Electronic oil pump rotating speed control method and system for dual-motor hybrid system and vehicle

Abstract

The application discloses a dual-motor hybrid system electronic oil pump rotating speed control method, system and vehicle, relates to the vehicle energy source technical field, and aims to solve the problem of high power consumption of the electronic oil pump in the prior art. The method comprises the following steps: collecting the motor temperature and the lubricating oil temperature in the oil sump if the motor does not have a stall failure; obtaining the cooling demand flow of the motor, the shaft tooth lubrication flow and the actual output flow 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 value and the motor temperature is less than or equal to a preset second temperature threshold value; obtaining the total demand flow according to the cooling demand flow of the motor and the shaft tooth lubrication flow; and adjusting the rotating speed of the electronic oil pump according to the difference between the total demand flow and the actual output flow and the lubricating oil temperature if the difference is greater than zero.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle energy, in particular to a dual-motor hybrid system electronic oil pump speed control method, system and vehicle. BACKGROUND

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

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

[0004] Therefore, a dual-motor hybrid system electronic oil pump speed control method, system and vehicle are provided to solve the problem of high power consumption of the electronic oil pump in related technologies.

[0005] In a first aspect, the present application provides a dual-motor hybrid system electronic oil pump speed control method, which comprises:

[0006] If the motor does not have a stall fault, the motor temperature and the lubricating oil temperature in the oil sump are collected;

[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, the cooling demand flow of the motor, the shaft tooth lubrication flow and the actual output flow of the mechanical oil pump under the current working condition are obtained;

[0008] According to the cooling demand flow of the motor and the shaft tooth lubrication flow, the total demand flow is obtained;

[0009] If the difference between the total demand 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.

[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 an axle gear lubrication flow and an actual output flow of the mechanical oil pump under a current working condition;

[0012] obtaining a total required flow according to the axle gear lubrication flow;

[0013] if a difference between the total required flow and the actual output flow is greater than zero, adjusting a rotating speed of the electronic oil pump 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, adjusting the rotating speed of the electronic oil pump to a preset highest rotating speed.

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

[0017] if the motor has a stall failure, adjusting the rotating speed of the electronic oil pump to a preset highest rotating speed.

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

[0019] obtaining a rotating speed and a torque of the motor under the current working condition;

[0020] calculating a heat dissipation of the motor according to the rotating speed and the torque;

[0021] calculating the cooling required flow of the motor according to the heat dissipation of the motor.

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

[0023] the obtaining the total required flow according to the cooling required flow of the motor and the axle gear lubrication flow comprises:

[0024] obtaining a preset flow distribution coefficient, the flow distribution coefficient comprising a first motor flow distribution coefficient, a second motor flow distribution coefficient and an axle gear flow distribution coefficient;

[0025] obtaining a first total flow according to the first motor flow distribution coefficient and the cooling required flow of the first motor;

[0026] obtaining a second total flow according to the second motor flow distribution coefficient and the cooling required flow of the second motor;

[0027] obtaining a third total flow according to the axle gear flow distribution coefficient and the axle gear lubrication flow;

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

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

[0030] The rotating speed of the mechanical oil pump is obtained.

[0031] The volumetric efficiency and the theoretical oil supply flow of the mechanical oil pump are obtained according to the lubricating oil temperature and the rotating speed of the mechanical oil pump.

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

[0033] In some embodiments, the rotating speed of the electronic oil pump is regulated according to the difference and the lubricating oil temperature, including:

[0034] The volumetric efficiency of the electronic oil pump is obtained according to the lubricating oil temperature.

[0035] The theoretical oil supply flow of the electronic oil pump is calculated based on the difference and the volumetric efficiency of the electronic oil pump.

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

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

[0038] The acquisition module is configured to acquire the motor temperature and the lubricating oil temperature in the oil sump if the motor does not have a stall fault.

[0039] The acquisition module is configured to obtain the cooling demand flow of the motor, the shaft tooth lubrication flow and the actual output flow 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] The calculation module is configured to obtain a total demand flow according to the cooling demand flow of the motor and the shaft tooth lubrication flow.

