Battery pack driving cooling gradient control method, device and equipment for pure electric vehicle and storage medium

Abstract

The application discloses a kind of pure electric vehicle battery pack driving cooling gradient control method, device, equipment and storage medium, is related to pure electric vehicle whole vehicle thermal management control technical field, comprising: obtaining battery pack temperature signal and battery pack cooling opening signal;When battery pack cooling opening signal is in the opening state, according to battery pack temperature signal, query pre-stored two-dimensional calibration mapping table, obtain battery pack coolant temperature request value;Battery pack coolant temperature request value is sent to air conditioning system, so that air conditioning system controls compressor power according to battery pack coolant temperature request value, and battery pack loop water temperature is cooled to battery pack coolant temperature request value, by the gradient control of battery pack temperature associated with coolant target temperature, reduce the duration of high-power continuous operation of compressor, reduce battery cooling system energy consumption and improve high-temperature driving endurance.

Description

Technical Field

[0001] This invention relates to the field of thermal management control technology for pure electric vehicles, and in particular to a method, apparatus, equipment, and storage medium for controlling the cooling gradient of a battery pack during driving in a pure electric vehicle. Background Technology

[0002] With the deepening of national energy conservation and emission reduction policies and the rapid development of the new energy vehicle industry, the market share of pure electric vehicles continues to rise, and consumers are placing higher demands on vehicle performance and range in high-temperature environments. High-temperature range anxiety has become one of the core pain points restricting the user experience and market acceptance of pure electric vehicles. Effectively improving the energy utilization efficiency of pure electric vehicles under high-temperature conditions and extending their range on hot roads is of great significance for enhancing product market competitiveness, increasing user willingness to purchase, and promoting the high-quality development of the new energy vehicle industry.

[0003] In existing pure electric vehicle battery pack cooling strategies, when the vehicle is in a high-temperature driving environment and the battery pack temperature exceeds a set threshold, the vehicle controller activates the battery pack cooling function and controls the compressor to cool the battery pack circuit coolant to a fixed, lower temperature. To ensure cooling effectiveness, this fixed temperature is usually set low, requiring the compressor to maintain high-power operation for extended periods, resulting in a significant increase in the power consumption of the battery pack cooling system. With the total battery pack discharge remaining constant, the power consumed by the cooling system directly reduces the available power of the drive motor, causing a decrease in the vehicle's high-temperature driving range. This easily leads to customer and after-sales complaints, weakening the market competitiveness of pure electric vehicles.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a method, apparatus, device, and storage medium for controlling the cooling gradient of a battery pack in a pure electric vehicle, aiming to solve the technical problem of how to reduce the power consumption for cooling the battery pack during high-temperature driving of a pure electric vehicle and improve its range on high-temperature roads.

[0006] To achieve the above objectives, the present invention provides a method for controlling the cooling gradient of a battery pack while driving in a pure electric vehicle. The method includes the following steps: Acquire battery pack temperature signal and battery pack cooling start signal; When the battery pack cooling activation signal is in the activated state, the battery pack temperature request value is obtained by querying the pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal. The requested battery pack coolant temperature value is sent to the air conditioning system, so that the air conditioning system controls the compressor power according to the requested battery pack coolant temperature value to cool the battery pack circuit water temperature to the requested battery pack coolant temperature value.

[0007] In one embodiment, the step of acquiring the battery pack temperature signal and the battery pack cooling activation signal includes: Receives the highest battery pack temperature signal sent by the battery management system via the controller area network bus; The battery pack temperature signal is determined based on the highest temperature signal of the battery pack. The system receives the battery pack cooling start signal from the battery management system via the controller local area network bus, and obtains the battery pack temperature signal and the battery pack cooling start signal.

[0008] In one embodiment, the step of receiving the battery pack maximum temperature signal sent by the battery management system via the controller area network bus includes: Receive raw temperature signals from the battery management system via the controller area network bus; Extract the highest temperature value of the battery pack from the original temperature signal; The maximum temperature value of the battery pack is calibrated by measuring its range. The highest temperature value of the battery pack that passes the verification is used as the highest temperature signal of the battery pack.

[0009] In one embodiment, the step of querying a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal to obtain the requested value of the battery pack coolant temperature when the battery pack cooling activation signal is in the Activated state includes: Read the pre-stored two-dimensional calibration mapping table, which includes multiple battery pack temperature values ​​and multiple battery pack coolant temperature request values ​​that correspond one-to-one with the multiple battery pack temperature values; Determine the target battery pack temperature value corresponding to the battery pack temperature signal; The target battery pack coolant temperature request value is obtained by searching the two-dimensional calibration mapping table for the target battery pack temperature value.

[0010] In one embodiment, the step of determining the target battery pack temperature value corresponding to the battery pack temperature signal includes: Extract the current battery pack temperature value from the battery pack temperature signal; The current battery pack temperature value is compared with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table; Calculate the temperature difference between the current battery pack temperature value and the temperature value of each battery pack; The target battery pack temperature value is determined by identifying the battery pack temperature with the smallest temperature difference.

[0011] In one embodiment, the step of searching for the target battery pack coolant temperature request value corresponding to the target battery pack temperature value from the two-dimensional calibration mapping table as the battery pack coolant temperature request value includes: The target battery pack temperature value is matched with multiple battery pack temperature values ​​in a two-dimensional calibration mapping table; When the target battery pack temperature value is successfully matched with any one of the plurality of battery pack temperature values, the battery pack coolant temperature request value corresponding to the successfully matched battery pack temperature value is used as the candidate coolant temperature request value. When the target battery pack temperature value fails to match all of the multiple battery pack temperature values, the first battery pack temperature value and the second battery pack temperature value adjacent to the target battery pack temperature value are determined, as well as the first coolant temperature request value corresponding to the first battery pack temperature value and the second coolant temperature request value corresponding to the second battery pack temperature value. Based on the first temperature difference between the target battery pack temperature value and the first battery pack temperature value, and the second temperature difference between the target battery pack temperature value and the second battery pack temperature value, a weighted interpolation calculation is performed on the first coolant temperature request value and the second coolant temperature request value to obtain the interpolated coolant temperature request value. The candidate coolant temperature request value or the interpolated coolant temperature request value is used as the target battery pack coolant temperature request value.

