Battery cooling control method, system and vehicle

Abstract

The present invention discloses a battery cooling control method, system and vehicle. The method determines different control logics by judging whether there is a battery cooling demand and a passenger compartment cooling demand, and adjusts the battery cooling start-up conditions according to different vehicle speeds, different external temperatures, different internal temperatures and different air conditioning cooling demands, thereby reducing the time when the passenger compartment cooling and battery cooling are simultaneously turned on. At the same time, by adjusting the speed of the battery water pump, the opening and closing of the expansion valve stop valve and the battery cooler, the impact of the battery cooling on the passenger compartment cooling when turned on is reduced, thereby achieving a comfortable passenger compartment driving environment, while ensuring that the battery temperature does not exceed the temperature, thereby ensuring vehicle safety.

Description

Technical Field

[0001] The present invention is applicable to the field of plug-in hybrid electric vehicles, and in particular relates to a vehicle battery cooling control method and system. Background Art

[0002] With the progress of society, human beings have higher and higher requirements for the environment. New energy vehicles have become a trend, and the battery as its power source is one of the most core components. Since the battery will generate a lot of heat during the charging and discharging process, which directly affects the performance and safety of the battery, battery cooling technology has gradually become an important direction for the development of new energy vehicles. As a type of new energy vehicle, plug-in hybrid vehicles usually use direct cooling and water cooling for battery cooling. The present invention mainly focuses on the water-cooled battery cooling strategy.

[0003] In the prior art, new energy vehicle battery cooling and air conditioning cooling generally use a set of systems. When the battery needs to be cooled, the air conditioning cooling effect of the passenger compartment will be reduced, affecting comfort. In order to ensure the best comprehensive effect of battery cooling and air conditioning cooling, an electronic expansion valve is usually added to the battery cooling system to replace the thermal expansion valve. The thermal expansion valve cannot control the cooling capacity, while the electronic expansion valve can accurately control the cooling capacity and reasonably allocate the needs of battery cooling and passenger compartment cooling. Under the premise of meeting the battery cooling, the comfort of the passenger compartment is guaranteed at the same time. However, the price of an electronic expansion valve is several times more expensive than that of a thermal expansion valve, and there is no cost advantage.

[0004] The prior art discloses a power battery cooling control method, which includes: when the power system of the vehicle is not started, judging the working state of the power battery; when it is determined that the power battery is charging an electrical battery, obtaining the temperature of the power battery; when the temperature of the power battery is higher than the set high temperature, controlling the thermal management system, turning off the refrigeration device and turning on the liquid circulation cooling of the whole vehicle. This method uses the coolant of the whole vehicle in the thermal management system to exchange heat with the high-temperature power battery, without turning on the refrigeration device, which can avoid the influence of power consumption and high noise when the refrigeration device is turned on, and saves electric energy. However, it does not take into account the combined cooling demand of the passenger compartment and the battery cooling demand to coordinate the cooling control of the battery, and cannot meet the refined control requirements. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention discloses a battery cooling control method, system and vehicle, which perform cooling control on a water-cooled battery of an automobile, and control the battery cooling start-up conditions in a step-by-step manner by judging different vehicle speeds, interior temperature, exterior temperature and user air-conditioning usage scenarios, thereby meeting the passenger compartment cooling needs and the battery cooling needs, while reducing the impact of temperature fluctuations on the passenger compartment cooling after the battery cooling is turned on, and achieving high-cost requirements with low-cost and refined control.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for controlling cooling of an automobile battery. The method determines whether different control logics are adopted by judging whether there is a need for battery cooling and a need for cooling the passenger compartment, and comprises the following steps:

[0008] When only the battery needs cooling and there is no need to cool the passenger compartment, only the battery cooler is turned on and the battery water pump working ratio is adjusted to more than 80%; the expansion valve stop valve at the air-conditioning end is in the closed state.

