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

Abstract

The invention discloses a battery pack thermal runaway early warning method, device and equipment and a storage medium, relates to the technical field of battery pack thermal management, and discloses a battery pack thermal runaway early warning method, which comprises the following steps: when a battery management system is in a dormant state, acquiring a voltage difference value between a reference voltage and a temperature sensor voltage, the temperature sensor is located at the position of an anti-explosion valve of the battery pack; controlling a battery management system according to the voltage difference value, so that the battery management system acquires a temperature sensor state parameter and a battery cell state parameter; determining a battery pack thermal runaway state based on the temperature sensor state parameter and the battery cell state parameter; and performing thermal runaway early warning according to the thermal runaway state of the battery pack, thereby realizing thermal runaway detection on the battery pack subjected to thermoelectric separation, and improving the safety of the battery pack.

Description

Technical Field

[0001] The present application relates to the technical field of battery pack thermal management, and in particular to a battery pack thermal runaway warning method, device, equipment and storage medium. Background Art

[0002] As electric vehicles become more and more popular, there are more and more thermal runaway incidents in the market, and people are paying more and more attention to the thermal safety of battery packs in electric vehicles. In order to improve the thermal safety of battery packs, the industry has proposed the concept of thermal-electric separation, that is, the high-temperature substances and gases generated by the eruption of the battery cells will not pass through other electrical components in the battery pack, avoiding arcing caused by abnormal insulation of electrical components and further exacerbating thermal runaway.

[0003] The thermal-electric separation solution requires that the exhaust passages of the electrical compartment and the battery cell be completely isolated. When the battery cell thermally runs away, the temperature sensor on the top of the battery cell cannot sense or cannot sense the change in the temperature of the battery cell in time, making the original temperature monitoring ineffective. In addition, since the valve opening products and gases are discharged through the box body and not into the electrical compartment, the traditional BPS (Battery Protection System) or BAS (Battery Alarm System) sensors placed in the battery pack cannot play a detection role. When the battery pack thermally runs away in the dormant state, the BMS (Battery Management System) cannot be awakened and the thermal runaway signal cannot be effectively reported.

[0004] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of this application is to provide a battery pack thermal runaway warning method, device, equipment and storage medium, aiming to solve the technical problem of how to detect thermal runaway of a battery pack with thermoelectric separation.

[0006] To achieve the above objectives, the present application proposes a battery pack thermal runaway early warning method, the battery pack thermal runaway early warning method comprising:

[0007] When the battery management system is in a dormant state, obtaining a voltage difference between a reference voltage and a temperature sensor voltage, wherein the temperature sensor is located at an explosion-proof valve position of the battery pack;

[0008] Controlling a battery management system according to the voltage difference so that the battery management system collects temperature sensor state parameters and battery cell state parameters;

[0009] Determine a thermal runaway state of a battery pack based on the temperature sensor state parameter and the battery cell state parameter;

[0010] A thermal runaway warning is performed according to the thermal runaway state of the battery pack.

[0011] In one embodiment, the step of determining the thermal runaway state of the battery pack based on the temperature sensor state parameter and the battery cell state parameter includes:

[0012] Acquire the temperature of the temperature sensor based on the temperature sensor state parameter to obtain a temperature acquisition result of the temperature sensor;

[0013] Acquire the battery cell temperature, battery cell temperature difference, battery cell temperature change rate and battery cell voltage based on the battery cell state parameters;

[0014] The thermal runaway state of the battery pack is determined based on the temperature acquisition result of the temperature sensor, the battery cell temperature, the battery cell temperature difference, the battery cell temperature change rate and the battery cell voltage.

[0015] In one embodiment, the step of determining the thermal runaway state of the battery pack based on the temperature acquisition result of the temperature sensor, the battery cell temperature, the battery cell temperature difference, the battery cell temperature change rate and the battery cell voltage includes:

[0016] Determine whether the battery cell temperature is greater than or equal to a first preset temperature within a preset time, and obtain a first determination result of the battery cell temperature;

[0017] Determine whether the battery cell temperature difference is greater than or equal to a second preset temperature within the preset time, and obtain a second determination result of the battery cell temperature;

[0018] Determine whether the battery cell temperature change rate is greater than or equal to a preset rate for a consecutive preset number of times, and obtain a third determination result of the battery cell temperature;

[0019] Determine whether the battery cell voltage is less than or equal to a preset voltage, and obtain a battery cell voltage determination result;

[0020] Determine whether thermal runaway occurs in the battery pack based on the first determination result of the battery cell temperature, the second determination result of the battery cell temperature, the third determination result of the battery cell temperature, and the battery cell voltage determination result, to obtain a first determination result of thermal runaway of the battery pack;

[0021] When the first determination result of thermal runaway of the battery pack is that thermal runaway of the battery pack does not occur, determining whether thermal runaway of the battery pack occurs based on the first determination result of thermal runaway of the battery pack and the temperature acquisition result of the temperature sensor, to obtain a second determination result of thermal runaway of the battery pack;

[0022] A battery pack thermal runaway state is determined based on the battery pack thermal runaway first determination result and the battery pack thermal runaway second determination result.

