Cooling control method and system for vehicle-mounted power source system, and vehicle and storage medium

Abstract

Disclosed in the present application are a cooling control method and system for a vehicle-mounted power source system, and a vehicle and a storage medium. The method comprises: acquiring, in real time, an operation state of a vehicle-mounted power source system, the temperature of a cooling liquid at a water inlet, the temperature of an internal device, and a real-time input voltage, input current, output voltage and output current of the vehicle-mounted power source system in the current operation mode; calculating a theoretical cooling flow demand corresponding to the current operation mode of the vehicle-mounted power source system, and calculating a target cooling flow demand value of the vehicle-mounted power source system; and looking up a relationship table between the duty ratio and the flow of a water pump according to the target cooling flow demand value, so as to obtain a real-time target duty ratio of the water pump, and on the basis of the real-time target duty ratio of the water pump, controlling the operation of the water pump by means of a closed loop. By means of the present application, adaptive and active flow adjustment can be performed on a vehicle-mounted power source system.

Description

Cooling control method, system, vehicle and storage medium for vehicle power system Technical Field

[0001] The present application belongs to the field of automotive thermal management technology, and specifically relates to a cooling control method, system, vehicle, and storage medium for an on-board power system. Background Art

[0002] The onboard power system is a two-in-one system integrating an onboard charger and DC-DC converter, primarily used in new energy vehicles. It performs AC charging and discharging, converting the high-voltage power of the power battery into low-voltage power, powering the vehicle's low-voltage loads, and simultaneously charging the battery. During operation, the onboard power system generates heat due to switching and conduction losses in internal power devices. This heat must be cooled by a cooling medium to ensure that the internal components do not suffer thermal failure and thus affect their performance. The cooling requirements for onboard power systems are typically as follows: First, the water inlet temperature of the onboard power system must not exceed 85°C, with output derated if the inlet temperature exceeds 65°C. Second, the temperature of the internal components of the onboard power system must be within their corresponding limits.

[0003] Currently, the current cooling control method for on-board power systems relies entirely on the vehicle's thermal management controller to obtain real-time cooling control of the system's water inlet coolant temperature. The system adjusts the water pump and fan duty cycles by determining the coolant temperature range, with the required coolant flow rate within the range of 4 to 9 L / min. The inlet coolant temperature gradient is detected: in the first range (<45°C), the water pump output flow rate is 4 L / min; in the second range (45°C to 50°C), the water pump output flow rate is 6 L / min; in the third range (≥50°C), or if the on-board power system experiences power derating, the water pump output flow rate is 9 L / min, and the fan is turned on to assist in cooling. This cooling method is relatively rough, broad, and popular, and cannot be combined with the specific technical solutions of the vehicle power system to perform adaptive and refined active adjustment and control according to actual heat dissipation needs. Under normal circumstances, the target request flow rate will be much greater than the actual demand flow rate, resulting in the water pump and fan running at high speed for a long time, poor NVH and high energy consumption. At the same time, this cooling control method is not conducive to the selection of components such as water pumps, fans and radiators, and the cooling system cost is relatively high.

[0004] Another example is patent document CN110316006A, which discloses a cooling control system and method for electric vehicle charging equipment. This method monitors the temperature of the onboard charger in real time and sends it to the vehicle's thermal management controller to determine whether the charger temperature has reached a preset value. If so, a command is sent to start the water pump. This onboard charger cooling control system controls the water pump based solely on the difference between the charger temperature and the preset temperature. This single condition forces the water pump to operate at a constant flow rate, preventing flow adjustment based on power changes during charging. This results in a poor cooling process.

[0005] Therefore, it is necessary to develop a cooling control method, system, vehicle and storage medium for an on-board power system.

[0006] Summary of the Invention

[0007] The purpose of this application is to provide a cooling control method, system, vehicle and storage medium for an on-board power system, which can actively adjust the adaptive flow of the on-board power system.

[0008] In a first aspect, the cooling control method of the vehicle power system described in the present application includes the following steps:

[0009] Real-time acquisition of the vehicle power system's operating status, water inlet coolant temperature, internal device temperature, and the vehicle power system's real-time input voltage, input current, output voltage, and output current in its current operating mode;

[0010] The theoretical cooling flow requirement corresponding to the current operating mode is calculated based on the actual coolant temperature at the water inlet of the vehicle power system, as well as the real-time input voltage, input current, output voltage, and output current in the corresponding operating mode. The flow correction coefficient corresponding to each internal component is obtained by referring to the correction coefficient map based on the difference between the real-time temperature of the internal components of the vehicle power system and their corresponding temperature thresholds. The flow correction coefficient of the vehicle power system is obtained by taking the largest of the flow correction coefficients of all internal components. The target cooling flow requirement value of the vehicle power system is calculated based on the theoretical cooling flow requirement and the flow correction coefficient of the vehicle power system.

[0011] According to the target cooling flow demand value, the relationship table between the duty cycle and flow of the water pump is checked to obtain the real-time target duty cycle of the water pump, and the operation of the water pump is controlled through a closed loop based on the real-time target duty cycle of the water pump.

[0012] Optionally, it also includes:

[0013] The real-time difference between the coolant temperature at the water inlet of the vehicle power system and the power derating temperature threshold is calculated, and the fan gear is dynamically adjusted according to the interval corresponding to the real-time temperature difference to assist in cooling the radiator.

[0014] Optionally, the real-time theoretical cooling flow demand is calculated as follows:

[0015] a: According to the actual coolant temperature at the water inlet of the vehicle power system, refer to the corresponding relationship table between the coolant temperature and the heat dissipation of the vehicle power system and the basic flow rate to find the corresponding relationship table between the heat dissipation of the vehicle power system and the basic coolant flow rate;

[0016] b: Calculate the theoretical heat dissipation of the vehicle power system based on its operating mode and its corresponding real-time input voltage, input current, output voltage, and output current;

[0017] c: Based on the current operating mode and theoretical heat dissipation of the vehicle power system, query the corresponding basic required coolant flow rate through the relationship table of vehicle power system heat dissipation - basic coolant flow rate confirmed in step a.

