Method for determining, method for allocating, system for determining and architecture for allocating cold demand

Abstract

The application provides a cold demand determination method, a cold demand allocation method, a cold demand determination system and a cold demand allocation architecture. The maximum charging cold demand, i.e. the first cold demand, of a power battery is determined according to the initial state and the final state of the power battery and the first charging rate, i.e. the theoretical average charging rate of the power battery during the charging process. The first coefficient is determined according to the first charging rate, the second charging rate, i.e. the actual charging rate of the power battery during the charging process, the third charging rate, i.e. the theoretical charging rate of the power battery in different states, and the ratio of the second charging rate duration to the total charging time. Finally, the actual cold demand, i.e. the second cold demand, of the power battery during the charging process is determined according to the first coefficient and the first cold demand. The sum of the second cold demand and the actual refrigeration demand, i.e. the first refrigeration demand, of the passenger cabin is compared with the refrigeration capacity, i.e. the first refrigeration capacity, of the refrigeration system, and the cold is allocated to the power battery and the passenger cabin according to the comparison result.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle charging, and more particularly to a method for determining and allocating cooling demand, a system for determining cooling demand, and an allocation architecture. Background Technology

[0002] As the fast charging power of power batteries increases, the cooling requirements of power batteries also increase, posing a challenge to meeting the overall vehicle cooling capacity and other cooling needs during fast charging.

[0003] Existing technologies typically determine the cooling requirements of a power battery based on the maximum fast charging rate measured by the fast charging meter and a fixed state of charge (SOC) range. Therefore, in actual operating conditions, this cooling requirement is set to a fixed value.

[0004] The problem with the existing technology is that when the actual charging rate of the power battery is small, i.e. the cooling demand is small, while the cooling demand of the passenger cabin is large, if the power battery is still cooled according to the set fixed cooling demand, the power battery will determine an excessive amount of cooling capacity, while the passenger cabin will not be able to determine the required amount of cooling capacity, so that the cooling capacity of the air conditioning system cannot be reasonably allocated to the system that needs it.

[0005] Therefore, there is a need for a method that can determine the cooling requirements of the power battery based on its actual charging rate, and then allocate cooling capacity reasonably based on the determined cooling requirements. Summary of the Invention

[0006] This invention provides a method for determining cooling demand, a method for allocating cooling demand, a system for determining cooling demand, and an allocation architecture, so as to determine the actual cooling demand of the power battery based on the actual charging rate of the power battery, and to allocate cooling demand reasonably based on the actual cooling demand and the actual cooling demand of the passenger compartment.

[0007] According to a first aspect of the present invention, a method for determining cooling demand is provided for determining the actual cooling demand of a power battery in an electric vehicle during the charging process, the method comprising:

[0008] The initial state and final state of the power battery are obtained; wherein the initial state includes at least the state of charge and temperature of the power battery at the start of charging; and the final state includes at least the state of charge and temperature of the power battery at the end of charging.

[0009] Based on the initial state, the final state, and the first charging rate, a first cooling requirement is obtained; wherein, the first charging rate is used to characterize the theoretical average charging rate of the power battery during the charging process; and the first cooling requirement is used to characterize the maximum charging cooling requirement of the power battery.

[0010] Obtain the second charging rate of the power battery; wherein the second charging rate is used to characterize the actual charging rate of the power battery during the charging process;

[0011] A first coefficient is obtained based on the first charging rate, the second charging rate, the third charging rate, and the ratio of the duration of the second charging rate to the total charging time; wherein, the third charging rate is used to characterize the theoretical charging rate of the power battery under different states;

[0012] Based on the first coefficient and the first cooling demand, a second cooling demand is obtained; wherein, the second cooling demand is used to characterize the actual cooling demand of the power battery during the charging process.

[0013] Optionally, based on the initial state and the first charging rate, the first cooling requirement of the power battery is obtained, specifically including:

[0014] The average charging current of the power battery during the charging process is obtained; and the heat generation power of the power battery during the charging process is obtained based on the average charging current and the equivalent internal resistance of the power battery.

[0015] The average temperature difference of the power battery before and after charging is obtained; and the heat absorbed by the power battery during the charging process is obtained based on the specific heat capacity of the power battery, the total mass of the power battery and the average temperature difference.

[0016] Obtain the charge difference of the power battery before and after charging; and obtain the cooling time of the power battery based on the charge difference and the first charging rate.

[0017] The first cooling demand is obtained based on the heat generation power, the absorbed heat, the cooling time, and the heat exchange efficiency of the refrigeration system in the electric vehicle.

[0018] Optionally, the formula for calculating the first cooling demand is:

[0019]

[0020] Wherein, Qb0 is used to characterize the first cooling demand; η_cooling is used to characterize the heat exchange efficiency of the refrigeration system in the electric vehicle; Qg0 is used to characterize the heat generation power; Qa0 is used to characterize the absorbed heat; and t_cooling is used to characterize the cooling time.

