Motor torque control method and device and hybrid electric vehicle torque control method

Abstract

The invention provides a motor torque control method and device and a hybrid electric vehicle torque control method. The method comprises the steps that the motor rated torque corresponding to the required rotating speed of a motor is searched for; if the motor demand torque is smaller than or equal to the motor rated torque, controlling the motor output torque to be equal to the motor demand torque; if the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the decreasing threshold, controlling the motor output torque to be equal to the motor demand torque; if the required torque of the motor is larger than the rated torque of the motor and the real-time temperature of the motor is smaller than the temperature protection threshold value and larger than the amplitude reduction threshold value, the output torque of the motor is controlled between zero and the required torque of the motor, and the closer the real-time temperature of the motor is the amplitude reduction threshold value, the closer the output torque of the motor is the required torque of the motor. The closer the real-time temperature of the motor is to the temperature protection threshold value, the closer the output torque of the motor is to zero. According to the application, the torque requirement can be met as far as possible on the premise of avoiding forced outage triggered by overheating of the motor.

Description

Technical Field

[0001] The present application relates to the technical field of motor control, and in particular to a motor torque control method and device, and a hybrid vehicle torque control method. Background Art

[0002] In many industrial, transportation and various electromechanical equipment application scenarios, motors play a vital role as key power output components. Accurate control of motor torque has a profound impact on the normal operation, performance and service life of the equipment.

[0003] Traditional motor torque control methods usually adopt a relatively simple and direct method, that is, the motor output torque is equal to the motor demand torque. However, in practical applications, the motor demand torque often increases suddenly. When the motor faces such a situation of excessive demand torque, it will bring a series of serious problems. When the motor outputs high torque, its internal current will increase significantly, causing the motor winding to generate a lot of heat, causing the motor temperature to continue to rise.

[0004] At present, most motors are equipped with overheat protection mechanisms. When the motor temperature reaches the preset temperature protection threshold, the system will forcibly cut off the power supply to the motor to prevent the motor from suffering irreversible damage due to overheating, such as insulation damage, winding short circuit, etc. Although this forced power-off situation protects the hardware safety of the motor itself, it causes great inconvenience and adverse effects on the entire device or system.

[0005] Therefore, when faced with a situation where the motor torque demand is too large, the traditional motor torque control method has the defect of triggering forced power off due to motor overheating, affecting the normal operation of the equipment and bringing many potential risks. A more reasonable and effective motor torque control method is urgently needed to solve the above problems. Summary of the invention

[0006] The present application provides a motor torque control method and device, and a hybrid vehicle torque control method, which can solve the technical problem of forced power off triggered by motor overheating in the prior art.

[0007] In a first aspect, an embodiment of the present application provides a motor torque control method, the motor torque control method comprising:

[0008] Find the motor rated torque corresponding to the motor required speed on the motor external characteristic curve;

[0009] If the motor required torque is less than or equal to the motor rated torque, the motor output torque is controlled to be equal to the motor required torque;

[0010] If the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the reduction threshold, the motor output torque is controlled to be equal to the motor demand torque, wherein the reduction threshold is less than the temperature protection threshold;

[0011] If the motor demand torque is greater than the motor rated torque, the motor real-time temperature is less than the temperature protection threshold but greater than the reduction threshold, the motor output torque is controlled between zero and the motor demand torque, wherein the closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor demand torque, and the closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero.

[0012] Furthermore, in one embodiment, the reduction threshold is greater than or equal to a balance temperature when the motor runs at a required motor speed and a rated motor torque.

[0013] Furthermore, in one embodiment, the step of controlling the motor output torque to be between zero and the motor required torque comprises:

[0014] The output torque of the controlled motor is equal to the product of the motor demand torque and the reduction coefficient. The calculation formula of the reduction coefficient is:

[0015]

[0016] Where k represents the reduction coefficient, T i Indicates the real-time temperature of the motor, T e represents the equilibrium temperature, T LIM Indicates the temperature protection threshold.