[0018] Optionally, in step a, when the confirmed operating mode is the charging mode, the method for calculating the theoretical heat dissipation of the vehicle power system is:

[0019] Q ACDC =U ACDC_in *I ACDC_in –U ACDC_out *I ACDC_out -U DCDC_out *I DCDC_out

[0020] Among them, Q ACDC Indicates the theoretical heat dissipation of the vehicle power system to be cooled when it is in charging mode, U ACDC_in Indicates the real-time input voltage of the AC terminal of the vehicle power system to be cooled, I ACDC_in Indicates the real-time input current of the AC terminal of the vehicle power system to be cooled, U ACDC_out Indicates the real-time charging voltage of the vehicle power system to be cooled, I ACDC_out Indicates the real-time charging current of the vehicle power system to be cooled, U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled, I DCDC_out Indicates the DCDC low-voltage current of the on-board power system to be cooled.

[0021] Optionally, in step a, when the confirmed operating mode is the discharge mode, the method for calculating the theoretical heat dissipation of the vehicle power system is:

[0022] Q DCAC =U DCAC_in *I DCAC_in -U DCAC_out *I DCAC_out -U DCDC_out *I DCDC_out

[0023] Among them, Q DCAC Indicates the theoretical heat dissipation of the vehicle power system to be cooled when it is in discharge mode, U DCAC_in Indicates the DCAC input voltage of the vehicle power system to be cooled, I DCAC_in Indicates the DCAC input current of the vehicle power system to be cooled, U DCAC_out Indicates the DCAC output voltage of the vehicle power system to be cooled, I DCAC_out Indicates the DCAC output current of the on-board power system to be cooled, U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled, I DCDC_out Indicates the DCDC low-voltage current of the on-board power system to be cooled.

[0024] Optionally, in step a, when the confirmed operating mode is the DCDC mode, the method for calculating the theoretical heat dissipation of the vehicle power system is:

[0025] Q DCDC =U DCDC_in *I DCDC_in -U DCDC_out *I DCDC_out

[0026] Among them, Q DCDC Indicates the theoretical heat dissipation of the vehicle power system to be cooled in DCDC mode, U DCDC_in Indicates the DCDC high voltage voltage of the vehicle power system to be cooled, I DCDC_in Indicates the DCDC high voltage current of the vehicle power system to be cooled, U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled, I DCDC_out Indicates the DCDC low-voltage current of the on-board power system to be cooled.

[0027] Optionally, the target cooling flow requirement value is calculated as follows:

[0028] CF _Real =CF _Basic *K int_0

[0029] Among them, CF _Real Indicates the target cooling flow demand value; CF _Basic represents the theoretical cooling flow requirement of the vehicle power system, K int_0 Indicates the flow correction factor of the vehicle power system.

[0030] In a second aspect, the present application provides a cooling control system for an on-board power system, comprising:

[0031] The parameter acquisition module is used to obtain the working status of the vehicle power system, the water inlet coolant temperature, the internal device temperature, and the real-time input voltage, input current, output voltage and output current of the vehicle power system in the current working mode;

[0032] A flow calculation module is used to calculate the theoretical cooling flow requirement corresponding to the current operating mode based on the actual coolant temperature at the water inlet of the on-board power system, as well as the real-time input voltage, input current, output voltage, and output current in the corresponding operating mode; and to obtain the flow correction coefficient corresponding to each internal component based on the difference between the real-time temperature of the internal components of the on-board power system and their corresponding temperature thresholds, with reference to the correction coefficient map, and to obtain the flow correction coefficient of the on-board power system by taking the maximum of the flow correction coefficients of all internal components. The flow calculation module is then connected to the parameter acquisition module to calculate the target cooling flow requirement value of the on-board power system based on the theoretical cooling flow requirement and the flow correction coefficient of the on-board power system.

[0033] And a cooling control module, which is used to check the relationship table between the water pump's duty cycle and flow according to the target cooling flow demand value to obtain the water pump's real-time target duty cycle, and control the water pump operation through a closed loop based on the water pump's real-time target duty cycle. The cooling control module is connected to the flow calculation module.

[0034] Optionally, the cooling control module is also used to calculate the real-time difference between the coolant temperature at the water inlet of the vehicle power system and the power derating temperature threshold, and dynamically adjust the fan gear according to the interval corresponding to the real-time temperature difference to assist the radiator in dissipating heat.

[0035] Optionally, the parameter acquisition module includes:

[0036] The first parameter acquisition submodule is used to obtain the current operating mode of the vehicle power system according to the current operating state of the vehicle and its usage scenario;

[0037] The second parameter acquisition submodule is used to obtain the corresponding first flow calculation strategy when the current operating mode of the vehicle power system is the charging mode;

[0038] The third parameter acquisition submodule is used to obtain the corresponding second flow calculation strategy when the current operating mode of the vehicle power system is the discharge mode;

[0039] And a fourth parameter acquisition submodule is used to obtain the corresponding third flow calculation strategy when the current operating mode of the vehicle power system is the DCDC mode.

[0040] Optionally, the flow calculation module includes:

[0041] The first flow calculation submodule is used to calculate the corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is the charging mode;

[0042] The second flow calculation submodule is used to calculate the corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is the discharge mode;

[0043] The third flow calculation submodule is used to calculate the corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is the DCDC mode;

[0044] A fourth flow calculation submodule, configured to calculate a corresponding target cooling flow demand value when the current operating mode of the vehicle power system is the charging mode;

[0045] a fifth flow calculation submodule, configured to calculate a corresponding target cooling flow demand value when the current operating mode of the vehicle power system is a discharge mode;

[0046] And a sixth flow calculation submodule is used to calculate the corresponding target cooling flow demand value when the current operating mode of the vehicle power system is the DCDC mode.

