A method and device for controlling motor temperature

Abstract

This application discloses a method and apparatus for controlling motor temperature. It obtains the basic heat dissipation power and the heat dissipation power due to motor operating losses in a vehicle. The basic heat dissipation power of the vehicle's motor is determined by the current motor temperature and the target motor temperature. The total heat dissipation power of the motor is calculated based on the basic heat dissipation power and the heat dissipation power due to motor operating losses. The motor inlet is connected to the outlet of a cooling device, and the cooling fluid supplied by the cooling device is used to control the motor temperature. Based on the heat dissipation power of the cooling device, the temperature of the cooling fluid at the outlet of the cooling device is obtained. Based on the total heat dissipation power of the motor, the temperature of the cooling fluid at the outlet of the cooling device, and the temperature rise of the cooling fluid, the target flow rate of the cooling fluid required at the current moment is obtained. The motor temperature is controlled by the cooling fluid at the target flow rate, reducing the motor temperature from the current temperature to the target temperature. This application obtains a relatively accurate target flow rate of the cooling fluid, enabling relatively precise motor temperature control.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method and apparatus for controlling motor temperature. Background Technology

[0002] In hybrid systems, the drive motor serves as the primary power source, enabling vehicle propulsion under most operating conditions. In practical applications, motor temperature control is crucial. For example, under heavy loads, the motor generates significant heat, causing it to overheat. Excessive heat can lead to demagnetization, rendering the motor inoperable, or even causing permanent damage. Therefore, cooling control of the motor is necessary.

[0003] In motor cooling control, coolant (such as cooling water or cooling oil) can be used to control the motor temperature, for example, to cool the motor down. In practice, it is necessary to first estimate the required flow rate of the coolant for motor temperature control based on the motor temperature. Currently, the estimation and control of coolant flow rate requirements are rather crude, which may lead to coolant waste. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a method and apparatus for controlling motor temperature, which can precisely control the flow rate of the cooling liquid required for motor temperature control.

[0005] To achieve the above objectives, the technical solution provided in this application is as follows:

[0006] In a first aspect, this application provides a method for controlling the temperature of a motor, the method comprising:

[0007] The vehicle's motor base heat dissipation power and motor operating loss heat dissipation power are obtained; the motor base heat dissipation power is determined by the motor's current temperature and target temperature.

[0008] The total heat dissipation power of the motor is calculated based on the basic heat dissipation power of the motor and the heat dissipation power of the motor's operating losses.

[0009] The temperature of the cooling liquid at the outlet of the cooling equipment is obtained based on the heat dissipation power of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor;

[0010] Based on the total heat dissipation power of the motor, the temperature of the cooling liquid at the outlet of the cooling equipment, and the temperature rise of the cooling liquid, the target flow rate of the cooling liquid at the current moment corresponding to the motor is obtained. The motor temperature is controlled based on the cooling liquid with the target flow rate, so that the temperature of the cooling liquid rises from the temperature of the cooling liquid at the outlet of the cooling equipment to the temperature rise of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, so as to reduce the motor temperature from the current motor temperature to the target motor temperature.

[0011] The temperature rise of the cooling liquid is the same as the temperature of the cooling liquid at the inlet of the cooling equipment.

[0012] Secondly, this application provides a motor temperature control device, the device comprising:

[0013] The first acquisition unit is used to acquire the vehicle's basic motor heat dissipation power and motor operating loss heat dissipation power; the basic motor heat dissipation power is determined by the current motor temperature and the target motor temperature.

[0014] The calculation unit is used to calculate the total heat dissipation power of the motor based on the basic heat dissipation power of the motor and the heat dissipation power of the motor's operating losses.

[0015] The second acquisition unit is used to acquire the temperature of the cooling liquid at the outlet of the cooling equipment based on the heat dissipation power of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor;

[0016] The third acquisition unit is used to acquire the target flow rate of the cooling liquid at the current moment corresponding to the motor based on the total heat dissipation power of the motor, the cooling liquid temperature at the outlet of the cooling equipment, and the heating temperature of the cooling liquid. The unit then uses the cooling liquid at the target flow rate to control the temperature of the motor, so that the temperature of the cooling liquid rises from the cooling liquid temperature at the outlet of the cooling equipment to the heating temperature of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, thereby reducing the motor temperature from the current motor temperature to the target motor temperature.

[0017] The temperature rise of the cooling liquid is the same as the temperature of the cooling liquid at the inlet of the cooling equipment.

[0018] Thirdly, this application provides an electronic device, comprising:

[0019] One or more processors;

[0020] Storage device, on which one or more programs are stored,

[0021] When the one or more programs are executed by the one or more processors, the one or more processors implement any of the motor temperature control methods described above.

[0022] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the described motor temperature control methods.

[0023] As can be seen from the above technical solution, this application has the following beneficial effects:

[0024] This application provides a method and apparatus for motor temperature control. First, the basic heat dissipation power and the heat dissipation power due to motor operating losses of the vehicle are obtained. The basic heat dissipation power of the vehicle's motor is determined by the current motor temperature and the target motor temperature. The total heat dissipation power of the motor is calculated based on the basic heat dissipation power and the heat dissipation power due to motor operating losses. The motor inlet is connected to the outlet of a cooling device, and the cooling fluid supplied to the motor by the cooling device is used to achieve motor temperature control. To achieve motor temperature control, such as cooling, the total heat dissipation power of the motor represents the heat that the motor needs to dissipate; that is, the power corresponding to the heat dissipated by the motor needs to be controlled by the cooling fluid to make the power equal to the total heat dissipation power of the motor. Furthermore, based on the heat dissipation power of the cooling device, the temperature of the cooling fluid at the outlet of the cooling device is obtained. Based on the total heat dissipation power of the motor, the temperature of the cooling fluid at the outlet of the cooling device, and the rising temperature of the cooling fluid, the target flow rate of the cooling fluid corresponding to the current moment of the motor is obtained. The motor temperature is controlled by the cooling fluid based on the target flow rate, so that the temperature of the cooling fluid rises from the temperature of the cooling fluid at the outlet of the cooling device to the rising temperature of the cooling fluid, and the output power is equal to the total heat dissipation power of the motor. In this way, the motor temperature can be reduced from the current motor temperature to the target motor temperature. Specifically, the temperature rise of the cooling liquid is set to be the same as the temperature of the cooling liquid at the inlet of the cooling equipment. It can be seen that this application obtains a relatively accurate target flow rate of the cooling liquid at the current moment, which is not an estimate, resulting in better temperature control of the motor based on this target flow rate. Attached Figure Description

[0025] 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, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A flowchart of a motor temperature control method provided in an embodiment of this application;

[0027] Figure 2 A schematic diagram illustrating the flow of motor cooling oil according to an embodiment of this application;

[0028] Figure 3a A schematic diagram of a motor temperature control provided in an embodiment of this application;

[0029] Figure 3b A schematic diagram of a motor temperature control framework provided for an embodiment of this application;

[0030] Figure 4 This is a schematic diagram of the structure of a motor temperature control device provided in an embodiment of this application;

[0031] Figure 5 A schematic diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0032] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] To facilitate understanding and explanation of the technical solutions provided in the embodiments of this application, the background technology involved in the embodiments of this application will be introduced first.

