Battery Cooling System Control Method and Battery Cooling System

Abstract

The present application discloses a method for controlling a battery cooling system, belonging to the technical field of vehicle battery cooling. The method is executed by a controller and includes: obtaining a first temperature measurement value, a second temperature measurement value, a third temperature measurement value, a first target temperature value, and a second target temperature value, where the first temperature measurement value is from a first temperature measuring element, the second temperature measurement value is from a second temperature measuring element, the third temperature measurement value is from a third temperature measuring element, the first target temperature value is the target temperature value at the liquid inlet end, and the second target temperature value is the target temperature value at the liquid outlet end; determining a target duty ratio in response to the first temperature measurement value being greater than or equal to a first cooling threshold temperature; determining a target rotational speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value; determining a target opening degree according to the target rotational speed, the third temperature measurement value, and the second target temperature value; sending the target duty ratio to a pump body, sending the target rotational speed to a compressor, and sending the target opening degree to an electronic expansion valve. This method can control the temperature of the in-vehicle battery pack more precisely.

Description

Technical Field

[0001] This application relates to the technical field of vehicle battery cooling, and particularly relates to a battery cooling system control method and a battery cooling system. Background Art

[0002] On-vehicle batteries are an important part of electric vehicles, and their direct function is to provide power for electric vehicles. When on-vehicle batteries are working, they will generate heat, and the accumulation of heat will cause the temperature of the on-vehicle battery pack to be too high, affecting the performance of the on-vehicle battery.

[0003] In related technologies, when it is measured that the temperature of the on-vehicle battery is higher than the temperature threshold, it is determined that the on-vehicle battery needs to be cooled. At this time, the on-vehicle battery located on the battery cooling circuit can take the heat of the on-vehicle battery away from the on-vehicle battery pack through the circulating flow of the coolant in the battery cooling circuit. However, only determining whether the on-vehicle battery pack needs to be cooled by measuring the temperature of the on-vehicle battery cannot ensure that the on-vehicle battery is always in a suitable temperature working range, which easily affects the performance of the on-vehicle battery and shortens the service life of the on-vehicle battery. Summary of the Invention

[0004] In view of this, this application provides a battery cooling system control method and a battery cooling system, which can ensure that the on-vehicle battery is always in a suitable temperature working range, improve the performance of the on-vehicle battery, and extend the service life of the on-vehicle battery.

[0005] Specifically, the technical solutions include the following:

[0006] On the one hand, an embodiment of this application provides a battery cooling system control method, which is applied in a battery cooling system. The battery cooling system includes a controller, a refrigeration circuit, and a battery cooling circuit. A compressor, an evaporator, an electronic expansion valve, and a heat exchanger are sequentially arranged on the refrigeration circuit. An on-vehicle battery pack, a pump body, and the heat exchanger are sequentially arranged on the battery cooling circuit. A first temperature measuring element is provided at the core of the on-vehicle battery pack, a second temperature measuring element is provided at the liquid inlet end of the cooling pipeline of the on-vehicle battery pack, and a third temperature measuring element is provided at the liquid outlet end of the heat exchanger on the refrigeration circuit. The controller is in signal connection with the pump body, the compressor, the electronic expansion valve, and the third temperature measuring element. The method is executed by the controller and includes:

[0007] Obtain a first temperature measurement value, a second temperature measurement value, a third temperature measurement value, a first target temperature value, and a second target temperature value, where the first temperature measurement value comes from the first temperature measuring element, the second temperature measurement value comes from the second temperature measuring element, the third temperature measurement value comes from the third temperature measuring element, the first target temperature value is the target temperature value of the liquid inlet end, and the second target temperature value is the target temperature value of the liquid outlet end;

[0008] Determine a target duty cycle in response to the first temperature measurement value being greater than or equal to a first cooling threshold temperature;

[0009] Determine a target rotational speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value;

[0010] Determine a target opening degree according to the target rotational speed, the third temperature measurement value, and the second target temperature value;

[0011] Send the target duty cycle to the pump body, send the target rotational speed to the compressor, and send the target opening degree to the electronic expansion valve.

[0012] In some embodiments, the determining the target rotational speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value includes:

[0013] Subtract the second temperature measurement value from the first target temperature value to obtain a first temperature difference;

[0014] Determine the target rotational speed according to a first temperature range in which the first temperature difference is located and a second temperature range in which the first temperature measurement value is located.

[0015] In some embodiments, the determining the target opening degree according to the target rotational speed, the third temperature measurement value, and the second target temperature value includes:

[0016] Subtract the third temperature measurement value from the second target temperature value to obtain a second temperature difference;

[0017] Determine the target opening degree according to a third temperature range in which the second temperature difference is located and a rotational speed range in which the target rotational speed is located.

