bottom explosion-proof valve to guide the high-temperature exhaust gas emitted from the valve outside the power battery pack. Multiple temperature monitoring points in the high-temperature exhaust channel are implemented using temperature sensors (such as NTC (Negative Temperature Coefficient Thermistors)) located in the exhaust holes of the housing side beams or on the bottom plate. The battery cells are supported and fixed by support strips.

[0032] Based on the above structure, such as power battery packs Figure 2As shown, the thermal runaway early warning method in this embodiment includes the following steps: Step 201: Obtain the first temperature data of multiple temperature monitoring points located in the high-temperature exhaust channel.

[0033] High-temperature exhaust channel: refers to... Figure 1 The battery pack shown has a specially designed gas flow path inside, which is used to discharge the high-temperature exhaust gas ejected from the explosion-proof valve at the bottom of the battery cell to the outside of the battery pack. This channel is formed in the space structure enclosed by the side beams and the bottom plate of the box.

[0034] Temperature monitoring point: refers to the installation location of the NTC thermistor sensor in the exhaust channel, including the installation point inside the exhaust hole of the side beam of the enclosure and the preset installation point on the bottom plate.

[0035] First temperature data: refers to the temperature values ​​collected in real time by NTC thermistor sensors placed in the high-temperature exhaust channel. These data reflect the airflow temperature distribution at different spatial locations within the exhaust channel.

[0036] In the embodiments of this application, Figure 1 In the battery pack structure shown, temperature monitoring is achieved by arranging multiple NTC sensors in the vent holes of the side beams of the casing and / or on the bottom plate. When thermal runaway occurs in a cell, the high-temperature exhaust gas ejected from the bottom explosion-proof valve flows through the exhaust channel, and the NTC sensors installed in the channel can collect the exhaust temperature data in real time, providing a data basis for subsequent analysis.

[0037] Step 202: Determine the target temperature value based on multiple sets of the first temperature data.

[0038] Target temperature value: refers to the representative temperature value obtained by processing data from multiple temperature monitoring points.

[0039] In an optional embodiment, step 202 may include the following steps: determining the maximum value among a plurality of first temperature data; and determining the maximum value as the target temperature value. In this embodiment, the BMS (Battery Management System) continuously receives temperature data from all exhaust temperature sensors and selects the maximum value from all data as the target temperature value through a comparison algorithm. This maximum value selection method ensures that the system can detect any local high-temperature areas within the exhaust channel, effectively avoiding missed detections.

[0040] In another optional embodiment, the BMS can calculate a weighted average of the data from all temperature monitoring points, where the weighting coefficients are set based on the importance of each monitoring point's location in the exhaust channel and the reliability index of its historical data. This approach, by introducing weighting coefficients, can more accurately reflect the actual contribution of different monitoring points to thermal runaway detection, reduce the interference of occasional fluctuations at individual monitoring points on the overall judgment, and improve the system's stability and anti-interference capability.

[0041] In another optional embodiment, the BMS can employ a time-series-based temperature change trend analysis method, specifically including: performing linear fitting on the temperature data of each monitoring point within a preset time window, and weightedly fusing the fitted temperature change rate with the measured temperature value to determine the target temperature value. This approach, by combining the absolute temperature value with the change trend for comprehensive judgment, can identify the risk of thermal runaway in advance before the temperature reaches the absolute threshold, significantly improving the system's early warning response speed and buying valuable time for safety protection.

[0042] Step 203: Compare the target temperature value with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway.

[0043] Thermal runaway warning temperature threshold: refers to the pre-set temperature critical value used to determine whether thermal runaway has occurred.

[0044] Exhaust temperature characteristics: refers to the data characteristics obtained through experiments that can characterize the exhaust temperature pattern of thermal runaway.

[0045] In this embodiment, temperature data from multiple temperature monitoring points under thermal runaway conditions are collected through battery pack-level thermal runaway testing to establish a historical temperature dataset. Then, based on this dataset, a specific statistical algorithm is used to determine a warning threshold. In actual operation, the BMS compares the target temperature value obtained in step 202 with this experimentally verified threshold in real time. If the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, the process proceeds to step 204; if the target temperature value is lower than the threshold, the BMS maintains normal system monitoring and returns to step 201 to continue the data acquisition and monitoring cycle.

[0046] Step 204: If the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, trigger a thermal runaway alarm.