[0034] In hybrid systems, the drive motor serves as the primary power source, enabling vehicle propulsion under most operating conditions. The drive motor can be oil-cooled or water-cooled, and either type can be integrated into the vehicle's hybrid transmission. In practical applications, motor temperature control is crucial. For example, under heavy loads, the motor generates significant heat, causing it to overheat. Excessive heat can lead to demagnetization, rendering the motor inoperable, or even causing permanent damage. Therefore, cooling control of the motor is necessary.

[0035] In motor cooling control, coolant can be used to control the motor temperature, for example, to cool the motor. When the motor is oil-cooled, the coolant is cooling oil, which is used to control the motor temperature. When the motor is water-cooled, the coolant is cooling water, which is used to control the motor temperature. In practice, it is necessary to first estimate the required flow rate of the coolant for motor temperature control based on the motor temperature. Currently, the estimation and control of the coolant flow rate is rather crude. For example, when the motor temperature is high, the coolant flow rate is increased, and when the motor temperature decreases, the coolant flow rate is decreased. However, the increased or decreased coolant flow rate is obtained based on manual experience and is not precise, which may lead to waste of coolant.

[0036] Based on this, this application provides a motor temperature control method and apparatus. First, the basic heat dissipation power and the heat dissipation power of the vehicle's motor due to operating losses are obtained. The basic heat dissipation power of the vehicle's motor is determined by the current motor temperature and the target motor temperature. The total heat dissipation power of the motor is calculated based on the basic heat dissipation power and the heat dissipation power of the motor's operating losses. The motor inlet is connected to the outlet of a cooling device, and the cooling liquid supplied to the motor by the cooling device is used to achieve motor temperature control. To achieve motor temperature control, such as cooling, the total heat dissipation power of the motor represents the heat that the motor needs to dissipate; that is, the power corresponding to the heat dissipated by the motor needs to be controlled by the cooling liquid so that the power is equal to the total heat dissipation power. Furthermore, based on the heat dissipation power of the cooling device, the temperature of the cooling liquid at the outlet of the cooling device is obtained. Based on the total heat dissipation power of the motor, the temperature of the cooling liquid at the outlet of the cooling device, and the rising temperature of the cooling liquid, the target flow rate of the cooling liquid corresponding to the current moment of the motor is obtained. The motor temperature is controlled by the cooling liquid based on the target flow rate, so that the temperature of the cooling liquid rises from the temperature at the outlet of the cooling device to the rising temperature of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor. In this way, the motor temperature can be reduced from its current temperature to its target temperature. The cooling fluid's temperature rise is set to be the same as the cooling fluid temperature at the inlet of the cooling equipment. Therefore, this application obtains a relatively accurate target flow rate of the cooling fluid at the current moment, which is not an estimate, resulting in better temperature control of the motor based on this target flow rate.

[0037] It is understandable that the shortcomings of the above solutions are the result of the applicant's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed by the embodiments of this application below should be considered contributions made by the applicant to the embodiments of this application.

[0038] To facilitate understanding of this application, the following description, in conjunction with the accompanying drawings, illustrates a motor temperature control method provided in an embodiment of this application.

[0039] See Figure 1 This figure is a flowchart of a motor temperature control method provided in an embodiment of this application. This method can be applied to the automatic transmission control unit (TCU) of a vehicle, which is integrated into the transmission. For example, the transmission may be a hybrid transmission. Figure 1 As shown, the method may include S101-S104:

[0040] S101: Obtain the vehicle's basic motor cooling power and motor operating loss cooling power; the basic motor cooling power is determined by the current motor temperature and the target motor temperature.

[0041] The hybrid transmission may integrate an oil-cooled motor and / or a water-cooled motor, which provides the vehicle's primary power source. The TCU executes the motor temperature control method provided in the embodiments of this application to precisely control the temperature of the motor in the hybrid transmission, such as performing cooling control.

[0042] In practical applications, motor temperature is regulated based on the cooling liquid. Oil-cooled motors use cooling oil as the cooling liquid, while water-cooled motors use cooling water. The cooling liquid is stored in the corresponding devices. When cooling liquid is supplied to the motor from the pump, a cooling device is required. The cooling device is used to control the temperature of the cooling liquid output from the pump, for example, by lowering the temperature of the cooling liquid to supply a lower-temperature cooling liquid to the motor, thereby controlling the motor's temperature. When the motor is oil-cooled, the cooling liquid used is cooling oil, and the corresponding cooling device is an oil cooler; the device for storing the cooling oil can be an oil pump. When the motor is water-cooled, the cooling liquid used is cooling water, and the corresponding cooling device is a water cooler; the device for storing the cooling water can be a water pump. The embodiments in this application will subsequently use an oil-cooled motor, an oil cooler, cooling oil, and an oil pump as examples for illustration, but are not limited to this.

[0043] The process of regulating motor temperature based on coolant (such as cooling oil) will be explained below.

[0044] See Figure 2 , Figure 2 This is a schematic diagram illustrating the flow of cooling oil in an electric motor, provided as an embodiment of this application. As an optional example, the motor in the hybrid transmission may include a P1 motor and a P3 motor. Both P1 and P3 motors are oil-cooled motors. The oil pump includes a mechanical oil pump (MOP) and / or an electronic oil pump (EOP). Figure 2 As shown, the mechanical oil pump MOP and / or electronic oil pump EOP output cooling oil for cooling the motors. However, the oil temperature is still relatively high at this point, insufficient to effectively cool the motors. Therefore, the MOP and / or EOP output cooling oil to an oil cooler to lower its temperature. Specifically, in the oil cooler, cooling air is used to cool the oil. This air is supplied from outside the vehicle by a fan. The oil cooler outputs cooled oil at a suitable temperature, which is then further delivered to motors P1 and P3 via solenoid valves to adjust their temperatures, for example, by cooling them down.

[0045] As an optional example, such as Figure 2As shown, both motors P1 and P3 are equipped with temperature sensors to collect their current temperatures. An oil temperature sensor is also located near the oil pump to collect the oil temperature in the oil pan. Additionally, if the vehicle's clutch also requires cooling, cooled oil can be supplied to the clutch for clutch temperature control.

[0046] Based on the above, the motor temperature control method provided in this application embodiment can determine the flow rate of the cooling liquid used to regulate the motor temperature more accurately, so as to control the motor temperature more precisely.

[0047] In practice, when the motor in the vehicle starts working and the activation conditions for motor temperature control are met, temperature control, such as cooling control, can be applied to the motor. The activation conditions for motor temperature control may include one or more of the following:

[0048] The adaptive cruise control (ACC) and KL15 hardwires are pulled up, the motors (e.g., P1 and P3 motors) start working, there are no fault codes in the TCU, and the coolant storage devices (e.g., MOP and / or EOP for storing oil) are operating normally.

