Motor torque control method and apparatus and hybrid vehicle torque control method
By finding the rated torque on the motor's external characteristic curve and adjusting the motor's output torque in conjunction with real-time temperature, the problem of motor overheating and power failure in traditional methods is solved, achieving a balance between stable equipment operation and torque demand.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DONGFENG AUTOMOBILE CO LTD
- Filing Date
- 2025-09-15
- Publication Date
- 2026-06-11
AI Technical Summary
Traditional motor torque control methods can cause the motor to overheat and trigger a forced power-off when faced with excessive torque demand, affecting the normal operation of the equipment and posing potential risks.
By finding the rated torque corresponding to the required motor speed on the motor's external characteristic curve, and combining it with real-time temperature and derating threshold, the motor's output torque is dynamically adjusted to avoid overheating and meet torque requirements.
While avoiding motor overheating and power failure, we should try our best to meet torque requirements, improve equipment operation stability, and reduce adverse effects.
Smart Images
Figure CN2025121284_11062026_PF_FP_ABST
Abstract
Description
Motor torque control method and device, hybrid vehicle torque control method Technical Field
[0001] This application relates to the field of motor control technology, specifically to a motor torque control method and device, and a torque control method for hybrid electric vehicles. Background Technology
[0002] In numerous industrial, transportation, and electromechanical equipment applications, electric motors play a crucial role as key power output components. Accurate control of motor torque has a profound impact on the normal operation, performance, and lifespan of equipment.
[0003] Traditional motor torque control methods typically employ a simple and direct approach: the motor's output torque equals its required torque. However, in practical applications, situations often arise where the motor's required torque suddenly increases. When faced with such excessive torque demand, a series of serious problems can occur. Because the motor's internal current increases significantly when outputting high torque, a large amount of heat is generated in the motor windings, causing the motor temperature to rise continuously.
[0004] Currently, most motors are equipped with overheat protection mechanisms. When the motor temperature reaches a preset temperature protection threshold, the system will forcibly disconnect the power to prevent irreversible damage such as insulation failure or winding short circuits caused by overheating. While this forced power disconnection protects the motor's hardware, it causes significant inconvenience and adverse effects on the entire equipment or system.
[0005] Therefore, traditional motor torque control methods have drawbacks when faced with situations where the motor's torque demand is too high. These drawbacks include the risk of forced power-off due to motor overheating, which can affect the normal operation of the equipment and bring about many potential risks. There is an urgent need for a more reasonable and effective motor torque control method to solve these problems. Summary of the Invention
[0006] This 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, embodiments of this application provide a motor torque control method, the motor torque control method comprising:
[0008] Find the rated torque of the motor corresponding to the required motor speed on the motor's external characteristic curve;
[0009] If the required torque of the motor is less than or equal to the rated torque of the motor, then control the output torque of the motor to be equal to the required torque of the motor.
[0010] If the motor's required torque is greater than the motor's rated torque, and the motor's real-time temperature is less than or equal to the derating threshold, then the motor's output torque is controlled to be equal to the motor's required torque, where the derating threshold is less than the temperature protection threshold.
[0011] If the motor's required torque is greater than its rated torque, and the motor's real-time temperature is less than the temperature protection threshold but greater than the derating threshold, then the motor's output torque will be controlled between zero and the motor's required torque. Specifically, the closer the motor's real-time temperature is to the derating threshold, the closer the motor's output torque is to the motor's required torque; and the closer the motor's real-time temperature is to the temperature protection threshold, the closer the motor's output torque is to zero.
[0012] Furthermore, in one embodiment, the reduction threshold is greater than or equal to the equilibrium temperature at which the motor operates at its required speed and rated torque.
[0013] Further, in one embodiment, the step of controlling the motor output torque between zero and the motor's required torque includes:
[0014] The controlled motor output torque is equal to the product of the motor's required torque and the reduction factor. The formula for calculating the reduction factor is:
[0015] Where k represents the reduction coefficient, T i This indicates the real-time temperature of the motor, T. e T represents the equilibrium temperature. LIM This indicates the temperature protection threshold.
