Electric drive assembly cooling and lubrication system, control method, and vehicle

Abstract

The present invention relates to the technical field of new energy vehicles, and discloses an electric drive assembly cooling and lubrication system, a control method and a vehicle. The system includes an oil circuit system and a water circuit system. The oil circuit system includes a transmission oil pan, an electric drive assembly, an electronic oil pump, a first temperature-controlled three-way valve and an oil cooler; the water circuit system includes a low-temperature radiator, a battery pack, an electronic water pump, a vehicle control device and a second temperature-controlled three-way valve; the water circuit system and the oil circuit system perform heat exchange through an oil cooler; the method includes: identifying a current control mode, the control mode includes a heating mode and a cooling mode, the heating mode is used to heat the battery pack in the water circuit system, and the cooling mode is used to cool the oil circuit system; controlling the opening and closing of the ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve according to the control mode. The present invention realizes fine control of the electric drive oil temperature, thereby improving the driving efficiency and transmission efficiency of the electric drive assembly, and significantly reducing the energy loss of the electric drive assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to an electric drive assembly cooling and lubrication system, a control method, and a vehicle. Background Art

[0002] For new energy vehicles, energy consumption is a crucial metric for their survival. Low energy consumption can achieve a higher range for the same cost, or reduce vehicle costs for the same range. The electric drive assembly integrates components such as the transmission, drive motor, controller, and electronic oil pump. As the transmission unit and power source of the powertrain, the energy losses during operation account for a significant portion of the vehicle's overall energy losses. Reducing this energy loss is crucial to improving the vehicle's economic efficiency. Summary of the Invention

[0003] In view of this, the present invention provides an electric drive assembly cooling and lubrication system, a control method, and a vehicle to solve the problem of large energy loss in the electric drive assembly.

[0004] In the first aspect, the present invention provides an electric drive assembly cooling and lubrication system, including: an oil circuit system and a water circuit system, the oil circuit system includes a transmission oil pan, an electric drive assembly, an electronic oil pump, a first temperature-controlled three-way valve and an oil cooler; the water circuit system includes a low-temperature radiator, a battery pack, an electronic water pump, a vehicle control device and a second temperature-controlled three-way valve; the transmission oil pan is used to store oil, the transmission oil pan is connected to the electronic oil pump pipeline, the electronic oil pump is connected to the first end pipeline of the first temperature-controlled three-way valve, the second end of the first temperature-controlled three-way valve is connected to the electric drive assembly pipeline, the third end of the first temperature-controlled three-way valve is connected to the oil cooler pipeline, the oil cooler is connected to the electric drive assembly pipeline, the electric drive assembly is connected to the transmission The oil pan pipeline is connected; the vehicle control device and the oil cooler pipeline are connected, the oil cooler and the first end of the second temperature control three-way valve are connected, the second end of the second temperature control three-way valve is connected to the low-temperature radiator pipeline, the third end of the second temperature control three-way valve is connected to the battery pack pipeline, the low-temperature radiator and the battery pack are both connected to the electronic water pump pipeline, and the electronic water pump is connected to the vehicle control device pipeline; wherein, the oil cooler is used for heat exchange between the oil system and the water system, by controlling the opening and closing of the ports of the first temperature control three-way valve and the second temperature control three-way valve, it is used to use the heat of the oil system to heat the battery pack in the water system, and to use the cooling water of the water system to assist in cooling the oil system.

[0005] Based on the above technical means, the present invention provides an electric drive assembly cooling and lubrication system that couples the oil circuit system used to cool the electric drive assembly with the heat dissipation system used to dissipate heat from the battery and controller, and heat is exchanged between the two systems via an oil cooler. By controlling the opening and closing of different ports of the first and second temperature-controlled three-way valves, the heat from the oil circuit system is used to heat the water circuit system in heating mode, and the cold water from the water circuit system is used to cool the oil circuit system in cooling mode. This achieves precise control of the electric drive oil temperature, thereby improving the drive efficiency and transmission efficiency of the electric drive assembly and significantly reducing the energy loss of the electric drive assembly.

[0006] In an optional embodiment, it further includes: a coarse filter and a fine filter, the coarse filter pipeline is connected between the transmission oil pan and the electronic oil pump, and the fine filter pipeline is connected between the electronic oil pump and the first temperature control three-way valve.

[0007] According to the above technical means, the oil circulating in the oil system is filtered by the coarse filter and the fine filter, which further improves the quality of the oil, thereby improving the lubrication performance and cooling performance.

[0008] In an optional embodiment, it also includes a connecting oil pipe, the electric drive assembly includes a motor rotor, a motor stator, a first transmission unit and a second transmission unit; the connecting oil pipe is connected between the electronic oil pump and the first end of the first temperature control three-way valve, and is connected to the first transmission unit pipeline, the motor rotor, the motor stator and the second transmission unit are all connected to the second end pipeline of the first temperature control three-way valve, and the motor rotor, the motor stator and the second transmission unit are all connected to the oil cooler pipeline; the motor rotor, the motor stator, the first transmission unit and the second transmission unit are all connected to the transmission oil pan pipeline.

[0009] According to the above technical means, the electric drive assembly is divided into the motor rotor, motor stator, second transmission unit part that need to be cooled and the first transmission unit part that does not need to be cooled according to the needs of the electric drive assembly, which further improves the control accuracy of the cooling temperature, reduces energy loss, and reduces cooling control costs.

[0010] In second aspect, the present invention provides a cooling and lubrication control method for an electric drive assembly, the method comprising: identifying a current control mode, the control mode comprising a heating mode and a cooling mode, the heating mode being used to heat the battery pack in the water system, and the cooling mode being used to cool the oil system; controlling the opening and closing of ports of a first temperature-controlled three-way valve and a second temperature-controlled three-way valve according to the control mode.

[0011] Based on the above technical means, the present invention provides an electric drive assembly cooling and lubrication system that couples the oil circuit system used to cool the electric drive assembly with the heat dissipation system used to dissipate heat from the battery and controller, and heat is exchanged between the two systems via an oil cooler. By controlling the opening and closing of different ports of the first and second temperature-controlled three-way valves, the heat from the oil circuit system is used to heat the water circuit system in heating mode, and the cold water from the water circuit system is used to cool the oil circuit system in cooling mode. This achieves precise control of the electric drive oil temperature, thereby improving the drive efficiency and transmission efficiency of the electric drive assembly and significantly reducing the energy loss of the electric drive assembly.

[0012] In an optional embodiment, the opening and closing of the ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve are controlled according to the control mode, including: when the control mode is a heating mode, controlling the first end and the third end of the first temperature-controlled three-way valve to open, and controlling the second end of the first temperature-controlled three-way valve to close; controlling the first end and the third end of the second temperature-controlled three-way valve to open, and controlling the second end of the second temperature-controlled three-way valve to close; when the control mode is a cooling mode, controlling the first end and the second end of the second temperature-controlled three-way valve to open, and controlling the third end of the second temperature-controlled three-way valve to close; judging whether the oil temperature is greater than a preset cooling temperature threshold; if the oil temperature is greater than the preset cooling temperature threshold, controlling the first end and the third end of the first temperature-controlled three-way valve to open, and controlling the second end of the first temperature-controlled three-way valve to close; if the oil temperature is less than or equal to the preset cooling temperature threshold, controlling the first end and the second end of the first temperature-controlled three-way valve to open, and controlling the third end of the first temperature-controlled three-way valve to close.