[0047] In this embodiment, when the target temperature reaches or exceeds the warning threshold, the BMS immediately sends a high-priority alarm signal to the entire vehicle via the CAN (Controller Area Network) bus. Simultaneously, it can activate the audible and visual alarm devices and trigger the fire suppression system within the battery pack. This solution achieves rapid response and tiered handling of thermal runaway events by establishing a clear temperature threshold judgment mechanism. The warning threshold setting based on exhaust channel temperature characteristics accurately distinguishes between normal temperature rise and thermal runaway states, effectively avoiding false alarms. Furthermore, the CAN bus priority setting ensures that the alarm signal is responded to promptly by the entire vehicle system, buying valuable time for personnel evacuation and emergency rescue, and improving the safety and reliability of the battery system.

[0048] The technical solution provided in this application shifts the monitoring target from the battery cell itself to the exhaust flow path. First, temperature monitoring is implemented at multiple key locations within the exhaust channel to ensure direct capture of the high-temperature medium generated by thermal runaway. Then, multiple temperature signals are fused to extract representative temperature values, effectively improving detection reliability. Finally, these values ​​are compared with a warning threshold specifically calibrated based on exhaust characteristics to form a decision-making mechanism suitable for bottom-exhaust conditions. Through this solution, the system can promptly trigger an alarm by monitoring changes in thermal characteristics within the exhaust channel when thermal runaway occurs, effectively solving the technical challenge of detecting failures of traditional top-mounted temperature sensors in novel battery pack structures.

[0049] Figure 3 A flowchart illustrating an embodiment of another thermal runaway early warning method for a power battery pack provided in this application. Figure 3 The process shown is in Figure 3 Based on the illustrated process, the following steps are included: Step 301: Obtain a historical temperature dataset by performing a preset number of battery pack-level thermal runaway tests. The historical temperature dataset consists of multiple subsets, each subset consisting of second temperature data collected from multiple temperature monitoring points during a single thermal runaway test when the cell enters a thermal runaway state.

[0050] Battery pack-level thermal runaway testing: refers to a verification experiment that simulates real-world fault scenarios by triggering thermal runaway in one or more cells at the level of a complete battery pack system.

[0051] Historical temperature dataset: refers to a complete set of data accumulated through multiple experiments for analyzing the characteristics of thermal runaway exhaust temperature.

[0052] Second temperature data: refers to the temperature values ​​collected by temperature sensors placed in the exhaust channel during the thermal runaway test phase, used for calibration and modeling.

[0053] In this embodiment, a preset number of independent battery pack thermal runaway tests (at least 3) are conducted. During each test, when a cell enters a thermal runaway state (determined by a sudden voltage drop and a rapid temperature rise), temperature data from all monitoring points (including the side beams and bottom plate of the casing) are recorded, forming a single test subset. These subsets collectively constitute a historical temperature dataset containing both spatial distribution and temporal series characteristics. During the test, it is essential to ensure that the trigger location includes the cell furthest from the exhaust channel to obtain temperature data under the most unfavorable operating conditions.

[0054] Step 302: Determine the thermal runaway warning temperature threshold based on the historical temperature dataset.

[0055] In an optional embodiment, step 302 may include the following steps: for each subset constituting the historical temperature dataset, selecting the minimum value from all second temperature data of the subset as a candidate value; and selecting the minimum value from the candidate values ​​corresponding to all subsets as the thermal runaway warning temperature threshold.

[0056] In this scheme, the minimum temperature value of all monitoring points in the test is taken for each subset of the historical temperature dataset, and then the final minimum value among these minimum values ​​is taken as the thermal runaway early warning temperature threshold. This scheme can ensure that the alarm is triggered even under the most unfavorable operating conditions, and minimize the risk of missed alarms.

[0057] In another optional embodiment, statistical analysis can be performed on the temperature data of all subsets in the historical temperature dataset, and a specific percentile (such as the 5th percentile) of all data points can be taken as the thermal runaway warning temperature threshold. This approach can reduce threshold deviations caused by individual abnormal data while ensuring safety.

[0058] Figure 3 The process described above establishes a historical temperature dataset based on actual test data and uses statistical analysis methods to determine the warning threshold, ensuring the scientific validity and reliability of the threshold setting. This method fully considers the non-uniformity of temperature distribution within the exhaust channel and the differences in test conditions. The obtained threshold can trigger an alarm in a timely manner when real thermal runaway occurs, while effectively avoiding false alarms caused by normal temperature fluctuations, significantly improving the accuracy and practicality of the warning system.