[0049] If the motor starts working and the activation conditions for motor temperature control described above are met, the flow rate of the cooling liquid used to regulate the motor temperature can be determined based on the motor temperature control method provided in this application embodiment, so as to control the motor temperature, for example, by cooling.

[0050] First, we need to obtain the vehicle's motor's basic heat dissipation power and motor operating loss heat dissipation power. The motor's basic heat dissipation power is determined by the motor's current temperature and target temperature; the current temperature is greater than the target temperature. The motor's basic heat dissipation power represents the power dissipated to lower the motor's temperature from its current temperature to its target temperature, or the heat removed during this temperature drop. The target temperature can be set. It is known that when the motor's temperature is controlled, the motor is in operation. Motor operation generates motor operating loss heat dissipation power. Motor operating loss heat dissipation power represents the power dissipated as heat during motor operation.

[0051] The basic heat dissipation power and the heat dissipation power of motor operating losses represent the total heat dissipation requirements of the motor. The motor temperature needs to be regulated by coolant to meet these heat dissipation requirements.

[0052] In one possible implementation, this application provides a specific method for obtaining the basic heat dissipation power of a vehicle's motor and the heat dissipation power due to motor operating losses, including A1-A2:

[0053] A1: Set the target temperature of the motor, and obtain the basic heat dissipation power of the vehicle's motor based on the target temperature, the current temperature of the motor, the specific heat capacity of the motor, and the mass of the motor.

[0054] The current motor temperature can be obtained by a temperature sensor installed in the motor. Different motors (e.g., P1 and P3 motors) can be equipped with corresponding temperature sensors. The target motor temperature is the temperature the motor should reach after temperature control based on the coolant; it is a desired temperature value and can be set. Typically, the current motor temperature is higher than the target motor temperature. In practical applications, the target motor temperatures may be the same or different for different motors; this is not a limitation here.

[0055] As an optional example, the difference between the current temperature and the target temperature of the motor is calculated, and the product of the motor's specific heat capacity, motor mass, and this difference is used as the vehicle's basic motor cooling power. Based on this, this application provides the basic motor cooling power P. base The calculation formula is as follows:

[0056] P base =C m M m (T mActual -T mTarget )

[0057] Among them, C m The specific heat capacity of the motor is expressed in J / (kg*K), M. m The mass of the motor is expressed in kg or T. mActual The current temperature of the motor, in K and T. mTarget The target temperature for the motor is expressed in Kelvin (K).

[0058] It is understandable that if the current temperature of the motor can be obtained at any given moment, and the target temperature of the motor can be set at any given moment, then the basic heat dissipation power of the vehicle's motor at any given moment can be obtained.

[0059] A2: Based on the electric power and mechanical power of the motor, obtain the motor operating loss and heat dissipation power of the vehicle; the electric power of the motor is determined by the motor supply current and the motor supply voltage, and the mechanical power of the motor is determined by the motor output torque and the motor speed.

[0060] The power supplied by the vehicle to the motor is electrical power, and the power used by the motor to perform work is mechanical power. The electrical power of the motor is the product of the motor's supply current and the motor's supply voltage, while the mechanical power of the motor is the product of the motor's output torque and the motor's speed.

[0061] As an optional example, the difference between the electric power and the mechanical power of the motor is determined as the motor's operating loss heat dissipation power, that is, the power lost by the motor in the form of heat dissipation. Based on this, this application provides the motor operating loss heat dissipation power P. Loss The calculation formula is as follows:

[0062] P Loss =I m U m -Torq m Spd m

[0063] Among them, I m The current supplied to the motor, in amperes (A) and watts (U). m The power supply voltage for the motor, measured in V, Torq m Spd represents the motor output torque, measured in Nm. m Let I be the motor speed, in rpm. m U m Torq represents the electrical power of the motor. m Spd m This represents the mechanical power of the motor.

[0064] It is understandable that if the electrical and mechanical power of the motor can be obtained at any given moment, then the motor's operating loss and heat dissipation power at any given moment can be obtained.

[0065] See Figure 3a , Figure 3a This is a schematic diagram of a motor temperature control provided in an embodiment of this application. Figure 3a The following example illustrates the process using an oil pump, cooling oil, and oil cooler. Figure 3a As shown, when the motors in the vehicle include motor P1 and motor P3, the flow requirements of the coolant for motor P1 and motor P3 may be different. Therefore, the basic heat dissipation power (characterizing the basic heat dissipation power requirement) and the heat dissipation power of motor P1 (characterizing the basic heat dissipation power requirement) and the heat dissipation power of motor operating loss can be obtained simultaneously based on the A1-A2 method, so as to calculate the required flow rate of coolant for each motor.

[0066] S102: Calculate the total heat dissipation power of the motor based on the motor's basic heat dissipation power and the heat dissipation power of the motor's operating losses.

[0067] As an alternative example, the sum of the motor's basic heat dissipation power and the heat dissipation power from the motor's operating losses can be taken as the total heat dissipation power of the motor, i.e., the total heat dissipation power of the motor is P. base +P LossThe total heat dissipation power of a motor represents the total heat that the motor needs to dissipate, that is, the total heat that needs to be removed by the cooling liquid for temperature control. It can be understood that the total heat dissipation power of the motor at any given moment can be calculated based on the motor's basic heat dissipation power and the heat dissipation power from motor operating losses.

[0068] like Figure 3a As shown, the total heat dissipation power of motor P1 is calculated by summing its basic heat dissipation power and its operating loss heat dissipation power. Similarly, the total heat dissipation power of motor P3 is calculated by summing its basic heat dissipation power and its operating loss heat dissipation power.

[0069] S103: Based on the heat dissipation power of the cooling equipment, obtain the temperature of the cooling liquid at the outlet of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor.

[0070] The cooling equipment cools the coolant entering it, so the coolant temperature at the equipment outlet is lower than the coolant temperature at the equipment inlet. The lower coolant temperature at the outlet allows for temperature regulation of the motor, for example, reducing its overall temperature. Since the motor inlet is connected to the cooling equipment outlet, the coolant temperature at the outlet is the same as the coolant temperature at the motor inlet. When the coolant is cooling oil, the coolant temperature at the motor inlet is... Figure 3a The oil temperature at the motor inlet.

[0071] The temperature of the cooling liquid at the outlet of the cooling equipment is used to determine the required flow rate of cooling liquid for the motor. It is understandable that after the lower-temperature cooling liquid is used to cool the motor, the motor temperature will decrease, and the cooling liquid temperature will increase (the increased temperature is set to be fixed). The power dissipated is the total heat dissipation power of the motor.