[0023] In one embodiment, the step of determining whether thermal runaway occurs in the battery pack based on the first determination result of the battery cell temperature, the second determination result of the battery cell temperature, the third determination result of the battery cell temperature, and the battery cell voltage determination result to obtain the first determination result of thermal runaway of the battery pack includes:

[0024] When the first determination result of the battery cell temperature is that the battery cell temperature is greater than or equal to the first preset temperature within the preset time and the second determination result of the battery cell temperature is that the battery cell temperature difference is greater than or equal to the second preset temperature within the preset time, and the third determination result of the battery cell temperature is that the battery cell temperature change rate is greater than or equal to the preset rate for a consecutive preset number of times and the battery cell voltage determination result is that the battery cell voltage is less than or equal to the preset voltage, the first determination result of thermal runaway of the battery pack is determined to be that thermal runaway has occurred in the battery pack.

[0025] In one embodiment, determining whether thermal runaway occurs in the battery pack based on the first determination result of thermal runaway of the battery pack and the temperature acquisition result of the temperature sensor to obtain a second determination result of thermal runaway of the battery pack includes:

[0026] Determine whether the temperature of the temperature sensor fails based on the temperature acquisition result of the temperature sensor, and obtain a first determination result of the temperature of the temperature sensor;

[0027] When the first determination result of the temperature sensor temperature is that the temperature sensor temperature is valid, determining whether the temperature sensor temperature is greater than or equal to a third preset temperature within a preset time, and obtaining a second determination result of the temperature sensor temperature;

[0028] When the first determination result of the temperature sensor temperature is that the temperature sensor temperature has failed or the second determination result of the temperature sensor temperature is that the temperature sensor temperature is greater than or equal to the third preset temperature within the preset time, whether the battery pack has thermal runaway is determined based on the first determination result of the battery pack thermal runaway to obtain a second determination result of the battery pack thermal runaway.

[0029] In one embodiment, the step of determining the thermal runaway state of the battery pack based on the first determination result of thermal runaway of the battery pack includes:

[0030] When the first determination result of the battery cell temperature is that the battery cell temperature is greater than or equal to the first preset temperature within the preset time, the second determination result of the battery cell temperature is that the battery cell temperature difference is greater than or equal to the second preset temperature within the preset time, the third determination result of the battery cell temperature is that the battery cell temperature change rate is greater than or equal to the preset rate for a consecutive preset number of times, and the battery cell voltage determination result is that the battery cell voltage is less than or equal to the preset voltage, the second determination result of thermal runaway of the battery pack is determined to be that thermal runaway occurs in the battery pack.

[0031] In one embodiment, the step of controlling the battery management system according to the voltage difference includes:

[0032] When the voltage difference reaches a preset threshold, the voltage difference is amplified by a preset amplification module to wake up a preset power supply module, so that the preset power supply module supplies power to a preset control module to wake up the battery management system, wherein the preset amplification module, the preset power supply module and the preset control module are connected in sequence.

[0033] In addition, to achieve the above-mentioned purpose, the present application also proposes a battery pack thermal runaway warning device, the battery pack thermal runaway warning device comprising:

[0034] A voltage detection module, used to obtain a voltage difference between a reference voltage and a temperature sensor voltage when the battery management system is in a dormant state, wherein the temperature sensor is located at the explosion-proof valve position of the battery pack;

[0035] A data acquisition module, used for controlling a battery management system according to the voltage difference, so that the battery management system acquires temperature sensor state parameters and battery cell state parameters;

[0036] A thermal runaway determination module, used to determine a thermal runaway state of a battery pack based on the temperature sensor state parameter and the battery cell state parameter;

[0037] The thermal runaway warning module is used to provide a thermal runaway warning according to the thermal runaway state of the battery pack.

[0038] In addition, to achieve the above-mentioned purpose, the present application also proposes a battery pack thermal runaway warning device, which includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the battery pack thermal runaway warning method as described above.

[0039] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by the processor, the steps of the battery pack thermal runaway warning method as described above are implemented.

[0040] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, it implements the steps of the battery pack thermal runaway warning method as described above.

[0041] One or more technical solutions proposed in this application have at least the following technical effects:

[0042] When the battery management system is in a dormant state, a voltage difference between a reference voltage and a temperature sensor voltage is obtained, the temperature sensor being located at the explosion-proof valve position of the battery pack, and the battery management system is controlled according to the voltage difference, so that the battery management system collects temperature sensor status parameters and battery cell status parameters, determines the thermal runaway state of the battery pack based on the temperature sensor status parameters and the battery cell status parameters, and performs a thermal runaway warning according to the thermal runaway state of the battery pack, thereby solving the technical problem of thermal runaway detection of a battery pack with thermal and electrical separation. When the voltage difference reaches a preset threshold, the battery management system is awakened so that the thermal runaway risk of the battery pack can be monitored and responded to in a timely manner, thereby reducing safety accidents caused by battery failures and improving the reliability and safety of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0045] Figure 1 A flow chart of the first embodiment of the thermal runaway warning method for a battery pack provided in this application;

[0046] Figure 2 A thermoelectric separation structure diagram of the battery pack thermal runaway warning method provided in Example 1 of the present application;

[0047] Figure 3 A circuit schematic diagram of a battery pack thermal runaway warning method provided in Example 1 of the present application;

[0048] Figure 4 A flow chart of the second embodiment of the thermal runaway warning method for a battery pack provided in this application;

[0049] Figure 5 This is a schematic diagram of the module structure of the battery pack thermal runaway warning device according to an embodiment of the present application;

[0050] Figure 6 Schematic diagram of the device structure of the hardware operating environment involved in the battery pack thermal runaway warning method in the embodiment of the present application.