[0059] Figure 4 A flowchart illustrating an embodiment of another thermal runaway early warning method for a power battery pack provided in this application. Figure 4 The process shown is in Figure 3 Based on the illustrated process, the following steps are included: Step 401: Monitor the pressure signal inside the power battery pack and calculate the rate of change of the pressure signal.

[0060] Pressure signal: refers to a physical quantity signal that reflects the gas pressure state inside the battery pack, collected by a pressure sensor installed inside the pack.

[0061] Pressure signal change rate: refers to the amount of change in pressure signal per unit time, used to characterize the dynamic change trend of internal pressure of battery pack.

[0062] In this embodiment, high-precision pressure sensors are placed at key locations inside the battery pack to continuously monitor the internal pressure at a sampling frequency of no less than 10Hz. After filtering and denoising the acquired raw pressure signal using a digital signal processing circuit, a time-difference algorithm is employed to calculate the pressure change rate. Specifically, a sliding time window method (such as a 1-second window) can be used to perform real-time differential calculations on the pressure data, ensuring that the system can accurately capture the characteristic pressure surge unique to the initial stage of thermal runaway.

[0063] Step 402: Compare the rate of change with a preset pressure rate threshold.

[0064] Pressure rate threshold: refers to the critical rate of change value determined based on a large amount of experimental data, used to judge abnormal pressure growth.

[0065] In this embodiment, the pressure change rate calculated in real time is compared with a pressure rate threshold pre-stored in the BMS. This threshold is determined based on the statistical characteristics of pressure change data from multiple thermal runaway tests, typically taking 1.5-2 times the maximum pressure change rate under normal operating conditions as a benchmark. In practical applications, this threshold can be optimized and adjusted through calibration tests according to the structural characteristics and environmental conditions of different battery packs.

[0066] Step 403: When the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, and the rate of change reaches or exceeds the pressure rate threshold, a thermal runaway alarm is triggered.

[0067] In this embodiment, when both temperature and pressure conditions are met simultaneously, the BMS immediately responds through the following multi-tiered alarm mechanism: first, it sends a high-priority alarm message to the vehicle controller via the CAN bus; second, it activates the audible and visual alarm device inside the battery pack; and finally, it determines whether to trigger the fire extinguishing device based on the system configuration. This dual-criteria alarm mechanism ensures that the highest-level alarm is triggered only when both temperature and pressure signals are confirmed to be abnormal.

[0068] Figure 4The illustrated process, by introducing the rate of pressure change as an auxiliary judgment parameter, forms a dual verification mechanism with temperature monitoring, effectively avoiding system malfunctions caused by false alarms from a single sensor. The pressure signal has a rapid response characteristic to the gas generated in the early stages of thermal runaway, complementing temperature monitoring in terms of timing. This provides early warning signals and confirms the thermal runaway state later, significantly improving the reliability and accuracy of the alarm system while reducing the false alarm rate, thus buying valuable time for taking safety measures.

[0069] In another embodiment of this application, the method may further include the following steps: periodically performing signal diagnosis on multiple temperature monitoring points; marking the temperature monitoring point as a failed monitoring point if the signal of any temperature monitoring point shows abnormality within a consecutive preset number of cycles; and filtering out the failed monitoring points and collecting only the first temperature data of other valid temperature monitoring points when subsequently performing the step of acquiring the first temperature data of multiple temperature monitoring points located in the high-temperature exhaust channel.

[0070] Signal diagnostics: refers to the automated process of checking and evaluating the signal quality and sensor status of temperature monitoring points through preset detection logic.

[0071] Failure monitoring point: refers to the installation location of the temperature sensor that is determined by the system to have an abnormal signal and has lost its normal temperature measurement function.

[0072] Effective temperature monitoring point: refers to the installation location of a temperature sensor that has been confirmed to be in normal working condition through signal diagnosis.

[0073] In this embodiment, the system performs signal diagnosis on all temperature monitoring points at a fixed cycle (e.g., once per second). The diagnosis includes, but is not limited to, whether the signal amplitude exceeds a reasonable range, whether the signal rate of change is abnormal, and whether the signal remains constant. When any monitoring point is determined to be abnormal for three consecutive diagnostic cycles, the system marks it as a failed monitoring point and records the fault information in the system status register. During subsequent temperature data acquisition, the battery management system will automatically skip all marked failed monitoring points and only obtain valid first temperature data from normally functioning monitoring points for subsequent processing.