[0016] Furthermore, in one embodiment, the motor torque control method is applied to a hybrid electric vehicle with a P2 architecture;
[0017] When the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is equal to the difference between the required torque at the drive axle wheel end and the engine's optimal torque.
[0018] The engine's optimal torque is the torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve.
[0019] Furthermore, in one embodiment, when the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall within the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is zero.
[0020] Furthermore, in one embodiment, when the clutch between the engine and the motor is disengaged, the required speed of the motor is equal to the required speed of the drive axle wheel, and the required torque of the motor is equal to the required torque of the drive axle wheel.
[0021] Secondly, this application also provides a torque control method for hybrid electric vehicles, applied to hybrid electric vehicles with a P2 architecture, the torque control method for hybrid electric vehicles including:
[0022] When the clutch between the engine and the electric motor is engaged, check whether the required torque and speed at the drive axle wheel end fall within the engine's economic output band.
[0023] If the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, then find the engine's optimal torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve.
[0024] Set the required motor speed to be equal to the required speed at the drive axle wheel end, and the required motor torque to be equal to the difference between the required torque at the drive axle wheel end and the optimal torque of the engine, and execute the steps of the above motor torque control method.
[0025] The engine output torque is controlled to be equal to the engine's optimal torque or the difference between the required torque at the drive axle wheel end and the motor's output torque.
[0026] Furthermore, in one embodiment, after the step of checking whether the required torque and speed at the drive axle wheel ends fall within the engine's economic output band, the method further includes:
[0027] If the required torque and speed at the drive axle wheel end fall within the engine's economic output band, then the engine output torque is equal to the required torque at the drive axle wheel end, and the motor output torque is zero.
[0028] Furthermore, in one embodiment, the hybrid vehicle torque control method further includes:
[0029] When the clutch between the engine and the motor is engaged, the motor's required speed is made equal to the required speed at the drive axle wheel end, and the motor's required torque is made equal to the required torque at the drive axle wheel end, and the steps of the above motor torque control method are executed.
[0030] Secondly, embodiments of this application also provide a motor torque control device, the motor torque control device comprising:
[0031] The rated torque lookup module is used to find the motor rated torque corresponding to the required motor speed on the motor's external characteristic curve.
[0032] The first output module is used to control the motor output torque to be equal to the motor's required torque if the motor's required torque is less than or equal to the motor's rated torque.
[0033] The second output module is used to control the motor output torque to be equal to the motor's required torque if the motor's required torque is greater than the motor's rated torque and the motor's real-time temperature is less than or equal to the derating threshold. The derating threshold is less than the temperature protection threshold.
[0034] The third output module is used to control the motor output torque between zero and the motor's required torque if the motor's required torque is greater than the motor's rated torque, the motor's real-time temperature is less than the temperature protection threshold, or greater than the derating threshold. Specifically, the closer the motor's real-time temperature is to the derating threshold, the closer the motor's output torque is to the motor's required torque; the closer the motor's real-time temperature is to the temperature protection threshold, the closer the motor's output torque is to zero.
[0035] In this application, the required torque of the motor is first compared with its rated torque. When the required torque is not higher than the rated torque, the motor output torque is controlled to equal the required torque. When the required torque is higher, the real-time motor temperature and a derating threshold are further compared. When the real-time motor temperature is not higher than the derating threshold, the motor output torque is controlled to equal the required torque. When the real-time motor temperature is higher than the derating threshold, the motor output torque is controlled between zero and the required torque. The closer the real-time motor temperature is to the derating threshold, the closer the motor output torque is to the required torque, thus delaying the temperature rise while meeting the torque requirement as much as possible. The closer the real-time motor temperature is to the temperature protection threshold, the closer the motor output torque is to zero, so as to reduce the motor temperature as quickly as possible and prevent the motor temperature from reaching the temperature protection threshold. Through this application, the torque requirement can be met as much as possible without triggering a forced power-off due to motor overheating, thereby improving the operational stability of the equipment and reducing adverse effects. Attached Figure Description
[0036] Figure 1 is a schematic flowchart of a motor torque control method in one embodiment of this application;
[0037] Figure 2 is a schematic diagram of the drive system of a hybrid electric vehicle based on the P2 architecture;
[0038] Figure 3 is a flowchart illustrating a torque control method for a hybrid electric vehicle according to an embodiment of this application;
[0039] Figure 4 is a schematic diagram of the functional modules of the motor torque control device in one embodiment of this application. Detailed Implementation
[0040] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.
