Motor locked-rotor control method, device, equipment, vehicle, medium and program product

Abstract

The application provides a motor stall control method, device, equipment, vehicle, medium and program product, and relates to the technical field of motor control. The motor stall control method determines a target stall allowed torque that can be continuously operated for a long time through a current coolant temperature, further determines a target demand torque and a first allowed continuous operation time corresponding to the target demand torque in combination with the current coolant temperature and a current demand torque when the current demand torque is greater than the target stall allowed torque, improves the thermal safety of a motor drive system under a stall condition, then adopts a staged control strategy to control the output torque of the motor drive system based on the target demand torque, the first allowed continuous operation time and the target stall allowed torque, ensures that the motor drive system maximizes the release of the stall torque under the premise of meeting the thermal safety constraint, improves the power performance under the stall condition, and further realizes the balance between the power performance demand and the thermal safety of the motor drive system in the stall condition.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a method, device, equipment, vehicle, medium, and program product for controlling motor stall. Background Technology

[0002] During vehicle operation, when starting on a steep incline, when the wheels are stuck in a deep ditch, or when the vehicle is jammed by an obstacle, the drive motor typically enters a stalled state. In this stalled state, to quickly extricate themselves or climb the hill, the driver usually keeps pressing the accelerator pedal deeply, hoping the vehicle will output maximum power, and the motor drive system will correspondingly output maximum torque. Without a reasonable and effective stall control strategy, the motor drive system is highly susceptible to thermal failure, which can damage hardware such as the motor controller or the drive motor itself.

[0003] Currently, static stall protection strategies using a single dimension (such as temperature threshold or torque threshold) are commonly employed to protect hardware such as the motor controller and drive motor under stall conditions. However, this static stall protection strategy struggles to balance power output and thermal safety protection, resulting in an imbalance between power requirements and thermal safety. Summary of the Invention

[0004] The purpose of this invention is to provide a motor stall control method, device, equipment, vehicle, medium, and program product to solve the problem that a single-dimensional static stall protection strategy is difficult to balance power output and thermal safety protection, resulting in an imbalance between power requirements and thermal safety.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a motor stall control method, comprising: in response to a target vehicle entering a stall condition, acquiring the current coolant temperature and current required torque of the target vehicle; determining a target stall allowable torque based on the current coolant temperature; in response to the current required torque being greater than the target stall allowable torque, determining a target required torque and a first allowable continuous operating time corresponding to the target required torque based on the current coolant temperature and the current required torque; and controlling the output torque of the motor drive system of the target vehicle in stages based on the target required torque, the first allowable continuous operating time, and the target stall allowable torque.

[0007] Furthermore, based on the current coolant temperature, the target stall torque is determined, including: based on the first mapping relationship between coolant temperature and stall torque, the target stall torque is determined based on the current coolant temperature.

[0008] Furthermore, based on the current coolant temperature and the current required torque, the target required torque and the first allowable continuous operating time corresponding to the target required torque are determined, including: based on the second mapping relationship, based on the current coolant temperature, determining multiple different required torques corresponding to the current coolant temperature and the allowable continuous operating time corresponding to each required torque; and based on the current required torque, multiple different required torques and the allowable continuous operating time corresponding to each required torque, determining the target required torque and the first allowable continuous operating time.

[0009] The second mapping relationship is that each coolant temperature corresponds to multiple different required torques, and each required torque corresponds to an allowable continuous operating time.

[0010] Furthermore, based on the current demand torque, multiple different demand torques, and the allowable continuous operating time corresponding to each demand torque, the target demand torque and the first allowable continuous operating time are determined, including: determining whether the current demand torque is greater than the maximum demand torque among multiple different demand torques; if the current demand torque is greater than the maximum demand torque, then the maximum demand torque is determined as the target demand torque, and the allowable continuous operating time corresponding to the maximum demand torque is determined as the first allowable continuous operating time; if the current demand torque is less than the maximum demand torque, then the current demand torque is determined as the target demand torque, and the allowable continuous operating time corresponding to the current demand torque is determined as the first allowable continuous operating time.

[0011] Furthermore, the second mapping relationship is obtained in the following way: multiple different coolant temperatures and multiple different required torques are obtained; for each coolant temperature, thermal simulation analysis is performed on multiple different required torques of the motor drive system at each coolant temperature to obtain the allowable continuous running time corresponding to each required torque among multiple different required torques at each coolant temperature; based on the allowable continuous running time corresponding to each required torque at each coolant temperature, the second mapping relationship is constructed.

[0012] Specifically, when the coolant temperature is greater than the temperature threshold, multiple different required torques are divided using a first division gradient, and when the coolant temperature is less than or equal to the temperature threshold, multiple different required torques are divided using a second division gradient, with the first division gradient being less than the second division gradient.

[0013] Furthermore, based on the target required torque, the first permissible continuous operating time, and the target stall allowable torque, the output torque of the target vehicle's motor drive system is controlled in stages, including: controlling the motor drive system to output the target required torque within the first permissible continuous operating time; and controlling the motor drive system to output the target stall allowable torque in response to the actual continuous operating time of the target required torque being greater than the first permissible continuous operating time.

[0014] Furthermore, when the actual continuous operating time of the target required torque is less than the first permissible continuous operating time, the method further includes: in response to the target required torque decreasing to the first required torque, controlling the motor drive system to output the first required torque, wherein the remaining permissible continuous operating time of the first required torque is the difference between the first permissible continuous operating time and the actual continuous operating time; or in response to the target required torque increasing to the second required torque, determining the second permissible continuous operating time corresponding to the second required torque based on the current coolant temperature and the second required torque, and controlling the motor drive system to output the second required torque, wherein the remaining permissible continuous operating time of the second required torque is the difference between the second permissible continuous operating time and the actual continuous operating time.

[0015] Furthermore, in the process of controlling the output of the target stall allowable torque of the motor drive system, the following steps are also included: obtaining the current speed and current torque of the target vehicle; determining whether the current speed is greater than a first speed threshold and whether the current torque is less than or equal to a first torque threshold; if the current speed is greater than the first speed threshold or the current torque is less than or equal to the first torque threshold, then controlling the target vehicle to exit the stall condition; if the current speed is less than or equal to the first speed threshold and the current torque is greater than the first torque threshold, then controlling the output of the target stall allowable torque of the motor drive system.

[0016] Furthermore, the determination of whether the target vehicle has entered a stall condition is made by: determining whether the current speed is less than or equal to a second speed threshold, whether the current torque is greater than a second torque threshold, whether the second speed threshold is less than a first speed threshold, and whether the second torque threshold is greater than the first torque threshold; if the current speed is less than or equal to the second speed threshold and the current torque is greater than the second torque threshold, then the target vehicle is determined to have entered a stall condition; if the current speed is greater than the second speed threshold, or the current torque is less than or equal to the second torque threshold, then the target vehicle is determined not to have entered a stall condition.

[0017] Furthermore, the motor stall control method also includes: acquiring the fault code corresponding to the motor drive system; determining whether the motor drive system has a fault based on the fault code; and, in response to the presence of a fault in the motor drive system, controlling the output torque of the target vehicle's motor drive system in stages based on the target output torque, target demand torque, first permissible continuous operating time, and target stall allowable torque corresponding to the fault.

[0018] Furthermore, the current coolant temperature is the coolant temperature at the inlet of the motor controller cooling system in the motor drive system.

[0019] In a second aspect, the present invention provides a motor stall control device, comprising:

[0020] The acquisition module is used to acquire the current coolant temperature and current torque demand of the target vehicle in response to the target vehicle entering a stall condition.

[0021] The first determining module is used to determine the target stall torque based on the current coolant temperature;

[0022] The second determining module is used to determine the target demand torque and the first permissible continuous operating time corresponding to the target demand torque in response to the current demand torque being greater than the target stall allowable torque, based on the current coolant temperature and the current demand torque.

