Vehicle power battery thermal runaway early warning method, system and equipment and storage medium

Abstract

The invention provides a vehicle power battery thermal runaway early warning method, system and device and a storage medium, and relates to the technical field of power batteries, and the method comprises the steps: obtaining the temperature data and voltage data of each cell when a vehicle power battery is charged; the temperature change rate of each battery cell is calculated according to the temperature data, and the voltage difference value of two adjacent frames of each battery cell is calculated according to the voltage data; identifying the abnormal battery cell according to the temperature change rate and the voltage difference value, and sending a cloud thermal runaway early warning signal; and performing vehicle end thermal runaway early warning on the vehicle according to the cloud end thermal runaway early warning signal. According to the method, the temperature growth rate and the temperature growth rate difference value in the charging process of the power battery are analyzed and judged in a short duration, and meanwhile, the early-stage battery cell charging process abnormity can be identified according to the fluctuation of the two continuous frames of voltage difference in the charging process, so that the occurrence of a thermal runaway event caused by continuous charging is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a method, system, device and storage medium for early warning of thermal runaway of a vehicle power battery. Background Art

[0002] With the increasing popularity of new energy vehicles, the safety of new energy vehicles has also been widely concerned, especially new energy vehicles are prone to thermal runaway of power batteries, which can cause huge economic losses. The main cause of thermal runaway of power batteries is that lithium deposition or foreign matter causes a short circuit in the battery, causing the positive and negative electrodes to contact and release a large amount of heat. Abnormal batteries with thermal runaway risks will continue to accumulate heat due to side reactions inside the battery, causing the battery temperature to drop slowly or have an upward trend.

[0003] At present, new energy vehicles can set up sensors to monitor abnormal conditions of battery core data and issue early warnings for battery safety status, among which battery core data mainly include battery cell temperature and battery cell voltage. Before thermal runaway occurs, the battery cell temperature may have a continuous and rapid rise process, but this process may vary due to factors such as battery cell location and heat dissipation conditions, and the temperature change within the normal use threshold range may not be sufficient to trigger the early warning system. After thermal runaway occurs, the voltage of the battery cell will have a decline process, but this process may be very rapid, and because the battery cell directly burns and damages the detection sampling line, the voltage signal quickly becomes an invalid value. Setting a voltage threshold that is too low may cause the warning to be triggered during the normal discharge of the battery. Therefore, in the thermal runaway warning information obtained by the power battery early warning method of the prior art, there is a problem that the temperature and voltage fluctuations of the abnormal battery cell are difficult to identify within the normal use threshold range. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a vehicle power battery thermal runaway warning method, system, device and storage medium, which effectively solves the problem that the temperature and voltage fluctuations of abnormal battery cells in the existing power battery warning method are difficult to identify within the normal usage threshold range.

[0005] In a first aspect, the present invention provides a vehicle power battery thermal runaway early warning method, the method comprising:

[0006] Obtain the temperature and voltage data of each battery cell when the vehicle's power battery is charging;

[0007] Calculate the temperature change rate of each of the battery cells according to the temperature data, and calculate the voltage difference between two adjacent frames of each of the battery cells according to the voltage data;

[0008] Identify abnormal cells according to the temperature change rate and the voltage difference, and send a thermal runaway warning signal to the cloud;

[0009] A vehicle-side thermal runaway warning is issued to the vehicle according to the cloud-side thermal runaway warning signal.

[0010] Furthermore, the calculation formula of the temperature change rate is:

[0011]

[0012] In the above formula, n and i represent positive integers, j represents the time interval, and K n (i, j) represents the temperature change rate of the nth cell in the power battery at time i and time interval j, T n (i+j) represents the temperature of the nth cell at time i+j, T n (i) represents the temperature of the nth battery cell at time i.

[0013] Furthermore, the voltage difference is calculated as follows:

[0014] ΔV n =V n (i,l)-V n (i)

[0015] In the above formula, l represents the time interval for collecting voltage, ΔV n It represents the voltage difference between the cell n at time i and the next frame at time interval l, V n (i,l) represents the voltage value of the nth cell at time i+l, V n (i) represents the voltage value of the nth battery cell at time i.

