Method and system for controlling rotating speed of electronic oil pump of dual-motor hybrid power system and vehicle

Abstract

The invention discloses a rotating speed control method and system for an electronic oil pump of a dual-motor hybrid power system and a vehicle, relates to the technical field of vehicle energy, and is used for solving the problem that the power consumption of the electronic oil pump is high in the related art. The method comprises the steps that if a motor does not have a locked-rotor fault, the temperature of the motor and the temperature of lubricating oil in an oil pan are collected; if the temperature of the lubricating oil is larger than or equal to a preset first temperature threshold value and the temperature of the motor is smaller than or equal to a preset second temperature threshold value, the cooling demand flow of the motor, the shaft tooth lubricating flow and the actual output flow of a mechanical oil pump under the current working condition are obtained; obtaining the required total flow according to the cooling required flow and the shaft tooth lubricating flow of the motor; if the difference value between the required total flow and the actual output flow is larger than zero, the rotating speed of the electronic oil pump is adjusted and controlled according to the difference value and the lubricating oil temperature.

Description

Technical Field

[0001] The present application relates to the field of vehicle energy technology, and in particular to a method, system and vehicle for controlling the speed of an electronic oil pump in a dual-motor hybrid system. Background Art

[0002] With the continuous development of hybrid and electric vehicle technologies, the extended-range electric drive system with a dual-motor hybrid architecture has become the mainstream architecture of extended-range hybrid vehicles with its low fuel consumption and high performance. Under the current development trend, high-speed, high-efficiency, high-integration and high-power density hybrid systems have become the main direction and consensus of drive system development. However, with the continuous increase in motor power density and operating speed, the resulting thermal management problems have become more and more prominent, which will affect the operating efficiency of the motor, shorten its service life, and even endanger safety. Therefore, it is particularly important to ensure that the motor operates stably within the set temperature range to avoid the risk of overheating.

[0003] In the related art, in order to achieve this goal, when the motor temperature exceeds the set temperature range, the electronic oil pump operating speed is increased according to the empirical value, that is, the oil supply flow of the electronic oil pump is increased to cool the vehicle motor. This control method is simple and has low development cost, but it also leads to high power consumption of the electronic oil pump. Summary of the invention

[0004] Based on this, a method, system and vehicle for controlling the speed of an electronic oil pump in a dual-motor hybrid system are provided to solve the problem of high power consumption of the electronic oil pump in the related art.

[0005] In a first aspect, the present application provides a method for controlling the speed of an electronic oil pump of a dual-motor hybrid system, the method comprising:

[0006] If the motor does not have a stall fault, collect the motor temperature and the lubricating oil temperature in the oil pan;

[0007] If the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold, then obtaining the cooling demand flow rate, shaft gear lubrication flow rate, and actual output flow rate of the mechanical oil pump of the motor under the current working condition;

[0008] Obtaining a required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear;

[0009] If the difference between the required total flow rate and the actual output flow rate is greater than zero, the rotation speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0010] In some embodiments, the method further comprises:

[0011] If the lubricating oil temperature is less than the first temperature threshold, and the motor temperature is less than or equal to the second temperature threshold, obtaining the shaft gear lubrication flow and the actual output flow of the mechanical oil pump under the current working condition;

[0012] According to the shaft gear lubrication flow, a required total flow is obtained;

[0013] If the difference between the required total flow rate and the actual output flow rate is greater than zero, the rotation speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0014] In some embodiments, the method further comprises:

[0015] If the motor temperature is greater than the second temperature threshold, the speed of the electronic oil pump is regulated to be a preset maximum speed.

[0016] In some embodiments, the method further comprises:

[0017] If the motor is blocked, the speed of the electronic oil pump is adjusted to a preset maximum speed.

[0018] In some embodiments, obtaining the cooling demand flow of the motor under the current working condition includes:

[0019] Obtaining the speed and torque of the motor under the current working condition;

[0020] Calculating the heat dissipation of the motor according to the rotational speed and torque;

[0021] The required cooling flow of the motor is calculated according to the heat dissipation of the motor.

[0022] In some embodiments, the motor includes a first motor and a second motor;

[0023] The step of obtaining the required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear comprises:

[0024] Obtaining a preset flow distribution coefficient, wherein the flow distribution coefficient includes a first motor flow distribution coefficient, a second motor flow distribution coefficient, and a shaft gear flow distribution coefficient;

[0025] Obtaining a first total flow rate according to the first motor flow distribution coefficient and the cooling demand flow rate of the first motor;

[0026] Obtaining a second total flow rate according to the second motor flow distribution coefficient and the cooling demand flow rate of the second motor;

[0027] Obtaining a third total flow rate according to the shaft-tooth flow distribution coefficient and the shaft-tooth lubrication flow rate;

[0028] The maximum value among the first total flow, the second total flow and the third total flow is used as the required total flow.

[0029] In some embodiments, obtaining the actual output flow of the mechanical oil pump under the current working condition includes:

[0030] Obtaining the rotation speed of the mechanical oil pump;

[0031] According to the lubricating oil temperature and the rotation speed of the mechanical oil pump, the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump are obtained;

[0032] The actual output flow of the mechanical oil pump is obtained by calculation according to the volumetric efficiency and theoretical oil supply flow of the mechanical oil pump.

