A power battery thermal runaway monitoring method and system, and an electric vehicle

Abstract

The application provides a power battery thermal runaway monitoring method and system and an electric vehicle. The method comprises the following steps: in response to completion of charging of a power battery or completion of power-off of a power consumption device using the power battery, a battery management system starts a first monitoring mode for a first preset time length, and collects first battery data of the power battery; in response to the first battery data meeting a first preset condition, the battery management system enters a second monitoring mode for a second preset time length, wherein the second monitoring mode is a short-time periodic wake-up monitoring mode in a dormant state, and the second preset time length is shorter than the first preset time length. Such a design can monitor the battery during a period when the probability of thermal runaway of the power battery is the highest, facilitate problem tracing and vehicle background early warning, and enable the battery management system to enter the second monitoring mode after it is determined that thermal runaway will not occur, thereby reducing energy consumption.

Description

Technical Field

[0001] The present application relates to the field of batteries, and specifically to a method and system for monitoring thermal runaway of a power battery and an electric vehicle. Background Art

[0002] Current electric vehicles typically have a monitoring mode to detect thermal runaway in the battery system. Battery system monitoring systems often employ a timed monitoring approach, such as a vehicle wake-up monitoring period of five minutes and a wake-up interval of at least one hour.

[0003] However, the above monitoring mode is relatively simple, resulting in irrational early warning effect of monitoring. Therefore, the existing technology is in urgent need of improvement. Summary of the Invention

[0004] In view of the above problems, the present application provides a power battery thermal runaway monitoring method, system and electric vehicle, which can enable the vehicle to monitor thermal runaway related data and facilitate vehicle background early warning.

[0005] In a first aspect, the present application provides a method for monitoring thermal runaway of a power battery, characterized by comprising: in response to the completion of charging of the power battery or the completion of power-off of an electrical device using the power battery, the battery management system activates a first monitoring mode, wherein the first monitoring mode includes: continuously monitoring the power battery for a first preset duration and collecting first battery data of the power battery; in response to the first battery data satisfying a first preset condition, the battery management system enters a second monitoring mode, wherein the second monitoring mode is a periodic short-term wake-up monitoring mode in a dormant state, and continuously monitors the power battery for a second preset duration after each wake-up, wherein the second preset duration is less than the first preset duration. This design enables monitoring of the battery during the time period with the highest risk of thermal runaway of the power battery and collecting relevant data of the power battery, facilitating problem tracing and background warning. After determining that thermal runaway will not occur, the battery management system enters the regular second monitoring mode to reduce energy consumption.

[0006] In some embodiments, the first preset time period is greater than or equal to 20 minutes, thereby ensuring the monitoring time period of the first monitoring mode and performing thermal runaway monitoring more effectively.

[0007] In some embodiments, the first battery data includes temperature data, and the first preset condition includes a temperature threshold, so as to determine whether the power battery is in thermal runaway based on the detected temperature of the power battery and the set temperature threshold.

[0008] In some embodiments, the temperature data T1 and T2, where T1 is the maximum temperature of the battery cells of the power battery monitored at the start of the first preset time period of continuous monitoring of the power battery, and T2 is the maximum temperature of the battery cells of the power battery monitored at the end of the first preset time period of continuous monitoring of the power battery, the temperature thresholds include Tx and Ty, where Tx is 50-60°C and Ty is 3-7°C; wherein the first preset condition includes (T2 ≤ T1), or (T2> T1 and T2 ≤ Tx and T2-T1 ≤ Ty). Such a design enables the power battery thermal runaway monitoring to determine whether the battery will experience thermal runaway based on relevant data such as T1, T2, Tx, and Ty, and whether to switch to the second monitoring mode to reduce energy consumption.

[0009] In some embodiments, in response to the first battery data not meeting the first preset condition, the battery management system first sleeps for a third preset duration and then wakes up to collect the temperature data; wherein the third preset duration is less than or equal to 10 minutes, and the temperature data includes T3, which is the maximum temperature of the battery cells of the power battery monitored by the battery management system at the end of the third preset duration. In response to the temperature data T3 meeting the following conditions: (T3 ≤ T2), or (T3 > T2 and T3 ≤ Tx and T3 - T2 ≤ Ty), the battery management system enters a second monitoring mode; otherwise, the battery management system continues to monitor the power battery for the first preset duration. By comparing the maximum temperature of the battery cells at the start of monitoring with the maximum temperature of the battery cells at the end of the previous monitoring, it is determined whether thermal runaway has occurred during the battery sleep period, thereby improving the reliability of thermal runaway detection.

[0010] In some embodiments, the temperature data only includes T2, which is the maximum temperature of the power battery cells monitored at the end of the first preset period of continuous monitoring of the power battery. The temperature threshold only includes Tx, which is 50-60°C. The first preset condition includes T2 ≤ Tx. By determining the maximum temperature of the battery cells at the end of monitoring and comparing it with the preset temperature threshold, it is possible to determine whether the battery has experienced thermal runaway, and the comparison logic is simplified.

[0011] In some embodiments, the first battery data further includes: the lowest voltage Vd of the power battery cells; and the first preset condition further includes: Vd ≥ Vx, where Vx is 1-3 volts. This design enhances battery voltage judgment, improves the reliability of thermal runaway detection, and increases the data collection range.

[0012] In some embodiments, the first battery data also includes the insulation value of the power battery; the first preset condition also includes the absence of insulation faults during the first preset period of continuous monitoring of the power battery. This design further enhances the determination of the battery's insulation value, improves the reliability of thermal runaway detection, and increases the data collection range.

[0013] In some embodiments, the first monitoring mode includes: prior to the step of continuously monitoring the power battery for the first preset time period, the battery management system first sleeps for a fourth preset time period, and then wakes up the battery management system to execute the step of continuously monitoring the power battery for the first preset time period; wherein the fourth preset time period is less than or equal to 10 minutes. This design is because the power battery fault may be eliminated after charging is completed or the power-consuming device is powered off, thereby reducing the occurrence of false detections and substantially not affecting subsequent monitoring of the power battery during the stage with the highest risk of thermal runaway.

