Battery electronic expansion valve control method and device, vehicle thermal management system and automobile

Abstract

The application relates to a battery electronic expansion valve control method and device, a vehicle thermal management system and an automobile. The method comprises the following steps: in the case that a battery and a passenger cabin of a target vehicle are cooled at the same time, obtaining a cooling priority relationship between the battery and the passenger cabin; based on the cooling priority relationship, obtaining an initial opening degree of an electronic expansion valve of the battery, and performing opening degree control based on the initial opening degree; after a cooling system of the target vehicle enters a quasi-steady state operation stage, obtaining an evaporator temperature difference and a battery water inlet temperature difference of the target vehicle; according to the cooling priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, obtaining an opening degree adjustment step length of the electronic expansion valve, and performing opening degree control based on the opening degree adjustment step length. By adopting the method, the control of the electronic expansion valve is realized in a double-temperature-difference cooperative mode, the real requirements of the battery and the passenger cabin cooling are fully considered, and therefore the opening degree control precision of the battery electronic expansion valve can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicles, in particular to a battery electronic expansion valve control method and device, a vehicle thermal management system and a vehicle. BACKGROUND

[0002] With the development of new energy vehicle technology, a new energy vehicle with a double refrigeration system equipped with an evaporator electronic expansion valve and a battery electronic expansion valve has appeared. When the passenger cabin and the battery need to be cooled at the same time, the evaporator electronic expansion valve can be controlled to make the liquid refrigerant evaporate and absorb heat at the evaporator through the evaporator electronic expansion valve, enter the compressor to be compressed into high-temperature and high-pressure gas, pass through the condenser to be condensed into liquid refrigerant, and then pass through the evaporator electronic expansion valve to complete the refrigeration cycle, thereby achieving passenger cabin cooling. For battery cooling, the battery electronic expansion valve is controlled to make the refrigerant exchange heat with the battery water side at the refrigeration machine and evaporate and absorb heat, enter the compressor to be compressed into high-temperature and high-pressure gas, pass through the condenser to be condensed into liquid refrigerant, and then pass through the battery electronic expansion valve to complete the refrigeration cycle.

[0003] At present, the opening control of the battery electronic expansion valve is usually determined based on the cooling level priority of the passenger cabin and the battery, for example, a table can be looked up according to the cooling level priority of the passenger cabin and the battery to determine the opening of the battery electronic expansion valve. However, the above control method does not consider the real demand for battery and passenger cabin cooling, and therefore the opening control accuracy of the battery electronic expansion valve is poor. SUMMARY

[0004] Therefore, it is necessary to provide a battery electronic expansion valve control method, device, vehicle thermal management system and vehicle capable of improving the opening control accuracy of the battery electronic expansion valve.

[0005] In a first aspect, the present application provides a battery electronic expansion valve control method, comprising:

[0006] In the case that the battery and the passenger cabin of the target vehicle are cooled at the same time, the cooling priority relationship of the battery and the passenger cabin is obtained;

[0007] Based on the cooling priority relationship, the initial opening of the electronic expansion valve of the battery is obtained, and the opening of the electronic expansion valve is controlled based on the initial opening until the refrigeration system of the target vehicle enters the quasi-steady state operation stage;

[0008] After the refrigeration system of the target vehicle enters the quasi-steady state operation stage, the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle are obtained;

[0009] According to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, an opening degree adjustment step length of the electronic expansion valve is obtained, and the opening degree of the electronic expansion valve is controlled to be adjusted according to the opening degree adjustment step length.

[0010] In a second aspect, the present application further provides a battery electronic expansion valve control device, comprising:

[0011] A refrigeration priority obtaining module is configured to obtain a refrigeration priority relationship between a battery and a passenger compartment of a target vehicle when the battery and the passenger compartment are refrigerated at the same time.

[0012] A first instruction generating module is configured to obtain an initial opening degree of an electronic expansion valve of the battery based on the refrigeration priority relationship, and control the opening degree of the electronic expansion valve based on the initial opening degree until the refrigeration system of the target vehicle enters a quasi-steady state operation stage.

[0013] A refrigeration temperature difference obtaining module is configured to obtain an evaporator temperature difference and a battery water inlet temperature difference of the target vehicle after the refrigeration system of the target vehicle enters the quasi-steady state operation stage.

[0014] A second instruction generating module is configured to obtain an opening degree adjustment step length of the electronic expansion valve according to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, and control the opening degree of the electronic expansion valve to be adjusted according to the opening degree adjustment step length.

[0015] In a third aspect, the present application further provides a controller, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method of any one of the embodiments of the first aspect when executing the computer program.

[0016] In a fourth aspect, the present application further provides a vehicle thermal management system, comprising: a controller, a battery electronic expansion valve and an evaporator electronic expansion valve connected in communication with the controller, wherein the battery electronic expansion valve is connected to a refrigerant side of a refrigerating machine, a water side of the refrigerating machine is connected to a battery pack and a water pump, the evaporator electronic expansion valve is connected to an evaporator, and the evaporator is connected to the refrigerating machine through a compressor and a condenser; and wherein the controller is configured to implement the steps of the method of any one of the embodiments of the first aspect.

[0017] In a fifth aspect, the present application further provides an automobile comprising the vehicle thermal management system of the fourth aspect.

[0018] In a sixth aspect, the present application further provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the method of any one of the embodiments of the first aspect.

[0019] In a seventh aspect, the present application also provides a computer program product comprising a computer program which, when executed by a processor, implements the steps of the method according to any one of the first aspect.

[0020] The battery electronic expansion valve control method, device, vehicle thermal management system and automobile described above, by obtaining the refrigeration priority relationship between the battery and the passenger cabin of the target vehicle when the battery and the passenger cabin of the target vehicle need to be refrigerated at the same time, obtaining the initial opening degree of the electronic expansion valve of the battery based on the refrigeration priority relationship, and controlling the opening degree of the electronic expansion valve based on the initial opening degree until the refrigeration system of the target vehicle enters the quasi-steady state running stage, obtaining the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle after the refrigeration system of the target vehicle enters the quasi-steady state running stage, and obtaining the opening degree adjustment step length of the electronic expansion valve according to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, and controlling the opening degree of the electronic expansion valve to adjust according to the opening degree adjustment step length. When the battery and the passenger cabin of the target vehicle need to be refrigerated at the same time, the present application can first determine the refrigeration priority relationship between the battery and the passenger cabin, then determine the initial opening degree of the electronic expansion valve based on the priority, control the opening degree of the electronic expansion valve to remain at the initial opening degree until the refrigeration system of the target vehicle enters the quasi-steady state running stage, and then obtain the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle, so as to determine the opening degree adjustment step length of the electronic expansion valve in combination with the refrigeration priority relationship and the above-mentioned temperature differences, and then control the opening degree of the electronic expansion valve to adjust according to the opening degree adjustment step length. In this way, the adjustment of the electronic expansion valve can be realized in combination with the evaporator temperature difference and the battery water inlet temperature difference, that is, the control of the electronic expansion valve is realized in a double-temperature-difference cooperative manner, the real needs of the battery and the passenger cabin refrigeration are fully considered, and therefore the opening degree control precision of the battery electronic expansion valve can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can also be obtained by those skilled in the art without any creative effort.

[0022] Figure 1 It is a flowchart of the battery electronic expansion valve control method in one embodiment.

[0023] Figure 2 It is a flowchart of obtaining the opening degree adjustment step length of the electronic expansion valve in one embodiment.

[0024] Figure 3 It is a flowchart of the initial opening degree of the electronic expansion valve in one embodiment.

[0025] Figure 4 A structural schematic diagram of a vehicle thermal management system in an embodiment.

[0026] Figure 5 A structural block diagram of a battery electronic expansion valve control device in an embodiment.

[0027] Figure 6 An internal structural diagram of a controller in an embodiment.

[0028] Figure 7 A structural schematic diagram of a vehicle thermal management system in an embodiment.

[0029] Figure 8 A structural schematic diagram of an automobile in an embodiment. DETAILED DESCRIPTION

[0030] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0031] It should be noted that the terms "first", "second", and the like used in the present application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "include" and "have" and any variations thereof used in the present application are intended to cover non-exclusive inclusion. The term "multiple" used in the present application refers to two or more. The term "and / or" used in the present application refers to one of the options or any combination of multiple options.

[0032] In an embodiment, as shown in Figure 1 A battery electronic expansion valve control method is provided, and the present embodiment is exemplified by the method applied to a controller. In the present embodiment, the method comprises the following steps:

[0033] In step S101, in the case of simultaneously refrigerating the battery and the passenger compartment of the target vehicle, the refrigeration priority relationship between the battery and the passenger compartment is obtained.

[0034] The refrigeration priority relationship can be used to represent the relationship between the battery refrigeration priority and the passenger compartment refrigeration priority of the target vehicle. In the present embodiment, the controller can first obtain the priority of refrigerating the battery and the priority of refrigerating the passenger compartment when it is necessary to simultaneously refrigerate the battery and the passenger compartment of the target vehicle, so as to obtain the refrigeration priority relationship between the battery and the passenger compartment based on the above priorities.

[0035] In step S102, based on the refrigeration priority relationship, an initial opening degree of the electronic expansion valve of the battery is obtained, and the opening degree of the electronic expansion valve is controlled based on the initial opening degree until the refrigeration system of the target vehicle enters a quasi-steady state running stage.

