Battery thermal runaway multi-stage prevention and control method and device

Abstract

This invention discloses a multi-level prevention and control method and device for battery thermal runaway, comprising the following steps: real-time acquisition of a first gas pressure signal inside the battery pack, the ambient temperature inside the battery pack, the battery state of charge, and a second gas pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane; construction of an ideal gas state compensation model, using the first gas pressure signal, the ambient temperature inside the battery pack, and the battery state of charge to decouple the abnormal gas generation pressure difference inside the battery pack in real time; and performing time-frequency domain correlation analysis on the decoupled abnormal gas generation pressure difference and the second gas pressure signal to extract the coupling characteristics of the internal and external pressure waveforms. Beneficial effects: This invention can extract weak early gas generation signals from complex background noise, significantly advancing the thermal runaway early warning time window to the stage of trace gas generation in the battery cell, thus gaining valuable golden time for safe handling.

Description

Technical Field

[0001] This invention relates to the field of battery temperature control technology, and in particular to a multi-level prevention and control method and device for battery thermal runaway. Background Technology

[0002] The power battery system is the core energy storage component of electric vehicles, and its safety directly affects the safety of the entire vehicle and its occupants. Battery thermal runaway is a major cause of battery fires and explosions. It typically manifests as a side reaction within the battery cell producing a large amount of high-temperature flammable gas. When this gas accumulates and causes a sharp increase in internal pressure within the battery pack, it sequentially ruptures the individual cell explosion-proof valves, the battery pack's waterproof and breathable membrane, and the exhaust pipes, ultimately expelling the high-temperature exhaust gases outside the vehicle. Therefore, real-time monitoring of the internal pressure and pressure relief channels of the battery pack is one of the key technologies for achieving early warning and precise prevention of thermal runaway.

[0003] Currently, common methods for detecting battery thermal runaway mainly include temperature detection, voltage detection, and smoke or gas concentration detection. Among these, temperature detection is limited by the delay in thermal conduction, making it difficult to respond quickly in the early stages of gas generation; voltage detection only reflects the state after a severe internal short circuit in the cell, resulting in a late warning; and gas sensors (such as VOC and CO sensors) suffer from low sensitivity, susceptibility to environmental interference, and delayed response. In contrast, thermal runaway detection schemes based on gas pressure sensors have attracted attention due to their fast response speed and ability to directly sense the gas generation process.

[0004] For example, a prior art disclosure discloses a battery pressure relief valve opening pressure detection device and system (comparative document), which includes a thermal runaway induction module, a pressure detection module, a voltage detection module, a temperature detection module, and a control module. The thermal runaway induction module is used to incite thermal runaway in the battery; the pressure detection module is located above the battery pressure relief valve and is used to detect the valve's opening pressure; the voltage detection module is electrically connected to the battery and is used to detect voltage changes; the temperature detection module is connected to the battery and is used to detect temperature changes; the control module is electrically connected to each module and receives and processes data. The system also includes a reaction chamber, in which the battery, thermal runaway induction module, voltage detection module, and temperature detection module are all installed, with the pressure detection module installed at the top of the reaction chamber. This device can detect the opening pressure of the pressure relief valve during battery thermal runaway, obtaining parameters such as voltage and temperature, providing data support for monitoring the internal pressure of the battery system, and to some extent avoiding false alarms caused by internal pressure differences due to temperature and operating conditions.

[0005] However, the aforementioned existing technologies still have the following shortcomings:

[0006] First, it lacks layered decoupling logic, making it unable to eliminate "false pressure rises" caused by environmental interference. This technology directly reads the absolute pressure value or pressure change rate during battery thermal runaway using only a single pressure sensor. While it mentions avoiding false alarms caused by temperature and operating conditions, its technical approach mainly relies on physical isolation (reaction chamber) and post-event data comparison, lacking a real-time algorithm compensation mechanism. In actual vehicle applications, the internal pressure of the battery pack will experience significant normal fluctuations (typically within the range of 1.3~1.4 atm) due to changes in ambient temperature (such as summer sun exposure and winter cold starts) and altitude. If an absolute pressure threshold is directly used for judgment, it is very easy for the system to falsely alarm when there is no thermal runaway, or to set an excessively high threshold to avoid false alarms, thus missing the early gas production warning window.

