Control method and device for drive motor oil cooling system, drive motor oil cooling system, vehicle and storage medium

Abstract

This invention belongs to the field of electric vehicle drive motor cooling technology, specifically relating to a control method, device, drive motor oil cooling system, vehicle, and storage medium for a drive motor oil cooling system. The drive motor oil cooling system includes a drive motor and an oil pump motor. The drive motor contains a stator and a rotor, and the drive motor and oil pump motor are connected via an oil circuit. The method includes: detecting whether the oil pump motor is overheating; setting an oil pump motor temperature threshold and controlling a power limit flag based on the oil pump motor temperature; and determining the output speed V of the oil pump motor based on the power limit flag. The purpose is to adjust the output speed of the oil pump motor accordingly based on its specific operating conditions, ensuring normal operation of the oil pump motor and improving the safety of the oil pump cooling system.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle drive motor cooling technology, specifically relating to a control method, device, drive motor oil cooling system, vehicle, and storage medium for a drive motor oil cooling system. Background Technology

[0002] Currently, the power limit of electric vehicle motors is often constrained by their temperature rise limit, and the performance of permanent magnet motors decreases with increasing temperature. Therefore, improving the motor's cooling capacity can immediately increase power density. Existing cooling methods for new energy vehicle motors primarily use water cooling. However, since the high-temperature components of the motor are mainly concentrated at the winding ends, water cooling cannot directly contact these high-temperature parts, resulting in inadequate cooling of the rotor and stator windings, which act as heat sources. This leads to less than ideal heat dissipation efficiency. Compared to water cooling, oil cooling offers the advantage of non-conductive and non-magnetic oil with excellent insulation properties. It can directly contact the internal components of the motor, penetrating deep into the rotor and stator windings for more complete heat exchange, resulting in higher heat dissipation efficiency. Furthermore, as electric vehicles continue to develop, the demand for higher motor power density is constantly increasing; therefore, oil cooling technology with even higher heat dissipation efficiency will become the trend.

[0003] Current oil cooling technologies include oil immersion cooling and oil-cooled shafts for rotors, and oil immersion cooling, winding spray cooling, and in-slot cooling for stators. Both the rotor and stator are cooled by oil, and the drive motor also requires oil for lubrication during rotation. The oil pump motor needs to simultaneously cool the stator and rotor as well as lubricate the drive motor. If the oil pump motor speed is not adjusted in time according to the operating conditions of the drive motor and the oil pump motor, the oil pump motor may burn out. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, device, drive motor oil cooling system, vehicle, and storage medium for a drive motor oil cooling system, which adjusts the output speed of the oil pump motor according to the specific working conditions of the oil pump motor, so as to ensure the normal operation of the oil pump motor and improve the safety of the oil pump cooling system.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, embodiments of this application provide a control method for a drive motor oil cooling system, applied to a drive motor oil cooling system, the drive motor oil cooling system including a drive motor and an oil pump motor, the drive motor having a stator and a rotor, the drive motor and the oil pump motor being connected via an oil circuit, the method including:

[0007] When the current temperature of the oil pump motor does not exceed the over-temperature threshold, the power limit flag is determined based on the current temperature and the preset temperature threshold.

[0008] The target flow rate for the oil pump motor is determined based on the first temperature of the rotor in the drive motor, the second temperature of the stator of the drive motor, the torque of the drive motor, and a preset algorithm.

[0009] The target rotational speed of the oil pump motor corresponding to the target flow rate is determined based on the power limit flag.

[0010] The oil pump motor is controlled to operate at the target speed, so as to drive the coolant in the oil circuit to cool the drive motor.

[0011] In conjunction with the first aspect, in some optional embodiments, the method further includes:

[0012] A temperature threshold is set in advance for the oil pump motor, which is less than the over-temperature threshold of the oil pump motor, and a safe over-temperature time t0 is set.

[0013] The oil pump motor temperature is below the temperature threshold, and the power limit flag is 0.

[0014] When the oil pump motor temperature is higher than the temperature threshold and the over-temperature time is less than t0, the power limit flag is 0.

[0015] The oil pump motor temperature is higher than the temperature threshold, the over-temperature time reaches t0, and the power limit flag is set to 1.

