Battery pack thermal runaway protection method and system

Abstract

The invention relates to the technical field of battery pack energy storage control, and discloses a battery pack thermal runaway protection method and system, and the method comprises the steps: collecting the real-time parameters of a battery cell; a control instruction is generated to drive a cluster-level electromagnetic valve to spray; multi-parameter trend consistency verification is executed; after receiving the signal, the fire-fighting host judges whether full-cluster spraying is triggered or not; and subsequent closed-loop control is completed. In the prior art, static judgment is carried out based on a single temperature or voltage threshold, and especially under the complex working conditions that thermal runaway development of a battery cell has nonlinear mutability, local sensing point abnormity or communication delay, linkage response processing of a real thermal runaway event cannot be realized. Due to the fact that the layered trend fusion judgment mechanism and the after-fire-extinguishing temperature trend closed-loop verification mechanism are constructed, the complete closed-loop process from early-stage thermal runaway judgment to multi-stage linkage spraying to fire extinguishing effectiveness feedback is achieved, and the thermal safety protection capacity under the extreme working condition is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack energy storage control, and in particular to a battery pack thermal runaway protection method and system. Background Art

[0002] Currently, existing energy storage systems typically incorporate thermal runaway triggering logic within the battery management system (BMS) and employ dry contact linkage to fire sprinkler systems for suppression. However, existing technologies still suffer from significant shortcomings. First, thermal runaway triggering criteria generally rely on single-threshold logic, such as a temperature exceeding 80°C or a voltage below 2V being considered abnormal. However, these static criteria fail to fully reflect the dynamic evolution of thermal runaway and are susceptible to interference from short-term fluctuations, leading to misjudgments or missed detections. For example, high ambient temperatures or slowly rising average temperatures can mask the early signs of localized thermal abrupt changes, while transient high-temperature disturbances can be mistakenly identified as runaway signals. Furthermore, the linkage logic between the BMS and firefighting systems often lacks real-time reliability and credibility verification. In existing solutions, the BMS only directly outputs a dry contact signal upon identifying a suspected thermal runaway event. The firefighting host has no way of verifying the authenticity of the reported data, and lacks cross-node data verification or trend consistency mechanisms. This makes it prone to misjudgment or missed detections due to communication anomalies, node failures, or data drift. In actual projects, a false alarm in a cluster will trigger the activation of the firefighting system in the entire station, and all the chemicals will be released, causing economic losses and system shutdown. However, a real thermal runaway of the battery cell will cause the fire to spread due to the delayed triggering and the failure to spray in time.

[0003] Existing technologies cannot fully meet the safety requirements of high-precision identification of thermal runaway events, stable linkage control, and closed-loop feedback of fire extinguishing effects under complex operating conditions, local abnormal evolution, or linkage scenarios. Therefore, a battery thermal runaway protection method with dynamic multi-parameter trend judgment capabilities, linkage consistency verification mechanisms, and closed-loop feedback capabilities for post-fire extinguishing effectiveness is urgently needed to improve the accuracy of risk identification, linkage response stability, and overall thermal safety protection of energy storage systems under abnormal operating conditions. Summary of the Invention

[0004] In response to the above-mentioned technical deficiencies, the purpose of the present invention is to propose a battery pack thermal runaway protection method, aiming to solve the technical problem that the existing technology is mostly based on static judgment based on a single temperature or voltage threshold, especially under complex working conditions where the development of thermal runaway of the battery cell has nonlinear mutations, local sensor point abnormalities or communication delays, and it is impossible to achieve a linked response to real thermal runaway events.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a battery pack thermal runaway protection method, The battery pack thermal runaway protection method includes: Step S10: The preset BCU unit collects the real-time operating parameters of the cell i in the target battery pack at time t, and uses the continuous interval joint state mechanism based on the real-time operating parameters to determine whether the thermal runaway trigger condition is met, and outputs the thermal runaway identification flag. ; Step S20: Based on thermal runaway identification flag Generate corresponding electrical signal control instructions, and the preset BCU unit outputs the electrical signal control instructions to the cluster-level solenoid valve control interface on the top of the battery cluster, and at the same time sends real-time operating parameters and thermal runaway identification flags to the battery cluster. sent to the superior BAU unit; Step S30: Obtain the thermal runaway feedback data of the battery cell. The upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs a dry contact closure signal. ; Step S40: The fire host receives the dry contact closing signal , when the dry contact closes the signal =1, it is determined whether the global spraying and fire extinguishing linkage condition is met. If so, a cluster-wide spraying and fire extinguishing instruction is issued and the global protection state flag F is output; Step S50: When the global protection status flag F is 1, the temperature data of the target area is collected based on the preset infrared temperature measurement unit, the average temperature drop rate of the target area is calculated within the preset continuous time window, and the total temperature drop amplitude of the target area is obtained; the effectiveness of the fire extinguishing action is judged based on the average temperature drop rate and the total temperature drop amplitude of the target area, and the post-drive behavior closed-loop control is performed based on the judgment result.