[0072] In practical applications, the temperature of the cooling liquid at the outlet of the cooling equipment can be obtained at any given moment. The outlet temperature of the cooling liquid is related to the cooling capacity of the cooling equipment, and can be adjusted by regulating the cooling capacity. It is known that the stronger the cooling capacity of the cooling equipment, the lower the outlet temperature of the cooling liquid. When the dissipated power is a fixed value equal to the total heat dissipation power of the motor, and the temperature rise of the cooling liquid after cooling the motor is also fixed, a lower outlet temperature of the cooling liquid requires a smaller flow rate of cooling liquid.

[0073] In one possible implementation, this application provides a specific method for obtaining the cooling liquid temperature at the outlet of a cooling device based on the heat dissipation power of the cooling device, including B1-B2:

[0074] B1: Obtain the heat exchange power between the cooling liquid and the cooling air, as well as the heat dissipation power of the cooling liquid; both the heat exchange power between the cooling liquid and the cooling air and the heat dissipation power of the cooling liquid are used to characterize the heat dissipation power of the cooling equipment.

[0075] Cooling equipment enables heat exchange between two fluid media with a certain temperature difference (such as a higher-temperature coolant and a lower-temperature cooling air), thereby reducing the temperature of the coolant. Cooling air is supplied to the cooling equipment by a fan in the vehicle that has cooled the outside air.

[0076] During heat exchange, two processes occur: the heat exchange power between the cooling liquid and the cooling air, and the heat dissipation power of the cooling liquid. The heat exchange power between the cooling liquid and the cooling air is the power generated by the heat exchange between the higher-temperature cooling liquid (specifically, the cooling liquid temperature at the inlet of the cooling equipment) and the lower-temperature cooling air (specifically, the ambient temperature). The heat dissipation power of the cooling liquid is the power generated when its temperature is reduced from the cooling liquid temperature at the inlet of the cooling equipment to the cooling liquid temperature at the outlet of the cooling equipment. This reduction in temperature is achieved through heat exchange between the cooling liquid and the cooling air within the cooling equipment.

[0077] As an optional example, obtaining the heat exchange power between the cooling liquid and the cooling air includes:

[0078] The heat exchange power between the cooling liquid and the cooling air is obtained based on the convective heat transfer coefficient of the cooling equipment, the heat transfer area of ​​the cooling equipment, the temperature of the cooling liquid at the inlet of the cooling equipment, and the ambient temperature. Among them, the convective heat transfer coefficient of the cooling equipment is related to the vehicle speed and the opening of the fan in the vehicle. The fan is used to deliver cooling air to the vehicle to reduce the temperature of the cooling liquid.

[0079] Typically, the temperature of the cooling liquid at the inlet of the cooling equipment is higher than the ambient temperature. For example, first calculate the difference between the cooling liquid temperature at the inlet and the ambient temperature. Then, multiply the convective heat transfer coefficient of the cooling equipment, the heat transfer area of ​​the cooling equipment, and this difference as the heat exchange power between the cooling liquid and the cooling air.

[0080] Based on this, when taking an oil cooler and cooling oil as examples, this application provides the heat exchange power between the cooling liquid and the cooling air. The calculation formula is as follows:

[0081]

[0082] Among them, h Oil This refers to the convective heat transfer coefficient of an oil cooler (i.e., an example of the convective heat transfer coefficient of a cooling device), with units of W / (m³).2 *K), A Oil This refers to the heat exchange area of ​​an oil cooler (i.e., an example of the heat exchange area of ​​a cooling device), in meters (m²). 2 T OilIn T Air These are the oil cooler inlet temperature (an example of the cooling liquid temperature at the inlet of the cooling equipment) and the ambient temperature, respectively, in K.

[0083] It should be noted that the term "oil" in the formula parameters described in this application as an example can be replaced with "cooling liquid".

[0084] It is understandable that since the cooling equipment cools the coolant by cooling air, once the vehicle speed and the fan opening level are determined, the airflow velocity of the cooling air is also determined, and thus the convective heat transfer coefficient of the cooling equipment is also determined. For example, the cooling capacity of the cooling equipment can be adjusted by adjusting the convective heat transfer coefficient.

[0085] As an optional example, obtaining the heat dissipation power of the cooling liquid includes:

[0086] The heat dissipation power of the cooling liquid is obtained based on the cooling liquid temperature at the inlet of the cooling equipment, the cooling liquid temperature at the outlet of the cooling equipment, the specific heat capacity of the cooling liquid, the density of the cooling liquid, and the total flow rate of the cooling liquid passing through the cooling equipment at the previous moment.

[0087] For example, first calculate the difference between the cooling liquid temperature at the inlet of the cooling equipment and the cooling liquid temperature at the outlet of the cooling equipment. Then, multiply the specific heat capacity of the cooling liquid, the density of the cooling liquid, the total flow rate of the cooling liquid through the cooling equipment at the previous moment, and this difference as the heat dissipation power of the cooling liquid.

[0088] Based on this, when taking oil coolers and cooling oil as examples, this application provides the heat dissipation power of the cooling liquid. The calculation formula is as follows:

[0089]

[0090] Among them, C Oil ρ is the specific heat capacity of oil (an example of the specific heat capacity of cooling liquids), in units of J / (kg*k). Oil This refers to the density of the oil (an example of coolant density), in kg / m³. 3 Q OilTotal This represents the total flow rate of cooling oil passing through the oil cooler at the previous moment (an example of the total flow rate of cooling liquid passing through the cooling equipment at the previous moment), in meters. 3 / s. T OilOut This is the oil outlet temperature of the oil cooler (an example of the cooling liquid temperature at the outlet of the cooling equipment), in K.

[0091] It is understandable that when the P1 motor, P3 motor, and clutch in the vehicle all require coolant for temperature control, the total coolant flow rate through the cooling equipment at the previous moment is the sum of the total motor cooling flow rate at the previous moment and the coolant flow rate required by the target device (such as the clutch) at the previous moment. Furthermore, the total motor cooling flow rate at the previous moment is the sum of the coolant flow rate required by the P1 motor and the coolant flow rate required by the P3 motor at the previous moment.

[0092] B2: Based on the conservation relationship between the heat exchange power between the cooling liquid and the cooling air and the heat dissipation power of the cooling liquid, the temperature of the cooling liquid at the outlet of the cooling equipment is obtained.

[0093] It is known that the heat exchange power between the cooling liquid and cooling air, and the heat dissipation power of the cooling liquid, are both used to characterize the heat dissipation power of the cooling equipment. The heat dissipation power of the cooling equipment can be expressed either by the heat exchange power between the cooling liquid and cooling air, or by the heat dissipation power of the cooling liquid itself. That is, the value of the heat dissipation power of the cooling equipment is equal to the heat exchange power between the cooling liquid and cooling air plus the heat dissipation power of the cooling liquid, and also equal to the heat dissipation power of the cooling liquid. This is because there is a conservation relationship between the heat exchange power between the cooling liquid and cooling air and the heat dissipation power of the cooling liquid.