[0033] In some embodiments, regulating the speed of the electronic oil pump according to the difference and the lubricating oil temperature includes:

[0034] Acquiring the volumetric efficiency of the electronic oil pump according to the lubricating oil temperature;

[0035] Calculating a theoretical oil supply flow rate of the electronic oil pump based on the difference and the volumetric efficiency of the electronic oil pump;

[0036] The rotation speed of the electronic oil pump is obtained according to the lubricating oil temperature and the theoretical oil supply flow rate of the electronic oil pump.

[0037] In a second aspect, the present application provides a dual-motor hybrid system electronic oil pump speed control system, the system comprising:

[0038] A collection module is used to collect the temperature of the motor and the temperature of the lubricating oil in the oil pan if the motor does not have a stall fault;

[0039] an acquisition module, configured to acquire the cooling demand flow rate of the motor, the shaft gear lubrication flow rate, and the actual output flow rate of the mechanical oil pump under the current working condition if the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold;

[0040] A calculation module, used for obtaining a required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear;

[0041] A control module is used to control the rotation speed of the electronic oil pump according to the difference between the required total flow and the actual output flow if the difference between the required total flow and the actual output flow is greater than zero.

[0042] In a third aspect, the present application provides a vehicle, comprising the dual-motor hybrid system electronic oil pump speed control system of the second aspect described above.

[0043] In a fourth aspect, the present application provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for controlling the electronic oil pump speed of a dual-motor hybrid system according to the first aspect is implemented.

[0044] In a fifth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for controlling the electronic oil pump speed of a dual-motor hybrid system according to the first aspect above is implemented.

[0045] The above-mentioned dual-motor hybrid system electronic oil pump speed control method, system and vehicle calculate the difference in oil volume between the required total flow and the actual output flow of the mechanical oil pump. The difference in oil volume is replenished by the electronic oil pump, so that the electronic oil pump can meet the required total flow volume at the lowest speed, reduce the power consumption of the electronic oil pump, and thus achieve the purpose of energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of a hydraulic oil circuit architecture of a dual-motor hybrid system provided in an embodiment of the present application;

[0047] Figure 2 A schematic flow chart of a method for controlling the speed of an electronic oil pump in a dual-motor hybrid system provided in an embodiment of the present application;

[0048] Figure 3 A flowchart of a method for controlling the speed of an electronic oil pump in a dual-motor hybrid system according to an embodiment of the present application;

[0049] Figure 4 A flowchart of a method for calculating total demand flow provided in an embodiment of the present application;

[0050] Figure 5 A structural block diagram of an electronic oil pump speed control system for a dual-motor hybrid system provided in an embodiment of the present application;

[0051] Figure 6 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application;

[0052] Figure 7 An internal structure diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The specific operating methods in the method embodiments can also be applied to device embodiments or system embodiments. It should be noted that in the description of the present application, "multiple" is understood as "at least two". "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, and A and B exist, and B exists alone. A is connected to B, which can represent: A is directly connected to B and A is connected to B through C. In addition, in the description of the present application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0054] In the technical solution of this application, the acquisition, transmission, storage, and use of data are in compliance with the requirements of relevant national laws and regulations.

[0055] Before introducing the electronic oil pump speed control method for a dual-motor hybrid system provided in an embodiment of the present application, in order to facilitate understanding, the technical background of the embodiment of the present application is first introduced in detail.

[0056] In the related art, in order to ensure that the motor operates stably within the set temperature range, when the motor temperature exceeds the set temperature range, the electronic oil pump operating speed is increased according to the empirical value, that is, the oil supply flow of the electronic oil pump is increased to cool the vehicle motor. This control method is simple and has low development cost, but it also leads to high power consumption of the electronic oil pump.

[0057] In view of this, the embodiments of the present application provide a method, system and vehicle for controlling the speed of an electronic oil pump in a dual-motor hybrid system, so as to solve the problem of high power consumption of the electronic oil pump in the related art.

[0058] The following is a brief introduction to the dual-motor hybrid system in the embodiment of the present application, wherein the dual-motor hybrid system described below is only used to illustrate the embodiment of the present application and is not intended to be limiting. In specific implementation, the technical solution provided in the embodiment of the present application can be flexibly applied according to actual needs.

[0059] The electronic oil pump speed control method for a dual-motor hybrid system provided in the embodiment of the present application can be applied to Figure 1 The hydraulic oil circuit of the dual-motor hybrid system shown includes an electronic oil pump 10 and a mechanical oil pump 11. The first motor may be a P1 motor, and the second motor may be a P3 motor, which drives the mechanical oil pump 11. The P1 motor is generally referred to as an integrated intelligent starter generator, which has the functions of starting and generating electricity; the P3 motor can directly drive the wheels to achieve pure electric drive, but cannot be used to start the engine and usually needs to be used in conjunction with other motors or generators.

[0060] For example, Figure 1 The oil flow direction of the lubricating oil in the hydraulic oil circuit of the dual-motor hybrid system starts from the oil pan, passes through the filter, and reaches the electronic oil pump 10 and the mechanical oil pump 11 respectively. Then, it reaches the oil cooler through the electronic oil pump 10, and reaches the oil cooler through the mechanical oil pump 11 and the filter, and then passes through the fine filter. According to the distribution relationship of the motor and shaft gear flow in the hydraulic oil circuit, it is distributed to the shaft gear lubrication, the first motor cooling and the second motor cooling, and finally flows back into the oil pan to achieve circulation.