[0018] In some embodiments, the vehicle-mounted battery pack has a plurality of battery cell modules, and the first temperature measuring member includes a plurality of temperature measuring units, and each temperature measuring unit correspondingly measures the temperature of one of the battery cell modules;

[0019] Wherein, the first temperature measurement value is the highest temperature value measured by the plurality of temperature measuring units.

[0020] In some embodiments, the method further includes:

[0021] In response to the first temperature measurement value being less than a second cooling threshold temperature, update the target duty cycle and the target opening degree, and stop sending the target rotational speed to the compressor, wherein the second cooling threshold temperature is less than the first cooling threshold temperature;

[0022] Send the updated target duty cycle to the pump body and send the updated target opening degree to the electronic expansion valve.

[0023] In some embodiments, the control method further includes:

[0024] Obtaining a fourth temperature measurement value, where the fourth temperature measurement value is from a first temperature measuring element, and the fourth temperature measurement value is the lowest temperature value measured by the plurality of temperature measuring units;

[0025] In response to the first temperature measurement value being less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value being greater than or equal to a first target difference, updating the target duty cycle;

[0026] Sending the updated target duty cycle to the pump body.

[0027] In some embodiments, the control method further includes:

[0028] In response to the first temperature measurement value being less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value being less than a second target difference, updating the target duty cycle, where the second target difference is less than the first target difference;

[0029] Sending the updated target duty cycle to the pump body.

[0030] In some embodiments, the battery cooling system further includes a battery manager, and the battery manager is in signal connection with the controller, the first temperature measuring element, and the second temperature measuring element. The method further includes:

[0031] In response to the first temperature measurement value being greater than or equal to the first cooling threshold temperature, obtaining a battery cooling request, the first target temperature value, and the second target temperature value;

[0032] Sending the battery cooling request, the first temperature measurement value, the second temperature measurement value, the first target temperature value, and the second target temperature value to the controller.

[0033] On the other hand, an embodiment of the present application provides a battery cooling system, and the system includes: a battery cooling circuit, a refrigeration circuit, and a controller;

[0034] A vehicle-mounted battery pack, a pump body, and a first heat exchange pipe of a heat exchanger are sequentially arranged on the battery cooling circuit. A first temperature measuring element is provided at the core of the vehicle-mounted battery pack, and a second temperature measuring element is provided at the liquid inlet end of the vehicle-mounted battery pack. The circulating medium in the battery cooling circuit is a first solvent;

[0035] A compressor, an evaporator, an electronic expansion valve, and a second heat exchange pipe of a heat exchanger are sequentially arranged on the refrigeration circuit. A third temperature measuring element is provided at the liquid outlet end of the second heat exchange pipe. The circulating medium in the refrigeration circuit is a second solvent;

[0036] The controller is in signal connection with the pump body, the compressor, the electronic expansion valve, and the third temperature measuring element.

[0037] In some embodiments, the system further includes a heat pump loop;

[0038] A compressor, the evaporator, a thermal expansion valve, and a radiator are sequentially arranged on the heat pump loop, and the circulating medium in the heat pump loop is the second solvent.

[0039] In the battery cooling system control method provided by the embodiments of the present application, when the first temperature measurement value of the in-vehicle battery pack is greater than or equal to the first cooling threshold temperature, the target duty ratio of the pump body is determined, and according to the first temperature measurement value of the in-vehicle battery pack, the second temperature measurement value at the liquid inlet end of the cooling pipeline, and the first target temperature value at the liquid inlet end of the cooling pipeline, the target rotation speed of the compressor is determined. According to the target rotation speed of the compressor, the third temperature measurement value at the liquid outlet end, and the second target temperature value at the liquid outlet end, the target opening degree of the electronic expansion valve is determined. By controlling the pump body, the compressor, and the electronic expansion valve, the temperature of the battery cells of the in-vehicle battery pack and the temperature at the liquid inlet end of the cooling pipeline of the in-vehicle battery pack are controlled. Therefore, in the battery cooling system control method provided by the embodiments of the present application, it is determined whether the in-vehicle battery pack needs to be cooled by measuring the temperature of the battery cells of the in-vehicle battery pack and the temperature at the liquid inlet end of the cooling pipeline of the in-vehicle battery pack, making the temperature control of the in-vehicle battery pack more accurate. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic structural diagram of a battery cooling system provided by an exemplary embodiment of the present application;

[0042] Figure 2 It is a schematic structural diagram of a battery cooling system provided by an exemplary embodiment of the present application;

[0043] Figure 3 It is a flowchart of a battery cooling system control method provided by an exemplary embodiment of the present application;

[0044] Figure 4 It is a flowchart of a method for determining the target rotation speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value in a battery cooling system control method provided by an exemplary embodiment of the present application;

[0045] Figure 5The flowchart of a method for determining a target opening degree according to a target rotational speed, a third temperature measurement value, and a second target temperature value in a battery cooling system control method provided by an exemplary embodiment of the present application.