[0036] The initial opening degree refers to the opening degree value maintained by the electronic expansion valve of the battery in the initial adjustment stage, and the quasi-steady state running stage refers to that the refrigeration system of the target vehicle reaches a dynamic balance state in the initial adjustment stage, for example, after maintaining for 3 minutes in the initial adjustment stage, or the compressor inlet superheat is relatively stable, which can refer to that the superheat continuously changes less than or equal to 2 for 10 seconds, so that it can be determined that the refrigeration system of the target vehicle enters the quasi-steady state running stage.

[0037] Specifically, after the controller determines the refrigeration priority relationship between the battery and the passenger compartment, the initial opening degree of the electronic expansion valve of the battery in the initial adjustment stage can be determined based on the refrigeration priority relationship, and the opening degree of the electronic expansion valve is controlled to maintain the initial opening degree, until the target vehicle refrigeration system enters the quasi-steady state running stage after maintaining for 3 minutes in the initial adjustment stage, or the compressor inlet superheat is relatively stable.

[0038] In step S103, after the refrigeration system of the target vehicle enters the quasi-steady state running stage, the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle are obtained.

[0039] The evaporator temperature difference can refer to the temperature difference between the actual temperature value and the target temperature value of the evaporator in the refrigeration system, and the battery water inlet temperature difference refers to the temperature difference between the actual temperature value and the target temperature value of the battery water inlet in the refrigeration system. The target temperature value can refer to the refrigeration target temperature. After the refrigeration system of the target vehicle enters the quasi-steady state running stage, the controller can also collect the actual temperature value of the evaporator of the target vehicle and the actual temperature value of the battery water inlet, and then the evaporator temperature difference can be obtained based on the temperature difference between the actual temperature value and the target temperature value of the evaporator, and the battery water inlet temperature difference can be obtained based on the temperature difference between the actual temperature value and the target temperature value of the battery water inlet.

[0040] In step S104, according to the refrigeration priority relationship, and the evaporator temperature difference and the battery water inlet temperature difference, an opening degree adjustment step length of the electronic expansion valve is obtained, and the opening degree of the electronic expansion valve is adjusted according to the opening degree adjustment step length.

[0041] The opening degree adjustment step length represents the opening degree adjustment amount of the electronic expansion valve corresponding to each step, and each step can be 50 ms. Taking the opening degree adjustment step length of 0.3 as an example, it means that the opening degree of the electronic expansion valve is adjusted by increasing 0.3 steps every 50 ms. The opening degree adjustment step length can be used to fine-tune the opening degree of the electronic expansion valve of the battery when the refrigeration system of the target vehicle enters the quasi-steady state running stage.

[0042] Specifically, after obtaining the evaporator temperature difference and the battery water inlet temperature difference, the controller can combine the refrigeration priority relationship of the battery and the passenger compartment to determine the opening adjustment increment of the electronic expansion valve of the battery, and then control the opening of the electronic expansion valve to adjust according to the opening adjustment increment, so that the refrigeration system of the target vehicle enters the quasi-steady state running stage, and the opening of the electronic expansion valve of the battery is fine-tuned.

[0043] In the above battery electronic expansion valve control method, the refrigeration priority relationship of the battery and the passenger compartment is obtained when the battery and the passenger compartment of the target vehicle are refrigerated at the same time; based on the refrigeration priority relationship, the initial opening of the electronic expansion valve of the battery is obtained, and the opening of the electronic expansion valve is controlled based on the initial opening until the refrigeration system of the target vehicle enters the quasi-steady state running stage; after the refrigeration system of the target vehicle enters the quasi-steady state running stage, the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle are obtained; according to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, the opening adjustment increment of the electronic expansion valve is obtained, and the opening of the electronic expansion valve is controlled to adjust according to the opening adjustment increment. The present application can determine the refrigeration priority relationship of the battery and the passenger compartment when the battery and the passenger compartment of the target vehicle need to be refrigerated at the same time, and then the initial opening of the electronic expansion valve can be determined based on the priority to control the opening of the electronic expansion valve to remain at the initial opening until the refrigeration system of the target vehicle enters the quasi-steady state running stage, and then the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle are obtained, so as to determine the opening adjustment increment of the electronic expansion valve by combining the refrigeration priority relationship and the above temperature difference, and then control the opening of the electronic expansion valve to adjust according to the opening adjustment increment. By this way, the adjustment of the electronic expansion valve can be realized by combining the evaporator temperature difference and the battery water inlet temperature difference, that is, the control of the electronic expansion valve is realized by the double-temperature-difference cooperative method, which fully considers the real demand of the battery and the passenger compartment refrigeration, so as to improve the opening control precision of the battery electronic expansion valve.

[0044] In one embodiment, as shown in FIG. 1 1, step S104 can further include: Figure 2

[0045] Step S201 : According to the refrigeration priority relationship and the evaporator temperature difference, a first opening adjustment increment is obtained.

[0046] The first opening adjustment increment refers to the opening adjustment increment determined by the evaporator temperature difference. Specifically, the controller can obtain the corresponding opening adjustment increment according to the refrigeration priority relationship and the evaporator temperature difference, and take the opening adjustment increment as the first opening adjustment increment.

[0047] ​In step S202, the second opening degree adjustment increment is obtained according to the refrigeration priority relationship and the battery water inlet temperature difference.

[0048] The second opening degree adjustment increment refers to the opening degree adjustment increment determined by the battery water inlet temperature difference. Similar to the first opening degree adjustment increment, the controller can obtain the corresponding opening degree adjustment increment according to the refrigeration priority relationship and the battery water inlet temperature difference, and the opening degree adjustment increment can be taken as the second opening degree adjustment increment.

[0049] In step S203, the smaller value of the first opening degree adjustment increment and the second opening degree adjustment increment is taken as the opening degree adjustment increment of the electronic expansion valve.

[0050] Finally, the final opening degree adjustment increment of the electronic expansion valve can be obtained based on the first opening degree adjustment increment and the second opening degree adjustment increment. For example, the smaller value of the first opening degree adjustment increment and the second opening degree adjustment increment can be taken as the opening degree adjustment increment of the electronic expansion valve. That is, if the first opening degree adjustment increment is greater than the second opening degree adjustment increment, the second opening degree adjustment increment is taken as the opening degree adjustment increment of the electronic expansion valve; if the first opening degree adjustment increment is less than the second opening degree adjustment increment, the first opening degree adjustment increment is taken as the opening degree adjustment increment of the electronic expansion valve.

[0051] In the embodiment, two opening degree adjustment increments can be obtained by the refrigeration priority relationship and the two temperature differences, respectively, so that the smaller value of the two opening degree adjustment increments is taken as the opening degree adjustment increment of the electronic expansion valve. In this way, the accuracy of obtaining the opening degree adjustment increment of the electronic expansion valve can be improved.

[0052] Further, the evaporator temperature difference is the difference between the actual temperature value of the evaporator of the passenger compartment and the target temperature value of the evaporator. In step S201, in the case that the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, the opening degree adjustment increment matched with the evaporator temperature difference is obtained as the first opening degree adjustment increment according to the pre-labeled first increment mapping relationship. The first increment mapping relationship stores the corresponding relationship between different evaporator temperature differences and different opening degree adjustment increments. The evaporator temperature difference and the opening degree adjustment increment are negatively correlated, and the change trend of the opening degree adjustment increment is slower when the evaporator temperature difference is negative than when the evaporator temperature difference is positive.

[0053] The evaporator temperature difference refers to a difference between an actual temperature value of the evaporator of the passenger cabin and a target temperature value. The first step increase mapping relationship refers to a corresponding relationship between the evaporator temperature difference and the opening degree adjustment step increase used when the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger cabin. The mapping relationship can be represented by a mapping relationship table. Specifically, if the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger cabin, the controller can obtain the first step increase mapping relationship after obtaining the evaporator temperature difference, so as to obtain the opening degree adjustment step increase matched with the evaporator temperature difference from the first step increase mapping relationship as the first opening degree adjustment step increase. Moreover, the evaporator temperature difference and the opening degree adjustment step increase are negatively correlated in the first step increase mapping relationship, that is, the smaller the evaporator temperature difference, the larger the opening degree adjustment step increase.

[0054] Moreover, the positive and negative signs of the evaporator temperature difference and the opening degree adjustment step increase are opposite. When the evaporator temperature difference is less than zero, that is, the actual temperature value of the evaporator is less than the target temperature value, the passenger cabin has met the cooling target at this time, and therefore the opening degree of the electronic expansion valve of the battery needs to be increased to enhance the refrigeration effect of the battery, so the opening degree adjustment step increase is greater than zero. Similarly, when the evaporator temperature difference is greater than zero, that is, the actual temperature value of the evaporator is greater than the target temperature value, the passenger cabin has not met the cooling target at this time, and therefore the opening degree of the electronic expansion valve of the battery needs to be reduced to reduce the refrigeration effect of the battery, so the opening degree adjustment step increase is less than zero.

[0055] Meanwhile, since the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger cabin, that is, the refrigeration of the passenger cabin is more prioritized, in this case, the evaporator temperature difference is negative, that is, the refrigeration of the passenger cabin meets the target, and the change trend of the opening degree adjustment step increase is relatively slow at this time, and the increase trend of the opening degree is also relatively slow. When the evaporator temperature difference is positive, that is, the refrigeration of the passenger cabin does not meet the target, the change trend of the opening degree adjustment step increase needs to be relatively rapid at this time, and the decrease trend of the opening degree is also relatively rapid. Through this mode, the prioritized refrigeration of the passenger cabin is ensured.

[0056] For example, the first step increase mapping relationship can be shown in Table 1.