[0007] Second, the lack of gradient coupling logic makes it impossible to accurately determine whether the pressure relief channel is effectively open. The pressure detection module of this technology is located only above the pressure relief valve, employing a single-point, single-dimensional threshold determination method. It can only detect the impact force or local pressure changes at the moment the pressure relief valve opens. It cannot determine whether the overall pressure relief channels of the battery pack system (such as the waterproof and breathable membrane and exhaust pipe) are truly ruptured or unobstructed. In practical applications, even if the individual explosion-proof valve is open, if the external waterproof and breathable membrane is intact or the exhaust pipe is blocked, high-temperature toxic gases will still accumulate inside the battery pack, posing an explosion risk. Furthermore, a single pressure surge signal is easily interfered with by noise from vehicle vibrations and mechanical impacts, resulting in low reliability. Summary of the Invention

[0008] Purpose of the invention: The purpose of this invention is to solve the technical problems in the prior art and provide a multi-level prevention and control method and device for battery thermal runaway.

[0009] Technical solution: In the first aspect, this application proposes a multi-stage prevention and control method for battery thermal runaway, including the following steps:

[0010] Step S1: Real-time acquisition of the first air pressure signal inside the battery pack cavity. Ambient temperature inside the battery pack Battery state of charge And a second air pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane. ;

[0011] Step S2: Construct an ideal gas state compensation model, utilizing the... , and Real-time decoupling of abnormal gas generation pressure differences within the battery pack ;

[0012] Step S3: Decouple the... With the second air pressure signal Time-frequency domain correlation analysis was performed to extract the coupling characteristics of internal and external pressure waveforms;

[0013] Step S4: Based on the extracted coupling features, determine the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane;

[0014] Step S5: Based on the determined stage and status, execute the corresponding graded prevention and control strategy, which includes Level 1 warning, Level 2 warning and Level 3 warning.

[0015] Preferably, the ideal gas state compensation model in step S2 is specifically as follows:

[0016] The background pressure prediction model calculates the following estimated background pressure value:

[0017] ;

[0018] in, As the initial reference pressure, P ref As the initial reference pressure, The initial temperature, This is a correction factor for the leakage rate of the battery pack's airtightness. This is the battery volume expansion correction factor;

[0019] The abnormal gas production pressure difference decoupling formula is used to calculate the abnormal gas production pressure difference:

[0020] .

[0021] Preferably, it also includes a dynamic baseline learning algorithm to correct the baseline in real time. :

[0022] The system extracts data through a set time sliding window during normal vehicle operation and outside of peak charging / discharging periods. and Peak and trough data;

[0023] The slope of the actual pressure change with temperature is calculated and compared with the theoretical expansion coefficient. If the deviation continues to exceed a preset threshold and there are no signs of thermal runaway, it is determined that the battery pack is leaking naturally or is aging and releasing gas. The system automatically and smoothly updates the airtightness correction coefficient in the formula. .

[0024] Preferably, step S3, extracting coupling features, includes:

[0025] Calculate the rate of change of the first air pressure signal and the rate of change of the second air pressure signal .

[0026] Preferably, step S4 includes:

[0027] After decoupling It suddenly dropped from a high level, and time-frequency domain analysis captured... A sharp negative pulse characteristic appears, and When a rapid positive pulse characteristic appears simultaneously, it is determined that the waterproof and breathable membrane has been blown open by the thermal runaway gas generation, and the pressure relief channel is in a clear state.

[0028] Among them, the rate of change of the first air pressure signal The rate of change of the second pressure signal is used to characterize the severity of internal gas accumulation or depressurization. This represents the rate of change of pipeline pressure over time.

[0029] Preferably, step S5, the first-level early warning, includes: when an abnormal gas production pressure difference occurs... The pressure remained above the set first threshold, but the battery temperature was monitored. If there is no abnormal temperature rise, the system determines that it is due to a small leakage in the battery cell or abnormal gas production due to aging.

[0030] Execute control actions: Activate the active balancing function of the battery management system to perform voltage reduction processing, while limiting the peak power of the vehicle drive and charging to 50% of the rated value.

[0031] Preferably, step S5, the secondary early warning, includes: when the first air pressure signal... A slope warning is triggered when the pressure exceeds the set second pressure threshold, and the second air pressure signal... When the value remains at 0, it is determined that the individual explosion-proof valve has been opened to produce gas and the waterproof and breathable membrane has not been broken.

[0032] Execute control actions: Immediately execute the high-voltage main relay disconnect command to cut off the power circuit, and start the cooling water pump of the thermal management system for full-power circulation.

[0033] Preferably, step S5, the third-level warning, includes: a third-level warning is issued when it is determined that the waterproof and breathable membrane has been blown open by thermal runaway gas generation and the pressure relief channel is unobstructed;

[0034] Execute control actions: activate the fire extinguishing agent spray device configured in the battery pack, and send coordinate information with a label indicating that the pressure relief channel is open and an emergency distress signal to the cloud server through the vehicle-mounted T-Box.