[0061] This will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0062] Figure 2 The present invention provides a flow chart of a dual-motor hybrid system electronic oil pump speed control method, which can be executed by a dual-motor hybrid system electronic oil pump speed control system, which can be implemented by software, hardware, or a combination of software and hardware. Figure 2 As shown, the process includes the following steps:

[0063] S201, if the motor does not have a stall fault, collect the motor temperature and the lubricating oil temperature in the oil pan;

[0064] Among them, the motor temperature and the lubricating oil temperature in the oil pan can be obtained through the temperature sensor.

[0065] S202, if the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold, obtaining the motor cooling demand flow, shaft gear lubrication flow, and actual output flow of the mechanical oil pump under the current working condition;

[0066] Among them, the mechanical oil pump is set as follows Figure 1 In the hydraulic oil circuit of the dual-motor hybrid system shown in FIG. 1 , in this embodiment, the temperature of the lubricating oil in the oil pan is used as the operating temperature of the hybrid box, the first temperature threshold is the preset minimum temperature of the electric drive system, and the second temperature threshold is the preset maximum temperature of the motor.

[0067] It is understandable that when the external ambient temperature is very low and the vehicle has been parked for a long time, the temperature inside the hybrid box can be reduced to less than the first temperature threshold.

[0068] In a low temperature environment, the properties of the magnetic materials in the motor will change, the magnetization degree of the magnet will decrease, resulting in a decrease in the magnetic flux density, thereby reducing the output power of the motor. In addition, the magnetic permeability of the core material will also be affected by temperature, further reducing the efficiency of the motor. On the other hand, the electrical conductivity of the motor is also subject to temperature. At low temperatures, the resistance increases, and the flow of current in the metal conductor will be hindered, which will also affect the efficiency of the motor.

[0069] Therefore, in a low-temperature environment, for the vehicle just started, the hybrid box is in a low-temperature environment, and the lubricating oil temperature is very low. The motor heat dissipation needs can be ignored, and only the hybrid box shaft gear lubrication needs can be considered. This design ensures that the hybrid box can work normally on the one hand, and on the other hand, it allows the motor to heat up quickly while meeting the lubrication requirements, thereby improving the motor's working efficiency. Since only the hybrid box shaft gear lubrication flow requirements need to be met under this condition, the total flow required for lubricating oil is low, and the electronic oil pump only needs to work at a lower speed or not work, thereby saving power loss.

[0070] S203, obtaining a required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear;

[0071] S204: If the difference between the required total flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0072] The electronic oil pump is arranged in Figure 1 In the hydraulic oil circuit of the dual-motor hybrid system shown.

[0073] Optionally, if the difference between the required total flow and the actual output flow is less than or equal to zero, the speed of the electronic oil pump 10 is adjusted to zero, that is, the electronic oil pump 10 does not need to be powered on to work, and the power consumption of the electronic oil pump 10 is zero.

[0074] In the embodiment of the present application, the motor stall fault, the motor temperature, and the lubricating oil temperature in the oil pan will affect the output of the electronic oil pump 10. Therefore, before adjusting the speed of the electronic oil pump 10 according to the actual output flow of the mechanical oil pump 11, the motor stall fault, the motor temperature, and the lubricating oil temperature in the oil pan should be judged first. Figure 3 As shown, it is a flowchart of a method for controlling the speed of an electronic oil pump of a dual-motor hybrid system provided by an embodiment of the present application, including:

[0075] S301, determine whether the motor has a shutdown fault, if so, proceed to S306; if not, proceed to S302.

[0076] S302, determine whether the motor has a stall fault, if so, proceed to S307; if not, proceed to S303.

[0077] Exemplarily, when the motor speed is zero and the motor torque is not zero, it is determined that the motor has a stall fault.

[0078] S303, collecting the motor temperature and determining whether the motor temperature is greater than a preset second temperature threshold, if so, proceeding to S307; if not, proceeding to S304.

[0079] S304, collecting the lubricating oil temperature in the oil pan, and determining whether the lubricating oil temperature is greater than or equal to a preset first temperature threshold, if so, proceeding to S202; if not, proceeding to S305.

[0080] S305, obtain the shaft gear lubrication flow and the actual output flow of the mechanical oil pump 11 under the current working conditions; obtain the required total flow based on the shaft gear lubrication flow; if the difference between the required total flow and the actual output flow is greater than zero, adjust the speed of the electronic oil pump 10 based on the difference and the lubricating oil temperature.

[0081] Among them, the shaft gear lubrication flow is the sum of the lubrication flow of the motor rotor bearing and the reducer shaft gear.

[0082] Optionally, if the difference between the required total flow rate and the actual output flow rate is less than or equal to zero, the rotation speed of the electronic oil pump 10 is adjusted to zero.

[0083] S306, regulating the speed of the electronic oil pump 10 to zero.

[0084] S307, regulating the speed of the electronic oil pump 10 to a preset maximum speed.