[0012] In one embodiment, the step of sending the requested battery pack coolant temperature value to the air conditioning system, so that the air conditioning system controls the compressor power according to the requested battery pack coolant temperature value, to cool the battery pack circuit water temperature to the requested battery pack coolant temperature value, includes: The requested battery pack coolant temperature value is sent to the air conditioning system via the controller area network bus; Receive the battery pack circuit water temperature signal sent by the air conditioning system; Determine whether the battery pack circuit water temperature signal reaches the requested value of the battery pack coolant temperature; When the battery pack circuit water temperature signal reaches the battery pack coolant temperature request value, it is confirmed that the battery pack coolant temperature request value has been successfully sent and the battery pack circuit water temperature has been cooled to the battery pack coolant temperature request value.

[0013] Furthermore, to achieve the above objectives, the present invention also proposes a vehicle battery pack cooling gradient control device, the device comprising: The acquisition module is used to acquire battery pack temperature signals and battery pack cooling activation signals; The query module is used to query a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal when the battery pack cooling activation signal is in the Activated state, in order to obtain the requested value of the battery pack coolant temperature. The sending module is used to send the battery pack coolant temperature request value to the air conditioning system, so that the air conditioning system controls the compressor power according to the battery pack coolant temperature request value to cool the battery pack circuit water temperature to the battery pack coolant temperature request value.

[0014] Furthermore, to achieve the above objectives, the present invention also proposes a pure electric vehicle battery pack driving cooling gradient control device, the device comprising: a memory, a processor, and a pure electric vehicle battery pack driving cooling gradient control program stored in the memory and executable on the processor, the pure electric vehicle battery pack driving cooling gradient control program being configured to implement the steps of the pure electric vehicle battery pack driving cooling gradient control method as described above.

[0015] Furthermore, to achieve the above objectives, the present invention also proposes a storage medium storing a pure electric vehicle battery pack driving cooling gradient control program, wherein when the pure electric vehicle battery pack driving cooling gradient control program is executed by a processor, the steps of the pure electric vehicle battery pack driving cooling gradient control method described above are implemented.

[0016] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the pure electric vehicle battery pack driving cooling gradient control method described above.

[0017] One or more technical solutions proposed in this application have at least the following technical effects: By establishing a dynamic correlation between the battery pack temperature and the target coolant temperature, the target coolant temperature is gradually adjusted according to changes in the battery pack temperature. This avoids the problem of prolonged high-power operation of the compressor caused by fixing the coolant to a lower temperature in existing technologies. This effectively reduces the power consumption of the battery pack cooling system, allowing more power to be used for motor drive while ensuring that the battery pack cooling effect is largely unaffected, significantly improving the high-temperature driving range of pure electric vehicles. Simultaneously, through weighted interpolation calculations of adjacent temperature nodes, the requested coolant temperature value can be accurately determined in temperature ranges not directly covered by the calibration mapping table, further improving the precision and adaptability of temperature control. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating an embodiment of the pure electric vehicle battery pack driving cooling gradient control method of this application. Figure 2 This is an overall control flowchart provided for Embodiment 1 of the pure electric vehicle battery pack driving cooling gradient control method of this application; Figure 3 This is a diagram illustrating the implementation effect of the intelligent control of battery pack cooling during driving, provided in Embodiment 1 of the pure electric vehicle battery pack cooling gradient control method of this application. Figure 4 This is a test flowchart provided for Embodiment 1 of the pure electric vehicle battery pack driving cooling gradient control method of this application; Figure 5 This is a flowchart illustrating Embodiment 2 of the pure electric vehicle battery pack driving cooling gradient control method of this application; Figure 6 This is a schematic diagram of the module structure of the battery pack driving cooling gradient control device for pure electric vehicles according to an embodiment of this application; Figure 7 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the pure electric vehicle battery pack driving cooling gradient control method in the embodiments of this application.

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0023] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0024] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device capable of performing the above functions, such as a pure electric vehicle battery pack driving cooling gradient control device. The following description uses a pure electric vehicle battery pack driving cooling gradient control device as an example to illustrate this embodiment and the subsequent embodiments.

[0025] Based on this, this application provides a method for controlling the cooling gradient of a battery pack while driving in a pure electric vehicle, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the pure electric vehicle battery pack driving cooling gradient control method of this application.

[0026] In this embodiment, the pure electric vehicle battery pack driving cooling gradient control method includes steps S10~S30: Step S10: Obtain the battery pack temperature signal and the battery pack cooling start signal; It should be noted that the battery pack temperature signal is data information used to characterize the temperature state of the cells inside the battery pack of a pure electric vehicle. This signal is usually collected and sent by the battery management function unit, reflecting the thermal state of the battery pack at the current moment. It should also be noted that the battery pack cooling activation signal is control information used to indicate whether the battery pack cooling function is activated. This signal is generated by the battery management function unit based on whether the battery pack temperature exceeds a preset temperature threshold, and is used to trigger the vehicle control device to execute subsequent cooling control logic.

[0027] Understandably, acquiring the battery pack temperature signal and the battery pack cooling activation signal means that the vehicle control device receives the two signals from the battery management function unit through the data communication network, which serve as the data basis and triggering conditions for subsequent cooling gradient control.

[0028] In one feasible implementation, step S10 includes steps A11 to A15: Step A11: Receive the battery pack maximum temperature signal sent by the battery management system via the controller area network bus; It should be noted that the Controller Area Network (CAN) bus is a serial communication protocol bus used for data communication between various electronic control units within a vehicle. This bus boasts high reliability and real-time performance and is widely used in vehicle network communication. It should also be noted that the Battery Management System (BMS) is a vehicle electronic control unit used to monitor the health status of each cell within the battery pack and to collect cell temperature and charge information. Finally, it should be noted that the battery pack maximum temperature signal is an electrical signal characterizing the highest temperature value among all cells within the battery pack; this signal reflects the most dangerous thermal state point within the battery pack.

