Battery coolant temperature estimation method, device and system

Abstract

The invention discloses a battery coolant temperature estimation method, device and system, and the method comprises the steps: firstly determining an initial temperature value of a coolant based on the temperature of a battery cell, the environment temperature, and the interval time between the last power-off and the current power-on; determining a battery heating power variation and a battery cooling power variation from the current moment to a target moment based on the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the cooling liquid and the heat exchange parameters from the environment where the vehicle is located to the cooling liquid; according to the method, the predicted temperature value of the battery coolant at the target moment is determined, the future temperature state of the battery is estimated by distinguishing the working condition scene and the thermal management scene of the vehicle, and then the temperature of the battery coolant at the target moment is predicted by estimating the future temperature state of the battery. According to the invention, the temperature of the battery coolant at the target moment can be accurately estimated without participation of a battery coolant temperature sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and in particular to a method, device and system for estimating the temperature of a battery coolant. Background Art

[0002] Battery thermal management has an important impact on the power performance of electric vehicles, and to a great extent affects the life of the battery, and is even related to safety issues such as thermal runaway. Therefore, solving the thermal problem of batteries is very urgent for electric vehicles.

[0003] Battery cooling is an effective way to deal with battery thermal issues, mainly liquid cooling and direct cooling. The liquid cooling solution has the highest integration and high heat dissipation efficiency, which can ensure that the battery is in a reasonable operating temperature range. The estimation of the battery coolant temperature can be used as a backup value when the battery coolant temperature sensor fails. In addition, it has important guiding significance for the use of the battery for accurately estimating the future temperature changes of the battery. Therefore, how to accurately estimate the battery coolant temperature has become one of the technical problems that technicians in this field need to solve urgently. Summary of the invention

[0004] In view of this, embodiments of the present invention provide a battery coolant temperature estimation method, device and system to accurately estimate the battery coolant temperature at a target time without the involvement of a battery coolant temperature sensor.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A battery coolant temperature estimation method, comprising:

[0007] Get the current vehicle operating conditions, battery cell temperature, ambient temperature, and the time interval between the last time the vehicle was powered off and the current time it was powered on;

[0008] Determine an initial value of a coolant temperature of a battery coolant according to the battery core temperature, the ambient temperature and the time interval;

[0009] Obtain the current battery thermal management status, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target time;

[0010] Determine a power parameter change from the current moment to the target moment according to the battery cell temperature, wherein the power parameter change includes a battery heating power change and a battery cooling power change;

[0011] The predicted temperature value of the battery coolant at the target time is determined based on the initial value of the coolant temperature, the change in power parameters, the battery cell temperature at the target time, the heat exchange parameters from the battery cell to the coolant, the vehicle's ambient temperature, and the heat exchange parameters from the vehicle's environment to the coolant.

[0012] Optionally, in the above-mentioned battery coolant temperature estimation method, determining the predicted temperature value of the battery coolant at the target time according to the initial value of the coolant temperature, the power parameter change, the battery cell temperature at the target time, the heat exchange parameter from the battery cell to the coolant, the ambient temperature of the vehicle, and the heat exchange parameter from the vehicle environment to the coolant includes:

[0013] By the formula Iterate to determine the predicted temperature value of the battery coolant at the target time until the Iterate until the temperature of the coolant corresponding to the target time is reached;

[0014] Among them, the For the The temperature of the coolant corresponding to the previous moment, The initial value of is the initial value of coolant temperature;

[0015] The Q input for The battery heating power or battery cooling power at the corresponding moment;

[0016] Said c is the specific heat capacity of the coolant;

[0017] The m is the mass of the coolant;

[0018] Said

[0019] Said for The battery cell temperature at the corresponding moment;

[0020] Wherein, h1*A1 is the heat exchange parameter from the battery cell to the coolant;

[0021] h1 is the equivalent convection heat transfer coefficient from the battery cell to the coolant;

[0022] A1 is the equivalent heat exchange area from the battery cell to the coolant;

[0023] Said

[0024] Among them, the for The vehicle's ambient temperature at the corresponding moment;

[0025] h2*A2 is the heat exchange parameter from the vehicle's environment to the coolant;

[0026] h2 is the equivalent convection heat transfer coefficient from the vehicle environment to the coolant;

[0027] A2 is the equivalent heat exchange area from the vehicle's environment to the coolant.