[0023] The control module is used to control the output torque of the motor drive system of the target vehicle in stages according to the target required torque, the first permissible continuous operating time and the target stall permissible torque.

[0024] Thirdly, the present invention provides a motor stall control device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executed instructions;

[0025] The processor executes computer-executable instructions stored in memory to implement the motor stall control method provided in the first aspect.

[0026] Fourthly, the present invention provides a vehicle, comprising: a vehicle body and a motor stall control device as provided in the third aspect, the motor stall control device being used to execute the motor stall control method as provided in the first aspect.

[0027] Fifthly, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the motor stall control method provided in the first aspect.

[0028] In a sixth aspect, the present invention provides a computer program product, comprising: a computer program that, when executed by a processor, implements the motor stall control method provided in the first aspect.

[0029] The beneficial effects of this invention are:

[0030] This invention provides a motor stall control method, apparatus, equipment, vehicle, medium, and program product. The motor stall control method, in response to a target vehicle entering a stall condition, obtains the current coolant temperature and current required torque of the target vehicle, and determines the target stall allowable torque based on the current coolant temperature. Further, in response to the current required torque being greater than the target stall allowable torque, it determines a target required torque less than or equal to the current required torque and a first allowable continuous operating time corresponding to the target required torque based on the current coolant temperature and the current required torque. Then, based on the target required torque, the first allowable continuous operating time, and the target stall allowable torque, it controls the output torque of the target vehicle's motor drive system in stages. This invention uses coolant temperature and required torque as dual-dimensional input parameters. When a target vehicle enters a stall condition, it determines the target allowable stall torque for long-term continuous operation based on the current coolant temperature. Furthermore, when the current required torque exceeds the target allowable stall torque, it determines the target required torque and the corresponding first allowable continuous operating time by combining the current coolant temperature and the current required torque. This improves the thermal safety of the motor drive system under stall conditions. Then, a phased control strategy is adopted to control the output torque of the motor drive system based on the target required torque, the first allowable continuous operating time, and the target allowable stall torque. This ensures that the motor drive system maximizes the release of stall torque while meeting thermal safety constraints, improving the power performance under stall conditions. Ultimately, this achieves a balance between the power performance requirements and thermal safety of the motor drive system under stall conditions. Attached Figure Description

[0031] Figure 1 A flowchart illustrating the motor stall control method provided in this embodiment of the invention. Figure 1 ;

[0032] Figure 2 This is a schematic diagram of the stall control strategy provided in an embodiment of the present invention;

[0033] Figure 3 A flowchart illustrating the motor stall control method provided in this embodiment of the invention. Figure 2 ;

[0034] Figure 4 A schematic diagram of the second mapping relationship provided in an embodiment of the present invention;

[0035] Figure 5 This is an illustration of the relationship between the allowable continuous operating time and the target torque requirement, provided in an embodiment of the present invention. Figure 1 ;

[0036] Figure 6 This is an illustration of the relationship between the allowable continuous operating time and the target torque requirement, provided in an embodiment of the present invention. Figure 2 ;

[0037] Figure 7 This is a schematic diagram of the motor stall control device provided in an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of the motor stall control device provided in an embodiment of the present invention.

[0039] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0040] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0041] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0043] The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, product, or apparatus. Without further limitation, the presence of additional identical or equivalent elements in the process, method, product, or apparatus that includes elements is not excluded. For example, the use of terms such as "first," "second," etc., to indicate names does not imply any particular order.

[0044] When a vehicle is in motion, such as when starting on a steep slope, when the wheels are stuck in a deep ditch, or when it is blocked by an obstacle, the drive motor will usually enter a stalled state. In a stalled state, in order to get out of trouble quickly or climb a hill smoothly, the driver will usually keep pressing the accelerator pedal deeply, hoping that the vehicle will output maximum power, and the motor drive system will also output maximum torque accordingly.

[0045] However, for vehicles driven by electric motors (such as electric vehicles), stall conditions require the electric motor drive system to output a large torque at or near zero speed. In this situation, the rotor of the drive motor is locked or its speed is approximately zero, causing the current in the motor drive system (including the drive motor (such as a permanent magnet synchronous motor) and the motor controller) to concentrate in one phase, resulting in a rapid increase in the temperature of the corresponding phase of the drive motor and motor controller. Without proper protection strategies, thermal failure can easily occur, damaging the drive motor, motor controller, and other hardware. Therefore, stall conditions have always been a challenging aspect of electric vehicle control and are among the most demanding operating conditions.

[0046] Currently, a single-dimensional static stall protection strategy is typically used to protect hardware such as the motor controller and drive motor under stall conditions. However, this static stall protection strategy does not dynamically adjust based on coolant temperature, required torque, and the stage characteristics of the stall condition. This leads to an over-limitation of the motor drive system's output torque (sacrificing power) in low-temperature environments, and an inability to provide timely and effective protection for hardware such as the motor controller power module in high-temperature environments (easily causing thermal failure). It is difficult to balance power output and thermal safety protection, resulting in an imbalance between power requirements and thermal safety.

[0047] To address the aforementioned issues, this invention employs coolant temperature and required torque as dual-dimensional input parameters. When a vehicle enters a stall condition, the coolant temperature is used to determine the allowable stall torque for long-term continuous operation. Furthermore, when the required torque exceeds the allowable stall torque, the coolant temperature and required torque are combined to determine the target required torque and the corresponding allowable continuous operating time, thereby improving the thermal safety of the motor drive system under stall conditions. Then, a phased control strategy is adopted to control the output torque of the motor drive system based on the target required torque, the allowable continuous operating time, and the allowable stall torque. This ensures that the motor drive system maximizes the release of stall torque while meeting thermal safety constraints, improving the power performance under stall conditions, and ultimately achieving a balance between power performance requirements and thermal safety of the motor drive system under stall conditions.

[0048] The application scenarios of the embodiments of the present invention will be described below first.

[0049] The motor stall control method provided in this invention is applicable to the motor drive system of electric vehicles (EVs), hybrid electric vehicles (HEVs), and range-extended electric vehicles (REEVs), especially for stall conditions such as starting on steep slopes, wheels stuck in mud, or wheels jammed by obstacles.

[0050] In stalled conditions, the drive motor speed approaches zero, and the driver typically needs to press the accelerator pedal deeply to request a large torque output from the vehicle to extricate it from the predicament. At this time, the motor controller needs to output a large current in a very short period of time. The power module (such as an insulated gate bipolar transistor (IGBT) or silicon carbide (SiC) chip) will rapidly accumulate heat due to switching and conduction losses. If the current heat dissipation capacity is insufficient (such as a high coolant temperature), it can easily lead to the junction temperature of the power module exceeding the standard, or even cause permanent damage to the device.

[0051] This invention dynamically adjusts the allowable continuous running time and allowable output torque during the high torque demand phase under stall conditions to adapt to the differences in heat dissipation capacity at different coolant temperatures. It also distinguishes between short-term high torque demand and long-term stall allowable torque, effectively balancing power requirements and thermal safety under complex operating conditions, thus solving the problem of traditional strategies struggling to balance power and thermal safety.

[0052] The specific implementation of the motor stall control method provided in this invention will be described in detail below with reference to specific embodiments.

[0053] Figure 1 A flowchart illustrating the motor stall control method provided in this embodiment of the invention. Figure 1 .like Figure 1 As shown, a specific implementation of this motor stall control method may include the following steps:

[0054] S101, in response to the target vehicle entering a stall condition, obtains the target vehicle's current coolant temperature and current torque demand.

[0055] In this step, the stall condition can be understood as the rotor of the drive motor in the target vehicle's motor drive system being completely restricted in its movement (speed approaching 0) or at an extremely low speed, but the driver needs to press the accelerator pedal deeply to request the vehicle to output a large torque in order to get the vehicle out of trouble.

[0056] For example, the target vehicle can be a vehicle driven by an electric motor drive system, such as an electric vehicle, a hybrid electric vehicle, and a range-extended electric vehicle.