[0029] Understandably, receiving the battery pack maximum temperature signal sent by the battery management system via the controller area network bus means that the vehicle control device obtains the highest cell temperature data inside the battery pack from the battery management functional unit through the vehicle's internal communication bus.

[0030] In one feasible implementation, step A11 includes steps B11 to B14: Step B11: Receive the raw temperature signal sent by the battery management system via the controller area network bus; It should be noted that the raw temperature signal is an initial temperature data packet that is directly collected and sent by the battery management function unit without being parsed or verified. This data packet may contain temperature information of multiple cells or temperature information of the entire battery pack.

[0031] Understandably, receiving the raw temperature signal sent by the battery management system via the controller area network bus refers to the vehicle control unit receiving the initial temperature data packet sent by the battery management functional unit via the communication bus.

[0032] Step B12: Extract the highest temperature value of the battery pack from the original temperature signal; It should be noted that the maximum temperature value of the battery pack is a specific value extracted from the raw temperature data to quantify the highest temperature inside the battery pack, and this value is expressed in degrees Celsius.

[0033] Understandably, extracting the highest battery pack temperature value from the original temperature signal means that the vehicle control device parses the received initial temperature data packet and identifies and extracts the specific temperature value representing the highest temperature inside the battery pack.

[0034] Step B13: Verify the range of the maximum temperature value of the battery pack; It should be noted that range calibration is a process of checking the reasonableness of the extracted temperature value, that is, determining whether the value is within the preset reasonable temperature range, in order to eliminate erroneous data caused by communication interference or sensor malfunction.

[0035] Understandably, range verification of the battery pack's maximum temperature value means that the vehicle control device compares the extracted temperature value with a preset reasonable temperature range to determine whether the value is within the effective range.

[0036] Step B14: Use the highest temperature value of the battery pack that has passed the verification as the highest temperature signal of the battery pack.

[0037] Understandably, using the verified maximum battery pack temperature value as the maximum battery pack temperature signal means that after the range verification is passed, the vehicle control device determines the verified temperature value as the valid maximum battery pack temperature signal.

[0038] Step A12: Determine the battery pack temperature signal based on the highest battery pack temperature signal; Understandably, determining the battery pack temperature signal based on the highest battery pack temperature signal means that the vehicle control device directly uses the verified highest battery pack temperature value as the battery pack temperature signal for subsequent query and control.

[0039] Step A13: Receive the battery pack cooling start signal sent by the battery management system through the controller LAN bus, and obtain the battery pack temperature signal and the battery pack cooling start signal.

[0040] Understandably, receiving the battery pack cooling start signal sent by the battery management system via the controller area network bus means that the vehicle control unit receives cooling start identification information from the battery management function unit through the communication bus, and then obtains the battery pack temperature signal and the battery pack cooling start signal.

[0041] In addition, the beneficial effect of step S10 is that the battery pack temperature status and cooling trigger status are uniformly obtained through the vehicle control device, which provides accurate data input and reliable trigger conditions for subsequent cooling gradient control. At the same time, the accuracy and reliability of the temperature data are ensured through the range verification mechanism.

[0042] Step S20: When the battery pack cooling start signal is in the start state, query the pre-stored two-dimensional calibration mapping table according to the battery pack temperature signal to obtain the battery pack coolant temperature request value. It should be noted that the two-dimensional calibration mapping table is a two-dimensional calibration MAP table pre-stored in the vehicle control unit. The first dimension of this table represents multiple discrete battery pack temperature values, and the second dimension represents the target battery pack coolant temperature value corresponding to each of these temperature values. This is used to establish a dynamic correlation between the battery pack temperature and the target coolant temperature. It should also be noted that the battery pack coolant temperature request value is a control parameter sent by the vehicle control unit to the air conditioning unit to indicate the target coolant temperature. This parameter determines the temperature level to which the air conditioning unit should cool the battery pack circuit coolant.

[0043] Understandably, when the battery pack cooling activation signal is in the active state, the vehicle control device queries the pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal to obtain the battery pack coolant temperature request value. This means that after receiving the cooling activation flag, the vehicle control device uses the current battery pack temperature value as input to search for or calculate the corresponding coolant target temperature value in the pre-stored two-dimensional data table, and uses this target temperature value as the control request value sent to the air conditioning function unit.

[0044] In addition, the beneficial effect of step S20 is that the dynamic correlation between the battery pack temperature and the target temperature of the coolant is realized through the two-dimensional calibration mapping table, so that the target temperature of the coolant can be adjusted in a gradient according to the change of battery pack temperature, avoiding the problem of the compressor running at high power for a long time due to the fixed low temperature target.

[0045] Step S30: Send the battery pack coolant temperature request value to the air conditioning system so that the air conditioning system controls the compressor power according to the battery pack coolant temperature request value to cool the battery pack circuit water temperature to the battery pack coolant temperature request value.

[0046] It should be noted that the air conditioning unit is a vehicle thermal management function unit used to regulate the temperature of the vehicle's cabin and the coolant temperature in the battery pack circuit. This unit regulates the refrigerant circulation in the cooling circuit by controlling the compressor speed and the solenoid valve status. The compressor is the core refrigeration component of the air conditioning unit. It compresses the refrigerant, causing it to circulate between the condenser and evaporator, thereby transferring heat from the coolant to the external environment. The battery pack circuit coolant temperature is a physical parameter characterizing the current temperature of the coolant in the battery pack cooling circuit; this parameter reflects the actual temperature state of the coolant within the battery pack's water-cooled plates.

[0047] Understandably, sending the requested battery pack coolant temperature value to the air conditioning system, so that the air conditioning system can control the compressor power according to the requested battery pack coolant temperature value, and cooling the battery pack circuit water temperature to the requested battery pack coolant temperature value means that the vehicle control unit sends the calculated target coolant temperature value to the air conditioning function unit through the communication bus. After receiving the request value, the air conditioning function unit adjusts the compressor operating power to reduce the coolant temperature in the battery pack cooling circuit to the target temperature value requested by the vehicle control unit.

