Torque distribution method and device for dual-motor hybrid system in vehicle and vehicle

Abstract

The invention discloses a torque distribution method and device for a dual-motor hybrid system in a vehicle and the vehicle. The dual-motor hybrid system comprises a permanent magnet synchronous motor and an asynchronous motor, and the method comprises the following steps: determining the working areas of the permanent magnet synchronous motor and the asynchronous motor based on the driving parameters of a vehicle and the required torque of the vehicle, the working area is used for representing an interval to which conditions satisfied by respective execution functions of the permanent magnet synchronous motor and the asynchronous motor belong; in the working area, an objective function and constraint conditions of the dual-motor hybrid system are constructed based on working condition parameters of the dual-motor hybrid system, and the working condition parameters are used for representing the operation state of the dual-motor hybrid system in the working area; determining a torque distribution parameter corresponding to the working area based on the target function and the constraint condition; and distributing torque to the permanent magnet synchronous motor and the asynchronous motor in the working area according to the torque distribution parameters. The technical problem that the torque distribution effect of a dual-motor hybrid system is poor is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle power systems, in particular to a torque distribution method and device for a dual-motor hybrid system in a vehicle and a vehicle. BACKGROUND

[0002] In the related art, in a dual-motor hybrid vehicle, the related torque distribution strategy is limited to the optimization of single motor efficiency, ignoring the advantages of permanent magnet synchronous motor and asynchronous motor in different speed and load intervals. The permanent magnet synchronous motor is known for its high efficiency and torque agile response in the medium and low speed range, while the asynchronous motor shows excellent performance and economy at high speed, and has lower manufacturing cost, becoming an ideal choice. However, the related torque distribution method often fails to finely distinguish the working conditions of the two kinds of motors, resulting in that in actual application, especially in complex environments such as frequent start-stop in cities and high-speed cruising, the overall efficiency of the dual-motor hybrid system is far from its potential, leading to energy waste and poor performance. This limitation highlights the technical bottleneck that the related technology lacks differentiated utilization of the characteristics of the dual-motor in the hybrid power system, and the torque distribution effect is not satisfactory. Therefore, there is still a technical problem of poor torque distribution effect of the dual-motor hybrid system.

[0003] At present, there is no effective solution to the above technical problems. SUMMARY

[0004] The embodiments of the present application provide a torque distribution method and device for a dual-motor hybrid system in a vehicle and a vehicle to at least solve the technical problem of poor torque distribution effect of the dual-motor hybrid system.

[0005] According to an aspect of the embodiments of the present application, a torque distribution method for a dual-motor hybrid system in a vehicle is provided. The dual-motor hybrid system includes a permanent magnet synchronous motor and an asynchronous motor. The method includes: determining working regions of the permanent magnet synchronous motor and the asynchronous motor based on driving parameters of the vehicle and a required torque of the vehicle, wherein the working region is used to represent an interval to which a condition that the functions performed by the permanent magnet synchronous motor and the asynchronous motor meet belong; within the working region, constructing a target function and a constraint condition of the dual-motor hybrid system based on working condition parameters of the dual-motor hybrid system, wherein the working condition parameter is used to represent a running state of the dual-motor hybrid system in the working region; determining torque distribution parameters corresponding to the working region based on the target function and the constraint condition; and distributing torque to the permanent magnet synchronous motor and the asynchronous motor in the working region according to the torque distribution parameters.

[0006] Optionally, based on the driving parameter of the vehicle and the demand torque of the vehicle, the working region of both the permanent magnet synchronous motor and the asynchronous motor is determined, including: determining a driving parameter interval in which the driving parameter is located, and a size relationship between the demand torque and a torque upper limit of the permanent magnet synchronous motor torque; based on the driving parameter interval and the size relationship, the working region is determined.

[0007] Optionally, the driving parameter interval includes a first driving parameter interval, a second driving parameter interval and a third driving parameter interval, the second driving parameter interval is greater than the first driving parameter interval, and the third driving parameter interval is greater than the second driving parameter interval; the working region includes a first working region, a second working region, a third working region and a fourth working region; based on the driving parameter interval and the size relationship, the working region is determined, including: in response to the driving parameter being in the first driving parameter interval and the demand torque being less than or equal to the torque upper limit, the working region is determined as the first working region, wherein the permanent magnet synchronous motor in the first working region is in a working state, and the asynchronous motor is in a standby state; in response to the driving parameter being in the first driving parameter interval and the demand torque being greater than the torque upper limit, the working region is determined as the second working region, wherein the permanent magnet synchronous motor in the second working region is in a main driving state, and the asynchronous motor is in an auxiliary driving state; in response to the driving parameter being in the second driving parameter interval, the working region is determined as the third working region, wherein both the permanent magnet synchronous motor and the asynchronous motor in the third working region enter a working state according to an efficiency maximum distribution parameter; in response to the driving parameter being in the third driving parameter interval, the working region is determined as the fourth working region, wherein the asynchronous motor in the fourth working region is in a main driving state, and the permanent magnet synchronous motor is in an auxiliary driving state.

[0008] Optionally, the working condition parameters include the permanent magnet synchronous motor torque, the asynchronous motor torque, the permanent magnet synchronous motor efficiency, the asynchronous motor efficiency, the total loss of the dual-motor hybrid system, the permanent magnet synchronous motor speed and the asynchronous motor speed; based on the working condition parameters of the dual-motor hybrid system in the working region, a target function of the dual-motor hybrid system is constructed, including: in the working region, based on the permanent magnet synchronous motor torque, the asynchronous motor torque, the permanent magnet synchronous motor efficiency, the asynchronous motor efficiency, the permanent magnet synchronous motor speed and the asynchronous motor speed, the target function is constructed with the target of minimizing the total loss.

[0009] Optionally, the constraint conditions comprise a first constraint condition, a second constraint condition and a third constraint condition, and the constraint conditions of the dual-motor hybrid system are constructed based on the working condition parameters of the dual-motor hybrid system in the working area, comprising: taking the sum of the permanent magnet synchronous motor torque and the asynchronous motor torque as the demand torque as the first constraint condition; taking the torque lower limit of the permanent magnet synchronous motor torque less than or equal to the permanent magnet synchronous motor torque, and the permanent magnet synchronous motor torque less than or equal to the torque upper limit of the permanent magnet synchronous motor torque as the second constraint condition; and taking the torque lower limit of the asynchronous motor torque less than or equal to the asynchronous motor torque, and the asynchronous motor torque less than or equal to the torque upper limit of the asynchronous motor torque as the third constraint condition.

[0010] Optionally, the method further comprises: modeling and simulating the objective function and the constraint conditions to obtain a simulation result; generating code information based on the simulation result, and entering the code information into a vehicle controller of the vehicle.

[0011] According to another aspect of the embodiments of the present application, a torque distribution device of a dual-motor hybrid system in a vehicle is also provided. The device can comprise: a first determination unit configured to determine a working area of a permanent magnet synchronous motor and an asynchronous motor in the dual-motor hybrid system based on driving parameters of the vehicle and a demand torque of the vehicle, wherein the working area is used to represent an interval to which a condition that the functions of the permanent magnet synchronous motor and the asynchronous motor are respectively satisfied belong; a construction unit configured to construct an objective function and constraint conditions of the dual-motor hybrid system in the working area based on working condition parameters of the dual-motor hybrid system, wherein the working condition parameters are used to at least represent a running state of the dual-motor hybrid system in the working area; a second determination unit configured to determine torque distribution parameters corresponding to the working area based on the objective function and the constraint conditions; and a distribution unit configured to distribute torque to the permanent magnet synchronous motor and the asynchronous motor in the working area according to the torque distribution parameters.

[0012] According to another aspect of the embodiments of the present application, a computer readable storage medium is also provided. The computer readable storage medium comprises a stored program, wherein the program, when running, controls a device where the computer readable storage medium is located to execute the above-mentioned method of the embodiments of the present application.

[0013] According to another aspect of the embodiments of the present application, a processor is also provided. The processor is used to run a program, wherein the program, when running, executes the above-mentioned method of the embodiments of the present application.