[0041] The regulation module is configured to regulate the rotating speed of the electronic oil pump according to the difference and the lubricating oil temperature if the difference between the total demand flow and the actual output flow is greater than zero.

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

[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 the processor executes the computer program to implement the electronic oil pump rotating speed control method of the dual-motor hybrid system according to the first aspect.

[0044] In a fifth aspect, the present application provides a computer readable storage medium, which stores a computer program, wherein the computer program is executable on a processor to implement the electronic oil pump rotating speed control method of the dual-motor hybrid system according to the first aspect.

[0045] The electronic oil pump rotating speed control method, system and vehicle of the dual-motor hybrid system achieve the purpose of energy saving by calculating the difference between the required total flow and the actual output flow of the mechanical oil pump, and supplementing the difference by the electronic oil pump, so that the electronic oil pump meets the required total flow at the lowest rotating speed and reduces the power consumption of the electronic oil pump. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 A hydraulic oil circuit architecture diagram of a dual-motor hybrid system is provided for the embodiments of the present application;

[0047] Figure 2 A flowchart of an electronic oil pump rotating speed control method of a dual-motor hybrid system is provided for the embodiments of the present application;

[0048] Figure 3 A program block diagram of an electronic oil pump rotating speed control method of a dual-motor hybrid system is provided for the embodiments of the present application;

[0049] Figure 4 A flowchart of a required total flow calculation method is provided for the embodiments of the present application;

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

[0051] Figure 6 A structural diagram of a vehicle is provided for the embodiments of the present application;

[0052] Figure 7 An internal structural diagram of a computer device is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0053] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be described in further detail below with reference to the drawings. The specific operation methods in the method embodiments can also be applied to the device embodiments or system embodiments. It should be noted that in the description of the present application, "multiple" is understood as "at least two". The association relationship of the associated objects is described, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. A and B are connected, which means that A and B are directly connected and A and B are connected through C. In addition, in the description of the present application, "first", "second", etc. are used only for the purpose of distinguishing the description, and cannot be understood as indicating or implying relative importance, nor can it be understood as indicating or implying order.

[0054] In the technical solutions of the present application, the acquisition, transmission, storage and use of data comply with the requirements of relevant national laws and regulations.

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

[0056] In the related art, in order to ensure that the motor runs stably within 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 when the motor temperature exceeds the set temperature range. 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 an electronic oil pump speed control method, system and vehicle of a dual-motor hybrid system, to solve the problem of high power consumption of the electronic oil pump in the related art.

[0058] The dual-motor hybrid system in the embodiments of the present application is briefly introduced below, and the dual-motor hybrid system introduced below is only used to illustrate the embodiments of the present application, but not to limit. In specific implementation, the technical solutions provided by the embodiments of the present application can be flexibly applied according to actual needs.

[0059] The electronic oil pump speed control method of the dual-motor hybrid system provided by the embodiments of the present application can be applied to the hydraulic oil circuit of the dual-motor hybrid system as shown in Figure 1 The electronic oil pump speed control method of the dual-motor hybrid system provided by the embodiments of the present application can be applied to the hydraulic oil circuit of the dual-motor hybrid system as shown in

[0060] Exemplarily, Figure 1 The oil flow direction of the lubricating oil in the hydraulic oil circuit of the dual-motor hybrid system is from the oil pan, through the filter screen, to the electronic oil pump 10 and the mechanical oil pump 11 respectively. Then, through the electronic oil pump 10 to the oil cooler, and through the mechanical oil pump 11 and the filter screen to the oil cooler, and after passing through the fine filter, the lubricating oil is distributed to the shaft tooth lubrication, the first motor cooling and the second motor cooling according to the distribution relationship of the motor and shaft tooth flow in the hydraulic oil circuit, and finally reflows into the oil pan to realize the circulation flow.

[0061] The above will be described in detail in combination with the accompanying drawings and specific embodiments.

[0062] Figure 2 A flowchart of a dual-motor hybrid system electronic oil pump speed control method provided by the embodiment is shown in the figure. The flowchart can be executed by a dual-motor hybrid system electronic oil pump speed control system. The system can be realized by software, by hardware, or by a combination of software and hardware. As shown in the figure, the flowchart includes the following steps: Figure 2

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

[0064] The motor temperature and the lubricating oil temperature in the oil pan can be obtained by a 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, the cooling demand flow of the motor, the shaft tooth lubrication flow and the actual output flow of the mechanical oil pump under the current working condition are obtained.

