Thermal management control method and system oriented to new energy automobile battery fast charging scene

Abstract

The invention discloses a heat management control method and system for a new energy automobile battery fast charging scene, and belongs to the technical field of automobile heat management. The current environment temperature, the current battery temperature and the battery remaining capacity are collected through the battery management module and processed through a fuzzy control algorithm and a gravity center method, and a thermal management control starting coefficient is determined; a thermal management control starting coefficient is obtained through the vehicle control unit, a battery thermal management operation mode is determined according to the thermal management control starting coefficient, and a control instruction is generated; a control instruction is obtained through the battery heat management device, and a battery air cooling loop or a battery refrigerant direct cooling loop is formed according to the control instruction. The optimal battery thermal management operation mode can be determined according to the real-time environment temperature and the battery temperature data, so that the purposes of cooling the battery and saving power are achieved; the problems of high safety risk and low charging efficiency of the existing battery due to over-high temperature are solved.

Description

Technical Field

[0001] The present invention relates to the field of automotive thermal management technology, and in particular to a thermal management control method and system for new energy vehicle battery fast charging scenarios. Background Art

[0002] The statements in this section merely mention background art related to the present invention and do not necessarily constitute prior art.

[0003] At present, with the rapid development of the new energy vehicle industry, new energy vehicles are gradually gaining favor among consumers for their high cost-effectiveness and other performance. Compared with traditional fuel vehicles, power batteries, as the main power source of new energy vehicles, are of self-evident importance.

[0004] The thermal management system of power batteries directly affects their service life, vehicle performance and safety. Especially during long-distance driving, when the battery needs to be charged quickly at high power, the internal resistance of the battery during the fast charging process will generate a large amount of Joule heat, causing the temperature to rise rapidly. The battery temperature is too high, affecting the charging efficiency. In addition, due to the dense stacking of cells in the battery pack, it is also relatively more difficult to dissipate heat in the middle area to a certain extent, exacerbating the temperature inconsistency between cells. A large amount of heat accumulates in a relatively small space over time, which will not only reduce the battery's charging and discharging efficiency and affect the battery's power, but if there are no effective thermal management measures, the battery temperature may exceed the safe operating range, affecting the battery's performance and life, and may even cause thermal runaway, leading to safety accidents.

[0005] The battery temperature is adjusted through the battery thermal management system. Whether it is cooling or heating, it needs to consume the electric energy stored in the battery itself, which leads to a long charging time. However, users expect to shorten the fast charging time while ensuring battery safety. How to shorten the charging time and ensure charging safety has become a hot topic for various car companies in the research and development of new energy vehicles. Summary of the invention

[0006] In order to address the deficiencies in the prior art, the present invention provides a thermal management control method and system for new energy vehicle battery fast charging scenarios, which improves battery safety and durability, shortens charging time, extends battery life, and thereby improves the energy utilization efficiency of electric vehicles.

[0007] In the first aspect, the present invention provides a thermal management control system for new energy vehicle battery fast charging scenarios;

[0008] A thermal management control system for new energy vehicle battery fast charging scenarios, including:

[0009] The battery management module is used to collect the current ambient temperature, the current battery temperature and the remaining battery power and process them through the fuzzy control algorithm and the center of gravity method, and use the membership function value of the battery energy distribution coefficient to determine the thermal management control opening coefficient;

[0010] The vehicle controller is used to obtain the thermal management control activation coefficient, determine the battery thermal management operation mode and generate control instructions according to the thermal management control activation coefficient;

[0011] The battery thermal management device is used to obtain control instructions and form a battery air cooling circuit or a battery refrigerant direct cooling circuit according to the control instructions; wherein the battery air cooling circuit removes excess heat and absorbs natural wind in the environment via a cooler, a heat exchanger and an evaporator, and the battery refrigerant direct cooling circuit cools down via a cooler, a heat exchanger, a water-cooled condenser and a compressor, and uses a drying bottle for drying.

[0012] In some implementations, the current ambient temperature, the current battery temperature, and the remaining battery power are processed by a fuzzy control algorithm and a gravity center method, and the membership function value of the battery energy allocation coefficient is used to determine the thermal management control activation coefficient, including:

[0013] The current ambient temperature, the current battery temperature, the remaining battery power and the preset battery comfort temperature are input into the fuzzy controller for processing, and the connection between the input and the output is constructed using the set fuzzy control rules to obtain the membership function of the corresponding battery energy allocation coefficient;

[0014] The thermal management control activation coefficient is calculated according to the membership function value of the battery energy allocation coefficient under all fuzzy control rules.