[0009] When there is a demand for both battery cooling and passenger compartment cooling, the expansion valve stop valve at the air-conditioning end is opened to supply cooling to the passenger compartment; then the battery cooler is turned on. At this time, the battery cooler is opened and closed at a certain frequency and performs N cycles; at this time, the battery water inlet temperature signal is collected and graded to determine the battery water inlet temperature signal. The battery water inlet temperature is divided into high, medium and low grades. When it is at high or low grade, the battery water pump working ratio is adjusted to a low ratio. When it is at medium grade, the battery water pump working ratio is adjusted to a high ratio.

[0010] Furthermore, according to the battery water inlet temperature signal, the battery water pump working ratio is controlled in the following graded manner:

[0011] If the battery water inlet temperature is ≥A, which is high, the battery water pump working ratio is controlled to 20%-30%;

[0012] If B≤battery water inlet temperature<A, which is mid-range, the battery water pump working ratio is controlled to be 50%-100%;

[0013] If the battery water inlet temperature is less than B, which is a low gear, the battery water pump working ratio is controlled to be 20%-30%;

[0014] Preferably, the mid-range is divided into:

[0015] If C≤battery water inlet temperature<A, set the battery water pump working ratio to 50%-60%;

[0016] If B≤battery water inlet temperature<C, the battery water pump working ratio is 90%-100%;

[0017] Furthermore, A is 30°C-35°C, B is 18°C-20°C, and C is 25°C-26°C.

[0018] Furthermore, the steps for determining whether the battery needs cooling are as follows:

[0019] (1) The vehicle's air conditioning cooling state and / or the vehicle's interior temperature and / or the vehicle's exterior temperature and / or the air conditioning air volume level are used to estimate whether the vehicle's air conditioning cooling demand meets the conditions. Specifically, the following conditions are met:

[0020] When the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the internal temperature sensor detects that the temperature inside the vehicle is greater than the set value; or when the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the air conditioning panel detects that the internal air conditioning opening gear is greater than the set value.

[0021] The above conditions can be defined as the conditions for high cooling demand mode with air conditioning on.

[0022] (2) If the conditions are met, the vehicle speed is divided into three levels for judgment;

[0023] When 0km / h<vehicle speed<first vehicle speed, the battery temperature is determined. If the maximum battery temperature is greater than the first set value, it is determined that the battery needs to be cooled.

[0024] When the first vehicle speed < vehicle speed < second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the second set value, it is determined that the battery needs to be cooled;

[0025] When the vehicle speed is greater than the second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the third set value, it is determined that the battery needs to be cooled;

[0026] The first set value is greater than the second set value, the second set value is greater than the third set value; and the first vehicle speed is less than the second vehicle speed.

[0027] Furthermore, the first vehicle speed is 45 km / h, the second vehicle speed is 75 km / h, the first set value is 41° C., the second set value is 40° C., and the third set value is 39° C., all of which can be obtained through calibration.

[0028] Furthermore, the battery cooling requirement can also be determined by the following judgment conditions:

[0029] When the battery is in charging state, the battery controller outputs a cooling request;

[0030] When the battery is not in charging state, if the maximum battery temperature is greater than the set value, it is determined that the battery needs cooling.

[0031] On the other hand, the present invention also discloses an automobile battery cooling control system, including a thermal management domain integrated controller assembly, an electric compressor, a battery controller, a battery water pump, a battery cooler with a shut-off valve, an expansion valve shut-off valve, and a battery water inlet temperature sensor.

[0032] The battery controller is an external controller, which is connected to the thermal management domain integrated controller through the vehicle communication network and determines the operating conditions of the vehicle;

[0033] The battery water pump drives the coolant in the battery cooling circuit to circulate and remove the heat inside the battery.

[0034] The battery cooler with a shut-off valve absorbs heat from the coolant in the battery cooling circuit and removes the heat from the coolant through heat exchange with the refrigerant.

