Preheating method and device before charging of lithium ion power battery, vehicle and medium

Abstract

The invention provides a method and a device for preheating a lithium ion power battery before charging, a vehicle and a medium. The method comprises the following steps: acquiring a first temperature rise rate under heating power which can be provided for a power battery system at present and a second temperature rise rate under heat exchange power of the power battery system at present; wherein the heating power is determined by the current target heating working medium temperature of the power battery, and the heat exchange power is determined by the maximum temperature rise rate of the power battery at the current temperature; and executing a corresponding pre-charging preheating strategy according to a comparison result of the first temperature rise rate and the second temperature rise rate so as to adjust an exit temperature of pre-charging preheating. According to the invention, the quit temperature of preheating before charging can be dynamically optimized based on the heating rates in different states, so that the charging time is shortened.

Description

Technical Field

[0001] The present invention relates to the field of power batteries, and in particular to a method, device, vehicle and medium for preheating a lithium-ion power battery before charging. Background Art

[0002] The lithium-ion power battery is designed with a liquid cooling / heating system. When charging at low temperature, it can be divided into three stages: the first stage is the preheating stage before charging; the second stage is the heating while charging stage; the third stage is the charging only stage. After introducing the pre-pulse heating function before charging, a higher-rate pulse method can be used for preheating in the preheating stage before charging, and a liquid heating method is used for heating in the heating while charging stage. In the existing preheating stage before charging, it is only judged whether to exit the preheating based on whether the temperature of the power battery reaches the temperature threshold. Under low temperature conditions, if the vehicle thermal management cannot provide enough heat for the power battery, it will cause the extension of the preheating stage before charging and affect the overall charging time. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the present invention provides a method, device, vehicle and medium for preheating a lithium-ion power battery before charging, mainly solving the problem that the existing method for judging the exit condition of the charging preheating stage is single, which may lead to the extension of the low-temperature charging time of the whole vehicle and affect the user experience.

[0004] In order to achieve the above and other objects, the technical solutions adopted by the present invention are as follows.

[0005] The present application provides a method for preheating a lithium-ion power battery before charging, the method comprising: obtaining a first temperature rise rate under the current heating power that can be provided to the power battery system and a second temperature rise rate under the current heat exchange power of the power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the maximum temperature rise rate of the power battery at the current temperature; executing a corresponding preheating strategy before charging according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the preheating before charging.

[0006] In an embodiment of the present application, the step of obtaining the first temperature rise rate under the current heating power that can be provided to the power battery system comprises: collecting the current temperature state of the power battery; determining the first heat exchange power between the power battery and the environment based on the deviation between the target heating medium temperature and the current temperature state of the power battery; determining the first temperature rise rate based on the heating power and the first heat exchange power.

[0007] In an embodiment of the present application, the steps of obtaining the second temperature rise rate at the heat exchange power of the current power battery system include: obtaining the second heat exchange power between the power battery and the battery heating unit; determining the maximum temperature rise rate at the current temperature based on the first heat exchange efficiency and the second heat exchange power as the second temperature rise rate.

[0008] In an embodiment of the present application, the steps of executing a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate include: if the first temperature rise rate is less than or equal to the second temperature rise rate, using the first temperature rise rate as the actual temperature rise rate of the power battery, and matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery; if the first temperature rise rate is greater than the second temperature rise rate, increasing the target heating medium temperature to re-determine the first temperature rise rate.

[0009] In an embodiment of the present application, after increasing the target heating medium temperature, it further includes: if the target heating medium temperature exceeds the allowable heating medium temperature of the power battery, using the second temperature rise rate as the actual temperature rise rate of the power battery.

[0010] In an embodiment of the present application, before matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery, it further includes: determining the mapping relationship between different power battery temperature rise rate ranges and different optimal exit temperatures of the pre-charging preheating based on the safe charging voltage of the power battery, the charging power of different charging devices, different power battery state of charge, and different temperature states.

[0011] In an embodiment of the present application, the steps of matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery include: comparing the actual temperature rise rate of the power battery with the power battery temperature rise rate range, and calling the corresponding optimal exit temperature according to the power battery temperature rise rate range in which the actual temperature rise rate of the power battery falls.

