Control method and device of electric oil pump of oil-cooled powertrain of electric vehicle

Abstract

The present invention provides a control method and device for an electric oil pump of an oil-cooled powertrain of an electric vehicle, the method comprising: generating an ambient oil temperature based on an estimation strategy; determining whether the ambient oil temperature meets a working oil temperature threshold; and controlling the electric oil pump to execute a corresponding rotation speed when the ambient oil temperature meets the working oil temperature threshold. The vehicle controller adopts an electric oil pump ambient oil temperature estimation strategy to replace the sensor hardware acquisition circuit, thereby reducing the hardware cost of the powertrain. Furthermore, the method provided by the present invention can fully utilize the temperature operating range of the electric oil pump, ensure the normal operation and heat exchange of the powertrain system while minimizing damage to the electric oil pump, and achieve continuous and stable operation of the oil-cooled powertrain under more demanding working conditions.

Description

Technical Field

[0001] The present invention relates to the field of vehicle design, and in particular to a control method and device for an electric oil pump of an oil-cooled powertrain of an electric vehicle. Background Art

[0002] At present, the powertrain of electric vehicles generally adopts oil cooling, and the oil pump motor controller is integrated into the electric oil pump system. The oil pump motor controller first obtains the ambient oil temperature of the electric oil pump through the thermistor, and then determines whether the ambient oil temperature meets the temperature threshold range for the normal operation of the electric oil pump. If so, the electric oil pump is controlled to use oil as a cooling medium to continuously and stably provide it to the hybrid transmission. If not, the electric oil pump is controlled to cut off power and stop working. However, the existing oil pump control method has the following defects:

[0003] 1. The external thermistor of the electric oil pump controller is required to collect the ambient oil temperature of the oil pump, which increases the material cost and production process cost of the electric oil pump;

[0004] 2. When the ambient oil temperature of the oil pump does not meet the temperature threshold range for the normal operation of the electric oil pump, the electric oil pump is powered off and stops working. This strategy may cause the electric oil pump of the vehicle to not work in extreme environments, which may cause the vehicle to be unable to drive normally and easily cause user complaints.

[0005] In view of this, the present invention is proposed to at least partially solve the technical problems existing in the prior art. Summary of the invention

[0006] The existing control method of the electric oil pump requires an external thermistor to collect the ambient oil temperature of the oil pump, and the electric oil pump can only operate within the normal operating temperature threshold range.

[0007] According to a first aspect of the present invention, a method for controlling an electric oil pump of an oil-cooled powertrain of an electric vehicle is provided, the method comprising:

[0008] An ambient oil temperature is generated based on an estimation strategy; whether the ambient oil temperature meets a working oil temperature threshold is determined; and when the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute a corresponding speed.

[0009] Preferably, generating the ambient oil temperature based on the estimation strategy includes: acquiring the rotation speed of the electric oil pump and the operating current of the electric oil pump; and obtaining the ambient oil temperature based on the rotation speed and the operating current.

[0010] Preferably, the working oil temperature threshold comprises a low temperature threshold for derating operation of the electric oil pump, a normal working oil temperature threshold and a high temperature threshold for derating operation, and the normal working oil temperature threshold is higher than the low temperature threshold and lower than the high temperature threshold;

[0011] When the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute the corresponding speed, including: when the ambient oil temperature meets the low temperature threshold for derating operation, the electric oil pump is controlled to periodically execute the first target speed, and at the same time, the power system torque and vehicle speed are limited to ensure vehicle driving safety and prevent over-temperature failure of the powertrain; or when the ambient oil temperature meets the high temperature threshold for derating operation, the electric oil pump is controlled to periodically execute the second target speed, and at the same time, the powertrain is controlled to have zero torque to prevent further temperature increase to ensure driving safety and avoid damage to the powertrain; or when the ambient oil temperature meets the normal working oil temperature threshold, the electric oil pump is controlled to execute the corresponding speed.