[0014] In some embodiments, the fourth preset time period is 2-7 minutes, so as not to affect subsequent monitoring of the stage with the highest risk of thermal runaway of the power battery.

[0015] In some embodiments, the method further includes: in response to the first battery data not satisfying the first preset condition, the battery management system repeatedly executing the first monitoring mode and continuing to determine whether the first battery data satisfies the first preset condition. If the first battery data does not satisfy the first preset condition, monitoring cannot be stopped because the risk of thermal runaway still exists, and monitoring continues to monitor the risk of thermal runaway.

[0016] In some embodiments, the method further includes: in response to the first battery data not meeting the second preset condition during the repeated execution of the first monitoring mode, and the number of times the battery management system executes the first monitoring mode is greater than the preset number or the sum of the first preset time lengths of multiple executions of the first monitoring mode is greater than the preset time threshold, the battery management system enters the second monitoring mode; wherein the preset number of times is 2-5 times, and the preset time threshold is 60-120 minutes. Specifically, when the first battery data does not meet the second preset condition, it means that the risk of thermal runaway is not great, and when the number of times the first monitoring mode is executed is greater than the preset number or the sum of the first preset time lengths of multiple executions of the first monitoring mode is greater than the preset time threshold, it means that the probability of thermal risk is very low. At this time, the battery management system enters the second monitoring mode, which can save electricity.

[0017] In some embodiments, the system further includes: in response to the first battery data not meeting the first preset condition but meeting the second preset condition, the battery management system repeatedly executing the first monitoring mode and collecting second battery data of the power battery during the next period of continuous monitoring of the power battery for the first preset duration; determining whether the power battery has experienced thermal runaway based on the first and second battery data; and issuing an early warning in response to the occurrence of thermal runaway of the power battery. This design enables the battery management system to increase the scope of battery data collection when the risk of battery thermal failure is high, thereby facilitating the determination of whether the battery has experienced thermal runaway, thereby alerting the user to take remedial measures, and facilitating problem tracing.

[0018] In some embodiments, the second preset condition includes T2 ≥ Tz and / or (T2 - T1) ≥ To, where Tz is 55-70°C and greater than Tx, and To is 5-10°C and greater than Ty; the second battery data includes the real-time temperature, and / or temperature rise rate, and / or real-time air pressure, and / or air pressure change rate, and / or real-time voltage, and / or voltage drop rate of the battery cells of the power battery. Specifically, by setting the second preset condition, it is possible to facilitate the judgment of thermal runaway risk. When the power battery data is greater than the second preset condition, the battery management system collects temperature and / or temperature rise rate, air pressure and / or air pressure change rate, voltage and / or voltage drop rate, thereby increasing the data collection range for the battery, so as to facilitate the judgment of whether the battery is in thermal runaway, thereby reminding the user to take remedial measures, and facilitating problem tracing.

[0019] In some embodiments, the second monitoring mode includes: the battery management system wakes up after each fourth preset duration of sleep to continuously monitor the power battery for the second preset duration, wherein the second preset duration is less than or equal to 10 minutes and the fourth preset duration is greater than or equal to 1 hour. This can reduce monitoring energy consumption and extend the monitoring duration.

[0020] In a second aspect, the present application provides a power battery thermal runaway monitoring system, comprising: a battery management system; a DCDC converter; wherein the battery management system cooperates with the DCDC converter to execute any one of the power battery thermal runaway monitoring methods described above.

[0021] In a third aspect, the present application provides an electric vehicle, including a power battery and the power battery thermal runaway monitoring system described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0023] Figure 1 A schematic flow chart of an embodiment of a method for monitoring thermal runaway of a power battery provided in this application;

[0024] Figure 2 A schematic flow chart of another embodiment of the method for monitoring thermal runaway of a power battery provided in this application;

[0025] Figure 3 A schematic flow chart of another embodiment of the method for monitoring thermal runaway of a power battery provided in this application;

[0026] Figure 4 A schematic flow chart of another embodiment of the method for monitoring thermal runaway of a power battery provided in this application;

[0027] Figure 5 A schematic flow chart of another embodiment of the method for monitoring thermal runaway of a power battery provided in this application;

[0028] Figure 6 This is a functional module diagram of an embodiment of the power battery thermal runaway monitoring system provided by the present application;

[0029] Figure 7 A schematic diagram of the functional modules of the electric vehicle provided in this application;

[0030] Figure 8 This is a flow chart of the method for monitoring thermal runaway of a power battery of an electric vehicle provided in this application.

[0031] Description of Figure Numbers:

[0032] Power battery thermal runaway monitoring system 60; battery management system 61; DCDC converter 62;

[0033] Electric vehicle 70; power battery 71; remote transmission equipment 72;

[0034] The first lead CAN1; the second lead CAN2; and the third lead CAN3. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] The terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features identified. Therefore, features identified as "first," "second," or "third" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined. All directional designations in the embodiments of this application (such as up, down, left, right, front, back, etc.) are intended only to illustrate the relative positional relationships and movement of components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional designations will also change accordingly. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to such process, method, product, or apparatus.

[0037] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0039] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0040] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0041] Currently, market developments indicate an increasing demand for electric vehicles, and battery safety is a major concern for electric vehicles. Thermal runaway can cause the battery or vehicle to explode, resulting in property damage and, in severe cases, personal injury.

[0042] Electric vehicles are vehicles powered by onboard batteries, with motors driving the wheels, and complying with all road traffic and safety regulations. Their environmental impact is lower than that of traditional fuel vehicles, and their prospects are widely optimistic. These include pure electric vehicles and hybrid electric vehicles powered by batteries.