[0012] The present application also provides a pre-charging preheating device for a lithium-ion power battery, including a temperature rise rate determination module for obtaining a first temperature rise rate at the heating power that can be provided to the power battery system currently and a second temperature rise rate at the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the theoretical maximum temperature rise rate of the power battery at the current temperature; a preheating strategy execution module for executing a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the pre-charging preheating.

[0013] The present application also provides a vehicle, including: one or more processors; and a memory for storing one or more programs, which, when executed by the one or more processors, cause the memory to implement the steps of the preheating method for a lithium-ion power battery before charging.

[0014] The present application also provides a readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the preheating method for a lithium-ion power battery before charging.

[0015] As described above, a preheating method, device, vehicle and medium for a lithium-ion power battery before charging proposed by the present application have the following beneficial effects.

[0016] The present application couples the temperature rise rate to adjust the exit temperature during preheating before charging, and can determine a more appropriate exit temperature according to the heating power that can be provided to the power battery system currently and the heat exchange power of the power battery, thereby effectively optimizing the exit temperature threshold in the charging preheating stage and shortening the time of the charging preheating stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic flowchart of a preheating method for a lithium-ion power battery before charging in an embodiment of the present application.

[0018] Figure 2 It is a module diagram of a preheating device for a lithium-ion power battery before charging in an embodiment of the present application.

[0019] Figure 3 It is a schematic diagram of a partial internal architecture of a vehicle in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0021] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape and size of the components in actual implementation. The types, quantities and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0022] The inventor has found through research that:

[0023] A liquid cooling / heating system is designed for a lithium-ion power battery. During low-temperature charging, it can be divided into three stages: the first stage is the pre-charging preheating stage; the second stage is the heating-while-charging stage; the third stage is the charging-only stage. After introducing the pre-charging pulse preheating function, a higher-rate pulse method can be used for preheating in the pre-charging preheating stage, and a liquid heating method is used for heating in the heating-while-charging stage. Currently, the temperature threshold for exiting the pre-charging preheating is often determined according to the shortest charging time for the whole process. The temperature rise rate of the power battery during pre-charging preheating can affect the shortest charging time.

[0024] Currently, the pulse preheating is exited only by determining whether the temperature of the power battery reaches the temperature threshold. If the passenger compartment and the power battery are heated simultaneously during charging and the vehicle thermal management cannot provide enough heat to the power battery end, resulting in the temperature rise rate of the power battery not reaching the lower limit value required by the current strategy, the time of the pre-charging preheating stage will be increased, and thus the charging time for the whole process will be increased.

[0025] Based on the above defects existing in the prior art, the present application proposes a pre-charging preheating method, device, vehicle and medium for a lithium-ion power battery. The technical solution of the present application will be elaborated in detail below with specific embodiments.

[0026] Please refer to Figure 1 , Figure 1 which is a schematic flow chart of a pre-charging preheating method for a lithium-ion power battery in an embodiment of the present application. The method includes the following steps:

[0027] Step S100, obtaining a first temperature rise rate under the heating power that can be provided to the power battery system currently and a second temperature rise rate under the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the maximum temperature rise rate of the power battery at the current temperature.

[0028] In one embodiment, the target heating working fluid temperature can be determined according to the current driving state of the vehicle or set according to the user's driving habits. For example, the target heating working fluid temperature in the preheating stage before vehicle charging can be determined according to the current external environmental temperature. The heating working fluid can be a resistance wire, water, molten salt, etc., which can be specifically set and adjusted according to the vehicle usage requirements and are not limited here. When the vehicle enters the charging preheating stage, the power battery system can communicate with the vehicle controller to obtain the current target heating working fluid temperature of the power battery feedback by the vehicle controller. The obtaining method can be sending a charging request or a charging preheating signal and receiving the response of the vehicle controller; it can also be that after the vehicle controller detects that the vehicle enters a specific stage, it actively feeds back the corresponding information to the power battery system. The specific method can be set and adjusted according to the actual application requirements and is not limited here. Since in a low-temperature environment, it is possible that both the passenger compartment and the power battery need heating, after obtaining the target heating working fluid temperature, the heating power that can be provided to the power battery system currently can be calculated according to the heat demand of the vehicle passenger compartment or other areas. This heating power is the difference between the total power at the target heating working fluid temperature and the power provided to the passenger compartment or other vehicle areas. Of course, the determination of the specific heating power can be set and adjusted according to the differences in application scenarios. For example, the influence of the environmental temperature on heating can be considered, etc., and it is not limited here.