[0012] Preferably, the normal operating oil temperature threshold includes a first temperature node and a second temperature node, and the first temperature node is lower than the second temperature node;

[0013] When the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute the corresponding speed, including: when the ambient oil temperature is lower than the first temperature node, the electric oil pump is controlled to execute the third target speed; or when the ambient oil temperature is higher than the second temperature node, the electric oil pump is controlled to execute the fourth target speed; or when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, the electric oil pump is controlled to execute the fifth target speed.

[0014] Preferably, when the ambient oil temperature is lower than the first temperature node, controlling the electric oil pump to execute the third target speed includes: obtaining a third target speed calibrated based on the flow demand of the power system for the cooling medium; and controlling the electric oil pump to execute the third target speed.

[0015] Preferably, when the ambient oil temperature is higher than the second temperature node, the electric oil pump is controlled to execute a fourth target speed, including: obtaining a pre-calibrated fourth target speed, wherein the fourth target speed is the maximum speed of the electric oil pump; and controlling the electric oil pump to execute the fourth target speed.

[0016] Preferably, when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, the electric oil pump is controlled to execute the fifth target speed, including: obtaining the fifth target speed calibrated in real time based on the ambient oil temperature; controlling the electric oil pump to execute the fifth target speed.

[0017] Preferably, when the ambient oil temperature meets the low temperature threshold for derating operation, controlling the electric oil pump to periodically execute the first target speed includes: obtaining a pre-calibrated first target speed; and controlling the electric oil pump to periodically execute the first target speed.

[0018] Preferably, when the ambient oil temperature meets the high temperature threshold for derating operation, controlling the electric oil pump to periodically execute the second target speed includes: obtaining a pre-calibrated second target speed; and controlling the electric oil pump to periodically execute the second target speed.

[0019] According to a second aspect of the present invention, a vehicle controller for an electric oil pump of an oil-cooled powertrain of an electric vehicle is provided, the vehicle controller comprising:

[0020] An estimation module, used to generate an ambient oil temperature based on an estimation strategy;

[0021] A judgment module, used to judge whether the ambient oil temperature meets the working oil temperature threshold;

[0022] The control module is used to control the electric oil pump to execute a corresponding speed when the ambient oil temperature meets the working oil temperature threshold.

[0023] Preferably, the estimation module is used to:

[0024] The rotation speed of the electric oil pump and the operating current of the electric oil pump are obtained; based on the rotation speed and the operating current, the ambient oil temperature is obtained.

[0025] Preferably, the working oil temperature threshold comprises a low temperature threshold for derating operation of the electric oil pump, a normal working oil temperature threshold and a high temperature threshold for derating operation, and the normal working oil temperature threshold is higher than the low temperature threshold and lower than the high temperature threshold;

[0026] The control module is used to: when the ambient oil temperature meets the low temperature threshold of derating operation, control the electric oil pump to periodically execute the first target speed, and at the same time, limit the torque of the power system and the speed to ensure the driving safety of the vehicle and prevent the powertrain from over-temperature failure; or when the ambient oil temperature meets the high temperature threshold of derating operation, control the electric oil pump to periodically execute the second target speed, and at the same time, perform zero torque control on the powertrain to prevent further temperature increase to ensure driving safety and avoid damage to the powertrain; or when the ambient oil temperature meets the normal working oil temperature threshold, control the electric oil pump to execute the corresponding speed.

[0027] Preferably, the normal operating oil temperature threshold includes a first temperature node and a second temperature node, and the first temperature node is lower than the second temperature node;

[0028] The control module is used to: control the electric oil pump to execute a third target speed when the ambient oil temperature is lower than a first temperature node; or control the electric oil pump to execute a fourth target speed when the ambient oil temperature is higher than a second temperature node; or control the electric oil pump to execute a fifth target speed when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node.

[0029] Preferably, the control module is used to: obtain a third target speed calibrated based on the flow demand of the power system for the cooling medium; and control the electric oil pump to execute the third target speed.

[0030] Preferably, the control module is used to: obtain a pre-calibrated fourth target speed, wherein the fourth target speed is the maximum speed of the electric oil pump; and control the electric oil pump to execute the fourth target speed.

[0031] Preferably, the control module is used to: obtain a fifth target speed calibrated in real time based on the ambient oil temperature; and control the electric oil pump to execute the fifth target speed.