[0047] Optionally, the cooling control module includes:

[0048] The first cooling control submodule is used to obtain the corresponding duty cycle of the water pump by looking up the table according to the target cooling flow demand value, and control the operation of the water pump.

[0049] Optionally, the cooling control module includes:

[0050] The first cooling control submodule is used to obtain the corresponding duty cycle of the water pump by looking up the table according to the target cooling flow demand value, and control the operation of the water pump;

[0051] And the second cooling control submodule is used to obtain the corresponding duty cycle of the fan by looking up the table according to the target cooling flow demand value, and control the operation of the fan.

[0052] In a third aspect, a vehicle described in the present application adopts the cooling control system of the on-board power system described in the present application.

[0053] In a fourth aspect, a storage medium described in the present application stores a computer-readable program, which, when called, can execute the steps of the cooling control method of the vehicle power system described in the present application.

[0054] The present application has the following advantages: the present application obtains the working status of the vehicle power system, the water inlet coolant temperature, the internal device temperature, and the real-time input voltage, input current, output voltage, and output current of the vehicle power system in the current working mode in real time; and calculates the theoretical cooling flow demand corresponding to the current working mode based on the actual coolant temperature of the vehicle power system water inlet and the real-time input voltage, input current, output voltage, and output current in the corresponding working mode; obtains the flow correction coefficient corresponding to each internal device according to the difference between the real-time temperature of the internal device of the vehicle power system and its corresponding temperature threshold, takes the largest flow correction coefficient of all internal devices to obtain the flow correction coefficient of the vehicle power system, and calculates the target cooling flow demand value of the vehicle power system based on the theoretical cooling flow demand and the flow correction coefficient of the vehicle power system; calculates the theoretical flow of the motor controller to be cooled according to the real-time power and real-time coolant temperature of the motor controller; and adaptively and dynamically adjusts the water pump operation according to a preset water pump flow-duty cycle map. The present application also actively adjusts the fan operation in real time according to a preset coolant temperature-fan gear map at the water inlet of the vehicle power system. In this method, the control of the water pump and fan is actively and adaptively adjusted dynamically based on the real-time flow requirements of the on-board power system. Compared with the wide-range constant-flow cooling method that usually uses the coolant temperature to determine the water pump flow, the control is more precise and detailed, which can avoid the water pump from running at high speed for a long time, and NVH is significantly improved. Under the premise of meeting the actual cooling needs of the on-board power system, the cooling process is more energy-efficient. At the same time, it can optimize the selection of cooling system components and reduce the cost of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0056] FIG1 is a schematic structural diagram of a cooling circulation loop of an on-board power supply system provided by this embodiment;

[0057] FIG2 is a flow chart of a cooling control method for a vehicle power system provided by this embodiment;

[0058] FIG3 is a second flow chart of a cooling control method for a vehicle power system provided by this embodiment;

[0059] FIG4 is a specific flow chart of a cooling control method for a vehicle power system provided by this embodiment;

[0060] FIG5 is a functional block diagram of a cooling control device for a vehicle-mounted power supply system provided by this embodiment;

[0061] Icon description: 10-on-board power system; 11-water reservoir; 12-water pump; 13-radiator; 14-fan; 15-temperature collector; 310-parameter acquisition module; 311-first parameter acquisition submodule; 312-second parameter acquisition submodule; 313-third parameter acquisition submodule; 314-fourth parameter acquisition submodule; 320-flow calculation module; 321-first flow calculation submodule; 322-second flow calculation submodule; 323-third flow calculation submodule; 324-fourth flow calculation submodule; 325-fifth flow calculation submodule; 326-sixth flow calculation submodule; 330-cooling control module; 331-first cooling control submodule; 332-second cooling control submodule. DETAILED DESCRIPTION

[0062] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are for illustrative purposes only and are not intended to limit the scope of protection of the present application.

[0063] As shown in Figure 1, this is a structural diagram of a cooling cycle circuit of an on-board power system, including an on-board power system 10 that needs to be cooled. The water pump 12 is operated to circulate the coolant in the cooling circuit, wherein the coolant is mainly stored in a water reservoir 11. The radiator 13 is used to dissipate heat from the coolant that flows through the on-board power system 10 and exchanges heat with the heat generated therein; the fan 14 is used to assist in cooling the radiator 13 and promote the heat dissipation effect of the radiator 13. The temperature of the coolant flowing into the water inlet of the on-board power system 10 is collected in real time by the temperature collector 15, which is used to perform real-time dynamic adjustment and control of the water pump 12 and the fan 14.

[0064] As shown in FIG2 , in this embodiment, a cooling control method for a vehicle-mounted power system includes the following steps:

[0065] Real-time acquisition of the vehicle power system's operating status, water inlet coolant temperature, internal device temperature, and the vehicle power system's real-time input voltage, input current, output voltage, and output current in its current operating mode;

[0066] The theoretical cooling flow requirement corresponding to the current operating mode is calculated based on the actual coolant temperature at the water inlet of the vehicle power system, as well as the real-time input voltage, input current, output voltage, and output current in the corresponding operating mode. The flow correction coefficient corresponding to each internal component is obtained by referring to the correction coefficient map based on the difference between the real-time temperature of the internal components of the vehicle power system and their corresponding temperature thresholds. The flow correction coefficient of the vehicle power system is obtained by taking the largest of the flow correction coefficients of all internal components. The target cooling flow requirement value of the vehicle power system is calculated based on the theoretical cooling flow requirement and the flow correction coefficient of the vehicle power system.

[0067] According to the target cooling flow demand value, the relationship table between the duty cycle and flow of the water pump is checked to obtain the real-time target duty cycle of the water pump, and the operation of the water pump is controlled through a closed loop based on the real-time target duty cycle of the water pump.