[0028] Optionally, in the above-mentioned battery coolant temperature estimation method, determining the initial value of the coolant temperature of the battery coolant according to the battery cell temperature, the ambient temperature and the time interval includes:

[0029] The initial coolant temperature value of the corresponding battery coolant is determined from a first preset mapping table according to the battery cell temperature, the ambient temperature and the time interval, and the first preset mapping table stores the initial coolant temperature values ​​corresponding to the battery cell temperature, the ambient temperature and the time interval.

[0030] Optionally, in the above-mentioned battery coolant temperature estimation method, obtaining the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target moment includes:

[0031] Collecting vehicle operating parameters, and extracting the current battery thermal management state, heat exchange parameters from the battery cell to the coolant, and heat exchange parameters from the vehicle environment to the coolant from the vehicle state data;

[0032] The preset battery cell thermal model is used to calculate the battery cell temperature at the target time.

[0033] Optionally, in the above-mentioned battery coolant temperature estimation method, determining the power parameter change from the current moment to the target moment according to the battery cell temperature includes:

[0034] The power parameter change from the current moment to the target moment is determined from a second preset mapping table according to the battery cell temperature, and the second preset table stores the power parameter change from the current moment to the target moment that matches the battery cell temperature.

[0035] Optionally, in the above-mentioned battery coolant temperature estimation method, determining the power parameter change from the current moment to the target moment according to the battery cell temperature includes:

[0036] When the battery cooling function is turned on, the second preset mapping table determines the battery cooling power change from the current moment to the target moment according to the battery core temperature;

[0037] When the battery heating function is turned on, the second preset mapping table determines the battery heating power change from the current moment to the target moment according to the battery core temperature.

[0038] A battery coolant temperature estimation device, comprising:

[0039] The coolant temperature initial value determination unit is used to: obtain the vehicle operating condition, battery cell temperature, ambient temperature and the interval time between the last power-off and the current power-on of the vehicle at the current moment; determine the coolant temperature initial value of the battery coolant according to the battery cell temperature, the ambient temperature and the time interval;

[0040] A target-time battery cell temperature determination unit is used to obtain the battery thermal management state at the current time, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target time;

[0041] A power variation calculation unit, used to determine a power parameter variation from the current moment to the target moment according to the battery cell temperature, wherein the power parameter variation includes a battery heating power variation and a battery cooling power variation;

[0042] The prediction unit is used to determine the predicted temperature value of the battery coolant at the target time according to the initial value of the coolant temperature, the change in power parameter, the battery cell temperature at the target time, the heat exchange parameter from the battery cell to the coolant, the ambient temperature of the vehicle, and the heat exchange parameter from the environment of the vehicle to the coolant.

[0043] Optionally, in the above-mentioned battery coolant temperature estimation device, the prediction unit is specifically used for:

[0044] By the formula Iterate to determine the predicted temperature value of the battery coolant at the target time until the Iterate until the temperature of the coolant corresponding to the target time is reached;

[0045] Among them, the For the The temperature of the coolant corresponding to the previous moment, The initial value of is the initial value of coolant temperature;

[0046] The Q input for The battery heating power or battery cooling power at the corresponding moment;

[0047] Said c is the specific heat capacity of the coolant;

[0048] The m is the mass of the coolant;

[0049] Said

[0050] Said for The battery cell temperature at the corresponding moment;

[0051] Wherein, h1*A1 is the heat exchange parameter from the battery cell to the coolant;

[0052] h1 is the equivalent convection heat transfer coefficient from the battery cell to the coolant;

[0053] A1 is the equivalent heat exchange area from the battery cell to the coolant;

[0054] Said

[0055] Among them, the for The vehicle's ambient temperature at the corresponding moment;

[0056] h2*A2 is the heat exchange parameter from the vehicle's environment to the coolant;

[0057] h2 is the equivalent convection heat transfer coefficient from the vehicle environment to the coolant;

[0058] A2 is the equivalent heat exchange area from the vehicle's environment to the coolant.

