Method and device for constant temperature cooling of power battery water inlet based on electronic expansion valve

Abstract

The application provides a method and device for constant-temperature cooling of a power battery water inlet based on an electronic expansion valve, which comprises the following steps: receiving a cooling request of a power battery; acquiring a current temperature and a target temperature of a power battery water inlet in real time; calculating a difference between the current temperature and the target temperature; judging whether the difference is greater than a first threshold value; in the case that the difference is greater than the first threshold value, controlling the electronic expansion valve to execute an overheating degree mode; and in the case that the difference is less than or equal to the first threshold value, controlling the electronic expansion valve to execute a constant-opening degree mode, adjusting and maintaining the difference to be zero. In any working condition, the temperature of the power battery water inlet can be cooled at a constant temperature, and the service life of the power battery is prolonged; moreover, the control strategy can be completely extended, and is almost not affected by changes of other parts of the vehicle, so that the development cycle of the vehicle is shortened, the development cost of the vehicle is reduced, and the market competitiveness is improved.

Description

Technical Field

[0001] This application relates to the field of thermal management for new energy vehicles, and in particular to a method and apparatus for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve. Background Technology

[0002] Currently, most manufacturers still use fans to cool the coolant in the cooling control schemes of power batteries for new energy vehicles. However, air cooling is greatly affected by vehicle environmental factors and cannot significantly reduce the temperature, resulting in the inlet temperature of the power battery not being accurately controlled. Under harsh driving conditions, the target temperature of the power battery inlet may not even be reached, causing the power battery to operate at abnormal operating temperatures for a long time, which will reduce the service life of the power battery.

[0003] Furthermore, although some power battery cooling control schemes use electronic expansion valves, which, along with the battery cooler, cool the power battery, existing control strategies all employ overheat-based control of the electronic expansion valve's operation. This often results in cooling overshoot, wasting cooling resources. Moreover, the existing control strategies exhibit varying cooling effects under different operating conditions, demonstrating poor versatility.

[0004] Furthermore, the current cooling control strategy for power batteries in new energy vehicles is also greatly affected by changes in other components, resulting in poor software usability.

[0005] In view of this, the present invention is proposed to partially solve the problems existing in the prior art. Summary of the Invention

[0006] In existing technologies, the inlet temperature of power batteries cannot be precisely controlled, causing the power batteries to operate at abnormal temperatures for extended periods, which reduces their lifespan or leads to cooling overshoot and wastes cooling resources.

[0007] According to a first aspect of the present invention, a method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve is provided, the method comprising:

[0008] Upon receiving a cooling request from the power battery; the current temperature and target temperature of the power battery inlet are acquired in real time; the difference between the current temperature and the target temperature is calculated; it is determined whether the difference is greater than a first threshold; if the difference is greater than the first threshold, the electronic expansion valve is controlled to execute the superheat mode; if the difference is less than or equal to the first threshold, the electronic expansion valve is controlled to execute the constant opening mode, adjusting and maintaining the difference at zero.

[0009] Preferably, the superheat mode includes: sending a target superheat to the electronic expansion valve; wherein the target superheat is a calibrated superheat based on the development target of the vehicle's cooling rate for the power battery; so that the electronic expansion valve automatically adjusts based on the target superheat and reaches the corresponding opening degree.

[0010] Preferably, the electronic expansion valve automatically adjusts to achieve the corresponding opening degree based on the target superheat degree, including: the electronic expansion valve automatically adjusts to achieve the corresponding opening degree based on the target superheat degree using feedback control.

[0011] Preferably, the feedback control is PID control.

[0012] Preferably, the fixed opening mode includes: determining the first opening degree of the electronic expansion valve based on the difference and the first mapping relationship; wherein, the first mapping relationship is the mapping relationship between the difference and the first opening degree; and controlling the electronic expansion valve to reach the corresponding opening degree based on the first opening degree.

[0013] Preferably, the fixed opening mode includes: acquiring the pressure at the water inlet of the power battery; determining the second opening degree of the electronic expansion valve based on the difference, pressure, and a second mapping relationship; wherein, the second mapping relationship is the mapping relationship between the difference, pressure, and the second opening degree; and controlling the electronic expansion valve to reach the corresponding opening degree based on the second opening degree.