[0015] In some embodiments, the battery thermal management operation mode is determined based on the thermal management control activation coefficient: if the thermal management control activation coefficient is greater than or equal to a preset first threshold and less than a preset second threshold, the battery thermal management operation mode is an air cooling mode; if the thermal management control activation coefficient is greater than or equal to a preset second threshold and less than a preset third threshold, the battery thermal management operation mode is a refrigerant direct cooling mode.

[0016] In some embodiments, the battery thermal management device includes a cooler, a heat exchanger, an evaporator, a water-cooled condenser, a compressor, a thermostat, and a drying bottle;

[0017] The cooler is connected to the heat exchanger, the heat exchanger is connected to the evaporator and the water-cooled condenser respectively, and the evaporator is connected to the cooler; the output end of the water-cooled condenser is connected to a compressor, a temperature controller and a drying bottle in sequence, and the drying bottle is connected to the cooler.

[0018] In some embodiments, a first cooling solenoid valve and a first electronic expansion valve are provided between the cooler and the heat exchanger, and a second electronic expansion valve is provided between the cooler and the evaporator and the drying bottle.

[0019] In some embodiments, a pump is provided between the battery housing and the input end of the cooler, and a second cooling solenoid valve is provided between the output end of the cooler and the battery housing.

[0020] In some embodiments, the thermal management control opening coefficient is expressed as:

[0021]

[0022] In the formula, β i represents the i-th output, P i Represents the membership function value of the output quantity under the i-th fuzzy control rule.

[0023] In a second aspect, the present invention provides a thermal management control method for a new energy vehicle battery fast charging scenario;

[0024] A thermal management control method for a new energy vehicle battery fast charging scenario, based on the above-mentioned thermal management control system for a new energy vehicle battery fast charging scenario, includes:

[0025] The battery management module collects the current ambient temperature, current battery temperature and remaining battery power, processes them through fuzzy control algorithm and center of gravity method, and uses the membership function value of the battery energy distribution coefficient to determine the thermal management control activation coefficient and transmit it to the vehicle controller;

[0026] The vehicle controller receives the thermal management control activation coefficient, determines the battery thermal management operation mode according to the thermal management control activation coefficient, generates a control instruction, and sends it to the battery thermal management device;

[0027] The battery thermal management device receives control instructions and forms a battery air cooling circuit or a battery refrigerant direct cooling circuit according to the control instructions.

[0028] In some implementations, the current ambient temperature, the current battery temperature, and the remaining battery power are processed by a fuzzy control algorithm and a gravity center method, and the membership function value of the battery energy allocation coefficient is used to determine the thermal management control activation coefficient, including:

[0029] The current ambient temperature, the current battery temperature, the remaining battery power and the preset battery comfort temperature are input into the fuzzy controller for processing, and the connection between the input and the output is constructed using the set fuzzy control rules to obtain the membership function of the corresponding battery energy allocation coefficient;

[0030] The thermal management control activation coefficient is calculated according to the membership function value of the battery energy allocation coefficient under all fuzzy control rules.

[0031] In some embodiments, the battery thermal management operation mode is determined based on the thermal management control activation coefficient: if the thermal management control activation coefficient is greater than or equal to a preset first threshold and less than a preset second threshold, the battery thermal management operation mode is an air cooling mode; if the thermal management control activation coefficient is greater than or equal to a preset second threshold and less than a preset third threshold, the battery thermal management operation mode is a refrigerant direct cooling mode.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The technical solution provided by the present invention can determine the most suitable battery thermal management operation mode according to the real-time ambient temperature and battery temperature data when the new energy battery is fast charged, realize seamless switching of different cooling methods, achieve the cooling effect of the battery and achieve the purpose of power saving; it can shorten the battery fast charging time and save the time cost of the car owner during travel.