[0041] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0042] In a first aspect, embodiments of this application provide a method for controlling motor torque.
[0043] Figure 1 shows a schematic flowchart of a motor torque control method in one embodiment of this application.
[0044] Referring to Figure 1, in one embodiment, the motor torque control method includes the following steps:
[0045] S11. Find the rated torque of the motor corresponding to the required motor speed on the motor's external characteristic curve.
[0046] Specifically, when a motor is running under rated operating conditions, there is a specific relationship between the motor torque and the motor speed, which is described by the motor's external characteristic curve.
[0047] For example, the horizontal axis of the motor external characteristic curve represents the motor speed, and the vertical axis represents the motor torque. The vertical axis corresponding to the point on the motor external characteristic curve where the horizontal axis equals the required motor speed is the rated torque of the motor described in this embodiment.
[0048] S12. If the required torque of the motor is less than or equal to the rated torque of the motor, then control the output torque of the motor to be equal to the required torque of the motor.
[0049] Specifically, when the required torque of the motor is less than or equal to the rated torque of the motor, there is no risk of overheating of the motor. The output torque of the motor is controlled to be equal to the required torque of the motor, and the torque requirement is normally met.
[0050] S13. If the motor's required torque is greater than the motor's rated torque, and the motor's real-time temperature is less than or equal to the derating threshold, then control the motor's output torque to be equal to the motor's required torque, where the derating threshold is less than the temperature protection threshold.
[0051] Specifically, when the motor's required torque is greater than its rated torque, the motor's real-time temperature is added as a criterion for judgment. A certain margin is maintained between the reduction threshold and the temperature protection threshold. When the motor's real-time temperature is less than or equal to the reduction threshold, the motor does not have the risk of overheating in a short period of time. The motor's output torque is controlled to be equal to the motor's required torque, thus normally meeting the torque requirement.
[0052] S14. If the motor's required torque is greater than the motor's rated torque, and the motor's real-time temperature is less than the temperature protection threshold but greater than the derating threshold, then the motor's output torque will be controlled between zero and the motor's required torque. Specifically, the closer the motor's real-time temperature is to the derating threshold, the closer the motor's output torque is to the motor's required torque; and the closer the motor's real-time temperature is to the temperature protection threshold, the closer the motor's output torque is to zero.
[0053] Specifically, when the real-time motor temperature exceeds the reduction threshold, the motor is at risk of overheating in a short period of time. It is necessary to reduce the motor output torque to between zero and the required motor torque. The closer the real-time motor temperature is to the reduction threshold, the closer the motor output torque is to the required motor torque. This delays the temperature rise while meeting the torque requirement as much as possible. The closer the real-time motor temperature is to the temperature protection threshold, the closer the motor output torque is to zero, so as to reduce the motor temperature as quickly as possible and avoid the motor temperature reaching the temperature protection threshold, which would trigger a forced power-off due to overheating.
[0054] It should be noted that in all the above cases, the motor output speed is equal to the motor's required speed.
[0055] It should be noted that when the motor output torque is less than the motor's required torque, the entire equipment will experience a temporary performance decline if there is no other power source to make up for the missing part. However, in the long run, the equipment performance under this solution is better than that under the traditional solution.