[0048] like Figure 2 As shown, when the vehicle is operating at high temperatures, the VCU continuously receives the battery pack maximum temperature signal and the battery pack cooling activation signal from the CAN network. Upon receiving the battery pack cooling activation signal, the VCU calculates and sends a corresponding battery pack coolant temperature request value based on the battery pack temperature and the two-dimensional calibration MAP table. This request is then transmitted to the air conditioning system via the vehicle's CAN network. The air conditioning system then dynamically adjusts the compressor power to lower the coolant temperature in the battery pack circuit to the coolant temperature requested by the VCU.

[0049] The battery pack cooling gradient control method set in this scheme has the following effect after implementation: Figure 3 As shown.

[0050] In one feasible implementation, step S30 includes steps A21 to A24: Step A21: Send the requested battery pack coolant temperature value to the air conditioning system via the controller area network bus; Understandably, sending the battery pack coolant temperature request value to the air conditioning system via the controller area network bus means that the vehicle control unit sends the calculated coolant target temperature control parameters to the air conditioning function unit through the vehicle's internal communication bus.

[0051] Step A22: Receive the battery pack circuit water temperature signal sent by the air conditioning system; It should be noted that the battery pack circuit water temperature signal is an electrical signal collected and fed back by the air conditioning functional unit or water temperature sensor to characterize the current actual temperature of the coolant in the battery pack cooling circuit. This signal is used to monitor the execution status of the cooling process.

[0052] Understandably, receiving the battery pack circuit coolant temperature signal sent by the air conditioning system means that the vehicle control unit receives the actual coolant temperature data fed back by the air conditioning functional unit through the communication bus.

[0053] Step A23: Determine whether the battery pack circuit water temperature signal has reached the requested value for battery pack coolant temperature; Understandably, determining whether the battery pack circuit water temperature signal has reached the battery pack coolant temperature request value means that the vehicle control device compares the received actual coolant temperature value with the previously sent target coolant temperature value to determine whether the actual temperature has dropped to the target temperature level.

[0054] Step A24: When the battery pack circuit water temperature signal reaches the battery pack coolant temperature request value, confirm that the battery pack coolant temperature request value has been successfully sent and that the battery pack circuit water temperature has been cooled to the battery pack coolant temperature request value.

[0055] Understandably, when the battery pack circuit water temperature signal reaches the battery pack coolant temperature request value, confirming that the battery pack coolant temperature request value has been successfully sent and that the battery pack circuit water temperature has been cooled to the battery pack coolant temperature request value means that after the vehicle control device determines that the actual coolant temperature has reached the target temperature, it confirms that the cooling control request has been correctly executed and the cooling target has been achieved.

[0056] In addition, the beneficial effect of step S30 is that through the closed-loop control between the vehicle control device and the air conditioning function unit, the battery pack coolant temperature is precisely regulated, ensuring that the coolant temperature can accurately reach the gradient control target, while the feedback confirmation mechanism ensures the reliable execution of control commands.

[0057] like Figure 4 As shown in the figure, this diagram illustrates the test flow of a battery pack cooling gradient control method for pure electric vehicles. The flow begins with the pure electric vehicle, proceeds to the right through the following steps: connecting and collecting data from the equipment, calibrating and setting the two-dimensional MAP table, and conducting high-temperature driving conditions on the vehicle. Then, it moves down to the stage of observing the highest battery pack temperature, the battery pack cooling activation status, the battery pack circuit water temperature, and the compressor power. Subsequently, it moves to the left to the control stage where the requested battery pack coolant temperature value changes with the battery pack temperature value, and the compressor power also changes with the requested battery pack coolant temperature value. Next, it moves to the left to the stage of calculating the battery pack cooling rate and the compressor power consumption, and finally moves to the left to the end of the test.

[0058] This embodiment provides a method for gradient control of battery pack cooling during pure electric vehicle operation. By acquiring battery pack temperature signals and battery pack cooling activation signals, and when the battery pack cooling activation signal is active, the method queries a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal to obtain the requested battery pack coolant temperature value. This requested value is then sent to the air conditioning unit, which controls the compressor power to cool the battery pack circuit water temperature to the requested value, thus achieving a dynamic correlation between the battery pack temperature and the target coolant temperature. Through this dynamic correlation, the target coolant temperature can be gradient-adjusted according to changes in battery pack temperature, avoiding the problem of the compressor maintaining high power operation for extended periods due to fixed cooling of the battery pack circuit water temperature to a lower value in existing technologies. This effectively reduces power consumption during battery pack cooling. With the total battery pack discharge remaining constant, reducing cooling power consumption means more power can be used to drive the vehicle, significantly improving the high-temperature road range of pure electric vehicles without significantly affecting the battery pack cooling effect. Furthermore, since the target coolant temperature adjusts accordingly as the battery pack temperature rises, it ensures the battery pack's continuous and normal power output under high-temperature conditions while avoiding energy waste caused by excessive cooling. This strategy is applicable to all pure electric vehicles, demonstrating good versatility and helping to increase users' willingness to purchase and maintain pure electric vehicles, thereby contributing to the implementation of national energy conservation and emission reduction policies.

[0059] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 5 Step S20 includes steps S201 to S203: Step S201: Read the pre-stored two-dimensional calibration mapping table. The two-dimensional calibration mapping table includes multiple battery pack temperature values ​​and multiple battery pack coolant temperature request values ​​that correspond one-to-one with the multiple battery pack temperature values. It should be noted that the battery pack temperature values ​​are discrete temperature node values ​​pre-set in a two-dimensional calibration mapping table. These values ​​cover the typical temperature range that the battery pack may experience under high-temperature driving conditions, serving as the index benchmark for establishing the temperature lookup table. It should also be noted that the battery pack coolant temperature request value is a target coolant temperature control parameter corresponding one-to-one with each battery pack temperature value. This parameter is pre-determined through calibration tests and is used to guide the air conditioning unit to cool the coolant to the corresponding temperature level.