[0016] Furthermore, the identifying of abnormal cells according to the temperature change rate and the voltage difference and sending a thermal runaway warning signal to the cloud includes:

[0017] Obtaining a maximum temperature change rate according to the temperature change rate of each of the battery cells, and determining a first target battery cell according to the maximum temperature change rate;

[0018] If the maximum temperature change rate is greater than a first temperature change rate threshold, and the duration of the temperature change rate of the first target battery cell being at the maximum value is greater than or equal to a first time threshold, a cloud thermal runaway warning signal is sent;

[0019] If there is a second target battery cell whose voltage difference is less than 0, and the voltage difference is greater than the maximum voltage difference of the second target battery cell within the second time threshold, a cloud-based thermal runaway warning signal is sent.

[0020] Furthermore, after obtaining the maximum temperature change rate according to the temperature change rate of each of the battery cells, the method further includes:

[0021] Calculate the temperature change rate difference according to the maximum temperature change rate and the temperature change rates of the remaining battery cells at the same time;

[0022] If the temperature change rate difference is greater than the second temperature change rate threshold, and the duration is greater than or equal to the third time threshold, a cloud-based thermal runaway warning signal is sent.

[0023] Furthermore, the calculation formula of the temperature change rate difference is:

[0024] K nm (i,j)=K n (i,j)-K m (i,j)

[0025] In the above formula, n, m and i represent positive integers, j represents the time interval, and K nm (i, j) represents the difference in temperature change rate between the nth cell and the mth cell in the power battery at time i and time interval j, K n (i, j) represents the temperature change rate of the nth cell in the power battery at time i and time interval j, K m (i, j) represents the temperature change rate of the mth battery cell in the power battery at time i and time interval j.

[0026] Furthermore, if the maximum temperature change rate is greater than a first temperature change rate threshold, the method further includes:

[0027] If the maximum temperature change rate is greater than the maximum temperature change rate of the first target battery cell within the fourth time threshold, and the duration is greater than or equal to the fifth time threshold, a cloud-based thermal runaway warning signal is sent.

[0028] In a second aspect, the present invention provides a vehicle power battery thermal runaway warning system, the system comprising:

[0029] A data acquisition module is used to obtain temperature data and voltage data of each cell of the power battery;

[0030] A data calculation module, used for calculating the temperature change rate of each of the battery cells according to the temperature data, and calculating the voltage difference between two adjacent frames of each of the battery cells according to the voltage data;

[0031] A cloud warning module, used to identify abnormal cells according to the temperature change rate and the voltage difference, and send a cloud thermal runaway warning signal;

[0032] The vehicle-side warning module provides a vehicle-side thermal runaway warning to the vehicle according to the cloud-side thermal runaway warning signal.

[0033] In a third aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the vehicle power battery thermal runaway warning method as described in the first aspect of the present invention.

[0034] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the vehicle power battery thermal runaway warning method as described in the first aspect of the present invention is implemented.

[0035] The vehicle power battery thermal runaway warning method, system, device and storage medium provided by the present invention can identify the battery thermal runaway warning in advance by comparing the temperature growth rate and the temperature growth rate difference during the power battery charging process for analysis and judgment within a short duration, and immediately feedback to cut off the charging power supply, thereby avoiding the occurrence of more serious thermal runaway events caused by continuous charging. The temperature change characteristic monitoring is applicable to a variety of battery cell systems and has strong applicability in actual operation scenarios. At the same time, the early abnormality of the battery cell charging process can be identified according to the fluctuation of the voltage difference between two consecutive frames during the charging process, and the voltage abnormality can be fully analyzed by combining the difference of the actual voltage difference before and after within the set time, so as to avoid the misjudgment of the voltage difference caused by the charging current switching. The present invention monitors and identifies the recoverable instantaneous micro-short circuit inside the power battery during the fast charging process, has an agile response mechanism, can accurately identify the abnormal state battery cell in the early stage of thermal runaway, thereby issuing an alarm in advance and taking corresponding treatment measures, effectively avoiding major safety accidents and casualties that may occur later. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 This is a first schematic diagram of the process of the vehicle power battery thermal runaway warning method provided by an embodiment of the present invention;