[0066] The mechanical oil pump is arranged in the hydraulic oil circuit of the dual-motor hybrid system as shown in the figure. Figure 1 In the embodiment, the temperature of the lubricating oil in the oil pan is taken as the working 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 can be understood that after the vehicle is parked for a long time in a very low external environment temperature, the temperature in the hybrid box can be reduced to less than the first temperature threshold.

[0068] ​In a low temperature environment, the characteristics of the magnetic material 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 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, and the resistance increases at low temperature, which hinders the flow of current in the metal conductor and also affects the efficiency of the motor.

[0069] Therefore, in a low temperature environment, for the vehicle starting condition, at this time the hybrid box is in a low temperature environment, the temperature of the lubricating oil is very low, and the motor cooling demand can be ignored, only the lubrication demand of the hybrid box shaft tooth is considered. This design not only ensures that the hybrid box can work normally, but also enables the motor to quickly warm up under the condition of meeting the lubrication, thereby improving the working efficiency of the motor. Since only the lubrication flow demand of the hybrid box shaft tooth needs to be met under this condition, the total flow demand of the lubricating oil is low, and the electronic oil pump only needs to work at a low speed or not work, thereby saving electric energy consumption.

[0070] S203, obtaining a total flow demand according to the cooling flow demand of the motor and the shaft tooth lubrication flow;

[0071] S204, if the difference between the total flow demand and the actual output flow is greater than zero, then adjusting the speed of the electronic oil pump according to the difference and the temperature of the lubricating oil.

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

[0073] Optionally, if the difference between the total flow demand 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, and the power consumption of the electronic oil pump 10 is zero at this time.

[0074] In the embodiment of the present application, the locked-rotor fault of the motor, the temperature of the motor, and the temperature of the lubricating oil in the oil pan will all affect the output of the electronic oil pump 10, so before adjusting the speed of the electronic oil pump 10 according to the actual output flow of the mechanical oil pump 11, the locked-rotor fault of the motor, the temperature of the motor, and the temperature of the lubricating oil in the oil pan should be judged first. As shown in Figure 3 , it is a program block diagram of a dual-motor hybrid system electronic oil pump speed control method provided by the embodiment of the present application, which comprises:

[0075] S301, judging whether the motor has a shutdown fault, if yes, turning to S306; if no, turning to S302.

[0076] S302, judging whether the motor has a locked-rotor fault, if yes, turning to S307; if no, turning to S303.

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

[0078] S303, the motor temperature is collected, and it is determined whether the motor temperature is greater than a preset second temperature threshold. If yes, S307 is entered; if no, S304 is entered.

[0079] S304, the lubricating oil temperature in the oil sump is collected, and it is determined whether the lubricating oil temperature is greater than or equal to a preset first temperature threshold. If yes, S202 is entered; if no, S305 is entered.

[0080] S305, the shaft tooth lubrication flow and the actual output flow of the mechanical oil pump 11 under the current working condition are obtained; the required total flow is obtained according to the shaft tooth lubrication flow; if the difference between the required total flow and the actual output flow is greater than zero, the speed of the electronic oil pump 10 is regulated according to the difference and the lubricating oil temperature.

[0081] The shaft tooth lubrication flow is the sum of the lubrication flows of the motor rotor bearing and the reducer shaft tooth.

[0082] 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 regulated to zero.

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

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

[0085] Through the above method, in the case that the motor has a stall fault, the speed of the electronic oil pump 10 is regulated to zero to avoid energy waste; in the case that the motor has a stall fault, the electronic oil pump 10 is regulated to supply flow at a preset maximum speed in a timely manner to prevent the hybrid box from being damaged due to excessive temperature; in the case that the motor temperature is too high, the electronic oil pump 10 is regulated to supply flow at a preset maximum speed to prevent the hybrid box from being damaged due to excessive temperature; in the case that 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, only the shaft tooth lubrication flow needs to be satisfied to avoid energy waste.