[0060] Understandably, reading the pre-stored two-dimensional calibration mapping table refers to the vehicle control device retrieving a pre-written two-dimensional data table from the internal storage area. This table contains multiple discrete battery pack temperature values ​​and multiple battery pack coolant temperature request values ​​that correspond one-to-one with these temperature values.

[0061] Step S202: Determine the target battery pack temperature value corresponding to the battery pack temperature signal; It should be noted that the target battery pack temperature value is a specific temperature value parsed from the currently acquired battery pack temperature signal and used for matching and looking up in the two-dimensional calibration mapping table. This value represents the actual thermal state of the battery pack at the current moment. It should also be noted that the current battery pack temperature value is the raw, quantized temperature value extracted from the battery pack temperature signal without any lookup transformation. This value represents the real-time temperature of the battery pack in degrees Celsius.

[0062] Understandably, determining the target battery pack temperature value corresponding to the battery pack temperature signal means that the vehicle control device processes the acquired battery pack temperature signal to obtain the target temperature value for subsequent table lookup operations.

[0063] In one feasible implementation, step S202 includes steps A31 to A34: Step A31: Extract the current battery pack temperature value from the battery pack temperature signal; Understandably, extracting the current battery pack temperature value from the battery pack temperature signal means that the vehicle control device parses and extracts the specific value representing the real-time temperature of the battery pack from the received battery pack temperature signal.

[0064] Step A32: Compare the current battery pack temperature value with the multiple battery pack temperature values ​​in the two-dimensional calibration mapping table; Understandably, comparing the current battery pack temperature value with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table means that the vehicle control device compares the extracted real-time temperature value with each discrete temperature node value in the pre-stored two-dimensional calibration mapping table one by one.

[0065] Step A33: Calculate the temperature difference between the current battery pack temperature and the temperature of each battery pack; It should be noted that the temperature difference is the absolute difference between the current battery pack temperature value and a specific battery pack temperature value in the two-dimensional calibration mapping table. This difference is used to quantify the degree of deviation between the real-time temperature and the calibration temperature node.

[0066] Understandably, calculating the temperature difference between the current battery pack temperature value and the temperature value of each battery pack refers to the difference between the real-time temperature value calculated by the vehicle control device and the value of each discrete temperature node in the two-dimensional calibration mapping table.

[0067] Step A34: Determine the battery pack temperature value with the smallest temperature difference as the target battery pack temperature value.

[0068] Understandably, determining the target battery pack temperature value as the battery pack temperature value with the smallest temperature difference means that the vehicle control device finds the smallest difference among multiple calculated temperature differences and determines the calibration temperature node value corresponding to the smallest difference as the target battery pack temperature value for subsequent table lookup.

[0069] In addition, the beneficial effect of step S202 is that by comparing and calculating the difference between the real-time battery pack temperature and the discrete temperature nodes in the calibration mapping table, the calibration temperature node that is closest to the current temperature state can be accurately found, providing a reliable index basis for subsequent accurate table lookup.

[0070] Step S203: Find the target battery pack coolant temperature request value corresponding to the target battery pack temperature value from the two-dimensional calibration mapping table and use it as the battery pack coolant temperature request value.

[0071] It should be noted that the target battery pack coolant temperature request value is the final coolant temperature control parameter corresponding to the target battery pack temperature value, which is found in the two-dimensional calibration mapping table. This parameter will be used as the cooling control target value sent by the vehicle control unit to the air conditioning function unit.

[0072] Understandably, finding the target battery pack coolant temperature request value corresponding to the target battery pack temperature value in the two-dimensional calibration mapping table as the battery pack coolant temperature request value means that the vehicle control device locates the coolant temperature parameter corresponding to the target battery pack temperature value in the two-dimensional calibration mapping table and determines this parameter as the final output battery pack coolant temperature request value.

[0073] In one feasible implementation, step S203 includes steps A41-A45: Step A41: Match the target battery pack temperature value with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table; Understandably, matching the target battery pack temperature value with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table means that the vehicle control device performs a precise matching and comparison between the determined target battery pack temperature value and the discrete temperature node values ​​in the two-dimensional calibration mapping table.

[0074] Step A42: When the target battery pack temperature value is successfully matched with any one of the multiple battery pack temperature values, the battery pack coolant temperature request value corresponding to the successfully matched battery pack temperature value is taken as the candidate coolant temperature request value. It should be noted that the candidate coolant temperature request value is the coolant temperature parameter corresponding to a certain discrete temperature node in the two-dimensional calibration mapping table, which is obtained directly when the target battery pack temperature value is accurately matched with the value of a certain discrete temperature node. This parameter can be used directly without interpolation calculation.

[0075] Understandably, when the target battery pack temperature value is successfully matched with any one of the multiple battery pack temperature values, using the battery pack coolant temperature request value corresponding to the successfully matched battery pack temperature value as the candidate coolant temperature request value means that the vehicle control device directly uses the coolant temperature parameter corresponding to the matching node as the candidate value when the matching is accurate.

[0076] Step A43: When the target battery pack temperature value fails to match multiple battery pack temperature values, determine the first battery pack temperature value and the second battery pack temperature value adjacent to the target battery pack temperature value, as well as the first coolant temperature request value corresponding to the first battery pack temperature value and the second coolant temperature request value corresponding to the second battery pack temperature value. It should be noted that the first battery pack temperature value is the adjacent calibration temperature node value located on one side of the target temperature value, determined when the target battery pack temperature value does not match any of the discrete temperature node values. It should also be noted that the second battery pack temperature value is the adjacent calibration temperature node value located on the other side of the target temperature value, determined when the target battery pack temperature value does not match any of the discrete temperature node values. Furthermore, the first coolant temperature request value is a coolant temperature control parameter that corresponds one-to-one with the first battery pack temperature value in the two-dimensional calibration mapping table; this parameter represents the target coolant temperature to be set at the lower adjacent temperature node. Similarly, the second coolant temperature request value is a coolant temperature control parameter that corresponds one-to-one with the second battery pack temperature value in the two-dimensional calibration mapping table; this parameter represents the target coolant temperature to be set at the higher adjacent temperature node.