[0059] A battery coolant temperature estimation device, comprising: a memory and a processor;

[0060] The memory is used to store programs;

[0061] The processor is used to execute the program to implement any of the above-mentioned battery coolant temperature estimation methods.

[0062] Based on the above technical solution, the above solution provided by the embodiment of the present invention first obtains the vehicle operating condition, battery cell temperature, ambient temperature, and the interval time between the last power-off and the current power-on at the current moment, and then determines the initial value of the coolant temperature, and then obtains the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the coolant, and the heat exchange parameters from the vehicle environment to the coolant, and then determines the battery heating power change and the battery cooling power change from the current moment to the target moment according to the battery cell temperature at the current moment, and determines the predicted temperature value of the battery coolant at the target moment in combination with the initial value of the coolant temperature. This solution estimates the future temperature state of the battery by distinguishing between the vehicle's operating condition scenario and the thermal management scenario, and then predicts the battery coolant temperature at the target moment by estimating the future temperature state of the battery. In the above analysis process, there is no need for the battery coolant temperature sensor to participate, so that the battery coolant temperature at the target moment can be accurately estimated without the participation of the battery coolant temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0064] Figure 1 A schematic diagram of a flow chart of a battery coolant temperature estimation method disclosed in an embodiment of the present application;

[0065] Figure 2 A schematic diagram of the structure of a battery coolant temperature estimation device disclosed in an embodiment of the present application;

[0066] Figure 3 A schematic diagram of the structure of a battery coolant temperature estimation device disclosed in an embodiment of the present application;

[0067] Figure 4 A schematic diagram of the structure of a vehicle system disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 the present invention.

[0069] The present application discloses a battery coolant temperature prediction method, device and system, which can be used when the battery coolant temperature sensor fails, and can also predict future changes in battery coolant temperature to more accurately predict future changes in battery cell temperature.

[0070] For details, see Figure 1 , the present application discloses a battery coolant temperature estimation method, which may include:

[0071] Step S101: Obtain the current vehicle operating conditions, battery cell temperature, ambient temperature, and the interval time between the last time the vehicle was powered off and the current time it was powered on.

[0072] In this step, the vehicle operating condition, battery cell temperature, ambient temperature and the interval time can be directly extracted from the vehicle operating parameters, wherein the vehicle operating condition can be a fast charging condition after driving, a driving condition after soaking in temperature, a fast charging condition after soaking in temperature, etc. The values ​​of the initial parameters collected under different conditions are different.

[0073] Step S102: determining an initial value of the coolant temperature of the battery coolant according to the battery cell temperature, the ambient temperature and the time interval.

[0074] In this step, after the vehicle operating condition is determined, an initial coolant temperature value matching the battery core temperature, the ambient temperature and the time interval may be determined according to a first preset mapping table. The initial coolant temperature values ​​determined under different operating conditions are different.

[0075] Step S103: Obtain the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target moment.

[0076] In this step, after obtaining the vehicle operating parameters, the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the coolant, and the heat exchange parameters from the vehicle environment to the coolant can be directly extracted from the vehicle operating parameters, and then these parameters are substituted into the preset battery cell thermal model, and the battery cell thermal model can calculate the battery cell temperature at the target moment based on these parameters. Among them, the heat exchange parameters from the battery cell to the coolant are related to the battery thermal management state. Specifically, the heat exchange parameters are related to the duty cycle of the battery circuit water pump, and the two are in a positive proportional relationship.