[0035] The expansion valve stop valve is opened when there is a cooling demand in the passenger compartment to ensure that the air conditioner cools the passenger compartment. When there is no cooling demand in the passenger compartment but there is a need for battery cooling, the expansion valve stop valve is closed to cut off the refrigerant flowing to the evaporator to cool the passenger compartment and prevent the evaporator from frosting.

[0036] The battery water inlet temperature sensor transmits the battery water inlet temperature to the thermal management domain integrated controller.

[0037] The thermal management domain integrated controller assembly includes an air conditioning controller and a thermal management controller, which is configured to execute the following control logic:

[0038] When only the battery needs cooling and there is no need to cool the passenger compartment, only the battery cooler is turned on and the battery water pump working ratio is adjusted to more than 80%; the expansion valve stop valve at the air-conditioning end is in the closed state.

[0039] When there is a demand for both battery cooling and passenger compartment cooling, the expansion valve stop valve at the air-conditioning end is opened to supply cooling to the passenger compartment; then the battery cooler is turned on. At this time, the battery cooler is opened and closed at a certain frequency, and N cycles are performed; at this time, the thermal management domain integrated controller assembly collects the battery water inlet temperature signal through the battery water inlet temperature sensor, and judges the battery water inlet temperature signal in a graded manner. The battery water inlet temperature is divided into high, medium and low grades. When it is in high or low grade, the battery water pump working ratio is adjusted to a low ratio. When it is in medium grade, the battery water pump working ratio is adjusted to a high ratio.

[0040] Furthermore, the thermal management domain integrated controller assembly determines the battery water inlet temperature signal in a graded manner and controls the battery water pump working ratio according to the graded method:

[0041] If the battery water inlet temperature is ≥A, which is high, the battery water pump working ratio is controlled to 20%-30%;

[0042] If B≤battery water inlet temperature<A, which is mid-range, the battery water pump working ratio is controlled to be 50%-100%;

[0043] If the battery water inlet temperature is less than B, which is a low gear, the battery water pump working ratio is controlled to be 20%-30%;

[0044] The temperature of A is 30°C-35°C, and the temperature of B is 18°C-20°C.

[0045] Preferably, the mid-range is divided into:

[0046] If C≤battery water inlet temperature<A, set the battery water pump working ratio to 50%-60%;

[0047] If B≤battery water inlet temperature<C, the battery water pump working ratio is 90%-100%;

[0048] The C is 25°C-26°C.

[0049] Furthermore, the thermal management domain integrated controller assembly should meet the following conditions to determine whether the battery needs cooling:

[0050] Condition 1: Estimate whether the vehicle's air conditioning cooling demand meets the condition based on the vehicle's air conditioning cooling state and / or the vehicle's interior temperature and / or the vehicle's exterior temperature and / or the air conditioning air volume level. Estimate the vehicle's air conditioning cooling demand in the following ways:

[0051] When the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the internal temperature sensor detects that the temperature inside the vehicle is greater than the set value; or when the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the air conditioning panel detects that the internal air conditioning opening gear is greater than the set value.

[0052] Condition 2: If the condition is met, the vehicle speed is divided into three levels for judgment;

[0053] When the chassis controller determines that 0km / h < vehicle speed < first vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the first set value, the battery is determined to require cooling;

[0054] When the chassis controller determines that the first vehicle speed is less than the second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the second set value, the battery is determined to require cooling;

[0055] When the chassis controller determines that the vehicle speed is greater than the second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the third set value, the battery is determined to require cooling;

[0056] The first set value is greater than the second set value, the second set value is greater than the third set value; and the first vehicle speed is less than the second vehicle speed.

[0057] Furthermore, the need for battery cooling can be determined by the following judgment conditions:

[0058] The battery is charged, and the battery controller outputs a cooling request;

[0059] The battery is not charging, and the maximum battery temperature is greater than the set value, indicating that the battery needs cooling.

[0060] Furthermore, the first vehicle speed is 45 km / h, the second vehicle speed is 75 km / h, the first set value is 41°C, the second set value is 40°C, and the third set value is 39°C.

