Battery protection method and related device

Abstract

This application discloses a battery protection method and related apparatus. The method includes: determining the internal temperature of the battery based on battery state data, including the battery surface temperature; determining a temperature protection threshold for the battery if the difference between the internal temperature and the surface temperature is greater than a preset threshold; and performing temperature protection on the battery if the battery is determined to be in a first state based on the internal temperature, surface temperature, and temperature protection threshold, whereby the first state characterizes excessively high internal and / or surface temperatures. This allows for over-temperature protection of the battery by estimating its internal temperature and comparing it with a temperature threshold, thereby improving the battery's temperature operating range and extending its lifespan.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery protection method and related devices. Background Art

[0002] In electric vehicles, battery module temperature sensors are typically located on their surfaces. However, the heat generated by the battery during use originates internally, causing the highest temperature point inside the battery. In practical applications, a common method for protecting battery temperature is to determine whether the current battery temperature exceeds a threshold based on the surface temperature data collected by the temperature sensor, and then implement a corresponding battery protection strategy based on the judgment result. However, this approach can create a situation where the battery's internal temperature is already severely elevated before the surface temperature reaches the protection threshold, potentially causing irreversible damage to the battery or, worse still, thermal runaway.

[0003] Therefore, a battery protection method is urgently needed to solve the above problems. Summary of the Invention

[0004] The present invention provides a battery protection method and related device. This method calculates the internal battery temperature based on battery status data, then determines the battery status based on the temperature protection threshold, internal temperature, and surface temperature defined by the cell's chemical characteristics. Ultimately, based on the determination, the battery is protected against temperature fluctuations. This effectively increases the battery's temperature range and extends its service life. Furthermore, the retained surface temperature protection determination further ensures battery safety.

[0005] In a first aspect, an embodiment of the present application provides a battery protection method, the method comprising:

[0006] determining an internal temperature of the battery based on battery status data, the status data including a surface temperature of the battery;

[0007] If the difference between the internal temperature and the surface temperature is greater than a preset threshold, determining a temperature protection threshold of the battery;

[0008] If it is determined according to the internal temperature, the surface temperature and the temperature protection threshold that the battery is in a first state, temperature protection is performed on the battery, where the first state is used to indicate that the internal temperature and / or the surface temperature is too high.

[0009] In a second aspect, an embodiment of the present application provides a battery protection device, the device comprising: a determination unit and an execution unit, wherein:

[0010] The determining unit is configured to determine the internal temperature of the battery based on status data of the battery, wherein the status data includes a surface temperature of the battery;

[0011] The determining unit is further configured to determine a temperature protection threshold of the battery if the difference between the internal temperature and the surface temperature is greater than a preset threshold;

[0012] The execution unit is configured to perform temperature protection on the battery if it is determined that the battery is in a first state based on the internal temperature, the surface temperature, and the temperature protection threshold, wherein the first state is used to indicate that the internal temperature and / or the surface temperature is too high.

[0013] In a third aspect, an embodiment of the present application provides an electronic device comprising a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the program comprises instructions for executing the steps of any method of the first aspect of the embodiment of the present application.

[0014] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the above-mentioned computer-readable storage medium stores a computer program for electronic data exchange, wherein the above-mentioned computer program enables a computer to execute part or all of the steps described in any method of the first aspect of the embodiment of the present application.

[0015] In a fifth aspect, embodiments of the present application provide a computer program product comprising instructions, characterized in that when the computer program product is executed on an electronic device, the electronic device executes some or all of the steps described in any method of the first aspect of the embodiments of the present application. The computer program product may be a software installation package.

[0016] In a sixth aspect, an embodiment of the present application provides a battery, comprising a battery module and a battery management system, wherein the battery management system is used to execute some or all of the steps described in any method of the first aspect of the embodiment of the present application.

[0017] It can be seen that in the embodiment of the present application, the embodiment of the present application discloses a battery protection method and related devices, which determine the internal temperature of the battery based on the status data of the battery, and the status data includes the surface temperature of the battery; if the difference between the internal temperature and the surface temperature is greater than a preset threshold, the temperature protection threshold of the battery is determined; if the battery is determined to be in the first state based on the internal temperature, the surface temperature and the temperature protection threshold, temperature protection is performed on the battery, and the first state is used to characterize that the internal temperature and / or surface temperature are too high. This method is based on the internal temperature of the battery, and combines the internal temperature and surface temperature of the battery to determine whether it is necessary to obtain the temperature protection threshold, and performs over-temperature protection judgment based on the temperature protection threshold, so that the thermal runaway event of the battery can be discovered early. Furthermore, the over-temperature protection judgment based on the estimated internal temperature of the battery can effectively improve the temperature application range of the battery and extend the battery service life, while the retained over-temperature protection judgment based on the surface temperature can ensure the efficiency of the battery over-temperature protection, thereby improving the battery safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 This is a schematic diagram of the internal modules of a battery module provided in an embodiment of the present application;

[0020] Figure 2 This is a flow chart of a battery protection method provided in an embodiment of the present application;

[0021] Figure 3 This is a schematic diagram of a calculation process provided by an embodiment of the present application;

[0022] Figure 4 This is a schematic diagram of the overall process of a battery protection method provided in an embodiment of the present application;

[0023] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0024] Figure 6 This is a schematic diagram of the functional unit structure of a battery protection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In order to better understand the solutions of the embodiments of the present application, the electronic devices, related terms, concepts and related backgrounds that may be involved in the embodiments of the present application are first introduced below.