[0021] Optionally, the formula for calculating the heat generation power is:

[0022] Qg0 = I2 * Rcell;

[0023] Wherein, I is used to characterize the average charging current of the power battery during the charging process; Rcell is used to characterize the equivalent internal resistance of the power battery.

[0024] Optionally, the formula for calculating the average charging current is:

[0025] I = Q * C0 - avg;

[0026] Wherein, Q is used to characterize the rated capacity of the power battery; C0-avg is used to characterize the first charging rate.

[0027] Optionally, the formula for calculating the absorbed heat is:

[0028] Qa0=cp_cell*Mcell*ΔTcell;

[0029] Wherein, cp_cell is used to characterize the specific heat capacity of the power battery; Mcell is used to characterize the total mass of the power battery; and ΔTcell is used to characterize the average temperature difference of the power battery before and after charging.

[0030] Optionally, the formula for calculating the average temperature difference is:

[0031] △Tcell=Tmax_end-Tmax_int-△Tcell_offset;

[0032] Wherein, Tmax_end is used to characterize the highest temperature of the power battery at the end of charging; Tmax_int is used to characterize the highest temperature of the power battery at the beginning of charging; △Tcell_offset is used to characterize the compensation value between the average temperature difference and the highest temperature difference of the power battery before and after charging.

[0033] Optionally, the formula for calculating the cooling time is:

[0034]

[0035] Wherein, △SOC is used to characterize the charge difference of the power battery before and after charging.

[0036] Optionally, the formula for calculating the second cooling demand is:

[0037] Qb1 = k * Qb0;

[0038] Wherein, Qb1 is used to characterize the second cooling demand; k is used to characterize the first coefficient;

[0039] If the change of the first coefficient exceeds the first threshold, the second cooling demand is adjusted according to the formula; if the change of the first coefficient does not exceed the first threshold, the second cooling demand is not adjusted.

[0040] According to a second aspect of the present invention, a cooling capacity allocation method is provided, which determines a second cooling capacity requirement based on the cooling capacity requirement determination method provided by the first aspect and optional solutions of the present invention, and allocates cooling capacity to the passenger compartment and the power battery according to the cooling requirements of the passenger compartment in the electric vehicle and the second cooling capacity requirement. The method includes:

[0041] The heat load in the passenger compartment is obtained, and a first cooling demand is obtained based on the heat load; wherein, the first cooling demand is used to characterize the actual cooling demand of the passenger compartment;

[0042] Determine whether the first cooling demand is equal to zero; if it is equal to zero, allocate cooling capacity to the power battery according to the second cooling capacity demand; if it is not equal to zero,

[0043] Then determine whether the sum of the second cooling demand and the first cooling demand is less than or equal to the first cooling capacity; if yes, then allocate cooling capacity to the power battery according to the second cooling demand and allocate cooling capacity to the passenger cabin according to the first cooling demand; if no,

[0044] Then determine whether the sum of the second cooling demand and the second refrigeration demand is less than or equal to the first refrigeration capacity; if yes, then allocate cooling capacity to the power battery according to the second cooling demand, and allocate cooling capacity to the passenger cabin according to the difference between the first refrigeration capacity and the second cooling demand; if no,

[0045] Then, the cooling capacity is allocated to the passenger cabin according to the second cooling demand, and the cooling capacity is allocated to the power battery according to the difference between the first cooling capacity and the second cooling demand;

[0046] The second cooling requirement is used to characterize the minimum cooling requirement of the passenger cabin;

[0047] The first cooling capacity is used to characterize the cooling capacity of the cooling system inside the electric vehicle.

[0048] Optionally, the cooling capacity distribution method further includes: detecting whether the cooling capacity distribution task has been completed; if not, adjusting the refrigeration system that distributes the cooling capacity so that it can complete the cooling capacity distribution task.

[0049] According to a third aspect of the present invention, a system for determining cooling demand is provided for implementing the method for determining cooling demand provided by the first aspect and optional embodiments of the present invention. The system includes:

[0050] The battery management module is used to acquire and output the initial state and final state of the power battery, and is also used to acquire and output the first charging rate, the second charging rate and the third charging rate of the power battery.

[0051] A cooling capacity management unit is coupled to the battery management module; the cooling capacity management unit is used to calculate a first cooling capacity requirement based on the initial state, the final state, and the first charging rate; it is also used to calculate a first coefficient based on the first charging rate, the second charging rate, the third charging rate, the initial state, and the final state; it is also used to calculate a second cooling capacity requirement based on the first coefficient and the first cooling capacity requirement.

[0052] Optionally, the cooling capacity management unit includes a TMU.