[0017] Furthermore, in one embodiment, the motor torque control method is applied to a hybrid electric vehicle of a P2 architecture;

[0018] When the clutch between the engine and the motor is in the engaged state, and the required torque and speed of the drive axle wheel end fall outside the economic output band of the engine, the motor required speed is equal to the required speed of the drive axle wheel end, and the motor required torque is equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine;

[0019] The optimal engine torque is the torque corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve.

[0020] Furthermore, in one embodiment, when the clutch between the engine and the motor is in an engaged state, and the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall within the economic output band of the engine, the required speed of the motor is equal to the required speed of the drive axle wheel end, and the required torque of the motor is zero.

[0021] Furthermore, in one embodiment, when the clutch between the engine and the motor is in a disconnected state, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is equal to the drive axle wheel end required torque.

[0022] In a second aspect, an embodiment of the present application further provides a hybrid vehicle torque control method, which is applied to a hybrid vehicle of a P2 architecture. The hybrid vehicle torque control method includes:

[0023] When the clutch between the engine and the motor is in the engaged state, check whether the required torque and speed of the drive axle wheel end are within the economic output band of the engine;

[0024] If the required torque and speed of the drive axle wheel end fall outside the economic output band of the engine, then find the optimal torque of the engine corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve;

[0025] The motor torque control method is performed by setting the motor torque required speed equal to the drive axle wheel end required speed, and the motor torque required is equal to the difference between the drive axle wheel end required torque and the engine optimal torque;

[0026] The engine output torque is controlled to be equal to the difference between the engine optimal torque or the required torque at the drive axle wheel end and the motor output torque.

[0027] Furthermore, in one embodiment, after the step of checking whether the required torque at the wheel end of the drive axle and the required speed at the wheel end of the drive axle fall within the economic output band of the engine, the following step is further included:

[0028] If the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall within the economic output band of the engine, the engine output torque is controlled to be equal to the required torque at the drive axle wheel end, and the motor output torque is controlled to be equal to zero.

[0029] Furthermore, in one embodiment, the hybrid vehicle torque control method further includes:

[0030] When the clutch between the engine and the motor is in the engaged state, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is equal to the drive axle wheel end required torque, and the steps of the motor torque control method are executed.

[0031] In a second aspect, an embodiment of the present application further provides a motor torque control device, the motor torque control device comprising:

[0032] A rated search module is used to search the rated torque of the motor corresponding to the required speed of the motor on the motor external characteristic curve;

[0033] A first output module, used for controlling the motor output torque to be equal to the motor demand torque if the motor demand torque is less than or equal to the motor rated torque;

[0034] The second output module is used to control the motor output torque to be equal to the motor demand torque if the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the reduction threshold, wherein the reduction threshold is less than the temperature protection threshold;

[0035] The third output module is used to control the motor output torque between zero and the motor required torque if the motor required torque is greater than the motor rated torque, and the motor real-time temperature is less than the temperature protection threshold and greater than the reduction threshold, wherein the closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor required torque, and the closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero.

[0036] In this application, the motor demand torque and the motor rated torque are first compared. When the motor demand torque is not higher than the motor rated torque, the motor output torque is controlled to be equal to the motor demand torque. When the motor demand torque is higher, the motor real-time temperature and the reduction threshold are further compared. When the motor real-time temperature is not higher than the reduction threshold, the motor output torque is controlled to be equal to the motor demand torque. When the motor real-time temperature is higher than the reduction threshold, the motor output torque is controlled between zero and the motor demand torque. The closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor demand torque. The torque demand is met as much as possible while delaying the temperature rise. The closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero, so as to reduce the motor temperature as soon as possible and avoid the motor temperature reaching the temperature protection threshold. Through this application, the torque demand can be met as much as possible under the premise of avoiding the motor overheating triggering forced power off, thereby improving the stability of equipment operation and reducing adverse effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a flow chart of a motor torque control method in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of a drive system of a hybrid vehicle with a P2 architecture;

[0039] Figure 3 This is a flow chart of a torque control method for a hybrid vehicle in one embodiment of the present application;

[0040] Figure 4 Schematic diagram of functional modules of a motor torque control device in one embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution 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 part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0043] In a first aspect, an embodiment of the present application provides a motor torque control method.