[0029] The electronic device may be a portable electronic device that also includes other functions such as a personal digital assistant and / or a music player function, such as a mobile phone, a tablet computer, a wearable electronic device with a wireless communication function (such as a smart watch), etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with an IOS system, an Android system, a Microsoft system, or other operating systems. The above-mentioned portable electronic device may also be other portable electronic devices, such as a laptop computer (Laptop), etc. It should also be understood that in some other embodiments, the above-mentioned electronic device may also be an electronic device for battery protection in the present application solution.

[0030] It should be noted that the battery protection method proposed in this application is used in the vehicle-mounted electronic control unit (ECU). Based on the characteristics of vehicle-mounted ECU products, the optimal solution is one that is simple to calculate, consumes relatively little resources, and can calculate relatively accurate results.

[0031] Specifically, see Figure 1 , Figure 1 This is a schematic diagram of the internal modules of a battery module provided in an embodiment of the present application. Figure 1 As shown, the battery module includes: a thermal runaway calculation unit and a temperature protection unit, wherein the thermal runaway calculation unit includes an OCV voltage calculation module and an internal temperature calculation module.

[0032] For example, the OCV voltage calculation module calculates the current charge and discharge state of the battery, and calculates the current open circuit voltage E(OCV) of the battery based on the SOC. At the same time, the internal thermal capacity Cm and internal thermal resistance Rm are calculated based on the ambient temperature.

[0033] Furthermore, the internal temperature calculation module simultaneously calculates the current internal temperature of the battery based on the SOC, E(OCV), the surface temperature of the battery and its corresponding cell voltage.

[0034] Furthermore, the thermal runaway calculation unit determines whether to be activated based on the internal temperature and the surface temperature.

[0035] Furthermore, if it is determined to activate the thermal runaway calculation unit, a temperature protection threshold is obtained, and the temperature protection unit determines whether to perform temperature protection based on the internal temperature, the surface temperature, and the temperature protection threshold.

[0036] It can be seen that the present application scheme is based on the above-mentioned functional modules, and determines the internal temperature of the battery according to the status data of the battery, and the status data includes the surface temperature of the battery; if the difference between the internal temperature and the surface temperature is greater than a preset threshold, the temperature protection threshold of the battery is determined; if the battery is determined to be in the first state according to the internal temperature, the surface temperature and the temperature protection threshold, temperature protection is performed on the battery, and the first state is used to characterize that the internal temperature and / or surface temperature are too high. This method calculates the internal temperature of the battery, combines the internal temperature and the surface temperature of the battery to determine whether it is necessary to obtain the temperature protection threshold, and performs an over-temperature protection judgment based on the temperature protection threshold, so that the thermal runaway event of the battery can be discovered early. Furthermore, the over-temperature protection judgment based on the estimated internal temperature of the battery can effectively improve the temperature application range of the battery and extend the battery service life, while the retained over-temperature protection judgment based on the surface temperature can ensure the efficiency of the battery over-temperature protection, thereby improving the battery safety.

[0037] In order to better understand the above process, this application is described in detail below in conjunction with specific embodiments.

[0038] See also Figure 2 , Figure 2 This is a flow chart of a battery protection method provided by an embodiment of the present application. Figure 2 As shown, the battery protection method specifically includes the following steps:

[0039] S201 : Determine the internal temperature of the battery according to battery status data.

[0040] The status data includes the surface temperature of the battery.

[0041] For example, the battery is a battery module, and the battery module includes multiple battery elevators, wherein the battery status data includes but is not limited to: the surface temperature T sn , internal ambient temperature T a , the battery cell voltage V n , current I.

[0042] Specifically, in the solution of the present application, multiple NTC temperature sensors are arranged on multiple battery cells in a battery pack, and the surface temperature Ts of the battery is obtained through the NTC temperature sensors.

[0043] S202: If the difference between the internal temperature and the surface temperature is greater than a preset threshold, determine a temperature protection threshold of the battery.

[0044] An internal temperature of the battery is determined based on the status data.

[0045] For example, a target equation is established based on the state data obtained above and relevant parameters such as the lithium battery simulation heat generation formula and the battery open circuit voltage, and the state data is used as input data of the target equation to calculate the internal temperature Tc of the battery.