[0051] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0052] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0053] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0054] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a thermal runaway warning device, etc. The following takes the thermal runaway warning device as an example to illustrate this embodiment and the following embodiments.

[0055] Based on this, the present application embodiment provides a battery pack thermal runaway warning method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the battery pack thermal runaway warning method of the present application.

[0056] In this embodiment, the battery pack thermal runaway warning method includes steps S10 to S40:

[0057] Step S10, when the battery management system is in a dormant state, obtaining a voltage difference between a reference voltage and a temperature sensor voltage, wherein the temperature sensor is located at a position of an explosion-proof valve of the battery pack;

[0058] It should be noted that the battery pack thermal runaway warning method of the present application is applied to electric vehicle battery packs with thermal and electrical separation. Figure 2 , Figure 2 This is a thermoelectric separation structure diagram of the battery pack thermal runaway warning method provided in Example 1 of the present application. Figure 2As shown, the thermoelectric separation solution inverts the ventilation holes of the battery cells, makes grooves on the liquid cooling plate at the positions corresponding to the ventilation holes of the battery cells, avoids the ventilation holes of the battery cells, and makes grooves on the liquid cooling plate near the explosion-proof valve position of the battery pack for exhaust. An exhaust pipe is welded at the explosion-proof valve position on the battery pack body, and the exhaust pipe and the groove position of the liquid cooling plate are sealed by a pipe sealing cover to form a closed exhaust channel. A hole is opened on the sealing cover, and a rivet nut is installed. A bolt-type NTC (Negative Temperature Coefficient) temperature sensor is locked with the rivet nut. This structure can achieve thermoelectric separation while taking into account thermal runaway monitoring and early warning.

[0059] It should be understood that since the electrical compartment of the thermoelectrically separated battery pack and the exhaust channel of the battery cell are completely isolated, when the battery pack has thermal runaway, the chemical reaction inside the battery will produce a large amount of gas, such as CO, H2, CO2, etc. As the gas is generated, the internal pressure of the battery pack will increase sharply. When the internal pressure of the battery pack rises to a certain level, the explosion-proof valve will open, allowing the internal high-temperature gas and steam to be released to the external environment to prevent the battery pack from rupturing or exploding. However, the battery management system in the dormant state, that is, BMS, cannot detect the thermal runaway of the battery pack and cannot issue an early warning in time. After the BMS enters the dormant state, the difference between the voltage of the temperature sensor at the explosion-proof valve position of the battery pack and the reference voltage is detected through hardware circuit design. It can detect whether the temperature at the explosion-proof valve position changes while maintaining the dormant state of the BMS under normal circumstances, without continuously sampling the temperature sensor, saving energy. Among them, the reference voltage is a stable voltage source, and the temperature sensor voltage changes with the change of the temperature at the explosion-proof valve position.

[0060] Step S20, controlling a battery management system according to the voltage difference, so that the battery management system collects temperature sensor state parameters and battery cell state parameters;

[0061] It should be understood that when the voltage difference between the detected reference voltage and the temperature sensor voltage reaches the preset threshold, it means that the temperature change of the battery pack has exceeded the normal range of change and requires further monitoring and processing. At this time, the battery management system will be awakened, switched from sleep mode to working mode, collect temperature sensor state parameters and battery cell state parameters, and analyze the specific state of the battery pack. Among them, the temperature sensor state parameters include the temperature of the temperature sensor, which corresponds to the temperature at the explosion-proof valve position, and the battery cell state parameters include the cell temperature, cell temperature difference, cell temperature change rate and cell voltage.

[0062] In a feasible implementation, step S20 may include step S21:

[0063] Step S21, when the voltage difference reaches a preset threshold, the voltage difference is amplified by a preset amplification module to wake up a preset power supply module, so that the preset power supply module supplies power to a preset control module to wake up the battery management system, wherein the preset amplification module, the preset power supply module and the preset control module are connected in sequence.

[0064] It should be noted that the BMS has a preset amplifier module, a preset power module and a preset control module connected in sequence, wherein the preset amplifier module is used to enhance the signal, the preset power module is used to supply power to the preset control module and other electronic components, and the preset control module is used to monitor and control the battery pack status in real time. The voltage difference generated by the reference voltage and the temperature sensor voltage will be input into the preset amplifier module. After the preset amplifier module enhances the signal of the voltage difference, the tiny voltage change is recognized by the preset power module, and then the preset power module supplies power to the preset control module, waking up the BMS to perform the task of monitoring and controlling the battery pack status. This solution can effectively solve the temperature monitoring problem of the battery pack with thermal and electrical separation, as well as the problem that the traditional solution cannot reversely wake up the BMS when the BMS is in the dormant state, thereby improving the safety of the battery pack.