[0006] Preferably, in step S10, a continuous interval joint state mechanism is used based on real-time operating parameters to determine whether the thermal runaway trigger condition is met, and a thermal runaway identification flag is output. The steps include: Real-time operating parameters include cell voltage , battery cell temperature and the rate of temperature rise per unit time , construct a continuous criterion set based on the sliding time window Δt, and judge whether the following three conditions are met simultaneously in the continuous criterion set: Condition 1: Within the sliding time window Δt, the cell voltage The minimum value is less than 2V and there is no disconnection process; Condition 2: Within the sliding time window Δt, the cell temperature The maximum value is greater than 80℃; Condition 3: There is at least one time point within the sliding time window Δt , at the time point The temperature rise rate per unit time is greater than or equal to 1°C / s and lasts for more than 3 seconds; If the above three conditions are met within the sliding time window Δt, the thermal runaway identification flag is output. , otherwise output .

[0007] Preferably, in step S20, the cluster-level solenoid valve control interface drives the sprinklers in the cluster to start and realize the localized spraying fire extinguishing operation in real time.

[0008] Preferably, in step S30, the thermal runaway feedback data of the battery cell is obtained, and the upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs a dry contact closure signal. The steps include: Within the sliding time window Δt, the real-time operating parameters reported by the BCU unit are extracted, and the local operating parameters recorded locally by the BMS unit are collected at the same time; Compare the consistency of the three fitting trends based on the real-time operating parameters reported by the BCU unit and the local operating parameters recorded locally by the BMS unit, and output the dry contact closure signal based on the comparison results of the consistency of the three fitting trends .

[0009] Preferably, in step S30, the consistency of the three fitting trends is compared, and a dry contact closing signal is output according to the comparison result of the consistency of the three fitting trends. The steps specifically include: The data of the battery cell temperature in the real-time operating parameters are fitted using a least squares linear fitting method to obtain a first temperature trend line; the data of the battery cell temperature in the local operating parameters are fitted using a least squares linear fitting method to obtain a second temperature trend line; The data of the cell voltage in the real-time operating parameters are fitted using a sliding average combined with a first-order difference method to obtain a first voltage trend line; the data of the cell voltage in the local operating parameters are fitted using a sliding average combined with a first-order difference method to obtain a second voltage trend line; Compare the consistency of the following three fitted trends: Condition 1: The fitting error between the first temperature trend line and the second temperature trend line in slope does not exceed the set first error threshold ; Condition 2: The fitting error between the first voltage trend line and the second voltage trend line in terms of slope does not exceed the set second error threshold ; Condition 3: The spraying duration is obtained from the spraying status feedback data, and the spraying duration is greater than the set tolerance ; If all three conditions are met, the real-time operating parameters reported by the BCU unit are considered credible, and a dry contact closure signal is output. ; Otherwise, the dry contact closing signal is output 0.

[0010] Preferably, in step S40, if the condition is met, a full-cluster spraying fire extinguishing instruction is issued, and a global protection status flag F is output, specifically including: if the condition is met, the cylinder solenoid valve connected to the fire host is opened, and the full-cluster spraying unit connected to the fire host is started to perform a unified fire extinguishing operation, and at the same time, the data recorder, infrared thermal imaging and smoke monitoring unit connected to the fire host are activated for linkage recording; and the global protection status flag F is output.

[0011] Preferably, in step S50, the fire extinguishing action effectiveness judgment is performed based on the average temperature drop rate and the total temperature drop amplitude of the target area, and the post-driving behavior closed-loop control step is performed based on the judgment result, specifically including: The effectiveness of the fire extinguishing action is determined based on the average temperature drop rate and the total temperature drop amplitude in the target area. If both of the following conditions are met: Condition 1: The average temperature drop rate is less than or equal to 0.5°C / s; Condition 2: The total temperature drop amplitude in the target area is greater than or equal to 15°C, the fire extinguishing action is considered effective. Conversely, if either of the above conditions is not met, the fire extinguishing action is considered ineffective. When the fire extinguishing action is determined to be effective, the fire host controls the disconnection of the solenoid valve control circuit and records the current linkage event log; When it is determined that the fire extinguishing action is invalid, the fire host maintains the spraying action and sends a linkage failure signal to the BMS unit.