[0013] According to the above technical means, the present invention also sets a preset cooling temperature threshold for judging whether cooling is required. In the heating mode, by controlling the first temperature-controlled three-way valve and the corresponding port of the first temperature-controlled three-way valve, the hot oil of the electric drive assembly and the cold water flowing through the battery are heat-exchanged to heat the battery in a low-temperature environment. In the cooling mode, first determine whether the current oil temperature is greater than the preset cooling temperature threshold. If it is greater than, cooling is required, and the corresponding valve port is opened to allow the cold water of the water system that is further cooled by the low-temperature radiator to heat-exchange with the hot oil of the oil system to cool the oil system. If the current oil temperature is not greater than the preset cooling temperature threshold, the oil system does not need to be cooled but only lubricated. The port corresponding to the valve does not need to be connected to the oil cooler. The oil can be directly returned to the transmission oil pan through the electric drive assembly, further improving the temperature control accuracy.

[0014] In an optional embodiment, the method also includes: when the control mode is a heating mode, controlling the electronic oil pump to operate at a maximum speed; when the control mode is a cooling mode, obtaining the current motor operating parameters; judging whether the current motor operating parameters are greater than a preset operating threshold; if the current motor operating parameters are less than or equal to the preset operating threshold, controlling the speed of the electronic oil pump to zero; if the current motor operating parameters are greater than the preset operating threshold, calculating the required oil flow rate according to the structure of the electric drive assembly; and controlling the speed of the electronic oil pump according to the required oil flow rate.

[0015] According to the above technical means, in addition to improving the electric drive and transmission efficiency, the main path to reducing energy consumption can also be achieved by reducing the low-voltage power consumption of electrical components. In the present invention, the speed of the electronic oil pump is also finely controlled according to the oil flow demand of the oil circuit system, thereby reducing the low-voltage power consumption of the electronic oil pump itself and reducing the energy consumption of the electric drive system in all aspects.

[0016] In an optional embodiment, the required oil flow is calculated according to the structure of the electric drive assembly, including: calculating the required transmission system flow according to the structures of the first transmission unit and the second transmission unit; calculating the required motor flow according to the structures of the motor rotor and the motor stator; and adding the required transmission system flow and the required motor flow to obtain the required oil flow.

[0017] Based on the above technical means, the different physical structures of the transmission unit and motor are analyzed separately to determine their respective oil requirements for lubrication and cooling. The required flow rate of the transmission system and the required flow rate of the motor are then added together to obtain the required oil flow rate, thereby improving the calculation accuracy of the oil demand of the electric drive assembly.

[0018] In an optional embodiment, the transmission system demand flow is calculated based on the structure of the first transmission unit and the second transmission unit, including: obtaining the transmission lubrication demand flow based on the current motor working parameters; querying the reducer efficiency based on the current motor working parameters; calculating the heat generation of the transmission structure based on the reducer efficiency; creating a first simulation model based on the oil cooler structure, the oil circuit structure, the structure of the first transmission unit and the second transmission unit; performing flow demand simulation through the first simulation model and the heat generation of the transmission structure to obtain the transmission cooling demand flow; and determining the transmission system demand flow based on the transmission lubrication demand flow and the transmission cooling demand flow.

[0019] According to the above technical means, the present invention performs three-dimensional modeling based on the structure of the transmission unit, then calculates the heat generated by the transmission structure through the reducer efficiency, and uses the heat generated by the transmission structure to simulate the model fluid for cooling, so as to accurately obtain the transmission cooling demand flow; at the same time, the transmission lubrication demand flow proposed by the transmission unit for lubrication is obtained by looking up the table according to the speed and torque of the motor; finally, the transmission cooling demand flow and the transmission lubrication demand flow are combined to estimate the transmission system demand flow, considering the transmission unit's demand for oil from multiple angles, thereby improving the calculation accuracy of the transmission system demand flow.

[0020] In an optional embodiment, the motor required flow is calculated according to the structure of the motor rotor and the motor stator, including: querying the motor efficiency according to the current motor operating parameters; calculating the heat generated by the motor structure according to the motor efficiency; creating a second simulation model according to the oil cooler structure, the oil circuit structure, the motor rotor and the motor stator structure; simulating the flow demand through the second simulation model and the heat generated by the motor structure to obtain the basic cooling flow of the motor; calculating the closed-loop control compensation flow through the difference between the oil temperature and the preset cooling temperature threshold; and determining the motor required flow based on the basic cooling flow of the motor and the closed-loop control compensation flow.

[0021] According to the above technical means, the present invention also performs three-dimensional modeling based on the structure of the motor, and then calculates the heat generated by the motor structure through the motor efficiency, and uses the heat generated by the motor structure to simulate the model fluid for cooling, so as to accurately obtain the motor cooling demand flow; at the same time, considering the compensation control of control systems such as PID based on the temperature difference, the closed-loop control compensation flow is calculated; finally, the motor demand flow is estimated by combining the closed-loop control compensation flow and the motor cooling demand flow, considering the motor's demand for oil from multiple angles, and improving the calculation accuracy of the motor demand flow.

[0022] In an optional embodiment, the motor required flow is determined based on the motor basic cooling flow and the closed-loop control compensation flow, including: identifying the operating condition type of the cooling mode; if it is a first operating condition, determining the motor required flow based on the sum of the motor basic cooling flow and the closed-loop control compensation flow, the first operating condition is used to represent a stable driving state of the vehicle; if it is a second operating condition, calculating the operating condition compensation flow, the second operating condition is used to represent an extreme driving state of the vehicle; determining the motor required flow based on the sum of the motor basic cooling flow, the closed-loop control compensation flow and the operating condition compensation flow.

[0023] Based on the above technical means, the present invention also adopts different cooling strategies for different operating conditions during cooling. If the vehicle is in a stable driving condition, the required motor flow rate is calculated simply by summing the motor's base cooling flow rate and the closed-loop control compensation flow rate to achieve the cooling effect. If the vehicle is in an extreme driving condition, the motor is overloaded and requires more cooling. Therefore, the operating condition compensation flow rate is also calculated to compensate for the control flow rate, thereby increasing the speed of the electronic oil pump, further improving the control accuracy of the electronic oil pump, and reducing the low-voltage power consumption of the electrical components.

[0024] In an optional embodiment, the speed of the electronic oil pump is controlled according to the required oil flow rate, including: when the required oil flow rate is greater than a preset flow threshold, controlling the electronic oil pump to operate at a maximum speed; when the required oil flow rate is less than or equal to the preset flow threshold, determining the speed of the electronic oil pump according to the proportional relationship between the required oil flow rate and the preset speed.

[0025] According to the above technical means, if the required oil flow rate is less than or equal to the preset flow rate threshold corresponding to the maximum speed of the electronic oil pump, the electronic oil pump speed is adjusted according to the required oil flow rate through proportional control. If the required oil flow rate is greater than the preset flow rate threshold, this embodiment directly controls the electronic oil pump according to the maximum speed to further accelerate the cooling efficiency and ensure the reliability of the vehicle operation.