[0032] Preferably, the control module is used to: obtain a pre-calibrated first target speed; and control the electric oil pump to periodically execute the first target speed.

[0033] Preferably, the control module is used to: obtain a pre-calibrated second target speed; and control the electric oil pump to periodically execute the second target speed.

[0034] According to a third aspect of the present invention, there is provided an electronic device, comprising: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the control method of the electric oil pump of the oil-cooled powertrain of the electric vehicle is implemented.

[0035] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, implement the control method for the electric oil pump of the oil-cooled powertrain of the electric vehicle.

[0036] In summary, the present invention provides a control method for an electric oil pump of an oil-cooled powertrain of an electric vehicle, the method comprising: generating an ambient oil temperature based on an estimation strategy; determining whether the ambient oil temperature meets a working oil temperature threshold; and controlling the electric oil pump to execute a corresponding rotation speed when the ambient oil temperature meets the working oil temperature threshold. The vehicle controller adopts an electric oil pump ambient oil temperature estimation strategy to replace the sensor hardware acquisition circuit, thereby reducing the hardware cost of the powertrain. Furthermore, the method provided by the present invention can make full use of the temperature operating range of the electric oil pump, ensure the normal operation and heat exchange of the powertrain system while minimizing damage to the electric oil pump, and achieve continuous and stable operation of the oil-cooled powertrain under more demanding working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A flow chart of a method for controlling an electric oil pump of an oil-cooled powertrain of an electric vehicle provided by an embodiment of the present invention;

[0039] Figure 2 A flow chart of a method for controlling an electric oil pump of an oil-cooled powertrain of an electric vehicle provided by an embodiment of the present invention;

[0040] Figure 3 The control object of the embodiment of the present invention includes components and control modules;

[0041] Figure 4 A structural diagram of a control device for an electric oil pump of an oil-cooled powertrain of an electric vehicle provided by an embodiment of the present invention;

[0042] Figure 5 A structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the above and other features and advantages of the present invention more clear, the present invention is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0044] In the following description, many specific details are set forth to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that specific details need not be adopted to practice the present invention. In other cases, well-known steps or operations are not described in detail to avoid obscuring the present invention.

[0045] The existing control method of the electric oil pump requires an external thermistor to collect the ambient oil temperature of the oil pump, and the electric oil pump can only operate within the normal operating temperature threshold range.

[0046] refer to Figure 1 The present invention provides a method for controlling an electric oil pump of an oil-cooled powertrain of an electric vehicle, the method comprising:

[0047] S110, generating an ambient oil temperature based on the estimation strategy.

[0048] The executor of the present invention is the vehicle controller. Compared with the oil pump motor controller in the prior art, the vehicle controller has stronger storage capacity, higher computing power and operation stability, so it is easy to realize the generation of ambient oil temperature based on the estimation strategy. The vehicle controller can obtain the speed of the electric oil pump and the working current of the electric oil pump; based on the speed and the working current, the ambient oil temperature can be obtained.

[0049] Specifically, the vehicle controller has an ambient oil temperature estimation strategy. According to the test, different electric oil pump speeds correspond to different electric oil pump operating currents at different ambient oil temperatures, and multi-condition test calibration is performed based on the test data to improve the reliability of the temperature estimation algorithm. Therefore, after the powertrain is equipped with a vehicle thermal management system, the current ambient temperature can be estimated by looking up the actual speed of the electric oil pump and the actual operating current of the electric oil pump.

[0050] S120, determining whether the ambient oil temperature meets the operating oil temperature threshold.

[0051] S130: When the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to run at a corresponding speed.

[0052] Reference Figure 2 , Figure 3 , Figure 3 Among them, EOP: electric oil pump, realizes oil pump speed control, oil pump temperature collection, fault diagnosis, etc.; VCU: vehicle controller, realizes motor torque control, oil temperature estimation, EOP control; MCU: motor controller, realizes motor torque control and stator temperature feedback. Specifically, after the vehicle controller generates the ambient oil temperature based on the estimation strategy, it can determine whether the ambient oil temperature meets the working oil temperature threshold. When the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute the corresponding speed. Among them, the working oil temperature threshold includes the low temperature threshold of the electric oil pump for derating operation, the normal working oil temperature threshold and the high temperature threshold for derating operation, and the normal working oil temperature threshold is higher than the low temperature threshold and lower than the high temperature threshold.