[0016] In conjunction with the first aspect, in some optional embodiments, the method further includes:

[0017] When the power limit flag is 1, the operating current of the oil pump is reduced to limit the maximum output speed V3 of the oil pump motor, thus ensuring that the output speed of the oil pump motor is always lower than the maximum output speed V3 of the oil pump motor.

[0018] In conjunction with the first aspect, in some optional embodiments, 2. determining the power limiting flag based on the current temperature and a preset temperature threshold includes:

[0019] If the current temperature is less than the preset temperature threshold, the power limit flag is set to 0.

[0020] In conjunction with the first aspect, in some optional embodiments, determining the power limiting flag based on the current temperature and a preset temperature threshold includes:

[0021] If the current temperature is greater than or equal to the preset temperature threshold, determine whether the duration for which the current temperature is greater than or equal to the preset temperature threshold exceeds a first specified duration t0;

[0022] If the duration does not exceed the first specified duration t0, the power limit flag is determined to be 0;

[0023] After the duration exceeds the first specified duration t0, the oil pump motor is controlled to operate at a preset power limit, and the power limit flag is set to 1, while the maximum output torque of the drive motor is limited.

[0024] In conjunction with the first aspect, in some optional embodiments, the target flow rate for the oil pump motor output is determined based on the first temperature of the rotor in the drive motor, the second temperature of the stator of the drive motor, the torque of the drive motor, and a preset algorithm, including:

[0025] From the preset rotor temperature flow table of the drive motor, determine the flow rate L1 corresponding to the first temperature, wherein the rotor temperature flow table records the correspondence between the rotor temperature and the output flow rate of the oil pump motor;

[0026] From the preset stator temperature and flow rate table of the drive motor, determine the flow rate L2 corresponding to the second temperature, wherein the stator temperature and flow rate table records the correspondence between the temperature of the stator and the output flow rate of the oil pump motor;

[0027] From the preset torque-flow table of the drive motor, determine the flow rate L3 corresponding to the current torque of the drive motor, wherein the torque-flow table records the correspondence between the torque of the drive motor and the output flow rate of the oil pump motor;

[0028] The maximum flow rate among the flow rates L1, L2, and L3 is determined as the target flow rate.

[0029] In conjunction with the first aspect, in some optional embodiments, determining the target rotational speed of the oil pump motor corresponding to the target flow rate based on the power limiting flag includes:

[0030] According to the preset flow rate and speed table of the oil pump motor, the speed V2 of the oil pump motor corresponding to the target flow rate is determined. The flow rate and speed table records the correspondence between the flow rate and speed output by the oil pump motor.

[0031] If the power limit flag is 1, the minimum value between the maximum speed V3 and the speed V2 of the oil pump motor corresponding to the preset power limit is determined as the target speed.

[0032] If the power limit flag is 0, the target speed of the oil pump motor is determined to be the speed V2.

[0033] In conjunction with the first aspect, in some optional embodiments, the method further includes:

[0034] When the current temperature of the oil pump motor exceeds the over-temperature threshold, a fault warning message is issued, and the oil cooling system of the drive motor is controlled to stop operating.

[0035] Secondly, embodiments of this application also provide a control device for a drive motor oil cooling system, applied to a drive motor oil cooling system. The drive motor oil cooling system includes a drive motor and an oil pump motor. The drive motor has a stator and a rotor. The drive motor and the oil pump motor are connected through an oil circuit. The device includes:

[0036] Detection and analysis unit: used to detect the temperature of the oil pump motor; detect the temperature of the stator and rotor of the drive motor during operation, the torque of the drive motor, query the target flow rate L of the oil pump motor, query the corresponding speed V2 of the oil pump motor at the target flow rate; detect the status of the power limit flag and analyze to obtain the output speed V of the oil pump motor;

[0037] Control unit: Used to detect the temperature of the oil pump motor; detect the temperature of the stator and rotor of the drive motor during operation, and the torque of the drive motor; determine the target flow rate L of the oil pump motor according to a preset algorithm; determine the speed V2 of the oil pump motor corresponding to the target flow rate L; detect the status of the power limit flag and determine the target output speed of the oil pump motor.