[0086] In S202, it is exemplarily illustrated that the cooling demand flow of the motor under the current working condition is obtained, including but 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, the efficiency MAP of the motor (a so-called efficiency MAP is an efficiency distribution of the motor at a given rotating speed and torque) is acquired, the efficiency η of the motor at the rotating speed N and the torque T is determined according to the efficiency MAP of the motor, and the heat dissipation Q (unit: kilowatt) of the motor is calculated according to the efficiency η.

[0089] The motor includes a first motor and a second motor as shown in Figure 1 The first motor is used for power generation, and thus the heat dissipation Q1 of the first motor is T1*N1 / 9550*(1-η1); the second motor is used for driving, and thus the heat dissipation Q2 of the second motor is T2*N2 / 9550 / η2-T2*N2 / 9550.

[0090] Then, the cooling demand flow Lp of the motor is calculated according to the heat dissipation Q, that is, Lp=Q / (ρc△T), where ρ is the density (unit: kilogram / cubic meter) of the cooling liquid, c is the specific heat capacity (unit: joule / kilogram·degree Celsius) of the cooling liquid, and △T is the temperature change value (unit: degree Celsius) of the cooling liquid. The value of △T can be determined according to calibration experience, which is not limited here.

[0091] Optionally, the heat dissipation Q of the motor can also be calculated according to the voltage U and the current I of the motor, that is, Q=αUI, where the heat generation coefficient α refers to the proportion of the conversion of electrical energy into heat energy when the motor rotates normally. The specific calculation method of the heat dissipation is determined according to the situation, which is not limited here.

[0092] Through the above method, the cooling demand flow of the motor is accurately calculated, so as to accurately control the rotating speed of the electronic oil pump 10 according to the cooling demand flow of the motor.

[0093] In S203, it is exemplarily illustrated that the total demand flow is obtained according to the cooling demand flow of the motor and the shaft tooth lubrication flow, as shown in Figure 4 The flowchart of the total demand flow calculation method provided by the embodiment of the application includes the following steps:

[0094] S401, a preset flow distribution coefficient is acquired, the flow distribution coefficient includes a first motor flow distribution coefficient, a second motor flow distribution coefficient, and a shaft tooth flow distribution coefficient;

[0095] For example, the flow distribution to the first motor cooling, the second motor cooling, and the shaft tooth lubrication can be acquired by simulating the liquid flow field model in the hybrid box in advance (that is, simulating the hydraulic oil path as shown in Figure 1 The first motor flow distribution coefficient K1, the second motor flow distribution coefficient K2, and the shaft tooth flow distribution coefficient K3 are obtained, and the relationship is K1+K2+K3=1.

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

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

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

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

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

[0101] For example, the third total flow Lg3 = the shaft tooth lubrication flow Lc / the shaft tooth flow 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 demand total flow.

[0103] Similarly, in S305, it is exemplarily illustrated that obtaining the demand total flow according to the shaft tooth lubrication flow includes but is not limited to: obtaining a third total flow according to the shaft tooth flow distribution coefficient and the shaft tooth lubrication flow, and taking the third total flow as the demand total flow.

[0104] By the above method, the maximum value among the first total flow, the second total flow and the third total flow is taken as the demand total flow, so that the output of the mechanical oil pump 11 and the electronic oil pump 10 can meet the motor cooling demand and the shaft tooth lubrication demand, and the power consumption of the electronic oil pump 10 can be reduced.

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

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

[0107] Table 1: A table corresponding the lubricating oil temperature and the volumetric efficiency of the mechanical oil pump

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

[0109] From Table 1, after the temperature sensor obtains the lubricating oil temperature, Table 1 can be consulted to obtain the volumetric efficiency R of the mechanical oil pump 11.

[0110] Meanwhile, the application also provides a lubricating oil temperature T, mechanical oil pump 11 rotation speed Nm and theoretical oil supply amount K corresponding table, as shown in Table 2:

[0111] Table 2 Lubricating oil temperature, mechanical oil pump rotation speed and theoretical oil supply amount corresponding table

[0112]

[0113] From Table 2, according to the lubricating oil temperature and the rotation speed Nm of the mechanical oil pump 11, the theoretical oil supply amount K of the mechanical oil pump 11 can be determined from Table 2 by consulting and interpolating.