[0053] Optionally, the cooling capacity management unit includes a VCU.

[0054] According to a fourth aspect of the present invention, a cooling capacity allocation architecture is provided for implementing the cooling capacity allocation method provided by the second aspect and optional solutions of the present invention. The architecture includes a cooling capacity demand determination system and a corresponding refrigeration system provided by the third aspect and optional solutions of the present invention.

[0055] The cooling demand determination system is also used to calculate the first cooling demand based on the heat load of the passenger cabin; it is also used to analyze the cooling distribution of the passenger cabin and the power battery based on the second cooling demand, the first cooling demand, the second cooling demand, and the first cooling capacity of the cooling system, and output the first control signal, the second control signal, the third control signal, and the fourth control signal.

[0056] If the first cooling demand is equal to zero, the cooling demand determination system outputs a first control signal.

[0057] If the first cooling demand is greater than zero, and the sum of the first cooling demand and the second cooling capacity demand is less than or equal to the first cooling capacity, then the cooling capacity demand determination system outputs a second control signal.

[0058] If the sum of the first cooling demand and the second cooling capacity demand is greater than the first cooling capacity, and the sum of the second cooling demand and the second cooling capacity demand is less than or equal to the first cooling capacity, then the cooling capacity demand determination system outputs a third control signal.

[0059] If the sum of the first cooling demand and the second cooling capacity demand is greater than the first cooling capacity, and the sum of the second cooling demand and the second cooling capacity demand is greater than the first cooling capacity, then the cooling capacity demand determination system outputs a fourth control signal.

[0060] The refrigeration system is coupled to the cooling demand determination system, and the refrigeration system is used to distribute cooling capacity to the passenger cabin and the power battery according to the first control signal, the second control signal, the third control signal and the fourth control signal;

[0061] If the refrigeration system receives the first control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement;

[0062] If the refrigeration system receives the second control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement, and allocates cooling capacity to the passenger cabin according to the first cooling capacity requirement;

[0063] If the refrigeration system receives the third control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement, and allocates cooling capacity to the passenger cabin according to the difference between the first cooling capacity and the second cooling capacity requirement;

[0064] If the refrigeration system receives the fourth control signal, the refrigeration system allocates cooling capacity to the passenger cabin according to the second cooling demand, and allocates cooling capacity to the power battery according to the difference between the first cooling capacity and the second cooling demand.

[0065] Optionally, the refrigeration system includes an air conditioning system.

[0066] Optionally, the cooling capacity distribution architecture further includes a detection module; the detection module is coupled to the passenger compartment, the power battery, and the refrigeration system respectively; the detection module is used to detect whether the cooling capacity distribution task is completed; if not, the detection module adjusts the refrigeration system so that the refrigeration system can complete the cooling capacity distribution task.

[0067] According to a fifth aspect of the present invention, an electric vehicle is provided, including the cooling distribution architecture provided by the fourth aspect and alternatives of the present invention.

[0068] The present invention provides a method, allocation method, system, and allocation architecture for determining cooling demand. It determines the maximum charging cooling demand of the power battery (i.e., the first cooling demand) based on the initial state, final state, and the theoretical average charging rate (i.e., the first charging rate) of the power battery during charging. The method then determines a first coefficient based on the first charging rate, the actual charging rate (i.e., the second charging rate) of the power battery during charging, the theoretical charging rate (i.e., the third charging rate) of the power battery in different states, and the initial and final states. Finally, based on the first coefficient and the first cooling demand, the actual cooling demand of the power battery during charging (i.e., the second cooling demand) is determined. After determining the second cooling demand, the actual cooling demand of the passenger compartment (i.e., the first cooling demand) is determined. The second cooling demand and the first cooling demand are then compared with the cooling capacity (i.e., the first cooling capacity) of the refrigeration system, and cooling demand is allocated between the power battery and the passenger compartment based on the comparison result. The cooling demand allocation method developed by the present invention, based on the actual cooling demand of the power battery and the actual cooling demand of the passenger compartment, can rationally allocate cooling demand according to their respective needs, thus avoiding uneven cooling distribution. Attached Figure Description

[0069] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0070] Figure 1 A flowchart illustrating the method for determining cooling requirements provided in an embodiment of the present invention;

[0071] Figure 2 A flowchart for determining the first cooling capacity requirement provided in an embodiment of the present invention;

[0072] Figure 3 A flowchart of a cooling capacity distribution method provided in an embodiment of the present invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments determined by those skilled in the art without creative effort are within the scope of protection of the present invention. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0074] Please refer to Figure 1 This invention provides a method for determining cooling requirements, used to determine the actual cooling requirements of a power battery in an electric vehicle during the charging process. The method includes:

[0075] S1: Obtain the initial state and final state of the power battery; wherein, the initial state includes at least the state of charge and temperature of the power battery at the start of charging; and the final state includes at least the state of charge and temperature of the power battery at the end of charging.