[0061] A third aspect of the present invention further provides an automobile, wherein the automobile is equipped with the above-mentioned automobile battery cooling control system.

[0062] Beneficial technical effects of the present invention:

[0063] The present invention adjusts the battery cooling start-up conditions according to different vehicle speeds, different external temperatures, different internal temperatures, and different air conditioning refrigeration requirements, thereby reducing the time when the passenger compartment refrigeration and battery cooling are simultaneously turned on. At the same time, by adjusting the speed of the battery water pump, the opening and closing of the expansion valve stop valve and the battery cooler, the impact of the battery cooling on the passenger compartment refrigeration when turned on is reduced, thereby achieving a comfortable passenger compartment driving environment, while ensuring that the battery temperature does not exceed the temperature, thereby ensuring vehicle safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is a system architecture block diagram of the present invention;

[0065] Figure 2 is a control strategy flow chart of the present invention;

[0066] Among them, 1- thermal management domain integrated controller assembly, 2- air conditioning panel, 3- electric compressor, 4- chassis controller, 5- battery controller, 6- battery water pump, 7- battery cooler with shut-off valve, 8- expansion valve shut-off valve, 9- battery water inlet temperature sensor, 10- external temperature sensor, 11- internal temperature sensor. DETAILED DESCRIPTION

[0067] The following will illustrate the implementation of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0068] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0069] The present invention is further described below in conjunction with the system architecture block diagram and the control strategy flow chart:

[0070] See also Figure 1 In one embodiment of the present invention, the automobile battery cooling control system includes: a thermal management domain integrated controller assembly 1, an air conditioning panel 2, an electric compressor 3, a chassis controller 4, a battery controller 5, a battery water pump 6, a battery cooler with a shut-off valve 7, an expansion valve shut-off valve 8, a battery water inlet temperature sensor 9, an external temperature sensor 10 and an internal temperature sensor 11.

[0071] Among them, the thermal management domain integrated controller assembly includes two systems, an air-conditioning controller and a thermal management controller, which can effectively integrate the air-conditioning control strategy with the thermal management control strategy, reduce external signal interaction, and allocate air-conditioning cooling needs and battery cooling needs more quickly.

[0072] The air conditioning panel feeds back the air conditioning status set by the user, such as temperature, air volume, air conditioning refrigeration demand and other information to the thermal management domain integrated controller.

[0073] The electric compressor is a device that provides a cold source for air conditioning and battery cooling.

[0074] The chassis controller and battery controller are external controllers, which interact with the thermal management domain integrated controller through the vehicle communication network to determine the operating conditions of the vehicle.

[0075] The battery water pump is a device that drives the coolant circulation in the battery cooling circuit, and removes the internal heat of the battery through the coolant.

[0076] The battery cooler with a shut-off valve is a device in the battery cooling circuit that absorbs heat from the coolant and removes the heat from the coolant through heat exchange with the refrigerant.

[0077] The expansion valve stop valve is opened when there is a cooling demand in the passenger compartment to ensure that the air conditioner cools the passenger compartment. When there is no cooling demand in the passenger compartment but there is a need for battery cooling, the expansion valve stop valve is closed to cut off the refrigerant flowing to the evaporator to cool the passenger compartment and prevent the evaporator from frosting.

[0078] The external temperature sensor, internal temperature sensor, and battery water inlet temperature sensor are all signal acquisition devices of the thermal management domain integrated controller, which are used to judge the internal and external environment of the vehicle and the water temperature.

[0079] The thermal management domain integrated controller receives bus signals such as vehicle speed, maximum battery temperature, battery cooling request, battery charging status, temperature, air volume, etc. through the communication network, and collects sensor signals such as internal temperature, external temperature and battery water inlet temperature through hard lines, and analyzes and processes them comprehensively. Then, according to different working conditions, the speed of the electric compressor, the speed of the battery water pump, the opening and closing of the battery cooler with a shut-off valve, and the opening and closing of the expansion valve shut-off valve are controlled to achieve the purpose of reasonably allocating air conditioning refrigeration needs and battery cooling needs.