[0043] The power battery can be installed at the bottom, head, or tail of the electric vehicle to power the electric vehicle. The power battery can include a single or multiple battery cells, which can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to multiple battery cells being connected both in series and in parallel. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells is housed in a housing to form a power battery. Of course, the power battery can also be in the form of a battery module with multiple battery cells connected in series, in parallel, or in a hybrid configuration, and then the multiple battery modules are connected in series, in parallel, or in a hybrid configuration to form a complete structure, which is then housed in a housing. The power battery can also include other structures. For example, the power battery can also include a busbar component for electrically connecting the multiple battery cells. Each battery cell can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell can be cylindrical, flat, rectangular, or in other shapes.

[0044] Battery thermal runaway refers to a cumulative increase in battery current and temperature, leading to gradual damage. For example, in a typical lead-acid battery, since the positive and negative plates are filled with liquid, leaving no gaps between them, oxygen generated at the positive electrode during charging cannot reach the negative electrode. Consequently, the negative electrode, undepolarized, is more likely to produce hydrogen, which escapes the battery along with the oxygen, leading to thermal runaway. Another example is when the oxygen circulation path within a lead-acid battery is too unobstructed, oxygen released from the positive plate directly acts on the negative plate, causing the heat generated to be unable to be dissipated in a timely manner, leading to thermal runaway. Another example is when a cell in a lead-acid battery pack fails prematurely during use. During charging, while maintaining a constant charging voltage, the voltage of the prematurely failed cell will not rise or will rise very slowly, prolonging the charging time. This can cause the voltage of the healthy cell to be relatively high, and can also cause the cell or the entire battery pack to overheat due to overcharging, leading to thermal runaway.

[0045] Among them, for a power battery composed of multiple battery cells connected in series or parallel, as long as one battery cell experiences thermal runaway, it indicates that the entire power battery has experienced thermal runaway.

[0046] Among them, current electric vehicles are generally also equipped with a Battery Management System (BMS) to monitor and collect data from the power battery. The collected power battery data can be sent to the terminal to alarm relevant personnel, so that relevant personnel can trace the problem.

[0047] The battery management system (BMS) manages the battery, typically monitoring battery voltage to prevent or avoid abnormal conditions such as over-discharge, over-charging, and over-temperature. With technological advancements, numerous functions have been added, including communication, SoC estimation, SoH estimation, abnormality warnings, abnormality protection, balancing (passive or active balancing), other control circuits (such as battery circuit relay control), temperature measurement, current measurement, and diagnostics.

[0048] Monitoring refers to the detection, analysis, and judgment of relevant data / parameters of the monitored object. Taking this application as an example, monitoring refers to the battery management system collecting and detecting the voltage, current, air pressure, insulation value, temperature change rate, air pressure change rate, etc. of the power battery, and then analyzing and evaluating the thermal runaway risk and adjusting the monitoring mode based on the evaluation results.

[0049] However, existing battery monitoring systems often use a timed monitoring approach. For example, during vehicle wake-up monitoring, the monitoring duration is set to 5 minutes, with a wake-up interval of 1 hour. If battery thermal runaway does not occur during the monitoring period, even if the battery temperature is found to be too high or rising rapidly, the battery system will still wake up again after the preset 1-hour sleep period. During this sleep period, the possibility of thermal runaway is high. Because existing battery monitoring systems cannot monitor and collect battery data during sleep, the cause of subsequent battery thermal runaway cannot be traced, and the alarm is not issued in a timely manner, leaving users unable to remedy the situation in advance.

[0050] Furthermore, the inventors of this application have discovered that thermal runaway of power batteries often occurs within a few hours after charging or driving is completed, with the risk being highest within approximately half an hour. However, existing battery monitoring systems often use a timed monitoring method that goes dormant for an hour after charging or driving is completed, making it easy to miss monitoring periods with a higher risk of thermal runaway, leading to safety hazards. In view of this, this application proposes a method for monitoring thermal runaway of power batteries, which specifically includes:

[0051] In response to the completion of charging of the power battery or the completion of power-off of the electrical equipment using the power battery, the battery management system starts the first monitoring mode, wherein the first monitoring mode includes: continuously monitoring the power battery for a first preset time and collecting first battery data of the power battery; in response to the first battery data meeting the first preset condition, the battery management system enters the second monitoring mode, wherein the second monitoring mode is a periodic short-time wake-up monitoring mode in the sleep state, and continuously monitors the power battery for a second preset time after each wake-up, and the second preset time is less than the first preset time.

[0052] For details, please see Figure 1 , Figure 1 The present invention provides a flow chart of an embodiment of a method for monitoring thermal runaway of a power battery, which specifically includes:

[0053] Step S11: In response to the completion of charging of the power battery or the completion of power-off of the electrical equipment using the power battery, the battery management system continuously monitors the power battery for a first preset time period and collects first battery data of the power battery.

[0054] Specifically, since thermal runaway of electric vehicles often occurs after the vehicle is fully charged or driving and then goes into sleep mode, the battery management system starts the first monitoring mode after the power battery is fully charged or the electrical equipment using the power battery is fully powered off.

[0055] It should be noted that the first monitoring mode involves continuously monitoring the power battery for a first preset duration and collecting first battery data from the power battery. Because power battery thermal runaway often occurs within a few hours after charging is completed or the vehicle is powered off after driving, and the risk is particularly high within approximately half an hour, long-term monitoring of at least 20 minutes is performed after charging is completed or the vehicle is powered off after driving. This means that various power battery parameters are continuously monitored for at least 20 minutes. During this monitoring process, first battery data from the power battery is collected.

[0056] In some embodiments, optionally, the first preset duration is 30 to 60 minutes, for example, 30 minutes, 45 minutes, or 60 minutes, etc., which is not limited here.

[0057] It is understandable that the electrical equipment in the above step S11 can be not only an electric vehicle, but also other types of electrical equipment including a power battery, which is not specifically limited.

[0058] Step S12: In response to the first battery data satisfying the first preset condition, the battery management system periodically and briefly wakes up the monitoring mode in the dormant state, and continuously monitors the power battery for a second preset time after each wake-up, where the second preset time is less than the first preset time.