[0076] S2: Based on the initial state, the final state, and the first charging rate, a first cooling requirement is obtained; wherein, the first charging rate is used to characterize the theoretical average charging rate of the power battery during the charging process; the first cooling requirement is used to characterize the maximum charging cooling requirement of the power battery.

[0077] S3: Obtain the second charging rate of the power battery; wherein, the second charging rate is used to characterize the actual charging rate of the power battery during the charging process;

[0078] S4: Based on the first charging rate, the second charging rate, the third charging rate, and the ratio of the duration of the second charging rate to the total charging time, a first coefficient is obtained; wherein, the third charging rate is used to characterize the theoretical charging rate of the power battery under different states;

[0079] S5: Based on the first coefficient and the first cooling demand, a second cooling demand is obtained; wherein, the second cooling demand is used to characterize the actual cooling demand of the power battery during the charging process.

[0080] This invention, through the above-described technical solution, adjusts the cooling requirements of a power battery in real time according to different states of the battery. These states include the battery's temperature, state of charge (SOC), and actual charging rate. The principle is as follows: This invention determines the maximum cooling requirement of the power battery, i.e., the first cooling requirement, based on the initial state, final state, and the theoretical average charging rate (first charging rate) of the power battery during charging. Then, a first coefficient is determined based on the first charging rate, the actual charging rate (second charging rate) of the power battery during charging, the theoretical charging rate (third charging rate) corresponding to different states of the power battery, and the initial and final states. Finally, the actual cooling requirement of the power battery, i.e., the second cooling requirement, is obtained based on the first coefficient and the first cooling requirement.

[0081] Please refer to Figure 2 In one specific implementation, S2 obtains the first cooling demand based on the initial state, the final state, and the first charging rate, specifically including:

[0082] S21: Obtain the average charging current of the power battery during the charging process; and obtain the heat generation power of the power battery during the charging process based on the average charging current and the equivalent internal resistance of the power battery.

[0083] S22: Obtain the average temperature difference of the power battery before and after charging; and obtain the heat absorbed by the power battery during the charging process based on the specific heat capacity of the power battery, the total mass of the power battery and the average temperature difference.

[0084] S23: Obtain the charge difference of the power battery before and after charging; and obtain the cooling time of the power battery based on the charge difference and the first charging rate.

[0085] S24: The first cooling demand is obtained based on the heat generation power, the absorbed heat, the cooling time, and the heat exchange efficiency of the refrigeration system in the electric vehicle.

[0086] As one specific implementation method, the calculation formula for the first cooling capacity requirement in S24 is as follows:

[0087]

[0088] Wherein, Qb0 is used to characterize the first cooling demand; η_cooling is used to characterize the heat exchange efficiency of the refrigeration system in the electric vehicle; Qg0 is used to characterize the heat generation power; Qa0 is used to characterize the absorbed heat; and t_cooling is used to characterize the cooling time.

[0089] As one specific implementation method, the calculation formula for the heat generation power in S21 is as follows:

[0090] Qg0 = I² * Rcell; where I represents the average charging current of the power battery during charging; and Rcell represents the equivalent internal resistance of the power battery.

[0091] The formula for calculating the average charging current is: I = Q * C0avg; where Q represents the rated capacity of the power battery; and C0avg represents the first charging rate.

[0092] As one specific implementation method, the formula for calculating the absorbed heat in S22 is as follows:

[0093] Qa0 = cp_cell * Mcell * ΔTcell; where cp_cell represents the specific heat capacity of the power battery; Mcell represents the total mass of the power battery; and ΔTcell represents the average temperature difference of the power battery before and after charging.

[0094] The formula for calculating the average temperature difference is: △Tcell=Tmax_end-Tmax_int-△Tcell_offset; where Tmax_end is used to characterize the highest temperature of the power battery at the end of charging; Tmax_int is used to characterize the highest temperature of the power battery at the beginning of charging; and △Tcell_offset is used to characterize the compensation value between the average temperature difference and the highest temperature difference of the power battery before and after charging.

[0095] As one specific implementation method, the formula for calculating the cooling time in S23 is as follows:

[0096] Wherein, △SOC is used to characterize the charge difference of the power battery before and after charging.