[0080] See also Figure 2 In one embodiment of the present invention, the specific control method of the above automobile battery cooling control system is as follows:

[0081] The system needs to judge the battery cooling demand under different working conditions, including the battery cooling demand judgment in the high cooling demand mode with air conditioning on, the battery cooling demand judgment in the battery charging mode, and the battery cooling demand judgment in the battery non-charging mode.

[0082] In one embodiment of the present invention, for a high cooling demand mode with air conditioning on, the battery cooling demand is determined as follows:

[0083] When the thermal management domain integrated controller 1 receives the outside temperature ≥30°C collected by the external temperature sensor 10, and collects the inside temperature ≥25°C through the internal temperature sensor 11, or the outside temperature ≥30°C collected by the external temperature sensor 10, and receives the air volume gear ≥5 through the air conditioning panel 2, the current vehicle speed is first determined. When 0 km / h ≤ vehicle speed <45 km / h, if the battery maximum temperature received from the battery controller 5 is ≥41°C, the battery has a cooling requirement, and if the received battery maximum temperature is <41°C, the battery has no cooling requirement; when 45 km / h ≤ vehicle speed <75 km / h, if the battery maximum temperature received from the battery controller 5 is ≥40°C, the battery has a cooling requirement, and if the received battery maximum temperature is <40°C, the battery has no cooling requirement; when the vehicle speed is ≥75 km / h, if the battery maximum temperature received from the battery controller 5 is ≥39°C, the battery has a cooling requirement, and if the received battery maximum temperature is <39°C, the battery has no cooling requirement.

[0084] In this way, by judging the cooling demand in the car, when the cooling demand is large, because the heat dissipation of the air-conditioning system is poor at low vehicle speeds and the air-conditioning cooling capacity is poor, it is necessary to increase the battery cooling threshold and delay the battery cooling start time as much as possible to ensure the cooling effect of the passenger compartment. When the vehicle speed increases, the heat dissipation capacity increases, the air-conditioning cooling capacity increases, and the battery cooling threshold temperature is gradually lowered to ensure that there is sufficient cooling capacity for passenger compartment cooling and battery cooling.

[0085] In one embodiment of the present invention, for the battery charging mode, the battery cooling requirement is determined as follows:

[0086] When the outside temperature collected by the external temperature sensor 10 is less than 30°C, or the inside temperature collected by the internal temperature sensor 11 is less than 25°C and the air volume level received by the air-conditioning panel 2 is less than level 5, the thermal management domain integrated controller 1 receives the battery charging status signal from the battery controller 5 as a charging status. At this time, the battery controller 5 sends a battery cooling request signal, and the battery has a cooling requirement. If the battery controller 5 does not send a battery cooling request signal, the battery has no cooling requirement.

[0087] In one embodiment of the present invention, in the battery non-charging mode, the battery cooling demand is determined as follows:

[0088] When the outside temperature collected by the external temperature sensor 10 is less than 30°C, or the inside temperature collected by the internal temperature sensor 11 is less than 25°C and the air volume level received by the air-conditioning panel 2 is less than level 5, when the thermal management domain integrated controller 1 receives the battery charging status signal from the battery controller 5 as a non-charging state, if the maximum battery temperature received from the battery controller 5 is ≥39°C, the battery has a cooling requirement; if the received maximum battery temperature is less than 39°C, the battery has no cooling requirement.

[0089] Under the above working conditions, the thermal management domain integrated controller 1 processes the battery without cooling demand and the battery with cooling demand respectively.

[0090] When there is no cooling demand for the battery, if no cooling demand from the air conditioning panel 2 is received, the electric compressor 3 and the battery water pump 6 are not driven, and the battery cooler 7 with a shutoff valve and the expansion valve shutoff valve 8 are closed. If a cooling demand from the air conditioning panel 2 is received, the electric compressor 3 is driven, the expansion valve shutoff valve 8 is opened, and the battery cooler 7 with a shutoff valve and the battery water pump 6 are closed.

