Vehicle battery thermal management method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a vehicle battery thermal management method and device, electronic equipment and a storage medium. The temperature rise rate of a battery is determined by responding to starting operation of a battery thermal management function; the maximum temperature value of the battery is determined according to the heating rate, and the corresponding estimated charging current when the battery temperature reaches the maximum temperature value is determined; and after the actual charging current of the battery reaches the maximum charging current of the battery and the estimated charging current is smaller than the charging current threshold value corresponding to the maximum temperature value, the battery thermal management function is closed, so that the self-adaptive control of the start and stop of the battery thermal management function is realized. The charging efficiency of the power battery is prevented from being influenced by long-time operation of the battery thermal management function, the overall energy consumption of the battery thermal management function is reduced, the charging effect of the power battery is improved, and the charging time of the power battery is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle power batteries, and particularly to a vehicle battery thermal management method and device, an electronic device, and a storage medium. Background Art

[0002] The temperature of the power battery of a new energy vehicle determines its charging rate, and the charging rate affects the vehicle range under the same charging time. A suitable power battery temperature determines a faster charging rate. In high-temperature DC fast charging / normal-temperature DC fast charging scenarios, when the temperature of the power battery is higher than the preset charging temperature upper limit value, it is necessary to turn on the cooling of the battery thermal management system to dissipate heat from the power battery and reduce its temperature to the optimal charging temperature range.

[0003] During the fast charging process of the power battery, due to the high battery charging current, the battery temperature generally rises rapidly. In the early stage of charging, that is, when the SOC (State Of Charge) is low, the charging current will rise rapidly and the cooling of the battery thermal management system will be turned on when the power battery temperature is higher than the preset charging temperature upper limit value. In the later stage of charging, that is, when the SOC is high, considering the safety of the battery cells, the charging current generally decreases.

[0004] However, the decrease in the charging current in the later stage of charging will lead to a decrease in the heat generation of the battery itself. At this time, due to the continuous operation of the battery thermal management function, the battery temperature will continue to drop; not only will the charging time be lengthened, but also the energy consumption will increase due to the continuous operation of the thermal management function, seriously affecting the charging efficiency of the power battery. Summary of the Invention

[0005] In view of the above problems, a vehicle battery thermal management method and device, an electronic device, and a storage medium are provided to overcome the above problems or at least partially solve the above problems, including:

[0006] A vehicle battery thermal management method, the method includes:

[0007] Responding to the start operation of the battery thermal management function, determining the heating rate of the battery;

[0008] According to the heating rate, determining the maximum temperature of the battery, and determining the estimated charging current corresponding to when the battery temperature reaches the maximum temperature;

[0009] After the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than the charging current threshold corresponding to the maximum temperature, turning off the battery thermal management function.

[0010] Optionally, before turning off the battery thermal management function after the actual charging current of the battery reaches the maximum charging current of the battery and when the estimated charging current is less than the charging current threshold corresponding to the maximum temperature, the following steps are further included:

[0011] Determine the state of charge of the battery, and determine the charging current threshold according to the state of charge and the maximum temperature.

[0012] Optionally, the determining of the estimated charging current corresponding to when the battery temperature reaches the maximum temperature includes:

[0013] Determine the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single battery cells of the battery, and the internal resistance of a single battery cell of the battery;

[0014] Determine the estimated charging current corresponding to when the battery temperature reaches the maximum temperature according to the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single battery cells of the battery, and the internal resistance of a single battery cell of the battery.

[0015] Optionally, the heat exchange power between the battery and the environment is determined by the following method:

[0016] Determine the specific heat capacity of the battery cell and the mass of a single battery cell of the battery, and determine the heat exchange power between the battery and the environment according to the temperature rise rate of the battery, the number of single battery cells of the battery, the specific heat capacity of the battery cell, and the mass of a single battery cell of the battery.

[0017] Optionally, the cooling power of the battery coolant is determined by the following method:

[0018] Determine the specific heat capacity of the coolant, the density of the coolant, and the volume flow rate of the coolant, and determine the cooling power of the battery coolant according to the specific heat capacity of the coolant, the density of the coolant, and the volume flow rate of the coolant.

[0019] Optionally, the determining of the maximum temperature of the battery according to the temperature rise rate includes:

[0020] Determine the temperature value of the battery when the temperature rise rate is zero as the maximum temperature of the battery.