[0046] For example, the difference between the internal temperature and the surface temperature is calculated. When the difference between the calculated Tc and the Ts measured by the NTC temperature sensor is greater than a preset threshold value Tg (wherein Tg is a threshold value determined according to the worst case), it is necessary to activate the following Figure 1 The thermal runaway judgment module.

[0047] Furthermore, a temperature protection threshold is obtained through the thermal runaway judgment module, wherein the temperature protection threshold includes a first temperature protection threshold corresponding to the surface temperature and a second temperature protection threshold corresponding to the internal temperature.

[0048] S203: If it is determined that the battery is in a first state according to the internal temperature, the surface temperature, and the temperature protection threshold, perform temperature protection on the battery.

[0049] The first state is used to indicate that the internal temperature and / or the surface temperature is too high.

[0050] For example, when the thermal runaway judgment module is activated, it determines that the battery is in a first state by combining the internal temperature, surface temperature, and corresponding temperature protection. The first state indicates that the battery module may be in a temperature runaway state, and temperature protection is required to ensure the safety and normal use of the battery module.

[0051] For example, battery temperature protection refers to a series of measures taken to protect the safety and performance stability of the battery when the battery is overheated or overcooled during operation. When the battery is overheated or overcooled, it may cause the battery's performance to decline, shorten its lifespan, and even cause safety accidents. Therefore, temperature protection can effectively avoid the occurrence of these problems. Generally speaking, battery temperature protection includes the following aspects: Overheat protection: When the battery temperature exceeds the safe range, the system will automatically stop charging and discharging to prevent the battery from overheating and causing damage; Overcooling protection: In a low temperature environment, the performance of the battery will also be affected, so measures need to be taken to protect the battery from overcooling; Temperature monitoring: The temperature changes of the battery are monitored in real time through a temperature sensor, and temperature anomalies are detected in time and corresponding measures are taken; Temperature compensation: The charge and discharge strategy is adjusted according to the changes in battery temperature to keep the battery within a suitable operating temperature range.

[0052] Through the above measures, the safety and stability of the battery can be effectively protected, the battery life can be extended, and the battery can be ensured to work normally in various environments.

[0053] It can be seen that the battery protection method described in the embodiment of the present application determines the internal temperature of the battery based on the status data of the battery, and the status data includes the surface temperature of the battery; if the difference between the internal temperature and the surface temperature is greater than a preset threshold, the temperature protection threshold of the battery is determined; if the battery is determined to be in the first state based on the internal temperature, the surface temperature and the temperature protection threshold, temperature protection is performed on the battery, and the first state is used to characterize that the internal temperature and / or surface temperature are too high. This method calculates the internal temperature of the battery, combines the internal temperature and the surface temperature of the battery to determine whether it is necessary to obtain the temperature protection threshold, and performs an over-temperature protection judgment based on the temperature protection threshold, so that the thermal runaway event of the battery can be discovered early. Furthermore, the over-temperature protection judgment based on the estimated internal temperature of the battery can effectively improve the temperature application range of the battery and extend the battery service life, while the retained over-temperature protection judgment based on the surface temperature can ensure the efficiency of the battery over-temperature protection, thereby improving the battery safety.

[0054] In one possible example, the temperature protection threshold includes a first temperature protection threshold corresponding to the surface temperature and a second temperature protection threshold corresponding to the internal temperature, the battery is in a first state, and the method further includes the following steps: the surface temperature is less than the first temperature protection threshold, and the internal temperature is greater than or equal to the second temperature protection threshold; or, the surface temperature is greater than or equal to the first temperature protection threshold.

[0055] For example, the first temperature protection threshold and the second temperature protection threshold are different. In actual application scenarios, the internal temperature of the battery module may reach a higher value, while the surface temperature of the battery module will be reflected later. If the judgment is based solely on the surface temperature, the delay between the two may cause battery damage.

[0056] Specifically, if the surface temperature Ts of the battery is less than the first temperature protection threshold Tsp, that is, the surface temperature has not reached the temperature to determine that the battery is in a temperature out of control state, and the internal temperature Tc of the battery is greater than or equal to the second temperature protection threshold Tth, that is, the internal temperature of the battery has exceeded the second temperature protection threshold, at this time, it can be determined that the battery module is in the first state.

[0057] Alternatively, if it is determined according to the battery surface temperature measured by the NTC temperature sensor that the surface temperature is greater than or equal to the first temperature protection threshold, it is determined that the battery is in the first state.

[0058] Furthermore, when it is determined that the battery module is in the first state, a temperature protection strategy needs to be executed to allow the system to enter a safe state.

[0059] It can be seen that in this example, the calculated internal temperature and the measured surface temperature are used as monitoring indicators at the same time, and are compared with the corresponding temperature thresholds respectively, so that the status of the battery module can be determined more accurately and timely, and battery safety can be guaranteed to the greatest extent based on multi-level temperature protection strategies.