[0068] As shown in Figure 3, in this embodiment, a cooling control method for a vehicle-mounted power system also includes calculating the real-time difference between the real-time coolant temperature at the water inlet of the vehicle-mounted power system and the power derating temperature threshold, and dynamically adjusting the fan gear according to the interval corresponding to the real-time temperature difference to assist in cooling the radiator.

[0069] Regarding the cooling control method of the vehicle power system 10, in conjunction with FIG4 , the specific cooling control logic of the vehicle power system is further described in detail through one of the application examples (the data listed in the following charts are only used to illustrate the control method; the accurate design values ​​need to be determined through testing and calibration in combination with the actual state of the vehicle power system to be cooled):

[0070] Step S201: Determine whether the current vehicle CAN communication is normal. If normal, proceed to step S202; if abnormal, proceed to step S208.

[0071] Step S202: Read relevant parameters: read the message signal corresponding to the required parameters in real time through CAN communication, confirm the current status of the vehicle and the on-board power system to be cooled, obtain the real-time working status of the on-board power system to be cooled, the real-time coolant temperature of the water inlet, the real-time temperature of the internal components and the preset temperature threshold, as well as the real-time input voltage, input current, output voltage, output current and other parameters of the on-board power system to be cooled in different working modes.

[0072] Step S203: Based on the real-time working status of the vehicle power system to be cooled obtained in step S202, confirm whether the vehicle power system is currently in a fault state. If not, proceed to step S204; if so, proceed to step S208.

[0073] Step S204 , working mode determination: according to the real-time working status of the vehicle power system obtained in step S202 , the current working mode (charging mode / discharging mode / DCDC mode) of the vehicle power system to be cooled is determined.

[0074] Step S205, calculate the theoretical cooling flow requirement: According to the real-time coolant temperature of the water inlet of the vehicle power system to be cooled obtained in step S202 and the real-time input voltage, input current, output voltage, output current and other parameter values ​​corresponding to the working mode in step S204, determine the theoretical cooling flow requirement (CF) of the vehicle power system. _Basic ), as follows:

[0075] a: According to the actual coolant temperature at the water inlet of the vehicle power system (T cool_0 ) value, refer to Table 1 to find the corresponding vehicle power system heat dissipation-basic coolant flow relationship table.

[0076] Table 1: Correspondence between coolant temperature and vehicle power system heat dissipation-basic flow rate

[0077] b: Based on the vehicle power system operating mode determined in step S204 and its corresponding real-time input voltage, input current, output voltage, output current and other parameter values, calculate the theoretical heat dissipation of the vehicle power system as follows:

[0078] When the charging mode is determined according to step S204:

[0079] Q ACDC =U ACDC_in *I ACDC_in –U ACDC_out *I ACDC_out -U DCDC_out *I DCDC_out

[0080] Among them, Q ACDC Indicates the theoretical heat dissipation of the vehicle power system to be cooled when it is in charging mode (unit: W), U ACDC_in Indicates the real-time input voltage of the AC terminal of the vehicle power system to be cooled (unit: V), I ACDC_in Indicates the real-time input current of the AC end of the vehicle power system to be cooled (unit: A), U ACDC_out Indicates the real-time charging voltage of the vehicle power system to be cooled (unit: V), I ACDC_out Indicates the real-time charging current of the vehicle power system to be cooled (unit: A), U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled (unit: V), I DCDC_out Indicates the DCDC low-voltage current of the on-board power system to be cooled (unit: A).

[0081] When the discharge mode is determined according to step S204:

[0082] Q DCAC =U DCAC_in *I DCAC_in -U DCAC_out *I DCAC_out -U DCDC_out *I DCDC_out

[0083] Among them, Q DCAC Indicates the theoretical heat dissipation of the vehicle power system to be cooled in discharge mode (unit: W), U DCAC_in Indicates the DCAC input voltage of the vehicle power system to be cooled (unit: V), I DCAC_in Indicates the DCAC input current of the vehicle power system to be cooled (unit: A), U DCAC_out Indicates the DCAC output voltage of the vehicle power system to be cooled (unit: V), I DCAC_out Indicates the DCAC output current of the vehicle power system to be cooled (unit: A), U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled (unit: V), I DCDC_out Indicates the DCDC low-voltage current of the on-board power system to be cooled (unit: A).

[0084] When the DCDC mode is determined according to step S204:

[0085] Q DCDC =U DCDC_in *I DCDC_in -U DCDC_out *I DCDC_out

[0086] Among them, Q DCDC Indicates the theoretical heat dissipation of the vehicle power system to be cooled in DCDC mode (unit: W), U DCDC_in Indicates the DCDC high voltage of the vehicle power system to be cooled (unit: V), I DCDC_in Indicates the DCDC high voltage current of the vehicle power system to be cooled (unit: A), U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled (unit: V), I DCDC_out Indicates the DCDC low-voltage current of the on-board power system to be cooled (unit: A).

[0087] c: Based on the current operating mode and theoretical heat dissipation of the vehicle power system, query the corresponding basic required coolant flow rate (unit: L / min) through the relationship table confirmed in step a.

[0088] Table 2: Relationship between heat dissipation of vehicle power system and basic coolant flow rate (-40℃≤T cool_0 ≤-25℃)

[0089] Table 3: Relationship between heat dissipation of vehicle power system and basic coolant flow rate (-25℃ <T cool_0 ≤0℃)

[0090] Table 4: Relationship between heat dissipation of vehicle power system and basic coolant flow rate (0℃ <T cool_0 ≤30℃)

[0091] Table 5: Relationship between heat dissipation of vehicle power system and basic coolant flow rate (30℃ <T cool_0 ≤65℃)

[0092] Table 6: Relationship between heat dissipation of vehicle power system and basic coolant flow rate (65℃ <T cool_0 ≤85℃)

[0093] Step S206, calculating the target coolant flow requirement:

[0094] According to the real-time temperature of the internal components of the vehicle power system to be cooled and the preset temperature threshold obtained in step S202, the flow correction coefficient is determined, and the target cooling flow requirement value (CF _Real ), as follows:

[0095] (1) According to the preset temperature threshold (T Limit_n ) and its real-time temperature (T Real_n ) temperature difference (△T int_n =T Limit_n –T Real_n ), determine the flow correction coefficient (K int_n ).