[0034] 2. The technical solution provided by the present invention is that the battery thermal management device can take into account the existence of two thermal management operation modes only through the cooperation of components such as the cooler, evaporator and water-cooled condenser. The switching of the battery air cooling circuit and the battery refrigerant direct cooling circuit can be achieved by switching the cooling solenoid valve and the electronic expansion valve, which has significant advantages in layout space. Compared with the existing thermal management system of new energy vehicles, the water pipe loop structure is streamlined and highly integrated, with significant lightweight effect, obvious cost advantage and easy assembly.

[0035] 3. The technical solution provided by the present invention combines a battery air cooling circuit and a battery refrigerant direct cooling circuit to construct a battery thermal management device, and controls the energy output of the battery to the battery thermal management device according to the current battery status and environmental status. The structure is simple and easy to implement, low cost, easy to assemble, easy to use, intuitive and simple to operate, and has the characteristics of scalability.

[0036] 4. The technical solution provided by the present invention adopts fuzzy control algorithm and center of gravity method to realize the switching and coordinated operation of the two cooling methods, and comprehensively considers the battery SOC value, current ambient temperature, battery comfort temperature and battery current temperature to construct fuzzy rules, so as to realize the accurate solution of battery energy distribution coefficient and thermal management control activation coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0038] Figure 1A schematic diagram of the execution flow of a thermal management control system for a new energy vehicle battery fast charging scenario provided by an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the architecture of a battery thermal management device provided by an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a flow chart of a fuzzy control algorithm provided by an embodiment of the present invention;

[0041] Figure 4 A schematic flow chart of a thermal management control method for a new energy vehicle battery fast charging scenario provided by an embodiment of the present invention;

[0042] In the figure: 1. battery housing; 2. pump; 3. first cooling solenoid valve; 4. first electronic expansion valve; 5. heat exchanger; 6. cooler; 7. second cooling solenoid valve; 8. second electronic expansion valve; 9. evaporator; 10. water-cooled condenser; 11. temperature sensor; 12. drying bottle; 13. thermostat; 14. compressor. DETAILED DESCRIPTION

[0043] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0046] Embodiment 1

[0047] The rapid heating of the battery during the fast charging process will accelerate its aging, reduce its lifespan, and may even cause safety risks; therefore, the present invention provides a thermal management control system for new energy vehicle battery fast charging scenarios, which improves the safety and durability of the battery, shortens the charging time, extends the battery life and thereby improves the energy economy of electric vehicles.

[0048] Next, combine Figure 1-Figure 4 , a thermal management control system for a new energy vehicle battery fast charging scenario disclosed in this embodiment is described in detail. The thermal management control system for a new energy vehicle battery fast charging scenario includes a battery management module, a vehicle controller and a battery thermal management device. The battery management module is connected to the vehicle controller through a CAN bus, and the vehicle controller is connected to the battery thermal management device through a CAN bus; the battery management module is used to collect the current ambient temperature, the current battery temperature and the remaining battery power and process them through a fuzzy control algorithm and a center of gravity method to determine the thermal management control opening coefficient; the vehicle controller is used to obtain the thermal management control opening coefficient, and according to the thermal management control opening coefficient, determine the battery thermal management operation mode and generate a control instruction; the battery thermal management device is used to obtain the control instruction, and form a battery air cooling circuit or a battery refrigerant direct cooling circuit according to the control instruction; the battery air cooling circuit takes away excess heat and absorbs natural wind in the environment through a cooler 6, a heat exchanger 5 and an evaporator 9, and the battery refrigerant direct cooling circuit is cooled through a cooler 6, a heat exchanger 5, a water-cooled condenser 10, and a compressor 14, and is dried using a drying bottle 12.

[0049] Furthermore, the execution process of the thermal management control system for new energy vehicle battery fast charging scenarios is as follows:

[0050] S1. The battery management module collects the current ambient temperature, the current battery temperature and the remaining battery power and processes them through the fuzzy control algorithm and the center of gravity method, and uses the membership function value of the battery energy distribution coefficient to determine the thermal management control activation coefficient.

[0051] Here, the battery management module refers to the BMS system of the new energy vehicle battery.

[0052] As an implementation method, the current ambient temperature, the current battery temperature and the remaining battery power are processed by a fuzzy control algorithm and a gravity center method to determine the thermal management control activation coefficient, including:

[0053] Step 1: Input the current ambient temperature, current battery temperature, remaining battery power and preset battery comfort temperature into the fuzzy controller for processing, use the set fuzzy control rules to build the connection between input and output, and obtain the membership function of the corresponding battery energy allocation coefficient.