[0053] When the ambient oil temperature meets the low temperature threshold for derating operation, the electric oil pump is controlled to periodically execute the pre-calibrated first target speed, and at the same time, the power system torque limit and vehicle speed limit are imposed to ensure vehicle driving safety and prevent over-temperature failure of the powertrain; or when the ambient oil temperature meets the high temperature threshold for derating operation, the electric oil pump is controlled to periodically execute the pre-calibrated second target speed, and at the same time, the powertrain is subjected to zero torque control to prevent further temperature increase, so as to ensure driving safety and avoid damage to the powertrain.

[0054] Furthermore, the normal operating oil temperature threshold includes a first temperature node and a second temperature node, and the first temperature node is lower than the second temperature node; when the ambient oil temperature is lower than the first temperature node, the electric oil pump is controlled to execute the third target speed calibrated based on the flow demand of the power system for the cooling medium; or when the ambient oil temperature is higher than the second temperature node, the electric oil pump is controlled to execute the fourth target speed (the maximum speed of the electric oil pump); or when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, the electric oil pump is controlled to execute the fifth target speed calibrated in real time based on the ambient oil temperature.

[0055] When the ambient oil temperature exceeds the operating oil temperature threshold, the electric oil pump is controlled to stop working.

[0056] In some embodiments, the normal working environment oil temperature range of the electric oil pump is -30℃~120℃. When the vehicle controller estimates that the ambient oil temperature is between -30℃~120℃, the speed control strategy of the electric oil pump is as follows: set the first temperature node A and the second temperature node B within the normal working range of the ambient oil temperature, where A is less than B. When the ambient oil temperature is between -30℃~A℃ (A>-30), due to the large resistance of the oil circuit at low temperature, in order to ensure the flow demand of the power system, it is necessary to calibrate the target speed of the electric oil pump according to the flow demand of the power system for the cooling medium; when the vehicle controller estimates that the ambient oil temperature is between A℃~B℃ (B>A, B<120), the target speed of the electric oil pump is determined by actual vehicle calibration; when the vehicle controller estimates that the ambient oil temperature is between B℃~120℃, it is necessary to set the target speed of the electric oil pump to the maximum speed to ensure the heat dissipation of the powertrain system.

[0057] When the vehicle controller estimates that the ambient oil temperature is less than -30℃ and greater than -40℃ (the lowest value at which the oil pump controller can operate at a reduced rating), the vehicle controller periodically sends a smaller target speed to the electric oil pump (this cycle and target speed are required to avoid the electric water pump triggering a stall fault and an over-temperature fault). The purpose is to drive the electric oil pump with a small current to heat up the electric oil pump body. At the same time, the vehicle controller needs to limit the driving torque and speed range of the motor system, which can not only ensure that the vehicle can travel at a low speed in an extremely low temperature environment, but also allow the powertrain to heat the cooling medium through operating temperature increase, and gradually restore the powertrain cooling system to normal operating temperature (Note: the vehicle controller's torque limit and speed limit for the powertrain need to ensure vehicle driving safety and prevent the powertrain from over-temperature faults).

[0058] When the vehicle controller estimates that the ambient oil temperature is greater than 120°C and less than 145°C (the maximum temperature value for the oil pump to work at reduced rating), the vehicle controller periodically sends the target speed to the electric oil pump (the cycle time and target speed are pre-calibrated on the test bench) to achieve the basic heat dissipation function of the powertrain and prevent the electric oil pump from triggering an over-temperature shutdown fault. Under the condition of over-temperature of the cooling medium, the vehicle controller needs to perform zero torque control on the powertrain to prevent the system from further heating up, ensure driving safety, and avoid damage to the powertrain.

[0059] When the vehicle controller estimates that the ambient oil temperature is not within the above temperature range, the electric oil pump is controlled to stop working.