[0026] In a third aspect, the present invention provides a vehicle comprising a processor, a memory and an electric drive assembly cooling and lubrication system, wherein the memory and the processor are communicatively connected to each other, and computer instructions are stored in the memory. The processor executes the method of the second aspect or any corresponding embodiment thereof by executing the computer instructions, thereby controlling the electric drive assembly cooling and lubrication system of the first aspect or any corresponding embodiment thereof.

[0027] The technical solution provided by the present invention has the following advantages:

[0028] (1) Based on the above technical means, the present invention provides an electric drive assembly cooling and lubrication system, which couples the oil circuit system for cooling the electric drive assembly with the heat dissipation system for dissipating heat to the battery and controller, and performs heat exchange between the two systems through an oil cooler. By controlling the opening and closing of different ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve, the heat of the oil circuit system is used to heat the water circuit system in the heating mode, and the cold water of the water circuit system is used to cool the oil circuit system in the cooling mode, thereby achieving fine control of the electric drive oil temperature, thereby improving the driving efficiency and transmission efficiency of the electric drive assembly and significantly reducing the energy loss of the electric drive assembly.

[0029] (2) According to the above technical means, the oil circulating in the oil system is filtered by a coarse filter and a fine filter, thereby further improving the quality of the oil, thereby improving the lubrication performance and cooling performance.

[0030] (3) According to the above technical means, the electric drive assembly is divided into the motor rotor, motor stator, second transmission unit part that need to be cooled and the first transmission unit part that does not need to be cooled according to the needs of the electric drive assembly, which further improves the control accuracy of the cooling temperature, reduces energy loss, and reduces the cooling control cost.

[0031] (4) According to the above technical means, the present invention also sets a preset cooling temperature threshold for judging whether cooling is required. In the heating mode, by controlling the first temperature-controlled three-way valve and the corresponding port of the first temperature-controlled three-way valve, the hot oil of the electric drive assembly and the cold water flowing through the battery are heat-exchanged to heat the battery in a low-temperature environment. In the cooling mode, first determine whether the current oil temperature is greater than the preset cooling temperature threshold. If it is greater than, cooling is required, and the corresponding valve port is opened to allow the cold water of the water system that is further cooled by the low-temperature radiator to heat-exchange with the hot oil of the oil system to cool the oil system. If the current oil temperature is not greater than the preset cooling temperature threshold, the oil system does not need to be cooled but only needs lubrication. The port corresponding to the valve does not need to be connected to the oil cooler. The oil can be directly returned to the transmission oil pan through the electric drive assembly, further improving the temperature control accuracy.

[0032] (5) According to the above technical means, in addition to improving the electric drive and transmission efficiency, the main path to reducing energy consumption can also be achieved by reducing the low-voltage power consumption of electrical components. In the present invention, the speed of the electronic oil pump is also finely controlled according to the oil flow demand of the oil circuit system, thereby reducing the low-voltage power consumption of the electronic oil pump itself and reducing the energy consumption of the electric drive system in all aspects.

[0033] (6) Based on the above technical means, the different physical structures of the transmission unit and the motor are analyzed respectively to determine their respective oil requirements for lubrication and cooling. The required flow rate of the transmission system and the required flow rate of the motor are then added together to obtain the required oil flow rate, thereby improving the calculation accuracy of the oil demand of the electric drive assembly.

[0034] (7) According to the above technical means, the present invention performs three-dimensional modeling based on the structure of the transmission unit, and then calculates the heat generated by the transmission structure through the efficiency of the reducer, and uses the heat generated by the transmission structure to simulate the model fluid for cooling, so as to accurately obtain the transmission cooling demand flow; at the same time, the transmission lubrication demand flow proposed by the transmission unit for lubrication is obtained by looking up the table according to the speed and torque of the motor; finally, the transmission cooling demand flow and the transmission lubrication demand flow are combined to estimate the transmission system demand flow, considering the transmission unit's demand for oil from multiple angles, thereby improving the calculation accuracy of the transmission system demand flow.

[0035] (8) According to the above technical means, the present invention also performs three-dimensional modeling based on the structure of the motor, and then calculates the heat generated by the motor structure through the motor efficiency, and uses the heat generated by the motor structure to simulate the cooling model fluid, so as to accurately obtain the motor cooling demand flow; at the same time, considering the compensation control of control systems such as PID based on the temperature difference, the closed-loop control compensation flow is calculated; finally, the motor demand flow is estimated by combining the closed-loop control compensation flow and the motor cooling demand flow, considering the motor's demand for oil from multiple angles, and improving the calculation accuracy of the motor demand flow.

[0036] (9) According to the above technical means, the present invention also adopts different cooling strategies for different working conditions in the cooling state. If the vehicle is in a stable driving condition, the cooling effect can be achieved by calculating the motor demand flow rate by simply adding the motor basic cooling flow rate and the closed-loop control compensation flow rate. If the vehicle is in an extreme driving condition, the motor is overloaded and requires more cooling. Therefore, the working condition compensation flow rate is also calculated to compensate for the control flow rate, thereby increasing the speed of the electronic oil pump, further improving the control accuracy of the electronic oil pump, and reducing the low-voltage power consumption of the electrical components.

[0037] (10) According to the above technical means, if the required oil flow rate is less than or equal to the preset flow rate threshold corresponding to the maximum speed of the electronic oil pump, the speed of the electronic oil pump is adjusted according to the required oil flow rate through proportional control. If the required oil flow rate is greater than the preset flow rate threshold, this embodiment directly controls the electronic oil pump according to the maximum speed to further accelerate the cooling efficiency and ensure the reliability of the vehicle operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 2 is a schematic structural diagram of a cooling and lubrication system for an electric drive assembly according to an embodiment of the present invention;

[0040] Figure 2 is a flow chart of a cooling and lubrication control method for an electric drive assembly according to an embodiment of the present invention;

[0041] Figure 3 is another flow chart of a cooling and lubrication control method for an electric drive assembly according to an embodiment of the present invention;

[0042] Figure 4is another flow chart of a cooling and lubrication control method for an electric drive assembly according to an embodiment of the present invention;

[0043] Figure 5 is a lubrication flow meter according to an embodiment of the present invention;

[0044] Figure 6 is a schematic diagram of the efficiency of a reducer according to an embodiment of the present invention;

[0045] Figure 7 is a schematic diagram of a simulation process according to an embodiment of the present invention;

[0046] Figure 8 is a schematic diagram of motor efficiency according to an embodiment of the present invention;

[0047] Figure 9 is a schematic diagram of modes and working conditions according to an embodiment of the present invention;

[0048] Figure 10 is a schematic diagram of the relationship between flow rate and speed according to an embodiment of the present invention;

[0049] Figure 11 4 is a schematic diagram of the hardware structure of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0051] For new energy vehicles, energy consumption is an important indicator that determines their survival. Low energy consumption can enable the vehicle to obtain a higher mileage at the same cost, or reduce the cost of the vehicle while achieving the same mileage. The electric drive transmission integrates the transmission, drive motor, controller, electronic oil pump, etc. As the transmission unit and power source of the power system, its energy loss during operation accounts for a very large proportion of the energy loss of the entire vehicle. If the energy loss of the electric drive system can be reduced, or the energy can be used reasonably, it will be crucial to improving the economy of the entire vehicle. There are two main ways to reduce energy consumption: 1. Improve the electric drive efficiency and transmission efficiency, and 2. Reduce the low-voltage power consumption of electrical components. The electric drive efficiency and transmission efficiency of related technologies are not high, and the control strategy for the electronic oil pump is very rough, lacking refined control, and the low-voltage power consumption is high.