[0044] Figure 1 A flow chart of a motor torque control method in an embodiment of the present application is shown.

[0045] Reference Figure 1 In one embodiment, the motor torque control method includes the following steps:

[0046] S11. Find the rated torque of the motor corresponding to the required motor speed on the motor external characteristic curve.

[0047] Specifically, when the motor operates under rated working conditions, there is a specific relationship between the motor torque and the motor speed, which is described by the motor external characteristic curve.

[0048] For example, the abscissa of the motor external characteristic curve is the motor speed, and the ordinate is the motor torque. The ordinate corresponding to the point on the motor external characteristic curve where the abscissa is equal to the motor required speed is the rated torque of the motor described in this embodiment.

[0049] S12: If the motor required torque is less than or equal to the motor rated torque, control the motor output torque to be equal to the motor required torque.

[0050] Specifically, when the motor required torque is less than or equal to the motor rated torque, there is no risk of overheating of the motor, and the motor output torque is controlled to be equal to the motor required torque to normally meet the torque demand.

[0051] S13. If the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the reduction threshold, the motor output torque is controlled to be equal to the motor demand torque, wherein the reduction threshold is less than the temperature protection threshold.

[0052] Specifically, when the required torque of the motor is greater than the rated torque of the motor, the real-time temperature of the motor is added as a basis for judgment, and a certain margin is reserved between the reduction threshold and the temperature protection threshold. When the real-time temperature of the motor is less than or equal to the reduction threshold, there is no risk of overheating of the motor in a short period of time, and the output torque of the motor is controlled to be equal to the required torque of the motor, so the torque demand is met normally.

[0053] S14. If the motor demand torque is greater than the motor rated torque, and the motor real-time temperature is less than the temperature protection threshold but greater than the reduction threshold, the motor output torque is controlled between zero and the motor demand torque, wherein the closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor demand torque, and the closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero.

[0054] Specifically, when the real-time temperature of the motor is greater than the reduction threshold, the motor is at risk of overheating in a short period of time, and the motor output torque needs to be reduced and controlled between zero and the motor required torque. The closer the real-time temperature of the motor is to the reduction threshold, the closer the motor output torque is to the motor required torque, and the torque demand is met as much as possible while delaying the temperature rise. The closer the real-time temperature of the motor is to the temperature protection threshold, the closer the motor output torque is to zero, so as to reduce the motor temperature as soon as possible to avoid the motor temperature reaching the temperature protection threshold and the motor overheating triggering forced power off.

[0055] It should be noted that in all the above cases, the motor output speed is equal to the motor required speed.

[0056] It should be noted that when the motor output torque is less than the motor required torque, for the entire device, if there is no other power source to make up for the missing part, there will be a temporary performance decline. However, in the long run, the performance of the equipment under the control of this scheme is better than that of the equipment under the control of the traditional scheme.

[0057] For example, assuming that the motor demand torque is continuously greater than the motor rated torque, if the motor torque control is performed through the traditional scheme, the motor output torque is equal to the motor demand torque, the motor real-time temperature rises to the temperature protection threshold after the motor works for 10 minutes, the motor overheating triggers forced power off, and the motor is powered on again after 10 minutes of power off. If the motor torque control is performed through this scheme, in 1-5 minutes, the motor output torque is equal to the motor demand torque, the motor real-time temperature rises to the reduction threshold, in 6-10 minutes, the motor output torque gradually decreases, the motor real-time temperature first slowly rises to approach the temperature protection threshold, and then quickly decreases to below the reduction threshold, in 11-15 minutes, the motor output torque is equal to the motor demand torque, the motor real-time temperature rises to the reduction threshold, in 16-20 minutes, the motor output torque gradually decreases, the motor real-time temperature first slowly rises to approach the temperature protection threshold, and then quickly decreases to below the reduction threshold. In the first 10 minutes, the average motor output torque of this scheme is lower than the average motor output torque of the traditional scheme, and in the overall 20 minutes, the average motor output torque of this scheme is higher than the average motor output torque of the traditional scheme.