[0060] In one possible example, the internal temperature calculation satisfies the following formula:

[0061]

[0062] Wherein, the Tc is used to characterize the internal temperature, the Cm is used to characterize the internal heat capacity of the battery, the Rm is used to characterize the internal thermal resistance of the battery, the Ts is used to characterize the surface temperature, the E is used to characterize the open circuit voltage, the V is used to characterize the cell voltage, the I is used to characterize the current, and the k and the k+1 correspond to two adjacent moments.

[0063] Exemplarily, the internal temperature calculation module calculates the internal temperature of the battery at the current moment based on the acquired internal heat capacity, internal thermal resistance, surface temperature, open circuit voltage, and cell voltage, current and other status data.

[0064] When the internal temperature calculation module calculates the internal temperature at the current time k+1, it uses the internal temperature Tc(1) calculated at the previous time k (the adjacent time) as the input for the next iterative calculation of Tc(k=1) at time k+1. At the same time, all the required input parameters are updated to the data at time k=1, and Tc(k+1) at the current time k+1 is obtained in real time. In particular, the initial value of Tc, Tc(0), is equal to Ts(0).

[0065] It can be seen that in this example, based on the proposed temperature calculation method, the internal temperature of the battery is estimated by the battery surface temperature, and the calculated internal temperature and the measured surface temperature are used as parameters for temperature protection judgment, so that the status of the battery module can be determined more accurately and timely, and battery safety can be guaranteed to the greatest extent based on multiple levels of temperature protection strategies.

[0066] In a possible example, before determining the internal temperature of the battery according to the status data, the method further includes the following steps: determining the internal heat capacity and the internal thermal resistance; and determining the open circuit voltage.

[0067] Specifically, see Figure 3 , Figure 3 This is a schematic diagram of a calculation process provided by the embodiment of this application. Figure 3 As shown in FIG, by taking the ambient temperature Ta as input data, the internal heat capacity and internal thermal resistance of the battery are fitted and calculated.

[0068] For example, by Figure 1 The OCV voltage calculation module calculates the open circuit voltage E(OCV) of the battery by taking the cell voltage and surface temperature of the battery as input data, wherein E=Fun(soc).

[0069] Furthermore, the internal temperature of the battery is calculated based on the internal heat capacity, internal thermal resistance, surface temperature, and open circuit voltage of the battery.

[0070] It can be seen that in the example of this application, the open circuit voltage, internal heat capacity and internal thermal resistance of the battery are calculated respectively, and the calculated parameters are used as input parameters for the final calculation of the internal temperature of the battery, so as to realize the estimated calculation of the internal temperature of the battery based on the relevant parameters during the operation of the battery.

[0071] In one possible example, the status data includes the ambient temperature of the battery operation, the single cell voltage and current of the battery, and the determination of the internal heat capacity and the internal thermal resistance, the above method also includes the following steps: determining the internal heat capacity and the internal thermal resistance based on the ambient temperature, wherein the internal heat capacity is used to characterize the ability of the battery's material to absorb and dissipate heat, and the internal thermal resistance is used to characterize the rate of heat conduction inside the battery.

[0072] For example, in this application, the internal heat generation formula for the battery is simplified based on the Bernadi formula (Formula 1) and the battery chemical characteristics. The internal heat generation of the battery includes reaction heat, polarization heat, and Joule heat. Polarization heat and Joule heat are the main components of the heat source, corresponding to I(EV). Among them, reaction heat accounts for a relatively low proportion of the heat source and is therefore negligible.

[0073]

[0074] Furthermore, according to the above description, the Bernadi formula is finally simplified to Formula 2, where I is the current flowing through the battery, E is the open circuit voltage E (OCV), and V is the terminal voltage (Vcell) of the battery cell.

[0075] Q=I(EV) (Formula 2)

[0076] Furthermore, according to the energy conservation equation inside and outside the battery, Fourier's heat law and Newton's heat dissipation law, Formula 3 is derived:

[0077]

[0078] Furthermore, in order to reflect the dynamic characteristics of the lithium battery thermal model system, the internal temperature Tc of the system is used as the system state variable and the current I is used as the system input. Formula 3 is described to obtain the state equation Formula 4:

[0079]

[0080] Furthermore, a relatively simple single-cell battery thermal model is established based on the internal heat generation and heat transfer mechanisms of lithium batteries. Cc represents the internal heat capacity of the battery, which is used to characterize the ability of the battery's material to absorb and dissipate heat. Ri represents the internal thermal resistance, which is used to characterize the rate of heat conduction within the battery. Considering that Ts is a measurable point in actual use scenarios, where time t is defined as a unit time of 1, Formula 4 can be further simplified to Formula 5:

[0081]

[0082] In a possible example, the method for determining the open circuit voltage of the battery further includes the following steps: determining the state of charge of the battery based on the surface temperature and the cell voltage; and determining the open circuit voltage of the battery based on the state of charge.