[0029] In step S100, the step of obtaining the first temperature rise rate at the heating power that can be provided to the power battery system currently includes: collecting the current temperature state of the power battery; determining the first heat exchange power between the power battery and the environment based on the deviation between the target heating working fluid temperature and the current temperature state of the power battery; determining the first temperature rise rate based on the heating power and the first heat exchange power. The specific calculation method of the first temperature rise rate αv can be expressed as follows:

[0030] αv = (ηP + A e h e (T e -T a )) / Cm

[0031] Where η is the heating efficiency of the power battery, C is the specific heat capacity of the power battery, m is the mass of the power battery, A e is the heat exchange area between the power battery and the environment, h e is the heat exchange coefficient between the power battery and the environment, T e is the target heating working fluid temperature, P is the heating power, T a is the current temperature state of the power battery. (T e -T a ) represents the deviation between the target heating working fluid temperature and the current temperature state of the power battery; A e h e (T e -T a) represents the first heat exchange power.

[0032] In step S100, the steps of obtaining the second temperature rise rate at the heat exchange power of the current power battery system include: obtaining the second heat exchange power between the power battery and the battery heating unit; determining the maximum temperature rise rate at the current temperature based on the first heat exchange efficiency and the second heat exchange power as the second temperature rise rate. The specific calculation method of the second temperature rise rate αb can be expressed as follows:

[0033] αb = (A w h w (T w -T a ) + A e h e (T e -T a )) / Cm

[0034] Where, A w is the heat exchange area between the liquid heat system and the power battery, h w is the heat exchange coefficient between the liquid heat system and the power battery, T w is the temperature of the heating medium of the liquid heat system, A w h w (T w -T a ) can represent the second heat exchange power; of course, the battery heating unit is not limited to the liquid heat system, and here only the liquid heat system is taken as an example for illustration.

[0035] Step S110, execute a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the pre-charging preheating.

[0036] In one embodiment, corresponding pre - charging pre - heating strategies can be configured according to different temperature rise rates, so that the temperature at the end of pre - charging meets the requirements of the current scenario and the pre - charging pre - heating time is shortened. In step S110, the steps of executing the corresponding pre - charging pre - heating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate include: if the first temperature rise rate is less than or equal to the second temperature rise rate, the first temperature rise rate is taken as the actual temperature rise rate of the power battery, and the optimal exit temperature for pre - charging pre - heating is matched according to the actual temperature rise rate of the power battery; if the first temperature rise rate is greater than the second temperature rise rate, the target heating medium temperature is increased to re - determine the first temperature rise rate. The actual temperature rise rate of the power battery can take the minimum value of the first temperature rise rate and the second temperature rise rate. When the first temperature rise rate is less than or equal to the second temperature rise rate, it means that the heat exchange power of the power battery is greater than or equal to the heating power that the vehicle can provide, that is, the heating power P of the vehicle can be fully utilized, and the actual temperature rise rate of the power battery at this time is the first temperature rise rate. When the first temperature rise rate is greater than the second temperature rise rate, it means that the heat exchange power of the power battery is less than the heating power that the vehicle can provide. At this time, the heating power P of the vehicle cannot be fully utilized. The target heating medium temperature can be increased, and the first temperature rise rate is recalculated according to the foregoing steps. The target heating medium temperature can be increased in stages. The specific increase amplitude of the target heating medium temperature can be set and adjusted according to actual application requirements, and there is no limitation here.

[0037] In one embodiment, after increasing the target heating medium temperature, it further includes: if the target heating medium temperature exceeds the allowable medium temperature of the power battery, the second temperature rise rate is taken as the actual temperature rise rate of the power battery. Specifically, when the target heating medium temperature is increased and the first temperature rise rate is still greater than the second temperature rise rate, the target heating medium temperature can be increased again until the target heating medium temperature exceeds the allowable medium temperature of the power battery. If the first temperature rise rate is still greater than the second temperature rise rate at this time, the second temperature rise rate is taken as the actual temperature rise rate of the power battery.