[0065] For example, refer to Figure 3 , Figure 3 This is a circuit diagram of the battery pack thermal runaway warning method provided in Example 1 of this application. The vehicle KL30 power supply directly supplies power to the NTC temperature sensor through the power module DCDC in the BMS. When thermal runaway occurs in the vehicle's dormant state, the reference voltage point V ref and NTC temperature sensor voltage point V i The voltage difference is generated, and after amplification by the preset amplifier module, the preset power module SBC in the BMS is awakened. The SBC supplies power to the preset control module MCU in the BMS to wake up the BMS. After the BMS is powered on, the NTC temperature sensor voltage V is monitored. i , which can achieve the purpose of monitoring the temperature of the explosion-proof valve position, and provide thermal runaway warning in combination with the collected battery cell voltage and temperature.

[0066] Step S30, determining a thermal runaway state of the battery pack based on the temperature sensor state parameter and the battery cell state parameter;

[0067] It should be understood that thermal runaway refers to the runaway chemical reaction inside the battery, which causes a sharp rise in temperature, accompanied by gas generation, increased pressure, and even fire or explosion. By analyzing the collected temperature sensor status parameters and battery cell status parameters, it can be determined whether the battery pack is in a thermal runaway state. Specifically, it can be determined based on preset thresholds and combined with logical conditions.

[0068] Step S40: issuing a thermal runaway warning according to the thermal runaway state of the battery pack.

[0069] It should be noted that when the battery pack is in thermal runaway state, the corresponding early warning mechanism will be activated immediately to issue a thermal runaway warning. The early warning mechanism may specifically include sending a warning signal to the driver, automatically reducing the battery's charging or discharging rate, and cutting off the battery's power connection, etc., to prevent further heat accumulation from causing serious accidents such as explosions and fires.

[0070] It should be understood that when the thermal runaway state of the battery pack is that the battery pack does not experience thermal runaway, the battery management system will maintain normal operation.

[0071] This embodiment obtains the voltage difference between the reference voltage and the temperature sensor voltage when the battery management system is in a dormant state, and the temperature sensor is located at the explosion-proof valve position of the battery pack. The battery management system is controlled according to the voltage difference, so that the battery management system collects the temperature sensor status parameters and the battery cell status parameters, determines the thermal runaway state of the battery pack based on the temperature sensor status parameters and the battery cell status parameters, and performs a thermal runaway warning according to the thermal runaway state of the battery pack, thereby solving the technical problem of thermal runaway detection of a battery pack with thermal and electrical separation. When the voltage difference reaches a preset threshold, the battery management system is awakened so that the thermal runaway risk of the battery pack can be monitored and responded to in a timely manner, thereby reducing safety accidents caused by battery failures and improving the reliability and safety of the battery system.

[0072] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 4 , step S30 may include steps S31 to S33:

[0073] Step S31, acquiring the temperature of the temperature sensor based on the temperature sensor state parameter to obtain a temperature acquisition result of the temperature sensor;

[0074] It should be understood that the temperature sensor is located at the explosion-proof valve position of the battery pack, and is used to monitor the temperature at the explosion-proof valve position. The output signal of the temperature sensor can be read through the battery management system to obtain the temperature of the temperature sensor. When the temperature of the temperature sensor is successfully read, the obtained temperature sensor temperature acquisition result will include a valid temperature sensor temperature. When the temperature of the temperature sensor is not read, the obtained temperature sensor temperature acquisition result will include information that the temperature of the temperature sensor has failed. Specifically, the temperature sensor used can be an NTC temperature sensor, which integrates an NTC thermistor as its measuring element, and the NTC thermistor has the characteristic that the higher the temperature, the smaller the resistance.

[0075] Step S32, acquiring the battery cell temperature, battery cell temperature difference, battery cell temperature change rate and battery cell voltage based on the battery cell state parameters;

[0076] It should be noted that the cell temperature indicates the temperature of a single cell in a battery pack, the cell temperature difference indicates the temperature difference between different single cells in a battery pack, the cell temperature change rate indicates the rate of change of the temperature of a single cell in a battery pack in a short period of time, and the cell voltage indicates the voltage of a single cell in a battery pack. The above battery cell status parameters can only be obtained after the battery management system enters the working state.

[0077] Step S33, determining the thermal runaway state of the battery pack based on the temperature acquisition result of the temperature sensor, the battery cell temperature, the battery cell temperature difference, the battery cell temperature change rate and the battery cell voltage.

[0078] It should be understood that the safety status of the battery pack can be evaluated based on the temperature sensor temperature acquisition results, battery cell temperature, battery cell temperature difference, battery cell temperature change rate and battery cell voltage collected by the battery management system and according to certain thresholds, and whether the battery pack has thermal runaway can be determined based on the safety status of the battery pack. These status parameters can also be input into the algorithm model, and the algorithm can be used to evaluate the safety status of the battery pack and determine whether the battery pack has thermal runaway, so as to obtain the thermal runaway status of the battery pack.