[0014] According to another aspect of the embodiments of the present application, an electronic device is also provided. The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor is configured to run the computer program to execute the above-mentioned method of the embodiments of the present application.

[0015] According to another aspect of the embodiments of the present application, a computer program product is also provided. The computer program product comprises a computer program which, when executed by a processor, implements the above method according to the embodiments of the present application.

[0016] According to another aspect of the embodiments of the present application, a vehicle is also provided. The vehicle comprises a memory and a processor. The memory stores an executable program; and the processor is configured to execute the program, and the program, when executed, implements the above method according to the embodiments of the present application.

[0017] In the embodiments of the present application, based on the driving parameters of the vehicle and the demand torque of the vehicle, the working region of both the permanent magnet synchronous motor and the asynchronous motor is determined, wherein the working region is used to represent the interval to which the condition that the functions performed by the permanent magnet synchronous motor and the asynchronous motor meet belong; within the working region, based on the working condition parameters of the dual-motor hybrid system, the objective function and the constraint condition of the dual-motor hybrid system are constructed, wherein the working condition parameters are used to represent the running state of the dual-motor hybrid system within the working region; based on the objective function and the constraint condition, the torque distribution parameters corresponding to the working region are determined; and according to the torque distribution parameters, the torque is distributed to the permanent magnet synchronous motor and the asynchronous motor within the working region. That is, in this embodiment, by monitoring the driving parameters and the demand torque of the vehicle in real time, the working region of the dual-motor is intelligently identified and dynamically adjusted, so that each motor operates in the best performance interval. In each identified working region, the algorithm constructs an objective function with the optimization of efficiency as the target, sets the constraint condition in combination with the actual working condition parameters, and accurately calculates the torque distribution ratio. This method not only strengthens the synergistic effect of the dual-motor in the whole working condition, but also significantly improves the system energy utilization efficiency and driving performance, especially in the urban congestion and high-speed driving scenarios, and avoids energy waste and low efficiency. The embodiments of the present application emphasize the importance of intelligent torque distribution, and provide an innovative path for the performance optimization of the dual-motor hybrid electric vehicle by deeply exploiting the complementary advantages of the dual-motor, solve the technical problem of poor torque distribution effect of the dual-motor hybrid system, and achieve the technical effect of improving the torque distribution effect of the dual-motor hybrid system. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application. In the drawings:

[0019] Figure 1 FIG. 1 is a flowchart of a torque distribution method for a dual-motor hybrid system in a vehicle according to an embodiment of the present application;

[0020] Figure 2 FIG. 2 is a schematic diagram of a torque distribution system for a dual-motor hybrid electric vehicle according to an embodiment of the present application;

[0021] Figure 3 is a flow chart of a torque distribution method of a dual-motor hybrid system in a vehicle according to an embodiment of the present application.

[0022] Figure 4 is a schematic diagram of a torque distribution device of a dual-motor hybrid system in a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the personnel in the art better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0024] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to the steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] According to an embodiment of the present application, an embodiment of a torque distribution method of a dual-motor hybrid system in a vehicle is provided. It should be noted that the steps shown in the flow chart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flow chart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0026] Figure 1 is a flow chart of a torque distribution method of a dual-motor hybrid system in a vehicle according to an embodiment of the present application, as shown in Figure 1 the method can include the following steps:

[0027] Step S102, based on the driving parameters of the vehicle and the required torque of the vehicle, the working area of the permanent magnet synchronous motor and the asynchronous motor is determined.

[0028] In the technical solution provided in the step S102 of the present application, the dual-motor hybrid system comprises a permanent magnet synchronous motor and an asynchronous motor. The working region is used to represent the interval to which the conditions met by the respective functions of the permanent magnet synchronous motor and the asynchronous motor belong.

[0029] Optionally, the driving parameter can be the vehicle speed of the vehicle. The vehicle can be a dual-motor hybrid vehicle. The vehicle speed can not only reflect the current motion state of the vehicle, but also predict the future power demand. The vehicle speed has a direct impact on the efficiency of the motor: different types of motors perform differently at different speeds. The permanent magnet synchronous motor has high efficiency and fast response in the low-to-medium speed range, while the asynchronous motor has higher efficiency and cost advantage in the high speed range.

[0030] Optionally, the demand torque can also be referred to as power demand / demand torque Tq. The demand torque can refer to the torque that the vehicle must output in a certain working condition to achieve the required acceleration or overcome the road resistance. In a hybrid power system, the demand torque is an important basis for the vehicle controller to determine the torque contribution of the internal combustion engine, the electric motor or both. The size of the demand torque depends on various factors, including the driver's operation (such as the depth of the accelerator pedal), the road conditions (such as a slope or a flat road), and the vehicle load, etc., which is directly related to the driving performance and energy consumption of the vehicle.

[0031] Optionally, the working region can refer to a specific interval in which the permanent magnet synchronous motor and the asynchronous motor can achieve optimal efficiency or performance under certain conditions of driving parameters and demand torque. For a dual-motor hybrid system, the division of the working region is based on the inherent characteristics of the motor, aiming to make each motor run near the optimal point of its efficiency curve. For example, the permanent magnet synchronous motor has higher efficiency and torque response in the low-to-medium speed range, and is suitable for being used as the main driving source in this working region; while the asynchronous motor has higher efficiency at high speed, and has better cost-effectiveness, and is therefore more suitable for working in the high-speed working region. According to the current driving parameter and demand torque of the vehicle, the working region can be dynamically adjusted, so as to optimize the torque distribution of the entire power system, improve the overall efficiency and improve the driving experience.

[0032] In this embodiment, the working regions of the permanent magnet synchronous motor and the asynchronous motor can be determined based on the driving parameter and the demand torque of the vehicle.

[0033] Optionally, the driving parameters of the vehicle are collected, such as the vehicle speed (V), the remaining battery capacity, the accelerator pedal position, etc. The current demand torque (Tq_req) of the vehicle is read, which reflects the driver's operation intention or the demand of the vehicle automatic driving system. The vehicle speed V is analyzed to determine whether it is currently in a low-speed, medium-speed or high-speed driving condition. The accelerator pedal position is evaluated to determine whether the vehicle is accelerating, decelerating or maintaining a constant speed. The remaining battery capacity is considered to determine whether the vehicle has sufficient electrical energy to support the electric motor to provide torque under high power demand.

[0034] Optionally, based on the characteristic curve of the permanent magnet synchronous motor, the efficiency and torque output range of the permanent magnet synchronous motor under the current driving parameters are determined. Based on the characteristic curve of the asynchronous motor, the efficiency and torque output range of the asynchronous motor under the current driving parameters are determined. It is determined whether the current vehicle speed is in the high efficiency interval of the permanent magnet synchronous motor, and if the condition is met, the permanent magnet synchronous motor is the main drive motor and the asynchronous motor is the auxiliary or does not participate in driving. It is determined whether the current vehicle speed is in the high efficiency interval of the asynchronous motor, and if the condition is met, the participation degree of the asynchronous motor is increased until it becomes the main driving source.

[0035] Step S104, in the working area, based on the working condition parameters of the dual-motor hybrid system, the target function and the constraint condition of the dual-motor hybrid system are constructed.

[0036] In the technical solution provided by the above step S104 of the present application, the working condition parameters are used to represent the running state of the dual-motor hybrid system in the working area.

[0037] Optionally, the working condition parameters can be a series of variables reflecting the current running environment and state of the dual-motor hybrid system, which can directly or indirectly affect the efficiency, torque output of the motor and the overall performance of the system. The working condition parameters can include: pedal opening, power, total demand torque, efficiency of each motor, upper and lower limits of motor torque, etc. Among them, the pedal opening can reflect the driver's acceleration and deceleration intention, and directly affect the size of the demand torque. The remaining power can determine the ability of the system to use the electric motor and the degree of its participation in driving. The total demand torque (Tq_req) can be calculated according to the driving state of the vehicle and the operation of the driver, and is an important basis for determining the torque distribution of the motor. The efficiency of each motor can be the working efficiency of the motor under certain working conditions. The higher the efficiency, the less energy is consumed under the same output power, which is a key parameter for constructing the target function. The upper and lower limits of the motor torque can be the minimum and maximum torque output range for safe and stable operation of the motor, which is used as a constraint condition to limit the torque distribution of the motor and avoid overloading or ineffective use.