[0057] Table 1: First step increase mapping table

[0058]

[0059] In Table 1, the step-up represents the number of steps adjusted per 50 ms, for example, 0.2 represents 0.2 steps adjusted per 50 ms, and the number of steps of the electronic expansion valve used in the embodiment is 0-576, which represents the number of pulses of the stepper motor driving the valve needle to move. As can be seen in Table 1, when the battery refrigeration priority is not higher than the passenger cabin refrigeration priority, the evaporator temperature has achieved the target, at this time the evaporator temperature difference is less than 0, the battery electronic expansion valve opening is increased, the greater the target excess, the greater the battery electronic expansion valve opening, that is, A1>B1, and if the evaporator does not achieve the target, at this time the evaporator temperature difference is greater than 0, the battery electronic expansion valve opening is reduced, the greater the distance from the target, the greater the battery electronic expansion valve opening is reduced, that is, D1

[0060] In the embodiment, when the battery refrigeration priority is not higher than the passenger cabin refrigeration priority, the first opening adjustment step-up can be obtained by using the first step-up mapping relationship, so as to improve the accuracy of obtaining the first opening adjustment step-up.

[0061] Further, the evaporator temperature difference is the difference between the actual evaporator temperature value of the passenger cabin and the target evaporator temperature value, and step S201 can further include: in the case where the refrigeration priority relationship represents that the battery refrigeration priority is higher than the passenger cabin refrigeration priority, obtaining the opening adjustment step-up matched with the evaporator temperature difference as the first opening adjustment step-up according to the pre-calibrated second step-up mapping relationship; wherein the second step-up mapping relationship stores the corresponding relationship between different evaporator temperature differences and different opening adjustment step-ups, the evaporator temperature difference and the opening adjustment step-up are in a negative correlation relationship, and the change trend of the opening adjustment step-up when the evaporator temperature difference is negative is faster than the change trend of the opening adjustment step-up when the evaporator temperature difference is positive.

[0062] The second step-up mapping relationship refers to the corresponding relationship between the evaporator temperature difference and the opening adjustment step-up when the battery refrigeration priority is higher than the passenger cabin refrigeration priority, and the mapping relationship can also be represented by a mapping relationship table. Specifically, if the battery refrigeration priority is higher than the passenger cabin refrigeration priority, the controller can obtain the pre-calibrated second step-up mapping relationship after obtaining the evaporator temperature difference, so as to obtain the opening adjustment step-up matched with the evaporator temperature difference from the second step-up mapping relationship as the first opening adjustment step-up. Moreover, the evaporator temperature difference and the opening adjustment step-up in the second step-up mapping relationship are also in a negative correlation relationship, that is, the smaller the evaporator temperature difference, the greater the opening adjustment step-up.

[0063] And, the positive and negative signs of the evaporator temperature difference and the opening degree adjustment increment are also opposite, and the same as the first increment mapping relationship, when the evaporator temperature difference is less than zero, that is, the actual temperature value of the evaporator is less than the target temperature value, at this time the passenger compartment has met the cooling target, then the opening degree of the electronic expansion valve of the battery needs to be increased to enhance the refrigeration effect of the battery, so the opening degree adjustment increment is greater than zero. Similarly, when the evaporator temperature difference is greater than zero, that is, the actual temperature value of the evaporator is greater than the target temperature value, at this time the passenger compartment fails to meet the cooling target, then the opening degree of the electronic expansion valve of the battery needs to be reduced to reduce the refrigeration effect of the battery, so the opening degree adjustment increment is less than zero.

[0064] And since the current battery refrigeration priority is higher than the passenger compartment refrigeration priority, that is, the battery refrigeration is more prioritized, in this case, the evaporator temperature difference is negative, that is, the passenger compartment refrigeration meets the target, the change trend of the opening degree adjustment increment needs to be relatively rapid, at this time the increase trend of the opening degree is also relatively rapid. And the evaporator temperature difference is positive, that is, the passenger compartment refrigeration does not meet the target, the change trend of the opening degree adjustment increment can be relatively slow, at this time the decrease trend of the opening degree is also relatively slow, through this way to ensure the priority refrigeration of the battery.

[0065] For example, the second increment mapping relationship can be shown in Table 2:

[0066] Table 2 Second increment mapping table

[0067]

[0068] As can be seen in Table 2, when the battery refrigeration priority is higher than the passenger compartment refrigeration priority, the evaporator temperature has achieved the target, at this time the evaporator temperature difference is less than 0, the battery electronic expansion valve opening degree increases, the greater the target excess, the greater the battery electronic expansion valve opening degree increases, that is, A2>B2, and if the evaporator does not achieve the target, at this time the evaporator temperature difference is greater than 0, the battery electronic expansion valve opening degree decreases, the greater the distance from the target, the greater the battery electronic expansion valve opening degree decreases, that is, D2<C2. And when the evaporator achieves the target, the battery electronic expansion valve opening degree is allowed to increase, the increase trend changes rapidly, when the evaporator target temperature is not achieved, the battery electronic expansion valve decreases slowly, to ensure that the battery side refrigeration demand is prioritized, so the final result is A2>B2>|D2|>|C2|.

[0069] Meanwhile, compared with the first step-up mapping relationship, in the case of negative evaporator temperature difference, the battery electronic expansion valve opening degree increasing trend in the second step-up mapping relationship is faster than that in the first step-up mapping relationship, thus satisfying A2>B2≥A1>B1. Similarly, in the case of positive evaporator temperature difference, the battery electronic expansion valve opening degree decreasing trend in the second step-up mapping relationship is slower than that in the first step-up mapping relationship, thus satisfying |C2|<|D2|≤|C1|<|D1|.

[0070] In the embodiment, when the battery refrigeration priority is higher than the passenger cabin refrigeration priority, the second step-up mapping relationship is used to obtain the first opening degree adjustment step-up, so that the precision of the first opening degree adjustment step-up is improved.

[0071] In addition, the battery water inlet temperature difference is the difference between the actual temperature value and the target temperature value of the battery water inlet, and step S202 can further include: in the case of the refrigeration priority relationship representing that the battery refrigeration priority is not higher than the passenger cabin refrigeration priority, obtaining, according to a third step-up mapping relationship calibrated in advance, an opening degree adjustment step-up matched with the battery water inlet temperature difference as the second opening degree adjustment step-up; wherein the third step-up mapping relationship stores a corresponding relationship between different battery water inlet temperature differences and different opening degree adjustment step-ups, the battery water inlet temperature difference and the opening degree adjustment step-up are in a positive correlation relationship, and the change trend of the opening degree adjustment step-up in the case of negative battery water inlet temperature difference is faster than the change trend of the opening degree adjustment step-up in the case of positive battery water inlet temperature difference.

[0072] The battery water inlet temperature difference refers to the difference between the actual temperature value and the target temperature value of the battery water inlet, and the third step-up mapping relationship refers to the corresponding relationship between the battery water inlet temperature difference and the opening degree adjustment step-up used in the case of the battery refrigeration priority not being higher than the passenger cabin refrigeration priority. The mapping relationship can be represented by a mapping relationship table. Specifically, if the battery refrigeration priority is not higher than the passenger cabin refrigeration priority, the controller can obtain the third step-up mapping relationship calibrated in advance after obtaining the battery water inlet temperature difference, so as to obtain, from the third step-up mapping relationship, an opening degree adjustment step-up matched with the battery water inlet temperature difference as the second opening degree adjustment step-up. Moreover, the battery water inlet temperature difference and the opening degree adjustment step-up are in a positive correlation relationship in the third step-up mapping relationship, that is, the smaller the battery water inlet temperature difference, the smaller the opening degree adjustment step-up.

[0073] And, the positive and negative signs of the battery water inlet temperature difference and the opening degree adjustment increment are the same, the battery water inlet temperature difference is less than zero, that is, the actual temperature value of the battery water inlet is less than the target temperature value, then the battery has met the cooling target at this time, then the electronic expansion valve opening degree of the battery needs to be reduced to enhance the cooling effect of the passenger compartment, so the opening degree adjustment increment is less than zero. Similarly, the battery water inlet temperature difference is greater than zero, that is, the actual temperature value of the battery water inlet is greater than the target temperature value, then the battery has not met the cooling target at this time, then the electronic expansion valve opening degree of the battery needs to be increased to increase the cooling effect of the battery, so the opening degree adjustment increment is greater than zero.

[0074] At the same time, since the current battery cooling priority is not higher than the passenger compartment cooling priority, that is, the passenger compartment cooling is more preferential, in this case, the battery water inlet temperature difference is negative, that is, the battery cooling meets the target, the opening degree adjustment increment changes rapidly at this time, and the opening degree decreases rapidly. When the battery water inlet temperature difference is positive, that is, the battery cooling does not meet the target, the opening degree adjustment increment changes slowly at this time, and the opening degree increases slowly. Through this way, the priority cooling of the passenger compartment is ensured.

[0075] For example, the third increment mapping relationship can be shown in Table 3:

[0076] Table 3 Third increment mapping table

[0077]

[0078] As can be seen in Table 3, when the battery cooling priority is not higher than the passenger compartment cooling priority, the battery temperature has achieved the target, at this time the battery water inlet temperature difference is less than 0, the battery electronic expansion valve opening degree is reduced, the greater the target excess, the greater the battery electronic expansion valve opening degree is reduced, that is, A3

[0079] In this embodiment, when the battery cooling priority is not higher than the passenger compartment cooling priority, the third increment mapping relationship can be used to obtain the second opening degree adjustment increment, which can improve the accuracy of the second opening degree adjustment increment.