[0035] Preferably, before performing step S5, a cross-validation fault diagnosis redundancy mechanism is also included:

[0036] When the first air pressure signal With the second air pressure signal A non-physical divergence occurs between the readings, meaning the pressure difference instantaneously exceeds the physical burst limit of the battery pack casing, or the first air pressure signal. It reaches full capacity instantly;

[0037] The system synchronously retrieves the terminal voltage change rate of the corresponding battery cell or module. Cross-validation was performed on the current fluctuation signal;

[0038] like If the pressure sensor remains stable and there is no abnormal short-circuit current, it is determined to be a single-point electrical failure of the corresponding pressure sensor. The system then disables the gas generation alarm generated by the sensor to avoid false triggering of power outage.

[0039] Secondly, this application proposes a multi-stage battery thermal runaway prevention and control device, comprising the following steps:

[0040] The acquisition unit is used to acquire the first air pressure signal inside the battery pack in real time. Ambient temperature inside the battery pack Battery state of charge And a second air pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane. ;

[0041] The logic control unit is used to construct an ideal gas state compensation model, utilizing the aforementioned... , and Real-time decoupling of abnormal gas generation pressure differences within the battery pack ;

[0042] The decoupled version With the second air pressure signal Time-frequency domain correlation analysis was performed to extract the coupling characteristics of internal and external pressure waveforms;

[0043] Based on the extracted coupling features, the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane are determined.

[0044] The execution unit is used to execute the corresponding hierarchical prevention and control strategy according to the determined stage and state. The hierarchical prevention and control includes level 1 warning, level 2 warning and level 3 warning.

[0045] Thirdly, this application proposes an electronic device including a memory and a processor, wherein the memory stores a computer program that can run on the processor, and when the computer program is executed by the processor, the processor causes the processor to perform the method described in the above embodiments.

[0046] Fourthly, this application proposes a computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the method described in the above embodiments.

[0047] Beneficial effects:

[0048] This invention constructs an ideal gas state compensation model, utilizes real-time absolute pressure collected by an internal cavity pressure sensor, and combines this with ambient temperature (T) and battery state of charge (SOC) to calculate a predicted background pressure, thereby decoupling the "abnormal gas production pressure difference" that represents the actual gas production from the battery cell's side reactions. This solution successfully isolates background pressure fluctuations caused by physical thermal expansion and contraction (such as changes in ambient temperature and altitude), completely eliminating false pressure rise interference caused by seasonal temperature differences or changes in operating conditions. Compared to existing technologies that rely solely on a single absolute pressure threshold or pressure change rate, this invention can extract weak early gas production signals from complex background noise, significantly advancing the thermal runaway warning window to the stage of minimal gas production within the battery cell, thus gaining valuable golden time for safe handling.

[0049] This invention overcomes the limitations of single-point pressure detection by establishing a dual-sensing system consisting of an internal cavity sensor and an external pipeline sensor. This allows for the acquisition of high-precision... Based on this, a time-frequency domain correlation analysis was further performed with the second air pressure signal outside the waterproof and breathable membrane to extract the coupling characteristics of the internal and external pressure waveforms. This invention innovatively defines the only reliable physical indicator of a pressure relief channel rupture: namely, the appearance of a "negative pulse" in the internal pressure. A sharp negative change indicates that gas is instantly rushing out of the cavity, while a "positive pulse" appears in the pipeline pressure. A rapid positive change indicates the synchronous coupling characteristic of gas entering the pipeline instantaneously. Only when these two signals are highly matched in terms of time and frequency characteristics is it determined that the waterproof and breathable membrane has ruptured and the pressure relief channel has successfully opened. This technology offers the following advantages:

[0050] To confirm the effectiveness of pressure relief, existing technologies can only detect whether the pressure relief valve is activated, but cannot determine whether the subsequent waterproof and breathable membrane is ruptured or the exhaust pipe is blocked. This invention directly verifies whether the gas is actually discharged from the battery pack's inner cavity to the external pipeline through "gradient coupling," effectively identifying fatal hidden dangers such as "the explosion-proof valve is open but the waterproof and breathable membrane is not ruptured" or "the pipeline is blocked," thus avoiding the risk of battery pack explosion due to poor pressure relief.

