Oil pump control method of oil cooling electric drive system, electronic equipment and storage medium

Abstract

The invention provides an oil pump control method of an oil cooling electric drive system, electronic equipment and a storage medium, and relates to the field of electric drive systems. The method comprises the steps that after a vehicle is powered on, whether a driving request is received or not is judged; when a driving request is received, the motor stator and rotor flow demand, the shaft tooth and bearing flow demand and the differential mechanism flow demand are determined according to the obtained motor rotating speed, motor torque and wheel speed difference; the motor stator and rotor flow demand, the shaft tooth and bearing flow demand and the differential mechanism flow demand are compared, and the target flow demand is determined; and according to the target flow demand, controlling the electric oil pump to discharge oil according to the target flow demand. The method fully cools and lubricates all electric drive parts, enables the rotating speed change of the electric oil pump to be stable, and prolongs the service life of the electric oil pump.

Description

Technical Field

[0001] The present application relates to the field of electric drive systems, and in particular to an oil pump control method, electronic equipment, storage medium, and computer program product of an oil-cooled electric drive system. Background Art

[0002] As an efficient cooling technology, oil-cooled electric drive system has been widely used in new energy vehicles. The oil-cooled electric drive system can adjust the circulation loop in the oil-cooled electric drive system by controlling the speed of the electric oil pump to meet the cooling and lubrication needs of the electric drive system.

[0003] At present, when the oil-cooled electric drive system in the related technology controls the speed of the electric oil pump, it usually calculates and outputs the control speed command of the electric oil pump in real time based on the vehicle speed and the radiator inlet oil temperature.

[0004] The control method determined only by vehicle speed and radiator inlet oil temperature has lag and cannot meet the flow requirements of special differential working conditions; while adjusting the oil pump speed according to real-time working conditions will result in frequent changes in the oil pump speed, which may affect its life. Summary of the invention

[0005] The purpose of the present application is to provide an oil pump control method for an oil-cooled electric drive system in response to the above-mentioned deficiencies in the prior art, so as to fully cool and lubricate the electric drive components and at the same time make the speed of the electric oil pump change smoothly, thereby increasing the life of the electric oil pump.

[0006] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0007] In a first aspect, an embodiment of the present application provides an oil pump control method for an oil-cooled electric drive system, wherein the oil-cooled electric drive system comprises: a control unit, an electric oil pump connected to the control unit, a motor, a differential, and a reducer connected to the electric oil pump, wherein the oil pump control method is executed by the control unit, and the method comprises:

[0008] When the vehicle is powered on, it is determined whether a driving request is received;

[0009] When a drive request is received, the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements are determined based on the acquired motor speed, motor torque, and wheel speed difference;

[0010] Compare the flow requirements of the motor stator and rotor, the flow requirements of the shaft gear and bearings, and the flow requirements of the differential to determine the target flow requirement;

[0011] According to the target flow requirement, the electric oil pump is controlled to discharge oil according to the target flow requirement.

[0012] The control method provided in the above embodiment breaks down the cooling and lubrication requirements of the electric drive into three groups: the motor stator and rotor, gears and bearings, and the differential, and determines the cooling and lubrication strategies for each group, thereby improving the formulation dimensions of the oil cooling strategy for the oil-cooled electric drive, and can meet the flow requirements of the special working conditions of the differential, so that all components of the electric drive are fully cooled and lubricated. Moreover, compared with the strategy of using the temperature sensor feedback temperature as the control parameter, this control method overcomes the hysteresis problem and has better robustness, and can make the speed change of the electric oil pump smooth, thereby increasing the life of the electric oil pump.

[0013] In one embodiment, when no driving request is received, the control unit sends a preset fixed flow command to the electric oil pump.

[0014] In the above implementation process, it can be ensured that there is continuous oil flow out of each nozzle, thereby preventing the electric drive from being damaged due to failure to supply oil in time when the vehicle accelerates suddenly.

[0015] In one embodiment, the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements are determined according to the acquired motor speed, motor torque, and wheel speed difference, including:

[0016] According to the acquired motor speed and a known first mapping relationship between the motor speed and the flow rate, the shaft gear and bearing flow rate requirements corresponding to the motor speed are determined.

[0017] In one embodiment, the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements are determined according to the acquired motor speed, motor torque, and wheel speed difference, including:

[0018] According to the acquired motor torque and motor speed, and a known second mapping relationship among the motor speed, motor torque and flow, the motor stator and rotor flow requirements corresponding to the motor torque and motor speed are acquired.