[0038] Optionally, the objective function is a mathematical expression that quantifies the performance indicator of the dual-motor hybrid system under a specific operating condition. In the present application, the core of the objective function is to find the torque distribution scheme that maximizes the system comprehensive efficiency. The constraints can be the limitations on the parameters during the optimization process of the objective function, ensuring that the solution is physically and technically feasible.

[0039] In this embodiment, after determining the operating region based on the driving parameters and the demand torque, the objective function and the constraints can be constructed based on the operating condition parameters of the dual-motor hybrid system within the operating region.

[0040] Step S106, based on the objective function and the constraints, determine the torque distribution parameters corresponding to the operating region.

[0041] In the technical solution of step S106 of the present application, the torque distribution parameters are the optimal solution under the given objective function and constraints, which are used to guide the torque output of the permanent magnet synchronous motor and the asynchronous motor in a specific operating region. These parameters directly determine how the two motors work together to meet the power demand of the vehicle, while maximizing the system efficiency or meeting other optimization goals. The above-mentioned torque distribution parameters can include: torque ratio, torque distribution value, motor operating mode, dynamic adjustment strategy, optimization weight, etc.

[0042] Optionally, the above-mentioned torque ratio can be the most intuitive distribution parameter, indicating the torque share that each of the two motors should bear in the total demand torque. For example, in a certain specific operating condition, the permanent magnet synchronous motor bears 70% of the total torque, and the asynchronous motor bears 30%, such a ratio is the torque distribution parameter. The above-mentioned torque distribution value can directly give the specific torque value that each motor should output. In actual execution, the controller will send control instructions to the motor according to the calculated distribution value, so that the motor outputs the corresponding torque.

[0043] Optionally, the above-mentioned motor operating mode can be the operating mode of the motor within the operating region, such as no-load operation, full-load operation, auxiliary drive or switching of main drive motor, etc. This is closely related to the upper and lower limit constraints of the motor torque output. The above-mentioned dynamic adjustment strategy can dynamically adjust the torque distribution value and ratio according to real-time parameters such as vehicle speed change, battery power, road slope, etc. The above-mentioned strategy ensures that the dual-motor system can adapt to various operating conditions and maintain optimal efficiency.

[0044] Optionally, the above-mentioned optimization weight can be the weight of different operating condition parameters included in the objective function, which will also affect the torque distribution parameters. For example, if more attention is paid to system efficiency than to instant response when driving at high speed, the weight of efficiency will be higher than that of response speed in the objective function, thereby guiding different torque distribution strategies.

[0045] In this embodiment, after the objective function and the constraint conditions of the dual-motor hybrid system are constructed, the torque distribution parameters corresponding to the working region can be determined based on the objective function and the constraint conditions.

[0046] At step S108, the torque is distributed to the permanent magnet synchronous motor and the asynchronous motor in the working region according to the torque distribution parameters.

[0047] In the technical solution of step S108 of the present application, after the torque distribution parameters are determined based on the objective function and the constraint conditions, the torque can be distributed to the permanent magnet synchronous motor and the asynchronous motor in the working region according to the torque distribution parameters.

[0048] Optionally, the torque distribution parameters of the permanent magnet synchronous motor and the asynchronous motor in a specific working region have been determined through complex algorithm optimization. These parameters usually include torque output values or torque distribution ratios of the two motors, which are the optimal solutions obtained based on the objective function (such as minimizing the total system loss) and the constraint conditions (such as torque balance, upper and lower limits of motor torque).

[0049] Optionally, once the torque distribution parameters are determined, the next step is to convert these parameters into specific control instructions and send them to the motor control system. This process involves two key technical operations: torque conversion and instruction sending. The above-mentioned torque conversion can convert the theoretical torque distribution value into a signal or instruction format that can be understood by the motor control system. For example, if the input of the control system is a pulse width modulation signal, the torque value needs to be converted into the corresponding signal intensity. The above-mentioned instruction sending can be sending the control instructions corresponding to the torque distribution parameters to the motor controllers of the permanent magnet synchronous motor and the asynchronous motor through appropriate communication protocols after the torque distribution parameters are converted into control instructions. After receiving the instructions, the motor controller will adjust the current, voltage and other parameters of the motor to accurately output the required torque.

[0050] Optionally, after the motor controller receives the control instructions corresponding to the torque distribution parameters, each motor will start to perform the torque output task assigned to it. The permanent magnet synchronous motor has high efficiency characteristics in the low to medium speed region. According to the assigned torque value, the motor controller adjusts the size and frequency of the phase current to make the motor generate the predetermined torque. In low power or high power demand working conditions, the permanent magnet synchronous motor may need to output at full capacity to ensure sufficient driving ability. The asynchronous motor has higher efficiency and better cost-effectiveness in the high speed region. If the asynchronous motor is required to participate in the distribution strategy, the motor controller will adjust the frequency and voltage of the alternating current power supply accordingly to drive the asynchronous motor to output its assigned torque. In the case of sudden acceleration or other high power demand scenarios, the asynchronous motor quickly intervenes to supplement the torque to ensure the immediate satisfaction of power demand.

[0051] Optionally, after torque distribution, the vehicle controller will continuously monitor the actual operating conditions of the vehicle, including actual torque output, battery power, motor temperature and other key parameters. If deviations or changes in working conditions are found (such as sudden acceleration, power drop), the controller will re-evaluate the working condition parameters, update the torque distribution parameters, and perform step S108 again to ensure that the motor torque distribution always meets the optimal strategy. By accurately executing the torque distribution parameters, the dual-motor hybrid system can quickly respond to the needs of the driver, providing smooth and efficient power output. For the driver, this means better driving experience, higher energy utilization efficiency, and longer vehicle range.

[0052] The above steps S102 to S108 of the present application determine the working regions of the permanent magnet synchronous motor and the asynchronous motor based on the driving parameters of the vehicle and the demand torque of the vehicle, wherein the working region represents the interval to which the conditions met by the respective functions of the permanent magnet synchronous motor and the asynchronous motor belong; within the working region, the target function and the constraint condition of the dual-motor hybrid system are constructed based on the working condition parameters of the dual-motor hybrid system, wherein the working condition parameters represent the running state of the dual-motor hybrid system in the working region; the torque distribution parameters corresponding to the working region are determined based on the target function and the constraint condition; and the torque is distributed to the permanent magnet synchronous motor and the asynchronous motor in the working region according to the torque distribution parameters. That is, in this embodiment, by real-time monitoring of the driving parameters and demand torque of the vehicle, the working regions of the dual-motor are intelligently identified and dynamically adjusted, so that each motor operates in the best efficiency interval. In each identified working region, the algorithm constructs a target function with efficiency optimization, sets constraint conditions in combination with actual working condition parameters, and accurately calculates the torque distribution ratio. This method not only strengthens the synergistic effect of the dual-motor in the whole working condition, but also significantly improves the system energy utilization efficiency and driving performance, especially in urban congestion and high-speed driving scenarios, and avoids energy waste and low efficiency. The present application emphasizes the importance of intelligent torque distribution, deeply excavates the complementary advantages of the dual-motor, and provides an innovative path for the efficiency optimization of the dual-motor hybrid electric vehicle, solves the technical problem of poor torque distribution effect of the dual-motor hybrid system, and achieves the technical effect of improving the torque distribution effect of the dual-motor hybrid system.

[0053] The above method of this embodiment will be further introduced below.

[0054] As an optional embodiment, step S102, based on the driving parameters of the vehicle and the demand torque of the vehicle, determines the working regions of the permanent magnet synchronous motor and the asynchronous motor, comprising: determining the driving parameter interval in which the driving parameters are located, and the size relationship between the demand torque and the torque upper limit of the permanent magnet synchronous motor; and determining the working region based on the driving parameter interval and the size relationship.

