Motor control method, device and vehicle

Abstract

The embodiment of the application relates to the technical field of vehicles, and discloses a motor control method and device and a vehicle, the motor control method comprising the following steps: determining a current filtering power by first-order low-pass filtering calculation based on instantaneous power of a driving motor at a current moment and filtering power at a previous moment; determining motor continuous power of the driving motor based on the current filtering power and a preset mapping relationship; determining a target peak torque of the driving motor; the target peak torque is used for representing maximum instantaneous acceleration capability that can be output by an electric drive system under a current state; determining a target limiting torque of the driving motor based on motor continuous torque corresponding to the motor continuous power and the target peak torque; the target limiting torque is used for representing maximum torque that is allowed to be output by the driving motor at a next moment; and controlling the driving motor to operate based on vehicle demand torque and the target limiting torque. In this way, the motor can be continuously power-limited while short-time peak performance is not affected, and the motor is controlled to safely operate.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically to a motor control method, device, and vehicle. Background Technology

[0002] Electric drive systems have limited thermal capacity and cannot operate at peak power for extended periods. Prolonged high power output can damage components within the system. Therefore, it is necessary to limit the continuous power output of the motor to ensure reliable operation of the electric drive system.

[0003] Therefore, how to limit the continuous power of the motor has become a pressing technical problem that needs to be solved. Summary of the Invention

[0004] In view of the above shortcomings, the purpose of this application is to provide a motor control method, device and vehicle, which aims to solve the technical problem of how to continuously limit the power of a motor.

[0005] In a first aspect, embodiments of this application provide a motor control method, which includes: determining a current filtered power based on the instantaneous power of the drive motor at the current moment and the filtered power at the previous moment. The current filtered power characterizes the thermal load state of the drive motor at the current moment. Based on the current filtered power and a preset mapping relationship, determining the continuous power of the drive motor. The continuous power represents the power carrying capacity of the drive motor under the current thermal load state. In the mapping relationship, the continuous power decreases as the filtered power increases. Determining a target peak torque of the drive motor. The target peak torque characterizes the maximum instantaneous acceleration capability that the electric drive system can output under the current state. Based on the continuous torque corresponding to the continuous power and the target peak torque, determining a target limiting torque of the drive motor. The target limiting torque represents the maximum torque allowed to be output by the drive motor at the next moment. Controlling the operation of the drive motor based on the vehicle's required torque and the target limiting torque.

[0006] By comparing the instantaneous power of the drive motor at the current moment with the filtered power at the previous moment, the current filtered power is determined. Filtering can then transform the rapidly fluctuating instantaneous power into a slowly changing signal that reflects the heat accumulation effect. Subsequently, based on the current filtered power and a preset mapping relationship, the continuous power of the drive motor is determined. This continuous power can be dynamically adjusted according to the thermal load state, ensuring that the continuous power is inversely proportional to the current degree of motor heating. This allows for a reasonable representation of the drive motor's power carrying capacity under the current thermal load state, reasonably limiting the motor's continuous capacity and preventing overheating due to excessively high continuous power settings. Finally, combining the continuous torque, reflecting thermal load carrying capacity, with the peak torque, reflecting instantaneous acceleration capacity, ensures that the target limiting torque is both constrained by heat accumulation and retains a certain instantaneous strain margin. This allows for a reasonable representation of the maximum allowable torque output of the drive motor at the next moment, helping to prevent excessive temperature rise due to long-term overload and avoiding overly stringent limitations on acceleration performance. Subsequently, by controlling the operation of the drive motor based on the vehicle's required torque and the target limiting torque, the vehicle's required torque can be limited by the target limiting torque, so that the actual output torque of the drive motor does not exceed the limit allowed by the current thermal load state. This ensures that the drive motor operates within a safe temperature range while meeting driving needs, thereby improving the reliability and service life of the system.

[0007] In one possible embodiment, the corrected filter power is determined based on the current filter power and the correction coefficient. The corrected filter power is the product of the current filter power and the correction coefficient. The continuous motor power is determined based on a preset mapping relationship and the corrected filter power; the preset mapping relationship is the correspondence between a preset corrected filter power and a preset continuous power.

[0008] The corrected filter power is determined based on the current filter power and the correction coefficient. The correction coefficient is then used to dynamically adjust the current filter power, allowing it to more accurately reflect changes in the actual operating state or load conditions of the motor. Subsequently, the continuous power of the motor is determined based on a preset mapping relationship and the corrected filter power. This allows the corrected filter power to be used as a mapping basis to quickly obtain the continuous power of the motor, reducing calculation delays and improving the consistency and reliability of power control.

[0009] In one possible embodiment, the preset mapping relationship includes: multiple preset corrected filter powers and multiple preset continuous powers, with one preset corrected filter power corresponding to one preset continuous power. Determining the motor continuous power based on the preset mapping relationship and the corrected filter power includes: if the corrected filter power is the same as any one of the multiple preset corrected filter powers, then based on a second preset power correspondence relationship, determining the preset continuous power corresponding to the corrected filter power as the motor continuous power.

[0010] When determining the continuous power of the motor based on a preset mapping relationship and the corrected filtered power, the corrected filtered power is compared with multiple preset corrected filtered power values. If they are the same, the corresponding preset continuous power is determined as the continuous power of the motor according to a second preset power correspondence relationship. This allows for direct judgment using pre-established matching conditions, avoiding the uncertainties caused by real-time calculation or dynamic fitting, thus helping to improve the accuracy and consistency of the determination of the continuous power of the motor.

[0011] In one possible embodiment, the motor control method further includes: when the corrected filter power is different from any one of the multiple preset corrected filter powers, determining a first preset adjacent product and a second preset adjacent product, wherein the first preset adjacent product and the second preset adjacent product are the two preset corrected filter powers with the smallest difference between them and the corrected filter power. Based on the corrected filter power, the first preset adjacent product, and the second preset adjacent product, interpolation calculation is performed to obtain the continuous power of the motor.

[0012] When the corrected filter power is different from multiple preset corrected filter powers, by determining the two preset corrected filter powers with the smallest difference from the corrected filter power, the preset reference point closest to the current operating condition can be screened using the principle of minimizing the difference. Subsequently, any intermediate value in the power value range is filled according to the linear or nonlinear relationship between the first preset adjacent product and the second preset adjacent product. This enables the motor's continuous power to transition continuously and smoothly with the change of the corrected filter power, which helps to improve the stability and accuracy of power distribution during motor control, while reducing the risk of system oscillation or control overshoot caused by power jumps.

[0013] In one possible embodiment, the smaller of the motor continuous torque and the target peak torque is determined as the target limiting torque.

[0014] By defining the smaller of the motor's continuous torque and the target peak torque as the target limiting torque, the motor's continuous torque can be used as a long-term thermal stability boundary to constrain short-term peak output. This allows the system to meet instantaneous acceleration or hill-climbing requirements while avoiding the risk of overheating of the drive motor due to prolonged operation in the peak torque range. This decouples long-term continuous power limitation from short-term peak torque limitation, thus balancing power response and thermal safety.

[0015] In one possible embodiment, determining the target peak torque of the drive motor includes: acquiring the inverter peak torque, the motor peak torque, and the battery peak torque. The inverter peak torque is the torque corresponding to the inverter's peak current, where the peak current is the maximum instantaneous current the inverter can withstand in the current state. The motor peak torque is the maximum torque allowed to be output by the drive motor in the current state. The battery peak torque is the torque corresponding to the battery's discharge power capability. The discharge power capability is the maximum instantaneous power allowed to be output by the battery in the current state. Based on the motor peak torque, inverter peak torque, and battery peak torque, the target peak torque is determined.

[0016] The peak torques of the inverter, motor, and battery are obtained separately to extract the limit constraints of each component under instantaneous overload conditions. This provides independent boundary parameters for subsequent multi-constraint fusion, preventing the neglect of limitations of individual components. Subsequently, a target peak torque is determined based on the combined peak torques of the motor, inverter, and battery. This allows for a comprehensive evaluation of the instantaneous capabilities of the inverter, motor, and battery, ensuring that the final selected target peak torque simultaneously meets the physical limits of the three core components under peak conditions. This prevents system damage or protective shutdown due to insufficient capability of any single component.