[0096] The value of n is 1-6. The range of n should be determined according to actual application conditions and is not the only value range of this embodiment.

[0097] Here, the cooling control of the vehicle power system is to keep the real-time temperature T of the internal components under any working state. Real_n None of them exceed the corresponding preset temperature threshold T Limit_n , real-time temperature T Real_n The smaller it is, the smaller the cooling flow requirement is.

[0098] Table 7: Flow correction coefficients and temperature differences (△T) corresponding to key internal components of the vehicle power system int_n )

[0099] Here, the key internal components need to be determined based on the specific design scheme and structural layout of the on-board power system to be cooled, through CAE thermal simulation and NTC temperature sensor layout testing and other means to determine the key internal components that actually need to be monitored. The type and quantity of the key internal components are not the only implementation method of this example.

[0100] (2) Calculate the flow correction coefficient K of the vehicle power system int_0 .

[0101] K int_0 =Max(K int_1 ,K int_2 ,K int_3 ,…,K int_n )

[0102] Among them, K int_n It represents the flow correction coefficient corresponding to the key internal component n of the vehicle power system obtained by interpolation method according to Table 7.

[0103] (3) Calculate the target cooling flow demand value CF of the vehicle power system _Real .

[0104] CF _Real =CF _Basic *K int_0

[0105] Among them, CF _Basic The theoretical cooling flow requirement of the vehicle power system is obtained by interpolation according to Tables 1 to 6, K int_0 Indicates the flow correction factor of the vehicle power system.

[0106] Step S207: water pump and fan control:

[0107] By adjusting the operation of the water pump and fan in real time, the cooling temperature of the cooling cycle of the vehicle power system can be controlled.

[0108] The control method of the water pump and fan is as follows:

[0109] According to the target cooling flow demand value CF of the vehicle power system determined in step S206 _Real The duty cycle of the water pump is obtained by interpolation and the water pump is controlled to the target duty cycle through closed loop.

[0110] Table 8: Relationship between pump duty cycle and flow rate

[0111] Here, the duty cycle and speed of the water pump corresponding to the target flow rate are the calibration results at the standard temperature (25°C). Considering that a certain safety margin has been reserved in the above flow calculation process, the water pump duty cycle in this embodiment ignores the impact of temperature changes on the flow rate.

[0112] According to the actual coolant temperature T at the water inlet of the vehicle power system obtained in step S202 cool_0 The difference between the power derating coolant temperature of 65℃ (△T cool =T cool_0 –65), the gear position of the radiator fan is obtained by querying Table 9, so that the coolant temperature in the cooling circulation loop can be actively adjusted in real time. The following implementation example is given:

[0113] Table 9: Relationship between fan gear position and coolant temperature

[0114] Here, a stepless speed regulation fan is usually used. For the convenience of control, in actual application of the whole vehicle, the fan is generally divided into 3-10 gears, and the gear selection is matched according to the heat dissipation requirements. The relevant data shown in this application is only used for the purpose of describing the technical solution and does not represent the only implementation method of fan control.

[0115] The cooling control method for the on-board power system provided in this embodiment can be combined with the specific technical solution of the on-board power system to be cooled to perform adaptive real-time flow active correction and dynamically adjust the duty cycle of the water pump and radiator fan. Therefore, it is more precise and energy-saving than the current wide-temperature range constant flow cooling method.

[0116] The cooling control process of the vehicle power system shown in the above steps S201 to S207 is a cooling control method and process when the vehicle and the vehicle power system are in normal working conditions. In abnormal working conditions, in order to prevent unknown uncontrollable thermal failures that may cause damage to the vehicle power system to be cooled, for this situation, the preset cooling control mode is for the water pump to run at the highest speed, such as step S208.

[0117] Here, the abnormal working state includes but is not limited to high voltage failure on the vehicle, low power of the power battery or storage battery, abnormal CAN communication, poor line connection, fault mode reporting and other manifestations.

[0118] This method calculates the theoretical heat dissipation by obtaining the real-time input voltage and current, and the real-time output voltage and current corresponding to different working modes of the on-board power system. According to the heat dissipation-flow spectrum determined by experimental calibration, the theoretical cooling flow requirement is obtained by looking up the table; the target cooling flow requirement of the on-board power system is calculated according to the internal device temperature-correction coefficient spectrum preset for the on-board power system; the theoretical flow of the motor controller to be cooled is calculated according to the real-time power and real-time coolant temperature of the motor controller; the water pump operation is adaptively and dynamically adjusted according to the preset water pump flow-duty cycle spectrum; and the fan operation is actively adjusted in real time according to the preset coolant temperature-fan gear spectrum at the water inlet of the on-board power system. In this method, the control of the water pump and fan is actively and adaptively adjusted dynamically based on the real-time flow demand of the on-board power system. Compared with the wide-range constant-flow cooling method that usually uses the coolant temperature to determine the water pump flow, the control is more precise and detailed, which can avoid the water pump from running at high speed for a long time, and NVH is significantly improved. Under the premise of meeting the actual cooling needs of the on-board power system, the cooling process is more energy-efficient. At the same time, the component selection of the cooling system can be optimized to reduce the cost of the entire vehicle.