[0038] Figure 2 This is a second schematic diagram of the process of the vehicle power battery thermal runaway warning method provided by an embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of the temperature change rate of a cell of a power battery in an embodiment of the present invention;

[0040] Figure 4is a schematic diagram of the temperature change rate difference result of the battery cell of the power battery in an embodiment of the present invention;

[0041] Figure 5 is a schematic diagram of voltage difference results of a cell of a power battery in an embodiment of the present invention;

[0042] Figure 6 It is a schematic diagram of the structure of a vehicle power battery thermal runaway warning system provided by an embodiment of the present invention;

[0043] Figure 7 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention.

[0044] Description of main component symbols:

[0045] 600, vehicle power battery thermal runaway warning system; 610, data acquisition module; 620, data calculation module; 630, cloud-side warning module; 640, vehicle-side warning module; 700, electronic equipment; 710, processor; 720, communication interface; 730, memory; 740, communication bus. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be noted that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0049] At present, new energy vehicles can set up sensors to monitor abnormal conditions of battery core data and issue early warnings for battery safety status, among which battery core data mainly include battery cell temperature and battery cell voltage. Before thermal runaway occurs, the battery cell temperature may have a continuous and rapid rise process, but this process may vary due to factors such as battery cell location and heat dissipation conditions, and the temperature change within the normal use threshold range may not be sufficient to trigger the early warning system. After thermal runaway occurs, the voltage of the battery cell will have a decline process, but this process may be very rapid, and because the battery cell directly burns and damages the detection sampling line, the voltage signal quickly becomes an invalid value. Setting a voltage threshold that is too low may cause the warning to be triggered during the normal discharge of the battery. Therefore, in the thermal runaway warning information obtained by the power battery early warning method of the prior art, there is a problem that the temperature and voltage fluctuations of the abnormal battery cell are difficult to identify within the normal use threshold range.

[0050] Example 1

[0051] The embodiment of the present invention provides a vehicle power battery thermal runaway warning method, which effectively solves the problem that the temperature and voltage fluctuations of abnormal cells in the existing power battery warning methods are difficult to identify within the normal use threshold range. Figure 1 FIG. 1 is a first schematic diagram of a vehicle power battery thermal runaway warning method process according to an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0052] S100: Obtain temperature data and voltage data of each battery cell when the power battery of the vehicle is being charged.

[0053] In the embodiment of the present invention, the temperature of each battery cell during charging is collected through the temperature sensing line equipped with the power battery of the vehicle, and the voltage of each battery cell is collected through the voltage sampling line to obtain initial temperature data and initial voltage data. Then, the initial temperature data and initial voltage data are eliminated for abnormal values, which include but are not limited to negative values ​​and data far exceeding the normal range, and finally the temperature data and voltage data of each battery cell are obtained.

[0054] S200 , calculating the temperature change rate of each battery cell according to the temperature data, and calculating the voltage difference between two adjacent frames of each battery cell according to the voltage data.

[0055] The calculation formula of temperature change rate is:

[0056]

[0057] In the above formula, n and i represent positive integers, j represents the time interval, and K n (i,j) represents the temperature change rate of the nth cell in the power battery at time i and time interval j, T n(i+j) represents the temperature of the nth cell at time i+j, T n (i) represents the temperature of the nth battery cell at time i.

[0058] Optionally, considering that data is usually collected every 10 seconds during the power battery charging process, the value of the time interval j is preferably an integer multiple of 10, and the range of the time interval j is preferably j ≥ 20s. At the same time, considering that a certain escape time needs to be provided to the driver or passengers after the vehicle power battery has a thermal runaway warning, the preferred range of j is 20s ≤ j ≤ 180s.

[0059] The voltage difference is calculated as:

[0060] ΔV n =V n (i,l)-V n (i)

[0061] In the above formula, l represents the time interval for collecting voltage, ΔV n It represents the voltage difference between the cell n at time i and the next frame at time interval l, V n (i,l) represents the voltage value of the nth cell at time i+l, V n (i) represents the voltage value of the nth battery cell at time i.