[0017] In one possible embodiment, determining the target peak torque based on the motor peak torque, inverter peak torque, and battery peak torque includes: determining the smaller of the motor peak torque, inverter peak torque, and battery peak torque as the target peak torque.

[0018] By selecting the smallest value among the peak torque of the motor, inverter, and battery, the target peak torque can be automatically limited to the component with the lowest peak capacity. This effectively prevents overload, overheating, or protective shutdown caused by the torque request exceeding the peak capacity of any component. In this way, the limits of multiple components can be fused through simple comparison calculations, thereby reducing the complexity and computational overhead of the control algorithm while ensuring system safety and reliability.

[0019] In one possible embodiment, controlling the operation of the drive motor based on the vehicle's required torque and a target limiting torque includes: when the vehicle's required torque is greater than the target limiting torque, controlling the drive motor to output torque according to the target limiting torque; and when the vehicle's required torque is less than or equal to the target limiting torque, controlling the drive motor to output torque according to the vehicle's required torque.

[0020] When the vehicle's required torque exceeds the target limit torque, the drive motor is controlled to output torque according to the target limit torque. This clamps the actual output torque within the target limit torque range, preventing the motor output from exceeding the limit value and preventing the drive motor from exceeding its safe operating boundary due to instantaneous overload, thereby reducing the risk of overcurrent or overheating faults in the motor control system. When the vehicle's required torque is less than or equal to the target limit torque, the drive motor is controlled to output torque according to the vehicle's required torque. This ensures that the motor output torque is consistent with the driving intention or the vehicle controller's request, thus maintaining the dynamic following performance of the electric drive system without triggering limiting conditions, thereby helping to improve the vehicle's acceleration responsiveness and driving smoothness under normal operating conditions.

[0021] In one possible embodiment, determining the current filter power based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment includes: inputting the instantaneous power and the filter power at the previous moment into a low-pass filter to obtain the current filter power.

[0022] By inputting the current instantaneous power and the filtered power from the previous moment into a low-pass filter, the current filtered power can be determined. The low-pass filter's attenuation characteristics for high-frequency components in the input signal can be utilized to suppress high-frequency fluctuations in the instantaneous power signal caused by measurement noise or instantaneous load changes, resulting in a smoother trend in the current filtered power. Furthermore, since the filtered power from the previous moment is used as feedback input, the determination of the current filtered power depends on historical filtered values ​​rather than solely on the current instantaneous sampled value. This enables a first-order hysteresis filtering effect, reducing the direct impact of sudden changes in instantaneous power on the filtering result.

[0023] In one possible embodiment, the instantaneous power and the filtered power from the previous moment are input into a low-pass filter to obtain the current filtered power. This includes: multiplying a first filter factor by the instantaneous power through the low-pass filter to obtain a first filtered product; multiplying a second filter factor by the filtered power of the drive motor from the previous moment through the low-pass filter to obtain a second filtered product; and adding the first filtered product and the second filtered product through the low-pass filter to obtain the current filtered power of the drive motor.

[0024] Multiplying the first filter factor by the instantaneous power using a low-pass filter yields the first filter product. This first filter factor can be used to weight the instantaneous power, achieving initial suppression of high-frequency components in the instantaneous power. Multiplying the second filter factor by the filtered power of the drive motor at the previous moment using a low-pass filter yields the second filter product. This second filter factor can be used to weight and preserve historical filtering results, ensuring the continuation of the stable components of the filtered power at the previous moment. This allows the current filtered power to inherit the historical power variation trend, avoiding unreasonable jumps in the filtered output caused by random fluctuations in instantaneous power. Adding the first and second filter products using a low-pass filter yields the current filtered power of the drive motor. This allows for the linear superposition of the weighted instantaneous power components and historical power components, ensuring that the current filtered power reflects both the current instantaneous power input and retains the inertial characteristics of historical power, thus obtaining a smooth and appropriately responsive power estimate.

[0025] Secondly, embodiments of this application provide a motor control device, which includes: a filter power determination module, a continuous power determination module, a peak torque determination module, a limit torque determination module, and a motor control module.

[0026] The filter power determination module is used to determine the current filter power based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment. The current filter power is used to characterize the thermal load state of the drive motor at the current moment.

[0027] The continuous power determination module is used to determine the continuous power of the drive motor based on the current filtered power and a preset mapping relationship. The continuous power represents the power carrying capacity of the drive motor under the current thermal load condition. In the mapping relationship, the continuous power decreases as the filtered power increases.

[0028] The peak torque determination module is used to determine the target peak torque of the drive motor. The target peak torque is used to characterize the maximum instantaneous acceleration capability that the electric drive system can output under the current conditions.

[0029] The limiting torque determination module is used to determine the target limiting torque of the drive motor based on the continuous torque of the motor corresponding to the continuous power of the motor and the target peak torque. The target limiting torque is used to represent the maximum torque that the drive motor is allowed to output at the next moment.

[0030] The motor control module is used to control the operation of the drive motor based on the vehicle's required torque and target limit torque.

[0031] Thirdly, embodiments of this application provide a vehicle that includes the motor control device as described in the second aspect. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0033] Figure 1 This is a schematic diagram of the structure of a motor control system disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a long-term power limiting system for a new energy drive motor disclosed in an embodiment of this application; Figure 3 This is a schematic flowchart of a motor control method disclosed in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a motor control device disclosed in an embodiment of this application; Figure 5 This is a schematic diagram of another motor control device disclosed in an embodiment of this application. Detailed Implementation

[0034] The terms “first,” “second,” etc., are used for descriptive purposes only and have no sequential or technical meaning, nor should they be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0035] In the embodiments of this application, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0036] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include other steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or device.

[0037] Furthermore, in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplarily" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplarily" or "for example" is intended to present concepts in a concrete manner.

[0038] This application provides a motor control method. In this method, the current filtered power is determined by comparing the instantaneous power of the drive motor at the current moment with the filtered power at the previous moment. Filtering can convert the rapidly fluctuating instantaneous power into a slowly changing signal that reflects the heat accumulation effect. Subsequently, based on the current filtered power and a preset mapping relationship, the continuous power of the drive motor is determined. The value of the continuous power can be dynamically adjusted according to the thermal load state, making the continuous power inversely proportional to the current heating level of the motor. This allows for a reasonable representation of the drive motor's power carrying capacity under the current thermal load state, reasonably limiting the motor's continuous capacity and preventing overheating due to excessively high continuous power settings. Furthermore, the continuous torque, reflecting the thermal load carrying capacity, is combined with the peak torque, reflecting the instantaneous acceleration capacity. This ensures that the target limiting torque is constrained by heat accumulation while retaining a certain instantaneous strain margin, thus reasonably representing the maximum allowable output torque of the drive motor at the next moment. This helps prevent the motor from exceeding its temperature limit due to long-term overload and avoids overly stringent limitations on acceleration performance. Subsequently, by controlling the operation of the drive motor based on the vehicle's required torque and the target limiting torque, the vehicle's required torque can be limited by the target limiting torque, so that the actual output torque of the drive motor does not exceed the limit allowed by the current thermal load state. This ensures that the drive motor operates within a safe temperature range while meeting driving needs, thereby improving the reliability and service life of the system.

[0039] For ease of description, the application scenarios involved in the embodiments of this application are introduced below.

[0040] For example, such as Figure 1 As shown in the embodiments of this application, a motor control system may include a drive motor 1 and a motor control device 2. The drive motor 1 and the motor control device 2 may be an integrated device, such as an integrated motor controller assembly. Alternatively, the drive motor 1 and the motor control device 2 may be devices connected via communication. For example, the drive motor 1 may be a motor body mounted on the vehicle's drive axle, and may be a permanent magnet synchronous motor or an AC asynchronous motor. This application does not impose any restrictions on the specific type of motor. The motor control device 2 may be a single motor controller, or it may be a distributed control system composed of multiple units such as a vehicle controller, a motor controller, and a battery management system. In some implementations, this distributed control system may be a cluster of electronic control units in an in-vehicle network. This application does not impose any restrictions on the specific implementation of the drive motor 1 and the motor control device 2.