[0021] Optionally, before determining the temperature rise rate of the battery in response to the start operation of the battery thermal management function, the following steps are further included:

[0022] Determine the real-time highest temperature value of the battery, and start the battery thermal management function when the real-time highest temperature value of the battery is greater than the preset temperature threshold.

[0023] A vehicle battery thermal management device, the device comprising:

[0024] A heating rate determination module, configured to determine a heating rate of the battery in response to a start operation of the battery thermal management function;

[0025] An estimated charging current determination module, configured to determine a maximum temperature of the battery according to the heating rate, and determine an estimated charging current corresponding to when the battery temperature reaches the maximum temperature;

[0026] A battery thermal management function shutdown module, configured to shut down the battery thermal management function after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than a charging current threshold corresponding to the maximum temperature.

[0027] An electronic device, comprising a processor, a memory, and a computer program stored on the memory and capable of running on the processor, where when the computer program is executed by the processor, the vehicle battery thermal management method described above is implemented.

[0028] A computer-readable storage medium, on which a computer program is stored, where when the computer program is executed by a processor, the vehicle battery thermal management method described above is implemented.

[0029] The embodiments of the present invention have the following advantages:

[0030] In the embodiments of the present invention, by responding to a start operation of the battery thermal management function, a heating rate of the battery is determined; thus, a maximum temperature of the battery is determined according to the heating rate, and an estimated charging current corresponding to when the battery temperature reaches the maximum temperature is determined; further, after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than a charging current threshold corresponding to the maximum temperature, the battery thermal management function is shut down, realizing an adaptive control of the start and stop of the battery thermal management function; avoiding the long-term operation of the battery thermal management function from affecting the charging efficiency of the power battery, reducing the overall energy consumption of the battery thermal management function, improving the charging effect of the power battery, and shortening the charging time of the power battery. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the description of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0032] Figure 1It is a flowchart of the steps of a vehicle battery thermal management method provided by some embodiments of the present invention;

[0033] Figure 2 It is another execution logic schematic diagram of the present invention provided by some embodiments of the present invention;

[0034] Figure 3 It is a schematic diagram of the architecture of the calculation module of the present invention provided by some embodiments of the present invention;

[0035] Figure 4 It is a schematic diagram of the architecture of the controller of the present invention provided by some embodiments of the present invention;

[0036] Figure 5 It is a schematic diagram of the structure of a vehicle battery thermal management device provided by some embodiments of the present invention. Detailed implementation manners

[0037] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0038] During the fast charging process of the power battery, due to the high charging current of the battery, the battery temperature generally rises rapidly. In the early stage of charging, that is, when the state of charge (SOC) is low, the charging current will rise rapidly until it reaches the maximum charging current and the cooling of the battery thermal management system is turned on when the temperature is higher than the preset upper limit value of the charging temperature. In the later stage of charging, that is, when the SOC is high, considering the safety of the battery cells, the charging current generally decreases. However, the decrease in the charging current will lead to a decrease in the heat generated by the battery itself, that is, the battery temperature will not keep rising; but at this time, due to the continuous operation of the battery thermal management function, the battery temperature will continue to drop; and the drop in the battery temperature in the later stage of charging will further cause the system to select a lower charging current during charging; resulting in the power battery being unable to charge at the optimal charging current, which will not only increase the charging time, but also increase the energy consumption due to the continuous operation of the thermal management function, seriously affecting the charging efficiency of the power battery.

[0039] In the embodiments of the present invention, based on the core technical concept of turning off the battery thermal management function when the estimated charging current corresponding to the maximum battery temperature is less than the charging current threshold corresponding to the maximum temperature, the vehicle battery thermal management method in the related art is improved. The present invention will be described in detail below with reference to the accompanying drawings:

[0040] Refer to Figure 1, showing a flowchart of the steps of a vehicle battery thermal management method provided by some embodiments of the present invention, which may specifically include the following steps:

[0041] Step 101, in response to the start operation of the battery thermal management function, determine the heating rate of the battery;

[0042] In a specific implementation, the temperature rise rate at each temperature of the battery can be obtained in advance by calibration, and a corresponding table can be prepared accordingly for looking up to obtain the temperature rise rate of the battery;

[0043] In an example, as shown in Table 1 below, it is a calibration example table of the battery temperature rise rate at different temperatures and different SOCs:

[0044] Table 1: Calibration example table of battery temperature rise rate

[0045]

[0046] Among them, i, j, m, n are natural numbers, v is the battery temperature rise rate, the percentage is the SOC value. On this basis, after the battery thermal management function is started, the temperature rise rate of the battery can be determined by looking up the relevant data in the table.