[0085] Through the above method, when the motor stops functioning, the speed of the electronic oil pump 10 is adjusted to zero to avoid energy waste; when the motor is blocked, the electronic oil pump 10 is promptly adjusted to supply flow at the preset maximum speed to prevent the hybrid box from being damaged due to overtemperature; when the motor temperature is too high, the electronic oil pump 10 is adjusted to supply flow at the preset maximum speed to prevent the hybrid box from being damaged due to overtemperature; when the lubricating oil temperature is less than the first temperature threshold and the motor temperature is less than or equal to the second temperature threshold, it is only necessary to meet the shaft gear lubrication flow to avoid energy waste.

[0086] In S202, for example, obtaining the required cooling flow of the motor under the current working condition includes but is not limited to:

[0087] The speed and torque of the motor under the current working condition are obtained, the heat dissipation of the motor is calculated according to the speed and torque, and the cooling demand flow of the motor is calculated according to the heat dissipation of the motor.

[0088] For example, obtain the efficiency MAP of the motor (the so-called efficiency MAP is the efficiency distribution of the motor at a given speed and torque), determine the efficiency η of the motor at the speed N and torque T according to the efficiency MAP of the motor, and calculate the heat dissipation Q (in kilowatts) of the motor based on the efficiency η.

[0089] The motor includes: Figure 1 The first motor and the second motor shown, the first motor is used for generating electricity, therefore, the heat dissipation of the first motor is Q1=T1*N1 / 9550*(1-η1); the second motor is used for driving, therefore, the heat dissipation of the second motor is Q2=T2*N2 / 9550 / η2-T2*N2 / 9550.

[0090] Then, the cooling requirement flow rate Lp=Q / (ρc△T) of the motor is calculated according to the heat dissipation Q, where ρ is the density of the coolant (in kilograms / cubic meter), c is the specific heat capacity of the coolant (in joules / kilogram·degrees Celsius), and △T is the temperature change of the coolant (in degrees Celsius). The value of △T can be determined based on calibration experience and is not limited here.

[0091] Optionally, the heat dissipation of the motor can be calculated according to the voltage U and current I of the motor: Q=αU I, where the heat generation coefficient α refers to the ratio of electrical energy converted to thermal energy when the motor rotates normally. The specific method for calculating the heat dissipation depends on the situation and is not limited here.

[0092] Through the above method, the required cooling flow of the motor is accurately calculated, so that the rotation speed of the electronic oil pump 10 can be precisely controlled according to the required cooling flow of the motor.

[0093] In S203, it is exemplified that the required total flow is obtained according to the required cooling flow of the motor and the lubrication flow of the shaft gear, such as Figure 4 FIG. 1 is a flow chart of a method for calculating total demand flow provided in an embodiment of the present application, comprising the following steps:

[0094] S401, obtaining a preset flow distribution coefficient, where the flow distribution coefficient includes a first motor flow distribution coefficient, a second motor flow distribution coefficient, and a shaft gear flow distribution coefficient;

[0095] For example, the internal liquid flow field model of the hybrid box can be simulated and calculated in advance (i.e., Figure 1 The hydraulic oil circuit shown in the figure is simulated and calculated), and the flow allocated to the first motor cooling, the second motor cooling and the shaft gear lubrication is obtained, and the first motor flow distribution coefficient K1, the second motor flow distribution coefficient K2 and the shaft gear flow distribution coefficient K3 are obtained, and the relationship between them is K1+K2+K3=1.

[0096] S402, obtaining a first total flow rate according to a first motor flow rate distribution coefficient and a cooling demand flow rate of the first motor;

[0097] For example, the first total flow rate Lg1 = the cooling demand flow rate Lp1 of the first motor / the first motor flow rate distribution coefficient K1.

[0098] S403, obtaining a second total flow rate according to the second motor flow distribution coefficient and the cooling demand flow rate of the second motor;

[0099] For example, the second total flow rate Lg2 = the cooling demand flow rate Lp2 of the second motor / the second motor flow rate distribution coefficient K2.

[0100] S404, obtaining a third total flow rate according to the shaft gear flow rate distribution coefficient and the shaft gear lubrication flow rate;

[0101] For example, the third total flow rate Lg3 = shaft gear lubrication flow rate Lc / shaft gear flow rate distribution coefficient K3.

[0102] S405: taking the maximum value among the first total flow, the second total flow and the third total flow as the required total flow.

[0103] Similarly, in S305, it is exemplified that obtaining the required total flow according to the shaft gear lubrication flow includes but is not limited to: obtaining a third total flow according to the shaft gear flow distribution coefficient and the shaft gear lubrication flow, and using the third total flow as the required total flow.

[0104] Through the above method, the maximum value among the first total flow, the second total flow and the third total flow is taken as the required total flow, thereby ensuring that the output of the mechanical oil pump 11 and the electronic oil pump 10 can meet the motor cooling requirements and shaft gear lubrication requirements, and can reduce the power consumption of the electronic oil pump 10.

[0105] In S203 and S305, it is exemplified that the actual output flow of the mechanical oil pump 11 under the current working condition is obtained, including but not limited to:

[0106] First, the speed of the mechanical oil pump 11 is obtained, and the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump 11 are obtained according to the lubricating oil temperature and the speed of the mechanical oil pump 11. In a feasible implementation, the second motor drives the mechanical oil pump 11 to rotate, and the speed of the mechanical oil pump 11 can be calculated based on the collected speed of the second motor and the preset speed ratio between the second motor and the mechanical oil pump 11. As shown in Table 1, it is a correspondence table between the lubricating oil temperature T and the volumetric efficiency R of the mechanical oil pump 11:

[0107] Table 1 A correspondence table between lubricating oil temperature and volumetric efficiency of mechanical oil pump

[0108] Lubricating oil temperature T1 T2 T3 …… Volumetric efficiency R1 R2 R3 ……

[0109] It can be seen from Table 1 that after the lubricating oil temperature is obtained by the temperature sensor, the volumetric efficiency R of the mechanical oil pump 11 can be obtained by looking up Table 1.