[0080] In one embodiment, the battery water inlet temperature difference is the difference between the actual temperature value of the battery water inlet and the target temperature value of the water inlet, and the second opening degree adjustment step is obtained according to the refrigeration priority relationship and the battery water inlet temperature difference, including: in the case that the refrigeration priority relationship represents that the refrigeration priority of the battery is higher than that of the passenger compartment, obtaining the opening degree adjustment step matched with the battery water inlet temperature difference as the second opening degree adjustment step according to the fourth step mapping relationship calibrated in advance; wherein the fourth step mapping relationship stores the corresponding relationship between different battery water inlet temperature differences and different opening degree adjustment steps, the battery water inlet temperature difference and the opening degree adjustment step are positively correlated, and the change trend of the opening degree adjustment step is slower in the case that the battery water inlet temperature difference is negative than in the case that the battery water inlet temperature difference is positive.

[0081] The fourth step mapping relationship refers to the corresponding relationship between the battery water inlet temperature difference and the opening degree adjustment step used in the case that the refrigeration priority of the battery is higher than that of the passenger compartment, which is similar to the third step mapping relationship. The mapping relationship can also be represented by a mapping relationship table. Specifically, if the refrigeration priority of the battery is higher than that of the passenger compartment, the controller can obtain the fourth step mapping relationship calibrated in advance after obtaining the battery water inlet temperature difference, so as to obtain the opening degree adjustment step matched with the battery water inlet temperature difference from the fourth step mapping relationship as the second opening degree adjustment step. Moreover, the battery water inlet temperature difference and the opening degree adjustment step are positively correlated in the fourth step mapping relationship, that is, the smaller the battery water inlet temperature difference, the smaller the opening degree adjustment step.

[0082] Moreover, the battery water inlet temperature difference and the opening degree adjustment step have the same positive and negative signs, and similar to the third step mapping relationship, the battery water inlet temperature difference is less than zero, that is, the actual temperature value of the battery water inlet is less than the target temperature value, so that the battery has met the cooling target, and the opening degree of the electronic expansion valve of the battery needs to be reduced to enhance the refrigeration effect of the passenger compartment, so the opening degree adjustment step is less than zero. Similarly, the battery water inlet temperature difference is greater than zero, that is, the actual temperature value of the battery water inlet is greater than the target temperature value, so that the battery has not met the cooling target, and the opening degree of the electronic expansion valve of the battery needs to be increased to increase the refrigeration effect of the battery, so the opening degree adjustment step is greater than zero.

[0083] Meanwhile, since the refrigeration priority of the current battery is higher than that of the passenger cabin, i.e., the refrigeration of the battery is more prioritized, in this case, the battery water inlet temperature difference is negative, i.e., after the battery refrigeration meets the target, the change trend of the opening degree adjustment step length can be relatively slow, at this time, the decreasing trend of the opening degree is also relatively slow, while the battery water inlet temperature difference is positive, i.e., the battery refrigeration does not meet the target, the change trend of the opening degree adjustment step length needs to be relatively rapid, at this time, the increasing trend of the opening degree is also relatively rapid, and through this way, the priority refrigeration of the battery is ensured.

[0084] For example, the fourth step length increase mapping relationship can be shown in Table 4:

[0085] Table 4 Fourth step length increase mapping table

[0086]

[0087] As can be seen in Table 4, when the refrigeration priority of the battery is higher than that of the passenger cabin, the battery temperature has achieved the target, at this time, the battery water inlet temperature difference is less than 0, the battery electronic expansion valve opening degree decreases, the greater the target excess is, the greater the battery electronic expansion valve opening degree decreases, i.e., A4

[0088] Meanwhile, compared with the third step length increase mapping relationship, in the case of the battery water inlet temperature difference being negative, the decreasing trend of the battery electronic expansion valve opening degree in the fourth step length increase mapping relationship is slower than that in the third step length increase mapping relationship, therefore, it is satisfied that |A3| > |B3| ≥ |A4| > |B4|, and for the same reason, in the case of the battery water inlet temperature difference being positive, the increasing trend of the battery electronic expansion valve opening degree in the fourth step length increase mapping relationship is faster than that in the third step length increase mapping relationship, therefore, it is satisfied that D4 > C4 ≥ D3 > C3.

[0089] In this embodiment, when the refrigeration priority of the battery is higher than that of the passenger cabin, the fourth step length increase mapping relationship is adopted to obtain the second opening degree adjustment step length, and through this way, the accuracy of the second opening degree adjustment step length can be improved.

[0090] In one embodiment, as shown in Figure 3 Step S102 can further include:

[0091] Step S301, obtaining the maximum core temperature of the battery and the instantaneous charging and discharging power of the battery.

[0092] The maximum core temperature can refer to the battery core temperature when the refrigeration is started, and the instantaneous charging and discharging power refers to the charging and discharging power of the battery at a certain time, which is equal to the product of the voltage and the current at that time. Specifically, when the target vehicle starts to simultaneously refrigerate the battery and the passenger compartment, the core temperature of the battery and the current charging and discharging power can be collected as the maximum core temperature of the battery and the instantaneous charging and discharging power.

[0093] Step S302, obtaining the reference initial opening degree of the electronic expansion valve according to the refrigeration priority relationship and the maximum core temperature, and obtaining the initial opening degree correction amount of the electronic expansion valve according to the refrigeration priority relationship and the instantaneous charging and discharging power.

[0094] Step S303, correcting the reference initial opening degree by the initial opening degree correction amount to obtain the initial opening degree of the electronic expansion valve.

[0095] The reference initial opening degree refers to the initial opening degree value that is not corrected, and the initial opening degree correction amount is the opening degree correction amount for correcting the reference initial opening degree. In the embodiment, the initial opening degree of the electronic expansion valve can be obtained by correcting the reference initial opening degree by the initial opening degree correction amount, wherein the reference initial opening degree can be determined according to the refrigeration priority relationship and the maximum core temperature, and the initial opening degree correction amount can be determined according to the refrigeration priority relationship and the instantaneous charging and discharging power.

[0096] Specifically, after obtaining the maximum core temperature and the instantaneous charging and discharging power, the controller can also determine the reference initial opening degree of the battery electronic expansion valve by using the maximum core temperature and the refrigeration priority relationship, and can also obtain the initial opening degree correction amount of the electronic expansion valve by using the instantaneous charging and discharging power and the refrigeration priority relationship. Finally, the reference initial opening degree is corrected by the initial opening degree correction amount, for example, the initial opening degree correction amount can be superimposed on the reference initial opening degree, so as to obtain the final initial opening degree of the electronic expansion valve.

[0097] In the embodiment, the maximum core temperature of the battery and the instantaneous charging and discharging power can also be obtained, wherein the maximum core temperature can be used to determine the reference initial opening degree, and the instantaneous charging and discharging power can be used to correct the reference initial opening degree. When the maximum core temperature of the battery is raised due to the instantaneous high-power charging and discharging of the battery, the opening degree of the electronic expansion valve can be corrected in advance to realize early refrigeration. In this way, the accuracy of the battery electronic expansion valve control can be further improved.

[0098] Further, the step S302 can further include: in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, obtaining, according to a pre-labeled first opening degree mapping relationship, an opening degree value matched with the maximum cell temperature as the reference initial opening degree; wherein the first opening degree mapping relationship stores a corresponding relationship between different maximum cell temperatures and different opening degree values, and the maximum cell temperature and the opening degree value are in a positive correlation relationship.

[0099] The first opening degree mapping relationship refers to a mapping relationship between the maximum cell temperature and the opening degree value in a case where the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment. The mapping relationship can be represented in the form of a table. The mapping relationship can store a corresponding relationship between different maximum cell temperatures and different opening degree values, and the maximum cell temperature and the opening degree value are in a positive correlation relationship, that is, the higher the battery cell temperature, the more the battery electronic expansion valve needs to be increased to increase the efficiency of battery cooling.

[0100] Specifically, if the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, the controller can also use the maximum cell temperature to query a pre-labeled first opening degree mapping table, thereby obtaining the reference initial opening degree. The mapping table can be labeled by the following process, that is, given an initial opening degree, the battery maximum cell temperature should not exceed the specified safety threshold (such as 45℃) during the initial state refrigeration system adjustment, and the final inlet superheat degree of the compressor under the initial opening degree is maintained at 5℃-10℃. Ensure that the compressor inlet has a certain superheat to prevent liquid hammer phenomenon of the compressor. As the battery cell temperature increases, the initial opening degree value of the electronic expansion valve is gradually increased, and the above calibration verification process is repeated to obtain the initial opening degree value of the battery electronic expansion valve mapped according to the battery maximum cell temperature.

[0101] For example, the first opening degree mapping relationship can be as shown in Table 5:

[0102] Table 5 First opening degree mapping table

[0103]

[0104] Wherein, the unit of the initial opening degree of the battery electronic expansion valve is the number of steps, which represents the number of pulses of the stepping motor driven valve needle movement. It can be seen that as the battery maximum cell temperature gradually increases, the initial opening degree of the battery electronic expansion valve also gradually increases.

[0105] In the embodiment, when the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, the first opening degree mapping relationship can be used to obtain the reference initial opening degree, and the accuracy of obtaining the reference initial opening degree can be improved by this way.

[0106] The step S302 can further include: in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, obtaining, according to a second opening degree mapping relationship calibrated in advance, an opening degree value matched with the maximum cell temperature as the reference initial opening degree; wherein the second opening degree mapping relationship stores a corresponding relationship between different maximum cell temperatures and different opening degree values, the maximum cell temperature and the opening degree value are in a positive correlation relationship, and in a case where the maximum cell temperatures are the same, the opening degree value in the first opening degree mapping relationship is smaller than the opening degree value in the second opening degree mapping relationship.