[0038] In one embodiment, before matching the optimal exit temperature of pre - charging based on the actual temperature rise rate of the power battery, it further includes: determining the mapping relationship between different power battery temperature rise rate ranges and different optimal exit temperatures of pre - charging based on the safe charging voltage of the power battery, the charging power of different charging devices, different states of charge of the power battery, and different temperature states. Specifically, this mapping relationship can be obtained through simulation before the vehicle leaves the factory, or can be determined or corrected based on historical data during the actual use of the vehicle. For example, the charging power of common charging piles can be obtained, and the pre - charging duration corresponding to different states of charge of the vehicle's power battery under the vehicle's safe charging voltage can be statistically analyzed, and the temperature rise rate under the corresponding vehicle temperature state can be calculated. When the pre - charging duration meets the preset requirements, the corresponding temperature rise rate can be associated with the pre - charging exit temperature, and finally, the temperature rise rate range corresponding to the optimal pre - charging exit temperature can be statistically analyzed to obtain the mapping relationship between different power battery temperature rise rate ranges and different optimal exit temperatures of pre - charging. Here, the preset requirements can be set by the user or configured according to the product usage requirements, and there is no limitation here. Exemplarily, the mapping relationship between different power battery temperature rise rate ranges and different optimal exit temperatures of pre - charging is shown in the following table:

[0039] Temperature rise rate α of power battery Optimal exit temperature threshold T for preheating before charging α≤α1 T1 α1＜α≤α2 T2 … … αn＜α Tn

[0040] In one embodiment, the steps of matching the optimal exit temperature of pre - charging according to the actual temperature rise rate of the power battery include: comparing the actual temperature rise rate of the power battery with the power battery temperature rise rate range, and calling the corresponding optimal exit temperature according to the power battery temperature rise rate range in which the actual temperature rise rate of the power battery falls. If the current temperature rise rate α of the power battery ≤ α1 and the current temperature Tm of the power battery ≥ T1, then the pre - charging is exited and the charging - while - heating stage is entered; if not satisfied, the pre - charging continues; if the current temperature rise rate α of the power battery ∈ (α1, α2] and the current temperature Tm of the power battery ≥ T2, then the pre - charging is exited and the charging - while - heating stage is entered; if not satisfied, the pre - charging continues, and so on. If the current temperature rise rate α of the power battery > αn and the current temperature Tm of the power battery ≥ Tn, then the pre - charging is exited and the charging - while - heating stage is entered; if not satisfied, the pre - charging continues. After determining the optimal exit temperature according to the matched power battery temperature rise rate, when the power battery exceeds the corresponding exit temperature, the pre - charging stage ends and the charging - while - heating stage is entered.

[0041] Based on the technical solutions provided in the embodiments of the present application, the exit condition that couples the temperature threshold of the power battery with the actual temperature rise rate of the power battery can optimize the temperature threshold of the power battery according to the actual thermal management ability of the vehicle; fully utilize the heating capacity of the vehicle thermal management and the heating capacity of the power battery to calculate the actual temperature rise rate of the power battery, and can dynamically optimize the optimal exit temperature of preheating before charging according to the temperature rise rate of the power battery at different times, thereby shortening the low-temperature charging time.

[0042] Please refer to Figure 2 , Figure 2 which is a module diagram of a preheating device for a lithium-ion power battery before charging in an embodiment of the present application. The system includes: a temperature rise rate determination module 20, configured to obtain a first temperature rise rate under the heating power that can be provided to the power battery system currently and a second temperature rise rate under the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the theoretical maximum temperature rise rate of the power battery at the current temperature; a preheating strategy execution module 21, configured to execute a corresponding preheating strategy before charging according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the preheating before charging.

[0043] Each module in the above-mentioned preheating device for a lithium-ion power battery before charging can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in or independent of the memory of the terminal in the form of hardware, or stored in the memory of the terminal in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules. The processor can be a motor controller, a vehicle controller, a domain controller, etc.

[0044] As Figure 3 shown, it is a schematic diagram of the internal structure of a vehicle in an embodiment. A vehicle is provided, including: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented: obtaining a first temperature rise rate under the heating power that can be provided to the power battery system currently and a second temperature rise rate under the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the maximum temperature rise rate of the power battery at the current temperature; executing a corresponding preheating strategy before charging according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the preheating before charging.