[0054] Furthermore, first, the current ambient temperature, the current battery temperature, the remaining battery power and the preset battery comfort temperature are fuzzy processed.

[0055] Specifically, the battery SOC value S is fuzzified. When 0≤S<45%, it is a small positive value, when 45%≤S<70%, it is a middle positive value, and when 70≤S≤100%, it is a large positive value. Note that ps-small positive value, pm-middle positive value, and pb-large positive value. Then the domain of the S input variable is [0 1], and the fuzzy subset is S={ps, pm, pb}; the battery comfort temperature is T, and the difference Δt between the current ambient temperature and the battery comfort temperature is fuzzified. Δt=|h t -T|, 0≤Δt<10 is a small positive value, 10≤Δt<20 is a medium positive value, and 20≤Δt≤35 is a large positive value. Note that ps is a small positive value, pm is a medium positive value, and pb is a large positive value. The domain of the Δt input variable is [0 35]. After normalizing the domain of Δt, the domain of the Δt input variable is [0 1]. The fuzzy subset Δt={ps, pm, pb}; for the current battery temperature d t , fuzzy processing is performed based on the battery temperature variation range during charging. When 0≤d t When d<10, it is a positive minimum value. t <25 is the median value, and when 25≤d t When ≤40, it is a positive large value, ps-positive small, pm-positive medium, pb-positive large, then d t The domain of the input variable is [0 40], and similarly for d t The domain is normalized, then d t The domain is [0 1], and the fuzzy subset is S = {ps, pm, pb}; the membership function of the output variable battery energy allocation coefficient K adopts trigonometric function, the domain is [0 1], and the fuzzy subset is divided into {ps, pm, pb}.

[0056] Based on the above analysis, the fuzzy control rules are formulated in the form of "If...and...then..." logical language. For the multi-input single-output fuzzy control system, 27 fuzzy control rules are established as shown in Table 1-1 to link the input and output factors. The rule expression is:

[0057] If(v ˊ is v i ˊ and h is h i and f is f i )then freg=K.

[0058] Table 1-1 Fuzzy control rules table

[0059]

[0060] Step 2: According to the implementation rules of the center of gravity method, the thermal management control opening coefficient is calculated and transmitted to the vehicle controller. The thermal management control opening coefficient P is expressed as:

[0061]

[0062] Where P i is the output quantity β under each fuzzy control rule i Membership function value.

[0063] Fuzzy reasoning results in a fuzzy value, but the actual output required is an accurate value, so the fuzzy value needs to be clarified; the centroid method is actually an imitation technology, which can represent the intersection value of the centroid of the area composed of the curve of the membership function and the basic variable axis as an accurate value.

[0064] Step 2: The vehicle controller receives the thermal management control activation coefficient, determines the battery thermal management operation mode according to the thermal management control activation coefficient, and generates a corresponding control instruction which is sent to the battery thermal management device; the battery thermal management device performs cooling according to the control instruction.

[0065] Specifically, if the thermal management control activation coefficient is greater than or equal to 0 and less than the preset first threshold, the battery thermal management device will not be turned on for battery cooling; if the thermal management control activation coefficient is greater than or equal to the preset first threshold and less than the preset second threshold, the battery thermal management operation mode is the air cooling mode; if the thermal management control activation coefficient is greater than or equal to the preset second threshold and less than the preset third threshold, the battery thermal management operation mode is the refrigerant direct cooling mode.

[0066] Furthermore, the battery thermal management device includes a cooler 6, a heat exchanger 5, an evaporator 9, and a water-cooled condenser 10, a compressor 14, a thermostat 13 and a drying bottle 12 which are connected in sequence through pipelines; the battery is installed in a battery housing 1, the battery housing 1 is sleeved on the battery and has a certain distance from the outer surface of the battery, the output end of the battery housing 1 is connected to the input end of the cooler 6 through a pipeline, and a pump 2 is installed on the pipeline; the output end of the cooler 6 is connected to the input end of the battery housing 1, and a second cooling solenoid valve 7 is installed on the pipeline; the input end of the cooler 6 is connected to the input end of the heat exchanger 5 through a pipeline, and a first cooling solenoid valve 3 and a first electronic expansion valve 4 are installed between the cooler 6 and the heat exchanger 5 in sequence; the output end of the heat exchanger 5 is connected to the evaporator 9 and the water-cooled condenser 10 through pipelines, the output end of the evaporator 9 is connected to the input end of the cooler 6, and the drying bottle 12 is connected to the input end of the cooler 6; a second electronic expansion valve 8 is installed on the common pipeline between the cooler 6, the evaporator 9 and the drying bottle 12.