[0055] In this embodiment, the driving parameter interval can refer to dividing the driving parameters of the vehicle, such as the vehicle speed, the battery state, the accelerator pedal opening degree, the outside temperature, and the like, into a plurality of preset intervals according to the degree of influence of the driving parameters on the motor efficiency and the vehicle performance. Each interval represents a typical operating condition or state, so that the control strategy can automatically select the most suitable motor operating mode and torque distribution scheme according to the interval in which the vehicle is currently located. For example, the vehicle speed can be divided into a low-speed interval (such as 0-60 km / h), a medium-speed interval (such as 60-120 km / h), and a high-speed interval (such as >120 km / h).

[0056] Optionally, the permanent magnet synchronous motor torque refers to the torque amount that the permanent magnet synchronous motor can output when operating, which is a key indicator for measuring the power output capability of the motor. The size of the motor torque directly affects the acceleration and climbing ability of the vehicle. The permanent magnet synchronous motor exhibits higher efficiency in a specific torque and speed range due to its inherent characteristics, and therefore, the torque output capability is also an important consideration factor in the control strategy.

[0057] Optionally, the torque upper limit refers to the maximum torque value that the motor can provide in a safe and stable operating state, which is subject to a series of limitations such as the design of the motor, the efficiency of the cooling system, the power supply capability of the battery, and the like. For the permanent magnet synchronous motor, the torque upper limit is determined according to the safety threshold set by the physical characteristics of the motor and the vehicle control system. Exceeding this upper limit, the motor may enter an overheating or overloading state, leading to damage or shortening of the service life, and therefore, this is a hard constraint condition that must be strictly followed in torque distribution.

[0058] Optionally, the size relationship can refer to the comparison between the demand torque of the vehicle and the torque upper limit of the permanent magnet synchronous motor. The demand torque is calculated according to the current driving state of the vehicle and the driver's operation (such as the pedal opening degree), and the above-mentioned size relationship can reflect the total amount of torque that the vehicle needs to obtain from the drive system. If the demand torque is less than or equal to the torque upper limit of the permanent magnet synchronous motor, it indicates that the permanent magnet synchronous motor can independently bear all the torque demand; otherwise, when the demand torque exceeds the torque upper limit of the permanent magnet synchronous motor, it indicates that the permanent magnet synchronous motor cannot meet the demand alone, and at this time, the asynchronous motor needs to be introduced to share the torque together to ensure the normal operation of the vehicle and the timely response of the power demand.

[0059] Optionally, in the process of determining the working area based on the driving parameter and the demand torque, the driving parameter interval in which the driving parameter is located, and the size relationship between the demand torque and the torque upper limit of the permanent magnet synchronous motor can be determined. The working area can be determined based on the driving parameter interval and the size relationship.

[0060] Optionally, the above driving parameters are mapped into predefined driving parameter intervals, for example, the vehicle speed interval can be divided into low speed (0-65km / h), medium speed (65-100km / h), and high speed (>100km / h). The interval division of each driving parameter is based on the efficiency characteristics of the motor, vehicle performance requirements, and safety limits. For example, permanent magnet synchronous motor (PMSM) has the highest efficiency in the low speed interval, while asynchronous motor (IM) performs better in the high speed interval.

[0061] Optionally, the demand torque reflects the power required by the vehicle under the current working condition, which is determined by the driving state of the vehicle and the operation of the driver (such as pedal opening). Permanent magnet synchronous motor has a set of torque upper limit, i.e. the maximum torque value that the motor can safely and stably output under different working condition parameters. In the above step, it can be analyzed whether the demand torque exceeds the torque upper limit of the permanent magnet synchronous motor in the current driving parameter interval. If the demand torque is less than or equal to the torque upper limit, the permanent magnet synchronous motor can independently meet the demand. If the demand torque exceeds the torque upper limit, it means that the asynchronous motor needs to intervene to provide additional torque support.

[0062] Optionally, the determination of the working area is based on the above analysis results to guide the torque distribution strategy of the two motors. The following logic is mainly considered: low speed working area, if the vehicle speed is in the low speed interval and the demand torque is less than or equal to the torque upper limit of the permanent magnet synchronous motor, then the permanent magnet synchronous motor acts as the main drive motor, and the asynchronous motor generally does not participate in driving (unless there is a special high torque demand). Medium speed working area, this interval is the transition area of the two motors, according to the demand torque and efficiency characteristics, the torque distribution ratio of the two motors may need to be dynamically adjusted to ensure the overall efficiency of the system. High speed working area, if the vehicle speed is in the high speed interval, the participation of the asynchronous motor will increase regardless of the demand torque, and it may even become the main power source.

[0063] Optionally, based on the determined working area, the system adjusts the torque distribution strategy of the permanent magnet synchronous motor and the asynchronous motor. For example: in the low speed working area, only the permanent magnet synchronous motor may be used, or when the demand torque is high, the asynchronous motor is introduced as an auxiliary. In the medium speed working area, according to the real-time working condition, the optimal proportion of torque distribution of the two motors is found to ensure the balance between efficiency and power performance. In the high speed working area, the system tends to increase the torque proportion of the asynchronous motor to fully exert its high speed performance advantage.

[0064] Optionally, according to the determined working area and torque distribution strategy, the controller generates and sends corresponding control instructions to the two motors. At the same time, the actual driving parameters and motor states of the vehicle are continuously monitored to adjust the working area and torque distribution parameters in a timely manner when the working condition changes, so as to ensure that the system always operates in the optimal state.

[0065] As an optional embodiment, the driving parameter interval includes a first driving parameter interval, a second driving parameter interval and a third driving parameter interval, the second driving parameter interval is greater than the first driving parameter interval, and the third driving parameter interval is greater than the second driving parameter interval; the working area includes a first working area, a second working area, a third working area and a fourth working area; and the working area is determined based on the driving parameter interval and the size relationship, including: in response to the driving parameter being in the first driving parameter interval and the demand torque being less than or equal to the torque upper limit, the working area is determined as the first working area, wherein the permanent magnet synchronous motor in the first working area is in the working state, and the asynchronous motor is in the standby state; in response to the driving parameter being in the first driving parameter interval and the demand torque being greater than the torque upper limit, the working area is determined as the second working area, wherein the permanent magnet synchronous motor in the second working area is in the main driving state, and the asynchronous motor is in the auxiliary driving state; in response to the driving parameter being in the second driving parameter interval, the working area is determined as the third working area, wherein the permanent magnet synchronous motor and the asynchronous motor in the third working area both enter the working state according to the maximum efficiency distribution parameter; and in response to the driving parameter being in the third driving parameter interval, the working area is determined as the fourth working area, wherein the asynchronous motor in the fourth working area is in the main driving state, and the permanent magnet synchronous motor is in the auxiliary driving state.

[0066] In this embodiment, the driving parameter interval can be divided into multiple sections according to the main operating parameters of the vehicle, such as vehicle speed, so as to formulate a driving strategy more suitable for different speed ranges. In a dual-motor hybrid system, different driving parameter intervals correspond to different characteristics of motor efficiency and vehicle demand. The first driving parameter interval can be a low-speed stage, which can refer to a vehicle speed between 0-65 km / h. In this interval, the vehicle is usually in a city congestion or low-speed cruising state, and the permanent magnet synchronous motor is the ideal choice due to its high efficiency and response speed at low speed. The second driving parameter interval can be a medium-speed stage, with a vehicle speed of 65-100 km / h. In the second driving parameter interval, the vehicle can be in a medium-load working condition in the suburbs or on the highway, at which time the cooperation of the permanent magnet synchronous motor and the asynchronous motor begins to show its advantages. The third driving parameter interval can be a high-speed stage, which can refer to a vehicle speed exceeding 100 km / h. When the vehicle is on the highway or needs strong power output, the asynchronous motor can play an important role due to its good efficiency characteristics at high speed.