[0051] It has strong anti-interference ability. Existing single-dimensional threshold judgment is easily affected by noise interference such as vehicle vibration and mechanical impact, which may lead to false judgments. The "inner negative and outer positive" synchronous pulse feature required by this invention is a physical phenomenon unique to thermal runaway pressure relief, which is extremely difficult to be simulated by other interference factors, thus achieving a high reliability judgment with near-zero false alarms.

[0052] This invention also introduces a dynamic baseline learning algorithm, which extracts baselines through a sliding window during normal vehicle operation and outside of peak charging / discharging periods. and The system uses peak and trough data to calculate the slope of actual pressure change with temperature and compares it with the theoretical expansion coefficient. When the deviation continuously exceeds a preset threshold and there are no signs of thermal runaway, the system determines it as battery pack natural leakage or aging gas evolution, and automatically and smoothly updates the airtightness correction coefficient in the ideal gas state compensation model. This mechanism enables the model to adaptively compensate for baseline drift caused by sealing aging and trace gas evolution after long-term use of the battery pack, eliminating the need for manual calibration or periodic adjustment, and significantly improving the robustness and accuracy of the algorithm throughout its entire lifecycle.

[0053] Before implementing the prevention and control strategy, this invention also includes a cross-validation fault diagnosis redundancy mechanism. When the internal air pressure... With pipeline air pressure The readings show a non-physical deviation (such as the pressure difference instantaneously exceeding the shell burst limit or...). When at full scale, the system synchronously retrieves the terminal voltage change rate of the corresponding battery cell or module. Cross-validation was performed on the current fluctuation signal. If the pressure sensor remains stable and there is no abnormal short-circuit current, it is determined to be a single-point electrical failure of the pressure sensor. The system then disables the gas generation alarm generated by this sensor to prevent false triggering of power outages or fire suppression actions due to sensor failure. This redundancy mechanism significantly improves the system's fault tolerance and reliability, preventing malfunctions of safety functions caused by the failure of a single sensor. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the method according to an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of the system structure provided in one embodiment.

[0056] Figure 3 This is a block diagram of an electronic device structure provided in one embodiment of this application. Detailed Implementation

[0057] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] Example 1:

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "including" and similar expressions used herein mean that the element or object preceding the term covers the element or object listed after the term and its equivalents, but do not exclude other elements or objects.

[0060] In response to the problems existing in the current technology, such as Figure 1 As shown, a multi-stage prevention and control method for battery thermal runaway is proposed, including the following steps:

[0061] Step S1: Real-time acquisition of the first air pressure signal inside the battery pack cavity. Ambient temperature inside the battery pack Battery state of charge And a second air pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane. ;

[0062] When the battery pack is working normally, the internal pressure The pressure is affected by changes in ambient temperature and altitude, as well as gas production from side reactions within the battery cell. To separate the actual gas components from the total pressure, temperature TT must be simultaneously collected as a compensation reference. As a reference for the chemical activity state of the battery cell (high) (Due to the increased likelihood of secondary reactions within the battery cell). Simultaneously, a second pressure sensor is added to the outside of the waterproof and breathable membrane to detect whether gas has been successfully discharged into the exhaust pipe, forming a dual-pressure sensing system. This provides a complete physical data foundation for subsequent "layered decoupling" and "dual-pressure coupling," solving the problem of insufficient single-point detection information in existing technologies.

[0063] Step S2: Construct an ideal gas state compensation model, utilizing the... , and Real-time decoupling of abnormal gas generation pressure differences within the battery pack ;

[0064] It successfully eliminated the false pressure fluctuations caused by changes in ambient temperature and altitude, and upgraded the thermal runaway warning from "absolute pressure threshold judgment" to "net value detection of trace gas production". The sensitivity has been greatly improved, and it can issue a warning in the early stage of trace gas production in the battery cell (before traditional sensors have responded).

[0065] Step S3: Decouple the... With the second air pressure signal Time-frequency domain correlation analysis was performed to extract the coupling characteristics of internal and external pressure waveforms;

[0066] Thermal runaway pressure relief is a transient physical process. When a waterproof and breathable membrane is suddenly breached by high-pressure gas, the internal pressure... A rapid drop in "negative pulse" will occur, along with the pipeline pressure. A rapidly rising "positive pulse" will appear. These two pulses are strictly synchronized in time (on the order of microseconds to milliseconds) and highly correlated in waveform shape. Time-frequency domain analysis (such as short-time Fourier transform, wavelet transform, or cross-correlation calculation) can accurately identify this synchronization feature from the background noise. This breaks through the limitations of single-dimensional threshold determination and enables accurate identification of pressure relief physical events. This feature is unique and cannot be simulated, exhibiting extremely strong anti-interference capabilities.