[0079] In a feasible implementation, step S33 may include steps A11 to A17:

[0080] Step A11, determining whether the battery cell temperature is greater than or equal to a first preset temperature within a preset time, and obtaining a first determination result of the battery cell temperature;

[0081] It should be understood that by monitoring the temperature of the battery pack's single cell and comparing the cell temperature with the first preset temperature T1, determining whether the cell temperature is continuously greater than or equal to T1 within the preset time t, it is possible to identify whether there is a cell in the battery pack that is at risk of overheating. The preset time t and the first preset temperature T1 should be set according to the characteristics of the battery pack, and when the cell temperature does not continuously reach the first preset temperature within the preset time, the battery pack should be in a safe state.

[0082] Step A12, determining whether the battery cell temperature difference is greater than or equal to a second preset temperature within the preset time, and obtaining a second determination result of the battery cell temperature;

[0083] It should be understood that when the battery management system enters the working state, it will calculate the temperature difference between the cells inside the battery pack while collecting the cell temperature. Specifically, the temperature difference is the maximum temperature difference, that is, the battery management system will calculate the difference between the lowest cell temperature and the highest cell temperature collected, and determine whether the difference is continuously greater than or equal to the second preset temperature T2 within the preset time. Among them, the second preset temperature T2 should be set according to the characteristics of the battery pack.

[0084] Step A13, determining whether the battery cell temperature change rate is greater than or equal to a preset rate for a consecutive preset number of times, and obtaining a third determination result of the battery cell temperature;

[0085] It should be understood that when collecting the cell temperature, the real-time temperature change rate will also be calculated. When calculating the real-time temperature change rate, a suitable time window should be selected. The time window should be short enough to capture rapid temperature changes, but not too short to generate excessive noise or inaccurate data. When collecting the cell temperature change rate. When the cell temperature change rate is greater than or equal to the preset rate △T / △t for a continuous preset number of times, it means that the cell temperature may have increased abnormally. Among them, the preset number of times and the preset rate should be set according to the characteristics of the battery pack. In a specific implementation, the preset number of times can be set to 5.

[0086] Step A14, determining whether the cell voltage is less than or equal to a preset voltage, and obtaining a cell voltage determination result;

[0087] It should be understood that by comparing the collected cell voltage with the preset voltage V and determining whether the cell voltage is less than or equal to V, it is possible to detect whether the internal circuit of the battery is normal. When the cell voltage is less than or equal to the preset voltage V, the cell may have problems such as over-discharge or internal short circuit. The preset voltage should be set according to the characteristics of the battery pack.

[0088] Step A15, determining whether thermal runaway occurs in the battery pack based on the first determination result of the battery cell temperature, the second determination result of the battery cell temperature, the third determination result of the battery cell temperature, and the determination result of the battery cell voltage, to obtain a first determination result of thermal runaway of the battery pack;

[0089] It should be noted that by comprehensively analyzing the abnormal conditions of the battery pack identified by the first determination result of the battery cell temperature, the second determination result of the battery cell temperature, the third determination result of the battery cell temperature and the battery cell voltage determination result, and combining them with logical determination (such as all conditions are met at the same time or a specific combination of conditions are met), it can be determined whether the battery pack has thermal runaway.

[0090] In a feasible implementation, step A15 may include: when the first determination result of the battery cell temperature is that the battery cell temperature is greater than or equal to the first preset temperature within the preset time and the second determination result of the battery cell temperature is that the battery cell temperature difference is greater than or equal to the second preset temperature within the preset time, and the third determination result of the battery cell temperature is that the battery cell temperature change rate is greater than or equal to the preset rate for a consecutive preset number of times and the battery cell voltage determination result is that the battery cell voltage is less than or equal to the preset voltage, the first determination result of the thermal runaway of the battery pack is determined to be that the battery pack has experienced thermal runaway.

[0091] It should be understood that the preset time can be recorded as t, the first preset temperature can be recorded as T1, the second preset temperature can be recorded as T2, the preset rate can be recorded as △T / △t, and the preset number can be recorded as N. When the first determination result of thermal runaway of the battery pack is that thermal runaway of the battery pack occurs, it means that the data collected by the battery management system meets at least one of the following conditions: the battery cell temperature ≥ T1 lasts for t1 time, and the battery cell temperature change rate ≥ △T / △t lasts for N times; the battery cell temperature ≥ T1 lasts for t1 time, and the battery cell voltage ≤ V; the battery cell temperature difference ≥ T2 lasts for t1 time, and the battery cell temperature change rate ≥ △T / △t lasts for N times; the battery cell temperature difference ≥ T2 lasts for t1 time and the battery cell voltage ≤ V; the battery cell temperature difference ≥ T2 lasts for t1 time.

[0092] Step A16, when the first determination result of thermal runaway of the battery pack is that thermal runaway of the battery pack does not occur, determining whether thermal runaway of the battery pack occurs based on the first determination result of thermal runaway of the battery pack and the temperature acquisition result of the temperature sensor, to obtain a second determination result of thermal runaway of the battery pack;

[0093] It should be noted that when the first determination result indicates that the battery pack has not experienced thermal runaway, it is necessary to combine the temperature acquisition result of the temperature sensor to evaluate the safety status of the battery pack again, and perform additional safety checks based on the first determination result to ensure that when no thermal runaway risk is detected at the battery cell level, the entire battery pack is also in a safe state.