[0067] Optionally, the first working region can be in the first driving parameter interval (low speed stage), if the vehicle demand torque is less than or equal to the torque upper limit of the permanent magnet synchronous motor, the system will rely entirely on the permanent magnet synchronous motor to work, and the asynchronous motor remains in standby state. In the above-mentioned first working region, the high efficiency and fast response of the permanent magnet synchronous motor can meet most of the urban driving conditions. The second working region is also in the low speed stage, but when the vehicle demand torque exceeds the torque upper limit of the permanent magnet synchronous motor, the system will enter this region. At this time, the permanent magnet synchronous motor will bear the main driving responsibility, and the asynchronous motor will join as an auxiliary driving motor to jointly meet the demand torque exceeding the capacity of a single motor, so as to maintain the power performance of the vehicle.

[0068] Optionally, the third working region is when the vehicle is in the medium speed interval, the permanent magnet synchronous motor and the asynchronous motor will both enter the working state, according to the preset efficiency maximum distribution parameter, the two motors will work together to proportionally distribute the torque, so as to achieve the goal of optimal overall efficiency of the system. This mode not only ensures the power performance, but also considers the effective use of energy. The fourth working region is when the vehicle is in the high speed interval, it will rely more on the driving capacity of the asynchronous motor, so that it becomes the main driving source, and the permanent magnet synchronous motor changes into an auxiliary role to provide additional torque to meet the demand under the condition of high speed driving or heavy load. This mode makes full use of the efficiency advantage of the asynchronous motor at high speed to maintain good system performance.

[0069] Optionally, in the process of determining the working region based on the driving parameter interval and the size parameter, if the driving parameter is in the first driving parameter interval and the demand torque is less than or equal to the torque upper limit, the working region can be determined as the first working region. If the driving parameter is in the first driving parameter interval and the demand torque is greater than the torque upper limit, the working region can be determined as the second working region. If the driving parameter is in the second driving parameter interval, the working region can be determined as the third working region. If the driving parameter is in the third driving parameter interval, the working region can be determined as the fourth working region.

[0070] Optionally, when the vehicle driving parameter falls in the first driving parameter interval and the demand torque does not exceed the torque upper limit of the permanent magnet synchronous motor, the permanent magnet synchronous motor will independently undertake the driving task, and the asynchronous motor remains in standby state. This ensures that in low speed urban driving, the system can provide the required power output with minimum energy consumption. When the vehicle needs higher torque output in the low speed interval, i.e. the demand torque exceeds the torque upper limit of the permanent magnet synchronous motor, the second working region will be entered. At this time, the permanent magnet synchronous motor remains in the main driving state, but the asynchronous motor will be activated to enter the auxiliary driving state, to jointly provide the required torque, so as to ensure that the power demand of the vehicle is met.

[0071] Optionally, when the vehicle driving parameter falls in the second driving parameter interval, both the permanent magnet synchronous motor and the asynchronous motor will be activated and enter the working state. The torque distribution of the two will be dynamically adjusted according to the real-time maximum efficiency distribution parameter, which aims to ensure the highest overall system operation efficiency while adapting to the current medium-speed driving demand. In this region, there is no fixed primary and auxiliary driving motor, and they will flexibly distribute torque according to the efficiency characteristics.

[0072] Optionally, when the vehicle driving parameter is in the third driving parameter interval, i.e., high-speed driving, the asynchronous motor will change into the main driving motor of the system, and the permanent magnet synchronous motor will become the auxiliary driving role. The above change is based on the efficiency characteristics of the asynchronous motor at high speed, which improves the overall efficiency and performance of the system by maximizing the advantages of the asynchronous motor.

[0073] In the embodiment of the present application, by dynamically adjusting the working mode and torque distribution of the permanent magnet synchronous motor and the asynchronous motor in different driving parameter intervals, the embodiment realizes the optimal performance of the dual-motor system in the full working condition range. Each step is based on the accurate calculation and evaluation of real-time driving parameters and demand torque, ensuring that the system is more energy-efficient and responds faster at low speed; the system can dynamically adjust to improve overall efficiency and ensure smooth driving at medium speed; at high speed, the system utilizes the advantages of the asynchronous motor to continuously provide efficient power and reduce energy consumption. The above intelligent torque distribution strategy based on driving parameter intervals and demand torque not only improves the energy utilization efficiency of the dual-motor hybrid electric vehicle, but also optimizes the driving experience.

[0074] As an optional embodiment, the working condition parameters include permanent magnet synchronous motor torque, asynchronous motor torque, permanent magnet synchronous motor efficiency, asynchronous motor efficiency, total loss of the dual-motor hybrid system, permanent magnet synchronous motor speed, and asynchronous motor speed. In step S104, a target function of the dual-motor hybrid system is constructed based on the working condition parameters of the dual-motor hybrid system in the working area, including: in the working area, based on the permanent magnet synchronous motor torque, the asynchronous motor torque, the permanent magnet synchronous motor efficiency, the asynchronous motor efficiency, the permanent magnet synchronous motor speed, and the asynchronous motor speed, a target function is constructed with the goal of minimizing the total loss.

[0075] In this embodiment, the permanent magnet synchronous motor torque can refer to the torque value that the permanent magnet synchronous motor can output when working. Torque is an important parameter to measure the power output capability of the motor, which directly affects the acceleration performance and climbing ability of the vehicle. The asynchronous motor torque can refer to the torque output capability of the asynchronous motor, which is different from that of the permanent magnet synchronous motor, especially at high speed, which may have higher efficiency. The asynchronous motor torque represents the driving force that the motor can provide under given working conditions.

[0076] Optionally, the permanent magnet synchronous motor efficiency can measure the ability of the permanent magnet synchronous motor to convert electrical energy into mechanical energy, i.e. the energy conversion rate of the motor operation. The efficiency is affected by multiple factors, including the load, speed, temperature, etc. of the motor. The asynchronous motor efficiency is similar to the permanent magnet synchronous motor efficiency, which reflects the effective degree of the motor in converting electrical energy into mechanical energy. Compared with the permanent magnet synchronous motor, the efficiency performance of the asynchronous motor under different working conditions may be different, especially when running at high speed, which may have better efficiency.

[0077] Optionally, the total loss can refer to the total amount of energy consumed by the entire dual-motor hybrid system when working but not converted into useful work. This includes internal losses of the motor (such as copper loss, iron loss, mechanical loss), electrical control system loss, transmission system loss, etc. Minimizing the total loss is a key goal to improve the energy utilization efficiency of the system and reduce the cost.

[0078] Optionally, in the process of constructing the objective function based on the working condition parameters, within the working area, the objective function can be constructed based on the permanent magnet synchronous motor torque, the asynchronous motor torque, the permanent magnet synchronous motor efficiency, and the asynchronous motor efficiency, with the goal of minimizing the total loss.

[0079] For example, the objective function can be determined by the following formula:

[0080] min J =∑(T_m^2 / η_m(T_m,n_m)+T_a^2 / η_a(T_a,n_a))

[0081] Wherein, J can be used to represent the total loss; T_m can be used to represent the permanent magnet synchronous motor torque; T_a can be used to represent the asynchronous motor torque; η_m can be used to represent the permanent magnet synchronous motor efficiency, η_a can be used to represent the asynchronous motor efficiency; n_m can be used to represent the permanent magnet synchronous motor speed; n_a can be used to represent the asynchronous motor speed.

[0082] As an optional embodiment, the constraint conditions include a first constraint condition, a second constraint condition and a third constraint condition, and the constraint conditions of the dual-motor hybrid system are constructed based on the working condition parameters of the dual-motor hybrid system within the working area, including: taking the sum of the permanent magnet synchronous motor torque and the asynchronous motor torque as the demand torque as the first constraint condition; taking the torque lower limit of the permanent magnet synchronous motor torque less than or equal to the permanent magnet synchronous motor torque, and the permanent magnet synchronous motor torque less than or equal to the torque upper limit of the permanent magnet synchronous motor torque as the second constraint condition; and taking the torque lower limit of the asynchronous motor torque less than or equal to the asynchronous motor torque, and the asynchronous motor torque less than or equal to the torque upper limit of the asynchronous motor torque as the third constraint condition.