[0058] Therefore, through this embodiment, the torque demand can be met as much as possible under the premise of avoiding the motor overheating triggering forced power off, thereby improving the operating stability of the equipment and reducing adverse effects.

[0059] Furthermore, in one embodiment, the reduction threshold is greater than or equal to a balance temperature when the motor runs at a required motor speed and a rated motor torque.

[0060] In this embodiment, the equilibrium temperature of the motor when it runs at the required motor speed and rated motor torque is a fixed value that can be measured in advance. Using it as the basis for setting the reduction threshold helps to improve the effect of motor torque control.

[0061] Furthermore, in one embodiment, the step of controlling the motor output torque to be between zero and the motor required torque comprises:

[0062] The output torque of the controlled motor is equal to the product of the motor demand torque and the reduction coefficient. The calculation formula of the reduction coefficient is:

[0063]

[0064] Where k represents the reduction coefficient, T i Indicates the real-time temperature of the motor, T e represents the equilibrium temperature, T LIM Indicates the temperature protection threshold.

[0065] Specifically, T LIM -T e (referred to as the denominator) is a constant, T i -T e(referred to as numerator) is greater than zero, T i The closer to T LIM , the closer the ratio of the numerator to the denominator is to 1, the closer k is to 0, and the closer the product of the motor demand torque and the reduction coefficient is to zero, T i The closer to T e , the closer the ratio of the numerator to the denominator is to 0, the closer k is to 1, and the closer the product of the motor demand torque and the reduction coefficient is to the motor demand torque.

[0066] In this embodiment, a specific reduction strategy for the motor output torque is provided, and the calculation formula of the reduction coefficient k is obtained based on the fitting of a large amount of test data. Under the premise of avoiding the motor overheating and triggering forced power off, the motor output torque can be further improved.

[0067] Further, in one embodiment, the motor torque control method is applied to a hybrid electric vehicle of a P2 architecture;

[0068] When the clutch between the engine and the motor is in the engaged state, and the required torque and speed of the drive axle wheel end fall outside the economic output band of the engine, the motor required speed is equal to the required speed of the drive axle wheel end, and the motor required torque is equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine;

[0069] The optimal engine torque is the torque corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve.

[0070] Figure 2 A schematic diagram of the drive system of a hybrid vehicle with a P2 architecture is shown.

[0071] Reference Figure 2 The drive system of a hybrid vehicle with a P2 architecture includes an engine, a clutch, a drive motor, a multi-speed gearbox, an HCU (hybrid control unit), an MCU (motor control unit), an EOP (clutch control unit) and a drive axle. When the clutch between the engine and the motor is in the engaged state, the engine and the drive motor jointly provide torque to the drive axle, which is defined as a hybrid mode. When the clutch between the engine and the motor is in the disconnected state, only the drive motor provides torque to the drive axle, which is defined as a pure electric mode.

[0072] Specifically, after the vehicle enters the READY state, the hybrid mode is selected through the mode selection button, and the HCU puts the clutch in the engaged state through the EOP. The HCU checks whether the required torque and speed of the drive axle wheel end fall within the economic output band of the engine. When they fall outside the economic output band of the engine, in order to optimize the engine fuel consumption, the drive motor needs to bear part of the torque demand. The HCU searches for the engine optimal torque corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve, makes the motor required speed equal to the required speed of the drive axle wheel end, and makes the motor required torque equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine, and executes steps S11 to S14, and sends the obtained motor output torque to the MCU.