[0047] In some embodiments of the present invention, before the step of determining the heating rate of the battery in response to the start operation of the battery thermal management function, it further includes:

[0048] Determine the real-time maximum temperature value of the battery, and start the battery thermal management function when the real-time maximum temperature value of the battery is greater than a preset temperature threshold.

[0049] In practical applications, the real-time maximum temperature value of the battery can be determined, and when the real-time maximum temperature value of the battery is greater than a preset temperature threshold, the battery thermal management function is started, so as to execute the subsequent adaptive start-stop control process after the battery thermal management function is started; among them, the actual reference value of the preset temperature threshold can be the result of a large number of experiments and actual data calibration by the battery manufacturer, or can be determined based on the measured data accumulated in the battery management system, or can also be set with reference to industry standards or safety regulations.

[0050] Step 102, according to the heating rate, determine the maximum temperature value of the battery, and determine the estimated charging current corresponding to when the battery temperature reaches the maximum temperature value;

[0051] In a specific implementation, the change in the core temperature during the charging process of the battery system consists of three aspects: the heat taken away by battery cooling, the heat generated by the internal resistance of the battery core during charging, and the heat exchanged between the battery core and the environment. Therefore, according to the law of conservation of energy, we can get:

[0052] c * m * Δt * n = -Pw * t + I 2 * n * r * t + P am * t,

[0053] Wherein, c is the specific heat capacity of the battery cell, m is the mass of a single battery cell, Δt is the temperature change value of the battery cell, n is the number of single battery cells, Pw is the cooling power of the battery coolant, t is the charging time, r is the internal resistance of a single battery cell, Pam is the heat exchange power between the battery cell and the environment, and I is the estimated charging current.

[0054] Furthermore, the temperature rise rate of the battery cell can be obtained as:

[0055]

[0056] As can be seen from the content of the formula, since the battery temperature first rises and then falls, that is, the overall shows a curve opening downward. Therefore, at i.e., when Δt = 0, the battery temperature reaches the maximum value Tp.

[0057] Furthermore, the estimated charging current I corresponding to when the battery temperature reaches the maximum temperature can be obtained, that is, the following formula can be obtained from the above content:

[0058]

[0059] Wherein, n is the number of single battery cells, Pw is the cooling power of the battery coolant, r is the internal resistance of a single battery cell, Pam is the heat exchange power between the battery cell and the environment, and I is the estimated charging current; when heat is transferred from the environment to the battery cell, Pam takes a positive value; when heat is transferred from the battery cell to the environment, Pam takes a negative value. Generally speaking, for the fast charging operation of the battery in a high-temperature environment, usually Pam takes a positive value.

[0060] Furthermore, since the value of Pam is different at different battery temperatures and / or different SOCs, the heat exchange power between the battery cell and the environment of the battery can be determined according to the following formula:

[0061] Pam(T, SOC) = v * c * m * n

[0062] Wherein, T is the battery temperature, SOC is the state of charge of the battery, and Pam(T, SOC) means the heat exchange power between the battery cell and the environment corresponding to the corresponding battery temperature and the state of charge of the battery; c is the specific heat capacity of the battery cell, m is the mass of a single battery cell, n is the number of single battery cells, and v is the temperature rise rate of the battery; wherein v can be obtained by referring to the content of the foregoing steps through a pre-calibrated table.

[0063] Further, the cooling power Pw of the battery coolant can be calculated according to the following formula:

[0064] Pw = Cw * ρ * Vw / 60 / 1000

[0065] Wherein, Cw is the specific heat capacity of the coolant, ρ is the density of the coolant, and Vw is the volume flow rate of the coolant.

[0066] By comprehensively applying the above relational expressions, the estimated charging current I corresponding to when the battery temperature reaches the maximum temperature can be determined, so as to be used in the subsequent control process for starting and stopping the battery thermal management function.

[0067] In some embodiments of the present invention, determining the maximum temperature of the battery according to the heating rate includes:

[0068] Determining the temperature value of the battery when the heating rate is zero as the maximum temperature of the battery.