[0083] For example, the unknown parameters Cc and Ri in the above-mentioned state equation are identified according to the actual experimental process. Generally, the least square method is used to identify and fit the parameters Cc and Ri into a function related to the ambient temperature Ta based on the experimental data:

[0084] Ri=Func1(Ta) (Formula 6)

[0085] Cc=Func2(Ta) (Formula 7)

[0086] It should be noted that this simplified model represents the process by which heat from the battery's internal heat source Q diffuses to the battery surface. Since the surface temperature Ts is measurable in the usage scenario, the process of heat diffusion from the surface to the environment is not modeled here. When Ta is low, the internal central region with similar thermal characteristics is smaller, reducing the heat capacity of the internal structure consisting of the two poles and the central region. As Ta increases, the internal central region with similar thermal characteristics expands.

[0087] According to the above calculation formula, all the parameters required to calculate the internal temperature of a single battery have been completed. However, in actual use scenarios, batteries generally appear in the form of modules. Therefore, in this application solution, the internal thermal resistance Rm = Func1'(Ta) and the internal heat capacity Cm = Func2'(Ta) of the battery module are calculated by using the volume averaging method and the mass averaging method. The parameters Rm and Cm are substituted into Formula 6 to obtain the final required Ri and Cc.

[0088] Specifically, the ECU of the battery module collects the current status data of the battery, including the battery module surface temperature Tsn, the internal ambient temperature Ta, the battery cell voltage Vn and the battery current I, etc.

[0089] Further, according to Figure 3 The OCV voltage calculation module in the schematic diagram shown calculates the current SOC of the battery and calculates the current open circuit voltage E(OCV) based on the SOC; at the same time, Cm and Rm are calculated by substituting the ambient temperature Ta into the fitting formula.

[0090] Furthermore, the above state data is substituted into the formula satisfied by the internal temperature calculation. Figure 1 The internal temperature calculation module performs an internal temperature calculation process and outputs a maximum internal temperature Tc(1). In particular, the initial value Tc(0) of Tc is equal to Ts(0).

[0091] It should be noted that Tc(1) calculated at the current moment will be used as the input of Tc(k=1) for the next iterative calculation. At the same time, the input state data required for the calculation are updated to the data at the moment k=1, so as to obtain Tc(k+1) at the current moment k+1 in real time.

[0092] Furthermore, the surface temperature and internal temperature are input into the temperature calculation protection module (such as Figure 3 dotted box).

[0093] Furthermore, when the difference between the calculated Tc and the measured Ts is greater than the preset threshold Tg (Tg is the threshold determined based on the worst case), the thermal runaway judgment module needs to be activated. At this time, the status of the cell temperature and cell voltage sampling system is combined to predict in advance whether the battery will experience a thermal runaway event.

[0094] It can be seen that in the example of this application, by creating a corresponding calculation formula and storing the calculation formula in the ECU, the open circuit voltage, internal heat capacity and internal thermal resistance are subsequently calculated based on the battery status data, and the calculated parameters are used as input parameters for the final calculation of the internal temperature of the battery, so as to realize the estimation and calculation of the internal temperature of the battery based on the relevant parameters during the operation of the monitoring battery.

[0095] In one possible example, the battery includes at least one battery cell. Before determining the internal temperature of the battery based on the status data, the method further includes the following steps: determining a target battery cell based on the surface temperatures corresponding to the at least one battery cell, wherein the target battery cell is the battery cell corresponding to the maximum surface temperature; and determining the voltage corresponding to the target battery cell as the cell voltage.

[0096] For example, in this application, NTC temperature sensors are installed on the surface of one or more cells in the battery module to collect the surface temperature of the battery during use. However, in actual calculations, not every cell's corresponding data needs to be used in the internal temperature calculation. Specifically, in this application, by acquiring the surface temperature data of multiple cells, the cell with the highest surface temperature value is identified as the target cell.

[0097] Furthermore, the voltage corresponding to the target battery cell is obtained and input into the above formula as the cell voltage required for calculating the internal temperature.

[0098] As can be seen in the example of this application, due to the hysteresis of the surface temperature, the surface temperature may be lower than the internal temperature after the internal temperature has reached a certain value. Therefore, in order to more accurately calculate the internal temperature, the battery cell corresponding to the maximum surface temperature is determined as the target battery cell. This ensures more accurate calculation of the internal temperature and more timely detection of whether the battery is currently in a thermal runaway state, thereby ensuring battery safety and increasing battery life.

[0099] To better understand the entire process of this application, please refer to Figure 4 , Figure 4 This is a schematic diagram of the overall process of a battery protection method provided by an embodiment of the present application. The specific steps are as follows Figure 4 As shown:

[0100] Step S401: Validity determination of Ts and Tc.

[0101] Step S402: Determine whether the difference between Ts and Tc is greater than a preset threshold value Tg. If yes, proceed to step S403. If no, proceed to step S404.

[0102] Step S403: Activate the thermal runaway calculation unit.

[0103] Step S404: Obtain a temperature protection threshold.