[0107] The second opening degree mapping relationship refers to a mapping relationship between the maximum cell temperature and the opening degree value in a case where the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment. The mapping relationship can also be represented in the form of a table, and the mapping relationship can also store a corresponding relationship between different maximum cell temperatures and different opening degree values, and the maximum cell temperature and the opening degree value are in a positive correlation relationship, that is, the higher the battery cell temperature, the more the battery electronic expansion valve needs to be increased to increase the efficiency of battery cooling. And since the second opening degree mapping relationship is applicable to the case where the refrigeration priority of the battery is higher, therefore, in the case where the maximum cell temperatures are the same, the electronic expansion valve opening degree value in the second mapping relationship is larger than that in the first opening degree mapping relationship, so as to realize the refrigeration of the battery faster.

[0108] Specifically, if the refrigeration priority relationship indicates that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, the controller can also use the maximum cell temperature to query a second opening degree mapping relationship table calibrated in advance, so as to obtain the reference initial opening degree. The calibration of the mapping relationship table can be realized in the same way as the calibration of the first opening degree mapping relationship table.

[0109] For example, the second opening degree mapping relationship can be as shown in Table 6:

[0110] Table 6 Second opening degree mapping relationship table

[0111]

[0112] It can be seen that, with the gradual increase of the maximum cell temperature of the battery, the initial opening degree of the battery electronic expansion valve also gradually increases, and under the same maximum cell temperature of the battery, the reference initial opening degree in the second opening degree mapping relationship is also greater than the reference initial opening degree in the first opening degree mapping relationship.

[0113] In the embodiment, when the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, the second opening degree mapping relationship is used to obtain the reference initial opening degree, and in this way, the accuracy of obtaining the reference initial opening degree can be improved.

[0114] Further, the step S302 can further include: in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, obtaining, as the initial opening degree correction amount, an opening degree correction amount matched with the instantaneous charge-discharge power according to a third opening degree mapping relationship calibrated in advance; wherein the third opening degree mapping relationship stores a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction amounts, and the instantaneous charge-discharge power and the opening degree correction amount are in a positive correlation relationship.

[0115] The third opening degree mapping relationship refers to a mapping relationship between the instantaneous charge-discharge power and the opening degree correction amount in a case where the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment. The mapping relationship can be represented in a table form. The mapping relationship can store a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction amounts, and the instantaneous charge-discharge power and the opening degree correction amount are in a positive correlation relationship, that is, the higher the instantaneous charge-discharge power, the higher the battery core body temperature, and therefore it is necessary to increase the opening degree of the battery electronic expansion valve to increase the efficiency of battery cooling.

[0116] Specifically, if the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, the controller can also use the instantaneous charge-discharge power to query a third opening degree mapping relationship table calibrated in advance to obtain the initial opening degree correction amount. The calibration of the mapping relationship table can be realized through the following process. First, the battery instantaneous charge-discharge power and the battery maximum core body temperature mapping relationship can be obtained through a static charge-discharge test of the battery pack. Then, the initial opening degree correction amount of the electronic expansion valve is calibrated through the mapping table.

[0117] For example, the third opening degree mapping relationship can be as shown in Table 7:

[0118] Table 7 Third opening degree mapping relationship table

[0119]

[0120] The unit of the initial opening degree correction amount of the battery electronic expansion valve is step, and it can be seen that the initial opening degree correction amount of the battery electronic expansion valve gradually increases with the gradual increase of the battery instantaneous charge-discharge power.

[0121] In the embodiment, in a case where the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, the third opening degree mapping relationship can be used to obtain the initial opening degree correction amount, and the accuracy of obtaining the initial opening degree correction amount can be improved through this way.

[0122] In addition, the step S302 can further include: in a case where the refrigeration priority relationship table indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, obtaining, as the initial opening degree correction amount, an opening degree correction amount matched with the instantaneous charge-discharge power according to a fourth opening degree mapping relationship calibrated in advance; wherein the fourth opening degree mapping relationship stores a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction amounts, the instantaneous charge-discharge power and the opening degree correction amount are in a positive correlation relationship, and in a case where the instantaneous charge-discharge power is the same, the opening degree correction amount in the third opening degree mapping relationship is less than the opening degree correction amount in the fourth opening degree mapping relationship.

[0123] The fourth opening degree mapping relationship refers to a mapping relationship between the instantaneous charge-discharge power and the opening degree correction amount in a case where the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment. The mapping relationship can also be represented in the form of a table, and the mapping relationship can also store a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction amounts, and the instantaneous charge-discharge power and the opening degree correction amount are in a positive correlation relationship, that is, the higher the instantaneous charge-discharge power, the higher the battery core temperature to be increased, and therefore the opening degree of the battery electronic expansion valve needs to be increased to increase the efficiency of battery cooling.

[0124] Specifically, if the refrigeration priority relationship table indicates that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, the controller can also query a fourth opening degree mapping relationship table calibrated in advance by using the instantaneous charge-discharge power, so as to obtain the initial opening degree correction amount. The calibration of the mapping relationship table can be realized by calibrating the third opening degree mapping relationship table.

[0125] For example, the fourth opening degree mapping relationship can be as shown in Table 8:

[0126] Table 8 Fourth opening degree mapping relationship table

[0127]

[0128] It can be seen that, with the gradual increase of the battery instantaneous charge-discharge power, the initial opening degree correction amount of the battery electronic expansion valve also gradually increases, and under the same battery instantaneous charge-discharge power, the initial opening degree correction amount in the fourth opening degree mapping relationship is also greater than the initial opening degree correction amount in the third opening degree mapping relationship.

[0129] In the embodiment, in a case where the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, the fourth opening degree mapping relationship is used to obtain the initial opening degree correction amount, and in this way, the accuracy of obtaining the initial opening degree correction amount can be improved.

[0130] In one embodiment, a control method for a battery electronic expansion valve when cooling the passenger cabin and the battery simultaneously is also provided. The method uses a temperature difference-opening degree dynamic coupling mechanism to use the evaporator temperature difference as a dynamic scaling factor for the opening degree of the battery electronic expansion valve. A double temperature difference cooperative control algorithm is used to simultaneously respond to the passenger cabin state and the battery demand to achieve real-time flexible distribution of refrigeration capacity. Therefore, the control method can break the conventional control method of fixed battery electronic expansion valve opening degree, and use a continuous control method of temperature difference table electronic expansion valve variable gradient. The method can be applied to the thermal management system shown in Figure 4

[0131] Passenger cabin refrigeration circuit:

[0132] Evaporator electronic expansion valve → evaporator → compressor → condenser → evaporator electronic expansion valve.

[0133] Passenger cabin refrigeration principle:

[0134] Liquid refrigerant is evaporated and absorbs heat at the evaporator through the evaporator electronic expansion valve, compressed into high-temperature and high-pressure gas by the compressor, condensed into liquid refrigerant by the condenser, and then refrigeration cycle is performed through the evaporator electronic expansion valve.

[0135] Battery refrigeration circuit:

[0136] Battery electronic expansion valve → refrigeration machine refrigerant side → compressor → condenser → battery electronic expansion valve.

[0137] Battery refrigeration principle:

[0138] The refrigerant exchanges heat with the battery water side at the refrigeration machine through the battery electronic expansion valve, evaporates and absorbs heat, enters the compressor to be compressed into high-temperature and high-pressure gas, is condensed into liquid refrigerant by the condenser, and then refrigeration cycle is performed through the battery electronic expansion valve.

[0139] The control method of the thermal management system has the following specific process:

[0140] I. When the priority of the battery refrigeration level is not higher than that of the passenger cabin refrigeration level:

[0141] 1. Initial opening degree:

[0142] ​According to the battery maximum core temperature lookup table 5, the initial opening degree of the battery electronic expansion valve is calibrated. The calibration method is as follows: a given initial opening degree is required, and the maximum core temperature of the battery during the initial state adjustment of the refrigeration system shall not exceed the specified safety threshold (such as 45 DEG C). Under the initial opening degree, the final inlet superheat degree of the compressor is maintained at 5 DEG C to 10 DEG C. The compressor inlet is ensured to have a certain superheat degree to prevent liquid strike phenomenon of the compressor. As the battery core temperature rises, the initial opening degree value of the electronic expansion valve is gradually increased, and the above calibration verification process is repeated to obtain the initial opening degree value of the battery electronic expansion valve according to the battery maximum core temperature mapping.

[0143] 2. Introducing battery charge and discharge instantaneous power for correction:

[0144] The battery instantaneous high-power charge and discharge can cause the maximum core temperature of the battery to rise. When the battery is identified to perform high-power charge and discharge, the opening degree of the battery electronic expansion valve is increased in advance to perform refrigeration in advance. Purely according to the battery maximum core temperature lookup table, the response may be delayed.

[0145] It can be achieved by lookup table 7, which needs to be calibrated and corrected according to different battery types. Generally, the mapping relationship between the battery instantaneous charge and discharge power and the maximum core temperature of the battery can be obtained through the static charge and discharge test of the battery pack. The initial opening degree correction amount of the electronic expansion valve is calibrated and corrected by the mapping table. The verification of the calibration and correction amount of the electronic expansion valve requires that the maximum core temperature of the battery in the initial state shall not exceed the specified safety threshold (such as 45 DEG C), and the final inlet superheat degree of the compressor under the initial opening degree is maintained at 5 DEG C to 10 DEG C. The compressor inlet is ensured to have a certain superheat degree to prevent liquid strike phenomenon of the compressor.