[0069] In a specific implementation, the change in the core temperature during the charging process of the battery system consists of three aspects: the heat taken away by battery cooling, the heat generated by the internal resistance of the battery core during charging, and the heat exchanged between the battery core and the environment. Therefore, according to the law of conservation of energy, we can obtain:

[0070] c * m * Δt * n = -Pw * t + I 2 * n * r * t + P am * t,

[0071] Wherein, c is the specific heat capacity of the battery core, m is the mass of a single battery core, Δt is the change value of the battery core temperature, n is the number of single battery cores, Pw is the cooling power of the battery coolant, t is the charging time, r is the internal resistance of a single battery core, Pam is the heat exchange power between the battery core and the environment, and I is the estimated charging current.

[0072] Further, the temperature rise rate of the battery core can be obtained as:

[0073]

[0074] As can be seen from the content of the formula, since the battery temperature first rises and then falls, that is, the overall shows a curve opening downward. Therefore, at That is, when Δt = 0, the battery temperature reaches the maximum temperature Tp.

[0075] In some embodiments of the present invention, determining the estimated charging current corresponding to when the battery temperature reaches the maximum temperature includes:

[0076] Determine the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single battery cells in the battery, and the internal resistance of a single battery cell in the battery;

[0077] Based on the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single battery cells in the battery, and the internal resistance of a single battery cell in the battery, determine the estimated charging current corresponding to when the battery temperature reaches the maximum temperature.

[0078] In practical applications, the estimated charging current I corresponding to when the battery temperature reaches the maximum temperature can be obtained through the following formula:

[0079]

[0080] where n is the number of single battery cells in the battery, Pw is the cooling power of the battery coolant, r is the internal resistance of a single battery cell in the battery, Pam is the heat exchange power between the battery cell and the environment, and I is the estimated charging current; when heat is transferred from the environment to the battery cell, Pam takes a positive value; when heat is transferred from the battery cell to the environment, Pam takes a negative value. Generally speaking, for the fast charging operation of the battery in a high-temperature environment, Pam usually takes a positive value.

[0081] Furthermore, since the value of Pam varies at different battery temperatures and / or different states of charge (SOC), the heat exchange power between the battery cell and the environment can be determined according to the following formula:

[0082] Pam(T, SOC) = v * c * m * n

[0083] where T is the battery temperature, SOC is the state of charge of the battery, and Pam(T, SOC) means the heat exchange power between the battery cell and the environment corresponding to the respective battery temperature and the state of charge of the battery; c is the specific heat capacity of the battery cell, m is the mass of a single battery cell in the battery, n is the number of single battery cells in the battery, and v is the heating rate of the battery; where v can be obtained through a pre-calibrated table with reference to the content of the foregoing steps.

[0084] Furthermore, the cooling power Pw of the battery coolant can be calculated according to the following formula:

[0085] Pw = Cw * ρ * Vw / 60 / 1000

[0086] where Cw is the specific heat capacity of the coolant, ρ is the density of the coolant, and Vw is the volume flow rate of the coolant.

[0087] Through the comprehensive application of the above relationships, the estimated charging current I corresponding to when the battery temperature reaches the maximum temperature can be determined, so as to be used in the subsequent control process for starting and stopping the battery thermal management function.

[0088] In some embodiments of the present invention, the heat exchange power between the battery and the environment is determined by the following method:

[0089] Determine the specific heat capacity of the battery cell and the mass of a single battery cell of the battery, and determine the heat exchange power between the battery and the environment according to the temperature rise rate of the battery, the number of single battery cells of the battery, the specific heat capacity of the battery cell and the mass of a single battery cell of the battery.

[0090] In practical applications, the specific heat capacity of the battery cell and the mass of a single battery cell of the battery can be determined, and the heat exchange power between the battery and the environment can be determined according to the temperature rise rate of the battery, the number of single battery cells of the battery, the specific heat capacity of the battery cell and the mass of a single battery cell of the battery. Specifically, since the value of Pam varies at different temperatures and / or different SOCs of the battery, the heat exchange power between the battery cell and the environment can be determined according to the following formula:

[0091] Pam(T, SOC) = v * c * m * n

[0092] Wherein, T is the battery temperature, SOC is the state of charge of the battery, and Pam(T, SOC) means the heat exchange power between the corresponding battery cell and the environment under the conditions of the battery temperature and the state of charge of the battery; c is the specific heat capacity of the battery cell, m is the mass of a single battery cell of the battery, n is the number of single battery cells of the battery, and v is the temperature rise rate of the battery; wherein v can be determined by referring to the content of the foregoing steps through a pre-calibrated table.