[0083] In this embodiment, the first constraint condition can ensure that the sum of the torque outputs of the permanent magnet synchronous motor and the asynchronous motor can always meet the torque demand of the vehicle under the current working condition, regardless of how the system adjusts the torque output of the dual motor. This is the most basic and important constraint in the system design, which ensures that the power performance of the vehicle will not be affected by improper torque distribution.

[0084] Optionally, the second constraint condition limits the torque output range of the permanent magnet synchronous motor, ensuring that the torque output of the motor is neither too low to cause low efficiency, nor exceeds its design upper limit, avoiding safety hazards caused by overload operation. By setting reasonable torque upper and lower limits, torque distribution can be performed within the efficient working area of the motor, while protecting the motor from damage.

[0085] Optionally, the third constraint condition limits the torque output of the asynchronous motor. It ensures that the torque of the asynchronous motor when working is neither lower than its lower limit for effective work, nor exceeds its maximum torque it can withstand, thereby maintaining the healthy operation state of the motor and ensuring the stability and reliability of the system under various working conditions.

[0086] Optionally, in the process of constructing the constraint condition, the sum of the permanent magnet synchronous motor torque and the asynchronous motor torque can be determined as the first constraint condition.

[0087] For example, the first constraint condition is as follows:

[0088] T_m+T_a=T_req

[0089] Wherein, T_req can be used to represent the demand torque.

[0090] Optionally, in the process of constructing the constraint condition, the lower limit of the permanent magnet synchronous motor torque can be less than or equal to the permanent magnet synchronous motor torque, and the permanent magnet synchronous motor torque can be less than or equal to the upper limit of the permanent magnet synchronous motor torque, as the second constraint condition.

[0091] For example, the second constraint condition is as follows:

[0092] T_m_min≤T_m≤T_m_max

[0093] Wherein, T_m_min can be used to represent the lower limit of the permanent magnet synchronous motor torque; T_m_max can be used to represent the upper limit of the permanent magnet synchronous motor torque.

[0094] Optionally, in the process of constructing the constraint condition, the lower limit of the asynchronous motor torque can be less than or equal to the asynchronous motor torque, and the asynchronous motor torque can be less than or equal to the upper limit of the asynchronous motor torque, as the third constraint condition.

[0095] For example, the third constraint condition is as follows:

[0096] T_a_min≤T_a≤T_a_max

[0097] Wherein, T_a_min can be used to represent the torque lower limit of the asynchronous motor torque; T_a_max can be used to represent the torque upper limit of the asynchronous motor torque.

[0098] As an optional embodiment, the method further comprises: modeling and simulating the objective function and the constraint condition to obtain a simulation result; generating code information based on the simulation result, and inputting the code information into the vehicle controller.

[0099] In this embodiment, the objective function and the constraint condition can be modeled and simulated to obtain a simulation result. Code information can be generated based on the simulation result, and the code information can be input into the vehicle controller.

[0100] Optionally, according to the mathematical model discussed earlier, the objective function (system total loss minimization) and the constraint condition (torque sum equal to demand torque, motor torque upper and lower limit) have been established. The above mathematical relationship provides an optimization direction in theory, but before practical application, it still needs to be converted into a model in a simulation environment. The modeling tool (MATLAB / Simulink) can be a high-level mathematical toolbox and graphical programming environment widely used in engineering fields, especially suitable for modeling and simulation of control systems. Through Simulink, vehicle subsystem models including motors, power transmission systems, energy management systems, etc. can be built, and the objective function and the constraint condition can be integrated into these models.

[0101] Optionally, after building the model in Simulink, different working condition parameters (such as vehicle speed, demand torque, battery power, etc.) can be set, and the system can be simulated to observe the behavior of the system under different conditions. The Simulink environment supports dynamic simulation and can simulate the running conditions of the vehicle under various working conditions, including starting, accelerating, cruising, decelerating, etc.

[0102] Optionally, after the simulation is completed, a series of data can be obtained, including motor torque, motor efficiency, system total loss, vehicle dynamic response, etc., which are key indicators for evaluating system performance. By analyzing the simulation results, it can be verified whether the objective function and constraint conditions can effectively guide the optimization of the dual-motor system, and the problems and challenges that may be encountered in actual working conditions. Simulink is not only a simulation platform, but also provides a code generation tool that can convert the designed model into executable code (such as C code). This step is a key link to convert the theoretical model into an instruction set that the actual controller can run. The generated code needs to be optimized to ensure that it can be efficiently executed in an embedded environment. In addition, the code also needs to undergo detailed unit testing and integration testing to verify its correctness and stability.

[0103] Optionally, the finally optimized code is embedded into the vehicle's whole vehicle controller. The whole vehicle controller is the core of the vehicle's electronic system, responsible for receiving data from sensors, executing control algorithms, and sending commands to actuators such as motor controllers. By implementing the optimization algorithm in the controller, the system can automatically adjust the torque distribution strategy according to real-time working condition parameters, ensuring that the dual-motor system operates efficiently in the full working condition range.

[0104] In the embodiment of the present application, the abstract mathematical model is not only converted into practical control logic through the above method, but also passes strict simulation verification, ensuring the feasibility and effectiveness of the algorithm. Through code generation and embedding into the vehicle's whole vehicle controller, the combination of theory and practice is realized, so that the torque distribution strategy of the dual-motor hybrid power system can play its due role in the real world, improving the energy efficiency ratio and driving experience of the vehicle. This is a key step for control algorithms to go from the laboratory to the market, reflecting the rigor and practicality of control system development.

[0105] The technical solutions of the embodiments of the present application will be illustrated below in conjunction with preferred embodiments.

[0106] At present, most of the mainstream hybrid dual-motor vehicles use permanent magnet synchronous motors, but asynchronous motors have the advantages of low cost and simple structure, and are ideal auxiliary drive motors, and are gradually being applied to newly launched vehicle models. The torque distribution strategies of asynchronous motor + permanent magnet synchronous motor and permanent magnet synchronous motor + permanent magnet synchronous motor are very different. The current dual-motor torque distribution strategy on the market is for asynchronous motor + permanent magnet synchronous motor for pure electric vehicles or permanent magnet synchronous motor + permanent magnet synchronous motor for hybrid vehicles.

[0107] The main difficulties in the current technical field are as follows: insufficient efficiency optimization, without fully considering the characteristic differences of different motor types; poor adaptability to specific working conditions, and the existing torque distribution algorithm has insufficient adaptability to extreme working conditions, such as low temperature environment, low power state, large slope road and other special conditions.

[0108] In the embodiments of the present application, the following core problems are mainly solved: insufficient efficiency optimization of dual-motor: optimizing torque distribution in the full working condition range, so that the system always works in the state of optimal overall efficiency. The present application particularly considers the optimal working area of the two motors under different speed stages and power demand, realizing more refined efficiency management; power response delay: for some working conditions with high power demand, timely optimize the distribution ratio to ensure timely response of power demand; special working condition adaptability problem: an adaptive torque distribution algorithm based on working condition recognition is proposed, which can adjust the torque distribution strategy according to real-time parameters such as temperature, power, road slope, etc., so that the system can maintain excellent performance in various complex environments.

[0109] Implementation mechanism and beneficial effects: System efficiency is significantly improved: by fully utilizing the high efficiency characteristics of permanent magnet synchronous motor in the medium and low speed area and the advantages of asynchronous motor in the high speed area, the overall efficiency of the hybrid system is improved, especially in the city working condition of frequent start-stop and continuous high-speed cruising, the energy saving effect is more obvious. Power response improvement: due to the optimization of the torque distribution strategy of dual-motor, the system can respond more quickly to the power demand of the driver, providing a more smooth driving experience, and the timely participation of asynchronous motor in high power demand working conditions such as sudden acceleration makes the power performance of the vehicle fully exerted; by improving the overall efficiency of the system, the cruising range under the same power can be significantly increased, which has practical significance for relieving the range anxiety of users and reducing the charging frequency, especially in plug-in hybrid vehicles, the improvement effect is more obvious.

[0110] The embodiments of the present application are further introduced below.