[0094] In a feasible implementation, step A16 may include steps B11 to B13:

[0095] Step B11, determining whether the temperature of the temperature sensor is invalid based on the temperature acquisition result of the temperature sensor, and obtaining a first temperature determination result of the temperature sensor;

[0096] It should be understood that when obtaining the temperature of the temperature sensor, the temperature sensor may fail. When the temperature of the temperature sensor cannot be obtained, the first determination result of the temperature sensor is that the temperature of the temperature sensor has failed. It may be that the temperature sensor itself is damaged, or the thermal runaway is too serious to cause the temperature monitoring failure. It is necessary to combine the battery status parameters to determine whether the battery pack has thermal runaway.

[0097] Step B12, when the first determination result of the temperature sensor temperature is that the temperature sensor temperature is valid, determining whether the temperature sensor temperature is greater than or equal to a third preset temperature within a preset time, and obtaining a second determination result of the temperature sensor temperature;

[0098] It should be understood that when the temperature sensor temperature is obtained, the collected temperature sensor temperature will be recorded as valid and the temperature sensor temperature will be continuously monitored. When the temperature sensor temperature is greater than or equal to the third preset temperature T3 for a preset time t, it indicates that an abnormal chemical reaction may have occurred inside the battery, causing the temperature at the explosion-proof valve position to reach an abnormal value. Among them, the second preset temperature T3 should be a safety threshold set according to the characteristics of the battery pack.

[0099] Step B13, when the first determination result of the temperature sensor temperature is that the temperature sensor temperature has failed or the second determination result of the temperature sensor temperature is that the temperature sensor temperature is greater than or equal to the third preset temperature within the preset time, determine whether the battery pack has thermal runaway based on the first determination result of the battery pack thermal runaway, and obtain the second determination result of the battery pack thermal runaway.

[0100] It should be understood that when and only when the temperature of the temperature sensor is abnormal (the temperature of the temperature sensor fails or the temperature of the temperature sensor continues to be greater than or equal to the safety threshold for a preset time), it is possible that only the temperature sensor element itself is damaged, while the battery pack is still in normal working condition. Therefore, it is necessary to obtain the battery cell status parameters in combination with the first determination result of thermal runaway of the battery pack to accurately determine whether thermal runaway has occurred in the battery pack.

[0101] In a feasible implementation, the step of determining whether the battery pack has thermal runaway based on the first determination result of the battery pack thermal runaway in step B13 to obtain the second determination result of the battery pack thermal runaway may include: when the first determination result of the battery cell temperature is that the battery cell temperature is greater than or equal to the first preset temperature within the preset time, the second determination result of the battery cell temperature is that the battery cell temperature difference is greater than or equal to the second preset temperature within the preset time, the third determination result of the battery cell temperature is that the battery cell temperature change rate is greater than or equal to the preset rate for a consecutive preset number of times, and the battery cell voltage determination result is that the battery cell voltage is less than or equal to a preset voltage, the second determination result of the battery pack thermal runaway is determined to be that the battery pack has thermal runaway.

[0102] It should be understood that when the temperature of the temperature sensor is abnormal (the temperature of the temperature sensor fails or the temperature of the temperature sensor continues to be greater than or equal to the safety threshold for a preset time), if any parameter of the battery cell status parameters (cell temperature, cell temperature difference, cell temperature change rate and cell voltage) is abnormal, it can be determined that the second determination result is that thermal runaway of the battery pack has occurred.

[0103] Step A17: determining a thermal runaway state of the battery pack based on the first thermal runaway determination result of the battery pack and the second thermal runaway determination result of the battery pack.

[0104] It should be understood that, by combining the first determination result of thermal runaway of the battery pack and the second determination result of thermal runaway of the battery pack, it is possible to finally determine whether the battery pack has thermal runaway. The second determination result of thermal runaway of the battery pack is used to perform a supplementary check on the state of the explosion-proof valve of the battery pack when the battery pack has not experienced thermal runaway according to the first determination result of thermal runaway of the battery pack, taking into account the characteristics of thermal and electrical separation of the battery pack.

[0105] This embodiment sets multiple monitoring conditions and thresholds to evaluate the safety status of the battery pack from different angles and determine whether thermal runaway occurs in the battery pack, thereby reducing the possibility of false alarms and missed reports of thermal runaway of the battery pack. When only a small number of battery cell status parameters are abnormal, the temperature sensor status parameters are considered for further thermal runaway determination, so as to achieve accurate thermal runaway determination and ensure the safety of the battery pack.

[0106] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the battery pack thermal runaway method of the present application. More simple transformations based on this technical concept are all within the scope of protection of the present application.

[0107] This application also provides a battery pack thermal runaway device, please refer to Figure 5 , the battery pack thermal runaway device comprises:

[0108] A voltage detection module 10, used to obtain a voltage difference between a reference voltage and a temperature sensor voltage when the battery management system is in a dormant state, wherein the temperature sensor is located at an explosion-proof valve position of the battery pack;

[0109] A data acquisition module 20, used to control a battery management system according to the voltage difference, so that the battery management system acquires temperature sensor state parameters and battery cell state parameters;

[0110] A thermal runaway determination module 30, configured to determine a thermal runaway state of a battery pack based on the temperature sensor state parameter and the battery cell state parameter;

[0111] The thermal runaway warning module 40 is used to provide a thermal runaway warning according to the thermal runaway state of the battery pack.