[0094] The conservation relationship between the heat exchange power between the cooling liquid and the cooling air and the heat dissipation power of the cooling liquid indicates that the heat exchange power between the cooling liquid and the cooling air is the same as the heat dissipation power of the cooling liquid. Therefore, the cooling liquid temperature at the outlet of the cooling equipment can be calculated.

[0095] When the cooling device is an oil cooler, the temperature of the cooling liquid at the inlet of the cooling device is the same as the oil temperature at the inlet of the oil cooler, which can be considered as the oil temperature in the oil pan. For example... Figure 3a As shown, the coolant temperature at the outlet of the cooling equipment (which is the same as the coolant temperature at the motor inlet, such as the motor inlet oil temperature) is related to the ambient temperature, the coolant temperature at the inlet of the cooling equipment (such as the oil temperature in the oil pan), the fan opening, the vehicle speed, and the total flow rate of coolant passing through the cooling equipment at the previous moment (such as the total flow rate of cooling oil passing through the oil cooler at the previous moment).

[0096] S104: Based on the total heat dissipation power of the motor, the temperature of the cooling liquid at the outlet of the cooling equipment, and the rising temperature of the cooling liquid, obtain the target flow rate of the cooling liquid at the current moment corresponding to the motor, and use the cooling liquid based on the target flow rate to control the temperature of the motor, so that the temperature of the cooling liquid rises from the temperature of the cooling liquid at the outlet of the cooling equipment to the rising temperature of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, so as to reduce the motor temperature from the current motor temperature to the target motor temperature.

[0097] Once the total heat dissipation power of the motor is known, the total heat that the motor needs to dissipate for temperature control can be determined. After the coolant removes heat and cools the motor, the temperature of the coolant rises from the outlet temperature of the cooling equipment to its initial temperature rise. Therefore, its output power should equal the total heat dissipation power of the motor. The initial temperature rise of the coolant is fixed and can be the inlet temperature of the cooling equipment (e.g., for an oil cooler, this is the oil temperature in the oil pan). Since the above temperature control is based on a certain flow rate of coolant, the target flow rate of the coolant corresponding to the motor at the current moment can be determined to achieve the desired temperature control result.

[0098] In addition, after the motor temperature is controlled based on the target flow rate of the coolant, the heat corresponding to the total heat dissipation power of the motor is dissipated, causing the motor temperature to drop from its current temperature to the target temperature.

[0099] The temperature rise of the coolant is the same as the temperature of the coolant at the inlet of the cooling equipment. When the cooling equipment is an oil cooler, the temperature of the coolant at the inlet of the cooling equipment is the same as the temperature at the inlet of the oil cooler, which is the oil temperature in the oil pan.

[0100] The target flow rate of the coolant corresponding to the motor at the current moment is the flow rate of coolant required by the motor at the current moment. It is understood that the motor temperature control method provided in this application embodiment can calculate the flow rate of coolant required by the motor at each moment with relatively high accuracy.

[0101] In one possible implementation, this application provides a specific implementation method for obtaining the target flow rate of the cooling liquid at the current moment corresponding to the motor based on the total heat dissipation power of the motor, the cooling liquid temperature at the outlet of the cooling equipment, and the rising temperature of the cooling liquid, including C1-C2:

[0102] C1: Calculate the motor cooling convective heat transfer coefficient based on the total heat dissipation power of the motor, the motor cooling heat exchange area, the temperature of the cooling liquid at the outlet of the cooling equipment, and the temperature rise of the cooling liquid.

[0103] As an alternative example, first calculate the difference between the temperature rise of the cooling liquid and the temperature of the cooling liquid at the outlet of the cooling equipment, and then calculate the product of this difference and the heat exchange area of ​​the motor cooling. The quotient of the total heat dissipation power of the motor and this product is the motor cooling convective heat transfer coefficient.

[0104] Based on this, this application provides a formula for calculating the convective heat transfer coefficient of motor cooling, as follows:

[0105] P base +P Loss =h m A m (TOilActual -T OilOut )

[0106] Among them, h m The convective heat transfer coefficient for motor cooling is expressed in W / (m²). 2 *K), A m The heat exchange area of ​​the motor is measured in m². 2 T OilActual This refers to the temperature rise of the cooling oil (an example of the temperature rise of the cooling liquid).

[0107] C2: Based on the calibration relationship between the motor cooling convection heat transfer coefficient and the cooling liquid flow rate, obtain the target flow rate of the cooling liquid at the current moment corresponding to the motor cooling convection heat transfer coefficient.

[0108] It is understandable that the motor cooling convective heat transfer coefficient is related to the flow rate of the cooling liquid; the higher the flow rate of the cooling liquid, the greater the motor cooling convective heat transfer coefficient.

[0109] As an optional example, a calibration relationship between the motor cooling convective heat transfer coefficient and the coolant flow rate is predetermined. This calibration relationship can be recorded in a table, which records the correspondence between the motor cooling convective heat transfer coefficient and the coolant flow rate. This correspondence is obtained through actual vehicle testing and calibration.

[0110] Coolant flow rate is expressed as Q OilCooling The unit is m 3 / s. The calibration relationship between the motor cooling convective heat transfer coefficient and the cooling liquid flow rate is expressed as:

[0111] h m ∝Q OilCooling

[0112] Once the motor cooling convective heat transfer coefficient is determined at the current moment, the target flow rate of the cooling liquid at the current moment can be determined by looking up a table and based on the corresponding relationship.

[0113] Based on the above, the motor temperature control method provided in this application embodiment further includes the following steps D1-D3:

[0114] D1: Based on the target flow rate of the coolant corresponding to each motor at the current moment, obtain the total cooling flow rate of the motor at the current moment; the total cooling flow rate of the motor at the current moment and the cooling flow rate corresponding to the target equipment of the vehicle constitute the total cooling flow rate of the coolant at the current moment.

[0115] Understandably, each motor operates under different conditions, resulting in different operating parameters. Taking motors P1 and P3 as examples, when motor P1 is operating, motor P3 may not be operating. Their operating currents and voltages may differ, affecting their total heat dissipation power. Consequently, the target coolant flow rate for motor P1 at the current moment is typically different from that for motor P3.

[0116] Based on this, the target flow rate of coolant for each motor requiring temperature control in the vehicle at the current moment can be obtained, and the total motor cooling flow rate at the current moment can be obtained by summing these values. For example... Figure 3a As shown, the total cooling flow rate of the motor at the current moment can be the sum of the target flow rate of the cooling liquid corresponding to motor P1 at the current moment and the target flow rate of the cooling liquid corresponding to motor P3 at the current moment.

[0117] Additionally, the target equipment in the vehicle may require coolant for temperature control. For example, the target equipment might be the clutch. The cooling flow rate corresponding to the target equipment is fixed, usually a constant value, determined based on actual conditions. Therefore, the sum of the current total motor cooling flow rate and the cooling flow rate corresponding to the target equipment can be determined as the current total coolant flow rate.