[0041] The drive motor 1 can be the power actuator of the vehicle, and the motor control device 2 can be equipped with software modules such as a filtering calculation module, a mapping relationship storage unit, and a torque arbitration strategy. The motor control device 2 can collect the instantaneous power of the drive motor 1 and the filtering power of the previous moment in real time through the controller area network (CAN) or the vehicle Ethernet, and perform torque limiting decisions based on these parameters.

[0042] For example, when the vehicle is running and the drive motor is under dynamic load changes, the motor control device 2 collects the instantaneous power of the drive motor 1 at the current moment and the filtered power at the previous moment in real time to determine the current filtered power. The motor control device 2 then determines the continuous power of the drive motor 1 based on the current filtered power and a preset mapping relationship. This continuous power represents the power carrying capacity of the drive motor 1 under the current thermal load condition, and the continuous power decreases as the filtered power increases in the mapping relationship. Simultaneously, the motor control device 2 determines the target peak torque of the drive motor 1, which characterizes the maximum instantaneous acceleration capability that the electric drive system can output under the current condition. Furthermore, the motor control device 2 determines the target limiting torque based on the continuous torque corresponding to the continuous power and the target peak torque. Finally, the motor control device 2 controls the drive motor 1 to operate according to the vehicle's required torque and the target limiting torque, thereby achieving optimal power output matching while avoiding thermal overload.

[0043] In some embodiments, please refer to Figure 2 In this embodiment, the motor control device 2 is equipped with a long-term power limiting system for a new energy drive motor. This system may include the following modules: a signal acquisition module, a real-time power calculation module, a filtering module, a storage module, a lookup table limiting module, and a torque arbitration module. Specifically, the signal acquisition module is connected to the real-time power calculation module, the real-time power calculation module is connected to the filtering module, both the filtering module and the storage module are connected to the lookup table limiting module, and the torque arbitration module is connected to the lookup table limiting module.

[0044] The signal acquisition module is used to acquire the real-time speed signal and the real-time torque signal of the drive motor, and send the real-time speed signal and the real-time torque signal to the real-time power calculation module.

[0045] The real-time power calculation module is used to calculate instantaneous power based on real-time speed and torque signals, and send the instantaneous power to the filtering module.

[0046] The filtering module has a built-in first-order low-pass digital filter, which is used to calculate the filtered power based on the instantaneous power and send the filtered power to the lookup table limiting module.

[0047] The storage module is used to store the preset mapping relationship table.

[0048] The lookup table limitation module is used to query a preset mapping table based on the corrected filter power (i.e., the product of the filter power and the safety factor) to obtain the continuous power of the motor.

[0049] The torque arbitration module is used to convert the motor's continuous power into the motor's continuous torque, and to arbitrate the minimum value with the target peak torque to output the final target limit torque.

[0050] It should be noted that the system architecture and application scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0051] The motor control method provided in this application can be applied to motor control equipment, specifically to the processor of a motor control device. This application uses the execution of the motor control method by a motor control device as an example to illustrate the motor control method provided in this application embodiment.

[0052] like Figure 3 As shown, this application provides a motor control method, which includes: S301. Determine the current filter power based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment.

[0053] The current filter power is used to characterize the thermal load state of the drive motor at the current moment.

[0054] The instantaneous power collected at the current moment reflects the real-time power status of the motor at that moment, while the filtered power determined at the previous moment integrates the power change trends at multiple sampling points before that moment. By combining the current instantaneous power with the filtered power at the previous moment according to the preset signal processing relationship, the current filtered power can be obtained, so that the current filtered power can follow the change of instantaneous power to a certain extent, while not causing drastic jumps due to sudden changes at individual sampling points.

[0055] As a feasible implementation method, S301 includes: inputting the instantaneous power and the filtered power of the previous moment into a low-pass filter to obtain the current filtered power.

[0056] The order of the low-pass filter can be first, second, third, fourth or fifth order, and the type of the low-pass filter can be Butterworth filter, Chebyshev filter, Bessel filter, elliptic filter or Gaussian filter. The order and type of the low-pass filter can be set according to the actual situation. This application does not impose any restrictions on the order and type of the low-pass filter.

[0057] The detailed process of inputting the instantaneous power and the filtered power of the previous moment into the low-pass filter to obtain the current filtered power can be found in the following embodiments S701-S703.

[0058] By inputting the current instantaneous power and the filtered power from the previous moment into a low-pass filter, the current filtered power can be determined. The low-pass filter's attenuation characteristics for high-frequency components in the input signal can be utilized to suppress high-frequency fluctuations in the instantaneous power signal caused by measurement noise or instantaneous load changes, resulting in a smoother trend in the current filtered power. Furthermore, since the filtered power from the previous moment is used as feedback input, the determination of the current filtered power depends on historical filtered values ​​rather than solely on the current instantaneous sampled value. This enables a first-order hysteresis filtering effect, reducing the direct impact of sudden changes in instantaneous power on the filtering result.

[0059] As one possible implementation, the instantaneous power of the drive motor at the current moment is determined as follows: obtain the speed of the drive motor at the current moment, the torque of the drive motor at the current moment, and the unit conversion factor; and determine the instantaneous power of the drive motor at the current moment based on the speed of the drive motor at the current moment, the torque of the drive motor at the current moment, and the unit conversion factor.

[0060] The sampling and update frequencies for speed and torque can be 100 Hz, 120 Hz, 140 Hz, 160 Hz, or 200 Hz. These frequencies can be set according to actual conditions, and this application does not impose any restrictions. When the sampling and update frequencies for speed and torque are greater than or equal to 100 Hz, the real-time performance of motor control can be guaranteed. Before determining the instantaneous power of the drive motor at the current moment, the speed and torque of the drive motor at the current moment can be verified and filtered for rationality. For example, it can be checked whether the speed is within the physical limits, whether the torque signal has abrupt changes, and a moving average algorithm or inertial filter can be used to eliminate high-frequency measurement noise to ensure the stability and reliability of the input signal.

[0061] For example, the instantaneous power of the drive motor at the current moment satisfies Formula 1.

[0062] Formula 1.

[0063] Where Pi represents the instantaneous power of the drive motor at the current moment, N represents the speed of the drive motor at the current moment, T represents the torque of the drive motor at the current moment, and 9550 is the unit conversion factor.

[0064] The unit conversion factor is an engineering approximation coefficient, derived through the unit conversion between speed, torque, and power. Formula 1 can be derived as follows.

[0065] For example, the physical formula for power satisfies Formula 2.

[0066] Formula 2.

[0067] In this calculation, power is measured in watts (W), torque in Newton-meters (N·m), angular velocity in radians per second (rad / s), instantaneous power in kilowatts (kW), and rotational speed in revolutions per minute (rpm). To calculate instantaneous power from rotational speed and torque, a unit conversion between the units of rotational speed and power is required. This leads to Formula 3.

[0068] Formula 3.

[0069] By deriving the formula, we obtain Formula 4.

[0070] Formula 4.

[0071] Will Approximate calculations yielded a unit conversion factor of 9550.

[0072] Since the instantaneous power of the drive motor at the current moment directly reflects the instantaneous output power of the motor, it is the most direct variable for evaluating the motor load. Therefore, the instantaneous power of the drive motor at the current moment can be calculated once using Formula 1 in each control cycle, thereby generating a continuously changing instantaneous power sequence.

[0073] In some embodiments, after acquiring the filtered power at the previous moment, it is necessary to store the filtered power at the previous moment. When executing S301, the filtered power at the previous moment can be directly read for calculation. When the motor control device is powered on and initialized, the filtered power at the previous moment is 0.