[0012] The present invention also provides a battery pack thermal runaway protection system comprising: The thermal runaway judgment module is used to collect the real-time operating parameters of the battery cell i in the target battery pack at time t through the preset BCU unit, and use the continuous interval joint state mechanism based on the real-time operating parameters to determine whether the thermal runaway trigger condition is met, and output the thermal runaway identification flag bit ; Linkage signal output module, used to identify the flag based on thermal runaway Generate corresponding electrical signal control instructions, and the preset BCU unit outputs the electrical signal control instructions to the cluster-level solenoid valve control interface on the top of the battery cluster, and at the same time sends real-time operating parameters and thermal runaway identification flags to the battery cluster. sent to the superior BAU unit; The consistency verification module is used to obtain the thermal runaway feedback data of the battery cell. The upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs the dry contact closure signal ; Global linkage judgment module, used for fire host to receive dry contact closure signal , when the dry contact closes the signal =1, it is determined whether the global spraying and fire extinguishing linkage condition is met. If so, a cluster-wide spraying and fire extinguishing instruction is issued and the global protection state flag F is output; The fire extinguishing closed-loop control module is used to collect the temperature data of the target area based on the preset infrared temperature measurement unit when the global protection status flag F is 1, calculate the average temperature drop rate of the target area within a preset continuous time window, and obtain the total temperature drop amplitude of the target area; perform the effectiveness judgment of the fire extinguishing action based on the average temperature drop rate and the total temperature drop amplitude of the target area, and perform the post-drive behavior closed-loop control based on the judgment result.

[0013] The present invention also provides a battery pack thermal runaway protection device, comprising: a memory, a processor, and a battery pack thermal runaway protection program stored in the memory and runnable on the processor. When the battery pack thermal runaway protection program is executed by the processor, a battery pack thermal runaway protection method is implemented.

[0014] The present invention also provides a computer program product, including a battery pack thermal runaway protection program, which implements the battery pack thermal runaway protection method when executed by a processor.

[0015] The beneficial effect of the present invention is that by introducing continuous time window criteria of voltage, temperature and temperature rise rate, the present invention effectively avoids the non-real thermal runaway triggering caused by false alarm or omission of a single threshold in the prior art, and significantly improves the accuracy and anti-interference ability of thermal runaway identification.

[0016] The present invention realizes a multi-level response chain from front-end identification to end-point spraying and back-end review through the trend consistency verification of the upper-level BMS and the fire extinguishing effect judgment mechanism of the fire host. Compared with traditional technical solutions that cannot judge the effectiveness of fire extinguishing, it significantly improves the safety protection efficiency and reliability of the energy storage system under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a flow chart of a first embodiment of a battery pack thermal runaway protection method according to the present invention.

[0019] Figure 2 This is a schematic diagram of the overall logical framework of the first embodiment of a battery pack thermal runaway protection method of the present invention.

[0020] Figure 3 Schematic diagram of equipment for a battery pack thermal runaway protection method according to the present invention. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] Example 1: Figure 1 2 is a flow chart of the first embodiment of the battery pack thermal runaway protection method according to the present invention, which provides the first embodiment of the battery pack thermal runaway protection method according to the present invention.

[0023] In a first embodiment, the battery pack thermal runaway protection method includes: Step S10: The preset BCU unit collects the real-time operating parameters of the cell i in the target battery pack at time t, and uses the continuous interval joint state mechanism based on the real-time operating parameters to determine whether the thermal runaway trigger condition is met, and outputs the thermal runaway identification flag. ; It should be noted that the "continuous interval joint state mechanism" refers to real-time monitoring of multiple operating parameters of the same battery cell within a preset continuous time range (for example, 5 seconds or 10 seconds), and determining whether these parameters are continuously in an abnormal state throughout the entire time interval. Operating parameters include but are not limited to: whether the battery cell voltage has dropped significantly, whether the temperature has exceeded the set threshold, whether the temperature change is a rapid increase, etc. Only when these conditions are met simultaneously and continuously within the time range will it be determined as a true thermal runaway state and the corresponding identification flag will be output. This mechanism avoids excessive reliance on "single-moment abnormal values" and makes the judgment more temporally continuous and logically robust.