[0056] For example, assuming the motor's required torque consistently exceeds its rated torque, if the traditional method is used for motor torque control, the motor output torque equals the required torque. After 10 minutes of operation, the motor's real-time temperature rises to the temperature protection threshold, triggering a forced power-off due to overheating. Power is restored after 10 minutes. However, if this method is used for motor torque control, within 1-5 minutes, the motor output torque equals the required torque, and the motor's real-time temperature rises to the reduction threshold. Within 6-10 minutes, the motor output torque gradually decreases, and the motor's real-time temperature first slowly rises towards the temperature protection threshold, then rapidly decreases below the reduction threshold. Within 11-15 minutes, the motor output torque equals the required torque, and the motor's real-time temperature rises to the reduction threshold. Within 16-20 minutes, the motor output torque gradually decreases, and the motor's real-time temperature first slowly rises towards the temperature protection threshold, then rapidly decreases below the reduction threshold. In the first 10 minutes, the average motor output torque of this method is lower than that of the traditional method. Over the overall 20 minutes, the average motor output torque of this method is higher than that of the traditional method.
[0057] Therefore, through this embodiment, the torque requirement can be met as much as possible without triggering a forced power-off due to motor overheating, thereby improving the operational stability of the equipment and reducing adverse effects.
[0058] Furthermore, in one embodiment, the reduction threshold is greater than or equal to the equilibrium temperature at which the motor operates at its required speed and rated torque.
[0059] In this embodiment, the equilibrium temperature of the motor when it operates at the required motor speed and rated motor torque is a fixed value that can be measured in the early stage. Using this as the basis for setting the reduction threshold helps to improve the effect of motor torque control.
[0060] Further, in one embodiment, the step of controlling the motor output torque between zero and the motor's required torque includes:
[0061] The controlled motor output torque is equal to the product of the motor's required torque and the reduction factor. The formula for calculating the reduction factor is:
[0062] Where k represents the reduction coefficient, T i This indicates the real-time temperature of the motor, T. e T represents the equilibrium temperature. LIM This indicates the temperature protection threshold.
[0063] Specifically, T LIM -T e (referred to as the denominator) is a constant, T i -T e (referred to as molecule) 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's required torque and the reduction factor is to zero. 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's required torque and the reduction factor is to the motor's required torque.
[0064] In this embodiment, a specific strategy for reducing the output torque of the motor is provided. The calculation formula for the reduction coefficient k is obtained based on fitting a large amount of experimental data. Under the premise of avoiding the motor overheating and triggering forced power-off, the output torque of the motor can be further improved.
[0065] Furthermore, in one embodiment, the motor torque control method is applied to a hybrid electric vehicle with a P2 architecture;
[0066] When the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is equal to the difference between the required torque at the drive axle wheel end and the engine's optimal torque.
[0067] The engine's optimal torque is the torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve.
[0068] Figure 2 shows a schematic diagram of the drive system of a hybrid electric vehicle based on the P2 architecture.
[0069] Referring to Figure 2, the drive system of a P2 architecture hybrid electric vehicle includes an engine, clutch, drive motor, multi-speed transmission, HCU (Hybrid Control Unit), MCU (Motor Control Unit), EOP (Clutch Control Unit), and drive axle. When the clutch between the engine and the motor is engaged, the engine and the drive motor jointly provide torque to the drive axle, defined as hybrid mode. When the clutch between the engine and the motor is disengaged, only the drive motor provides torque to the drive axle, defined as pure electric mode.
[0070] Specifically, after the vehicle enters the READY state, the hybrid mode is selected via the mode selection button, and the HCU engages the clutch via EOP. The HCU checks whether the required torque and speed at the drive axle wheel end fall within the engine's economic output band. If they fall outside the economic output band, the drive motor needs to bear part of the torque demand to optimize engine fuel consumption. The HCU finds the engine's optimal torque corresponding to the required speed at the drive axle wheel end on the engine's optimal fuel economy curve, sets the motor's required speed to be equal to the required speed at the drive axle wheel end, and sets the motor's required torque to be equal to the difference between the required torque at the drive axle wheel end and the engine's optimal torque. Steps S11 to S14 are executed, and the obtained motor output torque is sent to the MCU.