[0091] Furthermore, the battery water inlet temperature is divided into high, medium and low levels. When it is at high or low level, the working ratio of the battery water pump 6 is adjusted to a low ratio. When it is at medium level, the working ratio of the battery water pump 6 is adjusted to a high ratio.

[0092] In one embodiment of the present invention, when the battery has a cooling demand, if the cooling demand of the air-conditioning panel 2 is not received, the electric compressor 3 is driven, the expansion valve stop valve 8 is closed, and the battery cooler 7 with the stop valve is opened, and the working ratio of the battery water pump is more than 80% (the greater the working ratio, the greater the flow rate of the water pump), for example, it can be 100%.

[0093] If a cooling demand is received from the air-conditioning panel 2, the electric compressor 3 is driven to open the expansion valve stop valve 8 and the battery cooler 7 with the stop valve. The battery cooler 7 will be opened and closed at a frequency of 5s / time, and a total of 10 cycles will be performed. By intermittently switching the battery cooler 7 with the stop valve, the impact of battery cooling on the cooling of the passenger compartment when the heat load is large at the initial stage of cooling can be reduced.

[0094] At this time, the thermal management domain integrated controller 1 collects the battery water inlet temperature through the battery water inlet temperature sensor 9. If the battery water inlet temperature is ≥30°C, the battery water inlet temperature is high. At high speed, the battery water pump 6 works at 20% (minimum working ratio). At this time, the battery inlet water temperature is relatively high. If the battery water pump 6 directly uses a large flow rate, it will cause a sharp increase in the load of the battery cooling circuit, and the temperature fluctuation of the passenger compartment is large, which is obvious to the user. The low speed of the battery water pump 6 can effectively reduce the temperature fluctuation of the passenger compartment refrigeration.

[0095] If the battery water inlet temperature is 25℃≤<30℃, and the battery water inlet temperature is mid-range, the working ratio of the battery water pump 6 is 50%. At this time, the load of the battery cooling circuit is reduced. While having little impact on the cooling of the passenger compartment, the working ratio of the battery water pump 6 can be increased to speed up the battery cooling speed.

[0096] If the battery water inlet temperature is 20℃≤<25℃, and the battery water inlet temperature is mid-range, the battery water pump 6 works at 100%. At this time, the battery cooling circuit load is low, and the user cannot clearly feel the impact on the passenger compartment cooling. The water pump works at full speed to take away the heat and cool the battery quickly.

[0097] If the battery water inlet temperature is less than 20°C, the battery water inlet temperature is at a low level, and the battery water pump 6 works at a rate of 30%. At this time, the battery water inlet temperature target value is reached, and the water pump speed is reduced to avoid excessive temperature differences between the highest and lowest temperatures of the battery, which may affect the safety of battery use.

[0098] It should be noted that the above temperature values ​​and vehicle speed values ​​are all specific values ​​cited as examples. In actual applications, they can also be set to other values ​​according to the actual conditions of the vehicle.

[0099] In summary, a hybrid vehicle battery cooling control method includes but is not limited to the above-mentioned functional description, on this basis, parameters of different vehicle models can be adapted and optimized to achieve a more comfortable and safe travel solution.

[0100] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0101] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0102] In addition, it should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

Claims

1. A battery cooling control method, characterized in that: The method determines different control logics by judging whether there is a battery cooling demand and a passenger compartment cooling demand, including: When it is determined that only battery cooling is required, the battery cooler is controlled to be turned on, and the working ratio of the battery water pump is adjusted to more than 80%; at this time, the expansion valve stop valve at the air conditioning end is closed; When it is determined that there is a demand for battery cooling and a demand for passenger compartment cooling at the same time, the air-conditioning end expansion valve stop valve is controlled to open, and the battery cooler is turned on; at the same time, the battery water inlet temperature signal is collected, the battery water inlet temperature signal is judged in a graded manner, and the battery water pump working ratio is controlled in a graded manner. The battery water inlet temperature is divided into high, medium and low grades. When it is in high or low grade, the battery water pump working ratio is adjusted to a low ratio. When it is in medium grade, the battery water pump working ratio is adjusted to a high ratio.