[0019] In one embodiment, the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements are determined according to the acquired motor speed, motor torque, and wheel speed difference, including:

[0020] According to the acquired wheel speed difference and a third mapping relationship between the known wheel speed difference and the flow rate, a differential flow rate demand corresponding to the wheel speed difference is acquired.

[0021] In the above implementation process, the method provided in the present application can quickly determine the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements through the mapping relationship between the pre-calibrated motor speed, motor torque, and wheel speed difference and the flow rate. Determining the flow requirements from multiple dimensions can make the oil quantity control strategy more perfect and ensure that all components can be adequately cooled and lubricated.

[0022] Further, in some examples, after obtaining the differential flow demand corresponding to the wheel speed difference based on the acquired wheel speed difference and the third mapping relationship between the known wheel speed difference and the flow, the method also includes: increasing the differential flow demand corresponding to the wheel speed difference by a preset value to obtain an updated differential flow demand.

[0023] When the differential is working, it takes a certain amount of time for the electric oil pump to increase the speed and output flow rate after the wheel speed difference is detected and the command is transmitted to the electric oil pump. The technical solution provided by the above embodiment can avoid the situation where the differential is insufficiently lubricated due to delayed oil supply by increasing the differential flow demand by a preset value.

[0024] In one embodiment, the method further includes: after the differential stops working, controlling the electric oil pump to continue supplying oil for a preset time.

[0025] The technical solution provided by the above embodiment ensures that the differential is adequately cooled and lubricated at every moment and throughout the entire process.

[0026] In one embodiment, comparing the motor stator and rotor flow requirements, shaft gear and bearing flow requirements, and differential flow requirements to determine the target flow requirement includes: taking the maximum value of the motor stator and rotor flow requirements, shaft gear and bearing flow requirements, and differential flow requirements as the target flow requirement.

[0027] In the above implementation process, it is ensured that all electric drive components can be fully cooled and lubricated, and the formulation dimension of the oil cooling strategy of the oil-cooled electric drive is improved.

[0028] According to a second aspect of the present application, there is provided an electronic device, comprising: a processor and a memory for storing instructions executable by the processor; the processor is configured to execute the oil pump control method of the oil-cooled electric drive system described in the above embodiment.

[0029] According to a third aspect of the present application, a computer-readable storage medium is provided, comprising a computer program, wherein the computer program can be executed by a processor to implement the oil pump control method of the oil-cooled electric drive system described in the above embodiment.

[0030] According to a fourth aspect of the present application, a computer program product is provided, including a computer program / instruction, which, when executed by a processor, implements the oil pump control method of the oil-cooled electric drive system described in the above embodiment.

[0031] The electronic device, storage medium and computer program product provided in the above embodiments decompose the cooling and lubrication requirements of the electric drive into three groups: the motor stator and rotor, gears and bearings, and differential, and determine the cooling and lubrication requirements respectively, thereby improving the formulation dimensions of the oil cooling strategy for the oil-cooled electric drive, and can meet the flow requirements of special working conditions of the differential, so that all components of the electric drive are fully cooled and lubricated. Moreover, compared with the strategy of using the temperature sensor feedback temperature as a control parameter, this control method overcomes the hysteresis problem and has better robustness, and can make the speed change of the electric oil pump smooth, thereby increasing the life of the electric oil pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the architecture of an oil-cooled electric drive system provided in one embodiment of the present application;

[0034] Figure 2 A flow chart of an oil pump control method for an oil-cooled electric drive system provided in one embodiment of the present application;

[0035] Figure 3 A cooling and lubrication flow calculation flow chart provided in an embodiment of the present application;

[0036] Figure 4 A two-dimensional representation diagram of motor speed and flow provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of a curve showing the relationship between motor speed and flow rate provided in an embodiment of the present application;

[0038] Figure 6 A schematic diagram of a three-dimensional mapping of motor speed, torque and flow provided in an embodiment of the present application;

[0039] Figure 7 A schematic diagram of a two-dimensional table a of wheel speed difference and flow rate provided in an embodiment of the present application;

[0040] Figure 8 A schematic diagram of a curve showing the relationship between wheel speed difference and flow rate provided in an embodiment of the present application;

[0041] Fig. 9 A schematic diagram of a two-dimensional table b of wheel speed difference and flow rate provided in an embodiment of the present application;

[0042] Fig.10A schematic diagram of a step-by-step mapping relationship between wheel speed difference and flow rate provided in an embodiment of the present application;

[0043] Fig.11 A schematic diagram of the relationship between time, wheel speed difference and flow rate provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0045] like Figure 1 As shown, Figure 1 It is a schematic diagram of the architecture of an oil-cooled electric drive system provided in this embodiment. The oil-cooled electric drive system includes: a control unit 7, an electric oil pump 3 connected to the control unit 7, and a cooling and lubrication component connected to the electric oil pump 3.