[0077] Step S104: determining a power parameter change from the current moment to the target moment according to the battery core temperature.

[0078] In this step, the power parameter variation includes the battery heating power variation and the battery cooling power variation.

[0079] In this solution, for the target moment, the power parameter change from the current moment to the target moment can be determined from the second preset mapping table according to the battery cell temperature at the current moment. The power change can include the battery heating power change and the battery cooling power change, which are recorded as the battery heating power change and the battery cooling power change from the current moment to the target moment. It should be noted that both the battery heating power change and the battery cooling power change change change with the passage of time. Whether to obtain the specific value of the battery heating power change or the battery cooling power change is related to the specific strategy of battery thermal management. For example, when the battery cooling function is turned on, the second preset mapping table determines the battery cooling power change from the current moment to the target moment according to the battery cell temperature; when the battery heating function is turned on, the second preset mapping table determines the battery heating power change from the current moment to the target moment according to the battery cell temperature.

[0080] Step S105: Determine the predicted temperature value of the battery coolant at the target time according to the initial value of the coolant temperature, the change in power parameter, the battery cell temperature at the target time, the heat exchange parameter from the battery cell to the coolant, the vehicle's ambient temperature, and the heat exchange parameter from the vehicle's environment to the coolant.

[0081] The technical solution disclosed in the above embodiment of the present application first obtains the vehicle operating condition, battery cell temperature, ambient temperature, and the interval time between the last power-off and the current power-on at the current moment, and then determines the initial value of the coolant temperature, and then obtains the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the coolant, and the heat exchange parameters from the vehicle environment to the coolant, and then determines the battery heating power change and the battery cooling power change from the current moment to the target moment according to the battery cell temperature at the current moment, and determines the predicted temperature value of the battery coolant at the target moment in combination with the initial value of the coolant temperature. This solution estimates the future temperature state of the battery by distinguishing between the vehicle's operating condition scenario and the thermal management scenario, and then predicts the battery coolant temperature at the target moment by estimating the future temperature state of the battery. In the above analysis process, there is no need for the participation of the battery coolant temperature sensor, so that the battery coolant temperature at the target moment can be accurately estimated without the participation of the battery coolant temperature sensor.

[0082] This embodiment also discloses a specific solution for calculating the predicted temperature value. In this solution, the calculation formula needs to be pre-configured. The predicted temperature value of the battery coolant at the target time is calculated based on the formula, that is, in the above scheme, the predicted temperature value of the battery coolant at the target time is determined according to the initial value of the coolant temperature, the change in the power parameter, the battery cell temperature at the target time, the heat exchange parameter from the battery cell to the coolant, the ambient temperature of the vehicle, and the heat exchange parameter from the vehicle environment to the coolant. Determining the predicted temperature value of the battery coolant at the target time may specifically include:

[0083] By the formula Iterate to determine the predicted temperature value of the battery coolant at the target time until the Iterate until the temperature of the coolant corresponding to the target time is reached;

[0084] Among them, the For the The temperature of the coolant corresponding to the previous moment, The initial value of is the initial value of coolant temperature;

[0085] The Q input for The battery heating power or battery cooling power at the corresponding moment;

[0086] Said c is the specific heat capacity of the coolant;

[0087] The m is the mass of the coolant;

[0088] Said

[0089] Said for The battery cell temperature at the corresponding moment;

[0090] Wherein, h1*A1 is the heat exchange parameter from the battery cell to the coolant;

[0091] h1 is the equivalent convection heat transfer coefficient from the battery cell to the coolant;

[0092] A1 is the equivalent heat exchange area from the battery cell to the coolant;

[0093] Said

[0094] Among them, the for The vehicle's ambient temperature at the corresponding moment;

[0095] h2*A2 is the heat exchange parameter from the vehicle's environment to the coolant;

[0096] h2 is the equivalent convection heat transfer coefficient from the vehicle environment to the coolant;

[0097] A2 is the equivalent heat exchange area from the vehicle's environment to the coolant.