[0014] Preferably, the first threshold is 3°C.

[0015] According to a second aspect of the present invention, a constant temperature cooling control device for the water inlet of a power battery based on an electronic expansion valve is provided, the device comprising:

[0016] The receiving module is used to receive cooling requests from the power battery;

[0017] The first acquisition module is used to acquire the current temperature and target temperature of the power battery water inlet.

[0018] The calculation module is used to calculate the difference between the current dimension and the target temperature;

[0019] The judgment module is used to determine whether the difference is greater than a first threshold.

[0020] The first control module is used to control the electronic expansion valve to execute the superheat mode when the difference is greater than the first threshold.

[0021] The second control module is used to control the electronic expansion valve to execute a constant opening mode when the difference is less than or equal to the first threshold, thereby adjusting and maintaining the difference at zero.

[0022] Preferably, the first control module is used to: send a target superheat to the electronic expansion valve; wherein the target superheat is a superheat calibrated based on the development target of the vehicle's cooling rate of the power battery; so that the electronic expansion valve automatically adjusts based on the target superheat and reaches the corresponding opening degree.

[0023] Preferably, the first control module is used to: automatically adjust the electronic expansion valve based on the target superheat using feedback control to achieve the corresponding opening degree.

[0024] Preferably, the feedback control is PID control.

[0025] Preferably, the second control module is used to: determine the first opening degree of the electronic expansion valve based on the difference and the first mapping relationship; wherein, the first mapping relationship is the mapping relationship between the difference and the first opening degree; and control the electronic expansion valve to reach the corresponding opening degree based on the first opening degree.

[0026] Preferably, the second control module is used to: acquire the pressure at the water inlet of the power battery; determine the second opening degree of the electronic expansion valve based on the difference, pressure and a second mapping relationship; wherein the second mapping relationship is the mapping relationship between the difference, pressure and the second opening degree; and control the electronic expansion valve to reach the corresponding opening degree based on the second opening degree.

[0027] Preferably, the first threshold is 3°C.

[0028] According to a third aspect of the present invention, a system for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve is provided, the system comprising:

[0029] Electronic expansion valve is used to control the flow rate of refrigerant that exchanges heat with the power battery coolant;

[0030] The air conditioning system, as the source of vehicle cooling, is used to exchange heat with the coolant of the power battery through the control of the electronic expansion valve;

[0031] A battery cooler is a device used to achieve heat exchange between the refrigerant and the power battery.

[0032] Battery water pump: Used to drive the flow of coolant in the power battery cooling circuit, so as to facilitate heat exchange between the coolant and the air conditioning refrigerant;

[0033] Temperature sensor: used to collect the water inlet temperature of the power battery in real time;

[0034] Electronic expansion valve controller: Used to control the electronic expansion valve in real time via CAN or LIN communication according to a pre-set control strategy.

[0035] According to a fourth aspect of the present invention, an electronic device is provided, comprising: a processor and a memory storing computer program instructions;

[0036] When the processor executes computer program instructions, it implements any of the above-mentioned methods for constant temperature cooling of the power battery inlet based on an electronic expansion valve.

[0037] According to a fifth aspect of the present invention, a computer-readable storage medium is provided, on which computer program instructions are stored, which, when executed by a processor, implement any of the above-described methods for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve.

[0038] In summary, this invention provides a method and apparatus for constant-temperature cooling of the power battery inlet based on an electronic expansion valve. The method includes: receiving a cooling request from the power battery; acquiring the current temperature and target temperature of the power battery inlet in real time; calculating the difference between the current temperature and the target temperature; determining whether the difference is greater than a first threshold; if the difference is greater than the first threshold, controlling the electronic expansion valve to execute a superheat mode; if the difference is less than or equal to the first threshold, controlling the electronic expansion valve to execute a constant-opening mode, adjusting and maintaining the difference at zero. Under any operating condition, constant-temperature cooling can be achieved at the power battery inlet, extending the power battery's lifespan. Furthermore, the control strategy is fully reusable, almost unaffected by changes to other vehicle components, shortening the vehicle development cycle, reducing vehicle development costs, and enhancing market competitiveness. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 A flowchart illustrating a method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve, provided for embodiments of this application;