[0046] The control unit 7 includes: an MCU control unit (Microcontroller Unit) 71 and a vehicle control system 72, and the MCU control unit 71 and the vehicle control system 72 are connected via a CAN (Controller Area Network). The MCU control unit 71 is used to receive data from various sensors and drive the electric oil pump 3 to execute commands. The vehicle control system 72 is used to ensure that the vehicle maintains optimal stability and safety under various driving conditions.

[0047] The electric oil pump 3 includes: an EOP (Electric Oil Pump) control unit 31, a motor 32 and an oil pump 33. The EOP control unit 31 is connected to the motor 32, and the MCU control unit 71 is also connected to the EOP control unit 31 via CAN communication; the motor 32 is connected to the oil pump 33, and the EOP control unit 31 receives the control command sent by the MCU control unit 71 to control the motor 32. The motor 32 is used to provide power to the oil pump 33, so that the output flow of the oil pump 33 can be controlled.

[0048] The inlet of the electric oil pump 3 is connected to the oil suction filter 2; the oil suction filter 2 is connected to the oil storage chamber 1, and is used to filter impurities in the oil. The outlet of the electric oil pump 3 is connected to the pressure filter 4, the pressure filter 4 is connected to the cooler 5, and the cooler 5 is connected to the oil temperature sensor 6, and the oil temperature sensor 6 is used to detect the oil temperature.

[0049] The cooling and lubrication assembly includes a motor, a differential 16, and a reducer. Specifically, the motor may include a motor rotor and a bearing 14, and a motor stator 20 connected to a stator temperature sensor 21; specifically, the reducer may include a reducer bearing 15, a reducer input shaft spline 11, a reducer primary gear 12, and a reducer bearing 13.

[0050] In some embodiments, in addition to the oil temperature sensor 6 and the stator temperature sensor 21, the oil-cooled electric drive system may also include other sensors for monitoring the operating state of the electric drive system and providing data to the control unit 7 as parameters for the control unit 7 to control the electric oil pump 3. Exemplarily, other sensors may include wheel speed sensors, which transmit the monitored wheel speed difference data to the CAN, which is received by the control unit 7, and the control unit 7 transmits a control command to the electric oil pump 3. The electric oil pump 3 receives the control command to adjust the rotation speed and adjust the output flow.

[0051] It should be noted that the above scenario is for the purpose of more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution provided by the embodiment of the present application. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution provided by the embodiment of the present application is also applicable to similar technical problems.

[0052] The oil pump control method provided in the embodiment of the present application is introduced below.

[0053] like Figure 2 As shown, Figure 2 is a flow chart of an oil pump control method for an oil-cooled electric drive system provided in an embodiment of the present application. The oil pump control method can be Figure 1 The method may be performed by the MCU control unit 71 in the corresponding embodiment and may include the following steps:

[0054] Step S01: After the vehicle is powered on, determine whether a driving request is received;

[0055] Specifically, Figure 3 As shown, after the vehicle is powered on at low voltage and high voltage, the electric drive health status self-check is performed, that is, the MCU control unit 71 and the EOP control unit 31 are self-checked. If the check result shows that there is no fault code and all parameters are normal, it is determined whether the vehicle has a drive request, specifically whether the vehicle has a speed and torque request; if the check result shows that there is a fault, the fault is handled. The drive request can be sent to the MCU control unit 71 by the vehicle control system 72.

[0056] Step S02: When a drive request is received, the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements are determined according to the acquired motor speed, motor torque, and wheel speed difference.

[0057] Among them, the motor stator and rotor flow demand refers to the oil flow required for motor cooling and lubrication; the shaft gear and bearing flow demand refers to the oil flow required for shaft gear and bearing cooling and lubrication of the reducer; the differential flow demand refers to the oil flow required for differential cooling and lubrication.