[0059] Among them, the first battery data meets the first preset condition, indicating that the various data of the power battery are in a safe state. In this way, the battery management system can be converted into a conventional second monitoring mode, and the second preset time length in the second monitoring mode is less than the first preset time length in the first monitoring mode, thereby saving energy consumption.

[0060] In one specific embodiment, the second monitoring mode includes: the battery management system wakes up after each sleep period of a fourth preset duration to continuously monitor the power battery for a second preset duration. For example, wake up for monitoring (monitoring for the second preset duration), sleep (for the fifth preset duration), wake up for monitoring (monitoring for the second preset duration), sleep (for the fifth preset duration), etc. The second preset duration is less than or equal to 10 minutes, and the fifth preset duration is greater than or equal to 1 hour. This approach reduces monitoring energy consumption while extending the monitoring duration. The fifth preset duration can be 1 hour, 2 hours, or 6 hours, and the system gradually transitions from shorter sleep periods to longer sleep periods. For example, the system may first wake up every hour, then determine the risk of thermal runaway based on the data detected after waking up. If the risk of thermal runaway is low, the system may wake up every 2 hours; and so on, ultimately waking up every 6 hours.

[0061] Understandably, since power battery thermal runaway often occurs within a few hours after charging or driving, and the risk is particularly high within the first half hour or so, setting the first preset duration to greater than 20 minutes can more effectively monitor thermal runaway. In a preferred embodiment, the first preset duration is 30 minutes.

[0062] In some embodiments, optionally, the first battery data includes temperature data of the power battery, and the first preset condition includes a temperature threshold.

[0063] Specifically, the battery management system collects temperature data of the power battery in the first monitoring mode, and determines the relationship between the collected temperature data and the temperature threshold according to a preset temperature threshold condition, thereby determining the risk of thermal runaway of the power battery.

[0064] It can be understood that the temperature of the power battery is a relatively intuitive basis for judging whether thermal runaway occurs in the power battery. The present application collects the temperature data of the power battery in the first monitoring mode, and compares the collected temperature data with the preset temperature threshold, which can intuitively reflect whether the power battery has the risk of thermal runaway.

[0065] In some embodiments, optionally, the temperature data includes T1 and T2, wherein T1 is the maximum temperature of the battery cell of the power battery monitored at the start time of continuously monitoring the power battery for the first preset time period, and T2 is the maximum temperature of the battery cell of the power battery monitored at the end time of continuously monitoring the power battery for the first preset time period, and the temperature thresholds include Tx and Ty, wherein Tx is 50-60°C and Ty is 3-7°C; wherein, the first preset condition includes (T2≤T1), or (T2>T1 and T2≤Tx and T2-T1≤Ty), wherein Tx is 50-60°C and Ty is 3-7°C.

[0066] Where T2 ≤ T1 indicates that the power battery temperature remains unchanged or decreases during the first preset time period. Where T2 > T1 and T2 ≤ Tx, T2 - T1 ≤ Ty, where Tx is 50-60°C and Ty is 3-7°C, indicates that the power battery temperature increases during the first preset time period, but the increased temperature remains within a safe range, and the increase is also within a safe range. In one embodiment, Tx is 55°C and Ty is 5°C.

[0067] Specifically, the power battery of an electric vehicle is typically composed of multiple battery cells. After the power battery is fully charged, or after the power-consuming device using the power battery is powered off, the battery management system continuously monitors the temperatures of the multiple battery cells for a first preset duration, such as greater than or equal to 20 minutes. The battery management system collects the temperature of the battery cell with the highest temperature at the start of monitoring as the maximum battery temperature T1 at the start of the first preset duration, and collects the temperature of the battery cell with the highest temperature at the end of monitoring as the maximum battery temperature T2 at the end of the first preset duration. If T2 ≤ T1, or (T2 > T1 and T2 ≤ Tx, T2 - T1 ≤ Ty), the likelihood of thermal runaway occurring during the first preset duration is low, and the battery management system enters a second monitoring mode. The second monitoring mode periodically wakes up from a dormant state for a short period of time, continuously monitoring the power battery for a second preset duration after each wakeup.

[0068] In some embodiments, optionally, in response to the first battery data not satisfying the first preset condition, the battery management system first sleeps for a third preset time period, and then wakes up the battery management system to collect temperature data; wherein, the third preset time period is less than or equal to 10 minutes, and the temperature data includes T3, and T3 is the maximum temperature of the battery cell of the power battery monitored by the battery management system at the end of the third preset time period of sleep; in response to the temperature data T3 satisfying: (T3≤T2), or (T3>T2 and T3≤Tx and T3-T2≤Ty), the battery management system enters the second monitoring mode; otherwise, continue to execute the step of continuously monitoring the power battery for the first preset time period.

[0069] For details, please see Figure 2 , Figure 2 This is a flow chart of another embodiment of the power battery thermal runaway monitoring method provided by this application, wherein step S21 is the same as the above Figure 1 The step S11 in the embodiment shown is the same as that in the above embodiment. Figure 1 The difference between the embodiment shown is that, after step S21, the embodiment includes:

[0070] Step S22: In response to the first battery data not satisfying the first preset condition, the battery management system first sleeps for a third preset time period, and then wakes up the battery management system to collect temperature data.

[0071] Specifically, if the first battery data does not meet the first preset condition, it means that the power battery may have a risk of thermal runaway, but the risk may not be large. It is possible that thermal runaway may occur during the dormant period after the monitoring period ends. Therefore, after the battery management system has been dormant for the third preset period, it wakes up the battery management system to collect temperature data of the power battery for comparison with the temperature data collected during the last monitoring period to determine whether the battery has thermal runaway.

[0072] The third preset duration is less than or equal to 10 minutes, such as 5 minutes or 8 minutes, to shorten the sleep period of the battery management system, thereby promptly monitoring data related to thermal runaway of the power battery. The temperature data includes T3, which is the maximum temperature of the power battery cells monitored by the battery management system at the end of the third preset sleep period, that is, the maximum temperature of the power battery cells monitored when the battery management system wakes up after the third preset sleep period.