[0067] Exemplarily, when 0≤p<0.45, the battery thermal management device is not activated to cool the battery.

[0068] When 0.45≤p<0.625, the battery thermal management device turns on air cooling to cool the battery; starts the pump 2, cooler 6, second cooling solenoid valve 7, first cooling solenoid valve 3, first electronic expansion valve 4, heat exchanger 5 and evaporator 9, and the other components are closed; starting from the battery housing 1, the first cooling solenoid valve 3 and the heat exchanger 5 take away excess heat and absorb natural wind in the environment through the evaporator 9 to the heat exchanger 5 to the battery housing 1 to form a battery air cooling circuit. This mode has the advantages of simple operation and low power consumption.

[0069] When 0.625≤p≤1, the battery thermal management device turns on the refrigerant direct cooling mode to cool the battery, starts the pump 2, cooler 6, the second cooling solenoid valve 7, the first cooling solenoid valve 3, the first electronic expansion valve 4, the heat exchanger 5, the water-cooled condenser 10, the compressor 14, the thermostat 13 and the drying bottle 12, and the other components are closed; starting from the battery housing 1, the excess heat is taken away through the cooler 6 and the heat exchanger 5, and the cooling effect is achieved through the water-cooled condenser 10 and the compressor 14. The temperature sensor 11 collects and controls the required temperature, and dries the low-temperature gas through the drying bottle 12 to prevent the humidity from damaging the battery. A battery refrigerant direct cooling circuit is formed from the cooler 6 to the battery housing 1, which has the advantage of fast cooling effect.

[0070] Embodiment 2

[0071] Combination Figure 4 Based on the thermal management control system for new energy vehicle battery fast charging scenario described in Example 1, this embodiment discloses a thermal management control method for new energy vehicle battery fast charging scenario, including:

[0072] The battery management module collects the current ambient temperature, current battery temperature and remaining battery power, processes them through fuzzy control algorithm and center of gravity method, and uses the membership function value of the battery energy distribution coefficient to determine the thermal management control activation coefficient and transmit it to the vehicle controller;

[0073] The vehicle controller receives the thermal management control activation coefficient, determines the battery thermal management operation mode according to the thermal management control activation coefficient, generates a control instruction, and sends it to the battery thermal management device;

[0074] The battery thermal management device receives control instructions and forms a battery air cooling circuit or a battery refrigerant direct cooling circuit according to the control instructions.

[0075] It should be noted here that the above steps correspond to the execution steps of the thermal management control system for the new energy vehicle battery fast charging scenario described in Example 1, and the specific details will not be repeated one by one in this embodiment.

[0076] The description of each embodiment in the above embodiments has different emphases. For parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thermal management control system for new energy vehicle battery fast charging scenarios, characterized by: include: The battery management module is used to collect the current ambient temperature, the current battery temperature and the remaining battery power and process them through the fuzzy control algorithm and the center of gravity method, and use the membership function value of the battery energy distribution coefficient to determine the thermal management control opening coefficient; The vehicle controller is used to obtain the thermal management control activation coefficient, determine the battery thermal management operation mode and generate control instructions according to the thermal management control activation coefficient; The battery thermal management device is used to obtain control instructions and form a battery air cooling circuit or a battery refrigerant direct cooling circuit according to the control instructions; wherein the battery air cooling circuit removes excess heat and absorbs natural wind in the environment via a cooler, a heat exchanger and an evaporator, and the battery refrigerant direct cooling circuit cools down via a cooler, a heat exchanger, a water-cooled condenser and a compressor, and uses a drying bottle for drying.