[0046] The reference numerals in the figure are respectively represented as:

[0047] 1. Battery cooling circuit; 2. Refrigeration circuit; 3. On-vehicle battery pack; 31. First temperature measuring element; 32. Liquid inlet end; 33. Second temperature measuring element; 4. Pump body; 5. Heat exchanger; 51. First heat exchange pipe; 52. Second heat exchange pipe; 53. Liquid outlet end; 54. Third temperature measuring element; 6. Compressor; 7. Evaporator; 8. Electronic expansion valve; 9. Controller; 10. Heat pump circuit; 11. Thermal expansion valve; 12. Radiator; 13. Battery manager. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0049] The orientation terms involved in the embodiments of the present application, such as "upper", "lower", "side", etc., generally take Figure 1 the relative relationship of the orientation shown in [the figure] as a reference, and these orientation terms are only used to more clearly describe the relationship between the structures and the structures, rather than to describe the absolute orientation. When the product is placed in different postures, the orientation may change. For example, "upper" and "lower" may be interchanged.

[0050] Unless otherwise defined, all technical terms used in the embodiments of the present application have the same meaning as commonly understood by those of ordinary skill in the art.

[0051] To make the technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0052] Due to the advantages of environmental protection, high efficiency, harmlessness, and sustainable endurance, electric vehicles powered by power batteries have great development prospects. However, the performance, lifespan, and safety of power batteries are very sensitive to temperature. If the heat generated during the charging and discharging process of the battery is not released, the accumulation of heat will cause the battery temperature to rise, thereby affecting the working efficiency of the battery. In addition, the temperature difference between the internal temperature of the battery and the actual ambient temperature, as well as the temperature difference between individual cells within the battery pack, will have an adverse impact on the performance, lifespan, and safety of the battery. Battery cooling technology is of great significance in the battery thermal management system. By formulating the control strategy of the battery cooling system, the battery can be maintained within an appropriate temperature range, which can better improve the performance and service life of the power battery.

[0053] In related technologies, when it is measured that the temperature of the vehicle-mounted battery is higher than the temperature threshold, it is determined that the vehicle-mounted battery needs to be cooled. At this time, the vehicle-mounted battery located on the battery cooling circuit can transfer the heat of the vehicle-mounted battery away from the vehicle-mounted battery pack through the circulating flow of the coolant within the battery cooling circuit. However, only determining whether the vehicle-mounted battery pack needs to be cooled by measuring the temperature of the vehicle-mounted battery cannot ensure that the vehicle-mounted battery is always within an appropriate temperature range, which is likely to affect the performance of the vehicle-mounted battery and shorten its service life.

[0054] In view of this, to solve the problems existing in the prior art, the embodiments of the present application provide a battery cooling system, the structural schematic diagram of which is as Figure 1 shown.

[0055] See Figure 1 , the battery cooling system includes: a battery cooling circuit 1, a refrigeration circuit 2, and a controller 9.

[0056] Among them, on the battery cooling circuit 1, a vehicle-mounted battery pack 3, a pump body 4, and a first heat exchange pipe 51 of a heat exchanger 5 are sequentially arranged. A first temperature measuring element 31 is provided at the core of the vehicle-mounted battery pack 3, and a second temperature measuring element 33 is provided at the liquid inlet end 32 of the vehicle-mounted battery pack 3, so that the first temperature measuring element 31 can measure the temperature at the core of the vehicle-mounted battery pack 3, and the second temperature measuring element 33 can measure the temperature at the liquid inlet end 32 of the vehicle-mounted battery pack 3. In addition, the circulating medium within the battery cooling circuit 1 is a first solvent, that is, the first solvent can circulate within the battery cooling circuit 1. When the vehicle-mounted battery pack 3 generates a large amount of heat, the first solvent can absorb part of the heat and carry it to the first heat exchange pipe 51 of the heat exchanger 5 for heat exchange.

[0057] A compressor 6, an evaporator 7, an electronic expansion valve 8, and a second heat exchange pipe 52 of a heat exchanger 5 are successively arranged on a refrigeration circuit 2. A third temperature measuring element 54 is provided at a liquid outlet end 53 of the second heat exchange pipe 52, so that the third temperature measuring element 54 can measure the temperature at the liquid outlet end 53 of the second heat exchange pipe 52. In addition, the circulating medium in the refrigeration circuit 2 is a second solvent, that is, the second solvent can circulate in the refrigeration circuit 2. When the second solvent evaporates after being decompressed by the electronic expansion valve 8, it absorbs heat at the second heat exchange pipe 52 of the heat exchanger 5, and then the steam is compressed by the compressor 6, so that the temperature of the second solvent rises. When passing through the evaporator 7, the absorbed heat is released and the second solvent is liquefied, and then it returns to the electronic expansion valve 8. By working in such a cycle, heat can be continuously transferred from the second heat exchange pipe 52 of the heat exchanger 5 to the evaporator 7.