[0073] Specifically, when the engine runs at optimal fuel consumption, there is a specific relationship between engine torque and engine speed, which is described by the engine economy optimal curve. The engine economic output band is an area including the engine economy optimal curve. The width is defined according to demand, indicating an operating state with better fuel consumption.

[0074] For example, the abscissa of the engine economy optimal curve is the engine speed, and the ordinate is the engine torque. To check whether the drive axle wheel end required torque and the drive axle wheel end required speed fall within the engine economic output band, the point whose ordinate is the drive axle wheel end required torque and whose abscissa is the drive axle wheel end required speed is found to see whether the point falls within the engine economic output band. The ordinate corresponding to the point whose abscissa on the engine economy optimal curve is equal to the drive axle wheel end required speed is the engine optimal torque described in this embodiment.

[0075] Furthermore, in one embodiment, when the clutch between the engine and the motor is in an engaged state, and the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall within the economic output band of the engine, the required speed of the motor is equal to the required speed of the drive axle wheel end, and the required torque of the motor is zero.

[0076] Specifically, when the HCU finds that the required torque and speed of the drive axle wheel end fall within the economic output band of the engine, the engine can meet all torque requirements with better fuel consumption, making the motor required speed equal to the required speed of the drive axle wheel end, and making the motor required torque equal to zero, executing steps S11 to S14, and sending the obtained motor output torque to the MCU. It can be understood that the obtained motor output torque is also zero.

[0077] Furthermore, in one embodiment, when the clutch between the engine and the motor is in a disconnected state, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is equal to the drive axle wheel end required torque.

[0078] Specifically, after the vehicle enters the READY state, the pure electric mode is selected through the mode selection button, and the HCU disconnects the clutch through the EOP, so that the motor demand speed is equal to the drive axle wheel end demand speed, and the motor demand torque is equal to the drive axle wheel end demand torque, and steps S11 to S14 are executed to send the obtained motor output torque to the MCU.

[0079] It should be noted that the above embodiments are only examples of application scenarios of the present solution, and the present solution can also be applied in other scenarios, such as pure electric vehicles and other equipment using motors.

[0080] In a second aspect, an embodiment of the present application also provides a hybrid vehicle torque control method, which is applied to a hybrid vehicle with a P2 architecture.

[0081] Figure 3 A schematic flow chart of a torque control method for a hybrid vehicle in an embodiment of the present application is shown.

[0082] Reference Figures 1 to 3 In one embodiment, the torque control method of a hybrid vehicle comprises the following steps:

[0083] S21, when the clutch between the engine and the motor is in the engaged state, check whether the required torque and the required speed of the drive axle wheel end are within the economic output band of the engine;

[0084] S22, if the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall outside the economic output band of the engine, then searching for the optimal engine torque corresponding to the required speed at the drive axle wheel end on the engine economy optimal curve;

[0085] S23, setting the motor required speed to be equal to the drive axle wheel end required speed, and the motor required torque to be equal to the difference between the drive axle wheel end required torque and the engine optimal torque, and executing steps S11 to S14;

[0086] S24, controlling the engine output torque to be equal to the optimal engine torque or the difference between the required torque at the drive axle wheel end and the motor output torque.

[0087] In this embodiment, if the engine output torque is controlled to be equal to the optimal torque of the engine, the engine can operate with optimal fuel consumption, but when the motor output torque is less than the motor required torque, the torque transmitted to the drive axle wheel end is lower than the drive axle wheel end required torque, resulting in the actual vehicle speed of the hybrid vehicle being lower than the target vehicle speed.

[0088] If the engine output torque is controlled to be equal to the difference between the required torque at the drive axle wheel end and the motor output torque, then when the motor output torque is less than the motor required torque, the engine will make up for the missing part at the expense of fuel consumption, so that the torque transmitted to the drive axle wheel end is equal to the required torque at the drive axle wheel end, ensuring that the actual vehicle speed of the hybrid vehicle is equal to the target vehicle speed.