[0074] S302. Based on the current filter power and the preset mapping relationship, determine the continuous power of the drive motor.

[0075] The continuous power of the motor represents the power carrying capacity of the drive motor under the current thermal load condition. In the mapping relationship, the continuous power of the motor decreases as the filter power increases. The preset mapping relationship can be a mapping table or a function expression. This application does not limit the form of the preset mapping relationship.

[0076] The current filtered power reflects the average thermal load level of the drive motor within a specific time scale. The motor's continuous power is mainly limited by its heat dissipation and temperature rise conditions, and is directly related to the thermal load. The preset mapping relationship is a correspondence rule between filtered power and motor continuous power established based on the motor's thermal model or experimental calibration. By using the current filtered power to query or calculate this preset mapping relationship, the continuous power value corresponding to the motor's ability to not exceed its thermal equilibrium limit under the current load conditions can be obtained.

[0077] For a detailed explanation of how to determine the continuous power of the drive motor based on the current filter power and the preset mapping relationship, please refer to the following embodiments S401-S402.

[0078] Long-term power limits are obtained by looking up the filtered power in a table. This method can convert real-time heat loads, which are difficult to measure directly, into easily processed filtered power signals. Furthermore, flexible and dynamic long-term power limits are achieved through a calibrable mapping table, which is completely independent of short-term peak power control and thus decouples the two systems.

[0079] S303, Determine the target peak torque of the drive motor.

[0080] The target peak torque is used to characterize the maximum instantaneous acceleration capability that the electric drive system can output under the current state. It can be obtained in real time through the motor control system and is independent of long-term thermal load.

[0081] Determining the target peak torque relies on multiple real-time or near-real-time acquired electric drive system status data, such as the motor's current speed, available battery power, motor and inverter temperatures, bus voltage, and overload capacity coefficient under the current operating mode. Based on this data, combined with the motor's electromagnetic torque characteristic model (e.g., the mapping relationship between torque, current, and flux linkage) and thermal management constraints, the maximum instantaneous torque value that the motor can output under the current operating conditions can be calculated using a preset algorithm or lookup table method, provided that it does not exceed safety boundaries (e.g., no overcurrent, no overheating, no overvoltage).

[0082] For a detailed explanation of how to determine the continuous power of the drive motor based on the current filter power and the preset mapping relationship, please refer to the following embodiments S601-S602.

[0083] S304. Based on the motor's continuous torque corresponding to the motor's continuous power and the target peak torque, determine the target limiting torque of the drive motor.

[0084] The target limiting torque is used to represent the maximum torque that the drive motor is allowed to output at the next moment.

[0085] The continuous torque corresponding to the continuous power of the motor represents the maximum torque value that the motor can stably output under long-term continuous operation. This value is directly related to the motor's thermal balance capability and temperature rise limit. Continuous operation exceeding this torque may lead to motor overheating and damage. The target peak torque, on the other hand, reflects the torque demand placed on the motor by the vehicle under transient conditions such as short-term acceleration or hill climbing. This demand is often higher than the continuous torque. By comparing the continuous torque corresponding to the continuous power of the motor and the target peak torque, the target limiting torque of the drive motor can be determined.

[0086] As a feasible implementation method, S304 includes: determining the smaller of the motor continuous torque and the target peak torque as the target limiting torque.

[0087] By defining the smaller of the motor's continuous torque and the target peak torque as the target limiting torque, the motor's continuous torque can be used as a long-term thermal stability boundary to constrain short-term peak output. This allows the system to meet instantaneous acceleration or hill-climbing requirements while avoiding the risk of overheating of the drive motor due to prolonged operation in the peak torque range. This decouples peak (short-term) power limitation from continuous (long-term) power limitation, thus balancing power response and thermal safety.

[0088] By receiving the continuous motor torque from the long-term thermal management channel and the target peak torque from the short-term peak capability channel, the system compares the continuous motor torque and the target peak torque. If the continuous motor torque is less than the target peak torque, it indicates that the system bottleneck is due to long-term thermal load accumulation (e.g., motor temperature rise caused by continuous high-speed driving) rather than instantaneous electrical capability. In this case, the continuous motor torque is determined as the target limiting torque, and the long-term limiting takes effect. If the continuous motor torque is greater than the target peak torque, it indicates that the current system bottleneck is short-term instantaneous capability (e.g., the battery or inverter reaches its instantaneous limit during the initial stage of rapid acceleration). In this case, the target peak torque is determined as the target limiting torque, the short-term peak power is fully released, and the long-term limiting does not intervene.

[0089] For example, when a vehicle is in a momentary operating condition (such as rapid acceleration from 0 to 100 km / h), the driver presses the accelerator pedal deeply, causing the drive motor's power to instantly surge to 200 kW, corresponding to a required torque of approximately 667 N·m. Due to the slow response of the drive motor's current filtered power, the initial value of the corrected filtered power is low, resulting in a higher continuous motor power obtained from the lookup table: 150 kW and 500 N·m. However, the target peak torque is 350 N·m, meaning the continuous motor torque exceeds the target peak torque. The arbitration result is that the target limiting torque is 350 N·m, and the drive motor outputs the target peak torque without affecting the vehicle's acceleration performance. This allows the instantaneous torque limiting and the continuous torque limiting of the motor to operate completely independently and in parallel, without interference. Short-term power performance is decoupled from long-term limiting, resulting in zero loss of peak performance.

[0090] Subsequently, the vehicle operates under prolonged conditions (e.g., 30 minutes of high-speed cruising). During this time, the drive motor's power stabilizes at 80kW, corresponding to a required torque of 268.45 N·m. The filtered power gradually increases to near 80kW. Referring to the table, the motor's continuous power decreases from 150kW to 70kW, and the continuous torque decreases to 250N·m, while the target peak torque remains at 350N·m. Therefore, the arbitration result is that the target torque limit is 250N·m, and the drive motor outputs its continuous power. In this way, the continuous power can be limited to within 70kW.

[0091] Through the above steps, this application enables intelligent management of the motor's long-term power. For conditions requiring rapid acceleration, although the instantaneous power is high, the filtered power takes time to rise. In the short term, the continuous motor power obtained from the lookup table remains high. Therefore, the continuous motor power is usually greater than the target peak torque, ensuring that the final limit of the drive motor torque is determined by the target peak torque, thus guaranteeing the peak performance of the drive motor. Subsequently, when the vehicle operates at medium to high power for extended periods, the filtered power gradually increases to a higher level, and the continuous motor torque obtained from the lookup table decreases. This makes the continuous motor torque a smaller limiting value, thereby actively limiting the continuous output power, protecting the motor, and adapting to cost-optimized hardware.

[0092] By defining the smaller of the motor's continuous torque and the target peak torque as the target limiting torque, the long-term power limitation problem under motor drive conditions can be solved, enabling proactive intervention for long-term limiting. Furthermore, it allows for on-demand control of long-term continuous output capability while ensuring short-term peak output capability. Simultaneously, it protects the motor and adapts to low-cost wiring harnesses. This ensures that under any circumstances, the final output capability of the drive motor does not exceed all physical constraints (including instantaneous electrical constraints and long-term thermal constraints), guaranteeing absolute safety while optimizing costs.

[0093] In some embodiments, the target limiting torque can be sent as the upper limit of torque to the torque control module of the motor controller to ensure that the actual torque output by the motor does not exceed this limit.

[0094] S305 controls the operation of the drive motor based on the vehicle's required torque and target limit torque.

[0095] Among them, the vehicle demand torque reflects the driver's operating intention or the expected output torque calculated by the vehicle controller based on the current operating conditions (such as accelerator pedal opening, vehicle speed, etc.).

[0096] The required torque of the vehicle can be compared with the limited torque. When the required torque is within the limited torque range, the control result can directly adopt the required torque to meet the driver's power request. When the required torque exceeds the limit of the limited torque, the control result is limited to the corresponding boundary value of the target limited torque.

[0097] As a feasible approach, when the vehicle's required torque exceeds the target limit torque, the drive motor is controlled to output torque according to the target limit torque.