[0074] This solution introduces a periodic signal diagnosis and failure monitoring point filtering mechanism to achieve real-time monitoring and autonomous fault-tolerant processing of the temperature sensor's operating status. This effectively avoids system misjudgment or functional loss caused by the failure of a single or multiple sensors, significantly improving the reliability and robustness of the thermal runaway early warning system. It ensures that the system can still maintain its core monitoring and early warning functions even in the abnormal situation of partial sensor failure.

[0075] In another embodiment of this application, the method may further include the following steps: acquiring third temperature data from a cell temperature sensor disposed on the cell body; comparing the third temperature data with a cell warning temperature threshold; and triggering a thermal runaway alarm when the third temperature data reaches or exceeds the cell warning temperature threshold, wherein the cell warning temperature threshold is higher than the thermal runaway warning temperature threshold and is set based on the maximum expected temperature difference between the thermal runaway warning temperature threshold and the cell body and the high-temperature exhaust channel.

[0076] Cell temperature sensor: refers to a sensing device installed on or inside the cell body to directly measure the cell temperature.

[0077] The third temperature data refers to the temperature data collected in real time by the cell temperature sensor, which reflects the thermal state of the cell body.

[0078] Cell warning temperature threshold: refers to the critical temperature value specifically set for the cell body temperature to trigger thermal runaway alarm.

[0079] Maximum expected temperature difference: refers to the maximum temperature difference that may occur between the battery cell body and the monitoring point of the high-temperature exhaust channel during thermal runaway, as determined by thermodynamic testing.

[0080] In this embodiment, while providing primary early warning through exhaust channel temperature monitoring points, the system simultaneously collects temperature sensor data deployed on the battery cell as an auxiliary monitoring method. The battery cell early warning temperature threshold is obtained by adding the thermal runaway early warning temperature threshold of the exhaust channel to the maximum expected temperature difference, where the maximum expected temperature difference is determined through statistical analysis of the difference between the highest temperature of the battery cell and the temperature of the exhaust channel monitoring points in a large number of thermal runaway tests. When the third temperature data of the battery cell reaches or exceeds this battery cell early warning temperature threshold, the system will immediately trigger a thermal runaway alarm, at which point it no longer relies on the judgment result of the exhaust channel temperature monitoring points.

[0081] This embodiment establishes a direct monitoring mechanism for the cell body temperature and forms a redundant backup with the exhaust temperature-based monitoring system. In the extreme case where the exhaust channel monitoring system completely fails, it can still provide a final safety guarantee. By setting a higher threshold based on the measured temperature difference, it avoids the risk of false alarms when the two systems are running in parallel and ensures that the alarm can be effectively triggered when a real thermal runaway occurs, which significantly improves the safety margin and fault response capability of the entire early warning system.

[0082] For ease of understanding, the following provides a specific implementation of a comprehensive embodiment of this application, which specifically includes the following steps: 1. Adaptive Data Acquisition Phase Based on the actual temperature sensor arrangement used in the battery pack, the corresponding data acquisition strategy is executed: When the box girder layout scheme is adopted, temperature data of temperature monitoring points inside the vent holes of the girder are collected. When using a base plate layout scheme, collect temperature data from temperature monitoring points on the base plate; When the main solution is to use the cell body sensor, the focus is on collecting cell body temperature data; All solutions simultaneously acquire internal pressure signals from the battery pack and monitor the working status of each sensor in real time.

[0083] 2. Intelligent Data Processing Stage Different data processing strategies are adopted depending on the completeness of the sensor system: When the sensor system is fully operational, the maximum value is selected as the target temperature value by comparing temperature data from multiple monitoring points. When some sensor failures are detected, a fault-tolerant calculation mechanism is activated, and the complete temperature field information is calculated based on the effective sensor data and the temperature correlation model. When only the cell body sensor is working, the exhaust temperature characteristics are inferred from the cell temperature data by using the established correspondence model.