[0057] For example, the current coolant temperature can be the coolant temperature at the inlet of the motor controller cooling system in the motor drive system. This embodiment of the invention does not limit the type of coolant in the motor controller cooling system; it can be determined according to actual application requirements.

[0058] For example, the current required torque can be the driving torque requested by the target vehicle at the current moment.

[0059] One possible implementation of this step is as follows: In response to the target vehicle entering a stall condition, the current coolant temperature is collected by a temperature sensor located at the inlet of the motor controller's cooling system, and the current required torque is received from the vehicle controller. The current required torque can be calculated by the vehicle controller based on signals such as the accelerator pedal opening.

[0060] S102, determine the target stall torque based on the current coolant temperature.

[0061] For example, the target stall allowable torque can be the upper limit of the torque that the motor drive system is allowed to output under stall conditions at the current coolant temperature, balancing stall recovery capability with the thermal safety of the power module. This upper limit of torque is not a fixed constant, but is dynamically adjusted with the coolant temperature. For example, the lower the coolant temperature, the more sufficient the heat capacity of the motor controller cooling system and the larger the heat dissipation margin, so the upper limit of torque can be set relatively high; the higher the coolant temperature, the more strained the thermal state of the motor controller cooling system becomes, and the upper limit of torque is correspondingly lowered to suppress further heat accumulation in the inverter power module, drive motor windings, and bus circuits.

[0062] Understandably, in the stall condition, the target stall allowable torque is the torque value that allows the power module to reach thermal equilibrium at the current coolant temperature. This means that the motor drive system is allowed to continuously output the target stall allowable torque for a long time until the stall condition exits when the exit conditions are met, or until abnormalities such as overheating of the negative temperature coefficient thermistor (NTC) of the drive motor or motor controller failure are detected.

[0063] S103, in response to the current demand torque being greater than the target stall torque, determines the target demand torque and the first permissible continuous operating time corresponding to the target demand torque based on the current coolant temperature and the current demand torque.

[0064] Among them, the target torque requirement is less than or equal to the current torque requirement.

[0065] Understandably, when the current required torque exceeds the target stall torque, it indicates that the driver's or vehicle control layer's power request has exceeded the safe stall torque boundary that can be maintained for an extended period under the current cooling conditions. In this situation, the motor drive system does not simply limit the output torque immediately to the target stall torque. Instead, it further considers the current coolant temperature and the current required torque to determine the target required torque that balances the power demand for getting out of trouble with thermal safety, and simultaneously determines the duration for which this target required torque can be sustained.

[0066] For example, the target torque demand can be a phased output target torque value determined under the current stall condition, without fully meeting all current torque demand, by combining the thermal state of the motor drive system (i.e., the current coolant temperature) and the torque request (i.e., the current torque demand).

[0067] For example, the first allowable continuous operating time can be a time window under the thermal conditions corresponding to the current coolant temperature, allowing the motor drive system to continuously output the target required torque. This is used to limit the continuous operating time of high-load stall output and prevent the power module and drive motor windings from accumulating heat too quickly due to long-term high-current operation.

[0068] For example, the first allowed continuous runtime can be 0.3 seconds, 0.5 seconds, etc. This embodiment of the invention does not limit the size of the first allowed continuous runtime; it can be determined according to actual application requirements.

[0069] Understandably, in this step, when the current required torque exceeds the target stall torque, that is, when the power request from the driver or vehicle control layer exceeds the safe stall torque boundary that can be maintained for a long time under the current cooling conditions, this embodiment of the invention adopts a joint decision-making mechanism of torque amplitude and continuous running duration. This makes the high demand torque output no longer limited by a single amplitude, but dynamically related to thermal conditions and the magnitude of the required torque. Thus, when the vehicle has a need to get out of trouble or climb hills, it provides higher torque support within a certain time window, while forming a constraint in the time dimension to avoid thermal protection lag caused by continuous high torque, thereby better balancing power demand and thermal safety boundaries.

[0070] Optionally, in response to the current required torque being less than or equal to the target stall torque, one possible implementation is as follows: the motor drive system uses the target stall torque as the upper limit of the torque command, and also adjusts the inverter phase current through a current closed loop to make the drive motor continuously output stall torque corresponding to the target stall torque, until the stall condition exit condition is met and the stall condition is exited, or until abnormal conditions such as drive motor NTC overheating or motor controller failure are detected.

[0071] S104 controls the output torque of the target vehicle's motor drive system in stages based on the target required torque, the first permissible continuous operating time, and the target stall permissible torque.

[0072] For example, a motor drive system can be an integrated drive actuator that includes a drive motor, an inverter, a power module, a current sampling unit, a motor controller, and software execution logic related to torque control.

[0073] In this step, phased control can be understood as dividing the torque output process of the motor drive system under stall conditions into multiple control stages with different torque targets and different continuous running durations, and switching and executing each stage according to the determined target torque requirement, the first allowable continuous running duration, and the target stall allowable torque.

[0074] For example, in one possible implementation, under stall conditions, when the current demand torque exceeds the target stall allowable torque, the motor drive system enters a phased stall control mode, and the first phase is set as an enhanced output phase. In this first phase, the motor drive system uses the target demand torque as the upper limit of the torque command and adjusts the inverter phase current through a current closed loop to ensure the drive motor outputs stall torque corresponding to the target demand torque for a first permissible continuous operating duration. When the first permissible continuous operating duration is reached, the motor drive system switches to using the target stall allowable torque as the upper limit of the torque command, and again adjusts the inverter phase current through a current closed loop to ensure the drive motor continuously outputs stall torque corresponding to the target stall allowable torque, until the stall condition exit condition is met and the stall condition is exited, or until abnormal conditions such as drive motor NTC overheating or motor controller failure are detected. The first phase is a short-term high-demand torque output phase, and the second phase is a long-term stall allowable torque output phase, i.e., a thermal balance maintenance phase.

[0075] Figure 2 This is a schematic diagram of the stall control strategy provided in an embodiment of the present invention. Figure 2 As shown in the figure, the horizontal axis represents time in seconds (s), and the vertical axis represents torque in Nm.

[0076] like Figure 2 As shown in the figure, during the short-term high-demand torque output phase, the motor drive system outputs the target demand torque T. max As the upper limit of torque command, the inverter phase current is adjusted through current closed-loop regulation to ensure the drive motor operates for the first permissible continuous operating time. The internal output stall torque corresponds to the target required torque; when the first permissible continuous operating time is reached (i.e., when the stall torque is reached) At any given moment, the motor drive system switches to a mode that operates based on the target stall allowable torque T. contAs the upper limit of torque command, the inverter phase current is also adjusted through current closed-loop regulation to ensure the drive motor operates for a continuous period of time. The internal output is the stall torque corresponding to the target stall torque.

[0077] Among them, the first allowed continuous runtime for The difference between time 0 and time 0, where time 0 represents the starting time of the target vehicle entering the stall condition, and the duration of operation. for Time and The difference in time, The moment indicates the instant when the upper limit of the torque command of the motor drive system switches from the target required torque to the target stall allowable torque. The moment indicates the end of the motor drive system at the target stall allowable torque T. cont This is the moment when the torque command reaches its upper limit.

[0078] In this embodiment of the invention, by using coolant temperature and required torque as dual-dimensional input parameters, when the target vehicle enters a stall condition, the target allowable stall torque for long-term continuous operation is determined based on the current coolant temperature. Furthermore, when the current required torque exceeds the target allowable stall torque, the target required torque and the corresponding first allowable continuous operating time are determined by combining the current coolant temperature and the current required torque. This improves the thermal safety of the motor drive system under stall conditions. Then, a phased control strategy is adopted to control the output torque of the motor drive system based on the target required torque, the first allowable continuous operating time, and the target allowable stall torque. This ensures that the motor drive system maximizes the release of stall torque while meeting thermal safety constraints, improving the power performance under stall conditions, and thus achieving a balance between the power performance requirements and thermal safety of the motor drive system under stall conditions.