[0071] Specifically, when an engine is running at its optimal fuel consumption, there is a specific relationship between engine torque and engine speed, which is described by the engine's optimal fuel economy curve. The engine's economic output band is a region that includes the engine's optimal fuel economy curve, and its width is defined according to demand, representing the operating state with better fuel consumption.
[0072] For example, the horizontal axis of the engine's optimal economy curve represents engine speed, and the vertical axis represents engine torque. To check whether the required torque and speed at the drive axle wheel ends fall within the engine's economic output band, we find the point where the vertical axis is the required torque at the drive axle wheel ends and the horizontal axis is the required speed at the drive axle wheel ends, and see if this point falls within the engine's economic output band. The vertical axis corresponding to the point on the engine's optimal economy curve where the horizontal axis equals the required speed at the drive axle wheel ends is the engine's optimal torque as described in this embodiment.
[0073] Furthermore, in one embodiment, when the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall within the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is zero.
[0074] Specifically, when the required torque and speed of the drive axle wheel end fall within the engine's economic output band, the engine can handle the entire torque demand with better fuel economy. 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. Steps S11 to S14 are executed, and the obtained motor output torque is sent to the MCU. It can be understood that the obtained motor output torque is also zero.
[0075] Furthermore, in one embodiment, when the clutch between the engine and the motor is disengaged, the required speed of the motor is equal to the required speed of the drive axle wheel, and the required torque of the motor is equal to the required torque of the drive axle wheel.
[0076] Specifically, after the vehicle enters the READY state, the pure electric mode is selected by the mode selection button. The HCU disengages the clutch through EOP, making the required motor speed equal to the required speed at the drive axle wheel end, and the required motor torque equal to the required torque at the drive axle wheel end. Steps S11 to S14 are executed, and the obtained motor output torque is sent to the MCU.
[0077] It should be noted that the above embodiments are only examples of application scenarios of this solution. This solution can also be applied in other scenarios, such as pure electric vehicles and other devices that use motors.
[0078] Secondly, embodiments of this application also provide a torque control method for hybrid electric vehicles, applied to hybrid electric vehicles with a P2 architecture.
[0079] Figure 3 shows a flowchart of a torque control method for a hybrid electric vehicle according to an embodiment of this application.
[0080] Referring to Figures 1 to 3, in one embodiment, the torque control method for a hybrid electric vehicle includes the following steps:
[0081] S21. When the clutch between the engine and the motor is engaged, check whether the required torque and required speed at the drive axle wheel end fall within the engine's economic output band.
[0082] S22. If the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, then find the engine's optimal torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve.
[0083] S23. Set the required speed of the motor to be equal to the required speed of the drive axle wheel end, and the required torque of the motor to be equal to the difference between the required torque of the drive axle wheel end and the optimal torque of the engine. Then execute steps S11 to S14.
[0084] S24. Control the engine output torque to be equal to the engine's optimal torque or the difference between the required torque at the drive axle wheel end and the motor output torque.
[0085] In this embodiment, if the engine output torque is controlled to be equal to the engine's optimal torque, the engine can operate with optimal fuel consumption. However, when the motor output torque is less than the motor's required torque, the torque transmitted to the drive axle wheel end is lower than the required torque at the drive axle wheel end, causing the actual speed of the hybrid vehicle to be lower than the target speed.
[0086] If the engine output torque is controlled to be equal to the difference between the torque required at the drive axle wheel end and the motor output torque, then when the motor output torque is less than the motor's required torque, the engine will make up for the missing part by sacrificing fuel consumption, so that the torque transmitted to the drive axle wheel end is equal to the torque required at the drive axle wheel end, ensuring that the actual speed of the hybrid vehicle is equal to the target speed.