[0052] According to an embodiment of the present invention, a cooling and lubrication system for an electric drive assembly is provided, such as Figure 1As shown, the system includes: an oil circuit system and a water circuit system. The oil circuit system includes a transmission oil pan 1, an electric drive assembly 0, an electronic oil pump 3, a first temperature control three-way valve 6 and an oil cooler 7; the water circuit system includes a low-temperature radiator 12, a battery pack 16, an electronic water pump 13, a vehicle control device 14 and a second temperature control three-way valve 15.

[0053] In this embodiment, the transmission oil pan 1 refers to a box for storing oil, and the stored oil is used to lubricate and cool the electric drive assembly 0. The electric drive assembly 0 is an assembly structure that integrates components such as a transmission and a drive motor. The electronic oil pump 3 is used to extract the oil from the transmission oil pan 1 and send it to the electric drive assembly 0, and then return it to the transmission oil pan 1 through the electric drive assembly 0. The oil cooler 7 is installed between the oil system and the water system and exists to perform heat exchange between the oil system and the water system. The first temperature-controlled three-way valve 6 is installed in the oil system and is used to determine whether the oil passes through the oil cooler 7 by controlling the opening or closing of each port of the first temperature-controlled three-way valve 6. The second temperature-controlled three-way valve 15 is installed in the water system and is used to determine whether the water flows through the battery or the low-temperature radiator 12 by controlling the opening and closing of each port of the second temperature-controlled three-way valve 15. The vehicle control device 14 is a vehicle circuit module that includes at least control chips such as a vehicle controller and a motor controller. The specific connection relationship of the cooling and lubrication system of the electric drive assembly 0 is as follows:

[0054] The transmission oil pan 1 is connected to the electronic oil pump 3 by a pipeline, the electronic oil pump 3 is connected to the first end A of the first temperature-controlled three-way valve 6 by a pipeline, the second end C of the first temperature-controlled three-way valve 6 is connected to the electric drive assembly 0 by a pipeline, the third end B of the first temperature-controlled three-way valve 6 is connected to the oil cooler 7 by a pipeline, the oil cooler 7 is connected to the electric drive assembly 0 by a pipeline, and the electric drive assembly 0 is connected to the transmission oil pan 1 by a pipeline;

[0055] Among them, the vehicle control device 14 is connected to the oil cooler 7 by pipeline, the oil cooler 7 is connected to the first end D of the second temperature control three-way valve 15 by pipeline, the second end E of the second temperature control three-way valve 15 is connected to the low-temperature radiator 12 by pipeline, the third end F of the second temperature control three-way valve 15 is connected to the battery pack 16 by pipeline, the low-temperature radiator 12 and the battery pack 16 are both connected to the electronic water pump 13 by pipeline, and the electronic water pump 13 is connected to the vehicle control device 14 by pipeline.

[0056] Specifically, according to the above-mentioned connection method, the embodiment of the present invention controls the opening or closing of each port of the first temperature-controlled three-way valve 6 and the second temperature-controlled three-way valve 15 through different control strategies, so that the oil of the oil circuit system can be conducted to the oil cooler 7. The heat of the oil circuit system can heat the battery pack 16 in the water circuit system, and the cooling water flowing through the low-temperature radiator 12 of the water circuit system can be sent to the oil cooler 7, thereby performing heat exchange and using cold water to assist in cooling the oil circuit system.

[0057] According to the cooling and lubrication system of the electric drive assembly 0 provided by the present invention, a solution is provided for coupling the oil circuit system for cooling the electric drive assembly 0 and the heat dissipation system for dissipating heat to the battery and the controller, and heat exchange is performed between the two systems through the oil cooler 7. By controlling the opening and closing of the first temperature-controlled three-way valve 6 and the different ports of the first temperature-controlled three-way valve 6, the heat of the oil circuit system is used to heat the water circuit system in the heating mode, and the cold water of the water circuit system is used to cool the oil circuit system in the cooling mode, thereby achieving fine control of the electric drive oil temperature. When the control accuracy of the electric drive oil temperature is higher, the technical effect of improving the driving efficiency and transmission efficiency of the electric drive assembly 0 is produced. Therefore, by optimizing the electric drive driving efficiency and transmission efficiency, the energy loss of the electric drive assembly 0 is significantly reduced, and the problem of excessive energy loss of the electric drive assembly 0 is solved.

[0058] In addition, in some optional implementations, it is also possible to cover more operating conditions through refined control of the electronic oil pump 3, flexibly adjust the flow of oil, and allow the electronic oil pump 3 to operate at low power consumption without requiring excessive flow, thereby further reducing the energy consumption of the electric drive assembly 0 by reducing the low-voltage power consumption of the electronic oil pump 3.

[0059] In some optional embodiments, the electric drive assembly cooling and lubrication system provided in an embodiment of the present invention further includes a coarse filter 2 and a fine filter 4, the coarse filter 2 pipeline is connected between the transmission oil pan 1 and the electronic oil pump 3, and the fine filter 4 pipeline is connected between the electronic oil pump 3 and the first temperature control three-way valve 6.

[0060] Specifically, in an embodiment of the present invention, the oil in the transmission oil pan 1 is preliminarily filtered by the coarse filter 2, pressurized by the electronic oil pump 3, and filtered again by the fine filter 4, which further improves the quality of the oil, thereby improving the lubrication performance and cooling performance.

[0061] In some optional embodiments, the electric drive assembly cooling and lubrication system provided by an embodiment of the present invention further includes a connecting oil pipe 5, and the electric drive assembly 0 includes a motor rotor 9, a motor stator 8, a first transmission unit 11 and a second transmission unit 10; the connecting oil pipe 5 is connected between the electronic oil pump 3 and the first end of the first temperature-controlled three-way valve 6, and is connected to the first transmission unit 11 pipeline, the motor rotor 9, the motor stator 8 and the second transmission unit 10 are all connected to the second end pipeline of the first temperature-controlled three-way valve 6, and the motor rotor 9, the motor stator 8 and the second transmission unit 10 are all connected to the oil cooler 7 pipeline; the motor rotor 9, the motor stator 8, the first transmission unit 11 and the second transmission unit 10 are all connected to the transmission oil pan 1 pipeline.

[0062] Specifically, if Figure 1As shown, the embodiment of the present invention also divides the electric drive assembly 0 into two parts according to the cooling requirements of the electric drive assembly 0. One part is a structure that needs to be cooled, including the motor rotor 9, the motor stator 8, and the second transmission unit 10, and the other part does not need to be cooled, which is the first transmission unit 11. In the embodiment of the present invention, the first transmission unit 11 and the second transmission unit 10 refer to the transmission structure composed of the transmission case and the shaft system. The connection between the motor rotor 9, the motor stator 8, the second transmission unit 10 and the transmission oil pan 1 includes both a heat exchange cooling circuit and a circuit that only lubricates but does not cool. The first transmission unit 11 is connected to the transmission oil pan 1 only through the lubrication circuit. The embodiment of the present invention further improves the control accuracy of the cooling temperature, reduces energy loss, and reduces the cooling control cost by customizing the deployment of oil circuits for different types of parts.