[0079] Optionally, one possible implementation of step S102, which determines the target stall torque based on the current coolant temperature, is as follows: based on the first mapping relationship between coolant temperature and stall torque, the target stall torque is determined according to the current coolant temperature.

[0080] Among them, the coolant temperature is the temperature at the inlet of the motor controller cooling system, which is used to characterize the heat dissipation conditions and heat accumulation state of the motor drive system; the stall torque is the torque boundary that the motor drive system is allowed to continuously output when the target vehicle enters the stall condition, which is used to limit the heat accumulation and heat burden of the power module and drive motor under high load conditions.

[0081] For example, the first mapping relationship is used to characterize the correspondence between coolant temperature and stall torque. This correspondence can be pre-established from calibration data, thermal test data or thermal model calculation results and stored in the mapping table, characteristic curve or function relationship inside the motor controller.

[0082] In one possible implementation, the first mapping relationship can be obtained as follows: Obtain the coolant temperature range; divide the coolant temperature range into multiple different coolant temperatures according to a preset temperature gradient; perform thermal simulation analysis on the power module for each coolant temperature to obtain the stall torque corresponding to each coolant temperature; and further, based on each coolant temperature and its corresponding stall torque, construct the first mapping relationship between the coolant temperature and the stall torque. Here, the coolant temperature range can be the operating temperature range corresponding to the motor controller cooling system, and the preset temperature gradient can be obtained based on experience or calibration tests.

[0083] Optionally, if the stall torque corresponding to a higher coolant temperature can meet the overall vehicle power requirements of the target vehicle, the stall torque corresponding to each coolant temperature lower than the higher coolant temperature can be uniformly set to the stall torque value corresponding to the higher coolant temperature. For example, if the stall torque corresponding to a coolant temperature of 55°C can meet the overall vehicle power requirements of the target vehicle, the stall torque corresponding to each coolant temperature lower than 55°C can be uniformly set to the stall torque value corresponding to 55°C.

[0084] In this embodiment, one possible implementation is as follows: when the first mapping relationship is a two-dimensional table corresponding to coolant temperature and stall torque, a target coolant temperature with the same current coolant temperature is found in the two-dimensional table, and the stall torque corresponding to the target coolant temperature is determined as the target stall torque. Another possible implementation is as follows: when the first mapping relationship is a linear relationship between coolant temperature and stall torque, the current coolant temperature is input into the first mapping relationship, and the target stall torque corresponding to the current coolant temperature is calculated. The linear relationship can be a phased linear relationship, such as a higher stall torque corresponding to a lower coolant temperature range and a lower stall torque corresponding to a higher coolant temperature range, thereby adaptively adjusting the upper limit of the stall torque according to the thermal state of the motor drive system.

[0085] In this embodiment of the invention, the first mapping relationship can also be modified based on the actual state of the motor controller cooling system. For example, when the heat exchange capacity of the radiator decreases or the coolant circulation capacity is limited, the stall torque at the same coolant temperature can be lowered to improve the consistency of thermal protection. In this embodiment of the invention, the first mapping relationship can be in the form of a function or a lookup table, etc. This embodiment of the invention does not limit the form of the first mapping relationship; it can be determined according to the actual application requirements.

[0086] This invention establishes a direct mapping between coolant temperature and stall torque, enabling the motor controller to quickly determine the stall torque boundary applicable to the current thermal state when stall occurs. This stall torque boundary serves as the basis for subsequent torque output control. By dynamically adjusting the stall torque based on coolant temperature, the target vehicle retains higher off-road capability under good cooling conditions and tightens the stall torque boundary promptly under poor cooling conditions, thereby reducing the risk of continuous overheating of the power module. Simultaneously, by controlling the target stall torque to remain synchronized with the current coolant temperature, the invention avoids thermal protection lag or premature torque limiting issues caused by fixed torque limits, improving the thermal adaptability and torque utilization of stall control, and providing a clear and stable stall torque benchmark for subsequent staged torque control.

[0087] The following is combined with Figure 3 A detailed explanation is provided of a specific implementation method for determining the target required torque and the first allowable continuous running time corresponding to the target required torque in step S103 based on the current coolant temperature and the current required torque.

[0088] Figure 3 A flowchart illustrating the motor stall control method provided in this embodiment of the invention. Figure 2 .like Figure 3 As shown, in this motor stall control method, a specific implementation of determining the target required torque and the first allowable continuous running time corresponding to the target required torque based on the current coolant temperature and the current required torque may include the following steps:

[0089] S301, based on the second mapping relationship, determines multiple different required torques corresponding to the current coolant temperature and the allowable continuous running time corresponding to each required torque, according to the current coolant temperature.

[0090] The second mapping relationship is that each coolant temperature corresponds to multiple different required torques, and each required torque corresponds to an allowable continuous operating time.

[0091] Understandably, the second mapping relationship is used to characterize the correspondence between the torque output capability and the heat accumulation state of the motor drive system under different coolant temperature conditions.

[0092] Optionally, in one possible implementation, the second mapping relationship can be obtained by: acquiring multiple different coolant temperatures and multiple different required torques; for each coolant temperature, performing thermal simulation analysis on the multiple different required torques of the motor drive system at each coolant temperature to obtain the allowable continuous running time corresponding to each required torque among the multiple different required torques at each coolant temperature; and constructing the second mapping relationship based on the allowable continuous running time corresponding to each required torque at each coolant temperature.

[0093] For example, one possible implementation is as follows: Based on the applicable operating conditions of the motor controller cooling system, select multiple different coolant temperatures as thermal simulation boundary conditions, and set multiple different required torques at each coolant temperature. Through thermal simulation analysis and calculation, the power loss, power module junction temperature change, and thermal diffusion process under the corresponding operating conditions can be obtained; further, based on whether the junction temperature reaches the preset thermal limit, thermal derating trigger threshold, or meets the continuous thermal stability condition, determine the allowable continuous operating time corresponding to each required torque at each coolant temperature, and store the correspondence between coolant temperature, required torque, and allowable continuous operating time as a calibration table or a two-dimensional lookup table data structure, thereby forming a second mapping relationship.

[0094] Optionally, when the coolant temperature is greater than the temperature threshold, multiple different required torques adopt a first division gradient, and when the coolant temperature is less than or equal to the temperature threshold, multiple different required torques adopt a second division gradient, wherein the first division gradient is less than the second division gradient.

[0095] Among them, the temperature threshold is used to distinguish between high temperature range and low temperature range. Different torque division densities are used for different temperature ranges in order to balance the fine control under high temperature conditions and the table lookup efficiency under low temperature conditions.

[0096] For example, the temperature threshold can be determined based on empirical values ​​or calibrated based on experimental data. This embodiment of the invention does not limit the magnitude or determination method of the temperature threshold; it can be determined according to the specific application requirements.

[0097] Understandably, when the coolant temperature exceeds the temperature threshold, the coolant's ability to remove heat decreases, leading to increased power module current and faster heating rate when the motor drive system outputs high torque. This causes the junction temperature to more easily approach the maximum allowable value, resulting in relatively unfavorable heat dissipation conditions. In this case, a smaller first partitioning gradient can be used to discretize the required torque, making adjacent required torque points more closely spaced. This more accurately characterizes the nonlinear characteristics of the allowable continuous operating time in the high-temperature region as a function of required torque. When the coolant temperature is less than or equal to the temperature threshold, the lower coolant temperature effectively removes the heat generated by the power module's output current, resulting in relatively sufficient system heat dissipation and better utilization of the power module's stall capability. In this case, a larger second partitioning gradient can be used to reduce the mapping table size and improve control query efficiency. This partitioning method allows the second mapping relationship to maintain high resolution in the high heat load range while maintaining high computational efficiency in the low heat load range.