[0111] Figure 2 is a schematic diagram of a torque distribution system of a hybrid vehicle dual-motor type according to the embodiments of the present application, as Figure 2 shown, the proposed torque distribution method of hybrid vehicle dual-motor adopts an innovative architecture of permanent magnet synchronous motor as the main drive motor and asynchronous motor as the auxiliary drive motor. The system includes engine, permanent magnet synchronous motor, asynchronous motor, power battery and vehicle controller and other components. The vehicle controller calculates the optimal motor torque distribution ratio according to the preset torque distribution algorithm by collecting the driver demand, vehicle state and component parameters, and executes the corresponding torque instruction through the motor controller.

[0112] Optionally, the core feature of the present application is to make full use of the inherent characteristics of two types of motors: permanent magnet synchronous motor, which has the characteristics of high power density, high efficiency and low speed large torque, making it very suitable as a main drive motor. In the low and medium speed range and small and medium load working condition, the system mainly relies on the permanent magnet synchronous motor to provide power, at this time the system efficiency is the highest. Asynchronous motor, with the characteristics of simple structure, low cost, good high speed performance, etc., making it an ideal auxiliary drive motor. In the high speed area and heavy load working condition, the asynchronous motor participates in the drive, making up for the lack of high speed performance of the permanent magnet synchronous motor.

[0113] Optionally, based on vehicle speed and power demand, the present application divides the working area into the following three main stages: low speed stage (0-65km / h), this stage mainly relies on the permanent magnet synchronous motor to provide power, the asynchronous motor generally does not participate in the drive (unless in the case of sudden acceleration or large slope). The permanent magnet synchronous motor has high efficiency and fast response in this speed range, which can meet the needs of most urban working conditions. When the battery is fully charged and the power demand is moderate, the system can even be driven by electricity, and the engine does not work, realizing zero emission operation. Medium speed stage (65-100km / h), this stage is the transition area of permanent magnet synchronous motor and asynchronous motor. With the increase of vehicle speed and the change of power demand, the system gradually lets the asynchronous motor participate in the drive according to the optimization algorithm. The torque distribution ratio is dynamically adjusted according to the principle of optimal efficiency to ensure that the system always works in the high efficiency area. Usually, the permanent magnet synchronous motor still provides the main power, and the asynchronous motor provides the auxiliary power, and the proportion is about 7:3. High speed stage (above 100km / h), the participation of asynchronous motor is further improved in this stage, and even becomes the main driving source in some working conditions. The efficiency of the permanent magnet synchronous motor decreases in the high speed area, while the asynchronous motor has good performance in the high speed area, so appropriately increasing the torque proportion of the asynchronous motor helps to improve the overall efficiency of the system. The proportion can be adjusted to 5:5 or 4:6 according to the actual situation.

[0114] Optionally, the torque distribution algorithm of the present application can be modeled and simulated through MATLAB / Simulink, and then C code is generated and embedded into the vehicle controller. The core part of the algorithm adopts the objective function based on efficiency optimization:

[0115] min J=∑(T_m^2 / η_m(T_m,n_m)+T_a^2 / η_a(T_a,n_a))

[0116] Constraint conditions:

[0117] T_m+T_a=T_req

[0118] T_m_min≤T_m≤T_m_max

[0119] T_a_min≤T_a≤T_a_max

[0120] wherein J is the objective function, representing the total loss of the system; T m is the permanent magnet synchronous motor torque; T a is the asynchronous motor torque; η m is the permanent magnet synchronous motor efficiency, which is a function of torque and speed; η a is the asynchronous motor efficiency, which is a function of torque and speed; T req is the total required torque; T m min and T m max are the upper and lower limits of the permanent magnet synchronous motor torque; T a min and T a max are the upper and lower limits of the asynchronous motor torque; n m can be used to represent the speed of the permanent magnet synchronous motor; and n a can be used to represent the speed of the asynchronous motor.

[0121] Figure 3 A flow chart of a torque distribution method for a dual-electricity architecture of a hybrid vehicle according to an embodiment of the present application is shown in FIG. 3, which can include the following steps: Figure 3

[0122] Step S301, vehicle speed V and required torque T req are collected.

[0123] In this embodiment, the current vehicle speed (V) and the required torque (T req) of the vehicle are collected. The vehicle speed is an important operating condition parameter that determines the torque distribution strategy, while the required torque reflects the instantaneous power demand of the driver and is a condition that needs to be met by the system.

[0124] Step S302, the maximum torque of the permanent magnet synchronous motor in the economic region is T m max.

[0125] In this embodiment, the maximum torque output capability (T m max) of the permanent magnet synchronous motor in its economic operating region is determined. The economic region is a range of high efficiency operation of the motor, and this parameter is used as a basis for decision-making in subsequent steps to ensure that the system can prioritize high-efficiency operation of the motor while meeting the required torque.

[0126] Step S303, V≥65km / h.

[0127] In this embodiment, when the vehicle speed is detected to reach or exceed 65km / h, it indicates that the system enters the medium speed stage. In this stage, the torque distribution strategy begins to consider the use of the permanent magnet synchronous motor and the asynchronous motor in combination to adapt to the power demand at higher vehicle speeds. If V≥65km / h, step S304 can be performed, otherwise step S307 can be performed.

[0128] Step S304, V≥100km / h.

[0129] ​In this embodiment, if the vehicle speed further increases to 100 km / h and above, the system will enter the high-speed phase. In this phase, the advantages of the asynchronous motor will be more fully utilized to meet the special requirements of high-speed driving. If V≥100 km / h, step S306 can be performed. Otherwise, step S305 can be performed.

[0130] Step S305: The permanent magnet synchronous motor and the asynchronous motor work together according to the optimal efficiency distribution ratio.

[0131] In this embodiment, when the vehicle speed is between 65 km / h and 100 km / h, the system calculates the optimal torque distribution scheme for the permanent magnet synchronous motor and the asynchronous motor to work together based on the principle of efficiency optimization. This step ensures that the dual-motor can work together in the most efficient way in the medium and high-speed section.

[0132] Step S306: The asynchronous motor is the main drive, and the permanent magnet synchronous motor assists.

[0133] In this embodiment, in the high-speed phase where the vehicle speed is higher than 100 km / h, the asynchronous motor will become the main source of driving force due to its better performance at high speed, while the permanent magnet synchronous motor will become an auxiliary role to provide additional power support. This strategy fully utilizes the high-speed performance advantage of the asynchronous motor.

[0134] Step S307: Treq≤T_m_max.

[0135] In this embodiment, if the required torque is less than or equal to the maximum torque in the economic zone of the permanent magnet synchronous motor (T_m_max), it means that only the permanent magnet synchronous motor is sufficient to meet the power demand under the current working condition. If Treq≤T_m_max, step S308 can be performed, otherwise step S309 can be performed.

[0136] Step S308: Only the permanent magnet synchronous motor works, and the asynchronous motor is on standby.

[0137] In this embodiment, only the permanent magnet synchronous motor will be selected to provide the required torque, while the asynchronous motor remains in standby state. This is done to take advantage of the high efficiency of the permanent magnet synchronous motor at low and medium speed and small load, saving energy.

[0138] Step S309: The permanent magnet synchronous motor is the main drive, and the asynchronous motor assists.

[0139] In this embodiment, the permanent magnet synchronous motor will be adjusted as the main driving source, and the asynchronous motor will provide auxiliary driving. In this mode, the permanent magnet synchronous motor undertakes most of the torque output, and the asynchronous motor participates in time according to the need to meet higher power demand.

[0140] According to the embodiment of the present application, the torque distribution device of the dual-motor hybrid system in the vehicle is also provided. It should be noted that the torque distribution device of the dual-motor hybrid system in the vehicle can be used to execute the torque distribution method of the dual-motor hybrid system in the vehicle in the above embodiment.

[0141] Figure 4 is a schematic diagram of a torque distribution device of a dual-motor hybrid system in a vehicle according to an embodiment of the present application, as shown in the figure, the torque distribution device 400 of the dual-motor hybrid system in the vehicle can include a first determination unit 402, a construction unit 404, a second determination unit 406 and a distribution unit 408. Figure 4

[0142] The first determination unit 402 is configured to determine the working area of both the permanent magnet synchronous motor and the asynchronous motor in the dual-motor hybrid system based on the driving parameter of the vehicle and the demand torque of the vehicle.