[0063] According to an embodiment of the present invention, an embodiment of a cooling and lubrication control method for an electric drive assembly is also provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0064] In this embodiment, a method for controlling cooling and lubrication of an electric drive assembly is provided, which can be used to control the above-mentioned cooling and lubrication system of the electric drive assembly. Figure 2 This is a flow chart of a cooling and lubrication control method for an electric drive assembly according to an embodiment of the present invention, the flow chart comprising the following steps:

[0065] Step S201, identifying the current control mode, which includes a heating mode and a cooling mode. The heating mode is used to heat the battery pack in the water system, and the cooling mode is used to cool the oil system.

[0066] Step S202 : controlling the opening and closing of the ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve according to the control mode.

[0067] Specifically, based on the electric drive assembly cooling and lubrication system provided by the present invention, the present invention provides a control method for the electric drive assembly cooling and lubrication system, so that the temperature of the two control modes, heating mode and cooling mode, can be precisely controlled. Since the electric drive assembly cooling and lubrication system couples the oil circuit system for cooling the electric drive assembly and the heat dissipation system for dissipating heat to the battery and controller, and performs heat exchange between the two systems through an oil cooler. In the embodiment of the present invention, by controlling the opening and closing of different ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve, the hot oil of the oil circuit system is conducted to the oil cooler in the heating mode, and the water circuit system is heated through heat exchange. The water circuit system passes the hot water through the battery pack position through the second temperature-controlled three-way valve, and heats the battery pack in a scenario where the external ambient temperature is low, thereby improving the power generation efficiency of the battery pack. In the cooling mode, the present invention can control the second temperature-controlled three-way valve of the water system to flow water through the low-temperature radiator, so that the circulating water in the water system is further cooled. After cooling, the cold water exchanges heat with the oil cooler and the oil system. The cooled oil in the oil system can cool the electric drive assembly, thereby realizing fine control of the oil temperature of the oil system, thereby improving the driving efficiency and transmission efficiency of the electric drive assembly and significantly reducing the energy loss of the electric drive assembly.

[0068] In some optional implementations, the above step S202 includes:

[0069] Step a1: when the control mode is the heating mode, the first end and the third end of the first temperature-controlled three-way valve are controlled to be open, and the second end of the first temperature-controlled three-way valve is controlled to be closed;

[0070] Step a2, controlling the first end and the third end of the second temperature-controlled three-way valve to be open, and controlling the second end of the second temperature-controlled three-way valve to be closed;

[0071] Specifically, the embodiment of the present invention performs lean control on the first temperature-controlled three-way valve and the second temperature-controlled three-way valve according to the oil temperature requirement for the highest electric drive efficiency, thereby improving the driving efficiency of the electric drive system and the efficiency performance of the transmission system. Figure 3As shown, when the control mode is heating, the first and third ends of the first thermostatic three-way valve are controlled to open, while the second end is closed. Simultaneously, the first and third ends of the second thermostatic three-way valve are controlled to open, while the second end is closed. Through this control scheme, the oil in the oil system is initially filtered by the coarse filter, pressurized by the electronic oil pump, and filtered again by the fine filter. One oil line is connected to the oil pipe and directly lubricates the first transmission unit before returning to the transmission oil sump. The other line flows into the first thermostatic three-way valve, which directs the oil to the oil cooler branch. After flowing through the oil cooler, the oil enters the motor stator, motor rotor, and second transmission unit, and then returns to the transmission oil sump. Cooling water in the water system is pressurized by the electronic water pump, passes through the vehicle control unit, and then to the oil cooler. It then enters the second thermostatic three-way valve. The first thermostatic three-way valve is controlled to direct the cooling water to the battery pack branch, closing the cooling branch to the low-temperature radiator. The cooling water then flows through the battery pack and returns to the electronic water pump. Therefore, through the valve port control strategy provided by the embodiment of the present invention, the heat of the oil system is transferred to the water system through the oil cooler. The water in the water system is heated by the oil cooler, and then the hot water flows through the battery pack to heat the battery, solving the problem of insufficient power generation efficiency of the battery pack in a low-temperature environment, and releasing the redundant heat of the electric drive assembly, thereby achieving precise temperature control for the electric drive assembly.

[0072] Step a3: when the control mode is the cooling mode, controlling the first end and the second end of the second temperature-controlled three-way valve to be open, and controlling the third end of the second temperature-controlled three-way valve to be closed;

[0073] Step a4, determining whether the oil temperature is greater than a preset cooling temperature threshold;

[0074] Step a5: If the oil temperature is greater than the preset cooling temperature threshold, the first end and the third end of the first temperature-controlled three-way valve are controlled to be open, and the second end of the first temperature-controlled three-way valve is controlled to be closed;

[0075] Step a6: If the oil temperature is less than or equal to the preset cooling temperature threshold, the first end and the second end of the first temperature-controlled three-way valve are controlled to be open, and the third end of the first temperature-controlled three-way valve is controlled to be closed.

[0076] Specifically, if Figure 3As shown, when the control mode is the cooling mode, the embodiment of the present invention also needs to determine whether the electric drive assembly really needs to be cooled through a preset cooling temperature threshold. When the oil temperature is greater than the preset cooling temperature threshold, it means that the oil temperature is high and the temperature of the electric drive assembly is high, so the oil circuit system needs to be cooled. The embodiment of the present invention controls the first end and the second end of the second temperature-controlled three-way valve to be open, and controls the third end of the second temperature-controlled three-way valve to be closed, so that the circulating water in the water system passes through the low-temperature radiator and then flows through the oil cooler, and the circulating water of the oil cooler is in a low-temperature state. For the oil circuit system, the first end and the third end of the first temperature-controlled three-way valve are controlled to be open, and the second end of the first temperature-controlled three-way valve is controlled to be closed, so that the oil flows through the oil cooler to cool down and then flows through the electric drive assembly to cool down the electric drive assembly. When the oil temperature is no greater than the preset cooling temperature threshold, the oil system temperature is already very low, and cooling is unnecessary even in cooling mode. Therefore, the first and second ends of the first temperature-controlled three-way valve are controlled to open, and the third end of the first temperature-controlled three-way valve is controlled to close. The oil pumped from the transmission oil pan flows directly through the first temperature-controlled three-way valve, through the electric drive assembly, and then back to the transmission oil pan, providing only lubrication. The valve port control strategy provided by the embodiments of the present invention transfers the low temperature of the water system to the oil system via the oil cooler, thereby cooling the electric drive assembly. This solves the problem of poor heat dissipation in the electric drive assembly, achieves precise temperature control for the electric drive assembly, improves its operating efficiency, and reduces energy loss.

[0077] In some optional embodiments, the electric drive assembly cooling and lubrication control method provided by the present invention further includes the following steps:

[0078] Step b1, when the control mode is the heating mode, controlling the electronic oil pump to operate at the maximum speed;

[0079] Step b2: when the control mode is cooling mode, obtain the current motor operating parameters;

[0080] Step b3, determining whether the current motor operating parameter is greater than a preset operating threshold;

[0081] Step b4: If the current motor operating parameter is less than or equal to the preset operating threshold, control the speed of the electronic oil pump to zero;

[0082] Step b5: If the current motor operating parameter is greater than the preset operating threshold, the required oil flow rate is calculated based on the structure of the electric drive assembly;

[0083] Step b6: Control the speed of the electronic oil pump according to the required oil flow rate.