[0024] It's understandable that by combining and continuously evaluating multiple physical indicators over a specific time period, the ability to identify early signs of thermal runaway is significantly improved. In the early stages of thermal runaway, although the instantaneous temperature or voltage values ​​may not yet reach the danger threshold, their changing trends already exhibit abnormal characteristics, such as a sustained rapid temperature rise or a continuous voltage drop. Through continuous observation and combined logic, this invention can issue a warning signal before a full thermal runaway event occurs, thereby increasing reaction time for subsequent spray control and coordinated response.

[0025] It should be understood that traditional technical solutions typically rely on a single indicator (such as a temperature exceeding 80°C) to trigger an alarm, lacking the ability to analyze the correlation and evolution of parameters. This approach is prone to misjudgment in the presence of sensor noise, data transients, or operating disturbances, especially when the battery cell temperature approaches but does not exceed the threshold, and may not respond at all. The mechanism adopted by this invention, through "combined judgment and continuous verification," requires that multiple abnormal characteristics exist simultaneously and for a certain period of time, thereby effectively reducing the false alarm rate and missed alarm rate, and improving the judgment accuracy and response reliability of actual thermal runaway events.

[0026] Step S20: Based on thermal runaway identification flag Generate corresponding electrical signal control instructions, and the preset BCU unit outputs the electrical signal control instructions to the cluster-level solenoid valve control interface on the top of the battery cluster, and at the same time sends real-time operating parameters and thermal runaway identification flags to the battery cluster. sent to the superior BAU unit; It should be noted that the "electrical signal control instruction" refers to a hardware-level output signal automatically generated by the BAU after detecting that the target battery cell meets the thermal runaway conditions. This signal can be a relay closure signal, a level trigger signal, or an analog switch signal. It is used to directly drive the solenoid valve mounted on the top of the battery cluster to open, thereby initiating local fire extinguishing. This step also includes reporting the current battery cell operating status data (such as temperature, voltage, and timestamp) and the generated thermal runaway identification flag to the upper-level BAU unit via a communication link (such as CAN, RS485, or Ethernet) to achieve coordinated response and synchronization of fault data.

[0027] As you can see, this step not only enables a rapid local response to thermal runaway events but also establishes a channel for reporting events to upper-level management units, forming a two-level control structure of "edge recognition + center linkage." This structure ensures autonomous spraying at the initial stages of thermal runaway, while also providing timely feedback to higher-level control units. This provides basic data support for subsequent global spraying linkage, power distribution, energy isolation, and other actions, significantly improving the timeliness and coordination of control responses.

[0028] It should be understood that unlike traditional BMSs, which fully control thermal runaway detection and fire extinguishing triggering, this invention moves detection and primary control functions to the BAU, achieving a cluster-level, integrated "detection-control-response" closed loop. This design ensures local response speed while avoiding the delays and bottlenecks associated with multi-node signal convergence in traditional centralized architectures. It is suitable for large-scale energy storage systems with a large number of clusters and high communication complexity.

[0029] For example, in a certain experimental scenario, a controlled heating simulation was performed on the sixth battery cell in the 104S-configured lithium battery cluster. Test data showed that after identifying the continuous temperature rise of the battery cell and meeting the thermal runaway criteria, a control instruction was generated within 0.5 seconds to directly drive the solenoid valve nozzle on the top of the cluster to perform local fire extinguishing. At the same time, the BCU uploaded the abnormal parameters and identification status to the superior BAU unit through the CAN interface. The superior BAU unit recorded the response time and determined whether to trigger global spraying based on multiple subsequent upload results. Compared with the traditional method of relying on BMS to make centralized judgments and then control spraying, this local response mechanism shortened the first response link by an average of about 4 seconds, effectively suppressing local heat diffusion.

[0030] Step S30: Obtain the thermal runaway feedback data of the battery cell. The upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs a dry contact closure signal. ; It should be noted that "multi-parameter fitting trend consistency detection" means that after receiving the thermal runaway identification flag and real-time parameters, the upper-level BAU unit will retrieve the operating data of the corresponding battery cell or adjacent battery cell in the corresponding time period recorded by itself, including temperature, voltage, temperature rise rate, etc., and fit the changing trends of these parameters respectively to determine whether the two maintain consistency in trend direction, slope change or parameter change amplitude, and then evaluate the credibility of the reported event. At the same time, "cross-node validity verification" means not only verifying the data of the battery cell itself, but also comparing the temperature and voltage changes of other battery cells adjacent to it or in the same cluster to see if they also show similar anomalies, thereby enhancing the spatial correlation of the judgment and reducing false triggering due to single-point anomalies.