[0114] Then, the actual output flow Kg of the mechanical oil pump 11 is calculated according to the volumetric efficiency R and the theoretical oil supply flow K of the mechanical oil pump 11.

[0115] Optionally, the actual output flow Kg of the mechanical oil pump 11 can also be directly obtained through a flow sensor, a flow meter, etc., and the specific obtaining method is determined according to the situation, which is not limited here.

[0116] Through the above method, considering the oil supply flow difference of the mechanical oil pump 11 at different lubricating oil temperatures due to the change of the viscosity-temperature characteristics of the oil, the volumetric efficiency of the mechanical oil pump 11 at the current lubricating oil temperature is determined, so that the actual output flow of the mechanical oil pump 11 is accurately calculated, so as to accurately control the rotation 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 exemplarily illustrated that if the difference between the total required flow and the actual output flow is greater than zero, the rotation 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, which is shown in Table 3, which is a lubricating oil temperature T and electronic oil pump 10 volumetric efficiency V corresponding table:

[0119] Table 3 Lubricating oil temperature and electronic oil pump volumetric efficiency corresponding table

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

[0121] From Table 3, after the temperature sensor obtains the lubricating oil temperature, Table 3 can be consulted to obtain the volumetric efficiency V of the electronic oil pump 10.

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

[0123] For example, if the total demand flow rate is the first total flow rate Lg1, the theoretical oil supply flow rate L of the electric oil pump 10 is (Lg1-Kg) / V; if the total demand flow rate is the second total flow rate Lg2, the theoretical oil supply flow rate L of the electric oil pump 10 is (Lg2-Kg) / V; if the total demand flow rate is the third total flow rate Lg3, the theoretical oil supply flow rate L of the electric oil pump 10 is (Lg3-Kg) / V.

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

[0125] Table 4: Correspondence table of a lubricating oil temperature, a rotation speed of the electric oil pump and a theoretical oil supply flow rate

[0126]

[0127] As can be seen from Table 4, after obtaining the lubricating oil temperature T and the theoretical oil supply flow rate L of the electric oil pump 10, the rotation speed Ne of the electric oil pump 10 can be obtained from Table 4 by table lookup interpolation.

[0128] By the above method, considering the difference in oil supply flow rate of the electric oil pump 10 at different lubricating oil temperatures due to the change in viscosity-temperature characteristics of the oil, the volumetric efficiency of the electric oil pump 10 at the current lubricating oil temperature is determined, so as to accurately obtain the rotation speed of the electric oil pump 10 according to the volumetric efficiency of the electric oil pump 10, and avoid the situation of insufficient flow rate.

[0129] In the above-mentioned electronic oil pump rotation speed control method of the dual-motor hybrid system, the difference between the total demand flow rate and the actual output flow rate of the mechanical oil pump is calculated, and the difference is supplemented by the electric oil pump, so as to realize that the electric oil pump meets the total demand flow rate at the lowest rotation speed and reduce the power consumption of the electric oil pump, thereby achieving the purpose of energy saving.

[0130] It should be understood that, although Figures 2-4 the steps in the flowchart of the method are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise explicitly stated herein, there is no strict order limitation for the execution of these steps, and these steps can be executed in other orders. Moreover, Figures 2-4At least one of the steps in the method can comprise a plurality of sub-steps or stages which are not necessarily performed at the same time but can be performed at different times, and the order of the sub-steps or stages is not necessarily sequential but can be performed in rotation or alternation with other steps or sub-steps or stages of other steps.

[0131] In some embodiments, as shown in FIG. 1, a dual-motor hybrid system electronic oil pump speed control system is provided, comprising: a collection module 501, an acquisition module 502, a calculation module 503 and a control module 504, wherein: Figure 5

[0132] The collection module 501 is configured to collect the motor temperature and the lubricating oil temperature in the oil sump if the motor does not have a stall fault.