[0060] In summary, the method provided by the present invention,

[0061] The ambient oil temperature estimation strategy and calibration are adopted to replace the ambient oil temperature sensor and related hardware circuits, which not only saves the hardware interface resources of the controller but also reduces the manufacturing cost of the powertrain.

[0062] When the current estimated ambient oil temperature is in the abnormal working range of the electric oil pump, the vehicle controller periodically sends speed instructions to the electric oil pump (the period and speed instructions are obtained according to the bench calibration). Specifically, when the ambient oil temperature exceeds the normal working threshold range of the electric oil pump, it is necessary to distinguish whether the ambient oil temperature is too high or too low. When the ambient oil temperature is too low, the vehicle controller can control the drive motor to operate in the low-speed and low-torque area, increase the oil temperature through motor heating and mechanical agitation, and control the electric oil pump to rotate at a low speed periodically (it is necessary to consider not triggering the stall protection function) to raise the temperature of the electric oil pump body to the normal working temperature range; when the ambient oil temperature is too high, the vehicle controller performs zero torque control on the drive system, and needs to control the oil pump to rotate at a low speed periodically to ensure that the power system dissipates heat without damaging the electric oil pump. The purpose of avoiding electric oil pump failure and expanding the operating temperature range of the powertrain is achieved.

[0063] Reference Figure 4 The present invention provides a vehicle controller for an electric oil pump of an oil-cooled powertrain of an electric vehicle, the vehicle controller comprising:

[0064] The estimation module 401 is used to generate the ambient oil temperature based on the estimation strategy.

[0065] The executor of the present invention is the vehicle controller. Compared with the oil pump motor controller in the prior art, the vehicle controller has stronger storage capacity, higher computing power and operation stability, so it is easy to realize the generation of ambient oil temperature based on the estimation strategy. The vehicle controller can obtain the speed of the electric oil pump and the working current of the electric oil pump; based on the speed and the working current, the ambient oil temperature can be obtained.

[0066] Specifically, the vehicle controller has an ambient oil temperature estimation strategy. According to the test, different electric oil pump speeds correspond to different electric oil pump operating currents at different ambient oil temperatures, and multi-condition test calibration is performed based on the test data to improve the reliability of the temperature estimation algorithm. Therefore, after the powertrain is equipped with a vehicle thermal management system, the current ambient temperature can be estimated by looking up the actual speed of the electric oil pump and the actual operating current of the electric oil pump.

[0067] A judgment module 402 is used to judge whether the ambient oil temperature meets the working oil temperature threshold;

[0068] The control module 403 is used to control the electric oil pump to execute a corresponding speed when the ambient oil temperature meets the working oil temperature threshold.

[0069] Reference Figure 2 , Figure 3 , Figure 3 Among them, EOP: electric oil pump, realizes oil pump speed control, oil pump temperature collection, fault diagnosis, etc.; VCU: vehicle controller, realizes motor torque control, oil temperature estimation, EOP control; MCU: motor controller, realizes motor torque control and stator temperature feedback. Specifically, after the vehicle controller generates the ambient oil temperature based on the estimation strategy, it can determine whether the ambient oil temperature meets the working oil temperature threshold. When the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute the corresponding speed. Among them, the working oil temperature threshold includes the low temperature threshold of the electric oil pump for derating operation, the normal working oil temperature threshold and the high temperature threshold for derating operation, and the normal working oil temperature threshold is higher than the low temperature threshold and lower than the high temperature threshold.

[0070] When the ambient oil temperature meets the low temperature threshold for derating operation, the electric oil pump is controlled to periodically execute the pre-calibrated first target speed, and at the same time, the power system torque limit and vehicle speed limit are imposed to ensure vehicle driving safety and prevent over-temperature failure of the powertrain; or when the ambient oil temperature meets the high temperature threshold for derating operation, the electric oil pump is controlled to periodically execute the pre-calibrated second target speed, and at the same time, the powertrain is subjected to zero torque control to prevent further temperature increase, so as to ensure driving safety and avoid damage to the powertrain.