[0031] It can be understood that by introducing the trend fitting and inter-node comparison mechanism, the authenticity of the event can be reconfirmed after receiving the spraying action trigger signal, avoiding false triggering due to communication errors, data mutations or local disturbances.

[0032] It should be understood that compared to the prior art method of triggering the fire protection system after receiving an alarm signal from the BMS, the present invention significantly reduces the probability of single-point false alarms and occasional triggering by introducing a trend-fitting-based parameter consistency judgment and spatial multi-point data comparison mechanism. Traditional methods lack analysis of data evolution and are prone to false triggering due to sensor errors, clock offsets, or short-term outliers. In contrast, the present invention only outputs a dry contact signal when it determines that BAU data is highly consistent with local or other node data at the trend level, thereby improving the reliability and redundancy of the fire protection response.

[0033] Step S40: The fire host receives the dry contact closing signal , when the dry contact closes the signal =1, it is determined whether the global spraying and fire extinguishing linkage condition is met. If so, a cluster-wide spraying and fire extinguishing instruction is issued and the global protection state flag F is output; It should be noted that the "global sprinkler fire extinguishing linkage condition" means that after the fire host receives the dry contact closure signal output by the superior BMS, it does not directly trigger the full-cluster spraying, but further confirms it in combination with the current status, such as checking whether the spraying execution unit is in an operational state, whether the agent reserves meet the spraying conditions, whether the power supply is normal, and other safety criteria. Only when all the preconditions are met, the fire host will determine that the linkage condition is met, and immediately send a control instruction to all cluster-level solenoid valves to implement the full-cluster spraying action. At the same time, the fire host will update the status flag to "global protection status", that is, F=1, to notify subsequent modules to enter the fire extinguishing closed-loop monitoring stage.

[0034] As can be understood, this step, as the hub of coordinated control, completes the logical closed loop from BMS event detection to actual spray command triggering, serving as the core bridge in the entire "perception-judgment-execution" chain of thermal runaway response. By combining the dry contact signal with its own execution status, it ensures that the fire sprinkler action will not be falsely triggered or fail due to misjudgment or equipment anomalies. Furthermore, the output global protection status flag F provides a synchronous trigger signal for subsequent temperature trend detection and other procedures, enabling coordinated control between modules.

[0035] It should be understood that, compared to traditional fire sprinkler systems, which are typically triggered directly by the BMS, manual intervention, or a fire host, lacking logical judgment and state synchronization regarding execution status, the fire host in this invention, as an independent response unit, possesses proactive judgment capabilities and coordinated linkage. Its secondary confirmation mechanism for sprinkler conditions effectively prevents erroneous fire extinguishing actions in the event of abnormal conditions or hardware defects. Furthermore, through the output of the status flag F, a unified control chain from "spraying triggering" to "fire extinguishing feedback" is established, helping to improve the accuracy and stability of the energy storage system's response to thermal runaway events in multi-cluster, highly complex environments.

[0036] Step S50: When the global protection status flag F is 1, the temperature data of the target area is collected based on the preset infrared temperature measurement unit, the average temperature drop rate of the target area is calculated within the preset continuous time window, and the total temperature drop amplitude of the target area is obtained; the effectiveness of the fire extinguishing action is judged based on the average temperature drop rate and the total temperature drop amplitude of the target area, and the post-drive behavior closed-loop control is performed based on the judgment result.

[0037] It should be noted that the "average temperature drop rate" in this step refers to the average rate of decrease in the overall temperature of the target area over a continuous period after the spraying operation is completed, reflecting the cooling trend after the fire is extinguished. The "total temperature drop amplitude" refers to the maximum temperature drop during this period, reflecting whether the fire extinguishing operation has achieved a significant thermal effect. Both indicators are obtained through real-time sampling data from infrared temperature measurement equipment and statistically processed on the host side. Based on this, the success of the fire extinguishing operation is determined based on preset thresholds, and the decision on whether to continue subsequent response actions such as spraying is made accordingly, forming a closed-loop control process for the fire extinguishing process.