[0062] In the embodiment of the present invention, the time interval l may be 10s. If the sampling frequency is higher, the time interval may be a multiple of 1s. The preferred value range of l is 1s≤l≤10s.

[0063] S300: Identify abnormal cells based on the temperature change rate and voltage difference, and send a thermal runaway warning signal to the cloud.

[0064] Figure 2 is a second schematic diagram of the vehicle power battery thermal runaway warning method process provided by an embodiment of the present invention, such as Figure 2 As shown, the identification of abnormal cells includes the following steps:

[0065] S310 , obtaining a maximum temperature change rate according to the temperature change rate of each battery cell, and determining a first target battery cell according to the maximum temperature change rate.

[0066] The maximum temperature change rate at the moment is obtained according to the temperature change rate of each battery cell at the moment i, and the corresponding battery cell is determined as the first target battery cell according to the maximum temperature change rate.

[0067] S320: If the maximum temperature change rate is greater than the first temperature change rate threshold, and the duration of the temperature change rate of the first target battery cell being at the maximum value is greater than or equal to the first time threshold, a thermal runaway warning signal is sent to the cloud.

[0068] In the embodiment of the present invention, the first temperature change rate threshold can be determined according to the value of the time interval j. If the range of the time interval j is 20s≤j<60s, the first temperature change rate threshold can be set to 0.05°C / j. If the range of the time interval j is j>60s, the first temperature change rate threshold can be set to 0.1°C / j. The first time threshold can be set according to the actual situation of the vehicle and the power battery and the warning requirements. In the embodiment of the present invention, the first time threshold is set to 20s.

[0069] Figure 3 FIG. 1 is a schematic diagram of the temperature change rate of the battery cell of the power battery in the embodiment of the present invention. Figure 3 As shown, the time interval j is 60s to obtain the temperature change rate of some cells of a power battery. 2-positive, 4-positive, and 5-positive represent the positions of the cells where the temperature is collected, namely, the positive electrode of cell 2, the positive electrode of cell 4, and the positive electrode of cell 5, respectively. 2-positive represents an abnormal cell. Figure 3 It can be concluded that at the 60s time interval of abnormal cell 2-positive, the temperature change rate near 670s in the time series is significantly higher than that of normal cells 4-positive and 5-positive.

[0070] S330: If there is a second target battery cell whose voltage difference is less than 0, and the voltage difference is greater than the maximum voltage difference of the second target battery cell within the second time threshold, a thermal runaway warning signal is sent to the cloud.

[0071] If the difference between the voltage values ​​of two consecutive frames of the second target cell is negative during the charging process, that is, the voltage difference ΔV n <0. The charging process is a continuous charging process without a rest time in the middle. If there is a rest time in the charging process, the voltage difference before and after the rest time are two continuous charging processes. When a negative value appears, the voltage difference is greater than the maximum voltage difference of the second target battery cell within the second time threshold. In the embodiment of the present invention, the second time threshold can be set to 1min, and optionally, it can also be set to be greater than 1mV.

[0072] Figure 4 is a schematic diagram of the voltage difference result of the battery cell of the power battery in the embodiment of the present invention, such as Figure 4 As shown in the figure, the time interval l is 10s to obtain the voltage difference of some cells of a power battery. 1#, 2#, 3#, 4#, 5# and 6# represent cells 1 to 6 respectively, among which cell 2 is an abnormal cell and the rest are normal cells. The voltage difference of two consecutive frames of normal cells shows a smooth change trend, while cell 2 also shows abnormal fluctuations at around 670s in the time series, and the voltage difference data of normal cells is relatively discrete.

[0073] As a further implementation method of an embodiment of the present invention, a temperature change rate difference is calculated based on the maximum temperature change rate and the temperature change rates of the remaining battery cells at the same time. If the temperature change rate difference is greater than a second temperature change rate threshold and the duration is greater than or equal to a third time threshold, the first target battery cell is determined to be an abnormal battery cell, and a thermal runaway warning signal is sent to the cloud.