[0098] Optionally, in one possible implementation, if the stall torque allowed to be output by the motor drive system can directly meet the maximum stall torque requirement of the vehicle when the coolant temperature is below a certain level, then the required torque-allowed continuous running time mapping table corresponding to each coolant temperature below that level can be uniformly set without distinguishing between temperatures.

[0099] In this embodiment, by constructing a second mapping relationship based on multiple different coolant temperatures and multiple different required torques, the impact of coolant temperature changes on the continuous stall output capability of the motor drive system can be reflected more accurately. At the same time, by using different required torque gradients based on temperature zones, the thermal boundary determination error caused by excessively sparse required torque points in the high-temperature zone can be avoided, as well as the data redundancy caused by excessively dense required torque points in the low-temperature zone. This improves the accuracy, response efficiency, and applicability of thermal protection control under stall conditions.

[0100] Figure 4 This is a schematic diagram of the second mapping relationship provided in an embodiment of the present invention. For example... Figure 4 As shown, the horizontal axis represents the required torque in Nm, which increases from left to right. The vertical axis represents the allowable continuous operating time in seconds. The black line 41 represents the coolant temperature corresponding to the high-temperature operating condition, and the black line 42 represents the coolant temperature corresponding to the low-temperature operating condition. That is, the coolant temperature represented by the black line 41 is greater than the coolant temperature represented by the black line 42.

[0101] like Figure 4As shown, when the required torque is low, the allowable continuous running time corresponding to black lines 41 and 42 is maintained at 5s, indicating that when the required torque is low (i.e., under low required torque conditions), even under different coolant temperature conditions, the heat accumulation rate of the drive motor is slow, and the allowable continuous running time can reach the set maximum value. When the required torque is high, for the coolant temperature corresponding to the high-temperature zone conditions (such as when the coolant temperature is greater than the temperature threshold), the discrete points of the required torque can adopt a smaller first division gradient (such as the corresponding allowable continuous running time of 2.32s and 0. The required torques at 55s, 0.33s, and 0.21s are respectively used to avoid thermal boundary judgment errors caused by excessively sparse sampling of required torques in the high-temperature zone. For the coolant temperature corresponding to the low-temperature zone (such as when the coolant temperature is less than or equal to the temperature threshold), the discrete sampling points of the required torque can adopt a larger second division gradient (such as the required torques corresponding to the allowable continuous running durations of 1.68s, 0.86s, and 0.54s respectively), to avoid data redundancy caused by excessively dense sampling of required torques in the low-temperature zone, thereby improving the accuracy, response efficiency, and applicability of thermal protection control under stall conditions.

[0102] S302, based on the current required torque, multiple different required torques and the allowable continuous operating time corresponding to each required torque, determine the target required torque and the first allowable continuous operating time.

[0103] Among them, the target torque requirement is less than or equal to the current torque requirement.

[0104] Optionally, one possible implementation is as follows: determine whether the current demand torque is greater than the maximum demand torque among multiple different demand torques; if the current demand torque is greater than the maximum demand torque, then determine the maximum demand torque as the target demand torque, and determine the allowable continuous running time corresponding to the maximum demand torque as the first allowable continuous running time; if the current demand torque is less than the maximum demand torque, then determine the current demand torque as the target demand torque, and determine the allowable continuous running time corresponding to the current demand torque as the first allowable continuous running time.

[0105] It is understandable that when the current required torque is greater than the maximum required torque, the maximum required torque is determined as the target required torque, and the allowable continuous running time corresponding to the maximum required torque is determined as the first allowable continuous running time. When the current required torque is less than the maximum required torque, the current required torque is determined as the target required torque, and the allowable continuous running time corresponding to the current required torque is determined as the first allowable continuous running time. This improves the adaptability and continuity of stall control, reduces control anomalies caused by out-of-range torque requests, and helps to constrain heat accumulation while meeting the needs of getting out of trouble or climbing, thereby improving the thermal safety and output coordination of the motor drive system.

[0106] Optionally, in practical applications, the target torque requirement can also be determined by rounding down, nearest neighbor matching, or interpolation matching, and this embodiment of the invention does not limit this. This embodiment of the invention, based on a second mapping relationship, determines multiple different torque requirements corresponding to the current coolant temperature and the allowable continuous operating time corresponding to each torque requirement, and further determines the target torque requirement and the first allowable continuous operating time based on the current torque requirement, the multiple different torque requirements, and the allowable continuous operating time corresponding to each torque requirement. This allows the output capability under stall conditions to be dynamically adjusted according to the thermal state. By incorporating temperature and torque requirement factors into the mapping decision, the motor controller can constrain the continuous operating time of high torque output while meeting the torque request for getting out of trouble or climbing, and provide accurate input for staged torque control. This reduces the risk of thermal accumulation in the power module and drive motor while ensuring vehicle power response, reduces control deviations caused by premature or delayed intervention of thermal protection, and improves the stability and thermal safety of stall control.

[0107] It is understood that the motor stall control method provided in this embodiment of the invention can maximize the stall capability of the motor controller while ensuring the thermal safety of the motor drive system. That is, by performing two-dimensional partitioning processing on the coolant temperature and the required torque, the output current capability of the power module can be maximized.

[0108] Optionally, one possible implementation of step S104, which controls the output torque of the motor drive system of the target vehicle in stages based on the target required torque, the first permissible continuous operating time, and the target stall allowable torque, is as follows: within the first permissible continuous operating time, control the motor drive system to output the target required torque; in response to the actual continuous operating time of the target required torque being greater than the first permissible continuous operating time, control the motor drive system to output the target stall allowable torque.

[0109] For example, in one possible implementation, after receiving the target torque requirement and the first permissible continuous running time, the motor controller first starts a continuous running timer in the timing module, and stabilizes the drive motor output at the current command corresponding to the target torque requirement through torque closed-loop control, thereby enabling the target vehicle to obtain the required power in scenarios such as getting out of trouble, climbing hills, or short-term high load. When the timing result (i.e., the actual continuous running time) reaches or exceeds the first permissible continuous running time, the motor controller switches the torque control target to the target stall allowable torque, and recalculates the current limit or torque upper limit based on the target stall allowable torque, so that the output torque falls back to the thermal safety range. The switching process can adopt a step switching method or a ramp transition method to reduce the impact caused by sudden torque changes. In practical applications, other control forms can also be used for this transition method, which is not limited in this embodiment of the invention.

[0110] Understandably, by adopting this phased control strategy, the system first fully utilizes the short-term output capability of the target torque demand during operation, enabling the target vehicle to obtain strong driving force in the initial stage of stall. Subsequently, when the continuous operating time exceeds the limit, it automatically switches to the target stall-allowed torque output to avoid continued heat accumulation in the power module and drive motor windings under high load conditions. By combining torque control with continuous operating time constraints, the motor drive system can suppress thermal risks while ensuring necessary traction capacity, thereby improving stability and reliability under stall conditions.

[0111] In this embodiment of the invention, by controlling the motor drive system to output the target required torque within a first permissible continuous operating time, and responding to the actual continuous operating time of the target required torque being greater than the first permissible continuous operating time, the motor drive system is controlled to output the target stall allowable torque, so that the target vehicle can take into account both short-term power release and thermal safety protection in stall conditions, reduce power shortage caused by uniform amplitude limitation, and avoid the risk of thermal runaway caused by long-term high torque output, thereby improving the vehicle's ability to get out of trouble and its continuous working ability in complex road conditions.

[0112] Optionally, when the actual continuous operating time of the target required torque is less than the first allowable continuous operating time, the motor stall control method provided in this embodiment of the invention further includes: responding to the target required torque decreasing to the first required torque, controlling the motor drive system to output the first required torque, wherein the remaining allowable continuous operating time of the first required torque is the difference between the first allowable continuous operating time and the actual continuous operating time; or responding to the target required torque increasing to the second required torque, determining the second allowable continuous operating time corresponding to the second required torque based on the current coolant temperature and the second required torque, and controlling the motor drive system to output the second required torque, wherein the remaining allowable continuous operating time of the second required torque is the difference between the second allowable continuous operating time and the actual continuous operating time.