[0067] Step S4: Based on the extracted coupling features, determine the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane;

[0068] Based on the extracted coupling features, the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane are determined.

[0069] according to The amplitude, rise rate, and coupling of internal and external pulses can distinguish different thermal runaway processes:

[0070] ①only Slow rise → Trace gas production in battery cells (sub-health).

[0071] ② Rapid rise and The slope warning was triggered, but No change → The explosion-proof valve has been opened, but the vent membrane has not been broken (critical state).

[0072] ③ When a synchronous double pulse of "negative inside and positive outside" appears, the breathable membrane has ruptured and the pressure relief channel is unobstructed (emergency pressure relief).

[0073] It enables refined hierarchical identification of thermal runaway processes, providing accurate decision-making basis for differentiated prevention and control strategies.

[0074] Step S5: Based on the determined stage and status, execute the corresponding graded prevention and control strategy, which includes Level 1 warning, Level 2 warning and Level 3 warning.

[0075] Based on the determined stage and state, corresponding tiered prevention and control strategies are implemented, including Level 1, Level 2, and Level 3 early warnings. The risk levels and optimal handling methods differ significantly at each stage. During the stage of trace gas production, measures such as "reducing power and pressure" should be taken to prevent escalation; during the stage where the explosion-proof valve is open but gas has not been released, measures such as "power off and cooling" should be taken to prevent heat spread; during the stage where the pressure relief channel is open, measures such as "fire extinguishing and alarm" should be taken to control the fire and request assistance. This approach avoids the drawbacks of traditional "one-size-fits-all" power off or alarm responses, maximizing vehicle availability while ensuring safety, and achieving an upgrade from "passive alarm" to "active prevention and control."

[0076] In some specific embodiments, the ideal gas state compensation model in step S2 is specifically as follows:

[0077] The background pressure prediction model calculates the following estimated background pressure value:

[0078] ;

[0079] in, As the initial reference pressure, P ref As the initial reference pressure, The initial temperature, This is a correction factor for the leakage rate of the battery pack's airtightness. This is the battery volume expansion correction factor;

[0080] The abnormal gas production pressure difference decoupling formula is used to calculate the abnormal gas production pressure difference:

[0081] .

[0082] By introducing an airtightness correction factor It can compensate for baseline drift caused by minor leaks or aging gas evolution after long-term use of the battery pack. This is the pure gas production contribution value.

[0083] It provides a quantifiable mathematical model, making it possible to accurately decouple the gas-producing components from complex measured signals. It is simple to calculate, has good real-time performance, and is suitable for implementation in automotive embedded systems.

[0084] In some specific embodiments, a dynamic baseline learning algorithm is also included to correct the baseline in real time. :

[0085] The system extracts data through a set time sliding window during normal vehicle operation and outside of peak charging / discharging periods. and Peak and trough data;

[0086] The slope of the actual pressure change with temperature is calculated and compared with the theoretical expansion coefficient. If the deviation continues to exceed a preset threshold and there are no signs of thermal runaway, it is determined that the battery pack is leaking naturally or is aging and releasing gas. The system automatically and smoothly updates the airtightness correction coefficient in the formula. .

[0087] During normal vehicle operation and in the non-charge / discharge peak range without thermal runaway characteristics (such as constant speed driving and moderate SOC), the number of gas moles n in the battery pack should remain essentially constant. At this time, and The ratio should remain constant. The system extracts peak and trough data through a sliding window and calculates the actual... The slope is compared with the theoretical value. If the deviation exceeds the threshold, it indicates that n has changed (natural leakage or aging gas production). Automatic smoothing update is then performed. It achieves adaptive online calibration of model parameters, eliminating the need for periodic manual calibration. It effectively compensates for reference drift caused by factors such as sealing aging and minor casing deformation throughout the battery pack's lifespan, ensuring the long-term accuracy and reliability of the decoupling algorithm.

[0088] In some specific embodiments, step S3, extracting coupling features, includes:

[0089] Calculate the rate of change of the first air pressure signal and the rate of change of the second air pressure signal .

[0090] It is a sensitive indicator for describing transient processes. Differential calculation can highlight high-frequency pulse components and suppress slow drift components. Converting the original pressure signal into a rate of change signal significantly amplifies the characteristic amplitudes of "negative pulses" and "positive pulses," facilitating threshold triggering and pattern recognition, and reducing algorithm complexity.