[0084] Specifically, in practical applications, the main way to solve the problem of high energy consumption of electric drive assemblies is not only to improve the efficiency of electric drive and transmission, but also to reduce the low-voltage power consumption of electrical components. The relevant technology does not fully cover the working conditions of the refined control of electronic oil pumps, lacks a clear method for the oil pump flow demand, and has insufficient contribution to reducing energy consumption. In an embodiment of the present invention, a control method for an electronic oil pump is also provided, such as Figure 4 As shown, first determine whether the vehicle computer is connected to high voltage electricity. If the vehicle computer is not connected to high voltage electricity, the electric drive assembly is not working, and the speed of the electronic oil pump is set to N = 0rpm. If the vehicle is already connected to high voltage electricity, then enter the second step to determine the current control mode of the vehicle. If the current control mode is heating mode, the embodiment of the present invention controls the electronic oil pump to operate at the maximum speed, and the electronic oil pump speed N = 100% rpm, so as to quickly complete heat transfer, improve battery power generation efficiency, and reduce energy waste. If the current control mode is cooling mode, it is necessary to analyze the working state of the motor in combination with the current motor operating parameters. The motor requires more cooling flow in a high-load working state, and less cooling flow in a low-load working state. Based on this, the working state of the motor is determined by judging whether the current motor operating parameters are greater than the preset working thresholds. For example, in a specific embodiment, the motor operating parameters include the torque and speed of the motor. Then, it is determined whether the current torque T and the current speed n of the motor are respectively greater than the preset torque threshold T1 and the preset speed threshold n1 (the preset torque threshold and the preset speed threshold belong to the preset working thresholds. The preset speed threshold is the minimum speed limit requiring cooling and lubrication, which is obtained through bench or actual vehicle calibration. The preset torque threshold is the minimum torque limit requiring cooling and lubrication, which is obtained through bench or actual vehicle calibration). If n≤n1 and T≤T1, the system is in cooling mode but the heat dissipation demand is less than the threshold. In other words, the system has no cooling and lubrication demand. The electronic oil pump speed N is controlled to be 0% rpm, and no oil flow is output, thereby saving electricity.

[0085] When the current motor operating parameters are greater than the preset operating threshold, it indicates that the electric drive assembly has a cooling requirement. The solution provided by the embodiment of the present invention is to control the electronic oil pump according to the cooling flow required by the electric drive assembly. The calculation of the required oil flow is implemented through the hardware structure of the electric drive assembly, fully considering the differences in the electric drive structures of different vehicle models. The required oil flow calculated based on the hardware structure of the electric drive assembly is more suitable for the heat dissipation conditions of the current vehicle model, thereby improving the accuracy of the calculation of the required oil flow. Finally, controlling the speed of the electronic oil pump based on the calculated required oil flow can significantly improve the speed control accuracy of the electronic oil pump, thereby reducing the low-voltage power consumption of the electronic oil pump itself and comprehensively reducing the energy consumption of the electric drive system.

[0086] In some optional implementations, the above step b5 includes:

[0087] Step b51, calculating the required flow of the transmission system according to the structures of the first transmission unit and the second transmission unit;

[0088] Step b52, calculating the motor required flow rate according to the structure of the motor rotor and the motor stator;

[0089] Step b53, add the transmission system required flow rate and the motor required flow rate to obtain the oil required flow rate.

[0090] Specifically, if Figure 4 As shown, the embodiment of the present invention analyzes the different physical structures of the transmission unit and the motor respectively, determines their respective oil requirements for lubrication and cooling, and then adds the transmission system demand flow Q1 and the motor demand flow Q2 to obtain the oil demand flow, thereby improving the calculation accuracy of the electric drive assembly oil demand.

[0091] In some optional implementations, the above step b51 includes:

[0092] Step c1, obtaining the transmission lubrication required flow rate according to the current motor operating parameters;

[0093] Step c2, querying the reducer efficiency based on the current motor operating parameters;

[0094] Step c3, calculating the heat generated by the transmission structure according to the reducer efficiency;

[0095] Step c4, creating a first simulation model based on the oil cooler structure, the oil circuit structure, the first transmission unit, and the second transmission unit structure;

[0096] Step c5, performing flow demand simulation using the first simulation model and the heat generated by the transmission structure to obtain the transmission cooling demand flow;

[0097] Step c6: determining the transmission system required flow rate based on the transmission lubrication required flow rate and the transmission cooling required flow rate.

[0098] Specifically, the embodiment of the present invention calculates the transmission system demand flow Q1 according to the structure of the first transmission unit and the second transmission unit, which includes two parts. The first part is to calculate the transmission lubrication demand flow Q11 required for basic lubrication of the transmission unit (shaft system and box body), and the other part is to calculate the transmission cooling demand flow Q12 required for cooling. Among them, the transmission lubrication demand flow Q11 is obtained by calibrating the output characteristics of the traditional unit, that is, obtaining the current motor operating parameters, such as the torque and speed of the motor, and then using the current torque and speed of the motor in the following example. Figure 5 Look up the lubrication flow table shown in the figure to obtain the current transmission lubrication demand flow Q **, where * represents a subscript. For the transmission cooling demand flow Q12, the embodiment of the present invention obtains it through simulation of the control system based on the heat generated by the shaft system box. First, the reducer efficiency f is queried based on the current motor operating parameters (including but not limited to the current motor speed n and the current motor torque T), such as Figure 6 The following table shows the efficiency of the reducer. ** Indicates the efficiency data of a reducer, * indicates the subscript, the data is obtained through efficiency test, n max Represents the peak speed of the motor, and Tmax represents the peak torque of the motor. Afterwards, the queried reducer efficiency is substituted into the formula H1=(1-f)*n*T*s to calculate the heat generation of the transmission structure H1, where f represents the reducer efficiency, n represents the current speed of the motor, T represents the current torque of the motor, and s represents the duration of heat calculation, usually s is 2 seconds. Then, a first simulation model for system simulation is created based on the oil cooler structure, the oil circuit structure, the first transmission unit, and the second transmission unit structure. In this embodiment, it can be created through offline software such as AMESim. AMESim is a complex system modeling and simulation platform in multiple disciplines, which can be used for fuel injection, braking system, power transmission, hydraulic system, electromechanical system, and cooling system, etc. The embodiment of the present invention uses the heat generation of the transmission structure as an input parameter, performs flow demand simulation on the working process of the first simulation model in the software, and records the simulation results to obtain the transmission cooling demand flow. Finally, the transmission lubrication demand flow Q11 and the transmission cooling demand flow Q12 are combined to obtain the transmission system demand flow Q1. In some optional embodiments, the coefficients of these two coefficients can be adjusted based on user needs and then added together. The present invention does not impose any specific restrictions on these coefficients. For example, in this embodiment, both coefficients can be set to 1, resulting in the transmission system demand flow equal to the sum of the transmission lubrication demand flow and the transmission cooling demand flow. Based on the above technical measures, the present invention considers the transmission unit's oil requirements from multiple perspectives, improving the accuracy of the calculation of the transmission system demand flow.