[0087] Furthermore, in one embodiment, after the step of checking whether the required torque and speed at the drive axle wheel ends fall within the engine's economic output band, the method further includes:
[0088] If the required torque and speed at the drive axle wheel end fall within the engine's economic output band, then the engine output torque is equal to the required torque at the drive axle wheel end, and the motor output torque is zero.
[0089] Furthermore, in one embodiment, the hybrid vehicle torque control method further includes:
[0090] When the clutch between the engine and the motor is engaged, set the motor's required speed to be equal to the required speed at the drive axle wheel end and the motor's required torque to be equal to the required torque at the drive axle wheel end, and execute steps S11 to S14.
[0091] Thirdly, embodiments of this application also provide a motor torque control device.
[0092] Figure 4 shows a schematic diagram of the functional modules of a motor torque control device in one embodiment of this application.
[0093] Referring to Figure 4, in one embodiment, the motor torque control device includes:
[0094] The rated torque lookup module 10 is used to find the motor rated torque corresponding to the motor's required speed on the motor's external characteristic curve.
[0095] The first output module 20 is used to control the motor output torque to be equal to the motor's required torque if the motor's required torque is less than or equal to the motor's rated torque.
[0096] The second output module 30 is used to control the motor output torque to be equal to the motor's required torque if the motor's required torque is greater than the motor's rated torque and the motor's real-time temperature is less than or equal to the derating threshold, wherein the derating threshold is less than the temperature protection threshold.
[0097] The third output module 40 is used to control the motor output torque between zero and the motor's required torque if the motor's required torque is greater than the motor's rated torque, the motor's real-time temperature is less than the temperature protection threshold, or greater than the derating threshold. Specifically, the closer the motor's real-time temperature is to the derating threshold, the closer the motor's output torque is to the motor's required torque, and the closer the motor's real-time temperature is to the temperature protection threshold, the closer the motor's output torque is to zero.
[0098] Furthermore, in one embodiment, the reduction threshold is greater than or equal to the equilibrium temperature at which the motor operates at its required speed and rated torque.
[0099] Furthermore, in one embodiment, the third output module 40 is used for:
[0100] The controlled motor output torque is equal to the product of the motor's required torque and the reduction factor. The formula for calculating the reduction factor is:
[0101] Where k represents the reduction coefficient, T i This indicates the real-time temperature of the motor, T. e T represents the equilibrium temperature. LIM This indicates the temperature protection threshold.
[0102] Furthermore, in one embodiment, the motor torque control device is applied to a hybrid electric vehicle with a P2 architecture;
[0103] When the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is equal to the difference between the required torque at the drive axle wheel end and the engine's optimal torque.
[0104] The engine's optimal torque is the torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve.
[0105] Furthermore, in one embodiment, when the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall within the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is zero.
[0106] Furthermore, in one embodiment, when the clutch between the engine and the motor is disengaged, the required speed of the motor is equal to the required speed of the drive axle wheel, and the required torque of the motor is equal to the required torque of the drive axle wheel.
[0107] The functions of each module in the motor torque control device correspond to the steps in the above-mentioned motor torque control method embodiment, and their functions and implementation processes will not be described in detail here.
[0108] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0109] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.
[0110] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.
[0111] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.
[0112] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish 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 sequentially or in parallel, and these operations or steps may be combined.
[0113] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.
[0114] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A method for controlling motor torque, characterized in that, The motor torque control method includes: Find the rated torque of the motor corresponding to the required motor speed on the motor's external characteristic curve; If the required torque of the motor is less than or equal to the rated torque of the motor, then control the output torque of the motor to be equal to the required torque of the motor. If the motor's required torque is greater than the motor's rated torque, and the motor's real-time temperature is less than or equal to the derating threshold, then the motor's output torque is controlled to be equal to the motor's required torque, where the derating threshold is less than the temperature protection threshold. If the motor's required torque is greater than its rated torque, and the motor's real-time temperature is less than the temperature protection threshold but greater than the derating threshold, then the motor's output torque will be controlled between zero and the motor's required torque. Specifically, the closer the motor's real-time temperature is to the derating threshold, the closer the motor's output torque is to the motor's required torque; and the closer the motor's real-time temperature is to the temperature protection threshold, the closer the motor's output torque is to zero.