[0041] Figure 2 A structural diagram of a device for constant temperature cooling of the water inlet of a power battery based on an electronic expansion valve, provided for an embodiment of this application;

[0042] Figure 3 A structural diagram of a power battery inlet constant temperature cooling system based on an electronic expansion valve, provided for an embodiment of this application;

[0043] Figure 4 A control principle diagram of a method for constant temperature cooling of the water inlet of a power battery based on an electronic expansion valve, provided for embodiments of this application;

[0044] Figure 5 This is a structural diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0045] To make the above and other features and advantages of this application clearer, the application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art and are exemplary only, not restrictive.

[0046] In the following description, numerous specific details are set forth to provide a thorough understanding of this application. However, it will be apparent to those skilled in the art that the specific details are not required to practice this application. In other instances, well-known steps or operations have not been described in detail to avoid obscuring this application.

[0047] Because existing technologies cannot accurately control the output flow of the oil pump based on oil demand, insufficient cooling may lead to system overheating, reducing the drivability of the vehicle and resulting in a poor customer experience; or excessive cooling may lead to increased power consumption of the thermal management system and energy waste.

[0048] refer to Figure 1 As shown, this application provides a method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve, the method comprising:

[0049] S110 received a cooling request for the power battery.

[0050] Specifically, the executing entity of this invention is a vehicle controller or an electronic expansion valve controller. Upon receiving a cooling request from the power battery, the vehicle controller or electronic expansion valve controller activates the power battery cooling function. This cooling request can be automatically generated after a preset vehicle driving time or a preset power battery charging time, or it can be triggered when the power battery temperature reaches a preset temperature.

[0051] S120 can acquire the current temperature and target temperature of the power battery water inlet in real time.

[0052] Specifically, after the vehicle controller or electronic expansion valve controller activates the power battery cooling function, it acquires the current temperature and target temperature of the power battery water inlet in real time. The target temperature of the power battery water inlet is the temperature of the cooling water suitable for cooling the power battery, which can be preset according to the power battery model, vehicle model, etc.

[0053] S130, calculate the difference between the current temperature and the target temperature.

[0054] S140, determine whether the difference is greater than the first threshold.

[0055] Specifically, after the vehicle controller or electronic expansion valve controller obtains the current temperature and target temperature of the power battery inlet, it calculates the difference between the current temperature and the target temperature and determines whether the difference is greater than a first threshold value; the first threshold value is a preset value. It should be noted that, based on the condition of activating the power battery cooling function, the difference between the current temperature and the target temperature is generally a positive value.

[0056] S150, if the difference is greater than the first threshold, control the electronic expansion valve to execute the superheat mode.

[0057] Specifically, based on the development goals for the vehicle's cooling rate of the power battery, a target superheat will be pre-defined to ensure the cooling effect on the power battery. The smaller the target superheat value, the better the cooling effect on the power battery.

[0058] In the first stage of the cooling process, when the difference between the current temperature and the target temperature at the power battery inlet is greater than the first threshold, the vehicle controller or the electronic expansion valve controller controls the electronic expansion valve to execute the superheat mode, that is, the target superheat is sent to the electronic expansion valve, and the electronic expansion valve will automatically control its internal position according to the target superheat, that is, automatically adjust to reach the corresponding opening degree.

[0059] In some preferred embodiments, the electronic expansion valve can be automatically adjusted to the corresponding opening degree using feedback control, wherein the feedback control can be PID control.

[0060] S160, when the difference is less than or equal to the first threshold, control the electronic expansion valve to execute the constant opening mode, adjust and maintain the difference to zero.

[0061] Specifically, because the superheat mode is greatly affected by vehicle operating conditions and environmental factors, it is difficult to achieve precise control of the water inlet temperature of the power battery. Therefore, the superheat mode can only be used in the first stage of the cooling process.

[0062] To ensure a constant temperature after the battery inlet temperature reaches the target temperature, in the second stage of the cooling process (when the difference between the current temperature and the target temperature at the battery inlet is less than or equal to a first threshold), the vehicle controller or electronic expansion valve controller controls the operation of the electronic expansion valve. The vehicle pre-stores the internal position (opening degree) of the electronic expansion valve corresponding to the difference between the target and current temperatures at the battery inlet. Therefore, the vehicle controller or electronic expansion valve controller can query the corresponding electronic expansion valve opening degree based on the difference and control the electronic expansion valve to achieve the appropriate opening. This enables dynamic adjustment of the refrigerant flow and ensures a constant battery inlet temperature under all operating conditions.