[0091] In some specific embodiments, step S4 includes:

[0092] After decoupling It suddenly dropped from a high level, and time-frequency domain analysis captured... A sharp negative pulse characteristic appears, and When a rapid positive pulse characteristic appears simultaneously, it is determined that the waterproof and breathable membrane has been blown open by the thermal runaway gas generation, and the pressure relief channel is in a clear state.

[0093] Among them, the rate of change of the first air pressure signal The rate of change of the second pressure signal is used to characterize the severity of internal gas accumulation or depressurization. This represents the rate of change of pipeline pressure over time.

[0094] when When the pressure drops suddenly from a high level, it indicates that the high-pressure gas inside the cavity has found a release outlet. A negative pulse indicates a rapid decrease in internal pressure (pressure relief). A positive pulse represents a sudden increase in pressure within the pipeline (gas inrush). The synchronicity of the two in the time and frequency domain is a unique "cause and effect" relationship in thermal runaway pressure relief: the decrease in internal pressure is the cause, and the increase in pipeline pressure is the effect; there is no time delay or phase difference between the two.

[0095] This criterion is the only reliable physical indicator of a ruptured waterproof and breathable membrane and the opening of the pressure relief channel. Disruptive sources such as vehicle vibration, mechanical shock, and sudden temperature changes cannot simultaneously generate strictly synchronized "inner negative, outer positive" pulse pairs, thus achieving near-zero false alarm reliability. Simultaneously, this criterion directly confirms that exhaust gases have been discharged outside the vehicle, eliminating the safety hazard of "the explosion-proof valve being open but the passage blocked."

[0096] In some specific embodiments, step S5, the first-level early warning, includes: when an abnormal gas production pressure difference... The pressure remained above the set first threshold, but the battery temperature was monitored. If there is no abnormal temperature rise, the system determines that it is due to a small leakage in the battery cell or abnormal gas production due to aging.

[0097] Execute control actions: Activate the active balancing function of the battery management system to perform voltage reduction processing, while limiting the peak power of the vehicle drive and charging to 50% of the rated value.

[0098] The continued rise in temperature without any abnormality indicates that a small amount of side reaction gas production has occurred in the battery cell, but it has not yet entered the self-heating stage (i.e., thermal runaway has not yet been triggered). Active balancing can consume some power, reduce cell voltage and internal stress; power limiting can reduce charging and discharging current, reducing Joule heating and side reaction rates. Active intervention in the early stages of thermal runaway prevents the situation from worsening. At the same time, without cutting off power, the vehicle can still be driven to a safe area or repair point, balancing safety and user experience.

[0099] In some specific embodiments, step S5, the secondary warning, includes: when the first air pressure signal... A slope warning is triggered when the pressure exceeds the set second pressure threshold, and the second air pressure signal... When the value remains at 0, it is determined that the individual explosion-proof valve has been opened to produce gas and the waterproof and breathable membrane has not been broken.

[0100] Execute control actions: Immediately execute the high-voltage main relay disconnect command to cut off the power circuit, and start the cooling water pump of the thermal management system for full-power circulation.

[0101] The trigger slope warning indicates a sharp rise in internal pressure (the explosion-proof valve has opened), while This indicates no pressure change on the pipeline side, and the gas is trapped inside the permeable membrane. At this time, high-temperature flammable gas accumulates inside the casing, posing an extremely high risk of explosion. The high-pressure circuit must be immediately cut off to eliminate the ignition source (the relay disconnection will produce a weak spark, but it is safe to operate until the gas concentration is sufficiently high). Simultaneously, the cooling water pump should be started at full power to circulate the gas and remove heat from the battery cells, suppressing heat spread. During the critical window period when "gas has been generated but not yet discharged," eliminating the ignition source by cutting off power and suppressing heat spread through cooling are the most effective means of preventing an explosion.

[0102] In some specific embodiments, the third-level warning in step S5 includes: a third-level warning is issued when it is determined that the waterproof and breathable membrane has been blown open by thermal runaway gas generation and the pressure relief channel is unobstructed;

[0103] Execute control actions: activate the fire extinguishing agent spray device configured in the battery pack, and send coordinate information with a label indicating that the pressure relief channel is open and an emergency distress signal to the cloud server through the vehicle-mounted T-Box.

[0104] The dual-pulse coupling criterion triggers, indicating that the permeable membrane has ruptured and high-temperature exhaust gas is being discharged outside the vehicle through the exhaust pipe. At this time, the battery pack may already be on fire or about to catch fire. Activating the fire extinguishing spray system (such as perfluorohexanone) can quickly extinguish the initial open flame; the T-Box sends a distress signal with a location tag, which can notify the cloud platform, fire center, and emergency contacts. This achieves the linkage of "active fire extinguishing + automatic alarm," buying time for fire rescue and reducing property damage and casualties.