[0099] In some optional implementations, the above step b52 includes:

[0100] Step d1, querying the motor efficiency based on the current motor operating parameters;

[0101] Step d2, calculating the heat generated by the motor structure according to the motor efficiency;

[0102] Step d3, creating a second simulation model based on the oil cooler structure, the oil circuit structure, the motor rotor structure, and the motor stator structure;

[0103] Step d4, performing flow demand simulation using the second simulation model and the heat generated by the motor structure to obtain a basic cooling flow of the motor;

[0104] Step d5, calculating the closed-loop control compensation flow rate by the difference between the oil temperature and the preset cooling temperature threshold;

[0105] Step d6: determining the motor required flow rate based on the motor basic cooling flow rate and the closed-loop control compensation flow rate.

[0106] Specifically, the embodiment of the present invention also conducts a multi-faceted analysis of the oil demand flow Q2 of the motor part. It mainly includes two aspects. The first aspect is similar to the transmission unit, and the motor basic cooling flow Q21 is simulated and calculated through the simulation model. The creation and calculation process of the simulation model is the same as the simulation calculation principle of the aforementioned transmission unit. The specific process is as follows Figure 7 As shown, this embodiment will not be described in detail. It should be noted that compared with the above simulation process, the difference is that the motor efficiency is queried according to the torque and speed of the motor as needed, such as Figure 8 The following table shows the motor efficiency query table. ** The formula for calculating the heat generation H2 of the motor structure based on the motor efficiency is: H2 = (1-F) / F*n*T*s, where F represents the motor efficiency, n represents the current motor speed, T represents the current motor torque, and s represents the duration of the heat generation calculation, usually 2 seconds.

[0107] In addition, in automatic control and systems, the closed-loop control compensation flow Q22 is usually calculated according to the error between the oil temperature and the preset cooling temperature threshold through closed-loop control methods such as PI, PID, fuzzy control, and neural networks. Based on this, the embodiment of the present invention also additionally calculates the closed-loop control compensation flow Q22 through the closed-loop control algorithm, and finally integrates the motor basic cooling flow Q21 and the closed-loop control compensation flow Q22 to obtain the motor demand flow Q2. The embodiment of the present invention considers the motor's demand for oil from multiple angles, thereby improving the calculation accuracy of the motor demand flow.

[0108] In some optional implementations, for the process of simulating and calculating the required flow by the above-mentioned first simulation model and the second simulation model, the embodiment of the present invention also verifies the simulation results through a cooling and lubrication test. If the verification passes, a calculation model for efficiency calculation flow demand is formed, and the calculation model is imported into the electronic oil pump controller software. If the verification fails, the simulation is performed again, wherein the cooling and lubrication test verification result data is obtained through tests such as lubrication cooling test and temperature rise test. The accuracy of the calculation of the transmission system required flow and the motor required flow is further improved through verification processing.

[0109] In some optional implementations, the above step d6 includes:

[0110] Step d61, identifying the operating condition type of the cooling mode;

[0111] Step d62: If the vehicle is in the first operating condition, the motor required flow rate is determined based on the sum of the motor basic cooling flow rate and the closed-loop control compensation flow rate. The first operating condition is used to indicate a stable vehicle driving state.

[0112] Step d63: If the vehicle is in the second operating condition, the operating condition compensation flow is calculated. The second operating condition is used to represent an extreme driving state of the vehicle.

[0113] Step d64, determining the motor required flow rate based on the sum of the motor basic cooling flow rate, the closed-loop control compensation flow rate and the working condition compensation flow rate.

[0114] Specifically, if Figure 9 As shown, in an embodiment of the present invention, the control modes of the electric drive assembly cooling and lubrication system include a heating mode and a cooling mode, and the heating mode includes stall heating, reduced efficiency heating and pulse heating, both of which are controlled by the control method of the aforementioned heating mode to control the first temperature-controlled three-way valve and the second temperature-controlled three-way valve. The cooling mode is further divided into a first working condition and a second working condition, wherein the first working condition is used to represent the stable driving state of the vehicle, and the second working condition is used to represent the extreme driving state of the vehicle, including but not limited to extreme driving conditions of users such as acceleration from 0 to 100 km / h, rapid acceleration and deceleration, continuous high speed, continuous stall, extreme heat, extreme cold, etc. In this embodiment, considering that the motor is overloaded when the vehicle is in an extreme driving state and requires more cooling, the working condition compensation flow Q23 is also calculated to compensate for the control flow, increase the speed of the electronic oil pump, further improve the control accuracy of the electronic oil pump, and reduce the low-voltage power consumption of electrical components. Therefore, under the second working condition, as Figure 4 As shown, the calculated motor demand flow is the sum of the motor basic cooling flow Q21, the closed-loop control compensation flow Q22 and the working condition compensation flow Q23.

[0115] In some optional implementations, the above step b6 includes:

[0116] Step b61: When the required oil flow rate is greater than a preset flow rate threshold, the electronic oil pump is controlled to operate at a maximum speed;

[0117] Step b62: When the required oil flow rate is less than or equal to the preset flow rate threshold, the speed of the electronic oil pump is determined according to the proportional relationship between the required oil flow rate and the preset speed.

[0118] Specifically, in cooling mode, the maximum speed of the electronic oil pump corresponds to the maximum preset flow threshold Qmax. If the calculated oil demand flow Q≤Qmax, the oil demand flow and the preset speed are proportional, and the query is as follows: Figure 10 The speed flow relationship table shown in the figure shows the speed N corresponding to the electronic oil pump. Figure 10As the required oil flow increases, the corresponding electronic oil pump speed increases. If Q ≥ Qmax, the electronic oil pump is controlled to operate at the maximum speed, that is, N = 100% rpm, to further improve cooling efficiency, ensure vehicle operation reliability, and ensure that the final electronic oil pump speed meets the cooling demand.

[0119] Through the technical solution provided by the embodiment of the present invention, the efficiency of electric drive transmission is improved through the lean control of the temperature-controlled three-way valve. At the same time, a method for forward control of the electronic oil pump is proposed, which innovates the calculation and compensation method of the flow demand of the electronic oil pump, and performs lean control on the speed of the electronic oil pump in all scenarios, effectively reducing the low-voltage power consumption of the electronic oil pump. The present invention can be widely applied to various types of electric drive products, systematically improving the transmission efficiency of the electric drive system and reducing the low-voltage power consumption, effectively increasing the mileage of the entire vehicle.

[0120] The embodiment of the present invention further provides a vehicle, such as Figure 11 As shown, the vehicle includes: one or more processors, memories, the cooling and lubrication system of the electric drive assembly of the aforementioned embodiment, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed in the vehicle, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple vehicles can be connected, with each device providing some of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system).

[0121] The processor may be a central processing unit, a network processor, or a combination thereof. The processor may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0122] The memory stores instructions that can be executed by at least one processor, so that the at least one processor executes the method shown in the above embodiment.

[0123] The memory may include a program storage area and a data storage area. The program storage area may store an operating system and applications required for at least one function; the data storage area may store data generated based on vehicle usage, etc. Furthermore, the memory may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state memory device. In some optional embodiments, the memory may optionally include memory remotely located relative to the processor, and such remote memory may be connected to the vehicle via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0124] The memory may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0125] The vehicle further includes a communication interface for the vehicle to communicate with other devices or a communication network.

[0126] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0127] A portion of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the form in which the computer program instruction exists in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc. Accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium that can be accessed by the computer.