[0113] For example, the first demand torque can be the new demand torque formed after the torque demand decreases, and the second demand torque can be the new demand torque formed after the torque demand increases.

[0114] In one possible implementation, when the target demand torque decreases before the first permissible continuous running time has been exhausted, the motor controller maintains a record of the accumulated actual continuous running time and associates the decreased first demand torque with the corresponding demand torque boundary. It then subtracts the actual continuous running time from the first permissible continuous running time to obtain a new remaining permissible continuous running time, and controls the motor drive system to continue outputting the first demand torque within this remaining permissible continuous running time. Conversely, when the target demand torque increases before the first permissible continuous running time has been exhausted due to driving requests or load conditions, the motor controller re-determines the second permissible continuous running time corresponding to the second demand torque based on the current coolant temperature and the increased second demand torque. It then subtracts the actual continuous running time from the second permissible continuous running time to obtain a new remaining permissible continuous running time, and controls the motor drive system to continue outputting the second demand torque within this remaining permissible continuous running time. This torque inheritance and recalculation mechanism enables smooth switching of output torque between different demand torques and avoids control deviations caused by recalculation due to changes in demand torque.

[0115] Understandably, rapid switching response is required to address changes in torque demand, preventing power module damage due to a mismatch between the allowable release time under stall conditions and the current actual output current. This invention continuously tracks changes in torque demand under stall conditions and incorporates the consumed runtime into the calculation of the remaining allowable runtime, ensuring both continuity of output torque and thermal safety boundary constraints. When torque demand decreases, the remaining allowable runtime after deducting the consumed runtime is directly inherited; when torque demand increases, the allowable runtime is re-matched based on the increased torque demand and the current coolant temperature, thus synchronizing thermal state assessment with power request updates. This improves torque response consistency under stall conditions, reduces frequent torque limiting and abrupt control changes, and enhances vehicle traction and driving smoothness while ensuring effective thermal protection.

[0116] Figure 5 This is an illustration of the relationship between the allowable continuous operating time and the target torque requirement, provided in an embodiment of the present invention. Figure 1 .like Figure 5 As shown in the figure, the horizontal axis represents time in seconds (s), and the vertical axis represents torque in Nm.

[0117] like Figure 5 As shown, in the target required torque T max Actual continuous runtime Less than the first allowed continuous runtime During the process, at time t1, the target required torque T maxWhen the torque drops to the first required torque T1, the motor drive system switches to use the first required torque T1 as the upper limit of the torque command, and adjusts the inverter phase current through a current closed loop to ensure that the drive motor continues to operate for the remaining allowable duration of the first required torque. Internal output stall torque corresponding to the first required torque; remaining allowable continuous operating time for the first required torque. Arrival time (i.e., arrival at t) m At any given moment, the motor drive system switches to a mode that operates based on the target stall allowable torque T. cont As the upper limit of torque command, the inverter phase current is also adjusted through current closed-loop regulation to ensure the drive motor operates for a continuous period of time. The internal output is the stall torque corresponding to the target stall torque.

[0118] Among them, the actual continuous running time The difference between time 0 and time t1 represents the remaining allowable runtime. for The difference between time t1 and time t2.

[0119] Figure 6 This is an illustration of the relationship between the allowable continuous operating time and the target torque requirement, provided in an embodiment of the present invention. Figure 2 .like Figure 6 As shown in the figure, the horizontal axis represents time in seconds (s), and the vertical axis represents torque in Nm.

[0120] like Figure 6 As shown, in the target required torque T max Actual continuous runtime Less than the first allowed continuous runtime During the process, at time t2, the target required torque T max When the torque reaches the second required torque T2, the motor drive system switches to use the second required torque T2 as the upper limit of the torque command. It then adjusts the inverter phase current through a current closed-loop system to extend the remaining allowable continuous operating time of the drive motor to the second required torque. Internal output stall torque corresponding to the second required torque; remaining allowable continuous operating time for the second required torque. Arrival time (i.e., arrival at t) v At any given moment, the motor drive system switches to a mode that operates based on the target stall allowable torque T. cont As the upper limit of torque command, the inverter phase current is also adjusted through current closed-loop regulation to ensure the drive motor operates for a continuous period of time. The internal output is the stall torque corresponding to the target stall torque.

[0121] Among them, the actual continuous running time The difference between time t2 and time 0 represents the remaining allowable runtime. for The difference between time t1 and time t2. The timing is based on the second permissible continuous operating time corresponding to the second required torque. Definitely, the second allowed continuous runtime for The difference between time 0 and time 0.

[0122] Optionally, in the process of controlling the output of the target stall allowable torque by the motor drive system, the motor stall control method provided in this embodiment of the invention further includes: obtaining the current speed and current torque of the target vehicle; determining whether the current speed is greater than a first speed threshold and whether the current torque is less than or equal to a first torque threshold; if the current speed is greater than the first speed threshold or the current torque is less than or equal to the first torque threshold, then controlling the target vehicle to exit the stall condition; if the current speed is less than or equal to the first speed threshold and the current torque is greater than the first torque threshold, then controlling the output of the target stall allowable torque by the motor drive system.

[0123] For example, the current rotational speed can be the output rotational speed of the drive motor rotor in the motor drive system at the current moment, and the current torque can be the output torque of the drive motor at the current moment.

[0124] Understandably, the first speed threshold and the first torque threshold serve as the boundary for exiting the stall condition, used to distinguish whether the target vehicle has recovered from the stall state of low speed and high load to the normal operating state.

[0125] The embodiments of the present invention do not limit the specific values ​​of the first speed threshold and the first torque threshold, which can be determined according to the actual application requirements.

[0126] Optionally, in the motor stall control method provided in this embodiment of the invention, it can be determined whether the target vehicle has entered a stall condition by: determining whether the current speed is less than or equal to a second speed threshold and whether the current torque is greater than a second torque threshold; if the current speed is less than or equal to the second speed threshold and the current torque is greater than the second torque threshold, then it is determined that the target vehicle has entered a stall condition; if the current speed is greater than the second speed threshold or the current torque is less than or equal to the second torque threshold, then it is determined that the target vehicle has not entered a stall condition.

[0127] Among them, the second speed threshold is less than the first speed threshold, and the second torque threshold is greater than the first torque threshold.

[0128] It is understood that, in this embodiment of the invention, hysteresis control in the torque dimension is achieved by setting a first speed threshold for determining exit from a stalled state greater than a second speed threshold for determining entry into a stalled state; and hysteresis control in the torque dimension is achieved by setting a first torque threshold for determining exit from a stalled state less than a second torque threshold for determining entry into a stalled state. The motor drive system can accurately determine the stalled state based on the current speed and current torque, and smoothly exit the stalled state when the exit conditions are met, while continuing to output the target stall-allowed torque when the exit conditions are not met. This reduces false exits and false holdings of the stalled state, improves control stability during vehicle extrication, and reduces the accumulation of ineffective thermal load on the motor drive system under stalled conditions.

[0129] Optionally, the motor stall control method provided in this embodiment of the invention further includes: obtaining a fault code corresponding to the motor drive system; determining whether the motor drive system has a fault based on the fault code; and, in response to the presence of a fault in the motor drive system, controlling the output torque of the motor drive system of the target vehicle in stages based on the target output torque, target demand torque, first allowable continuous running time, and target stall allowable torque corresponding to the fault.

[0130] For example, fault codes are used to characterize the current fault state of the motor drive system. Faults in the motor drive system include, but are not limited to, power module overheating and drive motor NTC overheating.

[0131] For example, the target output torque can be the boundary of the output torque that the motor drive system is allowed to apply under fault constraints. The target output torque can vary depending on the type of fault.