[0038] Control unit: Used to execute the received control signal, adjust the reading of the power limit flag, control the speed of the drive motor according to the reading of the power limit flag, and control the oil pump motor to run at the target output speed.

[0039] Thirdly, this application also provides a drive motor oil cooling system, the system including a drive motor, an oil pump motor and a memory, the drive motor having a stator and a rotor, the drive motor and the oil pump motor being connected by an oil circuit, the memory storing a computer program, and when the computer program is executed by the oil pump motor, causing the drive motor oil pump cooling system to perform the above-described method.

[0040] Fourthly, this application also provides a vehicle, the vehicle including a vehicle body and the aforementioned drive motor oil cooling system, the drive motor oil cooling system being disposed on the vehicle.

[0041] Fifthly, this application also provides a computer-readable storage medium storing a computer program that, when run on a computer, causes the computer to perform the above-described method.

[0042] The invention employing the above technical solution has the following advantages:

[0043] The design fully considers the operating conditions of the oil pump motor under different circumstances. When the set threshold of the oil pump motor is not exceeded, the minimum speed of the oil pump motor that can simultaneously meet the three conditions of stator cooling, rotor cooling, and drive motor lubrication is selected. When the oil pump motor reaches the set temperature threshold, if the safe time t0 is not exceeded, the oil pump motor operates at the minimum speed that meets the three conditions of stator cooling, rotor cooling, and drive motor lubrication. If the safe time t0 is exceeded, the current of the drive motor is reduced to reduce the torque of the drive motor. This reduces the amount of oil pumped by the oil pump motor and reduces the current of the oil pump motor to reduce the maximum output speed of the oil pump motor, thereby controlling the temperature of the oil pump motor and improving the safety of the oil pump motor operation. Attached Figure Description

[0044] The present invention can be further illustrated by the non-limiting embodiments given in the accompanying drawings;

[0045] Figure 1 This is a block diagram of the drive motor oil cooling system according to an embodiment of the present invention;

[0046] Figure 2 This is a flowchart illustrating the control method for the drive motor oil cooling system according to an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the control device for the drive motor oil cooling system according to an embodiment of the present invention;

[0048] The symbols for the main components are explained below:

[0049] 10. Drive motor oil cooling system; 11. Drive motor; 12. Oil pump motor; 200. Drive motor oil cooling system control device; 210. Detection and analysis unit; 220. Control unit. Detailed Implementation

[0050] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that similar or identical parts are referred to by the same reference numerals in the drawings or description. Implementations not shown or described in the drawings are forms known to those skilled in the art. In addition, directional terms mentioned in the embodiments, such as "up," "down," "top," "bottom," "left," "right," "front," and "back," are only for reference to the directions in the drawings and are not intended to limit the scope of protection of the present invention.

[0051] like Figure 1 As shown, this application provides a drive motor oil cooling system 10, which includes a drive motor 11 and an oil pump motor 12. The drive motor 11 is provided with a stator and a rotor. The drive motor 11 and the oil pump motor 12 are connected through an oil circuit.

[0052] When the drive motor 11 is working normally, the oil pump motor 12 pumps oil into the drive motor 11 through the oil circuit. The oil pump motor 11 pumps oil into the drive motor 12 at the optimal output speed. While taking into account the cooling of the stator and rotor of the drive motor 11 and the lubrication of the drive motor 11 itself, the output speed of the oil pump motor 12 and the output torque of the drive motor 11 are limited, thereby improving the safety of the oil pump motor 12 during use.

[0053] In the prior art, in order to effectively balance the cooling of the stator and rotor of the drive motor 11 and the lubrication of the drive motor 11 itself, the oil pump motor 12 will continuously operate at high intensity under the high-intensity operation of the drive motor 11, leading to the burnout of the oil pump motor 12. Therefore, it is necessary to control the operation of the oil pump motor 12 to improve its safety during use.

[0054] In this embodiment, the drive motor oil cooling system can be deployed on the vehicle, making the cooling and lubrication of the drive motor 11 safer and more reliable during vehicle operation. The drive motor 11 and the oil pump motor 12 can be connected to the storage module, allowing them to retrieve data or programs stored in the storage module.