[0074] The calculation formula for the temperature change rate difference is:

[0075] K nm (i,j)=K n (i,j)-K m (i,j)

[0076] In the above formula, n, m and i represent positive integers, j represents the time interval, and K nm (i,j) represents the temperature change rate difference between the nth cell and the mth cell in the power battery at time i and time interval j, K n (i,j) represents the temperature change rate of the nth cell in the power battery at time i and time interval j, K m (i,j) represents the temperature change rate of the mth cell in the power battery at time i and time interval j.

[0077] Optionally, the second temperature change rate threshold and the third time threshold can be set according to the actual conditions of the vehicle and the power battery and the warning requirements. In an embodiment of the present invention, the second temperature change rate threshold can be set to 0.1°C / j, and the third time threshold can be set to 20s.

[0078] Figure 5 is a schematic diagram of the temperature change rate difference result of the power battery cell in the embodiment of the present invention, such as Figure 5 As shown, 2+-4+ represents the difference in temperature change rate between the positive electrode position of cell 2 and the positive electrode position of cell 4, and 2+-5+ represents the difference in temperature change rate between the positive electrode position of cell 2 and the positive electrode position of cell 5. Both of them show obvious growth at around 670s in the time series.

[0079] As a further implementation method of the embodiment of the present invention, if the maximum temperature change rate is greater than the maximum temperature change rate of the first target battery cell within the fourth time threshold, and the duration is greater than or equal to the fifth time threshold, the first target battery cell is determined to be an abnormal battery cell, and a thermal runaway warning signal is sent to the cloud.

[0080] In an embodiment of the present invention, the fourth time threshold and the fifth time threshold can be set according to the actual situation of the vehicle and the power battery and the warning requirements. In an embodiment of the present invention, the fourth time threshold can be set to the first 1 minute, and the fifth time threshold can be set to 20 seconds.

[0081] S400. Provide a vehicle-side thermal runaway warning based on the cloud-based thermal runaway warning signal.

[0082] If the vehicle receives a thermal runaway warning signal from the cloud, it means that there is a high possibility of thermal runaway risk in the power battery. A control signal is sent to stop charging the vehicle, and an early warning is issued on the vehicle to remind relevant personnel to stop the vehicle for maintenance and other operations.

[0083] The vehicle power battery thermal runaway warning method provided by the embodiment of the present invention can identify the battery thermal runaway warning in advance by comparing the temperature growth rate and the temperature growth rate difference during the power battery charging process and analyzing and judging within a short duration, and can immediately feedback and cut off the charging power supply, thereby avoiding the occurrence of more serious thermal runaway events caused by continuous charging. At the same time, the early abnormality of the battery charging process can be identified based on the fluctuation of the voltage difference between two consecutive frames during the charging process, and the voltage abnormality can be fully analyzed by combining the difference comparison of the actual voltage difference before and after within the set time, avoiding the misjudgment of the voltage difference caused by the switching of the charging current.

[0084] Example 2

[0085] Based on the same technical concept as the method embodiment of the above embodiment 1, the embodiment of the present invention provides a vehicle power battery thermal runaway warning system, Figure 6 FIG. 1 is a schematic diagram of the structure of a vehicle power battery thermal runaway warning system provided by an embodiment of the present invention. Figure 6 As shown, the vehicle power battery thermal runaway warning system 600 includes:

[0086] The data acquisition module 610 is used to obtain temperature data and voltage data of each battery cell of the power battery.

[0087] The data calculation module 620 is used to calculate the temperature change rate of each battery cell according to the temperature data, and to calculate the voltage difference between two adjacent frames of each battery cell according to the voltage data.

[0088] The cloud warning module 630 is used to identify abnormal cells according to the temperature change rate and voltage difference, and send a thermal runaway warning signal to the cloud.

[0089] The vehicle-side warning module 640 provides a vehicle-side thermal runaway warning to the vehicle according to the cloud-side thermal runaway warning signal.

[0090] The vehicle power battery thermal runaway warning system provided by the embodiment of the present invention monitors the temperature change characteristics and is applicable to a variety of battery cell systems, and has strong applicability in actual operation scenarios. By monitoring and identifying the recoverable instantaneous micro-short circuit inside the power battery during the fast charging process, it has an agile response mechanism and can accurately identify abnormal state batteries in the early stage of thermal runaway, thereby issuing an alarm in advance and taking corresponding treatment measures, effectively avoiding major safety accidents and casualties that may occur later.