[0077] Understandably, when the target battery pack temperature value fails to match with multiple battery pack temperature values, determining the first and second battery pack temperature values ​​adjacent to the target battery pack temperature value, as well as the first coolant temperature request value corresponding to the first battery pack temperature value and the second coolant temperature request value corresponding to the second battery pack temperature value, means that when the vehicle control device fails to accurately match, it searches for and determines the closest adjacent calibration temperature nodes on both sides of the target temperature value and their corresponding coolant temperature parameters.

[0078] Step A44: Based on the first temperature difference between the target battery pack temperature value and the first battery pack temperature value, and the second temperature difference between the target battery pack temperature value and the second battery pack temperature value, perform a weighted interpolation calculation on the first coolant temperature request value and the second coolant temperature request value to obtain the interpolated coolant temperature request value. It should be noted that the first temperature difference is the temperature difference between the target battery pack temperature and the first battery pack temperature, reflecting the degree to which the target temperature deviates from its lower neighboring node. The second temperature difference is the temperature difference between the target battery pack temperature and the second battery pack temperature, reflecting the degree to which the target temperature deviates from its higher neighboring node. The weighted interpolation calculation is a data processing method that assigns weights based on the distance between the target temperature and the temperature values ​​of its two adjacent nodes, and then performs a weighted average calculation on the coolant temperature parameters corresponding to the two adjacent nodes. The interpolated coolant temperature request value is a coolant temperature parameter obtained through weighted interpolation, falling between the first and second coolant temperature request values.

[0079] Understandably, based on the first temperature difference between the target battery pack temperature value and the first battery pack temperature value, and the second temperature difference between the target battery pack temperature value and the second battery pack temperature value, a weighted interpolation calculation is performed on the first coolant temperature request value and the second coolant temperature request value to obtain the interpolated coolant temperature request value. This means that the vehicle control device performs a weighted calculation on the coolant temperature parameters corresponding to the nodes on both sides based on the target temperature and the temperature difference between the target temperature and the adjacent nodes on both sides, thereby obtaining the interpolated coolant temperature parameter corresponding to the target temperature value.

[0080] Step A45: Use the candidate coolant temperature request value or the interpolated coolant temperature request value as the target battery pack coolant temperature request value.

[0081] Understandably, using the candidate coolant temperature request value or the interpolated coolant temperature request value as the target battery pack coolant temperature request value means that the vehicle control device selects the candidate coolant temperature request value when the precise matching is successful, and selects the interpolated coolant temperature request value when the precise matching fails, and uses the selected value as the final target battery pack coolant temperature request value.

[0082] In addition, the beneficial effect of step S203 is that through the dual lookup table mechanism that combines precise matching and weighted interpolation, it can directly obtain calibration parameters when the battery pack temperature is exactly at the calibration node, and can obtain a continuous and smooth coolant temperature request value through interpolation calculation of adjacent nodes when the battery pack temperature is between calibration nodes. This avoids the problem of control parameter jumps caused by sparse calibration nodes and significantly improves the precision and continuity of coolant target temperature control.

[0083] This embodiment provides a method for cooling gradient control of a battery pack in a pure electric vehicle. It reads a pre-stored two-dimensional calibration mapping table and determines the target battery pack temperature value corresponding to the battery pack temperature signal. Then, it searches the two-dimensional calibration mapping table for the corresponding target battery pack coolant temperature request value, achieving a precise mapping between the battery pack temperature and the target coolant temperature. By comparing the current battery pack temperature value with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table and calculating the temperature difference, the battery pack temperature value with the smallest temperature difference is determined as the target battery pack temperature value, ensuring the accuracy of the temperature lookup. When searching for the target battery pack coolant temperature request value, candidate coolant temperature request values ​​are directly obtained through precise matching, or, if matching fails, an interpolated coolant temperature request value is obtained by weighted interpolation of the first and second coolant temperature request values ​​from adjacent nodes. This effectively avoids control parameter jumps caused by sparse calibration nodes, allowing the target coolant temperature to be continuously and smoothly adjusted with the battery pack temperature. Therefore, the vehicle control unit can output a more reasonable target coolant temperature request value based on the real-time thermal state of the battery pack, avoiding the problem of long-term high-power operation of the compressor caused by fixed low-temperature cooling in the existing technology. It reduces cooling power consumption without significantly affecting the cooling effect of the battery pack, and uses more power for motor drive, effectively improving the high-temperature road range of pure electric vehicles.

[0084] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the pure electric vehicle battery pack driving cooling gradient control method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0085] This application also provides a vehicle cooling gradient control device for a battery pack in a pure electric vehicle. Please refer to [reference needed]. Figure 6 The battery pack cooling gradient control device for pure electric vehicles includes: The acquisition module 10 is used to acquire the battery pack temperature signal and the battery pack cooling start signal; The query module 20 is used to query a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal when the battery pack cooling start signal is in the start state, in order to obtain the requested value of the battery pack coolant temperature. The sending module 30 is used to send the battery pack coolant temperature request value to the air conditioning system, so that the air conditioning system controls the compressor power according to the battery pack coolant temperature request value to cool the battery pack circuit water temperature to the battery pack coolant temperature request value.

[0086] The pure electric vehicle battery pack cooling gradient control device provided in this application adopts the pure electric vehicle battery pack cooling gradient control method in the above embodiments, which can solve the technical problem of how to reduce the power consumption of battery pack cooling during high-temperature driving of pure electric vehicles and improve the driving range on high-temperature roads. Compared with the prior art, the beneficial effects of the pure electric vehicle battery pack cooling gradient control device provided in this application are the same as the beneficial effects of the pure electric vehicle battery pack cooling gradient control method provided in the above embodiments, and other technical features in the pure electric vehicle battery pack cooling gradient control device are the same as the features disclosed in the methods of the above embodiments, and will not be repeated here.

[0087] In one embodiment, the acquisition module 10 is further configured to receive the battery pack maximum temperature signal sent by the battery management system via the controller local area network bus; The battery pack temperature signal is determined based on the highest battery pack temperature signal. The system receives the battery pack cooling start signal from the battery management system via the controller LAN bus, and obtains the battery pack temperature signal and the battery pack cooling start signal.