[0073] Step S23: In response to the temperature data T3 satisfying: (T3≤T2), or (T3>T2 and T3≤Tx and T3-T2≤Ty), the battery management system enters the second monitoring mode; otherwise, continues to execute the step of continuously monitoring the power battery for the first preset time period.

[0074] Specifically, T3≤T2 indicates that during the third preset sleep period of the battery management system, the maximum battery cell temperature of the power battery decreases or remains unchanged, and there is basically no overheating risk. The battery management system enters the second monitoring mode to reduce power consumption.

[0075] T3>T2 and T3≤Tx and T3-T2≤Ty indicates that during the third preset duration, the power battery temperature increases, but the increased temperature is within a safe temperature range, and the increase is also within a safe range, with little risk of overheating. The battery management system enters the second monitoring mode to reduce power consumption. The data values ​​of Tx and Ty are the same as those provided in the previous embodiment and are not repeated here.

[0076] If the temperature data T3 does not meet the above two conditions, the step of continuously monitoring the power battery for the first preset time period is continued to monitor the thermal runaway risk and ensure the safety and reliability of the power battery.

[0077] Specifically, in the power battery thermal runaway monitoring method provided by this embodiment, during the first monitoring mode, when the first battery data does not meet the first preset condition, the battery management system first sleeps for a third preset time because it meets the monitoring requirements of the first preset time, and then wakes up the battery management system to collect the temperature data of the power battery for the first time, and compares it with the temperature data collected at the end of the last monitoring, to judge the thermal runaway risk of the power battery during the sleep period of the third preset time, and when the temperature data is (T3≤T2), or (T3>T2 and T3≤Tx and T3-T2≤Ty), it indicates that there is no thermal runaway risk, and the battery management system enters the second monitoring mode to reduce power consumption; otherwise, the step of continuously monitoring the power battery for the first preset time is continued to be executed to continuously monitor the thermal runaway risk and ensure the safety and reliability of the power battery.

[0078] In some embodiments, optionally, the temperature data only includes T2, where T2 is the maximum temperature of the battery cell of the power battery monitored at the end of the first preset time period of continuous monitoring of the power battery; the temperature threshold only includes Tx, where Tx is 50-60°C; and the first preset condition includes T2≤Tx.

[0079] Specifically, in the first monitoring mode, the battery management system only monitors the maximum temperature T2 of the power battery cells at the end of the first preset time period, and compares it with the temperature threshold Tx. If T2 ≤ Tx, it indicates that there is no risk of thermal runaway in the power battery. The value range of Tx is 50-60°C, for example, Tx can be 50°C, 55°C, or 60°C.

[0080] Specifically, the battery management system of this embodiment only monitors the maximum temperature of the battery cells of the power battery at the end time of the first monitoring mode to compare with the preset temperature threshold, so as to judge the thermal runaway risk of the power battery and simplify the comparison logic, thereby reducing the amount of calculation and further reducing the power consumption of the equipment.

[0081] In some embodiments, optionally, the first battery data further includes: a minimum voltage Vd of a battery cell of the power battery, and the first preset condition further includes: Vd ≥ Vx, where Vx is 1-3 volts.

[0082] Specifically, if the lowest voltage Vd of a power battery cell is less than Vx, it indicates an increased risk of thermal runaway due to damage or failure of the cell. Therefore, this embodiment collects the lowest voltage Vd of the cell in addition to T1 and T2 within a first preset time period after the power battery is fully charged or the device using the power battery is powered off. If Vd ≥ Vx, the likelihood of thermal runaway is low. Specifically, this embodiment adds a voltage check for the cell, improving the reliability of thermal runaway detection and increasing the data collection range. In one embodiment, Vx is 2 volts.

[0083] In another embodiment, the first battery data further includes: an insulation value of the power battery; and the first preset condition further includes: no insulation fault during continuous monitoring of the power battery for a first preset time period.

[0084] The insulation value of a power battery refers to the impedance corresponding to the maximum leakage current between the positive and negative busbars of the power battery insulation resistance and ground. The power battery voltage in existing electric vehicles can reach as high as 300-600V, far exceeding the voltage that is safe for the human body. Insulation failures can lead to battery aging, thermal runaway, or breakdown, posing a safety hazard.

[0085] In this embodiment, when the power battery is fully charged or the power-consuming device using the power battery is powered off, in addition to collecting the aforementioned T1, T2, and Vd, the power battery's insulation value is also collected within a first preset duration. Based on the insulation value, it is determined whether an insulation fault exists during the first preset duration. If no insulation fault exists, the likelihood of thermal runaway is low. Specifically, this embodiment further utilizes the battery's insulation value to determine thermal runaway, improving the reliability of thermal runaway detection and increasing the data collection range.

[0086] Specifically, the power battery thermal runaway monitoring method provided in this embodiment can monitor the battery during the period when the probability of thermal runaway is highest, facilitating problem tracing and vehicle background warning. After determining that thermal runaway will not occur, the battery management system enters the second monitoring mode to reduce energy consumption.

[0087] In addition, the battery management system in the present application can also send the location of the battery cell that has experienced thermal runaway in the power battery composed of multiple battery cells connected in series / parallel to the terminal to facilitate subsequent maintenance.

[0088] In one embodiment, the first monitoring mode includes: before the step of continuously monitoring the power battery for the first preset time period, the battery management system first sleeps for a fourth preset time period, and then wakes up the battery management system to continue monitoring the power battery for the first preset time period, wherein the fourth preset time period is less than 10 minutes. In one embodiment, the fourth preset time period is 5 minutes.