[0055] In this embodiment, the drive motor 11 can be used to provide power to the vehicle during vehicle operation.

[0056] The oil pump motor 12 is used to pump oil to cool the stator and rotor of the drive motor 11 and to provide lubrication for the drive motor 11 during operation.

[0057] The storage module stores a computer program, which, when executed by the drive motor 11 or the oil pump motor 12, enables the braking device to perform the corresponding steps in the braking control method described below.

[0058] like Figure 2 As shown, this application also provides a control method for an oil-cooled system of a drive motor 11. The control method for the oil-cooled system of the drive motor 11 may include the following steps:

[0059] Step 110: When the current temperature of the oil pump motor 12 does not exceed the over-temperature threshold, determine the power limit flag based on the current temperature and the preset temperature threshold.

[0060] Step 120: Determine the target flow rate for the oil pump motor 12 based on the first temperature of the rotor in the drive motor 11, the second temperature of the stator in the drive motor 11, the torque of the drive motor 11, and a preset algorithm.

[0061] Step 130: Determine the target rotational speed of the oil pump motor 12 corresponding to the target flow rate based on the power limit flag.

[0062] Step 140: Control the oil pump motor 12 to run at the target speed, so as to drive the coolant in the oil circuit to cool the drive motor 11.

[0063] In the above embodiment, the stator and rotor of the drive motor 11 need to be cooled and the drive motor 11 needs to be lubricated. First, it is detected whether the oil pump motor 12 exceeds the critical temperature. Then, a temperature threshold lower than the critical temperature of the oil pump motor 12 is set. The power limit flag is controlled according to the temperature during the operation of the oil pump motor 12. Then, the output speed V of the oil pump motor 12 is determined according to the status of the power limit flag. In this way, the safety of the oil pump motor 12 during operation can be improved, and the oil pump motor 12 can be prevented from burning out due to excessive speed.

[0064] The steps of the braking control method will be explained in detail below:

[0065] In step 110, it is detected whether the oil pump motor 12 has exceeded the critical temperature. If the oil pump motor 12 has overheated, a fault warning message is issued, and the oil cooling system of the drive motor is controlled to stop operating. If the oil pump system temperature is normal, the next step is continued.

[0066] Set a temperature threshold below the critical temperature of the oil pump motor 12, compare the current temperature of the oil pump motor 12 with the temperature threshold, and determine the power limit flag based on the comparison result.

[0067] In step 120, the first temperature of the rotor, the second temperature of the stator of the drive motor 11, and the torque of the drive motor 11 are collected by the drive motor 11. The target flow rate that the oil pump motor 12 needs to output under the cooling conditions of the first and second temperatures and the lubrication conditions of the drive motor 11 is determined according to the preset algorithm.

[0068] In step 130, based on the different cases of the power limit flag, and according to the preset algorithm, the target speed of the oil pump motor 12 is determined to ensure the safe operation of the oil pump motor 12 while satisfying the requirements of cooling the stator and rotor of the drive motor 11 and lubricating the drive motor 11.

[0069] In step 140, the oil pump motor 12 is operated at the target speed so that the oil pump motor 12 can operate safely while meeting the requirements of the drive motor 11.

[0070] As an optional implementation, determining the power limiting flag based on the current temperature and a preset temperature threshold includes:

[0071] If the current temperature is less than the preset temperature threshold, the power limit flag is set to 0.

[0072] If the current temperature is greater than or equal to the preset temperature threshold, determine whether the duration for which the current temperature is greater than or equal to the preset temperature threshold exceeds a first specified duration t0;

[0073] If the duration does not exceed the first specified duration t0, the power limit flag is determined to be 0;

[0074] After the duration exceeds the first specified duration t0, the oil pump motor 12 is controlled to operate at a preset power limit, and the power limit flag is set to 1, while the maximum output torque of the drive motor is limited.

[0075] Understandably, when the power limit flag is set to 0, the oil pump motor 12 can operate normally under the conditions of cooling the stator and rotor of the drive motor 11 and lubricating the drive motor 11, and the oil pump motor 12 will not have any problems. When the current temperature of the oil pump motor 12 is lower than the preset temperature, the power limit flag is set to 0.