2. The motor torque control method of claim 1, wherein, The reduction threshold is greater than or equal to the equilibrium temperature of the motor when it is running at the required motor speed and rated motor torque.
3. The motor torque control method as described in claim 2, characterized in that, The step of controlling the motor output torque between zero and the motor's required torque includes: The controlled motor output torque is equal to the product of the motor's required torque and the reduction factor. The formula for calculating the reduction factor is: Where k represents the reduction coefficient, T i This indicates the real-time temperature of the motor, T. e T represents the equilibrium temperature. LIM This indicates the temperature protection threshold.
4. The motor torque control method according to any one of claims 1 to 3, characterized by, The motor torque control method is applied to hybrid electric vehicles with a P2 architecture; When the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is equal to the difference between the required torque at the drive axle wheel end and the engine's optimal torque. The engine's optimal torque is the torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve.
5. The motor torque control method as described in claim 4, characterized in that, When the clutch between the engine and the motor is engaged, and the required torque and speed at the drive axle wheel end fall within the engine's economic output band, the required speed of the motor is equal to the required speed at the drive axle wheel end, and the required torque of the motor is zero.
6. The motor torque control method as described in claim 4, characterized in that, When the clutch between the engine and the motor is disengaged, the motor's required speed is equal to the required speed at the drive axle wheel end, and the motor's required torque is equal to the required torque at the drive axle wheel end.
7. A hybrid vehicle torque control method characterized by comprising: The torque control method for hybrid electric vehicles applied to the P2 architecture includes: When the clutch between the engine and the electric motor is engaged, check whether the required torque and speed at the drive axle wheel end fall within the engine's economic output band. If the required torque and speed at the drive axle wheel end fall outside the engine's economic output band, then find the engine's optimal torque corresponding to the required speed at the drive axle wheel end on the engine's optimal economy curve. Set the required motor speed to be equal to the required speed at the drive axle wheel end, and the required motor torque to be equal to the difference between the required torque at the drive axle wheel end and the optimal torque of the engine, and execute the steps of the motor torque control method as described in any one of claims 1 to 3; The engine output torque is controlled to be equal to the engine's optimal torque or the difference between the required torque at the drive axle wheel end and the motor's output torque.
8. The torque control method for a hybrid electric vehicle as described in claim 7, characterized in that, Following the step of checking whether the required torque and speed at the drive axle wheel ends fall within the engine's economic output band, the following is also included: If the required torque and speed at the drive axle wheel end fall within the engine's economic output band, then the engine output torque is equal to the required torque at the drive axle wheel end, and the motor output torque is zero.
9. The hybrid vehicle torque control method according to claim 7, characterized by, The hybrid vehicle torque control method further includes: When the clutch between the engine and the motor is engaged, the required speed of the motor is made equal to the required speed of the drive axle wheel, and the required torque of the motor is made equal to the required torque of the drive axle wheel, and the steps of the motor torque control method as described in any one of claims 1 to 3 are executed.
10. An electric motor torque control apparatus characterized by comprising: The motor torque control device includes: The rated torque lookup module is used to find the motor rated torque corresponding to the required motor speed on the motor's external characteristic curve. The first output module is used to control the motor output torque to be equal to the motor's required torque if the motor's required torque is less than or equal to the motor's rated torque. The second output module is used to control the motor output torque to be equal to the motor's required torque if the motor's required torque is greater than the motor's rated torque and the motor's real-time temperature is less than or equal to the derating threshold. The derating 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's required torque if the motor's required torque is greater than the motor's rated torque, the motor's real-time temperature is less than the temperature protection threshold, or greater than the derating threshold. Specifically, the closer the motor's real-time temperature is to the derating threshold, the closer the motor's output torque is to the motor's required torque; the closer the motor's real-time temperature is to the temperature protection threshold, the closer the motor's output torque is to zero.