[0097] As one specific implementation method, the formula for calculating the second cooling capacity requirement in S5 is:

[0098] Qb1 = k * Qb0; where Qb1 represents the second cooling demand; k represents the first coefficient. Specifically, the second cooling demand is adjusted according to the change of the first coefficient, which is related to the ratio between the difference between the third charging rate and the second charging rate and the first charging rate, and to the ratio between the difference in state of charge of the power battery before and after charging and the set charging range of the power battery. When the actual charging rate of the power battery changes, it will cause a change in the first coefficient, which in turn will cause a change in the actual cooling demand of the power battery. Therefore, the first coefficient is updated periodically to achieve real-time adjustment of the actual cooling demand of the power battery, i.e., the second cooling demand. The periodicity here can be 5 seconds or 10 seconds, and the specific value can be adjusted according to the demand, which is not limited here. To avoid frequent adjustments to the second cooling demand interfering with subsequent cooling allocation strategies, this embodiment of the invention establishes a first threshold. The second cooling demand is only adjusted when the change in the first coefficient exceeds the first threshold. Here, the first threshold can be set to 10% or 5%, and the specific value can be adjusted according to the demand, without limitation.

[0099] As a supplementary explanation, another method for determining the second cooling capacity requirement is provided.

[0100] U1: Determine the first cooling capacity requirement.

[0101] U2: Determine the fourth charging rate; wherein the fourth charging rate is used to characterize the actual average charging rate of the power battery during the charging process.

[0102] U3: Determine the second cooling demand based on the first cooling demand, the fourth charging rate, and the first charging rate.

[0103] The formula for calculating the fourth charging rate in U2 is as follows:

[0104] Wherein, Cavg is used to characterize the fourth charging rate; C1-Cn are used to characterize the different charging rates experienced by the power battery during the charging process; △SOC1-△SOCn are used to characterize the charge range corresponding to the different charging rates experienced by the power battery during the charging process; for example, △SOC1 is used to characterize the charge range of the power battery when charged with C1; △SOC0 is used to characterize the difference between the charge of the power battery at the start of charging and the charge at the preset end of charging.

[0105] The formula for calculating the second cooling demand in U2 is as follows:

[0106] Qb1≈(Cavg / C0avg)*Qb0. The adjustment method for the second cooling capacity requirement is the same as described above and will not be repeated here.

[0107] Please refer to Figure 3 This invention also provides a cooling capacity allocation method, which determines a second cooling capacity requirement based on the cooling capacity requirement determination method, and allocates cooling capacity to the passenger compartment and the power battery according to the cooling requirements of the passenger compartment in the electric vehicle and the second cooling capacity requirement. The method includes:

[0108] Q1: Obtain the heat load in the passenger cabin and obtain the first cooling demand based on the heat load; wherein the first cooling demand is used to characterize the actual cooling demand of the passenger cabin.

[0109] Q2: Determine if the first cooling demand is equal to zero; if it is equal to zero, jump to Q3; if it is not equal to zero, jump to Q4.

[0110] Q3: Allocate cooling capacity to the power battery according to the second cooling capacity requirement.

[0111] Q4: Determine whether the sum of the second cooling demand and the first cooling demand is less than or equal to the first cooling capacity; if yes, proceed to Q5; if no, proceed to Q6.

[0112] Q5: Allocate cooling capacity to the power battery according to the second cooling capacity requirement, and allocate cooling capacity to the passenger cabin according to the first cooling capacity requirement.

[0113] Q6: Determine whether the sum of the second cooling demand and the second refrigeration demand is less than or equal to the first refrigeration capacity; if yes, proceed to Q7; if no, proceed to Q8.

[0114] Q7: Allocate cooling capacity to the power battery according to the second cooling capacity requirement, and allocate cooling capacity to the passenger cabin according to the difference between the first cooling capacity and the second cooling capacity requirement.

[0115] Q8: Allocate cooling capacity to the passenger cabin according to the second cooling requirement, and allocate cooling capacity to the power battery according to the difference between the first cooling capacity and the second cooling requirement.

[0116] The second cooling requirement is used to characterize the minimum cooling requirement of the passenger cabin;

[0117] The first cooling capacity is used to characterize the cooling capacity of the cooling system inside the electric vehicle.

[0118] The embodiments of the present invention, based on the above technical solution, achieve a reasonable distribution of cooling capacity. The principle is as follows:

[0119] Because the initial design determined that the cooling capacity of the refrigeration system, i.e., the first cooling capacity, must be greater than the maximum cooling capacity requirement for charging the power battery, i.e., the first cooling capacity requirement, the vehicle's refrigeration system will meet all the cooling capacity requirements of the power battery when only the power battery has a cooling requirement.

[0120] When both the power battery and the passenger cabin have cooling requirements, the sum of the second cooling demand and the actual cooling demand of the passenger cabin (i.e., the first cooling energy demand) is compared with the first cooling capacity. If the sum of the two is less than or equal to the first cooling capacity, it indicates that the cooling capacity of the cooling system can simultaneously meet the cooling needs of the power battery and the passenger cabin, and then the cooling capacity is allocated according to the needs of both.