[0105] In some specific embodiments, a cross-validation fault diagnosis redundancy mechanism is also included before performing step S5:

[0106] When the first air pressure signal With the second air pressure signal A non-physical divergence occurs between the readings, meaning the pressure difference instantaneously exceeds the physical burst limit of the battery pack casing, or the first air pressure signal. It reaches full capacity instantly;

[0107] The system synchronously retrieves the terminal voltage change rate of the corresponding battery cell or module. Cross-validation was performed on the current fluctuation signal;

[0108] like If the pressure sensor remains stable and there is no abnormal short-circuit current, it is determined to be a single-point electrical failure of the corresponding pressure sensor. The system then disables the gas generation alarm generated by the sensor to avoid false triggering of power outage.

[0109] Barometric pressure sensors may output non-physical signals due to electrical faults (such as ADC failure or abnormal power supply). When and Non-physical deviations occur (such as pressure difference > shell burst limit) or At full scale, the system retrieves electrical parameters. Perform cross-validation. This is because real thermal runaway gas production is almost always accompanied by voltage anomalies (internal short circuits causing a sudden voltage drop). A stable reading indicates the battery cell is functioning correctly, but the air pressure signal is unreliable. This effectively identifies single-point sensor failures, preventing accidental power outages or fire extinguishing due to sensor malfunctions, and significantly improves the system's fault tolerance and robustness.

[0110] In other embodiments of the invention, combined with Figure 2 This invention discloses a multi-stage battery thermal runaway prevention and control device, comprising the following steps:

[0111] Acquisition unit 201 is used to acquire the first air pressure signal inside the battery pack cavity in real time. Ambient temperature inside the battery pack Battery state of charge And a second air pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane. ;

[0112] Logic control unit 202 is used to construct an ideal gas state compensation model, utilizing the aforementioned... , and Real-time decoupling of abnormal gas generation pressure differences within the battery pack ;

[0113] The decoupled version With the second air pressure signal Time-frequency domain correlation analysis was performed to extract the coupling characteristics of internal and external pressure waveforms;

[0114] Based on the extracted coupling features, the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane are determined.

[0115] The execution unit 203 is used to execute the corresponding hierarchical prevention and control strategy according to the determined stage and state. The hierarchical prevention and control includes a first-level warning, a second-level warning and a third-level warning.

[0116] In other embodiments of the present invention, an electronic device 400 is disclosed, such as... Figure 3As shown, the electronic device may include: one or more processors 401; a memory 402; a display 403; one or more application programs (not shown); and one or more computer programs 404. These devices can be connected via one or more communication buses 405. The one or more computer programs 404 are stored in the memory 402 and configured to be executed by the one or more processors 401. The one or more computer programs 404 include instructions that can be used to perform actions such as... Figure 1 And the steps in the corresponding embodiments.

[0117] Through the above description of the embodiments, those skilled in the art will clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0118] In the various embodiments of the present invention, the functional units can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0119] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as flash memory, portable hard disk, read-only memory, random access memory, magnetic disk, or optical disk.

[0120] The above description is merely a specific implementation of the embodiments of the present invention, but the protection scope of the embodiments of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of the present invention should be covered within the protection scope of the embodiments of the present invention. Therefore, the protection scope of the embodiments of the present invention should be determined by the protection scope of the claims.

Claims

1. A multi-stage prevention and control method for battery thermal runaway, characterized in that, Includes the following steps: Step S1: Real-time acquisition of the first air pressure signal inside the battery pack cavity. Ambient temperature inside the battery pack Battery state of charge And a second air pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane. ; Step S2: Construct an ideal gas state compensation model using the first gas pressure signal. Ambient temperature inside the battery pack and battery state of charge Real-time decoupling of abnormal gas generation pressure differences within the battery pack ; Step S3: Decouple the abnormal gas generation pressure difference. With the second air pressure signal Time-frequency domain correlation analysis was performed to extract the coupling characteristics of internal and external pressure waveforms; Step S4: Based on the extracted coupling features, determine the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane; Step S5: Based on the determined stage and status, execute the corresponding graded prevention and control strategy, which includes Level 1 warning, Level 2 warning and Level 3 warning.