[0093] In some embodiments of the present invention, the cooling power of the battery coolant is determined by the following method:

[0094] Determine the specific heat capacity of the coolant, the density of the coolant and the volume flow rate of the coolant, and determine the cooling power of the battery coolant according to the specific heat capacity of the coolant, the density of the coolant and the volume flow rate of the coolant.

[0095] In a specific implementation, the specific heat capacity of the coolant, the density of the coolant and the volume flow rate of the coolant can be determined, and the cooling power of the battery coolant can be determined according to the specific heat capacity of the coolant, the density of the coolant and the volume flow rate of the coolant; specifically, the cooling power Pw of the battery coolant can be calculated according to the following formula:

[0096] Pw = Cw * ρ * Vw / 60 / 1000

[0097] Wherein, Cw is the specific heat capacity of the coolant, ρ is the density of the coolant, and Vw is the volume flow rate of the coolant.

[0098] Step 103, after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than the charging current threshold corresponding to the maximum temperature, turn off the battery thermal management function.

[0099] In specific implementation, the power battery is generally a lithium-ion battery. The rechargeable range of the lithium-ion power battery is -20°C to 55°C, and the dischargeable range is -30°C to 55°C. The optimal working range is 25°C to 35°C. When the battery temperature exceeds 35°C, generally, the battery thermal management strategy is required to request the air-conditioning compressor to cool the battery.

[0100] During the fast charging process of the power battery, due to the high charging current of the battery, the battery temperature generally rises rapidly; as the charging progresses, the charging SOC of the battery will also increase. The charging current selected by the system can generally be considered as a function of the battery temperature and the charging SOC, that is, i = I(T, SOC). In the early stage of charging (when the SOC is relatively low), the charging current will rise rapidly until it reaches the maximum charging current. In the later stage of charging (when the SOC is relatively high), considering the safety of the battery cells, the charging current will decrease. And the decrease in the charging current will lead to a decrease in the heat generated by the battery itself, that is, the battery temperature will not keep rising. The real-time maximum temperature value Tmax of the battery will have a maximum value Tp. Therefore, the battery temperature change curve will show a downward-opening curve that first rises and then falls. In the early stage of charging, when Tp ≥ Tmax ≥ Tmax1 (the preset temperature threshold for controlling the initial startup of the battery thermal management), the battery thermal management will start. In the later stage of charging, even when Tmax < Tp, due to the continuation of the battery cooling thermal management and the decrease in the charging current, the battery temperature will continue to decrease.

[0101] That is to say, the consequence of continuing to execute the battery thermal management strategy at this time is that the battery temperature is decreasing and the SOC is increasing. Due to the charging current function I(T, SOC), it will cause the system to select a lower charging current when charging the power battery. This will not only lengthen the charging time, but also cause the air-conditioning compressor to continue working during the continuous thermal management, increasing the energy consumption.

[0102] Therefore, after determining the estimated charging current corresponding to the maximum battery temperature, the charging current threshold corresponding to this maximum temperature can be determined. Specifically, the corresponding charging current value recorded in the correspondence table of temperature T and SOC created according to the charging current function I(T, SOC) can be used as this charging current threshold, that is, the corresponding charging current selected by the system according to the correspondence between battery temperature T and SOC during charging is used as this charging current threshold; since the vehicle battery does not require intervention in the battery thermal management system during the period from the start of charging until the maximum charging current of the battery is first reached, therefore, after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current corresponding to the maximum battery temperature is less than the charging current threshold corresponding to this maximum temperature and the actual SOC in the above correspondence table, the battery thermal management function can be turned off. The charging current threshold i can be obtained through the correspondence table of temperature T and SOC. For example, in the correspondence table of temperature T and SOC, each row can represent a fixed temperature and each column can represent a fixed SOC. Generally, at the same temperature (fixing a certain row), as the SOC increases (from left to right), the charging current will first increase and then decrease, and the higher the temperature (the larger the row number), the closer the SOC critical point where the charging current starts to decrease is to the left side of the table (low SOC); and at the same SOC (fixing a certain column), as the temperature increases (from top to bottom), the charging current will first increase and then decrease, and the higher the SOC (the larger the column number), the closer the temperature critical point where the charging current starts to decrease is to the upper side of the table (low temperature); the following Table 2 shows an example table of the correspondence between temperature T and SOC that can be used to query the charging current threshold i:

[0103] Table 2: Example Table of the Correspondence between Temperature T and SOC

[0104]

[0105] In one example, based on the above Table 2, when Tp = 45°C and the SOC is 80% (SOC is taken to the right), the corresponding charging current threshold can be obtained as i(9, n - 3). If the estimated charging current I obtained through the above calculation process is less than i(9, n - 3), it can be determined that the battery cooling thermal management strategy can be exited at this time (that is, the battery thermal management function is turned off).