[0063] In some preferred embodiments, the vehicle controller or electronic expansion valve controller can also collect the pressure at the power battery inlet, and based on the difference between the target temperature and the current temperature at the power battery inlet and the pressure at the power battery inlet, query and determine the opening degree of the electronic expansion valve, and control the electronic expansion valve to reach the corresponding opening degree.

[0064] In some other preferred solutions, the first threshold can be set to 3°C, which can ensure that there is sufficient buffer space in the first stage of the cooling process to prevent overshoot when using the overheating mode; and since 3°C is a small control space, the computational load of the vehicle controller and the electronic expansion valve controller can be reduced in the second stage of the cooling process, thereby improving the efficiency of controlling and regulating the electronic expansion valve.

[0065] In summary, 1) this invention solves the problem that the water inlet temperature of the power battery can be kept constant under different operating conditions of new energy vehicles, improves the control accuracy of power battery cooling in the current industry, ensures that the power battery works at the ideal temperature, and improves its service life.

[0066] 2) This invention uses the difference between the target temperature and the current temperature of the power battery inlet to perform detailed electronic expansion valve control. It is not affected by changes in other components, and the control strategy can be fully reused, thereby reducing the vehicle development cycle and cost and enhancing market competitiveness.

[0067] 3) This invention combines two control methods for the electronic expansion valve: superheat and constant opening, so that the advantages of each control method are maximized and the overall vehicle cooling effect is optimal.

[0068] like Figure 2 As shown, the present invention also provides a constant temperature cooling control device for the water inlet of a power battery based on an electronic expansion valve, the device comprising:

[0069] The receiving module 201 is used to receive a cooling request from the power battery;

[0070] Specifically, the executing entity of this invention is a vehicle controller or an electronic expansion valve controller. Upon receiving a cooling request from the power battery, the vehicle controller or electronic expansion valve controller activates the power battery cooling function. This cooling request can be automatically generated after a preset vehicle driving time or a preset power battery charging time, or it can be triggered when the power battery temperature reaches a preset temperature.

[0071] The first acquisition module 202 is used to acquire the current temperature and target temperature of the power battery water inlet.

[0072] Specifically, after the vehicle controller or electronic expansion valve controller activates the power battery cooling function, it acquires the current temperature and target temperature of the power battery water inlet in real time. The target temperature of the power battery water inlet is the temperature of the cooling water suitable for cooling the power battery, which can be preset according to the power battery model, vehicle model, etc.

[0073] Calculation module 203 is used to calculate the difference between the current dimension and the target temperature;

[0074] The judgment module 204 is used to determine whether the difference is greater than the first threshold.

[0075] Specifically, after the vehicle controller or electronic expansion valve controller obtains the current temperature and target temperature of the power battery inlet, it calculates the difference between the current temperature and the target temperature and determines whether the difference is greater than a first threshold value; the first threshold value is a preset value. It should be noted that, based on the condition of activating the power battery cooling function, the difference between the current temperature and the target temperature is generally a positive value.

[0076] The first control module 205 is used to control the electronic expansion valve to execute the superheat mode when the difference is greater than the first threshold.

[0077] Specifically, based on the development goals for the vehicle's cooling rate of the power battery, a target superheat will be pre-defined to ensure the cooling effect on the power battery. The smaller the target superheat value, the better the cooling effect on the power battery.

[0078] In the first stage of the cooling process, when the difference between the current temperature and the target temperature at the power battery inlet is greater than the first threshold, the vehicle controller or the electronic expansion valve controller controls the electronic expansion valve to execute the superheat mode, that is, the target superheat is sent to the electronic expansion valve, and the electronic expansion valve will automatically control its internal position according to the target superheat, that is, automatically adjust to reach the corresponding opening degree.

[0079] In some preferred embodiments, the electronic expansion valve can be automatically adjusted to the corresponding opening degree using feedback control, wherein the feedback control can be PID control.