[0133] The acquisition module 502 is configured to acquire the cooling demand flow of the motor, the shaft tooth lubrication flow and the actual output flow 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 configured to obtain a total demand flow according to the cooling demand flow of the motor and the shaft tooth lubrication flow.

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

[0136] In some embodiments, the acquisition module 502 is further configured to acquire the shaft tooth 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 further configured to obtain the total demand flow according to the shaft tooth lubrication flow.

[0138] The control module 504 is further configured to control the speed of the electronic oil pump according to the difference and the lubricating oil temperature if the difference between the total demand flow and the actual output flow 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 controlled to be a preset maximum speed.

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

[0142] ​If the motor appears to be stuck, the speed of the electronic oil pump is regulated to the preset maximum speed.

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

[0144] obtain the speed and torque of the motor under the current working condition;

[0145] calculate the heat dissipation of the motor according to the speed and torque;

[0146] calculate the cooling demand flow of the motor according to the heat dissipation of the motor.

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

[0148] The calculating module 503 is further configured to:

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

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

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

[0152] obtain a third total flow according to the shaft gear flow distribution coefficient and the shaft gear lubrication flow;

[0153] take the maximum value among the first total flow, the second total flow, and the third total flow as the demand total flow.

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

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

[0156] obtain the volumetric efficiency and the theoretical oil supply flow of the mechanical oil pump according to the lubricating oil temperature and the speed of the mechanical oil pump;

[0157] calculate the actual output flow of the mechanical oil pump according to the volumetric efficiency and the theoretical oil supply flow of the mechanical oil pump.

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

[0159] obtain the volumetric efficiency of the electronic oil pump according to the lubricating oil temperature;

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

[0161] obtain the speed of the electronic oil pump according to the lubricating oil temperature and the theoretical oil supply flow of the electronic oil pump.

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

[0163] In some embodiments, a vehicle is provided, which can be seen from Figure 6 , Figure 6 is a structural schematic diagram of a vehicle. As Figure 6 indicated, the vehicle includes an electronic oil pump rotating speed control system 601 of a dual-motor hybrid system.

[0164] The electronic oil pump rotating speed control system 601 of the dual-motor hybrid system is configured to collect the motor temperature and the lubricating oil temperature in the oil sump if there is no locked-rotor failure of the motor; obtain the cooling demand flow of the motor, the shaft tooth lubrication flow, and the actual output flow 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; obtain the total demand flow according to the cooling demand flow of the motor and the shaft tooth lubrication flow; and control the rotating speed of the electronic oil pump according to the difference between the total demand flow and the actual output flow and the lubricating oil temperature if the difference is greater than zero.

[0165] The specific definitions of the electronic oil pump rotating speed control system 601 of the dual-motor hybrid system can be seen from the above definitions of the electronic oil pump rotating speed control method of the dual-motor hybrid system, which will not be repeated here.

[0166] In some embodiments, a computer device is provided, which can be a server, and its internal structure diagram can be seen from Figure 7 . The computer device includes a processor, a memory, a network interface, and a database connected by a system bus. The processor of the computer device is configured 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 operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is configured to store the electronic oil pump rotating speed control data of the dual-motor hybrid system. The network interface of the computer device is configured to communicate with an external terminal through a network connection. The computer program is executed by the processor to implement the above-mentioned electronic oil pump rotating speed control method of the dual-motor hybrid system.

[0167] Those skilled in the art can understand that Figure 7 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can 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 on the memory and executable on the processor, and the processor implements the following steps when executing the computer program:

[0169] If the motor does not have a stall fault, the motor temperature and the lubricating oil temperature in the oil sump are collected;

[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 of the motor, the shaft tooth lubrication flow, and the actual output flow of the mechanical oil pump under the current working condition are obtained;

[0171] According to the cooling demand flow of the motor and the shaft tooth lubrication flow, the total demand flow is obtained;

[0172] If the difference between the total demand 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.

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

[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, the shaft tooth lubrication flow and the actual output flow of the mechanical oil pump under the current working condition are obtained;

[0175] According to the shaft tooth lubrication flow, the total demand flow is obtained;

[0176] If the difference between the total demand 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.

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

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

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

[0180] If the motor has a stall fault, the speed of the electronic oil pump is regulated to a preset maximum speed.