[0058] A controller 9 is in signal connection with a pump body 4, a compressor 6, an electronic expansion valve 8, and a third temperature measuring element 54, so that the controller 9 can realize signal control of the pump body 4, the compressor 6, the electronic expansion valve 8, and the third temperature measuring element 54.

[0059] The working principle of the battery cooling system provided by the embodiment of the present application is as follows:

[0060] In response to the first temperature measurement value detected by the first temperature measuring element 31 being greater than or equal to the first cooling threshold temperature, the controller 9 determines the target duty ratio of the pump body 4, thereby controlling the circulation of the first solvent in the battery cooling circuit 1 to transfer the heat of the in-vehicle battery pack 3 to the heat exchanger 5; determines the target speed of the compressor 6 according to the first temperature measurement value detected by the first temperature measuring element 31, the second temperature measurement value detected by the second temperature measuring element 33, and the first target temperature value; determines the target opening of the electronic expansion valve 8 according to the target speed, the third temperature measurement value detected by the third temperature measuring element 54, and the second target temperature value; controls the pump body 4, the compressor 6, and the electronic expansion valve 8 to control the temperature of the liquid inlet end 32 of the cooling pipeline of the in-vehicle battery pack 3; since the first heat exchange pipe 51 and the second heat exchange pipe 52 are arranged in the heat exchanger 5, and the first heat exchange pipe 51 is located in the battery cooling circuit 1 and the second heat exchange pipe 52 is located in the refrigeration circuit 2, heat exchange between the battery cooling circuit 1 and the refrigeration circuit 2 is realized through the heat exchanger 5, and cooling of the in-vehicle battery pack 3 can be achieved.

[0061] The battery cooling system provided by the embodiment of the present application determines whether the in-vehicle battery pack 3 needs to be cooled by measuring the core temperature of the in-vehicle battery pack 3 and the temperature of the liquid inlet end 32 of the cooling pipeline of the in-vehicle battery pack 3, which can make the temperature control of the in-vehicle battery pack more accurate.

[0062] In some embodiments, refer to Figure 1 The system further includes a heat pump circuit 10.

[0063] A compressor 6, an evaporator 7, a thermostatic expansion valve 11, and a radiator 12 are sequentially arranged on a heat pump circuit 10, and the circulating medium in the heat pump circuit 10 is a second solvent.

[0064] By arranging the heat pump circuit 10, the temperature in the vehicle occupant compartment can be adjusted. At the same time, the heat pump circuit 10 and the refrigeration circuit 2 share the compressor 6 and the evaporator 7, which can save costs.

[0065] It can be understood that when there is a cooling requirement in the vehicle occupant compartment, the compressor 6 compresses the second solvent in the heat pump circuit 10, and the temperature of the second solvent rises. The second solvent with the increased temperature flows through the evaporator 7, exchanges heat with the outside air of the vehicle in the evaporator 7 and then the temperature drops, then flows through the thermostatic expansion valve 11 and the temperature further drops, and then flows into the radiator 12, where it exchanges heat with the air in the occupant compartment, so that the temperature in the occupant compartment drops.

[0066] In some embodiments, the first solvent can be a mixture of water and ethylene glycol, and the second solvent can be a refrigerant.

[0067] In some embodiments, referring to Figure 2 , the system further includes a battery manager 13.

[0068] The battery manager 13 is in signal connection with the first temperature measuring element 31, the second temperature measuring element 33, and the controller 9.

[0069] By arranging the battery manager 13, it is convenient to obtain the cell temperature of the vehicle-mounted battery pack 3 and the temperature of the liquid inlet end 32 of the vehicle-mounted battery pack 3, and send the cell temperature and the temperature of the liquid inlet end 32 to the controller 9.

[0070] The battery manager 13 is used to obtain the cell temperature of the vehicle-mounted battery pack 3 and the temperature of the liquid inlet end 32, and determine whether the vehicle-mounted battery pack 3 needs to be cooled.

[0071] An embodiment of the present application also provides a method for controlling a battery cooling system, which is applied to the battery cooling system involved in the above embodiments and is executed by the controller 9 in the battery cooling system. The flowchart of the control method is as Figure 3 shown, and includes the following steps 201, 202, 203, 204, and 205.

[0072] In step 201, the controller 9 obtains a first temperature measurement value, a second temperature measurement value, a third temperature measurement value, a first target temperature value, and a second target temperature value.

[0073] Among them, the first temperature measurement value comes from the first temperature measuring element 31, the second temperature measurement value comes from the second temperature measuring element 33, the third temperature measurement value comes from the third temperature measuring element 54, the first target temperature value is the target temperature value of the liquid inlet end 32, and the second target temperature value is the target temperature value of the liquid outlet end 53.