[0118] The total cooling flow rate of the motor at the current moment is expressed as Q. OilTotal The total flow rate of the cooling liquid at the current moment is expressed as Q. OilCooling The relationship between the two can be expressed as:

[0119] Q OilTotal ∝Q OilCooling

[0120] It can be seen that Q OilTotal The sum of the cooling flow rates corresponding to the target equipment in the vehicle is Q. OilCooling It should be understood that "oil" in the parameter is used to refer to cooling oil, and is only an example of a cooling liquid; it can be replaced with any other cooling liquid.

[0121] Based on this, the device storing coolant can be controlled to deliver the required flow rate (i.e., the total coolant flow rate at the current moment) of coolant to control the temperature of the vehicle's motors and target equipment. For example... Figure 3a As shown, when the coolant is cooling oil, the device for storing the coolant is a MOP and / or an EOP. The flow rate requirement of the MOP and / or EOP is the total flow rate of the coolant at the current moment.

[0122] It is understandable that the total flow rate of the cooling liquid at the current moment calculated in this step can be used to calculate the cooling liquid temperature at the outlet of the cooling equipment (i.e., the cooling liquid temperature at the motor inlet) at the next moment.

[0123] D2: Based on the current total motor cooling flow rate, determine the control ratio of the valve corresponding to each motor; the motor is connected to the cooling equipment through the valve.

[0124] like Figure 2 As shown, the motors are connected to the cooling equipment via valves. Each motor can be equipped with one valve to control the supply of coolant to the motor. Once the target flow rate of the coolant for the corresponding motor at the current moment is determined, the control ratio of the valve for each motor can be determined based on the total cooling flow rate of the motors at the current moment and the target flow rate of the coolant for each motor at the current moment. For example, if the target flow rates of the coolant for motors P1 and P3 are the same at the current moment, then the control ratio of the valves for motors P1 and P3 is 1 / 2 each. The sum of the control ratios of the valves for all motors is 1.

[0125] D3: Determine the opening degree of each valve based on the control ratio of each valve.

[0126] As an alternative example, there is a correspondence between the valve's control ratio and its opening degree, which can be recorded in a table. Once the valve's control ratio is determined, the valve's opening degree can be obtained by looking up the table.

[0127] For example, the valve could be a solenoid valve. (e.g.) Figure 3a As shown, when the valve is a solenoid valve, the valve opening can be controlled by the solenoid valve's current. Specifically, based on the control ratio of each solenoid valve, the control current of each solenoid valve is calculated, and the opening of each solenoid valve is controlled by its control current. That is, there is a corresponding relationship between the solenoid valve's control ratio and its control current. After determining the solenoid valve's control ratio, the control current can be determined based on this correspondence. The solenoid valve's control current can control its opening, and there is also a corresponding relationship between the two.

[0128] See Figure 3b , Figure 3b This is a schematic diagram of a motor temperature control framework provided in an embodiment of this application. Figure 3bAs shown, taking cooling oil as an example, once the motor starts working and meets the activation conditions for motor temperature control, the total heat dissipation power of the motor and the inlet oil temperature can be calculated at the current moment. Then, based on the total heat dissipation power and inlet oil temperature, the total cooling flow rate of the motor at the current moment can be calculated. Furthermore, based on the total cooling flow rate of the motor at the current moment and the corresponding cooling flow rate of the target equipment in the vehicle, the target total flow rate of the oil pump at the current moment is obtained to control the oil pump to output the target total flow rate of cooling oil. On the other hand, after obtaining the total cooling flow rate of the motor at the current moment, the target flow rate of the cooling liquid corresponding to each motor at the current moment can be combined to determine the solenoid valve control ratio for each motor, thereby controlling the opening degree of the solenoid valve. Furthermore, after obtaining the target total flow rate of the oil pump at the current moment, this value can be applied to the calculation of the motor inlet oil temperature at the next moment.

[0129] In practical applications, the motor temperature control method provided in this application can achieve bidirectional control of motor temperature rise and fall. For example, by setting a negative basic heat dissipation power requirement under low-temperature conditions (i.e., setting the motor target temperature so that the motor's basic heat dissipation power is negative), the motor temperature can be increased through the heat dissipation power dissipated by the motor's operating losses, enabling the motor to quickly reach its efficient operating temperature range. For instance, if the motor target temperature is set so that the motor's basic heat dissipation power is -5kW and the motor's operating loss heat dissipation power is 15kW, then the total heat dissipation power of the motor is 10kW. Therefore, only 10kW of heat needs to be dissipated from the motor, with 5kW used for motor heating, thus enabling the motor to quickly reach its efficient operating temperature range. Alternatively, by increasing the basic heat dissipation power requirement under high-temperature conditions, the overall cooling flow rate requirement can be increased, achieving rapid cooling and high-temperature protection functions for the motor.

[0130] Furthermore, the motor temperature control method provided in this application embodiment can also reduce energy loss to the coolant storage device (e.g., oil pump). By calculating the motor cooling flow demand at each moment and adjusting the precise flow control of the coolant storage device (e.g., MOP and EOP) in real time, unnecessary energy loss can be reduced and overall energy efficiency improved. It is understood that each moment in this application embodiment can be determined according to actual conditions, for example, it can be each second or each minute; no limitation is made here.

[0131] Based on the above-mentioned S101-S104, this application embodiment provides a relatively accurate motor temperature control method, which can be used to control the real-time cooling of the motor of a hybrid transmission. It mainly estimates the motor cooling demand based on the motor's basic heat dissipation power requirement and the motor's operating loss heat dissipation power requirement, while simultaneously combining information such as ambient temperature, fan opening, and vehicle speed to estimate the total motor cooling flow rate requirement. Based on the individual motor cooling flow rate requirements and the total motor cooling flow rate requirement, the valves controlling the flow rate and the device storing the coolant are controlled respectively. In this way, considering the real-time heat generation of the motor, the motor cooling flow rate requirement can be calculated more accurately, and the motor cooling flow rate control is more refined, achieving precise control of motor cooling. This reduces the load on the coolant storage devices (such as MOP and EOP), reduces energy loss, avoids energy waste, thereby improving the overall vehicle fuel consumption and increasing the driving range.

[0132] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0133] Based on the motor temperature control method provided in the above embodiments, this application also provides a motor temperature control device, which will be described below with reference to the accompanying drawings. Since the principle by which the device in this disclosure solves the problem is similar to the motor temperature control method described above in this application, the implementation of the device can refer to the implementation of the method, and repeated details will not be elaborated further.

[0134] See Figure 4 As shown in the figure, this is a structural schematic diagram of a motor temperature control device provided in an embodiment of this application. Figure 4 As shown, the motor temperature control device includes:

[0135] The first acquisition unit 401 is used to acquire the basic heat dissipation power of the motor and the heat dissipation power of the motor operating loss of the vehicle; the basic heat dissipation power of the motor is determined by the current temperature of the motor and the target temperature of the motor.