[0112] The battery pack thermal runaway device provided in the present application adopts the battery pack thermal runaway method in the above embodiment, which can solve the technical problem of how to detect thermal runaway of a battery pack with thermoelectric separation. Compared with the prior art, the beneficial effects of the battery pack thermal runaway device provided in the present application are the same as the beneficial effects of the battery pack thermal runaway method provided in the above embodiment, and the other technical features of the battery pack thermal runaway device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0113] The present application provides a battery pack thermal runaway device, which 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 so that the at least one processor can execute the battery pack thermal runaway method in the above-mentioned embodiment one.

[0114] Reference below Figure 6 , which shows a schematic diagram of the structure of a battery pack thermal runaway device suitable for implementing an embodiment of the present application. The battery pack thermal runaway device in the embodiment of the present application 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), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 6 The battery pack thermal runaway device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0115] like Figure 6As shown, the battery pack thermal runaway device may include a processing device 1001 (such as a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for the operation of the battery pack thermal runaway device are also stored. The processing device 1001, ROM1002 and RAM1004 are connected to each other via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 1003 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 1009. The communication device 1009 can allow the battery pack thermal runaway device to communicate wirelessly or wired with other devices to exchange data. Although the figure shows a battery pack thermal runaway device with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or provided alternatively.

[0116] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a 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 through a communication device, or installed from a storage device 1003, or installed from a ROM 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 application are executed.

[0117] The battery pack thermal runaway device provided in the present application adopts the battery pack thermal runaway method in the above embodiment, which can solve the technical problem of how to detect thermal runaway of a battery pack with thermoelectric separation. Compared with the prior art, the beneficial effects of the battery pack thermal runaway device provided in the present application are the same as the beneficial effects of the battery pack thermal runaway method provided in the above embodiment, and the other technical features in the battery pack thermal runaway device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0118] It should be understood that the various parts disclosed in this application can be implemented by 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 one or more embodiments or examples in a suitable manner.

[0119] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0120] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the battery pack thermal runaway method in the above-mentioned embodiment.

[0121] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0122] The above-mentioned computer-readable storage medium may be included in the battery pack thermal runaway control device; or it may exist independently without being assembled into the battery pack thermal runaway control device.

[0123] The above-mentioned computer-readable storage medium carries one or more programs. When the above-mentioned one or more programs are executed by the battery pack thermal runaway device, the battery pack thermal runaway device: obtains the voltage difference between the reference voltage and the temperature sensor voltage when the battery management system is in a dormant state, and the temperature sensor is located at the explosion-proof valve position of the battery pack; controls the battery management system according to the voltage difference, so that the battery management system collects temperature sensor status parameters and battery cell status parameters; determines the thermal runaway state of the battery pack based on the temperature sensor status parameters and the battery cell status parameters; and issues a thermal runaway warning according to the thermal runaway state of the battery pack.

[0124] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0125] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0126] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0127] The readable storage medium provided in this application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned battery pack thermal runaway warning method, and can solve the technical problem of how to detect thermal runaway of a battery pack with thermoelectric separation. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the battery pack thermal runaway warning method provided in the above-mentioned embodiment, and will not be repeated here.

[0128] The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of the above-mentioned battery pack thermal runaway warning method.

[0129] The computer program product provided in this application can solve the technical problem of how to detect thermal runaway of a battery pack with thermoelectric separation. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as the beneficial effects of the battery pack thermal runaway warning method provided in the above embodiment, which will not be repeated here.

[0130] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A battery pack thermal runaway early warning method, characterized in that: The battery pack thermal runaway early warning method comprises: When the battery management system is in a dormant state, obtaining a voltage difference between a reference voltage and a temperature sensor voltage, wherein the temperature sensor is located at an explosion-proof valve position of the battery pack; Controlling a battery management system according to the voltage difference so that the battery management system collects temperature sensor state parameters and battery cell state parameters; Determine a thermal runaway state of a battery pack based on the temperature sensor state parameter and the battery cell state parameter; A thermal runaway warning is performed according to the thermal runaway state of the battery pack.

2. The battery pack thermal runaway warning method according to claim 1, characterized in that: The step of determining the thermal runaway state of the battery pack based on the temperature sensor state parameter and the battery cell state parameter comprises: Acquire the temperature of the temperature sensor based on the temperature sensor state parameter to obtain a temperature acquisition result of the temperature sensor; Acquire the battery cell temperature, battery cell temperature difference, battery cell temperature change rate and battery cell voltage based on the battery cell state parameters; The thermal runaway state of the battery pack is determined based on the temperature acquisition result of the temperature sensor, the battery cell temperature, the battery cell temperature difference, the battery cell temperature change rate and the battery cell voltage.