[0076] When the current temperature of the oil pump motor 12 exceeds the preset threshold, the oil pump motor 12 can still operate normally without damage within a first specified duration t0, provided that the stator and rotor of the drive motor 11 are cooled and the drive motor 11 is lubricated. Therefore, even if the current temperature of the oil pump motor 12 exceeds the preset threshold, the power limiting flag is set to 0 if the duration does not exceed the first specified duration t0.

[0077] When the power limit flag is set to 1, the oil pump motor 12 is at risk of overheating and damage. Therefore, when the current temperature of the oil pump motor 12 exceeds the preset threshold and the duration reaches the first specified duration t0, the power limit flag is set to 1. To reduce the risk of damage to the oil pump motor 12, when the power limit flag is set to 1, the output current of the oil pump motor 12 is limited, controlling the oil pump motor 12 to operate under limited power; simultaneously, the output current of the drive motor 11 is controlled, limiting the maximum torque of the drive motor 11, and controlling the oil supply of the oil pump motor 12 to meet the operating requirements of the drive motor 11.

[0078] As an optional implementation, the target flow rate for the oil pump motor output is determined based on the first temperature of the rotor in the drive motor, the second temperature of the stator of the drive motor, the torque of the drive motor, and a preset algorithm, including:

[0079] From the preset rotor temperature flow table of the drive motor, determine the flow rate L1 corresponding to the first temperature, wherein the rotor temperature flow table records the correspondence between the rotor temperature and the output flow rate of the oil pump motor;

[0080] From the preset stator temperature and flow rate table of the drive motor, determine the flow rate L2 corresponding to the second temperature, wherein the stator temperature and flow rate table records the correspondence between the temperature of the stator and the output flow rate of the oil pump motor;

[0081] From the preset torque-flow table of the drive motor, determine the flow rate L3 corresponding to the current torque of the drive motor, wherein the torque-flow table records the correspondence between the torque of the drive motor and the output flow rate of the oil pump motor;

[0082] The maximum flow rate among the flow rates L1, L2, and L3 is determined as the target flow rate.

[0083] Understandably, the first temperature sensor collects the first temperature of the rotor of the drive motor 11, and according to the preset rotor temperature flow table of the drive motor 11, finds and determines the flow rate L1 of the oil required to cool the rotor at the first temperature; the second temperature sensor collects the second temperature of the stator of the drive motor 11, and according to the preset stator temperature flow table of the drive motor 11, finds and determines the flow rate L2 of the oil required to cool the stator at the second temperature; the torque sensor collects the torque of the drive motor 11, and according to the preset torque flow table of the drive motor 11, finds and determines the flow rate L3 of the oil required to lubricate the drive motor 11 at that torque.

[0084] Understandably, the amount of oil supplied by the oil pump motor 12 to the drive motor 11 must at least meet the cooling requirements of the rotor and stator of the drive motor 11 and the lubrication requirements of the drive motor 11. Therefore, by comparing the values ​​of L1, L2, and L3, the maximum value is determined as the target flow rate L of the oil pump motor 12 to meet the operating conditions of the drive motor 11.

[0085] As an optional implementation, determining the target rotational speed of the oil pump motor 12 corresponding to the target flow rate based on the power limit flag includes:

[0086] According to the preset flow rate and speed table of the oil pump motor 12, the speed V2 of the oil pump motor 12 corresponding to the target flow rate is determined. The flow rate and speed table records the correspondence between the flow rate and speed output by the oil pump motor 12.

[0087] If the power limit flag is 1, the minimum value between the maximum speed V3 and the speed V2 of the oil pump motor 12 corresponding to the preset power limit is determined as the target speed;

[0088] If the power limit flag is 0, the target speed of the oil pump motor 12 is determined to be the speed V2.

[0089] Understandably, based on the speed and flow rate table of the oil pump motor 12, the speed V2 corresponding to the oil pump motor 12 at the target flow rate L is found and determined. When the power limit flag is 0, the oil pump motor 12 can meet the cooling and lubrication requirements of the drive motor 11 under normal operation, and the target speed of the oil pump motor is determined to be V2.