[0089] Furthermore, in one embodiment, after the step of checking whether the required torque at the wheel end of the drive axle and the required speed at the wheel end of the drive axle fall within the economic output band of the engine, the following step is further included:

[0090] If the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall within the economic output band of the engine, the engine output torque is controlled to be equal to the required torque at the drive axle wheel end, and the motor output torque is controlled to be equal to zero.

[0091] Furthermore, in one embodiment, the hybrid vehicle torque control method further includes:

[0092] When the clutch between the engine and the motor is in the engaged state, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is equal to the drive axle wheel end required torque, and steps S11 to S14 are executed.

[0093] In a third aspect, an embodiment of the present application also provides a motor torque control device.

[0094] Figure 4 A schematic diagram of the functional modules of a motor torque control device in an embodiment of the present application is shown.

[0095] Reference Figure 4 In one embodiment, the motor torque control device comprises:

[0096] A rated search module 10 is used to search the rated torque of the motor corresponding to the required speed of the motor on the motor external characteristic curve;

[0097] The first output module 20 is used to control the motor output torque to be equal to the motor demand torque if the motor demand torque is less than or equal to the motor rated torque;

[0098] The second output module 30 is used to control the motor output torque to be equal to the motor demand torque if the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the reduction threshold, wherein the reduction threshold is less than the temperature protection threshold;

[0099] The third output module 40 is used to control the motor output torque between zero and the motor required torque if the motor required torque is greater than the motor rated torque, and the motor real-time temperature is less than the temperature protection threshold and greater than the reduction threshold, wherein the closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor required torque, and the closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero.

[0100] Furthermore, in one embodiment, the reduction threshold is greater than or equal to a balance temperature when the motor runs at a required motor speed and a rated motor torque.

[0101] Furthermore, in one embodiment, the third output module 40 is used for:

[0102] The output torque of the controlled motor is equal to the product of the motor demand torque and the reduction coefficient. The calculation formula of the reduction coefficient is:

[0103]

[0104] Where k represents the reduction coefficient, T i Indicates the real-time temperature of the motor, T e represents the equilibrium temperature, T LIM Indicates the temperature protection threshold.

[0105] Further, in one embodiment, the motor torque control device is applied to a hybrid vehicle of a P2 architecture;

[0106] When the clutch between the engine and the motor is in the engaged state, and the required torque and speed of the drive axle wheel end fall outside the economic output band of the engine, the motor required speed is equal to the required speed of the drive axle wheel end, and the motor required torque is equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine;

[0107] The optimal engine torque is the torque corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve.

[0108] Furthermore, in one embodiment, when the clutch between the engine and the motor is in an engaged state, and the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall within the economic output band of the engine, the required speed of the motor is equal to the required speed of the drive axle wheel end, and the required torque of the motor is zero.

[0109] Furthermore, in one embodiment, when the clutch between the engine and the motor is in a disconnected state, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is equal to the drive axle wheel end required torque.

[0110] Among them, the functional implementation of each module in the above-mentioned motor torque control device corresponds to the various steps in the above-mentioned motor torque control method embodiment, and its functions and implementation processes will not be repeated here one by one.

[0111] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0112] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0113] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0114] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0115] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0116] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0117] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A motor torque control method, characterized in that: The motor torque control method comprises: Find the motor rated torque corresponding to the motor required speed on the motor external characteristic curve; If the motor required torque is less than or equal to the motor rated torque, the motor output torque is controlled to be equal to the motor required torque; If the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the reduction threshold, the motor output torque is controlled to be equal to the motor demand torque, wherein the reduction threshold is less than the temperature protection threshold; If the motor demand torque is greater than the motor rated torque, the motor real-time temperature is less than the temperature protection threshold but greater than the reduction threshold, the motor output torque is controlled between zero and the motor demand torque, wherein the closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor demand torque, and the closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero.