[0136] Calculation unit 402 is used to calculate the total heat dissipation power of the motor based on the basic heat dissipation power of the motor and the heat dissipation power of the motor working loss;

[0137] The second acquisition unit 403 is used to acquire the temperature of the cooling liquid at the outlet of the cooling equipment based on the heat dissipation power of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor;

[0138] The third acquisition unit 404 is used to acquire the target flow rate of the cooling liquid at the current moment corresponding to the motor based on the total heat dissipation power of the motor, the cooling liquid temperature at the outlet of the cooling device, and the heating temperature of the cooling liquid, and to perform temperature control on the motor based on the cooling liquid with the target flow rate, so that the temperature of the cooling liquid rises from the cooling liquid temperature at the outlet of the cooling device to the heating temperature of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, so as to reduce the motor temperature from the current motor temperature to the target motor temperature;

[0139] The temperature rise of the cooling liquid is the same as the temperature of the cooling liquid at the inlet of the cooling equipment.

[0140] In one possible implementation, the first acquisition unit 401 includes:

[0141] The first acquisition subunit is used to set the target temperature of the motor and acquire the basic heat dissipation power of the vehicle's motor based on the target temperature of the motor, the current temperature of the motor, the specific heat capacity of the motor and the mass of the motor.

[0142] The second acquisition subunit is used to acquire the vehicle's motor operating loss and heat dissipation power based on the motor's electrical power and mechanical power; the motor's electrical power is determined by the motor's supply current and supply voltage, and the motor's mechanical power is determined by the motor's output torque and motor speed.

[0143] In one possible implementation, the second acquisition unit 403 includes:

[0144] The third acquisition subunit is used to acquire the heat exchange power between the cooling liquid and the cooling air, as well as the heat dissipation power of the cooling liquid; the heat exchange power between the cooling liquid and the cooling air, and the heat dissipation power of the cooling liquid are both used to characterize the heat dissipation power of the cooling equipment.

[0145] The fourth acquisition subunit is used to acquire the temperature of the cooling liquid at the outlet of the cooling equipment based on the conservation relationship between the heat exchange power between the cooling liquid and the cooling air and the heat dissipation power of the cooling liquid.

[0146] Wherein, the heat exchange power between the cooling liquid and the cooling air is the heat dissipation power of the cooling liquid exchanging heat with the cooling air; the heat dissipation power of the cooling liquid is the heat dissipation power of reducing the temperature of the cooling liquid at the inlet of the cooling device to the temperature of the cooling liquid at the outlet of the cooling device; the reduction of the temperature of the cooling liquid at the inlet of the cooling device to the temperature of the cooling liquid at the outlet of the cooling device is achieved through heat exchange between the cooling liquid and the cooling air.

[0147] In one possible implementation, the third acquisition subunit includes:

[0148] The fifth acquisition subunit is used to acquire the heat exchange power between the cooling liquid and the cooling air based on the convective heat transfer coefficient of the cooling equipment, the heat transfer area of ​​the cooling equipment, the temperature of the cooling liquid at the inlet of the cooling equipment, and the ambient temperature.

[0149] The convective heat transfer coefficient of the cooling equipment is related to the vehicle speed and the opening degree of the fan in the vehicle. The fan is used to deliver cooling air to the vehicle to reduce the temperature of the coolant.

[0150] In one possible implementation, the third acquisition subunit includes:

[0151] The sixth acquisition subunit is used to acquire the heat dissipation power of the cooling liquid based on the cooling liquid temperature at the inlet of the cooling equipment, the cooling liquid temperature at the outlet of the cooling equipment, the specific heat capacity of the cooling liquid, the density of the cooling liquid, and the total flow rate of the cooling liquid passing through the cooling equipment at the previous moment.

[0152] The cooling liquid temperature at the outlet of the cooling equipment is the same as the cooling liquid temperature at the inlet of the motor.

[0153] In one possible implementation, the third acquisition unit 404 includes:

[0154] The calculation subunit is used to calculate the motor cooling convective heat transfer coefficient based on the total heat dissipation power of the motor, the motor cooling heat exchange area, the cooling liquid temperature at the outlet of the cooling equipment, and the temperature rise of the cooling liquid.

[0155] The seventh acquisition subunit is used to acquire the target flow rate of the cooling liquid at the current moment corresponding to the motor cooling convection heat transfer coefficient, based on the calibration relationship between the motor cooling convection heat transfer coefficient and the cooling liquid flow rate.

[0156] In one possible implementation, the device further includes:

[0157] The fourth acquisition unit is used to acquire the total motor cooling flow rate at the current moment based on the target flow rate of the cooling liquid corresponding to each motor at the current moment; the total motor cooling flow rate at the current moment and the cooling flow rate corresponding to the vehicle target equipment constitute the total cooling liquid flow rate at the current moment.

[0158] The first determining unit is used to determine the control ratio of the valve corresponding to each motor based on the total motor cooling flow rate at the current moment; the motor is connected to the cooling equipment through the valve.

[0159] The second determining unit is used to determine the opening degree of each valve based on the control ratio of each valve.

[0160] It should be noted that the specific implementation of each unit in this embodiment can be found in the relevant descriptions in the above method embodiments. The division of units in this application embodiment is illustrative and only represents a logical functional division; in actual implementation, there may be other division methods. The functional units in this application embodiment can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. For example, in the above embodiments, the processing unit and the sending unit can be the same unit or different units. The integrated unit can be implemented in hardware or as a software functional unit.

[0161] This application also provides a computer-readable medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the motor temperature control method as described above.

[0162] See Figure 5 , Figure 5 A schematic diagram of an electronic device according to an exemplary embodiment of the present disclosure is shown.

[0163] Reference Figure 5 An electronic device according to an exemplary embodiment of the present disclosure includes a storage device 51 and one or more processors 52, wherein the storage device 51 stores one or more programs that, when executed by the one or more processors, cause the one or more processors to implement the motor temperature control method as described above.

[0164] In an exemplary embodiment of this disclosure, when the computer program is executed by the processor 52, the following steps can be implemented:

[0165] The vehicle's motor base heat dissipation power and motor operating loss heat dissipation power are obtained; the motor base heat dissipation power is determined by the motor's current temperature and target temperature.

[0166] The total heat dissipation power of the motor is calculated based on the basic heat dissipation power of the motor and the heat dissipation power of the motor's operating losses.

[0167] The temperature of the cooling liquid at the outlet of the cooling equipment is obtained based on the heat dissipation power of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor;

[0168] Based on the total heat dissipation power of the motor, the temperature of the cooling liquid at the outlet of the cooling equipment, and the temperature rise of the cooling liquid, the target flow rate of the cooling liquid at the current moment corresponding to the motor is obtained. The motor temperature is controlled based on the cooling liquid with the target flow rate, so that the temperature of the cooling liquid rises from the temperature of the cooling liquid at the outlet of the cooling equipment to the temperature rise of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, so as to reduce the motor temperature from the current motor temperature to the target motor temperature.

[0169] The temperature rise of the cooling liquid is the same as the temperature of the cooling liquid at the inlet of the cooling equipment.