[0074] In step 202, the controller 9 determines the target duty cycle in response to the first temperature measurement value being greater than or equal to the first cooling threshold temperature.

[0075] The first temperature measurement value being greater than or equal to the first cooling threshold temperature means that the temperature of the battery cells of the vehicle-mounted battery pack 3 is greater than or equal to the first cooling threshold temperature. At this time, the target duty cycle of the pump body 4 is determined, and the pump body 4 operates to provide power for the circulating flow of the first solvent in the battery cooling circuit 1.

[0076] In some embodiments, in response to the first temperature measurement value being greater than or equal to the first cooling threshold temperature, the target duty cycle of the pump body 4 is determined to be 85%.

[0077] Table 1 is a table for determining the target duty cycle of the pump body 4 in the battery cooling system provided by an exemplary embodiment of the present application. Referring to Table 1 below, the target duty cycle of the pump body 4 can be determined according to the relationship between the first temperature measurement value and the first cooling threshold temperature.

[0078] Table 1 Table for Determining the Target Duty Cycle of the Pump Body 4

[0079] Relationship between the first temperature measurement value and the first cooling threshold temperature Target duty cycle The first temperature measurement value is greater than or equal to the first cooling threshold temperature 85％ The first temperature measurement value is less than the first cooling threshold temperature 13％

[0080] In step 203, the controller 9 determines the target speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value.

[0081] That is, according to the temperature of the battery cells of the vehicle-mounted battery pack 3, the temperature of the liquid inlet end 32 of the vehicle-mounted battery pack 3, and the first target temperature value, the target speed of the compressor 6 is determined.

[0082] Among them, the flowchart of the method for this step is as Figure 4 shown, and specifically includes the following steps 2031 and 2032:

[0083] In step 2031, the controller 9 subtracts the second temperature measurement value from the first target temperature value to obtain a first temperature difference.

[0084] That is, subtracting the temperature of the liquid inlet end 32 of the vehicle-mounted battery pack 3 from the target temperature of the liquid inlet end 32 of the vehicle-mounted battery pack 3 to obtain the difference between the actual temperature and the target temperature of the liquid inlet end 32 of the vehicle-mounted battery pack 3.

[0085] In step 2032, the controller 9 determines the target speed according to the first temperature range in which the first temperature difference is located and the second temperature range in which the first temperature measurement value is located.

[0086] According to the temperature of the battery cells of the vehicle-mounted battery pack 3 and the difference between the actual temperature and the target temperature of the liquid inlet end 32 of the vehicle-mounted battery pack 3, the target speed of the compressor 6 is jointly determined, so that the temperature control of the vehicle-mounted battery pack 3 is more accurate.

[0087] Table 2 is a table for determining the target speed of the compressor 6 provided by an exemplary embodiment of the present application. Referring to Table 2 below, the target speed can be determined according to the first temperature range in which the first temperature difference is located and the second temperature range in which the first temperature measurement value is located.

[0088] Table 2 Table for Determining the Target Speed of Compressor 6

[0089]

[0090]

[0091] In step 204, the controller 9 determines the target opening according to the target speed, the third temperature measurement value, and the second target temperature value. That is, according to the target speed of the compressor 6, the temperature of the liquid outlet end 53 of the second heat exchange pipe 52, and the second target temperature value, the target opening of the electronic expansion valve 8 is determined.

[0092] It can be understood that the larger the target opening of the electronic expansion valve 8, the more the second solvent passes through the electronic expansion valve 8, so that the temperature of the second heat exchange pipe 52 of the heat exchanger 5 is lower.

[0093] Among them, the method flow chart of this step is as Figure 5 shown, and specifically includes the following steps 2041 and 2042:

[0094] In step 2041, the controller 9 subtracts the third temperature measurement value from the second target temperature value to obtain a second temperature difference.

[0095] Subtract the temperature of the liquid outlet end 53 of the second heat exchange pipe 52 from the second target difference to obtain the superheat of the temperature of the liquid outlet end 53 of the second heat exchange pipe 52, which is the second temperature difference.

[0096] In step 2042, the controller 9 determines the target opening according to the third temperature range in which the second temperature difference is located and the speed range in which the target speed is located.

[0097] According to the superheat of the temperature of the liquid outlet end 53 of the second heat exchange pipe 52 and the target speed of the compressor 6, the target opening of the electronic expansion valve 8 is jointly determined, so that the temperature control of the heat exchanger 5 is more accurate.

[0098] Table 3 is a table for determining the target opening of the electronic expansion valve 8 provided by an exemplary embodiment of the present application. Referring to Table 3 below, the target opening can be determined according to the third temperature range in which the second temperature difference is located and the speed range in which the target speed is located.