[0119] Corresponding to the vehicle power system cooling control method described in the above embodiment, this embodiment also provides a vehicle power system cooling control device, which is applied to a vehicle thermal management controller. The water pump and fan of the vehicle power system to be cooled are electrically connected to the vehicle thermal management controller. The water pump and fan control the coolant temperature of the vehicle power system to be cooled. As shown in Figure 5, the device includes a parameter acquisition module 310, a flow calculation module 320, and a cooling control module 330. The functions of each module are described in detail below.

[0120] The parameter acquisition module 310 is used to obtain parameters such as the vehicle power system's operating status, the system's water inlet coolant temperature, internal component temperatures, real-time input voltage / current, output voltage / current, and the calculation strategy corresponding to the vehicle power system's current operating mode. The module reads message signals corresponding to these required parameters in real time via CAN communication.

[0121] In this embodiment, the parameter acquisition module 310 includes:

[0122] The first parameter acquisition submodule 311 is used to obtain the current operating mode of the vehicle power system according to the current operating state and usage scenario of the vehicle. Specifically:

[0123] When the vehicle is in a plug-in charging or remote scheduled charging scenario, determine that the current operating mode of the vehicle power system is charging mode;

[0124] When the vehicle is in a usage scenario such as plug-in discharge, in-vehicle discharge, vehicle-to-vehicle discharge, or vehicle-to-grid discharge (depending on the actual discharge function), the current operating mode of the vehicle power system is determined to be the discharge mode;

[0125] When the vehicle is powered on and the power battery is supplying power to the low-voltage load of the vehicle or charging the battery, it is determined that the current operating mode of the vehicle power system is the DCDC mode.

[0126] The second parameter acquisition submodule 312 is used to obtain the corresponding first flow calculation strategy when the current operating mode of the vehicle power system is the charging mode;

[0127] The third parameter acquisition submodule 313 is used to obtain the corresponding second flow calculation strategy when the current operating mode of the vehicle power system is the discharge mode;

[0128] The fourth parameter acquisition submodule 314 is configured to acquire a corresponding third flow calculation strategy when the current operating mode of the vehicle power system is the DCDC mode.

[0129] In this embodiment, the flow calculation module 320 is used to calculate the corresponding theoretical flow demand and target flow demand according to the current operating mode of the vehicle power system and its corresponding parameters determined by the parameter acquisition module 310.

[0130] The flow calculation module 320 includes:

[0131] The first flow calculation submodule 321 is used to calculate the corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is the charging mode. Specifically:

[0132] First, the parameter acquisition module 310 obtains the real-time input voltage U of the AC terminal of the vehicle power system to be cooled. ACDC_in , AC end real-time input current I of the vehicle power system to be cooled ACDC_in , Real-time charging voltage U of the on-board power system to be cooled ACDC_out , the real-time charging current I of the vehicle power system to be cooled ACDC_out , DCDC low voltage U of the vehicle power system to be cooled DCDC_out , DCDC low voltage current I of the vehicle power system to be cooled DCDC_out , calculate the theoretical heat dissipation of the onboard power system to be cooled when it is in charging mode: Q ACDC =U ACDC_in *I ACDC_in –U ACDC_out *I ACDC_out -U DCDC_out *I DCDC_outSecondly, according to the second parameter acquisition submodule 312 corresponding to the first flow calculation strategy, by looking up the table to determine the corresponding theoretical cooling flow demand CF _Basic .

[0133] The second flow calculation submodule 322 is used to calculate the corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is the discharge mode. Specifically:

[0134] First, the DCAC input voltage U of the vehicle power system to be cooled is obtained according to the parameter acquisition module 310. DCAC_in , DCAC input current I of the vehicle power system to be cooled DCAC_in , DCAC output voltage U of the vehicle power system to be cooled DCAC_out , DCAC output current I of the vehicle power system to be cooled DCAC_out , DCDC low voltage U of the vehicle power system to be cooled DCDC_out , DCDC low voltage current I of the vehicle power system to be cooled DCDC_out , calculate the theoretical heat dissipation of the vehicle power system to be cooled in discharge mode: Q DCAC =U DCAC_in *I DCAC_in -U DCAC_out *I DCAC_out -U DCDC_out *I DCDC_out Secondly, according to the third parameter acquisition submodule 313 corresponding to the second flow calculation strategy, by looking up the table to determine the corresponding theoretical cooling flow demand CF _Basic .

[0135] The third flow calculation submodule 323 is used to calculate the corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is the DCDC mode. Specifically:

[0136] First, the DCDC high voltage U of the vehicle power system to be cooled is obtained according to the parameter acquisition module 310. DCDC_in , DCDC high voltage current I of the vehicle power system to be cooled DCDC_in , DCDC low voltage U of the vehicle power system to be cooled DCDC_out , DCDC low voltage current I of the vehicle power system to be cooled DCDC_out , calculate the theoretical heat dissipation of the vehicle power system to be cooled in DCDC mode: Q DCDC =U DCDC_in *I DCDC_in -U DCDC_out *I DCDC_out Secondly, according to the third parameter acquisition submodule 314 corresponding to the third flow calculation strategy, by looking up the table to determine the corresponding theoretical cooling flow demand CF _Basic .

[0137] The fourth flow calculation submodule 324 is used to calculate the corresponding target cooling flow demand value when the current working mode of the vehicle power system is the charging mode. Specifically, the theoretical flow demand CF obtained by the first flow calculation submodule 321 is calculated. _Basic The first flow calculation strategy corresponding to the second parameter acquisition submodule 312 determines the corresponding flow correction coefficient K by looking up the table. int_0 , calculate the corresponding target cooling flow demand value CF _Real Among them, CF _Real =CF _Basic *K int_0 .