[0106] It can be understood that if the battery cooling thermal management strategy is not exited, the battery temperature will drop, such as dropping to 40°C. According to Table 2, at this time, the battery charging current selected by the system at this temperature will be i(8, n - 1) or i(7, n - 1). At this time, if the battery cooling strategy is exited, the battery temperature can be maintained at a relatively high level through the self-generated heat of the battery cells, so as to continue to maintain the battery charging current selected by the system at i(9, n - 1). Since i(9, n - 1) > i(8, n - 1), the power battery can obtain a relatively higher charging current at this time, thereby shortening the charging time and saving the corresponding energy consumption of the compressor and water pump.

[0107] In some embodiments of the present invention, after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than the charging current threshold corresponding to the maximum temperature, before turning off the battery thermal management function, it further includes:

[0108] Determine the state of charge of the battery, and determine the charging current threshold according to the state of charge and the maximum temperature.

[0109] In a specific implementation, after determining the estimated charging current corresponding to the maximum battery temperature, the charging current threshold corresponding to the maximum temperature can be determined. Specifically, the corresponding charging current value recorded in the correspondence table of temperature T and SOC created according to the charging current function I(T, SOC) can be used as the charging current threshold, that is, the corresponding charging current selected by the system according to the correspondence between battery temperature T and SOC during charging is used as the charging current threshold; and after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current corresponding to the maximum battery temperature is less than the charging current threshold corresponding to the maximum temperature and the actual SOC in the above correspondence table, the battery thermal management function is turned off. The charging current threshold i can be obtained through the correspondence table of temperature T and SOC. For example, in the correspondence table of temperature T and SOC, each row can represent a fixed temperature, and each column can represent a fixed SOC. Generally, at the same temperature (fixing a certain row), as the SOC increases (from left to right), the charging current will first increase and then decrease, and the higher the temperature (the larger the row number), the closer the SOC critical point where the charging current starts to decrease is to the left side of the table (low SOC); and at the same SOC (fixing a certain column), as the temperature increases (from top to bottom), the charging current will first increase and then decrease, and the higher the SOC (the larger the column number), the closer the temperature critical point where the charging current starts to decrease is to the upper side of the table (low temperature).

[0110] The following combines Figure 2 , Figure 3 with Figure 4An exemplary description of the embodiments of the present invention is as follows:

[0111] As can be seen from Figure 2 the content, another main execution logic of the present invention during battery thermal management can be summarized as follows: in response to the situation where the battery temperature rises after the battery fast charging gun is connected and charging starts, it is determined whether the real-time maximum temperature Tmax of the battery is greater than or equal to the temperature threshold Tmax1 for enabling the battery thermal management function, and the battery thermal management function is enabled when Tmax is greater than or equal to Tmax1; in this embodiment, it can be further determined whether the real-time maximum temperature Tmax of the battery is less than Tp. If the real-time maximum temperature Tmax of the battery is less than Tp, the battery thermal management function can also be turned off. If the real-time maximum temperature Tmax of the battery is ≥Tp, the continuous operation of the battery thermal management function can be maintained.

[0112] And as can be seen from Figure 3 the content, to implement the corresponding functions in the embodiments of the present invention, at least two major calculation modules are required, namely the BMS module and the battery temperature rise speed calculation module. The battery temperature rise calculation module can calculate the corresponding Tp and the corresponding estimated charging current I when the temperature rise speed of the battery cell Δt / t = 0 according to the map of the influence of the battery cell environment on the temperature rise change, and transmit Tp and the calculated estimated charging current I to the BMS module. The BMS module looks up the corresponding charging current threshold in the correspondence table of temperature T and SOC according to Tp and the corresponding charging SOC, and compares the calculated charging current with the charging current threshold, and executes the action of exiting the battery thermal management strategy according to the comparison result; among them, the internal resistance of the battery cell can be obtained from the map of the internal resistance DCR (direct current resistance) of the battery cell, and the cooling power of the battery coolant can be calculated and obtained by the heat calculation module carried away by the battery cooling.