[0110] At the same time, the embodiment of the present application also provides a corresponding table of lubricating oil temperature T, speed Nm of the mechanical oil pump 11 and theoretical oil supply amount K, as shown in Table 2:

[0111] Table 2 A correspondence table of lubricating oil temperature, mechanical oil pump speed and theoretical oil supply

[0112]

[0113] It can be seen from Table 2 that according to the lubricating oil temperature and the rotation speed Nm of the mechanical oil pump 11 , the theoretical oil supply K of the mechanical oil pump 11 can be determined from Table 2 by table lookup and interpolation.

[0114] Then, the actual output flow rate Kg=K*R of the mechanical oil pump 11 is calculated based on the volumetric efficiency R and the theoretical oil supply flow rate K of the mechanical oil pump 11 .

[0115] Optionally, the actual output flow rate Kg of the mechanical oil pump 11 may also be directly obtained through a flow sensor, a flow meter, etc. The specific method of obtaining it depends on the situation and is not limited here.

[0116] Through the above method, the difference in oil supply flow of the mechanical oil pump 11 caused by the change in the viscosity-temperature characteristics of the oil at different lubricating oil temperatures is taken into account, and the volumetric efficiency of the mechanical oil pump 11 at the current lubricating oil temperature is determined, so as to accurately calculate the actual output flow of the mechanical oil pump 11, so as to accurately control the speed of the electronic oil pump 10 according to the actual output flow of the mechanical oil pump 11.

[0117] In S204 and S305, it is exemplified that if the difference between the required total flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump 10 is regulated according to the difference and the lubricating oil temperature, including but not limited to:

[0118] First, the volumetric efficiency of the electronic oil pump is obtained according to the lubricating oil temperature, as shown in Table 3, which is a correspondence table between the lubricating oil temperature T and the volumetric efficiency V of the electronic oil pump 10:

[0119] Table 3 A correspondence table between lubricating oil temperature and volumetric efficiency of electronic oil pump

[0120] Lubricating oil temperature T1 T2 T3 …… Volumetric efficiency V1 V2 V3 ……

[0121] It can be seen from Table 3 that after the lubricating oil temperature is obtained by the temperature sensor, the volumetric efficiency V of the electronic oil pump 10 can be obtained by looking up Table 3.

[0122] Then, the theoretical oil supply flow rate L of the electronic oil pump 10 is calculated based on the difference between the required total flow rate and the actual output flow rate Kg of the mechanical oil pump 11 , and the volumetric efficiency V of the electronic oil pump 10 .

[0123] Exemplarily, if the required total flow is the first total flow Lg1, the theoretical oil supply flow L of the electronic oil pump 10 is L=(Lg1-Kg) / V; if the required total flow is the second total flow Lg2, the theoretical oil supply flow L of the electronic oil pump 10 is L=(Lg2-Kg) / V; if the required total flow is the third total flow Lg3, the theoretical oil supply flow L of the electronic oil pump 10 is L=(Lg3-Kg) / V.

[0124] Finally, the speed of the electronic oil pump is obtained according to the lubricating oil temperature and the theoretical oil supply flow L of the electronic oil pump 10. As shown in Table 4, it is a corresponding table of the lubricating oil temperature T, the speed Ne of the electronic oil pump 10 and the theoretical oil supply L:

[0125] Table 4 A correspondence table of lubricating oil temperature, electronic oil pump speed and theoretical oil supply

[0126]

[0127] It can be seen from Table 4 that after obtaining the lubricating oil temperature T and the theoretical oil supply flow rate L of the electronic oil pump 10, the rotation speed Ne of the electronic oil pump 10 can be obtained from Table 4 by looking up the table and interpolating.

[0128] Through the above method, the difference in oil supply flow of the electronic oil pump 10 caused by the change in the viscosity-temperature characteristics of the oil at different lubricating oil temperatures is taken into consideration, and the volumetric efficiency of the electronic oil pump 10 at the current lubricating oil temperature is determined, so that the rotation speed of the electronic oil pump 10 can be accurately obtained according to the volumetric efficiency of the electronic oil pump 10 to avoid insufficient flow.

[0129] In the above-mentioned dual-motor hybrid system electronic oil pump speed control method, the difference in oil volume between the required total flow and the actual output flow of the mechanical oil pump is calculated, and the difference in oil volume is replenished by the electronic oil pump, so that the electronic oil pump can meet the required total flow at the lowest speed, reduce the power consumption of the electronic oil pump, and thus achieve the purpose of energy saving.