[0098] When the vehicle's required torque exceeds the target limit torque, the drive motor is controlled to output torque according to the target limit torque. This clamps the actual output torque within the target limit torque range, preventing the motor output from exceeding the limit value and preventing the drive motor from exceeding its safe operating boundary due to instantaneous overload, thereby reducing the risk of overcurrent or overheating faults in the motor control system.

[0099] As another feasible approach, when the vehicle's required torque is less than or equal to the target limit torque, the drive motor is controlled to output torque according to the vehicle's required torque.

[0100] When the vehicle's required torque is less than or equal to the target limit torque, the drive motor is controlled to output torque according to the vehicle's required torque. This ensures that the motor's output torque is consistent with the driving intention or the vehicle controller's request, thereby maintaining the dynamic following performance of the electric drive system without triggering limiting conditions. This helps improve the vehicle's acceleration responsiveness and driving smoothness under normal operating conditions.

[0101] As one possible implementation, S305 includes: acquiring the torque request direction; determining a target control torque based on the vehicle's required torque and the target limiting torque, wherein the target control torque is the smaller of the vehicle's required torque and the target limiting torque; generating a torque control command according to the torque request direction and the target control torque; and sending the torque control command to the drive motor to control the operation of the drive motor.

[0102] Thus, by comparing the required torque with the limiting torque, when the required torque is within the limiting torque range, the control result can directly adopt the required torque to meet the driver's power request; when the required torque exceeds the limit torque limit, the control result is limited to the corresponding boundary value of the target limiting torque.

[0103] As can be seen from S301-S305, the solution provided in this application determines the current filtered power by comparing the instantaneous power of the drive motor at the current moment with the filtered power at the previous moment. This filtering process transforms the rapidly fluctuating instantaneous power into a slowly changing signal that reflects the heat accumulation effect. Subsequently, based on the current filtered power and a preset mapping relationship, the continuous power of the drive motor is determined. The value of the continuous power can be dynamically adjusted according to the thermal load state, ensuring that the continuous power is inversely proportional to the current degree of motor heating. This allows for a reasonable representation of the drive motor's power carrying capacity under the current thermal load state, reasonably limiting the motor's continuous capacity and preventing overheating due to excessively high continuous power settings. Furthermore, the continuous torque, reflecting the thermal load carrying capacity, is combined with the peak torque, reflecting the instantaneous acceleration capacity. This ensures that the target limiting torque is constrained by heat accumulation while retaining a certain instantaneous strain margin, thus reasonably representing the maximum allowable torque output of the drive motor at the next moment. This helps prevent the motor from exceeding its temperature limit due to long-term overload and avoids overly stringent limitations on acceleration performance. Subsequently, by controlling the operation of the drive motor based on the vehicle's required torque and the target limiting torque, the vehicle's required torque can be limited by the target limiting torque, so that the actual output torque of the drive motor does not exceed the limit allowed by the current thermal load state. This ensures that the drive motor operates within a safe temperature range while meeting driving needs, thereby improving the reliability and service life of the system.

[0104] In some embodiments, the filtered power can be corrected based on the correction coefficient, and the motor continuous power can be obtained by looking up the table based on the corrected filtered power. This achieves both the thermal inertia reflected by the filtering process and the margin for model error and operating conditions left by the correction coefficient, making the long-term power limiting strategy both accurate and reliable.

[0105] As a feasible implementation method, S302 includes: S401. Based on the current filter power and the correction coefficient, determine the corrected filter power.

[0106] The corrected filter power is the product of the current filter power and the correction coefficient.

[0107] The correction factor can be obtained through experimental calibration. In practice, during real-vehicle endurance road tests under extreme conditions such as high temperature, full load, and long uphill climbs, if the power limiting intervenes too early before the actual temperature reaches its limit, it indicates that the current correction factor (K) is too large, and it needs to be reduced to delay the intervention. If the actual temperature has exceeded the limit but the power limiting has not yet taken effect, it indicates that the current correction factor is too small, and it needs to be increased to trigger the limiting earlier. Through repeated calibration, the power limiting is made to intervene accurately when the actual temperature is close to but not exceeding the limit. The specific value of the correction factor is greater than or equal to 1. For example, the calibration range of the correction factor can be greater than or equal to 1 and less than or equal to 1.15, and the specific value of the correction factor can be 1.05.

[0108] S402. Determine the continuous power of the motor based on the preset mapping relationship and the corrected filter power.

[0109] The preset mapping relationship is the correspondence between the preset correction filter power and the preset continuous power.

[0110] For example, the preset mapping relationship is a preset mapping relationship table. The corrected filter power can be used as the lookup index value, and the motor continuous power corresponding to the corrected filter power can be obtained by looking up the table based on the preset mapping relationship table.

[0111] As a feasible implementation method, the preset mapping relationship includes: multiple preset corrected filter powers and multiple preset continuous powers, with one preset corrected filter power corresponding to one preset continuous power. S402 includes: when the corrected filter power is the same as any one of the multiple preset corrected filter powers, based on the second preset power correspondence relationship, determining the preset continuous power corresponding to the corrected filter power as the motor continuous power.

[0112] When determining the continuous power of the motor based on a preset mapping relationship and the corrected filtered power, the corrected filtered power is compared with multiple preset corrected filtered power values. If they are the same, the corresponding preset continuous power is determined as the continuous power of the motor according to a second preset power correspondence relationship. This allows for direct judgment using pre-established matching conditions, avoiding the uncertainties caused by real-time calculation or dynamic fitting, thus helping to improve the accuracy and consistency of the determination of the continuous power of the motor.

[0113] In some embodiments, the preset mapping table is a one-dimensional continuous power limit table, which can be calibrated through vehicle demand input and bench testing. The calibration process of the preset mapping table is divided into a basic thermal capability calibration stage and a vehicle cost adaptation calibration stage. The basic thermal capability calibration stage and the vehicle cost adaptation calibration stage are described below.

[0114] During the basic thermal capability calibration stage, temperature sensors for the stator windings, permanent magnets, and inverter power modules can be arranged on the test bench. A constant load power is applied at different speeds (e.g., 2000 rpm, 5000 rpm, 8000 rpm) and the test is continued until the temperature at each measuring point reaches the safe upper limit (e.g., 200℃ for the windings), and the steady-state power value at this time is recorded. An original continuous power limit table is generated based on the recorded results. The original continuous power limit table is simplified and corrected by using a safety factor to cover the influence of speed or by using a one-dimensional table with speed correction, thus obtaining the initial thermal limit table.

[0115] During the vehicle cost adaptation calibration phase, based on the target vehicle's design continuous speed (e.g., 120km / h, 160km / h), the continuous power at the motor shaft end required to maintain that speed is calculated through vehicle simulation (i.e., P_target). Based on the continuous power values ​​corresponding to each operating condition in the initial thermal limit table, continuous power values ​​greater than the continuous power at the motor shaft end are updated to the continuous power at the motor shaft end or less than the continuous power at the motor shaft end (e.g., the continuous power value corresponding to a filter power of 60kW in the initial thermal limit table is 100kW; if the continuous power at the motor shaft end of the target vehicle is 70kW, then the continuous power value corresponding to a filter power of 60kW is updated to 70kW). The updated continuous power values ​​are used as calibration results to obtain the updated initial thermal limit table. The updated initial thermal limit table is then determined as the preset mapping relationship table.

[0116] With the rapid development of new energy vehicle technology, oil-cooled motors, due to their superior heat dissipation performance, have significantly improved the continuous output power capability of drive motors. Higher continuous power enables vehicles to achieve higher continuous speeds (such as prolonged high-speed cruising) and better continuous hill-climbing ability. However, to handle higher continuous current, the wiring harnesses, copper busbars, connectors, and other components inside the motor and related parts require larger-specification designs, leading to increased costs for the electric drive system and the entire vehicle system. If the selection of wiring harnesses and other components for all models is based on the maximum continuous capacity of the motor during vehicle design, it will result in unnecessary cost waste for models that do not require extreme continuous performance (such as models primarily for urban commuting). Therefore, a strategy is needed to limit the long-term power of the motor according to the vehicle model's positioning, thereby optimizing system costs while meeting performance requirements.