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

[0182] Obtaining the rotation speed and torque of the motor under the current working condition;

[0183] Calculating the heat dissipation of the motor according to the rotation speed and torque;

[0184] Calculating the cooling demand flow of the motor according to the heat dissipation of the motor.

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

[0186] According to the cooling demand flow of the motor and the shaft tooth lubrication flow, obtaining the total demand flow, including:

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

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

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

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

[0191] Taking the maximum value among the first total flow, the second total flow and the third total flow as the total demand flow.

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

[0193] Obtaining the rotation speed of the mechanical oil pump;

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

[0195] Calculating the actual output flow of the mechanical oil pump according to the volumetric efficiency and the theoretical oil supply flow of the mechanical oil pump.

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

[0197] Obtaining the volumetric efficiency of the electronic oil pump according to the lubricating oil temperature;

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

[0199] Obtaining the rotation speed of the electronic oil pump according to the lubricating oil temperature and the theoretical oil supply flow of the electronic oil pump.

[0200] In some embodiments, a computer readable storage medium is provided, having stored thereon a computer program which, when executed by a processor, implements the following steps:

[0201] If the motor does not have a stall fault, the motor temperature and the lubricating oil temperature in the oil sump are collected;

[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 of the motor, the shaft tooth lubrication flow, and the actual output flow of the mechanical oil pump under the current working condition are obtained;

[0203] According to the cooling demand flow of the motor and the shaft tooth lubrication flow, the total demand flow is obtained;

[0204] If the difference between the total demand 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.

[0205] In some embodiments, the computer program, when executed by the processor, further implements the following steps:

[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, the shaft tooth lubrication flow and the actual output flow of the mechanical oil pump under the current working condition are obtained;

[0207] According to the shaft tooth lubrication flow, the total demand flow is obtained;

[0208] If the difference between the total demand 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.

[0209] In some embodiments, the computer program, when executed by the processor, further implements the following steps:

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

[0211] In some embodiments, the computer program, when executed by the processor, further implements the following steps:

[0212] If the motor has a stall fault, the speed of the electronic oil pump is regulated to a preset maximum speed.

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

[0214] The speed and torque of the motor under the current working condition are obtained;

[0215] The heat dissipation of the motor is calculated according to the speed and torque;

[0216] The cooling demand flow of the motor is calculated according to the heat dissipation of the motor.

[0217] In some embodiments, the computer program, when executed by the processor, further implements the following steps:

[0218] The total demand flow is obtained according to the cooling demand flow of the motor and the shaft gear lubrication flow, including:

[0219] A preset flow distribution coefficient is obtained, the flow distribution coefficient including a first motor flow distribution coefficient, a second motor flow distribution coefficient, and a shaft gear flow distribution coefficient;

[0220] The first total flow is obtained according to the first motor flow distribution coefficient and the cooling demand flow of the first motor;

[0221] The second total flow is obtained according to the second motor flow distribution coefficient and the cooling demand flow of the second motor;

[0222] The third total flow is obtained according to the shaft gear flow distribution coefficient and the shaft gear lubrication flow;

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

[0224] In some embodiments, the computer program, when executed by the processor, further implements the following steps:

[0225] The rotating speed of the mechanical oil pump is obtained;

[0226] The volumetric efficiency and the theoretical oil supply flow of the mechanical oil pump are obtained according to the lubricating oil temperature and the rotating speed of the mechanical oil pump;

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

[0228] In some embodiments, the computer program, when executed by the processor, further implements the following steps:

[0229] The volumetric efficiency of the electronic oil pump is obtained according to the lubricating oil temperature;

[0230] The theoretical oil supply flow of the electronic oil pump is calculated based on the difference and the volumetric efficiency of the electronic oil pump;

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

[0232] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, storage, databases, or other media in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synch link) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0233] The technical features of the above embodiments can be combined in any way. In order to make the description simple, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present application.