[0091] It can be understood that the implementation method of the vehicle power battery thermal runaway warning method provided in the above-mentioned embodiment 1 is also applicable to this embodiment and can achieve the same technical effect, so it will not be repeated here.

[0092] Example 3

[0093] Based on the same concept, an embodiment of the present invention further provides an electronic device, Figure 7 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention, such as Figure 7 As shown, the electronic device 700 may include: a processor 710, a communication interface 720, a memory 730 and a communication bus 740, wherein the processor 710, the communication interface 720 and the memory 730 communicate with each other through the communication bus 740. The processor 710 may call the logic instructions in the memory 730 to execute the steps of the vehicle power battery thermal runaway warning method as described in the above embodiments. For example, it includes:

[0094] S100, obtaining temperature data and voltage data of each battery cell of the power battery;

[0095] S200, calculating the temperature change rate of each battery cell according to the temperature data, and calculating the voltage difference between two adjacent frames of each battery cell according to the voltage data;

[0096] S300, identifying abnormal cells based on the temperature change rate and voltage difference, and sending a thermal runaway warning signal to the cloud;

[0097] S400. Provide a vehicle-side thermal runaway warning based on the cloud-based thermal runaway warning signal.

[0098] The processor 710 may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0099] In addition, the logic instructions in the above-mentioned memory 730 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0100] The memory 730 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required by at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0101] Example 4

[0102] Based on the same concept, an embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program, and the computer program includes at least one code segment, which can be executed by a main control device to control the main control device to implement the steps of the vehicle power battery thermal runaway warning method as described in the above embodiments. For example, it includes:

[0103] S100, obtaining temperature data and voltage data of each battery cell of the power battery;

[0104] S200, calculating the temperature change rate of each battery cell according to the temperature data, and calculating the voltage difference between two adjacent frames of each battery cell according to the voltage data;

[0105] S300, identifying abnormal cells based on the temperature change rate and voltage difference, and sending a thermal runaway warning signal to the cloud;

[0106] S400. Provide a vehicle-side thermal runaway warning based on the cloud-based thermal runaway warning signal.

[0107] Based on the same technical concept, an embodiment of the present invention further provides a computer program, which is used to implement the above method embodiment when executed by a main control device.

[0108] The computer program may be stored in whole or in part on a computer-readable storage medium packaged with the processor, or may be stored in whole or in part on a memory not packaged with the processor.

[0109] Based on the same technical concept, an embodiment of the present invention further provides a processor, which is used to implement the above method embodiment. The above processor can be a chip.

[0110] In summary, the vehicle power battery thermal runaway warning method, system, device and storage medium provided by the present invention can identify the battery thermal runaway warning in advance by comparing the temperature growth rate and the temperature growth rate difference during the power battery charging process for analysis and judgment within a short duration, and immediately feedback to cut off the charging power supply, thereby avoiding the occurrence of more serious thermal runaway events caused by continuous charging. Temperature change characteristic monitoring is applicable to a variety of battery cell systems and has strong applicability in actual operation scenarios. At the same time, the early abnormality of the battery cell charging process can be identified according to the fluctuation of the voltage difference between two consecutive frames during the charging process, and the difference between the actual voltage difference before and after is compared within the set time, and the voltage abnormality is fully analyzed to avoid the misjudgment of the voltage difference caused by the switching of the charging current. The present invention monitors and identifies the recoverable instantaneous micro-short circuit inside the power battery during the fast charging process, has an agile response mechanism, can accurately identify the abnormal state battery cell in the early stage of thermal runaway, thereby issuing an alarm in advance and taking corresponding treatment measures, effectively avoiding major safety accidents and casualties that may occur later.