[0132] For example, one possible implementation is as follows: obtain the fault code corresponding to the motor drive system and match the fault code with a preset fault table to determine whether the motor drive system has a fault; further, when a fault is detected in the motor drive system, determine the target output torque corresponding to the fault based on the correspondence between the preset fault and the control strategy; if the fault occurs in the stall torque stage corresponding to the target required torque of the motor drive system, when the target output torque is less than the target required torque, the motor drive system switches to controlling the output of the stall torque corresponding to the target output torque, and when the target output torque is greater than the target required torque, the motor drive system continues to control the output of the stall torque corresponding to the target output torque; if the fault occurs in the stall torque stage corresponding to the target allowable stall torque of the motor drive system, when the target output torque is less than the target allowable stall torque, the motor drive system switches to controlling the output of the stall torque corresponding to the target output torque, and when the target output torque is greater than the target allowable stall torque, the motor drive system continues to control the output of the stall torque corresponding to the target allowable stall torque.

[0133] In this embodiment of the invention, when a fault exists in the motor drive system, the output torque of the target vehicle's motor drive system is controlled in stages according to the target output torque, target demand torque, first allowable continuous running time, and target stall allowable torque corresponding to the fault. This allows the vehicle to retain a certain driving capability while meeting safety constraints, thus avoiding excessive torque output in the fault state that could cause further damage, and also avoiding direct power cut-off that could cause the vehicle to lose its necessary ability to get out of trouble or drive at low speeds. This improves safety and availability in fault scenarios.

[0134] Optionally, the current coolant temperature is the coolant temperature at the inlet of the motor controller cooling system in the motor drive system.

[0135] It is understood that, in this embodiment of the invention, the current coolant temperature refers to the real-time coolant temperature collected at the inlet of the motor controller cooling system in the motor drive system. It is the measured temperature value of the cooling medium entering the front end of the cooling circuit of the motor controller and is used to characterize the coolant temperature state on the inlet side of the motor controller cooling system.

[0136] In summary, the motor stall control method provided by the embodiments of the present invention has the following beneficial effects:

[0137] 1) By using the coolant temperature at the inlet of the motor controller cooling system as a reference dimension for the allowable continuous operation time of stall torque, the thermal safety of the motor drive system under stall conditions is improved.

[0138] 2) By matching the corresponding allowable continuous operating time based on different stall torque requirements, the stall torque is released to the maximum extent while ensuring thermal safety, so as to meet the power requirements under stall conditions;

[0139] 3) By formulating corresponding control strategies for the changes in target torque demand under stall conditions, the system can protect components such as the motor controller power module while ensuring power performance, and further balance thermal safety and system reliability.

[0140] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not disclosed in the embodiments of the apparatus of the present invention, please refer to the embodiments of the method of the present invention.

[0141] Figure 7 This is a schematic diagram of the motor stall control device provided in an embodiment of the present invention. Figure 7 As shown, the motor stall control device 70 includes an acquisition module 710, a first determination module 720, a second determination module 730, and a control module 740.

[0142] The acquisition module 710 is used to acquire the current coolant temperature and current torque demand of the target vehicle in response to the target vehicle entering a stall condition.

[0143] The first determining module 720 is used to determine the target stall torque based on the current coolant temperature;

[0144] The second determining module 730 is used to determine the target demand torque and the first permissible continuous operating time corresponding to the target demand torque in response to the current demand torque being greater than the target stall allowable torque, based on the current coolant temperature and the current demand torque.

[0145] The control module 740 is used to control the output torque of the motor drive system of the target vehicle in stages according to the target required torque, the first permissible continuous operating time and the target stall permissible torque.

[0146] Furthermore, the first determining module 720 is specifically used to: determine the target stall torque based on the first mapping relationship between coolant temperature and stall torque, according to the current coolant temperature.

[0147] Furthermore, the second determining module 730 is specifically used to: based on the second mapping relationship, determine multiple different required torques corresponding to the current coolant temperature and the allowable continuous running time corresponding to each required torque according to the current coolant temperature; and determine the target required torque and the first allowable continuous running time according to the current required torque, multiple different required torques and the allowable continuous running time corresponding to each required torque.

[0148] The second mapping relationship is that each coolant temperature corresponds to multiple different required torques, and each required torque corresponds to an allowable continuous operating time.

[0149] Furthermore, the second determining module 730 is also used to: determine whether the current demand torque is greater than the maximum demand torque among multiple different demand torques; if the current demand torque is greater than the maximum demand torque, then the maximum demand torque is determined as the target demand torque, and the allowable continuous running time corresponding to the maximum demand torque is determined as the first allowable continuous running time; if the current demand torque is less than the maximum demand torque, then the current demand torque is determined as the target demand torque, and the allowable continuous running time corresponding to the current demand torque is determined as the first allowable continuous running time.

[0150] Furthermore, the second mapping relationship is obtained in the following way: multiple different coolant temperatures and multiple different required torques are obtained; for each coolant temperature, thermal simulation analysis is performed on multiple different required torques of the motor drive system at each coolant temperature to obtain the allowable continuous running time corresponding to each required torque among multiple different required torques at each coolant temperature; based on the allowable continuous running time corresponding to each required torque at each coolant temperature, the second mapping relationship is constructed.

[0151] Specifically, when the coolant temperature is greater than the temperature threshold, multiple different required torques are divided using a first division gradient, and when the coolant temperature is less than or equal to the temperature threshold, multiple different required torques are divided using a second division gradient, with the first division gradient being less than the second division gradient.

[0152] Furthermore, the control module 740 is specifically used to: control the motor drive system to output the target required torque during the first permissible continuous operating time; and control the motor drive system to output the target stall allowable torque in response to the actual continuous operating time of the target required torque being greater than the first permissible continuous operating time.

[0153] Furthermore, when the actual continuous operating time of the target required torque is less than the first allowable continuous operating time, the control module 740 is also configured to: in response to the target required torque decreasing to the first required torque, control the motor drive system to output the first required torque, wherein the remaining allowable continuous operating time of the first required torque is the difference between the first allowable continuous operating time and the actual continuous operating time; or in response to the target required torque increasing to the second required torque, determine the second allowable continuous operating time corresponding to the second required torque based on the current coolant temperature and the second required torque, and control the motor drive system to output the second required torque, wherein the remaining allowable continuous operating time of the second required torque is the difference between the second allowable continuous operating time and the actual continuous operating time.

[0154] Furthermore, during the process of controlling the motor drive system to output the target stall allowable torque, the control module 740 is also used to: acquire the current speed and current torque of the target vehicle; determine whether the current speed is greater than a first speed threshold and whether the current torque is less than or equal to a first torque threshold; if the current speed is greater than the first speed threshold or the current torque is less than or equal to the first torque threshold, then control the target vehicle to exit the stall condition; if the current speed is less than or equal to the first speed threshold and the current torque is greater than the first torque threshold, then control the motor drive system to output the target stall allowable torque.

[0155] Furthermore, the determination of whether the target vehicle has entered a stall condition is made by: determining whether the current speed is less than or equal to a second speed threshold, whether the current torque is greater than a second torque threshold, whether the second speed threshold is less than a first speed threshold, and whether the second torque threshold is greater than the first torque threshold; if the current speed is less than or equal to the second speed threshold and the current torque is greater than the second torque threshold, then the target vehicle is determined to have entered a stall condition; if the current speed is greater than the second speed threshold, or the current torque is less than or equal to the second torque threshold, then the target vehicle is determined not to have entered a stall condition.

[0156] Furthermore, the control module 740 is also used to: acquire the fault code corresponding to the motor drive system; determine whether there is a fault in the motor drive system based on the fault code; and, in response to the presence of a fault in the motor drive system, control the output torque of the motor drive system of the target vehicle in stages based on the target output torque, target demand torque, first permissible continuous operating time, and target stall permissible torque corresponding to the fault.