[0038] It's understandable that by introducing a dual judgment mechanism based on both the continuous temperature change trend and the temperature drop amplitude, the effectiveness of firefighting operations can be more accurately reflected. If the fire is extinguished successfully, spraying can be automatically terminated, freeing up equipment resources. If the fire is inadequately extinguished, with high temperatures remaining or the temperature dropping slowly, spraying can be extended and the next round of response can be initiated, preventing the fire from rekindling or being missed. This strategy uses perception results to drive subsequent response logic.

[0039] It should be understood that traditional firefighting linkage mechanisms primarily rely on fixed-time spraying, lacking the ability to evaluate firefighting effectiveness in real time. Incomplete firefighting is often not detected in a timely manner, potentially leading to secondary combustion or wasted resources due to redundant spraying. However, this invention, by introducing a firefighting effectiveness recognition mechanism that combines temperature change trends with the magnitude of the drop, achieves a result-driven response strategy switching. This not only autonomously determines whether to continue spraying, but also establishes a closed-loop, result-oriented, full-process control loop, significantly improving safety and resource efficiency.

[0040] For example, if Figure 2As shown in the figure, when a battery cell shows signs of thermal runaway due to overcharging or internal fault, multiple operating parameters of that cell are monitored in real time. If the voltage of any cell falls below 2V and there are no data collection interruptions, and the temperature exceeds 80°C with a temperature rise rate exceeding 1°C per second for more than 3 seconds, the cell is considered to have entered a thermal runaway state. Upon receiving this signal, the battery control unit (BCU) immediately reports the event and initiates the following parallel actions: First, the BCU directly opens the spray ball valve at the top of the corresponding battery cluster and continuously outputs a 24V drive signal, implementing a localized spray response. Second, the BCU transmits the relevant status to the battery management unit (BAU), which then outputs a firefighting trigger signal to the fire control unit. Upon receiving this trigger signal, the fire control unit determines that the linkage conditions have been met and opens the cylinder solenoid valve, releasing the fire extinguishing agent and initiating a cluster-wide spraying linkage, completing the firefighting activation process. The entire process has a short response time from thermal runaway identification to spray initiation, and can quickly respond in a linked manner at the initial stage of battery cell temperature rise. It has a clear judgment mechanism and a highly integrated linkage control link, which verifies the adaptability and practical effect of the method of the present invention in multi-parameter and cross-module scenarios.

[0041] Embodiment 2: In addition, the present invention provides a battery pack thermal runaway protection system that adopts a battery pack thermal runaway protection method in the above embodiment to solve the technical problem of battery pack thermal runaway protection. Compared with the prior art, the beneficial effects of the battery pack thermal runaway protection system provided by the present invention are the same as the beneficial effects of the battery pack thermal runaway protection method provided by the above embodiment, and the other technical features of the battery pack thermal runaway protection system are the same as those disclosed in the above embodiment method, and are not further described here.

[0042] Example 3: The present invention provides a battery pack thermal runaway protection device, please refer to Figure 3A battery pack thermal runaway protection device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform a battery pack thermal runaway protection method according to the first embodiment described above. The battery pack thermal runaway protection device in this embodiment of the present invention may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. The battery pack thermal runaway protection device is merely an example and should not limit the functionality or scope of use of this embodiment of the present invention. The battery pack thermal runaway protection device may include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which may perform various appropriate actions and processes based on a program stored in a read-only memory 1002 or a program loaded from a storage device 1003 into a random access memory 1004. Various programs and data required for the operation of a battery pack thermal runaway protection device are also stored in random access memory 1004. The processing device 1001, read-only memory 1002, and random access memory 1004 are interconnected via a bus 1005. An I / O interface 1006 is also connected to the bus. Typically, the following systems may be connected to the I / O interface 1006: an input device 1007 including, for example, a touchscreen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, hard disk, etc.; and a communication device 1009. The communication device 1009 allows the battery pack thermal runaway protection device to communicate with other devices wirelessly or wired to exchange data. Although the figure illustrates a battery pack thermal runaway protection device with various systems, it should be understood that implementation or presence of all the illustrated systems is not required. More or fewer systems may alternatively be implemented or present.