[0146] 3. Dynamic adjustment:

[0147] In the initial state, the refrigeration system is in the adjustment stage. After the initial state is maintained for 3 minutes or the compressor inlet superheat degree is relatively stable (the superheat degree changes by less than or equal to 2 for 10 seconds), the opening degree increase and decrease amount of the battery electronic expansion valve is calculated according to the difference between the evaporator temperature of the passenger compartment and the target temperature.

[0148] The opening degree change lookup table 1 is calculated according to the evaporator temperature difference (actual-target). The calibration method of table 1 is as follows: when the evaporator achieves the target, the opening degree of the battery electronic expansion valve is allowed to increase, and the increase trend changes slowly. When the target temperature of the evaporator is not achieved, the opening degree of the battery electronic expansion valve is rapidly reduced. The purpose is to ensure that the refrigeration demand of the passenger compartment side is given priority.

[0149] (1) When the priority of the battery refrigeration level is not higher than that of the passenger compartment refrigeration level, the evaporator temperature has achieved the target, and the opening degree of the battery electronic expansion valve is increased. The greater the target excess is, the greater the opening degree increase of the battery electronic expansion valve is, that is, A1 > B1.

[0150] (2) When the priority of the battery cooling level is not higher than that of the passenger cabin cooling level, the evaporator does not achieve the target, and the battery electronic expansion valve opening degree is reduced. The greater the gap from the target, the greater the reduction of the battery electronic expansion valve opening degree, i.e., |D1|>|C1|≥A1>B1.

[0151] After the initial state is maintained for 3 min, the increase / decrease amount of the battery electronic expansion valve opening degree is calculated according to the difference between the actual and target battery water inlet temperature.

[0152] The battery water inlet temperature difference (actual-target) opening degree change is calculated according to Table 3. The calibration method of Table 3 is as follows: when the battery achieves the target, the battery electronic expansion valve opening degree is allowed to be reduced, and the reduction trend changes fast. When the battery target temperature is not achieved, the battery electronic expansion valve is slowly increased. The purpose is to ensure that the passenger cabin side cooling demand is prioritized.

[0153] (1) When the priority of the battery cooling level is not higher than that of the passenger cabin cooling level, the battery temperature has achieved the target, and the battery electronic expansion valve opening degree is reduced. The greater the excess of the target, the greater the reduction of the battery electronic expansion valve opening degree, i.e., A3<B3.

[0154] (2) When the priority of the battery cooling level is not higher than that of the passenger cabin cooling level, the battery does not achieve the target, and the battery electronic expansion valve opening degree is increased. The greater the gap from the target, the greater the increase of the battery electronic expansion valve opening degree, i.e., |A3|>|B3|≥D3>C3.

[0155] The increase step length is set to change every 50 ms, and at most 6 steps per second, because there is an initial opening degree, and less than 10 steps per second meets the dynamic opening degree adjustment demand of the electronic expansion valve, preventing the electronic expansion valve from changing too much instantaneously and causing the refrigeration system to oscillate.

[0156] The two increase step lengths calculated for the passenger cabin side and the battery side demand are controlled by taking the minimum value.

[0157] II. When the priority of the battery cooling level is higher than that of the passenger cabin cooling level:

[0158] 1. Initial opening degree:

[0159] According to Table 6, the battery electronic expansion valve initial opening degree is calculated according to the maximum battery cell temperature. The calibration method is as follows: a given initial opening degree is required to ensure that the maximum battery cell temperature does not exceed the specified safety threshold (e.g., 45℃) during the initial state refrigeration system adjustment period. Under the initial opening degree, the final inlet superheat degree of the compressor is maintained at 5℃-10℃. Ensuring that the compressor inlet has a certain superheat degree prevents liquid hammer phenomenon from occurring in the compressor. As the battery cell temperature rises, the initial opening degree value of the electronic expansion valve is gradually increased, and the above calibration verification process is repeated to obtain the initial opening degree value of the battery electronic expansion valve mapped according to the maximum battery cell temperature.

[0160] 2. Introducing battery charge-discharge transient power for correction:

[0161] Battery transient high-power charge-discharge will cause the battery maximum core temperature to rise. When it is identified that the battery is performing high-power charge-discharge, the battery electronic expansion valve opening degree is increased in advance, and the refrigeration is advanced. Simply looking up the table according to the maximum core temperature of the battery may cause response lag.

[0162] This can be achieved by looking up Table 8, which needs to be calibrated and corrected according to different battery types. Generally, the mapping relationship between battery transient charge-discharge power and battery maximum core temperature can be obtained through static charge-discharge test of the battery pack. The initial opening degree correction amount of the electronic expansion valve is calibrated through the mapping table. The verification of the electronic expansion valve calibration correction amount requires that the maximum core temperature of the battery in the initial state should not exceed the specified safety threshold (such as 45℃), and the final inlet superheat of the compressor under the initial opening degree should be maintained at 5℃~10℃. Ensure that the compressor inlet has a certain superheat to prevent liquid strike phenomenon of the compressor.

[0163] When the priority of the battery refrigeration level is higher than that of the passenger cabin refrigeration level, the initial opening degree of the battery electronic expansion valve at the same battery maximum core temperature is greater than that when the priority of the battery refrigeration level is not higher than that of the passenger cabin refrigeration level. The initial opening degree correction amount of the battery electronic expansion valve is greater than that when the priority of the battery refrigeration level is not higher than that of the passenger cabin refrigeration level. Purpose: to ensure the priority demand of battery refrigeration.

[0164] 3. Dynamic adjustment:

[0165] In the initial state, the refrigeration system is in the adjustment stage. After the initial state is maintained for 3 minutes or the compressor inlet superheat is relatively stable (the superheat changes by less than or equal to 2 for 10s), the opening degree increase / decrease amount of the battery electronic expansion valve is calculated according to the difference between the passenger cabin evaporator temperature and the target temperature.

[0166] The evaporator temperature difference (actual-target) opening degree change is calculated by looking up Table 2. The calibration method of Table 2: when the evaporator achieves the target, the opening degree of the battery electronic expansion valve is allowed to increase, and the increase trend changes rapidly. When the target temperature of the evaporator is not achieved, the battery electronic expansion valve is slowly reduced. Purpose: to ensure the priority of battery side refrigeration demand.

[0167] (1) When the priority of the battery refrigeration level is higher than that of the passenger cabin refrigeration level, the evaporator temperature has achieved the target, and the opening degree of the battery electronic expansion valve is increased. The greater the excess amount, the greater the opening degree of the battery electronic expansion valve, i.e. A2>B2≥A1>B1.

[0168] (2) When the priority of the battery cooling level is higher than that of the passenger cabin cooling level, the evaporator does not achieve the target, and the battery electronic expansion valve opening degree is reduced. The greater the gap from the target, the greater the reduction of the battery electronic expansion valve opening degree, that is, A2>B2>=|D2|>|C2|, and |C2|<|D2|<=|C1|<|D1|.

[0169] After the initial state is maintained for 3 min, the battery electronic expansion valve opening degree increment or decrement is calculated according to the difference between the actual water inlet temperature of the battery and the target temperature.

[0170] The battery water inlet temperature difference (actual-target) opening degree change is calculated according to Table 4. The calibration method of Table 4 is as follows: when the battery achieves the target, the battery electronic expansion valve opening degree is allowed to be reduced, and the reduction trend is slow. When the target temperature of the battery is not achieved, the battery electronic expansion valve is rapidly increased. The purpose is to ensure that the battery side cooling demand is prioritized.

[0171] (1) When the priority of the battery cooling level is higher than that of the passenger cabin cooling level, the battery temperature has achieved the target, and the battery electronic expansion valve opening degree is reduced. The greater the excess of the target, the greater the reduction of the battery electronic expansion valve opening degree, that is, |A3|>|B3|>=|A4|>|B4|.

[0172] (2) When the priority of the battery cooling level is higher than that of the passenger cabin cooling level, the battery does not achieve the target, and the battery electronic expansion valve opening degree is increased. The greater the gap from the target, the greater the increase of the battery electronic expansion valve opening degree, that is, D4>C4>=D3>C3.

[0173] The step increment is set to change every 50 ms, and at most 6 steps per second, because there is an initial opening degree, and less than 10 steps per second meets the dynamic opening degree adjustment demand of the electronic expansion valve, preventing the electronic expansion valve from changing too much instantaneously and causing oscillation of the refrigeration system.

[0174] The two step increments calculated for the passenger cabin side and the battery side demand are controlled by taking the minimum value.

[0175] Through the embodiment, the battery electronic expansion valve control is relatively accurate, avoids unreasonable distribution of refrigerant, improves the accuracy of passenger cabin and battery cooling at the same time, and saves energy consumption. The double-temperature-difference cooperative control algorithm simultaneously considers the actual temperature demand of the passenger cabin and the battery, improves the reliability, and improves the refrigeration safety.

[0176] It should be understood that although each step in the flowchart involved in each embodiment as described above is shown in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, there is no strict order limitation for the execution of these steps, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each embodiment as described above can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be alternately or alternately executed with at least part of other steps or steps or stages in other steps. It can be understood that the steps in different embodiments can be freely combined as needed, and various non-contradictory schemes formed by the combination are within the scope of protection of the present application.

[0177] Based on the same inventive concept, the embodiments of the present application also provide a battery electronic expansion valve control device for implementing the battery electronic expansion valve control method described above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more battery electronic expansion valve control device embodiments provided below can refer to the limitations of the battery electronic expansion valve control method described above, and will not be repeated here.