[0045] In one embodiment, when the above-mentioned processor executes, the steps of obtaining the first temperature rise rate at the heating power currently available to the power battery system include: collecting the current temperature state of the power battery; determining the first heat exchange power between the power battery and the environment based on the deviation between the target heating medium temperature and the current temperature state of the power battery; and determining the first temperature rise rate based on the heating power and the first heat exchange power.

[0046] In one embodiment, when the above-mentioned processor executes, the steps of obtaining the second temperature rise rate at the heat exchange power of the current power battery system include: obtaining the second heat exchange power between the power battery and the battery heating unit; and determining the maximum temperature rise rate at the current temperature as the second temperature rise rate based on the first heat exchange efficiency and the second heat exchange power.

[0047] In one embodiment, when the above-mentioned processor executes, the steps of executing the corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate include: if the first temperature rise rate is less than or equal to the second temperature rise rate, using the first temperature rise rate as the actual temperature rise rate of the power battery, and matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery; if the first temperature rise rate is greater than the second temperature rise rate, increasing the target heating medium temperature to re-determine the first temperature rise rate.

[0048] In one embodiment, after increasing the target heating medium temperature when the above-mentioned processor executes, it further includes: if the target heating medium temperature exceeds the allowable medium temperature of the power battery, using the second temperature rise rate as the actual temperature rise rate of the power battery.

[0049] In one embodiment, before matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery when the above-mentioned processor executes, it further includes: determining the mapping relationship between different power battery temperature rise rate ranges and different optimal exit temperatures of the pre-charging preheating based on the safe charging voltage of the power battery, the charging power of different charging devices, different states of charge of the power battery, and different temperature states.

[0050] In one embodiment, when the above-mentioned processor executes, the steps of matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery include: comparing the actual temperature rise rate of the power battery with the power battery temperature rise rate range, and calling the corresponding optimal exit temperature according to the power battery temperature rise rate range in which the actual temperature rise rate of the power battery falls.

[0051] The processor of the vehicle is used to provide computing and control capabilities to support the operation of the entire vehicle. The non-volatile storage medium of the vehicle stores an operating system and a computer program. The computer program can be executed by the processor to implement a pre-charging preheating method for a lithium-ion power battery provided in each of the above embodiments. The internal memory in the vehicle provides a cache operating environment for the operating system and computer program in the non-volatile storage medium. The display interface can display data through a display screen. The display screen can be a touch screen, such as a capacitive screen or an electronic screen, and can generate corresponding instructions by receiving a click operation on a control displayed on the touch screen.

[0052] Those skilled in the art can understand that Figure 3 the structure of the vehicle shown in is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the vehicle to which the solution of this application is applied. The specific vehicle may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0053] In one embodiment, a readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented: obtaining a first temperature rise rate under the heating power that can be provided to the power battery system currently and a second temperature rise rate under the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the maximum temperature rise rate of the power battery at the current temperature; executing a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the pre-charging preheating.

[0054] In one embodiment, when the computer program is executed by the processor, the step of obtaining the first temperature rise rate under the heating power that can be provided to the power battery system currently includes: collecting the current temperature state of the power battery; determining the first heat exchange power between the power battery and the environment based on the deviation between the target heating medium temperature and the current temperature state of the power battery; determining the first temperature rise rate based on the heating power and the first heat exchange power.

[0055] In one embodiment, when the computer program is executed by the processor, the step of obtaining the second temperature rise rate under the heat exchange power of the current power battery system includes: obtaining the second heat exchange power between the power battery and the battery heating unit; determining the maximum temperature rise rate at the current temperature as the second temperature rise rate based on the first heat exchange efficiency and the second heat exchange power.

[0056] In one embodiment, when the computer program is executed by a processor, the step of implementing a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate includes: if the first temperature rise rate is less than or equal to the second temperature rise rate, using the first temperature rise rate as the actual temperature rise rate of the power battery, and matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery; if the first temperature rise rate is greater than the second temperature rise rate, increasing the target heating working medium temperature to re-determine the first temperature rise rate.

[0057] In one embodiment, after increasing the target heating working medium temperature when the computer program is executed by a processor, it further includes: if the target heating working medium temperature exceeds the allowable working medium temperature of the power battery, using the second temperature rise rate as the actual temperature rise rate of the power battery.