[0084] 3. Dynamic threshold determination stage The judgment logic is adaptively adjusted based on the actual sensor configuration used: For the exhaust channel temperature monitoring scheme, a dedicated threshold determined based on multiple thermal runaway tests is used for judgment; For the cell body temperature monitoring scheme, the temperature threshold calculated through the corresponding relationship is used for judgment; A dual verification mechanism using both temperature and pressure signals is preferred, while a single-temperature judgment strategy is employed in single-sensor systems.

[0085] 4. Tiered Alarm Response Phase Based on the level of certainty regarding the warning results, implement tiered emergency response measures: When both temperature and pressure signals meet the warning conditions, the highest level alarm will be triggered immediately, and all safety protection measures will be activated. When only the temperature signal meets the warning conditions, a medium-level warning is triggered, some safety measures are initiated, and further confirmation is requested. When an early warning is triggered in fault-tolerant operating mode, a basic alarm is activated and a system maintenance check is prompted.

[0086] 5. Continuously optimize the learning phase By continuously accumulating system operation data, the early warning parameters can be self-optimized. Record relevant data for each warning event to enrich the historical database; Based on the newly accumulated data, various temperature correlation parameters were recalculated and optimized. The warning threshold is adaptively adjusted based on changes in the system's operating environment.

[0087] This embodiment establishes an intelligent early warning system adaptable to different sensor configurations, ensuring both detection accuracy under ideal operating conditions and system reliability in the event of partial sensor failure, thus providing a comprehensive thermal safety protection solution for power battery packs. This method exhibits good adaptability and robustness, meeting the needs of different battery pack structures and configurations.

[0088] Figure 5 This is a block diagram illustrating an embodiment of a thermal runaway early warning device for a power battery pack provided in this application. Figure 5 As shown, the device includes: The acquisition module 51 is used to acquire first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; The determining module 52 is used to determine a target temperature value based on multiple sets of the first temperature data; The comparison module 53 is used to compare the target temperature value with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway. Trigger module 54 is used to trigger a thermal runaway alarm when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold.

[0089] In one possible implementation, the determining module is specifically used for: Determine the maximum value among multiple first temperature data; The maximum value is determined as the target temperature value.

[0090] In one possible implementation, the device further includes a testing module for: By performing a preset number of battery pack-level thermal runaway tests, a historical temperature dataset is obtained. The historical temperature dataset consists of multiple subsets, each subset consisting of second temperature data collected from multiple temperature monitoring points during a single thermal runaway test when the cell enters a thermal runaway state. Based on the historical temperature dataset, the thermal runaway early warning temperature threshold is determined.

[0091] In one possible implementation, the test module is further configured to: For each subset constituting the historical temperature dataset, the minimum value is selected from all the second temperature data of the subset as a candidate value; The minimum value is selected from all candidate values ​​corresponding to the subsets as the thermal runaway early warning temperature threshold.

[0092] In one possible implementation, the device further includes a monitoring module for: Monitor the pressure signal inside the power battery pack and calculate the rate of change of the pressure signal; The rate of change is compared with a preset pressure rate threshold; A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, and the rate of change reaches or exceeds the pressure rate threshold.

[0093] In one possible implementation, the device further includes a diagnostic module for: Periodically perform signal diagnosis on multiple temperature monitoring points; If the signal at any temperature monitoring point shows an abnormality within a preset number of consecutive cycles, the temperature monitoring point will be marked as a failed monitoring point. When performing the subsequent step of acquiring the first temperature data of multiple temperature monitoring points located in the high-temperature exhaust channel, the failed monitoring points are filtered out, and only the first temperature data of other valid temperature monitoring points are collected.

[0094] In one possible implementation, the triggering module is further configured to: Acquire third temperature data from the cell temperature sensor located on the cell body; The third temperature data is compared with the cell warning temperature threshold. If the third temperature data reaches or exceeds the cell warning temperature threshold, a thermal runaway alarm is triggered, wherein the cell warning temperature threshold is higher than the thermal runaway warning temperature threshold and is set based on the maximum expected temperature difference between the thermal runaway warning temperature threshold and the cell body and the high-temperature exhaust channel.

[0095] like Figure 6 As shown in the figure, this application provides a device including a processor 111, a communication interface 112, a memory 113, and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114. Memory 113 is used to store computer programs; In one embodiment of this application, processor 111, when executing a program stored in memory 113, implements the thermal runaway early warning method for a power battery pack provided in any of the foregoing method embodiments. The battery cells within the power battery pack are equipped with bottom explosion-proof valves, and a high-temperature exhaust channel is formed to discharge the high-temperature exhaust gas ejected from the bottom explosion-proof valves to the outside of the power battery pack. The method includes: Acquire first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; The target temperature value is determined based on multiple sets of the first temperature data; The target temperature value is compared with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway. A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold.