[0121] If the sum of the two is greater than the first cooling capacity, it indicates that the cooling capacity of the refrigeration system cannot simultaneously meet the cooling needs of the power battery and the passenger compartment. Therefore, the sum of the second cooling demand and the minimum cooling demand of the passenger compartment (i.e., the second cooling demand) needs to be compared with the first cooling capacity. If the sum is less than or equal to the first cooling capacity, it indicates that although the first cooling capacity cannot simultaneously meet the second cooling demand and the first cooling demand, it can simultaneously meet the second cooling demand and the minimum cooling demand of the passenger compartment (i.e., the second cooling demand). In this case, the second cooling demand of the power battery is prioritized, and the remaining cooling capacity is allocated to the passenger compartment. If the sum is greater than the first cooling capacity, it indicates that the first cooling capacity cannot even simultaneously meet the second cooling demand and the second cooling demand. In this case, the second cooling demand of the passenger compartment is prioritized, and the remaining cooling capacity is allocated to the power battery.

[0122] As one specific implementation, the cooling capacity distribution method further includes: Q9: detecting whether the cooling capacity distribution task has been completed; if not completed, adjusting the refrigeration system for distributing cooling capacity so that it can complete the cooling capacity distribution task.

[0123] This invention also provides a system for determining cooling demand, used to implement the method for determining cooling demand. The system includes:

[0124] The battery management module is used to acquire and output the initial state and final state of the power battery, and is also used to acquire and output the first charging rate, the second charging rate and the third charging rate of the power battery.

[0125] A cooling capacity management unit is coupled to the battery management module; the cooling capacity management unit is used to calculate a first cooling capacity requirement based on the initial state, the final state, and the first charging rate; it is also used to calculate a first coefficient based on the first charging rate, the second charging rate, the third charging rate, the initial state, and the final state; it is also used to calculate a second cooling capacity requirement based on the first coefficient and the first cooling capacity requirement.

[0126] In one specific implementation, the cooling capacity management unit includes a TMU. Of course, the cooling capacity management unit may also include a VCU, and this is not a limitation.

[0127] This invention also provides a cooling capacity allocation architecture for implementing the cooling capacity allocation method. The architecture includes a cooling capacity demand determination system and a corresponding refrigeration system.

[0128] The cooling demand determination system is also used to calculate the first cooling demand based on the heat load of the passenger cabin; it is also used to analyze the cooling distribution of the passenger cabin and the power battery based on the second cooling demand, the first cooling demand, the second cooling demand, and the first cooling capacity of the cooling system, and output the first control signal, the second control signal, the third control signal, and the fourth control signal.

[0129] If the first cooling demand is equal to zero, the cooling demand determination system outputs a first control signal.

[0130] If the first cooling demand is greater than zero, and the sum of the first cooling demand and the second cooling capacity demand is less than or equal to the first cooling capacity, then the cooling capacity demand determination system outputs a second control signal.

[0131] If the sum of the first cooling demand and the second cooling capacity demand is greater than the first cooling capacity, and the sum of the second cooling demand and the second cooling capacity demand is less than or equal to the first cooling capacity, then the cooling capacity demand determination system outputs a third control signal.

[0132] If the sum of the first cooling demand and the second cooling capacity demand is greater than the first cooling capacity, and the sum of the second cooling demand and the second cooling capacity demand is greater than the first cooling capacity, then the cooling capacity demand determination system outputs a fourth control signal.

[0133] The refrigeration system is coupled to the cooling demand determination system, and the refrigeration system is used to distribute cooling capacity to the passenger cabin and the power battery according to the first control signal, the second control signal, the third control signal and the fourth control signal;

[0134] If the refrigeration system receives the first control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement;

[0135] If the refrigeration system receives the second control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement, and allocates cooling capacity to the passenger cabin according to the first cooling capacity requirement;

[0136] If the refrigeration system receives the third control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement, and allocates cooling capacity to the passenger cabin according to the difference between the first cooling capacity and the second cooling capacity requirement;

[0137] If the refrigeration system receives the fourth control signal, the refrigeration system allocates cooling capacity to the passenger cabin according to the second cooling demand, and allocates cooling capacity to the power battery according to the difference between the first cooling capacity and the second cooling demand.

[0138] In one specific implementation, the refrigeration system includes an air conditioning system.

[0139] In one specific implementation, the cooling capacity distribution architecture further includes a detection module. This detection module is coupled to the passenger compartment, the power battery, and the refrigeration system. The detection module detects whether the cooling capacity distribution task has been completed. If not, the detection module adjusts the refrigeration system to enable it to complete the cooling capacity distribution task. Specifically, the detection module may be an MCU, a computer, or other digital processing chip, which is not limited here. The objects being adjusted include the air conditioning system's compressor, electronic expansion valve, solenoid valve, water pump, etc., which are not limited here. The adjustment method is specifically PID control.