[0130] It should be understood that although Figure 2-4 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 2-4At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0131] In some embodiments, Figure 5 As shown, a dual-motor hybrid system electronic oil pump speed control system is provided, including: a collection module 501, an acquisition module 502, a calculation module 503 and a control module 504, wherein:

[0132] The acquisition module 501 is used to acquire the temperature of the motor and the temperature of the lubricating oil in the oil pan if the motor does not have a stall fault;

[0133] An acquisition module 502 is used to acquire the cooling demand flow rate of the motor, the shaft gear lubrication flow rate and the actual output flow rate of the mechanical oil pump under the current working condition if the lubricating oil temperature is greater than or equal to a preset first temperature threshold and the motor temperature is less than or equal to a preset second temperature threshold;

[0134] The calculation module 503 is used to obtain the required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear;

[0135] The control module 504 is configured to control the rotation speed of the electronic oil pump according to the difference and the lubricating oil temperature if the difference between the required total flow rate and the actual output flow rate is greater than zero.

[0136] In some embodiments, the acquisition module 502 is further configured to acquire the shaft gear lubrication flow and the actual output flow of the mechanical oil pump under the current working condition if the lubricating oil temperature is less than the first temperature threshold and the motor temperature is less than or equal to the second temperature threshold;

[0137] The calculation module 503 is also used to obtain the required total flow rate according to the shaft gear lubrication flow rate;

[0138] The control module 504 is further configured to control the rotation speed of the electronic oil pump according to the difference and the lubricating oil temperature if the difference between the required total flow rate and the actual output flow rate is greater than zero.

[0139] In some embodiments, the control module 504 is further configured to:

[0140] If the motor temperature is greater than the second temperature threshold, the speed of the electronic oil pump is regulated to be a preset maximum speed.

[0141] In some embodiments, the control module 504 is further configured to:

[0142] If the motor is blocked, the speed of the electronic oil pump is adjusted to the preset maximum speed.

[0143] In some embodiments, the acquisition module 502 is further configured to:

[0144] Get the speed and torque of the motor under the current working conditions;

[0145] Calculate the heat dissipation of the motor based on the speed and torque;

[0146] Calculate the required cooling flow of the motor based on the heat dissipation of the motor.

[0147] In some embodiments, the motor includes a first motor and a second motor;

[0148] The calculation module 503 is also used for:

[0149] Obtaining a preset flow distribution coefficient, the flow distribution coefficient comprising a first motor flow distribution coefficient, a second motor flow distribution coefficient and a shaft gear flow distribution coefficient;

[0150] Obtaining a first total flow rate according to a first motor flow distribution coefficient and a cooling demand flow rate of the first motor;

[0151] Obtaining a second total flow rate according to a second motor flow distribution coefficient and a cooling demand flow rate of the second motor;

[0152] Obtaining a third total flow rate according to the shaft-tooth flow rate distribution coefficient and the shaft-tooth lubrication flow rate;

[0153] The maximum value among the first total flow, the second total flow and the third total flow is taken as the required total flow.

[0154] In some embodiments, the acquisition module 502 is further configured to:

[0155] Get the speed of the mechanical oil pump;

[0156] According to the lubricating oil temperature and the speed of the mechanical oil pump, the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump are obtained;

[0157] The actual output flow of the mechanical oil pump is calculated based on the volumetric efficiency of the mechanical oil pump and the theoretical oil supply flow.

[0158] In some embodiments, the control module 504 is further configured to:

[0159] Obtain the volumetric efficiency of the electronic oil pump based on the lubricating oil temperature;

[0160] Calculate the theoretical oil supply flow rate of the electronic oil pump based on the difference and the volumetric efficiency of the electronic oil pump;

[0161] The rotation speed of the electronic oil pump is obtained according to the lubricating oil temperature and the theoretical oil supply flow rate of the electronic oil pump.

[0162] For the specific definition of the electronic oil pump speed control system of the dual-motor hybrid system, please refer to the definition of the electronic oil pump speed control method of the dual-motor hybrid system mentioned above, which will not be repeated here. Each module in the above-mentioned dual-motor hybrid system electronic oil pump speed control system can be implemented in whole or in part through software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0163] In some embodiments, a vehicle is provided, see Figure 6 , Figure 6 Figure 1 is a schematic diagram of the structure of a vehicle. Figure 6 As shown, the vehicle includes a dual-motor hybrid system electronic oil pump speed control system 601.

[0164] The electronic oil pump speed control system 601 of the dual-motor hybrid system is used to collect the motor temperature and the lubricating oil temperature in the oil pan if the motor does not have a stall fault; if the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold, then the cooling demand flow of the motor, the shaft gear lubrication flow and the actual output flow of the mechanical oil pump under the current operating conditions are obtained; based on the cooling demand flow of the motor and the shaft gear lubrication flow, the required total flow is obtained; if the difference between the required total flow and the actual output flow is greater than zero, the speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0165] The specific limitations on the dual-motor hybrid system electronic oil pump speed control system 601 can be found in the above limitations on the dual-motor hybrid system electronic oil pump speed control method, which will not be repeated here.

[0166] In some embodiments, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown. The computer device includes a processor, a memory, a network interface and a database connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the electronic oil pump speed control data of the dual-motor hybrid system. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above-mentioned dual-motor hybrid system electronic oil pump speed control method is implemented.