[0080] The second control module 206 is used to control the electronic expansion valve to execute a constant opening mode and adjust and maintain the difference to zero when the difference is less than or equal to the first threshold.

[0081] Specifically, because the superheat mode is greatly affected by vehicle operating conditions and environmental factors, it is difficult to achieve precise control of the water inlet temperature of the power battery. Therefore, the superheat mode can only be used in the first stage of the cooling process.

[0082] To ensure a constant temperature after the battery inlet temperature reaches the target temperature, in the second stage of the cooling process (when the difference between the current temperature and the target temperature at the battery inlet is less than or equal to a first threshold), the vehicle controller or electronic expansion valve controller controls the operation of the electronic expansion valve. The vehicle pre-stores the internal position (opening degree) of the electronic expansion valve corresponding to the difference between the target and current temperatures at the battery inlet. Therefore, the vehicle controller or electronic expansion valve controller can query the corresponding electronic expansion valve opening degree based on the difference and control the electronic expansion valve to achieve the appropriate opening. This enables dynamic adjustment of the refrigerant flow and ensures a constant battery inlet temperature under all operating conditions.

[0083] In some preferred embodiments, the vehicle controller or electronic expansion valve controller can also collect the pressure at the power battery inlet, and based on the difference between the target temperature and the current temperature at the power battery inlet and the pressure at the power battery inlet, query and determine the opening degree of the electronic expansion valve, and control the electronic expansion valve to reach the corresponding opening degree.

[0084] In some other preferred solutions, the first threshold can be set to 3°C, which can ensure that there is sufficient buffer space in the first stage of the cooling process to prevent overshoot when using the overheating mode; and since 3°C is a small control space, the computational load of the vehicle controller and the electronic expansion valve controller can be reduced in the second stage of the cooling process, thereby improving the efficiency of controlling and regulating the electronic expansion valve.

[0085] Reference Figure 3 This invention provides a system for constant temperature cooling of the water inlet of a power battery based on an electronic expansion valve. The system includes:

[0086] Electronic expansion valve 301 is used to control the flow rate of refrigerant that exchanges heat with the power battery coolant;

[0087] The air conditioning system, as the source of vehicle cooling, is used to exchange heat with the coolant of the power battery through the control of the electronic expansion valve;

[0088] Battery cooler 302 is a device for realizing heat exchange between refrigerant and power battery.

[0089] Battery water pump 303: Used to drive the flow of coolant in the power battery cooling circuit, so as to facilitate heat exchange between the coolant and the air conditioning refrigerant;

[0090] Temperature sensor 304: used for real-time acquisition of the water inlet temperature of the power battery;

[0091] Electronic expansion valve controller: Used to control the electronic expansion valve in real time via CAN or LIN communication according to a pre-set control strategy.

[0092] Reference Figures 3-4 The working principle of the constant temperature cooling system for the water inlet of the power battery based on the electronic expansion valve provided in this application is as follows:

[0093] The air conditioning system (including compressor 305 and cooler 306) compresses the refrigerant and then cools it through the condenser. The flow rate of the refrigerant through the battery cooler is controlled by the electronic expansion valve, thereby indirectly controlling the heat exchange and cooling effect of the battery cooling circuit. In addition, the refrigeration function of the passenger compartment is achieved by combining the shut-off valve 307 with the evaporator 308. It shares an air conditioning system with the power battery cooling system.

[0094] Specifically, when the power battery 309 sends a cooling request, the air conditioning system starts working, and the battery cooling circuit cools the battery through the battery cooler. In the first stage of battery cooling (inlet temperature 3°C higher than the target temperature), the electronic expansion valve is controlled based on superheat mode. The target superheat is sent to the electronic expansion valve controller, and the electronic expansion valve automatically adjusts its position according to the target superheat. In the second stage of battery cooling (target temperature + 3°C ≥ inlet temperature ≥ target temperature) or below the target temperature (target temperature > inlet temperature), the electronic expansion valve is controlled based on a constant opening mode. Based on the difference between the current power battery inlet temperature and the target temperature, the corresponding electronic expansion valve position request value is output, so that the difference between the inlet temperature and the target temperature approaches and remains at 0°C.