[0140] The present invention also provides an electric vehicle including the aforementioned cooling distribution architecture.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining cooling demand, used to determine the actual cooling demand of a power battery in an electric vehicle during the charging process, characterized in that, The method includes: The initial state and final state of the power battery are obtained; wherein the initial state includes at least the state of charge and temperature of the power battery at the start of charging; and the final state includes at least the state of charge and temperature of the power battery at the end of charging. Based on the initial state, the final state, and the first charging rate, a first cooling requirement is obtained; wherein, the first charging rate is used to characterize the theoretical average charging rate of the power battery during the charging process; and the first cooling requirement is used to characterize the maximum charging cooling requirement of the power battery. Obtain the second charging rate of the power battery; wherein the second charging rate is used to characterize the actual charging rate of the power battery during the charging process; A first coefficient is obtained based on the first charging rate, the second charging rate, the third charging rate, and the ratio of the duration of the second charging rate to the total charging time; wherein, the third charging rate is used to characterize the theoretical charging rate of the power battery under different states; Based on the first coefficient and the first cooling demand, a second cooling demand is obtained; wherein, the second cooling demand is used to characterize the actual cooling demand of the power battery during the charging process.

2. The method for determining cooling demand according to claim 1, characterized in that, Based on the initial state and the first charging rate, the first cooling requirement of the power battery is obtained, specifically including: The average charging current of the power battery during the charging process is obtained; and the heat generation power of the power battery during the charging process is obtained based on the average charging current and the equivalent internal resistance of the power battery. The average temperature difference of the power battery before and after charging is obtained; and the heat absorbed by the power battery during the charging process is obtained based on the specific heat capacity of the power battery, the total mass of the power battery and the average temperature difference. Obtain the charge difference of the power battery before and after charging; and obtain the cooling time of the power battery based on the charge difference and the first charging rate. The first cooling demand is obtained based on the heat generation power, the absorbed heat, the cooling time, and the heat exchange efficiency of the refrigeration system in the electric vehicle.

3. The method for determining cooling demand according to claim 2, characterized in that, The formula for calculating the first cooling demand is: ）； in, Used to characterize the first cooling demand; Used to characterize the heat exchange efficiency of the refrigeration system inside the electric vehicle; Used to characterize the heat generation power; Used to characterize the absorbed heat; Used to characterize the cooling time.

4. The method for determining cooling demand according to claim 2, characterized in that, The formula for calculating the heat generation power is: ； Wherein, I is used to characterize the average charging current of the power battery during the charging process; Used to characterize the equivalent internal resistance of the power battery.

5. The method for determining cooling demand according to claim 4, characterized in that, The formula for calculating the average charging current is: I = Q * C0 - avg; Wherein, Q is used to characterize the rated capacity of the power battery; C0-avg is used to characterize the first charging rate.

6. The method for determining cooling demand according to claim 2, characterized in that, The formula for calculating the absorbed heat is: ； in, Used to characterize the specific heat capacity of the power battery; Used to characterize the total mass of the power battery; Used to characterize the average temperature difference of the power battery before and after charging.

7. The method for determining cooling demand according to claim 6, characterized in that, The formula for calculating the average temperature difference is: ； in, Used to characterize the highest temperature of the power battery at the end of charging; Used to characterize the highest temperature of the power battery at the start of charging; This is used to characterize the compensation value between the average temperature difference and the maximum temperature difference of the power battery before and after charging.

8. The method for determining cooling demand according to claim 5, characterized in that, The formula for calculating the cooling time is: ； in, Used to characterize the charge difference of the power battery before and after charging.

9. The method for determining cooling demand according to claim 1, characterized in that, The formula for calculating the second cooling capacity requirement is: Qb1 = k * Qb0; Wherein, Qb1 is used to characterize the second cooling demand; k is used to characterize the first coefficient; If the change of the first coefficient exceeds the first threshold, the second cooling demand is adjusted according to the formula; if the change of the first coefficient does not exceed the first threshold, the second cooling demand is not adjusted.