[0117] In some embodiments, the vehicle's wiring harness or busbar specifications can be selected based on the reduced continuous power value. Thus, by correcting the initial thermal limit table during the vehicle cost adaptation calibration phase, an updated initial thermal limit table is obtained. This allows the preset mapping table to adapt to the vehicle's power requirements, enabling the selection of the vehicle's wiring harness or busbar specifications during the vehicle design phase, thereby reducing vehicle costs. For example, if the vehicle's continuous power is reduced from 100kW to 70kW, the vehicle's wiring harness cost can be reduced by 20% to 30%. Furthermore, without affecting the motor's short-term peak output capability, the long-term continuous output power of the motor can be dynamically limited according to different vehicle configurations and cost requirements, thereby optimizing the cost of the electric drive system and related components.

[0118] As can be seen from S401-S402, the solution provided in this application determines the corrected filter power based on the current filter power and the correction coefficient, and dynamically adjusts the current filter power using the correction coefficient, so that the corrected filter power can more realistically reflect the changes in the actual operating state or load conditions of the motor. Subsequently, the continuous power of the motor is determined based on the preset mapping relationship and the corrected filter power. The corrected filter power can be used as the mapping basis to quickly obtain the continuous power of the motor, reducing calculation delay and improving the consistency and reliability of power control.

[0119] In some embodiments, the horizontal axis of the preset mapping table represents the corrected filtered power, and the vertical axis represents the continuous power of the motor. When the corrected filtered power falls between two calibration points in the preset mapping table, linear interpolation is required to calculate the continuous power of the motor.

[0120] As a feasible approach, the method also includes: S501. When the corrected filter power is different from any of the preset corrected filter powers, determine the first preset adjacent product and the second preset adjacent product.

[0121] Among them, the first preset adjacent product and the second preset adjacent product are the two preset corrected filter powers with the smallest difference between them and the corrected filter power among a plurality of preset corrected filter powers.

[0122] S502. Based on the corrected filtered power, the first preset adjacent product and the second preset adjacent product, interpolation calculation is performed to obtain the continuous power of the motor.

[0123] For example, the motor continuous power can be obtained by interpolating the corrected filtered power, the first preset adjacent product, and the second preset adjacent product using Formula 5.

[0124] Formula 5.

[0125] in, Used to indicate the continuous power of a motor This is used to represent the preset correction filter power corresponding to the smaller value between the first preset adjacent product and the second preset adjacent product. This is used to represent the preset correction filter power corresponding to the larger value between the first preset adjacent product and the second preset adjacent product. Used to represent the corrected filter power. Used to represent the smaller value between the first preset adjacent product and the second preset adjacent product. Used to represent the larger value between the first preset adjacent product and the second preset adjacent product.

[0126] In some embodiments, if the corrected filter power is less than the minimum value among a plurality of preset corrected filter powers, then the preset continuous power corresponding to the minimum value among the plurality of preset corrected filter powers is determined as the motor continuous power; if the corrected filter power is greater than the maximum value among a plurality of preset corrected filter powers, then the preset continuous power corresponding to the maximum value among the plurality of preset corrected filter powers is determined as the motor continuous power.

[0127] Among them, the minimum value among the multiple preset correction filter powers corresponds to the preset continuous power, which is the peak power capability, and the maximum value among the multiple preset correction filter powers corresponds to the preset continuous power, which is the ultimate protection power.

[0128] As can be seen from S501-S502, the solution provided in this application embodiment, when the corrected filter power is different from multiple preset corrected filter powers, can determine the two preset corrected filter powers with the smallest difference between them and the corrected filter power. The preset reference point closest to the current working condition can be screened using the principle of minimizing the difference. Subsequently, any intermediate value in the power value range is filled according to the linear or nonlinear relationship between the first preset adjacent product and the second preset adjacent product. This enables the motor's continuous power to transition continuously and smoothly with the change of the corrected filter power, which helps to improve the stability and accuracy of power distribution during motor control, while reducing the risk of system oscillation or control overshoot caused by power jumps.

[0129] In some embodiments, the target peak torque can be determined by comprehensively considering the maximum torque output by the motor, the maximum torque allowed to be output by the battery, and the maximum torque allowed to be output by the inverter.

[0130] As a feasible implementation method, S304 includes: S601: Obtain the peak torque of the inverter, the peak torque of the motor, and the peak torque of the battery.

[0131] The inverter peak torque is the torque corresponding to the inverter's peak current, which is the maximum instantaneous current the inverter can withstand under the current conditions. The motor peak torque is the maximum torque that the drive motor is allowed to output under the current conditions. The battery peak torque is the torque corresponding to the battery's discharge power capability. The discharge power capability is the maximum instantaneous power that the battery is allowed to output under the current conditions.

[0132] It should be noted that the peak torque of the motor is the maximum peak torque allowed under cold conditions or short-term overload conditions. It is usually limited by magnetic saturation and back EMF, and the duration is greater than or equal to 10 seconds and less than or equal to 30 seconds.

[0133] As one possible implementation, the inverter's peak torque is determined as follows: the maximum phase current peak value is calculated based on the upper limit of the short-time overload allowable junction temperature of the power modules in the inverter; the inverter's peak torque is then obtained based on the maximum phase current peak value. Thus, the maximum allowable phase current peak value of the inverter can be calculated based on the maximum short-time junction temperature limit of the power modules in the inverter and converted into torque.

[0134] As one possible implementation, the peak torque of the motor is determined as follows: based on the current speed of the drive motor and the preset peak torque mapping relationship, the peak torque of the motor is obtained by looking up a table.

[0135] One possible implementation is to determine the battery peak torque as follows: Obtain the battery's current SOC and current temperature through the Battery Management System (BMS); query the battery's short-time discharge power table using the BMS based on the current SOC and temperature, and extract the short-time maximum discharge power from the query results; obtain the battery peak torque based on the extracted short-time maximum discharge power. In this way, the short-time (e.g., 10s) maximum discharge power given by the battery's SOC and temperature can be converted into torque.

[0136] S602. Determine the target peak torque based on the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery.

[0137] As a feasible approach, the target peak torque is determined based on the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery. This includes determining the smaller of the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery as the target peak torque.

[0138] The target peak torque is used to reflect the instantaneous burst limit of the vehicle without sacrificing reliability.

[0139] By selecting the smallest value among the peak torque of the motor, inverter, and battery, the target peak torque can be automatically limited to the component with the lowest peak capacity. This effectively prevents overload, overheating, or protective shutdown caused by the torque request exceeding the peak capacity of any component. In this way, the limits of multiple components can be fused through simple comparison calculations, thereby reducing the complexity and computational overhead of the control algorithm while ensuring system safety and reliability.

[0140] As can be seen from S601-S602, the solution provided in this application embodiment obtains the peak torque of the inverter, the peak torque of the motor, and the peak torque of the battery respectively, so as to extract the limit constraints of the inverter, motor, and battery under instantaneous overload conditions. This provides independent boundary parameters for subsequent multi-constraint fusion, avoiding the neglect of single component limitations. Subsequently, the target peak torque is determined based on the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery. This allows for a comprehensive evaluation of the instantaneous capabilities of the inverter, motor, and battery, ensuring that the final selected target peak torque simultaneously meets the physical limits of the three core components under peak conditions, preventing system damage or protective shutdown due to insufficient capability of a single component.

[0141] In some embodiments, the low-pass filter can be a first-order low-pass digital filter. By inputting the instantaneous power into the first-order low-pass digital filter, the rapidly fluctuating instantaneous power can be converted into a slowly changing signal that reflects the thermal accumulation effect, i.e., the filtered power that reflects the power time integral.