[0113] As can be seen from Figure 4 the content, to implement the corresponding functions in the embodiments of the present invention, three controllers, namely VDC, CSU, and BMS, are also required. The three controllers are controlled by the vehicle controller VCU. VDC is the power controller, mainly controlling the flow rate of the cooling water in the battery circuit. CSU is the air conditioner compressor controller, controlling the relevant parameters during air conditioner operation. BMS is the battery management system, controlling the relevant parameters during battery operation. When the battery temperature rise speed = 0, BMS issues a request to exit the battery thermal management function. After receiving the instruction, CSU stops cooling the battery. After receiving the request to exit the battery thermal management function, VDC turns off the water pump in the battery cooling circuit.

[0114] In an embodiment of the present invention, by responding to the startup operation of the battery thermal management function, the temperature rise rate of the battery is determined; thus, according to the temperature rise rate, the maximum temperature of the battery is determined, and the estimated charging current corresponding to when the battery temperature reaches the maximum temperature is determined; furthermore, after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current corresponding to when the battery temperature reaches the maximum temperature is less than the charging current threshold corresponding to the maximum temperature, the battery thermal management function is turned off, thereby realizing the adaptive control of the start and stop of the battery thermal management function; avoiding the long-term operation of the battery thermal management function from affecting the charging efficiency of the power battery, reducing the overall energy consumption of the battery thermal management function, improving the charging effect of the power battery, and shortening the charging time of the power battery.

[0115] It should be noted that for the method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the embodiments of the present invention are not limited by the described action sequence, because according to the embodiments of the present invention, some steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0116] Referring to Figure 5 , a schematic structural diagram of a vehicle battery thermal management device provided by some embodiments of the present invention is shown, which may specifically include the following modules:

[0117] A temperature rise rate determination module 501, configured to determine the temperature rise rate of the battery in response to the startup operation of the battery thermal management function;

[0118] An estimated charging current determination module 502, configured to determine the maximum temperature of the battery according to the temperature rise rate, and determine the estimated charging current corresponding to when the battery temperature reaches the maximum temperature;

[0119] A battery thermal management function shutdown module 503, configured to turn off the battery thermal management function after the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than the charging current threshold corresponding to the maximum temperature.

[0120] In some embodiments of the present invention, the device further includes:

[0121] A charging current threshold determination sub-module, configured to determine the state of charge of the battery, and determine the charging current threshold according to the state of charge and the maximum temperature.

[0122] In some embodiments of the present invention, the estimated charging current determination module 502 includes:

[0123] A parameter determination sub-module, configured to determine the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single battery cells of the battery, and the internal resistance of a single battery cell of the battery;

[0124] A charging current determination sub-module, configured to determine a predicted charging current corresponding to when the battery temperature reaches the maximum temperature value according to the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single battery cells of the battery, and the internal resistance of a single battery cell of the battery.

[0125] In some embodiments of the present invention, the parameter determination sub-module includes:

[0126] A heat exchange power determination unit, configured to determine the specific heat capacity of the battery cell of the battery and the mass of a single battery cell of the battery, and determine the heat exchange power between the battery and the environment according to the temperature rise rate of the battery, the number of single battery cells of the battery, the specific heat capacity of the battery cell of the battery, and the mass of a single battery cell of the battery.

[0127] In some embodiments of the present invention, the parameter determination sub-module includes:

[0128] A cooling power determination unit of the battery coolant, configured to determine the specific heat capacity of the coolant, the density of the coolant, and the volume flow rate of the coolant, and determine the cooling power of the battery coolant according to the specific heat capacity of the coolant, the density of the coolant, and the volume flow rate of the coolant.

[0129] In some embodiments of the present invention, the predicted charging current determination module 502 includes:

[0130] A maximum temperature value determination sub-module, configured to determine the temperature value of the battery corresponding to when the temperature rise rate is zero as the maximum temperature value of the battery.

[0131] In some embodiments of the present invention, the device further includes:

[0132] A battery thermal management function activation module, configured to determine the real-time highest temperature value of the battery, and activate the battery thermal management function when the real-time highest temperature value of the battery is greater than a preset temperature threshold.