[0058] In one embodiment, before matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery when the computer program is executed by a processor, it further includes: determining the mapping relationship between different power battery temperature rise rate ranges and different optimal exit temperatures of the pre-charging preheating based on the safe charging voltage of the power battery, the charging power of different charging devices, different states of charge of the power battery, and different temperature states.

[0059] In one embodiment, the step of matching the optimal exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery when the computer program is executed by a processor includes: comparing the actual temperature rise rate of the power battery with the power battery temperature rise rate range, and calling the corresponding optimal exit temperature according to the power battery temperature rise rate range in which the actual temperature rise rate of the power battery falls.

[0060] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), etc.

[0061] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those of ordinary skill in the art in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preheating method for a lithium-ion power battery before charging, characterized in that, The method includes: Obtaining a first temperature rise rate at the heating power currently available to the power battery system and a second temperature rise rate at the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the maximum temperature rise rate of the power battery at the current temperature; Performing a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate to adjust the exit temperature of the pre-charging preheating.

2. The preheating method for a lithium-ion power battery before charging according to claim 1, wherein The step of obtaining the first temperature rise rate at the heating power currently available to the power battery system includes: Collecting the current temperature state of the power battery; Determining the first heat exchange power between the power battery and the environment based on the deviation between the target heating medium temperature and the current temperature state of the power battery; Determining the first temperature rise rate based on the heating power and the first heat exchange power.

3. The preheating method for a lithium-ion power battery before charging according to claim 2, wherein The step of obtaining the second temperature rise rate at the heat exchange power of the current power battery system includes: Obtaining the second heat exchange power between the power battery and the battery heating unit; Determining the maximum temperature rise rate at the current temperature as the second temperature rise rate based on the first heat exchange efficiency and the second heat exchange power.

4. The preheating method for a lithium-ion power battery before charging according to claim 1, wherein, The step of performing a corresponding pre-charging preheating strategy according to the comparison result of the first temperature rise rate and the second temperature rise rate includes: If the first temperature rise rate is less than or equal to the second temperature rise rate, taking the first temperature rise rate as the actual temperature rise rate of the power battery, and matching the best exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery; If the first temperature rise rate is greater than the second temperature rise rate, increasing the target heating medium temperature to re-determine the first temperature rise rate.

5. The preheating method for a lithium-ion power battery before charging according to claim 4, wherein After increasing the target heating medium temperature, it further includes: if the target heating medium temperature exceeds the allowable medium temperature of the power battery, taking the second temperature rise rate as the actual temperature rise rate of the power battery.

6. The preheating method for a lithium-ion power battery before charging according to claim 4 or 5, characterized in that, Before matching the best exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery, it further includes: Determining the mapping relationship between different power battery temperature rise rate ranges and different best exit temperatures of the pre-charging preheating based on the safe charging voltage of the power battery, the charging power of different charging devices, different states of charge of the power battery, and different temperature states.

7. The preheating method for a lithium-ion power battery before charging according to claim 6, wherein The step of matching the best exit temperature of the pre-charging preheating according to the actual temperature rise rate of the power battery includes: Comparing the actual temperature rise rate of the power battery with the power battery temperature rise rate range, and calling the corresponding best exit temperature according to the power battery temperature rise rate range in which the actual temperature rise rate of the power battery falls.

8. A pre-charging preheating device for a lithium-ion power battery, characterized in that a temperature rise rate determination module, configured to obtain a first temperature rise rate at the heating power currently available to the power battery system and a second temperature rise rate at the heat exchange power of the current power battery system; wherein, the heating power is determined by the target heating medium temperature of the current power battery, and the heat exchange power is determined by the theoretical maximum temperature rise rate of the power battery at the current temperature; A preheating strategy execution module, configured to execute a corresponding pre-charging preheating strategy according to a comparison result between the first temperature rise rate and the second temperature rise rate, so as to adjust an exit temperature of pre-charging preheating.

9. A vehicle, characterized in that, Comprising: One or more processors; And A memory, configured to store one or more programs, which, when executed by the one or more processors, cause the memory to implement the steps of the pre-charging preheating method for a lithium-ion power battery as described in any one of claims 1 to 7.

10. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, the steps of the pre-charging preheating method for a lithium-ion power battery as described in any one of claims 1 to 7 are implemented.

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