2. The motor torque control method according to claim 1, characterized in that: The reduction threshold is greater than or equal to the equilibrium temperature when the motor runs at the motor demand speed and the motor rated torque.

3. The motor torque control method according to claim 2, characterized in that: The step of controlling the motor output torque to be between zero and the motor required torque comprises: The output torque of the controlled motor is equal to the product of the motor demand torque and the reduction coefficient. The calculation formula of the reduction coefficient is: Where k represents the reduction coefficient, T i Indicates the real-time temperature of the motor, T e represents the equilibrium temperature, T LIM Indicates the temperature protection threshold.

4. The motor torque control method according to any one of claims 1 to 3, characterized in that: The motor torque control method is applied to a hybrid vehicle of a P2 architecture; When the clutch between the engine and the motor is in the engaged state, and the required torque and speed of the drive axle wheel end fall outside the economic output band of the engine, the motor required speed is equal to the required speed of the drive axle wheel end, and the motor required torque is equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine; The optimal engine torque is the torque corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve.

5. The motor torque control method according to claim 4, characterized in that: When the clutch between the engine and the motor is in the engaged state, and the required torque and speed of the drive axle wheel end fall within the economic output band of the engine, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is zero.

6. The motor torque control method according to claim 4, characterized in that: When the clutch between the engine and the motor is in a disconnected state, the motor demand speed is equal to the drive axle wheel end demand speed, and the motor demand torque is equal to the drive axle wheel end demand torque.

7. A method for controlling torque of a hybrid vehicle, characterized in that: Applied to a hybrid vehicle of a P2 architecture, the hybrid vehicle torque control method comprises: When the clutch between the engine and the motor is in the engaged state, check whether the required torque and speed of the drive axle wheel end are within the economic output band of the engine; If the required torque and speed of the drive axle wheel end fall outside the economic output band of the engine, then find the optimal torque of the engine corresponding to the required speed of the drive axle wheel end on the engine economy optimal curve; The motor required speed is set equal to the required speed of the drive axle wheel end, and the motor required torque is set equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine, and the steps of the motor torque control method according to any one of claims 1 to 3 are performed; The engine output torque is controlled to be equal to the difference between the engine optimal torque or the required torque at the drive axle wheel end and the motor output torque.

8. The hybrid vehicle torque control method according to claim 7, characterized in that: After the step of checking whether the required torque and the required speed of the drive axle wheel end fall within the economic output band of the engine, the method further includes: If the required torque at the drive axle wheel end and the required speed at the drive axle wheel end fall within the economic output band of the engine, the engine output torque is controlled to be equal to the required torque at the drive axle wheel end, and the motor output torque is controlled to be equal to zero.

9. The hybrid vehicle torque control method according to claim 7, characterized in that: The hybrid vehicle torque control method further includes: When the clutch between the engine and the motor is in the engaged state, the motor required speed is equal to the drive axle wheel end required speed, and the motor required torque is equal to the drive axle wheel end required torque, and the steps of the motor torque control method as described in any one of claims 1 to 3 are executed.

10. A motor torque control device, characterized in that: The motor torque control device comprises: A rated search module is used to search the rated torque of the motor corresponding to the required speed of the motor on the motor external characteristic curve; A first output module, used for controlling the motor output torque to be equal to the motor demand torque if the motor demand torque is less than or equal to the motor rated torque; The second output module is used to control the motor output torque to be equal to the motor demand torque if the motor demand torque is greater than the motor rated torque and the motor real-time temperature is less than or equal to the reduction threshold, wherein the reduction threshold is less than the temperature protection threshold; The third output module is used to control the motor output torque between zero and the motor required torque if the motor required torque is greater than the motor rated torque, and the motor real-time temperature is less than the temperature protection threshold and greater than the reduction threshold, wherein the closer the motor real-time temperature is to the reduction threshold, the closer the motor output torque is to the motor required torque, and the closer the motor real-time temperature is to the temperature protection threshold, the closer the motor output torque is to zero.

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