[0096] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the thermal runaway early warning method for a power battery pack as provided in any of the foregoing method embodiments.

[0097] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0098] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0099] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0100] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for early warning of thermal runaway in a power battery pack, characterized in that, The battery cells inside the power battery pack are equipped with bottom explosion-proof valves. The power battery pack also has a high-temperature exhaust channel connected to the bottom explosion-proof valves and the outside of the power battery pack for discharging high-temperature exhaust. The method includes: Acquire first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; The target temperature value is determined based on multiple sets of the first temperature data; The target temperature value is compared with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway. A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold.

2. The method according to claim 1, characterized in that, The step of determining the target temperature value based on multiple sets of first temperature data includes: Determine the maximum value among multiple first temperature data; The maximum value is determined as the target temperature value.

3. The method according to claim 1, characterized in that, The method further includes: By performing a preset number of battery pack-level thermal runaway tests, a historical temperature dataset is obtained. The historical temperature dataset consists of multiple subsets, each subset consisting of second temperature data collected from multiple temperature monitoring points during a single thermal runaway test when the cell enters a thermal runaway state. Based on the historical temperature dataset, the thermal runaway early warning temperature threshold is determined.

4. The method according to claim 3, characterized in that, Determining the thermal runaway early warning temperature threshold based on the historical temperature dataset includes: For each subset constituting the historical temperature dataset, the minimum value is selected from all the second temperature data of the subset as a candidate value; The minimum value is selected from all candidate values ​​corresponding to the subsets as the thermal runaway early warning temperature threshold.

5. The method according to claim 1, characterized in that, The method further includes: Monitor the pressure signal inside the power battery pack and calculate the rate of change of the pressure signal; The rate of change is compared with a preset pressure rate threshold; A thermal runaway alarm is triggered when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold, and the rate of change reaches or exceeds the pressure rate threshold.

6. The method according to claim 1, characterized in that, The method further includes: Periodically perform signal diagnosis on multiple temperature monitoring points; If the signal at any temperature monitoring point shows an abnormality within a preset number of consecutive cycles, the temperature monitoring point will be marked as a failed monitoring point. When performing the subsequent step of acquiring the first temperature data of multiple temperature monitoring points located in the high-temperature exhaust channel, the failed monitoring points are filtered out, and only the first temperature data of other valid temperature monitoring points are collected.

7. The method according to claim 1, characterized in that, The method further includes: Acquire third temperature data from the cell temperature sensor located on the cell body; The third temperature data is compared with the cell warning temperature threshold. If the third temperature data reaches or exceeds the cell warning temperature threshold, a thermal runaway alarm is triggered, wherein the cell warning temperature threshold is higher than the thermal runaway warning temperature threshold and is set based on the maximum expected temperature difference between the thermal runaway warning temperature threshold and the cell body and the high-temperature exhaust channel.

8. A thermal runaway early warning device for a power battery pack, characterized in that, The battery cells inside the power battery pack are equipped with bottom explosion-proof valves. The power battery pack also has a high-temperature exhaust channel, which connects the bottom explosion-proof valves to the outside of the power battery pack for discharging high-temperature exhaust. The device includes: The acquisition module is used to acquire first temperature data from multiple temperature monitoring points located in the high-temperature exhaust channel; The determining module is used to determine the target temperature value based on multiple sets of the first temperature data; The comparison module is used to compare the target temperature value with the thermal runaway warning temperature threshold, wherein the thermal runaway warning temperature threshold is set based on the exhaust temperature characteristics detected by multiple temperature monitoring points when the cell experiences thermal runaway. The triggering module is used to trigger a thermal runaway alarm when the target temperature value reaches or exceeds the thermal runaway warning temperature threshold.

9. An electronic device, characterized in that, include: A processor and a memory, the processor being configured to execute a thermal runaway warning program for a power battery pack stored in the memory, to implement the thermal runaway warning method for a power battery pack as described in any one of claims 1-7.

10. A storage medium, characterized in that, The storage medium stores one or more programs, which can be executed by one or more processors to implement the thermal runaway early warning method for the power battery pack according to any one of claims 1-7.

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