10. A method for distributing cooling capacity, characterized in that, The method for determining cooling demand according to any one of claims 1 to 9 determines a second cooling demand, and allocates cooling capacity between the passenger compartment and the power battery based on the cooling demand of the passenger compartment in the electric vehicle and the second cooling demand, the method comprising: The heat load in the passenger compartment is obtained, and a first cooling demand is obtained based on the heat load; wherein, the first cooling demand is used to characterize the actual cooling demand of the passenger compartment; Determine whether the first cooling demand is equal to zero; if it is equal to zero, allocate cooling capacity to the power battery according to the second cooling capacity demand; if it is not equal to zero, Then determine whether the sum of the second cooling demand and the first cooling demand is less than or equal to the first cooling capacity; if yes, then allocate cooling capacity to the power battery according to the second cooling demand and allocate cooling capacity to the passenger cabin according to the first cooling demand; if no, Then determine whether the sum of the second cooling demand and the second refrigeration demand is less than or equal to the first refrigeration capacity; if yes, then allocate cooling capacity to the power battery according to the second cooling demand, and allocate cooling capacity to the passenger cabin according to the difference between the first refrigeration capacity and the second cooling demand; if no, Then, the cooling capacity is allocated to the passenger cabin according to the second cooling demand, and the cooling capacity is allocated to the power battery according to the difference between the first cooling capacity and the second cooling demand; The second cooling requirement is used to characterize the minimum cooling requirement of the passenger cabin; The first cooling capacity is used to characterize the cooling capacity of the cooling system inside the electric vehicle.

11. The cold energy distribution method according to claim 10, characterized in that, The cooling capacity distribution method further includes: detecting whether the cooling capacity distribution task has been completed; if not, adjusting the cooling system to distribute the cooling capacity so that it can complete the cooling capacity distribution task.

12. A system for determining cooling demand, used to implement the method for determining cooling demand according to any one of claims 1 to 9, characterized in that, The system includes: The battery management module is used to acquire and output the initial state and final state of the power battery, and also to acquire and output the first charging rate, the second charging rate and the third charging rate of the power battery. A cooling capacity management unit is coupled to the battery management module; the cooling capacity management unit is used to calculate a first cooling capacity requirement based on the initial state, the final state, and the first charging rate; it is also used to calculate a first coefficient based on the first charging rate, the second charging rate, the third charging rate, the initial state, and the final state; it is also used to calculate a second cooling capacity requirement based on the first coefficient and the first cooling capacity requirement.

13. The system for determining cooling demand according to claim 12, characterized in that, The cooling capacity management unit includes a TMU.

14. The system for determining cooling demand according to claim 12, characterized in that, The cooling capacity management unit includes a VCU.

15. A cooling capacity distribution architecture for implementing the cooling capacity distribution method of claim 10 or 11, characterized in that, The architecture includes the system for determining cooling demand as described in any one of claims 12 to 14 and the corresponding refrigeration system: The cooling demand determination system is also used to calculate the first cooling demand based on the heat load of the passenger cabin; it is also used to analyze the cooling distribution of the passenger cabin and the power battery based on the second cooling demand, the first cooling demand, the second cooling demand, and the first cooling capacity of the cooling system, and output the first control signal, the second control signal, the third control signal, and the fourth control signal. If the first cooling demand is equal to zero, the cooling demand determination system outputs a first control signal. If the first cooling demand is greater than zero, and the sum of the first cooling demand and the second cooling capacity demand is less than or equal to the first cooling capacity, then the cooling capacity demand determination system outputs a second control signal. If the sum of the first cooling demand and the second cooling capacity demand is greater than the first cooling capacity, and the sum of the second cooling demand and the second cooling capacity demand is less than or equal to the first cooling capacity, then the cooling capacity demand determination system outputs a third control signal. If the sum of the first cooling demand and the second cooling capacity demand is greater than the first cooling capacity, and the sum of the second cooling demand and the second cooling capacity demand is greater than the first cooling capacity, then the cooling capacity demand determination system outputs a fourth control signal. The refrigeration system is coupled to the cooling demand determination system, and the refrigeration system is used to distribute cooling capacity to the passenger cabin and the power battery according to the first control signal, the second control signal, the third control signal and the fourth control signal; If the refrigeration system receives the first control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement; If the refrigeration system receives the second control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement, and allocates cooling capacity to the passenger cabin according to the first cooling capacity requirement; If the refrigeration system receives the third control signal, the refrigeration system allocates cooling capacity to the power battery according to the second cooling capacity requirement, and allocates cooling capacity to the passenger cabin according to the difference between the first cooling capacity and the second cooling capacity requirement; If the refrigeration system receives the fourth control signal, the refrigeration system allocates cooling capacity to the passenger cabin according to the second cooling demand, and allocates cooling capacity to the power battery according to the difference between the first cooling capacity and the second cooling demand.

16. The cooling capacity distribution architecture according to claim 15, characterized in that, The refrigeration system includes an air conditioning system.

17. The cooling capacity distribution architecture according to claim 15, characterized in that, The cooling capacity distribution architecture also includes a detection module; the detection module is coupled to the passenger cabin, the power battery, and the refrigeration system respectively; the detection module is used to detect whether the cooling capacity distribution task has been completed; if not, the detection module adjusts the refrigeration system so that the refrigeration system can complete the cooling capacity distribution task.

18. An electric vehicle, characterized in that, Includes the cooling capacity distribution architecture as described in any one of claims 15 to 17.

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