3. The battery pack thermal runaway warning method according to claim 2, characterized in that: The step of determining the thermal runaway state of the battery pack based on the temperature acquisition result of the temperature sensor, the battery cell temperature, the battery cell temperature difference, the battery cell temperature change rate and the battery cell voltage includes: Determine whether the battery cell temperature is greater than or equal to a first preset temperature within a preset time, and obtain a first determination result of the battery cell temperature; Determine whether the battery cell temperature difference is greater than or equal to a second preset temperature within the preset time, and obtain a second determination result of the battery cell temperature; Determine whether the battery cell temperature change rate is greater than or equal to a preset rate for a consecutive preset number of times, and obtain a third determination result of the battery cell temperature; Determine whether the battery cell voltage is less than or equal to a preset voltage, and obtain a battery cell voltage determination result; Determine whether thermal runaway occurs in the battery pack based on the first determination result of the battery cell temperature, the second determination result of the battery cell temperature, the third determination result of the battery cell temperature, and the battery cell voltage determination result, to obtain a first determination result of thermal runaway of the battery pack; When the first determination result of thermal runaway of the battery pack is that thermal runaway of the battery pack does not occur, determining whether thermal runaway of the battery pack occurs based on the first determination result of thermal runaway of the battery pack and the temperature acquisition result of the temperature sensor, to obtain a second determination result of thermal runaway of the battery pack; A battery pack thermal runaway state is determined based on the battery pack thermal runaway first determination result and the battery pack thermal runaway second determination result.

4. The battery pack thermal runaway warning method according to claim 3, characterized in that: The step of determining whether thermal runaway occurs in the battery pack based on the first determination result of the battery cell temperature, the second determination result of the battery cell temperature, the third determination result of the battery cell temperature and the battery cell voltage determination result to obtain the first determination result of thermal runaway of the battery pack includes: When the first determination result of the battery cell temperature is that the battery cell temperature is greater than or equal to the first preset temperature within the preset time and the second determination result of the battery cell temperature is that the battery cell temperature difference is greater than or equal to the second preset temperature within the preset time, and the third determination result of the battery cell temperature is that the battery cell temperature change rate is greater than or equal to the preset rate for a consecutive preset number of times and the battery cell voltage determination result is that the battery cell voltage is less than or equal to the preset voltage, the first determination result of thermal runaway of the battery pack is determined to be that thermal runaway has occurred in the battery pack.

5. The battery pack thermal runaway warning method according to claim 3, characterized in that: The determining whether the battery pack has thermal runaway based on the first determination result of the battery pack thermal runaway and the temperature acquisition result of the temperature sensor to obtain the second determination result of the battery pack thermal runaway includes: Determine whether the temperature of the temperature sensor fails based on the temperature acquisition result of the temperature sensor, and obtain a first determination result of the temperature of the temperature sensor; When the first determination result of the temperature sensor temperature is that the temperature sensor temperature is valid, determining whether the temperature sensor temperature is greater than or equal to a third preset temperature within a preset time, and obtaining a second determination result of the temperature sensor temperature; When the first determination result of the temperature sensor temperature is that the temperature sensor temperature has failed or the second determination result of the temperature sensor temperature is that the temperature sensor temperature is greater than or equal to the third preset temperature within the preset time, whether the battery pack has thermal runaway is determined based on the first determination result of the battery pack thermal runaway to obtain a second determination result of the battery pack thermal runaway.

6. The battery pack thermal runaway warning method according to claim 5, characterized in that: The step of determining the thermal runaway state of the battery pack based on the first determination result of the thermal runaway of the battery pack includes: When the first determination result of the battery cell temperature is that the battery cell temperature is greater than or equal to the first preset temperature within the preset time, the second determination result of the battery cell temperature is that the battery cell temperature difference is greater than or equal to the second preset temperature within the preset time, the third determination result of the battery cell temperature is that the battery cell temperature change rate is greater than or equal to the preset rate for a consecutive preset number of times, and the battery cell voltage determination result is that the battery cell voltage is less than or equal to the preset voltage, the second determination result of thermal runaway of the battery pack is determined to be that thermal runaway occurs in the battery pack.

7. The battery pack thermal runaway warning method according to claim 1, characterized in that: The step of controlling the battery management system according to the voltage difference comprises: When the voltage difference reaches a preset threshold, the voltage difference is amplified by a preset amplification module to wake up a preset power supply module, so that the preset power supply module supplies power to a preset control module to wake up the battery management system, wherein the preset amplification module, the preset power supply module and the preset control module are connected in sequence.

8. A battery pack thermal runaway warning device, characterized in that: The device comprises: A voltage detection module, used to obtain a voltage difference between a reference voltage and a temperature sensor voltage when the battery management system is in a dormant state, wherein the temperature sensor is located at the explosion-proof valve position of the battery pack; A data acquisition module, used for controlling a battery management system according to the voltage difference, so that the battery management system acquires temperature sensor state parameters and battery cell state parameters; A thermal runaway determination module, used to determine a thermal runaway state of a battery pack based on the temperature sensor state parameter and the battery cell state parameter; The thermal runaway warning module is used to provide a thermal runaway warning according to the thermal runaway state of the battery pack.

9. A battery pack thermal runaway warning device, characterized in that: The device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the battery pack thermal runaway warning method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the battery pack thermal runaway warning method according to any one of claims 1 to 7 are implemented.

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