[0167] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0168] In some embodiments, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the following steps when executing the computer program:

[0169] If the motor does not have a stall fault, collect the motor temperature and the lubricating oil temperature in the oil pan;

[0170] If the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold, the cooling demand flow rate of the motor, the shaft gear lubrication flow rate, and the actual output flow rate of the mechanical oil pump under the current working condition are obtained;

[0171] According to the required flow rate of motor cooling and the lubrication flow rate of shaft gear, the required total flow rate is obtained;

[0172] If the difference between the required total flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0173] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0174] If the lubricating oil temperature is less than the first temperature threshold, and the motor temperature is less than or equal to the second temperature threshold, then obtaining the shaft gear lubrication flow and the actual output flow of the mechanical oil pump under the current working condition;

[0175] According to the shaft gear lubrication flow, the required total flow is obtained;

[0176] If the difference between the required total flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0177] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0178] If the motor temperature is greater than the second temperature threshold, the speed of the electronic oil pump is regulated to be a preset maximum speed.

[0179] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0180] If the motor is blocked, the speed of the electronic oil pump is adjusted to the preset maximum speed.

[0181] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0182] Get the speed and torque of the motor under the current working conditions;

[0183] Calculate the heat dissipation of the motor based on the speed and torque;

[0184] Calculate the required cooling flow of the motor based on the heat dissipation of the motor.

[0185] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0186] According to the required flow rate of motor cooling and shaft gear lubrication, the required total flow rate is obtained, including:

[0187] Obtaining a preset flow distribution coefficient, the flow distribution coefficient comprising a first motor flow distribution coefficient, a second motor flow distribution coefficient and a shaft gear flow distribution coefficient;

[0188] Obtaining a first total flow rate according to a first motor flow distribution coefficient and a cooling demand flow rate of the first motor;

[0189] Obtaining a second total flow rate according to a second motor flow distribution coefficient and a cooling demand flow rate of the second motor;

[0190] Obtaining a third total flow rate according to the shaft-tooth flow rate distribution coefficient and the shaft-tooth lubrication flow rate;

[0191] The maximum value among the first total flow, the second total flow and the third total flow is taken as the required total flow.

[0192] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0193] Get the speed of the mechanical oil pump;

[0194] According to the lubricating oil temperature and the speed of the mechanical oil pump, the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump are obtained;

[0195] The actual output flow of the mechanical oil pump is calculated based on the volumetric efficiency of the mechanical oil pump and the theoretical oil supply flow.

[0196] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0197] Obtain the volumetric efficiency of the electronic oil pump based on the lubricating oil temperature;

[0198] Calculate the theoretical oil supply flow rate of the electronic oil pump based on the difference and the volumetric efficiency of the electronic oil pump;

[0199] The rotation speed of the electronic oil pump is obtained according to the lubricating oil temperature and the theoretical oil supply flow rate of the electronic oil pump.

[0200] In some embodiments, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0201] If the motor does not have a stall fault, collect the motor temperature and the lubricating oil temperature in the oil pan;

[0202] If the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold, the cooling demand flow rate of the motor, the shaft gear lubrication flow rate, and the actual output flow rate of the mechanical oil pump under the current working condition are obtained;

[0203] According to the required flow rate of motor cooling and the lubrication flow rate of shaft gear, the required total flow rate is obtained;

[0204] If the difference between the required total flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0205] In some embodiments, when the computer program is executed by the processor, the following steps are also implemented:

[0206] If the lubricating oil temperature is less than the first temperature threshold, and the motor temperature is less than or equal to the second temperature threshold, then obtaining the shaft gear lubrication flow and the actual output flow of the mechanical oil pump under the current working condition;

[0207] According to the shaft gear lubrication flow, the required total flow is obtained;

[0208] If the difference between the required total flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

[0209] In some embodiments, when the computer program is executed by the processor, the following steps are also implemented:

[0210] If the motor temperature is greater than the second temperature threshold, the speed of the electronic oil pump is regulated to be a preset maximum speed.

[0211] In some embodiments, when the computer program is executed by the processor, the following steps are also implemented:

[0212] If the motor is blocked, the speed of the electronic oil pump is adjusted to the preset maximum speed.

[0213] In some embodiments, when the processor executes the computer program, the processor further implements the following steps:

[0214] Get the speed and torque of the motor under the current working conditions;

[0215] Calculate the heat dissipation of the motor based on the speed and torque;

[0216] Calculate the required cooling flow of the motor based on the heat dissipation of the motor.

[0217] In some embodiments, when the computer program is executed by the processor, the following steps are also implemented:

[0218] According to the required flow rate of motor cooling and shaft gear lubrication, the required total flow rate is obtained, including:

[0219] Obtaining a preset flow distribution coefficient, the flow distribution coefficient comprising a first motor flow distribution coefficient, a second motor flow distribution coefficient and a shaft gear flow distribution coefficient;

[0220] Obtaining a first total flow rate according to a first motor flow distribution coefficient and a cooling demand flow rate of the first motor;

[0221] Obtaining a second total flow rate according to a second motor flow distribution coefficient and a cooling demand flow rate of the second motor;

[0222] Obtaining a third total flow rate according to the shaft-tooth flow rate distribution coefficient and the shaft-tooth lubrication flow rate;

[0223] The maximum value among the first total flow, the second total flow and the third total flow is taken as the required total flow.

[0224] In some embodiments, when the computer program is executed by the processor, the following steps are also implemented:

[0225] Get the speed of the mechanical oil pump;

[0226] According to the lubricating oil temperature and the speed of the mechanical oil pump, the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump are obtained;

[0227] The actual output flow of the mechanical oil pump is calculated based on the volumetric efficiency of the mechanical oil pump and the theoretical oil supply flow.