[0128] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cooling and lubrication control method for an electric drive assembly, characterized in that: Applied to the electric drive assembly cooling and lubrication system, the electric drive assembly cooling and lubrication system includes: an oil circuit system and a water circuit system, the oil circuit system includes a transmission oil pan, an electric drive assembly, an electronic oil pump, a first temperature-controlled three-way valve and an oil cooler; the water circuit system includes a low-temperature radiator, a battery pack, an electronic water pump, a vehicle control device and a second temperature-controlled three-way valve; the transmission oil pan is used to store oil, the transmission oil pan is connected to the electronic oil pump pipeline, the electronic oil pump is connected to the first end pipeline of the first temperature-controlled three-way valve, the second end of the first temperature-controlled three-way valve is connected to the electric drive assembly pipeline, the third end of the first temperature-controlled three-way valve is connected to the oil cooler pipeline, the oil cooler is connected to the electric drive assembly pipeline, and the electric drive assembly is connected to the transmission oil pan pipeline. The vehicle control device is connected to the oil cooler pipeline, the oil cooler is connected to the first end of the second temperature-controlled three-way valve pipeline, the second end of the second temperature-controlled three-way valve is connected to the low-temperature radiator pipeline, the third end of the second temperature-controlled three-way valve is connected to the battery pack pipeline, the low-temperature radiator and the battery pack are both connected to the electronic water pump pipeline, and the electronic water pump is connected to the vehicle control device pipeline; wherein the oil cooler is used for heat exchange between the oil system and the water system, and is used to utilize the heat of the oil system to heat the battery pack in the water system by controlling the opening and closing of the ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve, and is used to utilize the cooling water of the water system to auxiliary cool the oil system; The electric drive assembly cooling and lubrication control method includes: Identifying a current control mode, where the control mode includes a heating mode and a cooling mode. The heating mode is used to heat the battery pack in the water system, and the cooling mode is used to cool the oil system. Controlling the opening and closing of ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve according to the control mode; controlling the opening and closing of ports of the first temperature-controlled three-way valve and the second temperature-controlled three-way valve according to the control mode includes: When the control mode is the heating mode, the first end and the third end of the first temperature-controlled three-way valve are controlled to be open, and the second end of the first temperature-controlled three-way valve is controlled to be closed; the first end and the third end of the second temperature-controlled three-way valve are controlled to be open, and the second end of the second temperature-controlled three-way valve is controlled to be closed; when the control mode is the cooling mode, the first end and the second end of the second temperature-controlled three-way valve are controlled to be open, and the third end of the second temperature-controlled three-way valve is controlled to be closed; it is judged whether the oil temperature is greater than the preset cooling temperature threshold; if the oil temperature is greater than the preset cooling temperature threshold, the first end and the third end of the first temperature-controlled three-way valve are controlled to be open, and the second end of the first temperature-controlled three-way valve is controlled to be closed; if the oil temperature is less than or equal to the preset cooling temperature threshold, the first end and the second end of the first temperature-controlled three-way valve are controlled to be open, and the third end of the first temperature-controlled three-way valve is controlled to be closed; The method also includes: when the control mode is a heating mode, controlling the electronic oil pump to operate at a maximum speed; when the control mode is a cooling mode, obtaining current motor operating parameters; judging whether the current motor operating parameters are greater than a preset operating threshold; if the current motor operating parameters are less than or equal to the preset operating threshold, controlling the speed of the electronic oil pump to zero; if the current motor operating parameters are greater than the preset operating threshold, calculating the required oil flow rate according to the structure of the electric drive assembly; and controlling the speed of the electronic oil pump according to the required oil flow rate.

2. The method according to claim 1, characterized in that The required oil flow rate is calculated according to the structure of the electric drive assembly, including: Calculating the required flow of the transmission system according to the structures of the first transmission unit and the second transmission unit; Calculate the motor's required flow rate based on the structure of the motor rotor and stator; The required flow rate of the transmission system and the required flow rate of the motor are added together to obtain the required flow rate of the oil.

3. The method according to claim 2, characterized in that The step of calculating the required flow of the transmission system according to the structures of the first transmission unit and the second transmission unit includes: Obtaining the required transmission lubrication flow rate according to the current motor operating parameters; querying the reducer efficiency according to the current motor operating parameters; Calculating the heat generated by the transmission structure based on the efficiency of the reducer; Creating a first simulation model based on the oil cooler structure, the oil circuit structure, the first transmission unit, and the second transmission unit structure; Performing flow demand simulation based on the first simulation model and the heat generated by the transmission structure to obtain a transmission cooling demand flow; The transmission system required flow rate is determined based on the transmission lubrication required flow rate and the transmission cooling required flow rate.

4. The method according to claim 2, characterized in that The calculation of the motor required flow rate according to the structure of the motor rotor and the motor stator includes: querying the motor efficiency according to the current motor operating parameters; Calculating the heat generated by the motor structure according to the motor efficiency; Creating a second simulation model based on the oil cooler structure, the oil circuit structure, the motor rotor, and the motor stator structure; Perform flow demand simulation based on the second simulation model and the heat generated by the motor structure to obtain a basic cooling flow of the motor; Calculating a closed-loop control compensation flow rate according to a difference between the oil temperature and the preset cooling temperature threshold; The motor required flow is determined based on the motor basic cooling flow and the closed-loop control compensation flow.

5. The method according to claim 4, characterized in that The determining the motor required flow rate based on the motor basic cooling flow rate and the closed-loop control compensation flow rate includes: Identifying the operating condition type of the cooling mode; If it is the first operating condition, the motor required flow is determined according to the sum of the motor basic cooling flow and the closed-loop control compensation flow, and the first operating condition is used to represent a state where the vehicle is running stably; If it is the second operating condition, then the operating condition compensation flow is calculated, and the second operating condition is used to represent the extreme driving state of the vehicle; The motor required flow is determined according to the sum of the motor basic cooling flow, the closed-loop control compensation flow and the working condition compensation flow.

6. The method according to claim 1, characterized in that The controlling the rotation speed of the electronic oil pump according to the required oil flow rate includes: When the required oil flow rate is greater than a preset flow threshold, controlling the electronic oil pump to operate at a maximum speed; When the required oil flow rate is less than or equal to a preset flow rate threshold, the rotational speed of the electronic oil pump is determined according to a proportional relationship between the required oil flow rate and a preset rotational speed.

7. The method according to claim 1, characterized in that The electric drive assembly cooling and lubrication system also includes: a coarse filter and a fine filter, the coarse filter pipeline is connected between the transmission oil pan and the electronic oil pump, and the fine filter pipeline is connected between the electronic oil pump and the first temperature control three-way valve.

8. The method according to claim 1, characterized in that The electric drive assembly cooling and lubrication system also includes a connecting oil pipe, and the electric drive assembly includes a motor rotor, a motor stator, a first transmission unit and a second transmission unit; the connecting oil pipe is connected between the electronic oil pump and the first end of the first temperature control three-way valve, and is connected to the first transmission unit pipeline, the motor rotor, the motor stator and the second transmission unit are all connected to the second end pipeline of the first temperature control three-way valve, and the motor rotor, the motor stator and the second transmission unit are all connected to the oil cooler pipeline; the motor rotor, the motor stator, the first transmission unit and the second transmission unit are all connected to the transmission oil pan pipeline.

9. A vehicle, characterized in that: The invention comprises a processor, a memory and an electric drive assembly cooling and lubrication system, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 8 by executing the computer instructions, thereby controlling the electric drive assembly cooling and lubrication system.

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