[0143] The construction unit 404 is configured to construct the target function and the constraint condition of the dual-motor hybrid system in the working area based on the working condition parameter of the dual-motor hybrid system.

[0144] The second determination unit 406 is configured to determine the torque distribution parameter corresponding to the working area based on the target function and the constraint condition.

[0145] The distribution unit 408 is configured to distribute the torque to the permanent magnet synchronous motor and the asynchronous motor in the working area according to the torque distribution parameter.

[0146] In the embodiment of the present application, the first determination unit 402 determines the working area of both the permanent magnet synchronous motor and the asynchronous motor in the dual-motor hybrid system based on the driving parameter of the vehicle and the demand torque of the vehicle. The construction unit 404 constructs the target function and the constraint condition of the dual-motor hybrid system in the working area based on the working condition parameter of the dual-motor hybrid system. The second determination unit 406 determines the torque distribution parameter corresponding to the working area based on the target function and the constraint condition. The distribution unit 408 distributes the torque to the permanent magnet synchronous motor and the asynchronous motor in the working area according to the torque distribution parameter, thereby solving the technical problem of poor torque distribution effect of the dual-motor hybrid system in the vehicle and achieving the technical effect of improving the torque distribution effect of the dual-motor hybrid system in the vehicle.

[0147] According to the embodiment of the present application, a computer readable storage medium is also provided, which includes a stored program, wherein the program executes the above method in the embodiment of the present application.

[0148] According to the embodiment of the present application, a processor is also provided, which is used to run a program, wherein the program runs to execute the above method in the embodiment of the present application. ​

[0149] According to another aspect of the embodiments of the present application, an electronic device is provided. The electronic device includes a memory and a processor. The memory stores a computer program. The processor is configured to execute the computer program to perform the above method according to the embodiments of the present application.

[0150] According to another aspect of the embodiments of the present application, a computer program product is provided. The computer program product includes a computer program. The computer program, when executed by a processor, implements the above method according to the embodiments of the present application.

[0151] According to another aspect of the embodiments of the present application, a vehicle is provided. The vehicle includes a memory and a processor. The memory stores an executable program. The processor is configured to execute the program. The program, when executed, implements the above method according to the embodiments of the present application.

[0152] In the above embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0153] In several embodiments provided in the present application, it should be understood that the disclosed technical contents can be implemented by other manners. Among them, the above-described device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, which can be electrical or other forms.

[0154] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed to multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment.

[0155] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0156] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions to make a computer device (which can be a personal computer, a server or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0157] The above only describes the preferred embodiments of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A torque distribution method for a dual-motor hybrid system in a vehicle, characterized in that, The dual-motor hybrid system includes a permanent magnet synchronous motor and an asynchronous motor, and the method includes: Based on the vehicle's driving parameters and the vehicle's required torque, the operating ranges of the permanent magnet synchronous motor and the asynchronous motor are determined, wherein the operating range is used to represent the interval to which the conditions for the permanent magnet synchronous motor and the asynchronous motor to perform their respective functions belong; Within the working area, based on the operating parameters of the dual-motor hybrid system, the objective function and constraints of the dual-motor hybrid system are constructed, wherein the operating parameters are used to represent the operating state of the dual-motor hybrid system within the working area; Based on the objective function and the constraints, determine the torque distribution parameters corresponding to the working area; According to the torque distribution parameters, torque is distributed to the permanent magnet synchronous motor and the asynchronous motor in the working area.

2. The method according to claim 1, characterized in that, Based on the vehicle's driving parameters and required torque, the operating ranges of the permanent magnet synchronous motor and the asynchronous motor are determined, including: Determine the driving parameter range in which the driving parameters are located, and the relationship between the required torque and the upper limit of the torque of the permanent magnet synchronous motor. The working area is determined based on the driving parameter range and the magnitude relationship.

3. The method according to claim 2, characterized in that, The driving parameter range includes a first driving parameter range, a second driving parameter range, and a third driving parameter range. The second driving parameter range is larger than the first driving parameter range, and the third driving parameter range is larger than the second driving parameter range. The working area includes a first working area, a second working area, a third working area, and a fourth working area. The working area is determined based on the driving parameter ranges and their relative sizes, including: In response to the driving parameters being within the first driving parameter range and the required torque being less than or equal to the torque upper limit, the working area is determined as the first working area, wherein the permanent magnet synchronous motor in the first working area is in a working state and the asynchronous motor is in a standby state. In response to the driving parameters being within the first driving parameter range and the required torque being greater than the upper limit of torque, the working area is determined as the second working area, wherein the permanent magnet synchronous motor in the second working area is in the main driving state and the asynchronous motor is in the auxiliary driving state; In response to the driving parameters being within the second driving parameter range, the working area is determined to be the third working area, wherein the permanent magnet synchronous motor and the asynchronous motor within the third working area enter the working state according to the maximum efficiency allocation parameter; In response to the driving parameters being within the third driving parameter range, the working area is determined as the fourth working area, wherein the asynchronous motor in the fourth working area is in the main driving state and the permanent magnet synchronous motor is in the auxiliary driving state.

4. The method according to claim 1, characterized in that, The operating parameters include the torque of the permanent magnet synchronous motor, the torque of the asynchronous motor, the efficiency of the permanent magnet synchronous motor, the efficiency of the asynchronous motor, the total loss of the dual-motor hybrid system, the speed of the permanent magnet synchronous motor, and the speed of the asynchronous motor. Within the operating region, based on the operating parameters of the dual-motor hybrid system, an objective function for the dual-motor hybrid system is constructed, including: Within the operating region, with the goal of minimizing the total loss, the objective function is constructed based on the torque of the permanent magnet synchronous motor, the torque of the asynchronous motor, the efficiency of the permanent magnet synchronous motor, the efficiency of the asynchronous motor, the speed of the permanent magnet synchronous motor, and the speed of the asynchronous motor.

5. The method according to claim 4, characterized in that, The constraints include a first constraint, a second constraint, and a third constraint. Within the working area, based on the operating parameters of the dual-motor hybrid system, the constraints of the dual-motor hybrid system are constructed, including: The sum of the torque of the permanent magnet synchronous motor and the torque of the asynchronous motor is equal to the required torque, which is taken as the first constraint condition; The lower limit of the torque of the permanent magnet synchronous motor is less than or equal to the torque of the permanent magnet synchronous motor, and the upper limit of the torque of the permanent magnet synchronous motor is less than or equal to the torque of the permanent magnet synchronous motor, which is taken as the second constraint condition; The third constraint condition is that the lower limit of the asynchronous motor torque is less than or equal to the asynchronous motor torque, and the asynchronous motor torque is less than or equal to the upper limit of the asynchronous motor torque.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The objective function and the constraints are modeled and simulated to obtain simulation results. Based on the simulation results, code information is generated and then fed into the vehicle's overall controller.

7. A torque distribution device for a dual-motor hybrid system in a vehicle, characterized in that, The device includes: The first determining unit is used to determine the working areas of the permanent magnet synchronous motor and the asynchronous motor in the dual-motor hybrid system based on the driving parameters of the vehicle and the required torque of the vehicle. The working area is used to represent the interval to which the conditions for the functions performed by the permanent magnet synchronous motor and the asynchronous motor belong. A construction unit is configured to construct, within the working area, the objective function and constraints of the dual-motor hybrid system based on the operating parameters of the dual-motor hybrid system, wherein the operating parameters are used to at least represent the operating state of the dual-motor hybrid system within the working area; The second determining unit is used to determine the torque distribution parameters corresponding to the working area based on the objective function and the constraint conditions; The distribution unit is used to distribute torque to the permanent magnet synchronous motor and the asynchronous motor in the working area according to the torque distribution parameters.

8. A processor, characterized in that, The processor is used to run a program, wherein the program executes the method according to any one of claims 1 to 6 when it runs.

9. An electronic device, characterized in that, The method includes a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 6.

11. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method described in any one of claims 1 to 6.

12. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 6.

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