[0089] For details, please see Figure 3 , Figure 3 This is a flow chart of another embodiment of the power battery thermal runaway monitoring method provided by this application, wherein step S33 is the same as the above Figure 1 The step S12 in the embodiment shown is the same as that in the above embodiment. Figure 1 The difference between the embodiment shown is that, before step S33, this embodiment further includes:

[0090] Step S31: In response to the completion of charging of the power battery or the completion of power-off of the power-consuming device using the power battery, the battery management system first sleeps for a fourth preset time period.

[0091] Specifically, after the power battery is fully charged or the power-consuming device is powered off, the battery management system will first put it into hibernation for a fourth preset duration. During this hibernation period, any power battery faults may be automatically eliminated. Therefore, putting the battery management system into hibernation for the fourth preset duration can reduce the probability of false detections. Furthermore, the fourth preset duration is less than 10 minutes, which substantially does not affect subsequent monitoring of the power battery during the phase with the highest risk of thermal runaway. In some preferred embodiments, the fourth preset duration is 2-7 minutes, for example, 5 minutes.

[0092] Step S32: wake up the battery management system after the fourth preset time period to continuously monitor the power battery for the first preset time period and collect first battery data of the power battery.

[0093] That is, the first monitoring mode includes waking up after every fourth preset time period and continuously monitoring the power battery for the first preset time period.

[0094] Specifically, in the power battery thermal runaway monitoring method provided in this embodiment, the power battery fault may be automatically eliminated after the power battery is charged or the electrical equipment using the power battery is powered off. Therefore, the battery management system first sleeps for a fourth preset time period to reduce the occurrence of false detection. The fourth preset time period is less than 10 minutes, which basically does not affect the subsequent monitoring of the stage with the highest risk of thermal runaway of the power battery.

[0095] In some embodiments, in response to the first battery data not satisfying the first preset condition, the battery management system repeatedly executes the first monitoring mode and continues to determine whether the first battery data satisfies the first preset condition.

[0096] For details, please see Figure 4 , Figure 4 This is a flow chart of another embodiment of the power battery thermal runaway monitoring method provided by this application, wherein step S41 is the same as the above Figure 1 The step S11 in the embodiment shown is the same as that in the above embodiment. Figure 1 The difference between the embodiment shown is that, after step S41, this embodiment further includes:

[0097] Step S42: In response to the first battery data not satisfying the first preset condition, the battery management system repeatedly executes the first monitoring mode and continues to determine whether the first battery data satisfies the first preset condition.

[0098] Specifically, if the first battery data does not meet the first preset condition, it means that the power battery may have a thermal runaway risk. Therefore, it is necessary to continue to monitor the power battery in the first monitoring mode and continuously determine whether the first battery data of the power battery meets the first preset condition to monitor the thermal runaway risk and ensure the safety and reliability of the power battery.

[0099] In some embodiments, optionally, in response to the first battery data not meeting the second preset condition during repeated execution of the first monitoring mode, and the number of times the battery management system executes the first monitoring mode is greater than the preset number of times or the sum of the first preset time lengths of multiple executions of the first monitoring mode is greater than the preset time threshold, the battery management system enters the second monitoring mode; wherein the preset number of times is 2-5 times, and the preset time threshold is 60-120 minutes.

[0100] Specifically, if the first battery data does not meet the second preset condition, it means that the risk of thermal runaway of the power battery is not high. If the battery management system executes the first monitoring mode more than a preset number of times, such as 2 times, 3 times or 5 times, and the first battery parameters of the power battery collected under the first monitoring mode for multiple executions do not meet the first preset condition but do not exceed the safety range, it means that the risk of thermal runaway of the power battery has not increased. In this way, the battery management system can enter the second monitoring mode to reduce the energy loss of the battery management system.

[0101] Alternatively, if the battery management system executes the first monitoring mode multiple times, the total of the accumulated first preset time lengths is greater than the preset time threshold, such as the first preset time lengths accumulate to 60 minutes, 90 minutes, 120 minutes, etc., and the first battery parameters and first battery data of the power battery collected under the accumulated time length do not meet the second preset conditions, which means that the thermal runaway risk of the power battery has not increased, so the battery management system can enter the second monitoring mode to reduce the energy loss of the battery management system.

[0102] Specifically, in the power battery thermal runaway monitoring method provided in this embodiment, when first battery data fails to meet a first preset condition, the battery management system repeatedly executes the first monitoring mode and continues to determine whether the first battery data meets the first preset condition. This allows monitoring for thermal runaway risks within several hours after the power battery is charged or powered off after driving, thereby ensuring the safety and reliability of the power battery. Furthermore, if the first battery data fails to meet a second preset condition, the number of executions of the first monitoring mode reaches a preset number, or the total duration of execution of the first monitoring mode exceeds a preset time threshold, indicating that the thermal runaway risk has not increased, the battery management system enters the second monitoring mode to reduce energy loss in the battery management system.

[0103] In one embodiment, in response to the first battery data not satisfying the first preset condition but satisfying the second preset condition, the battery management system repeatedly executes the first monitoring mode, and collects the second battery data of the power battery for the first preset time period during the next continuous monitoring of the power battery; determines whether thermal runaway occurs in the power battery based on the first battery data and the second battery data; and issues an early warning in response to thermal runaway of the power battery.

[0104] For details, please see Figure 5 , Figure 5 This is a flow chart of another embodiment of the power battery thermal runaway monitoring method provided by this application, wherein step S51 is the same as the above Figure 1 The step S11 in the embodiment shown is the same as that in the above embodiment. Figure 1 The difference between the embodiment shown is that, after step S51, this embodiment further includes:

[0105] Step S52: In response to the first battery data not satisfying the first preset condition but satisfying the second preset condition, the battery management system repeatedly executes the first monitoring mode and collects second battery data of the power battery during the next continuous monitoring of the power battery for the first preset time period.

[0106] Among them, the second preset condition includes T2≥Tz and / or (T2-T1)≥To, wherein Tz is 55-70℃ and greater than Tx, and To is 5-10℃ and greater than Ty; the second battery data includes the real-time temperature of the battery cell of the power battery, and / or the heating rate, the real-time air pressure, and / or the air pressure change rate, and / or the real-time voltage, and / or the voltage drop rate.