[0090] When the power limit flag is 1, there is a risk of overheating damage to the oil pump motor 12. At this time, it is necessary to compare the speed V2 that meets the working conditions of the drive motor 11 and the maximum speed V3 of the oil pump motor 12 under the preset power limit, and take the minimum value as the target speed of the oil pump motor to ensure that the oil pump motor 12 works under safe conditions.

[0091] like Figure 3 As shown, this application also provides a drive motor oil cooling system control device 200, which includes at least one software function module that can be stored in a storage module or embedded in the operating system (OS) of the braking device in the form of software or firmware. The drive motor 11 and the oil pump motor 12 are used to execute the executable modules stored in the storage module, such as the software function modules and computer programs included in the drive motor 11 oil cooling system control device.

[0092] The drive motor oil cooling system control device 200 includes a detection and analysis unit 210 and a control unit 220. The functions of each unit are as follows:

[0093] Detection and analysis unit 210: used to detect the temperature of oil pump motor 12; detect the temperature of stator, rotor and torque of drive motor 11 during operation; determine the target flow rate L of oil pump motor 12 according to preset algorithm; determine the speed V2 of oil pump motor 12 corresponding to the target flow rate L; detect the status of power limit flag and determine the target output speed V of oil pump motor 12.

[0094] Control unit 220: Used to execute the received control signal, adjust the reading of the power limit flag, control the speed of the drive motor 11 according to the reading of the power limit flag, and control the oil pump motor 12 to run at the target output speed.

[0095] In this embodiment, the storage module can be, but is not limited to, random access memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, etc. In this embodiment, the storage module can be used to store the rotor temperature and flow rate meters of the drive motor 11, the stator temperature and flow rate meters of the drive motor 11, the torque and flow rate meters of the drive motor 11, and the flow rate and speed meters of the oil pump motor 12, etc. Of course, the storage module can also be used to store programs, which the processing module executes after receiving an execution instruction.

[0096] It is understood that the drive motor oil cooling system control device shown in the figure is only a structural schematic diagram, and the drive motor oil cooling system control device may also include more components than shown in the figure. The components shown in the figure can be implemented by hardware, software, or a combination thereof.

[0097] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the drive motor oil cooling system 10 and the drive motor oil cooling system control device 200 described above can be referred to the corresponding processes of each step in the aforementioned method, and will not be elaborated further here.

[0098] This application also provides a vehicle. The vehicle includes a vehicle body and the drive motor oil cooling system 10 described in the above embodiments. The drive motor oil cooling system 10 is deployed on the vehicle body. The drive motor oil cooling system 10 can be used to implement the drive motor oil cooling system control method described above, which can improve the reliability of the oil pump motor operation, thereby improving driving safety.

[0099] This application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program that, when executed on a computer, causes the computer to perform the braking control method as described in the above embodiments.

[0100] Based on the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by hardware or by using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application can be embodied in the form of a software product. The software product can be stored in a non-volatile storage medium (such as CD-ROM, USB flash drive, mobile hard drive, etc.) and includes several instructions to cause a computer device (such as a personal computer, braking device, or network device, etc.) to execute the methods described in the various implementation scenarios of this application.

[0101] In summary, this application provides a control method, apparatus, drive motor oil cooling system, vehicle, and storage medium for a drive motor oil cooling system. In this solution, when both the oil pump motor and the drive motor are operating normally, the power limit flag is adjusted based on the operating temperature of the oil pump motor. The output speed V of the oil pump motor is then determined based on the power limit flag. This allows for control of the oil pump motor's output speed, preventing damage due to overheating and improving vehicle safety.