[0088] In one embodiment, the acquisition module 10 is further configured to receive the raw temperature signal sent by the battery management system via the controller local area network bus; Extract the highest temperature value of the battery pack from the raw temperature signal; Perform range calibration on the maximum temperature value of the battery pack; The highest temperature value of the battery pack that passes the verification is used as the highest temperature signal of the battery pack.

[0089] In one embodiment, the query module 20 is further configured to read a pre-stored two-dimensional calibration mapping table, which includes multiple battery pack temperature values ​​and multiple battery pack coolant temperature request values ​​that correspond one-to-one with the multiple battery pack temperature values. Determine the target battery pack temperature value corresponding to the battery pack temperature signal; The target battery pack coolant temperature request value is obtained by finding the target battery pack temperature value in the two-dimensional calibration mapping table.

[0090] In one embodiment, the query module 20 is further configured to extract the current battery pack temperature value from the battery pack temperature signal; Compare the current battery pack temperature value with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table; Calculate the temperature difference between the current battery pack temperature and the temperature of each battery pack; The target battery pack temperature value is determined by finding the battery pack temperature with the smallest temperature difference.

[0091] In one embodiment, the query module 20 is further configured to match the target battery pack temperature value with multiple battery pack temperature values ​​in a two-dimensional calibration mapping table; When the target battery pack temperature value is successfully matched with any one of the multiple battery pack temperature values, the battery pack coolant temperature request value corresponding to the successfully matched battery pack temperature value is used as the candidate coolant temperature request value. When the target battery pack temperature value fails to match multiple battery pack temperature values, the first battery pack temperature value and the second battery pack temperature value adjacent to the target battery pack temperature value are determined, as well as the first coolant temperature request value corresponding to the first battery pack temperature value and the second coolant temperature request value corresponding to the second battery pack temperature value. Based on the first temperature difference between the target battery pack temperature value and the first battery pack temperature value, and the second temperature difference between the target battery pack temperature value and the second battery pack temperature value, a weighted interpolation calculation is performed on the first coolant temperature request value and the second coolant temperature request value to obtain the interpolated coolant temperature request value. Use the candidate coolant temperature request value or the interpolated coolant temperature request value as the target battery pack coolant temperature request value.

[0092] In one embodiment, the sending module 30 is further configured to send the battery pack coolant temperature request value to the air conditioning system via the controller area network bus; Receives the battery pack circuit water temperature signal sent by the air conditioning system; Determine whether the battery pack circuit water temperature signal has reached the requested value for battery pack coolant temperature; When the battery pack circuit water temperature signal reaches the battery pack coolant temperature request value, confirm that the battery pack coolant temperature request value has been successfully sent and that the battery pack circuit water temperature has been cooled to the battery pack coolant temperature request value.

[0093] This application provides a vehicle cooling gradient control device for a pure electric vehicle battery pack. The pure electric vehicle battery pack cooling gradient control device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the pure electric vehicle battery pack cooling gradient control method in the first embodiment described above.

[0094] The following is for reference. Figure 7This document illustrates a structural schematic diagram of a pure electric vehicle battery pack driving cooling gradient control device suitable for implementing embodiments of this application. The pure electric vehicle battery pack driving cooling gradient control device in this application embodiment may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 7 The illustrated electric vehicle battery pack cooling gradient control device is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0095] like Figure 7 As shown, the pure electric vehicle battery pack driving cooling gradient control device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to the program stored in ROM (Read Only Memory) 1002 or the program loaded from storage device 1003 into RAM (Random Access Memory) 1004. RAM 1004 also stores various programs and data required for the operation of the pure electric vehicle battery pack driving cooling gradient control device. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. Input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the electric vehicle battery pack driving cooling gradient control device to communicate wirelessly or wiredly with other devices to exchange data. Although the figure shows an electric vehicle battery pack driving cooling gradient control device with various systems, it should be understood that it is not required to implement or possess all the systems shown. More or fewer systems can be implemented alternatively.

[0096] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0097] The pure electric vehicle battery pack cooling gradient control device provided in this application adopts the pure electric vehicle battery pack cooling gradient control method in the above embodiments, which can solve the technical problem of how to reduce the power consumption of battery pack cooling during high-temperature driving of pure electric vehicles and improve the driving range on high-temperature roads. Compared with the prior art, the beneficial effects of the pure electric vehicle battery pack cooling gradient control device provided in this application are the same as the beneficial effects of the pure electric vehicle battery pack cooling gradient control method provided in the above embodiments, and other technical features in the pure electric vehicle battery pack cooling gradient control device are the same as the features disclosed in the previous embodiment method, and will not be repeated here.

[0098] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0099] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0100] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, which are used to execute the pure electric vehicle battery pack driving cooling gradient control method in the above embodiments.

[0101] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory or Flash Memory), optical fibers, CD-ROM (CD-Read Only Memory), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0102] The aforementioned computer-readable storage medium may be included in the vehicle cooling gradient control device for the battery pack of a pure electric vehicle; or it may exist independently and not be assembled into the vehicle cooling gradient control device for the battery pack of a pure electric vehicle.

[0103] The aforementioned computer-readable storage medium carries one or more programs. When the aforementioned one or more programs are executed by the pure electric vehicle battery pack driving cooling gradient control device, the pure electric vehicle battery pack driving cooling gradient control device: acquires a battery pack temperature signal and a battery pack cooling start signal; when the battery pack cooling start signal is in the start state, it queries a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal to obtain the battery pack coolant temperature request value; and sends the battery pack coolant temperature request value to the air conditioning system, so that the air conditioning system controls the compressor power according to the battery pack coolant temperature request value to cool the battery pack circuit water temperature to the battery pack coolant temperature request value.

[0104] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including LAN (Local Area Network) or WAN (Wide Area Network)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0105] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0106] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0107] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described pure electric vehicle battery pack cooling gradient control method. This method can solve the technical problem of how to reduce the power consumption for battery pack cooling during high-temperature driving of pure electric vehicles and improve their range on high-temperature roads. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the pure electric vehicle battery pack cooling gradient control method provided in the above embodiments, and will not be repeated here.