[0138] The fifth flow calculation submodule 325 is used to calculate the corresponding target cooling flow demand value when the current working mode of the vehicle power system is the discharge mode. Specifically, the theoretical flow demand CF obtained by the second flow calculation submodule 322 is respectively calculated. _Basic The second flow calculation strategy corresponding to the third parameter acquisition submodule 313 determines the corresponding flow correction coefficient K by looking up the table. int_0 , calculate the corresponding target cooling flow demand value CF _Real Among them, CF _Real =CF _Basic *K int_0 .

[0139] The sixth flow calculation submodule 326 is used to calculate the corresponding target cooling flow demand value when the current working mode of the vehicle power system is the DCDC mode. Specifically, the theoretical flow demand CF obtained by the third flow calculation submodule 323 is respectively calculated. _Basic The third flow calculation strategy corresponding to the fourth parameter acquisition submodule 314 determines the corresponding flow correction coefficient K by looking up the table. int_0 , calculate the corresponding target cooling flow demand value CF _Real Among them, CF _Real =CF _Basic *K int_0 .

[0140] In this embodiment, the cooling control module 330 is used to control the water pump and fan to operate at the corresponding target duty cycle according to the current operating mode of the vehicle power system and its corresponding parameters determined by the parameter acquisition module 310, and the target cooling flow demand value determined by the flow calculation module 320.

[0141] The cooling control module 330 includes:

[0142] The first cooling control submodule 331 is used to control the cooling flow rate according to the target cooling flow rate requirement value CF _Real, obtain the corresponding duty cycle of the water pump by looking up the table and control the operation of the water pump;

[0143] The second cooling control submodule 332 is used to control the cooling flow rate according to the target cooling flow rate requirement value CF _Real , get the corresponding duty cycle of the fan by looking up the table and control the fan operation.

[0144] In this embodiment, a vehicle adopts the cooling control system of the vehicle power system as described in this embodiment.

[0145] In this embodiment, a storage medium stores a computer-readable program. When the computer-readable program is called, it can execute the steps of the cooling control method of the vehicle power system as described in this embodiment.

[0146] The storage media of this embodiment include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0147] The above embodiments are preferred implementation modes of the present application, but the implementation modes of the present application are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present application should be considered as equivalent replacement methods and are included in the scope of protection of the present application.

Claims

1. A cooling control method for a vehicle power system, characterized in that: The following steps are involved: Real-time acquisition of the vehicle power system's operating status, water inlet coolant temperature, internal device temperature, and the vehicle power system's real-time input voltage, input current, output voltage, and output current in the current operating mode; According to the actual coolant temperature at the water inlet of the vehicle power system, and the real-time input voltage, input current, output voltage and output current in the corresponding working mode, the theoretical cooling flow demand corresponding to the current working mode is calculated; according to the difference between the real-time temperature of the internal components of the vehicle power system and the corresponding temperature threshold, the flow correction coefficient corresponding to each internal component is obtained by referring to the correction coefficient spectrum diagram, the flow correction coefficient of the vehicle power system is obtained by taking the larger flow correction coefficient of all internal components, and the target cooling flow demand value of the vehicle power system is calculated based on the theoretical cooling flow demand and the flow correction coefficient of the vehicle power system; According to the target cooling flow demand value, the relationship table between the duty cycle and flow of the water pump is checked to obtain the real-time target duty cycle of the water pump, and the operation of the water pump is controlled through a closed loop based on the real-time target duty cycle of the water pump.

2. The cooling control method of the vehicle power system according to claim 1, characterized in that: Also includes: The real-time difference between the coolant temperature at the water inlet of the vehicle power system and the power derating temperature threshold is calculated, and the fan gear is dynamically adjusted according to the interval corresponding to the real-time temperature difference to assist the radiator in dissipating heat.

3. The cooling control method of the vehicle power system according to claim 1, characterized in that: The real-time theoretical cooling flow requirement is calculated as: a: According to the actual coolant temperature at the water inlet of the vehicle power system, check the corresponding relationship table between the coolant temperature and the heat dissipation of the vehicle power system and the basic flow rate to find the corresponding relationship table between the heat dissipation of the vehicle power system and the basic coolant flow rate; b: Calculate the theoretical heat dissipation of the vehicle power system based on the working mode of the vehicle power system and its corresponding real-time input voltage, input current, output voltage and output current; c: According to the current working mode and theoretical heat dissipation of the vehicle power system, query the corresponding basic required coolant flow rate through the relationship table of the vehicle power system heat dissipation-basic coolant flow rate confirmed in step a.

4. The cooling control method of the vehicle-mounted power supply system according to claim 3, characterized in that: In step a, when the working mode determined to be the charging mode, the method for calculating the theoretical heat dissipation of the vehicle power system is: Q ACDC =U ACDC_in *I ACDC_in –U ACDC_out *I ACDC_out -U DCDC_out *I DCDC_out Among them, Q ACDC Indicates the theoretical heat dissipation of the vehicle power system to be cooled when it is in charging mode, U ACDC_in Indicates the real-time input voltage of the AC end of the vehicle power system to be cooled, I ACDC_in Indicates the real-time input current of the AC end of the vehicle power system to be cooled, U ACDC_out Indicates the real-time charging voltage of the vehicle power system to be cooled, I ACDC_out Indicates the real-time charging current of the on-board power system to be cooled, U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled, I DCDC_out Indicates the DCDC low voltage current of the on-board power system to be cooled.

5. The cooling control method of the vehicle-mounted power supply system according to claim 3, characterized in that: In step a, when the working mode determined to be the discharge mode, the method for calculating the theoretical heat dissipation of the vehicle power system is: Q DCAC =U DCAC_in *I DCAC_in -U DCAC_out *I DCAC_out -U DCDC_out *I DCDC_out Among them, Q DCAC Indicates the theoretical heat dissipation of the vehicle power system to be cooled in the discharge mode, U DCAC_in Indicates the DCAC input voltage of the vehicle power system to be cooled, I DCAC_in Indicates the DCAC input current of the on-board power system to be cooled, U DCAC_out Indicates the DCAC output voltage of the vehicle power system to be cooled, I DCAC_out Indicates the DCAC output current of the on-board power system to be cooled, U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled, I DCDC_out Indicates the DCDC low voltage current of the on-board power system to be cooled.