[0058] In some embodiments, the above step S02 specifically includes: determining the flow requirements of the shaft gear and bearing corresponding to the motor speed according to the acquired motor speed and the first mapping relationship between the known motor speed and the flow. Acquiring the flow requirements of the motor stator and rotor corresponding to the motor torque and the motor speed according to the acquired motor torque and the motor speed and the second mapping relationship between the known motor speed, the motor torque and the flow. Acquiring the flow requirements of the differential corresponding to the wheel speed difference according to the acquired wheel speed difference and the third mapping relationship between the known wheel speed difference and the flow.

[0059] Among them, the specific determination methods of the flow requirements of the shaft gears and bearings, the flow requirements of the motor stator and rotor, and the flow requirements of the differential are detailed below and will not be repeated here.

[0060] It should be noted that the above-mentioned methods for determining flow demand are only some examples given in the embodiments of the present disclosure. In actual implementation, different methods for determining flow demand may be selected according to different actual conditions.

[0061] Step S03: comparing the flow requirements of the motor stator and rotor, the flow requirements of the shaft gear and bearings, and the flow requirements of the differential to determine the target flow requirement.

[0062] In one embodiment, the maximum value among the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements may be used as the target flow requirement.

[0063] Specifically, Figure 3 As shown, the MCU control unit 71 includes three submodules, a bearing and shaft gear flow calculation module, a motor stator and rotor flow calculation module, and a differential flow calculation module, wherein the bearing and shaft gear flow calculation module is used to calculate the shaft gear and bearing flow demand Q1, the motor stator and rotor flow calculation module is used to calculate the motor stator and rotor flow demand Q2, and the differential flow calculation module is used to calculate the differential flow demand Q3. Then, the maximum value of Q1, Q2, and Q3 is taken, recorded as Qmax, and the validity of the maximum value is verified. If the verification result is valid, Qmax is used as the target flow demand, and the MCU control unit 71 sends a flow request to the electric oil pump 3 through the CAN network.

[0064] In one embodiment of the present application, the validity of the maximum value Qmax is checked, and if the check result is invalid, invalid data processing is performed.

[0065] Step S04: According to the target flow demand, control the electric oil pump to deliver oil according to the target flow demand.

[0066] Specifically, based on the target flow rate request, the electric oil pump 3 is controlled by converting the speed obtained by the maximum flow rate Qmax and taking the converted speed as the control target. Figure 3 As shown, the MCU control unit 71 may further include an electric oil pump signal confirmation module, which may receive a feedback signal from the electric oil pump 3 to confirm whether the electric oil pump 3 discharges oil according to a target flow requirement.

[0067] In one embodiment of the present application, when the vehicle is powered on, determining whether a driving request is received further includes the following steps:

[0068] Step S05: When no driving request is received, the MCU control unit sends a preset fixed flow command to the electric oil pump.

[0069] Specifically, the MCU control unit 71 gives the EOP control unit 31 a fixed flow command Qready to prevent the electric drive from being damaged due to failure to supply oil in time when the vehicle accelerates suddenly. For example, the flow command Qready can be 3L / min, which generally depends on the size of the pipeline volume of the electric drive system to ensure that each nozzle has continuous oil flow.

[0070] The following is a detailed description of the specific methods for determining the flow requirements of shaft teeth and bearings, the flow requirements of motor stators and rotors, and the flow requirements of differentials.

[0071] In one embodiment, the shaft gear and bearing flow requirements corresponding to the motor speed are determined based on the acquired motor speed and the known first mapping relationship between the motor speed and the flow rate, specifically:

[0072] The lubrication and cooling flow of rolling elements or sliding elements such as bearings is related to the speed. Therefore, the flow rate determined by the shaft teeth and bearing requirements can be determined based on the motor speed.

[0073] For example, Figure 4 It is a two-dimensional mapping diagram of motor speed and flow rate. Figure 4 The motor speed output corresponding flow can ensure sufficient lubrication and cooling of the bearing gear. According to the relationship between motor speed and flow, check Figure 4 The flow rate that matches the flow rate requirements of the shaft gear and the bearing can be determined. For example, the cooling flow rate required at different speeds can be obtained through bench calibration tests.

[0074] In some embodiments, the flow demand of the shaft gear and bearing is calibrated in a zoned manner, that is, the motor speed is divided into multiple zones, and each zone is independently tested and adjusted for flow demand. In this way, the calibration workload can be reduced, and the flow output of the oil pump can be controlled more accurately to meet the cooling and lubrication needs of the motor under different working conditions, thereby improving the energy efficiency and reliability of the system. It helps to reduce the frequent changes in the speed of the oil pump, extend its service life, and improve the efficiency of the entire electric drive system. Exemplary, Figure 5 Is Figure 4 The relationship curve between the converted motor speed and flow rate is shown in the figure below. Figure 5 As shown, the horizontal axis is the speed of the drive motor, and the vertical axis is the cooling flow rate. When the motor speed is between 5000-8000rpm, the flow rate is a fixed value Q.