[0043] Example 4: The present invention also provides a computer program product, including a computer program. When executed by a processor, the computer program implements the steps of the above-described method for protecting a battery pack from thermal runaway. The computer program product provided by the present invention can solve the technical problem of protecting a battery pack from thermal runaway. Compared with the prior art, the beneficial effects of the computer program product provided by the present invention are the same as those of the method for protecting a battery pack from thermal runaway provided by the above-described embodiment, and are not further elaborated here.

[0044] In particular, according to the embodiments disclosed in the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program comprising program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device 1003, or installed from a read-only memory 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present invention are performed.

[0045] It should be understood that the various parts disclosed in the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any appropriate manner in any one or more embodiments or examples.

[0046] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A battery pack thermal runaway protection method, characterized in that: Methods include: Step S10: The preset BCU unit collects the real-time operating parameters of the battery cluster in the target battery pack at time t of the battery cell i, and uses the continuous interval joint state mechanism based on the real-time operating parameters to determine whether the thermal runaway trigger condition is met, and outputs the thermal runaway identification flag. ; Step S20: Based on thermal runaway identification flag Generate corresponding electrical signal control instructions, and the preset BCU unit outputs the electrical signal control instructions to the cluster-level solenoid valve control interface on the top of the battery cluster, and at the same time sends real-time operating parameters and thermal runaway identification flags to the battery sent to the superior BAU unit; Step S30: Obtain the thermal runaway feedback data of the battery cell. The upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs a dry contact closure signal. ; Step S40: The fire host receives the dry contact closing signal , when the dry contact closes the signal =1, it is determined whether the global spraying and fire extinguishing linkage condition is met. If so, a cluster-wide spraying and fire extinguishing instruction is issued and the global protection state flag F is output; Step S50: When the global protection status flag F is 1, the temperature data of the target area is collected based on the preset infrared temperature measurement unit, the average temperature drop rate of the target area is calculated within the preset continuous time window, and the total temperature drop amplitude of the target area is obtained; the effectiveness of the fire extinguishing action is judged based on the average temperature drop rate and the total temperature drop amplitude of the target area, and the post-drive behavior closed-loop control is performed based on the judgment result.

2. A battery pack thermal runaway protection method according to claim 1, characterized in that: In step S10, the continuous interval joint state mechanism is used to determine whether the thermal runaway trigger condition is met based on the real-time operating parameters, and the thermal runaway identification flag is output. The steps include: Real-time operating parameters include cell voltage , battery cell temperature and the rate of temperature rise per unit time , construct a continuous criterion set based on the sliding time window Δt, and judge whether the following three conditions are met simultaneously in the continuous criterion set: Condition 1: Within the sliding time window Δt, the cell voltage The minimum value is less than 2V and there is no disconnection process; Condition 2: Within the sliding time window Δt, the cell temperature The maximum value is greater than 80℃; Condition 3: There is at least one time point within the sliding time window Δt , at the time point The temperature rise rate per unit time is greater than or equal to 1°C / s and lasts for more than 3 seconds; If the above three conditions are met within the sliding time window Δt, the thermal runaway identification flag is output. , otherwise output .

3. The battery pack thermal runaway protection method according to claim 1, wherein: In step S20, the cluster-level solenoid valve control interface drives the sprinklers in the cluster to start and implement localized fire extinguishing operations in real time.

4. A battery pack thermal runaway protection method according to claim 1, characterized in that: In step S30, the thermal runaway feedback data of the battery cell is obtained, and the upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs a dry contact closure signal The steps include: Within the sliding time window Δt, the real-time operating parameters reported by the BCU unit are extracted, and the local operating parameters recorded locally by the BMS unit are collected at the same time; Compare the consistency of the three fitting trends based on the real-time operating parameters reported by the BCU unit and the local operating parameters recorded locally by the BMS unit, and output the dry contact closure signal based on the comparison results of the consistency of the three fitting trends .

5. A battery pack thermal runaway protection method according to claim 4, characterized in that: In step S30, the consistency of the three fitting trends is compared, and a dry contact closing signal is output according to the comparison result of the consistency of the three fitting trends. The steps specifically include: The data of the battery cell temperature in the real-time operating parameters are fitted using a least squares linear fitting method to obtain a first temperature trend line; the data of the battery cell temperature in the local operating parameters are fitted using a least squares linear fitting method to obtain a second temperature trend line; The data of the cell voltage in the real-time operating parameters are fitted using a sliding average combined with a first-order difference method to obtain a first voltage trend line; the data of the cell voltage in the local operating parameters are fitted using a sliding average combined with a first-order difference method to obtain a second voltage trend line; Compare the consistency of the following three fitted trends: Condition 1: The fitting error between the first temperature trend line and the second temperature trend line in slope does not exceed the set first error threshold ; Condition 2: The fitting error between the first voltage trend line and the second voltage trend line in terms of slope does not exceed the set second error threshold ; Condition 3: The spraying duration is obtained from the spraying status feedback data, and the spraying duration is greater than the set tolerance ; If all three conditions are met, the real-time operating parameters reported by the BCU unit are considered credible, and a dry contact closure signal is output. ; Otherwise, the dry contact closing signal is output 0.