[0157] Furthermore, the current coolant temperature is the coolant temperature at the inlet of the motor controller cooling system in the motor drive system.

[0158] The motor stall control device provided in this embodiment of the invention can be used to execute the method steps of the above method embodiment. The specific implementation and technical effects are similar, and will not be repeated here.

[0159] Figure 8 This is a schematic diagram of the motor stall control device provided in an embodiment of the present invention. Figure 8 As shown, the motor stall control device 80 includes at least one processor 801 and a memory 802.

[0160] Optionally, the motor stall control device 80 also includes a communication component 803. The processor 801, memory 802, and communication component 803 are connected via a bus 804.

[0161] In a specific implementation, at least one processor 801 executes computer execution instructions stored in memory 802, causing at least one processor 801 to perform the above-described method.

[0162] The specific implementation process of processor 801 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0163] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0164] The memory may include random access memory (RAM) and non-volatile memory (NVM), such as at least one disk storage device.

[0165] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0166] This invention also provides a vehicle, including a vehicle body and a motor stall control device as described in the above embodiments.

[0167] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0168] This invention also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0169] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0170] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0171] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0172] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0173] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0174] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0175] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0176] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for controlling a stalled motor, characterized in that, include: In response to the target vehicle entering a stall condition, obtain the target vehicle's current coolant temperature and current torque demand; Determine the target stall torque based on the current coolant temperature; In response to the current demand torque being greater than the target stall allowable torque, a target demand torque and a first allowable continuous operating time corresponding to the target demand torque are determined based on the current coolant temperature and the current demand torque. The output torque of the motor drive system of the target vehicle is controlled in stages based on the target required torque, the first permissible continuous operating time, and the target stall allowable torque.

2. The motor stall control method according to claim 1, characterized in that, The step of determining the target stall torque based on the current coolant temperature includes: Based on the first mapping relationship between coolant temperature and stall torque, the target stall torque is determined according to the current coolant temperature.

3. The motor stall control method according to claim 1, characterized in that, The step of determining the target torque and the first allowable continuous operating time corresponding to the target torque based on the current coolant temperature and the current required torque includes: Based on the second mapping relationship, and according to the current coolant temperature, determine multiple different required torques corresponding to the current coolant temperature and the allowable continuous running time corresponding to each required torque; Based on the current required torque, the plurality of different required torques and the allowable continuous operating time corresponding to each required torque, the target required torque and the first allowable continuous operating time are determined. The second mapping relationship is that each coolant temperature corresponds to multiple different required torques, and each required torque corresponds to an allowable continuous operating time.

4. The motor stall control method according to claim 3, characterized in that, The step of determining the target demand torque and the first allowable continuous operating time based on the current demand torque, the plurality of different demand torques, and the allowable continuous operating time corresponding to each demand torque includes: Determine whether the current required torque is greater than the maximum required torque among the plurality of different required torques; If the current required torque is greater than the maximum required torque, then the maximum required torque is determined as the target required torque, and the allowable continuous running time corresponding to the maximum required torque is determined as the first allowable continuous running time. If the current required torque is less than the maximum required torque, then the current required torque is determined as the target required torque, and the allowable continuous running time corresponding to the current required torque is determined as the first allowable continuous running time.

5. The motor stall control method according to claim 3, characterized in that, The second mapping relationship is obtained in the following way: Obtain multiple different coolant temperatures and multiple different torque requirements; For each coolant temperature, a thermal simulation analysis is performed on the multiple different required torques of the motor drive system at each coolant temperature to obtain the allowable continuous running time corresponding to each required torque among the multiple different required torques at each coolant temperature. The second mapping relationship is constructed based on the allowable continuous operating time corresponding to each required torque at each coolant temperature; Specifically, when the coolant temperature is greater than a temperature threshold, the multiple different required torques are divided using a first division gradient; when the coolant temperature is less than or equal to the temperature threshold, the multiple different required torques are divided using a second division gradient, wherein the first division gradient is less than the second division gradient.

6. The motor stall control method according to any one of claims 1 to 5, characterized in that, The step of controlling the output torque of the motor drive system of the target vehicle in stages according to the target required torque, the first permissible continuous operating time, and the target stall allowable torque includes: During the first allowed continuous operating period, the motor drive system is controlled to output the target required torque; In response to the actual continuous operating time of the target required torque being greater than the first permissible continuous operating time, the motor drive system is controlled to output the target stall permissible torque.

7. The motor stall control method according to claim 6, characterized in that, During the process where the actual continuous operating time of the target required torque is less than the first allowable continuous operating time, the method further includes: In response to the target required torque decreasing to a first required torque, the motor drive system is controlled to output the first required torque, and the remaining allowable continuous running time of the first required torque is the difference between the first allowable continuous running time and the actual continuous running time. Alternatively, in response to the target required torque rising to a second required torque, a second allowable continuous operating time corresponding to the second required torque is determined based on the current coolant temperature and the second required torque, and the motor drive system is controlled to output the second required torque. The remaining allowable continuous operating time of the second required torque is the difference between the second allowable continuous operating time and the actual continuous operating time.

8. The motor stall control method according to claim 6, characterized in that, The process of controlling the motor drive system to output the target stall torque also includes: Obtain the current speed and current torque of the target vehicle; Determine whether the current rotational speed is greater than a first rotational speed threshold, and whether the current torque is less than or equal to a first torque threshold; If the current rotational speed is greater than the first rotational speed threshold, or the current torque is less than or equal to the first torque threshold, then control the target vehicle to exit the stall condition; If the current rotational speed is less than or equal to the first rotational speed threshold and the current torque is greater than the first torque threshold, then the motor drive system is controlled to output the target stall allowable torque.

9. The motor stall control method according to claim 8, characterized in that, The following methods are used to determine whether the target vehicle has entered a stalled operation: Determine whether the current rotational speed is less than or equal to a second rotational speed threshold, whether the current torque is greater than a second torque threshold, where the second rotational speed threshold is less than the first rotational speed threshold, and the second torque threshold is greater than the first torque threshold; If the current speed is less than or equal to the second speed threshold and the current torque is greater than the second torque threshold, then the target vehicle is determined to be in a stall condition. If the current rotational speed is greater than the second rotational speed threshold, or the current torque is less than or equal to the second torque threshold, then it is determined that the target vehicle has not entered a stall condition.

10. The motor stall control method according to any one of claims 1 to 5, characterized in that, Also includes: Obtain the fault code corresponding to the motor drive system; Based on the fault code, determine whether there is a fault in the motor drive system; In response to a fault in the motor drive system, the output torque of the motor drive system of the target vehicle is controlled in stages based on the target output torque corresponding to the fault, the target required torque, the first allowable continuous operating time, and the target stall allowable torque.

11. The motor stall control method according to any one of claims 1 to 5, characterized in that, The current coolant temperature is the coolant temperature at the inlet of the motor controller cooling system in the motor drive system.

12. A motor stall control device, characterized in that, include: The acquisition module is used to acquire the current coolant temperature and current torque demand of the target vehicle in response to the target vehicle entering a stall condition. The first determining module is used to determine the target stall torque based on the current coolant temperature; The second determining module is used to determine the target demand torque and the first allowable continuous operating time corresponding to the target demand torque in response to the current demand torque being greater than the target stall allowable torque, based on the current coolant temperature and the current demand torque. The control module is used to control the output torque of the motor drive system of the target vehicle in stages according to the target required torque, the first allowable continuous operating time and the target stall allowable torque.

13. A motor stall control device, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the motor stall control method as described in any one of claims 1 to 11.

14. A vehicle, characterized in that, include: The vehicle body and the motor stall control device as described in claim 13, wherein the motor stall control device is used to perform the motor stall control method as described in any one of claims 1 to 11.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the motor stall control method as described in any one of claims 1 to 11.

16. A computer program product, characterized in that, include: A computer program, which, when executed by a processor, implements the motor stall control method as described in any one of claims 1 to 11.

Images