[0107] Specifically, Tx can be 55°C, 60°C, 65°C, or 70°C. If Tx is 60°C, when T2 is greater than or equal to Tz, it indicates that the battery cell temperature is greater than or equal to 60°C, and the battery cell is judged to be at risk of thermal runaway due to excessive temperature. Alternatively, To can be 5°C, 7°C, 9°C, or 10°C. If To is 7°C, when T2-T1 is greater than or equal to To, it indicates that the power battery temperature has increased within the first preset time period, and the increase is greater than the safe range. In this case, the battery cell is judged to be at risk of thermal runaway due to excessive temperature rise.

[0108] In response to the first battery data meeting the second preset condition, the battery management system repeatedly executes the first monitoring mode, and collects the second battery data of the power battery during the next continuous monitoring of the power battery for the first preset time, wherein the second battery data includes the real-time temperature and / or heating rate, air pressure and / or air pressure change rate, voltage and / or voltage drop rate of the battery cells of the power battery, thereby increasing the data collection range to facilitate the judgment of whether the power battery is in thermal runaway, and then remind the user to take remedial measures, and facilitate problem tracing.

[0109] Step S53: Determine whether thermal runaway occurs in the power battery according to the first battery data and the second battery data.

[0110] Specifically, the battery monitoring system can determine whether the power battery has experienced thermal runaway based on the first and second battery data. Alternatively, the battery monitoring system can send the first and second battery data to a related device (such as a vehicle-mounted computer), which can then determine whether the power battery has experienced thermal runaway. The conditions for determining whether the power battery has experienced thermal runaway are the same as those in the prior art.

[0111] Step S54: In response to thermal runaway of the power battery, issuing a warning.

[0112] If the above steps determine that the power battery has thermal runaway, an early warning will be issued. The early warning methods include but are not limited to voice broadcast, flashing indicator lights, vibration, ringing warnings, and sending prompt messages to terminals (such as mobile phones and computers).

[0113] Specifically, the power battery thermal runaway monitoring method provided in this embodiment indicates that when first battery data does not meet a first preset condition but meets a second preset condition, it indicates a high probability of thermal runaway in the power battery. The battery management system then repeatedly executes the first monitoring mode and, during the next continuous monitoring of the power battery, collects second battery data from the power battery for a first preset duration. This further monitors other power battery data, expanding the data collection scope to facilitate subsequent fault cause analysis and repair. Furthermore, the method determines whether thermal runaway has occurred in the power battery based on the first and second battery data. In response to thermal runaway, the battery management system issues an early warning, enabling users to take remedial measures in advance.

[0114] Specifically, the power battery thermal runaway monitoring method provided in this application collects relevant data from the power battery during the phase with the highest risk of thermal runaway. Based on this data, the power battery is effectively monitored for thermal runaway, facilitating backend early warning and problem tracing, thereby improving vehicle safety. Furthermore, while ensuring improved vehicle safety, the switching strategy between the first and second monitoring modes is established, reducing monitoring energy consumption and conserving electricity.

[0115] See Figure 6 , Figure 6 This is a functional module diagram of an embodiment of a power battery thermal runaway monitoring system provided in this application. The power battery thermal runaway monitoring system 60 includes a battery management system 61 and a DC-DC converter 62. The battery management system 61 and the DC-DC converter 62 cooperate to execute the power battery thermal runaway monitoring method provided in any of the above embodiments.

[0116] Specifically, after the power battery is charged or the power-consuming device using the power battery is powered off, it enters a sleep state. After the sleep state ends, the DCDC converter 62 wakes up the battery management system 61 and cooperates with the battery management system 61 to execute the power battery thermal runaway monitoring method provided in any of the above embodiments.

[0117] In some embodiments, the power battery thermal runaway monitoring system described above can be applied to electric vehicles equipped with power batteries.

[0118] See Figure 7 , Figure 7 Schematic diagram of the functional modules of the electric vehicle provided in this application. The electric vehicle 70 provided in this application includes a power battery 71 and the power battery thermal runaway monitoring system 60 described above.

[0119] In one embodiment, the positive and negative electrodes of the power battery 71 are electrically connected to the DCDC converter 62. The battery management system 61 is connected to the power battery 61 via a first lead CAN1, and the battery management system 61 is connected to the DCDC converter 62 via a second lead CAN2.

[0120] Furthermore, the electric vehicle also includes a remote transmission device (T-BOX) 72, which is connected to the battery management system 61 via a third lead CAN3. After performing thermal runaway monitoring, the battery management system 61 can further transmit monitoring data and / or monitoring results (whether thermal runaway has occurred) to the remote transmission device 72. The remote transmission device 72 and / or the battery management system 61 can also transmit the monitoring data and / or monitoring results to a terminal to facilitate user monitoring of the vehicle status. It should be noted that when the remote transmission device 72 and / or the battery management system 61 transmit the monitoring data and / or monitoring results to the terminal, the transmission can be based on 4G or 5G communication, and can also be transmitted via Bluetooth, Wi-Fi, etc., without limitation.

[0121] See Figure 8 , Figure 8 This is a flow chart of the method for monitoring thermal runaway of a power battery of an electric vehicle provided in this application. The method for monitoring thermal runaway of a power battery includes:

[0122] Step S81: Charging completed / power off during driving.

[0123] Step S82: The battery management system sleeps normally for 5 minutes.

[0124] Step S83: The battery management system is powered on and continuously monitors the power battery in the first monitoring mode for 30 minutes. The battery management system records the maximum battery cell temperature T1 at the wake-up time, the maximum battery cell temperature T2 at the monitoring completion time, and the minimum voltage Vd.

[0125] Step S84: If the conditions (T2≤T1 or T2>T1 and T2≤55°C and T2-T1≤5°C) are met and there is no insulation fault during the process and the minimum cell voltage Vd≥2V, the battery management system enters the second monitoring mode.