6. The battery pack thermal runaway protection method according to claim 1, wherein: In step S40, in step S40, if it is determined that the global spraying fire extinguishing linkage condition is met, and the step of outputting the global protection status flag F specifically includes: if the linkage condition is met, opening the cylinder solenoid valve connected to the fire host, starting the full cluster spraying unit connected to the fire host to perform a unified fire extinguishing operation, and at the same time activating the data recorder, infrared thermal imaging and smoke monitoring unit connected to the fire host for linkage recording; and outputting the global protection status flag F.

7. The battery pack thermal runaway protection method according to claim 1, wherein: In step S50, the effectiveness of the fire extinguishing action is judged based on the average temperature drop rate and the total temperature drop amplitude of the target area, and the closed-loop control of the rear driving behavior is performed based on the judgment result, which specifically includes: The effectiveness of the fire extinguishing action is determined based on the average temperature drop rate and the total temperature drop amplitude in the target area. If both of the following conditions are met: Condition 1: The average temperature drop rate is less than or equal to 0.5°C / s; Condition 2: The total temperature drop amplitude in the target area is greater than or equal to 15°C, the fire extinguishing action is considered effective. Conversely, if either of the above conditions is not met, the fire extinguishing action is considered ineffective. When the fire extinguishing action is determined to be effective, the fire host controls the disconnection of the solenoid valve control circuit and records the current linkage event log; When it is determined that the fire extinguishing action is invalid, the fire host maintains the spraying action and sends a linkage failure signal to the BMS unit.

8. A battery pack thermal runaway protection system, applied to a battery pack thermal runaway protection method according to any one of claims 1 to 7, characterized in that: The battery pack thermal runaway protection system includes: The thermal runaway judgment module is used to collect the real-time operating parameters of the battery cell i in the target battery pack at time t through the preset BCU unit, and use the continuous interval joint state mechanism based on the real-time operating parameters to determine whether the thermal runaway trigger condition is met, and output the thermal runaway identification flag bit ; Linkage signal output module, used to identify the flag based on thermal runaway Generate corresponding electrical signal control instructions, and the preset BCU unit outputs the electrical signal control instructions to the cluster-level solenoid valve control interface on the top of the battery cluster, and at the same time sends real-time operating parameters and thermal runaway identification flags to the battery sent to the superior BAU unit; The consistency verification module is used to obtain the thermal runaway feedback data of the battery cell. The upper-level BAU unit performs multi-parameter fitting trend consistency detection and cross-node validity verification based on the real-time operating parameters and spraying status feedback data, and outputs the dry contact closure signal ; Global linkage judgment module, used for fire host to receive dry contact closure signal , when the dry contact closes the signal =1, it is determined whether the global spraying and fire extinguishing linkage condition is met. If so, a cluster-wide spraying and fire extinguishing instruction is issued and the global protection state flag F is output; The fire extinguishing closed-loop control module is used to collect the temperature data of the target area based on the preset infrared temperature measurement unit when the global protection status flag F is 1, calculate the average temperature drop rate of the target area within a preset continuous time window, and obtain the total temperature drop amplitude of the target area; perform the effectiveness judgment of the fire extinguishing action based on the average temperature drop rate and the total temperature drop amplitude of the target area, and perform the post-drive behavior closed-loop control based on the judgment result.

9. A battery pack thermal runaway protection device, characterized in that: The battery pack thermal runaway protection device includes: a memory, a processor, and a battery pack thermal runaway protection program stored in the memory and executable on the processor. When the battery pack thermal runaway protection program is executed by the processor, a battery pack thermal runaway protection method according to any one of claims 1 to 7 is implemented.

10. A computer program product, characterized in that The computer program product includes a battery pack thermal runaway protection program, which, when executed by a processor, implements a battery pack thermal runaway protection method according to any one of claims 1 to 7.

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