[0098] This embodiment discloses a battery coolant temperature estimation device. For the specific working contents of each unit in the device, please refer to the contents of the above method embodiment.

[0099] The battery coolant temperature estimation device provided by an embodiment of the present invention is described below. The battery coolant temperature estimation device described below and the battery coolant temperature estimation method described above can be referred to each other.

[0100] See also Figure 2 , the battery coolant temperature estimation device disclosed in the embodiment of the present application includes:

[0101] The coolant temperature initial value determination unit A corresponds to steps S101-S102 in the above method, and is used to: obtain the vehicle operating condition, battery cell temperature, ambient temperature and the interval time between the last power-off and the current power-on of the vehicle at the current moment; determine the coolant temperature initial value of the battery coolant according to the battery cell temperature, the ambient temperature and the time interval;

[0102] The target moment battery cell temperature determination unit B corresponds to step S103 in the above method, and is used to: obtain the battery thermal management state at the current moment, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target moment;

[0103] A power variation calculation unit C, which corresponds to step S104 in the above method, is used to: determine a power parameter variation from the current moment to the target moment according to the battery cell temperature, wherein the power parameter variation includes a battery heating power variation and a battery cooling power variation;

[0104] The prediction unit D corresponds to step S105 in the above method and is used to determine the predicted temperature value of the battery coolant at the target time according to the initial value of the coolant temperature, the change in the power parameter, the battery cell temperature at the target time, the heat exchange parameter from the battery cell to the coolant, the ambient temperature of the vehicle, and the heat exchange parameter from the environment of the vehicle to the coolant.

[0105] Corresponding to the above method, the prediction unit is specifically used for:

[0106] By the formula Iterate to determine the predicted temperature value of the battery coolant at the target time until the Iterate until the temperature of the coolant corresponding to the target time is reached;

[0107] Among them, the For the The temperature of the coolant corresponding to the previous moment, The initial value of is the initial value of coolant temperature;

[0108] The Q input for The battery heating power or battery cooling power at the corresponding moment;

[0109] Said c is the specific heat capacity of the coolant;

[0110] The m is the mass of the coolant;

[0111] Said

[0112] Said for The battery cell temperature at the corresponding moment;

[0113] Wherein, h1*A1 is the heat exchange parameter from the battery cell to the coolant;

[0114] h1 is the equivalent convection heat transfer coefficient from the battery cell to the coolant;

[0115] A1 is the equivalent heat exchange area from the battery cell to the coolant;

[0116] Said

[0117] Among them, the for The vehicle's ambient temperature at the corresponding moment;

[0118] h2*A2 is the heat exchange parameter from the vehicle's environment to the coolant;

[0119] h2 is the equivalent convection heat transfer coefficient from the vehicle environment to the coolant;

[0120] A2 is the equivalent heat exchange area from the vehicle's environment to the coolant.

[0121] Corresponding to the above method, the present application also discloses a battery coolant temperature estimation device, see Figure 3 , the apparatus may include: at least one processor 100, at least one communication interface 200, at least one memory 300 and at least one communication bus 400;

[0122] In the embodiment of the present invention, the number of the processor 100, the communication interface 200, the memory 300, and the communication bus 400 is at least one, and the processor 100, the communication interface 200, and the memory 300 communicate with each other through the communication bus 400; obviously, Figure 3 The communication connections shown for the processor 100, the communication interface 200, the memory 300, and the communication bus 400 are merely optional;

[0123] Optionally, the communication interface 200 may be an interface of a communication module, such as an interface of a GSM module;

[0124] The processor 100 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0125] The memory 300 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0126] The processor 100 is specifically configured to:

[0127] Get the current vehicle operating conditions, battery cell temperature, ambient temperature, and the time interval between the last time the vehicle was powered off and the current time it was powered on;

[0128] Determine an initial value of a coolant temperature of a battery coolant according to the battery core temperature, the ambient temperature and the time interval;

[0129] Obtain the current battery thermal management status, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target time;

[0130] Determine a power parameter change from the current moment to the target moment according to the battery cell temperature, wherein the power parameter change includes a battery heating power change and a battery cooling power change;

[0131] The predicted temperature value of the battery coolant at the target time is determined based on the initial value of the coolant temperature, the change in power parameters, the battery cell temperature at the target time, the heat exchange parameters from the battery cell to the coolant, the vehicle's ambient temperature, and the heat exchange parameters from the vehicle's environment to the coolant.

[0132] The processor is also used to execute various steps disclosed in other battery coolant temperature estimation method embodiments, which will not be described in detail.

[0133] Furthermore, the present application also discloses a vehicle system using the above-mentioned battery coolant temperature estimation device or battery coolant temperature estimation equipment. The above-mentioned battery coolant temperature estimation device or equipment can be applied to a battery system, see Figure 4 The vehicle system may include a battery system 501, a motor drive system 502, a computing control system 503, an air conditioning system 504, an interior and exterior decoration system 505, a body system 506, a chassis system 507 and a communication and entertainment system 508.

[0134] For the convenience of description, the above system is described by dividing it into various modules according to its functions. Of course, when implementing the present invention, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0135] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0136] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may 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 the present invention.

[0137] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0138] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0139] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for estimating battery coolant temperature, characterized in that: include: Get the current vehicle operating conditions, battery cell temperature, ambient temperature, and the time interval between the last time the vehicle was powered off and the current time it was powered on; Determine an initial value of a coolant temperature of a battery coolant according to the battery core temperature, the ambient temperature and the time interval; Obtain the current battery thermal management status, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target time; Determine a power parameter change from the current moment to the target moment according to the battery cell temperature, wherein the power parameter change includes a battery heating power change and a battery cooling power change; The predicted temperature value of the battery coolant at the target time is determined based on the initial value of the coolant temperature, the change in power parameters, the battery cell temperature at the target time, the heat exchange parameters from the battery cell to the coolant, the vehicle's ambient temperature, and the heat exchange parameters from the vehicle's environment to the coolant.

2. The battery coolant temperature estimation method according to claim 1, characterized in that: Determining a predicted temperature value of the battery coolant at the target time according to an initial value of the coolant temperature, a change in the power parameter, a battery cell temperature at a target time, a heat exchange parameter from the battery cell to the coolant, an ambient temperature of the vehicle, and a heat exchange parameter from the environment of the vehicle to the coolant, including: By the formula Iterate to determine the predicted temperature value of the battery coolant at the target time until the Iterate until the temperature of the coolant corresponding to the target time is reached; Among them, the For the The temperature of the coolant corresponding to the previous moment, The initial value of is the initial value of coolant temperature; The Q input for The battery heating power or battery cooling power at the corresponding moment; Said c is the specific heat capacity of the coolant; The m is the mass of the coolant; Said Said for The cell temperature at the corresponding moment; Wherein, h1*A1 is the heat exchange parameter from the battery cell to the coolant; h1 is the equivalent convection heat transfer coefficient from the battery cell to the coolant; A1 is the equivalent heat exchange area from the battery cell to the coolant; Said Among them, the for The vehicle's ambient temperature at the corresponding moment; h2*A2 is the heat exchange parameter from the vehicle's environment to the coolant; h2 is the equivalent convection heat transfer coefficient from the vehicle environment to the coolant; A2 is the equivalent heat exchange area from the vehicle's environment to the coolant.