[0099] Table 3 Table for Determining the Target Opening of Electronic Expansion Valve 8

[0100]

[0101] In some embodiments, the vehicle-mounted battery pack 3 has a plurality of battery cell modules, and the first temperature measuring member 31 includes a plurality of temperature measuring units, and each temperature measuring unit correspondingly measures the temperature of one battery cell module.

[0102] Wherein, the first temperature measurement value is the highest temperature value measured by the plurality of temperature measuring units.

[0103] With such a setting, it can be ensured that the temperature of each battery cell module of the vehicle-mounted battery pack 3 does not exceed the first cooling threshold temperature, so that each battery module in the vehicle-mounted battery pack 3 is at a relatively suitable operating temperature.

[0104] In step 205, the controller 9 sends a target duty ratio to the pump body 4, sends a target rotational speed to the compressor 6, and sends a target opening degree to the electronic expansion valve 8.

[0105] After determining the target duty ratio, the target rotational speed, and the target opening degree, by sending the target duty ratio to the pump body 4, sending the target rotational speed to the compressor 6, and sending the target opening degree to the electronic expansion valve 8, the pump body 4, the compressor 6, and the electronic expansion valve 8 can be controlled to operate according to the setting.

[0106] For the battery cooling system control method provided by the embodiments of the present application, when the first temperature measurement value of the vehicle-mounted battery pack 3 is greater than or equal to the first cooling threshold temperature, the target duty ratio of the pump body 4 is determined, and according to the first temperature measurement value of the vehicle-mounted battery pack 3, the second temperature measurement value of the liquid inlet end 32 of the cooling pipeline, and the first target temperature value of the liquid inlet end 32 of the cooling pipeline, the target rotational speed of the compressor 6 is determined. According to the target rotational speed of the compressor, the third temperature measurement value of the liquid outlet end 53, and the second target temperature value of the liquid outlet end 53, the target opening degree of the electronic expansion valve 8 is determined. By controlling the pump body 4, the compressor 6, and the electronic expansion valve 8, the control of the temperature of the battery cells of the vehicle-mounted battery pack 3 and the temperature of the liquid inlet end 32 of the cooling pipeline of the vehicle-mounted battery pack 3 is realized. Therefore, for the battery cooling system control method provided by the embodiments of the present application, by measuring the temperature of the battery cells of the vehicle-mounted battery pack 3 and the temperature of the liquid inlet end 32 of the cooling pipeline of the vehicle-mounted battery pack 3 to determine whether the vehicle-mounted battery pack 3 needs to be cooled, the temperature control of the vehicle-mounted battery pack 3 is made more accurate.

[0107] When the first temperature measurement value of the vehicle-mounted battery pack 3 is greater than or equal to the first cooling threshold temperature, the pump body 4, the compressor 6, and the electronic expansion valve all operate according to the set state, so that the vehicle-mounted battery pack 3 cools down. However, when the temperature of the vehicle-mounted battery pack 3 drops to a certain threshold temperature, the temperature requirement for the operation of the vehicle-mounted battery pack 3 has been met. If the temperature continues to drop, it will instead affect the performance of the vehicle-mounted battery pack.

[0108] Therefore, in some embodiments, the battery cooling system control method provided by the embodiments of the present application further includes:

[0109] In response to the first temperature measurement value being less than the second cooling threshold temperature, update the target duty cycle and the target opening degree, and stop sending the target rotational speed to the compressor, where the second cooling threshold temperature is less than the first cooling threshold temperature;

[0110] Send the updated target duty cycle to the pump body and send the updated target opening degree to the electronic expansion valve.

[0111] When the first temperature measurement value is less than the second cooling threshold temperature, that is, the core temperature of the in-vehicle battery pack 3 is less than the second cooling threshold temperature, update the target duty cycle of the pump body 4 and the target opening degree of the electronic expansion valve 8, so that the pump body 4 operates at a lower target duty cycle and the electronic expansion valve 8 is closed. Through this method, the in-vehicle battery pack 3 can always be in a suitable working temperature range.

[0112] In some embodiments, the updated target duty cycle is 13% and the updated target opening degree is 0.

[0113] When the temperatures of multiple core modules in the in-vehicle battery pack 3 are all within the first cooling threshold temperature range, but the temperature difference between each core module is too large, it is also not conducive to the normal operation of the in-vehicle battery pack 3. Therefore, when the temperature difference between each core module of the in-vehicle battery pack 3 is too large, temperature equalization processing of the in-vehicle battery pack 3, that is, battery temperature equalization, is required.

[0114] In some embodiments, the battery cooling system control method provided by the embodiments of the present application further includes:

[0115] Obtain a fourth temperature measurement value, where the fourth temperature measurement value comes from the first temperature measuring element 31 and the fourth temperature measurement value is the lowest temperature value measured by multiple temperature measuring units.