[0178] In one embodiment, as shown in Figure 5 A battery electronic expansion valve control device is provided, comprising: a refrigeration priority acquisition module 501, a first instruction generation module 502, a refrigeration temperature difference acquisition module 503, and a second instruction generation module 504, wherein:

[0179] The refrigeration priority acquisition module 501 is configured to acquire a refrigeration priority relationship between the battery and the passenger compartment of the target vehicle when the battery and the passenger compartment of the target vehicle are refrigerated at the same time.

[0180] The first instruction generation module 502 is configured to acquire an initial opening degree of the electronic expansion valve of the battery based on the refrigeration priority relationship, and control the opening degree of the electronic expansion valve based on the initial opening degree until the refrigeration system of the target vehicle enters a quasi-steady state operation stage.

[0181] The refrigeration temperature difference acquisition module 503 is configured to acquire an evaporator temperature difference and a battery water inlet temperature difference of the target vehicle after the refrigeration system of the target vehicle enters the quasi-steady state operation stage.

[0182] The second instruction generation module 504 is configured to acquire an opening degree adjustment step length of the electronic expansion valve according to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, and control the opening degree of the electronic expansion valve to be adjusted according to the opening degree adjustment step length.

[0183] In one embodiment, the second instruction generation module 504 is further configured to obtain a first opening degree adjustment increment according to the refrigeration priority relationship and the evaporator temperature difference; obtain a second opening degree adjustment increment according to the refrigeration priority relationship and the water inlet temperature difference of the battery; and take the smaller value of the first opening degree adjustment increment and the second opening degree adjustment increment as the opening degree adjustment increment of the electronic expansion valve.

[0184] In one embodiment, the evaporator temperature difference is the difference between the actual temperature value of the evaporator of the passenger compartment and the target temperature value of the evaporator, and the second instruction generation module 504 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than that of the passenger compartment, obtain an opening degree adjustment increment matched with the evaporator temperature difference as the first opening degree adjustment increment according to a first pre-labeled increment mapping relationship; wherein the first increment mapping relationship stores a corresponding relationship between different evaporator temperature differences and different opening degree adjustment increments, the evaporator temperature difference and the opening degree adjustment increment are in a negative correlation relationship, and the change trend of the opening degree adjustment increment in a case where the evaporator temperature difference is negative is slower than that in a case where the evaporator temperature difference is positive.

[0185] In one embodiment, the evaporator temperature difference is the difference between the actual temperature value of the evaporator of the passenger compartment and the target temperature value of the evaporator, and the second instruction generation module 504 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is higher than that of the passenger compartment, obtain an opening degree adjustment increment matched with the evaporator temperature difference as the first opening degree adjustment increment according to a second pre-labeled increment mapping relationship; wherein the second increment mapping relationship stores a corresponding relationship between different evaporator temperature differences and different opening degree adjustment increments, the evaporator temperature difference and the opening degree adjustment increment are in a negative correlation relationship, and the change trend of the opening degree adjustment increment in a case where the evaporator temperature difference is negative is faster than that in a case where the evaporator temperature difference is positive.

[0186] In one embodiment, the water inlet temperature difference of the battery is the difference between the actual temperature value of the water inlet of the battery and the target temperature value of the water inlet, and the second instruction generation module 504 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than that of the passenger compartment, obtain an opening degree adjustment increment matched with the water inlet temperature difference of the battery as the second opening degree adjustment increment according to a third pre-labeled increment mapping relationship; wherein the third increment mapping relationship stores a corresponding relationship between different water inlet temperature differences of the battery and different opening degree adjustment increments, the water inlet temperature difference of the battery and the opening degree adjustment increment are in a positive correlation relationship, and the change trend of the opening degree adjustment increment in a case where the water inlet temperature difference of the battery is negative is faster than that in a case where the water inlet temperature difference of the battery is positive.

[0187] In one embodiment, the battery water inlet temperature difference is a difference between an actual temperature value of the battery water inlet and a target temperature value of the water inlet, the second instruction generation module 504 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, acquire, according to a fourth step length increment mapping relationship calibrated in advance, an opening degree adjustment step length matched with the battery water inlet temperature difference as the second opening degree adjustment step length; wherein the fourth step length increment mapping relationship stores a corresponding relationship between different battery water inlet temperature differences and different opening degree adjustment step lengths, the battery water inlet temperature difference and the opening degree adjustment step length are in a positive correlation relationship, and a change trend of the opening degree adjustment step length in a case where the battery water inlet temperature difference is negative is slower than a change trend of the opening degree adjustment step length in a case where the battery water inlet temperature difference is positive.

[0188] In one embodiment, the first instruction generation module 502 is further configured to acquire a maximum core temperature of the battery and an instantaneous charge-discharge power of the battery; acquire a reference initial opening degree of the electronic expansion valve according to the refrigeration priority relationship and the maximum core temperature, and acquire an initial opening degree correction amount of the electronic expansion valve according to the refrigeration priority relationship and the instantaneous charge-discharge power; and correct the reference initial opening degree by using the initial opening degree correction amount to obtain the initial opening degree of the electronic expansion valve.

[0189] In one embodiment, the first instruction generation module 502 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, acquire, according to a first opening degree mapping relationship calibrated in advance, an opening degree value matched with the maximum core temperature as the reference initial opening degree; wherein the first opening degree mapping relationship stores a corresponding relationship between different maximum core temperatures and different opening degree values, and the maximum core temperature and the opening degree value are in a positive correlation relationship.

[0190] In one embodiment, the first instruction generation module 502 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger compartment, acquire, according to a second opening degree mapping relationship calibrated in advance, an opening degree value matched with the maximum core temperature as the reference initial opening degree; wherein the second opening degree mapping relationship stores a corresponding relationship between different maximum core temperatures and different opening degree values, the maximum core temperature and the opening degree value are in a positive correlation relationship, and in a case where the maximum core temperature is the same, the opening degree value in the first opening degree mapping relationship is smaller than the opening degree value in the second opening degree mapping relationship.

[0191] In one embodiment, the first instruction generation module 502 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, obtain, as the initial opening degree correction amount, an opening degree correction amount matched with the instantaneous charge-discharge power according to a third opening degree mapping relationship calibrated in advance; wherein the third opening degree mapping relationship stores a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction amounts, and the instantaneous charge-discharge power and the opening degree correction amount are in a positive correlation relationship.

[0192] In one embodiment, the first instruction generation module 502 is further configured to, in a case where the refrigeration priority relationship indicates that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger compartment, obtain, as the initial opening degree correction amount, an opening degree correction amount matched with the instantaneous charge-discharge power according to a fourth opening degree mapping relationship calibrated in advance; wherein the fourth opening degree mapping relationship stores a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction amounts, and the instantaneous charge-discharge power and the opening degree correction amount are in a positive correlation relationship, and in a case where the instantaneous charge-discharge power is the same, the opening degree correction amount in the third opening degree mapping relationship is smaller than the opening degree correction amount in the fourth opening degree mapping relationship.

[0193] The above-mentioned various modules in the battery electronic expansion valve control device can be realized by software, hardware, and combinations thereof, in whole or in part. The above-mentioned various modules can be embedded in or independent of the processor in the controller in hardware form, or can be stored in the memory in the controller in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned various modules.

[0194] In one embodiment, a controller is provided, and its internal structure diagram can be as shown in Figure 6 The controller includes a processor, a memory, an input / output interface, and a communication interface. The processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the controller is configured to provide computing and control capabilities. The memory of the controller includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The input / output interface of the controller is configured to exchange information between the processor and external devices. The communication interface of the controller is configured to perform wired or wireless communication with external terminals, and the wireless communication can be achieved through WIFI, mobile cellular network, near field communication (NFC), or other technologies. The computer program is executed by the processor to implement a battery electronic expansion valve control method.

[0195] Those skilled in the art can understand that Figure 6The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the controller to which the scheme of the present application is applied. The specific controller can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0196] In an embodiment, a controller is also provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method embodiments when executing the computer program.

[0197] In an embodiment, a vehicle thermal management system is also provided, as shown in Figure 7 The system can include a controller as shown in Figure 6 The controller is in communication connection with the battery electronic expansion valve in the vehicle thermal management system, and the opening degree of the battery electronic expansion valve can be controlled through the steps in the above method embodiments. The vehicle thermal management system can also include an evaporator electronic expansion valve, wherein the passenger cabin refrigeration circuit is evaporator electronic expansion valve -> evaporator -> compressor -> condenser -> evaporator electronic expansion valve, and the battery refrigeration circuit is battery electronic expansion valve -> refrigeration machine refrigerant side -> compressor -> condenser -> battery electronic expansion valve, so that the battery electronic expansion valve is connected to the refrigerant side in the refrigeration machine, the evaporator electronic expansion valve is connected to the evaporator, and the evaporator is connected to the compressor and the condenser in the refrigeration machine to form the passenger cabin refrigeration circuit and the battery refrigeration circuit, and the water side of the refrigeration machine is connected to the battery pack and the water pump, so that the refrigerant can exchange heat with the battery water side heat at the refrigeration machine and evaporate to absorb heat, enter the compressor to be compressed into high-temperature and high-pressure gas, be condensed into liquid refrigerant through the condenser, and then be refrigerated through the battery electronic expansion valve to form a refrigeration cycle.

[0198] In an embodiment, an automobile is also provided, as shown in Figure 8 The automobile can carry a vehicle thermal management system as shown in Figure 7

[0199] In an embodiment, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0200] In an embodiment, a computer program product is provided, including a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0201] ​It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0202] It can be understood by those skilled in the art that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. In the embodiments provided in the present application, any reference to memory, database or other medium can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0203] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, any combination of these technical features is deemed to be within the scope of the present application.