2. The battery cooling control method according to claim 1, characterized in that: According to the battery water inlet temperature signal, the battery water pump working ratio is controlled in the following graded manner: If the battery water inlet temperature is ≥A, which is high, the battery water pump working ratio is controlled to 20%-30%; If B≤battery water inlet temperature<A, which is mid-range, the battery water pump working ratio is controlled to be 50%-100%; If the battery water inlet temperature is less than B, which is a low gear, the battery water pump operating ratio is controlled to be 20%-30%.

3. The battery cooling control method according to claim 2, characterized in that: For mid-range, it is divided into: If C≤battery water inlet temperature<A, set the battery water pump working ratio to 50%-60%; If B≤battery water inlet temperature<C, the battery water pump working ratio is 90%-100%.

4. The battery cooling control method according to claim 3, characterized in that: The A is 30°C-35°C, B is 18°C-20°C, and C is 25°C-26°C.

5. The battery cooling control method according to any one of claims 1 to 4, characterized in that: The steps to determine whether the battery needs cooling are as follows: (1) First, estimate whether the vehicle's air conditioning cooling demand meets the conditions based on the vehicle's air conditioning cooling state and / or the vehicle's interior temperature and / or the vehicle's exterior temperature and / or the air volume level of the air conditioning; (2) If the conditions are met, the vehicle speed is divided into three levels for judgment; When 0km / h<vehicle speed<first vehicle speed, the battery temperature is determined. If the maximum battery temperature is greater than the first set value, it is determined that the battery needs to be cooled. When the first vehicle speed < vehicle speed < second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the second set value, it is determined that the battery needs to be cooled; When the vehicle speed is greater than the second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the third set value, it is determined that the battery needs to be cooled; The first set value is greater than the second set value, the second set value is greater than the third set value; and the first vehicle speed is less than the second vehicle speed.

6. The battery cooling control method according to claim 5, characterized in that: Estimate vehicle air conditioning cooling needs by: When the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the internal temperature sensor detects that the temperature inside the vehicle is greater than the set value; or when the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the air conditioning panel detects that the internal air conditioning opening gear is greater than the set value.

7. The battery cooling control method according to claim 5, characterized in that: The first vehicle speed is 45 km / h, the second vehicle speed is 75 km / h, the first set value is 41° C., the second set value is 40° C., and the third set value is 39° C., all of which are calibrated values.

8. The battery cooling control method according to claim 4, characterized in that: The need for battery cooling can also be determined by the following criteria: The battery is charged, and the battery controller outputs a cooling request; The battery is not charging, and the maximum battery temperature is greater than the set value, indicating that the battery needs cooling.

9. The battery cooling control method according to claim 4, characterized in that: When it is determined that there is a demand for battery cooling and a demand for passenger compartment cooling at the same time, the battery cooler is controlled to be turned on and off at a certain frequency, and N cycles are performed, the frequency is 5s / time, and the number of cycles N≥10.