2. The thermal management control system for new energy vehicle battery fast charging scenario as claimed in claim 1, characterized in that: The current ambient temperature, current battery temperature and remaining battery capacity are processed by fuzzy control algorithm and center of gravity method, and the membership function value of battery energy distribution coefficient is used to determine the thermal management control start coefficient, including: The current ambient temperature, the current battery temperature, the remaining battery power and the preset battery comfort temperature are input into the fuzzy controller for processing, and the connection between the input and the output is constructed using the set fuzzy control rules to obtain the membership function of the corresponding battery energy allocation coefficient; The thermal management control activation coefficient is calculated according to the membership function value of the battery energy allocation coefficient under all fuzzy control rules.

3. The thermal management control system for new energy vehicle battery fast charging scenario as claimed in claim 1, characterized in that: The battery thermal management operation mode is determined according to the thermal management control activation coefficient: if the thermal management control activation coefficient is greater than or equal to a preset first threshold and less than a preset second threshold, the battery thermal management operation mode is an air cooling mode; if the thermal management control activation coefficient is greater than or equal to a preset second threshold and less than a preset third threshold, the battery thermal management operation mode is a refrigerant direct cooling mode.

4. The thermal management control system for new energy vehicle battery fast charging scenario as claimed in claim 1, characterized in that: The battery thermal management device includes a cooler, a heat exchanger, an evaporator, a water-cooled condenser, a compressor, a thermostat and a drying bottle; The cooler is connected to the heat exchanger, the heat exchanger is connected to the evaporator and the water-cooled condenser respectively, and the evaporator is connected to the cooler; the output end of the water-cooled condenser is connected to a compressor, a temperature controller and a drying bottle in sequence, and the drying bottle is connected to the cooler.

5. The thermal management control system for new energy vehicle battery fast charging scenario as claimed in claim 4, characterized in that: A first cooling solenoid valve and a first electronic expansion valve are arranged between the cooler and the heat exchanger, and a second electronic expansion valve is arranged between the cooler, the evaporator and the drying bottle.

6. The thermal management control system for new energy vehicle battery fast charging scenario as claimed in claim 4, characterized in that: A pump is arranged between the battery housing and the input end of the cooler, and a second cooling solenoid valve is arranged between the output end of the cooler and the battery housing.

7. The thermal management control system for new energy vehicle battery fast charging scenario as claimed in claim 1, characterized in that: The thermal management control opening coefficient is expressed as: In the formula, β i Indicates the output, P i represents the output β under the i-th fuzzy control rule i The membership function value of .

8. A thermal management control method for a new energy vehicle battery fast charging scenario based on the thermal management control system for a new energy vehicle battery fast charging scenario according to any one of claims 1 to 7, characterized in that: include: The battery management module collects the current ambient temperature, current battery temperature and remaining battery power, processes them through fuzzy control algorithm and center of gravity method, determines the thermal management control activation coefficient and transmits it to the vehicle controller; The vehicle controller receives the thermal management control activation coefficient, determines the battery thermal management operation mode according to the thermal management control activation coefficient, generates a control instruction, and sends it to the battery thermal management device; The battery thermal management device receives control instructions and forms a battery air cooling circuit or a battery refrigerant direct cooling circuit according to the control instructions.

9. The thermal management control method for new energy vehicle battery fast charging scenario as claimed in claim 8, characterized in that: The current ambient temperature, current battery temperature and remaining battery capacity are processed by fuzzy control algorithm and center of gravity method to determine the thermal management control activation coefficient, including: The current ambient temperature, the current battery temperature, the remaining battery power and the preset battery comfort temperature are input into the fuzzy controller for processing, and the connection between the input and the output is constructed using the set fuzzy control rules to obtain the membership function of the corresponding battery energy allocation coefficient; The thermal management control activation coefficient is calculated according to the membership function value of the battery energy allocation coefficient under all fuzzy control rules.

10. The thermal management control method for new energy vehicle battery fast charging scenario as claimed in claim 8, characterized in that: The battery thermal management operation mode is determined according to the thermal management control activation coefficient: if the thermal management control activation coefficient is greater than or equal to a preset first threshold and less than a preset second threshold, the battery thermal management operation mode is an air cooling mode; if the thermal management control activation coefficient is greater than or equal to a preset second threshold and less than a preset third threshold, the battery thermal management operation mode is a refrigerant direct cooling mode.

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