[0075] In some embodiments, the motor stator and rotor flow requirements corresponding to the motor torque and motor speed are obtained based on the obtained motor torque and motor speed, and the second mapping relationship between the known motor speed, motor torque and flow, which can be specifically implemented as follows:

[0076] For example, Figure 6 The following is a three-dimensional mapping diagram of motor speed-torque and flow rate. Figure 6 The flow rate that matches the flow rate requirement of the motor stator and rotor can be determined. For example, the cooling flow rate required under different motor speeds and torques can be obtained through bench calibration tests.

[0077] In some embodiments, Figure 6 As shown in the figure, the speed-torque flow demand is calibrated in different zones, which can reduce the calibration workload and more accurately control the flow output of the oil pump to meet the cooling and lubrication needs of the motor under different working conditions, thereby improving the energy efficiency and reliability of the system. It helps to reduce the frequent changes in the speed of the oil pump, extend its service life, and improve the efficiency of the entire electric drive system.

[0078] In some embodiments, the differential flow demand corresponding to the wheel speed difference is obtained based on the obtained wheel speed difference and the third mapping relationship between the known wheel speed difference and the flow rate, which can be specifically implemented as follows:

[0079] For example, Figure 7 It is a two-dimensional table diagram of wheel speed difference and flow rate. According to the corresponding relationship between wheel speed difference and flow rate, Figure 7 The two-dimensional table a shown in FIG. 1 can determine the flow rate that matches the flow rate requirement of the differential. For example, the cooling flow rate required under different wheel speed differences can be obtained through bench calibration tests.

[0080] In some embodiments, the differential flow demand corresponding to the wheel speed difference is increased by a preset value to obtain an updated differential flow demand, which can be specifically implemented as follows:

[0081] When the differential is working, it takes a certain amount of time for the electric oil pump to increase the speed and output flow rate after the wheel speed difference is detected. In order to avoid the situation where the differential is not lubricated enough due to delayed oil supply, the actual control curve has a larger flow rate than the differential demand curve at the same speed difference. For example, Figure 8 Is Figure 7 The relationship curve between the converted wheel speed difference and flow rate is shown in the figure below. Figure 8 As shown, a larger flow rate than the actual demand is provided to ensure that the oil can quickly reach the differential, remove the heat generated by friction in time, and reduce wear. This control strategy helps to improve the robustness of the system and ensure the reliability and life of the differential even when there is uncertainty in system parameters or under extreme working conditions.

[0082] In some embodiments, Fig. 9 As shown, the flow demand of the differential is calibrated in a partitioned manner, which can reduce the calibration workload and more accurately control the flow output of the oil pump to meet the cooling and lubrication needs of the motor under different working conditions. Fig.10 Is Fig. 9 Schematic diagram of the step mapping relationship between the converted wheel speed difference and flow rate, as shown in Fig.10 As shown, when the wheel speed difference is 10-19.9r / min, the flow rate is a fixed value Q1.

[0083] In some examples, after the differential stops working, the electric oil pump is controlled to continue supplying oil for a preset time.

[0084] Specifically, when the differential is operating, especially when experiencing slipping conditions, its internal components such as bevel gears and slotted shafts will be subject to dramatically increased friction and heat. Fig.11 As shown, even after the differential slip condition ends, in order to ensure the safety and reliability of the differential under extreme conditions, the oil supply will continue for a certain period of time (Δt) to ensure that the differential is adequately cooled and lubricated at every moment and throughout the entire process to prevent component damage caused by insufficient lubrication or insufficient cooling.

[0085] An embodiment of the present application also provides an electronic device, which may include a processor and a memory for storing processor executable instructions, and the processor is configured to implement the steps of the control method described in any of the above embodiments.

[0086] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. The computer program can be executed by a processor to complete the steps of the oil pump control method of the oil-cooled electric drive system provided by the present disclosure.

[0087] An embodiment of the present application also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the oil pump control method of the oil-cooled electric drive system provided in the present disclosure.

[0088] In summary, the technical solution provided by the embodiment of the present invention has the following advantages:

[0089] When the oil-cooled electric drive system in the prior art controls the speed of the electric oil pump, it is mostly controlled according to the rated speed of the oil pump, or the vehicle speed and the radiator inlet oil temperature, and the control speed command of the electric oil pump is calculated and output in real time.