[0126] Step S85: If the conditions ((T2≤T1) or (T2>T1 and T2≤55℃ and T2-T1≤5℃)) are not met and (there is no insulation fault during the process) and the minimum cell voltage Vd≥2V are not met, then the above steps S82-S83 are re-executed to further perform the judgment process.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for monitoring thermal runaway of a power battery, characterized in that: include: In response to the power battery being charged completely or the power-consuming device using the power battery being powered off completely, the battery management system starts a first monitoring mode, wherein the first monitoring mode includes: continuously monitoring the power battery for a first preset time period and collecting first battery data of the power battery; In response to the first battery data satisfying a first preset condition, the battery management system enters a second monitoring mode, wherein the second monitoring mode is a periodic short-term wake-up monitoring mode in a dormant state, and continuously monitors the power battery for a second preset time period after each wake-up, the second preset time period being less than the first preset time period; the first battery data includes temperature data, and the first preset condition includes a temperature threshold; The temperature data includes T1 and T2, T1 is the maximum temperature of the battery cell of the power battery monitored at the start time of the first preset time period of continuous monitoring of the power battery, and T2 is the maximum temperature of the battery cell of the power battery monitored at the end time of the first preset time period of continuous monitoring of the power battery. The temperature thresholds include Tx and Ty, where Tx is 50-60°C and Ty is 3-7°C; the first preset condition includes T2>T1 and T2≤Tx and T2-T1≤Ty.

2. The method for monitoring thermal runaway of a power battery according to claim 1, wherein: The first preset duration is greater than or equal to 20 minutes.

3. The method for monitoring thermal runaway of a power battery according to claim 1, wherein: In response to the first battery data not satisfying the first preset condition, the battery management system first sleeps for a third preset time period, and then wakes up the battery management system to collect the temperature data; wherein the third preset time period is less than or equal to 10 minutes, and the temperature data includes T3, where T3 is the maximum temperature of the battery cell of the power battery monitored at the end of the third preset time period when the battery management system sleeps; In response to the temperature data T3 satisfying: T3≤T2, or T3>T2 and T3≤Tx and T3-T2≤Ty, the battery management system enters the second monitoring mode; otherwise, the step of continuously monitoring the power battery for the first preset time period is continued.

4. The method for monitoring thermal runaway of a power battery according to any one of claims 1 to 3, characterized in that: The first battery data further includes: the lowest voltage Vd of the battery cell of the power battery; the first preset condition further includes: Vd≥Vx, where Vx is 1-3 volts.

5. The method for monitoring thermal runaway of a power battery according to any one of claims 1 to 3, wherein: The first battery data further includes: an insulation value of the power battery; and the first preset condition further includes: no insulation fault during the process of continuously monitoring the power battery for a first preset time period.

6. The method for monitoring thermal runaway of a power battery according to any one of claims 1 to 3, characterized in that: The first monitoring mode includes: before the step of continuously monitoring the power battery for the first preset time, the battery management system first sleeps for a fourth preset time, and then wakes up the battery management system to execute the step of continuously monitoring the power battery for the first preset time; wherein, the fourth preset time is less than or equal to 10 minutes.

7. The method for monitoring thermal runaway of a power battery according to claim 6, wherein: The fourth preset duration is 2-7 minutes.

8. The method for monitoring thermal runaway of a power battery according to any one of claims 1 to 3, wherein: Also includes: In response to the first battery data not satisfying the first preset condition, the battery management system repeatedly executes the first monitoring mode and continues to determine whether the first battery data satisfies the first preset condition.

9. The method for monitoring thermal runaway of a power battery according to claim 8, characterized in that: Also includes: In response to the first battery data not meeting the second preset condition during the repeated execution of the first monitoring mode, and the number of times the battery management system executes the first monitoring mode is greater than the preset number or the sum of the first preset time lengths of multiple executions of the first monitoring mode is greater than the preset time threshold, the battery management system enters the second monitoring mode; wherein the preset number of times is 2-5 times, and the preset time threshold is 60-120 minutes.

10. The method for monitoring thermal runaway of a power battery according to claim 9, characterized in that: The second preset condition includes T2≥Tz and / or (T2-T1)≥To, wherein Tz is 55-70°C and greater than Tx, and To is 5-10°C and greater than Ty.

11. The method for monitoring thermal runaway of a power battery according to any one of claims 1 to 3, characterized in that: Also includes: In response to the first battery data not satisfying the first preset condition but satisfying a second preset condition, the battery management system repeatedly executes the first monitoring mode and collects second battery data of the power battery during the next continuous monitoring of the power battery for the first preset time period; determining whether thermal runaway occurs in the power battery according to the first battery data and the second battery data; as well as In response to thermal runaway of the power battery, an early warning is issued.

12. The method for monitoring thermal runaway of a power battery according to claim 11, characterized in that: The second preset condition includes T2≥Tz and / or (T2-T1)≥To, wherein Tz is 55-70°C and greater than Tx, and To is 5-10°C and greater than Ty; the second battery data includes the real-time temperature of the battery cell of the power battery, and / or the heating rate, and / or the real-time air pressure, and / or the air pressure change rate, and / or the real-time voltage, and / or the voltage drop rate.

13. The method for monitoring thermal runaway of a power battery according to any one of claims 1 to 3, characterized in that: The second monitoring mode includes: the battery management system is awakened after sleeping for a fourth preset time period to continuously monitor the power battery for a second preset time period, wherein the second preset time period is less than or equal to 10 minutes and the fourth preset time period is greater than or equal to 1 hour.

14. A power battery thermal runaway monitoring system, characterized in that: include: Battery management system; DCDC converter; The battery management system cooperates with the DCDC converter to execute the power battery thermal runaway monitoring method according to any one of claims 1 to 13.

15. An electric vehicle, characterized in that: It comprises a power battery and the power battery thermal runaway monitoring system according to claim 14.

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