[0228] In some embodiments, when the computer program is executed by the processor, the following steps are also implemented:

[0229] Obtain the volumetric efficiency of the electronic oil pump based on the lubricating oil temperature;

[0230] Calculate the theoretical oil supply flow rate of the electronic oil pump based on the difference and the volumetric efficiency of the electronic oil pump;

[0231] The rotation speed of the electronic oil pump is obtained according to the lubricating oil temperature and the theoretical oil supply flow rate of the electronic oil pump.

[0232] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0233] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0234] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for controlling the speed of an electronic oil pump in a dual-motor hybrid system, characterized in that: The method comprises: If the motor does not have a stall fault, collect the motor temperature and the lubricating oil temperature in the oil pan; If the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold, then obtaining the cooling demand flow rate, shaft gear lubrication flow rate, and actual output flow rate of the mechanical oil pump of the motor under the current working condition; Obtaining a required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear; If the difference between the required total flow rate and the actual output flow rate is greater than zero, the rotation speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

2. A dual-motor hybrid system electronic oil pump speed control method as claimed in claim 1, characterized in that: The method further comprises: If the lubricating oil temperature is less than the first temperature threshold, and the motor temperature is less than or equal to the second temperature threshold, obtaining the shaft gear lubrication flow and the actual output flow of the mechanical oil pump under the current working condition; According to the shaft gear lubrication flow, a required total flow is obtained; If the difference between the required total flow rate and the actual output flow rate is greater than zero, the rotation speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature.

3. The method for controlling the speed of an electronic oil pump of a dual-motor hybrid system according to claim 1, characterized in that: The method further comprises: If the motor temperature is greater than the second temperature threshold, the speed of the electronic oil pump is regulated to be a preset maximum speed.

4. The method for controlling the speed of an electronic oil pump of a dual-motor hybrid system according to claim 1, characterized in that: The method further comprises: If the motor is blocked, the speed of the electronic oil pump is adjusted to a preset maximum speed.

5. The method for controlling the speed of an electronic oil pump of a dual-motor hybrid system according to claim 1, characterized in that: The obtaining of the cooling demand flow of the motor under the current working condition includes: Obtaining the speed and torque of the motor under the current working condition; Calculating the heat dissipation of the motor according to the rotational speed and torque; The required cooling flow of the motor is calculated according to the heat dissipation of the motor.

6. The method for controlling the speed of an electronic oil pump of a dual-motor hybrid system according to claim 1, characterized in that: The motor comprises a first motor and a second motor; The step of obtaining the required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear comprises: Obtaining a preset flow distribution coefficient, wherein the flow distribution coefficient includes a first motor flow distribution coefficient, a second motor flow distribution coefficient, and a shaft gear flow distribution coefficient; Obtaining a first total flow rate according to the first motor flow distribution coefficient and the cooling demand flow rate of the first motor; Obtaining a second total flow rate according to the second motor flow distribution coefficient and the cooling demand flow rate of the second motor; Obtaining a third total flow rate according to the shaft-tooth flow distribution coefficient and the shaft-tooth lubrication flow rate; The maximum value among the first total flow, the second total flow and the third total flow is used as the required total flow.

7. The method for controlling the speed of an electronic oil pump of a dual-motor hybrid system according to claim 1, characterized in that: Get the actual output flow of the mechanical oil pump under the current working conditions, including: Obtaining the rotation speed of the mechanical oil pump; According to the lubricating oil temperature and the rotation speed of the mechanical oil pump, the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump are obtained; The actual output flow of the mechanical oil pump is obtained by calculation according to the volumetric efficiency and theoretical oil supply flow of the mechanical oil pump.

8. The method for controlling the speed of an electronic oil pump of a dual-motor hybrid system according to claim 1, characterized in that: The step of regulating the speed of the electronic oil pump according to the difference and the lubricating oil temperature includes: Acquiring the volumetric efficiency of the electronic oil pump according to the lubricating oil temperature; Calculating a theoretical oil supply flow rate of the electronic oil pump based on the difference and the volumetric efficiency of the electronic oil pump; The rotation speed of the electronic oil pump is obtained according to the lubricating oil temperature and the theoretical oil supply flow rate of the electronic oil pump.

9. A dual-motor hybrid system electronic oil pump speed control system, characterized in that: The system comprises: A collection module is used to collect the temperature of the motor and the temperature of the lubricating oil in the oil pan if the motor does not have a stall fault; an acquisition module, configured to acquire the cooling demand flow rate of the motor, the shaft gear lubrication flow rate, and the actual output flow rate of the mechanical oil pump under the current working condition if the lubricating oil temperature is greater than or equal to a preset first temperature threshold, and the motor temperature is less than or equal to a preset second temperature threshold; A calculation module, used for obtaining a required total flow rate according to the required cooling flow rate of the motor and the lubrication flow rate of the shaft gear; A control module is used to control the rotation speed of the electronic oil pump according to the difference between the required total flow and the actual output flow if the difference between the required total flow and the actual output flow is greater than zero.

10. A vehicle, characterized in that: The vehicle includes the dual-motor hybrid system electronic oil pump speed control system as claimed in claim 9.

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