[0104] Step S405: Determine whether the surface temperature is less than the first temperature protection threshold and whether the internal temperature is greater than or equal to the second temperature protection threshold. If yes, proceed to step S406; if not, proceed to step S407.

[0105] Step S406: Execute temperature protection.

[0106] Step S407: Determine whether the surface temperature is greater than or equal to the first temperature protection threshold. If yes, proceed to step S406; if no, end the current determination process.

[0107] Specifically, all the processing procedures of the above steps S401-S407 can be compared with the above Figure 2 The contents of steps S201-S204 correspond to each other and are not described in detail here.

[0108] It can be seen that the battery protection method described in the embodiment of the present application determines the internal temperature of the battery based on the status data of the battery, and the status data includes the surface temperature of the battery; if the difference between the internal temperature and the surface temperature is greater than a preset threshold, the temperature protection threshold of the battery is determined; if the battery is determined to be in the first state based on the internal temperature, the surface temperature and the temperature protection threshold, temperature protection is performed on the battery, and the first state is used to characterize that the internal temperature and / or surface temperature are too high. This method determines whether it is necessary to obtain the temperature protection threshold based on the internal temperature of the battery, combined with the internal temperature and the surface temperature of the battery, and performs an over-temperature protection judgment based on the temperature protection threshold, so that the thermal runaway event of the battery can be discovered early. Furthermore, the over-temperature protection judgment based on the estimated internal temperature of the battery can effectively improve the temperature application range of the battery and extend the battery service life, while the retained over-temperature protection judgment based on the surface temperature can ensure the efficiency of the battery over-temperature protection, thereby improving the battery safety.

[0109] See also Figure 5 , Figure 5 It is a structural diagram of an electronic device, such as Figure 5 As shown, the electronic device includes a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the above-mentioned programs of the electronic device include instructions for performing the following steps:

[0110] determining an internal temperature of the battery based on the status data, the status data including a surface temperature of the battery;

[0111] If the difference between the internal temperature and the surface temperature is greater than a preset threshold, determining a temperature protection threshold of the battery;

[0112] If it is determined that the battery is in a first state according to the internal temperature, the surface temperature, and the temperature protection threshold, temperature protection is performed on the battery.

[0113] It can be seen that the battery protection method described in the embodiment of the present application determines the internal temperature of the battery based on the status data of the battery, and the status data includes the surface temperature of the battery; if the difference between the internal temperature and the surface temperature is greater than a preset threshold, the temperature protection threshold of the battery is determined; if the battery is determined to be in the first state based on the internal temperature, the surface temperature and the temperature protection threshold, temperature protection is performed on the battery, and the first state is used to characterize that the internal temperature and / or surface temperature are too high. This method determines whether it is necessary to obtain the temperature protection threshold based on the internal temperature of the battery, combined with the internal temperature and the surface temperature of the battery, and performs an over-temperature protection judgment based on the temperature protection threshold, so that the thermal runaway event of the battery can be discovered early. Furthermore, the over-temperature protection judgment based on the estimated internal temperature of the battery can effectively improve the temperature application range of the battery and extend the battery service life, while the retained over-temperature protection judgment based on the surface temperature can ensure the efficiency of the battery over-temperature protection, thereby improving the battery safety.

[0114] In one possible example, the temperature protection threshold includes a first temperature protection threshold corresponding to the surface temperature and a second temperature protection threshold corresponding to the internal temperature, the battery is in a first state, and the program includes instructions for performing the following steps:

[0115] The surface temperature is lower than the first temperature protection threshold, and the internal temperature is higher than or equal to the second temperature protection threshold; or

[0116] The surface temperature is greater than or equal to the first temperature protection threshold.

[0117] In one possible example, the internal temperature calculation satisfies the following formula:

[0118]

[0119] Wherein, the Tc is used to characterize the internal temperature, the Cm is used to characterize the internal heat capacity of the battery, the Rm is used to characterize the internal thermal resistance of the battery, the Ts is used to characterize the surface temperature, the E is used to characterize the open circuit voltage, the V is used to characterize the cell voltage, the I is used to characterize the current, and the k and the k+1 correspond to two adjacent moments.

[0120] In a possible example, before determining the internal temperature of the battery according to the status data, the program includes instructions for performing the following steps:

[0121] determining the internal thermal capacitance and the internal thermal resistance; and,

[0122] The open circuit voltage is determined.

[0123] In one possible example, the state data includes the ambient temperature of the battery operation environment, and the determining of the internal thermal capacity and the internal thermal resistance, the program includes instructions for executing the following steps:

[0124] The internal heat capacity and the internal thermal resistance are determined according to the ambient temperature, wherein the internal heat capacity is used to characterize the ability of the battery material to absorb and dissipate heat, and the internal thermal resistance is used to characterize the rate of heat conduction inside the battery.