[0170] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that all or part of the steps in the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network communication device such as a media gateway, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0171] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Regarding the methods disclosed in the embodiments, since they correspond to the systems disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the system section description.

[0172] It should also be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0173] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling motor temperature, characterized in that, The method includes: The vehicle's motor base heat dissipation power and motor operating loss heat dissipation power are obtained; the motor base heat dissipation power is determined by the motor's current temperature and target temperature. The total heat dissipation power of the motor is calculated based on the basic heat dissipation power of the motor and the heat dissipation power of the motor's operating losses. The temperature of the cooling liquid at the outlet of the cooling equipment is obtained based on the heat dissipation power of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor; Based on the total heat dissipation power of the motor, the temperature of the cooling liquid at the outlet of the cooling equipment, and the temperature rise of the cooling liquid, the target flow rate of the cooling liquid at the current moment corresponding to the motor is obtained. The motor temperature is controlled based on the cooling liquid with the target flow rate, so that the temperature of the cooling liquid rises from the temperature of the cooling liquid at the outlet of the cooling equipment to the temperature rise of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, so as to reduce the motor temperature from the current motor temperature to the target motor temperature. The temperature rise of the cooling liquid is the same as the temperature of the cooling liquid at the inlet of the cooling equipment.

2. The method according to claim 1, characterized in that, The acquisition of the vehicle's basic motor cooling power and motor operating loss cooling power includes: Set the target temperature of the motor, and obtain the basic heat dissipation power of the vehicle's motor based on the target temperature, the current temperature of the motor, the specific heat capacity of the motor, and the mass of the motor. Based on the electric power and mechanical power of the motor, the heat dissipation power of the vehicle's motor operating loss is obtained; the electric power of the motor is determined by the motor's supply current and supply voltage, and the mechanical power of the motor is determined by the motor's output torque and motor speed.

3. The method according to claim 1, characterized in that, The method of obtaining the cooling liquid temperature at the outlet of the cooling device based on the heat dissipation power of the cooling device includes: The heat exchange power between the cooling liquid and the cooling air, as well as the heat dissipation power of the cooling liquid, are obtained; the heat exchange power between the cooling liquid and the cooling air, and the heat dissipation power of the cooling liquid are both used to characterize the heat dissipation power of the cooling equipment. Based on the conservation relationship between the heat exchange power between the cooling liquid and the cooling air and the heat dissipation power of the cooling liquid, the temperature of the cooling liquid at the outlet of the cooling equipment is obtained. Wherein, the heat exchange power between the cooling liquid and the cooling air is the heat dissipation power of the cooling liquid exchanging heat with the cooling air; the heat dissipation power of the cooling liquid is the heat dissipation power of reducing the temperature of the cooling liquid at the inlet of the cooling device to the temperature of the cooling liquid at the outlet of the cooling device; the reduction of the temperature of the cooling liquid at the inlet of the cooling device to the temperature of the cooling liquid at the outlet of the cooling device is achieved through heat exchange between the cooling liquid and the cooling air.

4. The method according to claim 3, characterized in that, The method of obtaining the heat exchange power between the cooling liquid and the cooling air includes: The heat exchange power between the cooling liquid and the cooling air is obtained based on the convective heat transfer coefficient of the cooling equipment, the heat transfer area of ​​the cooling equipment, the temperature of the cooling liquid at the inlet of the cooling equipment, and the ambient temperature. The convective heat transfer coefficient of the cooling equipment is related to the vehicle speed and the opening degree of the fan in the vehicle. The fan is used to deliver cooling air to the vehicle to reduce the temperature of the coolant.

5. The method according to claim 3, characterized in that, The method of obtaining the heat dissipation power of the cooling liquid includes: The heat dissipation power of the cooling liquid is obtained based on the cooling liquid temperature at the inlet of the cooling equipment, the cooling liquid temperature at the outlet of the cooling equipment, the specific heat capacity of the cooling liquid, the density of the cooling liquid, and the total flow rate of the cooling liquid passing through the cooling equipment at the previous moment. The cooling liquid temperature at the outlet of the cooling equipment is the same as the cooling liquid temperature at the inlet of the motor.

6. The method according to claim 1, characterized in that, The step of obtaining the target flow rate of the cooling liquid at the current moment corresponding to the motor, based on the total heat dissipation power of the motor, the cooling liquid temperature at the outlet of the cooling equipment, and the rising temperature of the cooling liquid, includes: The motor cooling convective heat transfer coefficient is calculated based on the total heat dissipation power of the motor, the motor cooling heat exchange area, the cooling liquid temperature at the outlet of the cooling equipment, and the temperature rise of the cooling liquid. Based on the calibration relationship between the motor cooling convective heat transfer coefficient and the cooling liquid flow rate, the target flow rate of the cooling liquid at the current moment corresponding to the motor cooling convective heat transfer coefficient is obtained.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: Based on the target flow rate of the cooling fluid corresponding to each motor at the current moment, the total cooling flow rate of the motor at the current moment is obtained; the total cooling flow rate of the motor at the current moment and the cooling flow rate corresponding to the target equipment of the vehicle constitute the total cooling fluid flow rate at the current moment. Based on the total cooling flow rate of the motor at the current moment, the control ratio of the valve corresponding to each motor is determined; the motor is connected to the cooling equipment through the valve. The opening degree of each valve is determined based on the control ratio of each valve.

8. A motor temperature control device, characterized in that, The device includes: The first acquisition unit is used to acquire the vehicle's basic motor heat dissipation power and motor operating loss heat dissipation power; the basic motor heat dissipation power is determined by the current motor temperature and the target motor temperature. The calculation unit is used to calculate the total heat dissipation power of the motor based on the basic heat dissipation power of the motor and the heat dissipation power of the motor's operating losses. The second acquisition unit is used to acquire the temperature of the cooling liquid at the outlet of the cooling equipment based on the heat dissipation power of the cooling equipment; the inlet of the motor is connected to the outlet of the cooling equipment, and the cooling liquid supplied by the cooling equipment to the motor is used to achieve temperature control of the motor; The third acquisition unit is used to acquire the target flow rate of the cooling liquid at the current moment corresponding to the motor based on the total heat dissipation power of the motor, the cooling liquid temperature at the outlet of the cooling equipment, and the heating temperature of the cooling liquid. The unit then uses the cooling liquid at the target flow rate to control the temperature of the motor, so that the temperature of the cooling liquid rises from the cooling liquid temperature at the outlet of the cooling equipment to the heating temperature of the cooling liquid, and the output power is equal to the total heat dissipation power of the motor, thereby reducing the motor temperature from the current motor temperature to the target motor temperature. The temperature rise of the cooling liquid is the same as the temperature of the cooling liquid at the inlet of the cooling equipment.

9. An electronic device, characterized in that, include: One or more processors; Storage device, on which one or more programs are stored, When the one or more programs are executed by the one or more processors, the one or more processors implement the motor temperature control method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a processor, implements the motor temperature control method as described in any one of claims 1-7.

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