[0071] Furthermore, the normal operating oil temperature threshold includes a first temperature node and a second temperature node, and the first temperature node is lower than the second temperature node; when the ambient oil temperature is lower than the first temperature node, the electric oil pump is controlled to execute the third target speed calibrated based on the flow demand of the power system for the cooling medium; or when the ambient oil temperature is higher than the second temperature node, the electric oil pump is controlled to execute the fourth target speed (the maximum speed of the electric oil pump); or when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, the electric oil pump is controlled to execute the fifth target speed calibrated in real time based on the ambient oil temperature.

[0072] When the ambient oil temperature exceeds the operating oil temperature threshold, the electric oil pump is controlled to stop working.

[0073] In some embodiments, the normal working environment oil temperature range of the electric oil pump is -30℃~120℃. When the vehicle controller estimates that the ambient oil temperature is between -30℃~120℃, the speed control strategy of the electric oil pump is as follows: set the first temperature node A and the second temperature node B within the normal working range of the ambient oil temperature, where A is less than B. When the ambient oil temperature is between -30℃~A℃ (A>-30), due to the large resistance of the oil circuit at low temperature, in order to ensure the flow demand of the power system, it is necessary to calibrate the target speed of the electric oil pump according to the flow demand of the power system for the cooling medium; when the vehicle controller estimates that the ambient oil temperature is between A℃~B℃ (B>A, B<120), the target speed of the electric oil pump is determined by actual vehicle calibration; when the vehicle controller estimates that the ambient oil temperature is between B℃~120℃, it is necessary to set the target speed of the electric oil pump to the maximum speed to ensure the heat dissipation of the powertrain system.

[0074] When the vehicle controller estimates that the ambient oil temperature is less than -30℃ and greater than -40℃ (the lowest value at which the oil pump controller can operate at a reduced rating), the vehicle controller periodically sends a smaller target speed to the electric oil pump (this cycle and target speed are required to avoid the electric water pump triggering a stall fault and an over-temperature fault). The purpose is to drive the electric oil pump with a small current to heat up the electric oil pump body. At the same time, the vehicle controller needs to limit the driving torque and speed range of the motor system, which can not only ensure that the vehicle can travel at a low speed in an extremely low temperature environment, but also allow the powertrain to heat the cooling medium through operating temperature increase, and gradually restore the powertrain cooling system to normal operating temperature (Note: the vehicle controller's torque limit and speed limit for the powertrain need to ensure vehicle driving safety and prevent the powertrain from over-temperature faults).

[0075] When the vehicle controller estimates that the ambient oil temperature is greater than 120°C and less than 145°C (the maximum temperature value for the oil pump to work at reduced rating), the vehicle controller periodically sends the target speed to the electric oil pump (the cycle time and target speed are pre-calibrated on the test bench) to achieve the basic heat dissipation function of the powertrain and prevent the electric oil pump from triggering an over-temperature shutdown fault. Under the condition of over-temperature of the cooling medium, the vehicle controller needs to perform zero torque control on the powertrain to prevent the system from further heating up, ensure driving safety, and avoid damage to the powertrain.

[0076] When the vehicle controller estimates that the ambient oil temperature is not within the above temperature range, the electric oil pump is controlled to stop working.

[0077] Reference Figure 5, the present invention provides an electronic device 500, the electronic device comprising: a processor 501 and a memory 502 storing computer program instructions;

[0078] When the processor 501 executes the computer program instructions, the control method of the electric oil pump of the oil-cooled powertrain of the electric vehicle is implemented.

[0079] The present invention provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the control method of the electric oil pump of the oil-cooled powertrain of the electric vehicle is implemented.

[0080] It should be understood that the specific features, operations and details described hereinabove about the method of the present invention may also be similarly applied to the device and system of the present invention, or, vice versa. In addition, each step of the method of the present invention described above may be performed by the corresponding parts or units of the device or system of the present invention.