[0234] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended 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 includes: If the motor does not experience 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 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 operating conditions are obtained. The total required flow rate is obtained based on the cooling flow rate of the motor and the lubrication flow rate of the shaft gear; If the difference between the total required flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is adjusted according to the difference and the lubricating oil temperature. 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 obtain the shaft gear lubrication flow rate and the actual output flow rate of the mechanical oil pump under the current operating conditions. Based on the shaft gear lubrication flow rate, the required total flow rate is obtained; If the difference between the total required flow rate and the actual output flow rate is greater than zero, the speed of the electronic oil pump is adjusted according to the difference and the lubricating oil temperature.

2. The method for controlling the speed of an electronic oil pump in a dual-motor hybrid system as described in claim 1, characterized in that, The method further includes: If the motor temperature is greater than the second temperature threshold, the speed of the electronic oil pump is adjusted to the preset maximum speed.

3. The method for controlling the speed of an electronic oil pump in a dual-motor hybrid system as described in claim 1, characterized in that, The method further includes: If the motor stalls, the speed of the electronic oil pump is adjusted to the preset maximum speed.

4. The method for controlling the speed of an electronic oil pump in a dual-motor hybrid system as described in claim 1, characterized in that, The step of obtaining the cooling flow requirement of the motor under the current operating conditions includes: Obtain the motor speed and torque under the current operating conditions; The heat dissipation of the motor is calculated based on the stated rotational speed and torque. The cooling flow rate required for the motor is calculated based on the heat dissipation of the motor.

5. The method for controlling the speed of an electronic oil pump in a dual-motor hybrid system as described in claim 1, characterized in that, The motor includes a first motor and a second motor; The step of obtaining the total required flow rate based on the cooling flow rate of the motor and the lubrication flow rate of the shaft gear includes: Obtain a preset flow distribution coefficient, which includes a first motor flow distribution coefficient, a second motor flow distribution coefficient, and a shaft tooth flow distribution coefficient; The first total flow rate is obtained based on the first motor flow rate allocation coefficient and the cooling flow rate requirement of the first motor; The second total flow rate is obtained based on the second motor flow rate allocation coefficient and the cooling flow rate requirement of the second motor; The third total flow rate is obtained based on 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 taken as the total demand flow.

6. The method for controlling the speed of an electronic oil pump in a dual-motor hybrid system as described in claim 1, characterized in that, Obtain the actual output flow rate of the mechanical oil pump under the current operating conditions, including: Obtain the rotational speed of the mechanical oil pump; Based on the lubricating oil temperature and the rotational 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 rate of the mechanical oil pump is calculated based on the volumetric efficiency and theoretical oil supply flow rate of the mechanical oil pump.

7. The method for controlling the speed of an electronic oil pump in a dual-motor hybrid system as described in claim 1, characterized in that, The step of adjusting the speed of the electronic oil pump based on the difference and the lubricating oil temperature includes: The volumetric efficiency of the electronic oil pump is obtained based on the lubricating oil temperature. The theoretical oil supply flow rate of the electronic oil pump is calculated based on the difference and the volumetric efficiency of the electronic oil pump. The rotational speed of the electronic oil pump is obtained based on the lubricating oil temperature and the theoretical oil supply flow rate of the electronic oil pump.

8. An electronic oil pump speed control system for a dual-motor hybrid system, characterized in that, The system includes: The data acquisition module is used to collect the motor temperature and the lubricating oil temperature in the oil pan if the motor does not experience a stall fault. The acquisition module 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 operating conditions 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 calculation module is used to obtain the total required flow rate based on the cooling flow rate of the motor and the lubrication flow rate of the shaft teeth; The control module is used to adjust the speed of the electronic oil pump according to the difference between the total required flow rate and the actual output flow rate if the difference is greater than zero and the lubricating oil temperature. The acquisition module is further configured to acquire the shaft gear lubrication flow rate and the actual output flow rate of the mechanical oil pump under the current operating conditions 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. The calculation module is also used to obtain the total required flow rate based on the shaft gear lubrication flow rate; The control module is further configured to adjust the rotational speed of the electronic oil pump based on the difference between the total required flow rate and the actual output flow rate if the difference is greater than zero and the lubricating oil temperature.

9. A vehicle, characterized in that, The vehicle includes the dual-motor hybrid system electronic oil pump speed control system as described in claim 8.

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