2. The method according to claim 1, characterized in that, The ideal gas state compensation model in step S2 is specifically as follows: The background pressure prediction model calculates the following estimated background pressure value: ； in, As the initial reference pressure, P ref As the initial reference pressure, The initial temperature, This is a correction factor for the leakage rate of the battery pack's airtightness. This is the battery volume expansion correction factor; The abnormal gas production pressure difference decoupling formula is used to calculate the abnormal gas production pressure difference: 。 3. The method according to claim 2, characterized in that, It also includes a dynamic baseline learning algorithm to correct the baseline in real time. : The system extracts data through a set time sliding window during normal vehicle operation and outside of peak charging / discharging periods. and Peak and trough data; The slope of the actual pressure change with temperature is calculated and compared with the theoretical expansion coefficient. If the deviation continues to exceed a preset threshold and there are no signs of thermal runaway, it is determined that the battery pack is leaking naturally or is aging and releasing gas. The system automatically and smoothly updates the airtightness correction coefficient in the formula. .

4. The method according to claim 1, characterized in that, Step S3, which extracts coupling features, includes: Calculate the rate of change of the first air pressure signal and the rate of change of the second air pressure signal .

5. The method according to claim 4, characterized in that, Step S4 includes: After decoupling It suddenly dropped from a high level, and time-frequency domain analysis captured... A sharp negative pulse characteristic appears, and When a rapid positive pulse characteristic appears simultaneously, it is determined that the waterproof and breathable membrane has been blown open by the thermal runaway gas generation, and the pressure relief channel is in a clear state. Among them, the rate of change of the first air pressure signal The rate of change of the second pressure signal is used to characterize the severity of internal gas accumulation or depressurization. This represents the rate of change of pipeline pressure over time.

6. The method according to claim 1, characterized in that, The first-level early warning step S5 includes: when there is an abnormal gas production pressure difference. The pressure remained above the set first threshold, but the battery temperature was monitored. If there is no abnormal temperature rise, the system determines that it is due to a small leakage in the battery cell or abnormal gas production due to aging. Execute control actions: Activate the active balancing function of the battery management system to perform voltage reduction processing, while limiting the peak power of the vehicle drive and charging to 50% of the rated value.

7. The method according to claim 1, characterized in that, The step S5, the secondary early warning, includes: when the first air pressure signal... A slope warning is triggered when the pressure exceeds the set second pressure threshold, and the second air pressure signal... When the value remains at 0, it is determined that the individual explosion-proof valve has been opened to produce gas and the waterproof and breathable membrane has not been broken. Execute control actions: Immediately execute the high-voltage main relay disconnect command to cut off the power circuit, and start the cooling water pump of the thermal management system for full-power circulation.

8. The method according to claim 5, characterized in that, The third-level warning in step S5 includes: when it is determined that the waterproof and breathable membrane has been blown open by thermal runaway gas generation and the pressure relief channel is unobstructed, it is a third-level warning. Execute control actions: activate the fire extinguishing agent spray device configured in the battery pack, and send coordinate information with a label indicating that the pressure relief channel is open and an emergency distress signal to the cloud server through the vehicle-mounted T-Box.

9. The method according to claim 1, characterized in that, Before performing step S5, a cross-validation fault diagnosis redundancy mechanism is also included: When the first air pressure signal With the second air pressure signal A non-physical divergence occurs between the readings, meaning the pressure difference instantaneously exceeds the physical burst limit of the battery pack casing, or the first air pressure signal. It reaches full capacity instantly; The system synchronously retrieves the terminal voltage change rate of the corresponding battery cell or module. Cross-validation was performed on the current fluctuation signal; like If the pressure sensor remains stable and there is no abnormal short-circuit current, it is determined to be a single-point electrical failure of the corresponding pressure sensor. The system then disables the gas generation alarm generated by the sensor to avoid false triggering of power outage.

10. A multi-stage prevention and control device for battery thermal runaway, characterized in that, Includes the following steps: The acquisition unit is used to acquire the first air pressure signal inside the battery pack in real time. Ambient temperature inside the battery pack Battery state of charge And a second air pressure signal located inside the exhaust pipe and outside the waterproof and breathable membrane. ; The logic control unit is used to construct an ideal gas state compensation model, utilizing the aforementioned... , and Real-time decoupling of abnormal gas generation pressure differences within the battery pack ; The decoupled version With the second air pressure signal Time-frequency domain correlation analysis was performed to extract the coupling characteristics of internal and external pressure waveforms; Based on the extracted coupling features, the stage of thermal runaway evolution of the battery system and the physical damage state of the waterproof and breathable membrane are determined. The execution unit is used to execute the corresponding hierarchical prevention and control strategy according to the determined stage and state. The hierarchical prevention and control includes level 1 warning, level 2 warning and level 3 warning.

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