[0081] It should be understood that each module / unit of the device of the present invention can be implemented in whole or in part by software, hardware, firmware or a combination thereof. Each module / unit can be embedded in the processor of the computer device in the form of hardware or firmware or can be stored in the memory of the computer device in the form of software for the processor to call to perform the operation of each module / unit. Each module / unit can be implemented as an independent component or module, or two or more modules / units can be implemented as a single component or module. In one embodiment, a computer device is provided, which includes a memory and a processor, and a computer instruction executable by the processor is stored on the memory. When the computer instruction is executed by the processor, it instructs the processor to perform each step of the method of the embodiment of the present invention. The computer device can be a server, a terminal, or any other electronic device with necessary computing and / or processing capabilities in a broad sense. In one embodiment, the computer device may include a processor, a memory, a network interface, a communication interface, etc. connected by a system bus. The processor of the computer device can be used to provide necessary computing, processing and / or control capabilities. The memory of the computer device may include a non-volatile storage medium and an internal memory. An operating system, a computer program, etc. may be stored in or on the non-volatile storage medium. The internal memory can provide an environment for the operation of the operating system and computer program in the non-volatile storage medium. The network interface and communication interface of the computer device can be used to connect and communicate with external devices through the network. When the computer program is executed by the processor, the steps of the method of the present invention are executed.

[0082] The present invention may be implemented as a computer-readable storage medium having a computer program stored thereon, which causes the steps of the method of an embodiment of the present invention to be executed when executed by a processor. In one embodiment, the computer program is distributed on a plurality of computer devices or processors coupled to a network so that the computer program is stored, accessed, and executed in a distributed manner by one or more computer devices or processors. A single method step / operation, or two or more method steps / operations, may be performed by a single computer device or processor or by two or more computer devices or processors. One or more method steps / operations may be performed by one or more computer devices or processors, and one or more other method steps / operations may be performed by one or more other computer devices or processors. One or more computer devices or processors may perform a single method step / operation, or perform two or more method steps / operations.

[0083] It will be appreciated by those skilled in the art that the method steps of the present invention may be performed by instructing related hardware such as a computer device or a processor through a computer program, and the computer program may be stored in a non-temporary computer-readable storage medium, which causes the steps of the present invention to be performed when the computer program is executed. Depending on the circumstances, any reference to memory, storage, database, or other media herein may include non-volatile and / or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0084] The various technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by this specification as long as there is no contradiction in such combination.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for an electric oil pump of an oil-cooled powertrain of an electric vehicle, characterized in that: The method comprises: Generating the ambient oil temperature based on the estimation strategy includes: obtaining the rotation speed of the electric oil pump and the working current of the electric oil pump; obtaining the ambient oil temperature based on the rotation speed and the working current; Determining whether the ambient oil temperature meets the operating oil temperature threshold; In the case where the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute a corresponding speed, wherein the working oil temperature threshold includes a low temperature threshold for derating operation of the electric oil pump, a normal operating oil temperature threshold and a high temperature threshold for derating operation, and the normal operating oil temperature threshold is higher than the low temperature threshold and lower than the high temperature threshold; in the case where the ambient oil temperature meets the working oil temperature threshold, the electric oil pump is controlled to execute a corresponding speed, including: in the case where the ambient oil temperature meets the low temperature threshold for derating operation, the electric oil pump is controlled to periodically execute a first target speed, and at the same time, the power system torque and vehicle speed are limited to ensure vehicle driving safety and prevent over-temperature failure of the powertrain; or in the case where the ambient oil temperature meets the high temperature threshold for derating operation, the electric oil pump is controlled to periodically execute a second target speed speed, and at the same time, perform zero torque control on the powertrain to prevent further temperature rise to ensure driving safety and avoid damage to the powertrain; or when the ambient oil temperature meets the normal operating oil temperature threshold, control the electric oil pump to execute the corresponding speed; the normal operating oil temperature threshold includes a first temperature node and a second temperature node; when the ambient oil temperature meets the operating oil temperature threshold, control the electric oil pump to execute the first corresponding speed, including: when the ambient oil temperature is lower than the first temperature node, control the electric oil pump to execute the third target speed; or when the ambient oil temperature is higher than the second temperature node, control the electric oil pump to execute the fourth target speed; or when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, control the electric oil pump to execute the fifth target speed.