[0108] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method for controlling the cooling gradient of a battery pack for a pure electric vehicle.

[0109] The computer program product provided in this application can solve the technical problem of how to reduce the power consumption of battery pack cooling during high-temperature driving of pure electric vehicles and improve the driving range on high-temperature roads. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the pure electric vehicle battery pack driving cooling gradient control method provided in the above embodiments, and will not be repeated here.

[0110] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for controlling the cooling gradient of a battery pack during driving in a pure electric vehicle, characterized in that, The method includes: Acquire battery pack temperature signal and battery pack cooling start signal; When the battery pack cooling activation signal is in the activated state, the battery pack temperature request value is obtained by querying the pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal. The requested battery pack coolant temperature value is sent to the air conditioning system, so that the air conditioning system controls the compressor power according to the requested battery pack coolant temperature value to cool the battery pack circuit water temperature to the requested battery pack coolant temperature value.

2. The method as described in claim 1, characterized in that, The steps of acquiring the battery pack temperature signal and the battery pack cooling activation signal include: Receives the highest battery pack temperature signal sent by the battery management system via the controller area network bus; The battery pack temperature signal is determined based on the highest temperature signal of the battery pack. The system receives the battery pack cooling start signal from the battery management system via the controller local area network bus, and obtains the battery pack temperature signal and the battery pack cooling start signal.

3. The method as described in claim 2, characterized in that, The step of receiving the battery pack maximum temperature signal sent by the battery management system via the controller area network bus includes: Receive raw temperature signals from the battery management system via the controller area network bus; Extract the highest temperature value of the battery pack from the original temperature signal; The maximum temperature value of the battery pack is calibrated by measuring its range. The highest temperature value of the battery pack that passes the verification is used as the highest temperature signal of the battery pack.

4. The method as described in claim 1, characterized in that, The step of querying a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal to obtain the requested battery pack coolant temperature value when the battery pack cooling activation signal is in the activated state includes: Read the pre-stored two-dimensional calibration mapping table, which includes multiple battery pack temperature values ​​and multiple battery pack coolant temperature request values ​​that correspond one-to-one with the multiple battery pack temperature values; Determine the target battery pack temperature value corresponding to the battery pack temperature signal; The target battery pack coolant temperature request value is obtained by searching the two-dimensional calibration mapping table for the target battery pack temperature value.

5. The method as described in claim 4, characterized in that, The step of determining the target battery pack temperature value corresponding to the battery pack temperature signal includes: Extract the current battery pack temperature value from the battery pack temperature signal; The current battery pack temperature value is compared with multiple battery pack temperature values ​​in the two-dimensional calibration mapping table; Calculate the temperature difference between the current battery pack temperature value and the temperature value of each battery pack; The target battery pack temperature value is determined by identifying the battery pack temperature with the smallest temperature difference.

6. The method as described in claim 4, characterized in that, The step of searching for the target battery pack coolant temperature request value corresponding to the target battery pack temperature value from the two-dimensional calibration mapping table as the battery pack coolant temperature request value includes: The target battery pack temperature value is matched with multiple battery pack temperature values ​​in a two-dimensional calibration mapping table; When the target battery pack temperature value is successfully matched with any one of the plurality of battery pack temperature values, the battery pack coolant temperature request value corresponding to the successfully matched battery pack temperature value is used as the candidate coolant temperature request value. When the target battery pack temperature value fails to match all of the multiple battery pack temperature values, the first battery pack temperature value and the second battery pack temperature value adjacent to the target battery pack temperature value are determined, as well as the first coolant temperature request value corresponding to the first battery pack temperature value and the second coolant temperature request value corresponding to the second battery pack temperature value. Based on the first temperature difference between the target battery pack temperature value and the first battery pack temperature value, and the second temperature difference between the target battery pack temperature value and the second battery pack temperature value, a weighted interpolation calculation is performed on the first coolant temperature request value and the second coolant temperature request value to obtain the interpolated coolant temperature request value. The candidate coolant temperature request value or the interpolated coolant temperature request value is used as the target battery pack coolant temperature request value.

7. The method as described in claim 1, characterized in that, The step of sending the requested battery pack coolant temperature value to the air conditioning system, so that the air conditioning system controls the compressor power according to the requested battery pack coolant temperature value, and cools the battery pack circuit water temperature to the requested battery pack coolant temperature value, includes: The requested value for the battery pack coolant temperature is sent to the air conditioning system via the controller area network bus; Receive the battery pack circuit water temperature signal sent by the air conditioning system; Determine whether the battery pack circuit water temperature signal reaches the requested value of the battery pack coolant temperature; When the battery pack circuit water temperature signal reaches the battery pack coolant temperature request value, it is confirmed that the battery pack coolant temperature request value has been successfully sent and the battery pack circuit water temperature has been cooled to the battery pack coolant temperature request value.

8. A cooling gradient control device for a battery pack in a pure electric vehicle, characterized in that, The device includes: The acquisition module is used to acquire battery pack temperature signals and battery pack cooling activation signals; The query module is used to query a pre-stored two-dimensional calibration mapping table based on the battery pack temperature signal when the battery pack cooling activation signal is in the Activated state, in order to obtain the requested value of the battery pack coolant temperature. The sending module is used to send the battery pack coolant temperature request value to the air conditioning system, so that the air conditioning system controls the compressor power according to the battery pack coolant temperature request value to cool the battery pack circuit water temperature to the battery pack coolant temperature request value.

9. A cooling gradient control device for a battery pack in a pure electric vehicle, characterized in that, The device includes: a memory, a processor, and a pure electric vehicle battery pack driving cooling gradient control program stored in the memory and executable on the processor, the pure electric vehicle battery pack driving cooling gradient control program being configured to implement the steps of the pure electric vehicle battery pack driving cooling gradient control method as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium stores a pure electric vehicle battery pack driving cooling gradient control program, which, when executed by a processor, implements the steps of the pure electric vehicle battery pack driving cooling gradient control method as described in any one of claims 1 to 7.

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