[0095] like Figure 5 As shown, this application provides an electronic device 500, which includes: a processor 501 and a memory 502 storing computer program instructions;

[0096] When the processor 501 executes computer program instructions, it implements the above-described method for precisely controlling the output flow of the oil pump in the electric drive assembly.

[0097] This application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the above-described method for precisely controlling the output flow of an oil pump in an electric drive assembly.

[0098] It should be understood that the specific features, operations, and details described herein with respect to the methods of this application can also be similarly applied to the apparatus and system of this application, or vice versa. Furthermore, each step of the methods of this application described above can be performed by a corresponding component or unit of the apparatus or system of this application.

[0099] It should be understood that the various modules / units of the apparatus of this application can be implemented wholly or partially through software, hardware, firmware, or a combination thereof. Each module / unit can be embedded in the processor of a computer device in hardware or firmware form or independent of the processor, or it can be stored in the memory of a computer device in software form for the processor to call to execute the operation of each module / unit. Each module / unit can be implemented as an independent component or module, or two or more modules / units can be implemented as a single component or module. In one embodiment, a computer device is provided, which includes a memory and a processor. The memory stores computer instructions executable by the processor. When executed by the processor, the computer instructions instruct the processor to perform the steps of the methods of the embodiments of this application. The computer device can be broadly defined as a server, a terminal, or any other electronic device with the necessary computing and / or processing capabilities. In one embodiment, the computer device may include a processor, memory, network interface, communication interface, etc., connected via a system bus. The processor of the computer device can be used to provide the necessary computing, processing, and / or control capabilities. The memory of the computer device may include non-volatile storage media and internal memory. The non-volatile storage media may store an operating system, computer programs, etc. The internal memory provides an environment for the operation of an operating system and computer programs stored in a non-volatile storage medium. The network interface and communication interface of the computer device can be used to connect and communicate with external devices via a network. When the computer program is executed by the processor, it performs the steps of the method described in this application.

[0100] This application can be implemented as a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, causes the steps of the methods of embodiments of this application to be performed. In one embodiment, the computer program is distributed across multiple network-coupled computer devices or processors, such that the computer program is stored, accessed, and executed by one or more computer devices or processors in a distributed manner. A single method step / operation, or two or more method steps / operations, may be executed by a single computer device or processor or by two or more computer devices or processors. One or more method steps / operations may be executed by one or more computer devices or processors, and one or more other method steps / operations may be executed by one or more other computer devices or processors. One or more computer devices or processors may execute a single method step / operation, or execute two or more method steps / operations.

[0101] Those skilled in the art will understand that the method steps of this application can be performed by a computer program instructing related hardware, such as a computer device or processor. The computer program can be stored in a non-transitory computer-readable storage medium, and its execution causes the steps of this application to be performed. Depending on the context, any references herein to memory, storage, databases, or other media may include non-volatile and / or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0102] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve, characterized in that, The method includes: A cooling request for the power battery has been received. The current temperature and target temperature of the power battery inlet are obtained in real time, wherein the target temperature is the temperature of the cooling water suitable for cooling the power battery. Calculate the difference between the current temperature and the target temperature; Determine whether the difference is greater than a first threshold, where the first threshold is 3°C; When the difference is greater than a first threshold, i.e., the first stage of the cooling process, the electronic expansion valve is controlled to execute a superheat mode. The superheat mode includes sending a target superheat to the electronic expansion valve. The target superheat is a calibrated superheat based on the development target of the vehicle's cooling rate for the power battery. This causes the electronic expansion valve to automatically adjust and reach the corresponding opening degree based on the target superheat. When the difference is less than or equal to the first threshold, i.e., the second stage of the cooling process, the electronic expansion valve is controlled to execute a constant opening mode to adjust and maintain the difference at zero. The constant opening mode includes: acquiring the pressure at the power battery inlet; determining the second opening of the electronic expansion valve based on the difference, the pressure, and a second mapping relationship; wherein the second mapping relationship is the mapping relationship between the difference, the pressure, and the second opening; and controlling the electronic expansion valve to reach the corresponding opening based on the second opening.

2. The method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve according to claim 1, characterized in that, The electronic expansion valve automatically adjusts its opening degree based on the target superheat, including: The electronic expansion valve automatically adjusts to the corresponding opening degree based on the target superheat using feedback control.