[0102] In the embodiments provided in this application, it should be understood that the disclosed apparatus, systems, and methods can also be implemented in other ways. The apparatus, systems, and methods embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0103] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of the invention, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. A control method for a drive motor oil cooling system, characterized in that: An oil cooling system for a drive motor, comprising a drive motor and an oil pump motor, wherein the drive motor has a stator and a rotor, and the drive motor and the oil pump motor are connected via an oil circuit, the method comprising: When the current temperature of the oil pump motor does not exceed the over-temperature threshold, the power limit flag is determined based on the current temperature and the preset temperature threshold. The target flow rate for the oil pump motor is determined based on the first temperature of the rotor in the drive motor, the second temperature of the stator of the drive motor, the torque of the drive motor, and a preset algorithm. The target rotational speed of the oil pump motor corresponding to the target flow rate is determined based on the power limit flag. The oil pump motor is controlled to operate at the target speed, so as to drive the coolant in the oil circuit to cool the drive motor; The power limiting flag is determined based on the current temperature and a preset temperature threshold, including: If the current temperature is greater than or equal to the preset temperature threshold, determine whether the duration for which the current temperature is greater than or equal to the preset temperature threshold exceeds a first specified duration t0; If the duration does not exceed the first specified duration t0, the power limit flag is determined to be 0; After the duration exceeds the first specified duration t0, the oil pump motor is controlled to operate at a preset power limit, and the power limit flag is set to 1, while the maximum output torque of the drive motor is limited. Based on the first temperature of the rotor in the drive motor, the second temperature of the stator of the drive motor, the torque of the drive motor, and a preset algorithm, the target flow rate for the output of the oil pump motor is determined, including: From the preset rotor temperature flow table of the drive motor, determine the flow rate L1 corresponding to the first temperature, wherein the rotor temperature flow table records the correspondence between the rotor temperature and the output flow rate of the oil pump motor; From the preset stator temperature and flow rate table of the drive motor, determine the flow rate L2 corresponding to the second temperature, wherein the stator temperature and flow rate table records the correspondence between the temperature of the stator and the output flow rate of the oil pump motor; From the preset torque-flow table of the drive motor, determine the flow rate L3 corresponding to the current torque of the drive motor, wherein the torque-flow table records the correspondence between the torque of the drive motor and the output flow rate of the oil pump motor; The maximum flow rate among the flow rates L1, L2, and L3 is determined as the target flow rate L.

2. The control method for a drive motor oil cooling system according to claim 1, characterized in that: The power limiting flag is determined based on the current temperature and the preset temperature threshold, including: If the current temperature is less than the preset temperature threshold, the power limit flag is set to 0.

3. The method according to claim 1, characterized in that, Determining the target speed of the oil pump motor corresponding to the target flow rate based on the power limit flag includes: According to the preset flow rate and speed table of the oil pump motor, the speed V2 of the oil pump motor corresponding to the target flow rate is determined. The flow rate and speed table records the correspondence between the flow rate and speed output by the oil pump motor. If the power limit flag is 1, the minimum value between the maximum speed V3 and the speed V2 of the oil pump motor corresponding to the preset power limit is determined as the target speed. If the power limit flag is 0, the target speed of the oil pump motor is determined to be the speed V2.

4. The control method for a drive motor oil cooling system according to claim 1, characterized in that: The method further includes: When the current temperature of the oil pump motor exceeds the over-temperature threshold, a fault warning message is issued, and the oil cooling system of the drive motor is controlled to stop operating.

5. A control device for a drive motor oil cooling system, characterized in that: An oil cooling system for a drive motor, comprising a drive motor and an oil pump motor, wherein the drive motor has a stator and a rotor, and the drive motor and the oil pump motor are connected via an oil circuit, the device comprising: Detection and analysis unit: used to detect the temperature of the oil pump motor; detect the temperature of the stator and rotor of the drive motor during operation, and the torque of the drive motor; determine the target flow rate L of the oil pump motor according to a preset algorithm; determine the speed V2 of the oil pump motor corresponding to the target flow rate L; detect the status of the power limit flag and determine the target output speed of the oil pump motor. Control unit: Used to execute the received control signal, adjust the reading of the power limit flag, control the speed of the drive motor according to the reading of the power limit flag, and control the oil pump motor to run at the target output speed.

6. A drive motor oil cooling system, characterized in that: The system includes a drive motor, an oil pump motor, and a memory. The drive motor has a stator and a rotor. The drive motor and the oil pump motor are connected by an oil circuit. The memory stores a computer program. When the computer program is executed by the oil pump motor, the drive motor oil pump cooling system performs the method as described in any one of claims 1-4.

7. A vehicle, characterized in that, The vehicle includes a vehicle body and a drive motor oil cooling system as described in claim 5, wherein the drive motor oil cooling system is disposed on the vehicle.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1-4.

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