[0125] In a possible example, the status data includes the single cell voltage and current of the battery, and the open circuit voltage of the battery is determined. The program includes instructions for executing the following steps:

[0126] determining a state of charge of the battery according to the surface temperature and the cell voltage;

[0127] An open circuit voltage of the battery is determined according to the state of charge.

[0128] In one possible example, the battery includes at least one battery cell. Before determining the internal temperature of the battery according to the status data, the program includes instructions for performing the following steps:

[0129] Determining a target battery cell according to the surface temperatures respectively corresponding to the at least one battery cell, wherein the target battery cell is the battery cell corresponding to the maximum surface temperature;

[0130] The voltage corresponding to the target battery cell is determined as the cell voltage.

[0131] The above mainly introduces the solution of the embodiment of the present application from the perspective of the execution process of the method side. It is understandable that, in order to realize the above functions, the electronic device includes a hardware structure and / or software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiment provided herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0132] The embodiment of the present application can divide the functional units of the electronic device according to the above method example. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. It should be noted that the division of units in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0133] It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0134] In the case of dividing each functional module into corresponding functional modules, Figure 6 A battery protection device is shown, the device comprising: a determination unit 601 and an execution unit 602, wherein:

[0135] The determining unit 601 is configured to determine the internal temperature of the battery according to battery status data, wherein the status data includes the surface temperature of the battery;

[0136] The determining unit 601 is further configured to determine a temperature protection threshold of the battery if the difference between the internal temperature and the surface temperature is greater than a preset threshold;

[0137] The execution unit 602 is configured to perform temperature protection on the battery if it is determined that the battery is in a first state based on the internal temperature, the surface temperature, and the temperature protection threshold, wherein the first state is used to indicate that the internal temperature and / or the surface temperature is too high.

[0138] It can be seen that the battery protection device described in the embodiment of the present application, the determination unit determines the internal temperature of the battery based on the status data of the battery, and the status data includes the surface temperature of the battery; if the difference between the internal temperature and the surface temperature is greater than a preset threshold, the temperature protection threshold of the battery is determined; if the battery is determined to be in the first state based on the internal temperature, the surface temperature and the temperature protection threshold, temperature protection is performed on the battery, and the first state is used to characterize that the internal temperature and / or surface temperature are too high. This method determines whether it is necessary to obtain the temperature protection threshold based on the internal temperature of the battery, combined with the internal temperature and the surface temperature of the battery, and performs an over-temperature protection judgment based on the temperature protection threshold, so that the thermal runaway event of the battery can be discovered early. Furthermore, the over-temperature protection judgment based on the estimated internal temperature of the battery can effectively improve the temperature application range of the battery and extend the battery service life, while the retained over-temperature protection judgment based on the surface temperature can ensure the efficiency of the battery over-temperature protection, thereby improving the battery safety.

[0139] In a possible example, the temperature protection threshold includes a first temperature protection threshold corresponding to the surface temperature and a second temperature protection threshold corresponding to the internal temperature, the battery is in the first state, and the execution unit 602 is further configured to perform the following steps:

[0140] The surface temperature is lower than the first temperature protection threshold, and the internal temperature is higher than or equal to the second temperature protection threshold; or

[0141] The surface temperature is greater than or equal to the first temperature protection threshold.

[0142] In one possible example, the internal temperature calculation satisfies the following formula:

[0143]

[0144] Wherein, the Tc is used to characterize the internal temperature, the Cm is used to characterize the internal heat capacity of the battery, the Rm is used to characterize the internal thermal resistance of the battery, the Ts is used to characterize the surface temperature, the E is used for the open circuit voltage, the V is used to characterize the cell voltage, the I is used for the current, and the k and the k+1 correspond to two adjacent moments.

[0145] In a possible example, before determining the internal temperature of the battery according to the status data, the executing unit 602 is further configured to perform the following steps:

[0146] determining the internal thermal capacitance and the internal thermal resistance; and,

[0147] The open circuit voltage is determined.

[0148] In a possible example, the state data includes the ambient temperature of the battery operation, and the determining of the internal thermal capacity and the internal thermal resistance, the execution unit 602 is further configured to perform the following steps:

[0149] The internal heat capacity and the internal thermal resistance are determined according to the ambient temperature, wherein the internal heat capacity is used to characterize the ability of the battery material to absorb and dissipate heat, and the internal thermal resistance is used to characterize the rate of heat conduction inside the battery.

[0150] In a possible example, the state data includes the single cell voltage and current of the battery, and in determining the open circuit voltage of the battery, the execution unit 602 is further configured to perform the following steps:

[0151] determining a state of charge of the battery according to the surface temperature and the cell voltage;

[0152] An open circuit voltage of the battery is determined according to the state of charge.

[0153] In a possible example, the battery includes at least one battery cell. Before determining the internal temperature of the battery according to the status data, the execution unit 602 is further configured to perform the following steps:

[0154] Determining a target battery cell according to the surface temperatures respectively corresponding to the at least one battery cell, wherein the target battery cell is the battery cell corresponding to the maximum surface temperature;

[0155] The voltage corresponding to the target battery cell is determined as the cell voltage.