[0204] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method of controlling a battery electronic expansion valve, characterized by, The method comprises: In the case that the battery of the target vehicle is refrigerated at the same time as the passenger cabin, the refrigeration priority relationship between the battery and the passenger cabin is obtained; Based on the refrigeration priority relationship, the initial opening degree of the electronic expansion valve of the battery is obtained, and the opening degree of the electronic expansion valve is controlled based on the initial opening degree until the refrigeration system of the target vehicle enters the quasi-steady state operation stage; the refrigeration priority relationship, the maximum core temperature of the battery and the instantaneous charging and discharging power of the battery are obtained; the reference initial opening degree of the electronic expansion valve is obtained according to the refrigeration priority relationship and the maximum core temperature, and the initial opening degree correction of the electronic expansion valve is obtained according to the refrigeration priority relationship and the instantaneous charging and discharging power; the initial opening degree of the electronic expansion valve is obtained by correcting the reference initial opening degree by using the initial opening degree correction. After the refrigeration system of the target vehicle enters the quasi-steady state operation stage, the evaporator temperature difference and the battery water inlet temperature difference of the target vehicle are obtained. According to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, the opening degree adjustment step length of the electronic expansion valve is obtained, and the opening degree of the electronic expansion valve is controlled to adjust according to the opening degree adjustment step length.

2. The method of claim 1, wherein, According to the refrigeration priority relationship and the evaporator temperature difference, a first opening degree adjustment step length is obtained; According to the refrigeration priority relationship and the battery water inlet temperature difference, a second opening degree adjustment step length is obtained; The smaller value of the first opening degree adjustment step length and the second opening degree adjustment step length is taken as the opening degree adjustment step length of the electronic expansion valve. The evaporator temperature difference is the difference between the actual temperature value of the evaporator of the passenger cabin and the target temperature value of the evaporator, and the first opening degree adjustment step length is obtained according to the refrigeration priority relationship and the evaporator temperature difference, comprising:

3. The method of claim 2, wherein, In the case that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger cabin, the opening degree adjustment step length matched with the evaporator temperature difference is obtained as the first opening degree adjustment step length according to the first step length mapping relationship calibrated in advance; wherein the first step length mapping relationship stores the corresponding relationship between different evaporator temperature differences and different opening degree adjustment step lengths, the evaporator temperature difference and the opening degree adjustment step length are in a negative correlation relationship, and the change trend of the opening degree adjustment step length is slower than that of the evaporator temperature difference when the evaporator temperature difference is negative. The evaporator temperature difference is the difference between the actual temperature value of the evaporator of the passenger cabin and the target temperature value of the evaporator, and the first opening degree adjustment step length is obtained according to the refrigeration priority relationship and the evaporator temperature difference, comprising:

4. The method of claim 2, wherein, ​ In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger cabin, a second opening degree adjustment step length matched with the evaporator temperature difference is obtained as the first opening degree adjustment step length according to a second step length mapping relationship calibrated in advance, wherein the second step length mapping relationship stores a corresponding relationship between different evaporator temperature differences and different opening degree adjustment step lengths, the evaporator temperature difference and the opening degree adjustment step length are in a negative correlation relationship, and a change trend of the opening degree adjustment step length in a case where the evaporator temperature difference is negative is faster than a change trend of the opening degree adjustment step length in a case where the evaporator temperature difference is positive.

5. The method of claim 2, wherein, The battery water inlet temperature difference is a difference between an actual temperature value and a target temperature value of a water inlet of the battery, and the second opening degree adjustment step length is obtained according to the refrigeration priority relationship and the battery water inlet temperature difference, including: In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is not higher than the refrigeration priority of the passenger cabin, a second opening degree adjustment step length matched with the battery water inlet temperature difference is obtained as the second opening degree adjustment step length according to a third step length mapping relationship calibrated in advance, wherein the third step length mapping relationship stores a corresponding relationship between different battery water inlet temperature differences and different opening degree adjustment step lengths, the battery water inlet temperature difference and the opening degree adjustment step length are in a positive correlation relationship, and a change trend of the opening degree adjustment step length in a case where the battery water inlet temperature difference is negative is faster than a change trend of the opening degree adjustment step length in a case where the battery water inlet temperature difference is positive.

6. The method of claim 2, wherein, The battery water inlet temperature difference is a difference between an actual temperature value and a target temperature value of a water inlet of the battery, and the second opening degree adjustment step length is obtained according to the refrigeration priority relationship and the battery water inlet temperature difference, including: In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is higher than the refrigeration priority of the passenger cabin, a second opening degree adjustment step length matched with the battery water inlet temperature difference is obtained as the second opening degree adjustment step length according to a fourth step length mapping relationship calibrated in advance, wherein the fourth step length mapping relationship stores a corresponding relationship between different battery water inlet temperature differences and different opening degree adjustment step lengths, the battery water inlet temperature difference and the opening degree adjustment step length are in a positive correlation relationship, and a change trend of the opening degree adjustment step length in a case where the battery water inlet temperature difference is negative is slower than a change trend of the opening degree adjustment step length in a case where the battery water inlet temperature difference is positive.

7. The method of claim 1, wherein, The reference initial opening degree of the electronic expansion valve is obtained according to the refrigeration priority relationship and the maximum core temperature, including: In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is not higher than that of the passenger cabin, an opening degree value matched with the maximum core temperature is obtained as the reference initial opening degree according to a first opening degree mapping relationship calibrated in advance, wherein the first opening degree mapping relationship stores a corresponding relationship between different maximum core temperatures and different opening degree values, and the maximum core temperature and the opening degree value are in a positive correlation relationship.

8. The method of claim 7, wherein, The method further includes: In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is higher than that of the passenger cabin, an opening degree value matched with the maximum core temperature is obtained as the reference initial opening degree according to a second opening degree mapping relationship calibrated in advance, wherein the second opening degree mapping relationship stores a corresponding relationship between different maximum core temperatures and different opening degree values, the maximum core temperature and the opening degree value are in a positive correlation relationship, and in a case where the maximum core temperatures are the same, the opening degree value in the first opening degree mapping relationship is smaller than that in the second opening degree mapping relationship.

9. The method of claim 1, wherein, The method further includes: In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is not higher than that of the passenger cabin, an opening degree correction value matched with the instantaneous charge-discharge power is obtained as the initial opening degree correction value according to a third opening degree mapping relationship calibrated in advance, wherein the third opening degree mapping relationship stores a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction values, and the instantaneous charge-discharge power and the opening degree correction value are in a positive correlation relationship.

10. The method of claim 9, wherein, The method further includes: In a case where the refrigeration priority relationship represents that the refrigeration priority of the battery is not higher than that of the passenger cabin, an opening degree correction value matched with the instantaneous charge-discharge power is obtained as the initial opening degree correction value according to a fourth opening degree mapping relationship calibrated in advance, wherein the fourth opening degree mapping relationship stores a corresponding relationship between different instantaneous charge-discharge powers and different opening degree correction values, the instantaneous charge-discharge power and the opening degree correction value are in a positive correlation relationship, and in a case where the instantaneous charge-discharge powers are the same, the opening degree correction value in the third opening degree mapping relationship is smaller than that in the fourth opening degree mapping relationship.

11. A battery electronic expansion valve control device characterized by comprising: The apparatus includes: a refrigeration priority obtaining module configured to obtain a refrigeration priority relationship of a battery and a passenger cabin of a target vehicle in a case where the battery and the passenger cabin are refrigerated at the same time; a refrigeration priority obtaining module configured to obtain a refrigeration priority relationship of a battery and a passenger cabin of a target vehicle in a case where the battery and the passenger cabin are refrigerated at the same time; The first instruction generation module is configured to obtain an initial opening degree of an electronic expansion valve of the battery based on the refrigeration priority relationship, and control the opening degree of the electronic expansion valve based on the initial opening degree until the refrigeration system of the target vehicle enters a quasi-steady state operation stage; further configured to obtain a maximum core temperature of the battery and an instantaneous charging and discharging power of the battery; obtain a reference initial opening degree of the electronic expansion valve according to the refrigeration priority relationship and the maximum core temperature, and obtain an initial opening degree correction amount of the electronic expansion valve according to the refrigeration priority relationship and the instantaneous charging and discharging power; and correct the reference initial opening degree by using the initial opening degree correction amount to obtain the initial opening degree of the electronic expansion valve; The refrigeration temperature difference acquisition module is configured to obtain an evaporator temperature difference and a battery water inlet temperature difference of the target vehicle after the refrigeration system of the target vehicle enters the quasi-steady state operation stage. The second instruction generation module is configured to obtain an opening degree adjustment step length of the electronic expansion valve according to the refrigeration priority relationship and the evaporator temperature difference and the battery water inlet temperature difference, and control the opening degree of the electronic expansion valve to be adjusted according to the opening degree adjustment step length.

12. A vehicle thermal management system characterized by, The controller is in communication connection with a battery electronic expansion valve and an evaporator electronic expansion valve, the battery electronic expansion valve is connected to a refrigerant side in a refrigeration machine, a water side of the refrigeration machine is connected to a battery pack and a water pump, the evaporator electronic expansion valve is connected to an evaporator, and the evaporator is connected to the refrigeration machine through a compressor and a condenser; wherein the controller is configured to implement the steps of the method of any one of claims 1 to 10. The vehicle thermal management system as claimed in claim 12.

13. An automobile characterized by comprising: The vehicle thermal management system as claimed in claim 12.

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