3. The battery coolant temperature estimation method according to claim 1, characterized in that: Determining an initial value of a coolant temperature of a battery coolant according to the battery core temperature, the ambient temperature, and the time interval includes: The initial coolant temperature value of the corresponding battery coolant is determined from a first preset mapping table according to the battery cell temperature, the ambient temperature and the time interval, and the first preset mapping table stores the initial coolant temperature values ​​corresponding to the battery cell temperature, the ambient temperature and the time interval.

4. The battery coolant temperature estimation method according to claim 1, characterized in that: Obtain the current battery thermal management status, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target time, including: Collecting vehicle operating parameters, and extracting the current battery thermal management state, heat exchange parameters from the battery cell to the coolant, and heat exchange parameters from the vehicle environment to the coolant from the vehicle state data; The preset battery cell thermal model is used to calculate the battery cell temperature at the target time.

5. The battery coolant temperature estimation method according to claim 1, characterized in that: Determine the power parameter change from the current moment to the target moment according to the battery core temperature, including The power parameter change from the current moment to the target moment is determined from a second preset mapping table according to the battery cell temperature, and the second preset table stores the power parameter change from the current moment to the target moment that matches the battery cell temperature.

6. The battery coolant temperature estimation method according to claim 5, characterized in that: Determining the power parameter change from the current moment to the target moment according to the battery core temperature includes: When the battery cooling function is turned on, a second preset mapping table determines a battery cooling power change from the current moment to the target moment according to the battery core temperature; When the battery heating function is turned on, the second preset mapping table determines the battery heating power change from the current moment to the target moment according to the battery core temperature.

7. A battery coolant temperature estimation device, characterized in that: include: The coolant temperature initial value determination unit is used to: obtain the vehicle operating condition, battery cell temperature, ambient temperature and the interval time between the last power-off and the current power-on of the vehicle at the current moment; determine the coolant temperature initial value of the battery coolant according to the battery cell temperature, the ambient temperature and the time interval; A target-time battery cell temperature determination unit is used to obtain the battery thermal management state at the current time, the heat exchange parameters from the battery cell to the coolant, the heat exchange parameters from the vehicle environment to the coolant, and the battery cell temperature at the target time; A power variation calculation unit, used to determine a power parameter variation from the current moment to the target moment according to the battery cell temperature, wherein the power parameter variation includes a battery heating power variation and a battery cooling power variation; The prediction unit is used to determine the predicted temperature value of the battery coolant at the target time according to the initial value of the coolant temperature, the change in power parameter, the battery cell temperature at the target time, the heat exchange parameter from the battery cell to the coolant, the ambient temperature of the vehicle, and the heat exchange parameter from the environment of the vehicle to the coolant.

8. The battery coolant temperature estimation device according to claim 7, characterized in that: The prediction unit is specifically used for: By the formula Iterate to determine the predicted temperature value of the battery coolant at the target time until the Iterate until the temperature of the coolant corresponding to the target time is reached; Among them, the For the The temperature of the coolant corresponding to the previous moment, The initial value of is the initial value of coolant temperature; The Q input for The battery heating power or battery cooling power at the corresponding moment; Said c is the specific heat capacity of the coolant; The m is the mass of the coolant; Said Said for The cell temperature at the corresponding moment; Wherein, h1*A1 is the heat exchange parameter from the battery cell to the coolant; h1 is the equivalent convection heat transfer coefficient from the battery cell to the coolant; A1 is the equivalent heat exchange area from the battery cell to the coolant; Said Among them, the for The vehicle's ambient temperature at the corresponding moment; h2*A2 is the heat exchange parameter from the vehicle's environment to the coolant; h2 is the equivalent convection heat transfer coefficient from the vehicle environment to the coolant; A2 is the equivalent heat exchange area from the vehicle's environment to the coolant.

9. A battery coolant temperature estimation device, characterized in that: include: Memory and processor; The memory is used to store programs; The processor is used to execute the program to implement the battery coolant temperature estimation method according to any one of claims 1 to 6.

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