3. The method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve according to claim 2, characterized in that, The feedback control is PID control.

4. The method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve according to claim 1, characterized in that, The fixed opening degree mode includes: Based on the difference and the first mapping relationship, the first opening degree of the electronic expansion valve is determined; wherein, the first mapping relationship is the mapping relationship between the difference and the first opening degree; Based on the first opening degree, the electronic expansion valve is controlled to reach the corresponding opening degree.

5. A constant temperature cooling control device for the water inlet of a power battery based on an electronic expansion valve, characterized in that, The device includes: The receiving module is used to receive cooling requests from the power battery; The first acquisition module is used to acquire the current temperature and target temperature of the power battery water inlet, wherein the target temperature is the temperature of the cooling water suitable for cooling the power battery. A calculation module is used to calculate the difference between the current dimension and the target temperature; The judgment module is used to determine whether the difference is greater than a first threshold, wherein the first threshold is 3°C; The first control module is used to control the electronic expansion valve to execute a superheat mode when the difference is greater than a first threshold, i.e., the first stage of the cooling process; the superheat mode includes: sending a target superheat to the electronic expansion valve; wherein the target superheat is a calibrated superheat based on the development target of the vehicle's cooling rate for the power battery; so that the electronic expansion valve automatically adjusts and reaches the corresponding opening degree based on the target superheat; The second control module is used to control the electronic expansion valve to execute a constant opening mode when the difference is less than or equal to the first threshold, i.e., the second stage of the cooling process, to adjust and maintain the difference at zero; the constant opening mode includes: acquiring the pressure at the water inlet of the power battery; determining the second opening of the electronic expansion valve based on the difference, the pressure, and a second mapping relationship; wherein the second mapping relationship is the mapping relationship between the difference, the pressure, and the second opening; and controlling the electronic expansion valve to reach the corresponding opening based on the second opening.

6. A system for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve, the system comprising: Electronic expansion valve is used to control the flow rate of refrigerant that exchanges heat with the power battery coolant; The air conditioning system, as the source of vehicle cooling, is used to exchange heat with the coolant of the power battery through the control of the electronic expansion valve; A battery cooler is a device used to achieve heat exchange between the refrigerant and the power battery. Battery water pump: Used to drive the flow of coolant in the power battery cooling circuit, so as to facilitate heat exchange between the coolant and the air conditioning refrigerant; Temperature sensor: used to collect the water inlet temperature of the power battery in real time; Electronic expansion valve controller: Used to control the electronic expansion valve in real time via CAN or LIN communication according to a pre-set control strategy, including: receiving a cooling request from the power battery; acquiring the current temperature and target temperature of the power battery inlet in real time, wherein the target temperature is the temperature of the cooling water suitable for cooling the power battery; calculating the difference between the current temperature and the target temperature; determining whether the difference is greater than a first threshold, wherein the first threshold is 3°C; and controlling the electronic expansion valve to execute a superheat mode when the difference is greater than the first threshold, i.e., the first stage of the cooling process; wherein the superheat mode includes: sending a target superheat to the electronic expansion valve; wherein the target superheat is based on the overall vehicle temperature... The development target for the cooling rate of the power battery is to calibrate the superheat; so that the electronic expansion valve automatically adjusts and reaches the corresponding opening degree based on the target superheat degree; when the difference is less than or equal to the first threshold, i.e., the second stage of the cooling process, the electronic expansion valve is controlled to execute a fixed opening mode, adjusting and maintaining the difference value to zero; the fixed opening mode includes: acquiring the pressure of the power battery inlet; determining the second opening degree of the electronic expansion valve based on the difference, the pressure, and a second mapping relationship; wherein, the second mapping relationship is the mapping relationship between the difference, the pressure, and the second opening degree; and controlling the electronic expansion valve to reach the corresponding opening degree based on the second opening degree.

7. An electronic device, characterized in that, The electronic device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, it implements the method for constant temperature cooling of the power battery inlet based on an electronic expansion valve as described in any one of claims 1-4.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the method for constant-temperature cooling of the water inlet of a power battery based on an electronic expansion valve as described in any one of claims 1-4.

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