[0142] As a feasible implementation method, in S301, the instantaneous power and the filtered power of the previous moment are input into the low-pass filter to obtain the current filtered power, including: S701. Multiply the first filter factor by the instantaneous power through a low-pass filter to obtain the first filter product.

[0143] The first filtering factor is a coefficient that can be calibrated according to the thermal model. The thermal model refers to a mathematical calculation model established based on the equivalent thermal circuit method to characterize the heat generation and heat dissipation process of the target component (such as motor winding).

[0144] As one possible implementation, the first filter factor is determined as follows: based on a preset sampling period and the cutoff frequency of the low-pass filter, the first filter factor is obtained.

[0145] For example, the first filter factor satisfies Formula 6.

[0146] Formula Six.

[0147] Where 'a' represents the first filter factor; T sThis is used to represent the preset sampling period, which can be obtained through experimental calibration; f c The cutoff frequency used to indicate the low-pass filter can be calibrated based on the thermal time constant of the motor.

[0148] In the design of digital low-pass filters, Formula 7 is generally used to calculate the first filter factor.

[0149] Formula 7.

[0150] in, Used to represent the thermal time constant of an electric motor.

[0151] In engineering practice, to simplify the calculation process of the first filter factor and reduce the computational burden, f is usually used. c replace Thus, we obtain Formula 6. The cutoff frequency of the low-pass filter satisfies Formula 8.

[0152] Formula 8.

[0153] S702. The second filter factor is multiplied by the filter power of the drive motor at the previous moment through a low-pass filter to obtain the second filter product.

[0154] The second filter factor is the difference between 1 and the first filter factor.

[0155] S703. The first filter product and the second filter product are added together through a low-pass filter to obtain the current filtered power of the drive motor.

[0156] For example, the low-pass filter satisfies Equation Nine.

[0157] Formula Nine.

[0158] Where Y(n) represents the current filtered power of the drive motor, that is, the output value of the low-pass filter at the current moment; a represents the first filter factor; X(n) represents the instantaneous power, that is, the input value of the low-pass filter at the current moment; (1-a) represents the second filter factor; Y(n-1) represents the filtered power of the drive motor at the previous moment; n represents the current moment; and n-1 represents the next moment after the current moment.

[0159] As can be seen from S701-S703, the solution provided in this application multiplies the first filter factor by the instantaneous power using a low-pass filter to obtain a first filter product. This first filter factor can be used to weight the instantaneous power, achieving initial suppression of high-frequency components in the instantaneous power. Multiplying the second filter factor by the filter power of the drive motor at the previous moment using a low-pass filter to obtain a second filter product allows for weighted preservation of historical filtering results, ensuring the continuation of the stable component of the filter power at the previous moment. This enables the current filter power to inherit the historical power variation trend, avoiding unreasonable jumps in the filter output due to random fluctuations in instantaneous power. Adding the first filter product and the second filter product using a low-pass filter yields the current filter power of the drive motor. This allows for the linear superposition of the weighted instantaneous power component and the historical power component, ensuring that the current filter power reflects both the current instantaneous power input and retains the inertial characteristics of historical power, thereby obtaining a smooth and appropriately responsive power estimate.

[0160] In some embodiments, the continuous torque of the motor can be calculated in reverse by using the current speed of the drive motor and the continuously available power of the motor, thereby obtaining the upper limit of torque calculated from the perspective of long-term thermal protection.

[0161] As one possible implementation, in conjunction with S304, the continuous torque of the motor corresponding to the continuous power of the motor is determined as follows: the speed of the drive motor is obtained; based on the continuous power of the motor and the speed of the drive motor, the continuous torque of the motor is obtained.

[0162] For example, the continuous torque of the motor satisfies Formula 10.

[0163] Formula 10.

[0164] in, Used to indicate the continuous torque of an electric motor.

[0165] In some embodiments, when the speed of the drive motor is less than a preset low speed threshold, the continuous torque of the motor is determined to be the target peak torque.

[0166] The preset low speed threshold can be 50 rpm, 70 rpm, 80 rpm, 90 rpm or 100 rpm. The specific value of the preset low speed threshold can be set according to the actual situation. This application does not impose any restrictions on this.

[0167] The foregoing mainly describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the motor control device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0168] This application embodiment can divide the motor control device into functional modules according to the above method. For example, the motor control device may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. The module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0169] Reference Figure 4 The motor control device includes: a filter power determination module 401, a continuous power determination module 402, a peak torque determination module 403, a limit torque determination module 404, and a motor control module 405.

[0170] The filter power determination module 401 is used to determine the current filter power based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment. The current filter power is used to characterize the thermal load state of the drive motor at the current moment.

[0171] The continuous power determination module 402 is used to determine the continuous power of the drive motor based on the current filtered power and a preset mapping relationship. The continuous power of the motor represents the power carrying capacity of the drive motor under the current thermal load condition. In the mapping relationship, the continuous power of the motor decreases as the filtered power increases.

[0172] The peak torque determination module 403 is used to determine the target peak torque of the drive motor. The target peak torque is used to characterize the maximum instantaneous acceleration capability that the electric drive system can output under the current state.

[0173] The limiting torque determination module 404 is used to determine the target limiting torque of the drive motor based on the continuous torque of the motor corresponding to the continuous power of the motor and the target peak torque. The target limiting torque is used to represent the maximum torque that the drive motor is allowed to output at the next moment.

[0174] The motor control module 405 is used to control the operation of the drive motor based on the vehicle's required torque and target limit torque.

[0175] In some embodiments, the motor control device further includes: a filter power correction module. The filter power correction module is used to determine a corrected filter power based on the current filter power and a correction coefficient. The corrected filter power is the product of the current filter power and the correction coefficient. A continuous power determination module is used to determine the continuous power of the motor based on a preset mapping relationship and the corrected filter power. The preset mapping relationship is a mapping relationship between a preset corrected filter power and a preset continuous power.

[0176] In some embodiments, the preset mapping relationship includes: multiple preset corrected filter powers and multiple preset continuous powers, with one preset corrected filter power corresponding to one preset continuous power. The continuous power determination module is used to determine the preset continuous power corresponding to the corrected filter power as the motor continuous power based on the preset mapping relationship, when the corrected filter power is the same as any one of the multiple preset corrected filter powers.

[0177] In some embodiments, the motor control device further includes: a preset adjacent product determination module. The preset adjacent product determination module is used to determine a first preset adjacent product and a second preset adjacent product when the corrected filter power is different from any one of the multiple preset corrected filter powers. The first preset adjacent product and the second preset adjacent product are the two preset corrected filter powers with the smallest difference between them and the corrected filter power among the multiple preset corrected filter powers. A continuous power determination module is used to perform interpolation calculations based on the corrected filter power, the first preset adjacent product, and the second preset adjacent product to obtain the continuous power of the motor.

[0178] In some embodiments, the limiting torque determination module is used to determine the smaller of the motor continuous torque and the target peak torque as the target limiting torque.

[0179] In some embodiments, the motor control device further includes: a torque acquisition module. The torque acquisition module is used to acquire the inverter peak torque, the motor peak torque, and the battery peak torque. The inverter peak torque is the torque corresponding to the inverter's peak current, where the peak current is the maximum instantaneous current the inverter can withstand in the current state. The motor peak torque is the maximum torque allowed to be output by the drive motor in the current state. The battery peak torque is the torque corresponding to the battery's discharge power capability. The discharge power capability is the maximum instantaneous power allowed to be output by the battery in the current state. A peak torque determination module is used to determine a target peak torque based on the motor peak torque, the inverter peak torque, and the battery peak torque.

[0180] In some embodiments, the peak torque determination module is used to determine the smaller of the motor peak torque, inverter peak torque, and battery peak torque as the target peak torque.

[0181] In some embodiments, the motor control module is configured to control the drive motor to output torque according to the target limit torque when the vehicle's required torque is greater than the target limit torque. The motor control module is also configured to control the drive motor to output torque according to the vehicle's required torque when the vehicle's required torque is less than or equal to the target limit torque.