6. The cooling control method of the vehicle-mounted power supply system according to claim 3, characterized in that: In step a, when the working mode determined to be the DCDC mode, the method for calculating the theoretical heat dissipation of the vehicle power system is: Q DCDC =U DCDC_in *I DCDC_in -U DCDC_out *I DCDC_out Among them, Q DCDC Indicates the theoretical heat dissipation of the vehicle power system to be cooled in DCDC mode, U DCDC_in Indicates the DCDC high voltage voltage of the vehicle power system to be cooled, I DCDC_in Indicates the DCDC high voltage current of the on-board power system to be cooled, U DCDC_out Indicates the DCDC low voltage of the vehicle power system to be cooled, I DCDC_out Indicates the DCDC low voltage current of the on-board power system to be cooled.

7. The cooling control method of the vehicle-mounted power supply system according to claim 3, characterized in that: The target cooling flow requirement value is calculated as follows: CF _Real =CF _Basic *K int_0 Among them, CF _Real Indicates the target cooling flow demand value; CF _Basic represents the theoretical cooling flow requirement of the vehicle power system; K int_0 Indicates the flow correction factor of the vehicle power system.

8. A cooling control system for a vehicle power system, characterized in that: include: A parameter acquisition module (310), used to acquire the working state of the vehicle power system, the water inlet coolant temperature, the internal device temperature, and the real-time input voltage, input current, output voltage and output current of the vehicle power system in the current working mode; A flow calculation module (320) is used to calculate a theoretical cooling flow requirement corresponding to a current working mode according to an actual coolant temperature at a water inlet of the vehicle power system, and real-time input voltage, input current, output voltage and output current in a corresponding working mode; and obtaining the flow correction coefficient corresponding to each internal component according to the difference between the real-time temperature of the internal components of the vehicle power system and the corresponding temperature threshold, referring to the correction coefficient spectrum diagram, taking the maximum of the flow correction coefficients of all the internal components to obtain the flow correction coefficient of the vehicle power system, and calculating the target cooling flow demand value of the vehicle power system based on the theoretical cooling flow demand and the flow correction coefficient of the vehicle power system, wherein the flow calculation module (320) is connected to the parameter acquisition module (310); and a cooling control module (330) for obtaining a real-time target duty cycle of the water pump by looking up a relationship table between the duty cycle and the flow rate of the water pump according to a target cooling flow rate demand value, and controlling the operation of the water pump through a closed loop based on the real-time target duty cycle of the water pump. The cooling control module (330) is connected to the flow rate calculation module (320).

9. The cooling control system of the vehicle-mounted power supply system according to claim 8, characterized in that: The cooling control module (330) is also used to calculate the real-time difference between the coolant temperature at the water inlet of the vehicle power system and the power derating temperature threshold, and dynamically adjust the fan gear according to the interval corresponding to the real-time temperature difference to assist the radiator in cooling.

10. The cooling control system of the vehicle-mounted power system according to claim 8, characterized in that: The parameter acquisition module (310) comprises: A first parameter acquisition submodule (311) is used to acquire the current operating mode of the vehicle power system according to the current operating state of the vehicle and its usage scenario; A second parameter acquisition submodule (312), used to acquire a corresponding first flow calculation strategy when the current operating mode of the vehicle power system is a charging mode; A third parameter acquisition submodule (313), used for acquiring a corresponding second flow calculation strategy when the current operating mode of the vehicle power system is a discharge mode; And a fourth parameter acquisition submodule (314) is used to obtain the corresponding third flow calculation strategy when the current operating mode of the vehicle power system is the DCDC mode.

11. The cooling control system of the vehicle-mounted power supply system according to claim 10, characterized in that: The flow calculation module (320) comprises: A first flow calculation submodule (321), used for calculating a corresponding theoretical cooling flow requirement when the current operating mode of the vehicle power system is a charging mode; A second flow calculation submodule (322), used for calculating the corresponding theoretical cooling flow demand when the current operating mode of the vehicle power system is a discharge mode; A third flow calculation submodule (323), used for calculating the corresponding theoretical cooling flow demand when the current operating mode of the vehicle power system is the DCDC mode; A fourth flow calculation submodule (324), used for calculating a corresponding target cooling flow demand value when the current operating mode of the vehicle power system is a charging mode; A fifth flow calculation submodule (325), used for calculating a corresponding target cooling flow demand value when the current operating mode of the vehicle power system is a discharge mode; And a sixth flow calculation submodule (326), used for calculating the corresponding target cooling flow demand value when the current operating mode of the vehicle power system is the DCDC mode.

12. The cooling control system of the vehicle-mounted power supply system according to claim 10, characterized in that: The cooling control module (330) comprises: The first cooling control submodule (331) is used to obtain a duty cycle corresponding to the water pump by looking up a table according to a target cooling flow demand value, and control the operation of the water pump.

13. The cooling control system of the vehicle-mounted power supply system according to claim 11, characterized in that: The cooling control module (330) comprises: A first cooling control submodule (331) is used to obtain a corresponding duty cycle of the water pump by looking up a table according to a target cooling flow demand value, and control the operation of the water pump; and a second cooling control submodule (332), which is used to obtain the corresponding duty cycle of the fan by looking up a table according to the target cooling flow demand value, and control the operation of the fan.

14. A vehicle, characterized in that: A cooling control system for a vehicle-mounted power supply system as claimed in any one of claims 8 to 13 is adopted.

15. A storage medium, characterized in that: A computer-readable program is stored therein, and when the computer-readable program is called, the steps of the cooling control method of the vehicle-mounted power supply system as claimed in any one of claims 1 to 7 can be executed.

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