[0116] In response to the first temperature measurement value being less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value being greater than or equal to the first target difference, that is, when the core temperature of the in-vehicle battery pack is less than the first cooling threshold temperature and the difference between the highest temperature value and the lowest temperature value measured by multiple temperature measuring units is greater than or equal to the first target difference, update the target duty cycle.

[0117] Send the updated target duty cycle to the pump body 4.

[0118] When the in-vehicle battery pack 3 does not need to be cooled and the difference between the first temperature measurement value and the fourth temperature measurement value is greater than or equal to the first target difference, determine the target duty cycle of the pump body 4 so that the first solvent in the battery cooling circuit 1 circulates, and the temperature difference between multiple core modules of the in-vehicle battery pack 3 is reduced to achieve battery temperature equalization.

[0119] In some embodiments, when the first temperature measurement value is less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value is greater than or equal to the first target difference, the updated target duty cycle is 40%.

[0120] When the first temperature measurement value of the vehicle-mounted battery pack 3 is less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value is greater than or equal to the first target difference, the pump body 4 operates according to the set state to achieve uniform battery temperature. After the uniform battery temperature is completed, if the pump body 4 continues to operate as in the uniform temperature process, it will cause unnecessary resource waste.

[0121] Therefore, in some embodiments, the battery cooling system control method provided by the embodiments of the present application further includes:

[0122] In response to the first temperature measurement value being less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value being less than the second target difference, update the target duty cycle, where the second target difference is less than the first target difference.

[0123] Send the updated target duty cycle to the pump body.

[0124] When the uniform battery temperature is completed, update the target duty cycle of the pump body 4 so that the pump body 4 operates at a lower speed.

[0125] In some embodiments, when the first temperature measurement value is less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value is less than the second target difference, the updated target duty cycle is 13%.

[0126] Generally, a battery management system (BMS) is set in the vehicle. The battery management system is an important bridge connecting the vehicle-mounted battery pack and the vehicle controller, and can monitor and manage. The battery management system obtains various parameters of the vehicle-mounted battery pack 3 and sends the various parameters and requests of the vehicle-mounted battery pack 3 to the controller 9.

[0127] In some embodiments, the battery cooling system control method provided by the embodiments of the present application further includes:

[0128] In response to the first temperature measurement value being greater than or equal to the first cooling threshold temperature, the battery manager 13 obtains a battery cooling request, a first target temperature value, and a second target temperature value.

[0129] The battery manager 13 sends a battery cooling request, a first temperature measurement value, a second temperature measurement value, a first target temperature value, and a second target temperature value to the controller 9.

[0130] Through the cooperation of the battery manager 13 and the controller, the vehicle-mounted battery pack 3 can always be in a suitable temperature working range, and the temperature control of the vehicle-mounted battery pack is more accurate.

[0131] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "plural" refers to two or more, unless otherwise specifically defined.

[0132] Other embodiments of the present application will be readily apparent to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include common general knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and examples are only illustrative.

[0133] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A control method for a battery cooling system, characterized in that Applied in a battery cooling system, the battery cooling system includes a controller, a refrigeration circuit, and a battery cooling circuit. A compressor, an evaporator, an electronic expansion valve, and a heat exchanger are sequentially arranged on the refrigeration circuit. An in-vehicle battery pack, a pump body, and the heat exchanger are sequentially arranged on the battery cooling circuit. A first temperature measuring element is provided at the battery cells of the in-vehicle battery pack, and a second temperature measuring element is provided at the liquid inlet end of the cooling pipeline of the in-vehicle battery pack. A third temperature measuring element is provided at the liquid outlet end of the heat exchanger on the refrigeration circuit. The controller is in signal connection with the pump body, the compressor, the electronic expansion valve, and the third temperature measuring element; The method is executed by the controller and includes: Obtaining a first temperature measurement value, a second temperature measurement value, a third temperature measurement value, a first target temperature value, and a second target temperature value, where the first temperature measurement value is from the first temperature measuring element, the second temperature measurement value is from the second temperature measuring element, the third temperature measurement value is from the third temperature measuring element, the first target temperature value is the target temperature value at the liquid inlet end, and the second target temperature value is the target temperature value at the liquid outlet end; In response to the first temperature measurement value being greater than or equal to a first cooling threshold temperature, determining a target duty cycle; Determining a target rotational speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value; Determining a target opening degree according to the target rotational speed, the third temperature measurement value, and the second target temperature value; Sending the target duty cycle to the pump body, sending the target rotational speed to the compressor, and sending the target opening degree to the electronic expansion valve.