[0182] In some embodiments, the filter power determination module is used to input the instantaneous power and the filter power at the previous moment into a low-pass filter to obtain the current filter power.

[0183] In some embodiments, the filter power determination module is configured to multiply a first filter factor by the instantaneous power using a low-pass filter to obtain a first filter product. The filter power determination module is further configured to multiply a second filter factor by the filter power of the drive motor at the previous moment using a low-pass filter to obtain a second filter product. The filter power determination module is further configured to add the first filter product and the second filter product using a low-pass filter to obtain the current filter power of the drive motor.

[0184] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0185] In an exemplary embodiment, this application also provides a computing device, which may include a processor and a memory. The processor may be a computing cluster composed of multiple computing nodes, and the memory may adopt a distributed memory architecture. The processor integrated into the computing device is configured to execute the motor control method of any of the above embodiments.

[0186] Figure 5 This is a schematic diagram of the architecture of a motor control device provided in an embodiment of this application. Figure 5 As shown, the motor control device includes: one or more memories 520, one or more processors 510, a communication bus 540, and a communication interface 530. The processors 510 and memories 520 are connected via the communication bus 540; the one or more memories 520 are used to store computer program code, which includes computer instructions; when the one or more processors 510 execute the computer instructions, the computing device performs the motor control method provided in this embodiment.

[0187] Optionally, the memory 520 may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc. This application embodiment does not impose any restrictions on this.

[0188] The processor 510 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof, and the embodiments of this application do not impose any limitations on this.

[0189] The communication bus 540 can be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. This communication bus 540 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 It is represented by a single thick line, but this does not mean that there is only one bus or one type of communication bus.

[0190] Communication interface 530 uses any transceiver-like device for communicating with other devices or communication networks, such as control systems, radio access networks (RAN), wireless local area networks (WLAN), etc.

[0191] This application also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be executed by computer instructions instructing related hardware; exemplarily, the related hardware can be a processor of a computing device. The program instructions can be stored in the above-described computer-readable storage medium, and when executed, the processes of the above method embodiments can be implemented. The computer-readable storage medium can be memory. The above-described computer-readable storage medium can also be an external storage device, such as a hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. Further, the above-described computer-readable storage medium can include both memory and external storage devices. The above-described computer-readable storage medium is used to store the above-described computer program instructions and other programs and data required by the above-described motor control method.

[0192] This application also provides a vehicle that can be executed by a motor control device to perform the methods described in the above embodiments.

[0193] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0194] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

[0195] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A motor control method, characterized in that, The motor control method includes: The current filter power is determined based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment; the current filter power is used to characterize the thermal load state of the drive motor at the current moment. Based on the current filter power and the preset mapping relationship, the continuous power of the drive motor is determined; the continuous power of the motor is used to represent the power carrying capacity of the drive motor under the current thermal load condition; in the mapping relationship, the continuous power of the motor decreases as the filter power increases; Determine the target peak torque of the drive motor; the target peak torque is used to characterize the maximum instantaneous acceleration capability that the electric drive system can output under the current state; Based on the continuous torque of the motor corresponding to the continuous power of the motor and the target peak torque, the target limiting torque of the drive motor is determined; the target limiting torque is used to represent the maximum torque that the drive motor is allowed to output at the next moment. The drive motor is controlled to operate based on the vehicle's required torque and the target limiting torque.

2. The motor control method according to claim 1, characterized in that, Determining the continuous power of the drive motor based on the current filter power and the preset mapping relationship includes: Based on the current filter power and the correction coefficient, the corrected filter power is determined; the corrected filter power is the product of the current filter power and the correction coefficient. Based on the preset mapping relationship and the corrected filter power, the continuous power of the motor is determined. The preset mapping relationship is the mapping relationship between the preset corrected filter power and the preset continuous power.

3. The motor control method according to claim 2, characterized in that, The preset mapping relationship includes: multiple preset corrected filter powers and multiple preset continuous powers, where one preset corrected filter power corresponds to one preset continuous power; determining the motor continuous power based on the preset mapping relationship and the corrected filter power includes: If the corrected filter power is the same as any one of the plurality of preset corrected filter powers, the preset continuous power corresponding to the corrected filter power is determined as the motor continuous power based on the preset mapping relationship.

4. The motor control method according to claim 3, characterized in that, The motor control method further includes: When the corrected filter power is different from any of the multiple preset corrected filter powers, a first preset adjacent product and a second preset adjacent product are determined. The first preset adjacent product and the second preset adjacent product are the two preset corrected filter powers with the smallest difference between the multiple preset corrected filter powers and the corrected filter power. The continuous power of the motor is obtained by interpolation calculation based on the corrected filtered power, the first preset adjacent product, and the second preset adjacent product.

5. The motor control method according to claim 1, characterized in that, Determining the target limiting torque of the drive motor based on the continuous torque of the motor corresponding to the continuous power of the motor and the target peak torque includes: The smaller of the motor's continuous torque and the target peak torque is determined as the target limiting torque.

6. The motor control method according to claim 1, characterized in that, Determining the target peak torque of the drive motor includes: The peak torque of the inverter, the peak torque of the motor, and the peak torque of the battery are obtained. The peak torque of the inverter is the torque corresponding to the peak current of the inverter, and the peak current is the maximum instantaneous current that the inverter can withstand in the current state. The peak torque of the motor is the maximum torque that the drive motor is allowed to output in the current state. The peak torque of the battery is the torque corresponding to the discharge power capability of the battery, and the discharge power capability is the maximum instantaneous power that the battery is allowed to output in the current state. The target peak torque is determined based on the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery.

7. The motor control method according to claim 6, characterized in that, Determining the target peak torque based on the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery includes: The smaller of the peak torque of the motor, the peak torque of the inverter, and the peak torque of the battery is determined as the target peak torque.

8. The motor control method according to claim 1, characterized in that, The control of the drive motor operation based on the vehicle's required torque and the target limiting torque includes: When the required torque of the vehicle is greater than the target limiting torque, the drive motor is controlled to output torque according to the target limiting torque; When the required torque of the vehicle is less than or equal to the target limiting torque, the drive motor is controlled to output torque according to the required torque of the vehicle.

9. The motor control method according to claim 1, characterized in that, Determining the current filter power based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment includes: The instantaneous power and the filtered power at the previous moment are input into a low-pass filter to obtain the current filtered power.

10. The motor control method according to claim 9, characterized in that, The step of inputting the instantaneous power and the filtered power from the previous moment into a low-pass filter to obtain the current filtered power includes: The first filter factor is multiplied by the instantaneous power through the low-pass filter to obtain the first filter product; The second filter factor is multiplied by the filter power of the drive motor at the previous moment through the low-pass filter to obtain the second filter product; The first filtered product and the second filtered product are added together by the low-pass filter to obtain the current filtered power of the drive motor.

11. A motor control device, characterized in that, The motor control device includes: a filter power determination module, a continuous power determination module, a peak torque determination module, a limit torque determination module, and a motor control module; The filter power determination module is used to determine the current filter power based on the instantaneous power of the drive motor at the current moment and the filter power at the previous moment; the current filter power is used to characterize the thermal load state of the drive motor at the current moment. The continuous power determination module is used to determine the continuous power of the drive motor based on the current filtered power and a preset mapping relationship; the continuous power of the motor is used to represent the power carrying capacity of the drive motor under the current thermal load state; in the mapping relationship, the continuous power of the motor decreases as the filtered power increases; A peak torque determination module is used to determine the target peak torque of the drive motor; the target peak torque is used to characterize the maximum instantaneous acceleration capability that the electric drive system can output under the current state; The limiting torque determination module is used to determine the target limiting torque of the drive motor based on the continuous torque of the motor corresponding to the continuous power of the motor and the target peak torque; the target limiting torque is used to represent the maximum torque that the drive motor is allowed to output at the next moment; The motor control module is used to control the operation of the drive motor based on the vehicle's required torque and the target limiting torque.

12. A vehicle, characterized in that, The vehicle includes the motor control device as described in claim 11.

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