[0156] When integrated, the electronic device may include a processing module, a storage module, and a communication module. The processing module may be used to control and manage the electronic device's operations, for example, supporting the electronic device in executing all the steps described above. The storage module may be used to support the electronic device in executing and storing program code and data. The communication module may be used to support communication between the electronic device and other devices.

[0157] The processing module may be a processor or a controller. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, and so on. The storage module may be a memory. The communication module may specifically be a device that interacts with other electronic devices, such as a radio frequency circuit, a Bluetooth chip, or a Wi-Fi chip.

[0158] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute part or all of the steps of any method described in the above method embodiments, and the above computer includes an electronic device.

[0159] The present application also provides a computer program product comprising a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a computer to perform some or all of the steps of any of the methods described in the above method embodiments. The computer program product may be a software installation package, and the computer may comprise an electronic device.

[0160] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0161] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0162] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0163] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0164] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0165] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a memory and includes a number of instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the above-mentioned methods of each embodiment of the present application. The aforementioned memory includes: various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk.

[0166] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program. The program can be stored in a computer-readable memory, and the memory can include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0167] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery protection method, characterized in that: The method comprises: determining an internal temperature of the battery according to status data of the battery, the status data including a surface temperature of the battery; If the difference between the internal temperature and the surface temperature is greater than a preset threshold, determining a temperature protection threshold of the battery; If it is determined according to the internal temperature, the surface temperature and the temperature protection threshold that the battery is in a first state, temperature protection is performed on the battery, wherein the first state is used to indicate that the internal temperature and / or the surface temperature is too high.

2. The method according to claim 1, characterized in that The temperature protection threshold comprises a first temperature protection threshold corresponding to the surface temperature and a second temperature protection threshold corresponding to the internal temperature, and the battery is in a first state, including: The surface temperature is lower than the first temperature protection threshold, and the internal temperature is higher than or equal to the second temperature protection threshold; or, The surface temperature is greater than or equal to the first temperature protection threshold.

3. The method according to claim 2, characterized in that The internal temperature calculation satisfies the following formula: Wherein, the Tc is used to characterize the internal temperature, the Cm is used to characterize the internal heat capacity of the battery, the Rm is used to characterize the internal thermal resistance of the battery, the Ts is used to characterize the surface temperature, the E is used to characterize the open circuit voltage, the V is used to characterize the single cell voltage, the I is used to characterize the current, and the k and the k+1 correspond to two adjacent moments.

4. The method according to any one of claims 1 to 3, characterized in that: Before determining the internal temperature of the battery according to the status data, the method further includes: determining the internal thermal capacitance and the internal thermal resistance; and, The open circuit voltage is determined.

5. The method according to claim 4, characterized in that The state data includes the ambient temperature of the battery operation, and the determining the internal thermal capacity and the internal thermal resistance includes: The internal heat capacity and the internal thermal resistance are determined according to the ambient temperature, wherein the internal heat capacity is used to characterize the ability of the battery material to absorb and dissipate heat, and the internal thermal resistance is used to characterize the rate of heat conduction inside the battery.

6. The method according to claim 5, characterized in that The state data includes a single cell voltage and a current of the battery, and determining the open circuit voltage of the battery includes: determining a state of charge of the battery according to the surface temperature and the cell voltage; An open circuit voltage of the battery is determined according to the state of charge.

7. The method according to claim 6, characterized in that The battery includes at least one battery cell. Before determining the internal temperature of the battery according to the status data, the method further includes: Determine a target battery cell according to the surface temperature respectively corresponding to the at least one battery cell, wherein the target battery cell is the battery cell corresponding to the maximum surface temperature; The voltage corresponding to the target battery cell is determined as the cell voltage.

8. A battery protection device, characterized in that: The device comprises: a determination unit and an execution unit, wherein: The determining unit is used to determine the internal temperature of the battery according to the status data of the battery, wherein the status data includes the surface temperature of the battery; The determination unit is further configured to determine a temperature protection threshold of the battery if the difference between the internal temperature and the surface temperature is greater than a preset threshold; The execution unit is used to perform temperature protection on the battery if it is determined that the battery is in a first state according to the internal temperature, the surface temperature and the temperature protection threshold, wherein the first state is used to indicate that the internal temperature and / or the surface temperature is too high.

9. An electronic device, characterized in that: The method comprises a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the programs include instructions for executing the steps in the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: A computer program for electronic data exchange is stored, wherein the computer program causes a computer to execute the method according to any one of claims 1 to 7.

11. A computer program product comprising instructions, characterized in that When the computer program product runs on an electronic device, the electronic device is enabled to execute the method according to any one of claims 1 to 7.

12. A battery, characterized in that: The battery includes a battery module and a battery management system, and the battery management system is used to execute the method according to any one of claims 1-7.

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