2. The method for controlling a battery cooling system according to claim 1, wherein The determining the target rotational speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value includes: Subtracting the second temperature measurement value from the first target temperature value to obtain a first temperature difference; Determining the target rotational speed according to a first temperature range in which the first temperature difference is located and a second temperature range in which the first temperature measurement value is located.

3. The battery cooling system control method according to claim 1, wherein The determining the target opening degree according to the target rotational speed, the third temperature measurement value, and the second target temperature value includes: Subtracting the third temperature measurement value from the second target temperature value to obtain a second temperature difference; Determining the target opening degree according to a third temperature range in which the second temperature difference is located and a rotational speed range in which the target rotational speed is located.

4. The method for controlling a battery cooling system according to claim 1, wherein The in-vehicle battery pack has a plurality of battery cell modules, and the first temperature measuring element includes a plurality of temperature measuring units, and each temperature measuring unit correspondingly measures the temperature of one battery cell module; Wherein, the first temperature measurement value is the highest temperature value measured by the plurality of temperature measuring units.

5. The battery cooling system control method according to claim 4, wherein The method further includes: In response to the first temperature measurement value being less than a second cooling threshold temperature, updating the target duty cycle and the target opening degree, and stopping sending the target rotational speed to the compressor, where the second cooling threshold temperature is less than the first cooling threshold temperature; Sending the updated target duty cycle to the pump body and sending the updated target opening degree to the electronic expansion valve.

6. The method for controlling a battery cooling system according to claim 4, wherein The control method further includes: Obtaining a fourth temperature measurement value, where the fourth temperature measurement value is from the first temperature measuring element, and the fourth temperature measurement value is the lowest temperature value measured by the plurality of temperature measuring units; In response to the first temperature measurement value being less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value being greater than or equal to the first target difference, update the target duty cycle; Send the updated target duty cycle to the pump body.

7. The method for controlling a battery cooling system according to claim 6, wherein The control method further includes: In response to the first temperature measurement value being less than the first cooling threshold temperature and the difference between the first temperature measurement value and the fourth temperature measurement value being less than the second target difference, update the target duty cycle, where the second target difference is less than the first target difference; Send the updated target duty cycle to the pump body.

8. The method for controlling a battery cooling system according to claim 1, wherein The battery cooling system further includes a battery manager, and the battery manager is in signal connection with the controller, the first temperature measuring element, and the second temperature measuring element. The method further includes: In response to the first temperature measurement value being greater than or equal to the first cooling threshold temperature, obtain a battery cooling request, the first target temperature value, and the second target temperature value; Send the battery cooling request, the first temperature measurement value, the second temperature measurement value, the first target temperature value, and the second target temperature value to the controller.

9. A battery cooling system, characterized in that, The system includes: a battery cooling circuit (1), a refrigeration circuit (2), and a controller (9); On the battery cooling circuit (1), a first heat exchange pipe (51) of a vehicle-mounted battery pack (3), a pump body (4), and a heat exchanger (5) are sequentially arranged. A first temperature measuring element (31) is provided at the battery core of the vehicle-mounted battery pack (3), and a second temperature measuring element (33) is provided at the liquid inlet end (32) of the vehicle-mounted battery pack (3). The circulating medium in the battery cooling circuit (1) is a first solvent; On the refrigeration circuit (2), a compressor (6), an evaporator (7), an electronic expansion valve (8), and a second heat exchange pipe (52) of the heat exchanger (5) are sequentially arranged. A third temperature measuring element (54) is provided at the liquid outlet end (53) of the second heat exchange pipe (52). The circulating medium in the refrigeration circuit (2) is a second solvent; The controller (9) is in signal connection with the pump body (4), the compressor (6), the electronic expansion valve (8), and the third temperature measuring element (54); Among them, the controller (9) is configured to obtain a first temperature measurement value, a second temperature measurement value, a third temperature measurement value, a first target temperature value, and a second target temperature value, where the first temperature measurement value is from the first temperature measuring element (31), the second temperature measurement value is from the second temperature measuring element (33), the third temperature measurement value is from the third temperature measuring element (54), the first target temperature value is the target temperature value of the liquid inlet end (32), and the second target temperature value is the target temperature value of the liquid outlet end (53); determine a target duty cycle in response to the first temperature measurement value being greater than or equal to a first cooling threshold temperature; determine a target rotational speed according to the first temperature measurement value, the second temperature measurement value, and the first target temperature value; determine a target opening degree according to the target rotational speed, the third temperature measurement value, and the second target temperature value; send the target duty cycle to the pump body (4), send the target rotational speed to the compressor (6), and send the target opening degree to the electronic expansion valve (8).

10. The battery cooling system according to claim 9, wherein The system further includes a heat pump circuit (10); The compressor (6), the evaporator (7), the thermal expansion valve (11), and the radiator (12) are sequentially arranged on the heat pump circuit (10), and the circulating medium in the heat pump circuit (10) is the second solvent.

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