[0111] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0112] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle power battery thermal runaway early warning method, characterized in that: The method comprises: Obtain the temperature and voltage data of each battery cell when the vehicle's power battery is charging; Calculate the temperature change rate of each of the battery cells according to the temperature data, and calculate the voltage difference between two adjacent frames of each of the battery cells according to the voltage data; Identify abnormal cells according to the temperature change rate and the voltage difference, and send a thermal runaway warning signal to the cloud; A vehicle-side thermal runaway warning is issued to the vehicle according to the cloud-side thermal runaway warning signal.

2. The vehicle power battery thermal runaway early warning method according to claim 1, characterized in that: The calculation formula of the temperature change rate is: In the above formula, n and i represent positive integers, j represents the time interval, and K n (i, j) represents the temperature change rate of the nth cell in the power battery at time i and time interval j, T n (i+j) represents the temperature of the nth cell at time i+j, T n (i) represents the temperature of the nth battery cell at time i.

3. The vehicle power battery thermal runaway early warning method according to claim 2, characterized in that: The voltage difference is calculated as follows: ΔV n =V n (i,l)-V n (i) In the above formula, l represents the time interval for collecting voltage, ΔV n It represents the voltage difference between the nth cell at time i and the next frame with a time interval of l, V n (i,l) represents the voltage value of the nth cell at time i+l, V n (i) represents the voltage value of the nth battery cell at time i.

4. The vehicle power battery thermal runaway early warning method according to claim 1, characterized in that: The identifying of abnormal cells according to the temperature change rate and the voltage difference, and sending a thermal runaway warning signal to the cloud, includes: Obtaining a maximum temperature change rate according to the temperature change rate of each of the battery cells, and determining a first target battery cell according to the maximum temperature change rate; If the maximum temperature change rate is greater than a first temperature change rate threshold, and the duration of the temperature change rate of the first target battery cell being at the maximum value is greater than or equal to a first time threshold, a cloud thermal runaway warning signal is sent; If there is a second target battery cell whose voltage difference is less than 0, and the voltage difference is greater than the maximum voltage difference of the second target battery cell within the second time threshold, a cloud-based thermal runaway warning signal is sent.

5. The vehicle power battery thermal runaway early warning method according to claim 4, characterized in that: After obtaining the maximum temperature change rate according to the temperature change rate of each of the battery cells, the method further includes: Calculate the temperature change rate difference according to the maximum temperature change rate and the temperature change rates of the remaining battery cells at the same time; If the temperature change rate difference is greater than the second temperature change rate threshold, and the duration is greater than or equal to the third time threshold, a cloud-based thermal runaway warning signal is sent.

6. The vehicle power battery thermal runaway early warning method according to claim 5, characterized in that: The calculation formula of the temperature change rate difference is: K nm (i,j)=K n (i,j)-K m (i,j) In the above formula, n, m and i represent positive integers, j represents the time interval, and K nm (i, j) represents the difference in temperature change rate between the nth cell and the mth cell in the power battery at time i and time interval j, K n (i, j) represents the temperature change rate of the nth cell in the power battery at time i and time interval j, K m (i, j) represents the temperature change rate of the mth battery cell in the power battery at time i and time interval j.

7. The vehicle power battery thermal runaway early warning method according to claim 4, characterized in that: If the maximum temperature change rate is greater than the first temperature change rate threshold, the method further includes: If the maximum temperature change rate is greater than the maximum temperature change rate of the first target battery cell within the fourth time threshold, and the duration is greater than or equal to the fifth time threshold, a cloud-based thermal runaway warning signal is sent.

8. A vehicle power battery thermal runaway warning system, characterized in that: The system comprises: A data acquisition module is used to obtain temperature data and voltage data of each cell of the power battery; A data calculation module, used for calculating the temperature change rate of each of the battery cells according to the temperature data, and calculating the voltage difference between two adjacent frames of each of the battery cells according to the voltage data; A cloud warning module, used to identify abnormal cells according to the temperature change rate and the voltage difference, and send a cloud thermal runaway warning signal; The vehicle-side warning module provides a vehicle-side thermal runaway warning to the vehicle according to the cloud-side thermal runaway warning signal.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: The processor executes the computer program to implement the vehicle power battery thermal runaway warning method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the vehicle power battery thermal runaway warning method as described in any one of claims 1 to 7 is implemented.

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