2. The control method of the electric oil pump of the oil-cooled powertrain of an electric vehicle according to claim 1, characterized in that: When the ambient oil temperature is lower than the first temperature node, controlling the electric oil pump to execute a third target speed includes: Obtaining a third target speed calibrated based on a flow demand of a cooling medium by the power system; The electric oil pump is controlled to execute the third target speed.

3. The control method of the electric oil pump of the oil-cooled powertrain of an electric vehicle according to claim 1, characterized in that: When the ambient oil temperature is higher than the second temperature node, controlling the electric oil pump to execute a fourth target speed includes: Acquiring a pre-calibrated fourth target speed, wherein the fourth target speed is a maximum speed of the electric oil pump; The electric oil pump is controlled to execute the fourth target speed.

4. The control method of the electric oil pump of the oil-cooled powertrain of an electric vehicle according to claim 1, characterized in that: When the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, controlling the electric oil pump to execute a fifth target speed includes: Acquiring a fifth target speed calibrated in real time based on the ambient oil temperature; The electric oil pump is controlled to execute the fifth target speed.

5. The control method of the electric oil pump of the oil-cooled powertrain of an electric vehicle according to claim 1, characterized in that: When the ambient oil temperature meets the low temperature threshold of the derating operation, controlling the electric oil pump to periodically execute the first target speed includes: Obtaining a pre-calibrated first target speed; The electric oil pump is controlled to periodically execute the first target speed.

6. The control method of the electric oil pump of the oil-cooled powertrain of an electric vehicle according to claim 1, characterized in that: When the ambient oil temperature meets the high temperature threshold of the derated operation, controlling the electric oil pump to periodically execute the second target speed includes: Obtaining a pre-calibrated second target speed; The electric oil pump is controlled to periodically execute the second target speed.

7. A vehicle controller for an electric oil pump of an oil-cooled powertrain of an electric vehicle, characterized in that: The vehicle controller comprises: An estimation module, used to generate an ambient oil temperature based on an estimation strategy, comprising: obtaining a rotation speed of an electric oil pump and an operating current of the electric oil pump; and obtaining the ambient oil temperature based on the rotation speed and the operating current; A judgment module, used to judge whether the ambient oil temperature meets the working oil temperature threshold; A control module, for controlling the electric oil pump to execute a corresponding speed when the ambient oil temperature meets a working oil temperature threshold, wherein the working oil temperature threshold includes a low temperature threshold for derating operation of the electric oil pump, a normal operating oil temperature threshold, and a high temperature threshold for derating operation, and the normal operating oil temperature threshold is higher than the low temperature threshold and lower than the high temperature threshold; when the ambient oil temperature meets the working oil temperature threshold, controlling the electric oil pump to execute a corresponding speed, including: when the ambient oil temperature meets the low temperature threshold for derating operation, controlling the electric oil pump to periodically execute a first target speed, and at the same time, limiting the torque of the power system and the vehicle speed to ensure vehicle driving safety and prevent over-temperature failure of the powertrain; or when the ambient oil temperature meets the high temperature threshold for derating operation, controlling the electric oil pump to periodically execute a second target speed speed, and at the same time, perform zero torque control on the powertrain to prevent further temperature rise to ensure driving safety and avoid damage to the powertrain; or when the ambient oil temperature meets the normal operating oil temperature threshold, control the electric oil pump to execute the corresponding speed; the normal operating oil temperature threshold includes a first temperature node and a second temperature node; when the ambient oil temperature meets the operating oil temperature threshold, control the electric oil pump to execute the corresponding speed, including: when the ambient oil temperature is lower than the first temperature node, control the electric oil pump to execute the third target speed; or when the ambient oil temperature is higher than the second temperature node, control the electric oil pump to execute the fourth target speed; or when the ambient oil temperature is higher than the first temperature node and lower than the second temperature node, control the electric oil pump to execute the fifth target speed.

8. An electronic device, characterized in that: The electronic device comprises: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the control method of the electric oil pump of the oil-cooled powertrain of the electric vehicle as described in any one of claims 1-6 is implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by the processor, the control method of the electric oil pump of the oil-cooled powertrain of the electric vehicle as described in any one of claims 1-6 is implemented.

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