10. A battery cooling control system, characterized in that: It includes a thermal management domain integrated controller assembly (1), an electric compressor (3), a battery controller (5), a battery water pump (6), a battery cooler with a shut-off valve (7), an expansion valve shut-off valve (8), and a battery water inlet temperature sensor (9); The battery controller is an external controller, which is connected to the thermal management domain integrated controller through the vehicle communication network and determines the operating conditions of the vehicle; The battery water pump drives the coolant to circulate in the battery cooling circuit to remove the heat inside the battery; The battery cooler with a shut-off valve absorbs heat from the coolant in the battery cooling circuit and removes the heat from the coolant through heat exchange with the refrigerant; The expansion valve stop valve is opened when there is a cooling demand in the passenger compartment to ensure that the air conditioner cools the passenger compartment, and is closed when there is no cooling demand in the passenger compartment but there is a need for battery cooling to cut off the refrigerant to the evaporator to cool the passenger compartment to prevent the evaporator from frosting; The battery water inlet temperature sensor transmits the battery water inlet temperature to the thermal management domain integrated controller; The thermal management domain integrated controller assembly includes an air conditioning controller and a thermal management controller, which is configured to determine different control logics by judging whether there is a battery cooling demand and a passenger compartment cooling demand, including: When it is determined that only battery cooling is required, the battery cooler (7) is controlled to be turned on, and the working ratio of the battery water pump (6) is adjusted to be above 80%; at this time, the expansion valve stop valve (8) at the air-conditioning end is in a closed state; When it is determined that there is a demand for cooling the battery and a demand for cooling the passenger compartment at the same time, the air-conditioning end expansion valve stop valve (8) is controlled to be opened, and the battery cooler (7) is turned on; at the same time, the battery water inlet temperature signal is collected, the battery water inlet temperature signal is graded and determined, and the battery water pump working ratio is controlled in a graded manner, wherein the battery water inlet temperature is divided into high, medium and low grades, and when it is at a high grade or a low grade, the battery water pump working ratio is adjusted to a low grade, and when it is at a medium grade, the battery water pump working ratio is adjusted to a high grade.

11. The battery cooling control system according to claim 10, characterized in that: The thermal management domain integrated controller assembly controls the battery water pump working ratio according to the battery water inlet temperature signal in the following graded manner: If the battery water inlet temperature is ≥A, which is high, the battery water pump working ratio is controlled to 20%-30%; If B≤battery water inlet temperature<A, which is mid-range, the battery water pump working ratio is controlled to be 50%-100%; If the battery water inlet temperature is less than B, which is a low gear, the battery water pump working ratio is controlled to be 20%-30%; The temperature of A is 30°C-35°C, and the temperature of B is 18°C-20°C.

12. The battery cooling control system according to claim 11, characterized in that: For mid-range, it is divided into: If C≤battery water inlet temperature<A, set the battery water pump working ratio to 50%-60%; If B≤battery water inlet temperature<C, the battery water pump working ratio is 90%-100%; The C is 25°C-26°C.

13. The battery cooling control system according to any one of claims 10 to 12, characterized in that: The steps to determine whether the battery needs cooling are as follows: (1) Estimate whether the vehicle's air conditioning cooling demand meets the conditions based on the vehicle's air conditioning cooling state and / or the vehicle's interior temperature and / or the vehicle's exterior temperature and / or the air volume level of the air conditioning; (2) If the conditions are met, the vehicle speed is divided into three levels for judgment; When 0km / h<vehicle speed<first vehicle speed, the battery temperature is determined. If the maximum battery temperature is greater than the first set value, it is determined that the battery needs to be cooled. When the first vehicle speed < vehicle speed < second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the second set value, it is determined that the battery needs to be cooled; When the vehicle speed is greater than the second vehicle speed, the battery temperature is determined, and if the maximum battery temperature is greater than the third set value, it is determined that the battery needs to be cooled; The first set value is greater than the second set value, the second set value is greater than the third set value; and the first vehicle speed is less than the second vehicle speed.

14. The battery cooling control system according to claim 13, characterized in that: For condition 1, the vehicle cooling demand is estimated in the following way: When the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the internal temperature sensor detects that the temperature inside the vehicle is greater than the set value; or when the vehicle's air conditioner is turned on for cooling, the external temperature sensor detects that the temperature outside the vehicle is greater than the set value, and the air conditioning panel detects that the internal air conditioning opening gear is greater than the set value.

15. A vehicle, characterized in that: The vehicle is equipped with a battery cooling control system according to any one of claims 10 to 14.

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