[0090] The control is based on the rated speed of the oil pump, without considering the working conditions of the vehicle. The control of the electric oil pump has limitations, resulting in high energy consumption of the electric oil pump and obvious problems in noise, vibration and harshness (NVH). The control method determined only by vehicle speed and radiator inlet oil temperature has hysteresis and cannot meet the flow requirements of special working conditions of the differential; and the frequent changes in the oil pump speed caused by adjusting the oil pump speed according to the real-time working conditions may affect its life.

[0091] The technical solution provided by the embodiment of the present invention decomposes the cooling and lubrication requirements of the electric drive into three groups: the motor stator and rotor, gears and bearings, and differential, and determines the cooling and lubrication strategies respectively. During the operation of the electric drive, the maximum value of the three is taken as the control target of the electric oil pump, and it is no longer controlled according to the rated speed, which reduces power consumption and has higher NVH performance. At the same time, it can ensure that all components of the electric drive can be fully cooled and lubricated to meet the flow requirements of special working conditions of the differential. At the same time, the speed of the electric oil pump changes smoothly, which can increase the life of the oil pump. Moreover, compared with the control strategy that uses the temperature sensor feedback temperature as the control parameter, this control strategy can reduce the hysteresis of the existing temperature control method and has better robustness.

[0092] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely illustrative.

[0093] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0094] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0095] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for controlling an oil pump of an oil-cooled electric drive system, characterized in that: The oil-cooled electric drive system includes: a control unit, an electric oil pump connected to the control unit, a motor, a differential, and a reducer connected to the electric oil pump. The oil pump control method is executed by the control unit, and the method includes: When the vehicle is powered on, it is determined whether a driving request is received; When a drive request is received, the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements are determined based on the acquired motor speed, motor torque, and wheel speed difference; Compare the flow requirements of the motor stator and rotor, the flow requirements of the shaft gear and bearings, and the flow requirements of the differential to determine the target flow requirement; According to the target flow requirement, the electric oil pump is controlled to discharge oil according to the target flow requirement.

2. The control method according to claim 1, characterized in that: The method further comprises: When no driving request is received, the control unit sends a preset fixed flow command to the electric oil pump.

3. The control method according to claim 1, characterized in that: The method of determining the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements based on the acquired motor speed, motor torque, and wheel speed difference includes: According to the acquired motor speed and a known first mapping relationship between the motor speed and the flow rate, the shaft gear and bearing flow rate requirements corresponding to the motor speed are determined.

4. The control method according to claim 1, characterized in that: The method of determining the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements based on the acquired motor speed, motor torque, and wheel speed difference includes: According to the acquired motor torque and motor speed, and a known second mapping relationship among the motor speed, motor torque and flow, the motor stator and rotor flow requirements corresponding to the motor torque and motor speed are acquired.

5. The control method according to claim 1, characterized in that: The method of determining the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements based on the acquired motor speed, motor torque, and wheel speed difference includes: According to the acquired wheel speed difference and a third mapping relationship between the known wheel speed difference and the flow rate, a differential flow rate demand corresponding to the wheel speed difference is acquired.

6. The control method according to claim 5, characterized in that: After obtaining the differential flow demand corresponding to the wheel speed difference according to the obtained wheel speed difference and the known third mapping relationship between the wheel speed difference and the flow, the method further includes: The differential flow demand corresponding to the wheel speed difference is increased by a preset value to obtain an updated differential flow demand.

7. The control method according to claim 6, characterized in that: The method further comprises: After the differential finishes working, the electric oil pump is controlled to continue supplying oil for a preset time.

8. The control method according to claim 1, characterized in that: The comparing the flow requirements of the motor stator and rotor, the flow requirements of the shaft gear and bearings, and the flow requirements of the differential to determine the target flow requirement includes: The maximum value among the motor stator and rotor flow requirements, the shaft gear and bearing flow requirements, and the differential flow requirements is used as the target flow requirement.

9. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to execute the oil pump control method of the oil-cooled electric drive system according to any one of claims 1-8.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program can be executed by a processor to complete the oil pump control method of the oil-cooled electric drive system according to any one of claims 1 to 8.

11. A computer program product, characterized in that It includes a computer program / instruction, which, when executed by a processor, implements the oil pump control method of the oil-cooled electric drive system according to any one of claims 1 to 8.

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