[0133] Some embodiments of the present invention further provide an electronic device, which may include a processor, a memory, and a computer program stored on the memory and capable of running on the processor. When the computer program is executed by the processor, the above vehicle battery thermal management method is implemented.

[0134] Some embodiments of the present invention also provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the above vehicle battery thermal management method is implemented.

[0135] Some embodiments of the present invention also provide a computer program product, including a computer program which, when executed by a processor, implements the above vehicle battery thermal management method.

[0136] For the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference may be made to the partial description of the method embodiments.

[0137] Each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference may be made to each other.

[0138] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a device, or a computer program product. Therefore, the embodiments of the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0139] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0140] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal devices to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0141] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable terminal device provide for implementing the steps in a process Figure 1 a process or multiple processes and / or blocks Figure 1 steps of the functions specified in a block or multiple blocks.

[0142] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

[0143] Finally, it should also be noted that in this article, relational terms such as first and second 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 term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or terminal device comprising the above elements.

[0144] The above provides a detailed introduction to a vehicle battery thermal management method and device, an electronic device, and a storage medium. Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A vehicle battery thermal management method, characterized in that: The method comprises: In response to a start-up operation of the battery thermal management function, determining a temperature rise rate of the battery; Determining a maximum temperature of the battery according to the heating rate, and determining an estimated charging current corresponding to when the battery temperature reaches the maximum temperature; After the actual charging current of the battery reaches the maximum charging current of the battery and the estimated charging current is less than the charging current threshold corresponding to the maximum temperature, the battery thermal management function is turned off.

2. The method according to claim 1, characterized in that After the actual charging current of the battery reaches the maximum charging current of the battery, and when the estimated charging current is less than the charging current threshold corresponding to the maximum temperature, before shutting down the battery thermal management function, the method further includes: The state of charge of the battery is determined, and the charging current threshold is determined according to the state of charge and the maximum temperature.

3. The method according to claim 1, characterized in that: The determining the estimated charging current corresponding to when the battery temperature reaches the maximum temperature includes: Determining the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single cells of the battery, and the internal resistance of a single cell of the battery; Determine an estimated charging current corresponding to when the battery temperature reaches the maximum temperature according to the heat exchange power between the battery and the environment, the cooling power of the battery coolant, the number of single cells of the battery, and the internal resistance of the single cells of the battery.

4. The method according to claim 3, characterized in that The heat exchange power between the battery and the environment is determined by the following method: Determine the specific heat capacity of the battery cell and the mass of a single battery cell of the battery, and determine the heat exchange power between the battery and the environment according to the heating rate of the battery, the number of single batteries of the battery, the specific heat capacity of the battery cell and the mass of a single battery cell of the battery.

5. The method according to claim 3, characterized in that: The cooling power of the battery coolant is determined by the following method: The specific heat capacity of the coolant, the density of the coolant, and the volume flow rate of the coolant are determined, and the cooling power of the battery coolant is determined according to the specific heat capacity of the coolant, the density of the coolant, and the volume flow rate of the coolant.

6. The method according to claim 1, characterized in that Determining the maximum temperature of the battery according to the heating rate includes: The temperature value of the battery corresponding to when the heating rate is zero is determined as the maximum temperature of the battery.

7. The method according to claim 1, characterized in that Before determining the temperature rise rate of the battery in response to the start-up operation of the battery thermal management function, the method further includes: The real-time maximum temperature value of the battery is determined, and when the real-time maximum temperature value of the battery is greater than a preset temperature threshold, the battery thermal management function is started.

8. A vehicle battery thermal management device, characterized in that: The device comprises: a temperature rise rate determination module, configured to determine a temperature rise rate of the battery in response to a start-up operation of the battery thermal management function; an estimated charging current determination module, used to determine the maximum temperature of the battery according to the heating rate, and determine the estimated charging current corresponding to when the battery temperature reaches the maximum temperature; The battery thermal management function shutoff module is used to shut down the battery thermal management function after the actual charging current of the battery reaches the maximum charging current of the battery and the estimated charging current is less than the charging current threshold corresponding to the maximum temperature.

9. An electronic device, characterized in that: The invention comprises a processor, a memory and a computer program stored in the memory and capable of running on the processor, wherein when the computer program is executed by the processor, the vehicle battery thermal management method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the vehicle battery thermal management method according to any one of claims 1 to 7 is implemented.

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